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Spatial aggregations of organisms are common in nature. Aggregations have often been thought to play important roles in mate-finding, predator avoidance, reduction of water loss, or the acquisition of food and other resources, yet few empirical studies have been done on the processes that lead to aggregation. We studied aggregations of the giant isopod Tylos granulatus, which lives as a scavenger in the intertidal zone of sandy beaches on the west coast of South Africa. Individuals emerge with the receding tide leaving exit holes, then forage for about two hours before returning to the vicinity of the high-water mark where they aggregate to bury themselves, leaving behind cone-shaped mounds. Our observations showed there was no correlation between aggregations and the availability of food, and that manipulating the position of food had no effect on the aggregations. Reproduction, which is seasonal and synchronous, also seems unlikely to explain the year-round aggregations. Experiments showed T. granulatus preferentially burrows in existing holes or mounds rather than creating new ones. The advantages of this are analysed in terms of energy conservation, and as a means of reducing risks of exposure to predators or being swept away by the incoming tide. Whatever the benefit, the preferential use of existing holes can incidentally lead to aggregation, which may not itself have any adaptive function. [ABSTRACT FROM AUTHOR]

Background: Sexual assault in South Africa has reached alarming proportions. Mental illness amongst offenders accused of rape is one of the complicating factors., Aim: To describe the sociodemographic, clinical and forensic profile of alleged offenders accused of rape referred to a South African tertiary public psychiatric hospital for forensic evaluation, as well as describe the profile of the reported victims., Setting: Free State Psychiatric Complex (FSPC) Observation Ward, Bloemfontein, South Africa., Methods: This cross-sectional retrospective study compiled a sociodemographic, clinical and forensic profile of offenders accused of rape referred to the FSPC for forensic assessment between 2011 and 2015. The study population comprised 159 alleged offenders. Sociodemographic data, mental status, clinical diagnoses, comorbid substance use and forensic outcomes were collected from clinical files., Results: All accused offenders were male with a median age of 30 years. About half obtained primary school level education. Unemployment was common (37.3%) with 40% receiving government grants. Most accused offenders were single (78.0%). Clinically, schizophrenia spectrum and other psychotic disorders were the most common diagnoses (30.8%), followed by intellectual disability (16.3%). Almost a third of the accused offenders did not suffer from any mental illness. Alcohol (20.1%) and cannabis use disorders (12.6%) were dominant comorbidities. After a 30-day evaluation period, 53.2% of alleged offenders were found competent to stand trial. The verdict of criminal responsibility was made for 43.7% of this sample., Conclusion: This study contributes data on sociodemographics, psychiatric morbidities and comorbidities and forensic findings amongst alleged offenders of rape referred for forensic assessment., Competing Interests: The authors declare that they have no financial or personal relationships that may have inappropriately influenced them in writing this article., (© 2022. The Authors.)

The increasing prevalence of diseases such as AIDS and hepatitis B makes safe surgical techniques more important than ever before. Intact surgical gloves act as a barrier against these infections and a study was therefore done to determine the incidence of surgical glove perforation during obstetric and gynaecological surgical procedures. Surgical gloves were collected and tested for perforations following 353 consecutive obstetric and gynaecological operations. Forty pairs of new unused surgical gloves were tested for perforations in the same way. Whereas none of the 40 control pairs of gloves was found to be perforated, 22%-24% of used gloves were perforated. The experience of the surgeon had no influence on the incidence of glove perforation (P = 0.997; chi 2-test). Left-hand gloves were more frequently perforated than right-hand gloves, but this difference was not statistically significant (P = 0.075: chi 2-test). These findings must be a source of concern to all those practising obstetrics and gynaecology and measures are therefore suggested to decrease the risk of HIV or hepatitis B transmission during operations.

Males of Euphydryas editha (Lepidoptera: Nymphalidae) need their antennae to mate successfully, but females do not. Antennal structure was investigated in the hope of explaining this functional dimorphism, which is opposite to that in other butterflies (e.g., Myers, '68; Grula and Taylor, '80). No external differences between the sexes were observed with electron microscopy. There are four types of antennal sensilla: the spine, which acts mainly as a mechanoreceptor, shallow dish hairs and hidden hairs, which are chemoreceptors, and a whiplike sensillum of uncertain function. The internal morphology of male and female antennae differs in several respects which may relate to functional differences. The mating systems of butterflies are discussed briefly to explain our results and those of others., (Copyright © 1985 Wiley-Liss, Inc.)

Iridoid glycosides were found to be sequestered by natural populations ofEuphydryas anicia after ingestion from the host plantsBesseya alpina, B. plantaginea, andCastilleja integra. Both major iridoids ofB. alpina, cataipol and aucubin, were found in butterfly populations where this was the only host plant. The catalpol-aucubin ratio was higher in the butterflies than in the host plant. AnE. anicia population which uses bothB. plantaginea andC. integra as host plants was found to sequester cataipol as well as another iridoid, macfadienoside. Macfadienoside was the major iridoid ofC. integra, while catalpol esters were the major iridoids ofB. plantaginea. Although it was a major sequestered iridoid, catalpol was a minor constituent in both host plants. The macfadienoside-catalpol ratio in the butterflies from this population was highly variable, and there appeared to be both sex and individual variation in host plant and/or iridoid glucoside utilization byE. anicia. Although other iridoids were present in the host plants, none was sequestered in more than trace amounts.