bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observational and Numerical Evidence of Depressed Convective Boundary Layer Heights near a Mountain Base
Authors: De Wekker Stephan F. J. 
Published: May 2008

Abstract
Recent field and numerical studies show evidence of the existence of a convective boundary layer height depression near a mountain base. This depression can have implications for air pollutant transport and concentrations in complex terrain. To investigate the mechanisms underlying this phenomenon, idealized simulations with a mesoscale numerical model are performed and combined with available observations. The idealized simulations with a single mountain ridge of various dimensions suggest that the depression evolves in time, is most pronounced in the late afternoon, and becomes larger as slope steepness increases. Observations and modeling results show that the atmosphere is heated more intensely near the mountain base than far away from the mountain base, not only inside the boundary layer but also above. The enhanced heating aloft affects boundary layer growth near the mountain base and is associated with the boundary layer height depression. An analysis of the different terms in the temperature tendency equation indicates that vertical and horizontal advection of warm air, associated with the thermally driven circulation along the mountain slope, play a role in this enhanced heating aloft.
The Operational Mesogamma-Scale Analysis and Forecast System of the U.S. Army Test and Evaluation Command. Part II: Interrange Comparison of the Accuracy of Model Analyses and Forecasts
Authors: Liu Yubao , Warner Thomas T. , Astling Elford G. , Bowers James F. , Davis Christopher A. , Halvorson Scott F. , Rife Daran L. , Sheu Rong-Shyang , Swerdlin Scott P. , Xu Mei 
Published: May 2008

Abstract
This study builds upon previous efforts to document the performance of the U.S. Army Test and Evaluation Command’s Four-Dimensional Weather Modeling System using conventional metrics. Winds, temperature, and specific humidity were verified for almost 15 000 forecasts at five U.S. Army test ranges using near-surface mesonet data. The primary objective was to use conventional metrics to characterize the degree to which forecast accuracy varies from range to range, within the diurnal cycle, with elapsed forecast time, and among the seasons. It was found that there are large interrange differences in forecast error, with larger errors typically associated with the ranges located near complex orography. Similarly, significant variations in accuracy were noted for different times in the diurnal cycle, but the diurnal dependency varied greatly among the ranges. Factor of 2 differences in accuracy were also found across the seasons.
The Operational Mesogamma-Scale Analysis and Forecast System of the U.S. Army Test and Evaluation Command. Part III: Forecasting with Secondary-Applications Models
Authors: Sharman Robert D. , Liu Yubao , Sheu Rong-Shyang , Warner Thomas T. , Rife Daran L. , Bowers James F. , Clough Charles A. , Ellison Edward E. 
Published: May 2008

Abstract
Output from the Army Test and Evaluation Command’s Four-Dimensional Weather System’s mesoscale model is used to drive secondary-applications models to produce forecasts of quantities of importance for daily decision making at U.S. Army test ranges. Examples of three specific applications—a sound propagation model, a missile trajectory model, and a transport and diffusion model—are given, along with accuracy assessments using cases in which observational data are available for verification. Ensembles of application model forecasts are used to derive probabilities of exceedance of quantities that can be used to help range test directors to make test go–no-go decisions. The ensembles can be based on multiple meteorological forecast runs or on spatial ensembles derived from different soundings extracted from a single meteorological forecast. In most cases, the accuracies of the secondary-application forecasts are sufficient to meet operational needs at the test ranges.
Dynamic LES Modeling of a Diurnal Cycle
Authors: Basu Sukanta , Vinuesa Jean-François , Swift Andrew 
Published: May 2008

Abstract
The diurnally varying atmospheric boundary layer observed during the Wangara (Australia) case study is simulated using the recently proposed locally averaged scale-dependent dynamic subgrid-scale (SGS) model. This tuning-free SGS model enables one to dynamically compute the Smagorinsky coefficient and the subgrid-scale Prandtl number based on the local dynamics of the resolved velocity and temperature fields. It is shown that this SGS-model-based large-eddy simulation (LES) has the ability to faithfully reproduce the characteristics of observed atmospheric boundary layers even with relatively coarse resolutions. In particular, the development, magnitude, and location of an observed nocturnal low-level jet are depicted quite well. Some well-established empirical formulations (e.g., mixed layer scaling, spectral scaling) are recovered with good accuracy by this SGS parameterization. The application of this new-generation dynamic SGS modeling approach is also briefly delineated to address several practical wind-energy-related issues.
Polarimetric Radar Observations at Low Levels during Tornado Life Cycles in a Small Sample of Classic Southern Plains Supercells*
Authors: Van Den Broeke Matthew S. , Straka Jerry M. , Rasmussen Erik N. 
Published: May 2008

Abstract
Preliminary schematics of polarimetric signatures at low levels in southern plains classic supercells are developed for pretornado, tornado, and tornado demise times from a small collection of cases, most of which are cyclic tornado producers. Characteristic signatures and patterns are identified for the reflectivity factor (ZHH), the differential reflectivity (ZDR), the correlation coefficient (ρhv), and the specific differential phase (KDP). Signatures likely related to an ongoing tornado are also discussed. Major findings in ZHH at tornado times include “wings” of higher values often extending away from the updraft region, a stronger gradient on the west side of the echo appendage, and a local maximum at the storm location favorable for tornadogenesis. Increasing cyclonic curvature of the hook-echo region was noted through the tornado life cycle. The ZDR tended to indicate hail shafts most commonly at tornado times, with the highest storm values typically located along the storm’s forward flank throughout the tornado life cycle. A ZDR minimum often occurred at the tornado-favorable location, while low ZDR occasionally trailed the tornado region. Storm-minimum ρhv typically occurred at the tornado-favorable location at tornado times and in hail shafts or heavy rain areas at other times. Another region of low correlation was the storm updraft, while the highest storm correlation was typically found in the downwind light-precipitation shield. The KDP typically exhibited a storm-core temporal maximum at tornado times, with the highest storm values in regions of hail and heavy rain and the lowest values in the downwind light-precipitation region. Values in the tornado-favorable region were typically near zero and sometimes strongly negative.
Section Modulus is the Optimum Geometric Predictor for Stress Fractures and Medial Tibial Stress Syndrome in both Male and Female Athletes
Authors: Franklyn Melanie , Oakes Barry , Field Bruce , Wells Peter , Morgan David 
Published: May 2008

Background Various tibial dimensions and geometric parameters have been linked to stress fractures in athletes and military recruits, but many mechanical parameters have still not been investigated. Hypotheses Sedentary people, athletes with medial tibial stress syndrome, and athletes with stress fractures have smaller tibial geometric dimensions and parameters than do uninjured athletes. Study Design Cohort study; Level of evidence, 3. Methods Using a total of 88 subjects, male and female patients with either a tibial stress fracture or medial tibial stress syndrome were compared with both uninjured aerobically active controls and uninjured sedentary controls. Tibial scout radiographs and cross-sectional computed tomography images of all subjects were scanned at the junction of the midthird and distal third of the tibia. Tibial dimensions were measured directly from the films; other parameters were calculated numerically. Results Uninjured exercising men have a greater tibial cortical cross-sectional area than do their sedentary and injured counterparts, resulting in a greater value of some other cross-sectional geometric parameters, particularly the section modulus. However, for women, the cross-sectional areas are either not different or only marginally different, and there are few tibial dimensions or geometric parameters that distinguish the uninjured exercisers from the sedentary and injured subjects. In women, the main difference between the groups was the distribution of cortical bone about the centroid as a result of the different values of section modulus. Last, medial tibial stress syndrome subjects had smaller tibial cross-sectional dimensions than did their uninjured exercising counterparts, suggesting that medial tibial stress syndrome is not just a soft-tissue injury but also a bony injury. Conclusion The results show that in men, the cross-sectional area and the section modulus are the key parameters in the tibia to distinguish exercise and injury status, whereas for women, it is the section modulus only.
Effect of Osteochondral Graft Insertion Forces on Chondrocyte Viability
Authors: Patil Shantanu , Butcher William , D'Lima Darryl D. , Steklov Nikolai , Bugbee William D. , Hoenecke Heinz R. 
Published: May 2008

Background Because chondrocytes are responsible for articular cartilage matrix synthesis and maintenance, reduced chondrocyte viability could compromise graft survival, healing, and clinical outcome. Hypothesis Typical forces used in osteochondral grafting reduce the viability of the chondrocytes in the graft. Study Design: Controlled laboratory study. Methods Osteochondral grafting was performed in 4 fresh-frozen cadaver knees (n = 16 per knee). Impact force was measured during extrusion of the donor graft from the harvester into the recipient site, seating the graft flush with the articular surface of the surrounding cartilage using a tamp, and recessing the graft surface below the recipient articular surface. The magnitudes of forces measured during cadaver surgery (200,400, and 800 N) were reproduced using a drop-tower apparatus on 80 fresh osteochondral grafts harvested from knee blocks provided by tissue banks. Cell viability and glycosaminoglycan release in media were measured at 48 hours after injury. Results Forces were relatively low (range, 124-356 N) during graft extrusion from the harvester into the recipient defect or during flush seating (range, 191-418 N) of the graft. Attempts to recess the graft generated significantly greater force (range, 147-685- P < .01). When the donor graft length was 2 mm longer than the depth of the recipient hole, the mean impact force generated was even higher (range, 240-1114 N) than the force seen in a donor graft of equal length. No reduction in viability was seen at 200-N and 400-N impacts. However, a significant decrease in chondrocyte viability was seen in the group impacted with 800 N (only 50% of cells were viable, compared with 91 % in the sham group; P < .01). Glycosaminoglycan levels in culture media did not correlate significantly with insertion force. Conclusion Typical graft insertion forces did not significantly reduce chondrocyte viability. However, increased graft length relative to the depth of the recipient hole and attempts to recess the graft generated higher forces, which reduced chondrocyte viability. Clinical Relevance Any theoretical benefits of cancellous bone compaction that may occur in grafts that are recessed or are longer than the recipient holes must be balanced against the potential reduction in chondrocyte viability.
Prospective Clinical Comparisons of Anatomic Double-Bundle versus Single-Bundle Anterior Cruciate Ligament Reconstruction Procedures in 328 Consecutive Patients
Authors: Kondo Eiji , Yasuda Kazunori , Azuma Hirotaka , Tanabe Yoshie , Yagi Tomonori 
Published: May 2008

Background Several trials have been conducted to compare the clinical results between anatomic double-bundle and single-bundle anterior cruciate ligament (ACL) reconstruction procedures. In these studies, however, the number of patients was insufficient to compare the clinical results of the 2 procedures. Hypothesis The anatomic double-bundle procedure may be significantly better concerning the anterior laxity and the pivot-shift test than the single-bundle procedure, while there may be no significant differences in the other clinical evaluations and the intraoperative and postoperative complications between the 2 procedures. Study Design Cohort study; Level of evidence, 2. Methods Three hundred and twenty-eight patients with unilateral ACL reconstruction using hamstring autografts were divided into 2 groups. The first 157 consecutive patients underwent single-bundle reconstruction and the remaining 171 patients underwent anatomic double-bundle reconstruction. Concerning all background factors, there were no statistical differences between the 2 groups. Each patient was examined 2 years after surgery. Results No serious complications were experienced in either group. The anterior laxity was significantly less in the double-bundle reconstruction (mean, 1.2 mm) than in the single-bundle reconstruction (mean, 2.5 mm). In the pivot-shift test, the double bundle (+ indication 16%; ++, 3%) was significantly better than the single bundle (+ result, 37%; ++, 12%). The mean Lysholm score averaged 96.5 points’ and 97.3 points in single-bundle and double-bundle reconstructions, respectively, while the International Knee Documentation Committee evaluation showed that 90 and 110 patients, respectively, were evaluated as rank A (no significant difference between groups). There were no significant differences in the other clinical evaluations and the complications between the 2 procedures. Conclusions The postoperative anterior and rotational stability after the anatomic double-bundle ACL reconstruction was significantly better than that after the single-bundle reconstruction, although there were no significant differences between the 2 Procedures concerning the complications and the clinical evaluations.
Maternal Par4 and platelets contribute to defective placenta formation in mouse embryos lacking thrombomodulin
Authors: Sood Rashmi , Sholl Lynette , Isermann Berend , Zogg Mark , Coughlin Shaun R. , Weiler Hartmut 
Published: May 2008

AbstractAbsence of the blood coagulation inhibitor thrombomodulin (Thbd) from trophoblast cells of the mouse placenta causes a fatal arrest of placental morphogenesis. The pathogenesis of placental failure requires tissue factor, yet is not associated with increased thrombosis and persists in the absence of fibrinogen. Here, we examine the role of alternative targets of coagulation that might contribute to the placental failure and death of Thbd−/− embryos. We demonstrate that genetic deficiency of the protease-activated receptors, Par1 or Par2, in the embryo and trophoblast cells does not prevent the death of Thbd−/− embryos. Similarly, genetic ablation of the complement pathway or of maternal immune cell function does not decrease fetal loss. In contrast, Par4 deficiency of the mother, or the absence of maternal platelets, restores normal development in one-third of Thbd-null embryos. This finding generates new evidence implicating increased procoagulant activity and thrombin generation in the demise of thrombomodulin-null embryos, and suggests that platelets play a more prominent role in placental malfunction associated with the absence of thrombomodulin than fibrin formation. Our findings demonstrate that fetal prothrombotic mutations can cause localized activation of maternal platelets at the feto-maternal interface in a mother with normal hemostatic function.
Neutrophil secretion products pave the way for inflammatory monocytes
Authors: Soehnlein Oliver , Zernecke Alma , Eriksson Einar E. , Rothfuchs Antonio Gigliotti , Pham Christine T. , Herwald Heiko , Bidzhekov Kiril , Rottenberg Martin E. , Weber Christian , Lindbom Lennart 
Published: May 2008

AbstractThe leukocyte response in inflammation is characterized by an initial recruitment of polymorphonuclear leukocytes (PMN) preceding a second wave of monocytes to the site of injury or infection. In the mouse, 2 populations of monocytes have been identified, Gr1−CCR2−CX3CR1hi resident monocytes and Gr1+CCR2+CX3CR1lo inflammatory monocytes. Here, intravital microscopy of the musculus cremaster and a subcutaneous air pouch model were used to investigate a possible link between PMN extravasation and the subsequent emigration of inflammatory monocytes in response to local stimulation with PAF. In mice that were made neutropenic by injection of a PMN-depleting antibody, the extravasation of inflammatory monocytes, but not resident monocytes, was markedly reduced compared with mice with intact white blood cell count but was restored by local treatment with secretion of activated PMN. Components of the PMN secretion were found to directly activate inflammatory monocytes and further examination revealed PMN-derived LL-37 and heparin-binding protein (HBP/CAP37/azurocidin) as primary mediators of the recruitment of inflammatory monocytes via activation of formyl-peptide receptors. These data show that LL-37 and HBP specifically stimulate mobilization of inflammatory monocytes. This cellular cross-talk functionally results in enhanced cytokine levels and increased bacterial clearance, thus boosting the early immune response.
Comparative study of mesenchymal stem cells from C57BL/10 and mdx mice
Authors: Li Yong , Zhang Cheng , Xiong Fu , Yu Mei-juan , Peng Fu-lin , Shang Yan-chang , Zhao Cui-ping , Xu Yong-feng , Liu Zheng-shan , Zhou Chang , Wu Jin-lang 
Published: May 2008

Abstract

Background
Human mesenchymal stem cells (MSCs) have been studied and applied extensively because of their ability to self-renew and differentiate into various cell types. Since most human diseases models are murine, mouse MSCs should have been studied in detail. The mdx mouse – a Duchenne muscular dystrophy model – was produced by introducing a point mutation in the dystrophin gene. To understand the role of dystrophin in MSCs, we compared MSCs from mdx and C57BL/10 mice, focusing particularly on the aspects of light and electron microscopic morphology, immunophenotyping, and differentiation potential.

Results
Our study showed that at passage 10, mdx-MSCs exhibited increased heterochromatin, larger vacuoles, and more lysosomes under electron microscopy compared to C57BL/10-MSCs. C57BL/10-MSCs formed a few myotubes, while mdx-MSCs did not at the same passages. By passage 21, mdx-MSCs but not C57BL/10-MSCs had gradually lost their proliferative ability. In addition, a significant difference in the expression of CD34, not Sca-1 and CD11b, was observed between the MSCs from the 2 mice.

Conclusion
Our current study reveals that the MSCs from the 2 mice, namely, C57BL/10 and mdx, exhibit differences in proliferative and myogenic abilities. The results suggest that the changes in mouse MSC behavior may be influenced by lack of dystrophin protein in mdx mouse.
On the role of the MAGUK proteins encoded by Drosophila varicoseduring embryonic and postembryonic development
Authors: Bachmann André , Draga Margarete , Grawe Ferdi , Knust Elisabeth 
Published: May 2008

Abstract

Background
Membrane-associated guanylate kinases (MAGUKs) form a family of scaffolding proteins, which are often associated with cellular junctions, such as the vertebrate tight junction, the Drosophila septate junction or the neuromuscular junction. Their capacity to serve as platforms for organising larger protein assemblies results from the presence of several protein-protein interaction domains. They often appear in different variants suggesting that they also mediate dynamic changes in the composition of the complexes.

Results
Here we show by electron microscopic analysis that Drosophila embryos lacking varicose function fail to develop septate junctions in the tracheae and the epidermis. In the embryo and in imaginal discs varicose expresses two protein isoforms, which belong to the MAGUK family. The two isoforms can be distinguished by the presence or absence of two L27 domains and are differentially affected in different varicose alleles. While the short isoform is essential for viability, the long isoform seems to have a supportive function. Varicose proteins co-localise with Neurexin IV in pleated septate junctions and are necessary, but not sufficient for its recruitment. The two proteins interact in vitro by the PDZ domain of Varicose and the four C-terminal amino acids of Neurexin IV. Postembryonic reduction of varicose function by expressing double-stranded RNA affects pattern formation and morphogenesis of the wing and the development of normal-shaped and -sized eyes.

Conclusion
Expression of two Varicose isoforms in embryonic epithelia and imaginal discs suggests that the composition of Varicose-mediated protein scaffolds at septate junctions is dynamic, which may have important implications for the modulation of their function.
Landforms predict phylogenetic structure on one of the world's most ancient surfaces
Authors: Pepper Mitzy , Doughty Paul , Arculus Richard , Keogh J Scott 
Published: May 2008

Abstract

Background
The iconic Pilbara in northwestern Australia is an ancient geological and biophysical region that is an important zone of biodiversity, endemism and refugia. It also is overlain by some of the oldest erosion surfaces on Earth, but very little is known about the patterns of biotic diversity within the Pilbara or how they relate to the landscape. We combined phylogenetic and spatial-autocorrelation genetic analyses of mitochondrial DNA data on populations of the gekkotan lizard Lucasium stenodactylum within the Pilbara with geological, distributional and habitat data to test the hypothesis that ancient surface geology predicts current clade-habitat associations in saxicoline animals.

Results
This is the first detailed phylogenetic examination of a vertebrate organism across the Pilbara region. Our phylogeny provides strong support for a deep and ancient phylogenetic split within L. stenodactylum that distinguishes populations within the Pilbara region from those outside the Pilbara. Within the Pilbara region itself, our phylogeny has identified five major clades whose distribution closely matches different surface geologies of this ancient landscape. Each clade shows strong affinities with particular terrain types and topographic regions, which are directly related to different geological bedrock.

Conclusion
Together our phylogenetic, distributional, geological and habitat data provide a clear example of ecological diversification across an ancient and heterogeneous landscape. Our favoured hypothesis is that ancestors of the Pilbara lineages radiated into the region at the onset of aridity in Australia approximately 5 mya and locally adapted to the various ancient and highly stable terrain types and the micro-habitats derived from them. In terms of specimen recovery and analysis, we are only beginning to reconstruct the biotic history of this ancient landscape. Our results show the geological history and the habitats derived from them will form an important part of this emerging story.