Using digital images of the zebra finch song system as a tool to teach organizational effects of steroid hormones: a free downloadable module

Zebra finch song behavior is sexually dimorphic: males sing and females do not. The neural system underlying this behavior is sexually dimorphic, and this sex difference is easy to quantify. During development, the zebra finch song system can be altered by steroid hormones, specifically estradiol, which actually masculinizes it. Because of the ease of quantification and experimental manipulation, the zebra finch song system has great potential for use in undergraduate labs. Unfortunately, the underlying costs prohibit use of this system in undergraduate labs. Further, the time required to perform a developmental study renders such undertakings unrealistic within a single academic term. We have overcome these barriers by creating digital tools, including an image library of song nuclei from zebra finch brains. Students using this library replicate and extend a published experiment examining the dose of estradiol required to masculinize the female zebra finch brain. We have used this library for several terms, and students not only obtain significant experimental results but also make gains in understanding content, experimental controls, and inferential statistics (analysis of variance and post hoc tests). We have provided free access to these digital tools at the following website: http://mdcune.psych.ucla.edu/modules/birdsong.     

Why do high jumpers use a curved approach?

Currently, all elite high jumpers use the Fosbury Flop technique with a curved approach. This suggests that the curved approach presents some clear advantage, although there is no general agreement upon the mechanism or the mechanics. This study aimed to determine the characteristics of the approach curve and to investigate how it contributes to the generation of somersault rotation. A simple theoretical model was used to demonstrate that a tightening approach curve would change the inward lean towards the centre of the curve into outwards lean. Three-dimensional video analysis was used to record the performances of two elite male high jumpers in competition. It was found that in each case the radius of the approach curve and the inward lean angle both decreased towards the end of the approach. The amount of outward lean angular velocity generated was shown to be a major proportion of the required somersault angular velocity for a jump. It was concluded that the main advantage of a curved approach was that it resulted in the generation of somersault velocity providing the curve tightened towards the end of the approach.     

Sleep restriction and degraded reaction-time performance in Figaro solo sailing races

Abstract

In solo offshore sailing races like those of the Solitaire du Figaro, sleep must be obtained in multiple short bouts to maintain competitive performance and safety. Little is known about the amount of sleep restriction experienced at sea and the effects that fatigue from sleep loss have on sailors’ performance. Therefore, we assessed sleep in sailors of yachts in the Figaro 2 Beneteau class during races and compared response times on a serial simple reaction-time test before and after races. Twelve men (professional sailors) recorded their sleep and measured their response times during one of the three single-handed races of 150, 300 and 350 nautical miles (nominally 24–50 h in duration). Total estimated sleep duration at sea indicated considerable sleep insufficiency. Response times were slower after races than before. The results suggest that professional sailors incur severe sleep loss and demonstrate marked performance impairment when competing in one- to two-day solo sailing races. Competitive performance could be improved by actively managing sleep during solo offshore sailing races.     

Studying the Use of Peer Learning in the Introductory Computer Science Curriculum

This paper reports the results of studying the use of peer learning in the introductory computer science curriculum. The project involves educators from a variety of institutions who participated in two summer workshops and either introduced or continued their use of peer learning at their institutions as part of this project. The results of the collective work include much experience with different types of peer learning in different settings. Overall, the results indicate that peer learning is a valuable technique that should be used as one pedagogical approach in teaching the introductory computer science curriculum.     

When will a child be believed? The impact of the victim's age and juror's gender on children's credibility and verdict in a sexual-abuse case

OBJECTIVE: To provide insight into the central dimensions jurors may use when deciding a child victim's credibility and verdict. METHOD: Participants (N = 573) read a simulated trial (robbery or a sexual-assault case in which the defendant was either a stranger or an acquaintance) in which the alleged victim was either a 6- or 13-year-old girl. The trials were constructed to be as similar as possible with only minimal differences in the child's testimony. The supporting evidence was held constant across cases to allow for experimental assessment of the hypotheses. RESULTS: The defendant was more likely to be found guilty in the sexual-assault cases than in the robbery case. The child was perceived to be more credible, honest, and to have a better memory in the sexual-assault cases compared to the robbery case. Perceptions of memory and honesty predicted verdict and punishment. The child's age did not impact credibility or verdict. Finally, women, compared to men, perceived the child as more credible. CONCLUSIONS: Type of case was a potent factor in jurors' determination of guilt and the child's credibility. Contrary to expectations, neither the victim's age nor the interaction between this and type of case impacted verdict or credibility measures.