1,357 research outputs found
Prospective associations between sedentary time, physical activity, fitness and cardiometabolic risk factors in people with type 2 diabetes.
AIMS/HYPOTHESIS: The aim of this study was to examine the prospective associations between objectively measured physical activity energy expenditure (PAEE), sedentary time, moderate-to-vigorous-intensity physical activity (MVPA), cardiorespiratory fitness (CRF) and cardiometabolic risk factors over 4 years in individuals with recently diagnosed diabetes. METHODS: Among 308 adults (mean age 61.0 [SD 7.2] years; 34% female) with type 2 diabetes from the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen Detected Diabetes in Primary Care (ADDITION)-Plus study, we measured physical activity using individually calibrated combined heart rate and movement sensing. Multivariable linear regression models were constructed to examine the associations between baseline PAEE, sedentary time, MVPA, CRF and cardiometabolic risk factors and clustered cardiometabolic risk (CCMR) at follow-up, and change in these exposures and change in CCMR and its components over 4 years of follow-up. RESULTS: Individuals who increased their PAEE between baseline and follow-up had a greater reduction in waist circumference (-2.84 cm, 95% CI -4.84, -0.85) and CCMR (-0.17, 95% CI -0.29, -0.04) compared with those who decreased their PAEE. Compared with individuals who decreased their sedentary time, those who increased their sedentary time had a greater increase in waist circumference (3.20 cm, 95% CI 0.84, 5.56). Increases in MVPA were associated with reductions in systolic blood pressure (-6.30 mmHg, 95% CI -11.58, -1.03), while increases in CRF were associated with reductions in CCMR (-0.23, 95% CI -0.40,-0.05) and waist circumference (-3.79 cm, 95% CI -6.62, -0.96). Baseline measures were generally not predictive of cardiometabolic risk at follow-up. CONCLUSIONS/INTERPRETATION: Encouraging people with recently diagnosed diabetes to increase their physical activity and decrease their sedentary time may have beneficial effects on their waist circumference, blood pressure and CCMR.The trial is supported by the Medical Research Council (grant reference no. G0001164), the Wellcome Trust (grant reference no. G061895), National Health Service R&D support funding (including the Primary Care Research and Diabetes Research Networks) and National Institute of Health Research under its Programme Grants for Applied Research scheme (RP-PG-0606-1259). SJG is a member of the NIHR School for Primary Care Research. The views expressed in this publication are those of the authors and not necessarily those of the National Health Service, the NIHR, or the UK Department of Health. We are grateful to Diabetes UK for providing patient information materials.This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s00125-015-3756-
Benefits of robotic cystectomy with intracorporeal diversion for patients with low cardiorespiratory fitness: A prospective cohort study
BACKGROUND: Patients undergoing radical cystectomy have associated comorbidities resulting in reduced cardiorespiratory fitness. Preoperative cardiopulmonary exercise testing (CPET) measures including anaerobic threshold (AT) can predict major adverse events (MAE) and hospital length of stay (LOS) for patients undergoing open and robotic cystectomy with extracorporeal diversion. Our objective was to determine the relationship between CPET measures and outcome in patients undergoing robotic radical cystectomy and intracorporeal diversion (intracorporeal robotic assisted radical cystectomy [iRARC]).
METHODS: A single institution prospective cohort study in patients undergoing iRARC for muscle invasive and high-grade bladder cancer. Inclusion: patients undergoing standardised CPET before iRARC. Exclusions: patients not consenting to data collection. Data on CPET measures (AT, ventilatory equivalent for carbon dioxide [VE/VCO2] at AT, peak oxygen uptake [VO2]), and patient demographics prospectively collected. Outcome measurements included hospital LOS; 30-day MAE and 90-day mortality data, which were prospectively recorded. Descriptive and regression analyses were used to assess whether CPET measures were associated with or predicted outcomes.
RESULTS: From June 2011 to March 2015, 128 patients underwent radical cystectomy (open cystectomy, n = 17; iRARC, n = 111). A total of 82 patients who underwent iRARC and CPET and consented to participation were included. Median (interquartile range): age = 65 (58–73); body mass index = 27 (23–30); AT = 10.0 (9–11), Peak VO2 = 15.0 (13–18.5), VE/VCO2 (AT) = 33.0 (30–38). 30-day MAE = 14/111 (12.6%): death = 2, multiorgan failure = 2, abscess = 2, gastrointestinal = 2, renal = 6; 90-day mortality = 3/111 (2.7%). AT, peak VO2, and VE/VCO2 (at AT) were not significant predictors of 30-day MAE or LOS. The results are limited by the absence of control group undergoing open surgery.
CONCLUSIONS: Poor cardiorespiratory fitness does not predict increased hospital LOS or MAEs in patients undergoing iRARC. Overall, MAE and LOS comparable with other series
Elliptic Curves over Real Quadratic Fields are Modular
We prove that all elliptic curves defined over real quadratic fields are
modular.Comment: 38 pages. Magma scripts available as ancillary files with this arXiv
versio
The 1983 drought in the West Sahel: a case study
Some drought years over sub-Saharan west Africa (1972, 1977, 1984) have been previously related to a cross-equatorial Atlantic gradient pattern with anomalously warm sea surface temperatures (SSTs) south of 10°N and anomalously cold SSTs north of 10°N. This SST dipole-like pattern was not characteristic of 1983, the third driest summer of the twentieth century in the Sahel. This study presents evidence that the dry conditions that persisted over the west Sahel in 1983 were mainly forced by high Indian Ocean SSTs that were probably remanent from the strong 1982/1983 El Niño event. The synchronous Pacific impact of the 1982/1983 El Niño event on west African rainfall was however, quite weak. Prior studies have mainly suggested that the Indian Ocean SSTs impact the decadal-scale rainfall variability over the west Sahel. This study demonstrates that the Indian Ocean also significantly affects inter-annual rainfall variability over the west Sahel and that it was the main forcing for the drought over the west Sahel in 1983
The stellar and sub-stellar IMF of simple and composite populations
The current knowledge on the stellar IMF is documented. It appears to become
top-heavy when the star-formation rate density surpasses about 0.1Msun/(yr
pc^3) on a pc scale and it may become increasingly bottom-heavy with increasing
metallicity and in increasingly massive early-type galaxies. It declines quite
steeply below about 0.07Msun with brown dwarfs (BDs) and very low mass stars
having their own IMF. The most massive star of mass mmax formed in an embedded
cluster with stellar mass Mecl correlates strongly with Mecl being a result of
gravitation-driven but resource-limited growth and fragmentation induced
starvation. There is no convincing evidence whatsoever that massive stars do
form in isolation. Various methods of discretising a stellar population are
introduced: optimal sampling leads to a mass distribution that perfectly
represents the exact form of the desired IMF and the mmax-to-Mecl relation,
while random sampling results in statistical variations of the shape of the
IMF. The observed mmax-to-Mecl correlation and the small spread of IMF
power-law indices together suggest that optimally sampling the IMF may be the
more realistic description of star formation than random sampling from a
universal IMF with a constant upper mass limit. Composite populations on galaxy
scales, which are formed from many pc scale star formation events, need to be
described by the integrated galactic IMF. This IGIMF varies systematically from
top-light to top-heavy in dependence of galaxy type and star formation rate,
with dramatic implications for theories of galaxy formation and evolution.Comment: 167 pages, 37 figures, 3 tables, published in Stellar Systems and
Galactic Structure, Vol.5, Springer. This revised version is consistent with
the published version and includes additional references and minor additions
to the text as well as a recomputed Table 1. ISBN 978-90-481-8817-
Autism as a disorder of neural information processing: directions for research and targets for therapy
The broad variation in phenotypes and severities within autism spectrum disorders suggests the involvement of multiple predisposing factors, interacting in complex ways with normal developmental courses and gradients. Identification of these factors, and the common developmental path into which theyfeed, is hampered bythe large degrees of convergence from causal factors to altered brain development, and divergence from abnormal brain development into altered cognition and behaviour. Genetic, neurochemical, neuroimaging and behavioural findings on autism, as well as studies of normal development and of genetic syndromes that share symptoms with autism, offer hypotheses as to the nature of causal factors and their possible effects on the structure and dynamics of neural systems. Such alterations in neural properties may in turn perturb activity-dependent development, giving rise to a complex behavioural syndrome many steps removed from the root causes. Animal models based on genetic, neurochemical, neurophysiological, and behavioural manipulations offer the possibility of exploring these developmental processes in detail, as do human studies addressing endophenotypes beyond the diagnosis itself
The Formation and Evolution of the First Massive Black Holes
The first massive astrophysical black holes likely formed at high redshifts
(z>10) at the centers of low mass (~10^6 Msun) dark matter concentrations.
These black holes grow by mergers and gas accretion, evolve into the population
of bright quasars observed at lower redshifts, and eventually leave the
supermassive black hole remnants that are ubiquitous at the centers of galaxies
in the nearby universe. The astrophysical processes responsible for the
formation of the earliest seed black holes are poorly understood. The purpose
of this review is threefold: (1) to describe theoretical expectations for the
formation and growth of the earliest black holes within the general paradigm of
hierarchical cold dark matter cosmologies, (2) to summarize several relevant
recent observations that have implications for the formation of the earliest
black holes, and (3) to look into the future and assess the power of
forthcoming observations to probe the physics of the first active galactic
nuclei.Comment: 39 pages, review for "Supermassive Black Holes in the Distant
Universe", Ed. A. J. Barger, Kluwer Academic Publisher
"I am your mother and your father!": In vitro derived gametes and the ethics of solo reproduction
In this paper, we will discuss the prospect of human reproduction achieved with gametes originating from only one person. According to statements by a minority of scientists working on the generation of gametes in vitro, it may become possible to create eggs from men’s non-reproductive cells and sperm from women’s. This would enable, at least in principle, the creation of an embryo from cells obtained from only one individual: ‘solo reproduction’. We will consider what might motivate people to reproduce in this way, and the implications that solo reproduction might have for ethics and policy. We suggest that such an innovation is unlikely to revolutionise reproduction and parenting. Indeed, in some respects it is less revolutionary than in vitro fertilisation as a whole. Furthermore, we show that solo reproduction with in vitro created gametes is not necessarily any more ethically problematic than gamete donation—and probably less so. Where appropriate, we draw parallels with the debate surrounding reproductive cloning. We note that solo reproduction may serve to perpetuate reductive geneticised accounts of reproduction, and that this may indeed be ethically questionable. However, in this it is not unique among other technologies of assisted reproduction, many of which focus on genetic transmission. It is for this reason that a ban on solo reproduction might be inconsistent with continuing to permit other kinds of reproduction that also bear the potential to strengthen attachment to a geneticised account of reproduction. Our claim is that there are at least as good reasons to pursue research towards enabling solo reproduction, and eventually to introduce solo reproduction as an option for fertility treatment, as there are to do so for other infertility related purposes
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
- …
