Resveratrol improves health and survival of mice on a high-calorie diet

Resveratrol (3,5,4'-trihydroxystilbene) extends the lifespan of diverse species including Saccharomyces cerevisiae, Caenorhabditis elegans and Drosophila melanogaster. In these organisms, lifespan extension is dependent on Sir2, a conserved deacetylase proposed to underlie the beneficial effects of caloric restriction. Here we show that resveratrol shifts the physiology of middle-aged mice on a high-calorie diet towards that of mice on a standard diet and significantly increases their survival. Resveratrol produces changes associated with longer lifespan, including increased insulin sensitivity, reduced insulin-like growth factor-1 (IGF-I) levels, increased AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor-gamma coactivator 1alpha (PGC-1alpha) activity, increased mitochondrial number, and improved motor function. Parametric analysis of gene set enrichment revealed that resveratrol opposed the effects of the high-calorie diet in 144 out of 153 significantly altered pathways. These data show that improving general health in mammals using small molecules is an attainable goal, and point to new approaches for treating obesity-related disorders and diseases of ageing.     

New synonymy, new combinations, and new species of North American Pityophthorus (Coleoptera: Scolytidae), Part II

Four new species of Mexican Pityophthorus in the Lautus group are described: P. indefessus (Jalisco), P. inhabilis (Guerrero), P. tutulus (Veracruz), and P. vegrandis (Quintana Roo) and a new locality record is given for P. corruptus Wood.     

New synonymy, new species, and taxonomic notes of North American Pityophthorus (Coleoptera: Scolytidae), Part III

New synonymies and new data affecting North American Pityophthorus are proposed as follows: chalcoensis Hopkins ( = herrerai Hopkins) and nigricans Blandford ( = chiapensi s Bright). Neotypes are designated for the following species described by Eichhoff: concentralis, cribripennis, infans, puchellus, and tuberculatus. New species are: carinatus (Canada), cavatus (Manitoba, Saskatchewan), euterpes (Mexico), hesperius (British Columbia), impexus (Mexico), intentus (Arizona), laticeps (Mexico), malleatus (Arizona), mesembria (Guatemala), montezumae (Mexico), scalptus (British Columbia, Colorado), trepidus (California), and vespertinus (Mexico).     

American Pikas ( Ochotona princeps ) in northwestern Nevada: a newly discovered population at a low-elevation site

The central tenet of island biogeography theory—that species assemblages on islands are functions of island area, isolation from mainlands, and vicariance—has been altered by the demonstrable effects that rapid climate change is imposing on insular faunas, at least in isolated mountaintops. Although populations of American pikas ( Ochotona princeps ) continue to suffer extirpations, and although the lower bounds of the pika's elevational distribution are shifting upslope across the Great Basin, we report here on the new discovery of a low-elevation population of pikas in a mountain range from which they had not been reported previously. This discovery, particularly in the context of relatively rapid ecological change, highlights the importance of seeking out original sources of information and performing spatially extensive fieldwork. Results presented here further illustrate that although thermal influences appear to be the single strongest determinant of pika distribution currently, such influences interact with a number of other factors to determine persistence.     

Financial distress prediction model: The effects of corporate governance indicators

This paper constructs a financial distress prediction model that includes not only traditional financial variables, but also several important corporate governance variables. Using data from Taiwan, the empirical results show that the best in-sample and out-of-sample prediction models should combine the financial variables with the corporate governance variables. Moreover, the prediction accuracy is higher for the models using dynamic distress threshold values than those with tradition threshold values. Most financial ratios, except for the debt ratio, are higher in financially sound companies than in financial distressed ones. With regard to the corporate governance variables, we find that the CEO/Chairman duality may not result in the outbreak of financial distress, but higher equity pledge ratios of managers (shareholding ratios by board members and insiders) positively (negatively) correlate with financial distress.