67 research outputs found

    Developmental white matter microstructure in autism phenotype and corresponding endophenotype during adolescence.

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    During adolescence, white matter microstructure undergoes an important stage of development. It is hypothesized that the alterations of brain connectivity that have a key role in autism spectrum conditions (ASCs) may interact with the development of white matter microstructure. This interaction may be present beyond the phenotype of autism in siblings of individuals with ASC, who are 10 to 20 times more likely to develop certain forms of ASC. We use diffusion tensor imaging to examine how white matter microstructure measurements correlate with age in typically developing individuals, and how this correlation differs in n=43 adolescents with ASC and their n=38 siblings. Correlations observed in n=40 typically developing individuals match developmental changes noted in previous longitudinal studies. In comparison, individuals with ASC display weaker negative correlation between age and mean diffusivity in a broad area centred in the right superior longitudinal fasciculus. These differences may be caused either by increased heterogeneity in ASC or by temporal alterations in the group's developmental pattern. Siblings of individuals with ASC also show diminished negative correlation between age and one component of mean diffusivity-second diffusion eigenvalue-in the right superior longitudinal fasciculus. As the observed differences match for location and correlation directionality in our comparison of typically developing individuals to those with ASC and their siblings, we propose that these alterations constitute a part of the endophenotype of autism.This research was funded by an MRC Clinician Scientist Fellowship to MDS from the UK Medical Research Council (G0701919). LRC was supported by the Gates Cambridge Scholarship Trust. SB-C was supported by the Wellcome Trust, the MRC and the Autism Research Trust, during the period of this work.This is the final published version. It first appeared at http://www.nature.com/tp/journal/v5/n3/full/tp201523a.html

    CDC light traps underestimate the protective efficacy of an indoor spatial repellent against bites from wild Anopheles arabiensis mosquitoes in Tanzania

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    BACKGROUND: Methods for evaluating efficacy of core malaria interventions in experimental and operational settings are well established but gaps exist for spatial repellents (SR). The objective of this study was to compare three different techniques: (1) collection of blood-fed mosquitoes (feeding), (2) human landing catch (HLC), and (3) CDC light trap (CDC-LT) collections for measuring the indoor protective efficacy (PE) of the volatile pyrethroid SR product Mosquito Shield() METHODS: The PE of Mosquito Shield() against a wild population of pyrethroid-resistant Anopheles arabiensis mosquitoes was determined via feeding, HLC, or CDC-LT using four simultaneous 3 by 3 Latin squares (LS) run using 12 experimental huts in Tanzania. On any given night each technique was assigned to two huts with control and two huts with treatment. The LS were run twice over 18 nights to give a sample size of 72 replicates for each technique. Data were analysed by negative binomial regression. RESULTS: The PE of Mosquito Shield() measured as feeding inhibition was 84% (95% confidence interval (CI) 58-94% [Incidence Rate Ratio (IRR) 0.16 (0.06-0.42), p < 0.001]; landing inhibition 77% [64-86%, (IRR 0.23 (0.14-0.36) p < 0.001]; and reduction in numbers collected by CDC-LT 30% (0-56%) [IRR 0.70 (0.44-1.0) p = 0.160]. Analysis of the agreement of the PE measured by each technique relative to HLC indicated no statistical difference in PE measured by feeding inhibition and landing inhibition [IRR 0.73 (0.25-2.12) p = 0.568], but a significant difference in PE measured by CDC-LT and landing inhibition [IRR 3.13 (1.57-6.26) p = 0.001]. CONCLUSION: HLC gave a similar estimate of PE of Mosquito Shield() against An. arabiensis mosquitoes when compared to measuring blood-feeding directly, while CDC-LT underestimated PE relative to the other techniques. The results of this study indicate that CDC-LT could not effectively estimate PE of the indoor spatial repellent in this setting. It is critical to first evaluate the use of CDC-LT (and other tools) in local settings prior to their use in entomological studies when evaluating the impact of indoor SR to ensure that they reflect the true PE of the intervention

    Spatio-temporal variability of droughts in Bolivia: 1955-2012

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    In this study, the spatio-temporal variability and trends of droughts across Bolivia between 1955 and 2012 were investigated using two climate drought indices: the Standardized Precipitation Index (SPI), which is based on precipitation data, and the Standardized Precipitation Evapotranspiration Index (SPEI), which is based on the difference between the precipitation and the reference evapotranspiration (ETo). We found that the average drought conditions across the country showed a temporal behaviour mainly characterized by decadal variations. The spatial pattern of drought evolution showed marked differences between the Amazonian region and the Bolivian Altiplano. Both regions showed different drought periods, a lower frequency of drought variability in the Amazon region and trends towards drier conditions in the Altiplano, mainly due to a higher atmospheric water demand as a consequence of increased ETo. We also showed that inclusion of ETo, obtained from maximum and minimum temperature records, increased the spatial heterogeneity of the drought evolution in relation to the evolution observed when only precipitation droughts were considered. The SPEI, the calculation of which includes precipitation and ETo, indicated intensification in drought severity in the last years analysed relative to the pattern found when precipitation droughts alone were considered, and also indicated an increase in the magnitude and duration of drought events. The potential for increasing drought conditions under various climate change scenarios is discussed. © 2015 Royal Meteorological Society.This work has been supported by research projects I-COOP H2O 2013CD0006: ‘Test multisectorial y actividades demostrativa sobre el potencial desarrollo de sistemas de monitorización de sequías en tiempo real en la región del oeste de Sudamérica’ financed by the Spanish National Research Council (CSIC), CGL2011-27574-CO2-02 financed by the Spanish Commission of Science and Technology and FEDER, ‘Demonstration and validation of innovative methodology for regional climate change adaptation in the Mediterranean area (LIFE MEDACC)’ financed by the LIFE programme of the European Commission, C.A.-M. received a postdoctoral fellowship # JCI-2011-10263. A.S.-L. is supported by the ‘Secretaria per a Universitats i Recerca del Departament d'Economia i Coneixement, de la Generalitat de Catalunya i del programa Cofund de les Accions Marie Curie del 7è Programa marc d'R + D de la Unió Europea’ (2011 BP-B 00078) and the postdoctoral fellowship # JCI-2012-12508.Peer Reviewe

    Challenges in assessing exposure and vulnerability to natural hazards in large cities: the case study of Arequipa near the Misti volcano, south Peru

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    Assessing risk of potential natural catastrophes in cities remains challenging, in particular as we need to elaborate quantitative criteria for exposure and vulnerability. Statistical and probabilistic methods have been applied to Arequipa, one of the most vulnerable Latin America cities. The second largest city of Peru is highly exposed to natural hazards: earthquakes, eruptions from the historically active El Misti volcano, rain-triggered flash floods and mass flows together with landslides from the Río Chili canyon walls. First, we propose a long-term probabilistic multi-hazard assessment for the Misti composite cone located 17 km from Arequipa. Second, we examine criteria for delineating areas prone to mass flow hazards and characterizing multiple sources of vulnerability forthe city. Third, a statistical methodology to better estimate damage probability for buildings is proposed

    Quinoa Phenotyping Methodologies: An International Consensus

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    Quinoa is a crop originating in the Andes but grown more widely and with the genetic potential for significant further expansion. Due to the phenotypic plasticity of quinoa, varieties need to be assessed across years and multiple locations. To improve comparability among field trials across the globe and to facilitate collaborations, components of the trials need to be kept consistent, including the type and methods of data collected. Here, an internationally open-access framework for phenotyping a wide range of quinoa features is proposed to facilitate the systematic agronomic, physiological and genetic characterization of quinoa for crop adaptation and improvement. Mature plant phenotyping is a central aspect of this paper, including detailed descriptions and the provision of phenotyping cards to facilitate consistency in data collection. High-throughput methods for multi-temporal phenotyping based on remote sensing technologies are described. Tools for higher throughput post-harvest phenotyping of seeds are presented. A guideline for approaching quinoa field trials including the collection of environmental data and designing layouts with statistical robustness is suggested. To move towards developing resources for quinoa in line with major cereal crops, a database was created. The Quinoa Germinate Platform will serve as a central repository of data for quinoa researchers globally

    Mutations in DCC cause isolated agenesis of the corpus callosum with incomplete penetrance

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    Brain malformations involving the corpus callosum are common in children with developmental disabilities. We identified DCC mutations in four families and five sporadic individuals with isolated agenesis of the corpus callosum (ACC) without intellectual disability. DCC mutations result in variable dominant phenotypes with decreased penetrance, including mirror movements and ACC associated with a favorable developmental prognosis. Possible phenotypic modifiers include the type and location of mutation and the sex of the individual

    Enteric methane mitigation strategies for ruminant livestock systems in the Latin America and Caribbean region: a meta-analysis.

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    Latin America and Caribbean (LAC) is a developing region characterized for its importance for global food security, producing 23 and 11% of the global beef and milk production, respectively. The region?s ruminant livestock sector however, is under scrutiny on environmental grounds due to its large contribution to enteric methane (CH4) emissions and influence on global climate change. Thus, the identification of effective CH4 mitigation strategies which do not compromise animal performance is urgently needed, especially in context of the Sustainable Development Goals (SDG) defined in the Paris Agreement of the United Nations. Therefore, the objectives of the current study were to: 1) collate a database of individual sheep, beef and dairy cattle records from enteric CH4 emission studies conducted in the LAC region, and 2) perform a meta-analysis to identify feasible enteric CH4 mitigation strategies, which do not compromise animal performance. After outlier?s removal, 2745 animal records (65% of the original data) from 103 studies were retained (from 2011 to 2021) in the LAC database. Potential mitigation strategies were classified into three main categories (i.e., animal breeding, dietary, and rumen manipulation) and up to three subcategories, totaling 34 evaluated strategies. A random effects model weighted by inverse variance was used (Comprehensive Meta-Analysis V3.3.070). Six strategies decreased at least one enteric CH4 metric and simultaneously increased milk yield (MY; dairy cattle) or average daily gain (ADG; beef cattle and sheep). The breed composition F1 Holstein × Gyr decreased CH4 emission per MY (CH4IMilk) while increasing MY by 99%. Adequate strategies of grazing management under continuous and rotational stocking decreased CH4 emission per ADG (CH4IGain) by 22 and 35%, while increasing ADG by 22 and 71%, respectively. Increased dietary protein concentration, and increased concentrate level through cottonseed meal inclusion, decreased CH4IMilk and CH4IGain by 10 and 20% and increased MY and ADG by 12 and 31%, respectively. Lastly, increased feeding level decreased CH4IGain by 37%, while increasing ADG by 171%. The identified effective mitigation strategies can be adopted by livestock producers according to their specific needs and aid LAC countries in achieving SDG as defined in the Paris Agreement

    Exposure to lipid-rich follicular fluid is associated with endoplasmic reticulum stress and impaired oocyte maturation in cumulus-oocyte complexes

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    ObjectiveTo determine whether the high lipid content of human follicular fluid influences oocyte maturation.DesignMouse oocytes as substitutes for human oocytes were exposed to follicular fluids of differing lipid content with outcome monitoring.SettingPrivate infertility clinic and university laboratory.Patient(s)Seventy-four women seeking assisted reproduction, and gonadotropin-stimulated mice.Intervention(s)Assay of follicular fluids for triglyceride and free fatty acids, and stimulation of mouse cumulus-oocyte complexes (COCs) to maturity in vitro in the presence of lipid-rich or lipid-poor follicular fluid.Main outcome measure(s)Oocyte lipid content, expression of endoplasmic reticulum stress marker genes, and oocyte maturation assessed in mouse COCs exposed to lipid-rich follicular fluid were compared with complexes exposed to lipid-poor follicular fluid and complexes matured in vivo.Result(s)Follicular fluids were obtained from women of known body mass index undergoing oocyte aspiration at a private infertility clinic, and the follicular fluids were assayed for triglyceride and free fatty acids; those with the highest and lowest levels of these lipids were selected. The mouse COCs exposed to lipid-rich follicular fluid during their maturation had increased oocyte lipid content, induction of endoplasmic reticulum stress markers, and impaired oocyte nuclear maturation.Conclusion(s)Increased body mass index is associated with elevated triglycerides and free fatty acids in ovarian follicular fluid. Maturation within this lipid-rich environment is detrimental to oocytes.Xing Yang, Linda L. Wu, Lindsay R. Chura, Xiaoyan Liang, Michelle Lane, Robert J. Norman, and Rebecca L. Robke
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