4,144 research outputs found

    An examination of the control of endurance training, using heart rate and blood lactate analysis.

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    The purpose of this study was to examine the control of endurance training, using heart rate (HR) and blood lactate (La) analysis. This was done using three experiments covering the sports of endurance running, rowing and triathlon. The first aimed to establish a time efficient, incremental protocol for determining blood lactate profiles. The second examined control of training using running speed or HR in the laboratory and field. The third compared lactate threshold (Tlac) HRs between cycling and running in triathletes. A continuous 4 minute incremental (4I) protocol was compared with discontinuous 6 and 8 minute protocols, ANOVA with repeated measures revealed that there was no significant difference in HR and La measurements between the protocols. Subsequently, 4I was compared with a similar 3 minute (3I) version. Despite higher HR and La noted during the later stages of 41, the EDR - La relationship was unaffected by the protocol used. The 3I is a suitable, time efficient method of assessment. HR prescribed from 3I was compared with running speed to control training at maximal steady state blood lactate (MSS) in well-trained runners. HR appeared the better means of training control, where increased lactate within training sessions was less frequent than in the speed controlled sessions. The process of HR control during MSS training in the laboratory was also examined in elite junior rowers. In 9 out of 10 sessions MSS was not exceeded. A total of 80 other training sessions were also analysed. Thirty training sessions were performed by trained runners and 50 by trained rowers. Thirty four sessions were aimed at base endurance (BE) and 46 aimed at MSS intensity. In 20% of cases, athletes exceeded their prescribed HR. In all, 96% of the sessions were predicted correctly as either steady state or non-steady state on the basis of observed HR. HR from 3I was deemed an acceptable means of intensity control to avoid non-stable La. HR at Tlac and 2 mmo1.1-1 of blood La during 31 of both running and cycling exercise was compared in well-trained triathletes. In both cases mean HR was higher during running (t= 7.6, d.f = 15, p<0.001 and t = 7.6, d.f = 15, p<0.05, respectively). The mean difference in HR at Tlac was 13.4 b.min-1 with a range of 0 to 26. Separate tests should, therefore, be used for each mode of exercise in triathletes. In summary, it was concluded that a 3 minute incremental protocol is valid for the determination of blood lactate profiles and the prescription of HR for subsequent training prescription. Also, HR can predict blood lactate conditions during training sessions in well-trained runners and rowers. The HR for set training zones is likely to vary according to the mode of exercise employed

    Gossip on Weighted Networks

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    We investigate how suitable a weighted network is for gossip spreading. The proposed model is based on the gossip spreading model introduced by Lind et.al. on unweighted networks. Weight represents "friendship." Potential spreader prefers not to spread if the victim of gossip is a "close friend". Gossip spreading is related to the triangles and cascades of triangles. It gives more insight about the structure of a network. We analyze gossip spreading on real weighted networks of human interactions. 6 co-occurrence and 7 social pattern networks are investigated. Gossip propagation is found to be a good parameter to distinguish co-occurrence and social pattern networks. As a comparison some miscellaneous networks and computer generated networks based on ER, BA, WS models are also investigated. They are found to be quite different than the human interaction networks.Comment: 8 pages, 4 figures, 1 tabl

    Evolution of Ego-networks in Social Media with Link Recommendations

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    Ego-networks are fundamental structures in social graphs, yet the process of their evolution is still widely unexplored. In an online context, a key question is how link recommender systems may skew the growth of these networks, possibly restraining diversity. To shed light on this matter, we analyze the complete temporal evolution of 170M ego-networks extracted from Flickr and Tumblr, comparing links that are created spontaneously with those that have been algorithmically recommended. We find that the evolution of ego-networks is bursty, community-driven, and characterized by subsequent phases of explosive diameter increase, slight shrinking, and stabilization. Recommendations favor popular and well-connected nodes, limiting the diameter expansion. With a matching experiment aimed at detecting causal relationships from observational data, we find that the bias introduced by the recommendations fosters global diversity in the process of neighbor selection. Last, with two link prediction experiments, we show how insights from our analysis can be used to improve the effectiveness of social recommender systems.Comment: Proceedings of the 10th ACM International Conference on Web Search and Data Mining (WSDM 2017), Cambridge, UK. 10 pages, 16 figures, 1 tabl

    Laser-Derived Particle Size Data from CRP-3, Victoria Land Basin, Antarctica: Implications for Sequence and Seismic Stratigraphy

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    Seven hundred and nineteen samples from throughout the Cainozoic section in CRP-3 were analysed by a Malvern Mastersizer laser particle analyser, in order to derive a stratigraphic distribution of grain-size parameters downhole. Entropy analysis of these data (using the method of Woolfe & Michibayashi, 1995) allowed recognition of four groups of samples, each group characterised by a distinctive grain-size distribution. Group 1, which shows a multi-modal distribution, corresponds to mudrocks, interbedded mudrock/sandstone facies, muddy sandstones and diamictites. Group 2, with a sand-grade mode but showing wide dispersion of particle size, corresponds to muddy sandstones, a few cleaner sandstones and some conglomerates. Group 3 and Group 4 are also sand-dominated, with better grain-size sorting, and correspond to clean, well-washed sandstones of varying mean grain-size (medium and fine modes, respectively). The downhole disappearance of Group 1, and dominance of Groups 3 and 4 reflect a concomitant change from mudrock- and diamictite-rich lithology to a section dominated by clean, well-washed sandstones with minor conglomerates. Progressive downhole increases in percentage sand and principal mode also reflect these changes. Significant shifts in grain-size parameters and entropy group membership were noted across sequence boundaries and seismic reflectors, as recognised in other studies

    RESEARCH STRATEGIES OF THE NATIONAL WILDLIFE RESEARCH CENTER TO CONTROL BOVINE TUBERCULOSIS IN WILDLIFE IN MICHIGAN, USA

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    Bovine tuberculosis (bTB) is a zoonotic disease caused by Mycobaterium bovis and is transmissible to humans, wildlife, and domestic livestock. In the United Kingdom, the suspected wildlife reservoir of bTB is the badger (Meles meles) (HUTCHINGS and HARRIS, 1 997), and in New Zealand, the culprit is the brush-tailed possum (Trichosurus vulpecula) (MORRIS et al., 1994). In northern Michigan, USA, bovine tuberculosis is endemic in white-tailed deer (Odocoileus virginianus). In 1975 a hunter-killed white-tailed deer in Alpena County, Michigan, USA, was tested positive for bTB. Subsequent surveillance by the Michigan Department of Natural Resources (MDNR) of hunter-killed deer revealed no additional cases, and the situation was ruled an anomaly. However, in 1994, an additional hunter-killed white-tailed deer tested positive for bTB in Alcona County, only 13 km from the 1975 case. Between 1995 and 2005, a total of 509 deer tested positive for the disease (MDNR, 2005) and evidence suggested that deer transmitted the disease to domestic cattle (PALMER et al., 2004a). From 1997 to 2004, 33 cattle herds and 1 captive cervid farm tested positive for bTB (MDNR, 2005), most of them within a 5- county area. In addition, in 2006, 6 cattle farms and 1 captive cervid farm tested positive for the disease (MDNR, personal communication). In response to this outbreak, in the past several years MDNR has implemented management strategies to reduce the prevalence of bTB in deer in the outbreak area. These include reduction of deer densities through liberal hunting and restriction of baiting and supplemental feeding of white-tailed deer to reduce deer densities. In addition, Michigan Department of Agriculture and USDA/APHIS/Veterinary Services actively test cattle and captive deer herds with subsequent depopulation of infected herds. And while these actions have reduced the apparent prevalence of bTB in deer from 4.7 % to 1.7 %, a 64 % reduction (MDNR, 2005), other wildlife species may act as reservoirs for the disease. Bovine tuberculosis has been documented in many species of wildlife, including raccoons (Procyon lotor), coyotes (Canis latrans), red fox (Vulpes vulpes) and black bear (Ursus americanus) (BRUNING-FANN et al., 2001). In the outbreak area, bTB prevalence estimates in coyotes and raccoons are as high as 24% (VERCAUTEREN et al., unpublished data) and 2.5 % (WITMER et al., unpublished data), respectively. This raises the question of whether infected raccoons and coyotes actively shed M. bovis through either feces or oral/nasal secretions, thus increasing risks of infection to cattle and other wildlife

    Nudges and other moral technologies in the context of power: Assigning and accepting responsibility

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    Strawson argues that we should understand moral responsibility in terms of our practices of holding responsible and taking responsibility. The former covers what is commonly referred to as backward-looking responsibility , while the latter covers what is commonly referred to as forward-looking responsibility . We consider new technologies and interventions that facilitate assignment of responsibility. Assigning responsibility is best understood as the second- or third-personal analogue of taking responsibility. It establishes forward-looking responsibility. But unlike taking responsibility, it establishes forward-looking responsibility in someone else. When such assignments are accepted, they function in such a way that those to whom responsibility has been assigned face the same obligations and are susceptible to the same reactive attitudes as someone who takes responsibility. One family of interventions interests us in particular: nudges. We contend that many instances of nudging tacitly assign responsibility to nudgees for actions, values, and relationships that they might not otherwise have taken responsibility for. To the extent that nudgees tacitly accept such assignments, they become responsible for upholding norms that would otherwise have fallen under the purview of other actors. While this may be empowering in some cases, it can also function in such a way that it burdens people with more responsibility that they can (reasonably be expected to) manage

    Influence of a montmorency cherry juice blend on indices of exercise-induced stress and upper respiratory tract symptoms following marathon running—a pilot investigation

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    Background: Prolonged exercise, such as marathon running, has been associated with an increase in respiratory mucosal inflammation. The aim of this pilot study was to examine the effects of Montmorency cherry juice on markers of stress, immunity and inflammation following a Marathon. Methods: Twenty recreational Marathon runners consumed either cherry juice (CJ) or placebo (PL) before and after a Marathon race. Markers of mucosal immunity secretory immunoglobulin A (sIgA), immunoglobulin G (IgG), salivary cortisol, inflammation (CRP) and self-reported incidence and severity of upper respiratory tract symptoms (URTS) were measured before and following the race. Results: All variables except secretory IgA and IgG concentrations in saliva showed a significant time effect (P < 0.01). Serum CRP showed a significant interaction and treatment effect (P < 0.01). The CRP increase at 24 and 48 h post-Marathon was lower (P < 0.01) in the CJ group compared to PL group. Mucosal immunity and salivary cortisol showed no interaction effect or treatment effect. The incidence and severity of URTS was significantly greater than baseline at 24 h and 48 h following the race in the PL group and was also greater than the CJ group (P < 0.05). No URTS were reported in the CJ group whereas 50 % of runners in the PL group reported URTS at 24 h and 48 h post-Marathon. Conclusions: This is the first study that provides encouraging evidence of the potential role of Montmorency cherries in reducing the development of URTS post-Marathon possibly caused by exercise-induced hyperventilation trauma, and/or other infectious and non-infectious factors

    WISER Deliverable D3.3-2: The importance of invertebrate spatial and temporal variation for ecological status classification for European lakes

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    European lakes are affected by many human induced disturbances. In principle, ecological theories predict that the structure and functioning of benthic invertebrate assemblage (one of the Biological Quality Elements following the Water Framework Directive, WFD terminology) change in response to the level of disturbances, making this biological element suitable for assessing the status and management of lake ecosystems. In practice, to set up assessment systems based on invertebrates, we need to distiguish community changes that are related to human pressures from those that are inherent natural variability. This task is complicated by the fact that invertebrate communities inhabiting the littoral and the profundal zones of lakes are constrained by different factors and respond unevenly to distinct human disturbances. For example it is not clear yet how the invertebrates assemblages respond to watershed and shoreline alterations, nor the relative importance of spatial and temporal factors on assemblage dynamics and relative bioindicator values of taxa, the habitat constraints on species traits and other taxonomic and methodological limitations. The current lack of knowledge of basic features of invertebrate temporal and spatial variations is limiting the fulfillment of the EU-wide intercalibration of lake ecological quality assessment systems in Europe, and thus compromising the basis for setting the environmental objectives as required by the WFD. The aim of this deliverable is to provide a contribution towards the understanding of basic sources of spatial and temporal variation of lake invertebrate assemblages. The report is structured around selected case studies, manly involving the analysis of existing datasets collated within WISER. The case studies come from different European lake types in the Northern, Central, Alpine and Mediterranean regions. All chapters have an obvious applied objective and our aim is to provide to those dealing with WFD implementation at various levels useful information to consider when designing monitoring programs and / or invertebrate-based classification systems

    Infrared behavior of graviton-graviton scattering

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    The quantum effective theory of general relativity, independent of the eventual full theory at high energy, expresses graviton-graviton scattering at one loop order O(E^4) with only one parameter, Newton's constant. Dunbar and Norridge have calculated the one loop amplitude using string based techniques. We complete the calculation by showing that the 1/(d-4) divergence which remains in their result comes from the infrared sector and that the cross section is finite and model independent when the usual bremsstrahlung diagrams are included.Comment: 12 pages, uses axodra
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