Afternoon T : Testosterone level is higher in red than yellow male polychromatic lizards

Recent work on within-species polymorphism across a broad range of taxa has renewed and considerably increased the attention to this classic evolutionary area, notably in lizard species where colors covary with reproductive strategies. We demonstrate elsewhere that red-headed males beat yellow-headed males in staged contests for females in the Australian painted dragon lizard Ctenophorus pictus. This morph difference in behaviour is linked to what appears to be a convention of red dominance in male–male interactions set very early in ontogeny, long before coloration has developed. In the current note, we investigate the relationship between time of day, which is directly linked to vigilance time in territorial males, and plasma levels of testosterone and corticosterone. We show that red males have higher testosterone levels in late afternoon following a day of territory patrolling and a non-significant trend in plasma corticosterone levels that decline with time of day. In conclusion, there are significant differences in testosterone profile between the two color morphs, providing a potential proximate link to the behavioural differences between them.

Assessment of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D3 concentrations in male and female multiple sclerosis patients and control volunteers

Populations with insufficient ultraviolet exposure and who consume diets low in vitamin D have low vitamin D status (plasma 25-hydroxyvitamin D (25(OH)D) concentrations) and a reported higher incidence of multiple sclerosis (MS). The active form of vitamin D, 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃), is an effective anti-inflammatory molecule. No research to date has assessed 1,25(OH)₂D₃ concentrations in individuals with MS. In this study, plasma concentrations of 25(OH)D, 1,25(OH)₂D ₃ and parathyroid hormone (PTH) were measured in 29 individuals with MS and 22 age- and sex-matched control volunteers. There were no significant differences in plasma PTH, 25(OH)D and 1,25(OH)₂D₃ concentrations between individuals with MS and control volunteers. Women with MS had significantly higher 25(OH)D and 1,25(OH)₂D₃ concentrations than men with MS (79.1 ±45.4 versus 50.2±15.3 nmol/L, P=0.019 and 103.8± 36.8 versus 70.4±28.7 pmol/L, P=0.019, respectively). There was a significant positive correlation between 25(OH)D and 1,25(OH)₂D ₃ concentrations in all subjects (r=0.564, P=0.000), but secondary analysis revealed that the correlation was driven by women with MS (r=0.677, P= 0.001). Significant sex differences in vitamin D metabolism were observed and were most marked in individuals with MS, suggesting that vitamin D requirements may differ between the sexes, as well as by underlying disease state.

Substrate utilization during exercise performed with and without glucose ingestion in female and male endurance trained athletes

Compared to males, females oxidize proportionately more fat and less carbohydrate during endurance exercise performed in the fasted state. This study was designed to test the hypothesis that there may also be gender differences in exogenous carbohydrate (CHOexo) oxidation during exercise. Healthy, young males (n = 7) and females (n = 7) each completed 2 exercise trials (90 min cycle ergometry at 60% VO[sub2peak]), 1 week apart. Females were eumenorrheic and were tested in the midfollicular phase of their menstrual cycle. Subjects drank intermittently either 8% CHOexo (1 g glucose ⋅ kg ⋅ h[sup-1]) enriched with U-13C glucose or an artificially sweetened placebo during the trial. Whole-body substrate oxidation was determined from PER, urinary urea excretion, and the ratio of 13C:12C in expired gas during the final 60 min of exercise. During the placebo trial, fat oxidation was higher in females than in males (0.42 ± 0.07 vs. 0.32 ± 0.09 g ⋅ min[sup-1] . kg LBM[sup-1] x 10[sup-2]) at 30 min of exercise (p < .05). When averaged over the final 60 min of exercise, the relative proportions of fat, total carbohydrate, and protein were similar between groups. During CHOexo ingestion, both the ratio of 13C: 12C in expired gas (p < .05) and the proportion of energy derived from CHOexo relative to LBM (p < .05) were higher in females compared to males at 75- and 90-min exercise. When averaged over the final 60 min of exercise, the percentage of CHOexo to the total energy contribution tended to be higher in females (14.3 + 1.2%) than in males (11.2 ± 1.2%; p = .09). The reduction in endogenous CHO oxidation with CHOexo intake was also greater in females (12.9 ± 3.1%) than in males (5.1 ± 2.0%; p = .05). Compared to males, females may oxidize a greater relative proportion of CHOexo during endurance exercise which, in turn, may spare more endogenous fuel. Based on these observations, ingested carbohydrate may be a particularly beneficial source of fuel during endurance exercise for females.

Developmental stress affects the attractiveness of male song and female choice in the zebra finch (Taeniopygia guttata)

Developmental stress has recently been shown to have adverse effects upon adult male song structure in birds, which may well act as an honest signal of male quality to discriminating females. However, it still remains to be shown if females can discriminate between the songs of stressed and non-stressed males. Here we use a novel experimental design using an active choice paradigm to investigate preferences in captive female zebra finches (Taeniopygia guttata). Nine females were exposed to ten pairs of songs by previously stressed and non-stressed birds that had learned their song from the same tutor. Song pairs differed significantly in terms of song complexity, with songs of stressed males exhibiting lower numbers of syllables and fewer different syllables in a phrase. Song rate and peak frequency did not differ between stressed and non-stressed males. Females showed a significant preference for non-stressed songs in terms of directed perching activity and time spent on perches. Our results therefore indicate that developmental stress affects not only the structure of male song, but that such structural differences are biologically relevant to female mate choice decisions.

An empirical study on the relationship between intellectual ability and an understanding of the legal process in male remand prisoners

Research conducted in Australia and around the world in the last decade has shown that people with significant intellectual impairments are over-represented in all areas of the criminal justice system. They are particularly over-represented in remand populations appearing before court. Previous research has suggested that as many as one-quarter of offenders facing sentencing in court have difficulty in understanding court procedures and it is suspected that a majority of these individuals suffer a significant intellectual impairment. The purpose of this study was to establish whether remandees with significant intellectual impairments (IQ < 70) have an accurate understanding of the court system. Seventy-four remand prisoners took part in the study. Remandees with an IQ of less than 70 demonstrated a significantly poorer understanding of the court system than those remandees with an IQ of 70 and above. The implications of these results are discussed in relation to the need for law reform and diversionary practices for this population of remandees.

Sentencing of male and female child sex offenders : Australian study

Research suggests that, in line with the chivalry hypothesis of female offending, a range of mitigatory factors such as mental health problems, substance abuse, and personal experiences of abuse are brought into play when women who offend against children are brought to trial. This is reflected in sentencing comments made by judges and in the sanctions imposed on the offenders, and as a result female offenders are treated differently to male offenders. The current study investigated this in an Australian context. Seven cases of female-perpetrated child sexual abuse were identified over a 6-year period through the Austlii database. Seven cases of male-perpetrated child sex abuse matched as far as possible to these were identified. Court transcripts were then located, and sentencing comments and sanctions imposed were analysed. All offenders were sentenced to imprisonment, but in general the women were more likely than the men to receive less jail time and lower non-parole periods because their personal backgrounds or situation at the time of the offending (i.e., difficulties with intimate relationship, male dependence issues, depression, loneliness and anger) were perceived as worthy of sympathy, and they were considered as likely to be rehabilitated. Further investigations are needed to support these findings.

Malaysian and Australian male and female middle managers : a cross-cultural comparison of workplace attitudes, aspirations for promotion, and self-rated leadership styles

This paper outlines the rise of women in management worldwide, and considers why so few women achieve senior or executive management positions. This slow advance of women into senior roles is unexpected given that the changes in organisations today are believed to require more ‘feminine leadership’. A decrease in the emphasis on masculine characteristics for managers is reported, and a requirement that more ‘feminine leadership’ needs to be adopted by organisations in order to ensure their survival in the future (Powell, Butterfield & Parent, 2002, p.189). Recent empirical research reports that there are differences in leadership style between male and female managers, and the findings suggest that women exhibit more transformational leadership than their male counterparts, with this style being strongly equated with effective leadership (Eagly, Johannesen-Schmidt, van Engen, 2003). However, these findings are based on western research, and it may be that cross cultural research will yield a different picture (House, Hanges, Javidan, Dorfman, & Gupta, 2004). Leadership and leadership styles may be conceptualised differently in a more paternalistic society. To explore this possibility, a cross cultural study was conducted in Malaysia and Australia. It is hypothesised that countries that are paternalistic in cultural values will exhibit a stronger constraint on women in management roles, which may impact on workplace attitudes, aspirations for promotion and style of leadership exhibited. Therefore, it is possible that the career advancement of women may be more problematic for Malaysian managerial women than their Australian counterparts. Results from an initial pilot study in Malaysia and Australia are outlined, and highlight some interesting similarities and differences to what are reported in the western literature.

The effects of repetitive loading on bone mass and geometry in young male tennis players : a quantative study using magnetic resonance imaging

Pre- and early puberty seem to be the most opportune times for exercise to  improve bone strength in girls, but few studies have addressed this issue in boys. This study investigated the site-, surface-, and maturity-specific exercise-induced changes in bone mass and geometry in young boys. The osteogenic effects of loading were analyzed by comparing the playing and nonplaying humeri of 43 male pre-, peri-, and postpubertal competitive tennis players 10-19 yr of age. Total bone area, medullary area, and cortical area were determined at the mid (40-50%) and distal humerus (60-70%) of both arms using MRI. Humeral bone mass (BMC) was derived from a whole body DXA scan. In prepubertal boys, BMC was 17% greater in the playing compared with nonplaying arm (p < 0.001), which was accompanied by a 12-21% greater cortical area, because of greater periosteal expansion than medullary expansion at the midhumerus and periosteal expansion associated with medullary contraction at the distal humerus. Compared with prepuberty, the side-to-side differences in BMC (27%) and cortical area (20-33%) were greater in peripuberty (p < 0.01). No differences were found between peri- and postpuberty despite longer playing history in the postpubertal players.The osteogenic response to loading was greater in peri- compared with prepubertal boys, which is in contrast with our previous findings in girls and may be caused by differences in training history. This suggests that the window of opportunity to improve bone mass and size through exercise may be longer in boys than in girls.

The assessment and management of common male sexual difficulties in family practice

Sexual problems are distressing for patients, and their doctors need to feel comfortable giving advice about and treating the more common conditions. Treatment of sexual problems can prevent much anxiety and the development of depression. This article outlines approaches useful in managing the more common male sexual difficulties encountered in family practice.