VM capacity-aware scheduling within budget constraints in IaaS clouds

Recently, cloud computing has drawn significant attention from both industry and academia, bringing unprecedented changes to computing and information technology. The infrastructure-as-a-Service (IaaS) model offers new abilities such as the elastic provisioning and relinquishing of computing resources in response to workload fluctuations. However, because the demand for resources dynamically changes over time, the provisioning of resources in a way that a given budget is efficiently utilized while maintaining a sufficing performance remains a key challenge. This paper addresses the problem of task scheduling and resource provisioning for a set of tasks running on IaaS clouds; it presents novel provisioning and scheduling algorithms capable of executing tasks within a given budget, while minimizing the slowdown due to the budget constraint. Our simulation study demonstrates a substantial reduction up to 70% in the overall task slowdown rate by the proposed algorithms. © 2016 Thanasias et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Decreasing trend of Legionella isolation in a long-term microbial monitoring program in Greek hospitals

Legionnaires' disease is a known cause of severe pneumonia in a nosocomial setting. This study examined Legionella isolation in Greek hospitals. Water samples and swabs of showerheads from 41 hospitals were collected over a four-year period (2004-2007) from hot and cold water systems and cooling towers in Greece. In total, 1058 samples were examined for the presence of Legionella. From the hot water samples examined, 166 out of 607 (27.3%) were positive for Legionella, including 111 (18.3%) positive for Legionella pneumophila sg1 samples. The temperature of hot water samples less than 55 degrees C was statistically significant, associated with Legionella spp. isolation (RR 4.01, 95% CI 2.33-6.92). Ten out of 17 (58.8%) hospital cooling towers required remedial actions due to Legionella colonization. Reemergence of Legionella spp. colonization was evident in more than half of the hospitals where frequent monitoring and appropriate risk assessment plans were absent or lacking. Hospitals that were monitored continuously over the study period presented a decreasing trend of Legionella colonization. Environmental risk assessment together with Legionella isolation should be enforced systematically in hospitals

Municipal waste collectors and hepatitis b and c virus infection: A cross-sectional study

There is some evidence that municipal waste collectors are at risk of Hepatitis B virus infection (HBV). Published information on risk of Hepatitis C Virus (HCV) infection among waste collectors is scant. We aimed to investigate the prevalence and possible risk factors of HBV and HCV infections among waste collectors in a municipality of the broader region of Attica, Greece. A cross-sectional sero-prevalence study was conducted in a municipality of the broader region of Attica, Greece. Fifty waste collectors participated in the study (response rate: 95%). The group of municipal waste collectors was compared to a convenient sample of white collar employees not exposed to waste (n=83). Waste collectors recorded a significantly higher prevalence of hepatitis B virus infection (anti-HBc positivity) in comparison to the reference group (15% vs. 2.5%, respectively; p<001). Waste collectors who reported frequent exposure to needle-stick injuries had higher risk of HBV infection (RR=8.28; 95% CI=1.076-63.79; p=0.033). Only one municipal waste collector was anti-HCV (+). Our study corroborates previous results of an increased prevalence of Hepatitis B infection among municipal waste collectors. In addition we found that needle stick injuries were associated with the risk of HBV infection. By contrast, HCV infection does not seem to represent a significant occupational hazard among waste collectors. Vaccination against HBV among municipal solid waste collectors and promotion and use of safer methods for the collection of non-hospital medical waste could represent potential measures for the prevention of Hepatitis B Virus infection among municipal waste collectors. © 2014, Le Infezioni in Medicina. All rights reserved

Evaluation of the genetic damage to workers in a Greek shipyard

Shipyards are industrial areas where workers are likely exposed to environmental pollutants such as welding fumes, fine organic solvent and dye dust, that render the occupational environment a high risk one. Assessing the risk that workers are exposed to is a high critical factor in improving their working conditions. The present study aims to investigate the potential genetic damage to workers exposed to a harsh environment in a Greek shipyard. It is focused on assessing the percentage of induced micronuclei, as well as on changes in the various cell types of shipyard workers’ oral mucosa epithelium by implementing the buccal micronucleus cytome assay. Exposed workers appeared with statistically significant induced micronuclei as compared to office employees. Statistically, significant cell lesions were detected and are related to workers’ exposure to environmental conditions. The workers’ smoking habit contributed as well to the observed buccal epithelial cell alterations. The observed data signify the high-risk workers are exposed; resulting in the shipyard’s management the need to implement measures improving the working environment conditions and to reevaluate the workers’ personal protective equipment requirements. ©️ 2022 National Institute of Occupational Safety and Health