Short-term resource allocation during extensive athletic competition

© 2017 The Authors. American Journal of Human Biology Published by Wiley Periodicals, Inc. Objectives: Following predictions from life history theory, we sought to identify acute trade-offs between reproductive effort (as measured by psychological arousal) and somatic maintenance (via functional measures of innate immunity) during conditions of severe energetic imbalance. Methods: Sixty-six male ultramarathon runners (ages 20 to 37 years) were sampled before and after a lengthy race. Saliva and sera were collected for testosterone and immunological analyses (hemolytic complement activity and bacterial killing ability). Lean body mass was assessed by bioelectrical impedance, and libido was measured using a slideshow of arousing and neutral images. Results: Following predictions, there was a significant decrease in salivary testosterone levels (109.59 pg/mL versus 97.61 pg/mL, P <.001) and arousal scores in response to provocative images (5.40 versus 4.89, P =.001) between prerace and postrace time points. Additionally, participant bacterial killing ability (P =.035) and hemolytic complement activity (P =.021) increased between prerace and postrace. Conclusions: Decreased libido and testosterone with concomitant heightened innate immune responses suggest a shift in energetic priorities away from reproduction and toward maintenance/defense during a period of energetic stress

Ape Conservation Physiology: Fecal Glucocorticoid Responses in Wild Pongo pygmaeus morio following Human Visitation

Nature-based tourism can generate important revenue to support conservation of biodiversity. However, constant exposure to tourists and subsequent chronic activation of stress responses can produce pathological effects, including impaired cognition, growth, reproduction, and immunity in the same animals we are interested in protecting. Utilizing fecal samples (N = 53) from 2 wild habituated orangutans (Pongo pygmaeus morio) (in addition to 26 fecal samples from 4 wild unhabituated orangutans) in the Lower Kinabatangan Wildlife Sanctuary of Sabah, Malaysian Borneo, we predicted that i) fecal glucocorticoid metabolite concentrations would be elevated on the day after tourist visitation (indicative of normal stress response to exposure to tourists on the previous day) compared to samples taken before or during tourist visitation in wild, habituated orangutans, and ii) that samples collected from habituated animals would have lower fecal glucocorticoid metabolites than unhabituated animals not used for tourism. Among the habituated animals used for tourism, fecal glucocorticoid metabolite levels were significantly elevated in samples collected the day after tourist visitation (indicative of elevated cortisol production on the previous day during tourist visitation). Fecal glucocorticoid metabolite levels were also lower in the habituated animals compared to their age-matched unhabituated counterparts. We conclude that the habituated animals used for this singular ecotourism project are not chronically stressed, unlike other species/populations with documented permanent alterations in stress responses. Animal temperament, species, the presence of coping/escape mechanisms, social confounders, and variation in amount of tourism may explain differences among previous experiments. Acute alterations in glucocorticoid measures in wildlife exposed to tourism must be interpreted conservatively. While permanently altered stress responses can be detrimental, preliminary results in these wild habituated orangutans suggest that low levels of predictable disturbance can likely result in low physiological impact on these animals

Urinary C-Peptide Measurement as a Marker of Nutritional Status in Macaques

Studies of the nutritional status of wild animals are important in a wide range of research areas such as ecology, behavioural ecology and reproductive biology. However, they have so far been strongly limited by the indirect nature of the available non-invasive tools for the measurement of individual energetic status. The measurement of urinary C-peptide (UCP), which in humans and great apes shows a close link to individual nutritional status, may be a more direct, non-invasive tool for such studies in other primates as well and possibly even in non-primate mammals. Here, we test the suitability of UCPs as markers of nutritional status in non-hominid primates, investigating relationships between UCPs and body-mass-index (BMI), skinfold fatness, and plasma C-peptide levels in captive and free-ranging macaques. We also conducted a food reduction experiment, with daily monitoring of body weight and UCP levels. UCP levels showed significant positive correlations with BMI and skinfold fatness in both captive and free-ranging animals and with plasma C-peptide levels in captive ones. In the feeding experiment, UCP levels were positively correlated with changes in body mass and were significantly lower during food reduction than during re-feeding and the pre-experimental control condition. We conclude that UCPs may be used as reliable biomarkers of body condition and nutritional status in studies of free-ranging catarrhines. Our results open exciting opportunities for energetic studies on free-ranging primates and possibly also other mammals

Human evolutionary biology/ Edit.: Michael P. Muehlenbein

624 hal.: ill, tab.; 27 cm

Variation in human growth patterns due to environmental factors

The full-text of this book chapter is not available in ORA. Citation: Ulijaszek, S. J. (2010) Variation in human growth patterns due to environmental factors. In: Muehlenbein, M. P. (ed.) Human evolutionary biology. Cambridge: Cambridge University Press, pp. 396-404

Evolution of neuroendocrine mechanisms linking attachment and life history: The social neuroendocrinology of middle childhood

AbstractAn extended period of childhood and juvenility is a distinctive aspect of human life history. This stage appears to be important for learning cultural, social, and ecological skills that help prepare the child for the adult socio-competitive environment. The unusual pattern of adrenarche in humans (and chimpanzees) may facilitate adaptive modification of the neurobiological mechanisms that underpin reproductive strategies. Longitudinal monitoring of DHEA/S in naturalistic context could provide important new insights into these aspects of child development.</jats:p

The roles of cats and dogs in the transmission of Toxoplasma infection in Kuna and Embera children in eastern Panama El papel de los perros y gatos en la transmisión de la infección por Toxoplasma en niños kunas y emberas del este de Panamá

OBJECTIVE: To examine the relationship between antibody status and various hypothesized risk factors for Toxoplasma gondiiinfection among two different Amerindian populations in eastern Panama. Following up on earlier research that we conducted, we now explore the role of dogs in the natural transmission of Toxoplasma,the role that dogs play in promoting transmission, the interactive effect of cats and dogs, and the accessibility of infective material to children. METHODS: In 1991, 10 Panamanian medical students conducted interviews and took blood samples from 760 Kuna and Embera children aged 2 through 12 years in the Upper Bayano River Basin and the San Blas Islands. Serologic assays were performed using direct agglutination. The data analyses in the 1990s included univariate, bivariate, and multivariate analyses, without regard to data on dogs. Further bivariate and multivariate analyses were performed in 2003 to examine the contribution of dogs. RESULTS: In communities with high Toxoplasmaantibody prevalence in children, logistic regression suggested that the factors predictive of antibody presence were: compacted soil floors of huts (P= 0.001), having a dog (P= 0.038), and the interviewer seeing a cat in the house (P= 0.049). Our results suggest that the villagers' dogs play a significant role in facilitating the transmission of Toxoplasma gondiito humans, most often in the presence of cats in the houses, and only in those communities with higher Toxoplasmas eroprevalence in children. CONCLUSIONS: Dogs may act as mechanical vectors, by rolling in foul-smelling substances and by ingesting fecal material. In areas of high Toxoplasma prevalence in children and where dogs and cats are plentiful, immunocompromised individuals and pregnant women should be warned of the possibility of acquiring Toxoplasma gondii from dogs as well as from soil contaminated by cats. People should be encouraged to wash their hands after contact with soil, dogs, or cats as well as before eating.<br>OBJETIVO: Examinar la relación entre la presencia o ausencia de anticuerpos y los diversos factores de riesgo hipotéticos asociados con la infección por Toxoplasma gondii en dos poblaciones amerindias diferentes del este de Panamá. Como secuela a una investigación preliminar, en este trabajo se explora el papel de los perros en la transmisión natural de Toxoplasma y en la facilitación de la transmisión, así como el efecto interactivo de los perros y gatos y el acceso de los niños a materiales infecciosos. MÉTODOS: En 1991, 10 estudiantes de medicina panameños llevaron a cabo entrevistas y les tomaron muestras de sangre a 760 niños kunas y emberas de 2 a 12 años de edad en la cuenca superior del río Bayano y en las islas de San Blas. Se hicieron pruebas serológicas mediante aglutinación directa. Todos los datos, menos los de los perros, se estudiaron mediante análisis unifactorial, bifactorial y multifactorial. En 2003 se efectuaron nuevos análisis bifactoriales y multifactoriales para examinar la contribución de los perros. RESULTADOS: En comunidades con una alta prevalencia de anticuerpos contra Toxoplasma en niños, la regresión logística indicó que los siguientes factores tenían valor pronóstico en relación con la presencia de anticuerpos: pisos de tierra compacta en las chozas (P = 0,001), tener perro (P = 0,038), y que el investigador hubiera visto un gato dentro de la vivienda (P = 0,049). Según nuestros resultados, los perros de los habitantes de las aldeas desempeñan un papel importante en la facilitación de la transmisión de Toxoplasma gondii a los seres humanos, la mayor parte de las veces en presencia de gatos dentro de la vivienda y solamente en comunidades con una alta seroprevalencia de Toxoplasma en niños. CONCLUSIONES: Los perros pueden ser vectores mecánicos debido a su hábito de revolcarse en sustancias fétidas y de comer heces. En zonas donde la prevalencia de Toxoplasma en niños es alta y donde hay muchos perros y gatos, a las personas inmunodeprimidas y las mujeres embarazadas se les debe advertir del peligro de infectarse con Toxoplasma gondii por contacto con perros o con tierra contaminada por gatos. Se debe alentar a las personas a lavarse las manos después de tocar tierra, perros o gatos y antes de comer