251 research outputs found

    Morphometric characterization of parasite Varroa sp. of bee Apis Mellifera L. in Benin

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    Open Access JournalVarroa sp. is one of the most important pests of world of bees A. mellifera Linnaeus (Hymenoptera: Apidae). The aim of this study is to analyze the morphological variability of Varroa so as to identify the different morphotypes of V. destructor. The study was conducted in 24 localities and 24 municipalities located in three regions (North-East, North-West and the Centre) of Benin. One to two hives were randomly selected per locality for collecting samples. In total 46 Varroa were examined in this study. Analysis of variance components was used to determine the share of the variability of morphological characteristics of V. destructor based on localities and climatic zones. Numerical classification was performed to group the populations of V. destructor based on morphological descriptors. The results show that the variability of morphological descriptors of V. destructor is usually larger at the community level than in climatic zones. In total four morphotypes of V. destructor are distinguished in Benin through the 4 variables used in the study

    Engineering the spatial confinement of exciton-polaritons in semiconductors

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    We demonstrate the spatial confinement of electronic excitations in a solid state system, within novel artificial structures that can be designed having arbitrary dimensionality and shape. The excitations under study are exciton-polaritons in a planar semiconductor microcavity. They are confined within a micron-sized region through lateral trapping of their photon component. Striking signatures of confined states of lower and upper polaritons are found in angle-resolved light emission spectra, where a discrete energy spectrum and broad angular patterns are present. A theoretical model supports unambiguously our observations

    Foxh1/Nodal Defines Context-Specific Direct Maternal Wnt/β-Catenin Target Gene Regulation in Early Development

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    We thank Jessica Cheung (UC Irvine) and Yvonne Turnbull (University of Aberdeen) for technical and management support; Gert Jan Veenstra (Radboud University, Nijmegen) for discussion; and Adam Lynch and Victor Velecela (University of Aberdeen), for comments on the manuscript. We also thank Professor Masanori Taira (University of Tokyo, currently Chuo University) and Dr Norihiro Sudou (Nara Institute of Science and Technology, currently Tokyo Women's Medical University) for the siamois antibody; and Professor Dan Kessler (University of Pennsylvania) for siamois constructs. This research was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) in the United Kingdom (BB/M001695/1) and by NIH in the United States (NIH GM126395). SH additionally acknowledges personal funding support as a Royal Society/Leverhulme Trust Senior Research Fellow (SRF\R1\191017).Peer reviewedPublisher PD

    Herbage accumulation, nutritive value, and organic reserves of continuously stocked 'Ipyporã' and 'Mulato II' Brachiariagrasses.

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    Although Brachiaria spp. grasses are important components of sustainable forage?livestock systems in the Amazon biome, cultivar diversification is needed to reduce risk from pests and diseases. Brachiaria hybrid ?BRS RB331 Ipyporã? [B. ruziziensis Germ. & Evrard ´ B. brizantha (Hochst. ex A. Rich.) Stapf] was released in 2017 as an alternative for intensively managed forage?livestock systems. Our objective was to compare herbage accumulation (HA), nutritive value, and organic reserves of Ipyporã and standard hybrid ?Mulato II? (B. ruziziensis ´ B. brizantha ´ B. decumbens Stapf) under continuous stocking during 2 yr in the Amazon biome. Treatments were the two cultivars replicated four times in a randomized complete block design, and each experimental unit was 1.5 ha. Pastures of Mulato II presented 15% greater HA than Ipyporã (17,360 vs. 14,930 kg dry matter ha−1 yr−1) across the 2 yr, and Mulato II leaf mass was greater than Ipyporã (1440 vs. 1900 kg dry matter ha−1) in the dry season. Both cultivars had greater herbage mass, HA, and herbage bulk density during the rainy season of 2016?2017 compared with 2017?2018 due to a shorter period of water deficit (30 d) and greater rainfall (2147 vs. 1762 mm) in the first than second year. Mulato II herbage crude protein was 10 g kg−1 greater than Ipyporã. In this severe risk region for spittlebug, Mulato II required spittlebug monitoring and control due to occurrence of foliar damage. Although Ipyporã had lesser HA, no spittlebug damage was evident. Thus, Ipyporã is an attractive alternative for diversification of forage-based livestock systems in the Amazon biome

    Observation of bright polariton solitons in a semiconductor microcavity

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    Microcavity polaritons are composite half-light half-matter quasi-particles, which have recently been demonstrated to exhibit rich physical properties, such as non-equilibrium Bose-Einstein condensation, parametric scattering and superfluidity. At the same time, polaritons have some important advantages over photons for information processing applications, since their excitonic component leads to weaker diffraction and stronger inter-particle interactions, implying, respectively, tighter localization and lower powers for nonlinear functionality. Here we present the first experimental observations of bright polariton solitons in a strongly coupled semiconductor microcavity. The polariton solitons are shown to be non-diffracting high density wavepackets, that are strongly localised in real space with a corresponding broad spectrum in momentum space. Unlike solitons known in other matter-wave systems such as Bose condensed ultracold atomic gases, they are non-equilibrium and rely on a balance between losses and external pumping. Microcavity polariton solitons are excited on picosecond timescales, and thus have significant benefits for ultrafast switching and transfer of information over their light only counterparts, semiconductor cavity lasers (VCSELs), which have only nanosecond response time

    A semantic interoperability approach to support integration of gene expression and clinical data in breast cancer

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    [Abstract] Introduction. The introduction of omics data and advances in technologies involved in clinical treatment has led to a broad range of approaches to represent clinical information. Within this context, patient stratification across health institutions due to omic profiling presents a complex scenario to carry out multi-center clinical trials. Methods. This paper presents a standards-based approach to ensure semantic integration required to facilitate the analysis of clinico-genomic clinical trials. To ensure interoperability across different institutions, we have developed a Semantic Interoperability Layer (SIL) to facilitate homogeneous access to clinical and genetic information, based on different well-established biomedical standards and following International Health (IHE) recommendations. Results. The SIL has shown suitability for integrating biomedical knowledge and technologies to match the latest clinical advances in healthcare and the use of genomic information. This genomic data integration in the SIL has been tested with a diagnostic classifier tool that takes advantage of harmonized multi-center clinico-genomic data for training statistical predictive models. Conclusions. The SIL has been adopted in national and international research initiatives, such as the EURECA-EU research project and the CIMED collaborative Spanish project, where the proposed solution has been applied and evaluated by clinical experts focused on clinico-genomic studies.Instituto de Salud Carlos III, PI13/02020Instituto de Salud Carlos III, PI13/0028

    Sox17 and ß-catenin co-occupy Wnt-responsive enhancers to govern the endoderm gene regulatory network

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Mukherjee, S., Chaturvedi, P., Rankin, S. A., Fish, M. B., Wlizla, M., Paraiso, K. D., MacDonald, M., Chen, X., Weirauch, M. T., Blitz, I. L., Cho, K. W. Y., & Zorn, A. M. Sox17 and ß-catenin co-occupy Wnt-responsive enhancers to govern the endoderm gene regulatory network. Elife, 9, (2020): e58029, doi:10.7554/eLife.58029.Lineage specification is governed by gene regulatory networks (GRNs) that integrate the activity of signaling effectors and transcription factors (TFs) on enhancers. Sox17 is a key transcriptional regulator of definitive endoderm development, and yet, its genomic targets remain largely uncharacterized. Here, using genomic approaches and epistasis experiments, we define the Sox17-governed endoderm GRN in Xenopus gastrulae. We show that Sox17 functionally interacts with the canonical Wnt pathway to specify and pattern the endoderm while repressing alternative mesectoderm fates. Sox17 and β-catenin co-occupy hundreds of key enhancers. In some cases, Sox17 and β-catenin synergistically activate transcription apparently independent of Tcfs, whereas on other enhancers, Sox17 represses β-catenin/Tcf-mediated transcription to spatially restrict gene expression domains. Our findings establish Sox17 as a tissue-specific modifier of Wnt responses and point to a novel paradigm where genomic specificity of Wnt/β-catenin transcription is determined through functional interactions between lineage-specific Sox TFs and β-catenin/Tcf transcriptional complexes. Given the ubiquitous nature of Sox TFs and Wnt signaling, this mechanism has important implications across a diverse range of developmental and disease contexts.Eunice Kennedy Shriver National Institute of Child Health and Human Development (HD073179) Ken WY Cho Aaron M Zorn National Institute of Diabetes and Digestive and Kidney Diseases (P30DK078392) Aaron M Zorn Eunice Kennedy Shriver National Institute of Child Health and Human Development (P01HD093363) Aaron M Zor

    Reversing Melanoma Cross-Resistance to BRAF and MEK Inhibitors by Co-Targeting the AKT/mTOR Pathway

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    The sustained clinical activity of the BRAF inhibitor vemurafenib (PLX4032/RG7204) in patients with BRAF(V600) mutant melanoma is limited primarily by the development of acquired resistance leading to tumor progression. Clinical trials are in progress using MEK inhibitors following disease progression in patients receiving BRAF inhibitors. However, the PI3K/AKT pathway can also induce resistance to the inhibitors of MAPK pathway.The sensitivity to vemurafenib or the MEK inhibitor AZD6244 was tested in sensitive and resistant human melanoma cell lines exploring differences in activation-associated phosphorylation levels of major signaling molecules, leading to the testing of co-inhibition of the AKT/mTOR pathway genetically and pharmacologically. There was a high degree of cross-resistance to vemurafenib and AZD6244, except in two vemurafenib-resistant cell lines that acquired a secondary mutation in NRAS. In other cell lines, acquired resistance to both drugs was associated with persistence or increase in activity of AKT pathway. siRNA-mediated gene silencing and combination therapy with an AKT inhibitor or rapamycin partially or completely reversed the resistance.Primary and acquired resistance to vemurafenib in these in vitro models results in frequent cross resistance to MEK inhibitors, except when the resistance is the result of a secondary NRAS mutation. Resistance to BRAF or MEK inhibitors is associated with the induction or persistence of activity within the AKT pathway in the presence of these drugs. This resistance can be potentially reversed by the combination of a RAF or MEK inhibitor with an AKT or mTOR inhibitor. These combinations should be available for clinical testing in patients progressing on BRAF inhibitors

    A multicenter prospective trial evaluating fetal bovine dermal graft (Xenform® Matrix) for pelvic reconstructive surgery

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    <p>Abstract</p> <p>Background</p> <p>A prospective multicenter clinical study was performed to evaluate the safety and efficacy of a bovine dermal graft (Xenform<sup>® </sup>Matrix, Boston Scientific, Natick, MA, USA) during vaginal reconstructive surgery.</p> <p>Methods</p> <p>Forty-five women with ICS stage 2 or higher pelvic organ prolapse (POP) were enrolled at 4 centers. POP-Q, pelvic floor function (PFDI-20), sexual function (PISQ-12), and patient satisfaction tools were used to assess subjects at baseline, and at 2 and 6 weeks, and 3, 6 and 12 months post surgery. The significance of symptom score changes at 6 months and 1 year were determined by the t-test for paired data. Forty-three of the 45 patients completed the 12 month study.</p> <p>Results</p> <p>The majority of the subjects had cystocele (98%) and/or rectocele (84%) defects at study entry. At 12 months, 74% of the defects had improved to a stage 0 or 1. Mean PFDI-20 scores improved by 72% (p < 0.001) at 12 months, and PISQ-12 scores were maintained during the follow-up period indicating no decline in sexual function. Three subjects experienced one serious adverse event each; one of the adverse events (constipation) was deemed by the study physician to be unrelated to Xenform<sup>®</sup>. One subject had severe pyelonephritis resulting in dialysis. This subject had a previous history of pyelonephritis, sepsis and acute renal failure. The third subject had a reported recurrent cystocele of moderate severity, possibly related to the device. No graft related erosions or pain lasting more than 30 days were reported. No subjects withdrew due to an adverse event.</p> <p>Conclusion</p> <p>This study is the first to investigate the use of Xenform<sup>® </sup>Matrix in vaginal reconstructive surgery among patients with POP. Significant improvement was maintained at 12 months utilizing both objective and subjective assessment tools, confirming the safety and efficacy of this material in vaginal surgery.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov NCT01244165</p
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