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Severe bacterial or viral infections can induce a state of immune hyperactivation that can culminate in a potentially lethal cytokine storm. The classic example is toxic shock syndrome, a life-threatening complication of Staphylococcus aureus or Streptococcus pyogenes infection, which is driven by potent toxins known as superantigens (SAgs). SAgs are thought to promote immune evasion via the promiscuous activation of T cells, which subsequently become hyporesponsive, and act by cross-linking major histocompatibility complex class II molecules on antigen-presenting cells to particular β-chain variable (TRBV) regions of αβ T cell receptors (TCRs). Although some of these interactions have been defined previously, our knowledge of SAg-responsive TRBV regions is incomplete. In this study, we found that CD4+ and CD8+ T cells expressing TRBV12-3/12-4+ TCRs were highly responsive to streptococcal pyrogenic exotoxin C (SpeC) and toxic shock syndrome toxin-1 (TSST-1). In particular, SpeC and TSST-1 specifically induced effector cytokine production and the upregulation of multiple coinhibitory receptors among TRBV12-3/12-4+ CD4+ and CD8+ memory T cells, and importantly, these biological responses were dependent on human leukocyte antigen (HLA)-DR. Collectively, these data provided evidence of functionally determinative and therapeutically relevant interactions between SpeC and TSST-1 and CD4+ and CD8+ memory T cells expressing TRBV12-3/12-4+ TCRs, mediated via HLA-DR. In peripheral blood mononuclear cells from healthy human donors, the superantigens SpeC and TSST-1 are shown to specifically activate TRBV12-3/12-4+ memory T cells. [ABSTRACT FROM AUTHOR]

A key issue distinguishing prominent evolutionary models of human life history is whether prolonged childhood evolved to facilitate learning in a skill- and strength-intensive foraging niche requiring high levels of cooperation. Considering the diversity of environments humans inhabit, children's activities should also reflect local social and ecological opportunities and constraints. To better understand our species' developmental plasticity, the present paper compiled a time allocation dataset for children and adolescents from twelve hunter-gatherer and mixed-subsistence forager societies (n = 690; 3–18 years; 52% girls). We investigated how environmental factors, local ecological risk, and men and women's relative energetic contributions were associated with cross-cultural variation in child and adolescent time allocation to childcare, food production, domestic work, and play. Annual precipitation, annual mean temperature, and net primary productivity were not strongly associated with child and adolescent activity budgets. Increased risk of encounters with dangerous animals and dehydration negatively predicted time allocation to childcare and domestic work, but not food production. Gender differences in child and adolescent activity budgets were stronger in societies where men made greater direct contributions to food production than women. We interpret these findings as suggesting that children and their caregivers adjust their activities to facilitate the early acquisition of knowledge which helps children safely cooperate with adults in a range of social and ecological environments. These findings compel us to consider how childhood may have also evolved to facilitate flexible participation in productive activities in early life. [ABSTRACT FROM AUTHOR]

Hunting and gathering is, evolutionarily, the defining subsistence strategy of our species. Studying how children learn foraging skills can, therefore, provide us with key data to test theories about the evolution of human life history, cognition, and social behavior. Modern foragers, with their vast cultural and environmental diversity, have mostly been studied individually. However, cross-cultural studies allow us to extrapolate forager-wide trends in how, when, and from whom hunter-gatherer children learn their subsistence skills. We perform a meta-ethnography, which allows us to systematically extract, summarize, and compare both quantitative and qualitative literature. We found 58 publications focusing on learning subsistence skills. Learning begins early in infancy, when parents take children on foraging expeditions and give them toy versions of tools. In early and middle childhood, children transition into the multi-age playgroup, where they learn skills through play, observation, and participation. By the end of middle childhood, most children are proficient food collectors. However, it is not until adolescence that adults (not necessarily parents) begin directly teaching children complex skills such as hunting and complex tool manufacture. Adolescents seek to learn innovations from adults, but they themselves do not innovate. These findings support predictive models that find social learning should occur before individual learning. Furthermore, these results show that teaching does indeed exist in hunter-gatherer societies. And, finally, though children are competent foragers by late childhood, learning to extract more complex resources, such as hunting large game, takes a lifetime. [ABSTRACT FROM AUTHOR]

In the present article, we introduce the continuous unified electronic (CUE) diary method, a longitudinal, event-based, electronic parent report method that allows real-time recording of infant and child behavior in natural contexts. Thirty-nine expectant mothers were trained to identify and record target behaviors into programmed handheld computers. From birth to 18 months, maternal reporters recorded the initial, second, and third occurrences of seven target motor behaviors: palmar grasp, rolls from side to back, reaching when sitting, pincer grip, crawling, walking, and climbing stairs. Compliance was assessed as two valid entries per behavior: 97 % of maternal reporters met compliance criteria. Reliability was assessed by comparing diary entries with researcher assessments for three of the motor behaviors: palmar grasp, pincer grip and walking. A total of 81 % of maternal reporters met reliability criteria. For those three target behaviors, age of emergence was compared across data from the CUE diary method and researcher assessments. The CUE diary method was found to detect behaviors earlier and with greater sensitivity to individual differences. The CUE diary method is shown to be a reliable methodological tool for studying processes of change in human development. [ABSTRACT FROM AUTHOR]

This study estimates the economic costs associated with childhood diseases and disabilities attributable to environmental contaminants in Washington State, USA, including asthma, cancer, lead exposure, birth defects, and neurobehavioral disorders. The estimates are based on "cost of illness" models that include direct healthcare costs and indirect costs. The estimates are also based on an "environmentally attributable fraction" model which quantifies the proportions of each disease or disability that can reasonably be attributed to environmental contaminants. The study concludes that the annual cost of selected childhood diseases and disabilities attributable to environmental contaminants in Washington State is $1875 million in 2004 $, comprising $310.6 million in direct healthcare costs and $1565 million in indirect costs, and with a range of $1600-$2200 million a year. These estimates are consistent with other studies. Like the previous studies, a significant proportion of the estimated costs can be attributed to lead exposure. This estimate is equivalent to about 0.7% of the total Washington Gross State Product, and the estimated direct healthcare costs are equivalent to at least 0.2% of the total Washington State health expenditures. These costs could be lessened or prevented if exposures to environmental contaminants were reduced or eliminated. This study argues for the need for an ecosystem approach to human health in which the condition of the environment, in terms of exposures to environmental contaminants, must he addressed taking a systemic perspective. [ABSTRACT FROM AUTHOR]

The rehabilitation of sick or injured wildlife and their subsequent release back into the wild is considered important, not only for the welfare of the individual animal but also for the conservation and management of endangered and threatened wildlife. The European hedgehog Erinaceus europaeus has declined by 25% in Britain over the last decade and is the most common mammal admitted to wildlife rehabilitation centres in Britain, with a large proportion of individuals admitted to gain body weight overwinter prior to release in the spring. Consequently, many thousands of hedgehogs are housed overwinter which incurs significant costs for rehabilitation centres, and has potentially animal welfare issues, such as, stress in captivity, reintroduction stress, increased mortality risk and impaired or altered behaviour. To determine if releasing rehabilitated hedgehogs during autumn and winter had an effect on their survival, body weight or nesting behaviour, we compared these factors between 34 rehabilitated hedgehogs with 23 wild hedgehogs across five sites in England over four different winters. Overwinter survival was high for both wild and rehabilitated hedgehogs, with a significant decrease in survival across both groups when hedgehogs became active post hibernation in spring. We found no differences in the survival rates up to 150 days post release, in weight change, or nest use between wild- and winter-released rehabilitated hedgehogs. Our results suggest that under the correct conditions, rehabilitated hedgehogs can be released successfully during winter, therefore avoiding or reducing time in captivity. [ABSTRACT FROM AUTHOR]