Combinatorial Tools for Regge Calculus

In this short note we briefly review some recent mathematical results relevant to the classical Regge Calculus evolution problem.Comment: 5 pages, LaTeX, no figures. To appear on the Proceedings of the 12th Italian Conference on General Relativity and Gravitational Physic

Explicitly symmetrical treatment of three-body phase space

We derive expressions for three-body phase space that are explicitly symmetrical in the masses of the three particles. We study geometrical properties of the variables involved in elliptic integrals and demonstrate that it is convenient to use the Jacobian zeta function to express the results in four and six dimensions.Comment: 20 pages, latex, 2 postscript figure

Tuberculosis incidence correlates with sunshine : an ecological 28-year time series study

Birmingham is the largest UK city after London, and central Birmingham has an annual tuberculosis incidence of 80 per 100,000. We examined seasonality and sunlight as drivers of tuberculosis incidence. Hours of sunshine are seasonal, sunshine exposure is necessary for the production of vitamin D by the body and vitamin D plays a role in the host response to tuberculosis. Methods: We performed an ecological study that examined tuberculosis incidence in Birmingham from Dec 1981 to Nov 2009, using publicly-available data from statutory tuberculosis notifications, and related this to the seasons and hours of sunshine (UK Meteorological Office data) using unmeasured component models. Results: There were 9,739 tuberculosis cases over the study period. There was strong evidence for seasonality, with notifications being 24.1% higher in summer than winter (p<0.001). Winter dips in sunshine correlated with peaks in tuberculosis incidence six months later (4.7% increase in incidence for each 100 hours decrease in sunshine, p<0.001). Discussion and Conclusion: A potential mechanism for these associations includes decreased vitamin D levels with consequent impaired host defence arising from reduced sunshine exposure in winter. This is the longest time series of any published study and our use of statutory notifications means this data is essentially complete. We cannot, however, exclude the possibility that another factor closely correlated with the seasons, other than sunshine, is responsible. Furthermore, exposure to sunlight depends not only on total hours of sunshine but also on multiple individual factors. Our results should therefore be considered hypothesis-generating. Confirmation of a potential causal relationship between winter vitamin D deficiency and summer peaks in tuberculosis incidence would require a randomized-controlled trial of the effect of vitamin D supplementation on future tuberculosis incidence

Seasonlity of Kawasaki Disease: A global perspective

The authors are for the Kawasaki Disease Global Climate ConsortiumBACKGROUND: Understanding global seasonal patterns of Kawasaki disease (KD) may provide insight into the etiology of this vasculitis that is now the most common cause of acquired heart disease in children in developed countries worldwide. METHODS: Data from 1970-2012 from 25 countries distributed over the globe were analyzed for seasonality. The number of KD cases from each location was normalized to minimize the influence of greater numbers from certain locations. The presence of seasonal variation of KD at the individual locations was evaluated using three different tests: time series modeling, spectral analysis, and a Monte Carlo technique. RESULTS: A defined seasonal structure emerged demonstrating broad coherence in fluctuations in KD cases across the Northern Hemisphere extra-tropical latitudes. In the extra-tropical latitudes of the Northern Hemisphere, KD case numbers were highest in January through March and approximately 40% higher than in the months of lowest case numbers from August through October. Datasets were much sparser in the tropics and the Southern Hemisphere extra-tropics and statistical significance of the seasonality tests was weak, but suggested a maximum in May through June, with approximately 30% higher number of cases than in the least active months of February, March and October. The seasonal pattern in the Northern Hemisphere extra-tropics was consistent across the first and second halves of the sample period. CONCLUSION: Using the first global KD time series, analysis of sites located in the Northern Hemisphere extra-tropics revealed statistically significant and consistent seasonal fluctuations in KD case numbers with high numbers in winter and low numbers in late summer and fall. Neither the tropics nor the Southern Hemisphere extra-tropics registered a statistically significant aggregate seasonal cycle. These data suggest a seasonal exposure to a KD agent that operates over large geographic regions and is concentrated during winter months in the Northern Hemisphere extra-tropics.published_or_final_versio

Antioxidant and antimicrobial potential of Asteraceae species

Asteraceae species have been largely used in folk medicine for several therapeutic purposes. Thus, the aim of this work was to investigate the in vitro antimicrobial and antioxidant activities of methanol extracts from plants belonging to the Asteraceae family, most of which are commonly used in traditional medicine. Chemical prospecting of extracts was also performed. The antimicrobial activity was evaluated through the broth microdilution susceptibility method and the antioxidant activity was determined through DPPH assay. Leaf extract of Baccharis dracunculifolia presented a significant antimicrobial activity against Pseudomonas aeruginosa,Bacillus cereus and Cryptococcus neoformans (0.005, 0.005 and 0.039 mg mL-1 MIC, respectively). Leaf extracts of Bidens segetum and Matricaria chamomilla were selective for Shigella sonnei and P. aeruginosa (0.005 and 0.078 mg mL-1 MIC, respectively). On the other hand, Acanthospermun australe and Baccharis trimera leaves only showed significant activity against Candida albicans (0.039 mg mL-1 MIC), while Taraxacum officinale leaves were active against both yeasts, with 0.039 mg mL-1 MIC. As regards antioxidant activity, extracts of B. dracunculifolia and T. officinale leaves and B. segetum inflorescences presented significant activity, with 5, 5 and 4 µg mL-1 IC50, respectively. The chemical prospecting identified the presence of flavonoids, terpenes and other compounds which may be responsible for the observed activities.Espécies da família Asteraceae são amplamente utilizadas na medicina popular para diversos fins terapêuticos. Neste contexto, este estudo teve por objetivo averiguar a atividade antimicrobiana e antioxidante in vitro de extratos metanólicos de plantas pertencentes a Asteraceae, a maioria comumente utilizada na medicina tradicional. A prospecção química dos extratos também foi realizada. A atividade antimicrobiana foi avaliada pelo método de susceptibilidade em microdiluição em caldo e a atividade antioxidante determinada pelo ensaio com o radical DPPH. O extrato da folha de Baccharis dracunculifolia apresentou significativa atividade antimicrobiana para Pseudomonas aeruginosa,Bacillus cereus e Cryptococcus neoformans (CIM = 0,005; 0,005 e 0,039 mg mL-1, respectivamente). Os extratos das folhas de Bidens segetum e Matricaria chamomilla foram seletivos para Shigella sonnei e P. aeruginosa (CIM = 0,005 e 0,078 mg mL-1, respectivamente). Já as folhas de Acanthospermun australe e Baccharis trimera apresentaram atividade significativa apenas para Candida albicans (CIM = 0,039 mg mL-1) enquanto as folhas de Taraxacum officinale foram ativos contra ambas leveduras com CIM 0,039 mg mL-1. Em relação à atividade antioxidante, os extratos das folhas de B. dracunculifolia, T. officinale e das inflorescências de B. segetum apresentaram significativa atividade com CI50 de 5, 5 e 4 µg mL-1, respectivamente. A prospecção química dos extratos identificou presença de compostos como flavonoides, terpenos e outros que podem ser responsáveis pelas atividades observadas

Breaking Of Conformal Invariance And Electromagnetic Field Generation In The Universe

It is shown that the breaking of the conformal invariance in quantum electrodynamics due to the trace anomaly results in the generation of long wave electromagnetic fields during inflationary stage of the universe evolution. If the coefficient of the logarithmic charge renormalization is large (due to a large number of charged particles species), these primordial electromagnetic fields can be strong enough to create the observed galactic magnetic fields.Comment: 6 pages, UM - TH - 93 - 0