117 results on '"Travis AJ"'
Search Results
2. Community-driven development for computational biology at Sprints, Hackathons and Codefests
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Moeller, S, Afgan, E, Banck, M, Bonnal, RJP, Booth, T, Chilton, J, Cock, PJA, Gumbel, M, Harris, N, Holland, R, Kalas, M, Kajan, L, Kibukawa, E, Powel, DR, Prins, P, Quinn, J, Sallou, O, Strozzi, F, Seemann, T, Sloggett, C, Soiland-Reyes, S, Spooner, W, Steinbiss, S, Tille, A, Travis, AJ, Guimera, RV, Katayama, T, Chapman, BA, Moeller, S, Afgan, E, Banck, M, Bonnal, RJP, Booth, T, Chilton, J, Cock, PJA, Gumbel, M, Harris, N, Holland, R, Kalas, M, Kajan, L, Kibukawa, E, Powel, DR, Prins, P, Quinn, J, Sallou, O, Strozzi, F, Seemann, T, Sloggett, C, Soiland-Reyes, S, Spooner, W, Steinbiss, S, Tille, A, Travis, AJ, Guimera, RV, Katayama, T, and Chapman, BA
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BACKGROUND: Computational biology comprises a wide range of technologies and approaches. Multiple technologies can be combined to create more powerful workflows if the individuals contributing the data or providing tools for its interpretation can find mutual understanding and consensus. Much conversation and joint investigation are required in order to identify and implement the best approaches. Traditionally, scientific conferences feature talks presenting novel technologies or insights, followed up by informal discussions during coffee breaks. In multi-institution collaborations, in order to reach agreement on implementation details or to transfer deeper insights in a technology and practical skills, a representative of one group typically visits the other. However, this does not scale well when the number of technologies or research groups is large. Conferences have responded to this issue by introducing Birds-of-a-Feather (BoF) sessions, which offer an opportunity for individuals with common interests to intensify their interaction. However, parallel BoF sessions often make it hard for participants to join multiple BoFs and find common ground between the different technologies, and BoFs are generally too short to allow time for participants to program together. RESULTS: This report summarises our experience with computational biology Codefests, Hackathons and Sprints, which are interactive developer meetings. They are structured to reduce the limitations of traditional scientific meetings described above by strengthening the interaction among peers and letting the participants determine the schedule and topics. These meetings are commonly run as loosely scheduled "unconferences" (self-organized identification of participants and topics for meetings) over at least two days, with early introductory talks to welcome and organize contributors, followed by intensive collaborative coding sessions. We summarise some prominent achievements of those meetings and describ
- Published
- 2014
3. Anti-Müllerian Hormone in the Domestic Dog during the Anestrus to Oestrous Transition.
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Nagashima, JB, Hansen, BS, Songsasen, N, Travis, AJ, and Place, NJ
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DOG reproduction ,ESTRUS ,PROGESTERONE ,ANTI-Mullerian hormone ,BLOOD serum analysis ,HYSTERO-oophorectomy ,IMMUNOHISTOCHEMISTRY - Abstract
Contents The reproductive cycle of the domestic dog features a long period of relative ovarian inactivity or anestrus. The mechanism of anestrous termination/oestrous resumption is not yet fully understood, which presents a challenge to the development of oestrous induction protocols. In this study, we assess the possibility that anti-Müllerian hormone ( AMH) might play a role in this transition by characterizing its patterns of expression in the circulation during the transition from anestrus to oestrous and in all stages of ovarian follicular growth. Serum samples from five beagles (2.0-4.5 years) were collected three times per week at least 30 days prior to the onset of oestrous and assessed for AMH concentrations. Serum AMH concentration increased significantly during the transition from anestrus to proestrus and then declined back to the anestrous baseline beginning on day −4 before the luteinizing hormone surge, which was determined by changes in serum progesterone concentrations. Cortical sections of ovaries from females undergoing routine ovariohysterectomy (aged 8 months-5 years, n = 4) were evaluated for AMH by immunohistochemistry. Pre-antral and small antral follicles were most strongly immunoreactive for AMH. These data suggest that the increase in the number of antral follicles is associated with the rise in serum AMH as the anestrous period comes to an end. The rise in AMH might be useful in predicting the onset of oestrus and therefore assist with the optimization of oestrous induction protocols and possibly other assisted reproductive technologies. [ABSTRACT FROM AUTHOR]
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- 2016
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4. Computer simulation of cell wall degradation using cellular automata
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Travis, Aj, Metcalf, Mj, Chesson, A, and Revues Inra, Import
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[SDV.AEN] Life Sciences [q-bio]/Food and Nutrition ,[SDV.BDD] Life Sciences [q-bio]/Development Biology ,[SDV.BDLR] Life Sciences [q-bio]/Reproductive Biology - Published
- 1997
5. What Sperm Can Teach us About Energy Production
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Mukai, C, primary and Travis, AJ, additional
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- 2012
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6. Development of New Stem Cell-based Technologies for Carnivore Reproduction Research
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Travis, AJ, primary, Kim, Y, additional, and Meyers-Wallen, V, additional
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- 2009
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7. Computer simulation of cell wall degradation using cellular automata
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Travis, AJ, primary, Metcalf, MJ, additional, and Chesson, A., additional
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- 1997
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8. Magnetic resonance imaging of the behaviour of oil-in-water emulsions in the gastric lumen of man.
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Marciani L, Wickham MSJ, Bush D, Faulks R, Wright J, Fillery-Travis AJ, Spiller RC, and Gowland PA
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- 2006
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9. Real-Time Imaging of Calcium Dynamics in Human Sperm After Precise Single-Cell Stimulation.
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White MA, Cohen R, and Travis AJ
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- Humans, Male, Sperm Capacitation drug effects, Sperm Capacitation physiology, Acrosome Reaction drug effects, Exocytosis, Spermatozoa metabolism, Spermatozoa drug effects, Calcium metabolism, Calcium Signaling drug effects, Single-Cell Analysis methods
- Abstract
Calcium signaling is a critical regulator of sperm activation and function during the processes of capacitation and fertilization. Here, we describe a combined method for calcium imaging of single, live human sperm in response to stimuli administered with a precisely targeted delivery technique. This protocol is an adaptation of techniques developed for studies of murine sperm [1, 2], and enables real-time monitoring of human sperm calcium dynamics with high spatiotemporal resolution and concurrent detection of acrosome exocytosis (AE), a functional endpoint of sperm capacitation and requirement for physiological fertilization.The described imaging technique provides a valuable tool for exploration of calcium regulation in human sperm, which is essential to answer important questions and knowledge gaps regarding the link between calcium dynamics, AE, and fertilization. The versatility of this technique can be amplified through use of various indicator dyes or integration with pharmacological strategies such as pre-treating sperm with inhibitors or activators targeting specific receptors, channels, or intracellular signaling pathways of interest. Beyond fundamental inquiries into sperm physiology, this method can also be applied to assess the impact of potential contraceptive compounds on calcium signaling, AE, and membrane integrity., (© 2025. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2025
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10. Extracellular vesicles are involved in the paracrine communication between epithelial cells in different regions of the domestic cat epididymis†.
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Sosnicki DM, Travis AJ, and Comizzoli P
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- Animals, Male, Cats, Epididymis metabolism, Epididymis cytology, Extracellular Vesicles metabolism, Paracrine Communication, Epithelial Cells metabolism
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Sperm maturation depends on exposure to microenvironments within the different segments of the epididymis, but mechanisms underlying how these microenvironments are produced or maintained are not well understood. We hypothesized that epididymal extracellular vesicles could play a role in the process of maintaining microenvironments in different regions of the epididymis. Specifically, we tested whether the extracellular vesicles from different regions of the epididymis can ensure paracrine communication between cells in different segments. Domestic cat tissues were used to develop a reproducible in vitro culture system for corpus epididymis explants that were then exposed to extracellular vesicles collected from upstream (i.e., caput) segments. Impacts of different culture or exposure conditions were compared by analyzing the morphology, apoptosis, transcriptional activity, and gene expression in the explants. Here, we report the development of the first in vitro culture system for epididymal tissue explants in the domestic cat model. Using this system, we found that extracellular vesicles from the caput segment have a significant effect on the transcriptional profile of tissue from the corpus segment (1233 differentially expressed genes due to extracellular vesicle supplementation). Of note, expressions of genes associated with regulation of epithelial cell differentiation and cytokine signaling in the epididymis were influenced by the presence of extracellular vesicles. Together, our findings comprise the first report in any species of paracrine control of segmental gene regulation by epididymal extracellular vesicles. These results contribute to a better understanding of epididymis biology and could lead to strategies to enhance or suppress male fertility., (Published by Oxford University Press on behalf of Society for the Study of Reproduction 2024.)
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- 2024
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11. Genome-wide association study reveals effect of nsSNPs on candidate genes in rice during iron deficiency.
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Panda S, Anandan A, Shafi KM, Naika MBN, Sowdhamini R, Vanishree G, Sarkar S, Travis AJ, Norton GJ, and Price AH
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- Plant Proteins genetics, Plant Proteins metabolism, Plant Roots genetics, Plant Roots growth & development, Plant Roots metabolism, Chlorophyll metabolism, Oryza genetics, Oryza growth & development, Oryza metabolism, Polymorphism, Single Nucleotide, Genome-Wide Association Study, Iron Deficiencies
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Resource-poor areas with moisture deficit lands following aerobic and direct seeded rice (DSR) methods of cultivation face severe problems of iron deficiency. In this study, Bengal and Assam Aus rice panel was phenotyped at the seedling stage using an iron-deprived hydroponic medium for various shoot and root traits. A novel iron deficiency scoring scale was used to classify the tolerance reaction and could range anywhere between 0 and 9, indicating the most tolerant and susceptible, respectively. The GWAS results identified four putative candidate genes; OsFLA for number of leaves and shoot length, OsBIDK1 for root traits; average diameter, volume, biomass, projected area, and surface area, OsHPL3 for chlorophyll index of the third leaf and AKR2B (XBOS252) was for Fe score, (which was earlier reported in relation to Xa21). The nsSNP (nsSNPs) variations in these gene sequences were used to group the panel and identify superior haplotypes and donors. BR16 was identified as a superior donor, with higher chlorophyll index and shoot length than RA23, also higher values for root traits like root average diameter, root volume, root projected area and root surface area followed by Shete Bhado. The impact of identified nsSNPs on protein structure and stability was investigated. The conserved domains detected in the mutated proteins of the superior haplotypes are very informative, highlighting that natural selection favors abiotic stress tolerant variants in resource poor areas. Thus, justifying our choice of Aus landraces for association mapping of Fe deficiency tolerant genes in rice., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
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- 2024
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12. Facilitated Asynchronous Online Learning to Build Public Health Strategic Skills.
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Meredith GR, Leong D, Frost C, and Travis AJ
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- Humans, Pandemics prevention & control, Clinical Competence, Workforce, Public Health education, Education, Distance
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Context: The COVID-19 pandemic spurred significant government investments for hiring public health workers. There are clear opportunities to help build capacities among both current and incoming public health workers, closing well-elucidated skill gaps., Objective: To report on the development process, methods used, and outcomes seen from a point-in-time public health workforce capacity-building initiative, Public Health Essentials (PHE) ., Design: Capacity-building outcomes evaluation using pre/postintervention measures., Setting: The United States., Participants: A total of 512 learners working in roles (government or adjacent to) that support public health., Intervention: PHE, a cohort-based facilitated asynchronous online course comprising 5 units, 18 modules, 54 learning outcomes, and 266 teaching and applied assessment elements designed to build public health strategic skills., Main Outcome Measures: Two outputs and 3 outcomes were used to assess and improve progress in achieving our goal of building generalizable and transferrable public health ability and confidence among diverse public health workers: Use of PHE , PHE completion rate , Learner competence , Change in self-assessed ability , and Benefits of PHE., Results: From September 2021 to December 2022, 4 agencies used PHE for fellowship training or employee capacity building. Some 79% (n = 512) of learners completed the training, demonstrating competence in all 54 areas assessed by expert course facilitators. Of those, 79% (n = 321) completed both optional pre- and post-PHE surveys, reporting statistically significant gains in all strategic skill domains assessed (n = 9), regardless of demographics and public health experience. Learners gained new skills and knowledge (92%), developed a better understanding of public health (86%), and broadened their public health skill base (84%). A majority can apply the knowledge and skills gained directly to their work (94%), which benefits their team (92%), and have increased their confidence as public health practitioners (49%)., Conclusions: PHE can significantly improve learners' ability across 9 strategic skill areas in as few as 15 weeks, regardless of their demographics, training, or experience., Competing Interests: Conflicts of Interest: N/A., (Copyright © 2023 The Authors. Published by Wolters Kluwer Health, Inc.)
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- 2024
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13. Segmental differentiation of the murine epididymis: identification of segment-specific, GM1-enriched vesicles and regulation by luminal fluid factors†.
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Sosnicki DM, Cohen R, Asano A, Nelson JL, Mukai C, Comizzoli P, and Travis AJ
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- Mice, Male, Animals, Semen, Spermatozoa metabolism, Spermatogenesis, Epididymis metabolism, G(M1) Ganglioside metabolism
- Abstract
The murine epididymis has 10 distinct segments that provide the opportunity to identify compartmentalized cell physiological mechanisms underlying sperm maturation. However, despite the essential role of the epididymis in reproduction, remarkably little is known about segment-specific functions of this organ. Here, we investigate the dramatic segmental localization of the ganglioside GM1, a glycosphingolipid already known to play key roles in sperm capacitation and acrosome exocytosis. Frozen tissue sections of epididymides from adult mice were treated with the binding subunit of cholera toxin conjugated to AlexaFluor 488 to label GM1. We report that GM1-enriched vesicles were found exclusively in principal and clear cells of segment 2. These vesicles were also restricted to the lumen of segment 2 and did not appear to flow with the sperm into segment 3, within the limits of detection by confocal microscopy. Interestingly, this segment-specific presence was altered in several azoospermic mouse models and in wild-type mice after efferent duct ligation. These findings indicate that a lumicrine factor, itself dependent on spermatogenesis, controls this segmental differentiation. The RNA sequencing results confirmed global de-differentiation of the proximal epididymal segments in response to efferent duct ligation. Additionally, GM1 localization on the surface of the sperm head increased as sperm transit through segment 2 and have contact with the GM1-enriched vesicles. This is the first report of segment-specific vesicles and their role in enriching sperm with GM1, a glycosphingolipid known to be critical for sperm function, providing key insights into the segment-specific physiology and function of the epididymis., (© The Author(s) 2023. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
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- 2023
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14. Real-Time Imaging of Acrosomal Calcium Dynamics and Exocytosis in Live Mouse Sperm.
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Cohen R, Sosnicki DM, White MA, Nelson JL, Mukai C, and Travis AJ
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- Male, Mice, Animals, Spermatozoa, Exocytosis physiology, Mice, Transgenic, Calcium Signaling, Calcium metabolism, Semen metabolism
- Abstract
Acrosome exocytosis (AE), in which the sperm's single exocytotic vesicle fuses with the plasma membrane, is a complex, calcium-dependent process essential for fertilization. However, our understanding of how calcium signaling regulates AE is still incomplete. In particular, the interplay between intra-acrosomal calcium dynamics and the intermediate steps leading to AE is not well-defined. Here, we describe a method that provides spatial and temporal insights into acrosomal calcium dynamics and their relationship to membrane fusion and subsequent exocytosis of the acrosome vesicle. The method utilizes a novel transgenic mouse expressing an Acrosome-targeted Sensor for Exocytosis (AcroSensE). The sensor combines a genetically encoded calcium indicator (GCaMP) fused with mCherry. This fusion protein was specifically designed to enable the concurrent observation of acrosomal calcium dynamics and membrane fusion events. Real-time monitoring of acrosomal calcium dynamics and AE in live AcroSensE sperm is achieved using a combination of high frame-rate imaging and a stimulant delivery system that can target single sperm. This protocol also provides several examples of basic methods to quantify and analyze the raw data. Because the AcroSensE model is genetically encoded, its scientific significance can be augmented by using readily available genetic tools, such as crossbreeding with other mouse genetic models or gene-editing (CRISPR) based methods. With this strategy, the roles of additional signaling pathways in sperm capacitation and fertilization can be resolved. In summary, the method described here provides a convenient and effective tool to study calcium dynamics in a specific subcellular compartment-the sperm acrosome-and how those dynamics regulate the intermediate steps leading to membrane fusion and acrosome exocytosis.
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- 2023
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15. Defects in sperm capacitation/fertilizing ability are equally prevalent across ages in men seeking fertility assistance.
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Sharara FI, Ostermeier GC, and Travis AJ
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- Pregnancy, Female, Humans, Male, Aged, Fertilization, Fertility, Semen Analysis, Spermatozoa, Sperm Motility, Sperm Count, Sperm Capacitation, Semen
- Abstract
Research Question: How do capacitation ability, measured by Cap-Score™, and traditional semen analysis measures (volume, concentration, motility) change with age in men questioning their fertility (MQF)?, Design: Cap-Score and semen analysis measures were obtained from MQF (n = 2652; multicentric design: 35 reproductive endocrinologist prescribers, n = 16 clinics). Morphology was not included due to differences among clinics. A Mann-Whitney test was used to compare Cap-Scores between MQF and men with known recent paternity (n = 76). The following age groups were constructed for MQF: 20-24, 25-29, 30-34, 35-39, 40-44, 45-49 and 50+. Associations between semen analysis, Cap-Score and age groups were evaluated using mixed-model analysis of variance to identify possible influence of Cap-Score collection kit type (n = 763 collected at home; n = 1889 collected at clinics)., Results: MQF had reduced capacitation ability (mean ± SE; 29.25 ± 0.15 versus 35.34 ± 0.88; P < 0.001). No change in Cap-Score (P = 0.916) or concentration (P = 0.926) was detected with age group. In contrast, both volume (P = 0.008) and % motility (P < 0.001) declined with age., Conclusions: Men presenting because of difficulties in generating pregnancy showed equivalent reductions in capacitation ability regardless of age. In contrast, motility and volume declined with age. These data suggest that capacitation ability is a more sensitive indicator of male fertility across age groups than traditional semen analysis and should not be reserved for older men. Importantly, these data do not address whether sperm fertilizing ability declines in the general population as men age. Instead, they indicate that if men are having difficulty conceiving, no matter what their age, then defects in sperm fertilizing ability are equally likely to be the cause., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)
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- 2023
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16. Case-control study to identify risk factors for SARS-CoV-2 infection among university students in the northeastern USA.
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Cummings KJ, Clarkberg M, Busche J, Travis AJ, Meredith GR, Weisfuse I, Cazer CL, Koretzky GA, and Warnick LD
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- Animals, Case-Control Studies, Humans, Risk Factors, SARS-CoV-2, Students, Universities, COVID-19 epidemiology, COVID-19 veterinary
- Abstract
Curbing the coronavirus disease 2019 (COVID-19) pandemic requires a thorough understanding of risk factors for transmission of SARS-CoV-2, the etiologic agent. Institutions of higher education present unique challenges for controlling disease spread because of features inherent to these settings. Our objective was to determine risk factors for SARS-CoV-2 infection among a university student population in the northeastern USA during the spring and fall 2021 semesters, using the case-control study design. Cases were defined as students with a newly diagnosed SARS-CoV-2 infection detected either through the robust PCR-based surveillance testing program on campus or through healthcare testing if symptoms compatible with COVID-19 were present. Controls were defined as students with negative SARS-CoV-2 status, based on consistently negative PCR results at the time of selection. A comprehensive questionnaire was administered to each student enrolled in the study, covering a broad range of campus life activities. A total of 446 cases and 1,185 controls were included in this study. Multivariable logistic regression analysis showed that recent party attendance (adjusted OR = 2.3, p < .0001), recently visiting a bar (aOR = 1.6, p = .007), living in a campus residence hall (aOR = 1.6, p = .001), fraternity/sorority membership (aOR = 1.8, p = .002), and recent travel (aOR = 1.3, p = .04) were associated with being a COVID-19 case. Having an on-campus job was negatively associated with being a COVID-19 case (aOR = 0.6, p = .0003). Among cases, the most commonly reported symptoms were cough (43.9%), fatigue (38.1%) and sore throat (30.3%). These findings can be used to inform the development of COVID-19 mitigation strategies and public health outreach efforts in university settings, thus reducing SARS-CoV-2 transmission among students and helping to preserve the vital education and research missions of these institutions., (© 2022 Wiley-VCH GmbH.)
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- 2022
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17. Superior Haplotypes for Early Root Vigor Traits in Rice Under Dry Direct Seeded Low Nitrogen Condition Through Genome Wide Association Mapping.
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Anandan A, Panda S, Sabarinathan S, Travis AJ, Norton GJ, and Price AH
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Water and land resources have been aggressively exploited in the recent decades to meet the growing demands for food. The changing climate has prompted rice scientists and farmers of the tropics and subtropics to adopt the direct seeded rice (DSR) system. DSR system of rice cultivation significantly reduces freshwater consumption and labor requirements, while increasing system productivity, resource use efficiency, and reducing greenhouse gas emissions. Early root vigor is an essential trait required in an ideal DSR system of rice cultivation to ensure a good crop stand, adequate uptake of water, nutrients and compete with weeds. The aus subpopulation which is adapted for DSR was evaluated to understand the biology of early root growth under limited nitrogen conditions over two seasons under two-time points (14 and 28 days). The correlation study identified a positive association between shoot dry weight and root dry weight. The genome-wide association study was conducted on root traits of 14 and 28 days with 2 million single-nucleotide polymorphisms (SNPs) using an efficient mixed model. QTLs over a significant threshold of p < 0.0001 and a 10% false discovery rate were selected to identify genes involved in root growth related to root architecture and nutrient acquisition from 97 QTLs. Candidate genes under these QTLs were explored. On chromosome 4, around 30 Mbp are two important peptide transporters ( PTR5 and PTR6 ) involved in mobilizing nitrogen in the root during the early vegetative stage. In addition, several P transporters and expansin genes with superior haplotypes are discussed. A novel QTL from 21.12 to 21.46 Mb on chromosome 7 with two linkage disequilibrium (LD) blocks governing root length at 14 days were identified. The QTLs/candidate genes with superior haplotype for early root vigor reported here could be explored further to develop genotypes for DSR conditions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Anandan, Panda, Sabarinathan, Travis, Norton and Price.)
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- 2022
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18. Integrated Surveillance System for Controlling COVID-19 on a University Campus, 2020‒2021.
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Meredith GR, Osman M, Cazer CL, Cummings KJ, Hecht J, Madsen CG, Santacrose LB, Dubovi AS, Clarkberg M, Johnson T, Fitzpatrick MD, Parrilla L, Li Y, Francis L, Weisfuse IB, Travis AJ, Jones AC, Warnick LD, and Koretzky GA
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- Humans, Leadership, Universities, COVID-19 prevention & control
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To minimize the impacts of COVID-19 and to keep campus open, Cornell University's Ithaca, NY, campus implemented a comprehensive process to monitor COVID-19 spread, support prevention practices, and assess early warning indicators linked to knowledge, behaviors, and attitudes of campus community members. The integrated surveillance approach informed leadership and allowed for prompt adjustments to university policies and practices through evidence-based decisions. This approach enhanced healthy behaviors and promoted the well-being and safety of all community members. ( Am J Public Health . 2022;112(7):980-984. https://doi.org/10.2105/AJPH.2022.306838).
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- 2022
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19. A genetically targeted sensor reveals spatial and temporal dynamics of acrosomal calcium and sperm acrosome exocytosis.
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Cohen R, Mukai C, Nelson JL, Zenilman SS, Sosnicki DM, and Travis AJ
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- Acrosome Reaction physiology, Animals, Exocytosis physiology, Male, Mammals metabolism, Mice, Spermatozoa metabolism, Acrosome metabolism, Calcium metabolism
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Secretion of the acrosome, a single vesicle located rostrally in the head of a mammalian sperm, through a process known as "acrosome exocytosis" (AE), is essential for fertilization. However, the mechanisms leading to and regulating this complex process are controversial. In particular, poor understanding of Ca2+ dynamics between sperm subcellular compartments and regulation of membrane fusion mechanisms have led to competing models of AE. Here, we developed a transgenic mouse expressing an Acrosome-targeted Sensor for Exocytosis (AcroSensE) to investigate the spatial and temporal Ca2+ dynamics in AE in live sperm. AcroSensE combines a genetically encoded Ca2+ indicator (GCaMP) fused with an mCherry indicator to spatiotemporally resolve acrosomal Ca2+ rise (ACR) and membrane fusion events, enabling real-time study of AE. We found that ACR is dependent on extracellular Ca2+ and that ACR precedes AE. In addition, we show that there are intermediate steps in ACR and that AE correlates better with the ACR rate rather than absolute Ca2+ amount. Finally, we demonstrate that ACR and membrane fusion progression kinetics and spatial patterns differ with different stimuli and that sites of initiation of ACR and sites of membrane fusion do not always correspond. These findings support a model involving functionally redundant pathways that enable a highly regulated, multistep AE in heterogeneous sperm populations, unlike the previously proposed "acrosome reaction" model., Competing Interests: Conflict of interest A. J. T. discloses that he is a founder and an officer of Androvia LifeSciences, LLC, a biotechnology company investigating solutions for male infertility, in which he holds a minor equity stake. There are no conflicts with the current work. All other coauthors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)
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- 2022
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20. Identification of genomic loci regulating grain iron content in aus rice under two irrigation management systems.
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Talukdar P, Travis AJ, Hossain M, Islam MR, Norton GJ, and Price AH
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Iron (Fe) deficiency is one of the common causes of anaemia in humans. Improving grain Fe in rice, therefore, could have a positive impact for humans worldwide, especially for those people who consume rice as a staple food. In this study, 225-269 accessions of the Bengal and Assam Aus Panel (BAAP) were investigated for their accumulation of grain Fe in two consecutive years in a field experiment under alternative wetting and drying (AWD) and continuous flooded (CF) irrigation. AWD reduced straw Fe by 40% and grain Fe by 5.5-13%. Genotype differences accounted for 35% of the variation in grain Fe, while genotype by irrigation interaction accounted for 12% of the variation in straw and grain Fe in year 1, with no significant interactions detected in year 2. Twelve rice accessions were identified as having high grain Fe for both years regardless of irrigation treatment, half of which were from BAAP aus subgroup 3 which prominently comes from Bangladesh. On average, subgroup 3 had higher grain Fe than the other four subgroups of aus . Genome-wide association mapping identified 6 genomic loci controlling natural variation of grain Fe concentration in plants grown under AWD. For one QTL, nicotianamine synthase OsNAS3 is proposed as candidate for controlling natural variation of grain Fe in rice. The BAAP contains three haplotypes of OsNAS3 where one haplotype (detected in 31% of the individuals) increased grain Fe up to 11%. Haplotype analysis of this gene in rice suggests that the ability to detect the QTL is enhanced in the BAAP because the high Fe allele is balanced in aus , unlike indica and japonica subgroups., (© 2021 The Authors. Food and Energy Security published by John Wiley & Sons Ltd.)
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- 2022
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21. Genome-wide association mapping of sodium and potassium concentration in rice grains and shoots under alternate wetting and drying and continuously flooded irrigation.
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Chen C, Travis AJ, Hossain M, Islam MR, Price AH, and Norton GJ
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- Chromosome Mapping, Floods, Genes, Plant, Haplotypes, Oryza chemistry, Phenotype, Polymorphism, Single Nucleotide, Quantitative Trait Loci, Salinity, Oryza genetics, Plant Shoots chemistry, Potassium analysis, Seeds chemistry, Sodium analysis
- Abstract
Key Message: Identification of a large number of QTL and candidate genes for sodium accumulation in a field grown population of rice derived from the aus subpopulation. Rice (Oryza sativa L.) is a globally important cereal crop. Sodium (Na
+ ) and potassium (K+ ) are the major monovalent ions which affect rice growth, and exploring their uptake mechanisms will be useful for understanding rice biology. Since the balance of Na+ and K+ plays a significant role in adaptation of rice to salinity, that biology might inform the search for tolerance. In this study, the Na+ and K+ concentration and Na+ /K+ ratio in grains and shoots were analyzed in the Bengal and Assam Aus Panel grown in field conditions under continuously flooded (CF) and alternate wetting and drying (AWD) irrigation. Overall, AWD irrigation significantly reduced the Na+ concentration and increased the K+ concentration in shoots and grains compared to the plants grown under CF. Genome-wide association mapping was conducted on Na+ , K+ concentration and Na+ /K+ ratio with 2 million SNPs using an efficient mixed model. Only QTLs which contained more than two significant SNPs (p < 0.0001) and where at least one of these significant SNPs passed a 10% false discovery rate were reported. A total of 106 QTLs were identified as being associated with Na+ concentration and Na+ /K+ ratio across all traits and field conditions, with 48 QTLs found in multiple traits and/or water conditions. Four notable QTLs (one each on chromosomes 1 and 11, two on chromosome 2) and the haplotype variants of four candidate genes (OsHKT1;5, OsNHX2, LOC_Os02g32490 and OsFAD2_1) are discussed. The QTLs/candidate genes identified here could be useful for breeding rice that accumulates lower concentrations of sodium.- Published
- 2021
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22. Genome-wide association mapping for grain manganese in rice (Oryza sativa L.) using a multi-experiment approach.
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Ruang-Areerate P, Travis AJ, Pinson SRM, Tarpley L, Eizenga GC, Guerinot ML, Salt DE, Douglas A, Price AH, and Norton GJ
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- Chromosomes, Plant genetics, Genetic Association Studies, Plant Breeding, Manganese, Oryza genetics
- Abstract
Manganese (Mn) is an essential trace element for plants and commonly contributes to human health; however, the understanding of the genes controlling natural variation in Mn in crop plants is limited. Here, the integration of two of genome-wide association study approaches was used to increase the identification of valuable quantitative trait loci (QTL) and candidate genes responsible for the concentration of grain Mn across 389 diverse rice cultivars grown in Arkansas and Texas, USA, in multiple years. Single-trait analysis was initially performed using three different SNP datasets. As a result, significant loci could be detected using the high-density SNP dataset. Based on the 5.2 M SNP dataset, major QTLs were located on chromosomes 3 and 7 for Mn containing six candidate genes. In addition, the phenotypic data of grain Mn concentration were combined from three flooded-field experiments from the two sites and 3 years using multi-experiment analysis based on the 5.2 M SNP dataset. Two previous QTLs on chromosome 3 were identified across experiments, whereas new Mn QTLs were identified that were not found in individual experiments, on chromosomes 3, 4, 9 and 11. OsMTP8.1 was identified in both approaches and is a good candidate gene that could be controlling grain Mn concentration. This work demonstrates the utilisation of multi-experiment analysis to identify constitutive QTLs and candidate genes associated with the grain Mn concentration. Hence, the approach should be advantageous to facilitate genomic breeding programmes in rice and other crops considering QTLs and genes associated with complex traits in natural populations.
- Published
- 2021
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23. Nonstented Tubularized Incised Plate Distal Hypospadias Repair: A Single Center 5 Years' Experience.
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Assadi A, Alzubaidi AN, Cline JK, Sharadin C, Travis AJ, Marley K, Dewan C, and Gleason JM
- Subjects
- Humans, Hypospadias pathology, Infant, Male, Retrospective Studies, Stents, Time Factors, Treatment Outcome, Urologic Surgical Procedures, Male methods, Hypospadias surgery
- Abstract
Objectives: To report our immediate and delayed outcomes of nonstented tubularized incised plate (TIP) distal hypospadias repair., Methods: We retrospectively reviewed all charts of children who underwent distal hypospadias repair in a single children's hospital from 2013 to 2018. Patients' demographics, hypospadias characteristics, operative technique, and immediate and delayed outcomes were recorded., Results: Of 280 consecutive distal hypospadias repairs that were identified, 74 were excluded due to the use of a repair other than TIP. Eleven stented TIP repairs were excluded as well. Of 195 nonstented repairs, immediate postoperative voiding complications were recorded in 11 (5.6%) and included multiple/split stream in 6 (3%), dysuria and voiding difficulty in 2 (1%), urinary retention in 2 (1%), and gross hematuria that spontaneously resolved in 1 (0.5%). Late follow up was recorded in 142 of 195 (72.8%) repairs. Delayed urethroplasty/glansplasty complications were recorded in 12 (8.5%) and included urethrocutaneous fistula in 10 (7.0%), meatal stenosis in 6 (4.2%) and glans/urethroplasty dehiscence in 2 (1.4%)., Conclusion: Avoiding postoperative urethral stents in distal hypospadias TIP repair reduces the morbidity associated with the stent and is a feasible option that carries acceptable immediate and delayed complication rates. Avoiding the stent eliminates stent-related bladder spasms, the need for other medications, and the short-term office visit for stent removal, therefore reducing parental anxiety, patient discomfort, and reducing cost., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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24. Impacts of oocyte/zygote timing for in vitro fertilization and gene editing in the dog.
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Mukai C, Nelson JL, Cheong SH, Diel de Amorim M, and Travis AJ
- Subjects
- Animals, CRISPR-Cas Systems, DNA End-Joining Repair physiology, Embryo Transfer, Fibroblast Growth Factor 5 genetics, Fibroblast Growth Factor 5 metabolism, Gene Editing methods, Gene Expression Regulation, Genotype, Keratins, Hair-Specific genetics, Keratins, Hair-Specific metabolism, Time Factors, Dogs physiology, Fertilization in Vitro veterinary, Gene Editing veterinary, In Vitro Oocyte Maturation Techniques veterinary, Oocytes physiology, Zygote physiology
- Abstract
Previously, we reported the first live births of dogs using in vitro fertilization (IVF), embryo cryopreservation, and transfer. These techniques have potential applications in the conservation of endangered canids, and development of gene editing/repair technologies that could improve animal welfare by restoring normal gene function and removing predisposition to disease. Here, we used IVF as a springboard for initial attempts at genetic modification through gene editing/repair using the Clustered Regularly-Interspaced Short Palindromic Repeat (CRISPR)-CRISPR-associated endonuclease (Cas9) system. We showed previously that timing is critical for successful IVF in that the canine oocyte must be exposed to the oviductal environment beyond simply reaching metaphase II. Others have shown that timing of injection of CRISPR-Cas9 constructs is critical in gene editing, influencing the extent of genetic mosaicism. Therefore, we investigated whether timing of injection of the gene editing/repair constructs might influence the success of embryo production and gene editing in the dog. We achieved similar IVF success to our prior report in generating 2-cell control embryos, and found equally reduced embryo production whether injection was performed in oocytes prior to fertilization, or in presumptive single-cell zygotes already exposed to sperm. We had no success at generating offspring with precise single-nucleotide changes in KRT71 via homology-directed repair (HDR), but did identify mutation of FGF5 using non-homologous end joining (NHEJ). These findings underscore the difficulties inherent to gene repair, but represent important progress on reproducibility of canine IVF, improved techniques of oocyte/embryo handling, and impact of timing of injections on embryo development., (Copyright © 2020. Published by Elsevier Inc.)
- Published
- 2020
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25. Multicentric, prospective observational data show sperm capacitation predicts male fertility, and cohort comparison reveals a high prevalence of impaired capacitation in men questioning their fertility.
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Sharara F, Seaman E, Morris R, Schinfeld J, Nichols J, Sobel M, Lee A, Somkuti S, Hirshberg S, Budinetz T, Barmat L, Palermo G, Rosenwaks Z, Bar-Chama N, Bodie J, Nichols J, Payne J, McCoy T, Tarnawa E, Whitman-Elia G, Weissmann L, Doukakis M, Hurwitz J, Leondires M, Murdock C, Ressler I, Richlin S, Williams S, Wosnitzer M, Butcher M, Kashanian J, Ahlering P, Aubuchon M, Ostermeier GC, and Travis AJ
- Subjects
- Female, Humans, Male, Pregnancy, Pregnancy Rate, Prospective Studies, Semen Analysis, Sperm Motility physiology, Fertility physiology, Fertilization physiology, Infertility, Male physiopathology, Sperm Capacitation physiology, Spermatozoa physiology
- Abstract
Research Questions: Can a previously defined relationship between sperm capacitation and the probability of a man generating pregnancy within three cycles, prospectively predict male fertility in diverse clinical settings? A second study asked, what is the prevalence of impaired sperm fertilizing ability in men questioning their fertility (MQF), and does this relate to traditional semen analysis metrics?, Design: In the multicentric, prospective observational study, data (n = 128; six clinics) were analysed to test a published relationship between the percentage of fertilization-competent, capacitated spermatozoa (Cap-Score) and probability of generating pregnancy (PGP) within three cycles of intrauterine insemination. Logistic regression of total pregnancy outcomes (n = 252) assessed fit. In the cohort comparison, Cap-Scores of MQF (n = 2155; 22 clinics) were compared with those of 76 fertile men., Results: New outcomes (n = 128) were rank-ordered by Cap-Score and divided into quintiles (25-26 per group); chi-squared testing revealed no difference between predicted and observed pregnancies (P = 0.809). Total outcomes (n = 252; 128 new + 124 previous) were pooled and the model recalculated, yielding an improved fit (P < 0.001). Applying the Akaike information criterion found that the optimal model used Cap-Score alone. Cap-Scores were performed on 2155 men (with semen analysis data available for 1948). To compare fertilizing ability, men were binned by PGP (≤19%, 20-29%, 30-39%, 40-49%, 50-59%, ≥60%). Distributions of PGP and the corresponding Cap-Scores were significantly lower in MQF versus fertile men (P < 0.001). Notably, 64% of MQF with normal volume, concentration and motility (757/1183) had PGP of 39% or less (Cap-Scores ≤31), versus 25% of fertile men., Conclusions: Sperm capacitation prospectively predicted male fertility. Impaired capacitation affects many MQF with normal semen analysis results, informing diagnosis versus idiopathic infertility., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2020
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26. Localisation and function of glucose transporter GLUT1 in chicken (Gallus gallus domesticus) spermatozoa: relationship between ATP production pathways and flagellar motility.
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Setiawan R, Priyadarshana C, Tajima A, Travis AJ, and Asano A
- Subjects
- Animals, Glucose metabolism, Glucose pharmacology, Glycolysis physiology, Male, Oxidative Phosphorylation, Sperm Motility drug effects, Sperm Motility physiology, Spermatozoa chemistry, Spermatozoa ultrastructure, Adenosine Triphosphate biosynthesis, Chickens metabolism, Glucose Transporter Type 1 analysis, Glucose Transporter Type 1 physiology, Sperm Tail physiology, Spermatozoa physiology
- Abstract
Glucose plays an important role in sperm flagellar motility and fertility via glycolysis and oxidative phosphorylation, although the primary mechanisms for ATP generation vary between species. The glucose transporter 1 (GLUT1) is a high-affinity isoform and a major glucose transporter in mammalian spermatozoa. However, in avian spermatozoa, the glucose metabolic pathways are poorly characterised. This study demonstrates that GLUT1 plays a major role in glucose-mediated motility of chicken spermatozoa. Using specific antibodies and ligand, we found that GLUT1 was specifically localised to the midpiece. Sperm motility analysis showed that glucose supported sperm movement during incubation for 0-80min. However, this was abolished by the addition of a GLUT1 inhibitor, concomitant with a substantial decrease in glucose uptake and ATP production, followed by elevated mitochondrial activity in response to glucose addition. More potent inhibition of ATP production and mitochondrial activity was observed in response to treatment with uncouplers of oxidative phosphorylation. Because mitochondrial inhibition only reduced a subset of sperm movements, we investigated the localisation of the glycolytic pathway and showed glyceraldehyde-3-phosphate dehydrogenase and hexokinase I at the midpiece and principal piece of the flagellum. The results of this study provide new insights into the mechanisms involved in ATP production pathways in avian spermatozoa.
- Published
- 2020
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27. Genetic loci regulating arsenic content in rice grains when grown flooded or under alternative wetting and drying irrigation.
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Norton GJ, Travis AJ, Talukdar P, Hossain M, Islam MR, Douglas A, and Price AH
- Abstract
Background: Rice is a global staple crop, being the main calorific component of many people living subsistence livelihoods. Rice can accumulate toxic elements such as arsenic, with the crop water management strongly affecting uptake. This study utilises the Bengal and Assam Aus Panel to conduct genome wide association (GWA) mapping for arsenic in shoots and grains of rice grown over 2 years under continually flooded (CF) and alternate wetting and drying (AWD). The aim was to assess genotype by water management interaction, identify quantitative trait loci (QTL) for arsenic accumulation, and propose candidate genes for lowering grain arsenic., Results: AWD significantly reduced grain arsenic across all cultivars on average by 15.7 and 15.1% in year 1 and 2 respectively and shoot arsenic by 27.0% compared to the plants grown under CF. There was a weak cultivar by treatment interaction for grain for arsenic. All traits were strongly influenced by cultivar. GWA mapping identified a large number of 74 individual QTLs for arsenic, with six QTLs showing stability across years and/or water treatments. Three of the loci (one on chromosome 3, one on chromosome 4, and one on chromosome 5) were investigated in detail using an approach of clustering cultivars that had similar haplotypes for the QTL regions and then looking at the phenotypic values across the clusters. Two of the identified QTLs co-localised with known genes involved in arsenic accumulation, including Lsi2 which has not previously been reported to underlie a grain arsenic QTL., Conclusions: This study has identified a number of novel QTLs for arsenic accumulation, as well as cultivars that consistently accumulate less arsenic over multiple field traits. The use of a haplotype clustering approach after GWA mapping has allowed for the effect, in terms of arsenic accumulation, to be determined for cultivars that share similar genomic sequence. Allocating nine high yielding Bangladeshi cultivars to these clusters has identified the potential of utilising these QTLs in breeding programmes; for example, incorporation of the QTL on chromosome 5 should decrease grain arsenic in elite high yielding Bangladeshi cultivars by 10% in all high yielding cultivars studied.
- Published
- 2019
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28. Activin promotes growth and antral cavity expansion in the dog ovarian follicle.
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Nagashima JB, Wildt DE, Travis AJ, and Songsasen N
- Subjects
- Animals, Cell Culture Techniques veterinary, Female, Follicle Stimulating Hormone pharmacology, Oocytes growth & development, Ovarian Follicle growth & development, Receptors, FSH metabolism, Up-Regulation, Activins pharmacology, Dogs physiology, Ovarian Follicle drug effects
- Abstract
Understanding regulators of folliculogenesis remains limited in the domestic dog (Canis familiaris), which challenges our ability to develop in vitro follicle culture systems for canid genome rescue efforts. Here, we investigated the influence of activin on dog follicle development and survival, oocyte quality, and FSH receptor expression in culture. Preantral (150 - ≤230 μm diameter), early antral (231 - ≤330 μm), and antral (>330-550 μm) stage follicles were encapsulated in a fibrin-alginate hydrogel with 0, 100, or 200 ng/ml rhActivin plus 0, 0.1, 1, or 10 μg/ml FSH for 12 or 21 d of in vitro culture. All follicle groups increased in diameter (P < 0.05) with activin acting synergistically with FSH to improve (P < 0.05) growth and antral cavity expansion (to >630 μm) in early antral and antral cohorts. This complementary effect was not linked to changes in FSHR mRNA expression (P > 0.05). Although not influencing (P > 0.05) follicle survival or transzonal projection (TZP) density in shorter term 12 d culture, activin in the presence of 1 ng/ml FSH maintained TZP density from the 12-21 d interval. Activin also increased oocyte diameter and improved nuclear integrity compared to un-supplemented controls. These results indicate that activin acts synergistically with FSH to promote growth and antral cavity expansion of the dog follicle in vitro, information useful to formulating an effective culture microenvironment for this species., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
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29. The Domestic Dog Embryo: In Vitro Fertilization, Culture, and Transfer.
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Nagashima JB, Travis AJ, and Songsasen N
- Subjects
- Animals, Dogs, Embryo, Mammalian cytology, Female, Oocytes cytology, Embryo Culture Techniques methods, Embryo Transfer methods, Embryo, Mammalian embryology, Fertilization in Vitro methods, In Vitro Oocyte Maturation Techniques methods, Oocytes metabolism
- Abstract
Advances in embryo technologies in the domestic dog have made significant strides in the past decade. This progress has been spurred by interests in taking advantage of the dog as a biomedical research model for human and companion animal medicine, developing assisted reproductive technologies to manage genetic diversity in endangered canids maintained ex situ, and improving breeding in rare or working breeds of dogs. Here, we focus on recent advancements and techniques for collection of in vivo-matured oocytes, in vitro fertilization (IVF), in vitro culture of early (≤8-cell) and advanced stage (≥16-cell) embryos, and embryo transfer.
- Published
- 2019
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30. Small-scale egg production centres increase children's egg consumption in rural Zambia.
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Dumas SE, Lewis D, and Travis AJ
- Subjects
- Animals, Child Nutritional Physiological Phenomena, Child, Preschool, Cross-Sectional Studies, Diet, Healthy, Female, Humans, Infant, Infant Nutritional Physiological Phenomena, Male, Rural Population, Zambia, Agriculture methods, Chickens growth & development, Diet, Eggs, Social Welfare
- Abstract
Animal source foods can efficiently enhance dietary quality, but they remain inaccessible and unaffordable for many women and young children in remote, low-income communities. We piloted an intervention in which 20 groups established egg production centres (EPCs) in their rural Zambian communities to increase the availability of eggs in the local food system. In a repeated cross-sectional design over 1 year (midline [4 months after the start of egg production] and endline [11 months]), we evaluated programme impact on household egg acquisition within those communities and on egg consumption and height-for-age z score (HAZ) among young children (6-36 months) using multilevel linear, logistic, and truncated negative binomial regression techniques. At midline, households in project areas were significantly more likely to consume eggs than those in control areas (OR 2.08, 95% CI [1.56, 2.78]), particularly those located within 250 m of the EPC. Similarly, children living in project communities were significantly more likely to consume eggs at midline than those in control areas (OR 5.53, 95% CI [2.90, 10.58]). Although increased over baseline, egg acquisition and consumption decreased by endline because of depressed egg production over time. There was no impact on children's HAZ, likely because of the short follow-up time and relatively modest "dose" of egg consumption. Although productivity can be improved, the EPC programme offers a novel approach to improving access to eggs in rural communities, and optimization of the production practices and marketing is needed to ensure that egg consumption translates to improved dietary quality, growth, and health., (© 2018 John Wiley & Sons Ltd.)
- Published
- 2018
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31. Genome Wide Association Mapping of Grain and Straw Biomass Traits in the Rice Bengal and Assam Aus Panel (BAAP) Grown Under Alternate Wetting and Drying and Permanently Flooded Irrigation.
- Author
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Norton GJ, Travis AJ, Douglas A, Fairley S, Alves EP, Ruang-Areerate P, Naredo MEB, McNally KL, Hossain M, Islam MR, and Price AH
- Abstract
Growing demand for staple crops like rice will need to be achieved predominately through agricultural intensification and more efficient use of inputs. To meet this demand it is essential that the genetic diversity within rice is fully utilized. The aus subpopulation is considered an underappreciated resource within that diversity. A new rice panel, the Bengal and Assam Aus Panel (BAAP) of 266 aus accessions was generated with ∼2 million informative SNPs obtained using skim sequencing at ∼4× depth. The BAAP was grown in the field in Bangladesh in the 'boro' season under both continuously flooded and Alternate Wetting and Drying (AWD) irrigation during 2013 and 2014 in Mymensingh and during 2014 in Madhupur. Heading date, grain mass, straw biomass and harvest index were measured. The majority (94%) of BAAP accessions flowered within a relatively small window of 10 days. The AWD irrigation treatment generally caused an increase in grain mass, but no significant genotype by treatment interactions were detected for this trait. Shoot biomass was the only trait that showed evidence of genotype by treatment interaction. The average LD (Linkage Disequilibrium) decay across the genome was 243 Kbp. Genome wide association mapping revealed 115 quantitative trait loci (QTLs). There was little evidence of QTLs specific to the irrigation treatment, and only a few QTLs co-localized with known genes. However, some QTLs were detected across multiple sites and years. These QTLs should be targets for breeding, and include a region around 2.2 Mbp on chromosome 1, a large region in the middle of chromosome 7 and two regions on chromosome 11 (∼10 Mbp and ∼29 Mbp). The BAAP appears to be a valuable addition to the growing collection of GWA mapping populations of rice.
- Published
- 2018
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32. Cap-Score™ prospectively predicts probability of pregnancy.
- Author
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Schinfeld J, Sharara F, Morris R, Palermo GD, Rosenwaks Z, Seaman E, Hirshberg S, Cook J, Cardona C, Ostermeier GC, and Travis AJ
- Subjects
- Adult, Feasibility Studies, Female, Fertility, Fertilization physiology, Humans, Kaplan-Meier Estimate, Logistic Models, Male, Pregnancy Outcome, Pregnancy Rate, Prospective Studies, Sperm Motility physiology, Infertility, Male diagnosis, Pregnancy, Probability, Semen Analysis methods, Sperm Capacitation
- Abstract
Semen analysis (SA) poorly predicts male fertility, because it does not assess sperm fertilizing ability. The percentage of capacitated sperm determined by G
M1 localization ("Cap-Score™"), differs between cohorts of fertile and potentially infertile men, and retrospectively, between men conceiving or failing to conceive by intrauterine insemination (IUI). Here, we prospectively tested whether Cap-Score can predict male fertility with the outcome being clinical pregnancy within ≤3 IUI cycles. Cap-Score and SA were performed (n = 208) with outcomes initially available for 91 men. Men were predicted to have either low (n = 47) or high (n = 44) chance of generating pregnancy using previously-defined Cap-Score reference ranges. Absolute and cumulative pregnancy rates were reduced in men predicted to have low pregnancy rates versus high ([absolute: 10.6% vs. 29.5%; p = 0.04]; [cumulative: 4.3% vs. 18.2%, 9.9% vs. 29.1%, and 14.0% vs. 32.8% for cycles 1-3; n = 91, 64, and 41; p = 0.02]). Only Cap-Score, not male/female age or SA results, differed significantly between outcome groups. Logistic regression evaluated Cap-Score and SA results relative to the probability of generating pregnancy (PGP) for men who were successful in, or completed, three IUI cycles (n = 57). Cap-Score was significantly related to PGP (p = 0.01). The model fit was then tested with 67 additional patients (n = 124; five clinics); the equation changed minimally, but fit improved (p < 0.001; margin of error: 4%). The Akaike Information Criterion found the best model used Cap-Score as the only predictor. These data show that Cap-Score provides a practical, predictive assessment of male fertility, with applications in assisted reproduction and treatment of male infertility., (© 2018 The Authors. Molecular Reproduction and Development Published by Wiley Periodicals, Inc.)- Published
- 2018
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33. Timing of sperm capacitation varies reproducibly among men.
- Author
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Ostermeier GC, Cardona C, Moody MA, Simpson AJ, Mendoza R, Seaman E, and Travis AJ
- Subjects
- Adult, Humans, Male, Spermatozoa cytology, Sperm Capacitation, Sperm Motility, Spermatozoa metabolism
- Abstract
Sperm must mature functionally in the process of capacitation to become able to fertilize. Capacitation depends on membrane lipid changes, and can be quantitatively assessed by redistribution of the ganglioside G
M1 , the basis of the Cap-Score™ sperm function test. Here, differences in Cap-Score were compared among and within men at two time points. Ejaculates were liquefied, washed, and incubated for 3 hr under capacitating (Cap) conditions, then fixed and analyzed immediately (Day0); after being incubated 3 hr under Cap conditions then maintained 22-24 hr in fix (Day1-fix); or after 22-24 hr incubation under Cap conditions prior to fixation (Day1). In all cases, a light fixative previously shown to allow membrane lipid movements was used. Day1-fix and Day1 Cap-Scores were greater than Day0 (p < 0.001; n = 25), whereas Day1-fix and Day1 Cap-Scores were equivalent (p = 0.43; n = 25). In 123 samples from 52 fertile men, Cap-Score increased more than 1SD (7.7; calculated previously from a fertile cohort) from Day0 to Day1-fix in 44% (54/123) of the samples. To test whether timing of capacitation was consistent within an individual, 52 samples from 11 fertile men were classified into either "early" or "late" capacitation groups. The average capacitation group concordance within a donor was 81%. Median absolute deviation (MAD; in Cap-Score units) was used to assess the tightness of clustering of the difference from Day0 to Day1-fix within individuals. The average (2.21) and median (1.98) MAD confirmed consistency within individuals. Together, these data show that the timing of capacitation differed among men and was consistent within men., (© 2018 The Authors. Molecular Reproduction and Development Published by Wiley Periodicals, Inc.)- Published
- 2018
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34. Cysteine dioxygenase is essential for mouse sperm osmoadaptation and male fertility.
- Author
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Asano A, Roman HB, Hirschberger LL, Ushiyama A, Nelson JL, Hinchman MM, Stipanuk MH, and Travis AJ
- Subjects
- Acrosome Reaction, Animals, Antioxidants metabolism, Blotting, Western, Chromatography, High Pressure Liquid, Cysteine Dioxygenase genetics, Epididymis enzymology, Exocytosis, Female, Lipid Peroxidation, Male, Mice, Mice, Knockout, Phosphorylation, RNA, Messenger genetics, Reverse Transcriptase Polymerase Chain Reaction, Sperm Maturation, Spermatozoa physiology, Taurine analogs & derivatives, Taurine metabolism, Cysteine Dioxygenase metabolism, Fertility, Osmoregulation, Spermatozoa metabolism
- Abstract
Sperm entering the epididymis are immotile and cannot respond to stimuli that will enable them to fertilize. The epididymis is a highly complex organ, with multiple histological zones and cell types that together change the composition and functional abilities of sperm through poorly understood mechanisms. Sperm take up taurine during epididymal transit, which may play antioxidant or osmoregulatory roles. Cysteine dioxygenase (CDO) is a critical enzyme for taurine synthesis. A previous study reported that male CDO
-/- mice exhibit idiopathic infertility, prompting us to investigate the functions of CDO in male fertility. Immunoblotting and quantitative reverse transcription-polymerase chain reaction analysis of epididymal segments showed that androgen-dependent CDO expression was highest in the caput epididymidis. CDO-/- mouse sperm demonstrated a severe lack of in vitro fertilization ability. Acrosome exocytosis and tyrosine phosphorylation profiles in response to stimuli were normal, suggesting normal functioning of pathways associated with capacitation. CDO-/- sperm had a slight increase in head abnormalities. Taurine and hypotaurine concentrations in CDO-/- sperm decreased in the epididymal intraluminal fluid and sperm cytosol. We found no evidence of antioxidant protection against lipid peroxidation. However, CDO-/- sperm exhibited severe defects in volume regulation, swelling in response to the relatively hypo-osmotic conditions found in the female reproductive tract. Our findings suggest that epididymal CDO plays a key role in post-testicular sperm maturation, enabling sperm to osmoregulate as they transition from the male to the female reproductive tract, and provide new understanding of the compartmentalized functions of the epididymis., (© 2018 Federation of European Biochemical Societies.)- Published
- 2018
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35. Examining the association between livestock ownership typologies and child nutrition in the Luangwa Valley, Zambia.
- Author
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Dumas SE, Kassa L, Young SL, and Travis AJ
- Subjects
- Animals, Child, Cross-Sectional Studies, Humans, Zambia, Child Nutritional Physiological Phenomena, Livestock, Ownership
- Abstract
Objective: To investigate the association between livestock ownership and dietary diversity, animal-source food consumption, height-for-age z-score, and stunting among children living in wildlife "buffer zones" of Zambia's Luangwa Valley using a novel livestock typology approach., Methods: We conducted a cross-sectional study of 838 children aged 6-36 months. Households were categorized into typologies based on the types and numbers of animals owned, ranging from no livestock to large numbers of mixed livestock. We used multilevel mixed-effects linear and logistic regression to examine the association between livestock typologies and four nutrition-related outcomes of interest. Results were compared with analyses using more common binary and count measures of livestock ownership., Results: No measure of livestock ownership was significantly associated with children's odds of animal-source food consumption, child height-for-age z-score, or stunting odds. Livestock ownership Type 2 (having a small number of poultry) was surprisingly associated with decreased child dietary diversity (β = -0.477; p<0.01) relative to owning no livestock. Similarly, in comparison models, chicken ownership was negatively associated with dietary diversity (β = -0.320; p<0.01), but increasing numbers of chickens were positively associated with dietary diversity (β = 0.022; p<0.01). Notably, neither child dietary diversity nor animal-source food consumption was significantly associated with height, perhaps due to unusually high prevalences of morbidities., Conclusions: Our novel typologies methodology allowed for an efficient and a more in-depth examination of the differential impact of livestock ownership patterns compared to typical binary or count measures of livestock ownership. We found that these patterns were not positively associated with child nutrition outcomes in this context. Development and conservation programs focusing on livestock must carefully consider the complex, context-specific relationship between livestock ownership and nutrition outcomes-including how livestock are utilized by the target population-when attempting to use livestock as a means of improving child nutrition.
- Published
- 2018
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36. Human Gut Symbiont Roseburia hominis Promotes and Regulates Innate Immunity.
- Author
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Patterson AM, Mulder IE, Travis AJ, Lan A, Cerf-Bensussan N, Gaboriau-Routhiau V, Garden K, Logan E, Delday MI, Coutts AGP, Monnais E, Ferraria VC, Inoue R, Grant G, and Aminov RI
- Abstract
Objective: Roseburia hominis is a flagellated gut anaerobic bacterium belonging to the Lachnospiraceae family within the Firmicutes phylum. A significant decrease of R. hominis colonization in the gut of ulcerative colitis patients has recently been demonstrated. In this work, we have investigated the mechanisms of R. hominis -host cross talk using both murine and in vitro models., Design: The complete genome sequence of R. hominis A2-183 was determined. C3H/HeN germ-free mice were mono-colonized with R. hominis , and the host-microbe interaction was studied using histology, transcriptome analyses and FACS. Further investigations were performed in vitro and using the TLR5KO and DSS-colitis murine models., Results: In the bacterium, R. hominis , host gut colonization upregulated genes involved in conjugation/mobilization, metabolism, motility, and chemotaxis. In the host cells, bacterial colonization upregulated genes related to antimicrobial peptides, gut barrier function, toll-like receptors (TLR) signaling, and T cell biology. CD4
+ CD25+ FoxP3+ T cell numbers increased in the lamina propria of both mono-associated and conventional mice treated with R. hominis . Treatment with the R. hominis bacterium provided protection against DSS-induced colitis. The role of flagellin in host-bacterium interaction was also investigated., Conclusion: Mono-association of mice with R. hominis bacteria results in specific bidirectional gene expression patterns. A set of genes thought to be important for host colonization are induced in R. hominis , while the host cells respond by strengthening gut barrier function and enhancing Treg population expansion, possibly via TLR5-flagellin signaling. Our data reveal the immunomodulatory properties of R. hominis that could be useful for the control and treatment of gut inflammation.- Published
- 2017
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37. Biomass and elemental concentrations of 22 rice cultivars grown under alternate wetting and drying conditions at three field sites in Bangladesh.
- Author
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Norton GJ, Travis AJ, Danku JMC, Salt DE, Hossain M, Islam MR, and Price AH
- Abstract
As the global population grows, demand on food production will also rise. For rice, one limiting factor effecting production could be availability of fresh water, hence adoption of techniques that decrease water usage while maintaining or increasing crop yield are needed. Alternative wetting and drying (AWD) is one of these techniques. AWD is a method by which the level of water within a rice field cycles between being flooded and nonflooded during the growth period of the rice crop. The degree to which AWD affects cultivars differently has not been adequately addressed to date. In this study, 22 rice cultivars, mostly landraces of the aus subpopulation, plus some popular improved indica cultivars from Bangladesh, were tested for their response to AWD across three different field sites in Bangladesh. Grain and shoot elemental concentrations were determined at harvest. Overall, AWD slightly increased grain mass and harvest index compared to plants grown under continually flooded (CF) conditions. Plants grown under AWD had decreased concentrations of nitrogen in their straw compared to plants grown under CF. The concentration of elements in the grain were also affected when plants were grown under AWD compared to CF: Nickel, copper, cadmium and iron increased, but sodium, potassium, calcium, cobalt, phosphorus, molybdenum and arsenic decreased in the grains of plants grown under AWD. However, there was some variation in these patterns across different sites. Analysis of variance revealed no significant cultivar × treatment interaction, or site × cultivar × treatment interaction, for any of the plant mass traits. Of the elements analyzed, only grain cadmium concentrations were significantly affected by treatment × cultivar interactions. These data suggest that there is no genetic adaptation amongst the cultivars screened for response to AWD, except for grain cadmium concentration and imply that breeding specifically for AWD is not needed.
- Published
- 2017
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38. Society Is Ready for a New Kind of Science-Is Academia?
- Author
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Keeler BL, Chaplin-Kramer R, Guerry AD, Addison PFE, Bettigole C, Burke IC, Gentry B, Chambliss L, Young C, Travis AJ, Darimont CT, Gordon DR, Hellmann J, Kareiva P, Monfort S, Olander L, Profeta T, Possingham HP, Slotterback C, Sterling E, Ticktin T, and Vira B
- Published
- 2017
- Full Text
- View/download PDF
39. Validation of a laboratory-developed test of human sperm capacitation.
- Author
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Moody MA, Cardona C, Simpson AJ, Smith TT, Travis AJ, and Ostermeier GC
- Subjects
- Humans, Male, Acrosome metabolism, Calcimycin pharmacology, Exocytosis drug effects, Semen Analysis methods, Sperm Capacitation drug effects
- Abstract
Sperm must undergo capacitation to become fertilization competent. Here we validated that monosialotetrahexosylganglioside (G
M1 ) localization patterns, which were assessed in the Cap-Score™ Sperm Function Test, reflect a capacitated state in human sperm. First, we defined patterns representing sperm that do or do not respond to stimuli for capacitation. Sperm with "capacitated" patterns had exposed acrosomal carbohydrates and underwent acrosome exocytosis in response to calcium ionophore (A23187). Precision was evaluated by percent change of the Cap-Score measured for 50, 100, 150, and 200 sperm. Changes of 11%, 6%, and 5% were observed (n ≥ 23); therefore, we counted ≥150 sperm per condition. Variance within and between readers was evaluated using 20 stitched image files generated from unique ejaculates. Two trained readers randomly resampled each image 20 times, reporting an average standard deviation of 3 Cap-Score units and coefficient of variation of 13% when rescoring samples, with no difference between readers. Semen liquefaction times ≤2 hr and mechanical liquefaction with Pasteur or wide-orifice transfer pipettes did not alter Cap-Score values. However, liquefaction with chymotrypsin (p = 0.002) and bromelain (p = 0.049) reduced response to capacitating stimuli and induced membrane damage, while counterintuitively improving sperm motility. Together, these data validate the Cap-Score assay for the intended purpose of providing information on sperm capacitation and male fertility. In addition to its clinical utility as a diagnostic tool, this test of sperm function can reveal the impact of common practices of semen handling on the ability of sperm to respond to capacitation stimuli., (© 2017 The Authors. Molecular Reproduction and Development Published by Wiley Periodicals, Inc.)- Published
- 2017
- Full Text
- View/download PDF
40. Localization patterns of the ganglioside G M1 in human sperm are indicative of male fertility and independent of traditional semen measures.
- Author
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Cardona C, Neri QV, Simpson AJ, Moody MA, Ostermeier GC, Seaman EK, Paniza T, Rosenwaks Z, Palermo GD, and Travis AJ
- Subjects
- Adult, Humans, Male, Middle Aged, Fertility physiology, G(M1) Ganglioside metabolism, Semen Analysis methods, Sperm Capacitation, Spermatozoa metabolism
- Abstract
Semen analysis lacks a functional component and best identifies extreme cases of infertility. The ganglioside G
M1 is known to have functional roles during capacitation and acrosome exocytosis. Here, we assessed whether GM1 localization patterns (Cap-Score™) correspond with male fertility in different settings: Study 1 involved couples pursuing assisted reproduction in a tertiary care fertility clinic, while Study 2 involved men with known fertility versus those questioning their fertility at a local urology center. In Study 1, we examined various thresholds versus clinical history for 42 patients; 13 had Cap-Scores ≥39.5%, with 12 of these (92.3%) achieving clinical pregnancy by natural conception or ≤3 intrauterine insemination cycles. Of the 29 patients scoring <39.5%, only six (20.7%) attained clinical pregnancy by natural conception or ≤3 intrauterine insemination cycles. In Study 2, Cap-Scores were obtained from 76 fertile men (Cohort 1, pregnant partner or recent father) and compared to 122 men seeking fertility assessment (Cohort 2). Cap-Score values were normally distributed in Cohort 1, with 13.2% having Cap-Scores more than one standard deviation below the mean (35.3 ± 7.7%). Significantly, more men in Cohort 2 had Cap-Scores greater than one standard deviation below the normal mean (33.6%; p = 0.001). Minimal/no relationship was found between Cap-Score and sperm concentration, morphology, or motility. Together, these data demonstrate that Cap-Score provides novel, clinically relevant insights into sperm function and male fertility that complement traditional semen analysis. Furthermore, the data provide normal reference ranges for fertile men that can help clinicians counsel couples toward the most appropriate fertility treatment., (© 2017 The Authors. Molecular Reproduction and Development Published by Wiley Periodicals Inc.)- Published
- 2017
- Full Text
- View/download PDF
41. Follicular size and stage and gonadotropin concentration affect alginate-encapsulated in vitro growth and survival of pre- and early antral dog follicles.
- Author
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Nagashima J, Wildt DE, Travis AJ, and Songsasen N
- Subjects
- Alginates, Animals, Cell Survival physiology, Culture Media chemistry, Dogs, Estradiol analysis, Female, Glucuronic Acid, Hexuronic Acids, Ovarian Follicle physiology, Progesterone analysis, Cell Survival drug effects, Follicle Stimulating Hormone pharmacology, Luteinizing Hormone pharmacology, Ovarian Follicle drug effects
- Abstract
Understanding stage-specific requirements of mammalian folliculogenesis is limited in the domestic dog. The present study examined the effects of two potential regulators of dog follicle growth and survival in vitro, namely the original stage of the follicle (i.e. preantral (≤230µm diameter) vs early antral (diameter from >230 to ≤330µm) and FSH and/or LH concentrations. After isolation and alginate encapsulation, follicles were cultured in 0, 1, 10 or 100µgmL
-1 FSH and 0, 1 or 10ngmL-1 LH for 20 days. Regardless of stage, FSH promoted growth, but LH did the same only in the absence of FSH. Production of 17β-oestradiol and progesterone was detectable, indicating theca cell activity. The greatest growth occurred in preantral (mean (± s.d.) 61.4±25.9%) versus antral (42.6±20.3%) follicles, but neither developmental stage nor gonadotropin affected survival. Antrum detection was minimal due, in part, to antral collapse, and oocytes exhibited an increasingly pale appearance and chromatin degeneration over time. The results demonstrate that pre- and early antral stage dog follicles encapsulated in alginate grow significantly in vitro. However, because FSH and LH alone or in combination fail to promote antrum development, the next step is identifying factors that enhance antral expansion.- Published
- 2017
- Full Text
- View/download PDF
42. Biomimicry Promotes the Efficiency of a 10-Step Sequential Enzymatic Reaction on Nanoparticles, Converting Glucose to Lactate.
- Author
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Mukai C, Gao L, Nelson JL, Lata JP, Cohen R, Wu L, Hinchman MM, Bergkvist M, Sherwood RW, Zhang S, and Travis AJ
- Subjects
- Animals, Biological Mimicry, Biotechnology, Enzymes, Immobilized chemistry, Enzymes, Immobilized metabolism, Glucose chemistry, Humans, Lactic Acid chemistry, Nanoparticles chemistry, Nanotechnology, Enzymes metabolism, Glucose metabolism, Lactic Acid metabolism, Nanoparticles metabolism
- Abstract
For nanobiotechnology to achieve its potential, complex organic-inorganic systems must grow to utilize the sequential functions of multiple biological components. Critical challenges exist: immobilizing enzymes can block substrate-binding sites or prohibit conformational changes, substrate composition can interfere with activity, and multistep reactions risk diffusion of intermediates. As a result, the most complex tethered reaction reported involves only 3 enzymes. Inspired by the oriented immobilization of glycolytic enzymes on the fibrous sheath of mammalian sperm, here we show a complex reaction of 10 enzymes tethered to nanoparticles. Although individual enzyme efficiency was higher in solution, the efficacy of the 10-step pathway measured by conversion of glucose to lactate was significantly higher when tethered. To our knowledge, this is the most complex organic-inorganic system described, and it shows that tethered, multi-step biological pathways can be reconstituted in hybrid systems to carry out functions such as energy production or delivery of molecular cargo., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2017
- Full Text
- View/download PDF
43. Sustainable smallholder poultry interventions to promote food security and social, agricultural, and ecological resilience in the Luangwa Valley, Zambia.
- Author
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Dumas SE, Lungu L, Mulambya N, Daka W, McDonald E, Steubing E, Lewis T, Backel K, Jange J, Lucio-Martinez B, Lewis D, and Travis AJ
- Abstract
In Zambia's Luangwa Valley, highly variable rainfall and lack of education, agricultural inputs, and market access constrain agricultural productivity, trapping smallholder farmers in chronic poverty and food insecurity. Human and animal disease (e.g. HIV and Newcastle Disease, respectively), further threaten the resilience of poor families. To cope with various shocks and stressors, many farmers employ short-term coping strategies that threaten ecosystem resilience. Community Markets for Conservation (COMACO) utilizes an agribusiness model to alleviate poverty and food insecurity through conservation farming, market development and value-added food production. COMACO promotes household, agricultural and ecological resilience along two strategic lines: improving recovery from shocks (mitigation) and reducing the risk of shock occurrence. Here we focus on two of COMACO's poultry interventions and present data showing that addressing health and management constraints within the existing village poultry system resulted in significantly improved productivity and profitability. However, once reliable productivity was achieved, farmers preferred to sell chickens rather than eat either the birds or their eggs. Sales of live birds were largely outside the community to avoid price suppression; in contrast, the sale of eggs from community-operated, semi-intensive egg production facilities was invariably within the communities. These facilities resulted in significant increases in both producer income and community consumption of eggs. This intervention therefore has the potential to improve not only producers' economic resilience, but also resilience tied to the food security and physical health of the entire community.
- Published
- 2016
- Full Text
- View/download PDF
44. Lipid Regulation of Acrosome Exocytosis.
- Author
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Cohen R, Mukai C, and Travis AJ
- Subjects
- Acrosome chemistry, Acrosome drug effects, Acrosome Reaction drug effects, Animals, Calcium metabolism, Calcium Channels, R-Type metabolism, Cation Transport Proteins agonists, Cation Transport Proteins metabolism, Cholesterol pharmacology, Enzyme Activation, Exocytosis drug effects, Female, G(M1) Ganglioside pharmacology, Lysophospholipase metabolism, Male, Membrane Fusion drug effects, Membrane Fusion physiology, Membrane Microdomains chemistry, Membrane Microdomains metabolism, Phospholipids pharmacology, Sperm Capacitation drug effects, Sperm Capacitation physiology, Zona Pellucida physiology, Acrosome metabolism, Acrosome Reaction physiology, Cholesterol metabolism, G(M1) Ganglioside metabolism, Phospholipids metabolism
- Abstract
Lipids are critical regulators of mammalian sperm function, first helping prevent premature acrosome exocytosis, then enabling sperm to become competent to fertilize at the right place/time through the process of capacitation, and ultimately triggering acrosome exocytosis. Yet because they do not fit neatly into the "DNA--RNA-protein" synthetic pathway, they are understudied and poorly understood. Here, we focus on three lipids or lipid classes-cholesterol, phospholipids, and the ganglioside G(M1)--in context of the modern paradigm of acrosome exocytosis. We describe how these various- species are precisely segregated into membrane macrodomains and microdomains, simultaneously preventing premature exocytosis while acting as foci for organizing regulatory and effector molecules that will enable exocytosis. Although the mechanisms responsible for these domains are poorly defined, there is substantial evidence for their composition and functions. We present diverse ways that lipids and lipid modifications regulate capacitation and acrosome exocytosis, describing in more detail how removal of cholesterol plays a master regulatory role in enabling exocytosis through at least two complementary pathways. First, cholesterol efflux leads to proteolytic activation of phospholipase B, which cleaves both phospholipid tails. The resultant changes in membrane curvature provide a mechanism for the point fusions now known to occur far before a sperm physically interacts with the zona pellucida. Cholesterol efflux also enables G(M1) to regulate the voltage-dependent cation channel, Ca(V)2.3, triggering focal calcium transients required for acrosome exocytosis in response to subsequent whole-cell calcium rises. We close with a model integrating functions for lipids in regulating acrosome exocytosis.
- Published
- 2016
- Full Text
- View/download PDF
45. Live Births from Domestic Dog (Canis familiaris) Embryos Produced by In Vitro Fertilization.
- Author
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Nagashima JB, Sylvester SR, Nelson JL, Cheong SH, Mukai C, Lambo C, Flanders JA, Meyers-Wallen VN, Songsasen N, and Travis AJ
- Subjects
- Animals, Canidae, Dogs, Embryonic Development, Endangered Species, Female, Live Birth, Oocytes, Pregnancy, Embryo Transfer veterinary, Fertilization in Vitro veterinary
- Abstract
Development of assisted reproductive technologies (ART) in the dog has resisted progress for decades, due to their unique reproductive physiology. This lack of progress is remarkable given the critical role ART could play in conserving endangered canid species or eradicating heritable disease through gene-editing technologies-an approach that would also advance the dog as a biomedical model. Over 350 heritable disorders/traits in dogs are homologous with human conditions, almost twice the number of any other species. Here we report the first live births from in vitro fertilized embryos in the dog. Adding to the practical significance, these embryos had also been cryopreserved. Changes in handling of both gametes enabled this progress. The medium previously used to capacitate sperm excluded magnesium because it delayed spontaneous acrosome exocytosis. We found that magnesium significantly enhanced sperm hyperactivation and ability to undergo physiologically-induced acrosome exocytosis, two functions essential to fertilize an egg. Unlike other mammals, dogs ovulate a primary oocyte, which reaches metaphase II on Days 4-5 after the luteinizing hormone (LH) surge. We found that only on Day 6 are oocytes consistently able to be fertilized. In vitro fertilization of Day 6 oocytes with sperm capacitated in medium supplemented with magnesium resulted in high rates of embryo development (78.8%, n = 146). Intra-oviductal transfer of nineteen cryopreserved, in vitro fertilization (IVF)-derived embryos resulted in seven live, healthy puppies. Development of IVF enables modern genetic approaches to be applied more efficiently in dogs, and for gamete rescue to conserve endangered canid species.
- Published
- 2015
- Full Text
- View/download PDF
46. Assessing the genetic diversity of rice originating from Bangladesh, Assam and West Bengal.
- Author
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Travis AJ, Norton GJ, Datta S, Sarma R, Dasgupta T, Savio FL, Macaulay M, Hedley PE, McNally KL, Sumon MH, Islam MR, and Price AH
- Abstract
Background: Genetic diversity among rice cultivars from Bangladesh and North East India was assessed using a custom 384-SNP microarray assay. A total of 511 cultivars were obtained from several sources, choosing landraces likely to be from the aus subpopulation and modern improved cultivars from Bangladesh. Cultivars from the OryzaSNP set and Rice Diversity Panel 1 (RDP1) were also included for reference., Results: The population analysis program STRUCTURE was used to infer putative population groups in the panel, revealing four groups: indica (76 cultivars), japonica (55) and two distinct groups within the aus subpopulation (aus-1 = 99, aus-2 = 151). Principal Component Analysis was used to confirm the four population groups identified by STRUCTURE. The analysis revealed cultivars that belonged to neither aus-1 nor aus-2 but which are clearly aus based on the combined probabilities of their membership of the two aus groups which have been termed aus-admix (96). Information obtained from the panel of 511 cultivars was used to assign rice groups to 74 additional landraces obtained from Assam and West Bengal. While both the aus-1 and aus-2 groups were represented approximately equally in India, aus-2 (which includes cultivar N 22) was more common in Bangladesh, but was not found at all in West Bengal., Conclusions: Examining the distribution of landrace names within theaus-1 and aus-2 groups suggests that aus-1 is associated with the term "boro", a word used to describe a winter growing season in Bangladesh and Assam. The information described here has been used to select a population of 300 cultivars for Genome Wide Association studies of the aus rice subpopulation.
- Published
- 2015
- Full Text
- View/download PDF
47. Use of Tethered Enzymes as a Platform Technology for Rapid Analyte Detection.
- Author
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Cohen R, Lata JP, Lee Y, Hernández JC, Nishimura N, Schaffer CB, Mukai C, Nelson JL, Brangman SA, Agrawal Y, and Travis AJ
- Subjects
- Animals, Biomarkers blood, Disease Models, Animal, Enzyme-Linked Immunosorbent Assay, Enzymes, Immobilized genetics, Enzymes, Immobilized metabolism, Female, Genes, Reporter, Humans, Infarction, Middle Cerebral Artery diagnosis, Infarction, Middle Cerebral Artery physiopathology, Luciferases chemistry, Luciferases genetics, Luciferases metabolism, Male, Nanoparticles chemistry, Point-of-Care Systems, Pyruvate Kinase chemistry, Pyruvate Kinase genetics, Pyruvate Kinase metabolism, Rats, Rats, Sprague-Dawley, Recombinant Fusion Proteins chemistry, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins metabolism, Silicon Dioxide chemistry, Stroke diagnosis, Stroke physiopathology, Time Factors, Aging blood, Biological Assay standards, Enzymes, Immobilized chemistry, Infarction, Middle Cerebral Artery blood, Phosphopyruvate Hydratase blood, Stroke blood
- Abstract
Background: Rapid diagnosis for time-sensitive illnesses such as stroke, cardiac arrest, and septic shock is essential for successful treatment. Much attention has therefore focused on new strategies for rapid and objective diagnosis, such as Point-of-Care Tests (PoCT) for blood biomarkers. Here we use a biomimicry-based approach to demonstrate a new diagnostic platform, based on enzymes tethered to nanoparticles (NPs). As proof of principle, we use oriented immobilization of pyruvate kinase (PK) and luciferase (Luc) on silica NPs to achieve rapid and sensitive detection of neuron-specific enolase (NSE), a clinically relevant biomarker for multiple diseases ranging from acute brain injuries to lung cancer. We hypothesize that an approach capitalizing on the speed and catalytic nature of enzymatic reactions would enable fast and sensitive biomarker detection, suitable for PoCT devices., Methods and Findings: We performed in-vitro, animal model, and human subject studies. First, the efficiency of coupled enzyme activities when tethered to NPs versus when in solution was tested, demonstrating a highly sensitive and rapid detection of physiological and pathological concentrations of NSE. Next, in rat stroke models the enzyme-based assay was able in minutes to show a statistically significant increase in NSE levels in samples taken 1 hour before and 0, 1, 3 and 6 hours after occlusion of the distal middle cerebral artery. Finally, using the tethered enzyme assay for detection of NSE in samples from 20 geriatric human patients, we show that our data match well (r = 0.815) with the current gold standard for biomarker detection, ELISA-with a major difference being that we achieve detection in 10 minutes as opposed to the several hours required for traditional ELISA., Conclusions: Oriented enzyme immobilization conferred more efficient coupled activity, and thus higher assay sensitivity, than non-tethered enzymes. Together, our findings provide proof of concept for using oriented immobilization of active enzymes on NPs as the basis for a highly rapid and sensitive biomarker detection platform. This addresses a key challenge in developing a PoCT platform for time sensitive and difficult to diagnose pathologies.
- Published
- 2015
- Full Text
- View/download PDF
48. Complete Genome Sequence of the Human Gut Symbiont Roseburia hominis.
- Author
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Travis AJ, Kelly D, Flint HJ, and Aminov RI
- Abstract
We report here the complete genome sequence of the human gut symbiont Roseburia hominis A2-183(T) (= DSM 16839(T) = NCIMB 14029(T)), isolated from human feces. The genome is represented by a 3,592,125-bp chromosome with 3,405 coding sequences. A number of potential functions contributing to host-microbe interaction are identified., (Copyright © 2015 Travis et al.)
- Published
- 2015
- Full Text
- View/download PDF
49. Effects of Nanoparticle Size on Multilayer Formation and Kinetics of Tethered Enzymes.
- Author
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Lata JP, Gao L, Mukai C, Cohen R, Nelson JL, Anguish L, Coonrod S, and Travis AJ
- Subjects
- Adsorption, Histidine chemistry, Kinetics, Models, Molecular, Oligopeptides chemistry, Protein Conformation, Enzymes, Immobilized chemistry, Enzymes, Immobilized metabolism, Gold chemistry, Metal Nanoparticles chemistry, Particle Size
- Abstract
Despite numerous applications, we lack fundamental understanding of how variables such as nanoparticle (NP) size influence the activity of tethered enzymes. Previously, we showed that biomimetic oriented immobilization yielded higher specific activities versus nonoriented adsorption or carboxyl-amine binding. Here, we standardize NP attachment strategy (oriented immobilization via hexahistidine tags) and composition (Ni-NTA coated gold NPs), to test the impact of NP size (⌀5, 10, 20, and 50 nm) on multilayer formation, activity, and kinetic parameters (kcat, KM, kcat/KM) of enzymes representing three different classes: glucose-6-phosphate isomerase (GPI), an isomerase; Glyceraldehyde-3-phosphate dehydrogenase S (GAPDHS), an oxidoreductase; and pyruvate kinase (PK), a transferase. Contrary to other reports, we observed no trend in kinetic parameters for individual enzymes when found in monolayers (<100% enzyme coverage), suggesting an advantage for oriented immobilization versus other attachment strategies. Saturating the NPs to maximize activity per NP resulted in enzyme multilayer formation. Under these conditions, total activity per NP increased with increasing NP size. Conversely, specific activity for all three enzymes was highest when tethered to the smallest NPs, retaining a remarkable 73-94% of the activity of free/untethered enzymes. Multilayer formations caused a clear trend of kcat decreasing with increasing NP size, yet negligible change in KM. Understanding the fundamental relationships between NP size and tethered enzyme activity enables optimized design of various applications, maximizing activity per NP or activity per enzyme molecule.
- Published
- 2015
- Full Text
- View/download PDF
50. Slow freezing, but not vitrification supports complete spermatogenesis in cryopreserved, neonatal sheep testicular xenografts.
- Author
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Pukazhenthi BS, Nagashima J, Travis AJ, Costa GM, Escobar EN, França LR, and Wildt DE
- Subjects
- Animals, Cryopreservation methods, Freezing, Graft Survival, Heterografts, Male, Mice, SCID, Organ Preservation methods, Testis physiology, Testis ultrastructure, Transplantation, Heterologous, Vitrification, Cryopreservation veterinary, Organ Preservation veterinary, Sheep, Domestic physiology, Spermatogenesis, Testis transplantation
- Abstract
The ability to spur growth of early stage gametic cells recovered from neonates could lead to significant advances in rescuing the genomes of rare genotypes or endangered species that die unexpectedly. The purpose of this study was to determine, for the first time, the ability of two substantially different cryopreservation approaches, slow freezing versus vitrification, to preserve testicular tissue of the neonatal sheep and subsequently allow initiation of spermatogenesis post-xenografting. Testis tissue from four lambs (3-5 wk old) was processed and then untreated or subjected to slow freezing or vitrification. Tissue pieces (fresh, n = 214; slow freezing, then thawing, n = 196; vitrification, then warming, n = 139) were placed subcutaneously under the dorsal skin of SCID mice and then grafts recovered and evaluated 17 wk later. Grafts from fresh and slow frozen tissue contained the most advanced stages of spermatogenesis, including normal tubule architecture with elongating spermatids in ~1% (fresh) and ~10% (slow frozen) of tubules. Fewer than 2% of seminiferous tubules advanced to the primary spermatocyte stage in xenografts derived from vitrified tissue. Results demonstrate that slow freezing of neonatal lamb testes was far superior to vitrification in preserving cellular integrity and function after xenografting, including allowing ~10% of tubules to retain the capacity to resume spermatogenesis and yield mature spermatozoa. Although a first for any ruminant species, findings also illustrate the importance of preemptive studies that examine cryo-sensitivity of testicular tissue before attempting this type of male fertility preservation on a large scale.
- Published
- 2015
- Full Text
- View/download PDF
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