The Electrical Restiitution Curve (ERC) may play an important role in the generation and maintenance of Ventricular fibrillation (VF). As VF usually appears in ischemic hearts, we have studied the ...changes exerted by acute ischemia in ERCs using computer simulations. Our results show that the main effects of ischemia on rhe ERC are that (a) it shifts the ERC towards lower action potential durations (APDs) and (b) it significantly reduces the slope of the ERC. These findings are in accordance with experimental observations. When analyzing ionic currenis, it became clear that, as expected, the slow component of the delayed K current (I<sub)Ks ) was responsible for the slope of the ERC in normal conditions. However, an increased Ca inward current (I caL ) provoked by the altered Ca 2+ dynamics accounted for the flattening of the ERC in ischemia
It is well known that ventricular fibrillation (VF) is a major cause of sudden cardiac death in developed countries. Myocardial regional acute ischemia constitutes a heterogeneous substrate which ...tends to destabilize the electrical depolarizing wave front, thus favouring VF. Functional re-entry in the transmural wall has been hypothesized as the underlying mechanism of VF. In this work, we have theoretically studied (using computer simulations) the temporal evolution of the vulnerable window (VW) for re-entry in an acutely ischemic virtual tissue which represents the transmural ventricular wall. The model predicts that the VW for re-entry has biphasic behaviour during acute myocardial ischemia, with re-entry paths comprising endocardial, midmyocardial and epicardial tissue.
Fusarium cultures (27 isolates of Fusarium graminearum, 5 of F. sporotrichioides, 5 of F. semitectum, 2 of F. solani, and one isolate of F. equiseti, F. heterosporum and F. oxysporum respectively, ...from maize ears) were screened to determine their ability to produce different trichothecenes and zearalenone. Twenty of 27 F. graminearum isolates produced deoxynivalenol (384-5745 micrograms/kg), 7/27 produced 3-acetyl-deoxynivalenol (322-1840 micrograms/kg), 3/27 produced neosolaniol (199-898 micrograms/kg), 5/27 produced diacetoxyscirpenol (205-3095 micrograms/kg), 4/27 produced HT-2 toxin (278-1377 micrograms/kg) and 13/27 produced zearalenone (200-35045 micrograms/kg). No isolate of F. graminearum produced either nivalenol, 15-acetyl-deoxynivalenol, T-2 tosin, T-2 triol or T-2 tetraol. Only chemotype IA (deoxynivalenol and 3-acetyl-deoxynivalenol) was observed. F. sporotrichioides isolates produced deoxynivalenol (5/5), T-2 triol and T-2 tetraol (1/5) and zearalenone (1/5). One F. semitectum isolate produced diacetoxyscirpenol and F. equiseti and F. oxysporum isolates produced only deoxynivalenol. Thus, three of the toxins studied, deoxynivalenol, zearalenone and 3-acetyl-deoxynivalenol are most likely to appear as contaminants in freshly harvested maize.
Lidocaine is a class Ib antiarrythmic drug that acts blocking the fast sodium current. In this work, a mathematical model of lidocaine effects has been developed. This model has been incorporated to ...the Luo Rudy model of guinea pig ventricular action potential and the effect of different basic cycle lengths (BCL) and concentrations of drug on the action potential characteristics has been studied. Our results show that at BCL 300 ms lidocaine reduces maximum current sodium to 7% and 39% for 10 muM and 100 muM respectively. If we increase BCL, the blockade is reduced. In addition, lidocaine reduces the maximal upstroke velocity, for BCL 500 ms the inhibition is 0.9%, 7% and 38% for 1muM, 10 muM and 100 muM respectively. This reduction depends on BCL. Conduction velocity is also affected by lidocaine, It is reduced to 4% and 23% for 10 muM and 100 muM respectively (BCL 300 ms); lower concentrations do not affect the conduction velocity
Infrastructure Deployment Over the Cloud de Alfonso, C.; Caballer, M.; Alvarruiz, F. ...
2011 IEEE Third International Conference on Cloud Computing Technology and Science,
2011-Nov.
Conference Proceeding
With the advent of cloud technologies the scientists have access to different cloud infrastructures in order to deploy all the virtual machines they need to perform the computations required in their ...research works. This paper describes a software architecture and a description language to simplify the creation of all the needed resources, and the elastic evolution of the computing infrastructure depending on the application requirements and some QoS features.
The presence of trichothecenes (deoxynivalenol, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, nivalenol, neosolaniol and diacetoxyscirpenol) was studied in 50 samples of Argentinean beer (nine ...different brands). Gas chromatography with electron capture detector was used for identification and quantification of these mycotoxins. The only mycotoxin detected was deoxynivalenol (DON). It was present in 44% of the samples, 18% were contaminated with more than 20ng/ml. Toxin levels ranged from 4 to 221ng/ml in positive samples. This is the first report on DON contamination of Argentinean beer. The estimate of probable daily intake (PDI) of DON from beer consumption in Argentina does not indicate a health hazard, but it has to be taken into account in calculations of total DON exposure in the population.
A case study on climate models intercomparison data analysis addressing several classes of multi-model experiments is being implemented in the context of the EU H2020 INDIGO-DataCloud project. Such ...experiments require the availability of large amount of data (multi-terabyte order) related to the output of several climate models simulations as well as the exploitation of scientific data management tools for large-scale data analytics. More specifically, the paper discusses in detail a use case on precipitation trend analysis in terms of requirements, architectural design solution, and infrastructural implementation. The experiment has been tested and validated on CMIP5 datasets, in the context of a large scale distributed testbed across EU and US involving three ESGF sites (LLNL, ORNL, and CMCC) and one central orchestrator site (PSNC).
Although tumor growth requires the mitochondrial electron transport chain (ETC), the relative contribution of complex I (CI) and complex II (CII), the gatekeepers for initiating electron flow, ...remains unclear. In this work, we report that the loss of CII, but not that of CI, reduces melanoma tumor growth by increasing antigen presentation and T cell-mediated killing. This is driven by succinate-mediated transcriptional and epigenetic activation of major histocompatibility complex-antigen processing and presentation (MHC-APP) genes independent of interferon signaling. Furthermore, knockout of methylation-controlled J protein (MCJ), to promote electron entry preferentially through CI, provides proof of concept of ETC rewiring to achieve antitumor responses without side effects associated with an overall reduction in mitochondrial respiration in noncancer cells. Our results may hold therapeutic potential for tumors that have reduced MHC-APP expression, a common mechanism of cancer immunoevasion.
In this paper we describe the architecture of a Platform as a Service (PaaS) oriented to computing and data analysis. In order to clarify the choices we made, we explain the features using practical ...examples, applied to several known usage patterns in the area of HEP computing. The proposed architecture is devised to provide researchers with a unified view of distributed computing infrastructures, focusing in facilitating seamless access. In this respect the Platform is able to profit from the most recent developments for computing and processing large amounts of data, and to exploit current storage and preservation technologies, with the appropriate mechanisms to ensure security and privacy.
This paper combines high-performance computing and grid computing technologies to accelerate multiple executions of a biomedical application that simulates the action potential propagation on cardiac ...tissues. First, a parallelization strategy was employed to accelerate the execution of simulations on a cluster of personal computers (PCs). Then, grid computing was employed to concurrently perform the multiple simulations that compose the cardiac case studies on the resources of a grid deployment, by means of a service-oriented approach. This way, biomedical experts are provided with a gateway to easily access a grid infrastructure for the execution of these research studies. Emphasis is stressed on the methodology employed. In order to assess the benefits of the grid, a cardiac case study, which analyzes the effects of premature stimulation on reentry generation during myocardial ischemia, has been carried out. The collaborative usage of a distributed computing infrastructure has reduced the time required for the execution of cardiac case studies, which allows, for example, to take more accurate decisions when evaluating the effects of new antiarrhythmic drugs on the electrical activity of the heart.
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