Paradoxical effects of altruism on efforts to mitigate climate change.

It is common wisdom that altruism is a crucial element in addressing climate change and other public good issues. If individuals care about the welfare of others (including future generations) they can be expected to unilaterally adapt their behaviour to preserve the common good thus enhancing the wellbeing of all. We introduce a network game model featuring both altruism and a public good (e.g. climate) whose degradation affects all players. As expected, in an idealistic fully connected society where all players care about each other, increasing altruism results in a better protection of the public good. However, in more realistic networks where people are not all related to each other, we highlight an intrinsic trade-off between the effects of altruism on reducing inequality and the preservation of a global public good: the consumption redistribution generated by a higher altruism is partly achieved by lowering income transfers towards protection of the public good. Therefore, it increases overall consumption and is thereby detrimental to the public good. These results suggest that altruism, although good from a welfarist point of view, is not in itself sufficient to simultaneously solve public good and inequality issues.

Reversible action of diaminothiazoles in cancer cells is implicated by the induction of a fast conformational change of tubulin and suppression of microtubule dynamics.

Diaminothiazoles are novel cytotoxic compounds that have shown efficacy toward different cancer cell lines. They show potent antimitotic and antiangiogenic activity upon binding to the colchicine-binding site of tubulin. However, the mechanism of action of diaminothiazoles at the molecular level is not known. Here, we show a reversible binding to tubulin with a fast conformational change that allows the lead diaminothiazole DAT1 [4-amino-5-benzoyl-2-(4-methoxy phenyl amino)thiazole] to cause a reversible mitotic block. DAT1 also suppresses microtubule dynamic instability at much lower concentration than its IC(50) value in cancer cells. Both growth and shortening events were reduced by DAT1 in a concentration-dependent way. Colchicine, the long-studied tubulin-binding drug, has previously failed in the treatment of cancer due to its toxicity, even though it generates a strong apoptotic response. The toxicity is attributable to its slow removal from the cell due to irreversible tubulin binding caused by a slow conformational change. DAT1 binds to tubulin at an optimal pH lower than colchicine. Tubulin conformational studies showed that the binding environments of DAT1 and colchicine are different. Molecular dynamic simulations showed a difference in the number of H-bonding interactions that accounts for the different pH optima. This study gives an insight of the action of compounds targeting tubulin's colchicine-binding site, as many such compounds have entered into clinical trials recently.

Prevalence of chikungunya in urban field practice area of a private medical college, chennai.

BACKGROUND: The outbreak of Chikungunya in India started during December 2005 with more than 11,00,000 cases. Many cases with symptoms suggestive of Chikungunya reported to our urban health-training centre. Hence this study was done to estimate the prevalence of Chikungunya, to study the common treatment-seeking behavior, control measures and the sequalae of Chikungunya by follow-up. MATERIALS AND METHODS: This cross-sectional study was done in Anagaputhur an urban field practice area of our college. The study was done on a sample selected by systematic random sampling. Any person with fever and joint pain, with an onset from 1 August 2006 to 31 August 2006, were enrolled as cases. The cases were followed up after three months. RESULTS: Chikungunya prevalence in the community was 22.3%; 52% of them were females and 56% of cases were in the 15-44 years age group. Median duration of acute phase was three days. Ninety-one percent of them had multiple joints' involvement. Seventy-eight percent sought treatment from the private sector. Sixty-seven percent reported artificial collections of water around their household and 44% complained of mosquito problems during the day. Eighty-eight percent used mosquito repellents for personal protection. On follow-up 95% of them had residual joint pain, 43% had residual joint swelling and 11% had disabilities with median duration of 30 days. CONCLUSIONS: Prevalence of Chikungunya was 22.3%, predominantly affecting the age group of 15-44 years and females. The private sector was commonly sought for treatment. Entomological survey indicated Aedes breeding. Eleven percent had disabilities due to the sequelae.