9,396 research outputs found
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ASoP (v1.0): a set of methods for analyzing scales of precipitation in general circulation models
General circulation models (GCMs) have been criticized for their failure to represent the observed scales of precipitation, particularly in the tropics where simulated daily rainfall is too light, too frequent, and too persistent. Previous assessments have focused on temporally or spatially averaged precipitation, such as daily means or regional averages. These evaluations offer little actionable information for model developers, because the interactions between the resolved dynamics and parameterized physics that produce precipitation occur at the native gridscale and timestep.
We introduce a set of diagnostics (ASoP1) to compare the spatial and temporal scales of precipitation across GCMs and observations, which can be applied to data ranging from the gridscale and timestep to regional and sub-monthly averages. ASoP1 measures the spectrum of precipitation intensity, temporal variability as a function of intensity, and spatial and temporal coherence. When applied to timestep, gridscale tropical precipitation from ten GCMs, the diagnostics reveal that far from the "dreary" persistent light rainfall implied by daily mean data, most models produce a broad range of timestep intensities that span 1-100 mm/day. Models show widely varying spatial and temporal scales of timestep precipitation. Several GCMs show concerning quasi-random behavior that may influence alter the spectrum of atmospheric waves. Averaging precipitation to a common spatial (~600 km) or temporal (3-hr) resolution substantially reduces variability among models, demonstrating that averaging hides a wealth of information about intrinsic model behavior. When compared against satellite-derived analyses at these scales, all models produce features that are too large and too persistent
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Connecting spatial and temporal scales of tropical precipitation in observations and the MetUM-GA6
This study analyses tropical rainfall variability, on a range of temporal and spatial scales, in a set of parallel Met Office Unified Model (MetUM) simulations at a range of horizontal resolutions, compared with two satellite-derived rainfall datasets. We focus on the shorter scales i.e. from the native grid and time-step of the model through sub-daily to seasonal, since previous studies have paid relatively little attention to sub-daily rainfall variability and how this feeds through to longer scales. We find that the behaviour of the deep convection parametrization in this model on the native grid and time-step is largely independent of the grid-box size and time-step length over which it operates. There is also little difference in the rainfall variability on larger/longer spatial/temporal scales. Tropical convection in the model on the native grid/time-step is spatially and temporally intermittent, producing very large rainfall amounts interspersed with grid-boxes/time-steps of little or no rain. In contrast, switching off the deep convection parametrization, albeit at an unrealistic resolution for resolving tropical convection, results in very persistent (for limited periods), but very sporadic, rainfall. In both cases, spatial and temporal averaging smoothes out this intermittency. On the ~100 km scale, for oceanic regions, the spectra of 3-hourly and daily mean rainfall in the configurations with parametrized convection agree fairly well with those from satellite-derived rainfall estimates, while at ~10 day timescales the averages are overestimated, indicating a lack of intra-seasonal variability. Over tropical land the results are more varied, but the model often underestimates the daily mean rainfall (partly as a result of a poor diurnal cycle) but still lacks variability on intra-seasonal timescales. Ultimately, such work will shed light on how uncertainties in modelling the small/short scale processes relate to uncertainty in climate change projections of rainfall distribution and variability, with a view to reducing such uncertainty through improved modelling of the small/short scale processes
Breathlessness in the elderly during the last year of life sufficient to restrict activity
OBJECTIVES: Breathlessness is prevalent in older people. Symptom control at the end of life is important. This study investigated relationships between age, clinical characteristics and breathlessness sufficient to have people spend at least one half a day in that month in bed or cut down on their usual activities (restricting breathlessness) during the last year of life. DESIGN: Secondary data-analysis SETTING: General community PARTICIPANTS: 754 non-disabled persons, aged 70 and older. Monthly telephone interviews were conducted to determine the occurrence of restricting breathlessness. The primary outcome was the percentage of months with restricting breathlessness reported during the last year of life. RESULTS: Data regarding breathlessness were available for 548/589 (93.0%) decedents (mean age 86.7 years (range 71 to 106; males 38.8%). 311/548 (56.8%) reported restricting breathlessness at some time-point during the last year of life but no-one reported this every month. Frequency increased in the months closer to death irrespective of cause. Restricting breathlessness was associated with anxiety, (0.25 percentage point increase in months breathlessness per percentage point months reported anxiety, 95% CI 0.16 to 0.34, P<0.001), depression (0.14, 0.05 to 0.24, P=0.002) and mobility problems (0.07, 0.03 to 0.1, P=0.001). Percentage months of restricting breathlessness increased if chronic lung disease was noted at the most recent comprehensive assessment (6.62 percentage points, 95% CI 4.31 to 8.94, P<0.001), heart failure (3.34, 0.71 to 5.97, P<0.01), and ex-smoker status (3.01, 0.94 to 5.07, P=0.002), but decreased with older age (─0.19, ─0.37 to ─0.02, P=0.03). CONCLUSION: Restricting breathlessness increased in this elderly population in the months preceding death from any cause. Breathlessness should be assessed and managed in the context of poor prognosis
A Comparison of Competitive-Orientation Measures
We compared two sport-specific measures of competitive orientation, the Sport Orientation Questionnaire (SOQ; Gill & Deeter, 1988) and the Competitive Orientation Inventory (COI; Veasley, 1986), and an alternative 4-item version of the COI. Male and female athletes and nonathletes at two small colleges completed questionnaire packets. Competitive-orientation scores were similar to those reported in previous research. The 4-item measure correlated with the COI, and neither of those measures correlated with the SOQ. As in previous studies, males scored higher than females on SOQ competitiveness and win orientation, and athletes scored higher than nonathletes on all SOQ scores. Our results suggest that the SOQ and COI do not assess the same competitive-orientation constructs. The SOQ assesses sport-specific achievement orientation; the COI assesses the relative importance of performance versus outcome. Our 4-item measure is comparable and provides a reasonable substitute for the more complex COI
Competitive Orientations and Motives of Adult Sport and Exercise Participants
Participants in four different adult sport and exercise programs (running club, exercise classes, cardiac rehabilitation program, senior games) completed measures of competitive orientation and participation motivation. Our samples were older and more diverse than samples of previous research, and their competitive orientations and motives were similarly diverse. Multivariate analyses revealed gender and sample differences. Males were higher than females on competitiveness and win orientation, and runners were less win-oriented than other groups, but overall, all groups were similar to previous college-age samples in competitive orientation. Groups varied on specific motives, with females rating fitness, flexibility, affiliation, and appearance higher than males did. Generally, participants were diverse in orientations and motives, and positive about their participation. Research and conceptual models of sport orientation must extend beyond achievement motives to capture the diversity of adult participants. Program directors and instructors who offer activities and approaches to match this diversity will encourage wider participation and provide a more satisfying experience for more participants
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The effect of increased convective entrainment on Asian monsoon biases in the MetUM General Circulation Model
We demonstrate that summer precipitation biases in the South Asian monsoon domain are sensitive to increasing the convective parametrisation’s entrainment and detrainment rates in the Met Office Unified Model. We explore this sensitivity to improve our understanding of the biases and inform efforts to improve convective parametrisation. We perform novel targeted experiments in which we increase the entrainment and detrainment rates in regions of especially large precipitation bias. We use these experiments to determine whether the sensitivity at a given location is a consequence of the local change to convection or is a remote response to the change elsewhere. We find that a local change leads to different mean-state responses in comparable regions. When the entrainment and detrainment rates are increased globally, feedbacks between regions usually strengthen the local responses. We choose two regions of tropical ascent that show different mean-state responses, the western equatorial Indian Ocean and western north Pacific, and analyse them as case studies to determine
the mechanisms leading to the different responses. Our results indicate that several aspects of a region’s mean-state, including moisture content, sea surface temperature and circulation, play a role in local feedbacks that determine the response to increased entrainment and detrainment
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Sporormiella as a tool for detecting the presence of large herbivores in the Neotropics
The reliability of using the abundance of Sporormiella spores as a proxy for the presence and abundance of megaherbivores was tested in southern Brazil. Mud-water interface samples from nine lakes, in which cattle-use was categorized as high, medium, or low, were assayed for Sporormiella representation. The sampling design allowed an analysis of both the influence of the number of animals using the shoreline and the distance of the sampling site from the nearest shoreline. Sporormiella was found to be a reliable proxy for the presence of large livestock. The concentration and abundance of spores declined from the edge of the lake toward the center, with the strongest response being in sites with high livestock use. Consistent with prior studies in temperate regions, we find that Sporormiella spores are a useful proxy to study the extinction of Pleistocene megafauna or the arrival of European livestock in Neotropical landscapes
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Predictability of South China Sea summer monsoon onset
Predicting monsoon onset is crucial for agriculture and socioeconomic planning in countries where millions rely on the timely arrival of monsoon rains for their livelihoods. In this study we demonstrate useful skill in predicting year to year variations in South China Sea summer monsoon onset at up to 3 months lead time using the GloSea5 seasonal forecasting system. The main source of predictability comes from skilful prediction of Pacific sea surface temperatures associated with El Niño and La Niña. The South China Sea summer monsoon onset is a known indicator of the broadscale seasonal transition that represents the first stage of the onset of the Asian summer monsoon as a whole. Subsequent development of rainfall across East Asia is influenced by sub-seasonal variability and synoptic events that reduce predictability, but interannual variability in the broadscale monsoon onset for East Asian summer monsoon still provides potentially useful information for users about possible delays or early occurrence of the onset of rainfall over East Asia
Does bariatric surgery prior to total hip or knee arthroplasty reduce post-operative complications and improve clinical outcomes for obese patients? Systematic review and meta-analysis.
AIMS: Our aim was to determine whether, based on the current literature, bariatric surgery prior to total hip (THA) or total knee arthroplasty (TKA) reduces the complication rates and improves the outcome following arthroplasty in obese patients. METHODS: A systematic literature search was undertaken of published and unpublished databases on the 5 November 2015. All papers reporting studies comparing obese patients who had undergone bariatric surgery prior to arthroplasty, or not, were included. Each study was assessed using the Downs and Black appraisal tool. A meta-analysis of risk ratios (RR) and 95% confidence intervals (CI) was performed to determine the incidence of complications including wound infection, deep vein thrombosis (DVT), pulmonary embolism (PE), revision surgery and mortality. RESULTS: From 156 potential studies, five were considered to be eligible for inclusion in the study. A total of 23 348 patients (657 who had undergone bariatric surgery, 22 691 who had not) were analysed. The evidence-base was moderate in quality. There was no statistically significant difference in outcomes such as superficial wound infection (relative risk (RR) 1.88; 95% confidence interval (CI) 0.95 to 0.37), deep wound infection (RR 1.04; 95% CI 0.65 to 1.66), DVT (RR 0.57; 95% CI 0.13 to 2.44), PE (RR 0.51; 95% CI 0.03 to 8.26), revision surgery (RR 1.24; 95% CI 0.75 to 2.05) or mortality (RR 1.25; 95% CI 0.16 to 9.89) between the two groups. CONCLUSION: For most peri-operative outcomes, bariatric surgery prior to THA or TKA does not significantly reduce the complication rates or improve the clinical outcome. This study questions the previous belief that bariatric surgery prior to arthroplasty may improve the clinical outcomes for patients who are obese or morbidly obese. This finding is based on moderate quality evidence. Cite this article: Bone Joint J 2016;98-B:1160-6
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