7,362 research outputs found

    A note on some mathematical models on the effects of Bt-maize exposure

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    Some mathematical models for the estimation of the effects of Cry1Ab and Cry1F Bt-maize exposure in the biodiversity are discussed. Novel results about these models are obtained and described in the note. The exact formula for the proportion of the population that suffers mortality exposed to Cry1Ab pollen, underlining its dependence on the margin from the Bt crop edge, is derived. In addition, regarding Cry1F pollen effects, it is proposed a procedure, using a probabilistic and statistical approach, that computes the width of the non Bt-stripes used as mitigation measures. Finally, it has been derived a lower bound, using probabilistic consideration, on the species sensitivity of Lepidoptera.Comment: 10 pages, 1 figure. Early draft of a paper accepted for publication on Environmental and Ecological Statistic

    Mathematical model and experimental characterization of vertically stacked capacitive tactile sensors

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    Capacitive sensors are widely used in robotics for their compactness, high resolution, high sensitivity, and large dynamic range. In this article, we present a design solution for the manufacturing of capacitive tactile sensors with enhanced dynamic range and sensitivity. Herein, we adopted the approach of exploiting the vertical direction of the sensors by creating stacks of capacitors. The validation of the proposed model is conducted by means of finite element simulations and the effectiveness of stacked capacitors in suboptimal configurations has been experimentally tested by using inkjet printing and spin coating-based fabrication techniques. Results show that these sensors exhibit an enhanced dynamic range and sensitivity with respect to common single capacitors, for a given sensors area budget. Sensitivity increases of 235% passing from one-stack to two-stack capacitors (from 5.75 to 19.3 fF/kPa) and a growth of 23% from two-stack to three-stack capacitors (from 19.3 to 23.7 fF/kPa). These results suggest that the proposed methodology could be adopted for designing tactile sensors with higher spatial resolution and higher transduction sensitivity and dynamic range, in the perspective of an integration over large areas

    Apoptotic depletion of CD4<SUP>+</SUP> T cells in idiopathic CD4<SUP>+</SUP> T lymphocytopenia

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    Progressive loss of CD4+ T lymphocytes, accompanied by opportunistic infections characteristic of the acquired immune deficiency syndrome, ahs been reported in the absence of any known etiology. The pathogenesis of this syndrome, a subset of idiopathic CD4+ T lymphocytopenia (ICL), is uncertain. We report that CD4+ T cells from seven of eight ICL patients underwent accelerated programmed cell death, a process facilitated by T cell receptor cross-linking. Apoptosis was associated with enhanced expression of Fas and Fas ligand in unstimulated cell populations, and partially inhibited by soluble anti-Fas mAb. In addition, apoptosis was suppressed by aurintricarboxylic acid, an inhibitor of calcium-dependent endonucleases and proteases, in cells from four of seven patients, The in vivo significance of these findings was supported by three factors: the absence of accelerated apoptosis in persons with stable, physiologic CD4 lymphopenia without clinical immune deficiency; detection of serum antihistone H2B autoantibodies, one consequence of DNA fragmentation, in some patients; and its selectivity, with apoptosis limited to the CD4 population in some, and occurring among CD8+ T cells predominantly in those individuals with marked depletion of both CD4+ T lymphocytes linked to clinical immune suppression have evidence for accelerated T cell apoptosis in vitro that may be pathophysiologic and amenable to therapy with apoptosis inhibitors

    Assessing the effects of Bt maize on the non-target pest Rhopalosiphum maidis by demographic and life-history measurement endpoints

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    The most commercialized Bt maize plants in Europe were transformed with genes which express a truncated form of the insecticidal delta-endotoxin (Cry1Ab) from the soil bacterium Bacillus thuringiensis (Bt) specifically against Lepidoptera. Studies on the effect of transgenic maize on non-target arthropods have mainly converged on beneficial insects. However, considering the worldwide extensive cultivation of Bt maize, an increased availability of information on their possible impact on non-target pests is also required. In this study, the impact of Bt-maize on the non-target corn leaf aphid, Rhopalosiphum maidis, was examined by comparing biological traits and demographic parameters of two generations of aphids reared on transgenic maize with those on untransformed near-isogenic plants. Furthermore, free and bound phenolics content on transgenic and near-isogenic plants were measured. Here we show an increased performance of the second generation of R. maidis on Bt-maize that could be attributable to indirect effects, such as the reduction of defense against pests due to unintended changes in plant characteristics caused by the insertion of the transgene. Indeed, the comparison of Bt-maize with its corresponding near-isogenic line strongly suggests that the transformation could have induced adverse effects on the biosynthesis and accumulation of free phenolic compounds. In conclusion, even though there is adequate evidence that aphids performed better on Bt-maize than on non-Bt plants, aphid economic damage has not been reported in commercial Bt corn fields in comparison to non-Bt corn fields. Nevertheless, Bt-maize plants can be more easily exploited by R. maidis, possibly due to a lower level of secondary metabolites present in their leaves. The recognition of this mechanism increases our knowledge concerning how insect-resistant genetically modified plants impact on non-target arthropods communities, including tritrophic web interactions, and can help support a sustainable use of genetically modified crops

    Dieta com baixo teor de FODMAPs para distúrbios de dor abdominal funcional em crianças: revisão crítica do conhecimento atual (Low FODMAPs diet for functional abdominal pain disorders in children: critical review of current knowledge)

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    Objective: This narrative review aimed to provide practitioners a synthesis of the current knowledge on the role of a low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet in reducing symptoms associated with functional abdominal pain disorders in children. This review is focused on the pathophysiology, efficacy and criticism of low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet in children. / Sources: Cochrane Database, Pubmed and Embase were searched using specific terms for Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols diet interventions and functional abdominal pain disorders. / Summary of the findings: In children, only one Randomized Control Trial and one open‐label study reported positive results of low Fermentable Oligosaccharides Disaccharides Monosaccha‐rides and Polyols diet; one Randomized Control Trial showed exacerbation of symptoms with fructans in children with Irritable Bowel Syndrome; no effect was found for the lactose‐free diet whilst fructose‐restricted diets were effective in 5/6 studies. / Conclusions: In children there are few trials evaluating low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols in functional abdominal pain disorders, with encour‐aging data on the therapeutic efficacy particularly of fructose‐restricted diet. Additional effort sare still needed to fill this research gap and clarify the most efficient way for tailoring dietary restrictions based on the patient's tolerance and/or identification of potential biomarkers of low Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols efficacy, to maintain nutritional adequacy and to simplify the adherence to diet by labeling FermentableOligosaccharides Disaccharides Monosaccharides and Polyols content in commercial products
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