Impact du zooplancton métazoaire sur le phytoplancton et les protozoaires ciliés dans le réservoir Sahela (Maroc)

L'impact du zooplancton métazoaire sur le phytoplancton et les protozoaires ciliés a été mesuré durant la période de juillet à décembre 1999 dans le réservoir Sahela sous climat méditerranéen semi-aride.Les expériences ont été réalisées à l'aide de chambres de diffusion immergées in situ pendant 7 heures en absence (chambres témoins) et en présence (chambres expérimentales) du zooplancton.Les résultats indiquent que la mortalité moyenne à 4 m des algues est de 0,13 + 0,03 h-1, et celle des protozoaires ciliés de 0,07 + 0,03 h-1. Cryptomonas ovata et Halteria grandinella ont subi la plus forte prédation, respectivement, 0,31 + 0,14 h-1 et 0,11 + 0,04 h-1 à 4 m. Toutefois, les algues de grande taille (Pediastrum sp, Ceratium hirundinella et Peridinium cinctum) n'ont été que très peu ou pas consommées.The Sahela reservoir, located in Taounate at 90 km from Fès, lying at an altitude of 325 m, was built to provide drinking water for the population of Taounate and to contribute to irrigate neighbouring farming perimeters.In order to assess the impact of metazoan zooplankton on phytoplankton and protozoan ciliates in the Sahela reservoir under semi-arid climate, we conducted experiments during the period from July to December 1999 at the deepest point in the lake (15 m).Sampling and measurements were carried out in diffusion chambers submerged in situ over a period of 7 h without (control chambers) and with (experimental chambers) zooplankton. During these experiments, counts were conducted on phytoplankton and ciliates to determine the abundance and the mortality of these organisms due to zooplankton in each diffusion chambers at t=0 and t=7 h incubation. The metazooplankton were counted and dry weight of each taxa was calculated.In summer the highest zooplankton biomass (150 µg·L-1) mainly composed of cyclopoid Tropocyclops prasinus, caused mortality of the small-sized ciliates, such as Halteria grandinella (0.10 h-1). In Autumn, the zooplankton biomass (75 µg·l-1), dominated by Daphnia longispina, induced a higher mortality for phytoplankton (0.10 h-1) than for ciliates (0.05 h-1). In Winter, the zooplankton biomass (100 µg·L-1), also represented by Daphnia longispina, had a low impact on ciliate mortality (< 0.02 h-1).The study showed that a heavy predation by the metazoan zooplankton was exerted on small-sized phytoplankton and ciliates and clearly demonstrated the relationships between protozoans and metazoan zooplankton to transfering the matter and energy in aquatic food webs

Evidence of collaborative opportunities to ensure long-term sustainability in African farming

Farmers face the challenge of increasing production to feed a growing population and support livelihoods, whilst also improving the sustainability and resilience of cropping systems. Understanding the key factors that influence farming management practices is crucial for determining farmers’ adaptive capacity and willingness to engage in cooperative strategies. To that end, we investigated management practices that farmers adopt and the factors underlying farmers’ decision-making. We also aimed to identify the constraints that impede the adoption of strategies perceived to increase farming resilience and to explore how the acceleration of technology adoption through cooperation could ensure the long-term sustainability of farming. Surveys were distributed to farming stakeholders and professionals who worked across the contrasting environments of Morocco. We used descriptive statistics and analysis by log-linear modelling to predict the importance of factors influencing farmers’ decision- making. The results show that influencing factors tended to cluster around environmental pressures, crop characteristics and water availability with social drivers playing a lesser role. Subsidies were also found to be an important factor in decision-making. Farming stakeholders generally believed that collaborative networks are likely to facilitate the adoption of sustainable agricultural practices. We conclude that farmers need both eco- nomic incentives and technical support to enhance their adaptive capacity as this can lessen the socioeconomic vulnerability inherent in arid and semi-arid regions

Tuberculous Duodenal Stenosis: Report of Two Cases

Duodenal tuberculosis is a rare clinical entity. The authors report and emphasize the lack of special clinical, radiological and endoscopic signs of duodenal tuberculosis. The diagnosis is affirmed, at laparotomy, out of the findings of peritoneal granulations or histology of lymphatic nodes. We report our experience of two cases of duodenal tuberculosis presenting with proximal intestinal obstruction and review the available literature

Comparative Biology and Life Cycle of The Barley Stem Gall Midge and Hessian fly (Diptera: Cecidomyiidae) in Morocco

The barley stem gall midge, Mayetiola hordei (Keiffer) is the most serious pest of barley in Morocco. The biology and life cycle of this insect were studied in a laboratory and under natural weather conditions. The results showed that similarly to Hessian fly, barley stem gall midge has two feeding instars and a third non-feeding instar. The generation time was longer for barley stem gall midge than for Hessian fly (45 vs 32 days at 18 ± 1°C, and a 12:12 (L: D) h photoperiod). The eggs of barley stem gall midge hatched in 7 days compared to 4 days for Hessian fly. The largest discrepancy in developmental time was for second instar and pupa. Second instars and pupae of barley stem gall midge required twice as long as those of Hessian fly to develop and molt into next stage (12 vs. 6 days). The first and third instars of barley stem gall midge also required a little bit longer to complete development (9 and 10 days vs. 7 and 8 days for Hessian fly). Like for Hessian fly, barley stem gall midge reproduces mostly by unisexual progenies. Four progeny classes were observed; unisexual female progenies, unisexual male progenies, predominantly female progenies, and predominantly male progenies. The proportion of unisexual female and male progenies and the proportion of predominantly female and predominantly male progenies were similar. Overall, the sex ratio of both species was about 1:1. Under field weather conditions that prevail in the Chaouia region of Morocco, barley stem gall midge has two complete generations and a third partial one. The first generation starts late October, and ends late December. The second generation develops from January until early March. A high proportion of third instars of this generation fail to pupate (35%). The third generation is only partial; adults of the second generation emerge during March, oviposit and larvae develop to third instars but all go into summer diapause.

Péritonite primitive: entité réelle mais de diagnostic difficile

Les péritonites primitives sont rares chez des patients sans facteurs de risques. Elles simulent les péritonites secondaires. C’est pourquoi leurdiagnostic ne peut être que peropératoire. Nous rapportons deux cas de péritonites primitives dans le but de discuter leurs aspects diagnostique etthérapeutiques.Key words: Diagnostic, péritonite primitive, traitemen

ABSENCE DE LA GELEE DE WHARTON AUTOUR D’UNE ARTERE OMBILICALE

Introduction: Wharton's jelly is a mucoid connective tissue, avascular who plays the role of protection vis-à-vis the umbilical vessels avoiding compression. The umbilical arteries devoid of Wharton's jelly are more prone to compression. A complete absence is most often associated with fetal death. Clinical case: We report a case of a newborn in the maternity compiled des Orangers, having one of the umbilical arteries, devoid of Wharton's jelly over a distance of 10 cm from the umbilicus and whose clinical course was satisfactory. Discussion: In the literature, five cases have been reported, and several hypotheses have been discussed: Degeneration of Wharton tissue around the vessels, fusion incomplete coating amniotic mesenchymal umbilical cord during early embryonic development, hypoplastic amniotic coating with secondary loss of Wharton's jelly. In our context, since only one of the two umbilical arteries was not protected and covered by the thick meconium, two hypotheses arise: action "biochemical" thick meconium components of Wharton's jelly. A also discuss the underlying infection related with the absence of Wharton's jelly. Conclusion: The total absence of Wharton's jelly around the umbilical artery or two remains poorly understood, however, biochemical action of the components of meconium on Wharton's jelly or infectious origin can’t be excluded.Introduction : La gelée de Wharton est un tissu conjonctif mucoïde, avasculaire qui joue le rôle de protection vis-à-vis des vaisseaux ombilicaux en évitant leur compression. Les artères ombilicales dépourvues de la gelée de Wharton sont plus sujettes à la compression. Une absence complète est associée le plus souvent à la mort fœtale. Le cas clinique : Nous rapportons une observation d’un nouveau-né colligé à la maternité des Orangers, présentant une des artères ombilicales dépourvue de la gelée de Wharton sur une distance de 10 cm de l’ombilic et dont l’évolution clinique est satisfaisante. Discussion : Dans la littérature, cinq cas ont été rapportés, et plusieurs hypothèses ont été discutées : Dégénérescence du tissu de Wharton autour des vaisseaux, fusion incomplète du revêtement amniotique et du mésenchyme du cordon ombilical pendant le développement embryonnaire précoce, hypoplasie du revêtement amniotique avec perte secondaire de la gelée de Wharton. Dans notre contexte, vu que seule une des 2 artères ombilicales a été non protégée et recouverte par du liquide méconial épais, deux hypothèses se posent : l’action « biochimique » des composants du méconium épais sur la gelée de Wharton. A discuter aussi le contexte infectieux en rapport avec l’absence de la gelée de Wharton. Conclusion : L’absence totale de la gelée de Wharton autour d’une ou des 2 artères ombilicales reste encore mal comprise, toutefois une action biochimique des composants du méconium sur la gelée de Wharton ou une origine infectieuse ne peut être écartée

Pharmacological and chemical properties of some marine echinoderms

Echinoderms have attracted the attention of scientists over the past few years after identifying a variety of unique structures endowed by interesting biological properties. However, the Moroccan coast biodiversity is still uninvestigated. In our ongoing attempts to valorize the rich Moroccan marine environment, this study aimed at assessing the antimicrobial activity of extracts obtained from three echinoderms Astropecten irregularis, Luidia sarsi and Ophiura albida against the human pathogens: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica and Bacillus subtilis. Moreover, their antioxidant activities were tested using standard methods in addition to the antidiabetic activity which has been evaluated in vitro against α-amylase and α-glucosidase enzymes. HPLC-DAD-QTOF-MS analysis revealed a significant content of some phenolic compounds such as pyrogallol, gallic, sinapic, ferulic, p-hydroxybenzoic and salicylic acids whose existence can be related to the endophytic fungi and/or dietary intake whereas GC-MS analysis exhibited diverse chemical structures such as cholesterol, oleic acid and glycerol 1-palmitate

Holoprosencéphalie : A propos d’un cas

L'holoprosencéphalie (HPE) est une malformation cérébrale complexe résultant d'une division incomplète du prosencéphale, survenant entre le 18ème et le 28ème jour de vie embryonnaire et affectant à la fois le cerveau et la face. Trois degrés de sévérité croissante ont été décrits : l'holoprosencéphalie lobaire, semi-lobaire, et alobaire. Des anomalies de la face peuvent s'associer à la malformation cérébrale (leur gravité reflète grossièrement le degré de sévérité de l'holoprosencéphalie). Les étiologies sont essentiellement les anomalies chromosomiques et le diabète maternel. Le diagnostic repose sur l’échographie et l’IRM anténatales au troisième trimestre de la grossesse, la clinique, l’échographie trans-fontanellaire, la TDM et surtout l’IRM cérébrale. Le diagnostic génétique fait appel au caryotype. Nous décrivons un cas d’ holoprosencéphalie découverte après un accouchement survenu à 30 SA, chez une patiente primigeste de 26 ans, mal suivie, ayant une consanguinité du premier degré, non supplémentée en acide folique, et ayant pris du fenugrec au cours du premier trimestre de sa grossesse. Dans la majorité des cas, le pronostic est réservé.  

False aneurysm of the radial artery: Unusual complication of both-bone forearm fracture in children: A case report

False aneurysm or pseudo aneurysm of an artery in close proximity to fractured bone is a well-recognized entity, and fewer various cases, involving different sites have been reported in the literature. We report new case of a Moroccan's patient who had 10-year-old boy presented with a right non displaced both-bone forearm fracture; the patient was placed in a long arm splint. After, six weeks, the cast was removed. And a pulsatile mass on the volar-radial aspect of the forearm was decouvred. The mass was non-tender and the patient had radial and ulnar pulse. An Ultrasound and brachial angiography showed a false aneurysm of distal radial and the radial artery was ligated