1,699 research outputs found
Changes in handgrip force and blood lactate as response to simulated climbing competition
The aim of the study was to estimate post-competition changes in handgrip strength and blood lactate in climbers and relationships of the studied variables with declared climbing ability of the tested athletes. Twenty one male climbers volunteered to take part in the experiment. Each subject took part in simulated lead climbing competition on the artificial wall – (difficulty 7a in French scale). The blood lactate concentration was measured pre-climbing and then 3 min and 30 min post-climbing. Grip force of both hands (dominant and non-dominant) was measured twice – pre-climbing and 1 min post-climbing (semi-final). Maximum heart rate during climbing reached 181.4±7.7 beats per minute. Lactate concentration amounted to 6.35±1.50 mmol/l and 2.28±0.66 mmol/l 3 min and 30 min post-climbing, respectively. Handgrip force related to body mass (averaged for both hands) decreased significantly from 7.39±1.30 N/kg pre-climbing to 6.57±1.05 N/kg 1 min post-climbing. Self reported climbing ability was correlated with lactate concentration and handgrip force, as well. It was demonstrated that athletes reporting higher climbing ability showed better lactate recovery
Commensurate Priors on a Finite Mixture Model for Incorporating Repository Data in Clinical Trials
Docosahexaenoic acid (DHA) is a good source of fat that can be taken up through food, such as fish, or taken as a supplement. Evidence is building that DHA provides a high-yield, low-risk strategy to reduce preterm birth and/or low birth weight. These births are great costs to society. A recently completed Phase III trial revealed that higher birth weight and gestational age were associated with DHA dosed at 600 mg/day. In this article, we take a posterior predictive approach to assess impacts of these findings on public health. Simple statistical models are not adequate for accurate posterior predictive distribution estimation. Of particular interest is that the joint distribution of birth weight and gestational age is well modeled by a finite mixture of three normal distributions. Data from our own clinical trial exhibit similar features. Using the mean and variance-covariance matrices from a previous study and flexible commensurate priors for the mixing parameters, we estimate the effect of DHA supplementation on over 20,000 infants born in hospitals demographically similar to the hospital where the clinical trial was conducted
Longtime behavior of nonlocal Cahn-Hilliard equations
Here we consider the nonlocal Cahn-Hilliard equation with constant mobility
in a bounded domain. We prove that the associated dynamical system has an
exponential attractor, provided that the potential is regular. In order to do
that a crucial step is showing the eventual boundedness of the order parameter
uniformly with respect to the initial datum. This is obtained through an
Alikakos-Moser type argument. We establish a similar result for the viscous
nonlocal Cahn-Hilliard equation with singular (e.g., logarithmic) potential. In
this case the validity of the so-called separation property is crucial. We also
discuss the convergence of a solution to a single stationary state. The
separation property in the nonviscous case is known to hold when the mobility
degenerates at the pure phases in a proper way and the potential is of
logarithmic type. Thus, the existence of an exponential attractor can be proven
in this case as well
Antibiotic susceptibility and ability to form biofilm of Listeria monocytogenes strains isolated from frozen vegetables
L. monocytogenes poses a serious threat to public health, since most cases of listeriosis are connected with eating contaminated food. L. monocytogenes is often detected both in fresh and frozen vegetables. The aim of this study was to evaluate the antibiotic susceptibility and ability to form biofilm of L. monocytogenes strains isolated from frozen vegetable mixtures in Poland. Ninetynine genetically different strains were found among 100 isolates of L. monocytogenes. Among the 99 strains, 80 (80.8%) were susceptible to all tested antibiotics. Nineteen (19.2%) strains were resistant to one or more antibiotics. From this group of L. monocytogenes strains, most strains were resistant to erythromycin (16; 16,1%), penicillin (15; 15.1%), meropenem (12; 12.1%), cotrimoxazole (12; 12.1%), and ampicillin (3; 3.1%). According to the obtained results, differences in intensity of biofilm, both between those isolated in successive years and in the particular year, were observed. Performed analysis showed statistically insignificant faint negative correlation (r=–0.088) between the number of antibiotics to which strains were resistant and the intensity of biofilm formation by them.
Food contamination with L. monocytogenes poses a threat to consumers, therefore it is necessary to monitor their antibiotic susceptibility, ability to form biofilm, and genetic similarity, in order to evaluate the strains persistence time in plant
A Kohn-Sham system at zero temperature
An one-dimensional Kohn-Sham system for spin particles is considered which
effectively describes semiconductor {nano}structures and which is investigated
at zero temperature. We prove the existence of solutions and derive a priori
estimates. For this purpose we find estimates for eigenvalues of the
Schr\"odinger operator with effective Kohn-Sham potential and obtain
-bounds of the associated particle density operator. Afterwards,
compactness and continuity results allow to apply Schauder's fixed point
theorem. In case of vanishing exchange-correlation potential uniqueness is
shown by monotonicity arguments. Finally, we investigate the behavior of the
system if the temperature approaches zero.Comment: 27 page
Blood and marrow transplantation compensation: Perspective in payer and provider relations
AbstractThe high cost per patient of hematopoietic cell transplantation (HCT) causes this therapy to be the focus of much controversy, given the competing societal demands to provide all possible therapy to preserve life while simultaneously limiting global health care expenditures. Treatment and eligibility decisions for HCT often are heavily scrutinized by both governmental and private payers and not simply determined by physicians, facility providers, and the patient. In an effort to control costs, payers have administrative infrastructure to review resource utilization by these patients. Additionally payers have developed payment methodologies, usually in the form of a case rate payment structure, that place facilities and physician providers of HCT at financial risk for adverse patient financial outcomes in an effort to promote optimal utilization and selection of patients for HCT. As providers enter into such financial risk arrangements with payers, the providers need to understand the true cost of care and be able to identify predictable and unpredictable outlier risks for the financial consequences of medical complications. HCT providers try to protect themselves from excessive financial risk by having different payment rates for different types of transplant, eg, autologous versus HLA or genotypically matched related versus HLA mismatched transplants. Because at certain times in the HCT process risk is more unpredictable, HCT providers require different payment system strategies for the different time periods of care such as evaluation, pre-transplant disease management, harvesting, and cell processing, as well as short- and long-term follow-up. Involvement by clinicians is essential for this process to be done well, especially given the rapid changes technological innovation brings to HCT. Constant dialogue and interaction between providers and payers on these difficult financial issues with HCT is essential to preserve patient access to this potentially lifesaving therapy
Reliability of Peak Treadmill Exercise Tests in Mild Alzheimer Disease
This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Neuroscience on August 2011, available online: http://www.tandfonline.com/10.3109/00207454.2011.574762.The prevalence of Alzheimer disease (AD) doubles every 5 years after the age of 65, reaching nearly 50% after age 85 (Evans et al., 1989). This, along with an unprecedented growth in the elderly population, is leading to dramatic increases in the incidence of AD. Thus, effective strategies for promoting healthy brain aging and preventing AD are increasingly important. One strategy that appears promising in promoting healthy brain aging is exercise and physical activity. Evidence is accumulating that endurance exercise is beneficial to brain health (Laurin, Verreault, Lindsay, MacPherson, & Rockwood, 2001), and increased cardiorespiratory fitness is associated with increased brain volume in subjects with very mild to mild AD (Burns et al., 2008).
While enhancing cardiorespiratory fitness may be a strategy for preventing cognitive decline in AD, there is limited information available on the validity and reliability of cardiorespiratory fitness measures in this population. The gold standard measure of cardiorespiratory fitness is maximum oxygen consumption (VO2max) (Frankin, 2001), the highest rate of oxygen uptake attainable during maximal or exhaustive exercise (American College of Sports Medicine, 2005). If the subject becomes exhausted and ends the test prior to reaching the physiologic VO2max, the end of the test is called peak oxygen consumption (VO2peak). It is unknown if advanced age and cognitive difficulties in people with AD would limit their ability to fully participate in a standard graded exercise test to reliably assess VO2max or VO2peak.
Treadmill exercise testing has been found to be reliable in subjects with traumatic brain injury and mental retardation, although these subjects were very young (Fernhall, Millar, Tymeson, & Burkett, 1990; Mossberg & Greene, 2005). Traumatic brain injury and mental retardation are different disease processes than AD and would be expected to result in static rather than progressive cognitive symptoms. With AD, memory is impaired as is the ability to follow commands, however patients in the earliest stages of AD would be expected to respond to prompting and reminders to follow testing procedures. To our knowledge, no studies have assessed the reliability of peak treadmill exercise testing in subjects with AD. In our previous research on patients with very mild to mild AD (Burns, et al., 2008), we have found them to be capable of ambulating on a treadmill and completing peak treadmill exercise testing with 3 participants out of 74 (126 total peak exercise tests) identified as having EKG changes during testing. All 3 participants had negative follow-up testing in cardiology. The purpose of this study was to investigate the reliability of a graded peak treadmill exercise test in elderly people with early AD
Fluorescence calorimetry of an ion crystal
Motivated by the challenge of identifying intruder ions in a cold ion
crystal, we investigate calorimetry from emitted fluorescence light. Under
continuous Doppler cooling, the ion crystal reaches a temperature equilibrium
with a fixed level of fluorescence intensity and any change in the motional
energy of the crystal results in a modification of this intensity. We
theoretically determine the fluorescence rate of an ion crystal as a function
of the temperature, assuming that laser light is scattered along a two-level
electronic transition, which couples to the crystal's vibrations via the
mechanical effects of light. We analyse how the heat dissipated by collisions
of an incoming intruder ion alters the scattering rate. We argue that an energy
change by an incoming Th can be unambiguously detected within
50\,s via illuminating 50 ions out of a 10 ion crystal. This method
enables applications including capture and spectroscopy of charged states of
thorium isotopes and investigation of highly charged ions.Comment: 10 pages, 5 figure
Maternal Docosahexaenoic Acid Exposure Needed to Achieve Maternal–Newborn EQ
Achieving maternal docosahexaenoic acid (DHA) status equal to or greater than the infant’s DHA status at delivery is known as maternal–newborn DHA equilibrium (EQ) and is thought to be important for optimizing newborn DHA status throughout infancy. The objective of this study was to determine the daily DHA intake during pregnancy most likely to result in EQ. The participants (n = 1145) were from two randomized control trials of DHA supplementation in pregnancy. DHA intake was estimated using an abbreviated food frequency questionnaire. Total DHA exposure during pregnancy was calculated as a weighted average of the estimated DHA intake throughout pregnancy and the randomized DHA dose (200, 800, 1000 mg). Red blood cell DHA was measured from maternal and cord blood plasma at delivery and EQ status was calculated. The DHA intake required to achieve EQ was estimated by regression. In terms of DHA exposure, the point estimate and 95% confidence interval to achieve EQ was 643 (583, 735) mg of DHA/day. The results of our trial suggest an intake of 650 mg of DHA/day is necessary to increase the potential for EQ at delivery. The clinical benefits of achieving EQ deserves continued study
CF2 Represses Actin 88F Gene Expression and Maintains Filament Balance during Indirect Flight Muscle Development in Drosophila
The zinc finger protein CF2 is a characterized activator of muscle structural genes in the body wall muscles of the Drosophila larva. To investigate the function of CF2 in the indirect flight muscle (IFM), we examined the phenotypes of flies bearing five homozygous viable mutations. The gross structure of the IFM was not affected, but the stronger hypomorphic alleles caused an increase of up to 1.5X in the diameter of the myofibrils. This size increase did not cause any disruption of the hexameric arrangement of thick and thin filaments. RT-PCR analysis revealed an increase in the transcription of several structural genes. Ectopic overexpression of CF2 in the developing IFM disrupts muscle formation. While our results indicate a role for CF2 as a direct negative regulator of the thin filament protein gene Actin 88F (Act88F), effects on levels of transcripts of myosin heavy chain (mhc) appear to be indirect. This role is in direct contrast to that described in the larval muscles, where CF2 activates structural gene expression. The variation in myofibril phenotypes of CF2 mutants suggest the CF2 may have separate functions in fine-tuning expression of structural genes to insure proper filament stoichiometry, and monitoring and/or controlling the final myofibril size
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