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

Myiase scrotale chez l’enfant : à propos d’un cas

No Abstrac

Mitogen Activated Protein Kinase Phosphatase-1 Prevents the Development of Tactile Sensitivity In a Rodent Model of Neuropathic Pain

Neuropathic pain due to nerve injury is one of the most difficult types of pain to treat. Following peripheral nerve injury, neuronal and glial plastic changes contribute to central sensitization and perpetuation of mechanical hypersensitivity in rodents. The mitogen activated protein kinase (MAPK) family is pivotal in this spinal cord plasticity. MAPK phosphatases (MKPs) limit inflammatory processes by dephosphorylating MAPKs. For example, MKP-1 preferentially dephosphorylates p-p38. Since spinal p-p38 is pivotal for the development of chronic hypersensitivity in rodent models of pain, and p-p38 inhibitors have shown clinical potential in acute and chronic pain patients, we hypothesize that induction of spinal MKP-1 will prevent the development of peripheral nerve-injury-induced hypersensitivity and p-p38 overexpression. We cloned rat spinal cord MKP-1 and optimize MKP-1 cDNA in vitro using transfections to BV-2 cells. We observed that in vitro overexpression of MKP-1 blocked lipopolysaccharide-induced phosphorylation of p38 (and other MAPKs) as well as release of pro-algesic effectors (i.e., cytokines, chemokines, nitric oxide). Using this cDNA MKP-1 and a non-viral, in vivo nanoparticle transfection approach, we found that spinal cord overexpression of MKP-1 prevented development of peripheral nerve-injury-induced tactile hypersensitivity and reduced pro-inflammatory cytokines and chemokines and the phosphorylated form of p38

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

Impact de la Cochenille Phenacoccus manihoti (Homoptera, Pseudococcidae) sur les rendements du manioc (Manihot esculenta) au Gabon

La cochenille Phenacoccus manihoti est l’une des causes de la chute des rendements du manioc au Gabon. Par la randomisation, nous avons étudié  son impact sur la croissance de la plante et sur les rendements du manioc. P. manihoti réduit la croissance des plants à 40%, la distance entrenoeuds  des tiges à 45%. Il diminue le nombre, la longueur et le diamètre des tubercules ; respectivement pour le nombre de 7 à 4, de 34 à 9  cm pour la longueur et de 10 à 5 cm pour le diamètre en moyenne. L’action de la cochenille P. manihoti induit ainsi la dimunition de la croissance des  plants et la baisse des rendements du manioc au Gabon. Pour protéger le manioc contre la cochenille, nous pensons que l’utilisation des  techniques de lutte efficaces est indispensable. Elles pourraient même être associées, dans le cadre d’une lutte intégrée, excluant complètement la  lutte chimique, à l’origine de beaucoup de problèmes environnementaux. Les auteurs ont enfin attiré l’attention des gouvernements africains sur la  nécessité de promouvoir les politiques de développement agricole dans leurs pays. English title: Impact of the mealybug Phenacoccus manihoti (homoptera, pseudococcidae) on the yields of the cassava (Manihot esculenta) in Gabon The mealybug Phenacoccus manihoti is one of the causes in the drop of cassava yields in Gabon. Through the randomization, we have studied its  impact on the growth of the plant and on the yields of the cassava. P. manihoti reduces the growth of the plants to 40%, the interval among knots of  the stems to 45%. Its diminishes the number, the length and the diameter of the tubercules, respectively for the number of 7 to 4; of 34 to 9cm for  the length and for 10 to 5cm for the average diameter. Thus, the share of the mealybug P. manihoti induces the lessening of the growth of the plants  and the drop of the cassava yields in Gabon. For protect the cassava against the mealybug we think that the using of the efficient fight  techniques is indispensable. They must even be assoociated in integrated fight excuding completely the chemical fight which induces meny  environemental problems. At last the authors have attracted the car of the african governments abut the necessity to upgrade the agricultural  development politics in theirs contries.&nbsp