Uncertainty quantification in mechanistic epidemic models via cross-entropy approximate Bayesian computation

This paper proposes a data-driven approximate Bayesian computation framework for parameter estimation and uncertainty quantification of epidemic models, which incorporates two novelties: (i) the identification of the initial conditions by using plausible dynamic states that are compatible with observational data; (ii) learning of an informative prior distribution for the model parameters via the cross-entropy method. The new methodology's effectiveness is illustrated with the aid of actual data from the COVID-19 epidemic in Rio de Janeiro city in Brazil, employing an ordinary differential equation-based model with a generalized SEIR mechanistic structure that includes time-dependent transmission rate, asymptomatics, and hospitalizations. A minimization problem with two cost terms (number of hospitalizations and deaths) is formulated, and twelve parameters are identified. The calibrated model provides a consistent description of the available data, able to extrapolate forecasts over a few weeks, making the proposed methodology very appealing for real-time epidemic modeling

Saccharomyces cerevisiae Peroxiredoxins in Biological Processes: Antioxidant Defense, Signal Transduction, Circadian Rhythm, and More

The yeast Saccharomyces cerevisiae is a model organism for biochemical and genetic studies, and several very important discoveries of fundamental biological processes have been conducted using this yeast as an experimental organism. An emerging concept, which is validated by several works using this organism, relies on the biological importance of oxidant species, specially the hydroperoxides. These molecules were formed during aerobic biological process and control several intracellular mechanisms such as a range of signaling pathways, cell cycle, programmed cell death, circadian rhythm, aging, and lifespan extension. Thereby, cellular homeostasis depends on a refined control of hydroperoxides levels and low-molecular-weight molecules in combination with antioxidant enzymes playing a role in this equilibrium. This proposal is focused on the S. cerevisiae peroxiredoxins and their role in peroxide decomposition, signal transduction, circadian clocks, and aging as model enzymes for the study and comprehension of these biological processes in living organisms, including humans

Pretibial myxoedema: a case report with scanning electron microscopy.

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Vegetative Propagation of \u3cem\u3eStylosanthes scabra\u3c/em\u3e

One way to multiply genetically desirable plants in a more uniform manner is to use vegetative propagation, such as using plant cuttings. This technique multiplies a single plant into several, in an easy low-cost system (Fachinello et al. 2005), so it is useful in plant breeding. This technique may be enhanced through the use of hormonal regulators, with indolebutyric acid (IBA) being most frequently used, because of its stability in hydroalcoholic solution, low sensitivity to biological degradation and good establishment of adventitious roots (Fachinello et al. 1995). In spite of its large-scale use for fruit production, the technique is not commonly used for forage species, such as Stylosanthes. We evaluated different concentrations of IBA for root establishment and initial development of Stylosanthes scabra cuttings

Optimization of clavulanic acid production by Streptomyces daufpe 3060 by response surface methodology

Clavulanic acid is a β-lactam antibiotic which has a potent β-lactamase inhibiting activity. In order to optimize its production by the new isolate Streptomyces DAUFPE 3060, the influence of two independent variables, temperature and soybean flour concentration, on clavulanic acid and biomass concentrations was investigated in 250 mL-Erlenmeyers according to a 2² central composite design. To this purpose, temperature and soybean flour (SF) concentration were varied in the ranges 26-34°C and 10-50 g/L, respectively, and the results evaluated utilizing the Response Surface Methodology. The experimental maximum production of clavulanic acid (629 mg/L) was obtained at 32°C and 40 g/L SF after 48 h, while the maximum biomass concentration (3.9 g/L) at 30°C and 50 g/L soybean flour, respectively. These values are satisfactorily close to those (640 mg/L and 3.75 g/L, respectively) predicted by the model, thereby demonstrating the validity of the mathematical approach adopted in this study.Brazilian Research Funding InstitutionsCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES