Waiting list dropouts in a university counseling center.

Surveyed 59 clients at a university counseling center who had been placed on a waiting list and subsequently decided not to renew their request for counseling. Ss were asked why they did not renew their request and whether they were still interested in counseling. Responses were analyzed in terms of type of problem, time on the waiting list, and degree of urgency. Most Ss did not report negative reactions or effects from their placement on the waiting list, although Ss in the highest urgency category tended to report that the wait was too long. 30 Ss stated that the intake interview was enough or that the problem had been resolved, while 23 were still interested in counseling. It is suggested that (1) high-urgency clients should be given priority at university counseling centers, (2) directive crisis-intervention approaches can be used to resolve issues at intake sessions, (3) assessment should identify clients whose motivation for counseling is related to developmental issues that need to be dealt with immediately, and (4) alternative treatments such as groups or workshops should be made available to waiting-list clients. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Kinetics of the methanogenic fermentation of acetate

The kinetics of methanogenesis from a stirred batch-fed calcium acetate enrichment culture have been studied. A detailed kinetic analysis of the culture allowed four distinct phases to be distinguished. Phase 1 was a period of very rapid increase (from low initial values) in the rate of methanogenesis upon addition of acetate, and was not thought to be associated with cell growth. In Phase 2 the rate of methanogenesis increased exponentially with time reflecting exponential growth. Phase 3 was characterised by an approximately constant rate of methane production, and is discussed in relation to the uncoupling of growth and methanogenesis. Phase 4 is a period of rapid decline associated with depletion of acetate. The apparent size of the population of the acetate-utilising methanogenic bacteria subsequently declined, with a specific decay constant of 0.4 ± 0.1 d^?1. The significance of these phases, in particular 2 and 3, for industrial anaerobic digestion is discussed.     

Interrelationships between ideologically important thiol,disulphide groups and yield—quality parameters of wheat cultivars (triticu aestivumm L.)

Experiments were conducted with 22 wheat cultivars (Triticum aestivum L.) from the 1976 season which showed the following: grain yields and rheologically important SS/SH ratios were negatively correlated (r= ?0.78). Rdeologically important SS/SH ratios were positively correlated with total flour protein percentages (r=0.61), residue flour protein percentages (r=0.62) and all better dough quality properties. Grain yields and total flour protein percentages were negatively correlated (r=?0.66). However, only the first relationship was statistically valid for 12 recurrent cultivars within the group of 22 which had been yield tested annually from 1971 to 1976, inclusive. Their long-term average yield data (1971–76) were more negatively correlated (r= ?0.87) with the 1976 SS/SH values than their 1976 yield data (r= ?0.78). It is considered that grain yield differences between the cultivars studied were inherently related to differences in their abilities to synthesise more rheologically important thiol groups than disulphide groups during plant growth and grain formation. The SS/SH ratio and grain yield relationship appears to be largely independent of seasonal influences and therefore should be of interest to wheat breeders trying to combine higher yield and better quality objectives in their programmes.     

Fully automated on-wafer noise characterization of GaAs MESFETs andHEMTs

A technique is described that permits the rapid determination of all four noise parameters of a MESFET or HEMT at wafer level. The fully automated procedure, which has been implemented in the 2-8 GHz range, uses 16 accurately measured, very repeatable source impedance standards. The standards have been selected for optimum coverage of the input impedance plane to result in stable and rapidly convergent least-squares solutions for the minimum noise figure, optimum source impedance, and noise resistance of practical devices. The resultant system is very stable and produces accurate noise parameters for a wide range of devices     

Achievement goals in the classroom: Students' learning strategies and motivation processes.

We studied how specific motivational processes are related to the salience of mastery and performance goals in actual classroom settings. One hundred seventy-six students attending a junior high/high school for academically advanced students were randomly selected from one of their classes and responded to a questionnaire on their perceptions of the classroom goal orientation, use of effective learning strategies, task choices, attitudes, and causal attributions. Students who perceived an emphasis on mastery goals in the classroom reported using more effective strategies, preferred challenging tasks, had a more positive attitude toward the class, and had a stronger belief that success follows from one's effort. Students who perceived performance goals as salient tended to focus on their ability, evaluating their ability negatively and attributing failure to lack of ability. The pattern and strength of the findings suggest that the classroom goal orientation may facilitate the maintenance of adaptive motivation patterns when mastery goals are salient and are adopted by students. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structure of the cyclin-dependent kinase inhibitor p19Ink4d

In cancer, the biochemical pathways that are dominated by the two tumour-suppressor proteins, p53 and Rb, are the most frequently disrupted. Cyclin D-dependent kinases phosphorylate Rb to control its activity and they are, in turn, specifically inhibited by the Ink4 family of cyclin-dependent kinase inhibitors (CDKIs) which cause arrest at the G1 phase of the cell cycle. Mutations in Rb, cyclin D1, its catalytic subunit Cdk4, and the CDKI p16Ink4a, which alter the protein or its level of expression, are all strongly implicated in cancer. This suggests that the Rb 'pathway' is of particular importance. Here we report the structure of the p19Ink4d protein, determined by NMR spectroscopy. The structure indicates that most mutations to the p16Ink4a gene, which result in loss of function, are due to incorrectly folded and/or insoluble proteins. We propose a model for the interaction of Ink4 proteins with D-type cyclin-Cdk4/6 complexes that might provide a basis for the design of therapeutics against cancer. The sequences of the Ink4 family of CDKIs are highly conserved     

Cost effectiveness of screening for primary open angle glaucoma

OBJECTIVES AND SETTING: To determine the cost effectiveness of screening for glaucoma. METHODS: Information on treatment efficacy, diagnostic methods, epidemiological characteristics of glaucoma, and costs were determined from the literature, from administrative databases, and from experts. Scenarios with different screening frequency, age, participation in screening, compliance with treatment, treatment efficacy, and diagnostic tests were examined. RESULTS: The initial scenario comprised three-yearly screening of subjects aged 40-79 by funduscopy and tonometry, followed by perimetry when abnormalities were discovered. The assumption of levels of participation in screening and of compliance with treatment of 75%, and treatment efficacy of 50% resulted in a cost of $C100,000 per year of blindness prevented. A scenario in which screening was restricted to subjects aged 65-79, with the same input variables, would prevent 81% of the cases of blindness prevented with scenario 1, at a cost of $C42,000 per year of blindness prevented. Screening with tonometry only as the initial diagnostic test in subjects aged 65-79 would result in a cost of $C36,000 per year of blindness prevented, but would only prevent 59% of the cases prevented with scenario 1. CONCLUSIONS: There is as yet no proof that treatment of glaucoma or of high intraocular pressure will arrest the progression of glaucoma to blindness. Even when treatment efficacy is assumed to be as high as 50%, however, the cost effectiveness of most glaucoma screening programmes considered would not be competitive.     

Growth method,composition, and defect structure dependence of mercury diffusion in CdxHg1–xTe

Mercury radiotracer diffusion results are presented, in the range 254 to 452°C, for bulk and epitaxial Cd_xHg_1–xTe, and we believe this to be the first report for metalorganic vapor phase epitaxy (MOVPE) grown Cd_xHg_1–xTe. For all growth types studied, with compositions of x_Cd=0.2±0.04, the variation of the lattice diffusion coefficient, D_Hg, with temperature, under saturated mercury partial pressure, obeyed the equation: D_Hg=3×10⁻³ exp(−1.2 eV/kT) cm² s⁻¹. It was found to have a strong composition dependence but was insensitive to changes of substrate material or crystal orientation. Autoradiography was used to show that mercury also exploited defect structure to diffuse rapidly from the surface. Dislocation diffusion analysis is used to model defect tails in MOVPE Cd_xHg_1–xTe profiles.