Angelo State University

About: Angelo State University is a education organization based out in San Angelo, Texas, United States. It is known for research contribution in the topics: Population & Infrared. The organization has 471 authors who have published 742 publications receiving 9267 citations. The organization is also known as: Angelo State & San Angelo College.

Biomass Production of ‘Alamo’ Switchgrass in Response to Nitrogen, Phosphorus, and Row Spacing

Abstract: Management practices for biomass production of bioenergy grasses may differ from management for forage. Our objective was to determine the yield and stand responses of Alamo' switchgrass (Panicum virgatum L.) to N and P fertilization as affected by row spacing. A combination of five rates each of N and P were applied to plots during 1992 to 1998 at Stephenville, TX and 1993 to 1995 at Beeville, TX. Three row-spacing treatments were applied as subplots. Biomass production was determined each year with a single harvest in late summer. Tiller density and tiller mass were measured during 1993 to 1996 at Stephenville. Biomass production was not influenced by the addition of P. Biomass production response to N at Beeville was greater in narrow rows than wide rows during the establishment year only. Biomass production responses to N were quadratic in 5 of 7 yr at Stephenville and linear at Beeville. A maximum yield of 22.5 Mg ha -1 occurred during 1995 at Stephenville at 168 kg N ha -1 . Lodging occurred at both locations but only at the 224 kg N ha -1 rate. Tiller density and mass increased as row width increased. Tiller mass also increased with increasing N fertility at Stephenville. This response was more important in determining biomass production than was tiller density. Average biomass production at 168 kg N ha -1 yr -1 was 14.5 and 10.7 Mg ha -1 yr -1 at Stephenville and Beeville, respectively. Biomass production without applied N tended to decline over the years. Our data indicated that switchgrass biomass production is sustainable at Stephenville only with the application of at least 168 kg N ha -1 yr -1 , but P application and row spacing are not crucial.

Turning Points in the Development of Blended Families

Abstract: A modified retrospective interview technique (RIT) was employed with members of 53 blended families to determine the types of turning points they reported experiencing and the developmental trajectories of their respective blended family’s first 4 years. Findings revealed 15 primary types of turning points, of which ‘Changes in Household Configuration’, ‘Conflict’, ‘Holidays/Special Events’, ‘Quality Time’ and ‘Family Crisis’ were the most frequent. A cluster analysis revealed five basic trajectories of development for the first 48 months of family development: Accelerated, Prolonged, Stagnating, Declining and High-amplitude Turbulent. The trajectories differed in the overall positive-to-negative valence ratio, the frequency of conflict related events, the average amplitude of change in feeling like a family, and the current reported level of feeling like a family.

L-Glutamine or L-alanyl-L-glutamine prevents oxidant- or endotoxin-induced death of neonatal enterocytes.

Abstract: This study tested the hypothesis that L-glutamine (Gln) or L-alanyl-L-glutamine (Ala-Gln) prevents oxidant- or endotoxin-induced death of neonatal enterocytes. Enterocytes of neonatal pigs rapidly hydrolyzed Ala-Gln and utilized Gln. To determine whether Gln or Ala-Gln has a cytoprotective effect, IPEC-1 cells were cultured for 24 h in Gln-free Dulbecco’s modified Eagle’s-F12 Ham medium containing 0, 0.5, 2.0 or 5.0 mM Gln or Ala-Gln, and 0, 0.5 mM H2O2 or 30 ng/ml lipopolysaccharide (LPS). Without Gln or Ala-Gln, H2O2- or LPS-treated cells exhibited almost complete death. Gln or Ala-Gln at 0.5, 2 and 5 mM dose-dependently reduced H2O2- or LPS-induced cell death by 14, 54 and 95%, respectively, whereas d-glutamine, alanine, glutamate, ornithine, proline, glucosamine or nucleosides had no effect. To evaluate the effectiveness of Gln or Ala-Gln in vivo, 7-day-old piglets received one-week oral administration of Gln or Ala-Gln (3.42 mmol/kg body weight) twice daily and then a single intraperitoneal injection of LPS (0.1 mg/kg body weight); piglets were euthanized in 24 and 48 h to analyze intestinal apoptotic proteins and morphology. Administration of Gln or Ala-Gln to LPS-challenged piglets increased Gln concentrations in small-intestinal lumen and plasma, reduced intestinal expression of Toll-like receptor-4, active caspase-3 and NFkB, ameliorated intestinal injury, decreased rectal temperature, and enhanced growth performance. These results demonstrate a protective effect of Gln or Ala-Gln against H2O2- or LPS-induced enterocyte death. The findings support addition of Gln or Ala-Gln to current Gln-free pediatric amino acid solutions to prevent intestinal oxidative injury and inflammatory disease in neonates.

Covalency in lanthanides. An X-ray absorption spectroscopy and density functional theory study of LnCl6(x-) (x = 3, 2).

Abstract: Covalency in Ln–Cl bonds of Oh-LnCl6x– (x = 3 for Ln = CeIII, NdIII, SmIII, EuIII, GdIII; x = 2 for Ln = CeIV) anions has been investigated, primarily using Cl K-edge X-ray absorption spectroscopy (XAS) and time-dependent density functional theory (TDDFT); however, Ce L3,2-edge and M5,4-edge XAS were also used to characterize CeCl6x– (x = 2, 3). The M5,4-edge XAS spectra were modeled using configuration interaction calculations. The results were evaluated as a function of (1) the lanthanide (Ln) metal identity, which was varied across the series from Ce to Gd, and (2) the Ln oxidation state (when practical, i.e., formally CeIII and CeIV). Pronounced mixing between the Cl 3p- and Ln 5d-orbitals (t2g* and eg*) was observed. Experimental results indicated that Ln 5d-orbital mixing decreased when moving across the lanthanide series. In contrast, oxidizing CeIII to CeIV had little effect on Cl 3p and Ce 5d-orbital mixing. For LnCl63– (formally LnIII), the 4f-orbitals participated only marginally in covalent bo...