Cells in focus: endothelial cell

The endothelial cell is thought to arise from the splanchnopleuric mesoderm. Endothelial cells form the inner lining of a blood vessel and provides an anticoagulant barrier between the vessel wall and blood. In addition to its role as a selective permeability barrier, the endothelial cell is a unique multifunctional cell with critical basal and inducible metabolic and synthetic functions. The endothelial cell reacts with physical and chemical stimuli within the circulation and regulates hemostasis, vasomotor tone, and immune and inflammatory responses. In addition, the endothelial cell is pivotal in angiogenesis and vasculogenesis. Endothelial cell injury, activation or dysfunction is a hallmark of many pathologic states including atherosclerosis, loss of semi-permeable membrane function, and thrombosis.

Cell facts: (1) Endothelium consists of approximately (1–6)×10¹³ endothelial cells forming an almost 1 kg organ. (2) They uniquely contain Weibel–Palade bodies, 0.1 μm wide, 3 μm long membrane-bound structures that represent the storage organelle for von Willebrand factor (vWF). (3) The endothelial cell is not only a permeability barrier but also a multifunctional paracrine and endocrine organ. It is involved in the immune response, coagulation, growth regulation, production of extracellular matrix components, and is a modulator of blood flow and blood vessel tone.     

In focus: Film,focus groups and working children in Bangladesh

The use of visuals in anthropological research is an established though much debated practice, both as a research tool and as a means of reporting. Pile sorts, mapping, thematic drawing, photographs, visual scales and pictorial triad testing are all visual methods that have been used in participatory and conventional ethnographic research to encourage discussion among study participants and to clarify detail. Our experience in the use of visual tools in a study conducted in 1997–98, among former child garment workers in Bangladesh, reinforces the value of the use of visuals in research. A documentary film was used in focus groups with children, most aged 10–13. The results suggest that film is a powerfully evocative tool and, combined with focus groups, is an excellent qualitative research technique. The research experience in Bangladesh also suggests that children are able to participate meaningfully in the research not in spite of but because of the use of documentary film.     

First visceral leishmaniasis focus in Argentina

An eight-year old boy from Posadas (27 masculine 23'S, 55 masculine 54'W) was diagnosed with visceral leishmaniasis (VL) during 2006. Lutzomyia longipalpis was discovered in the backyard of his house, while the spread of canine visceral leishmaniasis was confirmed in Posadas. This is the southernmost report of a VL transmission focus and the first in Argentina.     

Human niche construction in interdisciplinary focus

Niche construction is an endogenous causal process in evolution, reciprocal to the causal process of natural selection. It works by adding ecological inheritance, comprising the inheritance of natural selection pressures previously modified by niche construction, to genetic inheritance in evolution. Human niche construction modifies selection pressures in environments in ways that affect both human evolution, and the evolution of other species. Human ecological inheritance is exceptionally potent because it includes the social transmission and inheritance of cultural knowledge, and material culture. Human genetic inheritance in combination with human cultural inheritance thus provides a basis for gene-culture coevolution, and multivariate dynamics in cultural evolution. Niche construction theory potentially integrates the biological and social aspects of the human sciences. We elaborate on these processes, and provide brief introductions to each of the papers published in this theme issue.