Hétérogénéité horizontale des peuplements microphytoplanctoniques et zooplanctoniques en relation avec les paramètres abiotiques dans la retenue El Kansera (Maroc)

La répartition horizontale du phytoplancton et du zooplancton a été étudiée dans le lac-réservoir El Kansera en période de stabilité thermique, en relation avec certains paramètres abiotiques (transparence, matières en suspension, conductivité, température, oxygène dissous, pH, nutriments azotés et phosphorés).La répartition longitudinale du phytoplancton montre un gradient décroissant, avec des maxima de biomasse (poids frais) situés au 2/3 de la longueur du réservoir, et des pics de chlorophylle a enregistrés vers l'amont de la retenue. L'abondance du zooplancton suit une évolution quasi-analogue à celle du phytoplancton avec en plus, une répartition hétérogène des Rotifères et des différents stades de développement des Crustacés. Les Rotifères et les petits stades de développement des Cladocères ou des Copépodes sont concentrés dans la zone médiane du lac, tandis que les stades adultes de ces Crustacés dominent vers l'aval. La prédation vertébrée des " Carpes Chinoises ", associée à la mauvaise qualité de la nourriture algale en période d'étiage (blooms à Microcystis), seraient à l'origine de cette répartition. Les résultats de cette étude permettent de distinguer 3 zones de la retenue : la zone d'embouchure de l'oued** Beht (station S1) agitée, turbide et peu oxygènée est la moins productive, la zone médiane (stations S2 et S3), constituant la transition entre le milieu lotique et lacustre, est la plus enrichie en peuplements algaux et la plus peuplée par le zooplancton. Enfin, la zone lacustre proprement dite (stations S4 et S5) est assez productive et constitue un site idéal pour les adultes des Crustacés.The goal of this study is to assess the degree of horizontal heterogeneity of phytoplankton and zooplankton communities in the lake-reservoir El Kansera (Morocco), in order to define the principal factors responsible for the plankton distribution in the lake.Five stations have been studied; station S1 is the most influenced by allochthonous inputs from oued Beht (a tributary), stations S2 and S3 represent a transition between the lotic and lacustrine environments, and stations S4 and S5 represent true lacustrine conditions.The phytoplankton and zooplankton samplings were carried out during two seasons in 1996 (spring and summer), with a plankton net which consisted of a silk cone (height: 120 cm, mesh size: 40 µm). An average sample was prepared by several vertical tows. The samplings of chlorophyll and abiotic parameters were performed at different depths with a polyvinylchloride bottle with a capacity of 5 L and an automatic closing device. The phytoplankton counting was done according to the method of Legendre and Watt (1972). The algal biomass (µg.L-1) was estimated by chlorophyll-a (method of Lorenzen 1967) and wet weight (method of Lohmann (1908). Zooplankton counting was done in a Dolfuss cell (method of Pont 1983). The biomass of Rotifers, Cladocerans or Copepods (µg.L-1) was calculated according to the method of Dumont et al. (1975) and Bottrell et al. (1976). The physico-chemical analyses were performed at LPEE (Public Laboratory of Essay and Studies). Temperature, pH and conductivity were measured in situ, with a sounding Horiba U7. Dissolved oxygen was measured by the method of Winkler (Rodier 1984). Water transparency was measured by Secchi disc (Reynolds). Suspended matter was determined according to the method of AFNOR (1994). Nitrates and total phosphorus were analysed by colorimetry, respectively after reduction on a cadmium column and mineralization in acid medium (AFNOR 1994).The lake-reservoir El Kansera presents a longitudinal gradient (oued Beht-dyke) of biotic and abiotic parameters in relation both to morphometric and hydrologic characteristics and to the importance of allochthonous inputs and the nutrient cycles (nitrates and phosphorus). The maximum phytoplankton abundance (wet weight) is observed at 2/3 of the lake's length, and the chlorophyll-a peaks are recorded in the upper zone. In the spring, two alga species are dominant in the lake, Scenedesmus ecornis and Cyclotella ocellata, whereas in summer, one species is abundant (Microcystis aeruginosa).Zooplankton abundance shows a similar evolution to that of the phytoplankton, with a longitudinal heterogeneity of Rotifers (Brachionus calyciflorus, Polyarthra vulgaris and Keratella tropica) and different development stages of Cladocerans (Bosminalongirostris and Diaphanosoma brachyurum) and Copepods (Acanthocyclops robustus). Rotifers and the small stages of Crustaceans are concentrated in the median zone, whereas the Crustacean adults are dominant in the deeper point of the reservoir. Vertebrate predation by the " Chinese carp " and the degraded quality of the algae (blooms of Microcystis) also seem to contribute to this distribution.The results of the study, confirmed by the statistical Student test, indicate three zones in the lake-reservoir: the upper zone (station S1), which is located at the mouth of the oued Beht, is the least productive due to its shallow depth, low oxygenation, high turbidity and frequent mixing. The intermediate zone, between lotic and lacustrine conditions (stations S2 and S3), is strongly enriched with nutrients (nitrates and phosphorus) and characterised by a higher productivity; this zone presents dense phytoplanktonic populations. The lacustrine zone (stations S4 and S5) is of intermediate productivity, and offers good conditions for large size classes of Crustacea

Milk production of ewes of Timahdite, Sardi and Béni Gull breeds in purebreeding and crossbreeding

La production laitière, durant 8 semaines de lactation, de 144 brebis de races Sardi, Béni Guil et Timahdite luttées par les béliers de leurs races respectives et par ceux des races Île de France, Mérinos Précoce et Suffolk a été estimée par la méthode de pesée avant et après tétée (PAAT) pendant trois années. L'étude a montré que la production laitière est influencée par la race de la brebis mais non par la race du bélier, et que les agneaux issus de pères de races île de France, Suffolk et Sardi transforment mieux le lait que ceux issus des autres races de pères. Il semble impératif de supplémenter les agneaux croisés à partir du 2ème mois d'âge.Milk production of ewes of Timahdite, Sardi and Béni Gull breeds in purebreeding and crossbreedingEight weeks milk production of 144 Sardi, Béni Guil and Timahdite ewes mated to rams of their respective breeds and to rams of Île de France, Mérinos Précoce and Suffolk breeds was estimated during three years by the method of weighting lambs before and after suckling. Milk production was affected by the breed of ewe but not the breed of ram, Lambs sired by île de France, Suffolk and Sardi rams had a better milk efficiency than those produced by rams ofthe other breeds. It seems necessary to supplement crossbred lambs from the age oftwo months

Performances d'engraissement et caractéristiques des carcasses d'agneaux issus du croisement des brebis de races Timahdite, Sardi et Béni Guil avec des béliers de races à viande

L'analyse des performances d'engraissement et des caractéristiques de carcasses de 242 agneaux issus du croisement des brebis de races Timahdite, Sardi et Béni Guil avec des béliers de leurs races respectives et avec des béliers de races Île de France, Suffolk et Mérinos Précoce a montré que les performances des agneaux croisés sont meilleures que celles des agneaux de races pures. De plus, parmi les races à viande, il semble que la race Île de France est celle qui conviendrait le mieux au croisement avec les brebis de races locales marocaines.Fattening performance and carcass characteristics of crossbred lambs born to Timahdite, Sardi and Béni Guil ewes and rams of meat breedsThe analysis offattening performance and carcass characteristics of 242 lambs born to Timahdite, Sardi and Béni Guil ewes mated to rams of their respective breeds and to rams of Ile de France, Suffolk and Mérinos Précoce showed a superiority of crossbred over purebred lambs. Moreover, among the three meat breeds, it seems that Ile de France is the most suitable breed to be crossed to ewes of Moroccan native breeds

Adaptability of irrigated spring canola oil production to the US High Plains

Canola oil is high in oleic acid which is commonly used for food and industrial purposes. To determine adaptability of spring canola (Brassica napus L.) to the High Plains for industrial oil production, 26 irrigated trials were conducted from 2005 to 2008. Trials were divided into five regions—1: 36–37◦N 108◦W; 2: 39–40◦N 101–103◦W; 3: 41–42◦N 102–103◦W; 4: 41–42◦N 104◦W; 5: 43–44◦N 106–108◦W. Cultural practices were based on site-specific protocols. Four cultivars, Hyola 401, Hyola 357 Magnum, SW Marksman, and SW Patriot, were planted in replicated plots in April or May under standard irrigation and harvested in July to October depending on region. Seed yield Hyola 401 and Hyola 357 Magnum were higher than SW Marksman and SW Patriot across the five regions and within Regions 1, 2, 3, and 5. Regions 1, 2 and 3 yielded significantly greater than did Regions 4 and 5. Samples from 18 trials were examined for their oil content and fatty acid distribution. The four cultivars had greater than 38% oil content; SW Marksman and SW Patriot had higher oil content than Hyola 401 and Hyola 357 Mag. Higher oil content was achieved in Regions 1, 4 and 5. Across and within regions, the percent of oleic acid did not differ for the four cultivars. The mean content of oleic acid decreased going north from Region 2 to Region 5, as did seed yield in the High Plains. Linoleic acid increased going north from Region 1. Linolenic acids showed little variation across regions. Considering yield and total oil content together, growing spring canola would be excellent in the High Plains

Adaptability of irrigated spring canola oil production to the US High Plains

Canola oil is high in oleic acid which is commonly used for food and industrial purposes. To determine adaptability of spring canola (Brassica napus L.) to the High Plains for industrial oil production, 26 irrigated trials were conducted from 2005 to 2008. Trials were divided into five regions—1: 36–37◦N 108◦W; 2: 39–40◦N 101–103◦W; 3: 41–42◦N 102–103◦W; 4: 41–42◦N 104◦W; 5: 43–44◦N 106–108◦W. Cultural practices were based on site-specific protocols. Four cultivars, Hyola 401, Hyola 357 Magnum, SW Marksman, and SW Patriot, were planted in replicated plots in April or May under standard irrigation and harvested in July to October depending on region. Seed yield Hyola 401 and Hyola 357 Magnum were higher than SW Marksman and SW Patriot across the five regions and within Regions 1, 2, 3, and 5. Regions 1, 2 and 3 yielded significantly greater than did Regions 4 and 5. Samples from 18 trials were examined for their oil content and fatty acid distribution. The four cultivars had greater than 38% oil content; SW Marksman and SW Patriot had higher oil content than Hyola 401 and Hyola 357 Mag. Higher oil content was achieved in Regions 1, 4 and 5. Across and within regions, the percent of oleic acid did not differ for the four cultivars. The mean content of oleic acid decreased going north from Region 2 to Region 5, as did seed yield in the High Plains. Linoleic acid increased going north from Region 1. Linolenic acids showed little variation across regions. Considering yield and total oil content together, growing spring canola would be excellent in the High Plains

A Physics-based Investigation of Pt-salt Doped Carbon Nanotubes for Local Interconnects

We investigate, by combining physical and electrical measurements together with an atomistic-to-circuit modeling approach, the conductance of doped carbon nanotubes (CNTs) and their eligibility as possible candidate for next generation back-end-of-line (BEOL) interconnects. Ab-initio simulations predict a doping-related shift of the Fermi level, which reduces shell chirality variability and improves electrical conductance up to 90% by converting semiconducting shells to metallic. Circuit-level simulations predict up to 88% signal delay improvement with doped vs. pristine CNT. Electrical measurements of Pt-salt doped CNTs provide up to 50% of resistance reduction which is a milestone result for future CNT interconnect technology

Bilateral anterior dislocation of the shoulders at the start of a backstroke competition

Bilateral anterior dislocation of the shoulders is very rare. A 20-year-old man presented with bilateral anterior shoulder dislocation as a result of a diving incident. He complained of pain and restriction of movement in both shoulders with abducted and externally rotated arms. Radiographs revealed that the shoulders were dislocated. The patient was treated with closed reduction and was able to resume swimming 3 months later. To our knowledge, this is the first bilateral anterior dislocation of the shoulders during a backstroke swimming competition that was caused by this mechanism of injury. The rarity of this lesion and its uncommon mechanism prompted us to relate this observation

VOLVULUS DU SIGMOIDE ET POST-PARTUM

The sigmoid volvulus during pregnancy is very rare and difficult to diagnose. It is often responsible for the mortality of the parturient and of the fetus. We report a case of sigmoid volvulus with postnatal complications. A multiparous woman aged 45, was admitted with a bowel obstruction and generalized abdominal spasm at 3 days postpartum. A laparotomy examination revealed a dolichocolon complicated by a sigmoid volvulus undergoing necrosis, with the presence of some pseudomembranes. Sigmoidectomy with proximal colostomy was performed according to Hartmann, following which the restoration of continuity was secured within two months. Sigmoid volvulus complicating pregnancy is a rare occurrence with a reserved maternal-fetal prognosis, the diagnosis should be suspected with the appearance of persistent abdominal pain associated with an occlusive syndrome. Urgent surgical intervention is required to reduce as far as possible fetomaternal morbidity and mortality.Le volvulus du sigmoïde au cours de la grossesse est très rare et difficile à diagnostiquer. Elle peut s’accompagner d’une mortalité maternelle et fœtale importante. Nous rapportons un cas de volvulus du sigmoïde compliquant les suites de couches. Une multipare de 45 ans, s'est présentée avec un syndrome occlusif et défense abdominale généralisée à J3 du post-partum. Une laparotomie exploratrice a mis en évidence un dolichocôlon compliqué par un volvulus du sigmoïde nécrosé, avec présence de quelques fausses membranes. Une résection sigmoïdienne avec colostomie proximale selon Hartmann a été pratiquée, le rétablissement de la continuité a été réalisé deux mois plus tard. Le volvulus du sigmoïde compliquant la grossesse est une entité rare avec un pronostic materno-fœtal réservé, le diagnostic doit être suspecté devant une douleur abdominale persistante associée à un syndrome occlusif. L’intervention chirurgicale s’impose en urgence pour réduire, au maximum, la morbidité et la mortalité maternofoetale

Distribution of antioxidant components in roots of different red beets (Beta vulgaris L.) cultivars

The beetroot is typically on the table in winter in form of pickles or juice, but for its nutritional values it would deserve more common consumption. Its curative effect in great part is due to the several vitamins, minerals, and compounds with antioxidant activity. But the division of biological active compounds is very different in the parts of the root. Based on our results, we could compare the differences between the morphology and some inner contents (soluble solid content, colour, betacyanin, betaxanthin, and polyphenol contents, antioxidant activity, and some flavonoids) of two beetroot cultivars. The results of the morphological investigations showed that the ‘Cylindre’ cultivar had more favourable crop parameters than the ‘Alto F1’ cultivar. In the ‘Cylindre’ cultivar the polyphenol content and the antioxidant capacity were significantly higher than in the ‘Alto F1’ cultivar. By determination of the betanin contents of the investigated beetroots, our results showed both betacyanin and betaxanthin contents were higher in the ‘Cylindre’ cultivar. The chlorogenic acid, gallic acid, the cumaric acid have been identified based on the peaks of HPLC in the studied beetroot cultivars

Dynamics of multipartite quantum correlations under decoherence

Quantum discord is an optimal resource for the quantification of classical and non-classical correlations as compared to other related measures. Geometric measure of quantum discord is another measure of quantum correlations. Recently, the geometric quantum discord for multipartite states has been introduced by Jianwei Xu [arxiv:quant/ph.1205.0330]. Motivated from the recent study [Ann. Phys. 327 (2012) 851] for the bipartite systems, I have investigated global quantum discord (QD) and geometric quantum discord (GQD) under the influence of external environments for different multipartite states. Werner-GHZ type three-qubit and six-qubit states are considered in inertial and non-inertial settings. The dynamics of QD and GQD is investigated under amplitude damping, phase damping, depolarizing and flipping channels. It is seen that the quantum discord vanishes for p>0.75 in case of three-qubit GHZ states and for p>0.5 for six qubit GHZ states. This implies that multipartite states are more fragile to decoherence for higher values of N. Surprisingly, a rapid sudden death of discord occurs in case of phase flip channel. However, for bit flip channel, no sudden death happens for the six-qubit states. On the other hand, depolarizing channel heavily influences the QD and GQD as compared to the amplitude damping channel. It means that the depolarizing channel has the most destructive influence on the discords for multipartite states. From the perspective of accelerated observers, it is seen that effect of environment on QD and GQD is much stronger than that of the acceleration of non-inertial frames. The degradation of QD and GQD happens due to Unruh effect. Furthermore, QD exhibits more robustness than GQD when the multipartite systems are exposed to environment.Comment: 15 pages, 4 figures, 4 table