280 research outputs found
Ranchers, Farmers, Soldiers, and the CCC: The Background for Seven Historical Sites at Camp Bowie, Brown County, Texas
During the mid-1900s, a cultural resources survey of Camp Bowie was conducted by the Environmental Resources Management Branch of the Adjutant General’s Department of Texas (AGTX-EV) which identified a number of historical sites within the camp’s boundaries. These sites included 41BR227, 41BR438, and 41BR266, all of which are sandstone walls; 41BR270 and 41BR477, both of which contain check dams built to control erosion; 41BR290, the remains of a farmstead; and 41BR299, a bunker dating to the World War II era. In 2001 the Center for Archeological Research at the University of Texas at San Antonio contracted with AGTX-EV to conduct additional archaeological investigations at Camp Bowie; part of that agreement called for a general investigation of the historical background of the seven sites mentioned above. This archival research was conducted under Texas Antiquities Permit no. 2591
Archeological Investigations for Fort Stabilization and Restoration, For McKavett State Historical Park, Menard County, Texas: 1978-1990 Seasons
The U.S. Army occupations at Fort McKavett from 1853 until 1859 and from 1868 until 1883 were part of Texas\u27s frontier defense. During the Civil War and from 1883 until the present, civilians have inhabited and used the fort buildings, creating the small town of Fort McKavett. The Texas Parks and Wildlife Department developed part of the town as a state historical park, restoring this property to its appearance during the second military occupation. Archeological investigations at the park between 1978 and 1990 focused on recovering architectural data and artifacts to support restoration, stabilization, and interpretation of the military occupations. The archeological work varied from surface collection to large-scale excavations, the latter generally confined to Officers\u27 Quarters 4, but the most common approach was limited testing in building foundations and suspected architectural features. Work took place in 16 structures. Most of the archeological work focused on officers\u27 quarters, although a few enlisted mens\u27 barracks and other buildings also were tested. Relatively few temporally diagnostic artifacts were recovered in the vicinity of walls, fireplaces, and other architectural features, and only sparse military and military-period artifacts were found. The 372 military and military-period artifacts recovered from the post-1977 work at Fort McKavett and described in this report represent less than 0.01 percent of the total artifact assemblage and likely represent only a small proportion of the trash generated by the military occupations. Much of that trash probably was disposed of and possibly burned off-site or, if on-site, in pit latrines or other deep features not excavated during the 1978-1990 work. Military conduct, discipline, and policing may have functioned in keeping public spaces at this frontier military fort relatively litter free and thus artifact poor
Camp Mabry Archaeological Survey and Testing, Travis County, Texas
In October 2001, the Center for Archaeological Studies (CAS) was contracted by the Adjutant General’s Department of the Texas Army National Guard (AGTX) to perform a 100% systematic archaeological survey on the grounds of Camp Mabry, in Austin. The project was comprised of a pedestrian survey, extensive shovel testing, and the excavation of two backhoe trenches. The survey resulted in the discovery of an 8 x 8-meter prehistoric site, 41TV1954. In addition, two previously recorded archaeological sites (41TV1667 and 41TV1722) were revisited, and shovel tests were excavated in order to reevaluate and document cultural resources and site boundaries. Based on data generated during the pedestrian survey and shovel testing, CAS has determined that 41TV1722 and 41TV1954 are not archaeologically significant and thus do not qualify for National Register consideration. After analyzing the results gathered from both shovel test and backhoe trench excavations on 41TV1667, CAS has concluded that the site does pose a moderate to high research potential. CAS thus recommends that further testing is needed on 41TV1667 in order to determine the site’s eligibility for nomination to the National Register of Historic Places
Pd-Catalyzed Nucleophilic Fluorination of Aryl Bromides
On the basis of mechanism-driven reaction design, a Pd-catalyzed nucleophilic fluorination of aryl bromides and iodides has been developed. The method exhibits a broad substrate scope, especially with respect to nitrogen-containing heteroaryl bromides, and proceeds with minimal formation of the corresponding reduction products. A facilitated ligand modification process was shown to be critical to the success of the reaction.National Science Foundation (U.S.) (CHE 0946721)Amgen Inc.National Science Foundation (U.S.) (Predoctoral fellowship (2010094243))National Institutes of Health (U.S.) (Award GM46059
Studying Regioisomer Formation in the Pd-Catalyzed Fluorination of Aryl Triflates by Deuterium Labeling
Isotopic labeling has been used to determine that a portion of the desired product in the Pd-catalyzed fluorination of electron-rich, non-ortho-substituted aryl triflates results from direct C–F cross-coupling. In some cases, formation of a Pd-aryne intermediate is responsible for producing undesired regioisomers. The generation of the Pd-aryne intermediate occurs primarily via ortho-deprotonation of a L·Pd(Ar)OTf (L = biaryl monophosphine) species by CsF and thus competes directly with the transmetalation step of the catalytic cycle. Deuterium labeling studies were conducted with a variety of aryl triflates.National Institutes of Health (U.S.) (Award GM46059)National Science Foundation (U.S.) (Predoctoral Fellowship 2010094243)Amgen Inc.Alexander von Humboldt-Stiftung (Feodor Lynen Postdoctoral Fellowship
Fatty acid composition of red drum maintained by fishmeal, fish oil substitutes in diets
Recent research by the authors evaluated strategies to reduce fishmeal and fish oil in diets for red drum by substituting terrestrial proteins and lipids while maintaining beneficial fatty acids with DHA supplements derived from marine algae. Results suggested fatty acid-enriched finishing diets can be used with growout diets containing little or no fishmeal and fish oil to achieve the desired DHA content in the final fish fillets
Stille Cross-Coupling Reactions of Aryl Mesylates and Tosylates Using a Biarylphosphine Based Catalyst System
A catalyst system for the Stille cross-coupling reactions of aryl mesylates and tosylates is reported. Using the combination of Pd(OAc)[subscript 2], XPhos, and CsF in t-BuOH an array of aryl and heteroaryl sulfonates were successfully employed in these reactions. Morever, heteroarylstannanes, such as furyl, thienyl, and N-methylpyrrolyl, which are often prone to decomposition, were efficiently coupled under these conditions. Ortho-substitution on the stannane coupling partner was well tolerated; however, the presence of ortho substituents on the aryl sulfonates greatly reduced the efficiency of these reactions.National Institutes of Health (U.S.) (Grant GM-46059)Merck & Co.Boehringer Ingelheim Pharmaceutical
Virtually Instantaneous, Room-Temperature [11C]-Cyanation Using Biaryl Phosphine Pd(0) Complexes
A new radiosynthetic protocol for the preparation of [[superscript 11]C]aryl nitriles has been developed. This process is based on the direct reaction of in situ prepared L·Pd(Ar)X complexes (L = biaryl phosphine) with [[superscript 11]C]HCN. The strategy is operationally simple, exhibits a remarkably wide substrate scope with short reaction times, and demonstrates superior reactivity compared to previously reported systems. With this procedure, a variety of [[superscript 11]C]nitrile-containing pharmaceuticals were prepared with high radiochemical efficiency.National Institutes of Health (U.S.) (NIH GM46059)National Science Foundation (U.S.) (NSF predoctoral fellowship (2010094243))Amgen Inc. (Educational donation)National Institutes of Health (U.S.) (NIH-NIDA postdoctoral fellowship (2T32DA015036)
Oxygen consumption of Litopenaeus vannamei juveniles in heterotrophic medium with zero water exchange
O objetivo deste trabalho foi determinar o consumo de oxigênio dissolvido (OD) de juvenis de Litopenaeus vannamei mantidos em sistema de cultivo de bioflocs bacterianos em alta densidade e ausência de aeração. Três garrafas de 4 L foram preenchidas para cada tratamento, fechadas hermeticamente e colocadas em sistema de cultivo fechado. Quatro camarões (13,2±1,42 g) foram colocados em dois dos conjuntos de garrafas. Os tratamentos aplicados foram: luminosidade, sem camarões; escuro, sem camarões; luminosidade, com camarões; escuro, com camarões. A concentração de oxigênio dissolvido foi determinada a cada 10 min durante 30 min. Foi observado um comportamento quadrático na concentração de OD ao longo do tempo. Diferenças significativas para consumo de oxigênio foram observadas apenas aos 10 e 20 min entre camarões mantidos no escuro e camarões em luminosidade. Aos 10 min, foi observada maior concentração no sistema mantido em luminosidade e, aos 20 min, no sistema mantido no escuro. Na análise do consumo de oxigênio ao longo do tempo e com luminosidade, foram constatadas diferenças significativas entre 10 e 20 min e entre 10 e 30 min. Em condições de escuridão, houve diferença significativa apenas entre 20 e 30 min. Concluiu-se que, sem aeração, a condição anóxica pode ser alcançada em menos de uma hora, tanto ao dia quanto à noite.This work aimed at determining the dissolved oxygen consumption rate of Litopenaeus vannamei juveniles maintained in a microbial biofloc raceway system at high density with no aeration. Three 4 L bottles were filled for each treatment, sealed hermetically, and placed in an enclosed greenhouse raceway system. Four shrimp (13.2±1.42 g) were assigned to two sets of the bottles, which underwent the following treatments: light conditions with no shrimp; dark conditions with no shrimp; light conditions with shrimp; and dark conditions with shrimp. Dissolved oxygen content was measured every 10 min for 30 min. A quadratic behavior was observed in dissolved oxygen concentration over time. Significant differences for oxigen consumption were observed only at 10 and 20 min between shrimp maintained in the dark and those under light conditions. At 10 min, a higher value was observed in shrimp maintained under light, and at 20 min, in the dark. Significant differences between 10 and 20 min and between 10 and 30 min were observed when oxygen consumption was analyzed over time in the presence of light. Under dark conditions there were significant differences only between 20 and 30 min. Lethal oxygen concentration (0.65 mg L-1) would be reached in less than one hour either under light or dark conditions with no aeration
A genetic assay for gene essentiality in Clostridium
Essential genes of pathogens are potential therapeutic targets, but are difficult to verify. Here, gene essentiality was determined by targeted knockout following engineered gene duplication. Null mutants of candidate essential genes of Clostridium difficile were viable only in the presence of a stable second copy of the gene
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