98 research outputs found
Mating skew in Barbary macaque males: the role of female mating synchrony, female behavior, and male–male coalitions
A fundamental question of sexual selection theory concerns the causes and consequences of reproductive skew among males. The priority of access (PoA) model (Altmann, Ann NY Acad Sci 102:338–435, 1962) has been the most influential framework in primates living in permanent, mixed-sex groups, but to date it has only been tested with the appropriate data on female synchrony in a handful of species. In this paper, we used mating data from one large semi-free ranging group of Barbary macaques: (1) to provide the first test of the priority-of-access model in this species, using mating data from 11 sexually active females (including six females that were implanted with a hormonal contraceptive but who showed levels of sexual activity comparable to those of naturally cycling females) and (2) to determine the proximate mechanism(s) underlying male mating skew. Our results show that the fit of the observed distribution of matings with sexually attractive females to predictions of the PoA model was poor, with lower-ranking males mating more than expected. While our work confirms that female mating synchrony sets an upper limit to monopolization by high-ranking individuals, other factors are also important. Coalitionary activity was the main tactic used by males to lower mating skew in the study group. Coalitions were expressed in a strongly age-related fashion and allowed subordinate, post-prime males to increase their mating success by targeting more dominant, prime males. Conversely, females, while mating promiscuously with several males during a given mating cycle, were more likely to initiate their consortships with prime males, thus reducing the overall effectiveness of coalitions. We conclude that high-ranking Barbary macaque males have a limited ability to monopolize mating access, leading to a modest mating skew among them
Factors influencing nurses' compliance with Standard Precautions in order to avoid occupational exposure to microorganisms: A focus group study
<p>Abstract</p> <p>Background</p> <p>Nurses may acquire an infection during the provision of nursing care because of occupational exposure to microorganisms. Relevant literature reports that, compliance with Standard Precautions (a set of guidelines that can protect health care professionals from being exposed to microorganisms) is low among nurses. Additionally, high rates of exposure to microorganisms among nurses via several modes (needlesticks, hand contamination with blood, exposure to air-transmitted microorganisms) occur. The aim of the study was to study the factors that influence nurses' compliance with Standard Precaution in order to avoid occupational exposure to pathogens, by employing a qualitative research design.</p> <p>Method</p> <p>A focus group approach was used to explore the issue under study. Four focus groups (N = 30) were organised to elicit nurses' perception of the factors that influence their compliance with Standard Precautions. The Health Belief Model (HBM) was used as the theoretical framework and the data were analysed according to predetermined criteria.</p> <p>Results</p> <p>Following content analysis, factors that influence nurses' compliance emerged. Most factors could be applied to one of the main domains of the HBM: benefits, barriers, severity, susceptibility, cues to action, and self-efficacy.</p> <p>Conclusions</p> <p>Changing current behavior requires knowledge of the factors that may influence nurses' compliance with Standard Precautions. This knowledge will facilitate in the implementation of programs and preventive actions that contribute in avoiding of occupational exposure.</p
Testing the priority-of-access model in a seasonally breeding primate species
In mammals, when females are clumped in space, male access to receptive females is usually determined by a dominance hierarchy based on fighting ability. In polygynandrous primates, as opposed to most mammalian species, the strength of the relationship between male social status and reproductive success varies greatly. It has been proposed that the degree to which paternity is determined by male rank decreases with increasing female reproductive synchrony. The priority-of-access model (PoA) predicts male reproductive success based on female synchrony and male dominance rank. To date, most tests of the PoA using paternity data involved nonseasonally breeding species. Here, we examine whether the PoA explains the relatively low reproductive skew in relation to dominance rank reported in the rhesus macaque, a strictly seasonal species. We collected behavioral, genetic, and hormonal data on one group of the free-ranging population on Cayo Santiago (Puerto Rico) for 2 years. The PoA correctly predicted the steepness of male reproductive skew, but not its relationship to male dominance: the most successful sire, fathering one third of the infants, was high but not top ranking. In contrast, mating success was not significantly skewed, suggesting that other mechanisms than social status contributed to male reproductive success. Dominance may be less important for paternity in rhesus macaques than in other primate species because it is reached through queuing rather than contest, leading to alpha males not necessarily being the strongest or most attractive male. More work is needed to fully elucidate the mechanisms determining paternity in rhesus macaques
Effects of specimen shape and size on water loss and drying shrinkage of cement-based materials
Post-tonsillectomy infiltration with bupivacaine reduces immediate postoperative pain in children
Exploring Women’s Beliefs and Perceptions About Healthy Eating Blogs: A Qualitative Study
Hiding under the skin: Interleukin-17-producing γδ T cells go under the skin?
Despite the irrefutable role of inflammation in psoriasis, a complete knowledge of what immune cells and cytokines are involved during initiation and progression of this skin disease is lacking. Moreover, the complexities of the immune cell network and potential differences between mice and humans have led to translational failures. It is therefore important that we acquire in-depth understanding of what inflammatory players, of the many involved, are crucial, if we wish to develop effective therapies. In 'Bedside to Bench', James Krueger discusses how a subset of T cells, TH17 cells, which release interleukin-17 in humans, seem to be essential for pathogenesis of psoriasis. The interplay between interleukin-17 and other cytokines that may potentially be involved in psoriasis also needs further investigation. Additionally, there are open questions as to what subset of T cells, other than TH17, also produce interleukin-17 and when. In 'Bench to Bedside', Burkhard Becher and Stanislav Pantelyushin examine this issue by looking at a mouse model of skin inflammation that resembles psoriasis in humans. A class of skin-invading innate immune cells called γδ T cells was shown to drive skin inflammation in this model, particularly during the early stages of the disease, suggesting that innate immunity plays an important part in the initiation of psoriasis
Respiratory Motion Reduction in PET/CT Using Abdominal Compression for Lung Cancer Patients
Early-age tensile creep and shrinkage-induced cracking in internally restrained concrete members
- …