The Late Quaternary Rio Grande Delta—A Distinctive, Underappreciated Geologic System

The delta of the Rio Grande/Rio Bravo in southernmost Texas and northern Tamaulipas is one of the major deltas of North America. Over 600,000 people live on the Holocene delta and river plain, and a million more on its Pleistocene ancestors, yet geo-logic knowledge is limited. Combining available geologic information with global satellite photography gives a balanced view of an important delta. The Holocene delta begins at a point west of San Benito, Texas, forming a classic eastward-opening delta. Over half of the delta lies south of the present Rio Grande drainage. The delta passes westward into a floodplain that becomes entrenched into older rocks westward to Roma. In this delta, distributary channels or resacas are extremely sinuous and show a pronounced levee rise. A yazoo stream in the floodplain cuts northward across Pleistocene deposits to form a displaced delta. The delta plain is extensively modified by eolian processes. Erosion of clay-rich algal mats from exposed esteros (large, shallow ephemeral lakes) create complex ‘clay dune’ deposits that form 6 m (20 ft) high hills (lomitas) on the flat plain. Dominant SE to SSE winds affect sand movement along the transgressive shorelines. Longshore movement is particularly effective on the north side of the delta, less so on the south side. The delta appears to have formed between 8000 and 3000 years BP by a robust, sediment-loaded Rio Grande. This period occurs during the Holocene Climatic Optimum, which was a dry time (altithermal) on the High Plains. Since 3000 years BP, the delta has been much less active and has been transgressed by barrier systems. The delta today is inactive, because of upstream reservoirs built since the 1940s. Before then, the river had irregular high discharge due to tropical systems and contributions from the upper Rio Grande system. The Pleistocene deltas that form the Beaumont surface underlying McAllen, Edinburg, and Harlingen probably exhibit similar landforms

Dental Treatment under General Anesthesia in Healthy and Medically Compromised/Developmentally Disabled Children: A Comparative Study

Aim: To compare the type, number of procedures and working time of dental treatment provided under dental general anesthesia (DGA) in healthy and medically compromised/developmentally disabled children (MCDD children). Design: This cross-sectional prospective study involved 80 children divided into two groups of 40 children each. Group 1 consisted of healthy and Group 2 consisted of MCDD children. Results: Healthy children needed more working time than MCDD children, the means being 161±7.9 and 84±5.7 minutes, respectively (P= 0.0001). Operative dentistry and endodontic treatments showed a significant statistical difference (P= 0.0001). The means of procedures were 17±5.0 for healthy children and 11±4.8 for MCDD children (P= 0.0001). Conclusions: Healthy children needed more extensive dental treatment than MCDD children under DGA. The information from this sample of Mexican children could be used as reference for determining trends both within a facility as well as in comparing facilities in cross-population studies

Deflation Troughs, Water, and Prehistoric Occupation on the Margins of the South Texas Sand Sheet

Within the South Texas Plains, the area broadly defined by the Rio Grande to the south and the Nueces River to the north, a distance of ca. 175 km, evidence of open human occupation is remarkably abundant. Because it is predominantly a region of loose, sandy soils and active and relict sand dunes where wind processes dominate, the area is known as the South Texas Sand Sheet (STSS). There is no running water within the STSS and all streams are ephemeral. Existing drainage systems are small, localized, and not integrated, carrying water for a few days and up to two weeks after the passage of a storm. The lack of running water makes human occupation on this semi-arid area even more remarkable. The STSS and the adjacent wind deflated areas have hundreds of small and shallow elongated deflation troughs. Most of these poorly drained swales retain seasonal fresh water that sustain high moisture plants and are ephemeral wetlands; a small percentage of them hold water year round. As a result, the long history of human occupation of the STSS was possible due to the presence of the deflation troughs. This study explores the connection between human occupation of the STSS and deflation troughs at four previously unreported archeological sites in northern Hidalgo County using a combination of intensive archeological and geological survey, oral history, GIS technology, and existing soil maps

Broad-host range expression vectors containing manipulated meta-cleavage pathway regulatory elements of the TOL plasmid

AbstractThe construction of pERD20 and pERD21, two broad-host range expression vectors, is described. The vectors contain the Pm promoter of the meta-cleavage pathway operon of the TOL plasmid pWWO; this promoter is present within a polylinker which provides a number of downstream cloning sites close to the transcription initiation site. Transcription from the Pm promoter in these vectors is controlled not by the natural positive regulator of Pm, the Xy1S protein, but by an Xy1S mutant analogue, Xy1S2tr6, which ??hibits an altered effector specificity and can mediate a 3–8-fold higher level of transcription than can Xy1S in a wide range of temperatures. Controlled expression of cloned genes can be achieved in a broad spectrum of Gram negative bacteria grown at a wide range of temperatures

From a Tabula Rasa to the Governor’s Award for Historic Preservation

Prior to 2009, South Texas was essentially an archaeological tabula rasa, largely unknown in the academic, public, or grey literature due to its location far from research universities, the state historic preservation office, and cultural resource management firms. Here, we relate how a consortium of anthropologists and archaeologists, biologists, historians, geologists, and geoarchaeologists have embraced a locally focused, place-based STEAM research approach to tell the story of a largely unknown region of the United States and make it accessible to K–17 educators,1 the public, and scholars with bilingual maps, books, exhibits, films, traveling trunks, and scholarly publications. The efforts of the Community Historical Archaeology Project with Schools Program at the University of Texas Rio Grande Valley have been recognized locally, nationally, and internationally

Mitochondrial bioenergetics and distribution in living human osteoblasts grown on implant surfaces

Osseointegration of implants is crucial for the long-term success of oral implants. The periimplant bone formation by osteoblasts is strongly dependent on the local mechanical environment in the interface zone. Robust demands for energy are placed on osteoblasts during the adhesion process to solid surfaces, and mitochondria are capital organelles in the production of most of the ATP needed for the process. We have assessed the relationship between osteoblast differentiation and mitochondrial bioenergetics in living cells grown on two different titanium surfaces, in order to provide valuable information for the design of material surfaces required for the development of the most appropriate osteogenic surface for osteoblastic anchorage. Combined backscattered and fluorescence confocal microscopy showed that in flat cells grown on a machined surface, highly energized mitochondria were distributed along the cell body. In contrast, cells grown on the rough surface emitted long protrusions in search of surface roughness, with actin stress fibers clearly polarized and highly energized mitochondria clustered at focal adhesion sites. This report using normal human osteoblastic cells indicates that these cells are especially sensitive to surface cues through energy production that enhances the necessary adhesion required for a successful osseointegration

Incidence, in-hospital case-fatality rates, and management practices in Puerto Ricans hospitalized with acute myocardial infarction

OBJECTIVE: There are extremely limited data on minority populations, especially Hispanics, describing the clinical epidemiology of acute coronary disease. The aim of this study is to examine the incidence rate of acute myocardial infarction (AMI), in-hospital case-fatality rate (CFR), and management practices among residents of greater San Juan (Puerto Rico) who were hospitalized with an initial AMI. METHODS: Our trained study staff reviewed and independently validated the medical records of patients who had been hospitalized with possible AMI at any of the twelve hospitals located in greater San Juan during calendar year 2007. RESULTS: The incidence rate (# per 100,000 population) of 1,415 patients hospitalized with AMI increased with advancing age and were significantly higher for older patients for men (198) than they were for women (134). The average age of the study population was 64 years, and women comprised 45% of the study sample. Evidence-based cardiac therapies, e.g., aspirin, beta blockers, ACE inhibitors/angiotensin receptor blockers, and statins, were used with 60% of the hospitalized patients, and women were less likely than men to have received these therapies (59% vs. 65%) or to have undergone interventional cardiac procedures (47% vs. 59%) (p \u3c 0.05). The in-hospital CFR increased with advancing age and were higher for women (8.6%) than they were for men (6.0%) (p \u3c 0.05). CONCLUSION: Efforts are needed to reduce the magnitude of AMI, enhance the use of evidence-based cardiac therapies, reduce possible gender disparities, and improve the short-term prognoses of Puerto Rican patients hospitalized with an initial AMI