Power-law distributions for the citation index of scientific publications and scientists

The number of citations of a scientific publication or of an individual scientist has become an important factor of quality assessment in science. We report a study of the statistical distribution of the citation index of both scientific publications and scientists. We give numerical evidence that Tsallis (power law) statistics explains the entire distribution over eight orders of magnitude (10-4 to 10(4)). Also, we draw Zipf plots in order to analyze the statistical distribution of the citation index of Brazilian and international physicists and chemists. The relatively small group of Brazilian scientists seems more adequate to explain the dynamics of the citation index. In this case, we find that the distribution of the citation index can also be explained by a gradually truncated power law with similar parameters. We finally discuss possible mechanisms behind the citation index of scientists and scientific publications.

Genes do eixo somatotrófico e características de crescimento numa população F2 de bovinos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influência de diferentes materiais de cobertura no conforto térmico de instalações para frangos de corte no oeste paulista

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Crescimento relativo e composição do ganho de tecidos da carcaça de zebuínos de quatro raças

Utilizaram-se 64 machos não-castrados das raças Gir, Guzerá, Mocho de Tabapuã e Nelore. em cada raça, os animais foram divididos, aleatoriamente, em cinco categorias. Uma categoria foi abatida imediatamente, três receberam, em baias individuais, ração contendo 50% de concentrado na MS ad libitum (I, II e III) e uma recebeu a mesma ração, em quantidade restrita, suprindo níveis de proteína e energia 15% acima da mantença. Os animais I, II e III foram abatidos ao atingirem pesos vivos individuais de 405, 450 e 500 kg, respectivamente. Adotou-se a equação de regressão do logaritmo da quantidade corporal de carcaça e de seus tecidos (muscular, adiposo e ósseo), em função do logaritmo do peso de corpo vazio. Na carcaça, o tecido adiposo, ósseo e muscular tiveram maior impulso para crescimento em idade mais tardia, precoce e intermediário, respectivamente. A carcaça apresentou alometria positiva, refletindo o seu desenvolvimento proporcionalmente maior que o do peso corporal vazio.

Structural and phenomenological characterization of the thermoreversible sol-gel transition of a zirconyl aqueous precursor modified by sulfuric acid

The thermoreversible sol-gel transition is well-known in biological and organic polymeric systems but has not been reported for inorganic systems. In this paper we put in evidence a thermoreversible sol-gel transition for zirconyl chloride aqueous solutions modified by sulfuric acid in the ratio 3:1 Zr:SO4. The synthesis conditions are detailed and a variety of experimental techniques (turbidimetry, dynamic rheology, and EXAFS) have been employed for investigating the thermal reversibility and the chemical structure of this new material. Turbidimetric measurements performed for solutions containing different concentrations of precursor have evidenced that the sol-gel transformation temperature increases from 50 to 80 degrees C as the concentration of zirconyl chloride decreases from 0.22 to 0.018 mol L-1. A more detailed study has been done for the sample with [Zr] = 0.156 mol L-1, in which the sol-gel-sol transformation has been repeated several times by a cyclic variation of the temperature. The mechanical properties of this sample, evaluated by measuring the storage and the loss moduli, show a change from liquid like to viscoelastic to elastic behavior during the sol-gel transition and vice versa during the gel-sol one. In situ EXAFS measurements performed at the Zr K-edge show that no change of the local order around Zr occurs during the sol-gel-sol transition, in agreement with the concept of physical gel formation. We have proposed for the structure of the precursor an inner core made of hydroxyl and oxo groups bridging together zirconium atoms surrounded in surface by complexing sulfate ligands, the sulfate groups act as a protective layer, playing a key role in the linking propagation among primary particles during sol-gel-sol transition.

Efeitos do tipo de ração inicial sobre a morfologia intestinal e digestibiliade dos nutrientes em leitões

Thirty piglets, weaned at an average age of 28 days, were used in experiment one. After weaning, 24 animals were transferred to the nursery in groups of two to each pen and fed simple or semi-complex diets ad libitum. On weaning day (day 0), six pigs were slaughtered. On days 7 and 21 post-weaning, one animal from each nursery pen was slaughtered to study mucosal thickness (MTD and MTJ) and villi heights (VHD and VHJ) in the duodenum and jejunum. The average values observed for MTD, VHD, MTJ, and VHJ were not influenced by type of diet. MTD, MTJ, and VHJ increased from days 7 to 21 post-weaning. Polynomial regression spanning days 0, 7, and 21 showed a linear effect for MTJ and a quadratic effect for VHD and VHJ. In experiment two, 16 piglets weaned at an average age of 28 days were used in two metabolic trials carried out during two periods of the initial phase (days 5 to 14 and days 19 to 28 postweaning), to determine the nutritional value of simple and semi-complex diets. There were no differences among treatments in apparent digestibility of crude protein and dry matter and the values for digestible or metabolizable energy of the diets. It was concluded that composition of the starter diet did not influence the intestinal morphology of piglets, the digestibilities of dry matter and crude protein, or the digestible and metabolizable energy contents of the diets.

Obesidade e sintomas de depressão, ansiedade e desesperança em mulheres sedentárias e não sedentárias

The aim of this field study was to verify if there is a relation between obesity and symptoms of depression, anxiety and hopelessness in 40 women aged 30,35 on average (± 8,60), divided into two groups: non-sedentary ones, characterized for doing a physical activity at least three times a week for three weeks in a row and sedentary ones, characterized by not practicing any type of regular physical activity when recruited. The method consisted of: objective evaluations of humor, through Beck Inventories of Anxiety (BAI), Depression (BDI) and Hopelessness (BHS) and Physical Evaluation, including total body mass, height, waist and hip circumferences and skin folds thickness. Calculations of the body mass index (BMI), of the waist/hip index (WHI) and of the percentage of corporal fat (%F) were performed in order to evaluate the presence and level of obesity. Results of the analysis of regression to square minimum supported the initial hypothesis concerning the existence of a relation between obesity and psychic symptoms only in sedentary women (BDI/WHI, p=0,035, BDI/BMI, p=0,009, BDI/%G, p=0,019, BAI/BMI, p=0,009, BAI/%G, p=0,037, BHS/WHI, p=0,025, BHS/BMI, p=0,041), once the relation of dependency could not be confirmed in non-sedentary women BDI/WHI, p=0,750, BDI/BMI, p=0,141, BDI/%G, p=0,064, BAI/WHI, p=0,729, BAI/BMI, p=0,384, BAI/%G, p=0,246, BHS/WHI, p=0,491, BHS/BMI, p=0,986, BHS/%G, p=0,322) and the greater the level of obesity, the greater the level of psychic symptoms in both groups. These observations seem to point out that the practice of physical activities was a factor of minimization of presence and intensity of psychic symptoms in non-sedentary women.

Study of whole genome linkage disequilibrium in Nellore cattle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Validation of the brazilian version of the apathy inventory

Background Apathy is a frequent neuropsychiatric condition in neurodegenerative disorders, depression, and often in mild cognitive impairment. The Apathy Inventory (AI) is a reliable instrument for improving the accuracy of the apathy diagnosis. The aim was to establish the validity of the Apathy Inventory for the Brazilian community. Methods We established the concurrent validity, internal consistency, inter-rater reliability, and the sensitivity and specificity of AI for the Brazilian community in a cohort of 175 individuals with Alzheimer's disease, Parkinson's disease, depression, mild cognitive impairment, and healthy controls. The three dimensions of the AI (emotional blunting, lack of initiative, and lack of interest) were compared with the Apathy domain of the Neuropsychiatric Inventory-Clinician rating scale (NPI-C) in an independent scheme. Results The analyses demonstrated high correlation coefficients in AI's individual dimensions and in AI-total score (F = 0.965). Concerning the NPI-C/Apathy domain, intra-class correlation coefficients were also high (F = 0.977). Concurrent validity was high according to both raters on AI dimensions × NPI-C/Apathy domain and regarding total score (rater 1: rho = 0.956 vs. rater 2: rho = 0.970). The internal consistency of the AI was also high concerning the AI's individual dimensions and total score (rater 1: 0.945 vs. rater 2: 0.958). Conclusion We observed high internal consistency, high concurrent validity, and inter-rater reliability of the Apathy Inventory. In addition, we found that its sensitivity and specificity were high. We suggest that the Brazilian version of the Apathy Inventory would be an appropriate instrument to identify the apathy syndrome in Brazilian patients. © 2012 John Wiley & Sons, Ltd.

Estimación de parámetros genéticos para producción de leche en el día de control en búfalas de primer parto

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desequilíbrio de ligação e associação entre polimorfismos de base única com maciez da carne e espessura de gordura em bovinos Nelore utilizando painéis de alta densidade

Pós-graduação em Genética e Melhoramento Animal - FCAV

Estimativas de parâmetros genéticos para escores de avaliação visual, peso e perímetro escrotal à desmama de bovinos da raça Canchim

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação bioeconômica de bezerros lactentes recebendo diferentes fontes protéicas em cocho privativo em pastagens de Brachiaria brizantha cv. Marandú manejada intensivamente

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise logística e ambiental no sistema de corte, carregamento e transporte da cana-de-açúcar

Pós-graduação em Engenharia Civil - FEIS