Encapsulation effects of galactomannans combined with xanthan on the survival of two lactic strains under simulated digestive hostilities

Galactomannans are the main component of locust bean gum from the fruit of the carob tree, Ceratonia siliqua L. They are a reserve of polysaccharides, found in the translucent endosperm of the seeds. They are designated as the best gels with thickening capacity and are, therefore, widely used as a natural food additive (E410) in many food, pharmaceutical and cosmetic preparations. In this study, we aim to exploit this gelling property of carob galactomannans in the microencapsulation of lactic bacteria in order to protect them from the negative effects of simulated digestive conditions. Two beneficial bacteria are used: Lactobacillus rhamnosus LBRE-LSAS and Bifidobacterium animalis subsp. lactis Bb12. Their survival in the free state or encapsulated in pure carob galactomannan gel combined with xanthan, was determined after residence in simulated in vitro digestive conditions (gastric: pH 2, pepsin 3 g/l and intestinal: bile 0.3%: W/V, pH 6.5. The results obtained show that gel encapsulation of carob galactomannans combined with xanthan improves the survival of these two beneficial strains to simulated digestive hostilities. the loss under gastric conditions 36.79% (3.55 log CFU/mL) for the non-encapsulated cells and only 12% (1.2 log CFU/mL) for the encapsulated ones. However, galactomannans alone do not appear to be effective in keeping a minimum of 106 bacterial cells viable when confronted with the hostile conditions of the digestive tract where they will be called upon to exert their positive effect on health. DOI: http://dx.doi.org/10.5281/zenodo.704863

Bayesian analysis of spectral mixture data using Markov Chain Monte Carlo Methods

This paper presents an original method for the analysis of multicomponent spectral data sets. The proposed algorithm is based on Bayesian estimation theory and Markov Chain Monte Carlo (MCMC) methods. Resolving spectral mixture analysis aims at recovering the unknown component spectra and at assessing the concentrations of the underlying species in the mixtures. In addition to non-negativity constraint, further assumptions are generally needed to get a unique resolution. The proposed statistical approach assumes mutually independent spectra and accounts for the non-negativity and the sparsity of both the pure component spectra and the concentration profiles. Gamma distribution priors are used to translate all these information in a probabilistic framework. The estimation is performed using MCMC methods which lead to an unsupervised algorithm, whose performances are assessed in a simulation study with a synthetic data set

The influence of immune cells on the existence of virus quasi-species

This article investigate a nonlocal reaction-diffusion system of equations modeling virus distribution with respect to their genotypes in the interaction with the immune response. This study demonstrates the existence of pulse solutions corresponding to virus quasi-species. The proof is based on the Leray-Schauder method, which relies on the topological degree for elliptic operators in unbounded domains and a priori estimates of solutions. Furthermore, linear stability analysis of a spatially homogeneous stationary solution identifies the critical conditions for the emergence of spatial and spatiotemporal structures. Finally, numerical simulations are used to illustrate nonlinear dynamics and pattern formation in the nonlocal model

Lågenergihus i torrt och varmt klimat

The construction sector currently accounts for 41.4% of the total energy consumption in Egypt and the residential sector accounts for more than half of all electricity consumed in the country. Therefore, there is great potential for reducing electricity use. Much of the electricity is used for lighting, air conditioning and hot water, a great part of this use can be reduced by passive climate control. We have made measurements in a traditional and a modern Egyptian house. Calculations of the building energy balance have also been carried out in order to find new ways to reduce the energy balance in the modern building. During the measurements, the relative humidity and temperature were measured. The traditional house is a good example of a 1600-1700 century private and wealthy Egyptian home that is using passive techniques to get a comfortable indoor climate. Measurements have been made in two different rooms: one in the southern part of the house with windows facing south and one in the northern part of the house with windows facing north. The room in the southern part of the house uses natural ventilation to cool the building. The modern house is a low-energy house and a good example of a modern house that uses passive techniques such as windcatcher to achieve comfortable indoor climate. Even a qualitative comparison was made between the traditional and the modern building. The calculation Program VIP Energy has been used to make energy balance calculation for the modern low-energy building. Energy calculation has been made for five different cases: - With no change in the building envelope - With external thermal insulation in the exterior walls - With internal thermal insulation in the exterior walls - With thermal insulation in the foundation - With additional insulation in the roof structure The results of these calculations show that the greatest reduction of required heat supply is with external thermal isolation in the exterior walls. When no change has been made in the building envelope, the required heat supply is 35.9 kWh / m² per year and with 50 mm mineral wool in the exterior walls, the heat supply is 14.3kWh/m² per year. The calculations also show that the required heat supply increases with thermal insulation in the foundation

On a two-strain epidemic model involving delay equations

We propose an epidemiological model for the interaction of either two viruses or viral strains with cross-immunity, where the individuals infected by the first virus cannot be infected by the second one, and without cross-immunity, where a secondary infection can occur. The model incorporates distributed recovery and death rates and consists of integro-differential equations governing the dynamics of susceptible, infectious, recovered, and dead compartments. Assuming that the recovery and death rates are uniformly distributed in time throughout the duration of the diseases, we can simplify the model to a conventional ordinary differential equation (ODE) model. Another limiting case arises if the recovery and death rates are approximated by the delta-function, thereby resulting in a new point-wise delay model that incorporates two time delays corresponding to the durations of the diseases. We establish the positiveness of solutions for the distributed delay models and determine the basic reproduction number and an estimate for the final size of the epidemic for the delay model. According to the results of the numerical simulations, both strains can coexist in the population if the disease transmission rates for them are close to each other. If the difference between them is sufficiently large, then one of the strains dominates and eliminates the other one

Thermodynamic Analysis of Moisture Adsorption of Taraxacum Officinale’ Powder

This work aims to model the adsorption isotherms and study the essential thermodynamic properties of Taraxacum Officinale’ powder during the moisture adsorption phenomenon at three temperatures 30, 40, and 50°C. The results have been determined by the application of the thermodynamics physical principles to the equilibrium data, which are experimentally measured. The estimated values of the isokinetic and harmonic temperatures and the Gibbs free energy change revealed that the sorption process is non-spontaneous and enthalpy driven

Permanence and periodic solution for a modified Leslie-Gower type predator-prey model with diffusion and non constant coefficients

In this paper we study a predator-prey system, modeling the interaction of two species with diffusion and T-periodic environmental parameters. It is a Leslie-Gower type predator-prey model with Holling-type-II functional response. We establish some sufficient conditions for the ultimate boundedness of solutions and permanence of this system. By constructing an appropriate auxiliary function, the conditions for the existence of a unique globally stable positive periodic solution are also obtained. Numerical simulations are presented to illustrate the results

Critères de gravité des brûlures: à propos de 337 cas de brûlés au Maroc

L'objectif était d'étudier les critères de gravité des brûlures chez des patients brûlés hospitalisés à  l'hôpital militaire d'instruction Mohamed V de Rabat. Il s'agit d'une étude rétrospective qui concernait 337 patients hospitalisés de 2004 à 2010. Les variables étudiés sont: l'âge, la surface corporelle brûlée, la profondeur, la localisation de la brûlure, l'indice de Baux et le score unité de brûlure standard. Ces  variables ont étaient analysés par une analyse en composante principale suivie d'une analyse de survie pour déterminer les facteurs  influençant la gravité de la brûlure. Parmi les 337 brûlés hospitalisés dans le service, nous avons enregistrés 19 décès. Le taux global de mortalité était 5,9%. L'analyse univariée a montrée que la TBSA ≥20%, la localisation de la brûlure au niveau de la tête et des  membres supérieurs et les scores pronostiques étaient statistiquement associés significativement à la mortalité. Toutes ces variables ont était inclus dans le  modèle de Cox pour une analyse multivariée et seulement la TBSA ≥20%, la localisation de la brûlure au niveau de la tête et des membres supérieurs et les indices  pronostiques sont des facteurs aggravant de la brûlure. La TBSA ≥20%, la localisation de la brûlure au niveau de la tête et des membres supérieurs et les scores pronostiques sont des facteurs prédictifs de la mortalité.Key words: Surface corporelle brölée, localisation de la brölure, mortalit