Electromagnetic radiation from collisions at almost the speed of light: an extremely relativistic charged particle falling into a Schwarzschild black hole

We investigate the electromagnetic radiation released during the high energy collision of a charged point particle with a four-dimensional Schwarzschild black hole. We show that the spectra is flat, and well described by a classical calculation. We also compare the total electromagnetic and gravitational energies emitted, and find that the former is supressed in relation to the latter for very high energies. These results could apply to the astrophysical world in the case charged stars and small charged black holes are out there colliding into large black holes, and to a very high energy collision experiment in a four-dimensional world. In this latter scenario the calculation is to be used for the moments just after the black hole formation, when the collision of charged debris with the newly formed black hole is certainly expected. Since the calculation is four-dimensional, it does not directly apply to Tev-scale gravity black holes, as these inhabit a world of six to eleven dimensions, although our results should qualitatively hold when extrapolated with some care to higher dimensions.Comment: 6 pages, 2 figure

Adherence to the planetary health diet index and obesity indicators in the Brazilian longitudinal study of adult health (ELSA-Brasil)

The EAT-Lancet Commission has proposed a model diet to improve the health of human beings and that of the planet. Recently, we proposed the Planetary Health Diet Index (PHDI) to assess adherence of the population to this model diet. In this study, we aimed to evaluate adherence to the PHDI and obesity outcomes using baseline data from 14, 515 participants in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). The dietary data were assessed using a 114-item FFQ. Body mass index (BMI) and waist circumference (WC) were both used continuously and cat-egorized. Linear and multinomial regression models adjusted for potential confounding factors were performed to assess the relationship between adherence to PHDI and outcomes. An inverse association was observed between adherence to PHDI and obesity indicators. Individuals with high adherence to the PHDI had lower BMI (ß-0.50 95% CI-0.73:-0.27) and WC (ß-1.70 95% CI-2.28:-1.12) values. They were also 24% less likely to be overweight (OR 0.76 95% CI 0.67:0.85) or obese (OR 0.76 95% CI 0.65:0.88), and they were 14% and 27% less likely to have increased WC (OR 0.86 95% CI 0.75:0.98) or substantially increased WC (OR 0.73 95% CI 0.64:0.83) than those with lower adherence. Our results showed that higher adherence to the PHDI may decrease obesity in-dicators. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Quasinormal modes of Schwarzschild black holes in four and higher dimensions

We make a thorough investigation of the asymptotic quasinormal modes of the four and five-dimensional Schwarzschild black hole for scalar, electromagnetic and gravitational perturbations. Our numerical results give full support to all the analytical predictions by Motl and Neitzke, for the leading term. We also compute the first order corrections analytically, by extending to higher dimensions, previous work of Musiri and Siopsis, and find excellent agreement with the numerical results. For generic spacetime dimension number D the first-order corrections go as $\frac{1}{n^{(D-3)/(D-2)}}$. This means that there is a more rapid convergence to the asymptotic value for the five dimensional case than for the four dimensional case, as we also show numerically.Comment: 12 pages, 5 figures, RevTeX4. v2. Typos corrected, references adde

Produção De Biomassa E Conteúdo De Fenóis E Flavonoides De Schinus Terebinthifolius Cultivada Em Fileira Simples E Dupla Com Cama De Frango

The aim of this study was to evaluate the influence of the addition of poultry litter on growth, biomass yield, flavonoid and phenol content, and antioxidant activity in leaves of pink pepper. The experiment was carried out at the Federal University of Grande Dourados, in Dourados, Mato Grosso do Sul state, from October 2009 to May 2010. Pink pepper was grown in single or double row in soil with incorporated poultry litter at doses of 0, 5, 10, 15 and 20 t ha-1. Treatments were arranged as 2 x 5 factorial in a randomized block design with four replications. There was a significant interaction between the doses of poultry litter and evaluation times for plant height and chlorophyll content. A linear increase in leaf area, fresh and dry weight of leaves and diameter of main stems with increasing doses of poultry litter was observed. Plants grown in single row showed higher fresh weight of stem with increasing doses of poultry litter. Poultry litter at 15 and 20 t ha-1 promoted an increase in flavonoid and phenolic contents in the leaves. No significant effect on the antioxidant activity was observed by the chemical method using DPPH. Therefore, it is recommended the cultivation of pink pepper plants with double row and 20 t ha-1 of poultry litter to higher growth, biomass yield, and flavonoid and phenol content. © 2016, Universidade Federal de Santa Maria. All rights reserved.26378779

Immobilization of bacterial feruloyl esterase on mesoporous silica particles and enhancement of synthetic activity by hydrophobic-modified surface

Here, we demonstrated the immobilization of bacterial feruloyl esterase (FAE) from Butyrivibrio sp. XPD2006, Lactobacillus crispatus, Butyrivibrio sp. AE2015, Ruminococcus albus, Cellulosilyticum ruminicola and Clostridium cellulovorans on SBA-15 and their ability to synthesize butyl ferulate (BFA). The BFae2 from Butyrivibrio sp. XPD2006 showed the best catalytic efficiency. High BFA yield was produced when the immobilization of BFae2 took place with a high protein loading and narrow pore sized SBA-15, suggesting alteration of enzyme behavior due to the crowding environment in SBA-15. Grafting of SBA-15 with octyl moieties led to shrinking pore size and resulted in 2.5-fold increment of BFA activity compared to the free enzyme and 70%mol BFA was achieved. The BFae2 encapsulated in hydrophobic-modified SBA-15 endured up to seven reaction cycles while the BFA activity remained above 60%. This is the first report showing the superior performance of hydrophobic-modified surface to entrap FAE to produce fatty phenolic esters

Impact of glycemic control on the incidence of acute kidney injury in critically ill patients: a comparison of two strategies using the RIFLE criteria

OBJECTIVE: To compare the renal outcome in patients submitted to two different regimens of glycemic control, using the RIFLE criteria to define acute kidney injury. INTRODUCTION: The impact of intensive insulin therapy on renal function outcome is controversial. The lack of a criterion for AKI definition may play a role on that. METHODS: Included as the subjects were 228 randomly selected, critically ill patients engaged in intensive insulin therapyor in a carbohydrate-restrictive strategy. Renal outcome was evaluated through the comparison of the last RIFLE score obtained during the ICU stay and the RIFLE score at admission; the outcome was classified as favorable, stable or unfavorable. RESULTS: The two groups were comparable regarding demographic data. AKI developed in 52% of the patients and was associated with a higher mortality (39.4%) compared with those who did not have AKI (8.2%) (p<0.001). Renal function outcome was comparable between the two groups (p=0.37). We observed a significant correlation between blood glucose levels and the incidence of acute kidney injury (p=0.007). In the multivariate logistic regression analysis, only APACHE III scores higher than 60 were identified as an independent risk factor for unfavorable renal outcome. APACHE III scores>60, acute kidney injury and hypoglycemia were risk factors for mortality. CONCLUSION: Intensive insulin therapy and a carbohydrate-restrictive strategy were comparable regarding the incidence of acute kidney injury evaluated using RIFLE criteria

Cytogenetic characterization and evaluation of c-MYC gene amplification in PG100, a new Brazilian gastric cancer cell line

Gastric cancer is the fourth most frequent type of cancer and the second cause of cancer mortality worldwide. The genetic alterations described so far for gastric carcinomas include amplifications and mutations of the c-ERBB2, KRAS, MET, TP53, and c-MYC genes. Chromosomal instability described for gastric cancer includes gains and losses of whole chromosomes or parts of them and these events might lead to oncogene overexpression, showing the need for a better understanding of the cytogenetic aspects of this neoplasia. Very few gastric carcinoma cell lines have been isolated. The establishment and characterization of the biological properties of gastric cancer cell lines is a powerful tool to gather information about the evolution of this malignancy, and also to test new therapeutic approaches. The present study characterized cytogenetically PG-100, the first commercially available gastric cancer cell line derived from a Brazilian patient who had a gastric adenocarcinoma, using GTG banding and fluorescent in situ hybridization to determine MYC amplification. Twenty metaphases were karyotyped; 19 (95%) of them presented chromosome 8 trisomy, where the MYC gene is located, and 17 (85%) presented a deletion in the 17p region, where the TP53 is located. These are common findings for gastric carcinomas, validating PG100 as an experimental model for this neoplasia. Eighty-six percent of 200 cells analyzed by fluorescent in situ hybridization presented MYC overexpression. Less frequent findings, such as 5p deletions and trisomy 16, open new perspectives for the study of this tumor.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal do Pará Instituto de Ciências Biológicas Laboratório de Citogenética HumanaUniversidade Federal de São Paulo (UNIFESP) Disciplina de GenéticaUNIFESP, Disciplina de GenéticaCNPq: 20/2007CNPq: 550885/2007-2SciEL

Quasi-Normal Modes of Schwarzschild Anti-De Sitter Black Holes: Electromagnetic and Gravitational Perturbations

We study the quasi-normal modes (QNM) of electromagnetic and gravitational perturbations of a Schwarzschild black hole in an asymptotically Anti-de Sitter (AdS) spacetime. Some of the electromagnetic modes do not oscillate, they only decay, since they have pure imaginary frequencies. The gravitational modes show peculiar features: the odd and even gravitational perturbations no longer have the same characteristic quasinormal frequencies. There is a special mode for odd perturbations whose behavior differs completely from the usual one in scalar and electromagnetic perturbation in an AdS spacetime, but has a similar behavior to the Schwarzschild black hole in an asymptotically flat spacetime: the imaginary part of the frequency goes as 1/r+, where r+ is the horizon radius. We also investigate the small black hole limit showing that the imaginary part of the frequency goes as r+^2. These results are important to the AdS/CFT conjecture since according to it the QNMs describe the approach to equilibrium in the conformal field theory.Comment: 2 figure

Quantum Radiation from a 5-Dimensional Rotating Black Hole

We study a massless scalar field propagating in the background of a five-dimensional rotating black hole. We showed that in the Myers-Perry metric describing such a black hole the massless field equation allows the separation of variables. The obtained angular equation is a generalization of the equation for spheroidal functions. The radial equation is similar to the radial Teukolsky equation for the 4-dimensional Kerr metric. We use these results to quantize the massless scalar field in the space-time of the 5-dimensional rotating black hole and to derive expressions for energy and angular momentum fluxes from such a black hole.Comment: references added, accepted for publication in Physical Review