379 research outputs found
Prototyping of the ILC Baseline Positron Target
The ILC positron system uses novel helical undulators to create a powerful
photon beam from the main electron beam. This beam is passed through a titanium
target to convert it into electron-positron pairs. The target is constructed as
a 1 m diameter wheel spinning at 2000 RPM to smear the 1 ms ILC pulse train
over 10 cm. A pulsed flux concentrating magnet is used to increase the positron
capture efficiency. It is cooled to liquid nitrogen temperatures to maximize
the flatness of the magnetic field over the 1 ms ILC pulse train. We report on
prototyping effort on this system.Comment: 7 pages, 9 figures, Proceedings of the International Workshop on
Future Linear Colliders, Granada Spain, 26-30 September 201
Convective dynamics and the response of precipitation extremes to warming in radiative-convective equilibrium
Tropical precipitation extremes are expected to strengthen with warming, but
quantitative estimates remain uncertain because of a poor understanding of
changes in convective dynamics. This uncertainty is addressed here by analyzing
idealized convection-permitting simulations of radiative-convective equilibrium
in long-channel geometry. Across a wide range of climates, the thermodynamic
contribution to changes in instantaneous precipitation extremes follows
near-surface moisture, and the dynamic contribution is positive and small, but
sensitive to domain size. The shapes of mass flux profiles associated with
precipitation extremes are determined by conditional sampling that favors
strong vertical motion at levels where the vertical saturation specific
humidity gradient is large, and mass flux profiles collapse to a common shape
across climates when plotted in a moisture-based vertical coordinate. The
collapse, robust to changes in microphysics and turbulence schemes, implies a
thermodynamic contribution that scales with near-surface moisture despite
substantial convergence aloft and allows the dynamic contribution to be defined
by the pressure velocity at a single level. Linking the simplified dynamic mode
to vertical velocities from entraining plume models reveals that the small
dynamic mode in channel simulations (<~2 %/K) is caused by opposing
height-dependences of vertical velocity and density, together with the
buffering influence of cloud-base buoyancies that vary little with surface
temperature. These results reinforce an emerging picture of the response of
extreme tropical precipitation rates to warming: a thermodynamic mode of about
7 %/K dominates, with a minor contribution from changes in dynamics.Comment: 28 pages, 15 figures, 1 table. This work has been accepted to Journal
of the Atmospheric Sciences. The AMS does not guarantee that the copy
provided here is an accurate copy of the final published wor
Lonesome Isle : Fox-Trot Song
https://digitalcommons.library.umaine.edu/mmb-vp/4275/thumbnail.jp
Elective surgery system strengthening: development, measurement, and validation of the surgical preparedness index across 1632 hospitals in 119 countries
Background
The 2015 Lancet Commission on global surgery identified surgery and anaesthesia as indispensable parts of holistic health-care systems. However, COVID-19 exposed the fragility of planned surgical services around the world, which have also been neglected in pandemic recovery planning. This study aimed to develop and validate a novel index to support local elective surgical system strengthening and address growing backlogs.
Methods
First, we performed an international consultation through a four-stage consensus process to develop a multidomain index for hospital-level assessment (surgical preparedness index; SPI). Second, we measured surgical preparedness across a global network of hospitals in high-income countries (HICs), middle-income countries (MICs), and low-income countries (LICs) to explore the distribution of the SPI at national, subnational, and hospital levels. Finally, using COVID-19 as an example of an external system shock, we compared hospitals' SPI to their planned surgical volume ratio (SVR; ie, operations for which the decision for surgery was made before hospital admission), calculated as the ratio of the observed surgical volume over a 1-month assessment period between June 6 and Aug 5, 2021, against the expected surgical volume based on hospital administrative data from the same period in 2019 (ie, a pre-pandemic baseline). A linear mixed-effects regression model was used to determine the effect of increasing SPI score.
Findings
In the first phase, from a longlist of 103 candidate indicators, 23 were prioritised as core indicators of elective surgical system preparedness by 69 clinicians (23 [33%] women; 46 [67%] men; 41 from HICs, 22 from MICs, and six from LICs) from 32 countries. The multidomain SPI included 11 indicators on facilities and consumables, two on staffing, two on prioritisation, and eight on systems. Hospitals were scored from 23 (least prepared) to 115 points (most prepared). In the second phase, surgical preparedness was measured in 1632 hospitals by 4714 clinicians from 119 countries. 745 (45·6%) of 1632 hospitals were in MICs or LICs. The mean SPI score was 84·5 (95% CI 84·1â84·9), which varied between HIC (88·5 [89·0â88·0]), MIC (81·8 [82·5â81·1]), and LIC (66·8 [64·9â68·7]) settings. In the third phase, 1217 (74·6%) hospitals did not maintain their expected SVR during the COVID-19 pandemic, of which 625 (51·4%) were from HIC, 538 (44·2%) from MIC, and 54 (4·4%) from LIC settings. In the mixed-effects model, a 10-point increase in SPI corresponded to a 3·6% (95% CI 3·0â4·1; p<0·0001) increase in SVR. This was consistent in HIC (4·8% [4·1â5·5]; p<0·0001), MIC (2·8 [2·0â3·7]; p<0·0001), and LIC (3·8 [1·3â6·7%]; p<0·0001) settings.
Interpretation
The SPI contains 23 indicators that are globally applicable, relevant across different system stressors, vary at a subnational level, and are collectable by front-line teams. In the case study of COVID-19, a higher SPI was associated with an increased planned surgical volume ratio independent of country income status, COVID-19 burden, and hospital type. Hospitals should perform annual self-assessment of their surgical preparedness to identify areas that can be improved, create resilience in local surgical systems, and upscale capacity to address elective surgery backlogs
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Preliminary prediction of individual response to electroconvulsive therapy using whole-brain functional magnetic resonance imaging data.
Electroconvulsive therapy (ECT) works rapidly and has been widely used to treat depressive disorders (DEP). However, identifying biomarkers predictive of response to ECT remains a priority to individually tailor treatment and understand treatment mechanisms. This study used a connectome-based predictive modeling (CPM) approach in 122 patients with DEP to determine if pre-ECT whole-brain functional connectivity (FC) predicts depressive rating changes and remission status after ECT (47 of 122 total subjects or 38.5% of sample), and whether pre-ECT and longitudinal changes (pre/post-ECT) in regional brain network biomarkers are associated with treatment-related changes in depression ratings. Results show the networks with the best predictive performance of ECT response were negative (anti-correlated) FC networks, which predict the post-ECT depression severity (continuous measure) with a 76.23% accuracy for remission prediction. FC networks with the greatest predictive power were concentrated in the prefrontal and temporal cortices and subcortical nuclei, and include the inferior frontal (IFG), superior frontal (SFG), superior temporal (STG), inferior temporal gyri (ITG), basal ganglia (BG), and thalamus (Tha). Several of these brain regions were also identified as nodes in the FC networks that show significant change pre-/post-ECT, but these networks were not related to treatment response. This study design has limitations regarding the longitudinal design and the absence of a control group that limit the causal inference regarding mechanism of post-treatment status. Though predictive biomarkers remained below the threshold of those recommended for potential translation, the analysis methods and results demonstrate the promise and generalizability of biomarkers for advancing personalized treatment strategies
Changes in perceptions of mental fatigue during a season in professional under-23 English Premier League soccer players
The present study assessed changes in academy soccer playersâ perception of mental fatigue (MF) across a competitive season, investigating the relationship between MF and other subjective measures of wellness. Ten players completed a modified Brief Assessment of Mood (BAM+) questionnaire that included the question: âHow mentally fatigued do you feelâ? on match-day (MD) and one (MD+1), two (MD+2) and three (MD+3) days post-match (35 matches). Players reported their MF, along with other subjective measures (sleep, muscle soreness, fatigue and motivation). Results found MF was elevated on MD+1 (43 ±1 mm) compared to all other days (all Pâ€0.001). Players reported lower MF on MD+1 in the late-season phase (34±2 mm) compared to both early- (50±2 mm, Pâ€0.001) and mid-season (46±2 mm, Pâ€0.001). This coincided with an 80%-win rate in the late-season phase versus the early- (33%) and mid-season (50%). There were very strong repeated- measures correlations between changes in MF and sleep (r=â0.77), muscle soreness (r=0.94), fatigue (r=0.92) and motivation (r=â0.89; all P †0.0005). In conclusion, MF was closely aligned to match success and other wellness variables. This data suggests a potential lack of sensitivity for identifying MF using a subjective questionnaire. Therefore, researchers and practitioners could work together to identify other ways of practically assessing MF.<br/
Countermovement Jump Recovery in Professional Soccer Players Using an Inertial Sensor
Purpose
The purpose of this study was to assess the utility of an inertial sensor for assessing recovery in professional soccer players.
Methods
In a randomized, crossover design, 11 professional soccer players wore shorts fitted with phase change material (PCM) cooling packs or uncooled packs (control) for 3 h after a 90 minute match. Countermovement jump (CMJ) performance was assessed simultaneously with an inertial sensor and an optoelectric system, pre match, and 12, 36 and 60 h post match. Inertial sensor metrics were flight height, jump height, low force, countermovement distance, force at low point, rate of eccentric force development, peak propulsive force, maximum power, and peak landing force. The only optoelectric metric was flight height. CMJ decrements, and effect of PCM cooling were assessed with repeated measures ANOVA. Jump heights were also compared between devices.
Results
For the inertial sensor data there were decrements in CMJ height on the days after matches (88±10% of baseline at 36 h P=0.012, effect size 1.2, for control condition) and accelerated recovery with PCM cooling (105±15% of baseline at 36 h, P=0.018 vs. control, effect size 1.1). Flight heights were strongly correlated between devices (r=0.905, P<0.001) but inertial sensor values were 1.8±1.8 cm lower (P=0.008). Low force during countermovement was increased (P=0.031) and landing force was decreased (P=0.043) after matches, but neither were affected by the PCM cooling intervention. Other CMJ metrics were unchanged after matches.
Conclusions
This small portable inertial sensor provides a practical means of assessing recovery in soccer players
Can chilling tolerance of C4 photosynthesis in \u3ci\u3eMiscanthus\u3c/i\u3e be transferred to sugarcane?
The goal of this study was to investigate whether chilling tolerance of C4 photosynthesis in Miscanthus can be transferred to sugarcane by hybridization. Net leaf CO2 uptake (Asat) and the maximum operating efficiency of photosystem II (Đ€PSII) were measured in warm conditions (25 °C/20 °C), and then during and following a chilling treatment of 10 °C/5 °C for 11 day in controlled environment chambers. Two of three hybrids (miscanes), âUS 84-1058â and âUS 87-1019â, did not differ significantly from the chilling tolerant M. xgiganteus âIllinoisâ (Mxg), for Asat, and ΊPSII measured during chilling. For Mxg grown at 10 °C/5 °C for 11 days, Asat was 4.4 ÎŒmol m-2 s-1, while for miscane âUS 84-1058â and âUS 87-1019â, Asat was 5.7 and 3.5 ÎŒmol m-2 s-1, respectively. Miscanes âUS 84-1058â and âUS 87-1019â and Mxg had significantly higher rates of Asat during chilling than three tested sugarcanes. A third miscane showed lower rates than Mxg during chilling, but recovered to higher rates than sugarcane upon return to warm conditions. Chilling tolerance of âUS 84-1058â was further confirmed under autumn field conditions in southern Illinois. The selected chilling tolerant miscanes have particular value for biomass feedstock and biofuel production and at the same time they can be a starting point for extending sugarcaneâs range to colder climates
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