Black Hole entropy for two higher derivative theories of gravity

The dark energy issue is focusing the attention of an incresing number of physicists all over the world. Among the possible alternatives in order to explain what as been named the "Mystery of the Millennium" are the so-called Modified Theories of Gravity. A crucial test for such models is represented by the existence and (if this is the case) the properties of their black hole solutions. Nowadays, to our knowledge, only two non-trivial, spherically symmetric, solutions with vanishing cosmological constant are known by Barrow & Clifton (2005) and Deser, Sarioglu & Tekin (2008). Aim of the paper is to discuss some features of such solutions, with emphasis on their thermodynamic properties such as entropy and temperature, little progress being possible along the way which leads to a consistent definition of mass.Comment: 10 pages, 1 figur

Potential of giant reed (Arundo donax L.) for second generation ethanol production

AbstractBackgroundThe production of second generation ethanol from lignocellulosic biomasses that have not had their potential fully explored as feedstock is of great importance. Arundo donax is one these biomasses. It is a promising grassy plant to be used as a renewable resource for the production of fuels and chemicals, because of its fast growth rate, ability to grow in different soil types and climatic conditions. The present study evaluated its use as feedstock for the production of second generation ethanol.ResultsInitially its chemical characterization was carried out, and a protocol for fractioning the biomass through diluted acid pretreatment followed by alkaline pretreatment was developed, providing a solid fraction which was undergone to enzymatic hydrolysis reaching 42g/L of glucose, obtained in 30h of enzymatic hydrolysis. This partially delignified material was subjected to a simultaneous saccharification and fermentation (SSF) process, resulting in an ethanol concentration of 39g/L at 70h.ConclusionsThe fermentability of the pretreated biomass was performed successfully through the conception of simultaneous saccharification and fermentation resulting in approximately 75L of ethanol per ton of cellulose

Factors affecting vitamin D status in different populations in the city of São Paulo, Brazil: the São Paulo vitamin D Evaluation Study (SPADES)

Background: Hypovitaminosis D is a common condition among elderly individuals in temperate-climate countries, with a clear seasonal variation on 25 hydroxyvitamin D [(25(OH)D] levels, increasing after summer and decreasing after winter, but there are few data from sunny countries such as Brazil. We aimed to evaluate 25-hydroxyvitamin D concentrations and its determining factors, in individuals in the city of São Paulo belonging to different age groups and presenting different sun exposure habits.Methods: 591 people were included as follows: 177 were living in institutions (NURSING HOMES, NH, 76.2 +/- 9.0 years), 243 were individuals from the community (COMMUNITY DWELLINGS, CD, 79.6 +/- 5.3 years), 99 were enrolled in physical activity program designed for the elderly (PHYSICAL ACTIVITY, PA, 67.6 +/- 5.4 years) and 72 were young (YOUNG, 23.9 +/- 2.8 years). Ionized calcium, PTH, 25(OH)D, creatinine and albumin were evaluated. ANOVA, Mann-Whitney and Kruskal Wallis tests, Pearson Linear Correlation and Multiple Regression were used in the statistical analysis.Results: 25(OH)D mean values during winter for the different groups were 36.1 +/- 21.2 nmol/L (NH), 44.1 +/- 24.0 nmol/L (CD), 78.9 +/- 30.9 nmol/L (PA) and 69.6 +/- 26.2 nmol/L (YOUNG) (p < 0.001) while during summer they were 42.1 +/- 25.9 nmol/L, 59.1 +/- 29.6 nmol/L, 91.6 +/- 31.7 nmol/L and 103.6 +/- 29.3 nmol/L, respectively (p < 0.001). the equation which predicts PTH values based on 25(OH)D concentration is PTH = 10 + 104.24.e(-(vitD-12.5)/62.36) and the 25(OH)D value above which correlation with PTH is lost is 75.0 nmol/L. in a multiple regression analysis having 25(OH)D concentration as the depending variable, the determining factors were PTH, ionized calcium and month of the year (p < 0.05).Conclusions: Much lower 25(OH)D values were found for the older individuals when compared to younger individuals. This finding is possibly due to age and habit-related differences in sunlight exposure. the existence of seasonal effects on 25(OH)D concentration throughout the year was evident for all the groups studied, except for the nursing home group. According to our data, PTH values tend to plateau above 75 nmol/L.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo UNIFESP, Escola Paulista Med, Dept Med, Div Endocrinol, Sao Carlos, SP, BrazilUNIFESP, Dept Geriatr Med, Sao Carlos, SP, BrazilUNIFESP, Dept Prevent Med, Sao Carlos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, Escola Paulista Med, Dept Med, Div Endocrinol, Sao Carlos, SP, BrazilUNIFESP, Dept Geriatr Med, Sao Carlos, SP, BrazilUNIFESP, Dept Prevent Med, Sao Carlos, SP, BrazilFAPESP: 03/13194-6Web of Scienc

Adenomioepitelioma de mama - Relato de caso

O adenomioepitelioma é uma lesão cuja terminologia sugere ser um tumor benigno, mas observado na literatura médica com potencialidade para o aparecimento de metástases, principalmente em gânglios axilares. Os autores apresentam um caso ocorrido após a lactação. A lesão foi tratada com cirurgia local e a paciente continua em segmento contínuo