Essai de domestication de lentinus squarrosulus mont. a partir d’une souche du Gabon

Dans le cadre d’un vaste programme de valorisation des ressources biologiques initié par les autorités gabonaises en vue de garantir la sécurité alimentaire des populations locales, une souche sauvage de Lentinus squarrosulus récoltée au nord du Gabon, a été mise en culture en utilisant essentiellement des matériaux locaux. Au cours de ce processus, cinq principales étapes ont été mise en œuvre; il s’agit notamment de la production du blanc de semis et du substrat de culture, du lardage du substrat, de l’incubation et de la  fructification du champignon. La production du blanc regroupe les étapes qui ont obligatoirement été exécutées dans un laboratoire parfaitement équipé en vue de garantir des conditions d’asepsie rigoureuses, tandis que la production du substrat de culture, l’inoculation et l’incubation ont parfaitement été réalisées à l’échelle villageoise en utilisant du matériel de fabrication traditionnelle; notamment une unité de pasteurisation constituée d’un fût en aluminium de 250 litres muni d’étagères et d’une chambre contenant de l’eau, ainsi qu’une armoire traditionnelle d’inoculation. Par ce processus, quatre-vingt sacs de 1kg ont été inoculés dont quatorze ont montré un très bon envahissement mycélien et une fructification satisfaisante; ce qui donne un rendement en terme de sac d’environ 17 %. Cependant, cinquante-six sacs n’ont pas été bien envahis par le mycélium et n’ont donc pas donné de champignon, de plus dix sacs ont été contaminés. Mots clés : domestication, souche sauvage, Lentinus squarrosulus, matériaux locaux, Gabon English title: Domestication test of lentinus squarrosulus mont. from a Gabon strain As part of a vast program to develop biological resources initiated by the Gabonese authorities with a view to guaranteeing food security for local populations, a wild strain of Lentinus squarrosulus harvested in northern Gabon was cultivated using mainly local materials. During this process, five main steps were implemented; these include the production of seedling white and growing medium, larding of the substrate, incubation and fruiting of the fungus. The production of the blank includes the steps which must have been carried out in a perfectly equipped laboratory in order to guarantee rigorous aseptic conditions, while the production of the culture substrate, inoculation and incubation have been perfectly carried out at village scale using traditional manufacturing  equipment; including a pasteurization unit consisting of a 250-liter aluminum drum with shelves and a chamber containing water, as well as a traditional inoculation cabinet. By this method, eighty bags (1kg) were inoculated, fourteen of which showed very good mycelial invasion and satisfactory fruiting; which gives a yield of around 17%. However, fifty-six bags were not well invaded by the mycelium and therefore did not give a fungus, and ten bags were contaminated. Keywords: domestication, wild strain, Lentinus squarrosulus, local materials, Gabo

A Chebychev propagator with iterative time ordering for explicitly time-dependent Hamiltonians

A propagation method for time-dependent Schr\"odinger equations with an explicitly time-dependent Hamiltonian is developed where time ordering is achieved iteratively. The explicit time-dependence of the time-dependent Schr\"odinger equation is rewritten as an inhomogeneous term. At each step of the iteration, the resulting inhomogeneous Schr\"odinger equation is solved with the Chebychev propagation scheme presented in J. Chem. Phys. 130, 124108 (2009). The iteratively time-ordering Chebychev propagator is shown to be robust, efficient and accurate and compares very favorably to all other available propagation schemes

Trypanosoma brucei gambiense in domestic livestock of Kogo and Mbini foci (Equatorial Guinea).

OBJECTIVE: To evaluate Trypanosoma brucei gambiense infection in peri-domestic livestock from Kogo and Mbini foci (Equatorial Guinea) in order to investigate its possible implication in the sleeping sickness transmission cycle in these hypoendemic foci. METHODS: Samples from 698 domestic animals (goats, sheep and pigs) from trypanosomiasis-endemic localities of Kogo and Mbini foci were tested for animal trypanosomes and T. b. gambiense (group I) by species-specific polymerase chain reaction. RESULTS: Trypanosoma brucei s.l., the predominant trypanosome species, was detected in 182 (52.6%) samples from Mbini and in 127 (36.1%) samples from Kogo. T. b. gambiense was only identified in seven (2%) of the Mbini samples and one co-infection (with T. vivax) was observed. CONCLUSION: The occurrence of T. b. gambiense in peri-domestic livestock in Mbini and its absence in Kogo could explain the epidemiological differences between the two foci and could have significant implications for sleeping sickness control in Equatorial Guinea

New, Highly Accurate Propagator for the Linear and Nonlinear Schr\"odinger Equation

A propagation method for the time dependent Schr\"odinger equation was studied leading to a general scheme of solving ode type equations. Standard space discretization of time-dependent pde's usually results in system of ode's of the form u_t -Gu = s where G is a operator (matrix) and u is a time-dependent solution vector. Highly accurate methods, based on polynomial approximation of a modified exponential evolution operator, had been developed already for this type of problems where G is a linear, time independent matrix and s is a constant vector. In this paper we will describe a new algorithm for the more general case where s is a time-dependent r.h.s vector. An iterative version of the new algorithm can be applied to the general case where G depends on t or u. Numerical results for Schr\"odinger equation with time-dependent potential and to non-linear Schr\"odinger equation will be presented.Comment: 14 page

Errors in quantum optimal control and strategy for the search of easily implementable control pulses

We introduce a new approach to assess the error of control problems we aim to optimize. The method offers a strategy to define new control pulses that are not necessarily optimal but still able to yield an error not larger than some fixed a priori threshold, and therefore provide control pulses that might be more amenable for an experimental implementation. The formalism is applied to an exactly solvable model and to the Landau-Zener model, whose optimal control problem is solvable only numerically. The presented method is of importance for applications where a high degree of controllability of the dynamics of quantum systems is required.Comment: 13 pages, 3 figure

Security Implications of Adopting a New Data Storage and Access Model in Big Data and Cloud Computing

This article examines the security implications of using cloud computing and Big Data. It employs a mixed methodology of qualitative and quantitative research and takes a critical realist epistemological approach. The objective is to identify the components of a theory for predicting and explaining [1, 4] the security implications associated with adopting the services provided by cloud computing and Big Data. The integration of various information sources and the widespread use of computing across diverse fields have resulted in a significant increase in data volume, scale, quantity, and diversity. Consequently, data management, storage, retrieval, and access have undergone significant changes. The latest developments in IT have brought forth novel technologies such as Cloud Computing and Big Data. Big Data comprises of technologies that rely on NoSQL (Not only SQL) databases, which enable the growth of data volumes, numbers, and types on a large scale. The new NoSQL systems are seen as solutions for meeting scalability requirements of large IT firms. Multiple open-source and pay-as-you-go NoSQL models are available for purchase

Viral markers of hepatitis B, C and D and HB vaccination status of a health care team in a rural district of Cameroon

UNLABELLED: Ninety-three health care workers (HCW) in the Tokombere sahelian district volunteered to participate in a trial to investigate viral markers of hepatitis B, C, and D and HB vaccination status. METHODS: . Sera were tested using the Vikia HBsAg kit followed by CMIA for detection of HBsAg, anti-HBs, anti-HBc, and anti-HCV. HBsAg-positive HCW were tested for HBV-DNA, anti-HDV, and, if positive for anti-HDV, HDV-RNA.RESULTS: Analysis of anti-HBc positivity indicated that 91% of HCW had been infected by HBV, regardless of vaccination history. Vikia HBsAg results were confirmed by chemiluminescent microparticle immunoassay (CMIA) in all HCW and were positive in 17 HCW with virus load >2000 IU/mL in 6 and HDV co-infection in 6. Anti-HCV was found in 6 HCW. Among the 55 HCW that had not been vaccinated, only 3 needed vaccination because of anti-HBc negativity. Among HCW considered for HBV treatment, one patient presenting HBV/HDV co-infection was excluded after diagnosis of hepatocarcinoma. CONCLUSION: Systematic HB vaccination of new HCW appears unnecessary in this rural region of Africa. Anti-HBc screening is cost-effective for identifying HCW requiring vaccination. Vikia HBsAg is effective for point-of-care screening. We underline the need for universal early (preferably neonatal) HB vaccination and for availability of anti-HBV drug in limited-resource countries

A mid-infrared Mueller ellipsometer with pseudo-achromatic optical elements

The purpose of this article is to present a new broadband Mueller ellipsometer designed to work in the mid-infrared range, from 3 to 14 microns. The Mueller ellipsometer, which can be mounted in reflection or in transmission configuration, consists of a polarization state generator (PSG), a sample holder, and a polarization state analyzer (PSA). The PSG consists in one linear polarizer and a retarder sequentially rotated to generate a set of four optimal polarization states. The retarder consists in a bi-prism made of two identical Fresnel rhombs disposed symmetrically and joined by optical contact, giving the ensemble a "V" shape. Retardation is induced by the four total internal reflections that the beam undergoes when it propagates through the bi-prism. Total internal reflection allows to generate a quasi-achromatic retardation. The PSA is identical to the PSG, but with its optical elements mounted in reverse order. After a measurement run, the instrument yields a set of sixteen independent values, which is the minimum amount of data required to calculate the Mueller matrix of the sample. The design of the Mueller ellipsometer is based on the optimization of an objective criterion that allows minimizing the propagation of errors from raw data to the Mueller matrix of the sample. The pseudo-achromatic optical elements ensure a homogeneous quality of the measurements for all wavelengths. The performance of the Mueller ellipsometer in terms of precision, and accuracy, is discussed and illustrated with a few examples