1,100 research outputs found
Declines in swimming performance with age: a longitudinal study of Masters swimming champions.
IntroductionBecause of its many participants and thorough records, competitive Masters swimming offers a rich data source for determining the rate of physical decline associated with aging in physically fit individuals. The decline in performance among national champion swimmers, both men and women and in short and long swims, is linear, at about 0.6% per year up to age 70-75, after which it accelerates in quadratic fashion. These conclusions are based primarily on cross-sectional studies, and little is known about individual performance declines with aging. Herein we present performance profiles of 19 male and 26 female national and international champion Masters swimmers, ages 25 to 96 years, participating in competitions for an average of 23 years.Methods and resultsSwimmers' longitudinal data were compared with the fastest times of world record holders across ages 35-100 years by two regression methods. Neither method proved to accurately model this data set: compared with the rates of decline estimated from the world record data, which represent the best recorded times at given ages, there was bias toward shallower rates of performance decline in the longitudinal data, likely owing to a practice effect in some swimmers as they began their Masters programs. In swimmers' later years, once maximum performance had been achieved, individual profiles followed the decline represented in the world records, and a few swimmers became the world record holders. In some instances, the individual profiles indicated performance better than the world record data; these swimmers achieved their times after the world record data were collected in 2005-2006.ConclusionDeclining physiological functional capacity occurs with advancing age, and this is reflected in the performance decrements of aging Masters swimmers. Individual swimmers show different performance trajectories with aging, declines being mitigated by practice, which improves both physiological capacity and swimming technique, particularly in the early years of participation. The longitudinal data of this study indicate that individuals can participate in high-intensity swimming over several decades, competitively improving over those decades until, in some instances, they become world record holders for their age groups
The Nature and Frequency of Outflows from Stars in the Central Orion Nebula Cluster
Recent Hubble Space Telescope images have allowed the determination with
unprecedented accuracy of motions and changes of shocks within the inner Orion
Nebula. These originate from collimated outflows from very young stars, some
within the ionized portion of the nebula and others within the host molecular
cloud. We have doubled the number of Herbig-Haro objects known within the inner
Orion Nebula. We find that the best-known Herbig-Haro shocks originate from a
relatively few stars, with the optically visible X-ray source COUP 666 driving
many of them.
While some isolated shocks are driven by single collimated outflows, many
groups of shocks are the result of a single stellar source having jets oriented
in multiple directions at similar times. This explains the feature that shocks
aligned in opposite directions in the plane of the sky are usually blue shifted
because the redshifted outflows pass into the optically thick Photon Dominated
Region behind the nebula. There are two regions from which optical outflows
originate for which there are no candidate sources in the SIMBAD data base.Comment: 152 pages, 46 figures, 7 tables. Accepted by A
Budesonide Foam Has a Favorable Safety Profile for Inducing Remission in Mild-to-Moderate Ulcerative Proctitis or Proctosigmoiditis.
BackgroundBudesonide foam, a rectally administered, second-generation corticosteroid with extensive hepatic first-pass metabolism, is efficacious for the treatment of mild-to-moderate ulcerative proctitis and ulcerative proctosigmoiditis.AimThe aim of this study was to comprehensively assess the safety and pharmacokinetic profile of budesonide foam.MethodsData from five phase III studies were pooled to further evaluate safety, including an open-label study (once-daily treatment for 8 weeks), an active-comparator study (once-daily treatment for 4 weeks), and two placebo-controlled studies and an open-label extension study (twice-daily treatment for 2 weeks, then once daily for 4 weeks). Data from the placebo-controlled studies and two phase I studies (i.e., patients with mild-to-moderate ulcerative colitis and healthy volunteers) were pooled to evaluate the pharmacokinetics of budesonide foam.ResultsA similar percentage of patients reported adverse events in the budesonide foam and placebo groups, with the majority of adverse events being mild or moderate in intensity (93.3 vs 96.0%, respectively). Adverse events occurred in 41.4 and 36.3% of patients receiving budesonide foam and placebo, respectively. Mean morning cortisol concentrations remained within the normal range for up to 8 weeks of treatment; there were no clinically relevant effects of budesonide foam on the hypothalamic-pituitary-adrenal axis. Population pharmacokinetic analysis demonstrated low systemic exposure after budesonide foam administration.ConclusionsThis integrated analysis demonstrated that budesonide foam for the induction of remission of distal ulcerative colitis is safe overall, with no clinically relevant effects on the hypothalamic-pituitary-adrenal axis
Factors associated with nonessential workplace attendance during the Covid-19 pandemic in the UK in early 2021
Objectives: Working from home where possible is important in reducing spread of Covid-19. In early 2021, a quarter of people in England who believed they could work entirely from home reported attending their workplace. To inform interventions to reduce this, this study examined associated factors. /
Study design: Data from the ongoing CORSAIR survey series of nationally representative samples of people in the UK aged 16+ years in January-February 2021 were used. /
Methods:. The study sample was 1422 respondents who reported that they could work completely from home. The outcome measure was self-reported workplace attendance at least once during the preceding week. Factors of interest were analysed in three blocks: 1) sociodemographic variables, 2) variables relating to respondentsâ circumstances, and 3) psychological variables. /
Results: 26.8% (95%CI=24.5%-29.1%) of respondents reported having attended their workplace at least once in the preceding week. Sociodemographic variables and living circumstances significantly independently predicted non-essential workplace attendance: male gender (OR=1.85,95%CI=1.33-2.58), dependent children in the household (OR=1.65,95%CI=1.17-2.32), financial hardship (OR=1.14,95%CI=1.08-1.21), socio-economic grade C2DE (OR=1.74, 95%CI=1.19-2.53), working in sectors such as health or social care (OR=4.18, 95%CI=2.56-6.81), education and childcare (OR=2.45, 95%CI=1.45-4.14) and key public service (OR=3.78, 95%CI=1.83-7.81), and having been vaccinated (OR=2.08,95%CI=1.33-3.24). /
Conclusions: Non-essential workplace attendance in the UK in early 2021 during the Covid-19 pandemic was significantly independently associated with a range of sociodemographic variables and personal circumstances. Having been vaccinated, financial hardship, socio-economic grade C2DE, having a dependent child at home, working in certain key sectors were associated with higher likelihood of workplace attendance
Factors associated with wearing a facemask in shops in England following removal of a legal requirement to do so during the COVID-19 pandemic
OBJECTIVES: We aimed to identify psychological factors associated with the use of facemasks in shops in England following removal of legal requirements to do so, and to compare associations with and without legal restrictions. DESIGN: Repeated cross-sectional online surveys (nâââ2000 adults) between August 2020 and April 2022 (68,716 responses from 45,682 participants) using quota sampling. METHODS: The outcome measure was whether those who had visited a shop for essentials in the previous seven days reported always having worn a facemask versus sometimes or not at all. Psychological predictor variables included worry, perceived risk and severity of COVID-19 and the perceived effectiveness of facemasks. Socio-demographic variables and measures of clinical vulnerability were also measured. For the period following removal of legal restrictions, multivariable regression was used to assess associations between the primary outcome variable and predictors adjusting for socio-demographic and clinical vulnerability measures. The analysis was repeated including interactions between psychological predictors and presence versus absence of legal restrictions. RESULTS: Worry about COVID-19, beliefs about risks and severity of COVID-19 and effectiveness of facemasks were substantially and independently associated with the use of facemasks. Removal of legal obligations to wear facemasks was associated with a 25% decrease in wearing facemasks and stronger associations between psychological predictors and wearing facemasks. CONCLUSIONS: Legal obligations increase rates of wearing a facemask. Psychological factors associated with wearing a facemask could be targets for interventions aiming to alter rates of wearing a facemask. These interventions may be more effective when there are no legal obligations to wear a face covering in place
Rapid Spin-Up Episodes in the Wind-Fed Accreting Pulsar GX 301-2
The accreting pulsar GX 301-2 (P = 680 s) has been observed continuously by the large-area detectors of the Burst and Transient Source Experiment (BATSE) instrument on the Compton Gamma Ray Observatory since 1991 April 5. Orbital parameters determined from these data are consistent with previous measurements, with improved accuracy in the current orbital epoch. The most striking features in the pulsar frequency history are two steady and rapid spin-up episodes, with ÎœË~(3-5)Ă10^(-12) Hz s^(-1), each lasting for about 30 days. They probably represent the formation of transient accretion disks in this wind-fed pulsar. Except for these spin-up episodes, there are virtually no net changes in the neutron star spin frequency on long timescales. We suggest that the long-term spin-up trend observed since 1984 (ÎœË~2Ă10^(-13) Hz s^(-1)) may be due entirely to brief (~20 days) spin-up episodes similar to those we have discovered.
We assess different accretion models and their ability to explain the orbital phase dependence of the observed flux. In addition to the previously observed preperiastron peak at orbital phase 0.956 +/- 0.022, we also find a smaller peak close to apastron at orbital phase 0.498 +/- 0.057. We show that if the companion star's effective temperature is less than 22,000 K, then it must have a mass M_c < 70 M_â and a radius R_c < 85 R_â so as not to overfill the tidal lobe at periastron. In order not to overflow the Roche lobe at periastron, the corresponding values are M_c < 55 M_â and R_c < 68 R_â. These constraints are nearly at odds with the reclassification by Kaper et al. of the companion as a B1 Ia + hypergiant
Knowledge of Self-Isolation Rules in the UK for Those Who Have Symptoms of COVID-19: A Repeated Cross-Sectional Survey Study
Objectives: To investigate knowledge of self-isolation rules and factors associated with knowledge. Methods: Repeated cross-sectional online surveys (n â 2000 UK adults) between 9 November 2020 and 16 February 2022 (78,573 responses from 51,881 participants). We computed a composite measure of knowledge of self-isolation rules and investigated associations between knowledge and survey wave, socio-demographic characteristics (age, gender, UK nation, index of multiple deprivation), trust in government, and participantsâ belief that they had received enough information about self-isolation. Results: In total, 87.9% (95% CI 87.7% to 88.1%, n = 67,288/76,562) of participants knew that if they had symptoms of COVID-19 they should âself-isolateâ. However, only 62.8% (n = 48,058/76,562, 95% CI 62.4% to 63.1%) knew the main rules regarding what that meant. Younger people had less knowledge than older people, and men had less knowledge than women. Knowledge was lower in people living in England versus in Scotland, Wales, and Northern Ireland. The pattern of association between knowledge and trust in government was unclear. Knowledge was lower in people living in a more deprived area and those who did not believe they had enough information about self-isolation. Knowledge was lower in December 2020 to January 2021, compared with before and after this period. Conclusions: Approximately 63% of UK adults between November 2020 and February 2022 appeared to know the main rules regarding self-isolation if symptomatic with COVID-19. Knowledge was lower in younger than older people, men than women, those living in England compared with Scotland, Wales or Northern Ireland, and those living in more deprived areas
Hydrothermal discharge during submarine eruptions : the importance of detection, response, and new technology
Author Posting. © The Oceanography Society, 2012. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 25, no. 1 (2012): 128â141, doi:10.5670/oceanog.2012.11.Submarine volcanic eruptions and intrusions construct new oceanic crust and build long chains of volcanic islands and vast submarine plateaus. Magmatic events are a primary agent for the transfer of heat, chemicals, and even microbes from the crust to the ocean, but the processes that control these transfers are poorly understood. The 1980s discovery that mid-ocean ridge eruptions are often associated with brief releases of immense volumes of hot fluids ("event plumes") spurred interest in methods for detecting the onset of eruptions or intrusions and for rapidly organizing seagoing response efforts. Since then, some 35 magmatic events have been recognized and responded to on mid-ocean ridges and at seamounts in both volcanic arc and intraplate settings. Field responses at mid-ocean ridges have found that event plumes occur over a wide range of eruption styles and sizes, and thus may be a common consequence of ridge eruptions. The source(s) of event plume fluids are still debated. Eruptions detected at ridges generally have high effusion rates and short durations (hours to days), whereas field responses at arc volcanic cones have found eruptions with very low effusion rates and durations on the scale of years. New approaches to the study of submarine magmatic events include the development of autonomous vehicles for detection and response, and the establishment of permanent seafloor observatories at likely future eruption sites.Support for these efforts came from
the NOAA Vents Program and the
National Science Foundation, primarily
through its long-term funding of the
RIDGE and Ridge 2000 Programs,
including grants OCE-9812294 and
OCE-0222069. SOSUS detection efforts were supported from 2006 to 2009 by
the National Science Foundation, grant
OCE-0623649
Kidney transplant nephrotic syndrome: Relationship between allograft histopathology and natural course
Kidney transplant nephrotic syndrome: Relationship between allograft histopathology and natural course. We analyzed clinical and pathologic data from 36 recipients of 38 renal allografts who developed nephrotic syndrome following transplantation. Three groups were identified on the basis of histologic changes in the graft, and each group had a distinct clinical course. Nine grafts (23.7%) had recurrent glomerulonephritis (GN) (5 membrano-proliferative, 4 focal glomerulosclerosis) and developed nephrotic syndrome at 5.1 months (mean) posttransplant. Renal function deteriorated rapidly, with a 2-year graft survival of 29.7%. Four grafts (10.5%) with de novo GN (3 epimembranous, 1 minimal change) developed nephrotic syndrome at 32 months post-transplant, and all functioned for more than 3 years. Twenty-five grafts (65.8%) had allograft glomerulopathy with the onset of nephrotic syndrome at 9.1 months posttransplant and a 2-year graft survival of 66.6%. The differences in duration of graft function between grafts with allograft glomerulopathy and recurrent GN (P < 0.01) and in graft survival rates at 2 years among the three groups (P < 0.05) are statistically significant. This analysis indicates that allograft glomerulopathy is the most common cause of kidney transplant nephrotic syndrome. Membranopro-liferative GN and focal glomerulosclerosis may recur soon after transplantation and rapidly progress to renal failure in marked contrast to grafts with either de novo epimembranous nephropathy or minimal glomerular change, lesions that are compatible with prolonged graft function.Syndrome néphrotique du rein transplanté: Relations entre l'histopathologies de l'allogreffe et l'évolution. Nous avons analysé les dossiers cliniques et anatomo-pathologiques de 36 receveurs de 38 allogreffes qui ont développé un syndrome néphrotique aprÚs transplantation. Trois groupes ont été identifiés sur la base des modifications histologiques de la greffe et chaque groupe a eu une évolution distincte. Neuf greffes (23,7%) ont eu une récidive de glomérulonéphrite (GN) (5 membrano-prolifératives, 4 gloméruloscléroses focales) et ont développé un syndrome néphrotique 5,1 mois (moyenne) aprÚs la transplantation. La fonction rénale s'est détériorée rapidement, avec une survie de la greffe à 2 ans de 29,7%. Quatre greffes (10,5%) atteintes de GN nouvelle (3 extra-membraneuses, 1 à modifications minimes) ont développé un syndrome néphrotique 32 mois aprÚs la transplantation et ont toutes fonctionné plus de 3 ans. Vingt cinq greffes (65,8%) ont eu une glomérulopathie de greffe avec l'installation d'un syndrome néphrotique à 9,1 mois aprÚs la transplantation et une survie de la greffe à 2 ans de 66,6%. Les différences de durée du fonctionnement de la greffe selon l'atteinte par une récidive de GN ou une glomérulopathie de greffe (P < 0,01) et dans la survie des greffes à 2 ans dans les trois groupes (P < 0,05) sont statistiquement significatives. Cette analyse indique que la glomérulonéphrite de la greffe est la cause la plus répandue de syndrome néphrotique du rein transplanté. La GN membrano-proliférative et la glomérulosclérose focale peuvent récidiver précocement aprÚs la transplantation et progresser rapidement vers l'insuffisance rénale à la différence des greffes atteintes de néphropathie extramembraneuse ou de modifications minimes, lésions compatibles avec une fonction prolongée de la greffe
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