To grow or not to grow: nutritional control of development during Caenorhabditis elegans L1 arrest.

It is widely appreciated that larvae of the nematode Caenorhabditis elegans arrest development by forming dauer larvae in response to multiple unfavorable environmental conditions. C. elegans larvae can also reversibly arrest development earlier, during the first larval stage (L1), in response to starvation. "L1 arrest" (also known as "L1 diapause") occurs without morphological modification but is accompanied by increased stress resistance. Caloric restriction and periodic fasting can extend adult lifespan, and developmental models are critical to understanding how the animal is buffered from fluctuations in nutrient availability, impacting lifespan. L1 arrest provides an opportunity to study nutritional control of development. Given its relevance to aging, diabetes, obesity and cancer, interest in L1 arrest is increasing, and signaling pathways and gene regulatory mechanisms controlling arrest and recovery have been characterized. Insulin-like signaling is a critical regulator, and it is modified by and acts through microRNAs. DAF-18/PTEN, AMP-activated kinase and fatty acid biosynthesis are also involved. The nervous system, epidermis, and intestine contribute systemically to regulation of arrest, but cell-autonomous signaling likely contributes to regulation in the germline. A relatively small number of genes affecting starvation survival during L1 arrest are known, and many of them also affect adult lifespan, reflecting a common genetic basis ripe for exploration. mRNA expression is well characterized during arrest, recovery, and normal L1 development, providing a metazoan model for nutritional control of gene expression. In particular, post-recruitment regulation of RNA polymerase II is under nutritional control, potentially contributing to a rapid and coordinated response to feeding. The phenomenology of L1 arrest will be reviewed, as well as regulation of developmental arrest and starvation survival by various signaling pathways and gene regulatory mechanisms.

Through the Lenses of Q’eqchi Maya: (Re)Framing the Story of Development in a Guatemalan Indigenous Community Through Participant-Created Photographs

The question of evaluations of development projects has been widely debated within the field of international development, with scholars and development practitioners calling for increased community-driven evaluations. However, there has been a paucity of research in community-led project evaluations, and a largely absent investigation utilizing visual anthropology/sociology methodologies. This paper seeks to shift this power by giving voice to the intended beneficiaries of an eco-tourism project in a rural indigenous Guatemala village. Through photographs taken by community members and corresponding interviews, this paper shows the way in which community members have and continue to reframe the idea of development in their village. Specifically, my analysis reveals how residents see changing forms of access, how they reframe ideas of beauty and modernization, and how they reframe their relationship to the land through Western conservation and private property ideals. This research thus provides an alternative narrative to the Western NGO’s evaluations and knowledge production, especially in respect to development and indigenous knowledge. By showing how community members are reframing the story of development, this paper demonstrates the usefulness of using participatory documentary photography in community-led evaluations, and helps balance the playing field by providing a much-needed alternative narrative of project evaluation.

Can information alone change behavior? Response to arsenic contamination of groundwater in Bangladesh

We study how effectively information induces Bangladeshi households to avoid a health risk. The response to information is large and rapid; knowing that the household's well water has an unsafe concentration of arsenic raises the probability that the household changes to another well within one year by 0.37. Households who change wells increase the time spent obtaining water fifteen-fold. We identify a causal effect of information, since incidence of arsenic is uncorrelated with household characteristics. Our door-to-door information campaign provides well-specific arsenic levels without which behavior does not change. Media communicate general information about arsenic less expensively and no less effectively. © 2006 Elsevier B.V. All rights reserved.