A Framework for Effective Placement of Virtual Machine Replicas for Highly Available Performance-sensitive Cloud-based Applications

REACTION 2012. 1st International workshop on Real-time and distributed computing in emerging applications. December 4th, 2012, San Juan, Puerto Rico.Applications are increasingly being deployed in the Cloud due to benefits stemming from economy of scale, scalability, flexibility and utility-based pricing model. Although most cloud-based applications have hitherto been enterprisestyle, there is a new trend towards hosting performancesensitive applications in the cloud that demand both high availability and good response times. In the current stateof- the-art in cloud computing research, there does not exist solutions that provide both high availability and acceptable response times to these applications in a way that also optimizes resource consumption in data centers, which is a key consideration for cloud providers. This paper addresses this dual challenge by presenting a design of a fault-tolerant framework for virtualized data centers that makes two important contributions. First, it describes an architecture of a fault-tolerance framework that can be used to automatically deploy replicas of virtual machines in data centers in a way that optimizes resources while assures availability and responsiveness. Second, it describes a specific formulation of a replica deployment combinatorial optimization problem that can be plugged into our strategizable deployment framework.This work was supported in part by the National Science Foundation NSF SHF/CNS Award CNS 0915976 and NSF CAREER CNS 0845789. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation

Increased risk of tuberculosis in health care workers: a retrospective survey at a teaching hospital in Istanbul, Turkey

BACKGROUND: Tuberculosis (TB) is an established occupational disease affecting health care workers (HCWs). Determining the risk of TB among HCWs is important to enable authorites to take preventative measures in health care facilities and protect HCWs. This study was designed to assess the incidence of TB in a teaching hospital in Istanbul, Turkey. This study is retrospective study of health records of HCWs in our hospital from 1991 to 2000. RESULTS: The mean workforce of the hospital was 3359 + 33.2 between 1991 and 2000. There were 31 cases (15 male) meeting the diagnostic criteria for TB, comprising eight doctors, one nurse and 22 other health professionals. Mean incidence of TB was 96 per 100,000 for all HCWs (relative risk: 2.71), 79 per 100,000 for doctors (relative risk: 2.2), 14 per 100,000 for nurses and 121 per 100,000 (relative risk: 3.4) for other professionals. The mean incidence of TB in Turkey between 1991 and 2000 was 35.4 per 100,000. Incidence of TB was similar in the Departments of Chest Diseases and Clinical Medicine but there were no TB cases in the Basic Science and Managerial Departments. CONCLUSION: HCWs in Turkey who work in clinics have an increased risk for TB. Post-graduate education and prevention programs reduce the risk of TB. Control programs to prevent nosocomial transmission of TB should be established in hospitals to reduce risk for HCWs

Does Europe Matter? A Comparative Study of Young People’s Identifications with Europe at a State School and a European School in England.

This article explores the extent to which young people in predominantly middle-class environments identify with Europe and considers the influence of European education policy, school ethos and curricula. We compare data drawn from individual and focus group interviews with students aged 15–17 at a state school and a European School in England. The empirical analysis was informed by post-structuralism and found that young people at both schools developed multidimensional, multifaceted identities. Students at the European School, which has an ethos of developing both national and European identities, identified themselves more as European than their peers at the state school, which integrated students on the basis of a common British citizenship. The findings suggest that the policy on the European dimension in education contributes towards developing students’ identification with Europe and to their knowledge of Europe, though not at the expense of their ethnic and national identities, which were stronger than their European identities. Lack of a European dimension in education (both in and out of school) seems to result in a lack of identification with and knowledge about Europe

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

Peer reviewe

Observation of tW production in the single-lepton channel in pp collisions at root s=13 TeV

A measurement of the cross section of the associated production of a single top quark and a W boson in final states with a muon or electron and jets in proton-proton collisions at root s = 13 TeV is presented. The data correspond to an integrated luminosity of 36 fb(-1) collected with the CMS detector at the CERN LHC in 2016. A boosted decision tree is used to separate the tW signal from the dominant t (t) over bar background, whilst the subleading W+jets and multijet backgrounds are constrained using data-based estimates. This result is the first observation of the tW process in final states containing a muon or electron and jets, with a significance exceeding 5 standard deviations. The cross section is determined to be 89 +/- 4 (stat) +/- 12 (syst) pb, consistent with the standard model.Peer reviewe

Measurement of the top quark mass using events with a single reconstructed top quark in pp collisions at root s=13 TeV

Abstract:A measurement of the top quark mass is performed using a data sample en-riched with single top quark events produced in thetchannel. The study is based on proton-proton collision data, corresponding to an integrated luminosity of 35.9 fb−1, recorded at√s= 13TeV by the CMS experiment at the LHC in 2016. Candidate events are selectedby requiring an isolated high-momentum lepton (muon or electron) and exactly two jets,of which one is identified as originating from a bottom quark. Multivariate discriminantsare designed to separate the signal from the background. Optimized thresholds are placedon the discriminant outputs to obtain an event sample with high signal purity. The topquark mass is found to be172.13+0.76−0.77GeV, where the uncertainty includes both the sta-tistical and systematic components, reaching sub-GeV precision for the first time in thisevent topology. The masses of the top quark and antiquark are also determined separatelyusing the lepton charge in the final state, from which the mass ratio and difference aredetermined to be0.9952+0.0079−0.0104and0.83+1.79−1.35GeV, respectively. The results are consistentwithCPTinvariance