Essais d'épuration des eaux usées de Marrakech par la jacinthe d'eau (Charges organique, bactérienne et parasitologique)

Cette étude est destinée à tester expérimentalement les capacités d'épuration des eaux usées par lagunage à macrophytes (jacinthe d'eau : Eichhornia crassipes), sous les conditions climatiques de Marrakech.L'installation fonctionne en continu avec un débit constant à l'entrée de 10 l/min. La charge admise est de 40 g DCO/M2/j.Sous l'aspect de la production de biomasse végétale, les effluents domestiques constituent un bon substrat nutritionnel. Les taux de croissance et les productions obtenues montrent dans l'ensemble une excellent adaptation d'Eichhornia crassipesà ce milieu. Le maximum de biomasse et de productivité ont été obtenu en période estivale et sont respectivement de: 40 kg MF/m2 et 38,6 MS/m2/j. Il s'est avéré également que la jacinthe d'eau est persistante toute l'année sous le climat méditerranéen aride de Marrakech.L'épuration des eaux usées domestiques par lagunage à macrophyles aboutit à des rendements satisfaisants surtout en période estivale où on obtient un abattement de 87 % de la DCO et une réduction de 95 % des MEST.Sur te plan sanitaire, l'abattement de la charge bactérienne exprimée par les bactéries témoins de contamination fécale peut atteindre jusqu'à 2ULog pour un temps de séjour théorique très court (7 jours).Ce système e par ailleurs fourni des abattement de 100 % des oeufs d'helminthes parasites au niveau de l'eau épurée.The aim of the present study is to experimentaly test the capacities of the mater hyacinth (Eichhornia crassipes) in order to purify wastewater under Manakesh climatic conditions.The experiment was carried al wastewater spreading zone of Marrakesh pretraitement.The experimant's installation is made of two lined water yacinth ponds that receive domestic wastewater.The proposed process is a continuous system with a constant flow rate of 10 l/mn. The theoritical retention time was estimated to 7 days. The allowed load is 40 g COD/m2/day. Macrophytic biomass was observed for both ponds during the experimental period (Match, 1986 - February, 1987). Parameters of organic, bacterial and parasitological loads are studied in order to determine the system efficiency under arid climate.Obtained results show the water hyacinth ability to adapt to Marrakesh climatic conditions. The number of plants doubled at 12 days, this is coherent with results obtained by PENFOUND (1956), BOCK (1969), WESTLAKE (1963, 1975) and SCULTHORPE (1967). Maximum biomass level and productivity were achieved during the summer period : 40 kg WW/m2/day and 38,6 g DW/m2/day respectively. Biomass and productivity obtained under arid climate are similar to results obtained by WOOTEN and DODD (1976), and by DINGES (1976) under subtropical conditions, and higher than chose obtained by JOHN (1985) under temperate climate. The growth period of water hyacinth is estimated to 9 months at Marrakesh, 10 months at subtropical climate (WOLVERTON and MC DONALD, 1976) and limited to 6 months under cold climate (COPELLI et al., 1982; DUBOIS, 1983; SAUZE, 1983; DE CASABIANCA, 1985). Temperature is considered as a limited growth factor of water yacinth. According to FRANCOIS et al. (1977), the water hyacinth growth was stopped when the temperature is lower than 10 °C. Linder Marrakesh arid climate, the temperature is always higher than 10 °C. It was also found that the water hyacinth survive all a year around in the arid climate of Marrakesh.Domestic sewage purification by water hyacinth leads to satisfactory efficiency during the summer concerning reduction of COD: 87 % and TSS : 95 %. This phenomenon may be jointed to the retention time wich was lengthed (9,4 days) in the summer, and the higher biomass density of water hyacinths in this one. The purifying action of floating macrophytes (Eichharnia crassipes) is physical and biological. The root system stabilizes the medium thus favoring sedimentation of TSS and particulate COD both on the bottom of the tank and by trapping in the root hairs. Elimination of COD is realized by means of the action of bacteria which are present, by sedimentation of particulate COD and root filtration.The biological action of the plants is not an important mechanism for COD elimination. The system efficiency is low at the winter and the reduction of COD and TSS have not exceed 60 % and 82 % respectively because the degenering of the water hyacinths.From sanitary point of view, bacterial load reduction expressed by control faecal contamination bacteria achieved 2 log Units for a short theoritical retention time (7 days). This is higher than the result obtained by DUBOIS (1985). Two hypothesis are given to explain reduction of bacterial load by water hyacinths :1) the bacteria are sedimented or trapped in the root hairs of the water hyacinths whith TSS. 2) Water hyacinths may have a capacity to secrete a chemical substance wich could have bactericid or bacteriostatic effect. The improvement of retention time and the addition of one or two supplementary ponds will probably lead to better results. Moreover, this process had also reduced parasitical helminth eggs to undetectable levels (100 %). The parasitical helminth eggs distinguisched at domestic sewage received by the experimental installation, are Taenia, Hymenolepis, Trichuris and Ascaris geints. Their total number vary tram 0 to 120 eggs/l with a mean of 32. Other types of eggs could be encountred generally in waste water as : Toxocara, Oxyure, Capillaria and Taxoascaris (FOX and FITZGERALD,1976) but was not detected by our technique. No helminth eggs were found in purified wastewater descended through water hyacinth ponds. This phenomenon is explained by supposing that the helminth eggs are present in the effluent but it was the detection limit of the employed technique (Bailenger method), or there is no eggs really at the effluent because of their higher specific weight. Ascaris, Taenia and Trichuris eggs have a sedimentation rate of 0,65 m/h, 0,26 m/h and 1,5 m/h respectively (FEACHEM et al.,1983). The eggs sedimented rapidly in the water hyacinths ponds involving a transfer of the effluent pollution to the sediment. Several authors affirmed that the stabilization ponds are an effective means to reduce parasitical helminth eggs of the wastewaters (GLOYNA, 1972; KOWAL, 1985). Hence, if the parasitical risk could be controled in the purified water (effluent), particular attention should be given to sediments. It is also important to point out, that no parasitical nematode is found at the influent. Nematofauna associated to wastewater and roots of water hyacinth, was represented by bacteria consumer nematode. The abundance of nematode is definite by the existence of bacterial food in the wastewaters (CALAWAY, 1963; SHIEMER, 1976). The principal genus determined are Rhabditis sp, Plectus sp. and Mononchoïdes sp. It appears that Rhabditis genus, is dominant in the first pond (94,7 %) of the nematode population. However, the two genus Rhabditis sp. and Plectus sp. are dominant in the second one and represent 50 % and 49 % respectively. The presence of Plectidae in the second basin indicates that is less loaded (ZULINI, 1976). However, under the arid climate conditions of Marrakesh, the process based on water hyacinth for wastewater purification, is faced with two major problems : first, the water loss by evapotranspiration reachs 60 % during the summer time under arid climate of Marrakesh. The development of Mousquito particularly in the summer, constitutes the second problem of our proposed process. Moreover, front economical point of view, the water hyacinths show a good productivity in the summer under arid climate and could be exploited in several field

Le partenariat orthophoniste – psychologue dans la prise en charge d’un déficit d’expression

Parfois la prise en charge orthophonique rencontre une limite qui est l’aspect psychologique de la problématique. Le travail en collaboration avec un psychologue peut s’avérer nécessaire mais rencontre un certain nombre de contraintes qui rendent impossible cette participation. Cet article présente un outil qui encourage l’expression d’une problématique psychologique et éventuellement des réajustements internes à la personne sans intervention extérieure. Pour ce faire, l’Epreuve des Trois Arbres utilise la médiation de l’arbre, favorise le discours subjectif en écartant tout jugement. L’arbre a été choisi en raison des nombreuses analogies que l’esprit établit spontanément entre un être humain et un arbre. Suite à un accompagnement orthophonique, l’étude de cas présentée retrace une pratique qui comprend une phase test avec l’Epreuve des Trois Arbres, un accompagnement personnalisé basé sur la production de saynètes centrées sur le thème de l’arbre et une phase retest. L’approche phénoménologique qui vise l’expression d’un discours subjectif, a permis une évolution considérable du cas présenté en réinstallant des voies de sens depuis le point de vue du sujet. L’Epreuve des Trois Arbres constitue un outil pour dépasser des limitations disciplinaires au service de la personne

Deep brain stimulation of the subthalamic nucleus modulates sensitivity to decision outcome value in Parkinson's disease.

Deep brain stimulation (DBS) of the subthalamic nucleus in Parkinson's disease is known to cause a subtle but important adverse impact on behaviour, with impulsivity its most widely reported manifestation. However, precisely which computational components of the decision process are modulated is not fully understood. Here we probe a number of distinct subprocesses, including temporal discount, outcome utility, instrumental learning rate, instrumental outcome sensitivity, reward-loss trade-offs, and perseveration. We tested 22 Parkinson's Disease patients both on and off subthalamic nucleus deep brain stimulation (STN-DBS), while they performed an instrumental learning task involving financial rewards and losses, and an inter-temporal choice task for financial rewards. We found that instrumental learning performance was significantly worse following stimulation, due to modulation of instrumental outcome sensitivity. Specifically, patients became less sensitive to decision values for both rewards and losses, but without any change to the learning rate or reward-loss trade-offs. However, we found no evidence that DBS modulated different components of temporal impulsivity. In conclusion, our results implicate the subthalamic nucleus in a modulation of outcome value in experience-based learning and decision-making in Parkinson's disease, suggesting a more pervasive role of the subthalamic nucleus in the control of human decision-making than previously thought.GRF gratefully acknowledges support by the German Research Council (Deutsche Forschungsgemeinschaft, KFO-219). Ray Dolan is supported by the Wellcome Trust (R.J.D., Senior Investigator Award 098362/Z/12/Z) and the the Senate of Berlin (R.J.D., Einstein Fellowship). Ben Seymour is funded by the Wellcome Trust and the National Institute of Information and Communications Technology, Japan; Peter Dayan is funded by the Gatsby Charitable Foundation

La relaxation contre l’épuisement des soignants en maison de retraite

Cette recherche avec des professionnels en maison de retraite étudie l\u27effet d\u27un programme de relaxation sur le burn-out. Il s\u27agit de mesurer l\u27impact de la relaxation sur la pratique des soignants. Après un entrainement à la relaxation (Jacobson, 1938 ; Schultz, 1958), une évaluation du degré de tension ressentie par les soignants et des symptômes psychologiques et comportementaux présentés par les personnes dépendantes lors de la toilette est réalisée avec des questionnaires (Dovero, 1998 ; MBI, 1981 ; NPI-ES, 2000) remplis par les soignants avant et après l\u27entraînement. Cette recherche montre que l\u27entraînement et la pratique régulière de la relaxation diminuent les tensions ressenties par les soignants et l\u27appréhension suscitée par certains soins comme la toilette. De plus, elle ouvre des perspectives concernant l\u27influence de l\u27état interne du soignant sur l\u27évaluation des troubles du comportement présents chez les personnes dépendantes lors de situations de soin

Acute effects of a selective cannabinoid-2 receptor agonist on neuroinflammation in a model of traumatic brain injury.

Proposed therapeutic strategies for attenuating secondary traumatic brain injury (TBI) include modulation of acute neuroimmune responses. The goal of this study was to examine the acute effects of cannabinoid-2 receptor (CB(2)R) modulation on behavioral deficits, cerebral edema, perivascular substance P, and macrophage/microglial activation in a murine model of TBI. Thirty male C57BL/6 mice underwent sham surgery, or cortical contusion impact injury (CCI). CCI mice received vehicle or the CB(2)R agonist 0-1966 at 1 and 24 h after injury. Performance on the rotarod, forelimb cylinder, and open-field tests were evaluated before and at 48 h after sham or CCI surgery. Cerebral edema was evaluated using the wet-dry weight technique. Immunohistochemical analysis was used to examine changes in substance P and macrophage/microglia-specific Iba1 protein immunoreactivity. Locomotor performance and exploratory behavior were significantly improved in mice receiving 0-1966 (CB(2)R agonist) compared to vehicle-treated mice. Significant reductions were found for cerebral edema, number of perivascular areas of substance P immunoreactivity, and number of activated macrophages/microglial cells in the injured brains of 0-1966-treated mice compared to vehicle-treated mice. The findings show that the effects of the CB(2)R agonist 0-1966 on edema, substance P immunoreactivity, and macrophage/microglial activation, were associated with recovery of acute motor and exploratory deficits. This study provides evidence of acute neuroprotective effects derived from selective CB(2)R activation that may represent an avenue for further development of novel therapeutic agents in the treatment of TBI

Performance of a repetitive task by aged rats leads to median neuropathy and spinal cord inflammation with associated sensorimotor declines

Epidemiological studies have demonstrated a relationship between advancing age and susceptibility to risk factors for median neuropathies and musculoskeletal disorders. In this study, we determined if performance of a voluntary reaching task by aged rats induced sensorimotor declines, median nerve dysfunction and increased inflammatory cytokines in peripheral nerves, muscle and spinal cord neurons. Aged (14 mon) rats were trained for 15 min/day for 4 weeks to learn a high repetition, low force (HRLF) task (19 reaches/min; 15% maximum pulling force). Aged task rats performed the task for 2 h/day, 3 days/wk, for 12 weeks (until they were 18 mon of age). No behavioral changes were detected in normal controls (NC) or food-restricted controls (FR C) as they aged. However, grip strength declined in HRLF rats in weeks 6-12 (P\u3c0.01 each) and 12-week trained-only rats (TR; P\u3c0.05), compared to NC. Mechanical hypersensitivity was present in weeks 9 and 12 HRLF reach limb forepaws (P\u3c0.01 and P\u3c0.05, respectively), and 12-week HRLF support limb forepaws (P\u3c0.01) and hindpaws (P=0.03), compared to NC. By week 12, median nerve conduction velocity declined 23%, bilaterally, in HRLF (P\u3c0.001 each), and 13% in TR (P\u3c0.05), compared to NC. Tumor necrosis factor alpha (TNFα) increased in 12-week HRLF muscle (P=0.005), median nerve (P\u3c0.01), and neurons in superficial lamina of HRLF cervical spinal cords (P\u3c0.01), compared to NC. interleukin 1 beta (IL1β) also increased in superficial lamina neurons (P\u3c0.01). Loss of grip strength was correlated with median nerve conduction slowing (r=0.70) as well as increased nerve and muscle TNFα (r=-0.38 and r=-0.41, respectively); decrease in forepaw withdrawal thresholds was correlated with median nerve conduction slowing (r=0.81), increased nerve TNFα (r=-0.59), and increased TNFα and IL1β in neurons in spinal cord dorsal horns (r=-0.52 and r=-0.47, respectively). Thus, aged rats performing a repetitive task exhibited sensorimotor declines that were associated with decreased median nerve conduction, and increased pro-inflammatory cytokines in the median nerve and cervical spinal cord neurons

Direct association between rainfall and non-typhoidal <i>Salmonella</i> bloodstream infections in hospital-admitted children in the Democratic Republic of Congo

Abstract Non-typhoidal Salmonella (NTS) ranks first among causes of bloodstream infection in children under five years old in the Democratic Republic of Congo and has a case fatality rate of 15%. Main host-associated risk factors are Plasmodium falciparum malaria, anemia and malnutrition. NTS transmission in sub-Saharan Africa is poorly understood. NTS bloodstream infections mostly occur during the rainy season, which may reflect seasonal variation in either environmental transmission or host susceptibility. We hypothesized that environment- and host-associated factors contribute independently to the seasonal variation in NTS bloodstream infections in children under five years old admitted to Kisantu referral hospital in 2013–2019. We used remotely sensed rainfall and temperature data as proxies for environmental factors and hospital data for host-associated factors. We used principal component analysis to disentangle the interrelated environment- and host-associated factors. With timeseries regression, we demonstrated a direct association between rainfall and NTS variation, independent of host-associated factors. While the latter explained 17.5% of NTS variation, rainfall explained an additional 9%. The direct association with rainfall points to environmental NTS transmission, which should be explored by environmental sampling studies. Environmental and climate change may increase NTS transmission directly or via host susceptibility, which highlights the importance of preventive public health interventions

Inflammatory response of endothelial cells to a human endogenous retrovirus associated with multiple sclerosis is mediated by TLR4.

The MSRV (multiple sclerosis-associated retrovirus) belongs to the human endogenous retrovirus HERV-W family. The envelope protein originating from the MSRV has been found in most patients with multiple sclerosis (MS). This protein (Env-ms) has pro-inflammatory properties for several types of immune cells and could therefore play a role in MS pathogenesis by promoting the leukocyte diapedesis observed in the central nervous system of patients. Our study aims to analyze the effects of Env-ms on the blood-brain barrier (BBB) at a molecular and functional level. We demonstrate that the recombinant MSRV envelope is able to stimulate several inflammatory parameters in a human BBB in vitro model, the HCMEC/D3 brain endothelial cell line. Indeed, Env-ms induces over-expression of ICAM-1, a major mediator of leukocyte adhesion to endothelial cells, in a dose-dependent manner as well as a strong dose-dependent production of the pro-inflammatory cytokines IL-6 and IL-8. Furthermore, using a silencing approach with siRNAs, we show that Env-ms is recognized via the Toll-like receptor 4 receptor, a pattern recognition receptor of innate immunity present on endothelial cells. We also show, using functional assays, that treatment of brain endothelial cells with Env-ms significantly stimulated the adhesion and the transmigration of activated immune cells through a monolayer of endothelial cells. These findings support the hypothesis that MSRV could be involved in the pathogenesis of MS disease or at least in maintenance of inflammatory conditions, thus fueling the auto-immune disorder. MSRV could also play a role in other chronic inflammatory diseases

Innovation et gouvernance territoriale : une analyse par les dispositifs

International audienceCette communication vise à présenter les outils méthodologiques d'analyse/évaluation de la gouvernance territoriale élaborés dans le cadre du projet de recherche PSDR Gouv.Innov sur les innovations organisationnelles relatives à la gouvernance territoriale. Il s'agit d'étudier les transformations introduites par les politiques de développement durable au niveau des dispositifs de gouvernance territoriale visant à favoriser une gestion intégrée des espaces ruraux. Dans un contexte de recomposition de l'action publique où les procédures d'aménagement sont plutôt normées par des représentations urbaines, l'accent est mis sur la question des modalités de représentation des activités rurales, pour lesquelles nous faisons l'hypothèse qu'elles sont sous représentées. Les premiers résultats méthodologiques permettent, dans une première partie, de proposer une définition générique et pragmatique de la gouvernance territoriale et de préciser la notion de dispositifs de gouvernance comme objet d'observation. A partir de cette définition une grille d'analyse permettant d'appréhender l'ensemble des dimensions en jeu dans les processus de gouvernance territoriale est élaborée. Dans la deuxième partie nous explorons l'intérêt de la notion de dispositif pour observer les processus de gouvernance et proposons une grille de collecte et de structuration des informations pour constituer des chroniques des dispositifs étudiés. / This paper seeks to present the methodological tools used in the analysis/evaluation of territorial governance developed during research undertaken within the framework of the PSDR Gouv-Innov project on organisational innovations with respect to territorial governance. It involves the study of the changes resulting from the emergence of sustainable development policies in territorial governance systems aiming to implement the integrated management of rural areas. In a context of changes in the way in which public action is implemented (for instance, public-private partnerships), where development procedures are usually standardised by urban representations, the emphasis is placed on the issue of the representation of rural activities, the hypothesis being that they are under-represented. The initial methodological results lead, in the first instance, to a proposition for a generic and pragmatic definition of territorial governance and a clarification of the notion of governance systems as objects of observation. This definition can be used as the basis of a framework to address all the analytical dimensions of the territorial governance process. In the second part, the authors explore the idea of system in order to observe governance processes and suggest a matrix for the collection and structuring of information in order to report on the studied systems