31 results on '"Chea L"'
Search Results
2. The 2020-2021 Whippoorwill Award: Redefining and Reconsidering What Counts as Rural YA Literature
- Author
-
Kedley, Kate E., Brenner, Devon, Parton, Chea L., Eppley, Karen, Kleese, Nick, Sanders, Jennifer, and Short, Stephanie
- Abstract
The Whippoorwill Award aims to bring attention to the theme of rural spaces and people in the larger genre of young adult literature. This award annually recognizes the best books for the middle grades and young adult readers that portray the value of rural spaces, knowledge, people, and cultures. The Whippoorwill Award is intended to be a resource for young readers, their teachers and other adults in their lives to help identify authentic, complex, meaningful, and well-written portrayals of rural life. This article discusses the third cycle of Whippoorwill Book Award winners, covering the publication years of 2020 and 2021. The winners include 13 diverse and compelling books that portray rural people and places in dynamic and energizing ways.
- Published
- 2022
3. Developing Solar-Powered Light Insect Trapper with Light Sensor.
- Author
-
Ballucanag, Mariah Francess A., Tolentino, Exodos John C., Verganio, Leenardvan A., Lopez, Mark Allen E., Tubayan, Jan Carlo M., Dumrique, Abegail P., Falceso, Trish Ashley G., Saludares, Eric A., Gascon, Vanessa Jane G., Cabansag, Kishen Chea L., Sesbreno, Janaree Leamar, and Bautista, Christian Jay A.
- Subjects
PESTICIDE resistance ,INSECT pests ,PRODUCTION losses ,PEST control ,FOOD security ,INSECTS - Abstract
Insect pests cause the highest crop production losses globally, and pest management is crucial in ensuring food security and farm income. Chemical pesticides are often used for control of insect pests but they are harmful to human health, the environment, and biodiversity and pest resistance to pesticides is acquired over time by pests due to excessive and frequent use of pesticides. Due to the ban on many insecticides over human and environmental health concerns, new strategies should be adopted. Insect pests cause major crop losses in agriculture worldwide, and many of them are vectors for animal and human diseases. Therefore, the improvisation of an effective solar-powered light insect trap will help in the proliferation of harmful insects that destroy the plants of farmers. The improvised solar-powered light insect trap could address the problems of farmers in reducing the harmful insects that destroy the plants. The study shows that the violet (UV light) solar-powered insect trapper emerged as the most effective and attractive in trapping insects. The study found that the color of the solar-powered light insect trapper plays an important role in attracting insects, with UV light showing significantly better performance compared to yellow, white, and blue lights. However, when considering the time factor, the statistical analysis did not show a significant difference in the number of trapped insects between the first and second hours. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. The 2023 Whippoorwill Award: The 2023 Whippoorwill Award: Complex Representations of Rural Identities and Places
- Author
-
Parton, Chea L, primary, Bass, Erika L, additional, Brenner, Devon, additional, Kedley, Kate E, additional, Hoffmann, Alan, additional, Sanders, Jennifer, additional, Yahn, Jacqueline, additional, and Young, Michael, additional
- Published
- 2023
- Full Text
- View/download PDF
5. The STEM Road Map for Grades 6–8
- Author
-
Johnson, Carla C., primary, Moore, Tamara J., additional, Utley, Juliana, additional, Breiner, Jonathan, additional, Burton, Steven R., additional, Peters-Burton, Erin E., additional, Walton, Janet, additional, and Parton, Chea L., additional
- Published
- 2015
- Full Text
- View/download PDF
6. Who's 'Ere?: Identifying and Addressing Rural Erasure in ELA Classrooms.
- Author
-
Parton, Chea L.
- Subjects
CLASSROOMS ,YOUNG adult literature ,CRITICAL analysis - Abstract
This article briefly discusses research on the role of rural out-migrant ELA teachers' place-connected identities on rural erasure through text selection and instructional practice. Based on the research findings, it provides resources such as an equity audit for course syllabi and classroom libraries as well as tools for finding and selecting rural young adult literature to combat rural erasure and support teachers' inclusion of critical rural perspectives in their teaching. [ABSTRACT FROM AUTHOR]
- Published
- 2021
7. Rural Youth and Urban-based Vocational Training: Gender, space and aspiring to ‘become someone’
- Author
-
Chea, L, Huijsmans, Roy, Naafs, S., Skelton, T, and Academic staff unit
- Published
- 2019
8. Functionally Distinct Subsets of Monocytes in Mouse and Human Blood
- Author
-
Rhee, Catherine S, primary, Scadden, Elizabeth W, primary, Phillip, Chea L, primary, Lee, Bum-Kyu, primary, Mistry, Meeta, primary, Hoyer, Friedrich F, primary, Kato, Hiroki, primary, Mantica, Giovanna, primary, Kim, Jonghwan, primary, Nahrendorf, Matthias, primary, Mansour, Michael K, primary, Sykes, David B, primary, and Scadden, David T., primary
- Published
- 2019
- Full Text
- View/download PDF
9. Rural youth and urban-based vocational training: gender, space and aspiring to 'become someone'
- Author
-
Chea, L, Huijsmans, Roy, Chea, L, and Huijsmans, Roy
- Published
- 2018
10. The STEM Road Map for Grades 6–8
- Author
-
Carla C. Johnson, Tamara J. Moore, Juliana Utley, Jonathan Breiner, Steven R. Burton, Erin E. Peters-Burton, Janet Walton, and Chea L. Parton
- Published
- 2015
11. Rural Internal Migrants Navigating Apprenticeships and Vocational Training: Insights from Cambodia and Laos
- Author
-
Chea, L. (Lyda), Huijsmans, R.B.C. (Roy), Chea, L. (Lyda), and Huijsmans, R.B.C. (Roy)
- Abstract
The policy phrase Technical and Vocational Education and Training (TVET) is rapidly gaining ground across Southeast Asia (and beyond). TVET is centrally about ‘skills’ development and considered an important policy component in smoothening young people’s ‘school-to-work transition’. It is seen as increasing young people’s employability and earning capacity thus contributing to alleviating important youth-related social problems such as youth unemployment, intergenerational transmission of poverty, and the mismatch between schooling and the labour market.
- Published
- 2014
12. Construction of laboratories for solar energy research in developing countries
- Author
-
Davidsson, H., Bernardo, R., Gomes, J., Gentile, N., Gruffmanc, C., Chea, L., Karlsson, Björn, Davidsson, H., Bernardo, R., Gomes, J., Gentile, N., Gruffmanc, C., Chea, L., and Karlsson, Björn
- Abstract
A large number of photovoltaic systems have been installed in developing countries around the world during numerous projects. The goal is often to improve the quality of life in rural areas often lacking electricity. Many of these installations provide important services such as lighting and charging of various devices. However, when the projects are finished, there is a large risk that maintenance is not carried out properly and that malfunctions are never repaired. This situation can leave an otherwise well- functioning system unusable. A key problem is that there are not enough trained technicians that can maintain and repair the system locally. One reason for this is the lack of practical education in many developing countries. Furthermore, the availability of spare parts is essential for long term effectiveness. During 2011 a group of researchers from Lund University in Sweden built a small scale laboratory in Maputo, Mozambique, with local researchers. The project was successful and today the laboratory functions both as a teaching facility and as a measurement station for solar energy research for licentiates, masters and Ph.D. students. The main goal now is to widen the project in order to incorporate more universities in developing countries. We are now looking for new interested partners in developing countries who believe that such a laboratory could strengthen their ability to teach practical work and to perform research at a local university. Partners for planning and executing the project are also needed.
- Published
- 2014
- Full Text
- View/download PDF
13. Management of Chronic Strongyloidiasis in Immigrants and Refugees: Is Serologic Testing Useful?
- Author
-
Biggs, B-A, Caruana, S, Mihrshahi, S, Jolley, D, Leydon, J, Chea, L, Nuon, S, Biggs, B-A, Caruana, S, Mihrshahi, S, Jolley, D, Leydon, J, Chea, L, and Nuon, S
- Abstract
We assessed the usefulness of serologic testing in monitoring strongyloidiasis in immigrants after treatment with two doses of ivermectin. An observational study was conducted in a group of Cambodian immigrants residing in Melbourne who were treated for strongyloidiasis and followed-up in a general practice setting. Two doses of ivermectin (200 microg/kg) were administered orally. Periodic serologic enzyme-linked immunosorbent assay testing was undertaken for up to 30 months after treatment. Antibody titers for Strongyloides sp. decreased in 95% (38 of 40) of the patients, 47.5% (19 of 40) had a decrease in optical density to less than 0.5, and 65% (26 of 40) reached levels consistent with a cure during the follow-up period. Serologic testing for Strongyloides sp. is a useful tool for monitoring a decrease in antibody levels after effective treatment. This testing should be carried out 6-12 months after treatment to ensure a sustained downward trend suggestive of cure.
- Published
- 2009
14. Undiagnosed and potentially lethal parasite infections among immigrants and refugees in Australia
- Author
-
Caruana, SR, Kelly, HA, Ngeow, JYY, Ryan, NJ, Bennett, CM, Chea, L, Nuon, S, Bak, N, Skull, SA, Biggs, B-A, Caruana, SR, Kelly, HA, Ngeow, JYY, Ryan, NJ, Bennett, CM, Chea, L, Nuon, S, Bak, N, Skull, SA, and Biggs, B-A
- Abstract
Intestinal parasite infections are a major cause of ill health in many resource-poor countries. This study compares the types and rates of these infections and their risk factors in recently arrived and long-term immigrants in Australia. Cross-sectional surveys of 127 East African and 234 Cambodian immigrants and refugees were undertaken in 2000 and 2002, respectively, to assess the burden of intestinal parasites and collect demographic information. Serum samples were assessed for eosinophilia and Strongyloides stercoralis and Schistosoma antibodies, and feces examined for ova, cysts, and parasites. Intestinal parasites were identified in 77/117 fecal samples from East African and in 25/204 samples collected from Cambodian participants. Eleven percent (14/124) of East Africans and 42% (97/230) of Cambodians had positive or equivocal serology for S stercoralis. Schistosoma serology was positive or equivocal in 15% (19/124) of East African participants. Potentially serious intestinal parasite infections are common among recent and longer term immigrants despite multiple visits to health care providers. Immigrants and refugees from high-risk countries would benefit from comprehensive health checks soon after resettlement.
- Published
- 2006
15. Knowledge about hepatitis and previous exposure to hepatitis viruses in immigrants and refugees from the Mekong Region
- Author
-
Caruana, SR, Kelly, HA, De Silva, SL, Chea, L, Nuon, S, Saykao, P, Bak, N, Biggs, BA, Caruana, SR, Kelly, HA, De Silva, SL, Chea, L, Nuon, S, Saykao, P, Bak, N, and Biggs, BA
- Abstract
OBJECTIVE: Infection with hepatitis B (HBV) and hepatitis C (HCV) viruses is relatively common throughout South-East Asia and chronic infection can lead to severe consequences. This study assesses knowledge about HBV and HCV and estimates the seroprevalence of markers for these viruses in immigrants from Laos and Cambodia. METHODS: Ninety-five Laotian (aged 18-82 years) and 234 Cambodian (15-92 years) immigrants participated in separate community-based surveys conducted during 1998 and 2002, respectively. Participants completed a questionnaire on health status and level of knowledge about viral hepatitis. Blood samples were collected and tested for the presence of HBV and HCV markers. RESULTS: Nine per cent of Laotian and 8% of Cambodian participants were infected with HBV. While 49% of Laotian and 64% of Cambodian participants showed evidence of previous exposure to HBV, 30% and 9%, respectively, were vulnerable to infection. The seroprevalence of antibodies to HCV was 3% in the Laotian and 8% in the Cambodian participants. Between one-fifth and one-third of the Laotians and Cambodians who had heard of HBV and HCV knew of possible transmission routes for the viruses. Most of those with HBV or HCV infection were unaware they were infected. CONCLUSIONS: These findings indicate a significant prevalence of undetected HBV and HCV infections and an urgent need for the provision of culturally relevant information about viral hepatitis in immigrants of South-East Asian origin.
- Published
- 2005
16. Letting Go of Literary Whiteness: Antiracist Literature Instruction for White Students.
- Author
-
Parton, Chea L.
- Subjects
MULTICULTURAL education ,NONFICTION - Published
- 2020
17. Regulated fluctuations in nanog expression mediate cell fate decisions in embryonic stem cells.
- Author
-
Tibor Kalmar, Chea Lim, Penelope Hayward, Silvia Muñoz-Descalzo, Jennifer Nichols, Jordi Garcia-Ojalvo, and Alfonso Martinez Arias
- Subjects
Biology (General) ,QH301-705.5 - Abstract
There is evidence that pluripotency of mouse embryonic stem (ES) cells is associated with the activity of a network of transcription factors with Sox2, Oct4, and Nanog at the core. Using fluorescent reporters for the expression of Nanog, we observed that a population of ES cells is best described by a dynamic distribution of Nanog expression characterized by two peaks defined by high (HN) and low (LN) Nanog expression. Typically, the LN state is 5%-20% of the total population, depending on the culture conditions. Modelling of the activity of Nanog reveals that a simple network of Oct4/Sox2 and Nanog activity can account for the observed distribution and its properties as long as the transcriptional activity is tuned by transcriptional noise. The model also predicts that the LN state is unstable, something that is born out experimentally. While in this state, cells can differentiate. We suggest that transcriptional fluctuations in Nanog expression are an essential element of the pluripotent state and that the function of Sox2, Oct4, and Nanog is to act as a network that promotes and maintains transcriptional noise to interfere with the differentiation signals.
- Published
- 2009
- Full Text
- View/download PDF
18. An artifacts removal post-processing for epiphyseal region-of-interest (EROI) localization in automated bone age assessment (BAA)
- Author
-
Salleh Sh-Hussain, Swee Tan, Wee Lai, Chai Hum, and Chea Lim
- Subjects
Medical technology ,R855-855.5 - Abstract
Abstract Background Segmentation is the most crucial part in the computer-aided bone age assessment. A well-known type of segmentation performed in the system is adaptive segmentation. While providing better result than global thresholding method, the adaptive segmentation produces a lot of unwanted noise that could affect the latter process of epiphysis extraction. Methods A proposed method with anisotropic diffusion as pre-processing and a novel Bounded Area Elimination (BAE) post-processing algorithm to improve the algorithm of ossification site localization technique are designed with the intent of improving the adaptive segmentation result and the region-of interest (ROI) localization accuracy. Results The results are then evaluated by quantitative analysis and qualitative analysis using texture feature evaluation. The result indicates that the image homogeneity after anisotropic diffusion has improved averagely on each age group for 17.59%. Results of experiments showed that the smoothness has been improved averagely 35% after BAE algorithm and the improvement of ROI localization has improved for averagely 8.19%. The MSSIM has improved averagely 10.49% after performing the BAE algorithm on the adaptive segmented hand radiograph. Conclusions The result indicated that hand radiographs which have undergone anisotropic diffusion have greatly reduced the noise in the segmented image and the result as well indicated that the BAE algorithm proposed is capable of removing the artifacts generated in adaptive segmentation.
- Published
- 2011
- Full Text
- View/download PDF
19. Carcinosarcoma: A Rare and Aggressive Breast Tumor in a Young Lady.
- Author
-
Leng PN, Wan Zain WZ, Mohammad Azmi MAF, Yahya MM, Azis KA, Mat Johar SFN, Wan Sulaiman WA, Balingi D, Tuan Sharif SE, Wan Abdul Rahman WF, Chiew Chea L, and Haron J
- Abstract
Carcinosarcoma of the breast is a subtype of metaplastic breast carcinoma characterized by differentiation of the neoplastic epithelium toward mesenchymal-looking elements. It is a highly aggressive rare subtype of invasive breast neoplasm that exhibits a distinct histologic entity. Only a limited number of reports related to this type of disease have been reported. Here, we present a case of breast carcinosarcoma in a lady in her early 20s, which is relatively young among all cases published. It was challenging to achieve diagnosis preoperatively with histopathological evaluation of the ultrasound-guided tru-cut biopsy sample. With no evidence of distant metastasis clinically and radiologically, a surgical option was opted for. Left mastectomy and left chest wall reconstruction with deep inferior epigastric artery free flap were performed. Post-excision specimen was confirmed to be carcinosarcoma., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Leng et al.)
- Published
- 2023
- Full Text
- View/download PDF
20. Neurodegeneration risk factor, EIF2AK3 (PERK), influences tau protein aggregation.
- Author
-
Park G, Xu K, Chea L, Kim K, Safarta L, Song KH, Wu J, Park S, Min H, Hiramatsu N, Han J, and Lin JH
- Subjects
- Humans, Disease Susceptibility, Mutation, Risk Factors, Tauopathies metabolism, Tauopathies pathology, eIF-2 Kinase chemistry, eIF-2 Kinase genetics, eIF-2 Kinase metabolism, Protein Aggregates, Protein Aggregation, Pathological, tau Proteins chemistry, tau Proteins metabolism
- Abstract
Tauopathies are neurodegenerative diseases caused by pathologic misfolded tau protein aggregation in the nervous system. Population studies implicate EIF2AK3 (eukaryotic translation initiation factor 2 alpha kinase 3), better known as PERK (protein kinase R-like endoplasmic reticulum kinase), as a genetic risk factor in several tauopathies. PERK is a key regulator of intracellular proteostatic mechanisms-unfolded protein response and integrated stress response. Previous studies found that tauopathy-associated PERK variants encoded functional hypomorphs with reduced signaling in vitro. But, it remained unclear how altered PERK activity led to tauopathy. Here, we chemically or genetically modulated PERK signaling in cell culture models of tau aggregation and found that PERK pathway activation prevented tau aggregation, whereas inhibition exacerbated tau aggregation. In primary tauopathy patient brain tissues, we found that reduced PERK signaling correlated with increased tau neuropathology. We found that tauopathy-associated PERK variants targeted the endoplasmic reticulum luminal domain; and two of these variants damaged hydrogen bond formation. Our studies support that PERK activity protects against tau aggregation and pathology. This may explain why people carrying hypomorphic PERK variants have increased risk for developing tauopathies. Finally, our studies identify small-molecule augmentation of PERK signaling as an attractive therapeutic strategy to treat tauopathies by preventing tau pathology., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Published by Elsevier Inc.)
- Published
- 2023
- Full Text
- View/download PDF
21. Lysine Ubiquitylation Drives Rhodopsin Protein Turnover.
- Author
-
Chen APF, Chea L, Lee EJ, and Lin JH
- Subjects
- Humans, Animals, Proteolysis, HEK293 Cells, Mutation, Ubiquitination, Disease Models, Animal, Rhodopsin metabolism, Lysine metabolism
- Abstract
Rhodopsin is a G-protein-coupled receptor that is specifically and abundantly expressed in rod photoreceptors. Over 150 rhodopsin mutations cause autosomal dominant retinitis pigmentosa (adRP). The most common mutation in the United States is the conversion of proline to histidine at position 23 (P23H) in the N-terminal domain of rhodopsin. We previously found that P23H rhodopsin was misfolded, ubiquitinylated, and rapidly degraded. Here, we investigated the role of lysine residues on P23H rhodopsin ubiquitinylation and turnover. We transfected HEK293 cells with a P23H human rhodopsin construct where all 11 lysine residues were mutated to arginine (K-null P23H). We found that the K-null P23H rhodopsin was significantly less ubiquitylated than intact P23H rhodopsin. We found that K-null P23H protein turnover was significantly slower compared to P23H rhodopsin through cycloheximide chase analysis. Finally, we also generated a wild-type rhodopsin construct where all lysines were converted to arginine and found significantly reduced ubiquitylation. Our findings identify ubiquitinylation of lysine residues as an important posttranslational modification involved in P23H rhodopsin protein degradation., (© 2023. The Author(s), under exclusive license to Springer Nature Switzerland AG.)
- Published
- 2023
- Full Text
- View/download PDF
22. Cultivar-Dependent Responses in Plant Growth, Leaf Physiology, Phosphorus Use Efficiency, and Tuber Quality of Potatoes Under Limited Phosphorus Availability Conditions.
- Author
-
Chea L, Meijide A, Meinen C, Pawelzik E, and Naumann M
- Abstract
The limited availability of phosphorus (P) in soils causes a major constraint in the productivity of potatoes, which requires increased knowledge of plant adaptation responses in this condition. In this study, six potato cultivars, namely, Agria, Lady Claire, Milva, Lilly, Sieglinde, and Verdi, were assessed for their responses on plant growth, leaf physiology, P use efficiency (PUE), and tuber quality with three P levels (P
low , Pmed , and Phigh ). The results reveal a significant variation in the cultivars in response to different P availabilities. P-efficient cultivars, Agria, Milva, and Lilly, possessed substantial plant biomass, tuber yield, and high P uptake efficiency (PUpE) under low P supply conditions. The P-inefficient cultivars, Lady Claire, Sieglinde, and Verdi, could not produce tubers under P deprivation conditions, as well as the ability to efficiently uptake P under low-level conditions, but they were efficient in P uptake under high soil P conditions. Improved PUpE is important for plant tolerance with limited P availability, which results in the efficient use of the applied P. At the leaf level, increased accumulations of nitrate, sulfate, sucrose, and proline are necessary for a plant to acclimate to P deficiency-induced stress and to mobilize leaf inorganic phosphate to increase internal PUE and photosynthesis. The reduction in plant biomass and tuber yield under P-deficient conditions could be caused by reduced CO2 assimilation. Furthermore, P deficiency significantly reduced tuber yield, dry matter, and starch concentration in Agria, Milva, and Lilly. However, contents of tuber protein, sugars, and minerals, as well as antioxidant capacity, were enhanced under these conditions in these cultivars. These results highlight the important traits contributing to potato plant tolerance under P-deficient conditions and indicate an opportunity to improve the P efficiency and tuber quality of potatoes under deficient conditions using more efficient cultivars. Future research to evaluate molecular mechanisms related to P and sucrose translocation, and minimize tuber yield reduction under limited P availability conditions is necessary., 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 © 2021 Chea, Meijide, Meinen, Pawelzik and Naumann.)- Published
- 2021
- Full Text
- View/download PDF
23. ATF6 is required for efficient rhodopsin clearance and retinal homeostasis in the P23H rho retinitis pigmentosa mouse model.
- Author
-
Lee EJ, Chan P, Chea L, Kim K, Kaufman RJ, and Lin JH
- Subjects
- Animals, Disease Models, Animal, Female, Male, Mice, Mice, Inbred C57BL, Retinal Degeneration metabolism, Retinal Rod Photoreceptor Cells metabolism, Activating Transcription Factor 6 metabolism, Homeostasis physiology, Retina metabolism, Retinitis Pigmentosa metabolism, Rhodopsin metabolism
- Abstract
Retinitis Pigmentosa (RP) is a blinding disease that arises from loss of rods and subsequently cones. The P23H rhodopsin knock-in (P23H-KI) mouse develops retinal degeneration that mirrors RP phenotype in patients carrying the orthologous variant. Previously, we found that the P23H rhodopsin protein was degraded in P23H-KI retinas, and the Unfolded Protein Response (UPR) promoted P23H rhodopsin degradation in heterologous cells in vitro. Here, we investigated the role of a UPR regulator gene, activating transcription factor 6 (Atf6), in rhodopsin protein homeostasis in heterozygous P23H rhodopsin (Rho
+/P23H ) mice. Significantly increased rhodopsin protein levels were found in Atf6-/- Rho+/P23H retinas compared to Atf6+/- Rho+/P23H retinas at early ages (~ P12), while rhodopsin mRNA levels were not different. The IRE1 pathway of the UPR was hyper-activated in young Atf6-/- Rho+/P23H retinas, and photoreceptor layer thickness was unchanged at this early age in Rho+/P23H mice lacking Atf6. By contrast, older Atf6-/- Rho+/P23H mice developed significantly increased retinal degeneration in comparison to Atf6+/- Rho+/P23H mice in all retinal layers, accompanied by reduced rhodopsin protein levels. Our findings demonstrate that Atf6 is required for efficient clearance of rhodopsin protein in rod photoreceptors expressing P23H rhodopsin, and that loss of Atf6 ultimately accelerates retinal degeneration in P23H-KI mice., (© 2021. The Author(s).)- Published
- 2021
- Full Text
- View/download PDF
24. Morphological and Metabolite Responses of Potatoes under Various Phosphorus Levels and Their Amelioration by Plant Growth-Promoting Rhizobacteria.
- Author
-
Chea L, Pfeiffer B, Schneider D, Daniel R, Pawelzik E, and Naumann M
- Subjects
- Plant Leaves anatomy & histology, Plant Leaves growth & development, Plant Leaves metabolism, Plant Leaves microbiology, Plant Roots anatomy & histology, Plant Roots growth & development, Plant Roots metabolism, Plant Roots microbiology, Solanum tuberosum growth & development, Solanum tuberosum microbiology, Phosphorus metabolism, Plant Development, Rhizobiaceae physiology, Solanum tuberosum anatomy & histology, Solanum tuberosum metabolism, Stress, Physiological
- Abstract
Low phosphorus (P) availability is a major limiting factor for potatoes. P fertilizer is applied to enhance P availability; however, it may become toxic when plants accumulate at high concentrations. Therefore, it is necessary to gain more knowledge of the morphological and biochemical processes associated with P deficiency and toxicity for potatoes, as well as to explore an alternative approach to ameliorate the P deficiency condition. A comprehensive study was conducted (I) to assess plant morphology, mineral allocation, and metabolites of potatoes in response to P deficiency and toxicity; and (II) to evaluate the potency of plant growth-promoting rhizobacteria (PGPR) in improving plant biomass, P uptake, and metabolites at low P levels. The results revealed a reduction in plant height and biomass by 60-80% under P deficiency compared to P optimum. P deficiency and toxicity conditions also altered the mineral concentration and allocation in plants due to nutrient imbalance. The stress induced by both P deficiency and toxicity was evident from an accumulation of proline and total free amino acids in young leaves and roots. Furthermore, root metabolite profiling revealed that P deficiency reduced sugars by 50-80% and organic acids by 20-90%, but increased amino acids by 1.5-14.8 times. However, the effect of P toxicity on metabolic changes in roots was less pronounced. Under P deficiency, PGPR significantly improved the root and shoot biomass, total root length, and root surface area by 32-45%. This finding suggests the potency of PGPR inoculation to increase potato plant tolerance under P deficiency.
- Published
- 2021
- Full Text
- View/download PDF
25. Response of Tomato Genotypes under Different High Temperatures in Field and Greenhouse Conditions.
- Author
-
Ro S, Chea L, Ngoun S, Stewart ZP, Roeurn S, Theam P, Lim S, Sor R, Kosal M, Roeun M, Dy KS, and Prasad PVV
- Abstract
Heat stress is one of the production constraints for tomato ( Solanum lycopersicum L.) due to unfavorable, above optimum temperatures. This research was undertaken to evaluate growth and fruit yield of tomato genotypes under three contrasting growing conditions (i.e., optimal temperature in field-, high temperature in field- and high temperature in greenhouse conditions) to determine their relative heat tolerance. Eleven tomato genotypes, including two local check varieties, were evaluated, and data on growth and yield were measured and analyzed. The interactions between the genotypes and growing conditions for all yield traits were significant. In general, the performance of tomato under optimal temperature field conditions was better than under high temperature field- and greenhouse conditions. Genotypes CLN1621L, CLN2026D, CLN3212C, and KK1 had consistently greater fruit yield per plant in all growing conditions. Although the local genotype, Neang Tamm, had lower yield under optimal conditions, it performed moderately well under high temperature field- and high temperature greenhouse conditions, and yield decrease under high temperature condition was minimal. Genotype CLN1621L had stable fruit setting compared to other genotypes under high temperature conditions. Since fruit setting and yield are important traits for heat tolerance, genotypes CLN1621L and Neang Tamm are potential candidates for breeding programs focused on improved yield and heat stress tolerance.
- Published
- 2021
- Full Text
- View/download PDF
26. Multiexon deletion alleles of ATF6 linked to achromatopsia.
- Author
-
Lee EJ, Chiang WJ, Kroeger H, Bi CX, Chao DL, Skowronska-Krawczyk D, Mastey RR, Tsang SH, Chea L, Kim K, Lambert SR, Grandjean JM, Baumann B, Audo I, Kohl S, Moore AT, Wiseman RL, Carroll J, and Lin JH
- Subjects
- Adolescent, Female, HEK293 Cells, Humans, Male, Activating Transcription Factor 6 genetics, Alleles, Base Sequence, Color Vision Defects genetics, Exons, Sequence Deletion
- Abstract
Achromatopsia (ACHM) is an autosomal recessive disease that results in severe visual loss. Symptoms of ACHM include impaired visual acuity, nystagmus, and photoaversion starting from infancy; furthermore, ACHM is associated with bilateral foveal hypoplasia and absent or severely reduced cone photoreceptor function on electroretinography. Here, we performed genetic sequencing in 3 patients from 2 families with ACHM, identifying and functionally characterizing 2 mutations in the activating transcription factor 6 (ATF6) gene. We identified a homozygous deletion covering exons 8-14 of the ATF6 gene from 2 siblings from the same family. In another patient from a different family, we identified a heterozygous deletion covering exons 2 and 3 of the ATF6 gene found in trans with a previously identified ATF6 c.970C>T (p.Arg324Cys) ACHM disease allele. Recombinant ATF6 proteins bearing these exon deletions showed markedly impaired transcriptional activity by qPCR and RNA-Seq analysis compared with WT-ATF6. Finally, RNAscope revealed that ATF6 and the related ATF6B transcripts were expressed in cones as well as in all retinal layers in normal human retina. Overall, our data identify loss-of-function ATF6 disease alleles that cause human foveal disease.
- Published
- 2020
- Full Text
- View/download PDF
27. PERK-mediated induction of microRNA-483 disrupts cellular ATP homeostasis during the unfolded protein response.
- Author
-
Hiramatsu N, Chiang K, Aivati C, Rodvold JJ, Lee JM, Han J, Chea L, Zanetti M, Koo EH, and Lin JH
- Subjects
- Activating Transcription Factor 4 genetics, Activating Transcription Factor 4 metabolism, Apoptosis, Creatine Kinase, BB Form genetics, Creatine Kinase, BB Form metabolism, HEK293 Cells, HeLa Cells, Homeostasis, Humans, MicroRNAs genetics, eIF-2 Kinase genetics, Adenosine Triphosphate metabolism, MicroRNAs metabolism, Unfolded Protein Response, eIF-2 Kinase metabolism
- Abstract
Endoplasmic reticulum (ER) stress activates the unfolded protein response (UPR), which reduces levels of misfolded proteins. However, if ER homeostasis is not restored and the UPR remains chronically activated, cells undergo apoptosis. The UPR regulator, PKR-like endoplasmic reticulum kinase (PERK), plays an important role in promoting cell death when persistently activated; however, the underlying mechanisms are poorly understood. Here, we profiled the microRNA (miRNA) transcriptome in human cells exposed to ER stress and identified miRNAs that are selectively induced by PERK signaling. We found that expression of a PERK-induced miRNA, miR-483, promotes apoptosis in human cells. miR-483 induction was mediated by a transcription factor downstream of PERK, activating transcription factor 4 (ATF4), but not by the CHOP transcription factor. We identified the creatine kinase brain-type ( CKB ) gene, encoding an enzyme that maintains cellular ATP reserves through phosphocreatine production, as being repressed during the UPR and targeted by miR-483. We found that ER stress, selective PERK activation, and CKB knockdown all decrease cellular ATP levels, leading to increased vulnerability to ER stress-induced cell death. Our findings identify miR-483 as a downstream target of the PERK branch of the UPR. We propose that disruption of cellular ATP homeostasis through miR-483-mediated CKB silencing promotes ER stress-induced apoptosis.
- Published
- 2020
- Full Text
- View/download PDF
28. Pathomechanisms of ATF6-Associated Cone Photoreceptor Diseases.
- Author
-
Chiang WJ, Kroeger H, Chea L, and Lin JH
- Subjects
- Endoplasmic Reticulum Stress, Golgi Apparatus, Humans, Mutation, Protein Folding, Activating Transcription Factor 6 metabolism, Retinal Cone Photoreceptor Cells pathology, Signal Transduction
- Abstract
Activating transcription factor 6 (ATF6) is a key regulator of the unfolded protein response (UPR). In response to endoplasmic reticulum (ER) stress, ATF6 is transported from the ER to the Golgi apparatus where it is cleaved by intramembrane proteolysis, releasing its cytosolic fragment. The cleaved ATF6 fragment, which is a basic leucine zipper (bZip) transcription factor, translocates to the nucleus and upregulates the expression of ER protein-folding chaperones and enzymes. Mutations in ATF6 cause heritable forms of cone photoreceptor dysfunction diseases. These mutations include missense, nonsense, splice site, and deletion or duplication changes found across the entire ATF6. To date, there are 11 ATF6 mutations reported, and we classified them into three classes based on their functional defects that interrupt distinct steps in the ATF6 signaling pathway.
- Published
- 2019
- Full Text
- View/download PDF
29. Management of chronic strongyloidiasis in immigrants and refugees: is serologic testing useful?
- Author
-
Biggs BA, Caruana S, Mihrshahi S, Jolley D, Leydon J, Chea L, and Nuon S
- Subjects
- Adolescent, Adult, Aged, Australia, Cambodia ethnology, Chronic Disease, Enzyme-Linked Immunosorbent Assay, Female, Humans, Male, Middle Aged, Strongyloidiasis blood, Strongyloidiasis ethnology, Strongyloidiasis immunology, Treatment Outcome, Young Adult, Anthelmintics therapeutic use, Antibodies, Helminth blood, Emigrants and Immigrants, Ivermectin therapeutic use, Refugees, Strongyloidiasis drug therapy
- Abstract
We assessed the usefulness of serologic testing in monitoring strongyloidiasis in immigrants after treatment with two doses of ivermectin. An observational study was conducted in a group of Cambodian immigrants residing in Melbourne who were treated for strongyloidiasis and followed-up in a general practice setting. Two doses of ivermectin (200 microg/kg) were administered orally. Periodic serologic enzyme-linked immunosorbent assay testing was undertaken for up to 30 months after treatment. Antibody titers for Strongyloides sp. decreased in 95% (38 of 40) of the patients, 47.5% (19 of 40) had a decrease in optical density to less than 0.5, and 65% (26 of 40) reached levels consistent with a cure during the follow-up period. Serologic testing for Strongyloides sp. is a useful tool for monitoring a decrease in antibody levels after effective treatment. This testing should be carried out 6-12 months after treatment to ensure a sustained downward trend suggestive of cure.
- Published
- 2009
30. Undiagnosed and potentially lethal parasite infections among immigrants and refugees in Australia.
- Author
-
Caruana SR, Kelly HA, Ngeow JY, Ryan NJ, Bennett CM, Chea L, Nuon S, Bak N, Skull SA, and Biggs BA
- Subjects
- Adolescent, Adult, Africa, Eastern ethnology, Aged, Aged, 80 and over, Animals, Antibodies, Protozoan blood, Cambodia ethnology, Cross-Sectional Studies, Feces parasitology, Female, Humans, Intestinal Diseases, Parasitic blood, Intestinal Diseases, Parasitic ethnology, Intestinal Diseases, Parasitic etiology, Intestinal Diseases, Parasitic parasitology, Male, Middle Aged, Schistosoma immunology, Schistosoma isolation & purification, Schistosomiasis blood, Schistosomiasis epidemiology, Schistosomiasis ethnology, Schistosomiasis etiology, Schistosomiasis parasitology, Strongyloides stercoralis immunology, Strongyloides stercoralis isolation & purification, Strongyloidiasis blood, Strongyloidiasis epidemiology, Strongyloidiasis ethnology, Strongyloidiasis etiology, Strongyloidiasis parasitology, Victoria epidemiology, Emigration and Immigration, Intestinal Diseases, Parasitic epidemiology
- Abstract
Intestinal parasite infections are a major cause of ill health in many resource-poor countries. This study compares the types and rates of these infections and their risk factors in recently arrived and long-term immigrants in Australia. Cross-sectional surveys of 127 East African and 234 Cambodian immigrants and refugees were undertaken in 2000 and 2002, respectively, to assess the burden of intestinal parasites and collect demographic information. Serum samples were assessed for eosinophilia and Strongyloides stercoralis and Schistosoma antibodies, and feces examined for ova, cysts, and parasites. Intestinal parasites were identified in 77/117 fecal samples from East African and in 25/204 samples collected from Cambodian participants. Eleven percent (14/124) of East Africans and 42% (97/230) of Cambodians had positive or equivocal serology for S stercoralis. Schistosoma serology was positive or equivocal in 15% (19/124) of East African participants. Potentially serious intestinal parasite infections are common among recent and longer term immigrants despite multiple visits to health care providers. Immigrants and refugees from high-risk countries would benefit from comprehensive health checks soon after resettlement.
- Published
- 2006
- Full Text
- View/download PDF
31. Knowledge about hepatitis and previous exposure to hepatitis viruses in immigrants and refugees from the Mekong Region.
- Author
-
Caruana SR, Kelly HA, De Silva SL, Chea L, Nuon S, Saykao P, Bak N, and Biggs BA
- Subjects
- Adolescent, Adult, Age Distribution, Aged, Aged, 80 and over, Analysis of Variance, Cross-Sectional Studies, Female, Health Surveys, Hepacivirus isolation & purification, Hepatitis B prevention & control, Hepatitis B virus isolation & purification, Hepatitis C prevention & control, Humans, Incidence, Logistic Models, Male, Middle Aged, Probability, Risk Assessment, Seroepidemiologic Studies, Sex Distribution, Statistics, Nonparametric, Victoria epidemiology, Emigration and Immigration, Health Knowledge, Attitudes, Practice, Hepatitis B epidemiology, Hepatitis C epidemiology, Refugees
- Abstract
Objective: Infection with hepatitis B (HBV) and hepatitis C (HCV) viruses is relatively common throughout South-East Asia and chronic infection can lead to severe consequences. This study assesses knowledge about HBV and HCV and estimates the seroprevalence of markers for these viruses in immigrants from Laos and Cambodia., Methods: Ninety-five Laotian (aged 18-82 years) and 234 Cambodian (15-92 years) immigrants participated in separate community-based surveys conducted during 1998 and 2002, respectively. Participants completed a questionnaire on health status and level of knowledge about viral hepatitis. Blood samples were collected and tested for the presence of HBV and HCV markers., Results: Nine per cent of Laotian and 8% of Cambodian participants were infected with HBV. While 49% of Laotian and 64% of Cambodian participants showed evidence of previous exposure to HBV, 30% and 9%, respectively, were vulnerable to infection. The seroprevalence of antibodies to HCV was 3% in the Laotian and 8% in the Cambodian participants. Between one-fifth and one-third of the Laotians and Cambodians who had heard of HBV and HCV knew of possible transmission routes for the viruses. Most of those with HBV or HCV infection were unaware they were infected., Conclusions: These findings indicate a significant prevalence of undetected HBV and HCV infections and an urgent need for the provision of culturally relevant information about viral hepatitis in immigrants of South-East Asian origin.
- Published
- 2005
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.