Bounds for DNA codes with constant GC-content

We derive theoretical upper and lower bounds on the maximum size of DNA codes of length n with constant GC-content w and minimum Hamming distance d, both with and without the additional constraint that the minimum Hamming distance between any codeword and the reverse-complement of any codeword be at least d. We also explicitly construct codes that are larger than the best previously-published codes for many choices of the parameters n, d and w.Comment: 13 pages, no figures; a few references added and typos correcte

Collective action and marketing of underutilized plant species: The case of minor millets in Kolli Hills, Tamil Nadu, India

"Minor millets are examples of underutilized plant species, being locally important but rarely traded internationally with an unexploited economic potential. In the Kolli hills of Tamil Nadu, India, a genetically diverse pool of minor millet varieties are grown by the tribal farming communities to meet their subsistence food needs. Most of these minor crops were not traded outside the farming community. Despite a consumption preference among the farming communities for minor millets, in the recent past the acreage under minor millet crops have declined considerably due to the availability of substitute cash crops. As a response, the M.S. Swaminathan Research Foundation (MSSRF) based in Chennai has led targeted conservation cum commercialization intervention programs over the last 7-9 years in the Kolli Hills. In this paper we provide a first evaluation of the success of marketing development for minor millets in the Kolli Hills with a specific focus on collective action and group initiatives undertaken by the women and men self-help groups organized by the concerned non-governmental organization. We analyze the key collective actions that are taking place in the minor millet marketing chain through a series of field visits and focus group discussions with the stakeholders involved. We then compare the role of collective action in this new market with the case of marketing chains for cassava and organic pineapples, two cash crops with an expanding production in Kolli Hills. Our analysis shows the critical role of collective action and group initiative as a necessary but not sufficient condition for the successful commercialization of underutilized plant species for the benefit of the poor and the conservation of agrobiodiversity." authors' abstractCollective action, Underutilized species, Agricultural marketing, Agrobiodiversity, Markets, Small farmers,

Daily Scheduled High Fat Meals Moderately Entrain Behavioral Anticipatory Activity, Body Temperature, and Hypothalamic c-Fos Activation

When fed in restricted amounts, rodents show robust activity in the hours preceding expected meal delivery. This process, termed food anticipatory activity (FAA), is independent of the light-entrained clock, the suprachiasmatic nucleus, yet beyond this basic observation there is little agreement on the neuronal underpinnings of FAA. One complication in studying FAA using a calorie restriction model is that much of the brain is activated in response to this strong hunger signal. Thus, daily timed access to palatable meals in the presence of continuous access to standard chow has been employed as a model to study FAA in rats. In order to exploit the extensive genetic resources available in the murine system we extended this model to mice, which will anticipate rodent high fat diet but not chocolate or other sweet daily meals (Hsu, Patton, Mistlberger, and Steele; 2010, PLoS ONE e12903). In this study we test additional fatty meals, including peanut butter and cheese, both of which induced modest FAA. Measurement of core body temperature revealed a moderate preprandial increase in temperature in mice fed high fat diet but entrainment due to handling complicated interpretation of these results. Finally, we examined activation patterns of neurons by immunostaining for the immediate early gene c-Fos and observed a modest amount of entrainment of gene expression in the hypothalamus of mice fed a daily fatty palatable meal