4,852 research outputs found

    Swimming and All-Cause Mortality Risk Compared With Running, Walking, and Sedentary Habits in Men

    Get PDF
    Swimming, water jogging, and aqua aerobics are lifetime physical activities that provide many health benefits comparable to those of walking and running. Research on the association between swimming and mortality is scarce, however. To evaluate the association between different types of physical activity and all-cause mortality, we studied 40,547 men age 20-90 years who completed a health examination during 1971 – 2003. Cox proportional-hazards regression was used to estimate the relative risks according to physical activity exposure categories. A total of 3,386 deaths occurred during 543,330 man-years of observation. After adjustment for age, body-mass index, smoking status, alcohol intake, and family history of cardiovascular disease, swimmers had 53%, 50%, and 49% lower all-cause mortality risks than did men who were sedentary, walkers, or runners, respectively (p \u3c 0.05 for each). Additional adjustment for baseline prevalent diseases did not change the inverse association between different activities and all-cause mortality. In conclusion, swimmers have lower mortality rates in comparison with those who were sedentary, walkers, and runners

    Comparison of the Health Aspects of Swimming With Other Types of Physical Activity and Sedentary Lifestyle Habits

    Get PDF
    Swimming, water jogging, and aqua aerobics may provide health benefits to the general population as well as patients with chronic diseases. Research on the health benefits of aquatic exercise in comparison with activities such as running and walking is scarce, however. The goal of this study was to evaluate characteristics of participants in the Aerobics Center Longitudinal Study and to compare health habits and physiological characteristics among swimmers, runners, walkers, and sedentary women and men in order to evaluate the health benefits of swimming compared to other types of physical activity. Participants were 10,518 women and 35,185 men ages 20-88 years who completed a health examination during 1970 and 2005. Differences in the distribution of selected characteristics between swimmers and those participating in other types of activities (sedentary, runners, or walkers) were tested using logistics regression for proportion and ANOVA for continuous variables. The principal findings of this report are that swimming, as well as walking and running, has health benefits compared with a sedentary lifestyle

    Adaptive constraints for feature tracking

    Get PDF
    In this paper extensions to an existing tracking algorithm are described. These extensions implement adaptive tracking constraints in the form of regional upper-bound displacements and an adaptive track smoothness constraint. Together, these constraints make the tracking algorithm more flexible than the original algorithm (which used fixed tracking parameters) and provide greater confidence in the tracking results. The result of applying the new algorithm to high-resolution ECMWF reanalysis data is shown as an example of its effectiveness

    Expert chess memory: Revisiting the chunking hypothesis

    Get PDF
    After reviewing the relevant theory on chess expertise, this paper re-examines experimentally the finding of Chase and Simon (1973a) that the differences in ability of chess players at different skill levels to copy and to recall positions are attributable to the experts' storage of thousands of chunks (patterned clusters of pieces) in long-term memory. Despite important differences in the experimental apparatus, the data of the present experiments regarding latencies and chess relations between successively placed pieces are highly correlated with those of Chase and Simon. We conclude that the 2-second inter-chunk interval used to define chunk boundaries is robust, and that chunks have psychological reality. We discuss the possible reasons why Masters in our new study used substantially larger chunks than the Master of the 1973 study, and extend the chunking theory to take account of the evidence for large retrieval structures (templates) in long-term memory

    Conformal string operators and evolution of skewed parton distributions

    Get PDF
    We have investigated skewed parton distributions in coordinate space. We found that their evolution can be described in a simple manner in terms of non-local, conformal operators introduced by Balitsky and Braun. The resulting formula is given by a Neumann series expansion. Its structure resembles, for all values of the asymmetry parameter, the well-known solution of the ERBL equation in the momentum space. Performing Fourier transformation we have reproduced known results for evolution of momentum-space distributions.Comment: 24 pages, 2 figure

    Neuronal background of positioning of the posterior tentacles in the snail Helix pomatia

    Get PDF
    The location of cerebral neurons innervating the three recently described flexor muscles involved in the orientation of the posterior tentacles as well as their innervation patterns were investigated, applying parallel retrograde Co- and Ni-lysine as well as anterograde neurobiotin tracings via the olfactory and the peritentacular nerves. The neurons are clustered in eight groups in the cerebral ganglion and they send a common innervation pathway via the olfactory nerve to the flexor and the tegumental muscles as well as the tentacular retractor muscle and distinct pathways via the internal and the external peritentacular nerves to these muscles except the retractor muscle. The three anchoring points of the three flexor muscles at the base of the tentacle outline the directions of three force vectors generated by the contraction of the muscles along which they can pull or move the protracted tentacle which enable the protracted tentacle to bend around a basal pivot. In the light of earlier physiological and the present anatomical findings we suggest that the common innervation pathway to the muscles is required to the tentacle withdrawal mechanism whereas the distinct pathways serve first of all the bending of the protracted posterior tentacles during foraging

    Caracol, Belize, and Changing Perceptions of Ancient Maya Society

    Full text link

    The mutation rate of mycobacterial repetitive unit loci in strains of M. tuberculosis from cynomolgus macaque infection

    Get PDF
    Background: Mycobacterial interspersed repetitive units (MIRUs) are minisatellites within the Mycobacterium tuberculosis (Mtb) genome. Copy number variation (CNV) in MIRU loci is used for epidemiological typing, making the rate of variation important for tracking the transmission of Mtb strains. In this study, we developed and assessed a whole-genome sequencing (WGS) approach to detect MIRU CNV in Mtb. We applied this methodology to a panel of Mtb strains isolated from the macaque model of tuberculosis (TB), the animal model that best mimics human disease. From these data, we have estimated the rate of MIRU variation in the host environment, providing a benchmark rate for future epidemiologic work. Results: We assessed variation at the 24 MIRU loci used for typing in a set of Mtb strains isolated from infected cynomolgus macaques. We previously performed WGS of these strains and here have applied both read depth (RD) and paired-end mapping (PEM) metrics to identify putative copy number variants. To assess the relative power of these approaches, all MIRU loci were resequenced using Sanger sequencing. We detected two insertion/deletion events both of which could be identified as candidates by PEM criteria. With these data, we estimate a MIRU mutation rate of 2.70 Ă— 10-03 (95% CI: 3.30 Ă— 10-04- 9.80 Ă— 10-03) per locus, per year. Conclusion: Our results represent the first experimental estimate of the MIRU mutation rate in Mtb. This rate is comparable to the highest previous estimates gathered from epidemiologic data and meta-analyses. Our findings allow for a more rigorous interpretation of data gathered from MIRU typing
    • …
    corecore