215 research outputs found

    Effects of transgenic maize expressing the Cry1Ab protein (event MON810) on locally adapted earthworms in a sandy loam soil in the Central Eastern Cape, South Africa

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    This field study investigated effects of growing Bacillus thuringiensis (Bt) maize (MON810) on local earthworms in the Central Eastern Cape, South Africa. Two Bt maize cultivars (DKC61-25B and PAN6Q-321B) and their near-isolines (DKC61-24 and PAN6777) were grown in the 2009/2010 and 2010/2011 summer seasons. Earthworms were sampled after six, nine and eighteen weeks in 2009/2010 and after six, twelve and twenty-one weeks in the 2010/2011 season. The four maize treatments had similar earthworm counts, irrespective of sampling time, in both seasons. Sampling time had no effect in the 2009/2010 season, whereas the earthworm counts at 21 weeks after planting (WAP) were lower than the other two sampling times during the 2010/2011 season. The findings suggested that, at least in the short-term, growing Bt maize does not have negative effects on the numbers of the earthworms in the Central Eastern Cape, South Africa.Key words: Bacillus thuringiensis (Bt) maize, Cry1Ab protein, earthworm counts

    Corticotropin-releasing factor receptor 1 activation during exposure to novelty stress protects against alzheimer's disease-like cognitive decline in AÎČPP/PS1 Mice

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    A lifestyle rich in physical and mental activities protects against Alzheimer's disease (AD) but the underlying mechanisms are unclear. We have proposed that this is mediated by a stress response and have shown that repeated exposure to novelty stress, which induces physical and exploratory activities, delays the progression of AD-like pathology in the TASTPM mouse model. Here, we aimed to establish the role played by corticotrophin-releasing factor receptor 1 (CRFR1), a major component of the stress axis, in TASTPM's behavioral and neuroendocrine responses to novelty and related protective effects. We show that the stress response of TASTPM mice is altered with reduced CRFR1-mediated neuroendocrine and behavioral responses to novelty and a distinct profile of behavioral responses. Repeated novelty-induced CRFR1 activation, however, mediated the improved contextual fear memory and extinction performance of TASTPM mice and increased hippocampal and fronto-cortical levels of synaptophysin, a marker of synaptic density, and fronto-cortical levels of the post-synaptic marker PSD95. The N-methyl-D-aspartate receptor (NMDAR) is the major receptor for synaptic plasticity underlying learning and memory. Although novelty-induced NMDAR activation contributed to enhancement of fear memory and synaptophysin levels, antagonism of CRFR1 and NMDAR prevented the novelty-induced increase in hippocampal synaptophysin levels but reversed the other effects of CRFR1 inactivation, i.e., the enhancement of contextual fear extinction and fronto-cortical synaptophysin and PSD95 levels. These findings suggest a novel mechanism whereby a stimulating environment can delay AD symptoms through CRFR1 activation, facilitating NMDAR-mediated synaptic plasticity and synaptogenesis in a region-dependent manner, either directly, or indirectly, by modulating PSD95. © 2013 - IOS Press and the authors. All rights reserved

    Modelling environmental impacts of agriculture, focusing on oil palm

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    Cultivation of crops affects the environment via flows of energy and materials. Impacts are felt in the atmosphere, hydrosphere, surrounding terrestrial ecosystems and the field itself. Models are useful tools for improving our understanding of the processes and predicting how they might be affected by changes in management. Current models range from simple indicators of risk or impact, based on empirical relationships, to dynamic process-based models. Increasingly complex and comprehensive models with increasing spatial and temporal resolution and extent are being developed, mostly by coupling diverse sub-models. This chapter reviews the range of models developed for oil palm systems, and discusses how other existing models might be adapted for oil palm

    IN-Palm - Technical Report: an agri-environmental indicator to assess potential nitrogen losses in oil palm plantations

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    [Extract] IN-Palm is an agri-environmental predictive indicator specific to oil palm plantations based on an operational model. It simulates the risk of nitrogen (N) losses from the field, through 6 loss pathways: ammonia (NH3) volatilisation; N losses through runoff-erosion; nitrous oxide (N2O), dinitrogen (N2) and nitrogen oxides (NOx) emissions; and N leaching. Simulations require 21 readily available input variables on crop factors, soil, weather and management practices. Calculations are done for one hectare of palms, for an age of palms chosen by the user, from 1 to 30-year-old

    Factors Associated with Bovine Neonatal Pancytopenia (BNP) in Calves: A Case-Control Study

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    Bovine neonatal pancytopenia (BNP; previously known as idiopathic haemorrhagic diathesis and commonly known as bleeding calf syndrome) is a novel haemorrhagic disease of young calves which has emerged in a number of European countries during recent years. Data were retrospectively collected during June to November 2010 for 56 case calves diagnosed with BNP between 17 March and 7 June of the same year. These were compared with 58 control calves randomly recruited from herds with no history of BNP. Multivariable logistic regression analysis showed that increased odds of a calf being a BNP case were associated with its dam having received PregSure¼ BVD (Pfizer Animal Health) vaccination prior to the birth of the calf (odds ratio (OR) 40.78, p<0.001) and its herd of origin being located in Scotland (OR 9.71, p = 0.006). Decreased odds of a calf being a BNP case were associated with the calf having been kept outside (OR 0.11, p = 0.006). The longer that a cattle herd had been established on the farm was also associated with decreased odds of a calf in that herd being a BNP case (OR 0.97, p = 0.011)

    Structure and flexibility of the endosomal Vps34 complex reveals the basis of its function on membranes

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    Phosphatidylinositol 3-kinase Vps34 complexes regulate intracellular membrane trafficking in endocytic sorting, cytokinesis and autophagy. We present the 4.4 Å crystal structure of the 385 kDa endosomal complex II (PIK3C3-CII), consisting of Vps34, Vps15 (p150), Vps30/Atg6 (Beclin 1) and Vps38 (UVRAG). The subunits form a Y-shaped complex, centered on the Vps34 C2 domain. Vps34 and Vps15 intertwine in one arm where the Vps15 kinase domain engages the Vps34 activation loop to regulate its activity. Vps30 and Vps38 form the other arm that brackets the Vps15/Vps34 heterodimer, suggesting a path for complex assembly. Hydrogen-Deuterium Exchange Mass Spectrometry (HDX-MS) revealed conformational changes accompanying membrane binding and identified a Vps30 loop that is critical for the ability of complex II to phosphorylate giant liposomes on which complex I is inactive

    A specific nanobody prevents amyloidogenesis of D76N \u3b22-microglobulin in vitro and modifies its tissue distribution in vivo

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    Systemic amyloidosis is caused by misfolding and aggregation of globular proteins in vivo for which effective treatments are urgently needed. Inhibition of protein self-aggregation represents an attractive therapeutic strategy. Studies on the amyloidogenic variant of \u3b22-microglobulin, D76N, causing hereditary systemic amyloidosis, have become particularly relevant since fibrils are formed in vitro in physiologically relevant conditions. Here we compare the potency of two previously described inhibitors of wild type \u3b22-microglobulin fibrillogenesis, doxycycline and single domain antibodies (nanobodies). The \u3b22-microglobulin -binding nanobody, Nb24, more potently inhibits D76N \u3b22-microglobulin fibrillogenesis than doxycycline with complete abrogation of fibril formation. In \u3b22-microglobulin knock out mice, the D76N \u3b22-microglobulin/ Nb24 pre-formed complex, is cleared from the circulation at the same rate as the uncomplexed protein; however, the analysis of tissue distribution reveals that the interaction with the antibody reduces the concentration of the variant protein in the heart but does not modify the tissue distribution of wild type \u3b22-microglobulin. These findings strongly support the potential therapeutic use of this antibody in the treatment of systemic amyloidosis
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