Inventaire des vergers de mangues dans le cercle de Bougouni au Mali : Approche par Télédétection

Objectif : Cette étude est réalisée dans le but d’organiser rationnellement la filière mangue constitue une importante source de revenus au Mali.Méthodologie et résultats : L’approche de détection et d’inventaire utilisée dans cette étude est essentiellement fondée sur l’exploitation d’une image satellitaire qui présente une fiabilité telle qu’elle mérite d’être généralisée pour la recherche afin de redonner vie à cette filière. Comme principaux résultats nous avons la répartition spatiale des vergers de mangues et la localisation de ceux attaqués par les insectes.Conclusions et application des résultats : De ces résultats, on peut retenir que la Télédétection a considérablement joué un rôle primordial dans le suivi et l’évaluation de la filière pour sa réorganisation à Bougouni.Mots clés : Vergers de mangue, inventaire par Télédétection, cercle de Bougouni, Mali

Approche SIG pour une analyse spatiale des infrastructures hydrauliques dans la commune de Zè, Benin

Objectif : cette étude est réalisée dans le but de faire l’inventaire des infrastructures hydrauliques afin d’analyser leur distribution spatiale.Méthodologie et résultats : La démarche méthodologique utilisée est exclusivement basée sur l’utilisation des données attributaires et spatiales en utilisant le logiciel ArcGIS 9.3.Des zones tampons (buffer) ont été réalisées afin d’apprécier la distribution spatiale et de voir la zone de desserte des points d’eau. Elles constituent une technique permettant de visualiser les espaces où la couverture des infrastructures hydrauliques est très dense, donc l’accessibilité physique très bonne. Les résultats obtenus montrent que les infrastructures hydrauliques sont inégalement réparties sur le territoire de la commune de Zè. La partie Nord-est de la commune est presque dépourvue en infrastructure hydraulique.Conclusions et application des résultats : De ces résultats, on peut retenir que la cartographie et surtout le SIG jouent un rôle primordial dans l’implantation, le suivi et la gestion des infrastructures hydrauliques. L’utilisation de ces outils peut atténuer les difficultés d’approvisionnement en eau.Mots clés : SIG, distribution spatiale, infrastructure hydraulique, Zè, Bénin.ABSTRACTObjective: This study was carried out with the aim of taking stock of water infrastructure in order to analyze their spatial distribution.Methods and Results: The methodology used is based solely on the use of spatial and attribute data using ArcGIS 9.3 software. Buffer zones were established to assess the spatial distribution and highlight the service area of the water points. This constitutes a technique to view areas where coverage of water infrastructure is very dense, with very good physical accessibility. The results show that water infrastructure is unevenly distributed on the municipality of Zè. The north-eastern part of the town is almost devoid of hydraulic infrastructure. Conclusions and application of results: From these results, we can say that the above mapping and GIS play a key role in the implementation, monitoring and management of water infrastructure. The use of these tools can facilitate the difficult conditions for water supply.Keywords: GIS, spatial distribution, hydraulic infrastructure, Zè, Benin

Bilateral facial nerve palsy secondary to an atypical presentation of Gullain-Barré syndrome

Bilateral simultaneous facial nerve palsy is an extremely rare clinical entity and may occur in association with a variety of neurological, infectious, neoplastic or degenerative disorders. We describe a patient, who presented with facial diplegia and normal reflexes on examination. During the entire hospitalization, he developed no motor weakness and remained ambulatory. Whether treatment is warranted for this and other milder variants of Gullain-Barré syndrome is also discussed. Atypical presentations with preserved or brisk reflexes, can be a diagnostic dilemma

Cerebrospinal fluid in the diagnosis of spinal schistosomiasis

Cerebrospinal fluid (CSF) changes in spinal shistosomiasis have been described. Its characteristic features are mild to moderate pleocytosis, presence of eosinophils, slight to moderate protein increase, elevated gamma globulin concentration and a positive immune assay. Nevertheless, these abnormalities are not always present together and therefore difficulties may arise in the assessment of the diagnosis. The purpose of this paper is to evaluate the importance of each CSF alteration concerning the diagnosis in 22 cases of spinal shistosomiasis. According to the results, only 20% of the cases had all the five feature that are considered to be characteristic of spinal shistomiasis. Abnormal cell count was present in 86%, protein increase in 77.3%, immunoglobulin G increase in 60,8%, eosinophils were present in 36.8% and indirect fluorescent antibody test was positive in 68.2%. In three cases all CSF parameters studied were within the normal limits. As the most specific test among those described was the indirect fluorescent antibody test, it should be regarded for the diagnosis.As três espécies de esquistossoma podem comprometer o sistema nervoso. O S. mansoni é responsável pela esquistossomose no Brasil, sendo a mielopatia uma forma grave desta helmintose. O propósito deste trabalho é analisar as alterações do líquido cefalorraquidiano (LCR) para dar mais subsídios para o diagnóstico da esquistossomose raquimedular. Fizeram parte deste estudo 22 amostras de LCR de pacientes com esquistossomose espinal. Os resultados das análises destas amostras mostraram que a associação de alterações do LCR com quadro inflamatório e RIFI-IgM positiva ocorreu em 88% dos pacientes, que o eosinófilo esteve presente em apenas 7 amostras (36,8%), e que 3 dos 22 pacientes estudados apresentaram LCR normal. Conclui-se que o exame de LCR é coadjuvante muito útil para o diagnóstico da neuroesquistossomose.Universidade Estadual de Londrina Centro de Ciências da SaúdeUniversidade Federal de São Paulo (UNIFESP)Universidade de São Paulo Faculdade de Ciências Farmacêuticas Departamento de Análises ClínicasUNIFESPSciEL

Oscillatory, Computational, and Behavioral Evidence for Impaired GABAergic Inhibition in Schizophrenia

The dysconnection hypothesis of schizophrenia (SZ) proposes that psychosis is best understood in terms of aberrant connectivity. Specifically, it suggests that dysconnectivity arises through aberrant synaptic modulation associated with deficits in GABAergic inhibition, excitation-inhibition balance and disturbances of high-frequency oscillations. Using a computational model combined with a graded-difficulty visual orientation discrimination paradigm, we demonstrate that, in SZ, perceptual performance is determined by the balance of excitation-inhibition in superficial cortical layers. Twenty-eight individuals with a DSM-IV diagnosis of SZ, and 30 age- and gender-matched healthy controls participated in a psychophysics orientation discrimination task, a visual grating magnetoencephalography (MEG) recording, and a magnetic resonance spectroscopy (MRS) scan for GABA. Using a neurophysiologically informed model, we quantified group differences in GABA, gamma measures, and the predictive validity of model parameters for orientation discrimination in the SZ group. MEG visual gamma frequency was reduced in SZ, with lower peak frequency associated with more severe negative symptoms. Orientation discrimination performance was impaired in SZ. Dynamic causal modeling of the MEG data showed that local synaptic connections were reduced in SZ and local inhibition correlated negatively with the severity of negative symptoms. The effective connectivity between inhibitory interneurons and superficial pyramidal cells predicted orientation discrimination performance within the SZ group; consistent with graded, behaviorally relevant, disease-related changes in local GABAergic connections. Occipital GABA levels were significantly reduced in SZ but did not predict behavioral performance or oscillatory measures. These findings endorse the importance, and behavioral relevance, of GABAergic synaptic disconnection in schizophrenia that underwrites excitation-inhibition balance

Extreme Mitogenomic Variation in Natural Populations of Chaetognaths

The extent of within-species genetic variation across the diversity of animal life is an underexplored problem in ecology and evolution. Although neutral genetic variation should scale positively with population size, mitochondrial diversity levels are believed to show little variation across animal species. Here, we report an unprecedented case of extreme mitochondrial diversity within natural populations of two morphospecies of chaetognaths (arrow worms). We determine that this diversity is composed of deep sympatric mitochondrial lineages, which are in some cases as divergent as human and platypus. Additionally, based on 54 complete mitogenomes, we observed mitochondrial gene order differences between several of these lineages. We examined nuclear divergence patterns (18S, 28S, and an intron) to determine the possible origin of these lineages, but did not find congruent patterns between mitochondrial and nuclear markers. We also show that extreme mitochondrial divergence in chaetognaths is not driven by positive selection. Hence, we propose that the extreme levels of mitochondrial variation could be the result of either a complex scenario of reproductive isolation, or a combination of large population size and accelerated mitochondrial mutation rate. These findings emphasize the importance of characterizing genome-wide levels of nuclear variation in these species and promote chaetognaths as a remarkable model to study mitochondrial evolution

The reference frame for encoding and retention of motion depends on stimulus set size

YesThe goal of this study was to investigate the reference frames used in perceptual encoding and storage of visual motion information. In our experiments, observers viewed multiple moving objects and reported the direction of motion of a randomly selected item. Using a vector-decomposition technique, we computed performance during smooth pursuit with respect to a spatiotopic (nonretinotopic) and to a retinotopic component and compared them with performance during fixation, which served as the baseline. For the stimulus encoding stage, which precedes memory, we found that the reference frame depends on the stimulus set size. For a single moving target, the spatiotopic reference frame had the most significant contribution with some additional contribution from the retinotopic reference frame. When the number of items increased (Set Sizes 3 to 7), the spatiotopic reference frame was able to account for the performance. Finally, when the number of items became larger than 7, the distinction between reference frames vanished. We interpret this finding as a switch to a more abstract nonmetric encoding of motion direction. We found that the retinotopic reference frame was not used in memory. Taken together with other studies, our results suggest that, whereas a retinotopic reference frame may be employed for controlling eye movements, perception and memory use primarily nonretinotopic reference frames. Furthermore, the use of nonretinotopic reference frames appears to be capacity limited. In the case of complex stimuli, the visual system may use perceptual grouping in order to simplify the complexity of stimuli or resort to a nonmetric abstract coding of motion information