4,049 research outputs found

    Non Parametric Distributed Inference in Sensor Networks Using Box Particles Messages

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    This paper deals with the problem of inference in distributed systems where the probability model is stored in a distributed fashion. Graphical models provide powerful tools for modeling this kind of problems. Inspired by the box particle filter which combines interval analysis with particle filtering to solve temporal inference problems, this paper introduces a belief propagation-like message-passing algorithm that uses bounded error methods to solve the inference problem defined on an arbitrary graphical model. We show the theoretic derivation of the novel algorithm and we test its performance on the problem of calibration in wireless sensor networks. That is the positioning of a number of randomly deployed sensors, according to some reference defined by a set of anchor nodes for which the positions are known a priori. The new algorithm, while achieving a better or similar performance, offers impressive reduction of the information circulating in the network and the needed computation times

    Saving energy in aggressive intrusion detection through dynamic latency sensitivity recognition

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    In an always connected world, cyber-attacks and computer security breaches can produce significant financial damages as well as introduce new risks and menaces in everyday's life. As a consequence, more and more sophisticated packet screening/filtering solutions are deployed everywhere, typically on network border devices, in order to sanitize Internet traffic. Despite the obvious benefits associated to the proactive detection of security threats, these devices, by performing deep packet inspection and inline analysis, may both affect latency-sensitive traffic introducing non-negligible delays, and increase the energy demand at the network element level. Starting from these considerations, we present a selective routing and intrusion detection technique based on dynamic statistical analysis. Our technique separates latency-sensitive traffic from latency-insensitive one and adaptively organizes the intrusion detection activities over multiple nodes. This allows suppressing directly at the network ingress, when possible, all the undesired components of latency-insensitive traffic and distributing on the innermost nodes the security check for latency sensitive flows, prioritizing routing activities over security scanning ones. Our final goal is demonstrating that selective intrusion detection can result in significant energy savings without adversely affecting latency-sensitive traffic by introducing unacceptable processing delays. \ua9 2017 Elsevier Ltd

    Increasing the “region of interest” and “time of interest”, both reduce the variability of blood flow measurements using laser speckle contrast imaging

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    ObjectiveBoth spatial variability and temporal variability of skin blood flow are high. Laser speckle contrast imagers (LSCI) allow non-contact, real-time recording of cutaneous blood flow on large skin surfaces. Thereafter, the observer can define different sizes for the region of interest (ROI) in the images to decrease spatial variability and different durations over which the blood flow values are averaged (time of interest, TOI) to decrease temporal variability. We aimed to evaluate the impact of the choices of ROI and TOI on the analysis of rest blood flow and post occlusive reactive hyperemia (PORH). Methods Cutaneous blood flow (CBF) was assessed at rest and during PORH. Three different sizes of ROI (1 mm2, 10 mm2 and 100 mm2), and three different TOI (CBF averaged over 1 s, 15 s, and 30 s for rest, and over 1 s, 5 s and 10 s for PORH peak) were evaluated. Inter-subjects and intra-subjects coefficient of variations (inter-CV and intra-CV) were studied. Results The inter-subject variability of CBF is about 25% at rest and is moderately improved when the size of the ROI increases (inter-CV = 31%, for 1 s and 1 mm2 versus inter-CV = 23%, for 15 s and 100 mm2). However, increasing the TOI does not improve the results. The variability of the PORH peak is lower with an inter-CV varying between 11.4% (10 s and 100 mm2) and 21.6% (5 s and 1 mm2). The lowest intra-CV for the CBF at rest was 7.3% (TOI of 15 s on a ROI of 100 mm2) and was 3.1% for the PORH peak (TOI of 10 s on a ROI of 100 mm2). Conclusion We suggest that a size of ROI larger than 10 mm2 and a TOI longer than 1 s are required to reduce the variability of CBF measurements both at rest and during PORH peak evaluations at the forearm level. Many technical aspects such as comparison of laser speckle contrast imaging and laser Doppler imaging or the effect of skin to head distance on recorded values with LCSI are required to improve future studies using this fascinating clinical tool

    A New Selective PPARγ Modulator Inhibits Triglycerides Accumulation during Murine Adipocytes’ and Human Adipose-Derived Mesenchymal Stem Cells Differentiation

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    Understanding the molecular basis of adipogenesis is vital to identify new therapeutic targets to improve anti-obesity drugs. The adipogenic process could be a new target in the management of this disease. Our aim was to evaluate the effect of GMG-43AC, a selective peroxisome proliferator-activated receptor \u3b3 (PPAR\u3b3) modulator, during adipose differentiation of murine pre-adipocytes and human Adipose Derived Stem Cells (hADSCs). We differentiated 3T3-L1 cells and primary hADSCs in the presence of various doses of GMG-43AC and evaluated the differentiation efficiency measuring lipid accumulation, the expression of specific differentiation markers and the quantification of accumulated triglycerides. The treatment with GMG-43AC is not toxic as shown by cell viability assessments after the treatments. Our findings demonstrate the inhibition of lipid accumulation and the significant decrease in the expression of adipocyte-specific genes, such as PPAR\u3b3, FABP-4, and leptin. This effect was long lasting, as the removal of GMG-43AC from culture medium did not allow the restoration of adipogenic process. The above actions were confirmed in hADSCs exposed to adipogenic stimuli. Together, these results indicate that GMG-43AC efficiently inhibits adipocytes differentiation in murine and human cells, suggesting its possible function in the reversal of adipogenesis and modulation of lipolysis

    Therapeutic effect of neural progenitor cells expanded in the 3D nano-engineered Nichoid substrate in a Parkinson’s disease preclinical model

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    3D microscaffoldsare becoming more and more relevant in regenerative medicine, as they lead to the creation of a structure similar to a physiologicalniche. An example is the nano-engineered Nichoid, a 3D structure in which the cells are able to proliferate. In this work,we investigated the proliferation and stemness properties of Er-NPCswhen grown inside the Nichoid, and their potential therapeutic application in the treatment of Parkinson\u2019s Disease.3D microscaffolds are becoming more and more relevant in regenerative medicine, as they lead to the creation of a structure similar to a physiological niche. An example is the nano-engineered Nichoid, a 3D structure in which the cells are able to proliferate. In this work, we investigated the proliferation and stemness properties of Er-NPCs when grown inside the Nichoid, and their potential therapeutic application in the treatment of Parkinson\u2019s Disease

    Application of COMPOCHIP Microarray to Investigate the Bacterial Communities of Different Composts

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    A microarray spotted with 369 different 16S rRNA gene probes specific to microorganisms involved in the degradation process of organic waste during composting was developed. The microarray was tested with pure cultures, and of the 30,258 individual probe-target hybridization reactions performed, there were only 188 false positive (0.62%) and 22 false negative signals (0.07%). Labeled target DNA was prepared by polymerase chain reaction amplification of 16S rRNA genes using a Cy5-labeled universal bacterial forward primer and a universal reverse primer. The COMPOCHIP microarray was applied to three different compost types (green compost, manure mix compost, and anaerobic digestate compost) of different maturity (2, 8, and 16 weeks), and differences in the microorganisms in the three compost types and maturity stages were observed. Multivariate analysis showed that the bacterial composition of the three composts was different at the beginning of the composting process and became more similar upon maturation. Certain probes (targeting Sphingobacterium, Actinomyces, Xylella/Xanthomonas/ Stenotrophomonas, Microbacterium, Verrucomicrobia, Planctomycetes, Low G + C and Alphaproteobacteria) were more influential in discriminating between different composts. Results from denaturing gradient gel electrophoresis supported those of microarray analysis. This study showed that the COMPOCHIP array is a suitable tool to study bacterial communities in composts

    Pressure-induced phonon-freezing in the ZnBeSe alloy: a study via the percolation mesoscope

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    We use the 1-bond -> 2-phonon percolation doublet of zincblende alloys as a mesoscope for an unusual insight into their phonon behavior under pressure. We focus on (Zn,Be)Se and show by Raman scattering that the original Be-Se doublet at ambient pressure, of the stretching-bending type, turns into a pure-bending singlet at the approach of the high-pressure ZnSe-like rocksalt phase, an unnatural one for the Be-Se bonds. The freezing of the Be-Se stretching mode is discussed within the scope of the percolation model (mesoscopic scale), with ab initio calculations in support (microscopic scale).Comment: 11 pages, 3 figure

    The presence of autoantibodies to cytoplasmic rod and ring particles in the serum of patients with chronic hepatitis C virus infection

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    Background: Chronic hepatitis C virus (HCV) is associated with extra hepatic autoimmune disorders, while peg-IFNa-2a/RBV combination therapy may exacerbate these conditions. Autoantibodies to cytoplasmic structures, called rod and ring particles (RR), have strong associations with these patients and are identified by HEp-2 cells. Objectives: Our purpose was to study the correlation of autoantibodies to cytoplasmic rod and ring particles in the serum of patients with chronic HCV infection with their response to standard therapy. Methods: Serum samples were gathered from 120 patients with HCV infection (40 naive treatments, 40 with sustained virological response (SVR), and 40 with relapse response) during peg-IFNa-2a/RBV combination therapy and analyzed for the presence of RR antibodies by IIF on commercially available HEp-2 cell substrate slides from Euroimmun (Lu beck, Germany). Results: Anti-rod and ring (anti-RR) autoantibodies were detected in only the serum of 1 out of 120 patients (0.8), which belonged to a patient (out of 40) with relapse response (2.5). No correlation was found between the types of response to peg-IFNa-2a/RBV combination therapy and the presence of anti-RR autoantibodies. Conclusions: The only HCV patient with RR autoantibodies previously had received IFN/ribavirin antiviral therapy. The presence of these autoantibodies is extremely rare in Iranian HCV patients. Further studies are warranted to determine the role of genetic background and geographical pattern in the prevalence of these novel autoantibodies worldwide. � 2016, Kowsar Corp

    The role of recent admixture in forming the contemporary West Eurasian genomic landscape

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    Over the past few years, studies of DNA isolated from human fossils and archaeological remains have generated considerable novel insight into the history of our species. Several landmark papers have described the genomes of ancient humans across West Eurasia, demonstrating the presence of large-scale, dynamic population movements over the last 10,000 years, such that ancestry across present-day populations is likely to be a mixture of several ancient groups [1-7]. While these efforts are bringing the details of West Eurasian prehistory into increasing focus, studies aimed at understanding the processes behind the generation of the current West Eurasian genetic landscape have been limited by the number of populations sampled or have been either too regional or global in their outlook [8-11]. Here, using recently described haplotype-based techniques [11], we present the results of a systematic survey of recent admixture history across Western Eurasia and show that admixture is a universal property across almost all groups. Admixture in all regions except North Western Europe involved the influx of genetic material from outside of West Eurasia, which we date to specific time periods. Within Northern, Western, and Central Europe, admixture tended to occur between local groups during the period 300 to 1200 CE. Comparisons of the genetic profiles of West Eurasians before and after admixture show that population movements within the last 1,500 years are likely to have maintained differentiation among groups. Our analysis provides a timeline of the gene flow events that have generated the contemporary genetic landscape of West Eurasia

    Distance between laser head and skin does not influence skin blood flow values recorded by laser speckle imaging

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    BackgroundLaser Speckle contrast imaging (LSCI) allows non-contact, real-time recording of cutaneous blood flow (CBF). Different distances from laser-head to skin (distancesL–S) can be chosen by the operator to perform these recordings. We aimed to evaluate the impact of different DistancesL–S on the analysis of rest blood flow and post-occlusive reactive hyperemia (PORH). Methods Four distancesL–S (10, 15, 20, and 30 cm) were evaluated in a random order in 11 healthy subjects. We analyzed the concordance between each recording at each distanceL–S. We compared CBF results (absolute values and cutaneous vascular conductance (CBF divided by mean arterial pressure)) obtained for each distanceL–S. The intra-subject coefficients of variation due to distancesL–S (intra-CV, in%) were also studied. Results The mean “r” (standard deviation) cross-correlation coefficient was 0.99 (0.00) between each CBF trace issued from different distanceL–S. Both kinds of CBF results, at rest and for PORH peak, show non-significant differences when the distanceL–S is modified. The intra-CV varies from 5.9% to 8.6% at rest and from 5.6% to 9.1% for the PORH peak. Conclusion DistanceL–S neither influences SBFR at rest, nor at peak post-occlusive hyperemia in the 10–30 cm interval using LSCI
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