70 research outputs found

    Mitotic Illegitimate Recombination Is a Mechanism for Novel Changes in High-Molecular-Weight Glutenin Subunits in Wheat-Rye Hybrids

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    Wide hybrids can have novel traits or changed expression of a quantitative trait that their parents do not have. These phenomena have long been noticed, yet the mechanisms are poorly understood. High-molecular-weight glutenin subunits (HMW-GS) are seed storage proteins encoded by Glu-1 genes that only express in endosperm in wheat and its related species. Novel HMW-GS compositions have been observed in their hybrids. This research elucidated the molecular mechanisms by investigating the causative factors of novel HMW-GS changes in wheat-rye hybrids. HMW-GS compositions in the endosperm and their coding sequences in the leaves of F1 and F2 hybrids between wheat landrace Shinchunaga and rye landrace Qinling were investigated. Missing and/or additional novel HMW-GSs were observed in the endosperm of 0.5% of the 2078 F1 and 22% of 36 F2 hybrid seeds. The wildtype Glu-1Ax null allele was found to have 42 types of short repeat sequences of 3-60 bp long that appeared 2 to 100 times. It also has an in-frame stop codon in the central repetitive region. Analyzing cloned allele sequences of HMW-GS coding gene Glu-1 revealed that deletions involving the in-frame stop codon had happened, resulting in novel ∼1.8-kb Glu-1Ax alleles in some F1 and F2 plants. The cloned mutant Glu-1Ax alleles were expressed in Escherichia coli, and the HMW-GSs produced matched the novel HMW-GSs found in the hybrids. The differential changes between the endosperm and the plant of the same hybrids and the data of E. coli expression of the cloned deletion alleles both suggested that mitotic illegitimate recombination between two copies of a short repeat sequence had resulted in the deletions and thus the changed HMW-GS compositions. Our experiments have provided the first direct evidence to show that mitotic illegitimate recombination is a mechanism that produces novel phenotypes in wide hybrids

    The use of mobile phone data for the estimation of the travel patterns and imported Plasmodium falciparum rates among Zanzibar residents

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    Background: malaria endemicity in Zanzibar has reached historically low levels, and the epidemiology of malaria transmission is in transition. To capitalize on these gains, Zanzibar has commissioned a feasibility assessment to help inform on whether to move to an elimination campaign. Declining local transmission has refocused attention on imported malaria. Recent studies have shown that anonimized mobile phone records provide a valuable data source for characterizing human movements without compromising the privacy of phone users. Such movement data in combination with spatial data on P. falciparum endemicity provide a way of characterizing the patterns of parasite carrier movements and the rates of malaria importation, which have been used as part of the malaria elimination feasibility assessment for the islands of Zanzibar. Data and methods: records encompassing three months of complete mobile phone usage for the period October-December 2008 were obtained from the Zanzibar Telecom (Zantel) mobile phone network company, the principal provider on the islands of Zanzibar. The data included the dates of all phone usage by 770,369 individual anonymous users. Each individual call and message was spatially referenced to one of six areas: Zanzibar and five mainland Tanzania regions. Information on the numbers of Zanzibar residents travelling to the mainland, locations visited and lengths of stay were extracted. Spatial and temporal data on P. falciparum transmission intensity and seasonality enabled linkage of this information to endemicity exposure and, motivated by malaria transmission models, estimates of the expected patterns of parasite importation to be made. Results: over the three month period studied, 88% of users made calls that were routed only through masts on Zanzibar, suggesting that no long distance travel was undertaken by this group. Of those who made calls routed through mainland masts the vast majority of trips were estimated to be of less than five days in length, and to the Dar Es Salaam Zantel-defined region. Though this region covered a wide range of transmission intensities, data on total infection numbers in Zanzibar combined with mathematical models enabled informed estimation of transmission exposure and imported infection numbers. These showed that the majority of trips made posed a relatively low risk for parasite importation, but risk groups visiting higher transmission regions for extended periods of time could be identified. Conclusion: anonymous mobile phone records provide valuable information on human movement patterns in areas that are typically data-sparse. Estimates of human movement patterns from Zanzibar to mainland Tanzania suggest that imported malaria risk from this group is heterogeneously distributed; a few people account for most of the risk for imported malaria. In combination with spatial data on malaria endemicity and transmission models, movement patterns derived from phone records can inform on the likely sources and rates of malaria importation. Such information is important for assessing the feasibility of malaria elimination and planning an elimination campaign

    Cardiomyocyte overexpression of miR-27b induces cardiac hypertrophy and dysfunction in mice

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    Recent studies have begun to reveal critical roles of microRNAs (miRNAs) in the pathogenesis of cardiac hypertrophy and dysfunction. In this study, we tested whether a transforming growth factor-β (TGF-β)-regulated miRNA played a pivotal role in the development of cardiac hypertrophy and heart failure (HF). We observed that miR-27b was upregulated in hearts of cardiomyocyte-specific Smad4 knockout mice, which developed cardiac hypertrophy. In vitro experiments showed that the miR-27b expression could be inhibited by TGF-β1 and that its overexpression promoted hypertrophic cell growth, while the miR-27b suppression led to inhibition of the hypertrophic cell growth caused by phenylephrine (PE) treatment. Furthermore, the analysis of transgenic mice with cardiomyocyte-specific overexpression of miR-27b revealed that miR-27b overexpression was sufficient to induce cardiac hypertrophy and dysfunction. We validated the peroxisome proliferator-activated receptor-γ (PPAR-γ) as a direct target of miR-27b in cardiomyocyte. Consistently, the miR-27b transgenic mice displayed significantly lower levels of PPAR-γ than the control mice. Furthermore, in vivo silencing of miR-27b using a specific antagomir in a pressure-overload-induced mouse model of HF increased cardiac PPAR-γ expression, attenuated cardiac hypertrophy and dysfunction. The results of our study demonstrate that TGF-β1-regulated miR-27b is involved in the regulation of cardiac hypertrophy, and validate miR-27b as an efficient therapeutic target for cardiac diseases

    COGAM: Measuring and Moderating Cognitive Load in Machine Learning Model Explanations

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    10.1145/3313831.3376615CHI '20: Proceedings of the 2020 CHI Conference on Human Factors in Computing System

    Travel patterns and imported plasmodium falciparum rates among Zanzibar residents

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    Records encompassing 3 months of complete mobile phone usage for the period October-December 2008 were obtained from the Zanzibar Telecom (Zantel) mobile phone network company, the principal provider on the islands of Zanzibar. The data included the dates of all phone usage by 770,369 individual anonymous users. Each individual call and message was spatially referenced to one of six areas: Zanzibar and fi ve mainland Tanzania regions. Information on the numbers of Zanzibar residents traveling to the mainland, locations visited and lengths of stay were extracted. Spatial and temporal data on P. falciparum transmission intensity and seasonality enabled linkage of this information to endemicity exposure and, motivated by malaria transmission models, estimates of the expected patterns of parasite importation to be made.</p
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