On the "remembrance of things past": A longitudinal evaluation of the retrospective method.

Examined the extent of agreement between retrospective and prospective measures of variables in 7 different content domains: residence changes, anthropometrics, injuries, reading ability, family characteristics, behavior problems, and delinquency. Retrospective reports using data from a large sample of 18-yr-old youth who have been studied prospectively since their births were evaluated. The findings suggest that (1) psychosocial variables (e.g., reports about subjective psychological states and family processes) revealed the lowest level of agreement between prospective and retrospective measures and (2) even when retrospective reports correlated significantly with prospective data, the absolute level of agreement between the 2 data sources was quite poor. It appears that reliance on retrospective reports about psychosocial variables should be approached with caution. Moreover, it is suggested that the use of retrospective reports should be limited to testing hypotheses about the relative standing of individuals in a distribution and should not be used to test hypotheses that demand precision in estimating event frequencies and event dates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibition and habituation: Preserved mechanisms of attentional selection in aging and Alzheimer's disease.

Are inhibition and habituation, processes that contribute to selective attention, impaired by aging or Alzheimer's disease (AD)? Younger adults, older adults, and adults with AD read lists of letters presented either alone or paired with distractor letters. Slower reading times for lists containing distractors relative to lists without distractors indexed concurrent interference (distraction). Slower rending times for lists in which distractors subsequently became targets relative to lists in which distractors and targets were unrelated indexed negative priming (inhibition). Faster reading times when distractors were constant in identity or location rather than random indexed repeated distractor effects (habituation). Distraction increased with aging and AD, whereas inhibition and habituation showed no age- or AD-related decline, suggesting that inhibition and habituation still function to aid attentional selection in older adults and adults with AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of external optical feedback on timing jitter in modulated laser diodes

Laser diodes with optical feedback are numerically modeled using single-mode rate equations. The effects of the optical feedback on the pulse turn-on delay and timing jitter are examined, for gain-switching, periodic and pseudorandom modulation formats. It is shown that there is a change in turn-on delay and a considerable increase in the timing jitter due to the changes in the output power distributions as optical feedback increases. The cause of the increased jitter is found to be the additional intensity noise introduced by the optical feedback.<>     

A novel thermoresponsive hydrogel matrix based on poly(N-ethoxypropylacrylamide)

Summary A new temperature sensitive hydrogel matrix, poly(N-ethoxypropylacrylamide), PNEPAM, was obtained by the bulk polymerization of N-ethoxypropylacrylamide (NEPAM). The monomer, NEPAM was synthesized by the nucleophilic substitution reaction of 3-ethoxypropylamine and acryloyl chloride. The polymerization was performed at +4 °C, by using N,N-methylenebisacrylamide (MBAM) as crosslinker, polyethyleneglycol (PEG) 4000 as diluent, and potassium persulfate (KPS) and tetramethylethylenediamine (TEMED) as the initiator and accelerator, respectively. PNEPAM gel matrices exhibited a thermosensitive bahaviour reasonably similar to poly(N-isopropylacrylamide), PNIPAM gels. The equilibrium swelling ratio at constant temperature increased with increasing initiator concentration and decreasing monomer concentration. The use of PEG 4000 as a diluent in the gel synthesis resulted in a significant enhacement in the thermosensitivity of gel matrix. The equilibrium swelling ratios up to 60 g water/g dry gel were observed in the low-temperature region. The results indicated that PNEPAM gel is a new alternative thermosensitive material to the NIPAM based gels.     

Teaching medical faculty how to apply continuous quality improvement to medical education

BACKGROUND: An eight-hour workshop was conducted at a professional meeting in 1996 to introduce medical faculty to the principles of continuous quality improvement (CQI) as they relate to change in medical education and to provide participants with opportunities to use specific tools for applications to education. Four two-hour sessions focused on an introduction to CQI, understanding and mapping processes, identifying change ideas, and testing a change for improvement. TESTING A CHANGE FOR IMPROVEMENT: The goals of the final session were to plan a pilot test of an improvement, identify the steps of the plan-do-study-act (PDSA) cycle, and consider change for improvement in the context of one's own organization. Working in small groups, participants chose a specific change one might try in the following example: improving student performance in a neuroscience course. POSTSESSION EVALUATION AND FOLLOW-UP: Immediately following the workshop sessions, participants represented by administrators in medical education and clinical and basic science teaching faculty completed evaluations on the usefulness and likelihood of their using CQI tools. One year later, of the 32 workshop registrants who were mailed surveys, 15 respondents rated their change in understanding of CQI and their use of CQI techniques. More than 60% of the respondents reported application of CQI principles at their organizations. CQI methods used most frequently included structured team meetings, prioritizing opportunities, and brainstorming. CONCLUSION: The significant application of CQI principles and methods reported by participants one year after a brief intervention supports a need and utility for CQI principles and tools in medical education.     

Personal and peers' word associations in relation to children's false recognition errors.

Attempted to show that false recognition errors would be more frequently elicited by children's personal associates to a set of target words than by associates based on peer norms; Ss were 80 White middle-class 2nd and 5th graders (mean ages, 7.6 and 10.6 yrs, respectively). In Session 1 Ss gave oral associations to 34 words. In the 1st phase of Session 2, target words were each read aloud once and Ss were required to memorize them; in the 2nd phase Ss worked for 5 min on a maze task to prevent rehearsal; and in the final phase, a 40-item recognition list was read. Ss determined whether a word was one they had been asked to remember. As predicted, responses occurred with decreasing frequency to target, personal, peer, and control words. Consistent with the expectation that personal associates would more frequently elicit false recognition errors than would peer associates, the difference between personal and control responses was larger than the difference between peer and control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Study of V-Be diffusion couple by ion backscattering

Ion backscattering has been used to study the diffusion couple V-Be at annealing temperatures in the range 800 to 1100 K. Analysis of proton and helium backscattering allowed determination of the average composition versus depth following in situ isothermal anneals of thin vapor-deposited vanadium films on beryllium substrates. The results were interpreted as an initial diffusion governed by grain boundary migration of the beryllium through the vanadium to form a beryllium oxide surface layer. Vanadium was found to be excluded from the beryllium oxide surface layer and also from the native oxide on the beryllium substrate. The initial rapid diffusion along grain boundaries was followed by a slower diffusion into the vanadium grains. The amount of beryllium which diffused into the vanadium film obeyed a $\text{t}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ dependence where t is the anneal time. Complete anneal sequences were taken at two temperatures and a tentative activation energy for the diffusion of beryllium in bulk vanadium of 3.4 eV was determined. The diffusion coefficient was estimated to be 1.0 × 10^?17cm²/sec at 958 K and 0.8 × 10^?18cm²/sec at 903 K.