542 research outputs found

    Heat-acclimatization and pre-cooling: a further boost for endurance performance?

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    © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd To determine if pre-cooling (PC) following heat-acclimatization (HA) can further improve self-paced endurance performance in the heat, 13 male triathletes performed two 20-km cycling time-trials (TT) at 35 °C, 50% relative humidity, before and after an 8-day training camp, each time with (PC) or without (control) ice vest PC. Pacing strategies, physiological and perceptual responses were assessed during each TT. PC and HA induced moderate (+10 ± 18 W; effect size [ES] 4.4 ± 4.6%) and very large (+28 ± 19 W; ES 11.7 ± 4.1%) increases in power output (PO), respectively. The overall PC effect became unclear after HA (+4 ± 14 W; ES 1.4 ± 3.0%). However, pacing analysis revealed that PC remained transiently beneficial post-HA, i.e., during the first half of the TT. Both HA and PC pre-HA were characterized by an enhanced PO without increased cardio-thermoregulatory or perceptual disturbances, while post-HA PC only improved thermal comfort. PC improved 20-km TT performance in unacclimatized athletes, but an 8-day HA period attenuated the magnitude of this effect. The respective converging physiological responses to HA and PC may explain the blunting of PC effectiveness. However, perceptual benefits from PC can still account for the small alterations to pacing noted post-HA

    Evidence of disturbed sleep and increased illness in overreached endurance athletes

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    PURPOSE: This study aimed to examine whether (i) objective markers of sleep quantity and quality are altered in endurance athletes experiencing overreaching in response to an overload training program and (ii) potential reduced sleep quality would be accompanied with a higher prevalence of upper respiratory tract infections in this population. METHODS: Twenty-seven trained male triathletes were randomly assigned to either overload (n = 18) or normal (CTL, n = 9) training groups. Respective training programs included a 1-wk moderate training phase followed by a 3-wk period of overload or normal training, respectively, and then a subsequent 2-wk taper. Maximal aerobic power and oxygen uptake (V̇O 2max) from incremental cycle ergometry were measured after each phase, whereas mood states and incidences of illness were determined from questionnaires. Sleep was monitored every night of the 6 wk using wristwatch actigraphy. RESULTS: Of the 18 overload training group subjects, 9 were diagnosed as functionally overreached (F-OR) after the overload period, as based on declines in performance and V̇O2max with concomitant high perceived fatigue (P 0.05). There was a significant time-group interaction for sleep duration (SD), sleep efficiency (SE), and immobile time (IT). Only the F-OR group demonstrated a decrease in these three parameters (-7.9% ± 6.7%,-1.6% ± 0.7%, and-7.6% ± 6.6% for SD, SE, and IT, respectively, P < 0.05), which was reversed during the subsequent taper phase. Higher prevalence of upper respiratory tract infections were also reported in F-OR (67%, 22%, and 11% incidence rate for F-OR, AF, and CTL, respectively). CONCLUSION: This study confirms sleep disturbances and increased illness in endurance athletes who present with symptoms of F-OR during periods of high volume training. © 2014 by the American college of Sports Medicine

    The Intrinsic Fundamental Group of a Linear Category

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    We provide an intrinsic definition of the fundamental group of a linear category over a ring as the automorphism group of the fibre functor on Galois coverings. If the universal covering exists, we prove that this group is isomorphic to the Galois group of the universal covering. The grading deduced from a Galois covering enables us to describe the canonical monomorphism from its automorphism group to the first Hochschild-Mitchell cohomology vector space.Comment: Final version, to appear in Algebras and Representation Theor

    HFI L2 DPC destripping and mapmaking modules

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    PoS(CMB2006)049International audienceThe data processing of the data from the High Frequency Instrument (HFI) of the Planck mission will use several modules. Destriping is expected to play a central role in the mapmaking stage. This paper outlines two existing HFI l2 DPC destriping modules together with estimations of their performances. MOKAPIX is a temperature data destriping tool based on scanning redundancies on the sky. We have developped another modules, BOGOPIX , based on the same philosophy, to perform simultaneously destriping and relative intercalibration

    Chronic wounds consultation by telemedicine between a rehabilitation healthcare center and nursing home or home

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    Saint-Hélier Rehabilitation Center (pôle MPR Saint-Hélier), located in Rennes, has been selected for a regional telemedicine project in 2014 about chronic wounds.AimTo make care access easier for heavy disabilities patients in nursing homes or at home with chronic wounds.MethodThe members of TLM Pl@ies chronic team are specialist doctors and nurses for wounds. On request, the occupational therapist or dietician involve in the consultation (multidisciplinary approach). A secure videoconference (web) is used.ResultsSince July 2014, over 100 teleconsultations have been done. Targeted population is constituted by patients:– whose access to care is decreased due to moving difficulties;– of which the health care team is crossing difficulties in the care process (wound care but also disability, nutrition..).Seventy percent of requests come from the nursing home, 30% from homes (pressure ulcers stages 3 and 4, arterial ulcers, venous or mixed). Middle age: 78 years (20–101 years). Only 3 patients refused. Time to organize the teleconsultation is on average 13 days. Consultations last on average 25 minutes. In 30% of cases the teleconsultation is extended by a real live training time for the nurse at home guided by the TLM Pl@ies chroniques team. We evaluate professional satisfaction and technical satisfaction. Without teleconsultation, in 77% of cases transportation request for consultation would be made, in 5% hospitalization. In 18% no request would be done.Discussion/conclusionThese first results, encouraging, confirms the interest of specialized consultations in medico-social settings, and telemedicine can be an effective solution

    Automatic Specialization of Protocol Stacks in OS kernels

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    Awarded best paperInternational audienceFast and optimized protocol stacks play a major role in the performance of network services. This role is especially important in embedded class systems, where performance metrics such as data throughput tend to be limited by the CPU. It is common on such systems, to have protocol stacks that are optimized by hand for better performance and smaller code footprint. In this paper, we propose a strategy to automate this process. Our approach uses program specialization, and enables applications using the network to request specialized code based on the current usage scenario. The specialized code is generated dynamically and loaded in the kernel to be used by the application. We have successfully applied our approach to the TCP/IP implementation in the Linux kernel and used the optimized protocol stack in existing applications. These applications were minimally modied to request the specialization of code based on the current usage context, and to use the specialized code generated instead of its generic version. Specialization can be performed locally, or deferred to a remote specialization server using a novel mechanism [1]. Experiments conducted on three platforms show that the specialized code runs about 25% faster and its size reduces by up to 20 times. The throughput of the protocol stack improves by up to 21%

    GUINEA-PIG++ : an upgraded version of the linear collider beam-beam interaction simulation code GUINEA-PIG

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    http://cern.ch/AccelConf/p07/PAPERS/THPMN010.PDFInternational audienceGUINEA-PIG++ is a newly developed object-oriented version of the Linear Collider beam-beam simulation program GUINEA-PIG. The main goals of this project are to provide an reliable, modular, documented and versatile framework enabling convenient implementation of new features and functionalities
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