bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling and Parameter Estimation of Hurricane Wind Fields with Asymmetry
Authors: Chang Derek , Amin Saurabh , Emanuel Kerry 
Published: March 2020

AbstractThis article presents an azimuthally asymmetric gradient hurricane wind field model that can be coupled with hurricane-track models for engineering wind risk assessments. The model incorporates low-wavenumber asymmetries into the maximum wind intensity parameter of the Holland et al. wind field model. The amplitudes and phases of the asymmetries are parametric functions of the storm-translation speed and wind shear. Model parameters are estimated by solving a constrained, nonlinear least squares (CNLS) problem that minimizes the sum of squared residuals between wind field intensities of historical storms and model-estimated winds. There are statistically significant wavenumber-1 asymmetries in the wind field resulting from both storm translation and wind shear. Adding the translation vector to the wind field model with wavenumber-1 asymmetries further improves the model’s estimation performance. In addition, inclusion of the wavenumber-1 asymmetry resulting from translation results in a greater decrease in modeling error than does inclusion of the wavenumber-1 shear-induced asymmetry. Overall, the CNLS estimation method can handle the inherently nonlinear wind field model in a flexible manner; thus, it is well suited to capture the radial variability in the hurricane wind field’s asymmetry. The article concludes with brief remarks on how the CNLS-estimated model can be applied for simulating wind fields in a statistically generated ensemble.
Detailed Dual-Doppler Structure of Kelvin–Helmholtz Waves from an Airborne Profiling Radar over Complex Terrain. Part I: Dynamic Structure
Authors: Grasmick Coltin , Geerts Bart 
Published: March 2020

AbstractKelvin–Helmholtz (KH) waves are remarkably common in deep stratiform precipitation systems associated with frontal disturbances, at least in the vicinity of complex terrain, as is evident from transects of vertical velocity and 2D circulation, obtained from a 3-mm airborne Doppler radar, the Wyoming Cloud Radar. The high range resolution of this radar (~40 m) allows detection and depiction of KH waves in fine detail. These waves are observed in a variety of wavelengths, depths, amplitudes, and turbulence intensities. Proximity rawinsonde data confirm that they are triggered in layers where the Richardson number is very small. Complex terrain may locally enhance wind shear, leading to KH instability. In some KH waves, the flow remains mostly laminar, while in other cases it breaks down into turbulence. KH waves are frequently locked to the terrain, and occur at various heights, including within the free troposphere, at the boundary layer top, and close to the surface. They are observed not only upwind of terrain barriers, as has been documented before, but also in the wake of steep terrain, where the waves can be highly turbulent. Vertical-plane dual-Doppler analyses of KH waves reveal the mixing of layers of differential momentum across the high-shear zone. Doppler radar data are used to explore the dynamics of KH waves, including the response of thermodynamic and kinematic variables above, below, and within the instability layer.
Extracting the Buoyancy-Driven Atlantic Meridional Overturning Circulation
Authors: Larson Sarah M. , Buckley Martha W. , Clement Amy C. 
Published: March 2020

AbstractVariations in the Atlantic meridional overturning circulation (AMOC) driven by buoyancy forcing are typically characterized as having a low-frequency time scale, interhemispheric structure, cross-equatorial heat transport, and linkages to the strength of Northern Hemisphere gyre circulations and the Gulf Stream. This study first tests whether these attributes ascribed to the AMOC are reproduced in a coupled model that is mechanically decoupled and, hence, is only buoyancy coupled. Overall, the mechanically decoupled model reproduces these attributes, with the exception that in the subpolar gyre, buoyancy drives AMOC variations on interannual to multidecadal time scales, yet only the multidecadal variations penetrate into the subtropics. A stronger AMOC is associated with a strengthening of the Northern Hemisphere gyre circulations, Gulf Stream, and northward oceanic heat transport throughout the basin. We then determine whether the characteristics in the mechanically decoupled model can be recovered by low-pass filtering the AMOC in a fully coupled version of the same model, a common approach used to isolate the buoyancy-driven AMOC. A major conclusion is that low-pass filtering the AMOC in the fully coupled model reproduces the buoyancy-driven AMOC pattern and most of the associated attributes, but not the statistics of the temporal variability. The strength of the AMOC–Gulf Stream connection is also not reproduced. The analyses reveal caveats that must be considered when choosing indexes and filtering techniques to estimate the buoyancy-driven AMOC. Results also provide insight on the latitudinal dependence of time scales and drivers of ocean circulation variability in coupled models, with potential implications for measurement and detection of the buoyancy-driven AMOC in the real world.
Assessment of the Teleconnection Patterns Affecting July Precipitation in China and Their Forcing Mechanisms in the Met Office Unified Model
Authors: Carvalho Maria João , Milton Sean F. , Rodríguez José M. 
Published: March 2020

AbstractIn this study, we evaluate the ability of the MetUM to reproduce the Silk Road (SR) and Europe–China (EC) teleconnection patterns and their relationship with precipitation over China. The SR and EC patterns are the main modes of interannual variability of July upper-tropospheric meridional wind. The three main factors to the formation of these patterns are analyzed: 1) the tropical precipitation anomalies, which act as a forcing mechanism; 2) the emission of Rossby waves in the Mediterranean–Caspian Sea region; and 3) the basic state of the tropospheric jet over Eurasia. It was found that the model has some difficulty reproducing the main modes of variability in atmosphere-only mode (SR and EC pattern correlation of 0.31 and 0.54, respectively) with some improvement in coupled mode (pattern correlations of 0.56 and 0.44, respectively). Relaxation experiments were used to assess the impact that improving circulation in key regions has on the teleconnections. It was found that nudging wind and temperatures in the forcing regions within the tropics improved the Silk Road pattern whereas nudging in the region where the jet transitions between the North Atlantic Ocean and Eurasian continent—correcting the basic state—had the most impact on the EC teleconnection pattern. This suggests that while the Silk Road pattern is more sensitive to changes in the forcing, the Europe–China pattern is more sensitive to the basic state.
Impact of Combined Assimilation of Radar and Rainfall Data on Short-Term Heavy Rainfall Prediction: A Case Study
Authors: Sun Juanzhen , Zhang Ying , Ban Junmei , Hong Jing-Shan , Lin Chung-Yi 
Published: March 2020

AbstractRadar and surface rainfall observations are two sources of operational data crucial for heavy rainfall prediction. Their individual values on improving convective forecasting through data assimilation have been examined in the past using convection-permitting numerical models. However, the benefit of their simultaneous assimilations has not yet been evaluated. The objective of this study is to demonstrate that, using a 4D-Var data assimilation system with a microphysical scheme, these two data sources can be assimilated simultaneously and the combined assimilation of radar data and estimated rainfall data from radar reflectivity and surface network can lead to improved short-term heavy rainfall prediction. In our study, a combined data assimilation experiment is compared with a rainfall-only and a radar-only (with or without reflectivity) experiments for a heavy rainfall event occurring in Taiwan during the passage of a mei-yu system. These experiments are conducted by applying the Weather Research and Forecasting (WRF) 4D-Var data assimilation system with a 20-min time window aiming to improve 6-h convective heavy rainfall prediction. Our results indicate that the rainfall data assimilation contributes significantly to the analyses of humidity and temperature whereas the radar data assimilation plays a crucial role in wind analysis, and further, combining the two data sources results in reasonable analyses of all three fields by eliminating large, unphysical analysis increments from the experiments of assimilating individual data only. The results also show that the combined assimilation improves forecasts of heavy rainfall location and intensity of 6-h accumulated rainfall for the case studied.
Applying the Passivhaus standard to a terraced house in a hot and humid tropical climate – Evaluation of comfort and energy performance
Authors: Sigalingging Roy Candra , Chow David , Sharples Steve 
Published: March 2020

In a hot and humid tropical climate, natural ventilation brings high levels of moisture into dwellings that, together with occupant activity, can result in very elevated internal relative humidity levels. Coupling these high relative humidities with high internal air temperatures creates occupant thermal discomfort, which is typically ameliorated in the tropics using energy-intensive air conditioning systems. This paper has investigated the potential benefits for thermal comfort and energy usage of applying the German Passivhaus standard to tropical dwellings. By creating a super insulated and air-tight envelope, the Passivhaus standard reduces fabric heat transfer, controls air infiltration and provides low-energy comfort. Applying this approach to a tropical terraced house might be effective but could, potentially, have an adverse impact on mechanical cooling demand. This study took an actual terraced property in Jakarta, Indonesia and thermally modelled its performance as insulation and airtightness levels were incrementally improved up to the Passivhaus standard. Field measurements in the dwelling of air temperature and relative humidity were used to validate the thermal model of the existing house. The validated model then tested the feasibility of meeting the Passivhaus energy standard for cooling in the modified tropical house. Simulation allowed the effects of air conditioning (AC) and dehumidifiers on thermal comfort and cooling loads to be investigated. The research develop the Passivhaus building model that had the floor insulation removed to let the ground floor act as a thermal sink and potentially provide radiant cooling. Analysis revealed that the building’s predicted air temperatures were affected in a beneficial way by having the Passivhaus without floor insulation. Practical application: Cooling in hot and humid tropical region is an energy-intensive approach. Design approaches that can bring comfort and save energy for the occupant are essential. The success of Passivhaus standard in mild climate might be transferable to bring comfort in tropical housing. Best practice can be developed by analysing the Passivhaus building performance in hot and humid tropical region.
Development and validation of a scale to assess the attitude of healthcare professionals toward persons with disability
Authors: Yi You Gyoung , Lee Jeong-Eun , Lee Seung Hee , Lee Jin Yong , Kwon Yong Jin , Shin Hyung-Ik 
Published: March 2020

Objective: This study aimed to develop and validate an instrument that measures the attitudes of healthcare professionals toward persons with disabilities. Design: The Delphi survey consensus method was used to compose a preliminary questionnaire for survey. Then, healthcare professionals responded to the questionnaire online, and the results were used for psychometric analysis. Setting: Three tertiary hospitals. Subjects: A total of 993 healthcare professionals. Interventions: Not applicable. Main measures: Attitudes of healthcare professionals toward persons with disabilities. Results: A 28-item preliminary questionnaire was initially developed after a two-round Delphi survey with 16 experts. Through an online survey, the final 20 items were categorized as follows: behaviors in clinical situation, knowledge and skills, emotional response, and responsibility of healthcare professionals. The Cronbach’s alpha coefficient for the total score was 0.890 and varied between 0.856 and 0.892 in the four subdomains. The newly developed tool showed an acceptable model fit. Healthcare professionals who participated in an education module showed higher scores in behavior and knowledge/skills subdomains than those who did not, whereas participants who had clinical experience with persons with disabilities demonstrated higher scores in emotional response and knowledge/skills subdomains. Conclusions: We developed a scale to measure the attitudes toward persons with disabilities of healthcare professionals. The scale demonstrated a sensitivity to measure a difference by participation in an education module or clinical experience with persons with disabilities.
A single administration of ‘microbial’ D-alanine to healthy volunteers augments reaction to negative emotions: A comparison with D-serine
Authors: Capitão Liliana P , Forsyth Jessica , Thomaidou Mia A , Condon Mark D , Harmer Catherine J , Burnet Philip WJ 
Published: March 2020

Background: Activation of the glutamate N-methyl-D-aspartate receptor with its co-agonist D-serine has been shown to improve subjective mood in healthy volunteers. D-alanine is another potent N-methyl-D-aspartate receptor co-agonist which arises from the natural breakdown of host gut microbes, and is predominantly sequestered in the pituitary. This may suggest that D-alanine influences the neuroendocrine stress response which may then impact on emotion. Aims: The current study explored the effects of D-serine and D-alanine on emotional processing, cognition and the levels of the stress hormone cortisol in healthy volunteers. Methods: In a double-blind, placebo-controlled randomised study, participants ( n=63) received a single oral dose of either D-serine, D-alanine (60 mg/kg) or placebo and then performed the Emotional Test Battery and N-back task (two hours post-administration) and provided saliva samples at fixed intervals. Results: Subjects administered with D-alanine were faster at identifying facial expressions of fear, surprise and anger, and at categorising negative self-referential words. Participants on D-alanine also showed a trend to recall more words than placebo in a memory task. D-serine did not have any meaningful effects in any of the tasks. Neither amino acid had a significant effect on salivary cortisol or working memory. Conclusion: This study is the first to suggest that D-alanine can modulate emotional cognitive processing after a single dose. The lack of findings for D-serine nevertheless contrasts a previous study, emphasising a need for further investigation to clarify discrepancies. A better understanding of the physiological actions of D-amino acids would be beneficial in evaluating their therapeutic potential.
Altered regional cerebral blood flow and hypothalamic connectivity immediately prior to a migraine headache
Authors: Meylakh Noemi , Marciszewski Kasia K , Di Pietro Flavia , Macefield Vaughan G , Macey Paul M , Henderson Luke A 
Published: March 2020

BackgroundThere is evidence of altered resting hypothalamic activity patterns and connectivity prior to a migraine, however it remains unknown if these changes are driven by changes in overall hypothalamic activity levels. If they are, it would corroborate the idea that changes in hypothalamic function result in alteration in brainstem pain processing sensitivity, which either triggers a migraine headache itself or allows an external trigger to initiate a migraine headache. We hypothesise that hypothalamic activity increases immediately prior to a migraine headache and this is accompanied by altered functional connectivity to pain processing sites in the brainstem.MethodsIn 34 migraineurs and 26 healthy controls, we collected a series comprising 108 pseudo-continuous arterial spin labelling images and 180 gradient-echo echo planar resting-state functional magnetic resonance volumes to measure resting regional cerebral blood flow and functional connectivity respectively. Images were pre-processed and analysed using custom SPM12 and Matlab software.ResultsOur results reflect that immediately prior to a migraine headache, resting regional cerebral blood flow decreases in the lateral hypothalamus. In addition, resting functional connectivity strength decreased between the lateral hypothalamus and important regions of the pain processing pathway, such as the midbrain periaqueductal gray, dorsal pons, rostral ventromedial medulla and cingulate cortex, only during this critical period before a migraine headache.ConclusionThese data suggest altered hypothalamic function and connectivity in the period immediately prior to a migraine headache and supports the hypothesis that the hypothalamus is involved in migraine initiation.
Ankle and Lower Leg Injuries in Professional Baseball Players
Authors: Lucasti Christopher J. , Dworkin Myles , Warrender William J. , Winters Brian , Cohen Steven , Ciccotti Michael , Pedowitz David 
Published: March 2020

Background: Ankle and lower leg injuries are very common in sports, and numerous studies have discussed their diagnosis and management. Our study differs in that we report lower leg injuries in professional baseball players spanning the 2011-2016 seasons by utilizing a comprehensive injury surveillance system developed by Major League Baseball (MLB). Purpose: To determine the injury characteristics of ankle and lower leg injuries in professional baseball players during the 2011-2016 seasons by utilizing the MLB injury surveillance system. Study Design: Descriptive epidemiology study. Methods: Our study is a descriptive epidemiological evaluation through a retrospective review of injury data from the MLB Health and Injury Tracking System (HITS) since its implementation in 2010. We included any professional baseball player (MLB and Minor League Baseball [MiLB]) who was identified as having an ankle or lower leg injury between January 1, 2011, and February 28, 2017. Results: Over the study period, there were a total of 4756 injuries, of which 763 (16%) occurred in MLB players and 3993 (84%) occurred in MiLB players. The mean number of days missed for all players was 27.8 ± 141.4 days, with a median of 3 days. From 2011 through 2016, it was estimated that there were 414,912 athlete exposures (AEs) in MLB and 1,796,607 AEs in MiLB. Of the 4756 injuries recorded, 550 (12%) took place during the MLB regular season, and 3320 (70%) took place during the MiLB regular season. Injuries in MLB players, however, were 1.7 times more likely to require surgery ( P < .001). Additionally, rates of injury to the lower leg were stratified by position, with infield players experiencing injuries at a 1.6 times greater rate than any other position ( P < .001). Conclusion: In conclusion, this is the only epidemiological study to focus primarily on ankle and lower leg injuries in professional baseball players, utilizing an injury surveillance system developed by MLB.
Activity Measures in Pediatric Athletes: A Comparison of the Hospital for Special Surgery Pediatric Functional Activity Brief Scale and Tegner Activity Level Scale
Authors: Wagner K. John , Sabatino Meagan J. , Zynda Aaron J. , Gans Catherine V. , Chung Jane S. , Miller Shane M. , Wilson Philip L. , Ellis Henry B. 
Published: March 2020

Background:In young athletes, patient-reported activity level is frequently used to determine return to the same level of sport after treatment.Purpose:To evaluate the validity and score distributions of the Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS) compared with the Tegner Activity Level Scale (Tegner) in pediatric athletes.Study Design:Cohort study (Diagnosis); Level of evidence, 2.Methods:A retrospective review of 517 consecutive youth athletes who came to a sports medicine specialty clinic for a knee evaluation was performed. Patients completed the HSS Pedi-FABS, Tegner, and a sports participation survey before evaluation. Scores were compared with reported hours, days, and weeks of participation in sports as well as level of competition. Floor or ceiling effects were identified, and finally, the means and distributions of scores in the 8 most common primary sports were analyzed.Results:A total of 398 participants (54.0% female) with an average age of 14.5 years (range, 10.0-18.8 years) were included in the study. The HSS Pedi-FABS demonstrated correlations with hours per week ( r = 0.302; P < .001), days per week ( r = 0.278; P < .001), and weeks per year ( r = 0.136; P = .014) playing a primary sport. The Tegner only demonstrated a correlation with days per week ( r = 0.211; P = .001). Additionally, club/select-level athletes scored higher than junior high/high school–level athletes on the HSS Pedi-FABS (23.8 vs 21.0; P = .004), but no difference was observed with the Tegner. No floor or ceiling effect was observed for the HSS Pedi-FABS, but a ceiling effect was present for the Tegner (32.8%). The HSS Pedi-FABS demonstrated a varied score distribution between the 8 most common primary sports ( P < .001), with soccer players scoring the highest, on average (23.5).Conclusion:The HSS Pedi-FABS, compared with the Tegner, demonstrated more correlations with an athlete’s participation in sport with no floor or ceiling effect and had a wide distribution of scores even among same-sport athletes. The HSS Pedi-FABS may be a more valuable activity measure than the Tegner in pediatric athletes.