bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synergistic Memory Impairment Through the Interaction of Chronic Cerebral Hypoperfusion and Amlyloid Toxicity in a Rat Model
Authors: Choi Bo-Ryoung , Lee Sang Rim , Han Jung-Soo , Woo Sang-Keun , Kim Kyeong Min , Choi Dong-Hee , Kwon Kyoung Ja , Han Seol-Heui , Shin Chan Young , Lee Jongmin , Chung Chin-Sang , Lee Seong-Ryong , Kim Hahn Young 
Published: July 2011

Background and Purpose—
Vascular pathology and Alzheimer disease (AD) pathology have been shown to coexist in the brains of dementia patients. We investigated how cognitive impairment could be exacerbated in a rat model of combined injury through the interaction of chronic cerebral hypoperfusion and amyloid beta (Aβ) toxicity.

Methods—
In Wistar rats, chronic cerebral hypoperfusion was modeled by permanent occlusion of bilateral common carotid arteries (BCCAo). Further, AD pathology was modeled by bilateral intracerebroventricular Aβ (Aβ toxicity) using a nonphysiological Aβ peptide (Aβ 25 to 35). The experimental animals were divided into 4 groups, including sham, single injury (Aβ toxicity or BCCAo), and combined injury (BCCAo-Aβ toxicity) groups (n=7 per group) . Cerebral blood flow and metabolism were measured using small animal positron emission tomography. A Morris water maze task, novel object location and recognition tests, and histological investigation, including neuronal cell death, apoptosis, neuroinflammation, and AD-related pathology, were performed.

Results—

Spatial memory impairment was synergistically exacerbated in the BCCAo–Aβ toxicity group as compared to the BCCAo or Aβ toxicity groups (
P
<0.05). Compared to the sham group, neuroinflammation with microglial or astroglial activation was increased both in multiple white matter lesions and the hippocampus in other experimental groups. AD-related pathology was enhanced in the BCCAo–Aβ toxicity group compared to the Aβ toxicity group.

Conclusion—
Our experimental results support a clinical hypothesis of the deleterious interaction between chronic cerebral hypoperfusion and Aβ toxicity. Chronic cerebral hypoperfusion-induced perturbation in the equilibrium of AD-related pathology may exacerbate cognitive impairment in a rat model of combined injury.
An Investigation of the Initial Development of the Double-ITCZ Warm SST Biases in the CCSM
Authors: Liu Hailong , Zhang Minghua , Lin Wuyin 
Published: July 2011

Abstract
This paper investigates the initial development of the double ITCZ in the Community Climate System Model version 3 (CCSM3) in the central Pacific. Starting from a resting initial condition of the ocean in January, the model developed a warm bias of sea surface temperature (SST) in the central Pacific from 5°S to 10°S in the first three months. This initial bias is caused by excessive surface shortwave radiation that is also present in the stand-alone atmospheric model. The initial bias is further amplified by biases in both surface latent heat flux and horizontal heat transport in the upper ocean. These biases are caused by the responses of surface winds to SST bias and the thermocline structure to surface wind curls. This study also showed that the warming biases in surface solar radiation and latent heat fluxes are seasonally offset by cooling biases from reduced solar radiation after the austral summer due to cloud responses and in the austral fall due to enhanced evaporation when the maximum SST is closest to the equator. The warming biases from the dynamic heat transport by ocean currents however stay throughout all seasons once they are developed, which are eventually balanced by enhanced energy exchange and penetration of solar radiation below the mixed layer. It was also shown that the equatorial cold tongue develops after the warm biases in the south-central Pacific, and the overestimation of surface shortwave radiation recurs in the austral summer in each year. The results provide a case study on the physical processes leading to the development of the double ITCZ. Applicability of the results in other models is discussed.
Improved Seasonal Precipitation Forecasts for the Asian Monsoon Using 16 Atmosphere–Ocean Coupled Models. Part I: Climatology
Authors: Kumar Vinay , Krishnamurti T. N. 
Published: July 2011

AbstractThe goal of this study is to utilize several recent developments on rainfall data collection, downscaling of available climate models, training and forecasts from such models within the framework of a multimodel superensemble, and first a detailed examination of the seasonal climatology. The unique aspect of this study is that it became possible to use the forecast results from as many as 16 state-of-the-art coupled climate models. A downscaling component, with respect to observed rainfall estimates, uses a very dense Asian rain gauge network. This feature enables the forecasts of each model to be bias corrected to a common 25-km resolution. The downscaling statistics for each model, at each grid location, are developed during a training phase of the model forecasts. This is done wherever the observed rainfall estimates are available. In the “forecast phase,” the forecasts from all of the member models use the downscaling coefficients of the “training phase.” The downscaling and the extraction of the superensemble weights are done during the training phase. This makes use of the cross-validation principle. This means that the season to be forecasted is left out of the entire forecast dataset. Thus all of the statistics for downscaling and the superensemble construction are done separately for the forecasts of each season for all the years. The forecast phase is the season that is being forecast, where the aforementioned statistics are deployed for constructing the final downscaled superensemble.These forecasts are next used for the construction of a multimodel superensemble. The geographical distributions of the downscaling coefficients provide a first look at the systematic errors of the member model forecasts. This combination of multimodels, the vast rain gauge dataset, the downscaling, and the superensemble provides a major improvement for the rainfall climatology and anomalies for the forecast phase. One of the main results of this paper is on the improvement of rainfall climatology of the member models. The downscaled multimodel superensemble shows a correlation of nearly 1.0 with respect to the observed climatology. This high skill is important for addressing the rainfall anomaly forecasts, which are defined in terms of departures from the observed (rather than a model based) climatology. This first part of the paper provides a description of the member models, the length of the training and forecast phases, the sensitivity of results as the numbers of forecast models are increased, and the skills of the downscaled climatology forecasts.
Global Warming, El Niño, and High-Impact Storms at Extreme Altitude: Historical Trends and Consequences for Mountaineers
Authors: Moore G. W. K. , Semple J. L. , Hoyland G. 
Published: July 2011

AbstractThe twentieth century was bracketed by two high-profile events on Mount Everest: the 1924 Mallory and Irvine disappearance and the 1996 Into Thin Air storm. During both events, fatalities occurred high on the mountain during deteriorating weather conditions. Although there have been dramatic improvements in knowledge of the mountain and in the technology used on it, it is shown that an unappreciated change that has also occurred, as a result of warming in the region, is an increase in barometric pressure. A rare and unique set of meteorological data collected at various elevations on the mountain during the 1924 British Everest expedition as well as modern datasets are used to compare and contrast conditions during the two storms and the two climbing seasons. It is shown that both storms were associated with weather systems known locally as western disturbances that resulted in summit barometric pressure drops sufficient to have exacerbated altitude-induced hypoxia. It is further shown that the Mallory and Irvine attempt occurred later in the season than typically is the case now and that this was most likely the result of a concurrent El Niño event. Despite the trend of increasing barometric pressure, the pressure drop associated with storms in the region should remain a concern for those who venture to extreme altitudes. The authors therefore argue that success and failure on Everest and other Himalayan peaks requires knowledge of the variability and trends in both the weather and climate.
An Equatorial Ocean Bottleneck in Global Climate Models
Authors: Karnauskas Kristopher B. , Johnson Gregory C. , Murtugudde Raghu 
Published: July 2011

Abstract
The Equatorial Undercurrent (EUC) is a major component of the tropical Pacific Ocean circulation. EUC velocity in most global climate models is sluggish relative to observations. Insufficient ocean resolution slows the EUC in the eastern Pacific where nonlinear terms should dominate the zonal momentum balance. A slow EUC in the east creates a bottleneck for the EUC to the west. However, this bottleneck does not impair other major components of the tropical circulation, including upwelling and poleward transport. In most models, upwelling velocity and poleward transport divergence fall within directly estimated uncertainties. Both of these transports play a critical role in a theory for how the tropical Pacific may change under increased radiative forcing, that is, the ocean dynamical thermostat mechanism. These findings suggest that, in the mean, global climate models may not underrepresent the role of equatorial ocean circulation, nor perhaps bias the balance between competing mechanisms for how the tropical Pacific might change in the future. Implications for model improvement under higher resolution are also discussed.
Impact of Shelf–Basin Freshwater Transport on Deep Convection in the Western Labrador Sea
Authors: McGeehan Timothy , Maslowski Wieslaw 
Published: July 2011

Abstract
Freshwater exiting the Arctic Ocean through the Canadian Arctic Archipelago (CAA) has been shown to affect meridional overturning circulation and thereby the global climate system. However, because of constraints of spatial resolution in most global ocean models, neither the flow of low salinity water through the CAA to the Labrador Sea nor the eddy activity that may transport freshwater from the shelf to areas of open ocean convection can be directly simulated. To address these issues, this study uses a high-resolution ice–ocean model of the pan-Arctic region with a realistic CAA and forced with realistic atmospheric data. This model resolves conditions in the Arctic Ocean upstream of the Labrador Sea and is coupled to a thermodynamic–dynamic sea ice model that responds to the atmospheric forcing. The major shelf–basin exchange of liquid freshwater occurs south of Hamilton Bank, whereas the largest ice flux occurs in the northwest of the basin. Freshwater flux anomalies entering the Labrador Sea through Davis Strait do not immediately affect deep convection. Instead, eddies acting on shorter time scales can move freshwater to locations of active convection and halt the process. Convection is modulated by the position of the ice edge, highlighting the critical need for a coupled ice–ocean model. Finally, the size of eddies and the short duration of events demonstrate the need for high resolution, both spatial and temporal.
Evaluation of Eye Metrics as a Detector of Fatigue
Authors: McKinley R. Andy , McIntire Lindsey K. , Schmidt Regina , Repperger Daniel W. , Caldwell John A. 
Published: July 2011

Objectives: This study evaluated oculometrics as a detector of fatigue in Air Force–relevant tasks after sleep deprivation. Using the metrics of total eye closure duration (PERCLOS) and approximate entropy (ApEn), the relation between these eye metrics and fatigue-induced performance decrements was investigated. Background: One damaging effect to the successful outcome of operational military missions is that attributed to sleep deprivation-induced fatigue. Consequently, there is interest in the development of reliable monitoring devices that can assess when an operator is overly fatigued. Method: Ten civilian participants volunteered to serve in this study. Each was trained on three performance tasks: target identification, unmanned aerial vehicle landing, and the psychomotor vigilance task (PVT). Experimental testing began after 14 hr awake and continued every 2 hr until 28 hr of sleep deprivation was reached. Results: Performance on the PVT and target identification tasks declined significantly as the level of sleep deprivation increased. These performance declines were paralleled more closely by changes in the ApEn compared to the PERCLOS measure. Conclusion: The results provide evidence that the ApEn eye metric can be used to detect fatigue in relevant military aviation tasks. Application: Military and commercial operators could benefit from an alertness monitoring device.
In Vivo Shoulder Function After Surgical Repair of a Torn Rotator Cuff
Authors: Bey Michael J. , Peltz Cathryn D. , Ciarelli Kristin , Kline Stephanie K. , Divine George W. , van Holsbeeck Marnix , Muh Stephanie , Kolowich Patricia A. , Lock Terrence R. , Moutzouros Vasilios 
Published: July 2011

Background: Surgical repair of a torn rotator cuff is based on the belief that repairing the tear is necessary to restore normal glenohumeral joint (GHJ) mechanics and achieve a satisfactory clinical outcome. Hypothesis: Dynamic joint function is not completely restored by rotator cuff repair, thus compromising shoulder function and potentially leading to long-term disability. Study Design: Controlled laboratory study and Case series; Level of evidence, 4. Methods: Twenty-one rotator cuff patients and 35 control participants enrolled in the study. Biplane radiographic images were acquired bilaterally from each patient during coronal-plane abduction. Rotator cuff patients were tested at 3, 12, and 24 months after repair of a supraspinatus tendon tear. Control participants were tested once. Glenohumeral joint kinematics and joint contact patterns were accurately determined from the biplane radiographic images. Isometric shoulder strength and patient-reported outcomes were measured at each time point. Ultrasound imaging assessed rotator cuff integrity at 24 months after surgery. Results: Twenty of 21 rotator cuff repairs appeared intact at 24 months after surgery. The humerus of the patients’ repaired shoulder was positioned more superiorly on the glenoid than both the patients’ contralateral shoulder and the dominant shoulder of control participants. Patient-reported outcomes improved significantly over time. Shoulder strength also increased over time, although strength deficits persisted at 24 months for most patients. Changes over time in GHJ mechanics were not detected for either the rotator cuff patients’ repaired or contralateral shoulders. Clinical outcome was associated with shoulder strength but not GHJ mechanics. Conclusion: Surgical repair of an isolated supraspinatus tear may be sufficient to keep the torn rotator cuff intact and achieve satisfactory patient-reported outcomes, but GHJ mechanics and shoulder strength are not fully restored with current repair techniques. Clinical Relevance: The study suggests that current surgical repair techniques may be effective for reducing pain but have not yet been optimized for restoring long-term shoulder function.
Results of Arthroscopic Repair of Type II Superior Labral Anterior Posterior Lesions in Overhead Athletes
Authors: Neuman Brian J. , Boisvert C. Brittany , Reiter Brian , Lawson Kevin , Ciccotti Michael G. , Cohen Steven B. 
Published: July 2011

Background: The majority of the literature on surgical outcomes of superior labral anterior posterior (SLAP) repairs has focused on short-term follow-up of 1 to 2 years, not allowing adequate time for full rehabilitation and return to maximum level of competition for all types of athletes. Also, previous studies have concentrated on using questionnaires that primarily evaluate patients’ activities of daily living, which do not focus on sport-specific performance. Purpose: To determine the midterm results of type II SLAP repairs in overhead athletes, focusing primarily on athletic performance as well as activities of daily living. Study Design: Case series; Level of evidence, 4. Methods: A retrospective review of 30 overhead athletes, who underwent an arthroscopic superior labral repair for a symptomatic type II SLAP tear between 2002 and 2007, was performed. Our study population included 22 male and 8 female patients with a mean age at the time of surgery of 24 years. Twenty-one patients participated in baseball or softball, and the remainder of patients were involved in javelin throwing or tennis. The average follow-up was 3.5 years. The outcome of treatment was evaluated using the American Shoulder and Elbow Society (ASES) scoring system, assessing activities of daily living, and the Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow (KJOC) score, assessing sport-specific performance. In addition, the length of time to return to sport and the degree of successful performance were evaluated. Results: Repairs resulted in ASES scores comparable with those from prior published studies (average ASES score, 87.9). The KJOC score averaged 73.6. The athletes’ perception was that they returned to approximately 84.1% of their preinjury level of function with a mean time to return to play of 11.7 months. There was a significant drop in the ASES to KJOC score for the baseball/softball players (87.9 ± 14.94 and 72 ± 19.24, respectively; P = .006). Patients reported an overall satisfaction rate of 93.3% with the procedure, with the majority being very satisfied. Conclusion: Arthroscopic SLAP repairs show excellent results and a high rate of overall satisfaction; however, the outcomes are less reliable in throwers. The KJOC score provides a more stringent assessment of overhead athletes’ function after SLAP repair than the ASES score. Our findings also indicate that SLAP repairs lead to improved shoulder function during routine daily activities but that consistent return to elite throwing sports may still remain somewhat problematic.
Prevalence of Jumper’s Knee Among Nonelite Athletes From Different Sports
Authors: Zwerver Johannes , Bredeweg Steven W. , van den Akker-Scheek Inge 
Published: July 2011

Background: The prevalence of jumper’s knee among nonelite athletes from different sports is unknown. Purpose: This study was undertaken to determine the prevalence of jumper’s knee in nonelite athletes from different sports and to determine potential risk factors for jumper’s knee. Design: Cohort study (prevalence); Level of evidence, 2. Methods: The authors interviewed 891 male and female nonelite athletes from 7 popular sports in The Netherlands: basketball, volleyball, handball, korfball, soccer, field hockey, and track and field. Using a specially developed questionnaire, information was obtained about individual characteristics (age, height, and weight), training background, previous and actual knee problems, and the VISA-P (Victorian Institute of Sport Assessment–Patella) score. Results: The overall prevalence of current jumper’s knee was 8.5% (78 of 891 athletes), showing a significant difference between sports with different loading characteristics. Prevalence was highest among volleyball players (14.4%) and lowest among soccer players (2.5%); it was significantly higher among male athletes (51 of 502 [10.2%]) than female athletes (25 of 389 [6.4%]) (χ2 = 3.91, P = .048). The mean duration of symptoms was 18.9 months (standard deviation [SD], 21.6; median value, 12.0; range, 2.0-59.8). The mean VISA-P score of the athletes with jumper’s knee was 71.4 (SD, 13.8). Athletes with jumper’s knee were significantly younger, taller, and heavier than those without jumper’s knee. Conclusion: Prevalence of jumper’s knee is high among nonelite athletes and varies between 14.4% and 2.5% for different sports. Jumper’s knee is almost twice as common among male nonelite athletes compared with female athletes. Different sport-specific loading characteristics of the knee extensor apparatus, a younger age, a taller body stature, and higher body weight seem to be risk factors associated with patellar tendinopathy.
When Do Rotator Cuff Repairs Fail? Serial Ultrasound Examination After Arthroscopic Repair of Large and Massive Rotator Cuff Tears
Authors: Miller Bruce S. , Downie Brian K. , Kohen Robert B. , Kijek Theresa , Lesniak Bryson , Jacobson Jon A. , Hughes Richard E. , Carpenter James E. 
Published: July 2011

Background: Despite advances in arthroscopic repair of rotator cuff tears, recurrent tears after repair of large and massive tears remain a significant clinical problem. The primary objective of this study was to define the timing of structural failure of surgically repaired large and massive rotator cuff tears by serial imaging with ultrasound. The secondary objective of this study was to investigate the association between recurrent tears and clinical outcome after rotator cuff repair. Hypothesis: Recurrent tear after arthroscopic repair of large rotator cuff tears is more likely to occur late (>3 months) in the postoperative period and will be associated with inferior clinical outcome scores. Study Design: Cohort study; Level of evidence, 3. Methods: Twenty-two consecutive patients with large (>3 cm) rotator cuff tears underwent arthroscopic repair with a standardized technique. Serial ultrasound examinations were performed at 2 days, 2 weeks, 6 weeks, 3 months, 6 months, 12 months, and 24 months after surgery. Western Ontario Rotator Cuff (WORC) Index scores were also collected at these time points. Results: Nine (41%) of the 22 arthroscopically repaired rotator cuff tears demonstrated recurrent tears. Seven of the 9 retears occurred within 3 months of surgery, and the other 2 occurred between 3 and 6 months. No retears occurred after 6 months. At 24-month follow-up, WORC scores favoring intact rotator cuffs over retears approached statistical significance (mean WORC intact 123.9 vs retear 659.8; P = .07). Conclusion: Recurrent rotator cuff tears are not uncommon after arthroscopic repair of large and massive tears. These recurrent tears appear to occur more frequently in the early postoperative period (within the first 3 months) and are associated with inferior clinical outcomes.