2,624 research outputs found
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Queues don't matter when you can JUMP them!
QJUMP is a simple and immediately deployable approach
to controlling network interference in datacenter
networks. Network interference occurs when congestion
from throughput-intensive applications causes queueing
that delays traffic from latency-sensitive applications.
To mitigate network interference, QJUMP applies Internet
QoS-inspired techniques to datacenter applications.
Each application is assigned to a latency sensitivity level
(or class). Packets from higher levels are rate-limited
in the end host, but once allowed into the network can
“jump-the-queue” over packets from lower levels. In settings
with known node counts and link speeds, QJUMP
can support service levels ranging from strictly bounded
latency (but with low rate) through to line-rate throughput
(but with high latency variance).
We have implemented QJUMP as a Linux Traffic Control
module. We show that QJUMP achieves bounded
latency and reduces in-network interference by up to
300×, outperforming Ethernet Flow Control (802.3x),
ECN (WRED) and DCTCP. We also show that QJUMP
improves average flow completion times, performing
close to or better than DCTCP and pFabric.This work was supported
by a Google Fellowship, EPSRC INTERNET Project
EP/H040536/1, Defense Advanced Research Projects
Agency (DARPA) and Air Force Research Laboratory
(AFRL), under contract FA8750-11-C-0249.This is the final published version. It first appeared at https://www.usenix.org/conference/nsdi15/technical-sessions/presentation/grosvenor
Urological referral of asymptomatic men in general practice in England
The Prostate Cancer Risk Management Programme (PCRMP) launched in November 2002 provides guidelines for general practitioners (GPs) on age-specific prostate-specific antigen (PSA) cutoff levels in asymptomatic men. The impact of the PCRMP on GP referrals is unknown. This study investigates whether there was a change in the proportion of asymptomatic men with raised PSA levels (⩾3 ng ml−1) who were referred to urologists since the launch of the guidelines. Sixty-nine general practices in four areas of England and the main pathology laboratory in each area, which had participated in our previous research, were asked to provide data. Forty-eight practices (70%) provided retrospective data on urological referrals in men who had a PSA test taken in the periods 1 December 2001 to 31 May 2002 (pre-launch) and 1 December 2003 to 31 May 2004 (post-launch). Data on referrals were completed for 709 (79%) out of 898 and 1040 (90%) out of 1157 raised records pre- and post-launch, respectively. The percentage of men with raised PSA levels who were asymptomatic was similar in both time periods (19–20%) and the proportion referred to urologists according to the PCRMP guidelines did not increase significantly over time (24% pre-launch and 29% post-launch, P=0.42). The referral rate was lower than expected if the guidelines had been followed. The influence of the guidelines seems to have been low. At the time of data collection, 56% (112 out of 200) of GP partners reported that they were aware of receiving the PCRMP pack. To ensure future, effective implementation of guidelines requires evaluation
Meeting the global protein supply requirements of a growing and ageing population
\ua9 The Author(s) 2024.Human dietary patterns are a major cause of environmental transformation, with agriculture occupying ~ 50% of global land space, while food production itself is responsible for ~ 30% of all greenhouse gas emissions and 70% of freshwater use. Furthermore, the global population is also growing, such that by 2050, it is estimated to exceed ~ 9 billion. While most of this expansion in population is expected to occur in developing countries, in high-income countries there are also predicted changes in demographics, with major increases in the number of older people. There is a growing consensus that older people have a greater requirement for protein. With a larger and older population, global needs for protein are set to increase. This paper summarises the conclusions from a Rank Prize funded colloquium evaluating novel strategies to meet this increasing global protein need
Measurement of Scintillation and Ionization Yield and Scintillation Pulse Shape from Nuclear Recoils in Liquid Argon
We have measured the scintillation and ionization yield of recoiling nuclei
in liquid argon as a function of applied electric field by exposing a
dual-phase liquid argon time projection chamber (LAr-TPC) to a low energy
pulsed narrow band neutron beam produced at the Notre Dame Institute for
Structure and Nuclear Astrophysics. Liquid scintillation counters were arranged
to detect and identify neutrons scattered in the TPC and to select the energy
of the recoiling nuclei. We report measurements of the scintillation yields for
nuclear recoils with energies from 10.3 to 57.3 keV and for median applied
electric fields from 0 to 970 V/cm. For the ionization yields, we report
measurements from 16.9 to 57.3 keV and for electric fields from 96.4 to 486
V/cm. We also report the observation of an anticorrelation between
scintillation and ionization from nuclear recoils, which is similar to the
anticorrelation between scintillation and ionization from electron recoils.
Assuming that the energy loss partitions into excitons and ion pairs from
Kr internal conversion electrons is comparable to that from Bi
conversion electrons, we obtained the numbers of excitons () and ion
pairs () and their ratio () produced by nuclear recoils from
16.9 to 57.3 keV. Motivated by arguments suggesting direction sensitivity in
LAr-TPC signals due to columnar recombination, a comparison of the light and
charge yield of recoils parallel and perpendicular to the applied electric
field is presented for the first time.Comment: v2 to reflect published versio
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State of the California current 2013-14: El niño looming
In 2013, the California current was dominated by strong coastal upwelling and high productivity. Indices of total cumulative upwelling for particular coastal locations reached some of the highest values on record. Chlorophyll a levels were high throughout spring and summer. Catches of upwelling-related fish species were also high. After a moderate drop in upwelling during fall 2013, the California current system underwent a major change in phase. Three major basin-scale indicators, the PDO, the NPGO, and the ENSO-MEI, all changed phase at some point during the winter of 2013/14. The PDO changed to positive values, indicative of warmer waters in the North Pacific; the NPGO to negative values, indicative of lower productivity along the coast; and the MEI to positive values, indicative of an oncoming El Niño. Whereas the majority of the California Current system appears to have transitioned to an El Niño state by August 2014, based on decreases in upwelling and chlorophyll a concentration, and increases in SST, there still remained pockets of moderate upwelling, cold water, and high chlorophyll a biomass at various central coast locations, unlike patterns seen during the more major El Niños (e.g., the 97-98 event). Catches of rockfish, market squid, euphausiids, and juvenile sanddab remained high along the central coast, whereas catches of sardine and anchovy were low throughout the CCS. 2014 appears to be heading towards a moderate El Niño state, with some remaining patchy regions of upwellingdriven productivity along the coast. Superimposed on this pattern, three major regions have experienced possibly non-El Niño-related warming since winter: the Bering Sea, the Gulf of Alaska, and offshore of southern California. It is unclear how this warming may interact with the predicted El Niño, but the result will likely be reduced growth or reproduction for many key fisheries species
Coordinated Ionospheric Reconstruction CubeSat Experiment (CIRCE) mission overview
The Coordinated Ionospheric Reconstruction Cubesat Experiment (CIRCE) is a joint US/UK mission consisting of two 6U CubeSats actively maintaining a lead-follow configuration in the same low Earth orbit with a launch planned for the 2020 timeframe. These nanosatellites will each feature multiple space weather payloads. From the US, the Naval Research Laboratory will provide two 1U Triple Tiny Ionospheric Photometers (Tri-TIPs) on each satellite, observing the ultraviolet 135.6 nm emission of atomic oxygen at nighttime. The primary objective is to characterize the twodimensional distribution of electrons in the Equatorial Ionization Anomaly (EIA). The methodology used to reconstruct the nighttime ionosphere employs continuous UV photometry from four distinct viewing angles in combination with an additional data source, such as in situ plasma density measurements, with advanced image space reconstruction algorithm tomography techniques. From the UK, the Defence Science and Technology Laboratory (Dstl) is providing the In-situ and Remote Ionospheric Sensing suite consisting of an Ion/Neutral Mass Spectrometer, a triple-frequency GPS receiver for ionospheric sensing, and a radiation environment monitor. We present our mission concept, simulations illustrating the imaging capability of the Tri-TIP sensor suite, and a range of science questions addressable via these measurements
Prevalence of systemic inflammatory response syndrome (SIRS) in hospitalized children: a point prevalence study
<p>Abstract</p> <p>Background</p> <p>In accordance with the 1st International pediatric sepsis consensus conference, where sepsis was defined as SIRS associated with suspected or proven infection, we have identified the need to assess the prevalence of SIRS and sepsis in children with abnormal temperatures hospitalized in The Children's Clinical University Hospital in Latvia.</p> <p>Methods</p> <p>A descriptive prospective point prevalence study (using two time periods, each 24 h, randomly chosen) was conducted on all children (n = 943) treated in the hospital. All children with abnormal temperatures – fever or hypothermia (n = 92) – were included in the study. Questionnaires evaluating age-specific SIRS criteria were completed. The prevalence of SIRS was detected with 95% CI.</p> <p>Results</p> <p>Out of a total of 943 patients treated in the hospital, 10% (n = 92) had abnormal temperatures. In all these cases the abnormal temperature was a fever; hypothermia was not established in any patient. Of the children with fever, 72% (n = 66) had SIRS. Of the SIRS patients, 8% (n = 5) developed sepsis, 5% (n = 3) severe sepsis and 2% (n = 1) septic shock. Seventy-six percent (n = 50) of the SIRS patients had fever in combination with respiratory rate >2 SD above normal for age; 50% (n = 33) had fever with abnormal leukocyte count; 15% (n = 10) had fever with tachycardia >2 SD above normal for age. Most of the SIRS patients (39%, n = 25) were aged 2–5 years. Twenty-one percent (n = 14) of the children with SIRS and 50% (n = 2) of those with severe sepsis and septic shock had an underlying disease. In no case was SIRS and sepsis recognized by doctors and the diagnoses were not recorded on the patients' cards.</p> <p>Conclusion</p> <p>Our results would indicate a high risk for sepsis development in children with SIRS. Early SIRS diagnosis and awareness of risk of developing sepsis could change the medical approach to the patient in everyday clinical practice, eventually leading to early, goal-directed therapy for sepsis.</p
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