532 results on '"Dickson, D"'
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2. The stallion sperm acrosome: Considerations from a research and clinical perspective
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Camilo Hernández-Avilés, Luisa Ramírez-Agámez, Dickson D. Varner, and Charles C. Love
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Food Animals ,Equine ,Animal Science and Zoology ,Small Animals - Abstract
During the fertilization process, the interaction between the sperm and the oocyte is mediated by a process known as acrosomal exocytosis (AE). Although the role of the sperm acrosome on fertilization has been studied extensively over the last 70 years, little is known about the molecular mechanisms that govern acrosomal function, particularly in species other than mice or humans. Even though subfertility due to acrosomal dysfunction is less common in large animals than in humans, the evaluation of sperm acrosomal function should be considered not only as a complementary but a routine test when individuals are selected for breeding potential. This certainly holds true for stallions, which might display lower levels of fertility in the face of "acceptable" sperm quality parameters determined by conventional sperm assays. Nowadays, the use of high throughput technologies such as flow cytometry or mass spectrometry-based proteomic analysis is commonplace in the research arena. Such techniques can also be implemented in clinical scenarios of males with "idiopathic" subfertility. The current review focuses on the sperm acrosome, with particular emphasis on the stallion. We aim to describe the physiological events that lead to the acrosome formation within the testis, the role of very specific acrosomal proteins during AE, the methods to study the occurrence of AE under in vitro conditions, and the potential use of molecular biology techniques to discover new markers of acrosomal function and subfertility associated with acrosomal dysfunction in stallions.
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- 2023
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3. Sperm factors associated with the production of equine blastocysts by intracytoplasmic sperm injection (ICSI) using frozen/thawed semen
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Luisa Ramírez-Agámez, Camilo Hernández-Avilés, Dickson D. Varner, and Charles C. Love
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Male ,Glycerol ,Formamides ,Equine ,Spermatozoa ,Blastocyst ,Food Animals ,Semen ,Animals ,Female ,Animal Science and Zoology ,Horses ,Sperm Injections, Intracytoplasmic ,Small Animals - Abstract
Intracytoplasmic Sperm Injection (ICSI) using frozen/thawed sperm is a common procedure to obtain embryos from fertile or subfertile mares and stallions. Stallion-associated factors that impact the efficiency of ICSI have been studied less than those associated with the mare. Three experiments were conducted: Experiment 1: the effect of freezing extender composition and cryoprotectant; Experiment 2: the effect of sperm exposure to seminal plasma prior to freezing (ejaculated vs. epididymal sperm; two-freeze/thaw cycles each); and Experiment 3: the effect of sperm morphologic feature used for fertilization (normal vs. cytoplasmic droplet vs. bent tail); on the blastocyst rate after ICSI. In Experiment 1, stallion sperm was cryopreserved using commercially available extenders containing: a) 2% egg-yolk + milk + 4% glycerol (MFR5); b) 2% egg-yolk + milk + 2% glycerol + 3% methyl formamide (CMMFR5); c) 20% egg-yolk + 4.75% glycerol (LE); or d) 20% egg-yolk + 2% glycerol + 3% methyl formamide (CMLE). Sperm from each of the treatment groups were used for Piezo-driven ICSI on in vitro-matured equine oocytes (n = 321). Extender CMLE resulted in a lower cleavage rate (35%) than the other treatment groups (MFR5: 74%, CMMFR5: 62%, LE: 68%; P 0.05). Extender MFR5 yielded a higher blastocyst rate per injected oocyte (21/82 [26%]) than the Groups LE (8/77 [10%]), CMLE (4/80 [5%]) or CMMFR5 (4/82 [5%]; P 0.05). Extender MFR5 also yielded a higher blastocyst rate per cleaved oocyte (34%) than Groups LE, CMLE or CMMFR5 (15%, 14%, 8%; respectively P 0.05). In Experiment 2, ejaculated (EJ) and epididymal (EPD) sperm from a fertile stallion which was initially cryopreserved in the CMLE extender, was thawed and re-cryopreserved in MFR5 extender for use in ICSI. Sperm from both groups (EJ vs. EPD) were used for ICSI on in vitro matured oocytes (n = 127). Differences were not detected for cleavage rate (EJ: 36/63 [57%] vs. EPD: 49/64 [77%]), blastocyst rate per injected oocyte (EJ: 11/63 [17%] vs. EPD: 11/64 [17%]), or blastocyst rate per cleaved oocyte (EJ: 31% vs. EPD: 22%) between treatment groups (P 0.05). In Experiment 3, morphologically normal sperm (N), or sperm with proximal droplets (PD) or bent tails (BT), were obtained from a single fertile stallion and were used for ICSI on in vitro matured oocytes (n = 75). No differences were detected among treatment groups for cleavage rate (N: 19/25 [77%] vs. PD: 20/25 [88%] vs. BT: 18/25 [72%]), blastocyst rate per injected oocyte (N: 6/25 [24%] vs. PD: 5/25 [20%] vs. BT: 2/25 [8%]), and blastocyst rate per cleaved oocyte (N: 32% vs. PD: 23% vs. BT: 11%; P 0.05). In conclusion, the current study indicates that freezing extender composition used for stallion sperm cryopreservation has an impact on the developmental competence of in vitro-matured equine oocytes after ICSI and in vitro culture. Furthermore, we were unable to detect differences on cleavage and blastocyst rates when performing ICSI when using: 1) ejaculated or epididymal sperm; or 2) sperm with different morphologic features. The results from the current study provide additional insight regarding stallion-related factors that should be considered when performing ICSI in horses.
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- 2023
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4. The role of impaired acrosomal exocytosis (IAE) in stallion subfertility: A retrospective analysis of the clinical condition, and an update on its diagnosis by high throughput technologies
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Camilo Hernández-Avilés, Caitlin Castaneda, Terje Raudsepp, Dickson D. Varner, and Charles C. Love
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Male ,Equine ,Spermatozoa ,Exocytosis ,Hospitals, Animal ,Fertility ,Food Animals ,Pregnancy ,Infertility ,Sperm Motility ,Animals ,Humans ,Female ,Horse Diseases ,Animal Science and Zoology ,Horses ,Hospitals, Teaching ,Small Animals ,Retrospective Studies - Abstract
Acrosomal dysfunction has been considered as a cause of subfertility in males of different species, including stallions. A subset of subfertile stallions with acrosomal dysfunction is unique because they have normal sperm quality (motility, morphology, viability, and DNA quality). The current work aims to describe the clinical characteristics of subfertile stallions that were diagnosed with Impaired Acrosomal Exocytosis (IAE) by using two high throughput methods: flow cytometry and molecular genetic analysis, and to identify the prevalence of subfertility due to IAE in stallions evaluated at Texas AM University. Clinical data from 1,128 stallions evaluated during 17 years at a Veterinary Teaching Hospital was retrospectively analyzed. Only stallions with a history of subfertility not explained following a breeding soundness examination and/or conventional semen analysis, were included. For those stallions, the acrosomal exocytosis test (AE test), in which sperm is incubated at 37 °C for up to 2 h in the presence of the calcium ionophore A23187, was used to determine IAE. The difference in AE-Rate (AE-Diff) between each pair of fertile control stallion and subfertile stallion was categorized as: Normal: AE-Diff14%; Questionable: AE-Diff 15-29%; Abnormal: AE-Diff30%. In selected cases, blood or hair was procured for identification of the susceptibility genotype for IAE, A/A-A/A, in the FKBP6 gene, exon 5. Twenty-one (21) stallions (1.86% total population analyzed) had reduced fertility despite having acceptable sperm quality. Sperm from these stallions were subjected to the AE Test. Of these, 8 stallions had reduced sperm AE-rate, based on the AE Test (8/21; 38.1%). Subsequently, blood or hair samples from these 8 stallions which had either questionable (AE-Diff 15 - 29%; n = 5) or abnormal (AE-Diff30%; n = 3) responses to the AE Test were analyzed for the susceptibility genotype for IAE, A/A-A/A (FKBP6 gene, exon 5). Seven out of the eight (7/8) stallions carried this susceptibility genotype. All of these were Thoroughbreds. After 2 h of incubation, the viability in fertile stallion sperm was lower than in A/A-A/A stallions (4% vs. 25%, respectively; P 0.05), while the AE-rate was higher for fertile than for A/A-A/A stallions (85% vs. 56%, respectively; P 0.05). The use of two high throughput tests (i.e., flow cytometry and molecular genetic analysis) may complement each other in the diagnosis of IAE in breeding stallions. In this study, 5/7 subfertile stallions diagnosed with the IAE susceptibility genotype would have been diagnosed as normal with the AE Test. This study introduces a subset of stallions with the IAE genotype with fertility higher than has been previously reported (i.e.,15% per-cycle pregnancy rate), suggesting that IAE manifests as a broader range of subfertility.
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- 2022
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5. Bis(azolyl)pyridine‐2,6‐dicarboxamide Derivatives: Synthesis, Bioassay Analysis and Molecular Docking Studies
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Momidi Bharath kumar, Vanam Hariprasad, Shrinivas D Joshi, Gururaj Kadur Jayaprakash, Parashuram L., A. Saranga Pani, Dickson D. Babu, and Praveen Naik
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General Chemistry - Published
- 2023
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6. Recent progress in organic solar cells based on non-fullerene acceptors: materials to devices
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Dou Luo, Woongsik Jang, Dickson D. Babu, Min Soo Kim, Dong Hwan Wang, and Aung Ko Ko Kyaw
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Renewable Energy, Sustainability and the Environment ,General Materials Science ,General Chemistry - Abstract
This review presents the recent progress in organic solar cells based on non-fullerene acceptors, with a wide coverage from material synthesis and processing to interface engineering, device structure, large-area fabrication, and device stability.
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- 2022
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7. Contributors
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Mark J. Abzug, Elisabeth E. Adderson, Aastha Agarwal, Allison L. Agwu, Lindsey Albenberg, Jonathan Albert, Kevin Alby, Grace M. Aldrovandi, Upton D. Allen, Gerardo Alvarez-Hernndez, Krow Ampofo, Evan J. Anderson, Grace D. Appiah, Monica I. Ardura, Stephen S. Arnon, Naomi E. Aronson, Ann M. Arvin, Shai Ashkenazi, Liat Ashkenazi-Hoffnung, Edwin J. Asturias, Kestutis Aukstuolis, Vahe Badalyan, Carol J. Baker, Karthik Balakrishnan, Elizabeth D. Barnett, Kirsten Bechtel, William E. Benitz, Rachel Berkovich, David M. Berman, Stephanie R. Bialek, Else M. Bijker, Matthew J. Bizzarro, Karen C. Bloch, Joseph A. Bocchini, Thomas G. Boyce, John S. Bradley, Denise F. Bratcher, Paula K. Braverman, Itzhak Brook, Kevin Edward Brown, Kristina P. Bryant, Andres F. Camacho-Gonzalez, Connie F. Caete-Gibas, Joseph B. Cantey, Paul Cantey, Cristina V. Cardemil, Mary T. Caserta, Luis A. Castagnini, Jessica R. Cataldi, Ellen Gould Chadwick, Rebecca J. Chancey, Cara C. Cherry, Silvia S. Chiang, Mary Choi, John C. Christenson, Susan E. Coffin, Amanda Cohn, Despina G. Contopoulos-Ioannidis, James H. Conway, Margaret M. Cortese, C. Buddy Creech, Jonathan D. Crews, Donna Curtis, Nigel Curtis, Lara A. Danziger-Isakov, Toni Darville, Gregory A. Dasch, Irini Daskalaki, H. Dele Davies, Fatimah S. Dawood, J. Christopher Day, M. Teresa de la Morena, Gregory P. DeMuri, Dickson D. Despommier, Daniel S. Dodson, Stephen J. Dolgner, Clinton Dunn, Jonathan Dyal, Kathryn M. Edwards, Morven S. Edwards, Dawn Z. Eichenfield, Lawrence F. Eichenfield, Dirk M. Elston, Beth Emerson, Leslie A. Enane, Moshe Ephros, Guliz Erdem, Marina E. Eremeeva, Douglas H. Esposito, Monica M. Farley, Anat R. Feingold, Kristina N. Feja, Adam Finn, Marc Fischer, Brian T. Fisher, Randall G. Fisher, Patricia Michele Flynn, Monique A. Foster, LeAnne M. Fox, Michael M. Frank, Douglas R. Fredrick, Robert W. Frenck, James Gaensbauer, Hayley A. Gans, Gregory M. Gauthier, Patrick Gavigan, Jeffrey S. Gerber, Yael Gernez, Francis Gigliotti, Mark A. Gilger, Carol A. Glaser, Jane M. Gould, James Graziano, Amanda M. Green, Michael Green, Daniel Griffin, Patricia M. Griffin, David C. Griffith, Piyush Gupta, Bruce J. Gutelius, Julie R. Gutman, Aron J. Hall, Rana F. Hamdy, Jin-Young Han, Lori K. Handy, Benjamin Hanisch, Marvin B. Harper, Aaron M. Harris, Christopher J. Harrison, David B. Haslam, Julia C. Haston, Sarah.J. Hawkes, Taylor Heald-Sargent, J. Owen Hendley, Adam L. Hersh, Joseph A. Hilinski, Susan L. Hills, David K. Hong, Peter J. Hotez, Katherine K. Hsu, Felicia Scaggs Huang, David A. Hunstad, W. Garrett Hunt, Loris Y. Hwang, Christelle M. Ilboudo, Preeti Jaggi, Sophonie Jean, Ravi Jhaveri, Kateina Jirk-Pomajbkov, Nadia A. Kadry, Mary L. Kamb, Ronak K. Kapadia, Ben Z. Katz, Sophie E. Katz, Ishminder Kaur, Gilbert J. Kersh, Muhammad Ali Khan, Ananta Khurana, David W. Kimberlin, Bruce Klein, Miwako Kobayashi, Larry K. Kociolek, Andrew Y. Koh, Karen L. Kotloff, Andrew T. Kroger, Matthew P. Kronman, Leah Lalor, Christine T. Lauren, Amy Leber, Eyal Leshem, David B. Lewis, Robyn A. Livingston, Eloisa Llata, Kevin Lloyd, Katrina Loh, Sarah S. Long, Benjamin A. Lopman, Yalda C. Lucero, Debra J. Lugo, Jorge Lujn-Zilbermann, Yvonne A. Maldonado, John J. Manaloor, Kalpana Manthiram, Stacey W. Martin, Roshni Mathew, Tony Mazzulli, Elizabeth J. McFarland, Kathleen A. McGann, Lucy A. McNamara, Debrah Meislich, H. Cody Meissner, Asuncion Mejias, Jussi Mertsola, Kevin Messacar, Mohammad Nael Mhaissen, Marian G. Michaels, Melissa B. Miller, Hilary Miller-Handley, Eric Mintz, Parvathi Mohan, Susan P. Montgomery, Jose G. Montoya, Anne C. Moorman, Pedro L. Moro, Anna-Barbara Moscicki, William J. Muller, Angela L. Myers, Simon Nadel, Jennifer Lynn Nayak, Michael Noel Neely, Karen P. Neil, Christina A. Nelson, Noele P. Nelson, Megin Nichols, William Nicholson, Amy Jo Nopper, Laura E. Norton, Theresa J. Ochoa, Liset Olarte, Timothy R. Onarecker, Walter A. Orenstein, Miguel ORyan, William R. Otto, Christopher P. Ouellette, Christopher D. Paddock, Debra L. Palazzi, Suresh Kumar Panuganti, Diane E. Pappas, Michal Paret, Daniel M. Pastula, Thomas F. Patterson, Brett W. Petersen, Mikael Petrosyan, Larry K. Pickering, Talia Pindyck, Swetha Pinninti, Laure F. Pittet, Paul J. Planet, Andrew J. Pollard, Klara M. Posfay-Barbe, Casper S. Poulsen, Susan M. Poutanen, Ann M. Powers, Nina Salinger Prasanphanich, Bobbi S. Pritt, Charles G. Prober, Neha Puar, Laura A.S. Quilter, Octavio Ramilo, Suchitra Rao, Adam J. Ratner, Sarah A. Rawstron, Jennifer S. Read, Ryan F. Relich, Megan E. Reller, Candice L. Robinson, Jos R. Romero, David A. Rosen, Shannon A. Ross, G. Ingrid J.G. Rours, Peter C. Rowe, Anne H. Rowley, Lorry G. Rubin, Edward T. Ryan, Alexandra Sacharok, Thomas J. Sandora, Sarah G.H. Sapp, Kabir Sardana, Jason B. Sauberan, Joshua K. Schaffzin, Sarah Schillie, Jennifer E. Schuster, Kevin L. Schwartz, Bethany K. Sederdahl, Jose Serpa-Alvarez, Kara N. Shah, Samir S. Shah, Nader Shaikh, Andi L. Shane, Eugene D. Shapiro, Jana Shaw, Avinash K. Shetty, Timothy R. Shope, Linda M. Dairiki Shortliffe, Stanford T. Shulman, Gail F. Shust, George Kelly Siberry, Jane D. Siegel, Robert David Siegel, Kari A. Simonsen, Upinder Singh, Christiana Smith, Lauren L. Smith, Eunkyung Song, Emily Souder, Paul Spearman, Joseph W. St. Geme, Mary Allen Staat, J. Erin Staples, Jeffrey R. Starke, Victoria A. Statler, William J. Steinbach, Christen Rune Stensvold, Erin K. Stokes, Bradley P. Stoner, Gregory A. Storch, Anne Straily, Kathleen E. Sullivan, Douglas S. Swanson, Robert R. Tanz, Gillian Taormina, Jacqueline E. Tate, Jeanette Taveras, Marc Tebruegge, Eyasu H. Teshale, George R. Thompson, Robert Thompson-Stone, Isaac Thomsen, Richard B. Thomson, Emily A. Thorell, Vivian Tien, Nicole H. Tobin, Philip Toltzis, James Treat, Stephanie B. Troy, Russell B. Van Dvke, Louise Elaine Vaz, Vini Vijayan, Jennifer Vodzak, Thor A. Wagner, Ellen R. Wald, Rebecca Wallihan, Huanyu Wang, Zoon Wangu, Matthew Washam, Valerie Waters, Joshua R. Watson, Jill E. Weatherhead, Geoffrey A. Weinberg, Mark K. Weng, Nathan P. Wiederhold, Harold C. Wiesenfeld, Cydni Williams, John V. Williams, Rodney E. Willoughby, Robert R. Wittler, James B. Wood, Charles Reece Woods, Kimberly A. Workowski, Terry W. Wright, Hsi-Yang Wu, Huan Xu, Pablo Yagupsky, Jumi Yi, Jonathan Yoder, Edward J. Young, Andrea L. Zaenglein, Petra Zimmermann, and Wenjing Zong
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- 2023
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8. Thoroughbred stallion fertility is significantly associated with FKBP6 genotype but not with inbreeding or the contribution of a leading sire
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Dickson D. Varner, Terje Raudsepp, C.C. Love, J Kjöllerström, E. G. Cothran, C Hernandez Aviles, Sheila R. Teague, Rytis Juras, and Caitlin Castaneda
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Male ,Genetics ,Haplotype ,Sire ,Single-nucleotide polymorphism ,General Medicine ,Biology ,Genotype frequency ,Tacrolimus Binding Proteins ,Fertility ,Genotype ,Animals ,Inbreeding ,Animal Science and Zoology ,Horses ,Allele ,Genotyping - Abstract
This is a follow-up study to validate the previously detected association of the FKBP6 gene with stallion subfertility. Using a select cohort of 150 Thoroughbred stallions with detailed breeding records, we confirm significant association (P 0.0001) between low per-cycle pregnancy rates (≤50%) and a combined A/A-A/A genotype of SNPs chr13:11 353 372GA and chr13:11 353 436AC in FKBP6 exon 5. We also show that stallion subfertility and the combined genotype A/A-A/A are not associated with the level of genetic diversity based on 12 autosomal microsatellite markers, or with pedigree-based inbreeding rate, or the extent of contribution of a leading Thoroughbred sire, Northern Dancer, in a stallion's pedigree. We develop a TaqMan allelic discrimination assay for the two SNPs to facilitate accurate and high-throughput genotyping. We determine allele, genotype and combined genotype frequencies of FKBP6 exon 5 SNPs in a global cohort of 518 Thoroughbreds (76% stallions or geldings and 24% mares) and show that the frequency of the A/A-A/A genotype is 4%. Because there is no similar association between the FKBP6 exon 5 genotype and stallion subfertility in Hanoverians, we suggest that the two SNPs are not causative but rather tagging a breed-specific haplotype with genetic variants unique to Thoroughbreds. Further WGS-based research is needed to identify the molecular causes underlying the observed genotype-phenotype association in Thoroughbred stallions.
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- 2021
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9. Effects of egg yolk level, penetrating cryoprotectant, and pre-freeze cooling rate, on the post-thaw quality of stallion sperm
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Camilo Hernández-Avilés, Luisa Ramírez-Agámez, Dickson D. Varner, and Charles C. Love
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Endocrinology ,Food Animals ,Animal Science and Zoology ,General Medicine - Abstract
The current study determined the effect of the egg-yolk (phospholipid source) level (egg yolk [20% EY] vs. skim-milk + egg yolk [SM + 2% EY]), cryoprotectant (glycerol [Gly] vs. glycerol + methylformamide [Gly + MF]), and pre-freeze cooling rate (-0.1 vs. -1 vs. -5 °C/min) on post-thaw stallion sperm quality. In Experiment 1, ejaculates (n = 27) from 9 stallions (3 ejaculates each) with varied sperm quality (High, Average, or Low) were frozen in EY-Gly, SMEY-Gly, EY-Gly + MF, or SMEY-Gly + MF extenders. Sperm in each group were cooled from 22° to 5°C using either -0.1 °C/min or -1 °C/min linear cooling rates prior to freezing. In Experiment 2, ejaculates (n = 24) from 12 stallions (2 ejaculates each) with High or Average sperm quality were frozen in EY-Gly, EY-Gly + MF, or in BotuCrio (BC) extenders. Sperm in each group were cooled from 22° to 5°C using either -1 or -5 °C/min linear cooling rates prior to freezing. In Experiment 1, for stallions with High or Average sperm quality, either cooling rate generally resulted in lower sperm quality for the SMEY-based extenders than for the EY-based extenders (P 0.05). Stallions with Low sperm quality were unaffected by any experimental treatment (P 0.05). In Experiment 2, a -5 °C/min cooling rate yielded lower sperm quality in BC than in EY-Gly or EY-Gly + MF groups (P 0.05); however, a -1 °C/min cooling rate yielded similar sperm quality among these treatments (P 0.05). In summary, the phospholipid level in the freezing extender and the pre-freeze cooling rate, but not the penetrating cryoprotectant, affected the post-thaw quality of stallion sperm.
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- 2022
10. THE ANALYSIS OF PRESCRIBED PEDAGOGY PRACTICES FOR DESIGN AND TECHNOLOGY IN ZAMBIAN SCHOOLS. THE CASE OF CHIPATA DISTRICT
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Dickson. D Ndenguma, M. Mnelemba, and Mabvuto Dweku Mhango
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Syllabus ,Class (computer programming) ,Process (engineering) ,Teaching method ,Pedagogy ,ComputingMilieux_COMPUTERSANDEDUCATION ,Retraining ,Sociology ,Design and Technology ,Curriculum ,Qualitative research - Abstract
Purpose: The study delved into prescribed pedagogy practices for Design and Technology in Zambian schools, “Chipata district in particular”. The main objective of this study was to contribute towards a comprehensive understanding of the prescribed pedagogies in the syllabus of Design and Technology. Thus, the rationale of the work is based on the application of prescribed pedagogies by practicing teachers for Design and Technology in the teaching and learning process in secondary schools. The, aim of the study is to analyse the application of the prescribed methods by teachers of Design and Technology. The research was undertaken in order to assess the application of the prescribed pedagogy in the newly rolled out curriculum for Design and Technology. This was on the premise that the curriculum was implemented without retraining of the subject teachers. The study covers three selected schools, from which six practicing teachers and three pupils were interviewed. Methodology: Data was collected through interviews, documented records used by the teachers and class observation. The collected data was analysed manually and through the use of qualitative data analysis (QDA) miner lite. During the data analysis themes emerged which served as a guide for discussion. Results: The study indicates that teachers need more orientation of the pedagogies in the syllabus to fully utilise them. Further, results show that there is need to enhance teacher content knowledge and ensure the availability of teaching and learning resources. For the sake of good application of the pedagogies the study recommends: orientation of teachers on prescribed teaching methods, provision of standard workroom, enough teaching and learning resources, and upgrading teacher qualifications. Unique contribution to theory, policy, and practice: Teachers need to read and understand the new syllabus demands for them to apply the prescribed pedagogies as required. Additionally it is great importance to orient teachers adequately before the new syllabus is rolled out. Therefore there is need to a deliberate program to retrain teachers or organize continuous professional development programs so that they are acquainted to new pedagogies.
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- 2021
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11. Wheat yield potential in controlled-environment vertical farms
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Dickson D. Despommier, Forrest Meggers, Mahadev Raman, Paul P. G. Gauthier, Senthold Asseng, Gregory Kiss, Oscar Monje, and Jose Rafael Guarin
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0106 biological sciences ,Climate ,Yield (finance) ,Sustainability Science ,01 natural sciences ,vertical farm ,03 medical and health sciences ,Nutrient ,wheat ,Market price ,Production (economics) ,Hectare ,Triticum ,030304 developmental biology ,0303 health sciences ,Multidisciplinary ,Agricultural Sciences ,business.industry ,Temperature ,food and beverages ,Vertical farming ,Biological Sciences ,yield ,Environment, Controlled ,Crop Production ,Agronomy ,Agriculture ,Food systems ,Environmental science ,Seasons ,business ,010606 plant biology & botany - Abstract
Significance Wheat is the most important food crop worldwide, grown across millions of hectares. Wheat yields in the field are usually low and vary with weather, soil, and crop management practices. We show that yields for wheat grown in indoor vertical farms under optimized growing conditions would be several hundred times higher than yields in the field due to higher yields, several harvests per year, and vertically stacked layers. Wheat grown indoors would use less land than field-grown wheat, be independent of climate, reuse most water, exclude pests and diseases, and have no nutrient losses to the environment. However, given the high energy costs for artificial lighting and capital costs, it is unlikely to be economically competitive with current market prices., Scaling current cereal production to a growing global population will be a challenge. Wheat supplies approximately one-fifth of the calories and protein for human diets. Vertical farming is a possible promising option for increasing future wheat production. Here we show that wheat grown on a single hectare of land in a 10-layer indoor vertical facility could produce from 700 ± 40 t/ha (measured) to a maximum of 1,940 ± 230 t/ha (estimated) of grain annually under optimized temperature, intensive artificial light, high CO2 levels, and a maximum attainable harvest index. Such yields would be 220 to 600 times the current world average annual wheat yield of 3.2 t/ha. Independent of climate, season, and region, indoor wheat farming could be environmentally superior, as less land area is needed along with reuse of most water, minimal use of pesticides and herbicides, and no nutrient losses. Although it is unlikely that indoor wheat farming will be economically competitive with current market prices in the near future, it could play an essential role in hedging against future climate or other unexpected disruptions to the food system. Nevertheless, maximum production potential remains to be confirmed experimentally, and further technological innovations are needed to reduce capital and energy costs in such facilities.
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- 2020
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12. Identification and quantification of coding and long non‐coding RNAs in stallion spermatozoa separated by density
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Charles D. Johnson, Charles C. Love, Noushin Ghaffari, Kranti Konganti, Dickson D. Varner, David W. Forrest, and Nancy H. Ing
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Male ,endocrine system ,Swine ,Urology ,Endocrinology, Diabetes and Metabolism ,Population ,Biology ,Andrology ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Gene expression ,Centrifugation, Density Gradient ,Animals ,Humans ,Horses ,RNA, Messenger ,education ,reproductive and urinary physiology ,Differential centrifugation ,Messenger RNA ,education.field_of_study ,030219 obstetrics & reproductive medicine ,urogenital system ,RNA ,Ribosomal RNA ,Spermatozoa ,Long non-coding RNA ,Fertility ,Reproductive Medicine ,Cattle ,RNA, Long Noncoding ,Sterol binding - Abstract
Background It is not unusual for stallions to have fertility problems. For many, artificial insemination with more dense spermatozoa (isolated by density gradient centrifugation) results in greater pregnancy rates compared with the rates when using unfractionated spermatozoa. RNAs in spermatozoa delivered to the oocyte at conception are required for embryo development. Novel molecular assays of spermatozoa that reflect function are needed to predict the fertility of stallions. Objectives To describe and compare the RNA populations in more dense and less dense spermatozoa from stallions. Materials and methods Spermatozoa from five stallions were separated into more dense and less dense populations by density gradient centrifugation. Complementary DNA libraries were made from each of the ten total RNA samples after ribosomal RNA removal. Next-generation sequencing characterized the RNA populations in more and less dense spermatozoa. Quantitative reverse transcription-PCR was used to confirm differential expression of selected RNAs. Results Stallion spermatozoa contain 11 215 RNAs, with the most prevalent RNA being a 1492 base long non-coding RNA. The levels of 159 RNAs were greater in more dense spermatozoa, while levels of seven other RNAs were greater in less dense spermatozoa. Quantitative reverse transcription-PCR confirmed the threefold greater levels of solute carrier family 26 member 8 (SLC26A8) mRNA in less dense spermatozoa, and sixfold and threefold greater expression levels of the SCP2 sterol binding domain containing 1 (SCP2D1) and spermatogenesis-associated protein 31D1 (SPATA31D1) mRNAs in more dense spermatozoa, respectively. Discussion and conclusion We identified 11 215 RNAs in stallion spermatozoa and 166 with differential expression between more dense and less dense fractions. Many prevalent RNAs were also found in bull, boar, and human spermatozoa. Many differentially expressed RNAs are known to be testis- or spermatozoa-specific. Our results may lead to identification of an RNA population in spermatozoa that is optimal for establishing successful pregnancies.
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- 2020
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13. Effects of glucose concentration in semen extender and storage temperature on stallion sperm quality following long-term cooled storage
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R. Serafini, Charles C. Love, Luisa Ramírez-Agámez, K.A. LaCaze, Steven P. Brinsko, Sheila R. Teague, Sharmila Ghosh, Camilo Hernández-Avilés, Macy Friedrich, and Dickson D. Varner
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Male ,Cell Survival ,Motility ,Semen ,law.invention ,03 medical and health sciences ,Cryoprotective Agents ,0302 clinical medicine ,Animal science ,Food Animals ,law ,Animals ,Horses ,Sperm quality ,Small Animals ,Sperm motility ,030219 obstetrics & reproductive medicine ,Equine ,Chemistry ,Extender ,Temperature ,0402 animal and dairy science ,04 agricultural and veterinary sciences ,Spermatozoa ,040201 dairy & animal science ,Sperm ,Semen Analysis ,Semen extender ,Glucose ,Sperm Motility ,Animal Science and Zoology ,Semen Preservation - Abstract
In Experiment 1, the effects of glucose concentration in extender (0 mM, 67 mM, 147 mM, 270 mM; G0, G67, G147, and G270, respectively) and storage temperature of extended semen (5, 10, 15 and 20 °C) were evaluated after storage for up to 5 days (T0h to T120h). For all time points tested, mean total (TMOT) and progressive (PMOT) sperm motility were lower in G0 than all other treatment groups (P 0.05). Mean curvilinear velocity (VCL) was lower in G0 than other treatment groups at all time points tested except T0h (P 0.05). Mean percentage of plasma membrane/acrosome intact sperm (VAI) was similar among treatments at T0h, T72h, and T120h (P 0.05). Mean TMOT and PMOT, were lower for semen stored at 20 °C than all lower storage temperatures (P 0.05) at all time points. In Experiment 2, semen was stored at 10 °C in extender containing no added glucose (G0) or 147 mM glucose (G147). Following storage, semen was centrifuged and resuspended in extender containing no added glucose (G0 - G0 or G147 - G0, respectively) or 147 mM of glucose (G0 - G147 or G147 - G147, respectively). Mean TMOT, PMOT, and VCL were higher in G147 than G0 at all time periods tested (P 0.05), whereas mean VAI was similar between these treatment groups throughout the experiment (P 0.05). Mean TMOT and PMOT were higher in G0 - G147 than G0 - G0 at T72h and T120h (P 0.05) and mean VCL was higher in G0 - G147 than G0 - G0 for all time periods. Mean TMOT, PMOT, and VCL were higher in G147 - G147 than G147 - G0 at all time points tested (P 0.05), whereas mean VAI was similar between these two treatment groups for each of the time points (P 0.05). In Experiment 3, the minimum concentration of glucose required to maintain sperm quality following long-term cooled storage (T120 h) was evaluated (G0, G5, G10, G20, G40, G67, G147 mM). At T120 h, mean TMOT was lowest in G0, G5, G10, and G20 (P 0.05), whereas mean PMOT and VCL were lower in G0, G5, G10, and G20 than in G40, G67, and G147 (P 0.05). Mean VAI was higher in G10 than G67, but similar among G10 and other treatment groups (P 0.05). In conclusion, the absence of added glucose in extender reduced the motion characteristics of stallion sperm during long-term storage (5 days), but VAI was not affected. The use of temperatures between 5 and 15 °C for long-term storage (5 days) best maintained sperm motility and VAI. The threshold concentration of added glucose in extender required to optimize sperm motion characteristics was 40 mM.
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- 2020
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14. Shine a light on papyrus: monitoring the aging process
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Florian Bausch, Dickson D. Owusu, Jörg Graf, Thomas Rosenau, and Antje Potthast
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Archeology ,Chemistry (miscellaneous) ,Materials Science (miscellaneous) ,Conservation ,Spectroscopy ,Computer Science Applications - Abstract
The aging behavior of ancient papyri is not entirely understood, although such understanding is crucial for tailored conservation concepts to preserve these precious historical documents for the millennia to come. In a study on accelerated aging, the effect of light on papyrus sheets was studied, and the consequences were monitored by a combination of non-invasive and invasive techniques. Papyrus sheets were aged for two months at 90 °C and 50% relative humidity, with and without the influence of light. Changes at the optical, mechanical, and molecular levels were monitored using CIELAB color measurements, tensile tests, Fourier transform-infrared spectroscopy (FTIR), and size exclusion chromatography—multi angle light scattering (SEC-MALS). Light exposure has severe consequences for the optical and mechanical properties of papyri, reflected by a strong decrease in cellulose chain length and tensile strength. SEC-MALS proved to be the best method to assess the conservation status of papyri due to its clear results and low sample demand. This publication seeks to highlight the effects of light-induced degradation of papyri and to facilitate an understanding of the underlying aging mechanisms, to support in future conservation measures.Graphical Abstract
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- 2022
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15. Additional file 1 of Shine a light on papyrus: monitoring the aging process
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Bausch, Florian, Owusu, Dickson D., Graf, Jörg, Rosenau, Thomas, and Potthast, Antje
- Abstract
Additional file 1: Figure S1. Transmission spectrum of the microscope slides used to mount the papyri during accelerated aging. Figure S2. FT-IR spectra of samples aged for up to 57 days with and without the influence of light. a Entire spectrum without the influence of light; b Entire spectrum with the influence of light; c Detail of the spectra (1750–1100 1/cm) aged in darkness. Figure S3. Chromatograms of aged samples without (left) and with (right) light influence, expressed as sample concentration (RI) vs. time, normalized to equal peak area. Note the different curve shapes—the “third peak”—for light aged samples after a longer aging treatment.
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- 2022
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16. Evaluation of a training intervention to improve cancer care in Zimbabwe: Strategies to Improve Kaposi Sarcoma Outcomes (SIKO), a prospective community-based stepped-wedge cluster randomized trial
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Katherine R. Sabourin, Margaret Borok, Samantha Mawhinney, Maxwell Matimba, Francis Jaji, Suzanne Fiorillo, Dickson D. Chifamba, Claudios Muserere, Busisiwe Mashiri, Chenjerai Bhodheni, Patricia Gambiza, Rachael Mandidewa, Mercia Mutimuri, Ivy Gudza, Matthew Mulvahill, Camille M. Moore, Jean S. Kutner, Eric A. F. Simões, and Thomas B. Campbell
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Zimbabwe ,Infectious Diseases ,Public Health, Environmental and Occupational Health ,Humans ,HIV Infections ,Prospective Studies ,Sarcoma, Kaposi ,Early Detection of Cancer - Abstract
Most Zimbabweans access medical care through tiered health systems. In 2013, HIV care was decentralized to primary care clinics; while oncology care remained centralized. Most persons in Zimbabwe with Kaposi sarcoma (KS) are diagnosed late in their disease, and the prognosis is poor. Little is known about whether educational interventions could improve KS outcomes in these settings.Interventions to improve KS detection and management were evaluated at eight Zimbabwe primary care sites (four rural/four urban) that provided HIV care. Interventions included a standardized KS clinical evaluation tool, palliative care integration, standardized treatment and improved consultative services. Interventions were implemented between February 2013 and January 2016 using a randomized stepped-wedge cluster design. Sites were monitored for KS diagnosis rates and KS outcomes, including early diagnosis (T0 vs. T1 tumour stage), participant retention and mortality. Analyses controlled for within-clinic correlations.A total of 1102 persons with suspected KS (96% HIV positive) were enrolled: 47% incident (new diagnosis), 20% prevalent (previous diagnosis) and 33% determined as not KS. Early (T0) diagnosis increased post-intervention, though not significant statistically (adjusted odds ratio [aOR] = 1.48 [95% confidence interval (95% CI): 0.66-3.79], p = 0.37). New KS diagnosis rates increased 103% (95% CI: 11-273%), p = 0.02) post-intervention; although paired with an increased odds of incorrectly diagnosing KS (aOR = 2.08 [95% CI: 0.33-3.24], p = 0.001). Post-intervention, non-significant decreases in 90-day return rates (adjusted hazard ratio [aHR] = 0.69 [95% CI: 0.38-1.45], p = 0.21) and survival (aHR = 1.36 [95% CI: 0.85-2.20], p = 0.20) were estimated.KS training interventions at urban and rural Zimbabwe decentralized primary care clinics significantly increased overall and incorrect KS diagnosis rates, but not early KS diagnosis rates, 90-day return rates or survival.
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- 2021
17. Evaluation of Stallion Testicular Cell Types by Flow Cytometry
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Dickson D. Varner, Charles C. Love, and R. Serafini
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Male ,Cell type ,medicine.diagnostic_test ,Equine ,Acridine orange ,Histology ,Biology ,Flow Cytometry ,Flow cytometry ,Andrology ,chemistry.chemical_compound ,chemistry ,Testis ,medicine ,Sexual maturity ,Animals ,Horses ,Spermatogenesis - Abstract
Flow cytometry procedures can be used for evaluation of both spermatogenic efficiency and diagnose disorders of stallion spermatogenesis. Aims of this study were to compare two testicular sample acquisition techniques (needle aspirate-N and tissue wedge-T) and results when using flow cytometry and histology procedures. Testicular cell types were stained with acridine orange, and nine regions (R2 to R10) were identified and enumerated following acquisition by either N or T. Testes were also grouped and analyzed by size and sexual maturity (Small [immature] compared with Large [mature]) and used to determine if flow cytometry procedures could be used to detect differences. For both N and T, percentages of 2n cell types were greater in the Small than Large testes, whereas percentages of 1n cell types in N were greater in the Large than Small testes (P.05). Testicular cell types in N regions were correlated to similar T regions (r between 0.51 and 0.99; P.05) in both groups. Flow cytometry and histology scores were correlated in both groups (r between -0.95 and 0.93, P.05). There were small differences in number of testicular cell types from N and T. With both sample acquisition methods, there was discrimination between the Small and Large testes, therefore, evaluation of testicular cell types using flow cytometry procedures might have clinical applications. Results with comparison of flow cytometry to histology procedures indicate that flow cytometry can be applied clinically to identify changes in testicular cell types of stallions using a needle aspirate.
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- 2021
18. Assessment of community-based flood early warning system in Malawi
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Dickson D. Chinguwo and Dorothea Deus
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river gauge ,floods ,community based early warning system ,civil protection committee ,Management, Monitoring, Policy and Law ,Safety Research ,early warning system - Abstract
One of the major natural hazards the world is facing these days are floods. Malawi has not been spared. Floods have affected the countries’ socio-economic developmental plans. River gauges have been installed along major rivers to monitor water levels in a bid to warn communities of imminent flooding. In Malawi, ever since the installation of river gauges no study has been done to assess their effectiveness. This study examines the effectiveness of these river gauges as part of community-based early warning system. The research employs both qualitative and quantitative approach. Questionnaires, interviews, group discussions, document analysis were all used in order to understand the behavioural aspect of communities under study. The current community-based early warning system practices were benchmarked against the following elements: risk knowledge, technical monitoring and warning services, dissemination and communication of warnings and response capability. The study revealed that Malawi has two distinct systems in place: at national level (managed by several government departments) and at community level [managed by Civil Protection Committees (CPCs)]. These systems were installed by non-governmental organisations (NGOs) and faith-based organisations. Apparently, no direct link exists between the two. Operational bureaucracy affects the speedy presentation of warning messages at national level. Lack of capacity and necessities affects the operation of the community-based system. Despite the efforts to develop the early warning systems, the failures outweigh the successes. Government needs to provide enough funding for systems sustainability, build capacity of CPCs and install more technologically advanced systems.
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- 2021
19. Factors affecting intracellular calcium influx in response to calcium ionophore A23187 in equine sperm
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B. F. B. Sampaio, H.L. Resende, Katrin Hinrichs, Isabel Ortiz, Dickson D. Varner, and M. Felix
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Male ,endocrine system ,Urology ,Endocrinology, Diabetes and Metabolism ,Ionophore ,chemistry.chemical_element ,Calcium ,Calcium in biology ,Andrology ,Mice ,Endocrinology ,Capacitation ,Animals ,Horses ,Bovine serum albumin ,Incubation ,reproductive and urinary physiology ,Calcimycin ,biology ,urogenital system ,Chemistry ,Albumin ,Serum Albumin, Bovine ,Sperm ,Spermatozoa ,Calcium Ionophores ,Reproductive Medicine ,biology.protein - Abstract
BACKGROUND Exposure to the calcium ionophore A23187 may present a "universal" sperm treatment for IVF, as it bypasses capacitation pathways. However, success in utilizing A23187 is variable, especially in equine spermatozoa. Notably, albumin is used during A23187 treatment but paradoxically is thought to suppress A23187 action. Essentially no critical data are available on the effects of A23187 and albumin concentrations, ratios, or addition protocols on changes in intracellular calcium ([Ca]i ) in any cell type. OBJECTIVE To determine factors that affect the action of A23187 on [Ca]i in equine and murine spermatozoa. METHODS Spermatozoa were loaded with Fluo-4 and changes in fluorescence after A23187 treatment were measured under various conditions using a microplate reader. RESULTS Concentrations of bovine serum albumin (BSA) and A23187, type of BSA, makeup of A23187 stock solutions (i.e., 1° stock (DMSO) or 2° stock made with medium, water or DMSO), order of addition of spermatozoa and A23187, incubation of media before sperm addition, species of spermatozoa, and time of addition of BSA all affected [Ca]i in response to A23187 treatment. In equine spermatozoa already exposed to 10 µM A23187, addition of BSA to 33 mg/ml to "quench" the A23187 did not affect [Ca]i . When this concentration of BSA was added to spermatozoa exposed to 1 µM A23187, [Ca]i in murine spermatozoa returned to baseline, however, equine spermatozoa continued to exhibit increased [Ca]i . Addition of BSA to 33 mg/ml to media containing 1 µM A23187, prior to addition of spermatozoa, completely inhibited change in [Ca]i in both murine and equine spermatozoa. CONCLUSION These results represent some of the first critical data on the effects of albumin and other procedural factors on A23187-induced changes in [Ca]i in any cell type. Our findings help to explain the variability in reported response of spermatozoa to A23187 among species and among laboratories.
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- 2021
20. List of contributors
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Rounak R. Atram, Dickson D. Babu, Sushmee Badhulika, J.N. Behera, Brahmananda Chakraborty, Himani Chauhan, Jiban K. Das, Sasanka Deka, Arthi Gopalakrishnan, Shobhnath P. Gupta, Bhalchandra Kakade, Subhash B. Kondawar, Dattatray J. Late, Shivsharan M. Mali, Minu Mathew, Heera T. Nair, Harishchandra Nishad, Haridas Parse, Mansi Pathak, Indrajit Patil, Chandra Sekhar Rout, Aneeya K. Samantara, Bhaskar R. Sathe, Nitin T. Shelke, Siby Thomas, and Pravin S. Walke
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- 2021
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21. Supercapacitors based on MXenes (transition metal carbides and nitrides) and their hybrids
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Siby Thomas, Dickson D. Babu, and Minu Mathew
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Supercapacitor ,Transition metal carbides ,Materials science ,Nanotechnology ,Nitride ,Electronic conductivity ,MXenes - Abstract
Ever since their discovery in 2011, a family of 2D transition metal carbides and nitrides (MXenes) have amassed a lot of attention owing to their inherent electronic conductivity, rich surface chemistry and superior hydrophilicity, which have made them a prospective candidate for application in energy conversion as well as electrochemical storage. In this chapter, we aim to summarize the recent advances in MXene and MXene-based hybrids for supercapacitor applications while also highlighting the current bottlenecks and new opportunities.
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- 2021
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22. Evaluation of a Training Intervention to Improve Kaposi Sarcoma Care in Zimbabwe: A Prospective Community-Based Stepped-Wedge Cluster Randomised Trial
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Eric A. F. Simões, Katherine R. Sabourin, Mercia Mutimuri, Margaret Borok, Camille M. Moore, Jean S. Kutner, Maxwell Matimba, Chenjerai Bhodheni, Thomas B. Campbell, Francis Jaji, Dickson D. Chifamba, Claudios Muserere, Patricia Gambiza, Busisiwe Mashiri, Samantha MaWhinney, Matthew Mulvahill, Ivy Gudza, Suzanne P. Fiorillo, Rachael Mandidewa, and James Hakim
- Subjects
History ,medicine.medical_specialty ,Palliative care ,Polymers and Plastics ,business.industry ,Hazard ratio ,Psychological intervention ,Odds ratio ,Disease cluster ,Industrial and Manufacturing Engineering ,Confidence interval ,Family medicine ,Medicine ,Business and International Management ,Medical diagnosis ,business ,Biomedical sciences - Abstract
Background: Most Zimbabweans access medical care through tiered health systems, with decentralized HIV care and centralized oncology care. Local health centre staff are trained in ART administration but not in AIDS-associated Kaposi sarcoma (AIDS-KS) diagnosis or management. To improve AIDS-KS prognoses, interventions on screening, diagnosis, and treatment must be integrated into primary HIV care settings. We conducted a community-based randomized step-wedge cluster trial for a package of KS care training interventions. Methods: Interventions intended to improve KS detection and management included a standardized KS clinical evaluation tool, palliative care integration, standardized treatment, and improved consultative services. Interventions were evaluated at eight Zimbabwe primary HIV care sites by monitoring KS diagnoses and outcomes, including early diagnosis (T0 vs T1 tumor stage), patient retention, and mortality. Analyses controlled for within clinic correlations. Findings: 1102 suspected KS patients (96% HIV+) were enrolled: 47% newly diagnosed, 20% previously diagnosed, and 33% determined as not KS (incorrectly diagnosed). Diagnosis at T0 stage increased post-intervention, though not significant statistically (adjusted odds ratio (aOR)=1·48 (95% confidence interval (95%CI):0·66-3·79);p=0·37). New KS diagnosis rates increased 103% (95%CI:11%-273%);p=0·02) post-intervention, with parallel increased odds of incorrect diagnosis (aOR=2·08 (95%CI:0·33-3·24);p=0·001). Post-intervention, non-significant changes in 90-day return rates (adjusted hazard ratio (aHR)=0·69 (95%CI:0·38-1·45);p=0·21) and survival (aHR=1·36 (95%CI:0·85-2·20);p=0·20) were estimated. Interpretation: KS training interventions increased overall and incorrect KS diagnosis, but not early KS diagnosis, 90-day return rates, or survival at HIV primary care sites. Approaches to increase KS diagnosis accuracy in low-resource settings are needed. Trial Registration: Study design details are available at ClinicalTrials.gov NCT01764360. Funding: Funding was provided by the National Cancer Institute, National Institutes of Health: grant 1R01CA172050. Declaration of Interest: None to declare. Ethical Approval: The study was approved by the institutional review boards of Zimbabwe (Medical Research Council of Zimbabwe, MRCZ), University of Colorado Anschutz Medical Campus (COMIRB), and the Joint Parirenyatwa Hospital and University of Zimbabwe College of Health Sciences Research Ethics Committee (JREC).
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- 2021
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23. Two Novel Cases of Autosomal Translocations in the Horse: Warmblood Family Segregating t(4;30) and a Cloned Arabian with a de novo t(12;25)
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Olivia Phelps, Terje Raudsepp, Mayra N. Mendoza, Sharmila Ghosh, Rytis Juras, C.C. Love, Candice F Carden, Jessie Dube, Matthew Jevit, Dickson D. Varner, Caitlin Castaneda, and Dale E. Kelley
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Male ,Nuclear Transfer Techniques ,Genotype ,Offspring ,Cloning, Organism ,Clone (cell biology) ,Abnormal Karyotype ,Chromosomal translocation ,Trisomy ,Reproductive technology ,Biology ,Breeding ,Translocation, Genetic ,Congenital Abnormalities ,03 medical and health sciences ,Genetics ,medicine ,Animals ,Horses ,Molecular Biology ,Genetics (clinical) ,030304 developmental biology ,0303 health sciences ,030305 genetics & heredity ,Breakpoint ,Karyotype ,medicine.disease ,Chromosomes, Mammalian ,Phenotype ,Infertility ,Karyotyping ,Somatic cell nuclear transfer ,Female - Abstract
We report 2 novel autosomal translocations in the horse. In Case 1, a breeding stallion with a balanced t(4p;30) had produced normal foals and those with congenital abnormalities. Of his 9 phenotypically normal offspring, 4 had normal karyotypes, 4 had balanced t(4p;30), and 1 carried an unbalanced translocation with tertiary trisomy of 4p. We argue that unbalanced forms of t(4p;30) are more tolerated and result in viable congenital abnormalities, without causing embryonic death like all other known equine autosomal translocations. In Case 2, two stallions produced by somatic cell nuclear transfer from the same donor were karyotyped because of fertility issues. A balanced translocation t(12q;25) was found in one, but not in the other clone. The findings underscore the importance of routine cytogenetic screening of breeding animals and animals produced by assisted reproductive technologies. These cases will contribute to molecular studies of translocation breakpoints and their genetic consequences in the horse.
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- 2020
24. Design and Evaluation of a Novel Mobile Phone Application to Improve Palliative Home-Care in Resource-Limited Settings
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Anil Kumar Paleri, Lovemore Mupaza, José Miguel Carrasco, Richard Harding, Emmanuel Luyirika, Cristina Lasmarías Martínez, Ludoviko Zirimenya, Eric L. Krakauer, Dickson D. Chifamba, Lulu Mathews, Marie-Charlotte Bouësseau, Terrymize Immanuel, Jeannine Lemaire, Eve Namisango, and Jordi Serrano-Pons
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Zimbabwe ,Palliative care ,Dashboard (business) ,India ,Qualitative property ,Context (language use) ,03 medical and health sciences ,0302 clinical medicine ,Resource (project management) ,Nursing ,Medicine ,Humans ,Uganda ,030212 general & internal medicine ,mHealth ,General Nursing ,business.industry ,Family caregivers ,Palliative Care ,Mobile Applications ,Anesthesiology and Pain Medicine ,Mobile phone ,030220 oncology & carcinogenesis ,Neurology (clinical) ,business ,Cell Phone - Abstract
Context Mobile health (mHealth) provides an opportunity to use internet coverage in low- and middle-income countries to improve palliative care access and quality. Objectives This study aimed to design a mobile phone application (app) to enable or improve communication between family caregivers, community caregivers, and palliative care teams; to evaluate its acceptability, processes, and mechanisms of action; and to propose refinements. Methods A codesign process entailed collaboration between a Project Advisory Group and collaborators in India, Uganda, and Zimbabwe. We then trained community and family caregivers to use an app to communicate patient-reported outcomes to their palliative care providers each week on a data dashboard. App activity was monitored, and qualitative in-depth interviews explored experience with the app and its mechanisms and impact. Results N = 149 caregivers participated and uploaded n = 837 assessments of patient-reported outcomes. These data were displayed to the palliative care team on an outcomes dashboard on n = 355 occasions. Qualitative data identified: 1) high acceptability and data usage; 2) improved understanding by team members of patient symptoms and concerns; 3) a need for better feedback to caregivers, for better prioritisation of patients according to need, for enhanced training and support to use the app, and for user-led recommendations for ongoing improvement. Conclusion An outcomes-focused app and data dashboard are acceptable to caregivers and health-care professionals. They are beneficial in identifying, monitoring, and communicating patient outcomes and in allocating staff resource to those most in need.
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- 2020
25. Inclusion of supplemental antibiotics (amikacin - penicillin) in a commercial extender for stallion semen: Effects on sperm quality, bacterial growth, and fertility following cooled storage
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Luisa Ramírez-Agámez, Dickson D. Varner, Sheila R. Teague, Charles C. Love, Dale E. Kelley, Camilo Hernández-Avilés, R. Serafini, Elena Martínez de Andino, K.A. LaCaze, and Steven P. Brinsko
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Male ,medicine.drug_class ,Antibiotics ,Penicillins ,Biology ,Microbiology ,law.invention ,03 medical and health sciences ,Semen quality ,0302 clinical medicine ,Food Animals ,law ,Pregnancy ,Semen ,medicine ,Animals ,Horses ,Small Animals ,Amikacin ,030219 obstetrics & reproductive medicine ,Equine ,Extender ,0402 animal and dairy science ,food and beverages ,04 agricultural and veterinary sciences ,Amikacin Sulfate ,040201 dairy & animal science ,Spermatozoa ,Anti-Bacterial Agents ,Penicillin ,Semen Analysis ,Semen extender ,Fertility ,Ticarcillin ,Sperm Motility ,Animal Science and Zoology ,Female ,medicine.drug ,Semen Preservation - Abstract
In this study, the effectiveness of supplementing INRA-96® extender (INRA-Control; original antibiotic formulation: potassium penicillin G = 38 μg/mL; gentamicin sulfate = 105 μg/mL; amphotericin B = 0.315 μg/mL) with amikacin sulfate and potassium penicillin G (AP) was determined. In Exp. 1, two sources of amikacin (INRA-AP-Sigma or INRA-AP-GoldBio) in combination with penicillin G were compared with ticarcillin/clavulanate (INRA-Tim) or no-supplemental antibiotics (INRA-Control) to examine effects on sperm quality and commensal bacterial growth. No differences were detected in semen quality among treatments after 30 min of exposure (Time 30min) or 24 h of cooled storage (Time 24 h; P 0.05). At both time periods, commensal bacterial growth was significantly lower in Groups INRA-AP-GoldBio and INRA-AP-Sigma than in INRA-Tim or INRA-Control (P 0.05). In Exp. 2, increasing doses of amikacin sulfate (GoldBio) plus potassium penicillin G (Sigma) - AP (AP-1000, 2000, 3000, 4000 or 5000 μg-IU/mL, respectively) were added to INRA-96® extender and their effects on sperm quality and commensal bacterial growth were evaluated at Time 30min and Time 24 h. Slight reductions in progressive motility and viability were observed at Time 30min in Groups AP-4000 and AP-5000 as compared to other treatment groups (P 0.05); however, no differences in sperm quality were detected among treatment groups at Time 24 h (P 0.05). At both time periods, commensal bacterial growth was significantly lower in Groups AP-3000, AP-4000 and AP-5000 than in AP-1000 and AP-2000 (P 0.05). In Exp. 3, a breeding trial was conducted to determine the effect of adding a high dose of AP (AP-5000) to INRA-96® extender on resulting pregnancy rates of mares bred with cool-stored semen (Time 24 h). Numerical, but not statistical differences, were observed in pregnancy rates between the mares bred with INRA-Control (6/11; 55%) or INRA-AP-5000 (9/11; 82%; P 0.05). Supplementation of INRA-96® extender with two different concentrations of AP (AP-1000 or AP-5000) was tested in two clinical cases of stallions where semen was moderately to heavily contaminated with Pseudomonas aeruginosa, or both Klebsiella pneumoniae and Pseudomonas aeruginosa. In both cases, addition of AP resulted in a considerable decrease on bacterial growth in cool-stored semen when compared to the use of the original INRA-96® extender without supplemental antibiotics. In conclusion, the addition of amikacin sulfate and potassium penicillin G to INRA-96® extender allowed for effective control of commensal bacteria without affecting sperm quality. Higher doses of amikacin and penicillin can be safely added to INRA-96® extender to improve the antibacterial activity of this extender against commensal, and potentially pathogenic bacteria, while sperm quality and fertility of cooled semen remains unaffected. Based on the results of the present study, we currently recommend that INRA-96® extender can be safely supplemented with amikacin/penicillin by using a conventional dose of 1000 μg/mL - 1000 IU/mL as a prophylactic measure in cases where contamination of the ejaculates with commensal bacteria is evident. Alternatively, a high dose (5000 μg/mL - 5000 IU/mL) can be used as a control method for potentially pathogenic bacteria.
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- 2020
26. Atomic iridium@cobalt nanosheets for dinuclear tandem water oxidation
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Xu Wang, Ganesan Anandhababu, Yaobing Wang, Jiannian Yao, Rui Si, Dickson D. Babu, Qiaohong Li, Maoxiang Wu, and Yiyin Huang
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Materials science ,Renewable Energy, Sustainability and the Environment ,Hydrogen bond ,Inorganic chemistry ,Oxygen evolution ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,engineering.material ,Overpotential ,021001 nanoscience & nanotechnology ,Electrocatalyst ,Catalysis ,chemistry ,engineering ,General Materials Science ,Noble metal ,Iridium ,0210 nano-technology ,Cobalt - Abstract
Atomization of noble metals enable their electrocatalysis applications with low cost, whereas the isolated mononuclear site after atomization might lead leads to limited performance. Herein, we present a general strategy of atomically confined alloying (ACA) to synthesize an electrocatalyst of single atom iridium-trapping cobalt nanosheets with dual-reactive Ir–Co sites. The atomic Ir@Co nanosheets (1.7 wt% Ir) exhibit excellent oxygen evolution reaction (OER) performance with a small overpotential (273 mV at 10 mA cm−2) and high stability, higher than that of the Ir/C catalyst (290 mV at 10 mA cm−2). More importantly, density functional theory (DFT) calculations combined with experiments demonstrated that water oxidation proceeded on atomic Ir@Co nanosheets via a dinuclear tandem mechanism, in which Ir–Co dual sites cooperatively worked in favour of the sequential transfer from Co–OH* to Ir–O* via a Co–O–Ir intermediate, and stabilization of OOH* species by hydrogen bonding interaction. The cooperative mechanism based on a dinuclear electrocatalyst by ACA is hoped to open up more possibilities of single atom noble metal electrocatalysts for various applications.
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- 2019
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27. The effects of antibiotic type and extender storage method on sperm quality and antibacterial effectiveness in fresh and cooled-stored stallion semen
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J. Wu, Sara D. Lawhon, R. Serafini, Camilo Hernández-Avilés, K.A. LaCaze, C.C. Love, Terry L. Blanchard, Sheila R. Teague, and Dickson D. Varner
- Subjects
Male ,040301 veterinary sciences ,medicine.drug_class ,Antibiotics ,Semen ,law.invention ,0403 veterinary science ,Food Animals ,law ,polycyclic compounds ,medicine ,Animals ,Horses ,Food science ,Small Animals ,Sperm motility ,urogenital system ,Equine ,Chemistry ,Extender ,0402 animal and dairy science ,04 agricultural and veterinary sciences ,Spermatozoa ,040201 dairy & animal science ,Sperm ,Anti-Bacterial Agents ,Semen Analysis ,Penicillin ,Ticarcillin ,Sperm Motility ,Piperacillin Sodium ,Animal Science and Zoology ,Semen Preservation ,medicine.drug - Abstract
Two experiments were conducted to evaluate the effects of antibiotic-containing extender of on sperm quality and control of bacterial growth. In Experiment 1, ejaculates were diluted in extender containing no antibiotics, potassium penicillin G-amikacin disulfate (PEN-AMIK), ticarcillin disodium-potassium clavulanate (TICAR-CLAV), piperacillin sodium/tazobactam sodium (PIP-TAZ), or meropenem (MERO). In freshly extended semen, only slight differences were detected among some antibiotic treatments for total sperm motility, curvilinear velocity, and viable acrosome-intact sperm (P 0.05). In cool-stored semen, slight differences were also detected among certain antibiotic treatments for curvilinear velocity and chromatin integrity (P 0.05). In Experiment 2, ejaculates were diluted in extender and subjected to no bacterial spiking, or inoculated with lower or higher doses of K. pneumoniae or P. aeruginosa. Following cooled storage of semen, colony forming units/ml (CFU/mL) were less in PEN-AMIK (706 ± 244) and MERO (1576 ± 1076) treatment groups than in TICAR-CLAV (4678 ± 1388) or PIP-TAZ (8108 ± 3198) treatment groups (P 0.05). The CFU/mL were lower in all antibiotic-containing treatment groups than the control group (18478 ± 4374; P 0.05). The percentage of culture plates containing no bacterial growth in unspiked semen was greater in PEN-AMIK (75%) than PIP-TAZ (15%) or TICAR-CLAV (20%; P 0.05). The percentages of culture plates containing no bacterial growth in semen spiked with a lower doses of K. pneumoniae or P. aeruginosa were higher in PEN-AMIK (70% and 50%, respectively) then in all other treatment groups (0-40% and 0-15% for K. pneumonia and P. aeruginosa, respectively; P 0.05); however, complete control of bacterial load was only modest even with PEN-AMIK. In both experiments, freezing and thawing extender prior to use did not have any appreciable detrimental effect on sperm quality or antibiotic efficacy. In summary, all antibiotics tested had minimal effects on measures of sperm quality in fresh or cool-stored semen extenders; however, PEN-AMIK, followed by MERO, yielded the best results in terms of antimicrobial efficacy. None of the antibiotic types controlled bacterial growth, in comparison with the antibiotic-free control group, when extended semen was spiked with a high concentration of Pseudomonas aeruginosa. Cooled storage of extended semen reduced bacterial growth in comparison with freshly extended semen.
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- 2018
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28. Synergistic Supports Beyond Carbon Black for Polymer Electrolyte Fuel Cell Anodes
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Dickson D. Babu, Yaobing Wang, Yiyin Huang, and Maoxiang Wu
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chemistry.chemical_classification ,Materials science ,Organic Chemistry ,02 engineering and technology ,Carbon black ,Polymer ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Anode ,Inorganic Chemistry ,Chemical engineering ,chemistry ,Fuel cells ,Physical and Theoretical Chemistry ,0210 nano-technology - Published
- 2018
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29. Spatio-Temporal Variation in Viability of Spermatozoa of Honey Bee, Apis mellifera, Drones in Central Texas Apiaries
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Juliana Rangel, Adrian Fisher, Kyle Harrison, Dickson D. Varner, and Charles C. Love
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0106 biological sciences ,Veterinary medicine ,Forage (honey bee) ,Ecology ,Apiary ,media_common.quotation_subject ,Honey bee ,Biology ,Reproductive season ,010603 evolutionary biology ,01 natural sciences ,Eusociality ,Drone ,010602 entomology ,Insect Science ,Reproduction ,Agronomy and Crop Science ,media_common - Abstract
Males of some eusocial hymenopterans live in sheltered hives where they are raised by sister workers until they are ready to mate. Large amounts of colony resources are invested in the care and nurturing of males, as they provide no contributions to colony maintenance apart from reproduction. Colonies of the honey bee, Apis mellifera L., have one queen, thousands of female workers, and a few thousand seasonal males (drones) that are reared only during the reproductive season when colony resources are plentiful. We examined the viability of spermatozoa in sexually mature drones from eight apiaries in three counties in Central Texas during the summers of 2013 and 2014. We sampled 1,622 drones from two counties in 2013, and 556 drones from three counties in 2014. Using dual fluorescent flow cytometry, viability of drone spermatozoa was measured as the proportion of total spermatozoa that was viable. The average spermatozoa viability was 46.2% in 2013 and 67.0% in 2014. We found significant variation in spermatozoa viability across apiaries, with viability in Apiary 5 significantly lower and viability in Apiary 11 significantly greater than viability in the other apiaries sampled in 2013. Likewise, males in apiaries 6 and 7 had significantly lower average viability of spermatozoa compared with other apiaries analyzed in 2014. However, the changes were not consistent across apiaries during the 2 years sampled. Our results suggested that other factors such as exposure to insecticides or seasonal availability of forage might be more important than inter-colonial genetic differences in fertility of honey bee drones during the reproductive season.
- Published
- 2018
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30. Atomic dispersion of Fe/Co/N on graphene by ball-milling for efficient oxygen evolution reaction
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Yiyin Huang, Maoxiang Wu, Wang Wenguo, Yaobing Wang, Dickson D. Babu, and Jiangquan Lv
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Materials science ,Renewable Energy, Sustainability and the Environment ,Graphene ,Oxygen evolution ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,Overpotential ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrocatalyst ,01 natural sciences ,0104 chemical sciences ,law.invention ,Fuel Technology ,chemistry ,Chemical engineering ,law ,Water splitting ,0210 nano-technology ,Dispersion (chemistry) ,Ball mill ,Cobalt - Abstract
Development of the electrochemical water splitting is impeded by the important yet sluggish half-reaction of oxygen evolution reaction (OER). Atomic dispersion of Fe Co species represents a new type of potential materials for OER. However, it is still highly challenging to exploit facile and efficient methods for such synthesis. Herein, we have developed a rapid mechanical ball milling approach to synthesize highly-dispersed Fe/Co/N on graphene as OER electrocatalyst, which displays high OER performance with overpotential of 288 mV at 10 mA cm−2 and no obvious decay after 9 h of continuous operation at 10 mA cm−2. This excellent electrocatalytic performance originates from atomic-scale accessible iron, cobalt and nitrogen electrocatalytic sites and highly conductive graphene. These results suggest feasibility of this facile and efficient ball milling method in synthesis of other electrocatalysts for various applications.
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- 2018
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31. Novel N-Mo2 C Active Sites for Efficient Solar-to-Hydrogen Generation
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Yaobing Wang, Ganesan Anandhababu, Maoxiang Wu, Muhammad Arsalan Ghausi, Yiyin Huang, Dickson D. Babu, Jing Wu, Syed Comail Abbas, and Zeng Peng
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Materials science ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrocatalyst ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Chemical engineering ,Electrochemistry ,Solar energy conversion ,Hydrogen evolution ,0210 nano-technology ,Hydrogen production - Published
- 2018
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32. Supplemental Antibiotics in a Commercial Extender for Stallion Semen
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R. Serafini, Camilo Hernández-Avilés, Charles C. Love, Sheila R. Teague, and Dickson D. Varner
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Male ,medicine.drug_class ,Antibiotics ,Semen ,law.invention ,Animal science ,law ,medicine ,Animals ,Humans ,Horses ,Equine ,Chemistry ,Extender ,food and beverages ,Antimicrobial ,Spermatozoa ,Sperm ,Anti-Bacterial Agents ,Penicillin ,Semen extender ,Amikacin ,Sperm Motility ,Semen Preservation ,medicine.drug - Abstract
Commonly marketed semen extenders contain various antibiotic types and concentrations to control bacterial growth from stallion's external genitalia. An experiment was conducted to test the effects of supplemental amikacin disulfate (1,000 μg/mL) + potassium penicillin G (1,000 IU/ML: INRA-AP), or ticarcillin-clavulanate (1,000 μg/mL: INRA-TIM) in the INRA 96 extender, on sperm function and antimicrobial activity, compared with extender without supplemental antibiotics (INRA-C). In freshly extended semen (Time 30m), no differences were observed among the three treatment groups for sperm motion characteristics or plasma membrane intactness (P.05). Following cooled storage (Time 24h), sperm progressive motility and straightness were higher in INRA-AP, as compared to INRA-C or INRA-TIM (P.05). For both time points, INRA-AP yielded lower bacterial colony-forming units (CFU/mL) than INRA-TIM or INRA-C (P.05). In addition, INRA-AP yielded a higher proportion of culture plates with no growth (59%), than INRA-TIM (14%) or INRA-C (22%; P.05). These findings suggest that INRA 96 extender can be supplemented with the tested concentrations of amikacin disulfate + potassium penicillin G to improve its antimicrobial effectiveness without impairing sperm quality.
- Published
- 2019
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33. Novel strongly coupled tungsten-carbon-nitrogen complex for efficient hydrogen evolution reaction
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Maoxiang Wu, Dickson D. Babu, Muhammad Arsalan Ghausi, Syed Comail Abbas, Yaobing Wang, Ganesan Anandhababu, Jing Wu, and Yiyin Huang
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Tafel equation ,Materials science ,Hydrogen ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,Overpotential ,Tungsten ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrocatalyst ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Fuel Technology ,chemistry ,Chemical engineering ,Tungsten carbide ,engineering ,Noble metal ,0210 nano-technology ,Tungsten nitride - Abstract
Alternatives to noble metal based electrocatalysts are vitally necessary to produce hydrogen from water at low overpotentials. Earlier research on tungsten based electrocatalyst has been mainly concentrated towards tungsten carbide (WC) and tungsten nitride (WN) as the potential electrocatalysts for hydrogen evolution reaction (HER), whereas tungsten carbide (W2C) has been least focused upon. Herein, we report a highly active novel strongly coupled tungsten-carbon-nitrogen complex (W2C-NC-WN complex) prepared by in situ carbonization method. This W2C-NC-WN complex exhibits a remarkable electrochemical performance for HER with a small onset potential of 33 mV vs. RHE and requires an overpotential (η) of 145 mV vs. RHE to render −10 mA cm−2 current density. The Tafel analysis demonstrates a slope of 96 mV dec−1 which is much better than WN (109.6 mV dec−1) and WC (142.4 mV dec−1). The strong coupling of W2C and WN within N-doped carbon (NC) framework brings about a significant enhancement in HER kinetics and faster electron transport due to the remarkable reduction in charge transfer resistance. The facile synthetic approach reported here, provides a powerful tool for the structurally controlled modification of the catalyst while simultaneously introducing active species.
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- 2018
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34. Synthesis, Characterization and Performance Studies of a New Metal-Free Organic Sensitizer for DSSC application
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A. Vasudeva Adhikari, Dickson D. Babu, Praveen Naik, Rui Su, and Ahmed El-Shafei
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chemistry.chemical_classification ,Materials science ,Band gap ,02 engineering and technology ,Electron acceptor ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensation reaction ,Photochemistry ,01 natural sciences ,Acceptor ,0104 chemical sciences ,Benzaldehyde ,chemistry.chemical_compound ,Dye-sensitized solar cell ,Aniline ,chemistry ,0210 nano-technology ,Benzoic acid - Abstract
In this present work we report, design, synthesis and performance studies of a new metal-free organic dye (N, N’-PABA) based on N,N-dimethyl-4-vinyl aniline carrying 4-amino benzoic acid as acceptor, as sensitizers for sensitizing photoanode (TiO2). In the sensitizers, N,N-dimethylaniline ring acts as anelectron donorwhile para amino benzoic acid function as electron acceptor/anchoring units. It was synthesized via condensation reaction starting from simple 4-(N,N-dimethyl amino)benzaldehyde and their structures were confirmed using spectral techniques like FTIR, 1HNMR, 13CNMR, MS and elemental analysis. Further, it was subjected to electrochemical and optical characterization in order to evaluate their band gap and absorption/emission behavior. Further, DFT studies were performed using turbo mole V6.6 software package to evaluate their optimized geometry and FMO levels. Finally, DSSC devices were fabricated using this dye under simulated solar radiation AM1.5G and result revealed that it shows a conversion efficiency of 1%.
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- 2018
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35. New carbazole based metal-free organic dyes with D-π-A-π-A architecture for DSSCs: Synthesis, theoretical and cell performance studies
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Mohamed R. Elmorsy, Praveen Naik, Ahmed El-Shafei, Rui Su, Airody Vasudeva Adhikari, and Dickson D. Babu
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Materials science ,Barbituric acid ,Renewable Energy, Sustainability and the Environment ,Carbazole ,02 engineering and technology ,Chromophore ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Acceptor ,0104 chemical sciences ,chemistry.chemical_compound ,Dye-sensitized solar cell ,Cyanoacetic acid ,chemistry ,Thiophene ,Physical chemistry ,General Materials Science ,0210 nano-technology ,HOMO/LUMO - Abstract
Herein we report the design, synthesis and photovoltaic performance studies of three new D-π-A-π-A architectured organic chromophores (N1-3) derived from (Z)-3-(9-hexyl-9H-carbazol-3-yl)-2-(thiophen-2-yl) acrylonitrile scaffold. In the new design, the electron rich carbazole unit is connected to three different electron withdrawing/anchoring species, viz. cyano acetic acid, rhodanine-3-acetic acid and barbituric acid via cyano vinyl thiophene as π-spacer. Newly synthesized dyes were characterized by spectral, photophysical and electrochemical analyses. Their optical band-gap, GSOP and ESOP values, as calculated from the optical and CV studies were found to be in the range of 2.12–2.21, −5.52 to −5.43 and −5.40 to −3.25 eV respectively. The DFT and TD-DFT studies were performed using Turbomole 7.1V software and the results indicated the existence of proper charge separation between HOMO and LUMO levels of the dyes. Also, the results revealed good matching of theoretically generated optical spectral data with the experimental values. Finally, DSSC devices were fabricated using these three dyes and the dye N1 containing cyanoacetic acid as an acceptor unit showed better photo conversion efficiency (η) of 3.55% than the other two dyes. It’s JSC, VOC, and IPCE parameters were shown to be 9.06 mA cm−2, 0.577 V and 48%, respectively. The obtained EIS data and electron lifetimes of N1–3 sensitized devices are well in accordance with experimental photovoltaic parameters.
- Published
- 2017
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36. Structurally simple D–A-type organic sensitizers for dye-sensitized solar cells: effect of anchoring moieties on the cell performance
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Ahmed El-Shafei, Dickson D. Babu, Rui Su, Airody Vasudeva Adhikari, and Praveen Naik
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chemistry.chemical_classification ,Barbituric acid ,010405 organic chemistry ,Band gap ,Electron donor ,General Chemistry ,Electron acceptor ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Acceptor ,0104 chemical sciences ,chemistry.chemical_compound ,Aniline ,chemistry ,Knoevenagel condensation ,HOMO/LUMO - Abstract
In this work, we report synthesis and device fabrication studies of four metal-free D–A-type dyes (A1–A4) based on structurally simple N,N-dimethyl-4-vinyl aniline carrying four different acceptor/anchoring groups, as sensitizers for sensitizing photoanode (TiO2). In the sensitizers, N,N-dimethylaniline ring acts as an electron donor, while barbituric acid, N,N-dimethyl barbituric acid, thiobarbituric acid and N,N-diethyl thiobarbituric acid function as electron acceptor/anchoring units. They were synthesized in good yield via Knoevenagel protocol in neutral condition without any catalyst. Further, they were subjected to structural, electrochemical and optical characterization in order to evaluate their structure, band gap and absorption/emission behavior. The studies reveal that all the four dyes have thermodynamic feasibility of electron injection as well as electron recombination; their optical band gaps were found to be in the range of 2.35–2.56 eV. High-quality crystals of A2 and A4 were grown by slow evaporation technique using its solution with 1:1 pet ether (60–80 °C)/ethyl acetate solvent mixture at room temperature. Their SC-XRD studies disclose that the crystals are in the triclinic system with space group P-1. Further, DFT studies were performed using Turbomole V7.1 software package to evaluate their optimized geometry and HOMO and LUMO levels. Finally, DSSC device fabricated with the dye A1 showed relatively good efficiency when compared to other dyes mainly due to the effective binding of barbituric acid on the surface of TiO2 through NH or OH functional group.
- Published
- 2017
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37. Molecular design and theoretical investigation of new metal-free heteroaromatic dyes with D-π-A architecture as photosensitizers for DSSC application
- Author
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Airody Vasudeva Adhikari, Rui Su, Ahmed El-Shafei, Mohamed R. Elmorsy, Praveen Naik, and Dickson D. Babu
- Subjects
Barbituric acid ,Carbazole ,General Chemical Engineering ,General Physics and Astronomy ,Quantum yield ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Suzuki reaction ,Cyanoacetic acid ,Phenylene ,Knoevenagel condensation ,0210 nano-technology ,HOMO/LUMO - Abstract
Herein, we report design, synthesis and photovoltaic performance of four new metal-free heteroaromatic dyes ( P 1-4 ) with D-π-A architecture carrying electron donating carbazole core connected to four different electron withdrawing/anchoring groups, viz. cyanoacetic acid, rhodanine-3-acetic acid, barbituric acid and thiobarbituric acid and phenylene ring as a π-spacer. The newly designed P 1-4 were synthesized from carbazole derivative using Suzuki cross coupling approach followed by Knoevenagel condensation reaction. Their structures were confirmed by FTIR, NMR, Mass spectral and elemental analyses. The dyes were subjected to optical and electrochemical studies in order to investigate their absorption/emission behavior as well as HOMO/LUMO energies. The UV–vis spectral studies reveal that the P 1-4 showed λ max at 412, 439, 458 and 489 nm, respectively. Their optical band-gap is in the range of 2.17 to 2.61 eV and fluorescence quantum yield is in the order of 44–70%. From energy level diagram, it is clear that all the dyes possess good thermodynamic feasibility for electron injection into CB edge of TiO 2 as well as their regeneration from electrolyte system. The photovoltaic performance studies indicate that among the tested dyes, P 1 anchored with cyanoacetic acid displayed the highest IPCE (32%), resulting in improved PCE (1.94%), J SC (4.68 mA cm −2 ), V OC (0.588 V) and FF (70.3%) values, when compared to other dyes. Finally, DFT studies were performed using Turbomole 7.1 V software to investigate their electron cloud delocalization in HOMO/LUMO levels and theoretical absorption spectral data. The results reveal that the dye P 1 showed effective charge separation in its FMO levels, which has reflected in its ICT behavior and hence P 1 displayed the improved photovoltaic performance.
- Published
- 2017
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38. Synthesis and photovoltaic performance of a novel asymmetric dual-channel co-sensitizer for dye-sensitized solar cell beyond 10% efficiency
- Author
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Airody Vasudeva Adhikari, Praveen Naik, Dickson D. Babu, Ahmed El-Shafei, and Rui Su
- Subjects
Process Chemistry and Technology ,General Chemical Engineering ,Photovoltaic system ,chemistry.chemical_element ,02 engineering and technology ,Chromophore ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Acceptor ,0104 chemical sciences ,law.invention ,Ruthenium ,Dye-sensitized solar cell ,chemistry ,law ,Solar cell ,Moiety ,Density functional theory ,0210 nano-technology - Abstract
In this paper, we report the design and synthesis of a new bi-anchoring indole based co-sensitizer DBA-8 with A-π-D-A (acceptor-π bridge-donor-acceptor) architecture, carrying indole moiety as a donor and barbituric acid as acceptor/anchoring groups. Its photo-physical and electrochemical properties along with molecular geometries, calculated from Density Functional Theory (DFT) are employed to comprehend the effect of co-sensitizer structure on photovoltaic characteristics of DSSCs. The abovementioned organic dye ( DBA-8 ) was employed as a co-sensitizer along with well-known ruthenium based sensitizer NCSU-10 in order to broaden the spectral responses of the co-sensitized DSSC. In the present work, for the first time we are demonstrating the profound role of a dual-anchoring co-sensitizer that can play in ameliorating the overall performance of a solar cell. The photovoltaic studies indicated that, the co-sensitizer DBA-8 succeeded in increasing the light harvesting ability in the device significantly. Notably, the device co-sensitized using 0.2 mM DBA-8 along with ruthenium based chromophore NCSU-10 , showed a maximum efficiency of 10.68% ( J sc = 25.14 mAcm −2 , V oc = 0.695 V, ff = 61.2%). Further, the good agreement between the theoretically and experimentally obtained λ max data vindicate that, the energy functional and basis set employed in this study can be successfully utilized for predicting the absorption spectra of new photosensitizers, with great precision before synthesis. Furthermore, all these findings showcase the vast potential of bi-anchoring molecules in improving the overall performance of the dye-sensitized solar cells.
- Published
- 2017
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39. Contributors
- Author
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Dorothy M. Ainsworth, Monica Aleman, John A. Angelos, Luis G. Arroyo, Scott M. Austin, Jane E. Axon, Lora Rickard Ballweber, Danika L. Bannasch, Safia Z. Barakzai, Emily A. Barrell, George M. Barrington, Michelle H. Barton, Dale E. Bauman, Erin McConachie Beasley, Daniela Bedenice, Catherine J. Benson, Dionne Benson, Caroline M. Betbeze, Danelle A. Bickett-Weddle, Anthony T. Blikslager, Andrea A. Bohn, Angela I. Bordin, Dwight D. Bowman, Ashley G. Boyle, Rana Bozorgmanesh, Barry J. Bradford, Babetta Breuhaus, Steven P. Brinsko, Nimet Browne, Ben Buchanan, Sébastien Buczinski, Alexandra J. Burton, Erin N. Burton, Stacey R. Byers, Barbara A. Byrne, David P. Byrne, Robert J. Callan, Canaan Whitfield Cargile, Gary P. Carlson, Elizabeth A. Carr, Renee T. Carter, Stan W. Casteel, M. Keith Chaffin, Berkley Chesen, Munashe Chigerwe, Bruce W. Christensen, Gemma Chuck, Kristin A. Clothier, Johann (Hans) F. Coetzee, Michelle C. Coleman, Robert J. Collier, Victor S. Cortese, Lais R. Costa, Beate M. Crossley, Jennifer L. Davis, Melody Anne de Laat, Fabio Del Piero, André Desrochers, Padraic Martin Dixon, Charles C. Dodd, Brandon J. Dominguez, Vincent Dore, Gerald E. Duhamel, Bettina Dunkel, Jack Easley, Kari J. Ekenstedt, John A. Ellis, Pablo Espinosa-Mur, Ronald J. Erskine, Krista E. Estell, Timothy J. Evans, Darien Feary, Gilles Fecteau, Marie-Eve Fecteau, M. Julia B. Felippe, C. Langdon Fielding, Carrie J. Finno, Sherrill A. Fleming, David Francoz, Nicholas Frank, Robert W. Fulton, Lisa E. Fultz, Tam Garland, Franklyn Garry, Anne J. Gemensky-Metzler, Philippa Gibbons, Steeve Giguère, Sandra Godden, Jesse Paul Goff, Kathleen Casey Gonda, Liara M. Gonzalez, Gretchen P. Grissett, Alison A. Gunn, Santiago D. Gutierrez-Nibeyro, Faisal Ghazi Habasha, Tiffany L. Hall, Spring K. Halland, Gayle D. Hallowell, Joanne Hardy, Kelsey A. Hart, Amanda K. Hartnack, Daniel A. Heinrich, Meera Heller, Troy Herthel, Sharon K. Hietala, Kenneth W. Hinchcliff, Melissa T. Hines, John K. House, Lynn R. Hovda, Angela M. Hughes, Pamela J. Hullinger, Alexandra Hund, David J. Hurley, Robert E. James, Emily John, Jennifer L. Johns, Philip J. Johnson, Meredyth L. Jones, Samuel L. Jones, Will C. Jordan, Carter E. Judy, Scott A. Katzman, Claudia Klein, Amanda J. Kreuder, Jeffrey Lakritz, Benjamin Landers, Gabriele A. Landolt, Kara M. Lascola, Mary Elizabeth Lassaline, Richard Andrew LeCouteur, Guy D. Lester, Christian M. Leutenegger, Michelle Linton, Jeanne Lofstedt, Ricardo Loinaz, Evelyn MacKay, Robert J. MacKay, N. James Maclachlan, John E. Madigan, K. Gary Magdesian, Muhammad Muzafar Makhdoomi, John B. Malone, Peggy S. Marsh, John F. Marshall, Krysta Martin, Christie E. Mayo, Melissa Mazan, Jessica A. McArt, Craig McConnel, Karen McDowell, Dianne McFarlane, Jodi L. McGill, Cathy McGowan, Sheila M. McGuirk, Bret R. McNabb, John R. Middleton, Suzanne T. Millman, Paul S. Morley, Derek A. Mosier, Michelle Mostrom, T.G. Nagaraja, Sylvain Nichols, Martin K. Nielsen, Tracy E. Norman, Jeffrey W. Norris, Daryl Nydam, Olimpo Oliver-Espinosa, Steven M. Parish, John R. Pascoe, Michael Payne, Caryn E. Plummer, Paul J. Plummer, Robert H. Poppenga, Shannon E. Pratt-Philips, Birgit Puschner, Nicola Pusterla, Virginia B. Reef, David G. Renter, Sarah M. Reuss, James P. Reynolds, Juan E. Romano, Sr., Pamela L. Ruegg, Robert Bascom Sager, Sarah N. Sampson, Chris Sanchez, Montague N. Saulez, Harold C. Schott, Leslie C. Sharkey, Jan K. Shearer, JoAnn Slack, Bradford P. Smith, Geoffrey W. Smith, Rachael L. Smith, Sharon Jane Spier, Brett A. Sponseller, Henry Stämpfli, Guy St. Jean, Allison Jean Stewart, Raymond W. Sweeney, Tamara M. Swor, Jared D. Taylor, Lisa A. Tell, Brett Tennent-Brown, Ronald L. Terra, Alain P. Théon, Joy E. Tomlinson, Ramiro E. Toribio, Mats H.T. Troedsson, Travis M. Tull, Francisco A. Uzal, Stephanie J. Valberg, Sarel R. Van Amstel, Andrew W. Van Eps, David C. Van Metre, Dickson D. Varner, Meredith L. Voyles, Kristina R. Vygantas, Paul Walz, Kevin Washburn, W. Ray Waters, Jeffrey P. Watkins, Johanna L. Watson, Ashlee E. Watts, J. Scott Weese, Maurice Edward White, Stephen D. White, Pamela A. Wilkins, Jarred Williams, Kurt J. Williams, W. David Wilson, Elizabeth M. Woodward, Amelia R. Woolums, and Kathryn L. Wotman
- Published
- 2020
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40. Diseases of the Reproductive System
- Author
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E.M. Woodward, Mats H.T. Troedsson, Bruce W. Christensen, Juan E. Romano, Steven P. Brinsko, Dickson D. Varner, and Bret R. McNabb
- Subjects
Zoology ,Reproductive system ,Biology - Published
- 2020
- Full Text
- View/download PDF
41. Effect of artificial vagina lubricants on stallion sperm quality
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K.A. LaCaze, Sharmila Ghosh, C.C. Love, Sheila R. Teague, J.M.R. Medrano, R. Serafini, and Dickson D. Varner
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Male ,endocrine system ,Semen ,Semen collection ,law.invention ,Andrology ,03 medical and health sciences ,Vaginal Lubricant ,0302 clinical medicine ,Food Animals ,law ,Animals ,Horses ,Small Animals ,Acrosome ,Sperm motility ,Lubricants ,030219 obstetrics & reproductive medicine ,urogenital system ,Equine ,Chemistry ,Extender ,0402 animal and dairy science ,04 agricultural and veterinary sciences ,040201 dairy & animal science ,Sperm ,Spermatozoa ,Semen Analysis ,Toxicity ,Sperm Motility ,Animal Science and Zoology - Abstract
Commercially available vaginal lubricants, typically labeled as non-spermicidal, are used to lubricate equine artificial vaginas prior to semen collection. Improper type or amount of lubricant might affect stallion sperm quality, either after short-time exposure or following cooled storage of extended semen previously exposed to lubricant. The aim of this study was to evaluate stallion sperm quality following exposure to lubricant-containing extender for 1 h (T1h) or 24 h (T24h). Three ejaculates were collected from each of four stallions using a small volume of petrolatum to lubricate artificial vaginas, and gel-free semen was diluted to 30 × 106 sperm/mL in extender containing: no lubricant (control), or 1 or 5% (v/v) HR® Lubricating Jelly (HR1 or HR5); K-Y® Jelly (KY1 or KY5); Therio-gel® (TG1 or TG5); Priority Care® Sterile Lubricating Jelly (PC1 or PC5); or Clarity® A.I. Lubricating Jelly (CL1 or CL5). Sperm were evaluated at T1h and T24h for percentages of: total and progressive sperm motility (TMOT and PMOT); curvilinear velocity (VCL; μm/s); and straightness (STR; %); viable acrosome intact sperm (VAI); sperm with abnormal DNA (COMP-αt); viable lipid peroxidation negative sperm (VLPN); and sperm with no detectable DNA oxidative injury [8OHdG(−)]. Following short-term exposure of sperm to lubricants, KY5 reduced TMOT, PMOT, VCL, VAI, VLPN, and COMP-αt in comparison with controls (i.e., P 0.05), except for VCL. Following long-term exposure, KY5 decreased TMOT, PMOT, VCL, VAI, VLPN, and COMP-αt as compared to controls (i.e., P 0.05). Overall, lubricant KY was the most detrimental to sperm quality, with most profound changes detected at a 5% concentration. Lubricants CL and HR were generally similar to controls and were less affected by lubricant concentration.
- Published
- 2019
42. Effects of media and promoters on different lipid peroxidation assays in stallion sperm
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Dickson D. Varner, R. Serafini, Camilo Hernández-Avilés, Sheila R. Teague, Sharmila Ghosh, K.A. LaCaze, and Charles C. Love
- Subjects
Male ,Ultraviolet Rays ,Lipid peroxidation ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Endocrinology ,Cryoprotective Agents ,Food Animals ,Animals ,Horses ,chemistry.chemical_classification ,Cryopreservation ,Reactive oxygen species ,030219 obstetrics & reproductive medicine ,0402 animal and dairy science ,Promoter ,04 agricultural and veterinary sciences ,General Medicine ,040201 dairy & animal science ,Sperm ,Spermatozoa ,Culture Media ,Biochemistry ,chemistry ,Animal Science and Zoology ,Lipid Peroxidation ,BODIPY ,Reactive Oxygen Species ,Semen Preservation - Abstract
Effects of different media and promoters on lipid peroxidation (LPO) in viable stallion sperm have not been reported. Aims of this study were to determine effects of three media (INRA-96™, Equipro CoolGuard™, and Biggers, Whitten and Whittingham [BWW]), and promoters (iron sulfate-Fe; ultraviolet light-UV; or control-no exposure to promoters) on viable sperm LPO using four different flow cytometric assays (i.e., BODIPY, Liperfluo, 4-hydroxylnonenal [4HNE], malonaldehyde [MDA]). Significant media x promoter interactions were detected using the Liperfluo, 4HNE, and MDA assays (P 0.05); therefore, data were sorted by media and by promoters. With inclusion of milk-based media, there were similar concentrations of LPO in control samples with use of all LPO assays. The effect of iron, as a promoter of LPO production, was media dependent, and milk-based media protected sperm from iron-induced LPO production when there were assessments with all assays. In contrast, iron promoted LPO in sperm diluted in BWW when there was use of in all assays, except BODIPY, probably because of the different target molecule with use of this assay. Ultraviolet light was the most potent LPO promoter with all media and assays evaluated. Data indicate milk-based extenders are generally more LPO-protective than BWW early in the LPO production pathway (based on BODIPY and Liperfluo assays), but are less protective during the later stages of LPO production (based on 4HNE and MDA assays). The use of different media and promoters of LPO allowed for determination of early and late stages of LPO in viable stallion sperm.
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- 2019
43. Dexamethasone downregulates expression of several genes encoding orphan nuclear receptors that are important to steroidogenesis in stallion testes
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Raul Valdez, Dickson D. Varner, Clay A. Cavinder, Nancy H. Ing, Thomas H. Welsh, and M.M. Vogelsang
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Male ,0301 basic medicine ,Steroidogenic factor 1 ,endocrine system ,medicine.medical_specialty ,Health, Toxicology and Mutagenesis ,Down-Regulation ,Biology ,Toxicology ,Biochemistry ,Dexamethasone ,03 medical and health sciences ,0302 clinical medicine ,Glucocorticoid receptor ,Cytochrome P-450 Enzyme System ,Internal medicine ,medicine ,Animals ,Testosterone ,Horses ,Molecular Biology ,030102 biochemistry & molecular biology ,Leydig cell ,Cholesterol side-chain cleavage enzyme ,Leydig Cells ,General Medicine ,Orphan Nuclear Receptors ,medicine.anatomical_structure ,Endocrinology ,Nuclear receptor ,030220 oncology & carcinogenesis ,Molecular Medicine ,Glucocorticoid ,medicine.drug - Abstract
Glucocorticoids impair testosterone synthesis by an unknown mechanism. Stallions treated with the synthetic glucocorticoid dexamethasone had testes collected at 6 or 12 hours postinjection. The testicular expression of selected genes encoding nuclear receptors and steroidogenic enzymes was measured. At 6 hours, dexamethasone treatment decreased levels of NR0B2, NR4A1, NR5A1, and NR5A2 messenger RNAs (mRNAs) and NR5A2 mRNA levels remained depressed at 12 hours. In contrast, dexamethasone increased levels of NFKBIA mRNA at both time points. At 6 hours, dexamethasone did not alter levels of NR0B1, NR2F1, NR2F2, NR3C1, CYP11A1, CYP17A1, CYP19A1, DHCR24, GSTA3, HSD3B2, HSD17B3, LHCGR, or STAR mRNAs. In primary cultures of Leydig cells, 10 -9 and 10 -7 M dexamethasone decreased levels of NR4A1 and NR5A1 mRNAs and increased those of NFKBIA mRNA. Our discovery that dexamethasone downregulates NR4A1, NR5A1, and NR5A2 genes, known to be important for testicular functions, may be part of the mechanism by which glucocorticoids acutely decreases testosterone.
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- 2019
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44. Lignin Quantification of Papyri by TGA—Not a Good Idea
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José C. del Río, Florian Bausch, Mario J. Rosado, Antje Potthast, Paul Jusner, Jorge Rencoret, Dickson D. Owusu, Sabine Rosner, Thomas Rosenau, Austrian Biorefinery Center Tulln, Lower Austria, Agencia Estatal de Investigación (España), European Commission, Junta de Andalucía, Bausch, Florian, Rosado, Mario J., Rencoret, Jorge, Río Andrade, José Carlos del, Rosenau, T., Potthast, Antje, Bausch, Florian [0000-0002-7076-2356], Rosado, Mario J. [0000-0001-6313-1890], Rencoret, Jorge [0000-0003-2728-7331], Río Andrade, José Carlos del [0000-0002-3040-6787], Rosenau, T. [0000-0002-6636-9260], and Potthast, Antje [0000-0003-1981-2271]
- Subjects
Thermogravimetric analysis ,lignin ,Pharmaceutical Science ,Conservation ,02 engineering and technology ,engineering.material ,Lignin ,01 natural sciences ,Article ,Analytical Chemistry ,chemistry.chemical_compound ,QD241-441 ,Quantification ,Drug Discovery ,papyrus ,Klason-lignin ,Physical and Theoretical Chemistry ,Cellulose ,Papyrus ,TGA ,Plant Extracts ,010401 analytical chemistry ,Organic Chemistry ,conservation ,DTG ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,quantification ,0104 chemical sciences ,ABSL ,chemistry ,Chemistry (miscellaneous) ,engineering ,Molecular Medicine ,Pith ,0210 nano-technology - Abstract
9 páginas.- 4 figuras.- 1 tabla.- 27 referencias, Papyri belong to the oldest writing grounds in history. Their conservation is of the highest importance in preserving our cultural heritage, which is best achieved based on an extensive knowledge of the materials’ constituents to choose a tailored conservation approach. Thermogravimetric Analysis (TGA) has been widely employed to quantify cellulose and lignin in papyrus sheets, yielding reported lignin contents of 25% to 40%. In this work, the TGA method conventionally used for papyrus samples was repeated and compared to other lignin determination approaches (Klason-lignin and acetyl bromide-soluble lignin). TGA can lead to a large overestimation of the lignin content of commercial papyrus sheets (~27%) compared to the other methods (~5%). A similar overestimation of the lignin content was found for the pith and rind of the native papyrus plant. We concluded that the TGA method should, therefore, not be used for lignin quantification., Funding by the Austrian Biorefinery Center Tulln (ABCT) and the County of Lower Austria is greatly acknowledged. J.C.d.R., J.R. and M.J.R were funded by the Spanish State Research Agency and the European Regional Development Fund (project AGL2017-83036-R), and by the Junta de Andalucía (project P20-00017).
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- 2021
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45. Highly exposed Fe–N4active sites in porous poly-iron-phthalocyanine based oxygen reduction electrocatalyst with ultrahigh performance for air cathode
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Syed Comail Abbas, Jiangquan Lv, Kui Ding, Jiafang Xie, Yaobing Wang, Dickson D. Babu, Yiyin Huang, Maoxiang Wu, Qin Liu, and Ganesan Anandhababu
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Battery (electricity) ,Open-circuit voltage ,Limiting current ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,Electrocatalyst ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Inorganic Chemistry ,chemistry ,Chemical engineering ,0210 nano-technology ,Platinum ,Methanol fuel - Abstract
Progress in the development of efficient electrocatalysts for oxygen reduction reactions is imperative for various energy systems such as metal–air batteries and fuel cells. In this paper, an innovative porous two-dimensional (2D) poly-iron–phthalocyanine (PFe–Pc) based oxygen reduction electrocatalyst created with a simple solid-state chemical reaction without pyrolysis is reported. In this strategy, silicon dioxide nanoparticles play a pivotal role in preserving the Fe–N4 structure during the polymerization process and thereby assist in the development of a porous structure. The new polymerized phthalocyanine electrocatalyst with tuned porous structure, improved specific surface area and more exposed catalytic active sites via the 2D structure shows an excellent performance towards an oxygen reduction reaction in alkaline media. The onset potential (E = 1.033 V) and limiting current density (I = 5.58 mA cm−2) are much better than those obtained with the commercial 20% platinum/carbon electrocatalyst (1.046 V and 4.89 mA cm−2) and also show better stability and tolerance to methanol crossover. For practical applications, a zinc–air (Zn–air) battery and methanol fuel cell equipped with the PFe–Pc electrocatalyst as an air cathode reveal a high open circuit voltage and maximum power output (1.0 V and 23.6 mW cm−2 for a methanol fuel cell, and 1.6 V and 192 mW cm−2 for the liquid Zn–air battery). In addition, using the PFe–Pc electrocatalyst as an air cathode in a flexible cable-type Zn–air battery exhibits excellent performance with an open-circuit voltage of 1.409 V. This novel porous 2D PFe–Pc has been designed logically using a new, simple strategy with ultrahigh electrochemical performances in Zn–air batteries and methanol fuel cell applications.
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- 2017
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46. CXCR4involvement in neurodegenerative diseases
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Bonham, Luke W, Karch, Celeste M, Ferrari, Raffaele, Danek, A., Van Deerlin, V. M., Grossman, M., Trojanowski, J. Q., van der Zee, J., Cruts, M., Van Broeckhoven, C., Cappa, S. F., Leber, I., Hannequin, D., Hardy, John, Golfier, V., Vercelletto, M., Brice, A., Nacmias, B., Sorbi, S., Bagnoli, S., Piaceri, I., Nielsen, J. E., Hjermind, L. E., Riemenschneider, M., Momeni, Parastoo, Mayhaus, M., Ibach, B., Gasparoni, G., Pichler, S., Gu, W., Rossor, M. N., Fox, N. C., Warren, J. D., Spillantini, M. G., Morris, H. R., Höglinger, Günter, Rizzu, P., Heutink, P., Snowden, J. S., Rollinson, S., Richardson, A., Gerhard, A., Bruni, A. C., Maletta, R., Frangipane, F., Cupidi, C., Müller, Ulrich, Bernardi, L., Anfossi, M., Gallo, M., Conidi, M. E., Smirne, N., Rademakers, R., Baker, M., Dickson, D. W., Graff-Radford, N. R., Petersen, R. C., Hess, Christopher P, Knopman, D., Josephs, K. A., Boeve, B. F., Parisi, J. E., Seeley, W. W., Miller, B. L., Karydas, A. M., Rosen, H., van Swieten, J. C., Dopper, E. G. P., Sugrue, Leo P, Seelaar, H., Pijnenburg, Y. A. L., Scheltens, P., Logroscino, G., Capozzo, R., Novelli, V., Puca, A. A., Franceschi, M., Postiglione, A., Milan, G., Dillon, William P, Sorrentino, P., Kristiansen, M., Chiang, H-H, Graff, C., Pasquier, F., Rollin, A., Deramecourt, V., Lebouvier, T., Kapogiannis, D., Ferrucci, L., Schellenberg, Gerard D, Pickering-Brown, S., Singleton, A. B., Hardy, J., Momeni, P., Miller, Bruce L, Fan, Chun C, Andreassen, Ole A, Dale, Anders M, Barkovich, A James, Yokoyama, Jennifer S, Desikan, Rahul S, Consortium, International FTD-Genomics, Consortium, International Parkinson’s Disease Genetics, Project, International Genomics of Alzheimer’s, Ferrari, R., Hernandez, D. G., Tan, Chin, Nalls, M. A., Rohrer, J. D., Ramasamy, A., Kwok, J. B. J., Dobson-Stone, C., Schofield, P. R., Halliday, G. M., Hodges, J. R., Piguet, O., Bartley, L., Geier, Ethan G, Thompson, E., Haan, E., Hernández, I., Ruiz, A., Boada, M., Borroni, B., Padovani, A., Cruchaga, C., Cairns, N. J., Benussi, L., Wang, Yunpeng, Binetti, G., Ghidoni, R., Forloni, G., Albani, D., Galimberti, D., Fenoglio, C., Serpente, M., Scarpini, E., Clarimón, J., Lleó, A., Wen, Natalie, Blesa, R., Waldö, M Landqvist, Nilsson, K., Nilsson, C., Mackenzie, I. R. A., Hsiung, G-Y R, Mann, D. M. A., Grafman, J., Morris, C. M., Attems, J., Broce, Iris J, Griffiths, T. D., McKeith, I. G., Thomas, A. J., Pietrini, P., Huey, E. D., Wassermann, E. M., Baborie, A., Jaros, E., Tierney, M. C., Pastor, P., Li, Yi, Razquin, C., Ortega-Cubero, S., Alonso, E., Perneczky, R., Diehl-Schmid, J., Alexopoulos, P., Kurz, A., Rainero, I., Rubino, E., Pinessi, L., Barkovich, Matthew J, Rogaeva, E., George-Hyslop, P St, Rossi, G., Tagliavini, F., Giaccone, G., Rowe, J. B., Schlachetzki, J. C. M., Uphill, J., Collinge, J., Mead, S., Bonham, Luke W., Karch, Celeste M., Fan, Chun C., Tan, Chin, Geier, Ethan G., Wang, Yunpeng, Wen, Natalie, Broce, Iris J., Li, Yi, Barkovich, Matthew J., Ferrari, Raffaele, Hardy, John, Momeni, Parastoo, Höglinger, Günter, Müller, Ulrich, Hess, Christopher P., Sugrue, Leo P., Dillon, William P., Schellenberg, Gerard D., Miller, Bruce L., Andreassen, Ole A., Dale, Anders M., Barkovich, A. Jame, Yokoyama, Jennifer S., Desikan, Rahul S., Hernandez, D. G., Nalls, M. A., Rohrer, J. D., Ramasamy, A., Kwok, J. B. J., Dobson-Stone, C., Schofield, P. R., Halliday, G. M., Hodges, J. R., Piguet, O., Bartley, L., Thompson, E., Haan, E., Hernández, I., Ruiz, A., Boada, M., Borroni, B., Padovani, A., Cruchaga, C., Cairns, N. J., Benussi, L., Binetti, G., Ghidoni, R., Forloni, G., Albani, D., Galimberti, D., Fenoglio, C., Serpente, M., Scarpini, E., Clarimón, J., Lleó, A., Blesa, R., Waldö, M. Landqvist., Nilsson, K., Nilsson, C., Mackenzie, I. R. A., Hsiung, G. -Y. R., Mann, D. M. A., Grafman, J., Morris, C. M., Attems, J., Griffiths, T. D., Mckeith, I. G., Thomas, A. J., Pietrini, P., Huey, E. D., Wassermann, E. M., Baborie, A., Jaros, E., Tierney, M. C., Pastor, P., Razquin, C., Ortega-Cubero, S., Alonso, E., Perneczky, R., Diehl-Schmid, J., Alexopoulos, P., Kurz, A., Rainero, I., Rubino, E., Pinessi, L., Rogaeva, E., George-Hyslop, P. St., Rossi, G., Tagliavini, F., Giaccone, G., Rowe, J. B., Schlachetzki, J. C. M., Uphill, J., Collinge, J., Mead, S., Danek, A., Van Deerlin, V. M., Grossman, M., Trojanowski, J. Q., Van Der Zee, J., Cruts, M., Van Broeckhoven, C., Cappa, S. F., Leber, I., Hannequin, D., Golfier, V., Vercelletto, M., Brice, A., Nacmias, B., Sorbi, S., Bagnoli, S., Piaceri, I., Nielsen, J. E., Hjermind, L. E., Riemenschneider, M., Mayhaus, M., Ibach, B., Gasparoni, G., Pichler, S., Gu, W., Rossor, M. N., Fox, N. C., Warren, J. D., Spillantini, M. G., Morris, H. R., Rizzu, P., Heutink, P., Snowden, J. S., Rollinson, S., Richardson, A., Gerhard, A., Bruni, A. C., Maletta, R., Frangipane, F., Cupidi, C., Bernardi, L., Anfossi, M., Gallo, M., Conidi, M. E., Smirne, N., Rademakers, R., Baker, M., Dickson, D. W., Graff-Radford, N. R., Petersen, R. C., Knopman, D., Josephs, K. A., Boeve, B. F., Parisi, J. E., Seeley, W. W., Karydas, A. M., Rosen, H., Van Swieten, J. C., Dopper, E. G. P., Seelaar, H., Pijnenburg, Y. A. L., Scheltens, P., Logroscino, G., Capozzo, R., Novelli, V., Puca, A. A., Franceschi, M., Postiglione, A., Milan, G., Sorrentino, P., Kristiansen, M., Chiang, H. -H., Graff, C., Pasquier, F., Rollin, A., Deramecourt, V., Lebouvier, T., Kapogiannis, D., Ferrucci, L., Pickering-Brown, S., Singleton, A. B., Rademakers, Rosa, International FTD-Genomics Consortium (IFGC), International Parkinsons Disease Genetics Consortium (IPDGC), and International Genomics of Alzheimers Project (IGAP)
- Subjects
0301 basic medicine ,Aging ,Gene Expression ,Genome-wide association study ,metabolism [Microglia] ,Neurodegenerative ,Bioinformatics ,Alzheimer's Disease ,Transgenic ,Mice ,0302 clinical medicine ,Risk Factors ,Receptors ,2.1 Biological and endogenous factors ,Psychology ,Gene Regulatory Networks ,Aetiology ,Alzheimer's Disease Related Dementias (ADRD) ,0303 health sciences ,Gene Regulatory Network ,Parkinson's Disease ,International Genomics of Alzheimer’s Project ,Neurodegeneration ,Brain ,Neurodegenerative Diseases ,Single Nucleotide ,International Parkinson’s Disease Genetics Consortium ,Frontotemporal Dementia (FTD) ,Psychiatry and Mental Health ,Neurological ,Public Health and Health Services ,Tauopathy ,Microglia ,Frontotemporal dementia ,Human ,Receptors, CXCR4 ,Tau protein ,Clinical Sciences ,Mice, Transgenic ,Computational biology ,Biology ,Polymorphism, Single Nucleotide ,Article ,CXCR4 protein, human ,Progressive supranuclear palsy ,lcsh:RC321-571 ,Cellular and Molecular Neuroscience ,03 medical and health sciences ,Rare Diseases ,Text mining ,Genetic predisposition ,medicine ,Genetics ,Acquired Cognitive Impairment ,Animals ,Humans ,Genetic Predisposition to Disease ,ddc:610 ,Polymorphism ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,Biological Psychiatry ,030304 developmental biology ,CXCR4 ,Neurodegenerative Disease ,Animal ,business.industry ,Risk Factor ,International FTD-Genomics Consortium ,Neurosciences ,Alzheimer's Disease including Alzheimer's Disease Related Dementias (AD/ADRD) ,medicine.disease ,genetics [Receptors, CXCR4] ,Brain Disorders ,Genome-Wide Association Study ,030104 developmental biology ,metabolism [Brain] ,genetics [Neurodegenerative Diseases] ,Expression quantitative trait loci ,biology.protein ,Dementia ,Human medicine ,metabolism [Receptors, CXCR4] ,business ,030217 neurology & neurosurgery - Abstract
Neurodegenerative diseases likely share common underlying pathobiology. Although prior work has identified susceptibility loci associated with various dementias, few, if any, studies have systematically evaluated shared genetic risk across several neurodegenerative diseases. Using genome-wide association data from large studies (total n = 82,337 cases and controls), we utilized a previously validated approach to identify genetic overlap and reveal common pathways between progressive supranuclear palsy (PSP), frontotemporal dementia (FTD), Parkinson’s disease (PD) and Alzheimer’s disease (AD). In addition to the MAPT H1 haplotype, we identified a variant near the chemokine receptor CXCR4 that was jointly associated with increased risk for PSP and PD. Using bioinformatics tools, we found strong physical interactions between CXCR4 and four microglia related genes, namely CXCL12, TLR2, RALB, and CCR5. Evaluating gene expression from post-mortem brain tissue, we found that expression of CXCR4 and microglial genes functionally related to CXCR4 was dysregulated across a number of neurodegenerative diseases. Furthermore, in a mouse model of tauopathy, expression of CXCR4 and functionally associated genes was significantly altered in regions of the mouse brain that accumulate neurofibrillary tangles most robustly. Beyond MAPT, we show dysregulation of CXCR4 expression in PSP, PD, and FTD brains, and mouse models of tau pathology. Our multi-modal findings suggest that abnormal signaling across a ‘network’ of microglial genes may contribute to neurodegeneration and may have potential implications for clinical trials targeting immune dysfunction in patients with neurodegenerative diseases.
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- 2017
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47. Signalment, clinical features, and outcome for male horses with urethral rents following perineal urethrotomy or corpus spongiotomy: 33 cases (1989–2013)
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Dickson D. Varner, James Schumacher, Carolyn E. Arnold, Kati G. Glass, and M. Keith Chaffin
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Male ,medicine.medical_specialty ,Urethrotomy ,040301 veterinary sciences ,medicine.medical_treatment ,0403 veterinary science ,Urethra ,Urethral Diseases ,medicine ,Animals ,Horses ,Surgical treatment ,Ureterostomy ,Hematuria ,General Veterinary ,business.industry ,Medical record ,0402 animal and dairy science ,Hemospermia ,04 agricultural and veterinary sciences ,040201 dairy & animal science ,Surgery ,medicine.anatomical_structure ,Horse Diseases ,business ,Penis - Abstract
OBJECTIVE To describe the signalment, clinical features, and outcome for male horses with urethral rents following perineal urethrotomy (PU) or corpus spongiotomy (CS). DESIGN Retrospective case series. ANIMALS 33 horses. PROCEDURES Medical records of male horses examined because of hematuria or hemospermia caused by urethral rents that underwent PU or CS at a referral hospital between 1989 and 2013 were reviewed. Data regarding signalment, clinical features, urethroscopic findings, surgical treatment, and outcome were recorded. Long-term follow-up information was obtained by telephone interviews. RESULTS Age of the study population ranged from 3 to 18 years. Nineteen geldings and 1 stallion were examined because of hematuria, of which 13 and 7 underwent PU and CS, respectively, at a mean of 56 days after onset of clinical signs. Thirteen stallions were examined because of hemospermia, of which 7 and 6 underwent PU and CS, respectively, at a mean of 193 days after onset of clinical signs. Hematuria resolved following 1 surgical procedure in all 17 horses for which long-term information was available. Of the 12 stallions for which long-term information was available, 7 had resolution of hemospermia after 1 PU or CS and 5 developed recurrent hemospermia that required additional PUs or CSs (n = 3) or primary closure of the urethral rent (2). CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that PU and CS were reliable treatments for resolution of hematuria in male horses with urethral rents; stallions with urethral rents may require multiple PUs or CSs or primary closure of the rent for resolution of hemospermia.
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- 2016
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48. Highly efficient panchromatic dye-sensitized solar cells: Synergistic interaction of ruthenium sensitizer with novel co-sensitizers carrying different acceptor units
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Airody Vasudeva Adhikari, Dickson D. Babu, Ahmed El-Shafei, Hammad Cheema, and Dalia Elsherbiny
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Indole test ,Chemistry ,Process Chemistry and Technology ,General Chemical Engineering ,chemistry.chemical_element ,02 engineering and technology ,Time-dependent density functional theory ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Acceptor ,0104 chemical sciences ,Ruthenium ,chemistry.chemical_compound ,Dye-sensitized solar cell ,Molecular geometry ,Thiophene ,Density functional theory ,0210 nano-technology - Abstract
Herein, we report the molecular design, synthesis and photovoltaic performance studies of three new organic co-sensitizers, N1-3 carrying indole and thiophene units linked to different acceptors/anchoring groups, as co-adsorbents for dye sensitized solar cells. We present the role of anchoring/acceptor units on co-sensitization properties N1-3. Their photo-physical and electrochemical results along with molecular geometry, obtained from Density Functional Theory are utilized to rationalize the influence of co-sensitizer structures on photovoltaic properties for DSSCs. We have shown that, the co-sensitization effect is profoundly dependent upon the anchoring/acceptor unit in the co-adsorbents. Among them, N3 containing 4-aminobenzoic acid shows promising co-sensitization results and exhibits an enhanced efficiency of 9.26%, when co-sensitized with a ruthenium dye, HD-14. Further, the study highlights the importance of molecular matching between the sensitizer and co-sensitizer in enhancing the efficiency. Furthermore, vertical electronic excitations are calculated using time dependent density functional theory studies.
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- 2016
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49. Mitochondrial oxygen consumption is a unique indicator of stallion spermatozoal health and varies with cryopreservation media
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Dickson D. Varner, Stuart A Meyers, Gino A Cortopassi, Christa R. Darr, and Sandipan Datta
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Male ,Motility ,chemistry.chemical_element ,Context (language use) ,Biology ,Oxygen ,Cryopreservation ,law.invention ,Andrology ,03 medical and health sciences ,Cryoprotective Agents ,Oxygen Consumption ,0302 clinical medicine ,Food Animals ,law ,Animals ,Horses ,Small Animals ,Incubation ,chemistry.chemical_classification ,Reactive oxygen species ,030219 obstetrics & reproductive medicine ,Equine ,Extender ,0402 animal and dairy science ,04 agricultural and veterinary sciences ,Spermatozoa ,040201 dairy & animal science ,Sperm ,Mitochondria ,Semen Analysis ,chemistry ,Animal Science and Zoology - Abstract
Mitochondrial oxygen consumption is a sensitive indicator of spermatozoal health in the context of cryopreservation. We investigated oxygen consumption of equine sperm mitochondria during incubation in four commercially available sperm cryopreservation extenders: modified INRA 96, BotuCrio, EZ Freezin-"LE" and "MFR5", in addition to several other parameters including motility, reactive oxygen species (ROS) production and viability. All experimental endpoints, with the exception of average path velocity, were affected significantly by freezing extender type after freezing and thawing. Sperm in INRA 96 had the lowest average progressive motility after thawing (24 ± 4.8%, P 0.05). Sperm in EZ Freezin-"LE" had the highest post thaw viability (79 ± 3.1%, P 0.05) and lowest post thaw ROS production (13 ± 2.4%), but sperm in BotuCrio had the highest maximal oxygen consumption levels, while also demonstrating similar ROS production and viability. This difference would not have been detected using conventional sperm analytical methods. In addition, sperm in BotuCrio had the highest average total motility (49 ± 7.4%), progressive motility (41 ± 6.4%), and velocity (VAP, 90 ± 3.6 μm/s) indicating that this medium preserved mitochondrial function optimally after cryopreservation. Mitochondrial oxygen consumption was positively correlated with traditional measures of sperm function including motility and viability (r = 0.62 and r = 0.49, respectively, P 0.05), thus making it a sensitive method for determining cryopreservation success and mitochondrial function in stallion sperm.
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- 2016
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50. Approaches to Breeding Soundness Examination and Interpretation of Results
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Dickson D. Varner
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Soundness ,030219 obstetrics & reproductive medicine ,ComputingMilieux_THECOMPUTINGPROFESSION ,Equine ,Computer science ,Artificial insemination ,medicine.medical_treatment ,media_common.quotation_subject ,0402 animal and dairy science ,Fertility ,04 agricultural and veterinary sciences ,040201 dairy & animal science ,03 medical and health sciences ,Pregnancy rate ,0302 clinical medicine ,Breeding soundness examination ,Forensic engineering ,medicine ,Operations management ,media_common - Abstract
The best indicator of stallion fertility is per-cycle pregnancy rate following cover or artificial insemination of fertile mares under good management conditions. This process can be lengthy, cumbersome, and impractical. As such, a laboratory-based examination is oftentimes performed to predict the fertility of a given stallion. This communication summarizes the approach to examination of a stallion for breeding soundness.
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- 2016
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