bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Attempt to Derive the ɛ Equation from a Two-Point Closure
Authors: Canuto V. M. , Cheng Y. , Howard A. M. 
Published: December 2009

Abstract
The goal of this paper is to derive the equation for the turbulence dissipation rate ɛ for a shear-driven flow. In 1961, Davydov used a one-point closure model to derive the ɛ equation from first principles but the final result contained undetermined terms and thus lacked predictive power. Both in 1987 (Schiestel) and in 2001 (Rubinstein and Zhou), attempts were made to derive the ɛ equation from first principles using a two-point closure, but their methods relied on a phenomenological assumption. The standard practice has thus been to employ a heuristic form of the ɛ equation that contains three empirical ingredients: two constants, c1,ɛ and c2,ɛ, and a diffusion term Dɛ. In this work, a two-point closure is employed, yielding the following results: 1) the empirical constants get replaced by c1, c2, which are now functions of K and ɛ; 2) c1 and c2 are not independent because a general relation between the two that are valid for any K and ɛ are derived; 3) c1, c2 become constant with values close to the empirical values c1,ɛ, c2,ɛ (i.e., homogenous flows); and 4) the empirical form of the diffusion term Dɛ is no longer needed because it gets substituted by the K–ɛ dependence of c1, c2, which plays the role of the diffusion, together with the diffusion of the turbulent kinetic energy DK, which now enters the new ɛ equation (i.e., inhomogeneous flows). Thus, the three empirical ingredients c1,ɛ, c2,ɛ, Dɛ are replaced by a single function c1(K, ɛ) or c2(K, ɛ), plus a DK term. Three tests of the new equation for ɛ are presented: one concerning channel flow and two concerning the shear-driven planetary boundary layer (PBL).
Transport and Mixing in the Extratropical Tropopause Region in a High-Vertical-Resolution GCM. Part II: Relative Importance of Large-Scale and Small-Scale Dynamics
Authors: Miyazaki Kazuyuki , Watanabe Shingo , Kawatani Yoshio , Sato Kaoru , Tomikawa Yoshihiro , Takahashi Masaaki 
Published: December 2009

Abstract
The relative roles of atmospheric motions on various scales, from mesoscale to planetary scale, in transport and mixing in the extratropical tropopause region are investigated using a high-vertical-resolution general circulation model (GCM). The GCM with a vertical resolution of about 300 m explicitly represents the propagation and breaking of gravity waves and the induced transport and mixing. A downward control calculation shows that the Eliassen–Palm (E-P) flux of the gravity waves diverges and induces a mean equatorward flow in the extratropical tropopause region, which differs from the mean poleward flow induced by the convergence of large-scale E-P fluxes. The diffusion coefficients estimated from the eddy potential vorticity flux in tropopause-based coordinates reveal that isentropic motions diffuse air between 20 K below and 10 K above the tropopause from late autumn to early spring, while vertical mixing is strongly suppressed at around 10–15 K above the tropopause throughout the year. The isentropic mixing is mainly caused by planetary- and synoptic-scale motions, while small-scale motions with a horizontal scale of less than a few thousand kilometers largely affect the three-dimensional mixing just above the tropopause. Analysis of the gravity wave energy and atmospheric instability implies that the small-scale dynamics associated with the dissipation and saturation of gravity waves is a significant cause of the three-dimensional mixing just above the tropopause. A rapid increase in the static stability in the tropopause inversion layer is considered to play an important role in controlling the gravity wave activity around the tropopause.
The Role of Ocean Dynamics in the Optimal Growth of Tropical SST Anomalies
Authors: Zanna Laure , Heimbach Patrick , Moore Andrew M. , Tziperman Eli 
Published: December 2009

AbstractThe role of ocean dynamics in optimally exciting interannual variability of tropical sea surface temperature (SST) anomalies is investigated using an idealized-geometry ocean general circulation model. Initial temperature and salinity perturbations leading to an optimal growth of tropical SST anomalies, typically arising from the nonnormal dynamics, are evaluated. The structure of the optimal perturbations is characterized by relatively strong deep salinity anomalies near the western boundary generating a transient amplification of equatorial SST anomalies in less than four years.The associated growth mechanism is linked to the excitation of coastal and equatorial Kelvin waves near the western boundary following a rapid geostrophic adjustment owing to the optimal initial temperature and salinity perturbations. The results suggest that the nonnormality of the ocean dynamics may efficiently create large tropical SST variability on interannual time scales in the Atlantic without the participation of air–sea processes or the meridional overturning circulation. An optimal deep initial salinity perturbation of 0.1 ppt located near the western boundary can result in a tropical SST anomaly of approximately 0.45°C after nearly four years, assuming the dynamics are linear. Possible mechanisms for exciting such deep perturbations are discussed. While this study is motivated by tropical Atlantic SST variability, its relevance to other basins is not excluded.The optimal initial conditions leading to the tropical SST anomalies’ growth are obtained by solving a generalized eigenvalue problem. The evaluation of the optimals is achieved by using the Massachusetts Institute of Technology general circulation model (MITgcm) tangent linear and adjoint models as well the the Arnoldi Package (ARPACK) software for solving large-scale eigenvalue problems.
A Trigger Mechanism for Loop Current Ring Separations
Authors: Sturges Wilton , Hoffmann Nicholas G. , Leben Robert R. 
Published: December 2009

Abstract
The Loop Current in the Gulf of Mexico sheds large anticyclonic rings on an irregular basis. The authors attempt to show what actually triggers the ring separations. Pulses of increased transport through the Florida Straits, as observed by the cable data, are observed prior to each ring separation. This finding is consistent over all separation events observed in the satellite altimetry record. The pulses of transport occur approximately two to four weeks before the rings separate. The increase in transport is usually accompanied by a corresponding increase in offshore sea level, suggesting forcing from the open ocean. The delay times between the pulses of increased transport and ring separations can be shown to be significantly correlated with the length of the Loop Current. Mean sea levels over the Caribbean and Gulf also peak before the separations, on average.
The New York Bight Jet: Climatology and Dynamical Evolution
Authors: Colle Brian A. , Novak David R. 
Published: December 2009

Abstract
This paper describes the southerly New York Bight (NYB) jet (11–17 m s−1) that develops primarily during the warm season just above the surface offshore (east) of the northern New Jersey coast and south of Long Island (the NYB). Observations from two offshore buoys are used to develop a 9-yr climatology of 134 jet events from 1997 to 2006. There is a seasonal maximum (2.5 events per month) during June and July, with a skew toward the spring months. The wind directions for the jet trace out a nearly elliptical orbit for the 24-h period around the time of jet maximum at ~2300 UTC [1900 eastern daylight time (EDT)] on average. Composites reveal that the NYB jet occurs on days with southwesterly synoptic flow, and the jet is part of a larger-scale (200–300 km) wind enhancement offshore of the mid-Atlantic and northeast U.S. coasts during the early evening hours.
High-resolution observations (surface mesonet, aircraft soundings, and a terminal Doppler weather radar) and Weather Research and Forecasting (WRF) model simulations down to 1.33-km grid spacing are used to diagnose the evolution of the NYB jet on 2 June 2007. The NYB jet at ~150 m MSL occurs within the sloping marine inversion near the coast. Low-level trajectories illustrate low-level diffluence and weak subsidence within the jet. A WRF momentum budget highlights the evolving pressure gradient and accelerations during jet formation. The maximum jet winds occur 1–2 h after the peak meridional pressure gradient is established through a geostrophic adjustment process. Sensitivity experiments show that jet occurrence is dependent on diurnal heating and that the concave bend in the southern New Jersey coast limits the southern extent of the jet.
Developmental Changes in Processing Speed: Influence of Accelerated Education for Gifted Children
Authors: Xiaoju Duan  , Jiannong Shi  , Dan Zhou  
Published: December 2009

There are two major hypotheses concerning the developmental trends of processing speeds. These hypotheses explore both local and global trends. The study presented here investigates the effects of people’s different knowledge on the speed with which they are able to process information. The participants in this study are gifted children aged 9, 11, and 13 years. A total of 94 of the participants were members of gifted programs, whereas the other 93 children received standard education. They were required to finish two information-processing tasks: a Choice Reaction Time task and an Abstract Matching task. The results show that the reaction time of gifted children who received accelerated education in gifted programs was significantly faster than that of the children who received standard education at every age. These results seem to imply that the educational atmosphere in which a child is placed plays a significant role in the development of gifted children’s speed of information processing. Putting the Research to Use This study serves to demonstrate that experience and knowledge may influence the development of information processing speed. It appears that specialized education for gifted children can actually accelerate development, suggesting that selection of educational system is of particular significance, especially for gifted children. Gifted children can study more quickly than average children because they have a higher speed of information processing. The efficacy of their study results in greater transmission of knowledge, and this in turn accelerates gifted children’s information processing speed. Accelerated education can not only satisfy the cognitive need of gifted children but also serve to enhance their cognitive development. Teachers and parents have to recognize that education is very important to children’s development and address the importance of experience in gifted children’s learning. The results of the present study also suggest a need for a special education system designed for gifted children, which can be viewed as a great investment in the future.
Exploring the Relationship of College Freshmen Honors Students’ Effort and Ability Attribution, Interest, and Implicit Theory of Intelligence With Perceived Ability
Authors: Siegle Del , Rubenstein Lisa Da Via , Pollard Elizabeth , Romey Elizabeth 
Published: December 2009

Although there are several explanations for why one succeeds or fails, effort and ability are the major causes that students report. The purpose of the present study was to measure the perceptions of 149 college freshmen enrolled in a university honors program about their skills in 15 talent areas. In addition, this study explored the relationship of interests and ability and effort attributions with self-efficacy and investigated gender differences in these perceptions. There was a positive relationship between students’ interest in a talent area and their assessment of their skill in that area. The strongest relationships tended to be in nonacademic areas. For some talents, males placed stronger attributions on the role that natural ability played, whereas females indicated that personal effort contributed to high levels of performance. Participants’ implicit theory of intelligence did not appear to influence their perceptions of the importance of ability in academic performance. Putting the Research to Use Educators and parents must recognize the important role interest plays in student achievement. Interest is one of the single best predictors of high performance in a variety of talent areas. For gifted students to sustain the effort necessary to reach high levels of academic rigor, they must either be interested in the topic or find the task meaningful. Educators may need to modify their instruction and curriculum to capitalize on student interests. Gifted students appear to be aware of their high ability and view it as contributing to their success. Although some researchers have cautioned against recognizing student ability at the peril of diminishing the importance of effort, educators and parents should not be fearful of discussing the role ability plays in gifted students’ performances, while also emphasizing the importance of hard work and perseverance.
Integrating Type 2 Diabetes Mellitus and Depression Treatment Among African Americans
Authors: Bogner Hillary R. , de Vries Heather F. 
Published: December 2009

Purpose The purpose of this study was to examine whether integrating depression treatment into care for type 2 diabetes mellitus among older African Americans improved medication adherence, glycemic control, and depression outcomes. Methods Older African Americans prescribed pharmacotherapy for type 2 diabetes mellitus and depression from physicians at a large primary care practice in west Philadelphia were randomly assigned to an integrated care intervention or usual care. Adherence was assessed at baseline, 2, 4, and 6 weeks using the Medication Event Monitoring System to assess adherence. Outcomes assessed at baseline and 12 weeks included standard laboratory tests to measure glycemic control and the Center for Epidemiologic Studies Depression Scale (CES-D) to assess depression. Results In all, 58 participants aged 50 to 80 years participated. The proportion of participants who had 80% or greater adherence to an oral hypoglycemic (intervention 62.1% vs usual care 24.1%) and an antidepressant (intervention 62.1% vs usual care 10.3%) was greater in the intervention group in comparison with the usual care group at 6 weeks. Participants in the integrated care intervention had lower levels of glycosylated hemoglobin (intervention 6.7% vs usual care 7.9%) and fewer depressive symptoms (CES-D mean scores: intervention 9.6 vs usual care 16.6) compared with participants in the usual care group at 12 weeks. Conclusion A pilot randomized controlled trial integrating type 2 diabetes mellitus treatment and depression was successful in improving outcomes among older African Americans. Integrated interventions may be more feasible and effective in real-world practices with competing demands for limited resources.
Skill Level-Specific Differences in Snowboarding-Related Injuries
Authors: Ogawa Hiroyasu , Sumi Hiroshi , Sumi Yasuhiko , Shimizu Katsuji 
Published: December 2009

Background Snowboarding-related injuries have been associated with specific snowboarding skill levels, but differences in specific skill level have not been identified. Hypothesis Injury patterns are different among skill levels. Study Design Descriptive epidemiology study. Methods The subjects were 19 539 snowboarders from the Oku-Mino region in Gifu Prefecture, Japan, who were admitted to our hospital during the 12 snowboarding seasons from 1996 to 2008. They were asked to complete a questionnaire regarding age, gender, self-estimated skill level, injury location, injury type, mechanism of injury, and protective gear. Physicians documented diagnostic variables and injury severity score; these variables were compared among the self-estimated skill levels. Results Of the total 19 539 injured snowboarders, 1204 (6.2%) were novices, 6409 (32.8%) were beginners, 9260 (47.4%) were intermediates, 1918 (9.8%) were experts, and the skill level was not known in 748 (3.8%). Proportions of the trunk and multiple injuries increased with increases in skill level; however, the number of head/face injuries decreased with increase in skill level. Upper extremity injuries also decreased with increase in skill level, except in novices. Dislocations and multiple injuries increased with increase in skill level, while lacerations/contusions, fractures, and bruises decreased. The mean overall injury severity score was 3.28 ± 0.02, and the value increased significantly with increase in skill level. The proportion of collision and isolated fall injuries significantly decreased with increase in skill level, but that of jump injuries significantly increased. The percentage of protective gear use increased with the increase in skill level. Conclusion Prevalence of injury type, injury location, mechanism of injury, and percentage of protective gear use varied according to skill level, and the severity of the injury increased with increase in skill level. On the basis of our observations, we believe that snowboarding injury prevention strategies should be formulated according to skill level.
Retear Patterns after Arthroscopic Rotator Cuff Repair
Authors: Cho Nam Su , Yi Jin Woong , Lee Bong Gun , Rhee Yong Girl 
Published: December 2009

Background A subset of patients is often seen with an unusual pattern of tendon failure after arthroscopic rotator cuff repair using a suture bridge technique. Purpose To evaluate retear patterns in cases with structural failure after arthroscopic primary repairs of rotator cuff tears. Study Design Cohort study; Level of evidence, 3. Methods Forty-six cases revealing retear on magnetic resonance imaging performed at least 6 months after arthroscopic repair for the treatment of full-thickness rotator cuff tear were evaluated. A single-row technique had been performed in 19 cases and a suture bridge in 27 cases. According to retear patterns on postoperative magnetic resonance imaging, cases were divided into type 1 (cuff tissue repaired at the insertion site of rotator cuff was not observed remaining on the greater tuberosity) and type 2 (remnant cuff tissue remained at the insertion site in spite of retear). Results In the single-row group, 14 cases (73.7%) had type 1 and 5 cases (26.3%) type 2 retear. In the suture bridge group, 7 cases (25.9%) had type 1 and 20 cases (74.1%) type 2. There were statistically significant differences between groups (P = .049). Extent of fatty degeneration of the rotator cuff did not affect retear patterns in the single-row group (P = .160). In the suture bridge group, the percentage of type 1 retear increased with severity of fatty degeneration (P = .030). Extent of muscle atrophy did not affect retear patterns of the single-row group; in the suture bridge group, the percentage of type 1 retear increased with severity of muscle atrophy (P = .904 vs .029). Conclusion The suture bridge technique tended to better preserve the cuff tissue repaired to the insertion site of the rotator cuff than a single-row technique did; the retear in cases with a suture bridge technique was mainly in the musculotendinous junction. Direct retear at the footprint of the rotator cuff increased with severity of fatty degeneration or muscle atrophy in cases with a suture bridge technique.
Clinical Outcomes After Anterior Cruciate Ligament Reconstruction: A Meta-Analysis of Autograft Versus Allograft Tissue
Authors: Tibor Lisa M. , Long Joy L. , Schilling Peter L. , Lilly Ryan J. , Carpenter James E. , Miller Bruce S. 
Published: December 2009

Background: Clinical outcomes of autograft and allograft anterior cruciate ligament (ACL) reconstructions are mixed, with some reports of excellent to good outcomes and other reports of early graft failure or significant donor site morbidity. Objective: To determine if there is a difference in functional outcomes, failure rates, and stability between autograft and allograft ACL reconstructions. Data Sources: Medline, Cochrane Central Register of Controlled Trials (Evidence Based Medicine Reviews Collection), Cochrane Database of Systematic Reviews, Web of Science, CINAHL, and SPORTDiscus were searched for articles on ACL reconstruction. Abstracts from annual meetings of the American Academy of Orthopaedic Surgeons, American Orthopaedic Society for Sports Medicine, and Arthroscopy Association of North America were searched for relevant studies. Study Selection: Inclusion criteria for studies were as follows: primary unilateral ACL injuries, mean patient age less than 41 years, and follow-up for at least 24 months postreconstruction. Exclusion criteria for studies included the following: skeletally immature patients, multiligament injuries, and publication dates before 1990. Data Extraction: Joint stability measures included Lachman test, pivot-shift test, KT-1000 arthrometer assessment, and frequency of graft failures. Functional outcome measures included Tegner activity scores, Cincinnati knee scores, Lysholm scores, and IKDC (International Knee Documentation Committee) total scores. Results: More than 5000 studies were identified. After full text review of 576 studies, 56 were included, of which only 1 directly compared autograft and allograft reconstruction. Allograft ACL reconstructions were more lax when assessed by the KT-1000 arthrometer. For all other outcome measures, there was no statistically significant difference between autograft and allograft ACL reconstruction. For all outcome measures, there was strong evidence of statistical heterogeneity between studies. The sample size necessary for a randomized clinical trial to detect a difference between autograft and allograft reconstruction varied, depending on the outcome. Conclusions: With the current literature, only KT-1000 arthrometer assessment demonstrated more laxity with allograft reconstruction. A randomized clinical trial directly comparing allograft to autograft ACL reconstruction is warranted, but a multicenter study would be required to obtain an adequate sample size.
The Prevalence of Medial Epicondylitis Among Patients With C6 and C7 Radiculopathy
Authors: Lee Aaron Taylor , Lee-Robinson Ayse L. 
Published: December 2009

Background: Medial epicondylitis, or golfer’s/pitcher’s elbow, develops as a result of medial stress overload on the flexor muscles at the elbow and presents as pain at the medial epicondyle. Cervical radiculopathy has been associated with lateral epicondylitis, but few associations between the cervical spine and medial epicondylitis have been made. Researchers propose that there is an association, suggesting that the weakness and imbalance in the elbow flexor and extensor muscles from C6 and C7 radiculopathy allow for easy onset of medial epicondylitis. Hypothesis: Medial epicondylitis will present in over half the patients diagnosed with C6 and C7 radiculopathy. Methodology: A total of 102 patients initially presenting with upper extremity or neck symptoms were diagnosed with cervical radiculopathy. They were then examined for medial epicondylitis. Data were collected by referring to patient charts from February 2008 until June 2009. Results: Fifty-five patients were diagnosed with medial epicondylitis. Of these, 44 had C6 and C7 radiculopathy whereas 11 presented with just C6 radiculopathy. Conclusion: Medial epicondylitis presented with cervical radiculopathy in slightly more than half the patients. Weakening of the flexor carpi radialis and pronator teres and imbalance of the flexor and extensor muscles from the C6 and C7 radiculopathy allow for easy onset of medial epicondylitis. Patients with medial epicondylitis should be examined for C6 and C7 radiculopathy to ensure proper treatment. Physicians dealing with golfers, pitchers, or other patients with medial epicondylitis should be aware of the association between these 2 diagnoses to optimize care.