6,706 research outputs found

    Multiplex cytokine analysis of dermal interstitial blister fluid defines local disease mechanisms in systemic sclerosis.

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    Clinical diversity in systemic sclerosis (SSc) reflects multifaceted pathogenesis and the effect of key growth factors or cytokines operating within a disease-specific microenvironment. Dermal interstitial fluid sampling offers the potential to examine local mechanisms and identify proteins expressed within lesional tissue. We used multiplex cytokine analysis to profile the inflammatory and immune activity in the lesions of SSc patients

    Data Association and Track Management for the Gaussian Mixture Probability Hypothesis Density Filter

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    The Gaussian mixture probability hypothesis density (GM-PHD) recursion is a closed-form solution to the probability hypothesis density (PHD) recursion, which was proposed for jointly estimating the time-varying number of targets and their states from a sequence of noisy measurement sets in the presence of data association uncertainty, clutter, and miss-detection. However the GM-PHD filter does not provide identities of individual target state estimates, that are needed to construct tracks of individual targets. In this paper, we propose a new multi-target tracker based on the GM-PHD filter, which gives the association amongst state estimates of targets over time and provides track labels. Various issues regarding initiating, propagating and terminating tracks are discussed. Furthermore, we also propose a technique for resolving identities of targets in close proximity, which the PHD filter is unable to do on its own

    Synaptically induced long-term modulation of electrical coupling in the inferior olive.

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    Electrical coupling mediated by gap junctions is widespread in the mammalian CNS, and the interplay between chemical and electrical synapses on the millisecond timescale is crucial for determining patterns of synchrony in many neural circuits. Here we show that activation of glutamatergic synapses drives long-term depression of electrical coupling between neurons of the inferior olive. We demonstrate that this plasticity is not triggered by postsynaptic spiking alone and that it requires calcium entry following synaptic NMDA receptor activation. These results reveal that glutamatergic synapses can instruct plasticity at electrical synapses, providing a means for excitatory inputs to homeostatically regulate the long-term dynamics of microzones in olivocerebellar circuits

    Ultracompact quantum splitter of degenerate photon pairs

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    Integrated sources of indistinguishable photons have attracted a lot of attention because of their applications in quantum communication and optical quantum computing. Here, we demonstrate an ultra-compact quantum splitter for degenerate single photons based on a monolithic chip incorporating Sagnac loop and a micro-ring resonator with a footprint of 0.011 mm2, generating and deterministically splitting indistinguishable photon pairs using time-reversed Hong-Ou-Mandel interference. The ring resonator provides enhanced photon generation rate, and the Sagnac loop ensures the photons travel through equal path lengths and interfere with the correct phase to enable the reversed HOM effect to take place. In the experiment, we observed a HOM dip visibility of 94.5 +- 3.3 %, indicating the photons generated by the degenerate single photon source are in a suitable state for further integration with other components for quantum applications, such as controlled-NOT gates

    Categorías sociopolíticas evaluadas en programas y políticas nutricionales en América Latina

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    ABSTRACT: The evaluation of nutrition programs and policies has traditionally focused on analysing the impact and biological outcomes of their actions. Objective: To examine whether evaluations of nutrition programs include the following sociopolitical categories: (a) the right to food; (b) citizenship building; (c) civil participation in public policies; (d) women’s empowerment; and (e) territoriality in policy planning. Methodology: A comprehensive literature review of articles and documents that evaluate food and nutrition programs carried out in different Latin American countries and published during 2005-2013. Results: It was found that the evaluations carried out generally do not use these categories. In the cases where they are used, the conceptual development applied to the evaluation process is still incipient. Discussion: This study analyzed the sociopolitical categories of: the right to food; citizenship building; civil participation in public policies; women’s empowerment; and territoriality in policy planning, and found that although these categories are not prioritised when nutritional programs in Latin America are assessed, in most cases they form the basis of these programs. Conclusion: Social protection nutrition programs demand new objectives and actions. It is necessary to apply evaluation criteria that account for these new underpinnings in order to establish consistency between government institutions’ discourse, and the reality of their efforts.RESUMEN: La evaluación de programas y políticas nutricionales se ha enfocado tradicionalmente al análisis del impacto y resultados biológicos de las intervenciones. Objetivo: Examinar si las evaluaciones a programas nutricionales incluyen las siguientes categorías socio-políticas: (a) El derecho a la alimentación, (b) La construcción de ciudadanía, (c) La participación ciudadana en las políticas públicas, (d) El empoderamiento de la mujer y (e) La territorialidad en las políticas de planificación. Metodología: Revisión integrativa de la literatura sobre artículos y documentos de evaluaciones a programas alimentarios y nutricionales en países de América Latina publicados entre 2005 y 2013. Resultados: Se encontró en general que en las evaluaciones no se indaga por estas categorías; en los casos en que se hace su desarrollo conceptual aplicado a los procesos de evaluación es incipiente. Discusión: El principal hallazgo es que las categorías sociopolíticas analizadas no se encuentran entre las prioridades en la evaluación de programas nutricionales en América Latina, aunque en la mayoría de los casos son la base de estos programas. Conclusión: Los programas nutricionales de protección social demandan nuevos objetivos e intervenciones. Es necesario aplicar criterios de evaluación con nuevas bases, con el fin de dar coherencia entre los discursos de las instituciones gubernamentales y sus acciones

    Nitrogen oxidation consortia dynamics influence the performance of full-scale rotating biological contactors.

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    Ammonia oxidising microorganisms (AOM) play an important role in ammonia removal in wastewater treatment works (WWTW) including rotating biological contactors (RBCs). Environmental factors within RBCs are known to impact the performance of key AOM, such that only some operational RBCs have shown ability for elevated ammonia removal. In this work, long-term treatment performance of seven full-scale RBC systems along with the structure and abundance of the ammonia oxidising bacteria (AOB) and archaea (AOA) communities within microbial biofilms were examined. Long term data showed the dominance of AOB in most RBCs, although two RBCs had demonstrable shift toward an AOA dominated AOM community. Next Generation Sequencing of the 16S rRNA gene revealed diverse evolutionary ancestry of AOB from RBC biofilms while nitrite-oxidising bacteria (NOBs) were similar to reference databases. AOA were more abundant in the biofilms subject to lower organic loading and higher oxygen concentration found at the distal end of RBC systems. Modelling revealed a distinct nitrogen cycling community present within high performing RBCs, linked to efficient control of RBC process variables (retention time, organic loading and oxygen concentration). We present a novel template for enhancing the resilience of RBC systems through microbial community analysis which can guide future strategies for more effective ammonia removal. To best of the author's knowledge, this is the first comparative study reporting the use of next generation sequencing data on microbial biofilms from RBCs to inform effluent quality of small WWTW

    Chemotactic response and adaptation dynamics in Escherichia coli

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    Adaptation of the chemotaxis sensory pathway of the bacterium Escherichia coli is integral for detecting chemicals over a wide range of background concentrations, ultimately allowing cells to swim towards sources of attractant and away from repellents. Its biochemical mechanism based on methylation and demethylation of chemoreceptors has long been known. Despite the importance of adaptation for cell memory and behavior, the dynamics of adaptation are difficult to reconcile with current models of precise adaptation. Here, we follow time courses of signaling in response to concentration step changes of attractant using in vivo fluorescence resonance energy transfer measurements. Specifically, we use a condensed representation of adaptation time courses for efficient evaluation of different adaptation models. To quantitatively explain the data, we finally develop a dynamic model for signaling and adaptation based on the attractant flow in the experiment, signaling by cooperative receptor complexes, and multiple layers of feedback regulation for adaptation. We experimentally confirm the predicted effects of changing the enzyme-expression level and bypassing the negative feedback for demethylation. Our data analysis suggests significant imprecision in adaptation for large additions. Furthermore, our model predicts highly regulated, ultrafast adaptation in response to removal of attractant, which may be useful for fast reorientation of the cell and noise reduction in adaptation.Comment: accepted for publication in PLoS Computational Biology; manuscript (19 pages, 5 figures) and supplementary information; added additional clarification on alternative adaptation models in supplementary informatio

    The N-terminal intrinsically disordered domain of mgm101p is localized to the mitochondrial nucleoid.

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    The mitochondrial genome maintenance gene, MGM101, is essential for yeasts that depend on mitochondrial DNA replication. Previously, in Saccharomyces cerevisiae, it has been found that the carboxy-terminal two-thirds of Mgm101p has a functional core. Furthermore, there is a high level of amino acid sequence conservation in this region from widely diverse species. By contrast, the amino-terminal region, that is also essential for function, does not have recognizable conservation. Using a bioinformatic approach we find that the functional core from yeast and a corresponding region of Mgm101p from the coral Acropora millepora have an ordered structure, while the N-terminal domains of sequences from yeast and coral are predicted to be disordered. To examine whether ordered and disordered domains of Mgm101p have specific or general functions we made chimeric proteins from yeast and coral by swapping the two regions. We find, by an in vivo assay in S.cerevisiae, that the ordered domain of A.millepora can functionally replace the yeast core region but the disordered domain of the coral protein cannot substitute for its yeast counterpart. Mgm101p is found in the mitochondrial nucleoid along with enzymes and proteins involved in mtDNA replication. By attaching green fluorescent protein to the N-terminal disordered domain of yeast Mgm101p we find that GFP is still directed to the mitochondrial nucleoid where full-length Mgm101p-GFP is targeted

    Effects of cell-to-cell fuel mal-distribution on fuel cell performance and a means to reduce mal-distribution using MEMS micro-valves

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    Achieving uniform flow among the cells of a fuel cell stack plays a significant role in being able to operate at maximum capability and efficiency. This paper presents experimental data showing the importance of cell-to-cell fuel flow balancing on fuel cell performance, and a fuel cell energy management (FCEM) technique that has demonstrated the ability to improve stack performance. In a specially instrumented four-cell polymer electrolyte fuel cell that allows external control of the air, fuel, and water-cooling flows to each cell, fuel to a single cell was reduced. V-I curves collected under these unbalanced conditions are compared to curves collected when the fuel flow to each cell was balanced. Reducing the fuel flow to a single cell by 11% decreased the V-I curve cutoff load by 10%-demonstrating the degree of negative effect that unbalanced fuel flows can have on stack performance. Typical fuel cell stacks have no dynamic means to keep flows in the stack balanced between the cells, but through the use of custom-built, piezoelectric micro-valves, a simple flow control strategy, and this custom four-cell laboratory stack, the positive effects of FCEM flow balancing at three different fuel flow rates was demonstrated. © 2006 Elsevier B.V. All rights reserved
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