2,272 research outputs found

    VIoLET: A Large-scale Virtual Environment for Internet of Things

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    IoT deployments have been growing manifold, encompassing sensors, networks, edge, fog and cloud resources. Despite the intense interest from researchers and practitioners, most do not have access to large-scale IoT testbeds for validation. Simulation environments that allow analytical modeling are a poor substitute for evaluating software platforms or application workloads in realistic computing environments. Here, we propose VIoLET, a virtual environment for defining and launching large-scale IoT deployments within cloud VMs. It offers a declarative model to specify container-based compute resources that match the performance of the native edge, fog and cloud devices using Docker. These can be inter-connected by complex topologies on which private/public networks, and bandwidth and latency rules are enforced. Users can configure synthetic sensors for data generation on these devices as well. We validate VIoLET for deployments with > 400 devices and > 1500 device-cores, and show that the virtual IoT environment closely matches the expected compute and network performance at modest costs. This fills an important gap between IoT simulators and real deployments.Comment: To appear in the Proceedings of the 24TH International European Conference On Parallel and Distributed Computing (EURO-PAR), August 27-31, 2018, Turin, Italy, europar2018.org. Selected as a Distinguished Paper for presentation at the Plenary Session of the conferenc

    Analysis of ankle alignment abnormalities as a risk factor for pediatric flexible flat foot

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    Majority of paediatric flat feet are flexible and asymptomatic;less than 0.1% of all flat feet are rigid. If these can be diagnosed and managed early, then various complications can be prevented and they will remain asymptomatic. This study was conducted to analyse the ankle rotational malalignments in the natural course of flexible flat foot in children. Seventy-six patients of flexible flat foot and one hundred controls were included in this study. The height of foot arches was judged clinically by inspecting the height of the medial arch and by measuring the arch index on weight-bearing podograms. Tibial torsion and bimalleolar angle were assessed in all subjects. Tibial torsion was assessed in the first twenty subjects (ten cases and ten controls) both by clinical methods (foot-thigh angle) and CT. As no statistical difference in the two methods was observed, tibial torsion was measured by clinical methods only in the remaining subjects. Bimalleolar angle was measured on weight-bearing podograms in all subjects. For a minimum of two years, cases were followed up regularly with a standard conservative protocol and the height of the arches observed. Majority of cases of flexible flat foot were found to have increased tibial torsion and increased foot-bimalleolar angle (high talar spin). The severity of collapse of the medial arch and the response to conservative treatment was found to correlate with these rotational mal-alignments of the ankle. Ankle rotational mal-alignments were seen to make these flexible flat foot deformities more complex and less responsive to conservative treatment.KEY WORDS: Flat foot; Pediatric flat feet; Flexible flat fee

    Brain abscesses in a patient with a patent foramen ovale: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Brain abscesses arising from right-to-left cardiac shunting are very rare in adults.</p> <p>Case presentation</p> <p>We describe the case of a 47-year-old non-hispanic white male with periodontal disease who developed several brain abscesses caused by <it>Streptococcus intermedius</it>. A comprehensive workup revealed a patent foramen ovale with oral flora as the only plausible explanation for the brain abscesses.</p> <p>Conclusion</p> <p>Based on this case and the relevant literature, we suggest an association between a silent patent foramen ovale, paradoxical microbial dissemination to the brain, and the development of brain abscesses.</p

    Catalytic decomposition of 2-chlorophenol using an ultrasonic-assisted Fe3O4-TiO2@MWCNT system: Influence factors, pathway and mechanism study.

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    As a reusable sonocatalyst, magnetically separable Fe3O4-TiO2@MWCNT (FMT) was synthesized by an ultrasound-assisted wet impregnation method and was evaluated in the removal of 2-chlorophenol (2CP). Physical and chemical properties of the catalyst composite materials were investigated by all catalysts were systematically characterized using Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-ray Analysis (EDX), Dynamic light scattering (DLS), and N2-physisorption. The efficiency and kinetics of 2CP removal by FMT-assisted sonocatalysis (FMT-US) was systematically investigated under various operational parameters i.e. pH, FMT and 2CP concentration, temperature and ultrasonic power. The results indicated that 0.4gL-1 FMT dosage, pH 5, temperature of 35°C as well as 50 w ultrasound power are the most favorable conditions for the degradation of the 2CP. Furthermore, both of the superoxide and hydroxyl radicals were produced in the reaction, however, superoxide radicals were assumed to be the dominating reactive species for the 2CP degradation, according to the scavenging tests and electron paramagnetic resonance tests. Moreover, the FMT catalyst exhibited a high reusability and stability in the US/FMT system during the five repetitive experiments. The intermediate products were identified by GC-MS, thereby a possible degradation pathway is proposed. The chemical oxygen demand (COD) and corresponding total organic carbon (TOC) removal efficiencies were 64.9% and 56.7%, respectively. Finally, toxicity tests showed that the toxicity of the solution increased during the first 5min and then decreased significantly with the progress of the oxidation. The mechanisms of ultrasound irritation enhanced FMT activation were also proposed. Copyright © 2017 Elsevier Inc. All rights reserved

    Depression, sleeping pattern, and suicidal ideation among medical students in Bangladesh: a cross-sectional pilot study

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    © 2020, Springer-Verlag GmbH Germany, part of Springer Nature. Background: Depression is a major morbidity and the most common mental disorder among the medical students in medical schools globally. Undergraduate students suffer stress more due to their academic curriculum than the students of other faculties. In low-resource settings like Bangladesh, there is a dearth in research on the mental health of undergraduate medical students. This pilot study was conducted to add to the existing limited evidence by reporting the prevalence of depression and describing sleeping pattern and suicidal tendencies among medical students. Relevantly, we have investigated the overall mental health status among the medical students in Bangladesh. Methods: This cross-sectional study was conducted in two medical colleges of Dhaka between July 2013 and December 2013, among 221 Bangladeshi medical students from first to fifth year. By the convenience sampling technique, data were collected by a pretested, structured, self-administered questionnaire and analysis was done by SPSS version 18.0. Depression was assessed by the validated Patient Health Questionnaire-9 (PHQ-9) tool among the respondents. Goldberg’s General Health Questionnaire (GHQ-28) was used for assessing overall mental health status. Results: Depression was found in 38.9% of participants, with 3.6%, 14.5%, and 20.8% being severe, moderate, and mild depression, respectively. 17.6% of medical students had suicidal tendency or attempted suicide at least once after attending medical school. The sleeping hours were inadequate and altered after starting this stressful academic course. 33.5% of medical students had poor mental health status. There was a statistically significant association between poor mental health status in the age group less than 22 years old and initial academic study year (1st to 3rd of MBBS). Conclusion: The findings are suggestive of a higher prevalence of depression among early-year medical students and marginal predominance in males. Suicidal tendency is also higher. This calls for further investigation with situation analysis, qualitative explorations, and surveys to explore the burden of such disorders in Bangladesh

    Synaptic terminal density early in the course of schizophrenia: an in vivo UCB-J positron emission tomographic imaging study of synaptic vesicle glycoprotein 2A (SV2a).

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    BACKGROUND: The synaptic hypothesis is an influential theory of the pathoaetiology of schizophrenia. Supporting this, there is lower uptake of the synaptic terminal density marker UCB-J in patients with chronic schizophrenia compared to controls. However, it is unclear whether these differences are present early in the illness. To address this, we investigated [11C]UCB-J volume of distribution (VT) in antipsychotic-naïve/free patients with schizophrenia (SCZ) recruited from first-episode services compared to healthy volunteers (HV). METHODS: Forty-two volunteers (SCZ n = 21, HV n = 21) underwent [11C]UCB-J positron emission tomography to index [11C]UCB-J VT and distribution volume ratio (DVR) in the anterior cingulate, frontal, and dorsolateral prefrontal cortices, temporal, parietal and occipital lobes, hippocampus, thalamus and amygdala. Symptom severity was assessed in the SCZ group using the Positive and Negative Syndrome Scale (PANSS). RESULTS: We found no significant effects of group on [11C]UCB-J VT or DVR in most regions of interest (effect sizes from d=0.0 to 0.7, p>0.05), other than lower DVR in the temporal lobe (d=0.7, uncorrected p<0.05) and lower VT/fp in the anterior cingulate cortex in patients (d=0.7, uncorrected p<0.05). PANSS total score was negatively associated with [11C]UCB-J VT in the hippocampus in the SCZ group (r =-0.48, p=0.03). CONCLUSIONS: These findings indicate that large differences in synaptic terminal density are not present early in schizophrenia, although there may be more subtle effects. When taken with prior evidence of lower [11C]UCB-J VT in patients with chronic illness, this may indicate synaptic density changes during the course of schizophrenia

    Plasma apolipoprotein J as a potential biomarker for Alzheimer\u27s disease: Australian Imaging, Biomarkers and Lifestyle study of aging

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    Introduction: For early detection of Alzheimer\u27s disease (AD), the field needs biomarkers that can be used to detect disease status with high sensitivity and specificity. Apolipoprotein J (ApoJ, also known as clusterin) has long been associated with AD pathogenesis through various pathways. The aim of this study was to investigate the potential of plasma apoJ as a blood biomarker for AD. Methods: Using the Australian Imaging, Biomarkers and Lifestyle (AIBL) study of aging, the present study assayed plasma apoJ levels over baseline and 18 months in 833 individuals. Plasma ApoJ levels were analyzed with respect to clinical classification, age, gender, apolipoprotein E (APOE) ε4 allele status, mini-mental state examination score, plasma amyloid beta (Aβ), neocortical Aβ burden (as measured by Pittsburgh compound B-positron emission tomography), and total adjusted hippocampus volume. Results: ApoJ was significantly higher in both mild cognitive impairment (MCI) and AD groups as compared with healthy controls (HC; P \u3c .0001). ApoJ significantly correlated with both standardized uptake value ratio (SUVR) and hippocampus volume and weakly correlated with the plasma Aβ1-42/Aβ1-40 ratio. Plasma apoJ predicted both MCI and AD from HC with greater than 80% accuracy for AD and greater than 75% accuracy for MCI at both baseline and 18-month time points. Discussion: Mean apoJ levels were significantly higher in both MCI and AD groups. ApoJ was able to differentiate between HC with high SUVR and HC with low SUVR via APOE ε4 allele status, indicating that it may be included in a biomarker panel to identify AD before the onset of clinical symptoms. © 2016 The Authors
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