Refractive temperature

Refraction tables used in navigation and surveying are almost all derived from those of Bessel, whose computations, based on English star observations, assume that atmospheric temperature decreases with height at the rate of about 0.6 F.° per 1,000 ft. Neither this assumption nor that of any subsequent investigator is entirely in accord with present-day knowledge of atmospheric structure, which generally has a temperature decrease of around 3 F.° per 1,000 ft. to the tropopause, with widely varying conditions above it. The Bessel tables in general use cannot be extrapolated for surface air temperatures much different from 50° F.; in particular, for extreme cold conditions it is desirable to use, in place of the actual air temperature, the refractive temperature, which is that temperature for which the refraction correction given in the tables equals the correction which is actually required, and which may be estimated from general climatic considerations.     

Maternal representations of the infant: associations with infant response to the still face

Mothers' representations of their infants may influence early development of emotional self-regulation. This study examined the associations between characteristics of mothers' (N = 100) narratives about their 7-month-old infants, maternal depression, and their infants' affect regulation during the Still Face procedure. Findings showed that (1) mothers' representations were linked with individual differences in their infants' behavior across the Still Face procedure, (2) the association between mothers' representations and their infants' behavior was mediated by parenting behavior, and (3) mothers' representations explained unique variance in their infants' affect regulation beyond the contribution of maternal depression. Although infants' displays of positive affect diminished while mothers held a still face, only infants of mothers in the balanced representation category returned to high levels of positive affect upon resuming interaction. These findings highlight the role of maternal representations in the process by which dyads repair temporary disruptions in interaction, as well as individual differences in infants' and mothers' responses to the Still Face.     

Disabled and successful: education in the life stories of disabled high achievers

There has been much debate concerning the pros and cons of special and mainstream education for young people with a disability. This paper adds data to this debate by reporting the educational experiences of 20 high-achievers with congenital disabilities who live in the United Kingdom and were born between 1950 and 1970. It presents personal accounts of the high-achievers' perceptions of how their education, which was either purely in special schools, in mainstream schools or a combination of both, had influenced their transition to adulthood. While those who attended special school considered it to provide a supportive environment that permitted the cultivation of their personalities without the constraints of non-disabled barriers, many others thought it prevented them as disabled children from interacting with non-disabled peers, thus inhibiting social integration between the disabled and non-disabled world. This was the main perceived advantage of mainstream education although problems of physical access meant that some choices were out of reach. The findings highlight how both special and mainstream education can be compatible with career success of individual disabled people. The paper implies that a combination of the two systems may be needed to facilitate disabled students to develop psychologically, socially and cognitively at the rate of their non-disabled peers, and proposes that link schools and partial integration could contribute to the achievement of such goals.     

Effects of violent and non-violent computer game content on memory performance in adolescents

The present study focuses on the short-term effects of electronic entertainment media on memory and learning processes. It compares the effects of violent versus non-violent computer game content in a condition of playing and in another condition of watching the same game. The participants consisted of 83 female and 94 male adolescents with a mean age of 17.6 years. The dependent variables are memory for previously learnt verbal and visual material, memory for media-related content and physiological measures of stress (heart rate, cortisol, salivary alpha-amylase). Besides the group comparisons, potential mediation effects and gender differences were examined. The results show that violent content leads to a poorer memory performance for verbal material and to an increased heart rate. The heart rate, however, does not mediate the effect on memory performance. Genders differ regarding their abilities to memorise verbal and visual material, with females showing a better performance (independent of the experimental condition), and for memorising media-contents, where the males outperform females (also independent of experimental condition). The study supports the assumption that violent and arousing media content has a negative short-term effect on simultaneous information processing and learning and that there are gender-specific media effects.     

The Impact of Gender,Accommodations, and Disability on the Academic Performance of Canadian University Students with LD and/or ADHD

Academic accommodations for students experiencing disabilities are increasingly available at postsecondary institutions. More studies of the efficacy of accommodations for student success are warranted, however. Given the increased gender gap in university participation, more focus on the unique impact of gender is also needed. Using a sample of students registered with Access and Inclusion Services with learning disabilities (LD), attention-deficit/hyperactivity disorder (ADHD), and combined LD/ADHD at a Canadian undergraduate university (N = 661), we explored the impact of gender on academic performance and accommodation usage. Next, we examined how gender intersected with the impact of academic accommodations on academic performance. Women, on average, demonstrated better academic performance. Academic strategies and assistive technologies were not associated with higher academic performance. However, testing accommodations (extended time and environmental accommodations) were positively associated with academic performance for men with LD or ADHD, but not for the combined group LD/ADHD. For the former two, the more tests accommodated, the higher the academic performance. Furthermore, this gender association was most prominent for students experiencing ADHD. Interpretations and policy recommendations related to these findings are presented.     

制度的基石、保障与功能——中美大学生实习比较及对就业的启示

在中国大学生就业竞争和就业压力日益增大的背景下,实习似乎正在成为大学生增强就业资本的一个必然选择。美国大学本科生参加与专业学习相关的实践工作已经有百余年的历史,美国大学关于实习的理念、制度与实践在不断地完善和创新。本文旨在通过深入介绍美国大学实习制度的价值观念、制度设计、组织实践、成效测量等趋势以及目前存在的问题和挑战,为我国大学实习问题的研究、政策制定提供借鉴资料。     

Do examinations influence student evaluations?

This paper measures the impact of timing on student evaluations of teaching effectiveness, using a dataset of close to 3000 observations from Erasmus School of Economics. A special feature of the data is that students were able to complete on-line questionnaires during a time window ranging from one week before to one week after the final examination. This allows for the isolation of the effect of the examination on student evaluations. Among students who subsequently pass the exam, we find little difference between pre- and post-exam ratings. Among students who fail, evaluation scores are significantly lower after the exam on a number of items. Our evidence is compatible with a self-serving bias in student evaluations, but does not indicate that students seek revenge on instructors through lower ratings.