752 research outputs found
Halogen occultation experiment intergrated test plan
The test program plan is presented for the Halogen Occultation Experiment (HALOE) instrument, which is being developed in-house at the Langley Research Center for the Upper Atmosphere Research Satellite (UARS). This comprehensive test program was developed to demonstrate that the HALOE instrument meets its performance requirements and maintains integrity through UARS flight environments. Each component, subsystem, and system level test is described in sufficient detail to allow development of the necessary test setups and test procedures. Additionally, the management system for implementing this test program is given. The HALOE instrument is a gas correlation radiometer that measures vertical distribution of eight upper atmospheric constituents: O3, HC1, HF, NO, CH4, H2O, NO2, and CO2
Test Excavations and Monitoring at 41BX1598 A Multicomponent Historic Site in Bexar County, Texas
From September through December of 2003, the Center for Archaeological Research (CAR) at The University of Texas at San Antonio performed archaeological testing and monitoring at site 41BX1598, the location for the proposed San Fernando Community Center. The site is adjacent to Military Plaza in downtown San Antonio, Bexar County, Texas. The work performed by CAR was done under contract with the San Antonio Archdiocese, and was conducted in accordance with and under the jurisdiction of the City Preservation Ordinance (Article VI, Historic Preservation and Urban Design, City of San Antonio, Unified Development Code). Dr. Steve Tomka served as the Principal Investigator and Antonia Figueroa was the Project Archaeologist. The proposed San Fernando Community Center will consist of a City Public Service (CPS) vault for utilities, two parking areas, and one large Community Center building. The initial phase of construction work consisted of excavations associated with the construction of the CPS vault. CAR’s involvement in the project was initiated after that excavation was complete and it became evident that the vault excavation cut through what appeared to be Colonial-age deposits. Using a variety of methods, including archival research, backhoe trenches, shovel tests, and hand excavations, CAR archaeologists sampled two Colonial-age middens, recorded a variety of wall segments, including one which may be Colonial in age, and documented use of the location from the 1700s through the early 1900s. Our work at the site recovered over 1,400 ceramics, 174 pieces of metal, 181 fragments of glass, 291 pieces of chipped stone debitage, two projectile points, six gun flints, more than 13,000 fragments of animal bone, and numerous pieces of burned rock. The remains of several domesticated and wild taxa, including bison, antelope, and fish, were recovered from the middens. Flotation analysis of matrix from one of the middens produced charcoal from a variety of different locally available woods, and while several carbonized mesquite seeds and nut shell fragments (pecan) were recovered, no domesticated species were present in the ethnobotanical samples. Analysis of the faunal material from the middens suggests the possibility that subsistence changed during the Colonial period. Faunal remains from the earliest deposits are dominated by small body sized animals, while later deposits reflect an increased emphasis on large and very large mammals. The stratified nature of selected midden deposits also allowed us to question some of the commonly assumed date ranges for selected ceramic types.
Following the completion of field work, CAR obtained site trinomial 41BX1598 for the location from the Texas Archeological Research Laboratory in Austin. After analysis, the bone and the burned rock were discarded in conformance with Texas Historical Commission guidelines and in agreement with the City of San Antonio Historic Preservation office. The remaining artifacts, along with all associated field and laboratory notes, project maps, photos, and other documents, are curated at the Center for Archaeological Research at The University of Texas at San Antonio under this trinomial
The Carboxyl-Terminal Segment of Apolipoprotein A-V Undergoes a Lipid-Induced Conformational Change
Apolipoprotein (apo) A-V is a 343-residue, multidomain protein that plays an important role in regulation of plasma triglyceride homeostasis. Primary sequence analysis revealed a unique tetraproline sequence (Pro293-Pro296) near the carboxyl terminus of the protein. A peptide corresponding to the 48-residue segment beyond the tetraproline motif was generated from a recombinant apoA-V precursor wherein Pro295 was replaced by Met. Cyanogen bromide cleavage of the precursor protein, followed by negative affinity chromatography, yielded a purified peptide. Nondenaturing polyacrylamide gel electrophoresis verified that apoA-V(296-343) solubilizes phospholipid vesicles, forming a relatively heterogeneous population of reconstituted high-density lipoprotein with Stokes’ diameters\u3e17 nm. At the same time, apoA-V(296-343) failed to bind a spherical lipoprotein substrate in vitro. Far-UV circular dichroism spectroscopy revealed the peptide is unstructured in buffer yet adopts significant R-helical secondary structure in the presence of the lipid mimetic solvent trifluoroethanol (TFE; 50% v/v). Heteronuclear multidemensional NMR spectroscopy experiments were conducted with uniformly 15N- and 15N/13C-labeled peptide in 50% TFE. Peptide backbone assignment and secondary structure prediction using TALOSþ reveal the peptide adopts R-helix secondary structure from residues 309 to 334. In TFE, apoA-V(296-343) adopts an extended amphipathic R-helix, consistent with a role in lipoprotein binding as a component of full-length apoA-V
Data Recovery Excavations at 41PR44, Fort Wolters, Parker County, Texas
During the spring of 2004, the Center for Archaeological Research (CAR) of The University of Texas at San Antonio conducted data recovery excavations at site 41PR44 on Fort Wolters. The site had been surveyed and tested by the Texas Archeological Research Laboratory (Brownlow 2001; Brownlow et al. 1999). The results of that testing suggested that the site contained a high density of burned rock features, chipped stone, and bone that dated to the Late Prehistoric period, with additional material possibly dating to the Late Archaic. Based on the testing, site 41PR44 was recommended as eligible for inclusion on the National Register of Historic Places under Criterion D. The site has been directly impacted by military traffic, and secondary erosion associated with a dirt road that cut through the center of the site has further damaged 41PR44. As continued use and maintenance of the road would result in continued erosion of the significant deposits, and as avoidance of this site area was not possible, CAR was contracted by the Adjutant General’s Office of the Texas Military Forces to develop a data recovery plan that targeted critical data from the Late Prehistoric, and potentially earlier, occupations. That plan was produced in early 2004, and field work was undertaken in March and April. The work was conducted under a Memorandum of Agreement (MOA) between the Texas Military Forces and the Texas Historical Commission.
CAR personnel excavated 46 shovel and hand-auger tests, 24 1-x-1-m units, and cut four backhoe trenches. We defined 12 thermal features in the field, but subsequent analysis reduced this number to three. A variety of artifacts were collected, including large quantities of sandstone and limestone rock, a variety of lithic tools, 883 pieces of chipped stone debitage, sediment samples, and small quantities of bone, charcoal, and mussel shell. We identified several occupation periods at the site, including use of the location during the Late Prehistoric and Late Archaic periods, as well as earlier Archaic use. The distribution of projectile points, as well as the assessment of context by the project geoarchaeologists, demonstrated that several areas of the site were mixed. Nevertheless, we were able to isolate Late Prehistoric, Late Archaic, and Archaic age deposits that were used to explore a variety of research areas, including aspects of subsistence, chipped stone technology, and feature technology. While limited by less than ideal temporal resolution and low recovery rates, the analysis of the 41PR44 data provides a basic description of archaeological material for this understudied portion of Texas.
Following laboratory processing and analysis, and in consultation with both the Texas Military Forces and the Texas Historical Commission, selected samples and certain classes of materials collected from 41PR44 were discarded. This discard was in conformance with Texas Historical Commission guidelines. Material disposed of included all sandstone and limestone rock collected from non-feature contexts, as well as roughly 75% of all feature rock. All sediment samples not associated with features were discarded as were all metal items. All remaining archaeological samples collected by CAR, along with all associated documents, notes, and photographs, were prepared for permanent curation at the Texas Archaeological Research Laboratory in Austin
An Archaeological Survey of Twin Buttes Reservoir, Tom Green County, Texas, Volume III
From December of 1998 through November of 1999, the Center for Archaeological Research (CAR), at The University of Texas at San Antonio (UTSA) conducted a Class III archaeology survey of 10,195 acres (4125 ha) within Twin Buttes Reservoir, a flood control and irrigation facility near the city of San Angelo in west-central Tom Green County, Texas. The 100 percent pedestrian survey, conducted for the Department of the Interior, Bureau of Reclamation (BOR), was primarily a section 110, of the National Historic Preservation Act (NHPA), effort. The survey was conducted in conjunction with repair of existing seepage at Twin Buttes Dam. The repair, conducted under the Safety of Dams program, involved the construction of several borrow pits. Since the Safety of Dams repair required BOR to inventory several areas of the reservoir lands under Section 106 of the NHPA, it was decided to expand the section 106 work, and do the entire Section 110 survey of the reservoir.
CAR recorded 178 new archaeological sites, and revisited 21 previously recorded sites, within the reservoir. On these 199 sites, 19 historic components were identified, reflecting primarily farming and ranching activities. The prehistoric sites reflect occupation from the early Paleoindian period through the Late Prehistoric period. While recommendations regarding the eligibility of sites to the National Register of Historic Places (NRHP) were not required by the survey, based on the survey results CAR recommends that 13 of the 19 historic components have moderate or high research potential. Within the prehistoric data set, 48 sites have high research potential, 33 have moderate research potential, and 111 sites have limited research value
NMR study of the role of M42 in the solution dynamics of E. COLI dihydrofolate reductase
It is widely recognized that key positions throughout a protein’s structure contribute unequally to function. In light of recent studies that suggest protein dynamics are required for function, a number of these residues may serve to promote motions required for ligand binding and catalysis. In the present NMR study, the conformational dynamics of the dihydrofolate reductase (DHFR) mutant M42W, in the presence of methotrexate and NADPH, are characterized and compared to the wild-type enzyme. M42 is distal to the active site, yet the M42W substitution regulates catalysis and ligand affinity, and is therefore analogous to an allosteric modulator of DHFR function. To gain understanding of how this mutation regulates activity, we employ a “pandynamic” strategy by measuring conformational fluctuations of backbone amide and side-chain methyl groups on multiple timescales. Changes in ps-ns dynamics indicate that the mutational effects are propagated throughout a network of interacting residues within DHFR, consistent with a role for M42 as a dynamic communication hub. On the μs-ms timescale, mutation increases the rate of switching in the catalytic core. Mutation also introduces switching in the adenosine binding subdomain that occurs at a higher frequency than in the catalytic core, and which correlates with the rate of product release for M42W-DHFR. Finally, a structurally inferred analysis of side-chain dynamics suggests that the M42W mutation dampens motional contributions from non-local effects. These data show that the M42W mutation alters the dynamics of DHFR and are consistent with theoretical analysis that suggests the mutation disrupts motion that promotes catalysis
Conservative Clothing Effects on Body Composition Assessment by Air Displacement Plethysmography
International Journal of Exercise Science 14(4): 687-695, 2021. Form-fitting spandex swimsuits or single-layer compression shorts are recommended during BOD POD® testing to ensure accurate results. The purpose of this study was to evaluate the effects of various outfit types on body composition measurements using the BOD POD®, and self-reported comfort level wearing each outfit. Twenty-one participants, 8 females and 13 males, (age 31.6 ± 9.8 years) wore a spandex swim cap and three different outfits during BOD POD® testing (manufacturer-recommended form-fitting spandex swimsuit, short sleeve spandex, long sleeve spandex). Measured variables include body mass, body fat percentage, body volume, and self-reported comfort level wearing each outfit. Calculated variables include BMI and body density. Mean body density when wearing the control outfit was 0.004 g/cm3 lower than both short (p \u3c 0.001) and long sleeve (p = 0.001) alternatives. Short and long sleeve outfits resulted in body fat percentage underestimations of 2.0% and 2.1%, respectively (p \u3c 0.001). The short sleeve outfit had the highest mean comfort rating followed by the long sleeve outfit, and the lowest was the control swimsuits. The short sleeve outfit and control outfit had the largest differences in reported comfort levels (p \u3c 0.05). Wearing short and long sleeve spandex outfits instead of recommended form-fitting swimsuits resulted in body density increases and body fat percentage underestimations. Participants should follow manufacturer recommendations by wearing spandex swimsuits. Participants had higher self-reported comfort levels when wearing short or long sleeve outfits
Exploring the LSU Libraries’ Virtual Reference Transcripts: An Analysis
Abstract
Virtual reference is an important service provided by the Louisiana State University Libraries. A subcommittee within the Reference Department of Middleton Library decided to quantitatively and qualitatively review virtual reference transcripts for the 2005-2006 school year in order to assess and evaluate strengths and weaknesses of the services provided. The transcript analysis provides information reflecting how our patrons are using virtual reference and how our librarians are performing in the virtual environment
- …