236 research outputs found

    Debugging of Web Applications with Web-TLR

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    Web-TLR is a Web verification engine that is based on the well-established Rewriting Logic--Maude/LTLR tandem for Web system specification and model-checking. In Web-TLR, Web applications are expressed as rewrite theories that can be formally verified by using the Maude built-in LTLR model-checker. Whenever a property is refuted, a counterexample trace is delivered that reveals an undesired, erroneous navigation sequence. Unfortunately, the analysis (or even the simple inspection) of such counterexamples may be unfeasible because of the size and complexity of the traces under examination. In this paper, we endow Web-TLR with a new Web debugging facility that supports the efficient manipulation of counterexample traces. This facility is based on a backward trace-slicing technique for rewriting logic theories that allows the pieces of information that we are interested to be traced back through inverse rewrite sequences. The slicing process drastically simplifies the computation trace by dropping useless data that do not influence the final result. By using this facility, the Web engineer can focus on the relevant fragments of the failing application, which greatly reduces the manual debugging effort and also decreases the number of iterative verifications.Comment: In Proceedings WWV 2011, arXiv:1108.208

    An efficient strategy of parcel modeling for polydispersed multiphase turbulent flows

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    A three-dimensional particle-laden two-phase turbulent flow by employing the Eulerian-Lagrangian method using multiphase Particle-In-Cell model is implemented to analyze the effects of parcel modeling. In order to achieve an optimal trade-off between accuracy and computational cost, a hybrid approach is proposed. This approach is a combination of two typical models: the volume fixed model, in which each parcel has the same volume, and the number fixed model, in which each parcel has the same number of particles. This approach is studied for the particle-laden turbulent flow benchmark case of Boreé et al. [1], with a mass loading of 22%, by using large eddy simulation through a two-way coupling between continuous and polydispersed phases

    Echocardiographic findings in haemodialysis patients according to their state of hydration

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    AbstractBackgroundChronic fluid overload is frequent in hemodialysis patients (P) and it associates with hypertension, left ventricular hypertrophy (LVH) and higher mortality. Moreover, echocardiographic data assessing fluid overload is limited. Our aim was to evaluate the relationship between fluid overload measured by bioimpedance spectroscopy (BIS) and different echocardiographic parameters.MethodsCross-sectional observational study including 76 stable patients. Dry weight was clinically assessed. BIS and echocardiography were performed. Weekly time-averaged fluid overload (TAFO) and relative fluid overload (FO/ECW) were calculated using BIS measurements.ResultsBased on TAFO three groups were defined: A- dehydrated, TAFO <-0.25 L 32 P (42%); B- normohydrated, TAFO between -0.25 and 1.5 l: 26 (34%); C- overhydrated, TAFO>1.5 l: 18 (24%). We found significant correlation between TAFO and left atrial volume index (LAVI) (r: 0.29; p=0.013) but not with FO/ECW (r 0.06; p=0.61). TAFO, but not FO/ECW kept a significant relationship with LAVI (p=0.03) using One-Way ANOVA test and linear regression methods. LVH was present in 73.7% (concentric 63.2%, eccentric in 10.5%). No differences between groups in the presence of LVH or left ventricular mass index were found.ConclusionsWe found that left atrial volume index determined by echocardiographic Area-length method, but not left ventricle hypertrophy or dimensions of cavities, are related on hydration status based on bioimpedance measured time-averaged fluid overload (TAFO), and not with FO/ECW

    Rabies screen reveals GPe control of cocaine-triggered plasticity.

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    Identification of neural circuit changes that contribute to behavioural plasticity has routinely been conducted on candidate circuits that were preselected on the basis of previous results. Here we present an unbiased method for identifying experience-triggered circuit-level changes in neuronal ensembles in mice. Using rabies virus monosynaptic tracing, we mapped cocaine-induced global changes in inputs onto neurons in the ventral tegmental area. Cocaine increased rabies-labelled inputs from the globus pallidus externus (GPe), a basal ganglia nucleus not previously known to participate in behavioural plasticity triggered by drugs of abuse. We demonstrated that cocaine increased GPe neuron activity, which accounted for the increase in GPe labelling. Inhibition of GPe activity revealed that it contributes to two forms of cocaine-triggered behavioural plasticity, at least in part by disinhibiting dopamine neurons in the ventral tegmental area. These results suggest that rabies-based unbiased screening of changes in input populations can identify previously unappreciated circuit elements that critically support behavioural adaptations

    A Global Review on Innovative, Sustainable, and Effective Materials Composing Growing Media for Forest Seedling Production

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    Purpose of Review: The demand for forest tree seedlings is increasing globally, and Sphagnum peat moss is widely used as a component of growing media for container plant production. However, peat extraction is environmentally unsustainable. The forest nursery sector needs to switch to more sustainable alternatives to peat. This review aims to identify potential substitutes for peat by reviewing the worldwide literature on alternative materials for growing media in forest nurseries. Recent Findings: Most studies on alternative growing media focused on single plant species growing under local conditions, thereby limiting generalizations about the effectiveness of alternative materials for plant production. To our knowledge, no systematic reviews of scientific literature on the effectiveness of new, alternative-to-peat materials for enhancing plant growth and the associated growing media characteristics for the forest nursery sector are currently available. Summary: Most of the analyzed case studies focused on angiosperms (73.1%), with the majority of studies coming from tropical seasonal forests/savannas (36.5%), followed by woodlands/shrublands (31.6%), and temperate forests (15.0%) biomes. Compost was the most studied material (19.5%), followed by bark, other organic materials, and manure (9.8, 9.7, and 8.0%, respectively). Green and municipal wastes were the principal sources of compost (&gt; 60%), while agriculture and green wastes were the first sources of other materials (&gt; 90%). Tested materials were dependent on the geographic region. Thus, manure was the most tested material in Africa and South America, tree bark in North America, and compost in Europe, Asia, and Oceania. Alternative materials effectively provided optimal physicochemical characteristics of growing media and enhanced seedling nursery growth when compared with peat-based growing media in more than 60% of the case studies. This review helps to identify research gaps and, most importantly, provides the basis for the future application of alternative growing media materials in forest nursery management worldwide

    Structural Operational Semantics of P Systems

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    Activation of mGluR5 Induces Rapid and Long-Lasting Protein Kinase D Phosphorylation in Hippocampal Neurons

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    Metabotropic glutamate receptors (mGluRs), including mGluR5, play a central role in regulating the strength and plasticity of synaptic connections in the brain. However, the signaling pathways that connect mGluRs to their downstream effectors are not yet fully understood. Here, we report that stimulation of mGluR5 in hippocampal cultures and slices results in phosphorylation of protein kinase D (PKD) at the autophosphorylation site Ser-916. This phosphorylation event occurs within 30 s of stimulation, persists for at least 24 h, and is dependent on activation of phospholipase C and protein kinase C. Our data suggest that activation of PKD may represent a novel signaling pathway linking mGluR5 to its downstream targets. These findings have important implications for the study of the molecular mechanisms underlying mGluR-dependent synaptic plasticity.Howard Hughes Medical InstituteFRAXA Research FoundationNational Institute of Mental Health (U.S.)Eunice Kennedy Shriver National Institute of Child Health and Human Development (U.S.

    Ciliary Neurotrophic Factor Protects Striatal Neurons against Excitotoxicity by Enhancing Glial Glutamate Uptake

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    Ciliary neurotrophic factor (CNTF) is a potent neuroprotective cytokine in different animal models of glutamate-induced excitotoxicity, although its action mechanisms are still poorly characterized. We tested the hypothesis that an increased function of glial glutamate transporters (GTs) could underlie CNTF-mediated neuroprotection. We show that neuronal loss induced by in vivo striatal injection of the excitotoxin quinolinic acid (QA) was significantly reduced (by ∼75%) in CNTF-treated animals. In striatal slices, acute QA application dramatically inhibited corticostriatal field potentials (FPs), whose recovery was significantly higher in CNTF rats compared to controls (∼40% vs. ∼7%), confirming an enhanced resistance to excitotoxicity. The GT inhibitor dl-threo-β-benzyloxyaspartate greatly reduced FP recovery in CNTF rats, supporting the role of GT in CNTF-mediated neuroprotection. Whole-cell patch-clamp recordings from striatal medium spiny neurons showed no alteration of basic properties of striatal glutamatergic transmission in CNTF animals, but the increased effect of a low-affinity competitive glutamate receptor antagonist (γ-d-glutamylglycine) also suggested an enhanced GT function. These data strongly support our hypothesis that CNTF is neuroprotective via an increased function of glial GTs, and further confirms the therapeutic potential of CNTF for the clinical treatment of progressive neurodegenerative diseases involving glutamate overflow

    Osmosensitivity of Transient Receptor Potential Vanilloid 1 Is Synergistically Enhanced by Distinct Activating Stimuli Such as Temperature and Protons

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    In animals, body-fluid osmolality is continuously monitored to keep it within a narrow range around a set point (∼300 mOsm/kg). Transient receptor potential vanilloid 1 (TRPV1), a cation channel, has been implicated in body-fluid homeostasis in vivo based on studies with the TRPV1-knockout mouse. However, the response of TRPV1 to hypertonic stimuli has not been demonstrated with heterologous expression systems so far, despite intense efforts by several groups. Thus, the molecular entity of the hypertonic sensor in vivo still remains controversial. Here we found that the full-length form of TRPV1 is sensitive to an osmotic increase exclusively at around body temperature using HEK293 cells stably expressing rat TRPV1. At an ambient temperature of 24°C, a slight increase in the intracellular calcium concentration ([Ca2+]i) was rarely observed in response to hypertonic stimuli. However, the magnitude of the osmosensitive response markedly increased with temperature, peaking at around 36°C. Importantly, the response at 36°C showed a robust increase over a hypertonic range, but a small decrease over a hypotonic range. A TRPV1 antagonist, capsazepine, and a nonspecific TRP channel inhibitor, ruthenium red, completely blocked the increase in [Ca2+]i. These results endorse the view that the full-length form of TRPV1 is able to function as a sensor of hypertonic stimuli in vivo. Furthermore, we found that protons and capsaicin likewise synergistically potentiated the response of TRPV1 to hypertonic stimuli. Of note, HgCl2, which blocks aquaporins and inhibits cell-volume changes, significantly reduced the osmosensitive response. Our findings thus indicate that TRPV1 integrates multiple different types of activating stimuli, and that TRPV1 is sensitive to hypertonic stimuli under physiologically relevant conditions
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