65 research outputs found

    The amyloid precursor protein of Alzheimer’s disease clusters at the organelle/microtubule interface on organelles that bind microtubules in an ATP dependent manner

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    © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 11 (2016): e0147808, doi:10.1371/journal.pone.0147808.The amyloid precursor protein (APP) is a causal agent in the pathogenesis of Alzheimer’s disease and is a transmembrane protein that associates with membrane-limited organelles. APP has been shown to co-purify through immunoprecipitation with a kinesin light chain suggesting that APP may act as a trailer hitch linking kinesin to its intercellular cargo, however this hypothesis has been challenged. Previously, we identified an mRNA transcript that encodes a squid homolog of human APP770. The human and squid isoforms share 60% sequence identity and 76% sequence similarity within the cytoplasmic domain and share 15 of the final 19 amino acids at the C-terminus establishing this highly conserved domain as a functionally import segment of the APP molecule. Here, we study the distribution of squid APP in extruded axoplasm as well as in a well-characterized reconstituted organelle/microtubule preparation from the squid giant axon in which organelles bind microtubules and move towards the microtubule plus-ends. We find that APP associates with microtubules by confocal microscopy and co-purifies with KI-washed axoplasmic organelles by sucrose density gradient fractionation. By electron microscopy, APP clusters at a single focal point on the surfaces of organelles and localizes to the organelle/microtubule interface. In addition, the association of APP-organelles with microtubules is an ATP dependent process suggesting that the APP-organelles contain a microtubule-based motor protein. Although a direct kinesin/APP association remains controversial, the distribution of APP at the organelle/microtubule interface strongly suggests that APP-organelles have an orientation and that APP like the Alzheimer’s protein tau has a microtubule-based function.Research reported in this publication was supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103430

    Global Assessment of the SMAP Level-4 Surface and Root-Zone Soil Moisture Product Using Assimilation Diagnostics

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    The Soil Moisture Active Passive (SMAP) mission Level-4 Soil Moisture (L4_SM) product provides 3-hourly, 9-km resolution, global estimates of surface (0-5 cm) and root-zone (0-100 cm) soil moisture and related land surface variables from 31 March 2015 to present with ~2.5-day latency. The ensemble-based L4_SM algorithm assimilates SMAP brightness temperature (Tb) observations into the Catchment land surface model. This study describes the spatially distributed L4_SM analysis and assesses the observation-minus-forecast (O-F) Tb residuals and the soil moisture and temperature analysis increments. Owing to the climatological rescaling of the Tb observations prior to assimilation, the analysis is essentially unbiased, with global mean values of ~0.37 K for the O-F Tb residuals and practically zero for the soil moisture and temperature increments. There are, however, modest regional (absolute) biases in the O-F residuals (under ~3 K), the soil moisture increments (under ~0.01 cu.m/cu.m), and the surface soil temperature increments (under ~1 K). Typical instantaneous values are ~6 K for O-F residuals, ~0.01 (~0.003) cu.m/cu.m for surface (root-zone) soil moisture increments, and ~0.6 K for surface soil temperature increments. The O-F diagnostics indicate that the actual errors in the system are overestimated in deserts and densely vegetated regions and underestimated in agricultural regions and transition zones between dry and wet climates. The O-F auto-correlations suggest that the SMAP observations are used efficiently in western North America, the Sahel, and Australia, but not in many forested regions and the high northern latitudes. A case study in Australia demonstrates that assimilating SMAP observations successfully corrects short-term errors in the L4_SM rainfall forcing

    Does Consideration and Assessment of Effects on Health Equity Affect the Conclusions of Systematic Reviews? A Methodology Study

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    INTRODUCTION: Tackling health inequities both within and between countries remains high on the agenda of international organizations including the World Health Organization and local, regional and national governments. Systematic reviews can be a useful tool to assess effects on equity in health status because they include studies conducted in a variety of settings and populations. This study aims to describe the extent to which the impacts of health interventions on equity in health status are considered in systematic reviews, describe methods used, and assess the implications of their equity related findings for policy, practice and research. METHODS: We conducted a methodology study of equity assessment in systematic reviews. Two independent reviewers extracted information on the reporting and analysis of impacts of health interventions on equity in health status in a group of 300 systematic reviews collected from all systematic reviews indexed in one month of MEDLINE, using a pre-tested data collection form. Any differences in data extraction were resolved by discussion. RESULTS: Of the 300 systematic reviews, 224 assessed the effectiveness of interventions on health outcomes. Of these 224 reviews, 29 systematic reviews assessed effects on equity in health status using subgroup analysis or targeted analyses of vulnerable populations. Of these, seven conducted subgroup analyses related to health equity which were reported in insufficient detail to judge their credibility. Of these 29 reviews, 18 described implications for policy and practice based on assessment of effects on health equity. CONCLUSION: The quality and completeness of reporting should be enhanced as a priority, because without this policymakers and practitioners will continue lack the evidence base they need to inform decision-making about health inequity. Furthermore, there is a need to develop methods to systematically consider impacts on equity in health status that is currently lacking in systematic reviews

    The mechanics of housing collectivism: How forms and functions affect affordability

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    In countries worldwide, limited access to affordable housing is fuelling interest in collectivist solutions. Different organizational models are being developed to enable groups of people to own and control housing collectively. The benefits of such models have been widely promoted, not least in terms of delivering enhanced housing affordability for residents. However, evidence to support such claims is scarce and it remains unclear whether affordability is the product of collective forms and functions, or some other factor(s). To address this gap in knowledge, the paper presents findings from three case studies of English and Canadian housing collectives. Applying realist theories of causation, the processes affecting housing affordability are explained, conceptualizing two causal mechanisms which depict how organizational form, internal rules and regulatory activity, along with the unique role of the resident-owner, influence the setting of rents and prices. Further research is required to understand the prevalence of these mechanisms and their general application

    Towards an appreciation of ethics in social enterprise business models

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    How can a critical analysis of entrepreneurial intention inform an appreciation of ethics in social enterprise business models? In answering this question, we consider the ethical commitments that inform entrepreneurial action (inputs) and the hybrid organisations that emerge out of these commitments and actions (outputs). Ethical theory can be a useful way to re-orient the field of social enterprise so that it is more critical of bureaucratic (charitable) and market-driven (business) enterprises connected to neo-liberal doctrine. Social enterprise hybrid business models are therefore reframed as outcomes of both ethical and entrepreneurial intentions. We challenge the dominant conceptualisation of social enterprise as a hybrid blend of mission and market (purpose-versus-resource) by reframing hybridity in terms of the moral choice of economic system (redistribution, reciprocity and market) and social value orientation (personal, mutual or public benefit). We deconstruct the political foundations of charitable trading activities (CTAs), co-operative and mutual enterprises (CMEs) and socially responsible businesses (SRBs) by examining the rationalities (formal, social and substantive) and ethical commitments (utilitarian, communitarian, pragmatic) that underpin them. Whilst conceptual modelling of social enterprise is not new, this paper contributes to knowledge by developing a theory of social enterprise ethics based on the moral/political choices that are made by entrepreneurs (knowingly and unknowingly) when choosing between systems of economic exchange and social value orientation, then expressing it through a legal form

    Pharmacist-led hypertension drug use review

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    Agronomy and soils: Genetic variation for waterlogging tolerance in cotton

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    In Australia, periodic waterlogging throughout the cotton growing season can cause production losses of up to 10%. There is limited information on the genetic variation in cotton for waterlogging tolerance. The aim of this study was to identify methods to evaluate physiological responses under waterlogging conditions that may lead to identifying waterlogging tolerant and sensitive cotton cultivars. A field experiment was conducted in Narrabri, north-western New South Wales using thirteen upland cotton (Gossypium hirsutum L.) cultivars (Georgia King, McNair 1032, PD93057, LA 887, Codetec 401, DP 16, DP 90, Coker 315, CIM 443, Gohar 87, Sicot 71, Sicot 73 and Sicot 80) and one Gossypium barbadense cultivar (Pima A-8) originating from diverse environmental regions. Parameters measured to assess response to waterlogging included: SPAD (leaf colour) readings, leaf nutritional status, leaf photosynthetic rate, plant and root morphology, and final yield. Leaf SPAD readings, nitrogen and potassium concentrations were reduced in waterlogged treatments compared to the respective controls, and varied with cultivar. Leaf phosphorus, calcium, magnesium, manganese and sulphur concentrations were reduced in the waterlogged treatment compared to the respective controls in all cultivars. Waterlogging increased leaf total iron concentration in all cultivars. No aerenchyma on cotton roots were observed in this study. Leaf SPAD readings, nitrogen and potassium concentrations suggested that the most waterlogging tolerant cultivars were Gohar 87, Pima A-8, Sicot 71, Sicot 73 and Sicot 80 which originate from production on heavy clays, and the most susceptible were Georgia King, LA 887, DP 16, DP 90 and CIM 443 which originate from production on lighter texture soils. This study helped to target those measurements that may be of most use to screen for waterlogging tolerance.9 page(s

    Can heat stress and water deficit affect cotton fiber wax content in field-grown plants?

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    Climate modelling predicts a warmer climate for cotton growing regions in the future. This will impose stresses on cotton plants that may impact on cotton fiber cuticle wax levels, and in turn may make cotton textile products more challenging to scour and dye. While previous research has measured the effect of abiotic stress on cuticle wax in cotton leaves and bracts, no research is known to have been undertaken specifically measuring the impact of abiotic stress on cotton fiber wax content. Five Upland (Gossypium hirsutum L.) cotton genotypes with known different tolerances to abiotic stress, were subjected over two growing seasons, to heat stress and or water deficit during the period when fiber cuticle wax deposition occurred. Total ethanol soluble wax content was determined in mature fiber using a standard protocol. Across all genotypes and treatments, fiber wax content varied between 0.2 and 1.6 %. For Sicot 71, a standard Australian commercial genotype, and for Siokra L23 and CIM-448 two genotypes known to be tolerant to abiotic stress, fiber wax content was either unaffected or decreased following the application of abiotic stress. For CS 50, a genotype with a poor tolerance to water deficit stress, fiber wax content increased following abiotic stress. For Sicala V-2, a genotype with less tolerance to abiotic stress, fiber wax content decreased following either heat stress or water deficit treatments alone, while wax content markedly increased following the combined application of both stress treatments. The genotypic variations observed in fiber wax content and the differences in the direction of the response to stresses suggest that conventional breeding could be used to generate new genotypes with acceptable fiber wax levels adapted to future extreme climates

    HairNet2: deep learning to quantify cotton leaf hairiness, a complex genetic and environmental trait

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    Abstract Background Cotton accounts for 80% of the global natural fibre production. Its leaf hairiness affects insect resistance, fibre yield, and economic value. However, this phenotype is still qualitatively assessed by visually attributing a Genotype Hairiness Score (GHS) to a leaf/plant, or by using the HairNet deep-learning model which also outputs a GHS. Here, we introduce HairNet2, a quantitative deep-learning model which detects leaf hairs (trichomes) from images and outputs a segmentation mask and a Leaf Trichome Score (LTS). Results Trichomes of 1250 images were annotated (AnnCoT) and a combination of six Feature Extractor modules and five Segmentation modules were tested alongside a range of loss functions and data augmentation techniques. HairNet2 was further validated on the dataset used to build HairNet (CotLeaf-1), a similar dataset collected in two subsequent seasons (CotLeaf-2), and a dataset collected on two genetically diverse populations (CotLeaf-X). The main findings of this study are that (1) leaf number, environment and image position did not significantly affect results, (2) although GHS and LTS mostly correlated for individual GHS classes, results at the genotype level revealed a strong LTS heterogeneity within a given GHS class, (3) LTS correlated strongly with expert scoring of individual images. Conclusions HairNet2 is the first quantitative and scalable deep-learning model able to measure leaf hairiness. Results obtained with HairNet2 concur with the qualitative values used by breeders at both extremes of the scale (GHS 1-2, and 5-5+), but interestingly suggest a reordering of genotypes with intermediate values (GHS 3-4+). Finely ranking mild phenotypes is a difficult task for humans. In addition to providing assistance with this task, HairNet2 opens the door to selecting plants with specific leaf hairiness characteristics which may be associated with other beneficial traits to deliver better varieties

    SDS-PAGE and immunoblot analysis of sucrose density gradient axoplasmic fractionations.

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    Total squid axoplasm was treated with 600 mM KI and centrifuged over a three-step sucrose density gradient. The resulting supernatant and organelle fractions were used for Coomassie stained gels (Coom, S, and O) and immunoblots (Blot, S, and O) probed with a C-terminal anti-APP polyclonal antibody (see materials and methods) and detected through chemiluminescence. Dashes indicate molecular weight markers: 250, 150, 100, 75, 50, 37 kDa.</p
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