6,035 research outputs found
Detection of the old stellar component of the major Galactic bar
We present near-IR colour--magnitude diagrams and star counts for a number of
regions along the Galactic plane. It is shown that along the l=27 b=0 line of
sight there is a feature at 5.7 +-0.7kpc with a density of stars at least a
factor two and probably more than a factor five times that of the disc at the
same position. This feature forms a distinct clump on an H vs. J-H diagram and
is seen at all longitudes from the bulge to about l=28, but at no longitude
greater than this. The distance to the feature at l=20 is about 0.5kpc further
than at l=27 and by l=10 it has merged with, or has become, the bulge. Given
that at l=27 and l=21 there is also a clustering of very young stars, the only
component that can reasonably explain what is seen is a bar with half length of
around 4kpc and a position angle of about 43+-7.Comment: 5 pages, 5 figures accepted as a letter in MNRA
Phenotypic Variation in Skull Size and Shape Between Newfoundland and Mainland Populations of North American Black Bears, Ursus americanus
It is well recognized that differences in environmental selection pressures among populations can generate phenotypic divergence in a suite of morphological characteristics and associated life history traits. Previous analysis of mitochondrial DNA and body size have suggested that Black Bears (Ursus americanus) inhabiting the island of Newfoundland represent a different subspecies or ecotype from mainland populations. Assuming that body size covaries positively with skull size, we predicted that skull size would be greater for bears on the island than the mainland, and the distribution of size-related shape components in multivariate space should show a distinct separation between Newfoundland and mainland populations. Measurements of 1080 specimens from Newfoundland, Alberta, New York, and Quebec did not provide unequivocal support for our prediction that skull size in Newfoundland bears would be larger than bears from the mainland populations. After removing ontogenetic effects of skull size, between-population variation in skull shape was greater in females than males, and the analysis significantly separated Newfoundland bears from mainland populations. Explanations for this pattern are numerous, but currently remain hypothetical. Limited covariation between skull size and body size suggests that genetic traits regulating the size of Black Bear skulls are more heritable (i.e., less influenced by environmental selection pressures) than characteristics affecting body size. We hypothesize that if gape size does not limit prey size in solitary terrestrial carnivores, large degrees of among-population variation in body size should be coupled with little covariation in skull size. In general, sexual dimorphism in skull size and shape was marginal for the phenotypic characters measured in our study. We believe that sexual dimorphism in skull size in Black Bears is primarily driven by intrasexual selection in males for increased gape size display, while similarity in skull shape between sexes is associated with the constraints of a temporally-selective, but similar diet
Exogenous application of platelet-leukocyte gel during open subacromial decompression contributes to improved patient outcome
Background: Platelet-leukocyte gel (PLG) is being used during various surgical procedures in an attempt to enhance the healing process. We studied the effects of PLG on postoperative recovery of patients undergoing open subacromial decompression (OSD). Methods: PLG was produced from platelet-leukocyte-rich plasma (P-LRP), prepared from a unit of whole blood. Forty patients were included in the study. Self-assessed evaluations, using the American Shoulder and Elbow Surgeons scoring system of activities of daily living (ADL), joint instability, pain levels, pain medications, and clinical evaluations for range of motion were conducted. Results: Platelet and leukocyte counts were significantly increased in the P-LRP compared to baseline counts. Treated patients demonstrated decreased visual analog scales for pain and used significantly less pain medication, had an improved range of motion during passive forward elevation, external rotation, external rotation with arm at 90 degrees abduction, internal rotation, and cross body adduction compared to control patients (p < 0.001). No differences in the instability score were observed between the groups. Furthermore, treated patients performed more ADL (p < 0.05). Conclusion: In the PLG-treated group, recovery was faster and patients returned earlier to daily activities and also took less pain medication than control subjects
Random Projections For Large-Scale Regression
Fitting linear regression models can be computationally very expensive in
large-scale data analysis tasks if the sample size and the number of variables
are very large. Random projections are extensively used as a dimension
reduction tool in machine learning and statistics. We discuss the applications
of random projections in linear regression problems, developed to decrease
computational costs, and give an overview of the theoretical guarantees of the
generalization error. It can be shown that the combination of random
projections with least squares regression leads to similar recovery as ridge
regression and principal component regression. We also discuss possible
improvements when averaging over multiple random projections, an approach that
lends itself easily to parallel implementation.Comment: 13 pages, 3 Figure
The Medio Creek Site (41BX1421): National Register Test Excavations, Bexar County Texas
During April 2001, the Center for Archaeological Research of The University of Texas at San Antonio conducted National Register of Historic Places eligibility testing for archeological site 41BX1421, located in southwest Bexar County, Texas, under contract with the Texas Department of Transportation. The investigations were conducted under Texas Antiquities Permit Number 2569. The Phase II testing fieldwork consisted of excavation of five test units across the site to investigate cultural deposits encountered during the previous survey phase. A single sheet midden consisting of burned limestone cobbles was encountered across the majority of the site. In concert with the archeological field investigations, the following special analyses and studies were performed to aid the determination of site integrity and eligibility: radiocarbon, lithic, aboriginal ceramic, vertebrate faunal. and magnetic sediment susceptibility. The synthesis of these analyses has provided adequate data to determine 41BX1421 ineligible for the National Register of Historic Places. It is therefore recommended that the Loop 1604 improvements proceed without further cultural resources investigations
Archeological Data Recovery Excavations along Becerra Creek (41WB556), Webb County, Texas
From June through August 2000, The Center for Archaeological Research of The University of Texas at San Antonio conducted archeological data recovery for prehistoric site 41WB556, under contract with Texas Department of Transportation. The investigations were conducted under Texas Antiquities Permit Number 2412. The Phase III data recovery consisted of excavation of 64 1-m2 units across the site in order to investigate significant cultural deposits encountered during the previous survey and testing phases. In concert with the archeological field investigations, the following special analyses and studies were performed to aid the determination of site integrity and chronology: geoarcheology, radiocarbon dating, lithic, lipid residue, vertebrate faunal, carbon/nitrogen isotope, macrobotanical, and magnetic soil susceptibility. The synthesis of these analyses provides substantive insights into the lifeways of the region’s prehistoric hunter-gatherers
Palmitoylation of Desmoglein 2 Is a Regulator of Assembly Dynamics and Protein Turnover.
Desmosomes are prominent adhesive junctions present between many epithelial cells as well as cardiomyocytes. The mechanisms controlling desmosome assembly and remodeling in epithelial and cardiac tissue are poorly understood. We recently identified protein palmitoylation as a mechanism regulating desmosome dynamics. In this study, we have focused on the palmitoylation of the desmosomal cadherin desmoglein-2 (Dsg2) and characterized the role that palmitoylation of Dsg2 plays in its localization and stability in cultured cells. We identified two cysteine residues in the juxtamembrane (intracellular anchor) domain of Dsg2 that, when mutated, eliminate its palmitoylation. These cysteine residues are conserved in all four desmoglein family members. Although mutant Dsg2 localizes to endogenous desmosomes, there is a significant delay in its incorporation into junctions, and the mutant is also present in a cytoplasmic pool. Triton X-100 solubility assays demonstrate that mutant Dsg2 is more soluble than wild-type protein. Interestingly, trafficking of the mutant Dsg2 to the cell surface was delayed, and a pool of the non-palmitoylated Dsg2 co-localized with lysosomal markers. Taken together, these data suggest that palmitoylation of Dsg2 regulates protein transport to the plasma membrane. Modulation of the palmitoylation status of desmosomal cadherins can affect desmosome dynamics
Camp Maxey IV Archaeological Testing of Six Sites, Lamar County, Texas
From June 14 through July 4, 2001, the Center for Archaeological Research of The University of Texas at San Antonio conducted National Register of Historic Places eligibility testing of six prehistoric archaeological sites (41LR190, 41LR194, 41LR196, 41LR200, 41LR258, and 41LR259) at Camp Maxey, Lamar County, Texas, under contract with the Texas Army National Guard. The investigations were conducted under Texas Antiquities Permit No. 2180. The Phase II testing fieldwork consisted of the excavation of twelve backhoe trenches and nineteen 1 x 1-m test units across the sites to investigate significant cultural deposits encountered during the previous survey phase. In concert with the archaeological field investigations, lithic and native ceramic analyses and magnetic sediment susceptibility studies were performed to aid in the determination of site integrity and eligibility.
The synthesis of these analyses has provided adequate data to determine temporal integrity and recommendation of National Register eligibility for site 41LR190. Further cultural resources investigations in the form of Phase III data recovery excavations are thus recommended for this site prior to proposed development. Conversely, due to lack of significance criteria, sites 41LR194, 41LR196, 41LR200, 41LR258, and 41LR259 are recommended as ineligible for inclusion in the National Register and require no further cultural resources investigations
Metabolic Responses to High Intensity Aerobic and Anaerobic Exercises
Please view abstract in the attached PDF file
Cardiovascular Responses to High Intensity Aerobic and Anaerobic Exercises
Please view abstract in the attached PDF file
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