Southwestern University

About: Southwestern University is a education organization based out in Georgetown, Texas, United States. It is known for research contribution in the topics: Population & Politics. The organization has 727 authors who have published 895 publications receiving 15630 citations. The organization is also known as: SU.

The Effects of Language Anxiety on Students' Oral Test Performance and Attitudes

Abstract: the development of students' speaking proficiency is considerable. This concern with oral competence, however, may be intensifying the already high levels of foreign language anxiety experienced by some learners. Research suggests that the oral skill is problematic for second language learners (22; 40; 42; 45; 49); although students indicate they are most interested in developing their capacity to communicate verbally in the target language (33), the anxiety they experience may have a debilitating impact on their ability to speak it. Unfortunately, this apprehension will likely be intensified by the ever-growing use of communicative oral testing, for research also provides ample evidence that anxiety increases in evaluative situations (55). This paper reports on a study that examined the effects of students' anxiety on performance on an oral test of French and investigates the attitudes of selected highly anxious students towards that exam. I argue that, although many variables may interact to affect language learning, foreign language anxiety should be of considerable concern to language educators and students because of its potential impact, not only on performance on oral tests, but also on students' affective reactions, hence their attitudes toward language learning in general.

A study of classification criteria for a diagnosis of juvenile rheumatoid arthritis.

Abstract: Criteria for the classification of juvenile rheumatoid arthritis were analyzed in a detailed database of 250 children in order to assess the accuracy of diagnosis and validity of onset types and course subtypes. A number of conclusions have been derived from this study: All definitions of the 1973 criteria for classification of juvenile rheumatoid arthritis should be retained. The addition of onset types to the 1976 revision of the criteria has been validated. The course of the disease after the onset period of 6 months is as important to the outcome of a group of children as is the onset type. The current classification should be broadened to include the course subtypes.

Why are nitrogen concentrations in plant tissues lower under elevated CO2? A critical examination of the hypotheses.

Abstract: Plants grown under elevated atmospheric [CO2] typically have decreased tissue concentrations of N compared with plants grown under current ambient [CO2]. The physiological mechanisms responsible for this phenomenon have not been definitely established, although a considerable number of hypotheses have been advanced to account for it. In this review we discuss and critically evaluate these hypotheses. One contributing factor to the decreases in tissue N concentrations clearly is dilution of N by increased photosynthetic assimilation of C. In addition, studies on intact plants show strong evidence for a general decrease in the specific uptake rates (uptake per unit mass or length of root) of N by roots under elevated CO2. This decreased root uptake appears likely to be the result both of decreased N demand by shoots and of decreased ability of the soil-root system to supply N. The best-supported mechanism for decreased N supply is a decrease in transpiration-driven mass flow of N in soils due to decreased stomatal conductance at elevated CO2, although some evidence suggests that altered root system architecture may also play a role. There is also limited evidence suggesting that under elevated CO2, plants may exhibit increased rates of N loss through volatilization and/or root exudation, further contributing to lowering tissue N concentrations.

Prolonged effect of intensive therapy on the risk of retinopathy complications in patients with type 1 diabetes mellitus: 10 years after the diabetes control and complications trial

Abstract: OBJECTIVE To examine the persistence of the original treatment effects 10 years after the Diabetes Control and Complications Trial (DCCT) in the follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study. In the DCCT, intensive therapy aimed at near-normal glycemia reduced the risk of microvascular complications of type 1 diabetes mellitus compared with conventional therapy. METHODS Retinopathy was evaluated by fundus photography in 1211 subjects at EDIC year 10. Further 3-step progression on the Early Treatment Diabetic Retinopathy Study scale from DCCT closeout was the primary outcome. RESULTS After 10 years of EDIC follow-up, there was no significant difference in mean glycated hemoglobin levels (8.07% vs 7.98%) between the original treatment groups. Nevertheless, compared with the former conventional treatment group, the former intensive group had significantly lower incidences from DCCT close of further retinopathy progression and proliferative retinopathy or worse (hazard reductions, 53%-56%; P < .001). The risk (hazard) reductions at 10 years of EDIC were attenuated compared with the 70% to 71% over the first 4 years of EDIC (P < .001). The persistent beneficial effects of former intensive therapy were largely explained by the difference in glycated hemoglobin levels during DCCT. CONCLUSION The persistent difference in diabetic retinopathy between former intensive and conventional therapy ("metabolic memory") continues for at least 10 years but may be waning. TRIAL REGISTRATION (clinicaltrials.gov) Identifiers: NCT00360815 and NCT00360893.

Discovery of Sodium in the Atmosphere of Mercury

Abstract: The spectrum of Mercury at the Fraunhofer sodium D lines shows strong emission features that are attributed to resonant scattering of sunlight from sodium vapor in the atmosphere of the planet. The total column abundance of sodium was estimated to be 8.1 x 10(11) atoms per square centimeter, which corresponds to a surface density at the subsolar point of about 1.5 x 10(5) atoms per cubic centimeter. The most abundant atmospheric species found by the Mariner 10 mission to Mercury was helium, with a surface density of 4.5 x 10(3) atoms per cubic centimeter. It now appears that sodium vapor is a major constituent of Mercury's atmosphere.