bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Density Gradients on Net Sediment Transport into the Wadden Sea
Authors: Burchard Hans , Flöser Götz , Staneva Joanna V. , Badewien Thomas H. , Riethmüller Rolf 
Published: March 2008

Abstract
This study tests the hypothesis that horizontal density gradients have the potential to significantly contribute to the accumulation of suspended particulate matter (SPM) in the Wadden Sea. It is shown by means of long-term observations at various positions in the Wadden Sea of the German Bight that the water in the inner regions of the Wadden Sea is typically about 0.5–1.0 kg m−3 less dense than the North Sea water. During winter this occurs mostly because of freshwater runoff and net precipitation; during summer it occurs mostly because of differential heating. It is demonstrated with idealized one-dimensional water column model simulations that the interaction of such small horizontal density gradients with tidal currents generates net onshore SPM fluxes. Major mechanisms for this are tidal straining, estuarine circulation, and tidal mixing asymmetries. Three-dimensional model simulations in a semienclosed Wadden Sea embayment with periodic tidal forcing show that SPM with sufficiently high settling velocity (ws = 10−3 m s−1) is accumulating in the Wadden Sea Bight because of density gradients. This is proven through a comparative model simulation in which the dynamic effects of the density gradients are switched off, with the consequence of no SPM accumulation. These numerical model results motivate future targeted field studies in different Wadden Sea regions with the aim to further support the hypothesis.
Seasonal Variability of the Observed Barrier Layer in the Arabian Sea*
Authors: Thadathil Pankajakshan , Thoppil Prasad , Rao R. R. , Muraleedharan P. M. , Somayajulu Y. K. , Gopalakrishna V. V. , Murtugudde Raghu , Reddy G. V. , Revichandran C. 
Published: March 2008

Abstract
The formation mechanisms of the barrier layer (BL) and its seasonal variability in the Arabian Sea (AS) are studied using a comprehensive dataset of temperature and salinity profiles from Argo and other archives for the AS. Relatively thick BL of 20–60 m with large spatial extent is found in the central-southwestern AS (CSWAS), the convergence zone of the monsoon wind, during the peak summer monsoon (July–August) and in the southeastern AS (SEAS) and northeastern AS (NEAS) during the winter (January–February). Although the BL in the SEAS has been reported before, the observed thick BL in the central-southwestern AS during the peak summer monsoon and in the northeastern AS during late winter are the new findings of this study. The seasonal variability of BL thickness (BLT) is closely related to the processes that occur during summer and winter monsoons. During both seasons, the Ekman processes and the distribution of low-salinity waters in the surface layer show a dominant influence on the observed BLT distributions. In addition, Kelvin and Rossby waves also modulate the observed BL thickness in the AS. The relatively low salinity surface water overlying the Arabian Sea high-salinity water (ASHSW) provides an ideal ground for strong haline stratification in the CSWAS (during summer monsoon) and in NEAS (during winter monsoon). During summer, northward advection of equatorial low-salinity water by the Somali Current and the offshore advection of low-salinity water from the upwelling region facilitate the salinity stratification that is necessary to develop the observed BL in the CSWAS. In the SEAS, during winter, the winter monsoon current (WMC) carries less saline water over relatively high salinity ambient water to form the observed BL there. The winter West India Coastal Current (WICC) transports the low-salinity water from the SEAS to the NEAS, where it lies over the subducted ASHSW leading to strong haline stratification. Ekman pumping together with the downwelling Kelvin wave in the NEAS deepen the thermocline to cause the observed thick BL in the NEAS.
Tendon-Bone Insertion Repair and Regeneration Using Polyglycolic Acid Sheet in the Rabbit Rotator Cuff Injury Model
Authors: Yokoya Shin , Mochizuki Yu , Nagata Yoshihiko , Deie Masataka , Ochi Mitsuo 
Published: March 2008

BackgroundThe quality of tendons has considerable limitations regarding torn rotator cuff tendons. Tissue-engineering techniques using a biodegradable scaffold offer potential alternatives for recreating a valid tendon-to-bone interface.HypothesisA polyglycolic acid (PGA) sheet could facilitate the regeneration of the rotator cuff tendon insertion in vivo.Study DesignControlled laboratory study.MethodsAn implant consisting of a PGA sheet, a rapidly absorbable material, was used to replace a completely resected infraspinatus tendon insertion in 33 adult Japanese white rabbits. The contralateral infraspinatus tendon was replaced by poly-L-lactate-epsilon-caprolactone (PLC), a slowly absorbable material, by the same methods based on the results of the pilot study. Histological comparisons were made at 4, 8, and 16 weeks, and mechanical evaluations were performed at 4 and 16 weeks in both groups. Unrepaired defects were created in a control group. Results: In the control group, the rotator cuff defects were covered with thin fibrous membranes with many fibroblasts arranged in an irregular pattern. In the PLC group, some chondrocytes were seen in the tendon insertion; however, these were not arranged along the long axis for a 16-week period. In the PGA group, a well-arranged fibrocartilage layer could be found in the regenerated tendon insertions; however, these tendon insertions were mainly regenerated by type III collagen. In mechanical examinations, the PGA group had significantly higher values in the maximum failure load, tensile strength, and Young's modulus for the 4-week and 16-week periods. These 3 categories statistically improved from 4 to 16 weeks postoperatively in both groups except for the Young's modulus in the PGA group (E = 5.66 at 4 weeks to 5.53 at 16 weeks).ConclusionThe PGA sheet scaffold material allows for tendon insertion regeneration with a fibrocartilage layer but displays mechanical properties inferior to those of the normal tendon in an animal model.Clinical RelevanceThe PGA sheet represent a possible alternative scaffold material for tendon regeneration in rotator cuff repair.
Transphyseal Anterior Cruciate Ligament Reconstruction Using Mesenchymal Stem Cells
Authors: Babb John R. , Ahn Jae I. , Azar Frederick M. , Canale S. Terry , Beaty James H. 
Published: March 2008

Background Conventional techniques for reconstruction of the anterior cruciate ligament in skeletally immature patients risk potential iatrogenic growth disturbance because of drilling across the physis. Animal models have demonstrated mixed results regarding growth disturbances from soft tissue grafts across the physis. Hypothesis Mesenchymal stem cells derived from bone marrow may be effective in preventing growth arrest after intraarticular anterior cruciate ligament reconstruction. Study Design Controlled laboratory study. Material and Methods The anterior cruciate ligament was removed from 15 skeletally immature rabbits, which were divided into 3 groups: 5 rabbits (group 1) had only drilling of tunnels through the distal femoral and proximal tibial physes 5 (group 2) underwent drilling of the tunnels and reconstruction with an extensor digitorum communis autograft; and 5 (group 3) had drilling and reconstruction with an extensor digitorum communis autograft that had been seeded with mesenchymal stem cells. Radiographs were obtained every 3 weeks, and the animals were sacrificed 3 to 20 weeks after surgery. The surgically treated and contralateral control knees were salvaged, and each knee was examined grossly, radiographically, and histologically. Results A bone bridge spanned the physis in all nongrafted knees (group 1) by 3 weeks after surgery. In group 2, the extensor digitorum communis autograft seemed to slow but not prevent the development of bony bridges and angular deformities. In contrast, the mesenchymal stem cell-seeded grafts (group 3) appeared to provide a marked protective effect against growth arrest and angular deformity. Conclusion The results of this study suggest that angular deformity and growth arrest that occur after drilling across the physis during anterior cruciate ligament reconstruction can be prevented or minimized by implanting mesenchymal stem cells onto the transphyseal soft tissue graft. Clinical Relevance These results may facilitate the development of strategies to prevent growth disturbances of the physis with intra-articular reconstructive procedures in pediatric patients.
Arthroscopic Reconstruction of the Anterior Cruciate Ligament Using Bone-Patellar Tendon-Bone Autograft
Authors: Lebel Benoit , Hulet Christophe , Galaud Bertrand , Burdin Gilles , Locker Bruno , Vielpeau Claude 
Published: March 2008

Background Anterior cruciate ligament reconstruction surgery and technique have changed over the past decade. Hypothesis Modern arthroscopic management of an anterior cruciate ligament tear using patellar tendon autograft offers a high Patient satisfaction rate and good clinical results over the long term. However, it may be associated with osteoarthritis changes over time. Study Design Case series; Level of evidence, 4. Methods In 1992, a prospective computerized database of anterior cruciate ligament reconstruction was established. Since that time, 101 anterior cruciate ligament arthroscopic reconstructions performed at our institution have been observed. Inclusion criteria were as follows: reconstruction with bone-patellar tendon-bone graft, a minimum 10-year follow-up, a standardized operative procedure, and no previous anterior cruciate ligament repair or associated ligament lesions. Before surgery, the mean age of the patients was 28.8 years ± 8.3 (mean ± SD). The follow-up assessment was established using the International Knee Documentation Committee (IKDC) 2000 form and quantitative laxity testing with a KT-1000 arthrometer. The joint space narrowing assessment used the IKDC score with a 30° posteroanterior weightbearing view. Results Mean follow-up was 11.6 ± 0.8 years. Nine graft ruptures occurred. The satisfaction rate was excellent (90%). Seventy Patients (74%) were still actively participating in sports. The mean subjective IKDC 2000 score was 90.5 ± 8.8 points. The IKDC score was statistically correlated to laxity, time from injury, and osteoarthritis development at final follow-up. Ninety-one percent of Patients were graded A or B according to the overall IKDC score. The radiological assessment reported osteoarthritis development in 17.8% of patients, and 39% showed radiological changes. Osteoarthritis was correlated with body mass index ( P = .01) and age at follow-up ( P = .006). In a selected population without meniscus and articular cartilage injury, an osteoarthritis rate of only 8% was found. Conclusion Arthroscopic anterior cruciate ligament reconstruction using bone-patellar tendon-bone autograft resulted in high Patient satisfaction levels and good clinical results after 10 years. Moreover, a high percentage of patients remained involved in sports activities, and anterior cruciate ligament reconstruction protected their meniscus from a secondary tear. However, knee osteoarthritis developed in 17.8% of patients so treated.
Bone Bruises Associated with ACL Rupture
Authors: Viskontas Darius G. , Giuffre Bruno M. , Duggal Naven , Graham David , Parker David , Coolican Myles 
Published: March 2008

Background Different patterns of bone bruising are seen on magnetic resonance imaging in acute anterior cruciate ligament ruptures. These patterns may relate to the mechanism of injury. Hypothesis There is a correlation between the mechanism of anterior cruciate ligament injury and bone bruise patterns on magnetic resonance imaging. Study Design Cohort study; Level of evidence, 2. Methods Data regarding the mechanism of anterior cruciate ligament rupture were collected prospectively on patients who had anterior cruciate ligament reconstructions. Inclusion criteria included a clear history of mechanism, magnetic resonance imaging within 6 weeks of injury, and no previous knee injury. Patients were divided into noncontact and contact mechanism groups. Bone bruise frequency, location, depth, and intensity were analyzed using magnetic resonance imaging and correlated with the mechanism of injury. Results Two hundred fifty-six patients were identified; 100 met the inclusion criteria, 86 were in the noncontact mechanism group, and 14 were in the contact mechanism group. The proportion of bone bruises in the lateral compartment in both groups was higher ( P < .001) than in the medial compartment. Bone bruising was more frequent, deeper, and more intense in the non-contact group, with frequency ( P = .019) and intensity ( P < .001) scores reaching significance at the lateral tibial plateau. Medial compartment bone bruising was seen more frequently than previously reported, particularly in the noncontact group. Conclusion The noncontact mechanism appears to cause more severe bone bruising in both the medial and lateral compartments.
Analysis of Interobserver and Intraobserver Variability in the Diagnosis and Treatment of SLAP Tears Using the Snyder Classification
Authors: Gobezie Reuben , Zurakowski David , Lavery Kyle , Millett Peter J. , Cole Brian J. , Wamer Jon J. P. 
Published: March 2008

Background Superior labral anterior posterior lesions are a relatively rare entity, and classification as a basis for selection of treatment has remained a point of controversy. Hypothesis There will be substantial interobserver and intraobserver variability in the diagnosis and treatment of superior labral anterior posterior tears by experienced arthroscopic specialists. Study Design Cohort study (diagnosis), Level of evidence, 2. Methods Compact discs containing 22 video vignettes of approximately 15 seconds duration were sent to the membership of the Arthroscopy Association of North America, American Shoulder and Elbow Society, and AOSSM. Each surgeon was asked to review the vignettes, classify the superior labral anterior posterior lesion type, and provide a treatment recommendation for each vignette. Seventy-three expert surgeons responded to the solicitation with a completed analysis. The same CD-ROM was re-sent to each of these 73 surgeons at a minimum of 12 months after the first viewing to obtain data on intraobserver reliability. Seventeen of the 73 surgeons returned this second CD-ROM with a complete analysis. Demographic data were also obtained from each surgeon. Multivariable logistic regression analysis was used to analyze the data, and 95% confidence intervals were established for each superior labral anterior posterior type (I-IV) with regard to diagnosis and treatment decision. Results The 22 vignettes analyzed by 73 surgeons resulted in 1606 responses. Several significant trends were noticed with regard to diagnosis and treatment from the responses: (1) surgeons had difficulty distinguishing type III lesions from type IV lesions, (2) the treatment of type III lesions is much more variable than that of any other subtype, and (3) surgeons had difficulty distinguishing normal shoulders from type II superior labral anterior posterior tears. No relationship was identified between correct treatment decisions based on diagnosis and any of the demographic factors analyzed. Our analysis of intraobserver variability showed only moderate agreement. The analysis of interobserver variability improved significantly when the diagnoses were analyzed based on treatment decision. Conclusions There is substantial interobserver and intraobserver variability among experienced shoulder arthroscopic specialists with regard to diagnosis and treatment of superior labral anterior posterior tears. Intraobserver agreement using the Snyder classification indicated only moderate agreement. Analysis of interobserver agreement based on treatment decisions results in superior concordance among experienced surgeons for the diagnosis of superior labral anterior posterior lesions.
Age and labour market commitment in Germany, Denmark, Norway and Sweden
Authors: Hult Carl , Edlund Jonas 
Published: March 2008

This study examines age differences in non-financial employment commitment in two types of `exit cultures'. Germany and Denmark represent the `early'-exit culture where early retirement has become the norm. Sweden and Norway represent the `late'-exit culture where labour market activity until advanced age is more common. The categorization of countries corresponds to the time for data collection (1997). The main question is whether suggested differences in exit culture are manifested in age differences in non-financial employment commitment. The claim that age differences in commitment relate to exit culture received some support. In the two early-exit countries, the probability for men to display low employment commitment was found to increase at the age of 43—54. Also women in these countries dropped in commitment but first at 55+. In the two late-exit countries there was no important loss in commitment related to the middle or old age groups.
Proliferation is not increased in airway myofibroblasts isolated from asthmatics
Authors: Ward J. E. , Harris T. , Bamford T. , Mast A. , Pain M. C. F. , Robertson C. , Smallwood D. , Tran T. , Wilson J. , Stewart A. G. 
Published: March 2008

Airway mesenchymal cells, such as myofibroblasts and airway smooth muscle cells, contribute to inflammation, airway remodelling and hyperresponsiveness in asthma by excessive proliferation and inflammatory mediator production.Using endobronchial biopsies obtained from both nonasthmatic and asthmatic subjects,in situproliferation was assessed by immunostaining for cyclin D1. The number of immunoreactive cells increased with asthma severity and was restricted to the epithelium and subepithelial connective tissue. Despite increases in smooth muscle area, cyclin D1 was not detected in cells in intact muscle bundles.Biopsy-derived cell cultures were characterised as predominantly myofibroblasts, and were assessed to determine whether proliferation and cytokine production varied with asthma status. Cell enumeration showed that basal proliferation was similar in cells from nonasthmatics and asthmatics, and mitogenic responses to fibroblast growth factor-2, thrombin or serum were either reduced or unchanged in cells from asthmatics. Interleukin (IL)-1-dependent granulocyte-macrophage colony-stimulating factor and IL-8 release was increased in cell supernatants from asthmatics.Thus, increased rates of cellular proliferation identifiedin situin the asthmatic airway occurred outside the expanded smooth muscle compartment. Although reduced proliferative responses were observed in cultured myofibroblasts from asthmatics, the increased cytokine production by these cells suggests that this contributes to and may perpetuate ongoing inflammation in asthma.
A comparative study of different machine learning methods on microarray gene expression data
Authors: Pirooznia Mehdi , Yang Jack Y , Yang Mary Qu , Deng Youping 
Published: March 2008

AbstractBackgroundSeveral classification and feature selection methods have been studied for the identification of differentially expressed genes in microarray data. Classification methods such as SVM, RBF Neural Nets, MLP Neural Nets, Bayesian, Decision Tree and Random Forrest methods have been used in recent studies. The accuracy of these methods has been calculated with validation methods such as v-fold validation. However there is lack of comparison between these methods to find a better framework for classification, clustering and analysis of microarray gene expression results.ResultsIn this study, we compared the efficiency of the classification methods including; SVM, RBF Neural Nets, MLP Neural Nets, Bayesian, Decision Tree and Random Forrest methods. The v-fold cross validation was used to calculate the accuracy of the classifiers. Some of the common clustering methods including K-means, DBC, and EM clustering were applied to the datasets and the efficiency of these methods have been analysed. Further the efficiency of the feature selection methods including support vector machine recursive feature elimination (SVM-RFE), Chi Squared, and CSF were compared. In each case these methods were applied to eight different binary (two class) microarray datasets. We evaluated the class prediction efficiency of each gene list in training and test cross-validation using supervised classifiers.ConclusionsWe presented a study in which we compared some of the common used classification, clustering, and feature selection methods. We applied these methods to eight publicly available datasets, and compared how these methods performed in class prediction of test datasets. We reported that the choice of feature selection methods, the number of genes in the gene list, the number of cases (samples) substantially influence classification success. Based on features chosen by these methods, error rates and accuracy of several classification algorithms were obtained. Results revealed the importance of feature selection in accurately classifying new samples and how an integrated feature selection and classification algorithm is performing and is capable of identifying significant genes.
Supervised learning-based tagSNP selection for genome-wide disease classifications
Authors: Liu Qingzhong , Yang Jack , Chen Zhongxue , Yang Mary Qu , Sung Andrew H , Huang Xudong 
Published: March 2008

Abstract

Background
Comprehensive evaluation of common genetic variations through association of single nucleotide polymorphisms (SNPs) with complex human diseases on the genome-wide scale is an active area in human genome research. One of the fundamental questions in a SNP-disease association study is to find an optimal subset of SNPs with predicting power for disease status. To find that subset while reducing study burden in terms of time and costs, one can potentially reconcile information redundancy from associations between SNP markers.

Results
We have developed a feature selection method named Supervised Recursive Feature Addition (SRFA). This method combines supervised learning and statistical measures for the chosen candidate features/SNPs to reconcile the redundancy information and, in doing so, improve the classification performance in association studies. Additionally, we have proposed a Support Vector based Recursive Feature Addition (SVRFA) scheme in SNP-disease association analysis.

Conclusions
We have proposed using SRFA with different statistical learning classifiers and SVRFA for both SNP selection and disease classification and then applying them to two complex disease data sets. In general, our approaches outperform the well-known feature selection method of Support Vector Machine Recursive Feature Elimination and logic regression-based SNP selection for disease classification in genetic association studies. Our study further indicates that both genetic and environmental variables should be taken into account when doing disease predictions and classifications for the most complex human diseases that have gene-environment interactions.