FlowQoS: Per-Flow Quality of Service for Broadband Access Networks

Research areas: Computer NetworksIn broadband access networks, one application may compete for the bandwidth of other applications, thus degrading overall performance. One solution to this problem is to allocate bandwidth to competing flows based on the application type at the gateway of the home network. Unfortunately, application-based quality of service (QoS) on a home network gateway faces significant constraints, as commodity home routers are not typically powerful enough to perform application classification, and many home users are not savvy enough to configure QoS parameters. This paper describes FlowQoS, an SDN-based approach for application-based bandwidth allocation where users can allocate upstream and downstream bandwidths for different applications at a high level, offloading application identification to an SDN controller that dynamically installs traffic shaping rules for application flows. FlowQoS has two modules: a flow classifier and an SDNbased rate limiter. We design a custom DNS-based classifier to identify different applications that run over common web ports; a second classifier performs lightweight packet inspection to classify non-HTTP traffic flows. We implement FlowQoS on OpenWrt and demonstrate that it can improve the performance of both adaptive video streaming and VoIP in the presence of active competing traffic

FlowQoS: QoS for the Rest of Us

International audienceWe describe the architecture of FlowQoS, a system that makes it easier for users in home broadband access networks to configure quality of service based on applications and devices, as opposed to obscure, low-level parameters. The central tenet of FlowQoS's design is control logic that performs application identification and uses flow-table rules to forward traffic through the appropriate rate shapers on a home router. The architecture has two components: a flow classifier, which maps application traffic to the appropriate parts of flow space; and an SDN-based rate shaper, which shapes application traffic by forwarding it through the appropriate shaped virtual links in the home gateway. This paper describes the high-level architecture of FlowQoS, as well as our current implementation

Stem-cell competition

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62534/1/418025a.pd

Prostate-specific antigen (PSA) testing of men in UK general practice : a 10-year longitudinal cohort study

OBJECTIVES: Cross-sectional studies suggest that around 6% of men undergo prostate-specific antigen (PSA) testing each year in UK general practice (GP). This longitudinal study aims to determine the cumulative testing pattern of men over a 10-year period and whether this testing can be considered equivalent to screening for prostate cancer (PCa). SETTING, PARTICIPANTS AND OUTCOME MEASURES: Patient-level data on PSA tests, biopsies and PCa diagnoses were obtained from the UK Clinical Practice Research Datalink (CPRD) for the years 2002 to 2011. The cumulative risks of PSA testing and of being diagnosed with PCa were estimated for the 10-year study period. Associations of a man's age, region and index of multiple deprivation with the cumulative risk of PSA testing and PCa diagnosis were investigated. Rates of biopsy and diagnosis, following a high test result, were compared with those from the programme of PSA testing in the Prostate Testing for Cancer and Treatment (ProtecT) study. RESULTS: The 10-year risk of exposure to at least one PSA test in men aged 45 to 69 years in UK GP was 39.2% (95% CI 39.0 to 39.4%). The age-specific risks ranged from 25.2% for men aged 45-49 years to 53.0% for men aged 65-69 years (p for trend <0.001). For those with a PSA level ≥3, a test in UK GP was less likely to result in a biopsy (6%) and/or diagnosis of PCa (15%) compared with ProtecT study participants (85% and 34%, respectively). CONCLUSION: A high proportion of men aged 45-69 years undergo PSA tests in UK GP: 39% over a 10-year period. A high proportion of these tests appear to be for the investigation of lower urinary tract symptoms and not screening for PCa. TRIAL REGISTRATION NUMBER: ISRCTN20141297,NCT02044172

The impact of interactions, bars, bulges, and AGN on star formation efficiency in local massive galaxies

Using observations from the GASS and COLD GASS surveys and complementary data from SDSS and GALEX, we investigate the nature of variations in gas depletion time observed across the local massive galaxy population. The large and unbiased COLD GASS sample allows us to assess the relative importance of galaxy interactions, bar instabilities, morphologies and the presence of AGN in regulating star formation efficiency. Both the H2 mass fraction and depletion time vary as a function of the distance of a galaxy from the main sequence in the SFR-M* plane. The longest gas depletion times are found in below-main sequence bulge-dominated galaxies that are either gas-poor, or else on average less efficient than disk-dominated galaxy at converting into stars any cold gas they may have. We find no link between AGN and these long depletion times. The galaxies undergoing mergers or showing signs of morphological disruptions have the shortest molecular gas depletion times, while those hosting strong stellar bars have only marginally higher global star formation efficiencies as compared to matched control samples. Our interpretation is that depletion time variations are caused by changes in the ratio between the gas mass traced by the CO(1-0) observations, and the gas mass in high density star-forming cores, with interactions, mergers and bar instabilities able to locally increase pressure and raise the ratio of efficiently star-forming gas to CO-detected gas. Building a sample representative of the local massive galaxy population, we derive a global Kennicutt-Schmidt relation of slope 1.18+/-0.24, and observe structure within the scatter around this relation, with galaxies having low (high) stellar mass surface densities lying systematically above (below) the mean relation, suggesting that gas surface density is not the only parameter driving the global star formation ability of a galaxy.Comment: 19 pages, 12 figures, accepted for publication in Ap

Development of a framework to improve the process of recruitment to randomised controlled trials (RCTs):the SEAR (Screened, Eligible, Approached, Randomised) framework

BackgroundResearch has shown that recruitment to trials is a process that stretches from identifying potentially eligible patients, through eligibility assessment, to obtaining informed consent. The length and complexity of this pathway means that many patients do not have the opportunity to consider participation. This article presents the development of a simple framework to document, understand and improve the process of trial recruitment. MethodsEight RCTs integrated a QuinteT Recruitment Intervention (QRI) into the main trial, feasibility or pilot study. Part of the QRI required mapping the patient recruitment pathway using trial-specific screening and recruitment logs. A content analysis compared the logs to identify aspects of the recruitment pathway and process that were useful in monitoring and improving recruitment. Findings were synthesised to develop an optimised simple framework that can be used in a wide range of RCTs. ResultsThe eight trials recorded basic information about patients screened for trial participation and randomisation outcome. Three trials systematically recorded reasons why an individual was not enrolled in the trial, and further details why they were not eligible or approached, or declined randomisation. A framework to facilitate clearer recording of the recruitment process and reasons for non-participation was developed: SEAR andndash; Screening, to identify potentially eligible trial participants; Eligibility, assessed against the trial protocol inclusion/exclusion criteria; Approach, the provision of oral and written information and invitation to participate in the trial, and Randomised or not, with the outcome of randomisation or treatment received. ConclusionsThe SEAR framework encourages the collection of information to identify recruitment obstacles and facilitate improvements to the recruitment process. SEAR can be adapted to monitor recruitment to most RCTs, but is likely to add most value in trials where recruitment problems are anticipated or evident. Further work to test it more widely is recommended.</p

Gas Source Molecular Beam Epitaxy of Compound Semiconductors

Contains an introduction and reports on six research projects.Advanced Research Projects Agency Subcontract 284-25041Joint Services Electronics Program Contract DAAL03-92-C-0001National Center for Integrated Photonic Technology Contract 542-381National Science Foundation Grant DMR 92-02957National Science Foundation Contract DMR 92-02957National Science Foundation Grant DMR 90-2293

Systematic review and meta-analysis of the associations between body mass index, prostate cancer, advanced prostate cancer, and prostate-specific antigen.

PURPOSE: The relationship between body mass index (BMI) and prostate cancer remains unclear. However, there is an inverse association between BMI and prostate-specific antigen (PSA), used for prostate cancer screening. We conducted this review to estimate the associations between BMI and (1) prostate cancer, (2) advanced prostate cancer, and (3) PSA. METHODS: We searched PubMed and Embase for studies until 02 October 2017 and obtained individual participant data from four studies. In total, 78 studies were identified for the association between BMI and prostate cancer, 21 for BMI and advanced prostate cancer, and 35 for BMI and PSA. We performed random-effects meta-analysis of linear associations of log-PSA and prostate cancer with BMI and, to examine potential non-linearity, of associations between categories of BMI and each outcome. RESULTS: In the meta-analyses with continuous BMI, a 5 kg/m2 increase in BMI was associated with a percentage change in PSA of - 5.88% (95% CI - 6.87 to - 4.87). Using BMI categories, compared to normal weight men the PSA levels of overweight men were 3.43% lower (95% CI - 5.57 to - 1.23), and obese men were 12.9% lower (95% CI - 15.2 to - 10.7). Prostate cancer and advanced prostate cancer analyses showed little or no evidence associations. CONCLUSION: There is little or no evidence of an association between BMI and risk of prostate cancer or advanced prostate cancer, and strong evidence of an inverse and non-linear association between BMI and PSA. The association between BMI and prostate cancer is likely biased if missed diagnoses are not considered

Gas Source Molecular Beam Epitaxy of Compound Semiconductors

Contains an introduction and reports on seven research projects.Advanced Research Projects Agency Subcontract 284-25041Joint Services Electronics Program Contract DAAL03-92-C-0001Joint Services Electronics Program Grant DAAH-04-95-1-0038National Center for Integrated Photonic Technology Contract 542-381National Center for Integrated Photonic Technology Grant subcontract 652-693U.S. Army Research Office/ AASERT Contract DAAH04-93-G-0175National Science Foundation Grant DMR 92-02957National Science Foundation Grant DMR 92-02957National Science Foundation Grant DMR 90-22933MIT Lincoln Laboratory Contract BX-5411National Science Foundation DMR 94-0033