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Sample records for le lac tanganyika

  1. Le lokonda des Bosanga du Lac Tumba | Mangulu | Annales ...

    African Journals Online (AJOL)

    Il s'agit particulièrement, dans la conjugaison, de l'expression d'aspects par le recours aussi bien aux auxiliaires qu'aux particules postposées à la forme verbale simple. Le tout tend donc à confirmer les hypothèses avancées récemment par la recherche historique : les Ekonda seraient parvenus dans la région des Lacs, ...

  2. Effet des conditions climatiques sur le niveau du lac Sidi Ali (Moyen Atlas, Maroc)

    OpenAIRE

    Sayad, Ahmed; Chakiri, Saïd; Martin, Claude; Bejjaji, Zohra; Echarfaoui, Hassan

    2012-01-01

    Le lac Sidi Ali est un lac naturel d'altitude (2070-2080 m), sans exutoire superficiel, déterminé par le barrage d'une coulée basaltique. Doté d'un bassin versant apparent de 15,6 km2, il est alimenté par des eaux de ruissellement et par des sources karstiques. Son niveau subit des variations très fortes, annuelles et interannuelles, sous le contrôle des conditions climatiques, et en particulier des pluies et de l'évapotranspiration. Les périodes de sécheresse qui ont marqué les trois dernièr...

  3. Effet des conditions climatiques sur le niveau du lac Sidi Ali (Moyen Atlas, Maroc

    Directory of Open Access Journals (Sweden)

    Claude Martin

    2011-11-01

    Full Text Available Le lac Sidi Ali est un lac naturel d'altitude (2070-2080 m, sans exutoire superficiel, déterminé par le barrage d'une coulée basaltique. Doté d'un bassin versant apparent de 15,6 km2, il est alimenté par des eaux de ruissellement et par des sources karstiques. Son niveau subit des variations très fortes, annuelles et interannuelles, sous le contrôle des conditions climatiques, et en particulier des pluies et de l'évapotranspiration. Les périodes de sécheresse qui ont marqué les trois dernières décennies, se sont traduites par un abaissement du niveau de près de 7 m. Mais les précipitations abondantes des années 2008-09 et 2009-10 ont provoqué une nette remontée. Une régression multiple d'assez bonne qualité (r = 0,87 lie la variation annuelle du niveau (d'août à août à différents paramètres (conditions climatiques et niveau initial du lac.Lake Sidi Ali is a natural lake at high altitude (2070-2080 m, without surface outlet, determined by the dam of a basalt flow. With an apparent catchment of 15.6 km2, it is fed by runoff and karst springs. Its level shows strong annual and interannual variations, depending on weather conditions, particularly rainfall and evapotranspiration. Droughts that have marked the last three decades have resulted in a lowering of about 7 m of the water level. But heavy rainfall that occurred in 2008-09 and 2009-10 caused a marked rise. A multiple regression of sufficient quality (r = 0.87 binds the annual change (from august to august at differents parameters (weather conditions and initial level of the lake.

  4. Le lac Titicaca: histoire perdue d'une mer intérieure

    Directory of Open Access Journals (Sweden)

    1992-01-01

    Full Text Available Cet article tente de reconstruire l’histoire de la région du lac Titicaca et de son peuplement pour la période précédant l’arrivée des espagnols. Á cet effet, nous avons utilisé une approche multidisciplinaire (sédimentologie, archéologie, mythologie qui autorise, depuis l’amont et dans la longue durée, un nouvel éclairage des données historiques du XVIe siècle. Malgré les changements climatiques et politiques ayant affecté les rives du Titicaca avant la Conquête espagnole, il existe une continuité historique qui va de la civilisation de Pukará à Hatuncolla en passant par Tiwanaku. Si la documentation espagnole ne rend pas compte de l’importance des anciennes populations riveraines et notamment des pukinas, c’est qu’il était de l’intérêt des envahisseurs successifs (aymaras, incas, espagnols de l’occulter. EL LAGO TITICACA: HISTORIA PERDIDA DE UN MAR INTERIOR. Este artículo constituye un intento de reconstrucción de la historia del lago Titicaca y de su poblamiento por el período que precede la llegada de los españoles. En esta perspectiva, hemos utilizado una aproximación multidisciplinaria (sedimentología, arqueología, mitología que autoriza una nueva lectura de las fuentes históricas del siglo XVI, a partir de datos remotos y en la larga duración. A pesar de los cambios climáticos y políticos que afectaron las orillas del Titicaca antes de la Conquista española, existe una continuidad histórica que va de la cultura de Pukará hasta Hatuncolla (pasando por Tiwanaku. Si la documentación española no toma en cuenta la importancia de las antiguas poblaciones lacustres, particularmente los pukinas, es porque el interés de sus sucesivos vencedores (aymara, incas, españoles era de ocultarla. THE TITICACA LAKE: HISTORY LOST IN THE CENTER OF A DEEP IMMENSITY. This article comprises an attempt to reconstruct the Titicaca Lake history and its colonization during the period preceding the Spanish arrival. On

  5. TYPOLOGIE DE LA PÊCHE SUR LE LAC FAÉ (CÔTE D’IVOIRE ET IMPLICATIONS POUR UNE GESTION RATIONNELLE DES RESSOURCES HALIEUTIQUES

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    DA COSTA K. S.

    2007-01-01

    Full Text Available Cette étude réalisée en septembre 1996 dans le cadre du Projet d’Étude Participative AISA/IDESSA a permis de faire l’historique des activités halieutiques et la typologie de la pêche sur le lac Faé. La pêche dans ce réservoir est artisanale et de type individuel. Démarrée en 1980 avec l’implantation des pêcheurs étrangers originaires du Mali, cette activité est pratiquée par deux types d’acteurs : les professionnels (étrangers et les occasionnels (Bakwés. Les engins de pêche sont ceux classiquement utilisés dans les pêcheries continentales de Côte d’Ivoire : filets maillants, mono et multifilaments, nasses (grillagées, en filets ou en bambou et pièges en bambous de Chine. La densité des pêcheurs artisans sur le lac Faé est de 6,4 pêcheurs/km2, soit trois fois supérieure à la norme optimale de 2 pêcheurs/km2 admise par la législation ivoirienne Par conséquent, des mesures de gestion devraient être prises par la Direction de la Production Halieutique (DPH pour contrôler le flux migratoire des pêcheurs vers cette retenue, afin d’infléchir la densité observée. Le maintien ou l’accroissement de celle-ci pourrait engendrer une surexploitation rapide des stocks, et constituer une source potentielle de conflits entre étrangers et autochtones. A cet effet, des recommandations pour une pratique durable de la pêche sur cette retenue sont proposées.

  6. Le black-bass (Micropterus salmoides Lacép. dans les eaux italiennes. Un antagoniste du brochet ?

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    ALESSIO G.

    1984-01-01

    Full Text Available Le black-bass à grande bouche est largement répandu dans les eaux italiennes et fait l'objet de repeuplement. Les alevins et estivaux nécessaires proviennent le plus souvent de la vidange automnale des étangs à cyprinidés avec lesquels ils sont élevés. Il n'y a pas vraiment d'élevage contrôlé de cette espèce en Italie, mais seulement une série d'essais qui portent sur la reproduction naturelle en étangs-frayères, l'introduction de nids artificiels dans le milieu et l'induction de la ponte par traitement hypophysaire (avec HCG, essais qui donnent des résultats satisfaisants. Dans le milieu naturel, la croissance en longueur et en poids du black-bass en Italie est comparable et quelquefois meilleure que celle enregistrée sur ses lieux d'origine. La croissance annuelle est d'abord lente (printemps, puis rapide (été, ensuite à nouveau lente (automne pour être finalement modeste ou pratiquement nulle en hiver. La population qui, avec des fluctuations annuelles, représente 0,5 à 1,6 % de l'ichthyofaune des eaux étudiées (fleuves Pô, Sesia et Ticino, est constituée surtout de sujets jeunes : environ 40 % des individus sont âgés de 2 hivers et ne dépassent pas un poids de 400 g et une longueur totale de 28 cm. La survie est considérée comme bonne avec une durée de vie de 8 à 9 hivers. La nourriture présente un spectre très large et est basée de préférence sur des petits poissons et sur les amphibiens, avec une large partie d'invertébrés (surtout des insectes. La reproduction intervient aux mois de mai et juin, mais elle peut être aussi plus précoce et, le plus souvent, plus tardive. Le black-bass est très sensible aux pollutions, mais ne semble pas particulièrement affecté par des épizooties ou du parasitisme. Par rapport à la niche écologique occupée, à son spectre trophique, à son rôle dans les équilibres biologiques et à ses caractéristiques éthologiques, le black-bass ne peut pas être consid

  7. REPEUPLEMENTS EN ALEVINS NOURRIS ET DÉMOGRAPHIE DE LA POPULATION DE TRUITE (SALMO TRUTTA L. DANS LE REDON, UN AFFLUENT DU LAC LÉMAN INTERROMPU PAR UN OBSTACLE

    Directory of Open Access Journals (Sweden)

    CHAMPIGNEULLE A.

    2003-01-01

    Full Text Available La démographie d’une population de truite (Salmo trutta L. a été étudiée, dans un contexte de repeuplements en alevins nourris, sur le Redon, un affluent du lac Léman. On trouve sur le Redon une situation typique de nombreux affluents du Léman : une zone aval ouverte sur le lac mais rapidement interrompue par un obstacle empêchant la remontée des truites de lac. Des relâchers d’alevins nourris issus d’œufs de géniteurs sauvages de truite de lac ou de géniteurs domestiques, pratiqués en fin de printemps-début été à des densités de 40-60 ind./100 m2, fournissent un recrutement additionnel important pouvant constituer la part dominante du peuplement automnal en 0 +, puis 1 +. Sur les zones ouvertes à la pêche, colonisées ou non par la truite de lac, la densité de la population automnale en place s’effondre entre le stade 1 + et les stades > 1 +. Les résultats comparatifs entre zones ouvertes ou fermées à la pêche indiquent que la pêche peut être un facteur de mortalité important. La dynamique comparée des truites d’origine lacustre ou sédentaire suggère l’existence d’un taux de sédentarisation plus faible pour les 1 + issus de truites de lac comparativement aux 1 + issus de la fraie de truites sédentaires en zone de réserve. Une expérimentation suggère l’existence de mouvements de dévalaison ayant lieu avant octobre et touchant préférentiellement les 0 + d’origine lacustre ayant eu la croissance initiale la plus forte. L’étude montre que : - des alevins nourris d’origine lacustre ou domestique, relâchés en fin de printemps-début été, fournissent des géniteurs de truite de lac remontant dans la rivière de relâcher, avec cependant une proportion moindre (4 fois dans le cas de l’origine domestique comparativement à l’origine lacustre. Malgré leur forte contribution aux stades de juvéniles 0 + et 1 +, les alevins domestiques de pisciculture contribuent peu aux retours de g

  8. Les roches basiques et ultrabasiques des Lacs Robert et le Trias de Chamrousse (Massif de Belledonne) Etude petrologique et geologique

    NARCIS (Netherlands)

    Tex, den E.

    1950-01-01

    La région que j’ai étudiée et relevée est située dans les Alpes françaises, à environ 4° longitude est et 50°15’ latitude nord, et à environ 2000 mètres d’altitude. Elle fait partie de la chaîne dite „chaîne de Belledonne” qui s’étend des massifs de Beaufort et du Grand Mont dans le N N E jusqu’à

  9. EFFICACITÉ DES REPEUPLEMENTS EN TRUITES (Salmo trutta L. et Oncorhynchus mykiss W. DE UN AN POUR LA PÊCHE PROFESSIONNELLE AUX FILETS ET LA PÊCHE AMATEUR À LA TRAÎNE DANS LE LAC DU BOURGET

    Directory of Open Access Journals (Sweden)

    CHAMPIGNEULLE A.

    2003-01-01

    Full Text Available L’étude visait à évaluer l’efficacité d’une pratique de repeuplement courante dans le lac du Bourget (4 400 ha consistant à déverser directement en lac des truitelles de un an avec pour objectif de soutenir des captures de truite du lac. Les recaptures par la pêche amateur et professionnelle ont été évaluées pour un lot de 15 900 truites fario (Salmo trutta L. domestiques de un an (longueur totale moyenne de 177 mm déversées fin avril 1988. Elles sont respectivement de 3,8 % (33 kg/1 000 truitelles pour la pêche professionnelle aux filets maillants et de 1,0 % (6 kg/1 000 truitelles pour la pêche amateur à la traîne en bateau. En relation avec une forte croissance, l’essentiel des recaptures a été réalisé en fin de saison 1988 et en début de saison 1989. Les recaptures par la pêche professionnelle aux filets maillants ont été évaluées pour un lot de 10 000 truitelles fario domestiques (longueur totale moyenne de 179 mm en comparaison avec un lot de 10 800 truitelles arc en ciel (Oncorhynchus mykiss W. de un an (longueur totale moyenne de 219 mm déversées en mai 1990. Les recaptures ont été respectivement de 3,2 % (20 kg/1 000 truitelles pour la fario et de 7,0 % (42 kg/1 000 truitelles pour l’arc en ciel. Pour la truite arc-en-ciel, l’essentiel des recaptures a été réalisé très rapidement sur une période brève : milieu et fin de saison 1990. Pour le lot de fario, l’essentiel de l’exploitation a été réalisé sur une période courte mais un peu plus tardive (fin de saison 1990 et début de saison 1991 que pour l’arc-en-ciel. Les repeuplements en mai avec des truitelles domestiques de un an conduisent effectivement à des captures de truite de lac en lac mais avec un rendement plutôt faible et en prenant des risques (écologiques et pathologiques. Ceci suggère de mobiliser les efforts de gestion vers la production naturelle et donc durable de la ressource truite de lac dans le lac du

  10. Mating and Parental Care in Lake Tanganyika's Cichlids

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    Kristina M. Sefc

    2011-01-01

    Full Text Available Cichlid fishes of Lake Tanganyika display a variety of mating and parental care behaviors, including polygamous and monogamous mouthbrooding and substrate breeding, cooperative breeding, as well as various alternative reproductive tactics such as sneaking and piracy. Moreover, reproductive behaviors sometimes vary within species both in space and in time. Here, I survey reports on mating and parenting behaviors of Lake Tanganyika cichlid species and address the evolution of mating and parental care patterns and sexual dimorphism. Notes on measures of sexual selection intensity and the difficulties of defining mating systems and estimating selection intensities at species level conclude the essay.

  11. Lac dayet Aoua (Maroc)

    African Journals Online (AJOL)

    Saad

    F.S.T. Fès - Sais, Université Sidi Mohammed Abdallah Fès, B.P. 2202, Maroc. 2Laboratoire des ... d'étude en complément de la composition phytoplanctonique et des analyses de la physico-chimie des eaux à l'entrée, au ... L'analyse des paramètres physico-chimiques, au point central du lac, a montré que l'eau du lac.

  12. THE LIMNOLOGY OF THE LAKE TANGANYIKA SUB CATCHMENT

    African Journals Online (AJOL)

    Mgina

    pressures from land, atmospheric, and riverine inputs. The Lake Tanganyika sub catchment includes the Malagarasi. Moyowosi wetland ecosystem in the ..... sediment-water interface disturbance through bioturbation process and bottom currents at these sites which promote nitrate diffusion process from the sediment pore ...

  13. Tempo and mode of diversification of lake Tanganyika cichlid fishes.

    Directory of Open Access Journals (Sweden)

    Julia J Day

    Full Text Available BACKGROUND: Understanding the causes of disparities in species diversity across taxonomic groups and regions is a fundamental aim in evolutionary biology. Addressing these questions is difficult because of the need for densely sampled phylogenies and suitable empirical systems. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigate the cichlid fish radiation of Lake Tanganyika and show that per lineage diversification rates have been more than six times slower than in the species flocks of Lakes Victoria and Malawi. The result holds even at peak periods of diversification in Lake Tanganyika, ruling out the age of the lake as an explanation for slow average rates, and is robust to uncertainties over the calibration of cichlid radiations in geological time. Moreover, Lake Tanganyika lineages, irrespective of different biological characteristics (e.g. sexually dichromatic versus sexually monochromatic clades, have diversified at similar rates, falling within typical estimates across a range of plant and animal clades. For example, the mostly sexually dichromatic haplochromines, which have speciated explosively in Lakes Victoria and Malawi, have displayed modest rates in Lake Tanganyika (where they are called Tropheini. CONCLUSION/SIGNIFICANCE: Our results show that either the Lake Tanganyika environment is less conducive for cichlid speciation or the remarkable diversifying abilities of the haplochromines were inhibited by the prior occupancy of older radiations. Although the results indicate a dominant role for the environment in shaping cichlid diversification, differences in the timing of diversification among the Tanganyikan tribes indicate that biological differences were still important for the dynamics of species build-up in the lake. While we cannot resolve the timing of the radiation relative to the origin of the lake, because of the lack of robust geological date calibrations for cichlids, our results are consistent with a scenario that the

  14. Origin of bistability in the lac Operon.

    Science.gov (United States)

    Santillán, M; Mackey, M C; Zeron, E S

    2007-06-01

    Multistability is an emergent dynamic property that has been invoked to explain multiple coexisting biological states. In this work, we investigate the origin of bistability in the lac operon. To do this, we develop a mathematical model for the regulatory pathway in this system and compare the model predictions with other experimental results in which a nonmetabolizable inducer was employed. We investigate the effect of lactose metabolism using this model, and show that it greatly modifies the bistable region in the external lactose (Le) versus external glucose (Ge) parameter space. The model also predicts that lactose metabolism can cause bistability to disappear for very low Ge. We have also carried out stochastic numerical simulations of the model for several values of Ge and Le. Our results indicate that bistability can help guarantee that Escherichia coli consumes glucose and lactose in the most efficient possible way. Namely, the lac operon is induced only when there is almost no glucose in the growing medium, but if Le is high, the operon induction level increases abruptly when the levels of glucose in the environment decrease to very low values. We demonstrate that this behavior could not be obtained without bistability if the stability of the induced and uninduced states is to be preserved. Finally, we point out that the present methods and results may be useful to study the emergence of multistability in biological systems other than the lac operon.

  15. Lake Tanganyika--a 'melting pot' of ancient and young cichlid lineages (Teleostei: Cichlidae?

    Directory of Open Access Journals (Sweden)

    Juliane D Weiss

    Full Text Available A long history of research focused on the East Africa cichlid radiations (EAR revealed discrepancies between mtDNA and nuclear phylogenies, suggesting that interspecific hybridisation may have been significant during the radiation of these fishes. The approximately 250 cichlid species of Lake Tanganyika have their roots in a monophyletic African cichlid assemblage, but controversies remain about the precise phylogenetic origin and placement of different lineages and consequently about L. Tanganyika colonization scenarios. 3312 AFLP loci and the mitochondrial ND2 gene were genotyped for 91 species representing almost all major lacustrine and riverine haplotilapiine east African cichlid lineages with a focus on L. Tanganyika endemics. Explicitly testing for the possibility of ancient hybridisation events, a comprehensive phylogenetic network hypothesis is proposed for the origin and diversification of L. Tanganyika cichlids. Inference of discordant phylogenetic signal strongly suggests that the genomes of two endemic L. Tanganyika tribes, Eretmodini and Tropheini, are composed of an ancient mixture of riverine and lacustrine lineages. For the first time a strong monophyly signal of all non-haplochromine mouthbrooding species endemic to L. Tanganyika ("ancient mouthbrooders" was detected. Further, in the genomes of early diverging L. Tanganyika endemics Trematocarini, Bathybatini, Hemibatini and Boulengerochromis genetic components of other lineages belonging to the East African Radiation appear to be present. In combination with recent palaeo-geological results showing that tectonic activity in the L. Tanganyika region resulted in highly dynamic and heterogeneous landscape evolution over the Neogene and Pleistocene, the novel phylogenetic data render a single lacustrine basin as the geographical cradle of the endemic L. Tanganyika cichlid lineages unlikely. Instead a scenario of a pre-rift origin of several independent L. Tanganyika precursor

  16. Eutrophication of Kigoma bay Lake Tanganyika, Tanzania | Chale ...

    African Journals Online (AJOL)

    Studies carried out in Kigoma bay (Tanzania) and at a deep water offshore station in lakeTanganyika showed marked differences in the water characteristics at the two locations. At the pelagic station, the water was more transparent (mean 11.47 m) and poor in phosphorus (mean 6.46 mg p/1 and 2.23 p/1 total and soluble ...

  17. Quantification des apports et des exores d'un lac : cas du lac Fetzara ...

    African Journals Online (AJOL)

    ... permet de déterminer l'impact des facteurs environnementaux sur les variations de la composition chimique des eaux aux entrées et à la sortie du lac. Les résultats des analyses chimiques couplés aux débits mesurés dans différents points des Oueds Zied, Mellah, Hout et Meboudja ont permis le calcul des flux transitant ...

  18. le lac municipal d'Ebol

    African Journals Online (AJOL)

    Nsom Zamo, Annie Claude

    et Akoa AMOUGOU1. 1Laboratoire des Biotechnologies Végétales et Environnement, Département de Biologie et Physiologie. Végétales, Faculté des Sciences, Université de Yaoundé I, BP 812 Yaoundé, Cameroun. 2Laboratoire des Sciences Géotechniques et Hydrotechniques, Département des Sciences de la Terre et ...

  19. Fish catches from Lake Tanganyika mainly reflect changes in fishery practices, not climate

    NARCIS (Netherlands)

    Sarvala, J.; Langenberg, V.T.; Salonen, K.; Chitamwebwa, D.; Coulter, G.W.; Huttula, T.; Kanyaru, R.; Kotilainen, P.; Makasa, S.; Mulimbwa, N.; Molsa, H.

    2006-01-01

    Recently it was claimed that an increase in regional temperature, related to global climate change, has resulted in substantial decline in the pelagic fish catches from Lake Tanganyika, East Africa. Surface temperatures of Tanganyika indeed show warming trends, but evidence for decreased

  20. BL Lac Reunification

    Science.gov (United States)

    Giommi, P.; Padovani, P.

    1994-05-01

    X-ray-selected BL Lacs (XBLs) are generally thought to outnumber the more extreme radio-selected objects (RBLs), on the grounds that their properties could be understood if the X-ray jet were broader than the radio one. Here we present an alternative explanation: RBLs and XBLs may well be two aspects of the same population, whose main difference is the frequency of the high-energy cut-off in their energy distribution, with XBLs constituting the small subclass with cut-offs at X-ray (or higher) energies. Under this assumption, we are able to reproduce the X-ray number counts of XBLs starting from the radio counts of RBLs. We also calculate the distribution of radio fluxes of BL Lacs in current and future (deeper) X-ray surveys (e.g ROSAT), wherein we predict that a strong selection effect arising from radio constraints will lead to the preferential discovery of objects of the RBL kind. our hypothesis implies that there is a single family of BL Lacs and that, within this family, XBL-like objects are a small minority, contrary to the common belief that they represent the most numerous class.

  1. Evolution of brain-body allometry in Lake Tanganyika cichlids.

    Science.gov (United States)

    Tsuboi, Masahito; Kotrschal, Alexander; Hayward, Alexander; Buechel, Severine Denise; Zidar, Josefina; Løvlie, Hanne; Kolm, Niclas

    2016-07-01

    Brain size is strongly associated with body size in all vertebrates. This relationship has been hypothesized to be an important constraint on adaptive brain size evolution. The essential assumption behind this idea is that static (i.e., within species) brain-body allometry has low ability to evolve. However, recent studies have reported mixed support for this view. Here, we examine brain-body static allometry in Lake Tanganyika cichlids using a phylogenetic comparative framework. We found considerable variation in the static allometric intercept, which explained the majority of variation in absolute and relative brain size. In contrast, the slope of the brain-body static allometry had relatively low variation, which explained less variation in absolute and relative brain size compared to the intercept and body size. Further examination of the tempo and mode of evolution of static allometric parameters confirmed these observations. Moreover, the estimated evolutionary parameters indicate that the limited observed variation in the static allometric slope could be a result of strong stabilizing selection. Overall, our findings suggest that the brain-body static allometric slope may represent an evolutionary constraint in Lake Tanganyika cichlids. © 2016 The Author(s).

  2. The Adaptive Radiation of Cichlid Fish in Lake Tanganyika: A Morphological Perspective

    Directory of Open Access Journals (Sweden)

    Tetsumi Takahashi

    2011-01-01

    Full Text Available Lake Tanganyika is the oldest of the Great Ancient Lakes in the East Africa. This lake harbours about 250 species of cichlid fish, which are highly diverse in terms of morphology, behaviour, and ecology. Lake Tanganyika's cichlid diversity has evolved through explosive speciation and is treated as a textbook example of adaptive radiation, the rapid differentiation of a single ancestor into an array of species that differ in traits used to exploit their environments and resources. To elucidate the processes and mechanisms underlying the rapid speciation and adaptive radiation of Lake Tanganyika's cichlid species assemblage it is important to integrate evidence from several lines of research. Great efforts have been, are, and certainly will be taken to solve the mystery of how so many cichlid species evolved in so little time. In the present review, we summarize morphological studies that relate to the adaptive radiation of Lake Tanganyika's cichlids and highlight their importance for understanding the process of adaptive radiation.

  3. Recent paleorecords document rising mercury contamination in Lake Tanganyika

    Science.gov (United States)

    Conaway, C.H.; Swarzenski, P.W.; Cohen, A.S.

    2012-01-01

    Recent Lake Tanganyika Hg deposition records were derived using 14C and excess 210Pb geochronometers in sediment cores collected from two contrasting depositional environments: the Kalya Platform, located mid-lake and more removed from watershed impacts, and the Nyasanga/Kahama River delta region, located close to the lake's shoreline north of Kigoma. At the Kalya Platform area, pre-industrial Hg concentrations are 23??0.2ng/g, increasing to 74ng/g in modern surface sediment, and the Hg accumulation rate has increased from 1.0 to 7.2??g/m 2/a from pre-industrial to present, which overall represents a 6-fold increase in Hg concentration and accumulation. At the Nyasanga/Kahama delta region, pre-industrial Hg concentrations are 20??3ng/g, increasing to 46ng/g in surface sediment. Mercury accumulation rate has increased from 30 to 70??g/m 2/a at this site, representing a 2-3-fold increase in Hg concentration and accumulation. There is a lack of correlation between charcoal abundance and Hg accumulation rate in the sediment cores, demonstrating that local biomass burning has little relationship with the observed Hg concentration or Hg accumulation rates. Examined using a sediment focusing-corrected mass accumulation rate approach, the cores have similar anthropogenic atmospheric Hg deposition profiles, suggesting that after accounting for background sediment concentrations the source of accumulating Hg is predominantly atmospheric in origin. In summary, the data document an increase of Hg flux to the Lake Tanganyika ecosystem that is consistent with increasing watershed sediment delivery with background-level Hg contamination, and regional as well as global increases in atmospheric Hg deposition. ?? 2011.

  4. Organisation spatiale du peuplement de poissons dans le Bandama ...

    African Journals Online (AJOL)

    L'évolution des peuplements de poissons sur le Bandama a été étudiée en considérant quatre zones d'échantillonnage : en amont du lac de Kossou, dans les lacs de Kossou et de Taabo, entre les lacs de Kossou et de Taabo, et en aval du lac de Taabo. Au total, 74 espèces de poisson réparties en 49 genres, 28 familles ...

  5. Climate change decreases aquatic ecosystem productivity of Lake Tanganyika, Africa.

    Science.gov (United States)

    O'Reilly, Catherine M; Alin, Simone R; Plisnier, Pierre-Denis; Cohen, Andrew S; McKee, Brent A

    2003-08-14

    Although the effects of climate warming on the chemical and physical properties of lakes have been documented, biotic and ecosystem-scale responses to climate change have been only estimated or predicted by manipulations and models. Here we present evidence that climate warming is diminishing productivity in Lake Tanganyika, East Africa. This lake has historically supported a highly productive pelagic fishery that currently provides 25-40% of the animal protein supply for the populations of the surrounding countries. In parallel with regional warming patterns since the beginning of the twentieth century, a rise in surface-water temperature has increased the stability of the water column. A regional decrease in wind velocity has contributed to reduced mixing, decreasing deep-water nutrient upwelling and entrainment into surface waters. Carbon isotope records in sediment cores suggest that primary productivity may have decreased by about 20%, implying a roughly 30% decrease in fish yields. Our study provides evidence that the impact of regional effects of global climate change on aquatic ecosystem functions and services can be larger than that of local anthropogenic activity or overfishing.

  6. Marine incursion: the freshwater herring of Lake Tanganyika are the product of a marine invasion into west Africa.

    Directory of Open Access Journals (Sweden)

    Anthony B Wilson

    Full Text Available The spectacular marine-like diversity of the endemic fauna of Lake Tanganyika, the oldest of the African Great Lakes, led early researchers to suggest that the lake must have once been connected to the ocean. Recent geophysical reconstructions clearly indicate that Lake Tanganyika formed by rifting in the African subcontinent and was never directly linked to the sea. Although the Lake has a high proportion of specialized endemics, the absence of close relatives outside Tanganyika has complicated phylogeographic reconstructions of the timing of lake colonization and intralacustrine diversification. The freshwater herring of Lake Tanganyika are members of a large group of pellonuline herring found in western and southern Africa, offering one of the best opportunities to trace the evolutionary history of members of Tanganyika's biota. Molecular phylogenetic reconstructions indicate that herring colonized West Africa 25-50MYA, at the end of a major marine incursion in the region. Pellonuline herring subsequently experienced an evolutionary radiation in West Africa, spreading across the continent and reaching East Africa's Lake Tanganyika during its early formation. While Lake Tanganyika has never been directly connected with the sea, the endemic freshwater herring of the lake are the descendents of an ancient marine incursion, a scenario which may also explain the origin of other Tanganyikan endemics.

  7. Specific point mutations in Lactobacillus casei ATCC 27139 cause a phenotype switch from Lac- to Lac+.

    Science.gov (United States)

    Tsai, Yu-Kuo; Chen, Hung-Wen; Lo, Ta-Chun; Lin, Thy-Hou

    2009-03-01

    Lactose metabolism is a changeable phenotype in strains of Lactobacillus casei. In this study, we found that L. casei ATCC 27139 was unable to utilize lactose. However, when exposed to lactose as the sole carbon source, spontaneous Lac(+) clones could be obtained. A gene cluster (lacTEGF-galKETRM) involved in the metabolism of lactose and galactose in L. casei ATCC 27139 (Lac(-)) and its Lac(+) revertant (designated strain R1) was sequenced and characterized. We found that only one nucleotide, located in the lacTEGF promoter (lacTp), of the two lac-gal gene clusters was different. The protein sequence identity between the lac-gal gene cluster and those reported previously for some L. casei (Lac(+)) strains was high; namely, 96-100 % identity was found and no premature stop codon was identified. A single point mutation located within the lacTp promoter region was also detected for each of the 41 other independently isolated Lac(+) revertants of L. casei ATCC 27139. The revertants could be divided into six classes based on the positions of the point mutations detected. Primer extension experiments conducted on transcription from lacTp revealed that the lacTp promoter of these six classes of Lac(+) revertants was functional, while that of L. casei ATCC 27139 was not. Northern blotting experiments further confirmed that the lacTEGF operon of strain R1 was induced by lactose but suppressed by glucose, whereas no blotting signal was ever detected for L. casei ATCC 27139. These results suggest that a single point mutation in the lacTp promoter was able to restore the transcription of a fully functional lacTEGF operon and cause a phenotype switch from Lac(-) to Lac(+) for L. casei ATCC 27139.

  8. Heterogeneity in physical, chemical and plankton-community structures in Lake Tanganyika

    NARCIS (Netherlands)

    Langenberg, V.T.; Tumba, J.M.; Tshibangu, K.; Lukwesa, C.; Chitamwebwa, D.; Bwebwa, D.; Makasa, L.; Roijackers, R.M.M.

    2008-01-01

    From 28 August to 6 September 1995, we monitored the lake-wide physical, chemical and biological properties of the pelagic waters in Lake Tanganyika. The aim of this study was to examine the spatial environmental variability and its relation to fluctuations in plankton abundance and community

  9. Century-Long Warming Trends in the Upper Water Column of Lake Tanganyika.

    Science.gov (United States)

    Kraemer, Benjamin M; Hook, Simon; Huttula, Timo; Kotilainen, Pekka; O'Reilly, Catherine M; Peltonen, Anu; Plisnier, Pierre-Denis; Sarvala, Jouko; Tamatamah, Rashid; Vadeboncoeur, Yvonne; Wehrli, Bernhard; McIntyre, Peter B

    2015-01-01

    Lake Tanganyika, the deepest and most voluminous lake in Africa, has warmed over the last century in response to climate change. Separate analyses of surface warming rates estimated from in situ instruments, satellites, and a paleolimnological temperature proxy (TEX86) disagree, leaving uncertainty about the thermal sensitivity of Lake Tanganyika to climate change. Here, we use a comprehensive database of in situ temperature data from the top 100 meters of the water column that span the lake's seasonal range and lateral extent to demonstrate that long-term temperature trends in Lake Tanganyika depend strongly on depth, season, and latitude. The observed spatiotemporal variation in surface warming rates accounts for small differences between warming rate estimates from in situ instruments and satellite data. However, after accounting for spatiotemporal variation in temperature and warming rates, the TEX86 paleolimnological proxy yields lower surface temperatures (1.46 °C lower on average) and faster warming rates (by a factor of three) than in situ measurements. Based on the ecology of Thaumarchaeota (the microbes whose biomolecules are involved with generating the TEX86 proxy), we offer a reinterpretation of the TEX86 data from Lake Tanganyika as the temperature of the low-oxygen zone, rather than of the lake surface temperature as has been suggested previously. Our analyses provide a thorough accounting of spatiotemporal variation in warming rates, offering strong evidence that thermal and ecological shifts observed in this massive tropical lake over the last century are robust and in step with global climate change.

  10. IGCSE English at the International School of Tanganyika: A Program in the Balance.

    Science.gov (United States)

    Born, Peter

    1999-01-01

    A teacher defends the effectiveness of the English language and literature program of the International General Certificate of Secondary Education at a Tanganyika international school, despite criticisms of its syllabus, exam structure, and criteria. The program is externally moderated, has sound assessments and strong parental support, and…

  11. LacR is a repressor of lacABCD and LacT is an activator of lacTFEG, constituting the lac gene cluster in Streptococcus pneumoniae.

    Science.gov (United States)

    Afzal, Muhammad; Shafeeq, Sulman; Kuipers, Oscar P

    2014-09-01

    Comparison of the transcriptome of Streptococcus pneumoniae strain D39 grown in the presence of either lactose or galactose with that of the strain grown in the presence of glucose revealed the elevated expression of various genes and operons, including the lac gene cluster, which is organized into two operons, i.e., lac operon I (lacABCD) and lac operon II (lacTFEG). Deletion of the DeoR family transcriptional regulator lacR that is present downstream of the lac gene cluster revealed elevated expression of lac operon I even in the absence of lactose. This suggests a function of LacR as a transcriptional repressor of lac operon I, which encodes enzymes involved in the phosphorylated tagatose pathway in the absence of lactose or galactose. Deletion of lacR did not affect the expression of lac operon II, which encodes a lactose-specific phosphotransferase. This finding was further confirmed by β-galactosidase assays with PlacA-lacZ and PlacT-lacZ in the presence of either lactose or glucose as the sole carbon source in the medium. This suggests the involvement of another transcriptional regulator in the regulation of lac operon II, which is the BglG-family transcriptional antiterminator LacT. We demonstrate the role of LacT as a transcriptional activator of lac operon II in the presence of lactose and CcpA-independent regulation of the lac gene cluster in S. pneumoniae. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  12. effort de pêche et production piscicole au lac d'ayame i

    African Journals Online (AJOL)

    USER

    d'Ayamé I a permis d'évaluer la production piscicole à 236,9 t de poisson dans ces stations. Cette production ... poisson. Le lac d'Ayamé I résulte de la construction, sur la rivière Bia, du premier barrage hydroélectrique du pays, entre septembre 1956 et mars 1960. (Reizer .... (1997), cette variable demeure le seul indice.

  13. Fish Diversity and Abundance of Lake Tanganyika: Comparison between Protected Area (Mahale Mountains National Park) and Unprotected Areas

    OpenAIRE

    Emmanuel A. Sweke; Julius M. Assam; Takashi Matsuishi; Abdillahi I. Chande

    2013-01-01

    High biodiversity is the most remarkable characteristic of Lake Tanganyika including vertebrates, invertebrates, and plants. A few protected areas have been created along the lake to protect its biodiversity. However, limited studies have been carried out to ascertain their effectiveness. The current study aimed at assessing and comparing fish diversity and abundance of Lake Tanganyika in a protected area (Mahale Mountains National Park (MMNP)) and unprotected areas surrounding it. The data w...

  14. Optical Spectra Evolution of BL Lac Objects

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Many quasi-simultaneous optical observations of nine BL Lac objects are obtained from literature. We study the relationship between the optical spectral index and the luminosity of BL Lac objects, and are tempted to exploit spectral evolution in the optical frequency ranges. Our results show that:.

  15. Du Lac de Geneve au Lac Baikal: deux metropoles en construction

    Directory of Open Access Journals (Sweden)

    Guy Mettan

    2006-08-01

    Full Text Available En apparence, Geneve et Irkutsk n'ont rien en commun. A part une amitie reciproque et la proximite d'un lac, il est difficile de trouver des points communs entre la Suisse francophone, dont Geneve est la ville le plus importante, et la Siberie centrale, dont Irkutsk, est la capitale. Et pourtant les deux regions, malgre les differences de taille, de densite de la population, de climat, d'economie et de traditions culturelles, sont confrontees au meme probleme: elles sont trop petites et trop limitees pour assurer, avec leurs seuls moyens, leur avenir et elles doivent imperativement s'unir a des villes voisines pour renforcer leur statut de metropole regionale et s'imposer face aux regions et aux pays concurrents.C'est ainsi qu'Irkutsk projette de s'unir aux villes voisines d'Angarsk et de Chelekhov pour constituer une megapole au c?ur de la Siberie, tandis qu'a Geneve le debat fait rage pour trouver des solutions a l'exiguite geographique et a l'insuffisance des moyens face aux grandes regions metropolitaines de France, d'Italie et d'Allemagne.Ce debat est propre a toute la Suisse. Malgre sa petitesse, la Suisse est divisee en 26 cantons. Ces unites administratives sont jugees trop couteuses, trop petites, trop lourdes et trop compliquees pour assurer l'avenir economique et meme politique du pays. De nombreux groupes de reflexion proposent donc de reduire ce nombre a 3, 5 ou 10 grandes provinces selon les cas. En Suisse, romande, il y a dix ans, des mouvements politiques ont meme lance l'idee de fusionner les cantons de Vaud (dont Lausanne est la capitale et de Geneve. Mais l'echec a ete fracassant : le peuple des deux cantons a refuse cette option a 80% des voix. On cherche donc d'autres solutions.Les discussions s'orientent desormais autour de la constitution d'une grande metropole lemanique qui regrouperait les deux grandes villes de Geneve et Lausanne et les villes plus petites de Montreux, Vevey, Nyon ainsi que la ville francaise d

  16. Century-Long Warming Trends in the Upper Water Column of Lake Tanganyika.

    Directory of Open Access Journals (Sweden)

    Benjamin M Kraemer

    Full Text Available Lake Tanganyika, the deepest and most voluminous lake in Africa, has warmed over the last century in response to climate change. Separate analyses of surface warming rates estimated from in situ instruments, satellites, and a paleolimnological temperature proxy (TEX86 disagree, leaving uncertainty about the thermal sensitivity of Lake Tanganyika to climate change. Here, we use a comprehensive database of in situ temperature data from the top 100 meters of the water column that span the lake's seasonal range and lateral extent to demonstrate that long-term temperature trends in Lake Tanganyika depend strongly on depth, season, and latitude. The observed spatiotemporal variation in surface warming rates accounts for small differences between warming rate estimates from in situ instruments and satellite data. However, after accounting for spatiotemporal variation in temperature and warming rates, the TEX86 paleolimnological proxy yields lower surface temperatures (1.46 °C lower on average and faster warming rates (by a factor of three than in situ measurements. Based on the ecology of Thaumarchaeota (the microbes whose biomolecules are involved with generating the TEX86 proxy, we offer a reinterpretation of the TEX86 data from Lake Tanganyika as the temperature of the low-oxygen zone, rather than of the lake surface temperature as has been suggested previously. Our analyses provide a thorough accounting of spatiotemporal variation in warming rates, offering strong evidence that thermal and ecological shifts observed in this massive tropical lake over the last century are robust and in step with global climate change.

  17. Out of Tanganyika: Genesis, explosive speciation, key-innovations and phylogeography of the haplochromine cichlid fishes

    Directory of Open Access Journals (Sweden)

    Verheyen Erik

    2005-02-01

    Full Text Available Abstract Background The adaptive radiations of cichlid fishes in East Africa are well known for their spectacular diversity and their astonishingly fast rates of speciation. About 80% of all 2,500 cichlid species in East Africa, and virtually all cichlid species from Lakes Victoria (~500 species and Malawi (~1,000 species are haplochromines. Here, we present the most extensive phylogenetic and phylogeographic analysis so far that includes about 100 species and is based on about 2,000 bp of the mitochondrial DNA. Results Our analyses revealed that all haplochromine lineages are ultimately derived from Lake Tanganyika endemics. We find that the three most ancestral lineages of the haplochromines sensu lato are relatively species poor, albeit widely distributed in Africa, whereas a fourth newly defined lineage – the 'modern haplochromines' – contains an unparalleled diversity that makes up more than 7% of the worlds' ~25,000 teleost species. The modern haplochromines' ancestor, most likely a riverine generalist, repeatedly gave rise to similar ecomorphs now found in several of the species flocks. Also, the Tanganyikan Tropheini are derived from that riverine ancestor suggesting that they successfully re-colonized Lake Tanganyika and speciated in parallel to an already established cichlid adaptive radiation. In contrast to most other known examples of adaptive radiations, these generalist ancestors were derived from highly diverse and specialized endemics from Lake Tanganyika. A reconstruction of life-history traits revealed that in an ancestral lineage leading to the modern haplochromines the characteristic egg-spots on anal fins of male individuals evolved. Conclusion We conclude that Lake Tanganyika is the geographic and genetic cradle of all haplochromine lineages. In the ancestors of the replicate adaptive radiations of the 'modern haplochromines', behavioral (maternal mouthbrooding, morphological (egg-spots and sexually selected (color

  18. Contribution à l'étude de la flore aquatique d'un lac de montagne ...

    African Journals Online (AJOL)

    L'étude présentée ici est réalisée durant la période allant de mars à octobre 2011 dans le lac Dayet Aoua situé dans la province d'Ifrane. ... the lake. the diversity and the quantitative importance of Macrophytes in this site is marked by the presence of emergent plants, plants with submerged organs and submerged plants.

  19. Évaluation du niveau de pollution par les métaux lourds des lacs ...

    African Journals Online (AJOL)

    La présente étude a pour objectif principal d'évaluer le niveau de pollution métallique des lacs Bini et Dang (Ngaoundéré, Cameroun) à travers l'analyse des eaux et des sédiments de surface. La concentration des métaux lourds (Ni, Cr, Fe, Pb, Cd, Zn) a été mesurée par spectrophotométrie d'absorption atomique.

  20. Comprendre les obstacles à la paix dans la région des Grands Lacs ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Dans la région des Grands Lacs, en Afrique, les conflits violents qui perdurent occasionnent énormément de souffrance et freinent le développement socioéconomique. Plusieurs initiatives sont en cours pour tenter de pacifier la région, mais la plupart portent sur des pays précis et, par conséquent, ne prennent pas en ...

  1. Stable Isotopes Reveal Nitrogen Loading to Lake Tanganyika from Remote Shoreline Villages.

    Science.gov (United States)

    Kelly, Brianne; Mtiti, Emmanuel; McIntyre, Peter B; Vadeboncoeur, Yvonne

    2017-02-01

    Access to safe water is an ongoing challenge in rural areas in Tanzania where communities often lack access to improved sanitation. Methods to detect contamination of surface water bodies, such as monitoring nutrient concentrations and bacterial counts, are time consuming and results can be highly variable in space and time. On the northeast shore of Lake Tanganyika, Tanzania, the low population density coupled with the high potential for dilution in the lake necessitates the development of a sensitive method for detecting contamination in order to avoid human health concerns. We investigated the potential use of nitrogen and carbon stable isotopes of snail tissues to detect anthropogenic nutrient loading along the northeast shore of Lake Tanganyika. δ 15 N of snails was positively related to human population size in the nearest village, but only for villages with >4000 inhabitants. The areal footprint of villages within their watershed was also significantly correlated with snail δ 15 N, while agricultural land use and natural vegetation were not. Dissolved nutrient concentrations were not significantly different between village and reference sites. Our results indicate that nitrogen isotopes provide a sensitive index of local nutrient loading that can be used to monitor contamination of oligotrophic aquatic environments with low surrounding population densities.

  2. Clustering environments of BL Lac objects

    Science.gov (United States)

    Wurtz, Ronald; Ellingson, Erica; Stocke, John T.; Yee, H. K. C.

    1993-01-01

    We report measurements of the amplitude of the BL Lac galaxy spatial covariance function, B(gb), for the fields of five BL Lacertae objects. We present evidence for rich clusters around MS 1207+39 and MS 1407+59, and confirm high richness for the cluster containing H0414+009. We discuss the ease of 3C 66 A and find evidence for a poor cluster based on an uncertain redshift of z = 0.444. These data suggest that at least some BL Lac objects are consistent with being FR 1 radio galaxies in rich clusters.

  3. The comparison between LAC and ALA

    Directory of Open Access Journals (Sweden)

    Tzu-heng Chiu

    2000-12-01

    Full Text Available A good library association serves its members, improves the librarianship, and helps library institutions achieving their missions. This article describes the history, missions and goals, organization structure, membership, financial sources, professional activities, publication, and website of the Library Association of China (LAC and American Library Association (ALA, respectively. Considering social / cultural / political differences between Taiwan and the United Sates, the author then compares these two library associations from the eight factors mentioned above. At the end, suggestions for the LAC are proposed.[Article content in Chinese

  4. Acquisition of the lac operon by Salmonella enterica.

    Science.gov (United States)

    Leonard, Susan R; Lacher, David W; Lampel, Keith A

    2015-08-25

    Classical bacteriological characteristics of Salmonella enterica indicate that the members of this species are unable to utilize lactose as a carbon source. However, lactose-fermenting (Lac+) strains of several Salmonella serovars have been isolated from different foodborne outbreaks as well as different geographical regions worldwide. In the present study, we sequenced the genomes of 13 Lac + S. enterica isolates and characterized the lac region, comparing it to the lac region in other enteric bacterial species. Genetic analysis of the lac operons in the S. enterica genomes revealed that they all contain intact lacI, lacZ, and lacY genes. However, lacA was truncated in all of the S. enterica subsp. enterica isolates, encoding a 56 amino acid peptide rather than the full length 220 amino acid LacA protein. Molecular analyses of the 13 isolates revealed that the lac operon resided on a plasmid in some strains and in others was integrated into the bacterial chromosome. In most cases, an insertion sequence flanked at least one end of the operon. Interestingly, the S. enterica Montevideo and S. enterica Senftenberg isolates were found to harbor a plasmid with a high degree of sequence similarity to a plasmid from Klebsiella pneumoniae strain NK29 that also harbors the lac operon. In addition, two S. enterica Tennessee isolates carried two copies of the lac operon. Phylogenetic analysis based on lacIZY gene sequences determines distinct clusters, and reveals a greater correlation between lacIZY sequence and flanking organization than with either bacterial species or genomic location. Our results indicate that the lac region is highly mobile among Enterobacteriaceae and demonstrate that the Lac + S. enterica subsp. enterica serovars acquired the lac region through parallel events. The acquisition of the lac operon by several S. enterica serovars may be indicative of environmental adaptation by these bacteria.

  5. Preliminary Nearshore Sedimentation Rate Analysis of the Tuungane Project Northern Mahale Conservation Area, Lake Tanganyika (Tanzania)

    Science.gov (United States)

    Smiley, R. A.; McGlue, M. M.; Yeager, K. M.; Soreghan, M. J.; Lucas, J.; Kimirei, I.; Mbonde, A.; Limbu, P.; Apse, C.

    2017-12-01

    The combined effects of climate change, overfishing, and sediment pollution are altering Lake Tanganyika's littoral fisheries in profoundly negative ways. One method for conserving critical fish resources and safeguarding biodiversity in Lake Tanganyika is by establishing small-scale nearshore protected zones, which can be administrated by lakeshore villagers organized into beach management units (BMUs). Each BMU endeavors to manage offshore "no-catch" protected zones, prohibit the use of illegal fishing gear, and promote sustainable agriculture that abates erosion in the lake watershed, in order to mitigate sediment pollution in the lake. We adopted a limnogeological approach to assist in characterizing the littoral zone associated with BMUs in the northern Mahale region of Lake Tanganyika (Tanzania), a critical conservation area for the Nature Conservancy's Tuungane Project (https://www.nature.org/ourinitiatives/regions/africa/wherewework/tuungane-project.xml). We hypothesized that BMUs with heavy onshore agricultural activity would experience relatively high offshore sedimentation rates, due to enhanced sediment-laden runoff in the wet season. Such changes are predicted to alter benthic substrates and degrade habitat available for fish spawning. We mapped bathymetry and sediment types along a 29 km2 area of the littoral zone using high-resolution geophysical tools, and assessed short-term sedimentation rates using sediment cores and radionuclide geochronology (210Pb). Initial results from 210Pb analyses show that sedimentation rates at the mud-line ( 85-100 m water depth) are relatively slow but spatially variable in the northern Mahale area. Offshore of the Kalilani village BMU, linear sedimentation rates are 0.50 mm/yr. By contrast, sedimentation rates offshore from the Igualula village BMU are 0.90-1.30 mm/yr. Higher sedimentation rates near Igualula are consistent with greater sediment inputs from the nearby Lagosa River and its watershed, which has been

  6. Structure and dynamics in Lac repressor-DNA interactions

    NARCIS (Netherlands)

    Kaptein, R.

    2013-01-01

    The E. coli lac operon is the classical model for gene regulation in bacteria. An overview will be given of our work on the lac repressor-operator system. An early result was the 3D structure of lac headpiece in 1985, one of the first protein structures determined by NMR. Our studies of the

  7. Hydrothermal vents in Lake Tanganyika harbor spore-forming thermophiles with extremely rapid growth

    DEFF Research Database (Denmark)

    Elsgaard, Lars; Prieur, Daniel

    2010-01-01

    endospores. Based on the 16 S rDNA sequence the novel strain was homologous to Thermobrachium celere and Caloramator indicus, which are closely related. The novel strain was strictly anaerobic, fermentative and had a doubling time as short as 10 min during growth on complex substrates, such as yeast extract......A thermophilic anaerobic bacterium was isolated from a sublacustrine hydrothermal vent site in Lake Tanganyika (East Africa) with recorded fluid temperatures of 66–103 °C and pH values of 7.7–8.9. The bacterium (strain TR10) was rod-shaped, about 1 by 5 μm in size, and readily formed distal...

  8. Natural LacI from E. coli Yields Faster Response and Higher Level of Expression than the LVA-Tagged LacI

    DEFF Research Database (Denmark)

    Andreassen, Patrick Rosendahl; Fredberg, Sofie; Horan, Mattias

    2014-01-01

    The lac promoter is one of the most commonly used promoters for expression control of recombinant genes in E. coli. In the absence of galactosides, the lac promoter is repressed by its repressor protein LacI. Since the lac promoter is regulated by a repressor, overexpression of LacI is necessary...

  9. Fish Diversity and Abundance of Lake Tanganyika: Comparison between Protected Area (Mahale Mountains National Park and Unprotected Areas

    Directory of Open Access Journals (Sweden)

    Emmanuel A. Sweke

    2013-01-01

    Full Text Available High biodiversity is the most remarkable characteristic of Lake Tanganyika including vertebrates, invertebrates, and plants. A few protected areas have been created along the lake to protect its biodiversity. However, limited studies have been carried out to ascertain their effectiveness. The current study aimed at assessing and comparing fish diversity and abundance of Lake Tanganyika in a protected area (Mahale Mountains National Park (MMNP and unprotected areas surrounding it. The data were collected in the near shore zone at 5 m and 10 m depths using stationary visual census (SVC technique. The protected area recorded higher fish richness and abundance than unprotected areas (P<0.05. It was concluded that the protected area is effective in conserving the fish diversity and abundance of the lake. However, more studies should be carried out regularly to explore the efficacy of the protected area in conservation of aquatic biodiversity and abundance.

  10. : tous les projets | Page 167 | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le lac Tonlé Sap, au Cambodge, est le plus grand lac d'eau douce en Asie du Sud-Est. End Date: 25 janvier 2017. Région: South Asia, Far East Asia, Cambodia, Canada. Programme: Climate Change. Financement total : CA$ 0.00. Amélioration de la gouvernance de l'eau et de l'adaptation aux changements climatiques ...

  11. Changements climatiques et infiltrations d'eau salée le long du ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Amélioration de la gouvernance de l'eau et de l'adaptation aux changements climatiques au Cambodge. Le lac Tonlé Sap, au Cambodge, est le plus grand lac d'eau douce en Asie du Sud-Est. Voir davantageAmélioration de la gouvernance de l'eau et de l'adaptation aux changements climatiques au Cambodge ...

  12. Fish communities in man-made lakes = Peuplements ichtyologiques des lacs de barrage

    OpenAIRE

    Jackson, P.N.B.; Marshall, B.E.; Paugy, Didier

    1988-01-01

    Il existe actuellement des réservoirs artificiels sur de nombreuses rivières africaines. Leur construction a modifié les conditions écologiques (facteurs édaphiques, apports en éléments nutritifs) et changé la composition des peuplements ichtyologiques ... Le barrage lui-même peut être un obstacle pour des poissons tels que les anguilles ou les mulets migrants depuis la mer et entraîner la disparition des espèces en amont ... Les lacs de barrage ont une vaste zone pélagique favorable au déve...

  13. Adsorption Properties of Lac Dyes on Wool, Silk, and Nylon

    OpenAIRE

    Wei, Bo; Chen, Qiu-Yuan; Chen, Guoqiang; Tang, Ren-Cheng; Zhang, Jun

    2013-01-01

    There has been growing interest in the dyeing of textiles with natural dyes. The research about the adsorption properties of natural dyes can help to understand their adsorption mechanism and to control their dyeing process. This study is concerned with the kinetics and isotherms of adsorption of lac dyes on wool, silk, and nylon fibers. It was found that the adsorption kinetics of lac dyes on the three fibers followed the pseudosecond-order kinetic model, and the adsorption rate of lac dyes ...

  14. L’ACTIVITÉ DE LA SUPEROXYDE DISMUTASE ET DE LA CATALASE DANS LES FEUILLES DE GRAND ROSEAU (PHRAGMITES COMMUNIS, DANS LES LACS DE LA RIVIÈRE CIRIC

    Directory of Open Access Journals (Sweden)

    Anca Negura

    2007-12-01

    Full Text Available Notre travail a suivi l’activité de deux enzymes du stress oxydatif, la superoxyde dismutase (SOD et la peroxydase (POD, dans les feuilles de grand roseau (Phragmites communis provenues de plantes ayant atteint la maturité, qui poussent dans les lacs sur le parcours de la rivière Ciric. Parmi les quatre lacs considérés dans l’étude, nous avons remarqué des valeurs élevées de l’activité SOD dans les plantes provenues du lac Ciric I, comparativement aux valeurs normales pour cette enzyme. Cette croissance d’activité pourrait représenter une réponse des plantes au stress oxydatif, apparu probablement dans des conditions de faible pollution de ce lac. Pour toutes les plantes issues de tous les lacs étudiés, la peroxydase n’a pas présenté des valeurs d’activité pouvant soulever le problème de quelconque pollution.

  15. LacR Is a Repressor of lacABCD and LacT Is an Activator of lacTFEG, Constituting the lac Gene Cluster in Streptococcus pneumoniae

    NARCIS (Netherlands)

    Afzal, Muhammad; Shafeeq, Sulman; Kuipers, Oscar P.

    Comparison of the transcriptome of Streptococcus pneumoniae strain D39 grown in the presence of either lactose or galactose with that of the strain grown in the presence of glucose revealed the elevated expression of various genes and operons, including the lac gene cluster, which is organized into

  16. Ecologie du phytoplancton du lac Kivu

    Directory of Open Access Journals (Sweden)

    Sarmento, H.

    2008-01-01

    Full Text Available Speciation within the African Coffee Pathogen. Cet article analyse s'il est avantageux d'utiliser le compost au lieu de l'engrais minéral pour produire la laitue dans la zone urbaine et péri-urbaine de Yaoundé. Les résultats de terrain montrent l'obtention de rendements et profits plus élevés lorsqu'on utilise le compost. Les résultats de la fonction de production Cobb-Douglas prouvent que l'utilisation du compost est statistiquement significative pour expliquer la variation de rendement de la laitue et que le compost est l'intrant le plus productif. D'autres résultats montrent que le compost fournit la matière organique utile au sol et que les besoins d'irrigation en eau de la culture sont réduits grâce à l'utilisation du compost. Par conséquent, malgré le fait que l'application du compost demande une main-d'oeuvre beaucoup plus élevée, son utilisation est généralement bénéfique pour les agriculteurs vivant aux alentours de Yaoundé. Les programmes de vulgarisation de cet intrant pour encourager son adoption devraient donc figurer parmi les points prioritaires dans la politique agricole du gouvernement camerounais.

  17. Opening Up Natural Resource Based Industries for Innovation (LAC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Opening Up Natural Resource Based Industries for Innovation (LAC). Commodities based on natural resources account for at least half of the exports of two-thirds of the countries in Latin America and the Caribbean (LAC). There is growing concern, however, that existing natural resource-based industries are ...

  18. High-Resolution Geochemical and Paleoecological Records of Climate Change Since the Late Glacial at Lake Tanganyika, East Africa

    Science.gov (United States)

    Alin, S. R.; Cohen, A. S.

    2002-12-01

    We used high-resolution geochemical and paleoecological records from shallow-water sediment cores to refine previous descriptions of climatic conditions at Lake Tanganyika, East Africa, for the period from the Late Glacial to the present. Radiocarbon and 210Pb dating were used to establish chronologies for the cores. Sedimentological changes indicate that lake level has risen approximately 50-70 m since the Late Glacial. A depositional hiatus occurred between 6.4 and 11.4 ka BP (all dates in calendar years) in several of the shallow-water cores. Elemental abundance (%C, %N) and stable isotopic (δ15N, δ13C) data for one core suggest that substantial changes in primary productivity and nutrient recycling regimes have occurred since 6.4 ka BP. Carbonate and ostracode crustacean preservation were low and nil, respectively, prior to 2.4 ka BP. Generally, these data support previous interpretations of regional paleoclimate and lake conditions, with wet and warm conditions during the interval from 6.4 to 4.0 ka, and increasingly arid conditions since 2.4 ka. However, for the interval from 4.0 to 2.4 ka, paleoenvironmental indicators (δ15N, reduced carbonate and ostracode preservation) suggest that the central part of Lake Tanganyika was stably stratified at a shallower depth than present as a result of diminished southerly trade winds. After 2.4 ka BP, sedimentary carbonate concentrations increase, and δ13C values become enriched, suggesting that lacustrine productivity increased with the resumption of deeper wind-driven mixing, lasting until 1 ka BP. For post-2.4 ka samples, species abundance data for ostracodes were used to generate an ostracode water depth index (OWDI). OWDI indicated that severe drought conditions were persistent or recurred at Lake Tanganyika between 1550 and 1850 A.D. Droughts resulted in marked lowstands at Lake Tanganyika at 1580+/-15 A.D., 1730+/-35 A.D., and 1800+/-30 A.D. These data contribute new information on the timing of Little Ice Age

  19. Doing colonialism: reading the banishment of a »native chief« in the Tanganyika territory

    OpenAIRE

    Brockmeyer, Bettina

    2017-01-01

    This article takes a closer look at the »colonial situation« (Balandier 1970). It seeks to shed light on a multifaceted non-colonizing colonial biography during the time of European conquest. The focus lies on the interpretation of the banishment of a »chief« in the British-mandated territory of Tanganyika. This chief, Sapi Mkwawa (1879–1951), was an important figure within European colonization. He experienced two colonizing powers in a prominent but ambiguous position. I argue that through ...

  20. Adsorption Properties of Lac Dyes on Wool, Silk, and Nylon

    Directory of Open Access Journals (Sweden)

    Bo Wei

    2013-01-01

    Full Text Available There has been growing interest in the dyeing of textiles with natural dyes. The research about the adsorption properties of natural dyes can help to understand their adsorption mechanism and to control their dyeing process. This study is concerned with the kinetics and isotherms of adsorption of lac dyes on wool, silk, and nylon fibers. It was found that the adsorption kinetics of lac dyes on the three fibers followed the pseudosecond-order kinetic model, and the adsorption rate of lac dyes was the fastest for silk and the slowest for wool. The activation energies for the adsorption process on wool, silk, and nylon were found to be 107.15, 87.85, and 45.31 kJ/mol, respectively. The adsorption of lac dyes on the three fibers followed the Langmuir mechanism, indicating that the electrostatic interactions between lac dyes and those fibers occurred. The saturation values for lac adsorption on the three fibers decreased in the order of wool > silk > nylon; the Langmuir affinity constant of lac adsorption on nylon was much higher than those on wool and silk.

  1. Déclin et restauration de la population de truites lacustres (Salmo trutta lacustris L. du lac de Constance

    Directory of Open Access Journals (Sweden)

    RUHLÉ C.

    1990-10-01

    Full Text Available Le déclin de la population de truites migratrices du lac de Constance a débuté vers 1950 quand un barrage a été construit sur le Rhin, affluent principal de ce lac, coupant ainsi l'accès aux plus importantes frayères. Ceci a suffi de prétexte pour renoncer à une longueur de capture garantissant la reproduction naturelle. Par la suite, la population en train de diminuer a servi de justification pour des déversements importants de truites arc-en-ciel. Un désintérêt croissant pour le maintien de frayères dans les affluents secondaires a, finalement, contribué à la baisse des captures de 12.000 kg à 3.000 kg entre 1950 et 1980.Les mesures réalisées au cours des dernières années pour restaurer la population de truites lacustres ont du succès. Il s'agit surtout de : — la détermination d'une nouvelle longueur de capture ainsi que de périodes de protection respectant la reproduction des truites migrant à longue et à courte distance,— l'élevage de stocks de géniteurs, — les déversements forcés et effectués surtout en affluents (au lieu du lac,— l'interdiction d'immersions de truites arc-en-ciel,— l'abolition de barrages. Le succès se manifeste par un nombre croissant de truites observées frayant dans les affluents ainsi que par des captures de plus en plus nombreuses faites par la pêche professionnelle.

  2. Comparing the Performance of Protected and Unprotected Areas in Conserving Freshwater Fish Abundance and Biodiversity in Lake Tanganyika, Tanzania

    Directory of Open Access Journals (Sweden)

    Emmanuel Andrew Sweke

    2016-01-01

    Full Text Available Marine protected areas have been shown to conserve aquatic resources including fish, but few studies have been conducted of protected areas in freshwater environments. This is particularly true of Lake Tanganyika, Tanzania. To better conserve the lake’s biodiversity, an understanding of the role played by protected areas in conserving fish abundance and diversity is needed. Sampling of fish and environmental parameters was performed within the Mahale Mountains National Park (MMNP and nearby unprotected areas at depths between 5 m and 10 m. Twelve replicates of fish sampling were performed at each site using gillnets set perpendicularly to the shore. Mann-Whitney tests were performed, and the total amount of species turnover was calculated. A total of 518 individual fish from 57 species were recorded in the survey. The fish weight abundance was fivefold greater in the MMNP than in the unprotected areas. Fish abundance and diversity were higher in the MMNP than in the unprotected areas and decreased with distance from it. Our findings confirmed the importance of the protected area in conserving fish resources in Lake Tanganyika. The study provides baseline information for management of the resources and guiding future studies in the lake and other related ecosystems. Management approaches that foster awareness and engage with communities surrounding the MMNP are recommended for successful conservation of the resources in the region.

  3. Spatio-temporal dynamics of phytoplankton and primary production in Lake Tanganyika using a MODIS based bio-optical time series

    DEFF Research Database (Denmark)

    Bergamino, N; Horion, Stéphanie; Stenuite, S

    2010-01-01

    dynamics throughout the lake. In the present work, daily MODIS-AQUA satellite measurements were used to estimate chlorophyll-a concentrations and the diffuse attenuation coefficient (K490) for surface waters. The spatial regionalisation of Lake Tanganyika, based on Empirical Orthogonal Functions...

  4. Ancyrocephalidae (Monogenea) of Lake Tanganyika: does the Cichlidogyrus parasite fauna of Interochromis loocki (Teleostei, Cichlidae) reflect its host’s phylogenetic affinities?

    NARCIS (Netherlands)

    Pariselle, A.; Van Steenberge, M.; Snoeks, J.; Volckaert, F.A.M.; Huyse, T.; Vanhove, M.P.M.

    2015-01-01

    The faunal diversity of Lake Tanganyika, with its fish species flocks and its importance as a cradle and reservoir of ancient fish lineages seeding other radiations, has generated a considerable scientific interest in the fields of evolution and biodiversity. The Tropheini, an endemic Tanganyikan

  5. Compulsory Land Acquisitions In Tanganyika Revisiting The British Colonial Expropriation Principles And Practices

    Directory of Open Access Journals (Sweden)

    Cletus Eligius Ndjovu

    2015-08-01

    Full Text Available Abstract The British took over Tanganyika from the Germans in 1919 after the First World War. In facilitating colonial economic policies the British Colonial Government enacted Land Ordinance Cap 113 of 1923 and Land Acquisition Ordinance Cap 118 of 1926. These laws facilitated the acquisition of native lands and considerably changed the way expropriation was handled leaving behind permanent marks on the later practice. The colonial practice exposed the inner most economic intents of the British government. Use of legal phrases like for public purpose embedded in the ordinance had multiple legal interpretations and loose definition befitting the colonial economic cravings of the time. Although major provisions of the colonial acquisition laws are reflected in the later laws evidence suggests that a few elements of colonial expropriation practices have also sneaked in as silent laws of expropriation but others have not. Quite a few practices had been deliberately discarded or inadvertently forgotten for lack of a political will to purify and emulate them or due to lack of good record keeping. Using historical data and archival records from the Tanzania National Archives this study explored colonial expropriations mainly by focusing on the principles laws practices and procedures used. The main objective of the study was to identify good practices used during the said era the intended and unintended consequences of these unreported practices especially those which need to be emulated by the current laws and practices. The study concluded by shedding light on bad practices which are being exercised to date uncritically but also acknowledging good colonial expropriation practices which existed then but could be emulated. First the study insists that public purpose clause in expropriation must be affected with good and fair intentions and a mechanism to check this be set. Secondly PAPs involvement in land acquisition and compensation negotiations

  6. The use of lac-type promoters in control analysis

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Westerhoff, H. v.; Michelsen, Ole

    1993-01-01

    , the tacI promoter when the latter is high. The endogenous lac operon is placed under the control of a second copy of the lacUV5 promoter and a lacYam mutation (eliminating lactose permease, the transport system for the inducer isopropyl-thio-beta-D-galactoside) is introduced. The method was demonstrated...... experimentally by constructing E. coli strains, in which the chromosomal atp operon is transcribed from the lacUV5 and the tacI promoter. We measured the concentration of the c subunit of H+-ATPase, and found that the expression of this enzyme could be modulated between non-detectable levels and up to five times...... the wild-type level. Thus, in the absence of inducer, no expression of atp genes could be detected when the atp operon was controlled by the lacUV5 promoter, and we estimate that the expression was less than 0.0025 times the wild-type level. We show that the introduction of a lac Y mutation facilitated...

  7. Boolean models can explain bistability in the lac operon.

    Science.gov (United States)

    Veliz-Cuba, Alan; Stigler, Brandilyn

    2011-06-01

    The lac operon in Escherichia coli has been studied extensively and is one of the earliest gene systems found to undergo both positive and negative control. The lac operon is known to exhibit bistability, in the sense that the operon is either induced or uninduced. Many dynamical models have been proposed to capture this phenomenon. While most are based on complex mathematical formulations, it has been suggested that for other gene systems network topology is sufficient to produce the desired dynamical behavior. We present a Boolean network as a discrete model for the lac operon. Our model includes the two main glucose control mechanisms of catabolite repression and inducer exclusion. We show that this Boolean model is capable of predicting the ON and OFF steady states and bistability. Further, we present a reduced model which shows that lac mRNA and lactose form the core of the lac operon, and that this reduced model exhibits the same dynamics. This work suggests that the key to model qualitative dynamics of gene systems is the topology of the network and Boolean models are well suited for this purpose.

  8. Lac Courte Oreilles Energy Analysis Project

    Energy Technology Data Exchange (ETDEWEB)

    Leslie Isham; Denise Johnson

    2009-04-01

    The Lac Courte Oreilles Tribe applied for first step funding in 2007 and was awarded in October of that year. We wanted to perform an audit to begin fulfilling two commitments we made to our membership and resolutions that we adopted. One was the Kyoto Protocol and reduce our carbon emissions by 25% and to produce 25% of our energy by sustainable means. To complete these goals we needed to begin with first assessing what our carbon emissions are and begin taking the steps to conserve on the energy we currently use. The First Step Grant gave us the opportunity to do this. Upon funding the Energy Project was formed under the umbrella of the LCO Public Works Department and Denise Johnson was hired as the coordinator. She quickly began fulfilling the objectives of the project. Denise began by contact the LCO College and hiring interns who were able to go to each Tribal entity and perform line logging to read and document the energy used for each electrical appliance. Data was also gathered for one full year from each entity for all their utility bills (gasoline, electric, natural gas, fuel oil, etc.). Relationships were formed with the Green Team and other Green Committees in the area that could assist us in this undertaking. The Energy Task Force was of great assistance as well recommending other committees and guidance to completing our project. The data was gathered, compiled and placed into spreadsheets that would be understandable for anyone who didn't have a background in Renewable Resources. While gathering the data Denise was also looking for ways to conserve energy usage, policies changes to implement and any possible viable renewable energy resources. Changes in the social behaviors of our members and employees will require further education by workshops, energy fairs, etc.. This will be looked into and done in coordination with our schools. The renewable resources seem most feasible are wind resources as well as Bio Mass both of which need further

  9. Dynamic model of gene regulation for the lac operon

    Science.gov (United States)

    Angelova, Maia; Ben-Halim, Asma

    2011-03-01

    Gene regulatory network is a collection of DNA which interact with each other and with other matter in the cell. The lac operon is an example of a relatively simple genetic network and is one of the best-studied structures in the Escherichia coli bacteria. In this work we consider a deterministic model of the lac operon with a noise term, representing the stochastic nature of the regulation. The model is written in terms of a system of simultaneous first order differential equations with delays. We investigate an analytical and numerical solution and analyse the range of values for the parameters corresponding to a stable solution.

  10. Dynamic model of gene regulation for the lac operon

    International Nuclear Information System (INIS)

    Angelova, Maia; Ben-Halim, Asma

    2011-01-01

    Gene regulatory network is a collection of DNA which interact with each other and with other matter in the cell. The lac operon is an example of a relatively simple genetic network and is one of the best-studied structures in the Escherichia coli bacteria. In this work we consider a deterministic model of the lac operon with a noise term, representing the stochastic nature of the regulation. The model is written in terms of a system of simultaneous first order differential equations with delays. We investigate an analytical and numerical solution and analyse the range of values for the parameters corresponding to a stable solution.

  11. In vivo expression of the lacY gene in two segments leads to functional lac permease

    International Nuclear Information System (INIS)

    Bibi, E.; Kaback, H.R.

    1990-01-01

    The lacY gene of Escherichia coli was cut into two approximately equal-size fragments with Afl II and subcloned individually or together under separate lac operator/promoters in plasmid pT7-5. Under these conditions, lac permease is expressed in two portions: (i) the N-terminal portion (the N terminus, the first six putative transmembrane helices, and most of putative loop 7) and (ii) the C-terminal portion (the last six putative transmembrane helices and the C terminus). Cells harboring pT7-5 encoding both fragments transport lactose at about 30% the rate of cells expressing intact permease to a comparable steady-state level of accumulation. In contrast, cells expressing either half of the permease independently do not transport lactose. As judged by [ 35 S]methionine labeling and immunoblotting, intact permease in completely absent from the membrane of cells expressing lacY fragments either individually or together. Thus, transport activity must result from an association between independently synthesized pieces of lac permease. When the gene fragments are expressed individually, the N-terminal portion of the permease is observed inconsistently, and the C-terminal portion is not observed. When the gene fragments are expressed together, polypeptides identified as the N- and C-terminal moieties of the permease are found in the membrane. It is concluded that the N- or C-terminal halves of lac permease are proteolyzed when synthesized independently and that association between the two complementing polypeptides leads to a more stable, catalytically active complex

  12. Structural explanation for allolactose (lac operon inducer) synthesis by lacZ β-galactosidase and the evolutionary relationship between allolactose synthesis and the lac repressor.

    Science.gov (United States)

    Wheatley, Robert W; Lo, Summie; Jancewicz, Larisa J; Dugdale, Megan L; Huber, Reuben E

    2013-05-03

    β-Galactosidase (lacZ) has bifunctional activity. It hydrolyzes lactose to galactose and glucose and catalyzes the intramolecular isomerization of lactose to allolactose, the lac operon inducer. β-Galactosidase promotes the isomerization by means of an acceptor site that binds glucose after its cleavage from lactose and thus delays its exit from the site. However, because of its relatively low affinity for glucose, details of this site have remained elusive. We present structural data mapping the glucose site based on a substituted enzyme (G794A-β-galactosidase) that traps allolactose. Various lines of evidence indicate that the glucose of the trapped allolactose is in the acceptor position. The evidence includes structures with Bis-Tris (2,2-bis(hydroxymethyl)-2,2',2″-nitrilotriethanol) and L-ribose in the site and kinetic binding studies with substituted β-galactosidases. The site is composed of Asn-102, His-418, Lys-517, Ser-796, Glu-797, and Trp-999. Ser-796 and Glu-797 are part of a loop (residues 795-803) that closes over the active site. This loop appears essential for the bifunctional nature of the enzyme because it helps form the glucose binding site. In addition, because the loop is mobile, glucose binding is transient, allowing the release of some glucose. Bioinformatics studies showed that the residues important for interacting with glucose are only conserved in a subset of related enzymes. Thus, intramolecular isomerization is not a universal feature of β-galactosidases. Genomic analyses indicated that lac repressors were co-selected only within the conserved subset. This shows that the glucose binding site of β-galactosidase played an important role in lac operon evolution.

  13. Photovoltaic system at Lac des Sables; Systeme photovoltaique du Lac des Sables

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-03-01

    The Societe des etablissements de plein air du Quebec (SEPAQ) has adopted a photovoltaic system coupled with an in-house generator to provide power to its buildings located at Lac des Sables in a remote area of Mont Tremblant Park, Quebec. The Societe came to this decision after analysing the costs associated with buying land, materials for an electric transmission line, followed by an analysis of the cost of fuel and the use of a power plant. The advantages include a reduction in fuel consumption, extends the life of the generator, reduces the emissions of greenhouse gases reduces exposition to noise. The photovoltaic system was provided by Energie Matrix Inc. and incorporates well with the building architecture. The data used to select the proper dimension of the photovoltaic system were: a theoretical maximum daily energy requirement of 8.9 kilowatt hour from May to mid-October, operation period of the photovoltaic from May to mid-October, and an autonomy of 5 to 6 days considering that the batteries would be kept at a temperature below 15 Celsius. The characteristics of the system were briefly described. The system has been in operation since September 2002. 2 figs.

  14. Purification and characterization of two phospho-β-galactosidases, LacG1 and LacG2, from Lactobacillus gasseri ATCC33323(T).

    Science.gov (United States)

    Honda, Hiroyuki; Nagaoka, Seiji; Kawai, Yasushi; Kemperman, Robèr; Kok, Jan; Yamazaki, Yukiko; Tateno, Yoshio; Kitazawa, Haruki; Saito, Tadao

    2012-01-01

    Lactobacillus gasseri ATCC33323(T) expresses four enzymes showing phospho-β-galactosidase activity (LacG1, LacG2, Pbg1 and Pbg2). We previously reported the purification and characterization of two phospho-β-galactosidases (Pbg1 and Pbg2) from Lactobacillus gasseri JCM1031 cultured in lactose medium. Here we aimed to characterize LacG1 and LacG2, and classify the four enzymes into 'phospho-β-galactosidase' or 'phospho-β-glucosidase.' LacG1 and recombinant LacG2 (rLacG2), from Lb. gasseri ATCC33323(T), were purified to homogeneity using column chromatography. Kinetic experiments were performed using sugar substrates, o-nitrophenyl-β-D-galactopyranoside 6-phosphate (ONPGal-6P) and o-nitrophenyl-β-D-glucopyranoside 6-phosphate (ONPGlc-6P), synthesized in our laboratory. LacG1 and rLacG2 exhibited high k(cat)/K(m) values for ONPGal-6P as compared with Pbg1 and Pbg2. The V(max) values for ONPGal-6P were higher than phospho-β-galactosidases previously purified and characterized from several lactic acid bacteria. A phylogenetic tree analysis showed that LacG1 and LacG2 belong to the phospho-β-galactosidase cluster and Pbg1 and Pbg2 belong to the phospho-β-glucosidase cluster. Our data suggest two phospho-β-galactosidase, LacG1 and LacG2, are the primary enzymes for lactose utilization in Lb. gasseri ATCC33323(T). We propose a reclassification of Pbg1 and Pbg2 as phospho-β-glucosidase.

  15. Period of Light Variability in BL Lac ON 231

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... In this paper, the authors have compiled the data of about 100 years in B-band of the BL Lac ON 231 and used this database to analyze periodicity signals in the optical light curve. Two different methods were applied: the wavelet analysis and the Discrete Correlation Function (DCF) method. We revealed ...

  16. Preliminary fish survey of Lac Tseny in north- western Madagascar

    African Journals Online (AJOL)

    ABSTRACT. We surveyed the fish fauna of Lac Tseny, in the Sofia Region of northwestern Madagascar, during October 2010 by observ- ing commercial catches and targeted netting of areas used by endemic species. We recorded seven native fish species at the lake, including three endemic cichlids, a herring and a catfish ...

  17. Structure and bonding of superconducting LaC2.

    Science.gov (United States)

    Babizhetskyy, V; Jepsen, O; Kremer, R K; Simon, A; Ouladdiaf, B; Stolovits, A

    2014-01-15

    We have synthesized polycrystalline samples of superconducting LaC2 and investigated them by x-ray and neutron powder diffraction, magnetic susceptibility and heat capacity measurements. Depending on the preparation conditions we find superconductivity below ~1.8 K. A comparison of the superconducting anomaly in the heat capacity with theoretical predictions indicates LaC2 to be a weak-coupling BCS-type superconductor. Evidence for a structural phase transition has not been found from the neutron powder diffraction experiments carried out down to 4 K. A negative thermal expansion of the c lattice parameter was observed below ~50 K. The electronic structure of LaC2 has been calculated ab initio and it is compared with that of YC2. The carbon-carbon distance of LaC2 has been determined from the neutron powder diffraction experiments and it is compared and discussed with respect to those observed in other superconducting binary and ternary La and Y carbides and carbide halides.

  18. RADIO-WEAK BL LAC OBJECTS IN THE FERMI ERA

    Energy Technology Data Exchange (ETDEWEB)

    Massaro, F.; Marchesini, E. J. [Dipartimento di Fisica, Università degli Studi di Torino (UniTO), via Pietro Giuria 1, I-10125 Torino (Italy); D’Abrusco, R.; Smith, Howard A. [Smithsonian Astrophysical Observatory, 60 Garden Street, 02138 Cambridge, MA (United States); Masetti, N. [INAF—Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna, via Gobetti 101, I-40129, Bologna (Italy); Andruchow, I. [Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque, B1900FWA, La Plata (Argentina)

    2017-01-10

    The existence of “radio-weak BL Lac objects” (RWBLs) has been an open question, and has remained unsolved since the discovery that quasars could be radio-quiet or radio-loud. Recently, several groups identified RWBL candidates, mostly found while searching for low-energy counterparts of the unidentified or unassociated gamma-ray sources listed in the Fermi catalogs. Confirming RWBLs is a challenging task since they could be confused with white dwarfs (WDs) or weak emission line quasars (WELQs) when there are not sufficient data to precisely draw their broadband spectral energy distribution, and their classification is mainly based on a featureless optical spectra. Motivated by the recent discovery that Fermi BL Lacs appear to have very peculiar mid-IR emission, we show that it is possible to distinguish between WDs, WELQs, and BL Lacs using the [3.4]–[4.6]–[12] μ m color–color plot built using the WISE magnitudes when the optical spectrum is available. On the basis of this analysis, we identify WISE J064459.38+603131 and WISE J141046.00+740511.2 as the first two genuine RWBLs, both potentially associated with Fermi sources. Finally, to strengthen our identification of these objects as true RWBLs, we present multifrequency observations for these two candidates to show that their spectral behavior is indeed consistent with that of the BL Lac population.

  19. NMR studies on DNA binding specificity of the lac repressor

    NARCIS (Netherlands)

    Kopke Salinas, Roberto

    2005-01-01

    The thesis describes NMR structures of two protein-DNA complexes. The first structure shows how the protein, the DNA binding domain of lac repressor, recognizes its natural DNA binding site, by adaptation and read out of the nucleotide sequence. The second one shows how the DNA binding specificity

  20. 76 FR 68124 - Television Broadcasting Services; Fond du Lac, WI

    Science.gov (United States)

    2011-11-03

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 [MB Docket No. 09-115, RM-11543; DA 11-1502] Television Broadcasting Services; Fond du Lac, WI AGENCY: Federal Communications Commission. ACTION: Proposed rule. SUMMARY: In this document, the Commission denies a petition for reconsideration of an August 12...

  1. The Lac-Mégantic Derailment, Corporate Regulation, and Neoliberal Sovereignty.

    Science.gov (United States)

    Dunford, David Tyler

    2017-02-01

    On July 6, 2013, Montreal, Maine, and Atlantic railcar 5017 hauling 72 tanker cars of Bakken crude oil derailed over the town of Lac-Mégantic, Quebec. The town erupted in a fiery inferno as 5,560,000 liters of highly flammable Bakken crude oil exploded over the town, killing 47 people and contaminating 558,000 tons of soil and local waterways. While Montreal, Maine, and Atlantic Rail Chairman Edward Burkhardt initially blamed the derailment on the lone engineer and local firefighters, this study shows how Transport Canada and the rail industry undermined regulatory and safety measures for several years before the derailment. This study uses a Foucauldian theoretical perspective to conceptualize and explain a new political mentality that transfers existing state regulatory authority to the corporate sector. This new mentality, neoliberal sovereignty, is composed of sovereign and neoliberal logics that monopolize "correct" trajectories of human economic development. This absolute market mentality merges with state sovereignty and eliminates existing safety and regulation frameworks to pursue unregulated corporate profits. Le 6 juillet 2013, un train de 72 wagons-citernes transportant du pétrole brute Bakken a déraillé de la ligne de chemin de fer de la Montréal, Maine et Atlantique, dans la ville de Lac-Mégantic au Québec. La ville c'est transformé en véritable enfer, alors que 5 560 000 litre de pétrole brute Bakken très inflammable ont fait explosé la ville, tuant quarante-sept personnes et contaminant 558 000 tonnes d'eaux et du sol de Lac-Mégantic et ses environs. Alors que le président de la MMA, Edward Burkhart, a d'abord blâmé l'ingénieur et le service d'incendie local, les études montrent que Transport Canada et l'industrie ferroviaire ont amoindrit les mesures de réglementation et de sécurité plusieurs années avant le déraillement. Cette étude utilise une perspective théorique foucauldienne pour conceptualiser et expliquer une

  2. De Paris à Lyon. Les mutations éditoriales du «Lancelot du Lac»

    Directory of Open Access Journals (Sweden)

    Gaëlle Burg

    2015-07-01

    Full Text Available Lancelot du Lac est le premier roman arthurien imprimé à la Renais­sance. Dans sa première édition parue en 1488, qui réunit deux imprimeurs (Jean Le Bourgeois à Rouen et Jean Du Pré à Paris, un découpage et un prologue inédits sont ajoutés par le remanieur. Le texte sera réédité six fois par divers imprimeurs-libraires parisiens jusqu’en 1533. L’édition de luxe d’Antoine Vérard (1494, destinée au roi Charles VIII, présente d’importantes modifications effectuées dans un but commercial. Après une longue période d’accalmie qui signe le début du déclin de la vogue des romans de chevalerie médiévaux, Benoît Rigaud publie à Lyon, sous une forme considérablement abrégée, la dernière édition connue du Lancelot au XVIe siècle (1591. Si elle ne présente que peu d’intérêt littéraire, elle apporte cependant des informations concernant les pratiques éditoriales et les goûts du  lecteur de la fin du XVIe siècle. De Paris à Lyon, entre renaissance et déclin, le parcours éditorial d’un incontournable roman arthurien.Lancelot du Lac is the editio princeps of an Arthurian romance in Renaissance France. The first edition in 1488, which brings together two printers (Jean Le Bourgeois from Rouen and Jean Du Pré from Paris, offers original arrangement and prologue added by the compositor. The text will be published six times by various printers and booksellers in Paris until 1533. The luxurious edition from Antoine Vérard (1494 dedicated to King Charles VIII provides interesting transformations in commercial purposes. After a long time without edition, showing the beginning of chivalry literature’s decline, Benoît Rigaud publish in Lyon, in a greatly abbreviated form, the last known edition of Lancelot in the XVIth century (1591. If it presents no literary interest, it provides nevertheless informations about editorial practices and reader’s tastes from the end of Renaissance France. From Paris to

  3. Using lead isotopes and trace element records from two contrasting Lake Tanganyika sediment cores to assess watershed – Lake exchange

    Science.gov (United States)

    Odigie, Kingsley; Cohen, A.D.; Swarzenski, Peter W.; Flegal, R

    2014-01-01

    Lead isotopic and trace element records of two contrasting sediment cores were examined to reconstruct historic, industrial contaminant inputs to Lake Tanganyika, Africa. Observed fluxes of Co, Cu, Mn, Ni, Pb, and Zn in age-dated sediments collected from the lake varied both spatially and temporally over the past two to four centuries. The fluxes of trace elements were lower (up to 10-fold) at a mid-lake site (MC1) than at a nearshore site (LT-98-58), which is directly downstream from the Kahama and Nyasanga River watersheds and adjacent to the relatively pristine Gombe Stream National Park. Trace element fluxes at that nearshore site did not measurably change over the last two centuries (1815–1998), while the distal, mid-lake site exhibited substantial changes in the fluxes of trace elements – likely caused by changes in land use – over that period. For example, the flux of Pb increased by ∼300% from 1871 to 1991. That apparent accelerated weathering and detrital mobilization of lithogenic trace elements was further evidenced by (i) positive correlations (r = 0.77–0.99, p < 0.05) between the fluxes of Co, Cu, Mn, Ni, Pb, and Zn and those of iron (Fe) at both sites, (ii) positive correlations (r = 0.82–0.98, p < 0.01, n = 9) between the fluxes of elements (Al, Co, Cu, Fe, Mn, Ni, Pb, and Zn) and the mass accumulation rates at the offshore site, (iii) the low enrichment factors (EF < 5) of those trace elements, and (iv) the temporal consistencies of the isotopic composition of Pb in the sediment. These measurements indicate that accelerated weathering, rather than industrialization, accounts for most of the increases in trace element fluxes to Lake Tanganyika in spite of the development of mining and smelting operations within the lake’s watershed over the past century. The data also indicate that the mid-lake site is a much more sensitive and useful recorder of environmental changes than the nearshore site. Furthermore, the lead isotopic compositions

  4. Reticulate phylogeny of gastropod-shell-breeding cichlids from Lake Tanganyika – the result of repeated introgressive hybridization

    Directory of Open Access Journals (Sweden)

    Blanc Michel

    2007-01-01

    Full Text Available Abstract Background The tribe Lamprologini is the major substrate breeding lineage of Lake Tanganyika's cichlid species flock. Among several different life history strategies found in lamprologines, the adaptation to live and breed in empty gastropod shells is probably the most peculiar. Although shell-breeding arose several times in the evolutionary history of the lamprologines, all obligatory and most facultative shell-breeders belong to the so called "ossified group", a monophyletic lineage within the lamprologine cichlids. Since their distinctive life style enables these species to live and breed in closest vicinity, we hypothesized that these cichlids might be particularly prone to accidental hybridization, and that introgression might have affected the evolutionary history of this cichlid lineage. Results Our analyses revealed discrepancies between phylogenetic hypotheses based on mitochondrial and nuclear (AFLP data. While the nuclear phylogeny was congruent with morphological, behavioral and ecological characteristics, several species – usually highly specialized shell-breeders – were placed at contradicting positions in the mitochondrial phylogeny. The discordant phylogenies strongly suggest repeated incidents of introgressive hybridization between several distantly related shell-breeding species, which reticulated the phylogeny of this group of cichlids. Long interior branches and high bootstrap support for many interior nodes in the mitochondrial phylogeny argue against a major effect of ancient incomplete lineage sorting on the phylogenetic reconstruction. Moreover, we provide morphological and genetic (mtDNA and microsatellites evidence for ongoing hybridization among distantly related shell-breeders. In these cases, the territorial males of the inferred paternal species are too large to enter the shells of their mate, such that they have to release their sperm over the entrance of the shell to fertilize the eggs. With sperm

  5. A single mutation in the core domain of the lac repressor reduces leakiness

    NARCIS (Netherlands)

    Gatti-Lafranconi, Pietro; Dijkman, Willem; Devenish, Sean RA; Hollfelder, Florian

    2013-01-01

    The lac operon provides cells with the ability to switch from glucose to lactose metabolism precisely when necessary. This metabolic switch is mediated by the lac repressor (LacI), which in the absence of lactose binds to the operator DNA sequence to inhibit transcription. Allosteric rearrangements

  6. lac operon induction in Escherichia coli: Systematic comparison of IPTG and TMG induction and influence of the transacetylase LacA.

    Science.gov (United States)

    Marbach, Anja; Bettenbrock, Katja

    2012-01-01

    Most commonly used expression systems in bacteria are based on the Escherichia coli lac promoter. Furthermore, lac operon elements are used today in systems and synthetic biology. In the majority of the cases the gratuitous inducers IPTG or TMG are used. Here we report a systematic comparison of lac promoter induction by TMG and IPTG which focuses on the aspects inducer uptake, population heterogeneity and a potential influence of the transacetylase, LacA. We provide induction curves in E. coli LJ110 and in isogenic lacY and lacA mutant strains and we show that both inducers are substrates of the lactose permease at low inducer concentrations but can also enter cells independently of lactose permease if present at higher concentrations. Using a gfp reporter strain we compared TMG and IPTG induction at single cell level and showed that bimodal induction with IPTG occurred at approximately ten-fold lower concentrations than with TMG. Furthermore, we observed that lac operon induction is influenced by the transacetylase, LacA. By comparing two Plac-gfp reporter strains with and without a lacA deletion we could show that in the lacA(+) strain the fluorescence level decreased after few hours while the fluorescence further increased in the lacA(-) strain. The results indicate that through the activity of LacA the IPTG concentration can be reduced below an inducing threshold concentration-an influence that should be considered if low inducer amounts are used. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Climate warming reduces fish production and benthic habitat in Lake Tanganyika, one of the most biodiverse freshwater ecosystems

    Science.gov (United States)

    Cohen, Andrew S.; Gergurich, Elizabeth L.; Kraemer, Benjamin M.; McGlue, Michael M.; McIntyre, Peter B.; Russell, James M.; Simmons, Jack D.; Swarzenski, Peter W.

    2016-01-01

    Warming climates are rapidly transforming lake ecosystems worldwide, but the breadth of changes in tropical lakes is poorly documented. Sustainable management of freshwater fisheries and biodiversity requires accounting for historical and ongoing stressors such as climate change and harvest intensity. This is problematic in tropical Africa, where records of ecosystem change are limited and local populations rely heavily on lakes for nutrition. Here, using a ∼1,500-y paleoecological record, we show that declines in fishery species and endemic molluscs began well before commercial fishing in Lake Tanganyika, Africa’s deepest and oldest lake. Paleoclimate and instrumental records demonstrate sustained warming in this lake during the last ∼150 y, which affects biota by strengthening and shallowing stratification of the water column. Reductions in lake mixing have depressed algal production and shrunk the oxygenated benthic habitat by 38% in our study areas, yielding fish and mollusc declines. Late-20th century fish fossil abundances at two of three sites were lower than at any other time in the last millennium and fell in concert with reduced diatom abundance and warming water. A negative correlation between lake temperature and fish and mollusc fossils over the last ∼500 y indicates that climate warming and intensifying stratification have almost certainly reduced potential fishery production, helping to explain ongoing declines in fish catches. Long-term declines of both benthic and pelagic species underscore the urgency of strategic efforts to sustain Lake Tanganyika’s extraordinary biodiversity and ecosystem services.

  8. Repeated parallel evolution of parental care strategies within Xenotilapia, a genus of cichlid fishes from Lake Tanganyika.

    Directory of Open Access Journals (Sweden)

    Michael R Kidd

    Full Text Available The factors promoting the evolution of parental care strategies have been extensively studied in experiment and theory. However, most attempts to examine parental care in an evolutionary context have evaluated broad taxonomic categories. The explosive and recent diversifications of East African cichlid fishes offer exceptional opportunities to study the evolution of various life history traits based on species-level phylogenies. The Xenotilapia lineage within the endemic Lake Tanganyika cichlid tribe Ectodini comprises species that display either biparental or maternal only brood care and hence offers a unique opportunity to study the evolution of distinct parental care strategies in a phylogenetic framework. In order to reconstruct the evolutionary relationships among 16 species of this lineage we scored 2,478 Amplified Fragment Length Polymorphisms (AFLPs across the genome. We find that the Ectodini genus Enantiopus is embedded within the genus Xenotilapia and that during 2.5 to 3 million years of evolution within the Xenotilapia clade there have been 3-5 transitions from maternal only to biparental care. While most previous models suggest that uniparental care (maternal or paternal arose from biparental care, we conclude from our species-level analysis that the evolution of parental care strategies is not only remarkably fast, but much more labile than previously expected.

  9. Repeated parallel evolution of parental care strategies within Xenotilapia, a genus of cichlid fishes from Lake Tanganyika.

    Science.gov (United States)

    Kidd, Michael R; Duftner, Nina; Koblmüller, Stephan; Sturmbauer, Christian; Hofmann, Hans A

    2012-01-01

    The factors promoting the evolution of parental care strategies have been extensively studied in experiment and theory. However, most attempts to examine parental care in an evolutionary context have evaluated broad taxonomic categories. The explosive and recent diversifications of East African cichlid fishes offer exceptional opportunities to study the evolution of various life history traits based on species-level phylogenies. The Xenotilapia lineage within the endemic Lake Tanganyika cichlid tribe Ectodini comprises species that display either biparental or maternal only brood care and hence offers a unique opportunity to study the evolution of distinct parental care strategies in a phylogenetic framework. In order to reconstruct the evolutionary relationships among 16 species of this lineage we scored 2,478 Amplified Fragment Length Polymorphisms (AFLPs) across the genome. We find that the Ectodini genus Enantiopus is embedded within the genus Xenotilapia and that during 2.5 to 3 million years of evolution within the Xenotilapia clade there have been 3-5 transitions from maternal only to biparental care. While most previous models suggest that uniparental care (maternal or paternal) arose from biparental care, we conclude from our species-level analysis that the evolution of parental care strategies is not only remarkably fast, but much more labile than previously expected.

  10. Acquisition of Lateralized Predation Behavior Associated with Development of Mouth Asymmetry in a Lake Tanganyika Scale-Eating Cichlid Fish.

    Directory of Open Access Journals (Sweden)

    Yuichi Takeuchi

    Full Text Available The scale-eating cichlid Perissodus microlepis with asymmetric mouth is an attractive model of behavioral laterality: each adult tears off scales from prey fishes' left or right flanks according to the direction in which its mouth is skewed. To investigate the development of behavioral laterality and mouth asymmetry, we analyzed stomach contents and lower jaw-bone asymmetry of various-sized P. microlepis (22 ≤ SL<115 mm sampled in Lake Tanganyika. The shapes of the pored scales found in each specimen's stomach indicated its attack side preference. Early-juvenile specimens (SL<45 mm feeding mainly on zooplankton exhibited slight but significant mouth asymmetry. As the fish acquired scale-eating (45 mm ≤ SL, attack side preference was gradually strengthened, as was mouth asymmetry. Among size-matched individuals, those with more skewed mouths ate more scales. These findings show that behavioral laterality in scale-eating P. microlepis is established in association with development of mouth asymmetry which precedes the behavioral acquisition, and that this synergistic interaction between physical and behavioral literalities may contribute to efficient scale-eating.

  11. Wind Resource Assessment Report: Mille Lacs Indian Reservation, Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Antonio C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Robichaud, Robi [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-12-01

    The U.S. Environmental Protection Agency (EPA) launched the RE-Powering America's Land initiative to encourage development of renewable energy on potentially contaminated land and mine sites. EPA collaborated with the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL) and the Mille Lacs Band of Chippewa Indians to evaluate the wind resource and examine the feasibility of a wind project at a contaminated site located on the Mille Lacs Indian Reservation in Minnesota. The wind monitoring effort involved the installation of a 60-m met tower and the collection of 18 months of wind data at multiple heights above the ground. This report focuses on the wind resource assessment, the estimated energy production of wind turbines, and an assessment of the economic feasibility of a potential wind project sited this site.

  12. Evolution and Biophysics of the Escherichia coli lac Operon

    Science.gov (United States)

    Ray, J. Christian; Igoshin, Oleg; Quan, Selwyn; Monds, Russell; Cooper, Tim; Balázsi, Gábor

    2011-03-01

    To understand, predict, and control the evolution of living organisms, we consider biophysical effects and molecular network architectures. The lactose utilization system of E. coli is among the most well-studied molecular networks in biology, making it an ideal candidate for such studies. Simulations show how the genetic architecture of the wild-type operon attenuates large metabolic intermediate fluctuations that are predicted to occur in an equivalent system with the component genes on separate operons. Quantification of gene expression in the lac operon evolved in growth conditions containing constant lactose, alternating with glucose, or constant glucose, shows characteristic gene expression patterns depending on conditions. We are simulating these conditions to show context-dependent biophysical sources and costs of different lac operon architectures.

  13. A geological survey of the Lac du Bonnet batholith, Manitoba

    International Nuclear Information System (INIS)

    McCrank, G.F.D.

    1985-02-01

    This report presents the results of a geological survey of the Lac du Bonnet batholith in Manitoba. The survey consisted of field mapping of the lithologies and the joint systems throughout the batholith, and the examination of lineaments identified on aerial photographs and Landsat imagery. Petrographic descriptions and a map of the lithologies, an analysis of the fracture systems and a lineament map are presented. The results of various regional geophysical surveys were used as an aid to the interpretation of the batholith's contacts and in the interpretation of lineaments as possible faults. A comparison of the Lac du Bonnet Batholith with the Eye-Dashwa Lakes Pluton near Atikokan, Ontario is also presented

  14. A geological reconnaissance study of the Lac du Bonnet batholith

    International Nuclear Information System (INIS)

    Tammemagi, H.Y.; Kerford, P.S.; Requeima, J.C.; Temple, C.A.

    1980-02-01

    A geological reconnaissance survey was carried out of the Lac du Bonnet batholith, southeastern Manitoba, as part of the concept verification phase of the nuclear fuel waste disposal program for Canada. This report summarizes available geological information, presents the results of field mapping and discusses the geochemical analyses of rock samples. The geological and structural aspects of the batholith are described as well as its regional setting and possible genesis. (auth)

  15. : tous les projets | Page 497 | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Projet. La mauvaise gestion de l'eau et de l'assainissement nuit à la santé humaine et pollue le lac Victoria en Afrique de l'Est. Date de début : 14 octobre 2007. End Date: 29 septembre 2009. Sujet: WATER POLLUTION, WATER QUALITY, WATER MANAGEMENT, WATER CONSERVATION, WATER SUPPLY, SANITARY ...

  16. METHODICAL APPROACHES TO THE CREATION MOOC (EXPERIENCE LAC

    Directory of Open Access Journals (Sweden)

    Larysa Nozdrina

    2016-03-01

    Full Text Available The article presents a number of problems, determining the current state of development of the domestic market of massive open online courses (MOOC. Considering the aim of the research, there is described national experience in this area, proposed and substantiated a number of the criteria and methodological approaches to the implementation of MOOC in higher education. The development of MOOC in the Lviv Academy of Commerce (LAC is reviewed as example. The main factors which determine the success of this educational innovation in the domestic market and are put under the research are software platforms, multimedia software for creating video lectures, course structure and support the learning process. The results of study which have been analyzed in this course can have a positive impact on the functioning of the market MOOC in Ukrainian universities. The article focuses on finding the ways of improving the process of developing and implementing MOOC in higher education in the example of LAC where Web-center on the MOODLE platform is used for e-learning. Further research should focus on the development of institutional mechanisms to ensure the effective design, implementation and operation of the MOOC in the universities in Ukraine. Particular attention during learning in massive open online course should be aimed at improving the educational process and to strengthen student's motivation in MOOC. Experience of MOOC's development in LAC can be useful at creating similar courses at other institutions of higher education in the different platforms, both MOODLE, and on the others

  17. Purification and characterization of two phospho-β-galactosidases, LacG1 and LacG2, from Lactobacillus gasseri ATCC33323T

    NARCIS (Netherlands)

    Honda, Hiroyuki; Nagaoka, Seiji; Kawai, Yasushi; Kemperman, Robèr; Kok, Jan; Yamazaki, Yukiko; Tateno, Yoshio; Kitazawa, Haruki; Saito, Tadao

    2012-01-01

    Lactobacillus gasseri ATCC33323T expresses four enzymes showing phospho-β-galactosidase activity (LacG1, LacG2, Pbg1 and Pbg2). We previously reported the purification and characterization of two phospho-β-galactosidases (Pbg1 and Pbg2) from Lactobacillus gasseri JCM1031 cultured in lactose medium.

  18. Gene-mutation assays in lambda-lacZ transgenic mice : comparison of lacZ with endogenous genes in splenocytes and small intestinal epithelium

    NARCIS (Netherlands)

    Delft, J.H.M. van; Bergmans, A.; Dam, F.J. van; Tates, A.D.; Howard, L.; Winton, D.J.; Baan, R.A.

    1998-01-01

    Comparison of results derived from transgenic animal gene-mutation assays with those from mutation analyses in endogenous genes is an important step in the validation of the former. We have used λlacZ transgenic mice to study alkylation-induced mutagenesis in vivo in (a) lacZ and hprt in spleen

  19. Induction of the lac carrier and an associated membrane protein in Escherichia coli

    International Nuclear Information System (INIS)

    Lagarias, D.M.

    1985-01-01

    Induction of the lac operon in wild type Escherichia coli strains results in synthesis of a 16 kilodalton inner membrane protein in addition to the known products of the lacZ, lacY and lacA genes. Cells carrying the lacY gene on a plasmid over produce this 16 kilodalton polypeptide as well as the Lac carrier, the membrane protein product of the lacY gene. However, [ 35 S]methionine labeling of minicells carrying the lacY plasmid shows that the 16 kDa protein is not synthesized from the plasmid DNA. The 16 kDa protein was purified and partially characterized. It is an acidic membrane protein of apparent molecular weight 15,800 whose amino terminal sequence (NH 2 -Met-Arg-Asn-Phe-Asp-Leu-) does not correspond to any nucleotide sequence known in lac operon DNA. Using antibody prepared to the purified 16 kDa protein, a quantitative analysis of conditions under which this protein is made was accomplished, and reveals that the amount of 16 kDa protein which appears in the membrane is proportional to lac operon expression. Hybridization of a synthetic oligonucleotide probe complementary to the 5' end of 16 kDa protein mRNA shows that its synthesis is regulated at the level of transcription. A description of attempts to clone this gene is given. Possible functional roles for the 16 kDa protein are discussed

  20. Chemo-enzymatic modification of poly-N-acetyllactosamine (LacNAc oligomers and N,N-diacetyllactosamine (LacDiNAc based on galactose oxidase treatment

    Directory of Open Access Journals (Sweden)

    Christiane E. Kupper

    2012-05-01

    Full Text Available The importance of glycans in biological systems is highlighted by their various functions in physiological and pathological processes. Many glycan epitopes on glycoproteins and glycolipids are based on N-acetyllactosamine units (LacNAc; Galβ1,4GlcNAc and often present on extended poly-LacNAc glycans ([Galβ1,4GlcNAc]n. Poly-LacNAc itself has been identified as a binding motif of galectins, an important class of lectins with functions in immune response and tumorigenesis. Therefore, the synthesis of natural and modified poly-LacNAc glycans is of specific interest for binding studies with galectins as well as for studies of their possible therapeutic applications. We present the oxidation by galactose oxidase and subsequent chemical or enzymatic modification of terminal galactose and N-acetylgalactosamine residues of poly-N-acetyllactosamine (poly-LacNAc oligomers and N,N-diacetyllactosamine (LacDiNAc by galactose oxidase. Product formation starting from different poly-LacNAc oligomers was characterised and optimised regarding formation of the C6-aldo product. Further modification of the aldehyde containing glycans, either by chemical conversion or enzymatic elongation, was established. Base-catalysed β-elimination, coupling of biotin–hydrazide with subsequent reduction to the corresponding hydrazine linkage, and coupling by reductive amination to an amino-functionalised poly-LacNAc oligomer were performed and the products characterised by LC–MS and NMR analysis. Remarkably, elongation of terminally oxidised poly-LacNAc glycans by β3GlcNAc- and β4Gal-transferase was also successful. In this way, a set of novel, modified poly-LacNAc oligomers containing terminally and/or internally modified galactose residues were obtained, which can be used for binding studies and various other applications.

  1. Europa-Latinoamérica: amigos complicados. Sobre la IV EU-LAC en Viena, Austria

    Directory of Open Access Journals (Sweden)

    Gerhard Drekonja-Kornat

    2014-06-01

    Full Text Available Para los presidentes latinoamericanos, las cumbres ya son rutina. Para Viena, la anfitriona de la IV reunión EU-LAC que se realizó del 11 al 13 de mayo de 2006, esta cumbre fue el acontecimiento del siglo. Se podría decir que fue la continuación del Congreso de Viena de 1815. Adecuadamente acicalada, se presentó la capital austriaca, a la cual después de Río, Madrid y Guadalajara, le tocó organizar la cuarta Cumbre de Jefes de Estado y de Gobierno de la Unión Europea, América Latina y el Caribe. Puesto que también se encontraban presentes los representantes de los países adherentes y candidatos a ingresar a la Unión –incluso el primer ministro de Turquía, R. T. Erdogan estuvo presente–, se tomó la tradicional “foto familiar” con 60 participantes.

  2. Ancyrocephalidae (Monogenea of Lake Tanganyika: I: Four new species of Cichlidogyrus from Ophthalmotilapia ventralis (Teleostei: Cichlidae, the first record of this parasite family in the basin

    Directory of Open Access Journals (Sweden)

    Maarten P. M. Vanhove

    2011-04-01

    Full Text Available Examination of gill parasites from Ophthalmotilapia ventralis (Boulenger, 1898 in Lake Tanganyika (Africa revealed the presence of four new species of Monogenea, all members of Cichlidogyrus Paperna, 1960 (Ancyrocephalidae. In view of the systematic importance of haptoral structure, the fish host shows a remarkable diversity of morphological groups. Cichlidogyrus vandekerkhovei sp. nov. and C. makasai sp. nov. are especially characterized by the unusual length of the dorsal transverse bar auricles, while C. sturmbaueri sp. nov. is distinguished by the unique shape of the accessory piece of its male copulatory organ. Importantly, C. centesimus sp. nov. displays a number of features new to the genus, namely a spirally coiled thickening at the end of the penis, the absence of an accessory piece in the genital apparatus, and a hitherto unknown uncinuli configuration in the haptor. This is the first record of ancyrocephalid parasites from the Tanganyika basin. Some mechanisms possibly contributing to this yet unknown diversity are discussed, identifying topics deserving further scientific scrutiny.

  3. Scientific Drilling at Lake Tanganyika, Africa: A Transformative Record for Understanding Evolution in Isolation and the Biological History of the African Continent, University of Basel, 6-8 June 2016

    Science.gov (United States)

    Cohen, Andrew S.; Salzburger, Walter

    2017-05-01

    We report on the outcomes of a workshop held to discuss evolutionary biology, paleobiology and paleoecology questions that could be addressed by a scientific drilling project at Lake Tanganyika, the largest, deepest and oldest of the African Rift Valley lakes. Lake Tanganyika is of special significance to evolutionary biologists as it harbors one of the most spectacular endemic faunas of any lake on earth, with hundreds of unique species of fish, molluscs, crustaceans and other organisms that have evolved over the lake's long history. Most of these groups of organisms are known from fossils in short cores from the lake, raising the possibility that both body fossil and ancient DNA records might be recovered from long drill cores. The lake's sedimentary record could also provide a record of African terrestrial ecosystem history since the late Miocene. This 3-day workshop brought together biological and geological specialists on the lake and its surroundings to prioritize paleobiological, ecological and microbiological objectives that could ultimately be incorporated into an overall drilling plan for Lake Tanganyika and to consider how biological objectives can effectively be integrated into the paleoclimate and tectonics objectives of a Lake Tanganyika drilling project already considered in prior workshops.

  4. Le Sanskrit

    CERN Document Server

    Balbir, Nalini

    2013-01-01

    Cet ouvrage est destiné à tous ceux qui souhaitent se mettre ou se remettre à l'étude du sanskrit et ne peuvent y consacrer que quelques minutes par jour. En suivant le principe de la méthode quotidienne Assimil, vous acquerrez progressivement le vocabulaire et la grammaire de base qui sont nécessaires à la lecture des textes de la littérature sanskrite classique. Vous trouverez dans cette méthode une approche vivante de la langue et de la culture sanskrite classique à travers des textes d'abord adaptés pour le débutant puis authentiques. En quelques mois, vous manierez la langue sans efforts ni hésitation, de manière très naturelle. Les enregistrements reprennent l'intégralité des textes en sanskrit des leçons et des exercices de traduction du livre. Ils sont interprétés, à un rythme progressif, par des locuteurs natifs professionnels.

  5. Physico-Mechanical Properties of Coprocessed Excipient MicroceLac® 100 by DM(3) Approach.

    Science.gov (United States)

    Haware, Rahul V; Kancharla, Joseph P; Udupa, Aishwarya K; Staton, Scott; Gupta, Mali R; Al-Achi, Antoine; Stagner, William C

    2015-11-01

    To determine the effect of relative humidity (RH) and hydroxypropyl methylcellulose (HPMC) on the physico-mechanical properties of coprocessed MacroceLac(®) 100 using 'DM(3)' approach. Effects of RH and 5% w/w HPMC on MacroceLac(®) 100 Compressibility Index (CI) and tablet mechanical strength (TMS) were evaluated by 'DM(3)'. The 'DM(3)' approach evaluates material properties by combining 'design of experiments', material's 'macroscopic' properties, 'molecular' properties, and 'multivariate analysis' tools. A 4X4 full-factorial experimental design was used to study the relationship of MacroceLac(®) 100 molecular properties (moisture content, dehydration, crystallization, fusion enthalpy, and moisture uptake) and macroscopic particle size and shape on CI and TMS. A physical binary mixture (PBM) of similar composition to MacroceLac(®) 100 was also evaluated. Multivariate analysis of variance (MANOVA), principle component analysis, and partial least squares (PLS) were used to analyze the data. MANOVA CI ranking was: PBM-HPMC > PBM > MicroceLac(®)100 > MicroceLac(®)100-HPMC (p TMS values were lower than MicroceLac(®)100 and MicroceLac(®)100-HPMC (p TMS. Significant MicroceLac(®)100 changes occurred with % RH exposure affecting performance attributes. HPMC physical addition did not prevent molecular or macroscopic matrix changes.

  6. Optical Spectra Evolution of BL Lac Objects XW Bi1,∗ , BZ Wang2 ...

    Indian Academy of Sciences (India)

    Abstract. Many quasi-simultaneous optical observations of nine BL. Lac objects are obtained from literature. We study the relationship between the optical spectral index and the luminosity of BL Lac objects, and are tempted to exploit spectral evolution in the optical frequency ranges. Our results show that: (i) The optical ...

  7. A mutant Ebg enzyme that converts lactose into an inducer of the lac operon.

    OpenAIRE

    Rolseth, S J; Fried, V A; Hall, B G

    1980-01-01

    Lactose is not itself an inducer of the lac operon, nor is it converted to an inducer by ebg+ beta-galactosidase of Escherichia coli. We report here the isolation of a mutant Ebg beta-galactosidase which is capable of converting lactose into an inducer of the lac operon.

  8. A mutant Ebg enzyme that converts lactose into an inducer of the lac operon.

    Science.gov (United States)

    Rolseth, S J; Fried, V A; Hall, B G

    1980-01-01

    Lactose is not itself an inducer of the lac operon, nor is it converted to an inducer by ebg+ beta-galactosidase of Escherichia coli. We report here the isolation of a mutant Ebg beta-galactosidase which is capable of converting lactose into an inducer of the lac operon. PMID:6769907

  9. In vivo biocompatibility of p(HPMAm-lac)-PEG hydrogels hybridized with hyaluronan

    NARCIS (Netherlands)

    Sabbieti, Maria Giovanna; Dubbini, Alessandra; Laus, Fulvio; Paggi, Emanuele; Marchegiani, Andrea; Capitani, Melania; Marchetti, Luigi; Dini, Fabrizio; Vermonden, Tina; Di Martino, Piera; Agas, Dimitrios; Censi, Roberta

    2017-01-01

    The present study reports on the biocompatibility in vivo after intramuscular and subcutaneous administration in Balb/c mice of vinyl sulphone bearing p(HPMAm-lac1-2)-PEG-p(HPMAm-lac1-2)/thiolated hyaluronic acid hydrogels, designed as novel injectable biomaterials for potential application in the

  10. LAC indicators: an evaluation of progress and list of proposed indicators

    Science.gov (United States)

    Alan E. Watson; David N. Cole

    1992-01-01

    One of the most critical, and difficult, steps in the Limits of Acceptable Change (LAC) process is the selection of indicators. To help with this step, this paper (I) briefly reviews some desirable characteristics of indicators and (2) lists indicators that have been proposed or adopted in LAC plans. From a comparison of this list of indicators and desirable...

  11. Louisiana SIP: LAC 33:III Ch 21 Subchap J, 2147--Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 1998-02-02 (LAc74) to more..

    Science.gov (United States)

    Louisiana SIP: LAC 33:III Ch 21 Subchap J, 2147--Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 1998-02-02 (LAc74) more...

  12. Le barde et le bouffon

    OpenAIRE

    Fasquel, Samuel

    2013-01-01

    La Gatomaquia de Lope de Vega, La Moschea de Villaviciosa et le Poema heroico de las necedades y locuras de Orlando el enamorado de Quevedo constituent un corpus poétique qui réunit les meilleurs fruits produits par la geste burlesque dans l’Espagne du Siècle d’or. Cet article analyse les profondes différences esthétiques qui caractérisent ces œuvres dans le but de montrer que, malgré ces différences et en dépit de l’importance des éléments carnavalesques et grotesques, ces trois poèmes ne pr...

  13. Preparation of a Ammonia-Treated Lac Dye and Structure Elucidation of Its Main Component.

    Science.gov (United States)

    Nishizaki, Yuzo; Ishizuki, Kyoko; Akiyama, Hiroshi; Tada, Atsuko; Sugimoto, Naoki; Sato, Kyoko

    2016-01-01

    Lac dye and cochineal extract contain laccaic acids and carminic acid as the main pigments, respectively. Both laccaic acids and carminic acid are anthraquinone derivatives. 4-Aminocarminic acid (acid-stable carmine), an illegal colorant, has been detected in several processed foods. 4-Aminocarminic acid is obtained by heating cochineal extract (carminic acid) in ammonia solution. We attempted to prepare ammonia-treated lac dye and to identify the structures of the main pigment components. Ammonia-treated lac dye showed acid stability similar to that of 4-aminocarminic acid. The structures of the main pigments in ammonia-treated lac dye were analyzed using LC/MS. One of the main pigments was isolated and identified as 4-aminolaccaic acid C using various NMR techniques, including 2D-INADEQUATE. These results indicated that ammonia-treatment of lac dye results in the generation of 4-aminolaccaic acids.

  14. Radiocarbon measurements at LAC-UFF: Recent performance

    Energy Technology Data Exchange (ETDEWEB)

    Linares, Roberto, E-mail: rlinares@if.uff.br [Laboratório de Radiocarbono, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/n, Niterói 24230-346 (Brazil); Macario, Kita D. [Laboratório de Radiocarbono, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/n, Niterói 24230-346 (Brazil); Santos, Guaciara M. [Earth System Science, University of California, Irvine, B321 Croul Hall, Irvine, CA 92697-3100 (United States); Carvalho, Carla [Laboratório de Radiocarbono, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/n, Niterói 24230-346 (Brazil); Departamento de Geoquímica, Universidade Federal Fluminense, Outeiro São João Batista, s/n, Niterói 24020-141 (Brazil); Santos, Hellen C. dos; Gomes, Paulo R.S.; Castro, Maikel D.; Oliveira, Fabiana M.; Alves, Eduardo Q. [Laboratório de Radiocarbono, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza, s/n, Niterói 24230-346 (Brazil)

    2015-10-15

    In 2012 a single stage accelerator mass spectrometer from NEC was installed at the Radiocarbon Laboratory of Universidade Federal Fluminense (LAC-UFF), Niterói, Brazil. Here, we present a status report of our facility. We discuss some modifications applied to our combustion protocol in an attempt to reduce our procedural blank, mostly to processed organic samples. Measurements of reference materials indicate low precision and accuracy that are partially related to beam optics through the acceleration tube. We observed that once the beam current intensity increases the measured {sup 13}C{sup +}/{sup 12}C{sup +} becomes erratic. Therefore, in order to maintain the AMS-δ{sup 13}C values within reasonable values, so that fractionation corrections using the spectrometer {sup 13}C{sup +}/{sup 12}C{sup +} values does not affect the final {sup 14}C results, we are forced to limit the {sup 12}C{sup −} beam intensity to ⩽30 μA. This requirement was confirmed during our accuracy tests, when measuring selected annual tree-rings wood samples from a Parana pine (Araucaria angustifolia) between 1927 and 1997 previously measured at the Keck Carbon Cycle AMS Facility (KCCAMS), at the University of California, Irvine (UCI). At the LAC-UFF tree-ring wood samples were processed and measured in 4 different batches during a period of about 5 months. The {sup 14}C results were later compared to the high-precision data obtained at KCCAMS/UCI and reached a good agreement. Recently a problem associated with graphitization yield were finally identified and new measurements with secondary standards are promising.

  15. Evolution of a unique predatory feeding apparatus: functional anatomy, development and a genetic locus for jaw laterality in Lake Tanganyika scale-eating cichlids

    Directory of Open Access Journals (Sweden)

    Albertson R Craig

    2010-01-01

    Full Text Available Abstract Background While bilaterality is a defining characteristic of triploblastic animals, several assemblages have managed to break this symmetry in order to exploit the adaptive peaks garnered through the lateralization of behaviour or morphology. One striking example of an evolved asymmetry in vertebrates comes from a group of scale-eating cichlid fishes from Lake Tanganyika. Members of the Perissodini tribe of cichlid fishes have evolved dental and craniofacial asymmetries in order to more effectively remove scales from the left or right flanks of prey. Here we examine the evolution and development of craniofacial morphology and laterality among Lake Tanganyika scale-eating cichlids. Results Using both geometric and traditional morphometric methods we found that the craniofacial evolution in the Perissodini involved discrete shifts in skeletal anatomy that reflect differences in habitat preference and predation strategies. Further, we show that the evolutionary history of the Perissodini is characterized by an accentuation of craniofacial laterality such that certain taxa show elaborate sided differences in craniofacial shape consistent with the sub-partitioning of function between sides of the head during attacks. Craniofacial laterality in the scale-eating specialist Perissodus microlepis was found to be evident early in development and exhibited a unimodal distribution, which is contrary to the adult condition where jaw laterality has been described as a discrete, bimodal antisymmetry. Finally, using linkage and association analyses we identified a conserved locus for jaw handedness that segregates among East African cichlids. Conclusions We suggest that, during the evolution of the Perissodini, selection has accentuated a latent, genetically determined handedness of the craniofacial skeleton, enabling the evolution of jaw asymmetries in order to increase predation success. Continued work on the developmental genetic basis of

  16. cas du lac Fetzara, région de Annaba

    African Journals Online (AJOL)

    Les analyses isotopiques réalisées sur les eaux de la région et portant sur le tritium, l'oxygène. 18 et le deutérium, montrent que les eaux de la région appartiennent au domaine des eaux évaporées. Ces mêmes eaux ont des valeurs en tritium oscillant entre 7 et 11 UT, ces valeurs sont supérieures à 5 UT valeur limitant les.

  17. PRODUCTION HALIEUTIQUE DU LAC FAE (BASSIN DU SAN ...

    African Journals Online (AJOL)

    ouvrage a ete entame en 1978, et mis en service en 1983 (Da Costa et Dietoa, 2007). Ce reservoir constitue pour le. Sud-Quest de la COte d'Ivoire, un centre important d'approvisionnement en poissons d'eau deuce (Da Costa et al., 2002a et 2002b ) ...

  18. L'astronomie dans le monde

    Science.gov (United States)

    Manfroid, J.

    2009-10-01

    Dunes de Titan; Lac Ontario; Titan; Anneaux de Saturne; Jupiter; Mars; Rotation de Saturne; Valles Marineris; Méthane martien; Epsilon Aurigae; Glycine cométaire; HD 87643; Pluton; Bételgeuse; Site astronomique; Andromède cannibale; Attaque de trou noir; BD+44 493; Formation d'étoiles; Gaz manquant; LIGO; M87; Naine blanche; Galaxie satellite; Galaxies naines sphéroïdales; Galaxies trapues; Cygnus X-1; L'avenir de la Voie Lactée; Naphtaline cosmique; Premiers trous noirs; Coup de foudre; Effet de serre; Glace lunaire; Impacts et extinctions; Exoplanètes rétrogrades; Kepler; Planète chaude; Collision planétaire; Disques dans le vent; Exoplanètes; Formation des planètes; Taches et transits

  19. lac repressor is an antivirulence factor of Salmonella enterica: its role in the evolution of virulence in Salmonella.

    Directory of Open Access Journals (Sweden)

    Sandeepa M Eswarappa

    Full Text Available The genus Salmonella includes many pathogens of great medical and veterinary importance. Bacteria belonging to this genus are very closely related to those belonging to the genus Escherichia. lacZYA operon and lacI are present in Escherichia coli, but not in Salmonella enterica. It has been proposed that Salmonella has lost lacZYA operon and lacI during evolution. In this study, we have investigated the physiological and evolutionary significance of the absence of lacI in Salmonella enterica. Using murine model of typhoid fever, we show that the expression of LacI causes a remarkable reduction in the virulence of Salmonella enterica. LacI also suppresses the ability of Salmonella enterica to proliferate inside murine macrophages. Microarray analysis revealed that LacI interferes with the expression of virulence genes of Salmonella pathogenicity island 2. This effect was confirmed by RT-PCR and Western blot analysis. Interestingly, we found that SBG0326 of Salmonella bongori is homologous to lacI of Escherichia coli. Salmonella bongori is the only other species of the genus Salmonella and it lacks the virulence genes of Salmonella pathogenicity island 2. Overall, our results demonstrate that LacI is an antivirulence factor of Salmonella enterica and suggest that absence of lacI has facilitated the acquisition of virulence genes of Salmonella pathogenicity island 2 in Salmonella enterica making it a successful systemic pathogen.

  20. The genus Hypostomus Lacépède, 1803, and its Surinam representatives (Siluriformes, Loricariidae)

    NARCIS (Netherlands)

    Boeseman, M.

    1968-01-01

    CONTENTS Introduction................... 3 The generic name................. 4 The type species of Hypostomus Lacépède.......... 6 The identity of Acipenser plecostomus Linnaeus........ 9 The distribution and habitats of the Surinam species........ 12 The relationship of the Surinam

  1. Sustaining the natural and economical resources of the Lac Courte Oreilles, Leslie Isham; Jason Weaver

    Energy Technology Data Exchange (ETDEWEB)

    Isham, Leslie; Weaver, Jason

    2013-09-30

    The Lac Courte Oreilles Band of Lake Superior Chippewa Indians, located in northwest Wisconsin has developed a project, entitled Sustaining the Natural and Economic Resources of the LCO Ojibwe. This technical report is a summary of the project.

  2. Paramètres de reproduction des vaches Kouri au Lac Tchad

    African Journals Online (AJOL)

    SARAH

    30 juin 2015 ... RESUME. Objectif : évaluer les performances de reproduction des vaches de la race Kouri au Tchad et proposer les .... aux pâturages des îles et du bord du Lac Tchad, et là où on rencontre les ... Tableau 1 : Variation de l'intervalle entre vêlage-vêlage (jours) des vaches Kouri au Lac-Tchad. IVV. IVV1.

  3. In Silico Evolved lac Operons Exhibit Bistability for Artificial Inducers, but Not for Lactose

    OpenAIRE

    van Hoek, M. J. A.; Hogeweg, P.

    2006-01-01

    Bistability in the lac operon of Escherichia coli has been widely studied, both experimentally and theoretically. Experimentally, bistability has been observed when E. coli is induced by an artificial, nonmetabolizable, inducer. However, if the lac operon is induced with lactose, the natural inducer, bistability has not been demonstrated. We derive an analytical expression that can predict the occurrence of bistability both for artificial inducers and lactose. We find very different condition...

  4. Regulation of endothelial-specific transgene expression by the LacI repressor protein in vivo.

    Directory of Open Access Journals (Sweden)

    Susan K Morton

    Full Text Available Genetically modified mice have played an important part in elucidating gene function in vivo. However, conclusions from transgenic studies may be compromised by complications arising from the site of transgene integration into the genome and, in inducible systems, the non-innocuous nature of inducer molecules. The aim of the present study was to use the vascular system to validate a technique based on the bacterial lac operon system, in which transgene expression can be repressed and de-repressed by an innocuous lactose analogue, IPTG. We have modified an endothelium specific promoter (TIE2 with synthetic LacO sequences and made transgenic mouse lines with this modified promoter driving expression of mutant forms of connexin40 and an independently translated reporter, EGFP. We show that tissue specificity of this modified promoter is retained in the vasculature of transgenic mice in spite of the presence of LacO sequences, and that transgene expression is uniform throughout the endothelium of a range of adult systemic and cerebral arteries and arterioles. Moreover, transgene expression can be consistently down-regulated by crossing the transgenic mice with mice expressing an inhibitor protein LacI(R, and in one transgenic line, transgene expression could be de-repressed rapidly by the innocuous inducer, IPTG. We conclude that the modified bacterial lac operon system can be used successfully to validate transgenic phenotypes through a simple breeding schedule with mice homozygous for the LacI(R protein.

  5. Modification of natural matrix lac-bagasse for matrix composite films

    Science.gov (United States)

    Nurhayati, Nanik Dwi; Widjaya, Karna; Triyono

    2016-02-01

    Material technology continues to be developed in order to a material that is more efficient with composite technology is a combination of two or more materials to obtain the desired material properties. The objective of this research was to modification and characterize the natural matrix lac-bagasse as composite films. The first step, natural matrix lac was changed from solid to liquid using an ethanol as a solvent so the matrix homogenly. Natural matrix lac was modified by adding citric acid with concentration variation. Secondly, the bagasse delignification using acid hydrolysis method. The composite films natural matrix lac-bagasse were prepared with optimum modified the addition citric acid 5% (v/v) and delignification bagasse optimum at 1,5% (v/v) in hot press at 80°C 6 Kg/cm-1. Thirdly, composite films without and with modification were characterized functional group analysis using FTIR spectrophotometer and mechanical properties using Universal Testing Machine. The result of research showed natural matrix lac can be modified by reaction with citric acid. FTIR spectra showed without and with modification had functional groups wide absorption 3448 cm-1 group -OH, C=O ester strong on 1712 cm-1 and the methylene group -CH2 on absorption 1465 cm-1. The mechanical properties showed tensile strength 0,55 MPa and elongation at break of 0,95 %. So that composite films natural matrix lac can be made with reinforcement bagasse for material application.

  6. Le CRDI au Cambodge

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le CRDI a été l'un des premiers bailleurs de fonds à établir des relations avec le Cambodge au début des années 1990, alors que le pays progres- sait vers la paix. Depuis, le Centre aide à reconstruire le Cambodge, qui se remet du régime inhumain des Khmers rouges et de décennies de conflits régionaux. Un État ...

  7. 1910 - Le mouchoir

    NARCIS (Netherlands)

    Winkler, M.F.; Cohen, Nadja; Reverseau, Anne

    2015-01-01

    Une histoire littéraire buissonnière. Ainsi pourrait-on qualifier le parcours original auquel nous convie cet ouvrage, qui propose une lecture insolente et insolite de cinquante années de littérature – de 1900 à 1950 – par le prisme des objets. Objets de tous les jours comme le tabac, le vélo ou le

  8. Loss of the lac operon contributes to Salmonella invasion of epithelial cells through derepression of flagellar synthesis.

    Science.gov (United States)

    Jiang, Lingyan; Ni, Zhiwei; Wang, Lei; Feng, Lu; Liu, Bin

    2015-03-01

    Salmonella, a genus that is closely related to Escherichia coli, includes many pathogens of humans and other animals. A notable feature that distinguishes Salmonella from E. coli is lactose negativity, because the lac operon is lost in most Salmonella genomes. Here, we expressed the lac operon in Salmonella enterica serovar Typhimurium and compared the virulence of the Lac(+) strain to that of the wild-type strain in a murine model, invasion assays, and macrophage replication assays. We showed that the Lac(+) strain is attenuated in vivo and the attenuation of virulence is caused by its defect in epithelial cell invasion. However, the invasion-defective phenotype is unrelated to lactose utilization. Through sequencing and the comparison of the transcriptome profile between the Lac(+) and wild-type strains during invasion, we found that most flagellar genes were markedly downregulated in the Lac(+) strain, while other genes associated with invasion, such as the majority of genes encoded in Salmonella pathogenicity island 1, were not differentially expressed. Moreover, we discovered that lacA is the major repressor of flagellar gene expression in the lac operon. In conclusion, these data demonstrate that the lac operon decreases Salmonella invasion of epithelial cells through repression of flagellar biosynthesis. As the ability to invade epithelial cells is a critical virulence determinant of Salmonella, our results provide important evidence that the loss of the lac operon contributes to the evolution of Salmonella pathogenicity.

  9. On the Redshift of TeV BL Lac Objects

    Energy Technology Data Exchange (ETDEWEB)

    Paiano, Simona; Falomo, Renato [INAF, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5 I-35122 Padova (PD) (Italy); Landoni, Marco; Righi, Chiara [INAF, Osservatorio Astronomico di Brera, Via E. Bianchi 46 I-23807 Merate (Italy); Treves, Aldo [Università degli Studi dell’Insubria, Via Valleggio 11 I-22100 Como (Italy); Scarpa, Riccardo [Instituto de Astrofisica de Canarias, C/O Via Lactea, s/n E38205—La Laguna (Tenerife) (Spain)

    2017-03-10

    We report results of a spectroscopic campaign carried out at the 10 m Gran Telescopio Canarias for a sample of 22 BL Lac objects detected (or candidates) at TeV energies, aiming to determine or constrain their redshift. This is of fundamental importance for the interpretation of their emission models and for population studies and is also mandatory for studying the interaction of high-energy photons with the extragalactic background light using TeV sources. Optical spectra with high signal-to-noise ratios in the range 4250–10000 Å were obtained to search for faint emission or absorption lines from both the host galaxy and the nucleus. We determine a new redshift for PKS 1424+240 ( z = 0.604) and a tentative one for 1ES 0033+595 ( z = 0.467). We are able to set new spectroscopic redshift lower limits for three other sources on the basis of Mg ii and Ca ii intervening absorption features: BZB J1243+3627 ( z > 0.483), BZB J1540+8155 ( z > 0.672), and BZB 0J2323+4210 ( z > 0.267). We confirm previous redshift estimates for four blazars: S3 0218+357 ( z = 0.944), 1ES 1215+303 ( z = 0.129), W Comae ( z = 0.102), and MS 1221.8+2452 ( z = 0.218). For the remaining targets, in seven cases (S2 0109+22, 3C 66A, VER J0521+211, S4 0954+65, BZB J1120+4214, S3 1227+25, BZB J2323+4210), we do not validate the proposed redshift. Finally, for all sources of still-unknown redshift, we set a lower limit based on the minimum equivalent width of absorption features expected from the host galaxy.

  10. Le vieillard et le chevalier

    Directory of Open Access Journals (Sweden)

    Mélanie JECKER

    2010-05-01

    Full Text Available La fin du Moyen Âge fascine. Deux facteurs principaux expliquent l’attraction qu’exerce cette période : elle apparaît d’une part comme un moment historique riche car double, phase de transition entre le Moyen Âge et la Renaissance, où se mêlent des cadres de représentation anciens et nouveaux. L’insinuation d’une pensée humaniste balbutiante s’y traduirait notamment par l’émergence de la notion d’individu, qui constitue l’un des objets de ce travail. Il faut invoquer, d’autre part, l’image macabre d’un bas Moyen Âge hanté par l’idée de la maladie et de la mort depuis l’épidémie de peste noire de 1348, obsédé par la brièveté de la vie humaine. Ces deux facettes de « l’automne du Moyen Âge » tel que l’évoque avec poésie Joan Huizinga sont-elles autre chose qu’une plaisante image d’Epinal? Cette étude cherche précisément à déterminer le degré de validité de ces deux topiques, à travers l’analyse de la représentation des âges de la vie dans un corpus bien défini, celui de la biographie chevaleresque castillane du XVe siècle. L’intérêt porté à l’individu, la conscience de la singularité impliquent en effet celle du caractère mouvant de la personne, or quel thème mieux que celui des âges permet de confirmer ou d’infirmer l’hypothèse du surgissement d’une nouvelle manière de concevoir l’homme, proprement « renaissante », en ce siècle de transition , La nature même du corpus retenu – des récits biographiques – suggère en effet une mutation dans l’appréhension de la personne, une attention prêtée à sa progressive transformation. L’étude de la représentation de la vieillesse, en particulier, révèle non seulement à quel point était alors réelle cette prétendue obsession de la déchéance physique et de la mortalité, mais aussi dans quelle mesure étaient soulignés et valorisés les changements individuels parallèles à l

  11. Le gouvernement Mansard

    OpenAIRE

    Curton, Émile de

    2013-01-01

    Le fait même de sa nomination au poste de Gouverneur allait donner au conflit qui opposait Mansard au docteur Alain toute sa dimension. Le Médecin-chef et ses complices avaient manqué leur premier objectif : remettre en cause le ralliement de la colonie avant le départ du Gouverneur de Géry. Toutefois, ils jugeaient toujours possible de saper l’autorité encore fragile du nouveau gouverneur en la contestant. Dans ce but, le chef du service de santé prenait, dès le 15 septembre, une double init...

  12. Evolutionary behaviour of AGN: Investigations on BL Lac objects and Seyfert II galaxies

    Science.gov (United States)

    Beckmann, V.

    2000-12-01

    The evolution and nature of AGN is still one of the enigmatic questions in astrophysics. While large and complete Quasar samples are available, special classes of AGN, like BL Lac objects and Seyfert II galaxies, are still rare objects. In this work I present two new AGN samples. The first one is the HRX-BL Lac survey, resulting in a sample of X-ray selected BL Lac objects. This sample results from 223 BL Lac candidates based on a correlation of X-ray sources with radio sources. The identification of this sample is 98% complete. 77 objects have been identified as BL Lac objects and form the HRX-BL Lac complete sample, the largest homogeneous sample of BL Lac objects existing today. For this sample, redshifts are now known for 62 objects (81 %). In total I present 101 BL Lac objects in the enlarged HRX-BL Lac survey, for which redshift information is available for 84 objects. During the HRX-BL Lac survey I found several objects of special interest. 1ES 1517+656 turned out to be the brightest known BL Lac object in the universe. 1ES 0927+500 could be the first BL Lac object with a line detected in the X-ray region. RX J1211+2242 is probably the the counterpart of the up to now unidentified gamma-ray source 3EG J1212+2304. Additionally I present seven candidates for ultra high frequency peaked BL Lac objects. RX J1054+3855 and RX J1153+3517 are rare high redshift X-ray bright QSO or accreting binary systems with huge magnetic fields. For the BL Lac objects I suggest an unified scenario in which giant elliptical galaxies, formed by merging events of spiral galaxies at z > 2, start as powerful, radio dominated BL Lacs. As the jet gets less powerful, the BL Lacs start to get more X-ray dominated, showing less total luminosities (for z definition to objects with a calcium break up to 40%, but do not support for the HBL the idea of allowing emission lines in the spectra of BL Lac galaxies. A way to find high redshift BL Lac objects might be the identification of faint X

  13. A fully consistent and conservative vertically adaptive coordinate system for SLIM 3D v0.4 with an application to the thermocline oscillations of Lake Tanganyika

    Science.gov (United States)

    Delandmeter, Philippe; Lambrechts, Jonathan; Legat, Vincent; Vallaeys, Valentin; Naithani, Jaya; Thiery, Wim; Remacle, Jean-François; Deleersnijder, Eric

    2018-03-01

    The discontinuous Galerkin (DG) finite element method is well suited for the modelling, with a relatively small number of elements, of three-dimensional flows exhibiting strong velocity or density gradients. Its performance can be highly enhanced by having recourse to r-adaptivity. Here, a vertical adaptive mesh method is developed for DG finite elements. This method, originally designed for finite difference schemes, is based on the vertical diffusion of the mesh nodes, with the diffusivity controlled by the density jumps at the mesh element interfaces. The mesh vertical movement is determined by means of a conservative arbitrary Lagrangian-Eulerian (ALE) formulation. Though conservativity is naturally achieved, tracer consistency is obtained by a suitable construction of the mesh vertical velocity field, which is defined in such a way that it is fully compatible with the tracer and continuity equations at a discrete level. The vertically adaptive mesh approach is implemented in the three-dimensional version of the geophysical and environmental flow Second-generation Louvain-la-Neuve Ice-ocean Model (SLIM 3D; www.climate.be/slim). Idealised benchmarks, aimed at simulating the oscillations of a sharp thermocline, are dealt with. Then, the relevance of the vertical adaptivity technique is assessed by simulating thermocline oscillations of Lake Tanganyika. The results are compared to measured vertical profiles of temperature, showing similar stratification and outcropping events.

  14. A large-scale experiment in the control of aquatic snails by the use of molluscicides on a sugar estate in the Northern Region of Tanganyika*

    Science.gov (United States)

    Crossland, N. O.

    1963-01-01

    The author describes a large-scale experiment in which the molluscicide Bayer 73 (Bayluscide) was used in an attempt to eliminate Biomphalaria pfeifferi, the snail host of Schistosoma mansoni, from an irrigation system in Tanganyika. Applied at a concentration of 1 p.p.m., the molluscicide gave a very high kill of snails and much of the treated area remained completely free of vector snails for seven months after treatment. However, there were a few survivors in small pockets associated with a drainage area that became flooded during heavy rains coincident with the application of molluscicide. From these survivors a dramatic resurgence of snails occurred in some of the treated canals. This resurgence may be analogous to similar phenomena observed in some insecticide work. The suggestion is made that removal of parasites and predators, in particular trematode parasites, by a molluscicide might increase the snail's capacity for repopulation. Studies of the seasonal fluctuations of snail population density in an adjacent, but separate, irrigation system suggest that molluscicide applications would be more effective if timed to coincide with the end of the rainy seasons. ImagesFIG. 2 PMID:14103411

  15. Le beau et le vrai

    Directory of Open Access Journals (Sweden)

    Létitia Mouze

    2006-05-01

    Full Text Available La vie des abeilles de Maeterlinck est un ouvrage à la fois scientifique et littéraire, non pas parce qu’il appartiendrait à la science par son exactitude et à la littérature par son style, mais en ce qu’il invite à penser l’unité des deux domaines. Les aspects littéraires de l’ouvrage (beauté de l’écriture, usage des images, de l’analogie, etc. ne sont pas des accessoires, mais des outils indispensables à l’élaboration d’un authentique savoir sur les abeilles, c’est-à-dire un savoir qui reconnaît la part d’inconnu et le mystère qui subsistent en dépit de toutes les explications physiques et mécaniques que l’on peut par ailleurs donner des phénomènes observés. Etre scientifique, dans cette perspective, c’est-à-dire donner à connaître, c’est donc être littéraire. Cette conception de la science repose en dernière instance sur une conception philosophique de l’univers comme un tout où toutes choses sont reliées, unies, par des relations d’analogies, ce qui fonde et justifie l’emploi d’un style symboliste.The life of bees, one of Maeterlinck’s works, is together a scientific and literary book, not because of it scientific exactness and its literary style, but for the reason it suggests the unity of both these domains. Literay’s aspects of this work (writing’s beauty, use of images, analogy, etc. are not secondary but necessary to elaborate an authentic knowledge about bees, that means a knowledge which admit the unknown part and the mistery that subsist despite all the physical and mechanical explanations we can give moreover about the observed phenomenons. Be a scientist, in this sense, that is give something to know, therefore means be literary. Finally, this conception of science consist in a philosophiacl conception of Universe as a whole where everything links together, and is united by analogical relations, that base and justify the use of a symbolist style.

  16. lacZ transduced human breast cancer xenografts as an in vivo model for the study of invasion and metastasis

    DEFF Research Database (Denmark)

    Brünner, N; Thompson, E W; Spang-Thomsen, M

    1992-01-01

    . The resulting cell lines were selected for antibiotic (G418) resistance, and cell-sorted for lacZ expression. lacZ continued to be expressed in cultured cells for at least 20 passages without further G418 selection. The lacZ gene codes for beta-D-galactosidase, and cells expressing this gene stain blue...... with the chromogenic substrate X-gal. The lacZ-expressing cells retained the pre-transduction ability to traverse Matrigel in vitro, to form subcutaneous tumours in nude mice, and to grow invasively with the formation of metastases. X-gal staining showed high specificity, staining the tumour cells...

  17. Solving a discrete model of the lac operon using Z3

    Science.gov (United States)

    Gutierrez, Natalia A.

    2014-05-01

    A discrete model for the Lcac Operon is solved using the SMT-solver Z3. Traditionally the Lac Operon is formulated in a continuous math model. This model is a system of ordinary differential equations. Here, it was considerated as a discrete model, based on a Boolean red. The biological problem of Lac Operon is enunciated as a problem of Boolean satisfiability, and it is solved using an STM-solver named Z3. Z3 is a powerful solver that allows understanding the basic dynamic of the Lac Operon in an easier and more efficient way. The multi-stability of the Lac Operon can be easily computed with Z3. The code that solves the Boolean red can be written in Python language or SMT-Lib language. Both languages were used in local version of the program as online version of Z3. For future investigations it is proposed to solve the Boolean red of Lac Operon using others SMT-solvers as cvc4, alt-ergo, mathsat and yices.

  18. The clean development mechanism (CDM) an international perspective and implications for the LAC region

    International Nuclear Information System (INIS)

    2004-08-01

    This paper addresses activity a) an analysis of international CDM experiences and its potential contribution to the LAC region. The paper begins with a section describing the basic principles of the CDM and retrieves the lessons learned from the first two years of the CDM operation. This is followed by a more detailed review in section 2 of the on-going baseline and monitoring methodology approval process. In section 3, the development value of the CDM is explored. Section 4 describes the current CDM markets, while section 5 reviews the response of host countries to the CDM outside the LAC region. Section 6 describes the various capacity building programs established by Annex 1 countries to support the CDM. In each of the first 6 sections, implications for the LAC region are identified. Section 7 brings these conclusions together into a concise summary. (The author)

  19. Lac repressor: Crystallization of intact tetramer and its complexes with inducer and operator DNA

    International Nuclear Information System (INIS)

    Pace, H.C.; Lu, P.; Lewis, M.

    1990-01-01

    The intact lac repressor tetramer, which regulates expression of the lac operon in Escherichia coli, has been crystallized in the native form, with an inducer, and in a ternary complex with operator DNA and an anti-inducer. The crystals without DNA diffract to better than 3.5 angstrom. They belong to the monoclinic space group C2 and have cell dimensions a = 164.7 angstrom, b = 75.6 angstrom, and c = 161.2 angstrom, with α = γ = 90 degree and β = 125.5 degree. Cocrystals have been obtained with a number of different lac operator-related DNA fragments. The complex with a blunt-ended 16-base-pair strand yielded tetragonal bipyramids that diffract to 6.5 angstrom. These protein-DNA cocrystals crack upon exposure to the gratuitous inducer isopropyl β-D-thiogalactoside, suggesting a conformational change in the repressor-operator complex

  20. STRUCTURAL ASPECTS REGARDING TO THE IMAGE OF ICE HOTEL BALEA LAC BREND

    Directory of Open Access Journals (Sweden)

    Marian ZAHARIA

    2008-06-01

    Full Text Available Applying a poll-based survey provides important information regarding the tourist offer particulars in Bâlea Lac area. On the day the survey is performed its main advantage is also outlined: the fact that this information display a good accuracy, are obtained in a short time span and involving relatively low expenses. Data collection and centralization of the answers provided by interviewed tourists regarding tourism practice in the Bâlea Lac area have led to drawing up distributions that are presented in the paper. Based on the respective information, statistics methods adequate to the study of tourist opinion on the Bâlea Lac Ice Hotel brand image. Several issues have been outlined, regarding the types of respondents based on their category, Romanian or foreigners, from Romania and based on destination countries, function of: the type of stay; the means of information; their answers referring to their first arrival at Bâlea Lac; the degree of destination assessment; their opinion on host reception; their preference for Bâlea Lac; appreciating value for money; age groups; gender; social and professional standing. The image created through the attractions and services provided in the Bâlea Lac tourist area by tourism activities closely related to the Ice Hotel is well appreciated, so that they have opened up a rather favourable expectancy for those willing to come back and for those tempted to try and spend their holidays in the presented hotel.

  1. Determinants of bistability in induction of the Escherichia coli lac operon.

    Science.gov (United States)

    Dreisigmeyer, D W; Stajic, J; Nemenman, I; Hlavacek, W S; Wall, M E

    2008-09-01

    The authors have developed a mathematical model of regulation of expression of the Escherichia coli lac operon, and have investigated bistability in its steady-state induction behaviour in the absence of external glucose. Numerical analysis of equations describing regulation by artificial inducers revealed two natural bistability parameters that can be used to control the range of inducer concentrations over which the model exhibits bistability. By tuning these bistability parameters, the authors found a family of biophysically reasonable systems that are consistent with an experimentally determined bistable region for induction by thio-methylgalactoside (TMG) (in Ozbudak et al. Nature, 2004, 427; p. 737). To model regulation by lactose, the authors developed similar equations in which allolactose, a metabolic intermediate in lactose metabolism and a natural inducer of lac, is the inducer. For biophysically reasonable parameter values, these equations yield no bistability in response to induction by lactose - only systems with an unphysically small permease-dependent export effect can exhibit small amounts of bistability for limited ranges of parameter values. These results cast doubt on the relevance of bistability in the lac operon within the natural context of E. coli, and help shed light on the controversy among existing theoretical studies that address this issue. The results also motivate a deeper experimental characterisation of permease-independent transport of lac inducers, and suggest an experimental approach to address the relevance of bistability in the lac operon within the natural context of E. coli. The sensitivity of lac bistability to the type of inducer emphasises the importance of metabolism in determining the functions of genetic regulatory networks.

  2. Radiation-induced point mutations, deletions and micronuclei in lacI transgenic mice

    International Nuclear Information System (INIS)

    Winegar, Richard A.; Hamer, Janice D.; O'Loughlin, Kathleen G.; Mirsalis, Jon C.; Lutze, Louise H.

    1994-01-01

    The development of transgenic mutagenesis systems has now made it possible to study the effects of ionizing radiation at both the molecular and chromosomal levels in the same animal. In this report we present preliminary data on the response of Big Blue TM lacI transgenic mice to ionizing radiation as measured by lacI mutations and micronuclei. C57Bl/6 transgenic mice were irradiated with 137 Cs γ-rays at doses ranging from 0.1 to 14 Gy, and expression times ranging from 2 to 14 days. Dose-related increases in the mutant frequency were observed after irradiations with longer expression times. Mutant plaques were analyzed by restriction enzyme digestion to detect large structural changes in the target sequence. Of 34 γ-ray- induced mutations analyzed, 4 were large-scale rearrangements. Three of these rearrangements were deletions within the lacI gene characterized by the presence of short regions of homology at the breakpoint junctions. The fourth rearrangement was a deletion that extended from within the αlacZ gene into downstream sequences and that had 43 bp of homology at the junction. These data indicate that the Big Blue TM lacI transgenic mouse system is sensitive to the types of mutations induced by ionizing radiation. To determine whether the presence of the transgene affects micronucleus induction we compared the response of nontransgenic to hemizygous transgenic B6C3F1 mice and the response of nontransgenic to hemizygous and homozygous transgenic C57Bl/6 mice. The presence or absence of the lacI transgene had no effect on spontaneous micronucleus frequencies for either strain. However, radiation-induced micronucleus frequencies were significantly higher in hemizygous lacI B6C3F1 mice than in nontransgenic litter mates; the converse was true in C57Bl/6 mice. These data suggest that the lacI transgene does not cause chromosome instability as measured by spontaneous micronucleus levels. However, the response of these transgenic mice to a variety of

  3. Are BL Lac-type objects nearby black holes. [gas accretion model

    Science.gov (United States)

    Shapiro, S. L.; Elliot, J. L.

    1974-01-01

    It is pointed out that isolated black holes accreting interstellar gas can account for the characteristic properties of the Lacertids. Emission spectra for various interstellar gas densities and black hole masses are compared with the data plotted by Strittmatter et al. (1972) for the BL Lac-type objects. Rough estimates indicate that there may indeed be a finite number of stellar-mass black holes close to the earth as required by the theory. If it is determined that the BL Lac-type objects lie outside of the galactic disk a black hole accretion model may still apply if certain conditions are satisfied.

  4. Multi-wavelength studies of TeV γ-ray emitting BL Lac objects

    International Nuclear Information System (INIS)

    Kaufmann, Sarah Sabine

    2012-01-01

    The discovery of TeV γ-ray emission of BL Lac objects gave new insights in the particle acceleration and the emission processes of the highly relativistic jets. To shed light on the conditions in the high energetic jets of the TeV γ-ray emitting BL Lac objects, I have studied in great detail the spectral energy distribution (SED) of sources with different characteristics. BL Lac objects with exceptional very high energy spectra (soft and hard spectra) and with large differences in the emission peak frequencies, to cover the different classes of BL Lac objects, have been chosen. The basic aim of this thesis was, to study with new, simultaneous multi- avelength (MWL) observations, if the emission processes of these extreme cases of TeV BL Lac objects can be explained by the synchrotron Self-Compton (SSC) model which is well established for the class of BL Lac objects at lower energies. We proposed MWL observations in the optical, UV and X-ray regime, to be conducted simultaneous to very high energy observations with the H.E.S.S. experiment, to study the emission processes. Simultaneous observations are crucial, since BL Lac objects are variable at all wavebands. I have analysed the MWL observations and conducted detailed variability and spectral studies in each wavelength range. The different kind of absorption at each wavelength as well as the influence of the host galaxy of the AGN has been considered to obtain the intrinsic jet spectrum. I have then applied the commonly used theoretical jet model, the SSC model, to the SED. I conducted a MWL campaign on a BL Lac object with the softest TeV spectrum, PKS 2005-489, during which it was observed in a very bright X-ray state. The good spectral coverage of the emission peaks allowed a detailed study of the SSC model. The extreme BL Lac object 1ES 0229+200 exhibits a hard intrinsic TeV spectrum. With my MWL campaign I found a clear cut-off in the optical range and therefore a high minimum Lorentz factor is needed to

  5. The Periplasmic Cavity of LacY Mutant Cys154→Gly : How Open Is Open?

    NARCIS (Netherlands)

    Jiang, Xiaoxu; Driessen, Arnold J.M.; Feringa, Ben L.; Kaback, H. Ronald

    2013-01-01

    The lactose permease from Escherichia coli (LacY) is a galactoside/H+ symporter that catalyzes the coupled stoichiometric transport of a sugar and an H+ across the cytoplasmic membrane. X-ray crystal structures of WT LacY and the conformationally restricted mutant Cys154→Gly exhibit an inward-facing

  6. L'habitat à une échelle globale : importance respective de l'immigration et de l'extinction pour les peuplements de poissons des petits lacs

    Directory of Open Access Journals (Sweden)

    TONN W. M.

    1995-04-01

    Full Text Available Les deux processus qui déterminent la structure des communautés dans les habitats insulaires sont l'immigration d'espèces vers une communauté et l'extinction de celles qui étaient présentes auparavant. Bien que l'immigration et l'extinction se produisent généralement à des échelles supérieures à celles qu'il est possible d'étudier avec des expériences plannifiées, les écologistes peuvent améliorer leur compréhension de ces processus par l'analyse des distributions observées ; l'isolation, le caractère discret et la réplication des systèmes insulaires présentent des avantages pour réaliser de telles analyses. Comme pour les communautés observées sur de vraies îles, la structure des peuplements de poissons dans les petits lacs forestiers est le résultat de l'immigration et de l'extinction. L'importance relative de ces processus peut dépendre des caractéristiques d'habitat des lacs et des espèces présentes, ainsi que du cadre régional et historique des lacs étudiés. Dans une région donnée, la composition des peuplements locaux de poissons peut être reliée à un ensemble particulier de conditions d'habitat et, dans la mesure où ces facteurs peuvent être liés à l'immigration et à l'extinction, il devrait être possible d'analyser les relations peuplement-environnement pour en déduire l'importance relative de ces processus dans la formation de peuplements locaux dans et entre les régions et les continents. Nous avons réalisé des analyses à large échelle des relations peuplement-environnement des petits lacs forestiers de quatre régions tempérées d'Europe et d'Amérique du Nord ; l'utilisation d'une série d'analyses canonique partielle des correspondances nous a permis de distinguer la variation due aux relations peuplements-environnement d'un ensemble de facteurs associés à l'immigration contre l'extinction. Les isolations passées et présentes varient selon les lacs et les régions, comme la

  7. Biologie de la reproduction du Cyprinidae, Barbus callensis dans le lac de barrage Hamiz (Algérie

    Directory of Open Access Journals (Sweden)

    Ould Rouis, S.

    2012-01-01

    Full Text Available Reproductive Biology of the Cyprinidae, Barbus callensis in an Algerian Dam. The freshwater fish, Barbus callensis (Valenciennes, 1842 was studied from 2005 to 2007 for the first time in Hamiz dam. This species endemic of North African continent is widely spread in the rivers of Algeria. This reservoir is situated in Boumerdes 35 km southeast of Algiers. During these three years, the monthly sampling was carried out by trammel nets, fishing near the dike during one night. At the same time, the fry was captured with a transparent plastic bottle baited with breadcrumbs put down near the lakeshore. The monthly follow-up of the gonadosomatic ratio (RGS reveals that the spawning period occurred between April and May. The evolution of the condition factor (K shows low seasonal variations. However, a lower value appears in spring when the temperature increases and the breeding begins. The sex ratio is higher for the adult females (1:2.8, more than 26 cm. The first sexual maturity size (L50 is lower for males (19.6 cm than for females (27.7 cm.

  8. [Fond du Lac archeological resources within the Draft Area Recommendation Report

    International Nuclear Information System (INIS)

    Danz, D.L.

    1986-01-01

    Research into archaeological resources of the Fond du Lac Band within the DOE proposed high-level nuclear waste sites resulted in the discovery of four traditional ancestral sites. A number of ancestral sites that are located within other proposed repository sites were also discovered

  9. Structural identification and biological activity of six new Shellolic esters from Lac.

    Science.gov (United States)

    Lu, Jin; Shang, Lei; Wen, Huimin; Huang, Jian; Li, Guoyu; Wang, Jinhui

    2018-03-01

    Six new sesquiterpenoid esters, named Shellolic ester A-F (1-6), along with four known Lac dyes (7-10) were isolated from methanol extract of the secretions of Laccifer lacca. Their structures were established on the basis of spectroscopic analyses (IR, HR-ESI-MS, 1D and 2D NMR) and by comparison with published data. Biological activities evaluation of the isolates showed that they were inactive against human cancer cell lines (HepG2, MCF-7, Hela and C6) and LPS-treated RAW264.7, which is well consistent with that Lac resin used as nontoxic material in agriculture applications, pharmaceutical formulations, and food additives. However, compound 2, 4, 7, 9, 10 were found to be considerable active against B. subtilis, E. coli, and S. aureus microorganisms. The results complements the current knowledge about Lac produced from China. Meanwhile, Our present study further reveals that Lac resin are edible with no toxicity and physiologically harmless at the level employed as an excipient. Copyright © 2017. Published by Elsevier B.V.

  10. Deterministic and stochastic population-level simulations of an artificial lac operon genetic network

    Directory of Open Access Journals (Sweden)

    Zygourakis Kyriacos

    2011-07-01

    Full Text Available Abstract Background The lac operon genetic switch is considered as a paradigm of genetic regulation. This system has a positive feedback loop due to the LacY permease boosting its own production by the facilitated transport of inducer into the cell and the subsequent de-repression of the lac operon genes. Previously, we have investigated the effect of stochasticity in an artificial lac operon network at the single cell level by comparing corresponding deterministic and stochastic kinetic models. Results This work focuses on the dynamics of cell populations by incorporating the above kinetic scheme into two Monte Carlo (MC simulation frameworks. The first MC framework assumes stochastic reaction occurrence, accounts for stochastic DNA duplication, division and partitioning and tracks all daughter cells to obtain the statistics of the entire cell population. In order to better understand how stochastic effects shape cell population distributions, we develop a second framework that assumes deterministic reaction dynamics. By comparing the predictions of the two frameworks, we conclude that stochasticity can create or destroy bimodality, and may enhance phenotypic heterogeneity. Conclusions Our results show how various sources of stochasticity act in synergy with the positive feedback architecture, thereby shaping the behavior at the cell population level. Further, the insights obtained from the present study allow us to construct simpler and less computationally intensive models that can closely approximate the dynamics of heterogeneous cell populations.

  11. Kinetic Analysis of Lactose Exchange in Proteoliposomes Reconstituted with Purified lac Permease

    NARCIS (Netherlands)

    Lolkema, Julius S.; Carrasco, Nancy; Kaback, H. Ronald

    1991-01-01

    Lactose exchange catalyzed by purified lac permease reconstituted into proteoliposomes was analyzed with unequal concentrations of lactose on either side of the membrane and at low pH so as to prevent equilibration of the two pools. Exchange with external concentrations below 1.0 mM is a

  12. Baseline survey of anthropogenic pressures for the Lac Bay ecosystem, Bonaire

    NARCIS (Netherlands)

    Debrot, A.O.

    2012-01-01

    Lac Bay of Bonaire is a shallow non-estuarine lagoon of about 700 hectares, separated from the open sea by a shallow coral barrier-reef. It possesses the only major concentration of seagrass beds and mangroves of the island. It is a designated Ramsar wetland of international significance, an

  13. In silico evolved lac operons exhibit bistability for artificial inducers, but not for lactose.

    Science.gov (United States)

    van Hoek, M J A; Hogeweg, P

    2006-10-15

    Bistability in the lac operon of Escherichia coli has been widely studied, both experimentally and theoretically. Experimentally, bistability has been observed when E. coli is induced by an artificial, nonmetabolizable, inducer. However, if the lac operon is induced with lactose, the natural inducer, bistability has not been demonstrated. We derive an analytical expression that can predict the occurrence of bistability both for artificial inducers and lactose. We find very different conditions for bistability in the two cases. Indeed, for artificial inducers bistability is predicted, but for lactose the condition for bistability is much more difficult to satisfy. Moreover, we demonstrate that in silico evolution of the lac operon generates an operon that avoids bistability with respect to lactose, but does exhibit bistability with respect to artificial inducers. The activity of this evolved operon strikingly resembles the experimentally observed activity of the operon. Thus our computational experiments suggest that the wild-type lac operon, which regulates lactose metabolism, is not a bistable switch. Nevertheless, for engineering purposes, this operon can be used as a bistable switch with artificial inducers.

  14. Determining the bistability parameter ranges of artificially induced lac operon using the root locus method.

    Science.gov (United States)

    Avcu, N; Alyürük, H; Demir, G K; Pekergin, F; Cavas, L; Güzeliş, C

    2015-06-01

    This paper employs the root locus method to conduct a detailed investigation of the parameter regions that ensure bistability in a well-studied gene regulatory network namely, lac operon of Escherichia coli (E. coli). In contrast to previous works, the parametric bistability conditions observed in this study constitute a complete set of necessary and sufficient conditions. These conditions were derived by applying the root locus method to the polynomial equilibrium equation of the lac operon model to determine the parameter values yielding the multiple real roots necessary for bistability. The lac operon model used was defined as an ordinary differential equation system in a state equation form with a rational right hand side, and it was compatible with the Hill and Michaelis-Menten approaches of enzyme kinetics used to describe biochemical reactions that govern lactose metabolism. The developed root locus method can be used to study the steady-state behavior of any type of convergent biological system model based on mass action kinetics. This method provides a solution to the problem of analyzing gene regulatory networks under parameter uncertainties because the root locus method considers the model parameters as variable, rather than fixed. The obtained bistability ranges for the lac operon model parameters have the potential to elucidate the appearance of bistability for E. coli cells in in vivo experiments, and they could also be used to design robust hysteretic switches in synthetic biology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Dynamical Black Hole Masses of BL Lac Objects from the Sloan Digital Sky Survey

    NARCIS (Netherlands)

    Plotkin, Richard M.; Markoff, Sera; Trager, Scott C.; Anderson, Scott F.

    2012-01-01

    We measure black hole masses for 71 BL Lac objects from the Sloan Digital Sky Survey (SDSS) with redshifts out to z ∼ 0.4. We perform spectral decompositions of their nuclei from their host galaxies and measure their stellar velocity dispersions. Black hole masses are then derived from the black

  16. Modelling the IDV Emissions of the BL Lac Objects with a Langevin ...

    Indian Academy of Sciences (India)

    Abstract. In this paper, we introduce a simplified model for explain- ing the observations of optical intra-day variability (IDV) of the BL. Lac Objects. We assume that the source of the IDV are the stochastic oscillations of an accretion disk around a supermassive black hole. The stochastic fluctuations on the vertical direction of ...

  17. Dynamical black hole masses of BL Lac objects from the Sloan Digital Sky Survey

    NARCIS (Netherlands)

    Plotkin, R. M.; Markoff, S.; Trager, S. C.; Anderson, S. F.

    We measure black hole masses for 71 BL Lac objects from the Sloan Digital Sky Survey with redshifts out to z˜ 0.4. We perform spectral decompositions of their nuclei from their host galaxies and measure their stellar velocity dispersions. Black hole masses are then derived from the black hole mass -

  18. Dynamical black hole masses of BL Lac objects from the Sloan Digital Sky Survey

    NARCIS (Netherlands)

    Plotkin, R. M.; Markoff, S.; Trager, S. C.; Anderson, S. F.

    We measure black hole masses for 71 BL Lac objects from the Sloan Digital Sky Survey with redshifts out to z similar to 0.4. We perform spectral decompositions of their nuclei from their host galaxies and measure their stellar velocity dispersions. Black hole masses are then derived from the black

  19. Dynamical black hole masses of BL Lac objects from the Sloan Digital Sky Survey

    NARCIS (Netherlands)

    Plotkin, R.M.; Markoff, S.; Trager, S.C.; Anderson, S.F.

    2011-01-01

    We measure black hole masses for 71 BL Lac objects from the Sloan Digital Sky Survey with redshifts out to z∼ 0.4. We perform spectral decompositions of their nuclei from their host galaxies and measure their stellar velocity dispersions. Black hole masses are then derived from the black hole mass -

  20. Short Note: Preliminary fish survey of Lac Tseny in north- western ...

    African Journals Online (AJOL)

    We surveyed the fish fauna of Lac Tseny, in the Sofia Region of northwestern Madagascar, during October 2010 by observing commercial catches and targeted netting of areas used by endemic species. We recorded seven native fish species at the lake, including three endemic cichlids, a herring and a catfish.

  1. Limits of acceptable change and natural resources planning: when is LAC useful, when is it not?

    Science.gov (United States)

    David N. Cole; Stephen F. McCool

    1997-01-01

    There are ways to improve the LAC process and its implementational procedures. One significant procedural modification is the addition of a new step. This step — which becomes the first step in the process — involves more explicitly defining goals and desired conditions. For other steps in the process, clarifications of concept and terminology are advanced, as are...

  2. Modelling the IDV Emissions of the BL Lac Objects with a Langevin ...

    Indian Academy of Sciences (India)

    random, white noise type force. Furthermore, preliminary numerical sim- ulation results are presented, which are based on the numerical analysis of the Langevin stochastic differential equation. Key words. Langevin type stochastic differential equation—BL Lac objects. 1. Introduction. Intraday variability is usually defined as ...

  3. Ecological rehabilitation of Lac Bonaire by wise management of water and sediments

    NARCIS (Netherlands)

    Wosten, J.H.M.

    2013-01-01

    Lac Bonaire is confronted with a gradually decreasing open water area because mangrove is occupying this area. At the same time mangrove growth deteriorates at the back of the mangrove belt, the area of hyper saline flats gradually increases and sediment is deposited in the bay area. During a field

  4. Analysis of Optical Variations of BL Lac Object AO 0235+ 164

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Historical optical BVRI band data are combined on the BL Lac object AO 0235 + 164. In order to examine the possible existence of lags and correlations between variations in different optical bands from this source, a statistical analysis is performed through the Discrete Correlation Function (DCF) method.

  5. Computing Optical Variable Periods of BL Lac Object S5 0716+714 ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... From a large volume of literature, we have collected effective observation of BL Lac object S5 0716+714 in the optical band, and constructed its long-term light curve from 1994 to 2006 AD. The light curve shows that S5 0716+714 is very active and exhibits very complicated non-sinusoidal variations.

  6. Computing Optical Variable Periods of BL Lac Object S5 0716+ 714 ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... From a large volume of literature, we have collected effective observation of BL Lac object S5 0716+714 in the optical band, and constructed its long-term light curve from 1994 to 2006 AD. The light curve shows that S5 0716+714 is very active and exhibits very complicated non-sinusoidal variations.

  7. Bilan des introductions de salmonidés dans les lacs et ruisseaux d'altitude des Hautes-Pyrénées

    Directory of Open Access Journals (Sweden)

    DELACOSTE M.

    1997-01-01

    Full Text Available Les introductions de Salmonidés ont été importantes au cours des 60 dernières années dans les lacs et ruisseaux d'altitude des Hautes-Pyrénées. Six espèces de Salmonidés ont été introduites dans des milieux qui, pour la plupart, étaient vierges de populations piscicoles : la truite commune (Salmo trutta L., la truite arc-en-ciel (Oncorhynchus mykiss Walbaum, l'omble de fontaine (Salvelinus fontinalis Mitchill, l'omble chevalier (Salvelinus alpinus L., le cristivomer (Salvelinus namaycush Walbaum et le splake (Salvelinus fontinalis x Salvelinus namaycush. Dans de très nombreux cas, ces introductions ont abouti à des acclimatations. En revanche, les naturalisations sont beaucoup plus rares. Seules les espèces lacustres (cristivomer et omble chevalier se sont naturalisées dans la majorité des lacs où elles ont été introduites. Les conditions de reproduction constituent le facteur clé permettant d'expliquer la naturalisation des espèces. En ruisseau, il faut y ajouter la compétition avec l'espèce indigène (la truite commune, la pression halieutique ainsi que les conditions hivernales très rigoureuses. Les incidences écologiques des introductions sur les populations de truites communes indigènes sont faibles. En revanche, elles ne sont pas négligeables pour les populations de batraciens. Cette politique d'introduction a largement participé au développement de l'halieutisme dans ces milieux d'altitude. En cela, les introductions ont parfaitement répondu aux objectifs halieutiques qu'on leur avait fixés. L'acquisition de connaissances sur l'ensemble de la chaîne pyrénéenne constitue aujourd'hui une étape incontournable pour une politique de gestion globale des introductions.

  8. Le CRDI au Vietnam

    International Development Research Centre (IDRC) Digital Library (Canada)

    des agriculteurs trouvent des solutions de rechange à la culture du tabac. □ des responsables de politiques agissent pour réduire la pauvreté. Soutien accordé par le CRDI depuis 1991. 111 activités d'une valeur de 30 millions cad. CRDI. Le CRDI au Vietnam centre de recherches pour le développement international ...

  9. THE CONTRIBUTION OF FERMI -2LAC BLAZARS TO DIFFUSE TEV–PEV NEUTRINO FLUX

    Energy Technology Data Exchange (ETDEWEB)

    Aartsen, M. G. [Department of Physics, University of Adelaide, Adelaide, 5005 (Australia); Abraham, K. [Physik-department, Technische Universität München, D-85748 Garching (Germany); Ackermann, M. [DESY, D-15735 Zeuthen (Germany); Adams, J. [Dept. of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Aguilar, J. A.; Ansseau, I. [Université Libre de Bruxelles, Science Faculty CP230, B-1050 Brussels (Belgium); Ahlers, M. [Dept. of Physics and Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin, Madison, WI 53706 (United States); Ahrens, M. [Oskar Klein Centre and Dept. of Physics, Stockholm University, SE-10691 Stockholm (Sweden); Altmann, D.; Anton, G. [Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen (Germany); Andeen, K. [Department of Physics, Marquette University, Milwaukee, WI, 53201 (United States); Anderson, T.; Arlen, T. C. [Dept. of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Archinger, M.; Baum, V. [Institute of Physics, University of Mainz, Staudinger Weg 7, D-55099 Mainz (Germany); Arguelles, C.; Axani, S. [Dept. of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Auffenberg, J. [III. Physikalisches Institut, RWTH Aachen University, D-52056 Aachen (Germany); Bai, X. [Physics Department, South Dakota School of Mines and Technology, Rapid City, SD 57701 (United States); Barwick, S. W., E-mail: thorsten.gluesenkamp@fau.de [Dept. of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Collaboration: IceCube Collaboration; and others

    2017-01-20

    The recent discovery of a diffuse cosmic neutrino flux extending up to PeV energies raises the question of which astrophysical sources generate this signal. Blazars are one class of extragalactic sources which may produce such high-energy neutrinos. We present a likelihood analysis searching for cumulative neutrino emission from blazars in the 2nd Fermi -LAT AGN catalog (2LAC) using IceCube neutrino data set 2009-12, which was optimized for the detection of individual sources. In contrast to those in previous searches with IceCube, the populations investigated contain up to hundreds of sources, the largest one being the entire blazar sample in the 2LAC catalog. No significant excess is observed, and upper limits for the cumulative flux from these populations are obtained. These constrain the maximum contribution of 2LAC blazars to the observed astrophysical neutrino flux to 27% or less between around 10 TeV and 2 PeV, assuming the equipartition of flavors on Earth and a single power-law spectrum with a spectral index of −2.5. We can still exclude the fact that 2LAC blazars (and their subpopulations) emit more than 50% of the observed neutrinos up to a spectral index as hard as −2.2 in the same energy range. Our result takes into account the fact that the neutrino source count distribution is unknown, and it does not assume strict proportionality of the neutrino flux to the measured 2LAC γ -ray signal for each source. Additionally, we constrain recent models for neutrino emission by blazars.

  10. Enzymatic Synthesis of N-Acetyllactosamine (LacNAc Type 1 Oligomers and Characterization as Multivalent Galectin Ligands

    Directory of Open Access Journals (Sweden)

    Thomas Fischöder

    2017-08-01

    Full Text Available Repeats of the disaccharide unit N-acetyllactosamine (LacNAc occur as type 1 (Galβ1, 3GlcNAc and type 2 (Galβ1, 4GlcNAc glycosylation motifs on glycoproteins and glycolipids. The LacNAc motif acts as binding ligand for lectins and is involved in many biological recognition events. To the best of our knowledge, we present, for the first time, the synthesis of LacNAc type 1 oligomers using recombinant β1,3-galactosyltransferase from Escherichia coli and β1,3-N-acetylglucosaminyltranferase from Helicobacter pylori. Tetrasaccharide glycans presenting LacNAc type 1 repeats or LacNAc type 1 at the reducing or non-reducing end, respectively, were conjugated to bovine serum albumin as a protein scaffold by squarate linker chemistry. The resulting multivalent LacNAc type 1 presenting neo-glycoproteins were further studied for specific binding of the tumor-associated human galectin 3 (Gal-3 and its truncated counterpart Gal-3∆ in an enzyme-linked lectin assay (ELLA. We observed a significantly increased affinity of Gal-3∆ towards the multivalent neo-glycoprotein presenting LacNAc type 1 repeating units. This is the first evidence for differences in glycan selectivity of Gal-3∆ and Gal-3 and may be further utilized for tracing Gal-3∆ during tumor progression and therapy.

  11. Le Minh Duc

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. Le Minh Duc. Articles written in Bulletin of Materials Science. Volume 36 Issue 5 October 2013 pp 779-788. Study on photocatalysis of TiO2 nanotubes prepared by methanol-thermal synthesis at low temperature · Chau Thanh Nam Wein-Duo Yang Le Minh Duc · More Details ...

  12. Le Bon, Gustave

    DEFF Research Database (Denmark)

    Borch, Christian

    2017-01-01

    Gustave Le Bon (1841–1931) was a French physician and crowd psychologist who published extensively on themes such as crowds, war, race, revolution, socialism, and war. His work on crowd psychology in particular was highly influential, including beyond scholarly circles. Le Bon argued that crowds ...

  13. Bistability of the lac operon during growth of Escherichia coli on lactose and lactose+glucose.

    Science.gov (United States)

    Narang, Atul; Pilyugin, Sergei S

    2008-05-01

    The lac operon of Escherichia coli can exhibit bistability. Early studies showed that bistability occurs during growth on TMG/succinate and lactose+glucose, but not during growth on lactose. More recently, studies with lacGFP-transfected cells show bistability during growth on TMG/succinate, but not during growth on lactose and lactose+glucose. In the literature, these results are invariably attributed to variations in the destabilizing effect of the positive feedback generated by induction. Specifically, during growth on TMG/succinate, lac induction generates strong positive feedback because the permease stimulates the accumulation of intracellular TMG, which in turn, promotes the synthesis of even more permease. This positive feedback is attenuated during growth on lactose because hydrolysis of intracellular lactose by beta-galactosidase suppresses the stimulatory effect of the permease. It is attenuated even more during growth on lactose + glucose because glucose inhibits the uptake of lactose. But it is clear that the stabilizing effect of dilution also changes dramatically as a function of the medium composition. For instance, during growth on TMG/succinate, the dilution rate of lac permease is proportional to its activity, e, because the specific growth rate is independent of e (it is completely determined by the concentration of succinate). However, during growth on lactose, the dilution rate of the permease is proportional to e2 because the specific growth rate is proportional to the specific lactose uptake rate, which in turn, proportional to e. We show that: (a) This dependence on e2 creates such a strong stabilizing effect that bistability is virtually impossible during growth on lactose, even in the face of the intense positive feedback generated by induction. (b) This stabilizing effect is weakened during growth on lactose+glucose because the specific growth rate on glucose is independent of e, so that the dilution rate once again contains a term that

  14. Le laboratoire, le temple et le marché

    International Development Research Centre (IDRC) Digital Library (Canada)

    Chapra est conseiller économique auprès de l'Agence monétaire d'Arabie Saoudite. Il a beaucoup écrit sur l'économie et la finance en pays islamique, et son ouvrage le plus important est Towards a Just Monetary System: A Discussion of Money, Banking, and Monetary Policy in the Light of Islamic Teachings (1985).

  15. Lele des chefs traditionnels au Ghana : un modèle inspirant ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    8 févr. 2011 ... Avec ses partenaires du Sud, avec aussi le soutien du Centre de recherches pour le développement international ( CRDI ), organisme canadien, Ray a étudié lele des chefs traditionnels au Ghana dans la lutte contre le VIH et le sida. Les collectivités politiques antérieures au colonialisme sont une ...

  16. lacY mutant of Escherichia coli with altered physiology of lactose induction.

    Science.gov (United States)

    Flagg, J L; Wilson, T H

    1976-01-01

    A mutant of Escherichia coli is described that grew on lactose only in the presence of isopropylthiogalactoside. This cell contained a defect in the lacY gene that resulted in the formation of a transport system with a poor affinity for lactose. The inability to grow on lactose alone was due to the failure of induction by this disaccharide. This failure of inducation was presumably due to a defect in lactose accumulation which resulted in significant reduction in the formation of allo-lactose, the true inducer of lac operon. These results are consistent with the view that the capacity to accumulate lactose plays an important physiological role in the induction of the enzymes necessary for its utilization. PMID:791924

  17. Tectonic inheritance in the development of the Kivu - north Tanganyika rift segment of the East African Rift System: role of pre-existing structures of Precambrian to early Palaeozoic origin.

    Science.gov (United States)

    Delvaux, Damien; Fiama Bondo, Silvanos; Ganza Bamulezi, Gloire

    2017-04-01

    The present architecture of the junction between the Kivu rift basin and the north Tanganyika rift basin is that of a typical accommodation zone trough the Ruzizi depression. However, this structure appeared only late in the development of the Western branch of the East African Rift System and is the result of a strong control by pre-existing structures of Precambrian to early Palaeozoic origin. In the frame of a seismic hazard assessment of the Kivu rift region, we (Delvaux et al., 2016) constructed homogeneous geological, structural and neotectonic maps cross the five countries of this region, mapped the pre-rift, early rift and Late Quaternary faults and compiled the existing knowledge on thermal springs (assumed to be diagnostic of current tectonic activity along faults). We also produced also a new catalogue of historical and instrumental seismicity and defined the seismotectonic characteristics (stress field, depth of faulting) using published focal mechanism data. Rifting in this region started at about 11 Ma by initial doming and extensive fissural basaltic volcanism along normal faults sub-parallel to the axis of the future rift valley, as a consequence of the divergence between the Nubia and the Victoria plate. In a later stage, starting around 8-7 Ma, extension localized along a series of major border faults individualizing the subsiding tectonic basins from the uplifting rift shoulders, while lava evolved towards alkali basaltic composition until 2.6 Ma. During this stage, initial Kivu rift valley was extending linearly in a SSW direction, much further than its the actual termination at Bukavu, into the Mwenga-Kamituga graben, up to Namoya. The SW extremity of this graben was linked via a long oblique transfer zone to the central part of Lake Tanganyika, itself reactivating an older ductile-brittle shear zone. In the late Quaternary-early Holocene, volcanism migrated towards the center of the basin, with the development of the Virunga volcanic massif

  18. Caractérisation des sables et morphologie du fond du lac du ...

    African Journals Online (AJOL)

    Une analyse sédimentologique et minéralogique réalisée sur un cycle hydrologique entre octobre 2004 et août 2005 a permis d\\'évaluer les charges solides en suspension et de caractériser les sédiments du lac du barrage de Taabo. La concentration moyenne en matières en suspension (12 mg.L-1) et la turbidité ...

  19. Caractérisation des sables et morphologie du fond du lac du ...

    African Journals Online (AJOL)

    Administrateur

    Une analyse sédimentologique et minéralogique réalisée sur un cycle hydrologique entre octobre 2004 et août 2005 a permis d'évaluer les charges solides en suspension et de caractériser les sédiments du lac du barrage de Taabo. La concentration moyenne en matières en suspension (12 mg.L-1) et la turbidité ...

  20. Hydrogen exchange in hydrated films of proteins. Application to the E. coli lac repressor core

    International Nuclear Information System (INIS)

    Pilet, J.; Szabo, A.G.; Maurizot, J.-C.

    1980-01-01

    An original easy method of hydrogen to deuterium exchange in hydrated films of proteins, followed by infrared absorption measurements, is described and applied to films of the E. coli lac repressor core, in order to examine the effect of isopropyl-β-D-thiogalactoside (IPTG) binding. An estimation of about 25% α helical structure in this protein fragment is deduced from the exchange curve. The binding of IPTG to the core does not affect the exchange curve within the experimental error limits. (Auth.)

  1. Influence of catabolite repression and inducer exclusion on the bistable behavior of the lac operon.

    Science.gov (United States)

    Santillán, Moisés; Mackey, Michael C

    2004-03-01

    A mathematical model of the lac operon which includes all of the known regulatory mechanisms, including external-glucose-dependent catabolite repression and inducer exclusion, as well as the time delays inherent to transcription and translation, is presented. With this model we investigate the influence of external glucose, by means of catabolite repression and the regulation of lactose uptake, on the bistable behavior of this system.

  2. Radio two-color diagram for QSOs, spiral galaxies, and BL Lac objects

    International Nuclear Information System (INIS)

    Pacht, E.

    1976-01-01

    A radio ''color---color'' diagram is presented for 311 QSOs with known redshifts, 26 BL Lacertae-type objects, and 75 spiral galaxies. The spiral galaxies and BL Lac objects are found to cluster in two different almost mutually exclusive regions of the radio two-color diagram. The QSOs display a greater dispersion in their spectra and the dispersion appears to increase with redshift. The mean spectral index i /of the QSOs indicates a flatter spectrum with increasing

  3. NEW MEGALOCYTIVIRUS INFECTED TO THE CULTURED FRESH WATER GIANT GOURAMI, Osphronemus gouramy Lac. IN INDONESIA

    OpenAIRE

    Isti Koesharyani; Lila Gardenia

    2013-01-01

    Giant gourami (Osphronemus gouramy Lac.) is one of freshwater fish having high economic value and very popular in Indonesian food restaurant. This fish have been cultured throughout Indonesia. Since two years ago, cultured fish in ponds infected by unknown pathogenic agent and may cause diseased fish and mass mortality. Mass mortality of pond cultured giant gourami occurred in West Java, Central Java, and Bali-Indonesia. The symptoms of diseased fish are the body color becomes darker, resting...

  4. Le dernier Wittgenstein et le dernier Husserl sur le langage

    Directory of Open Access Journals (Sweden)

    Paul Ricoeur

    2014-07-01

    Full Text Available This article presents an edited version of lectures given by Paul Ricœur at Johns Hopkins University in April 1966. Ricœur offers a comparative analysis of Wittgenstein’s and Husserl’s late works, taking the problem of language as the common ground of investigation for these two central figures of phenomenology and analytic philosophy. Ricœur develops his study in two parts. The first part considers Husserl’s approach to language after the Logical Investigations and concentrates on Formal and Transcendental Logic; leaving a transcendental reflection on language behind it re-examines a phenomenological conception, according to which the sphere of logic is not separable from that of experience. The main focus of the second part is Wittgenstein’s later philosophy as it moved on from the conception of an isomorphic relation between language and the world, as set out in the picture theory in the Tractatus Logico-Philosophicus, to the more pragmatic notion of a language-game in the Philosophical Investigations. In order to get beyond the irrevocable differences between the two philosophies and the unresolved theoretical issues on both sides, Ricœur suggests turning to a semiological paradigm based on the Saussurean distinction between “language” and “speaking.” Keyword: Analytic Philosophy, Husserl, Phenomenology, Semiology, Wittgenstein.  Résumé Cet article est une version éditée de conférences données par Paul Ricœur à la Johns Hopkins University en avril 1966. Ricœur propose une analyse comparée des dernières œuvres de Wittgenstein et Husserl, avec le problème du langage comme sol commun d’investigations pour ces deux figures centrales de la phénoménologie et la philosophie analytique. Cette analyse de Ricœur se joue à travers deux parties. La première partie revient sur l'approche du langage chez Husserl depuis Recherches logiques avec une attention particulière aux développements de Logique formelle et

  5. Integrating Usability Engineering in the Iterative Design Process of the Land Attack Combat System (LACS) Human Computer Interface (HCI)

    National Research Council Canada - National Science Library

    Borja, Ana T

    2004-01-01

    ...) for its intended purposes. This paper presents our approach of the usability engineering activities and the results from a 1-year Fiscal Year 2003 effort for the development of the LACS Human Computer Interface (HCI...

  6. Archive of Geosample Data and Information from the University of Minnesota National Lacustrine Core Repository (LacCore)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Lacustrine Core Repository (LacCore), operated by the University of Minnesota is a partner in the Index to Marine and Lacustrine Geological Samples...

  7. Vaincre le vampire violet | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Est depuis le début des années 1990 lorsque le Centre de recherches pour le développement international, une société d'État canadienne, l'a invité à se pencher sur le problème de la striga en Afrique subsaharienne.

  8. UVB-induced mutagenesis in hairless λlacZ-transgenic mice

    International Nuclear Information System (INIS)

    Frijhoff, A.F.W.; Rebel, H.; Mientjes, E.J.

    1997-01-01

    UVB-induced mutagenesis was studied in hairless 40.6 transgenic mice (Muta trademark Mouse), which contain the λgt1OlacZ shuttle vector as a target for mutagenesis. Mice were exposed at the dorsal side to either single doses of 200, 500, 800, or 1000 J/m 2 UVB or to two successive irradiations of either 200 and 800 J/m 2 UVB, with intervals of 1,3, or 5 days, or to 800 and 200 J/m 2 UVB with a 5-day interval. At 23 days after the last exposure, lacZ mutant frequencies (MF) were determined in the epidermis. The lacZ MF increased linearly with increasing dose of UVB. The mutagenic effect of two successive irradiations appeared to be additive. The UV-induced mutation spectrum was dominated by G:C→A:T transitions at dipyrimidine sites. DNA-sequence analysis of spontaneously mutated phages showed a diverse spectrum consisting of insertions, deletions and G:C → A:T transitions at CpG sites. the results indicate that the hairless λlacZ-transgenic mouse is a suitable in vivo model for studying UVB-induced mutations. 29 refs., 5 tabs

  9. STRUCTURED JETS IN BL LAC OBJECTS: EFFICIENT PeV NEUTRINO FACTORIES?

    Energy Technology Data Exchange (ETDEWEB)

    Tavecchio, Fabrizio; Ghisellini, Gabriele [INAF-Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807 Merate (Italy); Guetta, Dafne [INAF-Osservatorio astronomico di Roma, via Frascati 33, I-00040 Monte Porzio Catone (Italy)

    2014-09-20

    The origin of high-energy neutrinos (0.1–1 PeV range) detected by IceCube remains a mystery. In this work, we explore the possibility that efficient neutrino production can occur in structured jets of BL Lac objects, characterized by a fast inner spine surrounded by a slower layer. This scenario has been widely discussed in the framework of the high-energy emission models for BL Lac objects and radio galaxies. One of the relevant consequences of a velocity structure is the enhancement of the inverse Compton emission caused by the radiative coupling of the two zones. We show that a similar boosting could occur for the neutrino output of the spine through the photo-meson reaction of high-energy protons scattering off the amplified soft target photon field of the layer. Assuming the local density and the cosmological evolution of γ-ray BL Lac object derived from Fermi Large Area Telescope data, we calculate the expected diffuse neutrino intensity, which can match the IceCube data for a reasonable choice of parameters.

  10. Le paludisme au Mexique

    International Development Research Centre (IDRC) Digital Library (Canada)

    Nancy Minogue

    Le paludisme est depuis longtemps un important problème de santé publique au Mexique, où les conditions qui prévalent ... C'est dans les régions côtières que le problème a persisté le plus longtemps, les mesures ... recherche sur l'écologie des moustiques a permis d'en découvrir les raisons. « Les moustiques ne se ...

  11. Variabilité journalière de la qualité physico-chimique du lac M'koa ...

    African Journals Online (AJOL)

    d'enrichissement en matières organique, azote et phosphore capables d'influer sur la teneur de saturation en oxygène dissous. La Figure 4 montre des lavandiers communément appelés "fanico" exerçant leur activité quotidienne au lac. Cette activité est source d'enrichissement des eaux du lac. M'koa en phosphore et ...

  12. Le Jardin de Fleur

    Index Scriptorium Estoniae

    2008-01-01

    Ettevõtja Martin Reinsalu osalusel Marokosse kerkiv kuurortide kompleks Le Jardin de Fleur tunnistati CNBC Araabiamaade kinnisvaraarendusprojektide seas Maroko parimaks arendusprojektiks ning parimaks golfiarenduskeskuseks. Projekt toetub araabia arhitektuurile, mida on kombineeritud kaasaegse maroko disainiga

  13. Le CRDI en Tanzanie

    International Development Research Centre (IDRC) Digital Library (Canada)

    Il y a longtemps que le CRDI appuie la recherche en Tanzanie, une démocratie stable. Depuis la fin des années 1990, le pays jouit d'une croissance économique soutenue, bien qu'il demeure l'un des. États les plus pauvres de la planète. Ses gouvernements successifs ont reconnu que la réduction de la pauvreté passait ...

  14. Le CRDI au Mali

    International Development Research Centre (IDRC) Digital Library (Canada)

    contre le paludisme n les chercheurs contribuent à l'amélioration des services de santé n de jeunes femmes participent à la vie politique. Soutien accordé par le CRDI depuis 1971. 93 activités d'une valeur de 15 millions cad. Les chercheurs ont aidé à offrir l'enseignement primaire dans les langues maternelles. CRDI.

  15. Le CRDI au Maroc

    International Development Research Centre (IDRC) Digital Library (Canada)

    démocratiques. Au Maroc, le Centre d'études et de recherches en sciences sociales analyse ce que pourrait être la réaction du gouverne- ment aux pressions exercées par la population en vue d'un changement sur le plan politique. Rabat. Casablanca. Marrakech. Tan-Tan. Bou Arfa. Zagora. Oujda. Tanger. Fès. ALGÉRIE.

  16. Le CRDI en Afghanistan

    International Development Research Centre (IDRC) Digital Library (Canada)

    Depuis près de 40 ans, le CRDI collabore étroitement avec les chercheurs des pays en développement et les appuie dans leur quête de moyens de créer des sociétés en meilleure santé, plus équitables et plus prospères. Centre de recherches pour le développement international. CP 8500, Ottawa (Ontario) Canada K1G ...

  17. Le CRDI au Bhoutan

    International Development Research Centre (IDRC) Digital Library (Canada)

    Il en résulte des solutions locales, novatrices et durables, qui offrent des choix aux personnes qui en ont le plus besoin et font changer les choses. Centre de recherches pour le développement international. CP 8500, Ottawa (Ontario) Canada K1G 3H9. Pour en savoir plus, consulter la page. Web du Bureau régional de ...

  18. Le CRDI au Kenya

    International Development Research Centre (IDRC) Digital Library (Canada)

    afin d'y favoriser la croissance et le développement. Il en résulte des solutions novatrices et durables qui ont pour but d'améliorer les conditions de vie et les moyens de subsistance. Centre de recherches pour le développement international. CP 8500, Ottawa (Ontario) Canada K1G 3H9. Pour en savoir plus, consulter.

  19. Le CRDI en Jordanie

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... dans les pays en développement afin d'y favoriser la croissance et le développement. Il en résulte des solutions novatrices et durables qui ont pour but d'améliorer les conditions de vie et les moyens de subsistance. Centre de recherches pour le développement international. CP 8500, Ottawa (Ontario) Canada K1G 3H9.

  20. Le CRDI en Bolivie

    International Development Research Centre (IDRC) Digital Library (Canada)

    plus grandes responsabilités aux munici- palités en matière de développement économique. De 2002 à 2007, le CRDI a appuyé la collaboration entre l'Atlantic. Community Economic Development. Institute, de Halifax, en Nouvelle-Écosse, et deux organismes boliviens, le Centro de Servicios Agropecuarios Técnicos, du.

  1. Reduction of forecast uncertainty in the context of hydropower production: a case study for two catchment in Lac-St-Jean, Canada

    Science.gov (United States)

    Brisson, Cathy; Boucher, Marie-Amélie; Latraverse, Marco

    2014-05-01

    locations (intermediate location and downstream) leads to improved forecasts, as measured by the Nash-Sutcliffe efficiency criterion. The parameter sets thus determined best represent the phenomena of exchange and runoff in the watershed. Second, this study aims at reducing the uncertainty associated to the evacuation function for the Bonnard channel as well as the time delay related to this transfer. Instead of using a fixed 2-day time delay for the transfer, it was attempted to represent the channel in the hydrological model CEQUEAU and compute the time delay from this model. The results show that hydrological modelling does not improve the results and that the 2-day time delay is adequate, especially for first days of opening and few days after closure of the gate. In addition, this research shows that the evacuation function of Bonnard spillway is inexact for large streamflows. It is considered the main source of uncertainty for the prediction of inflows to the reservoirs. We also show that the evacuated streamflows can be successfully corrected by hydrological modelling. This case study shows that a careful revision of the inflow forecasting process for those important watersheds can help reduce predictive uncertainty. Although the application is specific to the Lac-St-Jean area, we believe that our experience could serve other users and water managers with similar issues regarding inflow uncertainty. Reference Morin, G., J.-P. Fortin, J.-P. Lardeau, W. Sochanska and S. Paquette. 1981. Modèle CEQUEAU : Manuel d'utilisation. Rapport de recherche no R-93, INRS-Eau, Sainte-Foy

  2. Le faussaire roman

    CERN Document Server

    D'Anna, Gianfranco

    2016-01-01

    À l'aube du XXIe siècle, le monde de la science est sur le point de vivre une révolution. Le jeune physicien allemand Albert Hendrick Thebell, des célèbres laboratoires de recherche B-Labs, à Summit, dans le New Jersey, publie, dans les plus grandes revues scientifiques internationales, une série d'articles dans lesquels il prétend avoir obtenu des résultats extraordinaires qui pourraient révolutionner les bases mêmes de la technologie. Rapidement, la communauté scientifique puis les médias saluent en lui un futur prix Nobel; on compare même son génie à celui d'Albert Einstein. Le progrès scientifique semble avoir franchi une étape décisive, susceptible d'amener un futur meilleur. Mais ces découvertes sont-elles authentiques ? Car pendant ce temps, dans les mêmeslaboratoires, des voix s'élèvent pour contester non seulement les théories de Thebell mais aussi la légitimité même de ses expériences ; certains le soupçonnent d'avoir combiné la plus grande fraude scientifique de tous l...

  3. Effector Overlap between the lac and mel Operons of Escherichia coli: Induction of the mel Operon with β-Galactosides

    Science.gov (United States)

    Narang, Atul

    2017-01-01

    ABSTRACT The lac (lactose) operon (which processes β-galactosides) and the mel (melibiose) operon (which processes α-galactosides) of Escherichia coli have a close historical connection. A number of shared substrates and effectors of the permeases and regulatory proteins have been reported over the years. Until now, β-thiogalactosides like TMG (methyl-β-d-thiogalactopyranoside) and IPTG (isopropyl-β-d-thiogalactopyranoside) have not generally been considered to be inducers of the mel operon. The same is true for β-galactosides such as lactose [β-d-galactopyranosyl-(1→4)-d-glucose], which is a substrate but is not itself an inducer of the lac operon. This report shows that all three sugars can induce the mel operon significantly when they are accumulated in the cell by Lac permease. Strong induction by β-thiogalactosides is observed in the presence of Lac permease, and strong induction by lactose (more than 200-fold) is observed in the absence of β-galactosidase. This finding calls for reevaluation of TMG uptake experiments as assays for Lac permease that were performed with mel+ strains. IMPORTANCE The typical textbook picture of bacterial operons is that of stand-alone units of genetic information that perform, in a regulated manner, well-defined cellular functions. Less attention is given to the extensive interactions that can be found between operons. Well-described examples of such interactions are the effector molecules shared by the lac and mel operons. Here, we show that this set has to be extended to include β-galactosides, which have been, until now, considered not to effect the expression of the mel operon. That they can be inducers of the mel operon as well as the lac operon has not been noted in decades of research because of the Escherichia coli genetic background used in previous studies. PMID:28193904

  4. Expression Cloning of Recombinant Escherichia coli lacZ Genes Encoding Cytoplasmic and Nuclear β-galactosidase Variants.

    Science.gov (United States)

    Naderian, Homayoun; Rezvani, Zahra; Atlasi, Mohammad Ali; Nikzad, Hossein; Antoine, Af de Vries

    2011-07-01

    Nonviral vector can be an attractive alternative to gene delivery in experimental study. In spite of some advantages in comparison with the viral vectors, there are still some limitations for efficiency of gene delivery in nonviral vectors. To determine the effective expression, the recombinant Escherichia coli lacZ genes were cloned into the different variants of pcDNA3.1 and then the mammalian cells were transfected. The coding sequences of cytoplasmic and nuclear variants of lacZ gene were inserted downstream of the human cytomegalovirus immediate-early gene promoter of plasmid pcDNA3.1/myc-His C. The new cytoplasmic and nuclear constricts of E. coli β-galactosidase-coding sequences were introduced into HeLa cells with the aid of linear polyethylenimine and at 2 days post-transfection the cells were stained using 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (X-gal). Restriction enzyme analyses revealed the proper insertion of E. coli β-galactosidase-coding sequences into the multiple cloning site of pcDNA3.1/myc-His C. The functionality of the resulting constructs designated pcDNA3.1-cyt.lacZ and pcDNA3.1-nls.lacZ(+) was confirmed by X-gal staining of HeLa cells transfected with these recombinant plasmids. While pcDNA3.1-cyt.lacZ directed the synthesis of cytoplasmically located β-galactosidase molecules, the β-galactosidase protein encoded by pcDNA3.1-nls.lacZ(+) was predominantly detected in the cell nucleus. The expression of cytoplasmic and nuclear variant of LacZ gene confirmed the ability of pcDNA3.1 as versatility nonviral vector for the experimental gene delivery study in mammalian cells.

  5. Effector Overlap between the lac and mel Operons of Escherichia coli: Induction of the mel Operon with β-Galactosides.

    Science.gov (United States)

    Narang, Atul; Oehler, Stefan

    2017-05-01

    The lac (lactose) operon (which processes β-galactosides) and the mel (melibiose) operon (which processes α-galactosides) of Escherichia coli have a close historical connection. A number of shared substrates and effectors of the permeases and regulatory proteins have been reported over the years. Until now, β-thiogalactosides like TMG (methyl-β-d-thiogalactopyranoside) and IPTG (isopropyl-β-d-thiogalactopyranoside) have not generally been considered to be inducers of the mel operon. The same is true for β-galactosides such as lactose [β-d-galactopyranosyl-(1→4)-d-glucose], which is a substrate but is not itself an inducer of the lac operon. This report shows that all three sugars can induce the mel operon significantly when they are accumulated in the cell by Lac permease. Strong induction by β-thiogalactosides is observed in the presence of Lac permease, and strong induction by lactose (more than 200-fold) is observed in the absence of β-galactosidase. This finding calls for reevaluation of TMG uptake experiments as assays for Lac permease that were performed with mel + strains. IMPORTANCE The typical textbook picture of bacterial operons is that of stand-alone units of genetic information that perform, in a regulated manner, well-defined cellular functions. Less attention is given to the extensive interactions that can be found between operons. Well-described examples of such interactions are the effector molecules shared by the lac and mel operons. Here, we show that this set has to be extended to include β-galactosides, which have been, until now, considered not to effect the expression of the mel operon. That they can be inducers of the mel operon as well as the lac operon has not been noted in decades of research because of the Escherichia coli genetic background used in previous studies. Copyright © 2017 American Society for Microbiology.

  6. The SOS-LUX-LAC-FLUORO-Toxicity-test on the International Space Station (ISS).

    Science.gov (United States)

    Rabbow, E; Rettberg, P; Baumstark-Khan, C; Horneck, G

    2003-01-01

    In the 21st century, an increasing number of astronauts will visit the International Space Station (ISS) for prolonged times. Therefore it is of utmost importance to provide necessary basic knowledge concerning risks to their health and their ability to work on the station and during extravehicular activities (EVA) in free space. It is the aim of one experiment of the German project TRIPLE-LUX (to be flown on the ISS) to provide an estimation of health risk resulting from exposure of the astronauts to the radiation in space inside the station as well as during extravehicular activities on one hand, and of exposure of astronauts to unavoidable or as yet unknown ISS-environmental genotoxic substances on the other. The project will (i) provide increased knowledge of the biological action of space radiation and enzymatic repair of DNA damage, (ii) uncover cellular mechanisms of synergistic interaction of microgravity and space radiation and (iii) examine the space craft milieu with highly specific biosensors. For these investigations, the bacterial biosensor SOS-LUX-LAC-FLUORO-Toxicity-test will be used, combining the SOS-LUX-Test invented at DLR Germany (Patent) with the commercially available LAC-FLUORO-Test. The SOS-LUX-Test comprises genetically modified bacteria transformed with the pBR322-derived plasmid pPLS-1. This plasmid carries the promoterless lux operon of Photobacterium leiognathi as a reporter element under control of the DNA-damage dependent SOS promoter of ColD as sensor element. This system reacts to radiation and other agents that induce DNA damages with a dose dependent measurable emission of bioluminescence of the transformed bacteria. The analogous LAC-FLUORO-Test has been developed for the detection of cellular responses to cytotoxins. It is based on the constitutive expression of green fluorescent protein (GFP) mediated by the bacterial protein expression vector pGFPuv (Clontech, Palo Alto, USA). In response to cytotoxic agents, this system

  7. Le modèle basque

    Directory of Open Access Journals (Sweden)

    Juan-Angel PORTUGAL

    1986-12-01

    Full Text Available À l'intérieur du quadrilatère basque se dessine un sous-espace triangulaire dont les sommets sont les capitales provinciales; les côtés délimitent une aire prospère. La localisation de ces trois noyaux résulte d'une décision politico-économique et d'une diffusion de l'industrialisation. Ce triangle est un espace dynamique et attractif, autant dans le domaine de la démographie que du développement économique et industriel.

  8. Le Carnaval de Schignano : un dernier salut aux émigrants

    Directory of Open Access Journals (Sweden)

    Cristina Del Biaggio

    2011-05-01

    Full Text Available Pour arriver à Schignano, il faut passer par una cürva al giazz e una cürva al suu [Un virage dans la glace et un virage au soleil], comme disent les mots en dialecte d’une récente chanson écrite par Davide Van De Sfroos, compositeur-interprète de la région. C’est dans ce petit hameau de la Vallée d’Intelvi, au-dessus du Lac de Côme, que, tous les ans, le carnaval anime le village. Une fête populaire spontanée, sans règles écrites, ni lois, qui survit grâce aux habitants qui l’animent, aux ar...

  9. Documentaire : « Le Cauchemar de Darwin ? »

    OpenAIRE

    Bart, François

    2008-01-01

    Avec son titre destiné à frapper le spectateur, ce documentaire autrichien d’1 heure 47 minutes, sorti sur les écrans français au début de mars 2005, présente un très grand intérêt pour tous ceux qui s’intéressent, au-delà du problème écologique qui sert de support à la démonstration du réalisateur Hubert Sauper, aux problèmes de développement en Afrique. Le cadre géographique est la ville de Mwanza, sur la rive sud du lac Victoria, en Afrique orientale, dans une région périphérique d’un pays...

  10. The effect of stochasticity on the lac operon: an evolutionary perspective.

    Science.gov (United States)

    van Hoek, Milan; Hogeweg, Paulien

    2007-06-01

    The role of stochasticity on gene expression is widely discussed. Both potential advantages and disadvantages have been revealed. In some systems, noise in gene expression has been quantified, in among others the lac operon of Escherichia coli. Whether stochastic gene expression in this system is detrimental or beneficial for the cells is, however, still unclear. We are interested in the effects of stochasticity from an evolutionary point of view. We study this question in the lac operon, taking a computational approach: using a detailed, quantitative, spatial model, we evolve through a mutation-selection process the shape of the promoter function and therewith the effective amount of stochasticity. We find that noise values for lactose, the natural inducer, are much lower than for artificial, nonmetabolizable inducers, because these artificial inducers experience a stronger positive feedback. In the evolved promoter functions, noise due to stochasticity in gene expression, when induced by lactose, only plays a very minor role in short-term physiological adaptation, because other sources of population heterogeneity dominate. Finally, promoter functions evolved in the stochastic model evolve to higher repressed transcription rates than those evolved in a deterministic version of the model. This causes these promoter functions to experience less stochasticity in gene expression. We show that a high repression rate and hence high stochasticity increases the delay in lactose uptake in a variable environment. We conclude that the lac operon evolved such that the impact of stochastic gene expression is minor in its natural environment, but happens to respond with much stronger stochasticity when confronted with artificial inducers. In this particular system, we have shown that stochasticity is detrimental. Moreover, we demonstrate that in silico evolution in a quantitative model, by mutating the parameters of interest, is a promising way to unravel the functional

  11. The effect of stochasticity on the lac operon: an evolutionary perspective.

    Directory of Open Access Journals (Sweden)

    Milan van Hoek

    2007-06-01

    Full Text Available The role of stochasticity on gene expression is widely discussed. Both potential advantages and disadvantages have been revealed. In some systems, noise in gene expression has been quantified, in among others the lac operon of Escherichia coli. Whether stochastic gene expression in this system is detrimental or beneficial for the cells is, however, still unclear. We are interested in the effects of stochasticity from an evolutionary point of view. We study this question in the lac operon, taking a computational approach: using a detailed, quantitative, spatial model, we evolve through a mutation-selection process the shape of the promoter function and therewith the effective amount of stochasticity. We find that noise values for lactose, the natural inducer, are much lower than for artificial, nonmetabolizable inducers, because these artificial inducers experience a stronger positive feedback. In the evolved promoter functions, noise due to stochasticity in gene expression, when induced by lactose, only plays a very minor role in short-term physiological adaptation, because other sources of population heterogeneity dominate. Finally, promoter functions evolved in the stochastic model evolve to higher repressed transcription rates than those evolved in a deterministic version of the model. This causes these promoter functions to experience less stochasticity in gene expression. We show that a high repression rate and hence high stochasticity increases the delay in lactose uptake in a variable environment. We conclude that the lac operon evolved such that the impact of stochastic gene expression is minor in its natural environment, but happens to respond with much stronger stochasticity when confronted with artificial inducers. In this particular system, we have shown that stochasticity is detrimental. Moreover, we demonstrate that in silico evolution in a quantitative model, by mutating the parameters of interest, is a promising way to unravel

  12. Fermi Transient J1544–0649: A Flaring Radio-weak BL Lac

    Science.gov (United States)

    Bruni, Gabriele; Panessa, Francesca; Ghisellini, Gabriele; Chavushyan, Vahram; Peña-Herazo, Harold A.; Hernández-García, Lorena; Bazzano, Angela; Ubertini, Pietro; Kraus, Alex

    2018-02-01

    On 2017 May 15, the FERMI/LAT gamma-ray telescope observed a transient source not present in any previous high-energy catalog: J1544–0649. It was visible for two consecutive weeks, with a flux peak on May 21. Subsequently observed by a Swift/XRT follow-up starting on May 26, the X-ray counterpart position was coincident with the optical transient ASASSN-17gs = AT2017egv, detected on May 25, with a potential host galaxy at z = 0.171. We conducted a 4-month follow-up in radio (Effelsberg-100 m) and optical (San Pedro Mártir, 2.1 m) bands, in order to build the overall Spectral Energy Distribution (SED) of this object. The radio data from 5 to 15 GHz confirmed the flat spectrum of the source, favoring a line of sight close to the jet axis, not showing significant variability in the explored post-burst time window. The Rx ratio, a common indicator of radio loudness, gives a value at the border between the radio-loud and radio-quiet active galactic nuclei (AGNs) populations. The CaII H&K break value (0.29 ± 0.05) is compatible with the range expected for the long-sought intermediate population between BL Lacs and FRI radio galaxies. An overall SED fitting from the radio to gamma-ray band shows properties typical of a low-power BL Lac. As a whole, these results suggest that this transient could be a new example of the recently discovered class of radio-weak BL Lac, showing for the first time a flare in the gamma/X-ray bands.

  13. Analysis of spontaneous deletions and gene amplification in the lac region of Escherichia coli

    International Nuclear Information System (INIS)

    Albertini, A.M.; Hofer, M.; Calos, M.P.; Tlsty, T.D.; Miller, J.H.

    1983-01-01

    Spontaneous rearrangements, such as large deletions and duplications, have important implications for the structure of the genome. It is therefore of great interest to analyze these events at the molecular level. We have constructed derivatives of a lacI-Z fusion strain, which allow us to study deletions in a more systematic manner than was previously possible. These derivatives have been used to investigate how frequently larger deletions (> 700 bp) occur between short homologies on both recA and recA - strains and to determine the effect of the lengths of the short homologies and of the distance between homologies on the frequency of deletion formation. 38 references, 11 figures

  14. Lac du Flambeau Band of Lake Superior Chippewa Indians Strategic Energy Plan

    Energy Technology Data Exchange (ETDEWEB)

    Bryan Hoover

    2009-11-16

    This plan discusses the current energy use on the Lac du Flambeau Reservation, the current status of the Tribe's energy program, as well as the issues and concerns with energy on the reservation. This plan also identifies and outlines energy opportunities, goals, and objectives for the Tribe to accomplish. The overall goal of this plan is to address the energy situation of the reservation in a holistic manner for the maximum benefit to the Tribe. This plan is an evolving document that will be re-evaluated as the Tribe's energy situation changes.

  15. Thermal cracking in Lac du Bonnet granite during slow heating to 205 degrees celsius

    International Nuclear Information System (INIS)

    Chernis, P.J.; Robertson, P.B.

    1993-09-01

    Acoustic emissions (AE) were recorded as drill core samples of Lac du Bonnet granite were slowly heated to between 66 and 205 degrees celsius to evaluate the effects of temperature on the properties of rock samples. Longitudinal and shear velocities of the samples were measured, and Young's moduli, shear moduli and Poisson's ratios were calculated. No significant AE activity was detected until temperatures reached approximately 73-80 degrees celsius. Above this 'threshold' temperature, calculated rock properties decreased, and at 205 degrees celsius calculated Young's modulus, shear modulus, and Poisson's ratio were reduced by 30, 26, and 29% respectively

  16. Hopf Bifurcation and Delay-Induced Turing Instability in a Diffusive lac Operon Model

    Science.gov (United States)

    Cao, Xin; Song, Yongli; Zhang, Tonghua

    In this paper, we investigate the dynamics of a lac operon model with delayed feedback and diffusion effect. If the system is without delay or the delay is small, the positive equilibrium is stable so that there are no spatial patterns formed; while the time delay is large enough the equilibrium becomes unstable so that rich spatiotemporal dynamics may occur. We have found that time delay can not only incur temporal oscillations but also induce imbalance in space. With different initial values, the system may have different spatial patterns, for instance, spirals with one head, four heads, nine heads, and even microspirals.

  17. Le sens du portrait.

    Directory of Open Access Journals (Sweden)

    Christophe Apprill

    2007-01-01

    Full Text Available À l’entrée du vieux port de Marseille, le projet Euroméditerranée prévoit la construction d’un musée, le Musée des Civilisations de l’Europe et de la Méditerranée (M ucem . Il accueillera les anciennes collections du Musée National des Arts et Traditions Populaires (M natp que les badauds en promenade au jardin d’acclimatation croisaient sans le savoir. Un concours d’architecture a été lancé, remporté par un architecte de la région, Rudy Riccioti. Son projet ...

  18. Le stockage inertiel

    OpenAIRE

    KAUV, J; BONAL, J

    2010-01-01

    La fourniture d'une énergie propre et abondante à une population mondiale largement appelée à croître va être un défi considérable pour le XXIe siècle. Aujourd'hui nous dépendons encore considérablement des énergies fossiles, certes très énergétiques et d'utilisation commode, mais épuisables et productrices de CO2 responsable du réchauffement climatique. Le stockage d'énergie électrique et de chaleur est un domaine technique difficile et délicat, mais dont le développement est indispensable p...

  19. Le Nouveau Monde

    Directory of Open Access Journals (Sweden)

    Alain Musset

    2006-04-01

    Full Text Available L’histoire de la conquête du Nouveau Monde par les Européens semble devoir se résumer au destin de deux femmes chargées d’assurer le truchement entre les deux mondes et de jouer lele d’intermédiaire amoureuse ou de grande traîtresse : au Nord, Pocahontas, au Sud, La Malinche. Quand Cortés débarque en 1519 sur les côtes du Tabasco, un cacique désireux de lui plaire lui offre vingt femmes dont une superbe jeune fille, Malintzin (la Malinche, rebaptisée Marina. Celle-ci deviendra sa maîtres...

  20. High-level expression of Bacillus naganoensis pullulanase from recombinant Escherichia coli with auto-induction: effect of lac operator.

    Directory of Open Access Journals (Sweden)

    Yao Nie

    Full Text Available Pullulanase plays an important role in specific hydrolysis of branch points in amylopectin and is generally employed as an important enzyme in starch-processing industry. So far, however, the production level of pullulanase is still somewhat low from wide-type strains and even heterologous expression systems. Here the gene encoding Bacillus naganoensis pullulanase was amplified and cloned. For expression of the protein, two recombinant systems, Escherichia coli BL21(DE3/pET-20b(+-pul and E. coli BL21(DE3/pET-22b(+-pul, were constructed, both bearing T7 promoter and signal peptide sequence, but different in the existance of lac operator and lacI gene encoding lac repressor. Recombinant pullulanase was initially expressed with the activity of up to 14 U/mL by E. coli BL21(DE3/pET-20b(+-pul with IPTG induction in LB medium, but its expression level reduced continually with the extension of cryopreservation time and basal expression was observed. However, E. coli BL21(DE3/pET-22b(+-pul , involving lac operator downstream of T7 promoter to regulate foreign gene transcription, exhibited pullulanase activity consistently without detected basal expression. By investigating the effect of lac operator, basal expression of foreign protein was found to cause expression instability and negative effect on production of target protein. Thus double-repression strategy was proposed that lac operators in both chromosome and plasmid were bound with lac repressor to repress T7 RNA polymerase synthesis and target protein expression before induction. Consequently, the total activity of pullulanase was remarkably increased to 580 U/mL with auto-induction by lac operator-involved E. coli BL21(DE3/pET-22b(+-pul. When adding 0.6% glycine in culture, the extracellular production of pullulanase was significantly improved with the extracellular activity of 502 U/mL, which is a relatively higher level achieved to date for extracellular production of pullulanase. The

  1. What makes the lac-pathway switch: identifying the fluctuations that trigger phenotype switching in gene regulatory systems.

    Science.gov (United States)

    Bhogale, Prasanna M; Sorg, Robin A; Veening, Jan-Willem; Berg, Johannes

    2014-10-01

    Multistable gene regulatory systems sustain different levels of gene expression under identical external conditions. Such multistability is used to encode phenotypic states in processes including nutrient uptake and persistence in bacteria, fate selection in viral infection, cell-cycle control and development. Stochastic switching between different phenotypes can occur as the result of random fluctuations in molecular copy numbers of mRNA and proteins arising in transcription, translation, transport and binding. However, which component of a pathway triggers such a transition is generally not known. By linking single-cell experiments on the lactose-uptake pathway in E. coli to molecular simulations, we devise a general method to pinpoint the particular fluctuation driving phenotype switching and apply this method to the transition between the uninduced and induced states of the lac-genes. We find that the transition to the induced state is not caused only by the single event of lac-repressor unbinding, but depends crucially on the time period over which the repressor remains unbound from the lac-operon. We confirm this notion in strains with a high expression level of the lac-repressor (leading to shorter periods over which the lac-operon remains unbound), which show a reduced switching rate. Our techniques apply to multistable gene regulatory systems in general and allow to identify the molecular mechanisms behind stochastic transitions in gene regulatory circuits. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  2. The effect of LacI autoregulation on the performance of the lactose utilization system in Escherichia coli.

    Science.gov (United States)

    Semsey, Szabolcs; Jauffred, Liselotte; Csiszovszki, Zsolt; Erdossy, János; Stéger, Viktor; Hansen, Sabine; Krishna, Sandeep

    2013-07-01

    The lactose operon of Escherichia coli is a paradigm system for quantitative understanding of gene regulation in prokaryotes. Yet, none of the many mathematical models built so far to study the dynamics of this system considered the fact that the Lac repressor regulates its own transcription by forming a transcriptional roadblock at the O3 operator site. Here we study the effect of autoregulation on intracellular LacI levels and also show that cAMP-CRP binding does not affect the efficiency of autoregulation. We built a mathematical model to study the role of LacI autoregulation in the lactose utilization system. Previously, it has been argued that negative autoregulation can significantly reduce noise as well as increase the speed of response. We show that the particular molecular mechanism, a transcriptional roadblock, used to achieve self-repression in the lac system does neither. Instead, LacI autoregulation balances two opposing states, one that allows quicker response to smaller pulses of external lactose, and the other that minimizes production costs in the absence of lactose.

  3. The effect of LacI autoregulation on the performance of the lactose utilization system in Escherichia coli

    Science.gov (United States)

    Semsey, Szabolcs; Jauffred, Liselotte; Csiszovszki, Zsolt; Erdőssy, János; Stéger, Viktor; Hansen, Sabine; Krishna, Sandeep

    2013-01-01

    The lactose operon of Escherichia coli is a paradigm system for quantitative understanding of gene regulation in prokaryotes. Yet, none of the many mathematical models built so far to study the dynamics of this system considered the fact that the Lac repressor regulates its own transcription by forming a transcriptional roadblock at the O3 operator site. Here we study the effect of autoregulation on intracellular LacI levels and also show that cAMP-CRP binding does not affect the efficiency of autoregulation. We built a mathematical model to study the role of LacI autoregulation in the lactose utilization system. Previously, it has been argued that negative autoregulation can significantly reduce noise as well as increase the speed of response. We show that the particular molecular mechanism, a transcriptional roadblock, used to achieve self-repression in the lac system does neither. Instead, LacI autoregulation balances two opposing states, one that allows quicker response to smaller pulses of external lactose, and the other that minimizes production costs in the absence of lactose. PMID:23658223

  4. Bistable behavior in a model of the lac operon in Escherichia coli with variable growth rate.

    Science.gov (United States)

    Santillán, M

    2008-03-15

    This work is a continuation from another study previously published in this journal. Both the former and the present works are dedicated to investigating the bistable behavior of the lac operon in Escherichia coli from a mathematical modeling point of view. In the previous article, we developed a detailed mathematical model that accounts for all of the known regulatory mechanisms in this system, and studied the effect of inducing the operon with lactose instead of an artificial inducer. In this article, the model is improved to account, in a more detailed way, for the interaction of the repressor molecules with the three lac operators. A recently discovered cooperative interaction between the CAP molecule (an activator of the lactose operon) and Operator 3 (which influences DNA folding) is also included in this new version of the model. The growth rate dependence on the rate of energy entering the bacteria (in the form of transported glucose molecules and of metabolized lactose molecules) is also considered. A large number of numerical experiments is carried out with this improved model. The results are discussed in regard to the bistable behavior of the lactose operon. Special attention is paid to the effect that a variable growth rate has on the system dynamics.

  5. In vitro transcription accurately predicts lac repressor phenotype in vivo in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Matthew Almond Sochor

    2014-07-01

    Full Text Available A multitude of studies have looked at the in vivo and in vitro behavior of the lac repressor binding to DNA and effector molecules in order to study transcriptional repression, however these studies are not always reconcilable. Here we use in vitro transcription to directly mimic the in vivo system in order to build a self consistent set of experiments to directly compare in vivo and in vitro genetic repression. A thermodynamic model of the lac repressor binding to operator DNA and effector is used to link DNA occupancy to either normalized in vitro mRNA product or normalized in vivo fluorescence of a regulated gene, YFP. An accurate measurement of repressor, DNA and effector concentrations were made both in vivo and in vitro allowing for direct modeling of the entire thermodynamic equilibrium. In vivo repression profiles are accurately predicted from the given in vitro parameters when molecular crowding is considered. Interestingly, our measured repressor–operator DNA affinity differs significantly from previous in vitro measurements. The literature values are unable to replicate in vivo binding data. We therefore conclude that the repressor-DNA affinity is much weaker than previously thought. This finding would suggest that in vitro techniques that are specifically designed to mimic the in vivo process may be necessary to replicate the native system.

  6. An Analysis of Periodic Components in BL Lac Object S5 0716 +714 with MUSIC Method

    Science.gov (United States)

    Tang, J.

    2012-01-01

    Multiple signal classification (MUSIC) algorithms are introduced to the estimation of the period of variation of BL Lac objects.The principle of MUSIC spectral analysis method and theoretical analysis of the resolution of frequency spectrum using analog signals are included. From a lot of literatures, we have collected a lot of effective observation data of BL Lac object S5 0716 + 714 in V, R, I bands from 1994 to 2008. The light variation periods of S5 0716 +714 are obtained by means of the MUSIC spectral analysis method and periodogram spectral analysis method. There exist two major periods: (3.33±0.08) years and (1.24±0.01) years for all bands. The estimation of the period of variation of the algorithm based on the MUSIC spectral analysis method is compared with that of the algorithm based on the periodogram spectral analysis method. It is a super-resolution algorithm with small data length, and could be used to detect the period of variation of weak signals.

  7. Dynamics and bistability in a reduced model of the lac operon

    Science.gov (United States)

    Yildirim, Necmettin; Santillán, Moisés; Horike, Daisuke; Mackey, Michael C.

    2004-06-01

    It is known that the lac operon regulatory pathway is capable of showing bistable behavior. This is an important complex feature, arising from the nonlinearity of the involved mechanisms, which is essential to understand the dynamic behavior of this molecular regulatory system. To find which of the mechanisms involved in the regulation of the lac operon is the origin of bistability, we take a previously published model which accounts for the dynamics of mRNA, lactose, allolactose, permease and β-galactosidase involvement and simplify it by ignoring permease dynamics (assuming a constant permease concentration). To test the behavior of the reduced model, three existing sets of data on β-galactosidase levels as a function of time are simulated and we obtain a reasonable agreement between the data and the model predictions. The steady states of the reduced model were numerically and analytically analyzed and it was shown that it may indeed display bistability, depending on the extracellular lactose concentration and growth rate.

  8. Intelligent Local Avoided Collision (iLAC) MAC Protocol for Very High Speed Wireless Network

    Science.gov (United States)

    Hieu, Dinh Chi; Masuda, Akeo; Rabarijaona, Verotiana Hanitriniala; Shimamoto, Shigeru

    Future wireless communication systems aim at very high data rates. As the medium access control (MAC) protocol plays the central role in determining the overall performance of the wireless system, designing a suitable MAC protocol is critical to fully exploit the benefit of high speed transmission that the physical layer (PHY) offers. In the latest 802.11n standard [2], the problem of long overhead has been addressed adequately but the issue of excessive colliding transmissions, especially in congested situation, remains untouched. The procedure of setting the backoff value is the heart of the 802.11 distributed coordination function (DCF) to avoid collision in which each station makes its own decision on how to avoid collision in the next transmission. However, collision avoidance is a problem that can not be solved by a single station. In this paper, we introduce a new MAC protocol called Intelligent Local Avoided Collision (iLAC) that redefines individual rationality in choosing the backoff counter value to avoid a colliding transmission. The distinguishing feature of iLAC is that it fundamentally changes this decision making process from collision avoidance to collaborative collision prevention. As a result, stations can avoid colliding transmissions with much greater precision. Analytical solution confirms the validity of this proposal and simulation results show that the proposed algorithm outperforms the conventional algorithms by a large margin.

  9. Northern hemisphere mid-latitude geomagnetic anomaly revealed from Levantine Archaeomagnetic Compilation (LAC).

    Science.gov (United States)

    Shaar, R.; Tauxe, L.; Agnon, A.; Ben-Yosef, E.; Hassul, E.

    2015-12-01

    The rich archaeological heritage of Israel and nearby Levantine countries provides a unique opportunity for archaeomagnetic investigation in high resolution. Here we present a summary of our ongoing effort to reconstruct geomagnetic variations of the past several millennia in the Levant at decadal to millennial resolution. This effort at the Southern Levant, namely the "Levantine Archaeomagnetic Compilation" (LAC), presently consists of data from over 650 well-dated archaeological objects including pottery, slag, ovens, and furnaces. In this talk we review the methodological challenges in achieving a robust master secular variation curve with realistic error estimations from a large number of different datasets. We present the current status of the compilation, including the southern and western Levant LAC data (Israel, Cyprus, and Jordan) and other published north-eastern Levant data (Syria and southern Turkey), and outline the main findings emerging from these data. The main feature apparent from the new compilation is an extraordinary intensity high that developed over the Levant region during the first two millennia BCE. The climax of this event is a double peak intensity maximum starting at ca. 1000 BCE and ending at ca. 735 BCE, accompanied with at least two events of geomagnetic spikes. Paleomagnetic directions from this period demonstrate anomalies of up to 20 degrees far from the averaged GAD field. This leads us to postulate that the maximum in the intensity is a manifestation of an intense mid-latitude local positive geomagnetic anomaly that persisted for over two centuries.

  10. Enhanced resistance of Saccharomyces cerevisiae to vanillin by expression of lacA from Trametes sp. AH28-2.

    Science.gov (United States)

    Ji, Lei; Shen, Yu; Xu, Lili; Peng, Bingyin; Xiao, Yazhong; Bao, Xiaoming

    2011-09-01

    Saccharomyces cerevisiae is affected by the presence of certain phenolic compounds such as vanillin during fermentation of pretreated lignocellulosic hydrolysates. Since vanillin can be polymerized in the presence of laccase into compounds with lower toxicity, the laccase gene, lacA, from Trametes sp. AH28-2 was fused to the α-factor signal sequence and transferred into S. cerevisiae CEN.PK strains for secretory expression. Furthermore, the chaperone gene, KAR2, was overexpressed to promote the translocation of laccase. In the presence of 8 mmol/L vanillin, a shorter lag phase was observed in the lacA gene expressing strains. The vanillin-specific conversion rate of the lacA-expressing strain BSJX0A2 was 0.069 g g(-1)biomass h(-1), while it was 0.065 g g(-1)biomass h(-1) in the reference strain. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Hydrogeologic characteristics of domains of sparsely fractured rock in the granitic Lac Du Bonnet Batholith, southeastern Manitoba, Canada

    International Nuclear Information System (INIS)

    Stevenson, D.R.; Kozak, E.T.; Davison, C.C.; Gascoyne, M.; Broadfoot, R.A.

    1996-06-01

    The hydrogeologic characteristics of the granitic Lac du Bonnet batholith in southeastern Manitoba have been studied since 1978, as part of AECL's program to assess the concept of disposing of Canada's nuclear fuel waste deep within plutonic rocks of the Canadian Shield (Davison et al. 1994a). These studies have included an extensive program of drilling, logging, testing, sampling and monitoring in 19 deep surface boreholes drilled at Grid areas located across the Lac du Bonnet batholith, at the Whiteshell Laboratory (WL), and in surface and underground boreholes at the Underground Research Laboratory (URL). Based on these investigations domains of low permeability, sparsely fractured rock (SFR) have been identified in the Lac du Bonnet batholith

  12. Oser le corps

    Directory of Open Access Journals (Sweden)

    Alex Cormanski

    2015-05-01

    Full Text Available Le corps est la voie primordiale dans le processus d’énonciation, mais reste encore (trop souvent corps étranger dans le processus d’enseignement/apprentissage des langues étrangères. Or entrer dans une langue étrangère, se l’approprier physiquement, sonner juste dans une autre langue, précisément pour qu’elle ne soit plus étrangère, implique un travail sur le corps, peut impliquer un transfert de corporéité. Oser les pratiques de corps dans la classe de langue : voie incontournable pour éviter les voix dissonantes. Dare the body voice Abstract: Focusing and working on the body is inescapable in the process of enunciation, but unfortunately not sufficiently put into practice in language learning. Speaking a foreign language, being attuned in that target language, i.e. to sound as close as possible to a native speaker, implies to work on the body physically as well as mentally, which means dealing with representation because of the transfer of identity the user may experience. Dare the body voice for a body change when switching from a language to another is a necessary direction the teacher ought to lead the learners to work on.

  13. Candide et le physicien

    CERN Document Server

    Espagnat, Bernard d'

    2008-01-01

    Les avancées considérables de la physique d'après guerre n'ont - on le sait - été possibles qu'au prix d'une vraie rupture entre elle et la physique dite " classique ". A quels changements cette rupture nous contraint-elle en ce qui concerne des notions essentielles, telles celles d'espace, de temps, d'objet et d'objectivité ? Quelles en sont les incidences quant à la portée de la connaissance, au rôle de la conscience, aux relations entre science et ontologie ? Ce sont là des questions de fond, fort délicates, auxquelles les personnes de tendance quelque peu philosophique sont plus sensibles que ne le sont les physiciens. Malheureusement, les premières ne disposent normalement pas des connaissances de pointe qui seules permettent d'approfondir de tels problèmes sans trop risquer de s'égarer. Etant donné l'impact que, par ses applications, la science a sur nos vies, nombreux sont ceux qui souhaitent se former une idée plus juste de ce qu'elle implique vraiment. Le présent ouvrage prend la for...

  14. Expression of lacZ reporter gene under the control of the polyhedrin promoter of Spodoptera litura nuclear polyhedrosis virus.

    Science.gov (United States)

    Behera, A K; Kumar, M; Bansal, A; Bansal, O B; Das, R H

    1997-04-29

    Promoter function of the putative polyhedrin-encoding gene (polh) of Spodoptera litura nuclear polyhedrosis virus (S1MNPV) was determined by transferring it to the Autographa californica nuclear polyhedrosis virus (AcMNPV) through the AcNPV polh based vector, pVL1393. Three transfer vectors pCBT2, pCBT3 and pCBT4 were constructed by substituting the promoter and the neighbouring sequences of AcNPV in pVL1393 by that of S1NPV. The Escherichia coli lacZ gene was placed downstream from the S1NPV polh promoter in the hybrid transfer vector (pCBT) constructs. Co-transfection of Spodoptera frugiperda cells (Sf9) with each of the pCBTlacZ vector and wild-type AcNPV DNAs led to synthesis of beta-galactosidase (beta Gal). The plaque-purified recombinant viruses (S1AcNPV.lacZ) expressing lacZ under the polh promoter of S1NPV are stable. The highest beta Gal activity was obtained with S1AcNPV4.lacZ. Production of beta Gal with recombinant virus, S1AcNPV3.lacZ in which S1NPV polh promoter is in the reverse orientation in the AcNPV genome, is 83% of that produced by S1AcNPV4.lacZ. These results indicate that the S1NPV polh promoter is active in the genetic environment of AcNPV; the polh of S1NPV is phylogenetically related to AcNPV like other baculoviruses.

  15. Le vase de Pandore

    Directory of Open Access Journals (Sweden)

    Nicola Panichi

    2000-06-01

    Full Text Available Il s’agit ici de suivre les stratégies discursives par lesquelles Érasme situe sa Lingua sous le patronage symbolique de deux mythes des plus opératoires à la Renaissance : le vase de Pandore et la tour de Babel, tous deux verrouillant le texte, l’un en guise d’incipit, l’autre d’explicit, dans un dialogue où chacun use de l’autre pour renforcer les significations et instaurer le régime sémantique du texte, tant linguistique qu’éthique. Ce sont ces jeux complexes entre différents niveaux de discours dont dépend le sens ultime de l’œuvre que cet article s’attache à saisir.Se trata de seguir aquí las estrategias discursivas mediante las cuales Erasmo sitúa su Lingua bajo el dominio simbólico de dos de los mitos más funcionales del Renacimiento: el vaso de Pandora y la torre de Babel, los cuales limitan el texto, uno a modo de íncipit, otro de excipit, en un diálogo en el que se valen el uno del otro para reforzar los significados y establecer el régimen semántico del texto, tanto lingüístico como ético. Son esos juegos complejos entre diferentes niveles de discurso, de los que depende el sentido último de la obra, que este artículo intenta captar.

  16. Regulation of proline utilization in Salmonella typhimurium: characterization of put::Mu d(Ap, lac) operon fusions.

    OpenAIRE

    Maloy, S R; Roth, J R

    1983-01-01

    The genes for proline utilization were fused to the structural genes of the lac operon by use of the hybrid Mu phage derivative Mu d(Ap lac). Stable deletion derivatives of these fusions were selected and used to study the transcriptional regulation of the put genes. Analysis of these fusions showed that the putA gene product, a bifunctional oxidase-dehydrogenase, also serves to negatively control transcription of the putA and putP genes. Transcription of the put genes is repressed only in pu...

  17. lacZ transduced human breast cancer xenografts as an in vivo model for the study of invasion and metastasis

    DEFF Research Database (Denmark)

    Brünner, N; Thompson, E W; Spang-Thomsen, M

    1992-01-01

    in the animals by usual histological procedures would require extensive sectioning of the whole animal. To overcome this problem, we transduced human breast cancer cells with a replication-defective Moloney murine leukaemia retroviral vector (M-MuLV) containing both neoR (neomycin resistance) and lacZ genes...... but not the surrounding mouse tissue on either whole tissue blocks or histological sections. The staining procedure was highly sensitive, allowing detection of microfoci of human cancer cells, and quantitative estimation of the metastatic capacity of the cells. These results indicate that lacZ transduction of human...

  18. Le concept d'alcalinité résiduelle et évolution géochimique des ...

    African Journals Online (AJOL)

    Les résultats obtenus sur les sols du lac Fetzara montrent que l‟alcalinité résiduelle calcite (ARc) diminue lorsque les solutions se concentrent. Elle est légèrement négative au départ pour devenir plus franche par la suite dans les échantillons les plus concentrés. L'alcalinité est dominée par le Ca2+, c'est la voie saline ...

  19. Conformational change from antiparallel beta-sheet to alpha-helix in a series of depsipeptide, -(Leu-Leu-Lac)(n)-: syntheses, spectroscopic studies, and crystal structures of Boc-Leu-Lac-OEt and Boc-(Leu-Leu-Lac)(n)-OEt (n = 1, 2).

    Science.gov (United States)

    Oku, Hiroyuki; Yamada, Keiichi; Katakai, Ryoichi

    2008-04-01

    The depsipeptides Boc-Leu-Lac-OEt (1) and Boc-(Leu-Leu-Lac)(n)-OEt (n = 1, 2) (2 and 3, respectively) (Boc = tert-butyloxycarbonyl, Lac = L-lactic acid residue) has been synthesized and studied by crystallographic, CD spectroscopic, and ESI-MS analyses. In the packing cells, those three compounds adopt beta-strand conformations. Each molecule is linked into a dimer (1) or an infinite assembly (2 and 3) by tight hydrogen bonds of the type NH...O==C. Interestingly, the hexamer, 3 shows the first example of antiparallel pleated beta-sheet crystal structure for a depsipeptide molecule. In the packing cells, especially for 3, the ester groups O--C==O are perpendicularly oriented to the amide groups NH--C==O and beta-sheet planes to avoid the interaction between --O--(ester) and O==C. Therefore, when the chain length become longer, the O...O==C repulsion interaction works as a beta-sheet breaker and hence promotes an alpha-helical structure as observed for Boc-(Leu-Leu-Lac)(3)-Leu-Leu-OEt (4) (Oku et al. Biopolymers 2004, 75, 242-254) and Boc-(Leu-Leu-Lac)(n)-OEt (n = 4-6) (5-7) (Katakai et al., Biopolymers 1996, 38, 285-290), in which the O...O==C repulsion does not cause significant structural changes in alpha-helical main chains. Therefore from the structural and spectroscopic analyses, we have found governing factors for the specificity in the beta-sheet and alpha-helix decision in this series of depsipeptides, -(Leu-Leu-Lac)(n)-.

  20. Influence of nucleotide excision repair on N-hydroxy-2-acetylaminofluorene-induced mutagenesis studied in λlacZ-transgenic mice

    NARCIS (Netherlands)

    Frijhoff, A.F.W.; Krul, C.A.M.; Vries, A. de; Kelders, M.C.J.M.; Weeda, G.; Steeg, H. van; Baan, R.A.

    1998-01-01

    To study the influence of nucleotide excision repair (NER) on mutagenesis in vivo, ERCC1+/-, XPA-/-, and wild-type (ERCC1+/+ and XPA+/+, respectively) λlacZ-transgenic mice were treated i.p. with N-hydroxy-2-acetylaminofluorene (N-OH-AAF) and lacZ mutant frequencies were determined in liver. No

  1. Decadal to millennial scale geomagnetic field variations in the Levantine archaeointensity curve (LAC): methodology and applications

    Science.gov (United States)

    Shaar, Ron; Tauxe, Lisa; Ron, Hagai; Agnon, Amotz; Ben-Yosef, Erez; Finkelstein, Israel; Zuckerman, Sharon; Levy, Thomas E.

    2014-05-01

    ) according to the dating method employed (archaeological, historical, radiocarbon). In addition, we cross check results from multiple archaeological sites using different source materials dated using different methodologies. The results of this effort are summarized in a regional compilation namely Levantine Archaeomagnetic Curve - LAC. The initial version of the LAC includes recently published data from ancient copper production sites, and new data from two important biblical archaeological mounds in Israel - Tel Megiddo ("Armageddon") and Tel Hazor. In this talk we review our working methodologies, report the current status of the LAC, and discuss its implications on our understanding of geomagnetic secular variations.

  2. Le monde quantique

    CERN Document Server

    Aspect, A; Bensaude-Vincent, B; Castiel, A; Chevalley, C; Darrigol, O; Deligeorges, S; D'Espagnat, B; Laloë, F; Lévy-Leblond, J-M; Messiah, A; Paty, M; Vuillemin, J; Wheaton, B R

    1984-01-01

    Le monde quantique La physique quantique, après trois quarts de siècle, n'en finit pas d'être moderne. Elle est présente quotidiennement dans les laboratoires où les physiciens étudient atomes, noyaux et particules. Elle est entrée dans l'industrie où lasers, transistors et supraconducteurs lui doivent d'exister. Et elle continue à alimenter le débat philosophique sur la nature de la réalité dont elle montre la non-séparabilité fondamentale. Ses concepts de base, son développement, ses applications, ses controverses sont ici présentés par une pléiade de physiciens, d'historiens et de philosophes.

  3. Le charme slave

    Directory of Open Access Journals (Sweden)

    Antonella Mauri

    2012-09-01

    Full Text Available Antonella Mauri analyse l’image des femmes slaves immigrées en Italie telle qu’elle apparaît à travers la publicité, la littérature romanesque (La ballata dei lavavetri de Peter Del monte, Luce Profuga de Valerio Aiolli, Pornokiller de Bruno Ventavoli, le cinéma, la bande dessinée (Danilo Maramotti, image qu’elle oppose aux résultats d’une enquête qu’elle a menée sur le terrain. Elle s’interroge en particulier sur la permanence des stéréotypes liés à la femme slave.

  4. Le Nordais on schedule

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    The first phase of the Le Nordais wind farm project in the Gaspe Peninsula in Quebec is on schedule. It was announced that the project's first turbines will be turning by September 1998. Hydro-Quebec has agreed to buy power from the 100 MW wind farm. The Le Nordais consortium plans to have 76,750 kW turbines in service in Cap-Chat by December 1998. Many of the foundations for the towers are poured and a substation is under construction. The turbines that are currently in use come from Denmark, but 20 of the 76 turbines being slated for installation this year will come from NEG Micon Canada Inc.'s assembly plant in Quebec. The Quebec government is providing a $5.6 million grant for their production and for turbine assembly in Quebec. During phase two, an additional 57 turbines will be installed in Matane by the end of 1999. 1 fig

  5. Le forme del fondo

    Directory of Open Access Journals (Sweden)

    Michel Maffesoli

    2004-12-01

    Full Text Available Non è vero che la natura ha paura del vuoto. Forse addirittura si completa. Il vuoto è anche una modalità dell'essere. È possibile nidificarvisi, avvolgersi pigramente e, così, proteggersi dall'angoscia del tempo che passa. Il vuoto delle apparenze è, in alcuni momenti, una delle forme d'espressione della vita sociale. Oltretutto occorre saperle riconoscere. Certamente, abbiamo tutti un'esistenza personale, ma siamo, ugualmente, i rappresentanti, a volte anche le vittime, di uno "spirito comune", forse anche di un "inconscio collettivo" che si è costituito di secolo in secolo. E, molto spesso, quando crediamo di esprimere le nostre idee, siamo soltanto dei portavoce, comparse di un vasto "theatrum mundi" dalle dimensioni infinite.

  6. Garder le rythme

    OpenAIRE

    Arnaud-Demir, Françoise

    2015-01-01

    Chez les Alévis de Turquie, hommes et femmes se réunissent pour de longues assemblées nocturnes, le cem ou « cérémonie collective », sous la houlette d’un guide spirituel appelé dede (« grand-père, ancêtre »), lui-même assisté par des bardes (aşık) et divers officiants. Ces cérémonies se composent de chants et de danses accompagnés au luth saz. Près de Divriği, dans la province de Sivas, cette danse rituelle, le semah (d’un étymon arabe signifiant « écoute »), applique un schéma complexe, alt...

  7. A set of lacZ mutations in Escherichia coli that allow rapid detection of each of the six base substitutions

    International Nuclear Information System (INIS)

    Cupples, C.G.; Miller, J.H.

    1989-01-01

    We describe the construction of six strains of Escherichia coli with different mutations at the same coding position in the lacZ gene, which specifies the active site glutamic acid residue at position 461 in beta'-galactosidase. Each strain is Lac- and reverts to Lac+ only by restoring the glutamic acid codon. The strains have been designed so that each reverts via one of the six base substitutions. The set of strains allows detection of each transition and transversion simply by monitoring the Lac- to Lac+ frequency, as demonstrated here with characterized mutagens and mutator alleles. These strains are useful for rapidly determining the mutagenic specificity of mutagens at a single site, for detecting low levels of stimulation of certain base substitutions, for monitoring specific base changes in response to various experimental conditions or strain backgrounds, and for isolating new mutator strains

  8. Le CRDI en Mongolie

    International Development Research Centre (IDRC) Digital Library (Canada)

    touchent la steppe de même que les régions forestières et montagneuses. Utilisation des technologies numériques. Dès le début des années 1990, grâce à des subventions et à des conseils techniques du CRDI, un fournisseur local de services de communication de données, Datacom, a pu fournir l'accès Internet à la ...

  9. Le CRDI au Ghana

    International Development Research Centre (IDRC) Digital Library (Canada)

    pour prévenir le paludisme, des études ayant démontré que leur utilisation pouvait réduire considérablement la mortalité infantile. Les chercheurs ont également suggéré aux gouvernements différents moyens pour inciter les gens à acheter les moustiquaires et à les utiliser correctement. Les TI au service de la démocratie.

  10. Le CRDI en Chine

    International Development Research Centre (IDRC) Digital Library (Canada)

    les employés du secteur non structuré ont de meilleures conditions de travail. □ les citoyens influencent les décisions relatives aux dépenses publiques. Soutien accordé par le CRDI depuis 1981. 222 activités d'une valeur de 59 millions CAD. Chercheurs et agriculteurs s'emploient à améliorer les moyens de subsistance.

  11. Le CRDI en Tunisie

    International Development Research Centre (IDRC) Digital Library (Canada)

    les citoyens arabes sont plus présents sur Internet. Soutien accordé depuis 1975. 49 activités. 8 millions cad. Dans la foulée du Printemps arabe, les chercheurs conçoivent des réformes visant à assurer l'essor de la démocratie et en examinent la validité. CRDI centre de recherches pour le développement international.

  12. Le CRDI au Bangladesh

    International Development Research Centre (IDRC) Digital Library (Canada)

    d'agriculteurs ont trouvé des solutions de remplacement à la culture du tabac. Petit à petit, les agriculteurs améliorent ... réduire la pollution de l'air et à mieux utiliser l'eau. Soutien accordé par le CRDI depuis 1974 ... violence endémique, car la cause profonde du mécontentement — l'absence de démocra- tie plutôt que les ...

  13. Le CRDI en Colombie

    International Development Research Centre (IDRC) Digital Library (Canada)

    activités de longue haleine qui ont eu pour but d'appuyer la réinsertion des anciens combattants ... Internet à son programme d'insertion sociale des enfants de la rue victimes d'exploitation ... Des travaux subventionnés par le CRDI ont aidé une fondation à intégrer Internet à son programme d'insertion sociale des enfants ...

  14. Geology and age of the Lac a la Perdrix fenite, southern Gatineau district, Quebec

    International Nuclear Information System (INIS)

    Hogarth, D.D.

    1996-01-01

    The Lac a Ia Perdrix fenite lies in the Central Metasedimentary Belt of the Grenville Province. This 30 m wide fenite, adjacent to a narrow calciocarbonatite sill, replaces diopside-oligoclase gneiss and is composed of magnesio-arfvedsonite, aegirine, microcline, albite, and fluorapatite. Near the contact with carbonatite, it contains appreciable monazite and barite whereas aegirine virtually disappears. Fenitization probably took place early in the igneous stage of carbonatite development. A Pb/U monazite age of 1026 ± 2 Ma is thought to date fenite formation. Together with published data, this age shows that carbonatite intruded metamorphic rocks near the close of the Grenville Orogeny. (author). 33 refs., 4 tabs., 5 figs

  15. The Redshift of the BL Lac Object TXS 0506+056

    Science.gov (United States)

    Paiano, Simona; Falomo, Renato; Treves, Aldo; Scarpa, Riccardo

    2018-02-01

    The bright BL Lac object TXS 0506+056 is the most likely counterpart of the IceCube neutrino event EHE 170922A. The lack of this redshift prevents a comprehensive understanding of the modeling of the source. We present high signal-to-noise optical spectroscopy, in the range 4100–9000 Å, obtained at the 10.4 m Gran Telescopio Canarias. The spectrum is characterized by a power-law continuum and is marked by faint interstellar features. In the regions unaffected by these features, we found three very weak (EW ∼ 0.1 Å) emission lines that we identify with [O II] 3727 Å, [O III] 5007 Å, and [N II] 6583 Å, yielding the redshift z = 0.3365 ± 0.0010.

  16. p21-LacZ reporter mice reflect p53-dependent toxic insult

    International Nuclear Information System (INIS)

    Vasey, Douglas B.; Wolf, C. Roland; MacArtney, Thomas; Brown, Ken; Whitelaw, C. Bruce A.

    2008-01-01

    There is an urgent need to discover less toxic and more selective drugs to treat disease. The use of transgenic mice that report on toxic insult-induced transcription can provide a valuable tool in this regard. To exemplify this strategy, we have generated transgenic mice carrying a p21-LacZ transgene. Transgene activity reflected endogenous p21 gene activation in various tissues, displayed compound-specific spatial expression signatures in the brain and immune tissues and enabled p53-dependent and p53-independent responses to be identified. We discuss the application of these mice in delineating the molecular events in normal cellular growth and disease and for the evaluation of drug toxicity

  17. Nutrient status of the lowbush blueberry, Lac-Saint-Jean area, Quebec, Canada. [Vaccinium angustifolium

    Energy Technology Data Exchange (ETDEWEB)

    Bouchard, A.R.; Gagnon, M.J.

    1987-01-01

    The lowbush blueberry (Vaccinium angustifolium Ait.) is an important commercial crop of the Lac-Saint-Jean area (Quebec, Canada). The major blueberry fields are located on sandy soils relatively poor in available mineral nutrients. The nutrients originate from a thin organic layer found on the top of these sandy soils. The leaf mineral contents (N, P, K, Mg, Ca, Mn, Fe, Cu, Zn and B) were measured in five blueberry fields during 1984 and 1985. Soil pH and soil available P, K, and Mg were also assessed. The results show that the leaf mineral contents are generally adequate. However, K and Zn might be occasionally deficient when compared to the actual established standards. The available Mg in soil was significantly correlated with the leaf Mg concentration. The data also suggest that the influence of the pH following the burn pruning seems to influence the nutrition of this species.

  18. Spectroscopy of 10 γ -Ray BL Lac Objects at High Redshift

    Energy Technology Data Exchange (ETDEWEB)

    Paiano, Simona; Falomo, Renato [INAF, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy); Landoni, Marco [INAF, Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807 Merate (Italy); Treves, Aldo [Università degli Studi dell’Insubria, Via Valleggio 11, I-22100 Como (Italy); Scarpa, Riccardo [Instituto de Astrofisica de Canarias, C/O Via Lactea, s/n E-38205 La Laguna, Tenerife (Spain)

    2017-08-01

    We present optical spectra with high signal-to-noise ratio of 10 BL Lac objects detected at GeV energies by the Fermi satellite (3FGL catalog), which previous observations suggested are at relatively high redshift. The new observations, obtained at the 10 m Gran Telescopio Canarias, allowed us to find the redshift for J0814.5+2943 ( z = 0.703), and we can set a spectroscopic lower limit for J0008.0+4713 ( z > 1.659) and J1107.7+0222 ( z > 1.0735) on the basis of Mg ii intervening absorption features. In addition we confirm the redshifts for J0505.5+0416 ( z = 0.423) and J1450+5200 ( z > 2.470). Finally we contradict the previous z estimates for five objects (J0049.7+0237, J0243.5+7119, J0802.0+1005, J1109.4+2411, and J2116.1+3339).

  19. DNA adducts, mutant frequencies, and mutation spectra in various organs of λlacZ mice exposed to ethylating agents

    NARCIS (Netherlands)

    Mientjes, E.J.; Luiten-Schuite, A.; Wolf, E. van der; Borsboom, Y.; Bergmans, A.; Berends, F.; Lohman, P.H.M.; Baan, R.A.; Delft, J.H.M. van

    1998-01-01

    To investigate tissue-specific relations between DNA adducts and mutagenesis in vivo, λlacZ transgenic mice were treated i.p. with N-ethyl-N-nitrosourea (ENU), diethylnitrosamine (DEN), and ethyl methanesulphonate (EMS). In liver, bone marrow, and brain DNA from mice sacrificed at several time

  20. Interplay of protein and DNA structure revealed in simulations of the lac operon.

    Directory of Open Access Journals (Sweden)

    Luke Czapla

    Full Text Available The E. coli Lac repressor is the classic textbook example of a protein that attaches to widely spaced sites along a genome and forces the intervening DNA into a loop. The short loops implicated in the regulation of the lac operon suggest the involvement of factors other than DNA and repressor in gene control. The molecular simulations presented here examine two likely structural contributions to the in-vivo looping of bacterial DNA: the distortions of the double helix introduced upon association of the highly abundant, nonspecific nucleoid protein HU and the large-scale deformations of the repressor detected in low-resolution experiments. The computations take account of the three-dimensional arrangements of nucleotides and amino acids found in crystal structures of DNA with the two proteins, the natural rest state and deformational properties of protein-free DNA, and the constraints on looping imposed by the conformation of the repressor and the orientation of bound DNA. The predicted looping propensities capture the complex, chain-length-dependent variation in repression efficacy extracted from gene expression studies and in vitro experiments and reveal unexpected chain-length-dependent variations in the uptake of HU, the deformation of repressor, and the folding of DNA. Both the opening of repressor and the presence of HU, at levels approximating those found in vivo, enhance the probability of loop formation. HU affects the global organization of the repressor and the opening of repressor influences the levels of HU binding to DNA. The length of the loop determines whether the DNA adopts antiparallel or parallel orientations on the repressor, whether the repressor is opened or closed, and how many HU molecules bind to the loop. The collective behavior of proteins and DNA is greater than the sum of the parts and hints of ways in which multiple proteins may coordinate the packaging and processing of genetic information.

  1. Kinetics of the stages of transcription initiation at the Escherichia coli lac UV5 promoter

    International Nuclear Information System (INIS)

    Straney, S.B.; Crothers, D.M.

    1987-01-01

    The kinetics of initiation by Escherichia coli RNA polymerase on the lac L8UV5 promoter was studied by a gel retardation method that separates protein-DNA complexes from free DNA. The binding constant of the closed complex, the forward and reverse rate constants of isomerization from closed to open complex, and the forward rate constant from the open to initiated complex were measured. Both the forward and reverse isomerization rates were found to be temperature dependent, and the activation energies for these steps were determined. The rates of open complex formation and dissociation were not affected by the addition of ribonucleotide triphosphates; however, the extent of dissociation was greatly reduced if the triphosphates added allowed a short, unstable RNA product to form. The dissociation rate was not affected by heparin, a polyanion competitor that sequesters the polymerase. The rate of initiated complex formation appeared to be dependent on whether the initiating moiety was a mononucleotide triphosphate or dinucleoside monophosphate and on the sequence of the dinucleoside. These results are compared to those found on both the lac L8UV5 and other bacterial and phage promoters by less direct measurements. We use the values obtained for the individual rate constants to investigate the predicted steady-state kinetics of initiation-limited transcription, with the conclusion that the rate-limiting step is formation of the open complex in the limit of low polymerase concentration. However, when RNA polymerase is saturating, the rate is determined by the transition from open complex into the stably initiated ternary complex

  2. Le nouveau modèle africain | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    22 juil. 2011 ... L'annulation de la dette, un commerce plus équitable, davantage d'aide : voilà le plan d'action mondial dont on convient qu'il faut de toute urgence mettre en oeuvre en vue d'accélérer le développement en Afrique. Or, ce serait rater le bateau que de ne pas s'engager dans la voie tout autre que les ...

  3. Le Conseil des gouverneurs | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le Conseil des gouverneurs guide le travail du CRDI en lui fournissant une orientation stratégique, en examinant ses activités et en approuvant ses budgets. Les gouverneurs – un maximum de 14 – sont nommés par le gouverneur en conseil du Canada pour un mandat d'au plus quatre ans, qui peut être reconduit. La Loi ...

  4. Sur le genre Apoleon, Gorh

    NARCIS (Netherlands)

    Fairmaire, L.

    1887-01-01

    Dans les »Notes from the Leyden Museum”, vol. VII (1885) p. 51, Mr. Gorham a décrit sous le nom d’ ’Apoleon un nouveau genre de Bostrychide, créé pour un insecte de Malacca, rencontré aussi au Laos, à Bornéo et à Sumatra, A. edax. Ce genre est identique avec le genre Dysides Perty, dont le type, D.

  5. Le regard anachronique

    Directory of Open Access Journals (Sweden)

    Jean-Paul Aubert

    2011-01-01

    Full Text Available Cet article a pour objet l’anachronisme dans le film historique. Il s’appuie sur l’étude du long métrage Goya à Bordeaux, réalisé en 1999 par le cinéaste espagnol Carlos Saura. Cette biographie filmée du peintre Francisco de Goya fait mieux que composer avec l’anachronisme inhérent à toute reconstitution historique. Il l’assume et le revendique. La mise en cause de la chronologie et l’effacement de l’Histoire prennent sens dans la perspective d’une réflexion originale sur l’Histoire de l’art conçue comme un dialogue entre les œuvres et entre les époques.Este artículo está dedicado al problema del anacronismo en las películas históricas. Se basa en el estudio de Goya en Burdeos, un largo metraje rodado en 1999 por el director de cine español Carlos Saura. Esta biografía de Goya no sólo se acomoda con el anacronismo propio de la reconstitución histórica sino que lo asume y lo reivindica. El cuestionamiento de la cronología y el desinterés por la Historia cobran un nuevo sentido en el marco de una reflexión original sobre la Historia del arte concebida como un diálogo entre las obras y entre las épocas.

  6. La piraterie sur le web

    CERN Multimedia

    2002-01-01

    Les échanges de toutes sortes sont facilités à l'extrême par le web: des forums, des vidéoconférences, le commerce à distance, ou tout simplement la célérité des courriers électroniques ou la convivialité des chats, tout cela participe de la société de communication. Une certaine partie du monde découvre le nouvel horizon des échanges quasi instantanés, mais... les transactions sur le web sont-elles vraiment s res?

  7. Le donne briganti

    OpenAIRE

    Cosco, Silvio

    2013-01-01

    Texto completo descargado desde Teseo Le donne briganti es una tesis interdisciplinaria, de carácter histórico-filológico con un enfoque de estudio de género. Es un trabajo que nace del interés por un argumento, el bandolerismo de la primera década del Reino de Italia, que durante mucho tiempo y a sabiendas, ha sido tratado como una reacción menor y criminal al proyecto de unificación italiana, callando las razones de las poblaciones meridionales afectada antes por la invasión y luego por...

  8. Travailler le vison

    OpenAIRE

    Gorre, Jean-François

    2007-01-01

    Dans notre société, la fourrure est porteuse de valeurs symboliques. D'autres travaux ont montré comment elle est l'expression du jeu entre nature et culture : investissement de la force de l'animal, expression du sauvage, marque de la domestication de la nature (Delort 1973, Pouchelle 1981). Notre propos sera différent. Nous étudierons dans le cadre du métier de fourreur, à travers une technique particulière, l'« allonge », la teneur de l'affrontement entre deux groupes socio-professionnels....

  9. Le CRDI au Bhoutan

    International Development Research Centre (IDRC) Digital Library (Canada)

    tance. Le collège a adopté une application. Web qui permet aux enseignants de créer des sites d'apprentissage en ligne, il a offert des cours en informatique aux enseignants et aux étudiants et il a conçu son propre site Web. Il a également établi neuf centres d'études régionaux dans des écoles. La mesure des progrès.

  10. Le survivant sans le syndrome Schreber

    Directory of Open Access Journals (Sweden)

    Richard Figuier

    2006-09-01

    Full Text Available On a pensé la catastrophe, mais a-t-on suffisamment pensé la survivance et la figure du survivant ? Ce n'est pas un hasard si celle-ci est au centre de Masse et puissance, oeuvre dans laquelle Canetti interroge la « mauvaise » survivance responsable de la poursuite de la logique de guerre. Mais où trouver la « bonne » ? Revenir de la catastrophe ne suffit pas pour être un « survivant authentique », selon l'expression de Kafka. Il faut avoir dépassé, avec Primo Levi et Robert Antelme, l'opposition de la vie comme croissance continue et de la mort comme son horrible contraire, par le don, dans la pauvreté solidaire, de cette vie retrouvée.Hemos reflexionado acerca de la catástrofe, pero ¿hemos meditado lo suficiente sobre la supervivencia y el superviviente? No es una coincidencia si el superviviente es el tema principal de Masse et puissance, obra en la cual Canetti analiza la «mala» supervivencia responsable de la persistencia de la lógica de guerra ¿Dónde sin embargo podemos encontrar la «buena» supervivencia? Superar la catástrofe no es suficiente para ser un «auténtico superviviente», según Kafka. Es fundamental ir más allá, con Primo Levi y Robert Antelme, de la oposición entre la vida, como crecimiento continuo, y la muerte, como su espantoso contrario, mediante la donación de forma solidaria de esta vida reencontrada.Disaster is the theme of many studies, but what about survival and of the figure of the survivor? This issue is central in Mass and power, work in which Canetti questions the “bad” survival, responsible for the continuation of the logic of war. But is there any “good” survival? Coming back from the catastrophe is not enough to be an “authentic survivor”, according to Kafka’s expression. To achieve this, it is necessary to have exceeded, with PrimoLevi and Robert Antelme, the opposition of life as a continuous growth and of death as its horrible opposite, by the gift, in a

  11. Copépodes, Cladocères et Rotifères du lac Sidi M'hamed Benali (Algérie Nord-Occidentale

    Directory of Open Access Journals (Sweden)

    Mohamed Ali Bouzidi

    2010-03-01

    Full Text Available En 2008, 33 espèces de Cladocères, Copépodes et Rotifères ont été observées dans le lac Sidi M'hamed Benali (contre 12 seulement en 1992.Les Copépodes dominent en mars, avril, juillet, août et septembre, avec respectivement des dominances (Do égales à : 56,6 %, 55,0 %, 55,0 %, 46,4 % et 90,0 %. Les Cladocères dominent en février (Do = 37,2 %, mai (Do = 47,4 % et décembre (Do = 48,6 %. Les Rotifères sont extrêmement abondants et présentent une large dominance en janvier (Do = 95,3 %. La population zooplanctonique est très faible en juillet et en août. Au cours de l'année le peuplement varie en fonction de la température, des conditions hydrologiques, de l'abondance de la nourriture et de la prédation par les poissons.In 2008, 33 species of Cladocers, Copepods and Rotifers have been observed in Sidi M’hamed Benali Lake (against only 12 species in 1992. The Copepods dominate in March, April, July, August and September, respectively with dominance (Do equal to 56.6 %, 55.0 %, 55.0 %, 46.4 % and 90.0 %. Cladocers dominated in February (Do = 37.2 %, May (Do = 47.4 % and December (Do = 48.6 %. The rotifers are extremely abundant and have a wide dominance in January (Do = 95.3%. The zooplankton population is very low in July and August. During the year, the population varies with temperature, water conditions, abundance of food and predation by fishes.

  12. Le Conseil des gouverneurs | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2 nov. 2010 ... La gouvernance du CRDI. Reddition de comptes, transparence et efficacité. Au cours de l'exercice 2009–2010, le Conseil des gouverneurs du CRDI a adopté un nouveau cadre stratégique quinquennal, Le développement par l'innovation. Pendant de nombreux mois, les gouverneurs et les membres de la ...

  13. Le rateau faucardeur relevable

    Directory of Open Access Journals (Sweden)

    ARRIGNON J.

    1976-07-01

    Full Text Available Un rateau monté sur deux bras mobiles à l'avant d'un bateau faucardeur permet de récupérer les végétaux coupés et de les déposer sur la berge. Le positionnement de la grille horizontale permet en outre l'enlèvement en profondeur des végétaux mous et notamment des algues filamenteuses ainsi que la récupération en surface des lentilles d'eau. La simplicité de la conception, la légèreté de l'outil, sa maniabilité et son coût modique s'associent à son efficacité pour le désigner comme une solution séduisante du problème de l'enlèvement des lentilles d'eau et des produits de faucardement dans les étangs et canaux.

  14. Le tournoi des ombres

    CERN Document Server

    Treille, Daniel

    2017-01-01

    Le lecteur, transporté avec le narrateur dans une région hors norme, est invité à partager sa fascination pour la beauté du lieu, à découvrir la chronique de son passé, rude et pittoresque. Il va côtoyer une galerie de personnages très attachants, mais aux destinées bousculées par l histoire, et assister à l agitation montante du présent dans un contexte d une actualité brûlante. Ce quatrième roman de Daniel Treille, mêlant hardiment les genres, du quotidien trivial au récit épique, de considérations géopolitiques à quelques avancées de la science moderne, confirme son talent à mener, d une écriture très aboutie, une histoire complexe, peuplée de héros singuliers

  15. Le principe roman

    CERN Document Server

    Ferrari, Jérôme

    2015-01-01

    Fasciné par la figure du physicien allemand Werner Heisenberg (1901-1976), fondateur de la mécanique quantique, inventeur du célèbre "principe d'incertitude" et Prix Nobel de physique en 1932, un jeune aspirant-philosophe désenchanté s'efforce, à l'aube du XXIe siècle, de considérer l'incomplétude de sa propre existence à l'aune des travaux et de la destinée de cet exceptionnel homme de sciences qui incarne pour lui la rencontre du langage scientifique et de la poésie, lesquels, chacun à leur manière, en ouvrant la voie au scandale de l'inédit, dessillent les yeux sur le monde pour en révéler la mystérieuse beauté que ne cessent de confisquer le matérialisme à l'œuvre dans l'Histoire des hommes.

  16. The HC-LAC: a Platform for Modeling Hydrology and Climate Change in Latin America and the Caribbean

    Science.gov (United States)

    Moreda, F.; Wyatt, A.; Bruhn, M.; Wheaton, W.; Miralles-Wilhelm, F.; Muñoz-Castillo, R.; Rineer, J.

    2013-05-01

    This platform, called the Hydrology and Climate Change in Latin America and The Caribbean, or "HC-LAC", is an integrated quantitative simulation of hydrology and climate change. The HC-LAC is composed of two principal components: the Analytical Hydrography Dataset (AHD) and an enhanced version of the Generalized Watershed Loading Function (GWLF). The AHD is a spatially explicit surface water data layer of Central and South America derived from digital elevation data from the Shuttle Radar Topography Mission (SRTM) and modified by the USGS to provide more accurate flow between cells in the raster data. For the LAC area, AHD consists 230, 000 catchments and stream segments with an average area of 100 km2 and length of 10 km, respectively. The AHD data structure is patterned after the US National Hydrography Dataset Plus (NHDPlus), thus providing a proven structure for flexible data integration and analyses necessary for spatial models like the HC-LAC. The structure of the AHD enables the implementation of water balance modeling and general routing of flows through the stream network thus supporting a range of environmental models. GWLF is applied on each AHD catchment which is characterized by multiple land use and soil type. The response of each land use in a given catchment is modeled separately in generating stream flow as well as recharge to soil storage. The stream flows generated from each catchment are routed through stream networks, providing total flow at any point in the stream network. A pilot implementation of the HC-LAC was established for the Rio Grande basin in North West Argentina (drainage area 6,700 km2). The model was parameterized and calibrated using readily available data. Three stream flow time series were generated using a reference climate case and two climate change projections. The reference case was based on historical records and assumes no climate change. The two climate change projections were generated using the IPCC "A2" high

  17. ESTIMASI HERITABILITAS DAN RESPONS SELEKSI PERSILANGAN IKAN GURAMI (Osphronemus goramy Lac.

    Directory of Open Access Journals (Sweden)

    Sularto Sularto

    2016-11-01

    Full Text Available Ikan gurami (Osphronemus goramy Lac. dikenal sebagai ikan yang lambat tumbuh. Perbaikan mutu genetik dapat dilakukan untuk mengatasi kendala tersebut, salah satunya adalah melalui program seleksi. Pembentukan populasi dasar dengan menggabungkan persilangan empat populasi Kalimantan, Jambi, Majalengka (M, dan Tasikmalaya dilakukan untuk meningkatkan keragaman genetik. Tujuan penelitian ini untuk mengestimasi nilai heritabilitas dan respons seleksi karakter pertumbuhan bobot ikan gurami hasil persilangan empat populasi gurami sebagai populasi dasar. Persilangan dilakukan dengan rasio jantan: betina (1:1 dan terbentuk 12 famili. Seleksi dilakukan menggunakan metode seleksi famili berdasarkan karakter bobot. Parameter yang diamati adalah karakter pertumbuhan bobot. Data yang digunakan untuk perhitungan etimasi heritabilitas dan respons seleksi adalah data bobot pada umur 11 bulan. Dari data tersebut digunakan untuk menghitung koefisien keragaman (CV, diferensial seleksi (S, estimasi nilai heritabilitas (h2, estimasi respons seleksi (R, dan standard error (SE. Hasil penelitian menunjukkan bahwa populasi dasar yang terbentuk memiliki nilai estimasi heritabilitas 0,4991 yang termasuk kategori tinggi, diferensial seleksi sebesar 124,22 g; sehingga mendapatkan nilai estimasi respons seleksi sebesar 62 g atau (18,2%. Giant gourami (Osphronemus goramy Lac. is known as a slow growing fish. Genetic improvement can be done to overcome this obstacle; one way is through the selection program. Formation of base population by combining cross four populations can increase genetic diversity. The crosses four populations were: Kalimantan (Borneo, Jambi, Majalengka, and Tasikmalaya. The purpose of this study was to estimate the heritability and response to selection of characters in length and weights of giant gourami from four crosses population as the base population of synthetic material. Crossings were made with the ratio of male: female (1:1 to form 12 families

  18. Blood Glukose Response of Giant Gouramy (Osphronemus gaouramy, Lac. to the Stress of Environmental Temperature Changes

    Directory of Open Access Journals (Sweden)

    S. Hastuti

    2007-08-01

    Full Text Available This experiment was conducted to investigate blood glucose performance of giant gouramy (Osphronemus gouramy, Lac. to environmental changes. Fish with body weight of about 52,15 g was used in the experiment. A hundred and twenty fish were subjected to stress by moving them to another aquarium containing cooler water for 5 minute before put them back to the origin aquarium. The stress treatments were Δ 0°C (A, Δ-3°C (B, Δ-6°C(C, and Δ-9°C(D. Blood glucose was measured at 0, 1, 2, 3, 4 and 5 hours post stress, each for 5 fish. During stress treatment, the survival offish were recorded. To study the role of insulin activation on reducing the stress effects, thirty fish were injected with insulin 2 IU/100 g body weight before subjected them to stressar. Blood glucose level of fish subjected to temperature stress of Δ-9°C was the greatest. The blood glucose response to temperature changes was linear, Y = 4,4543 X + 35,553 with R2 = 0,09976. The survival rate of fish was 100% for all treatments. Injected of insulin 2 IU/100 g body weight was able to reduce hyperglycemia that caused by stress. Key words: Blood glucose, giant gouramy, Osphronemus gouramy, stress   ABSTRAK Penelitian ini dilakukan dengan tujuan untuk mengetahui performa glukosa darah ikan gurami (Osphronemus gouramy, Lac. dalam merespon perubahan suhu lingkungan. Ikan berbobot rata-rata 52,15 g sebanyak 120 ekor diberi stres dengan cara diangkat dan dipindahkan ke suatu wadah yang bersuhu lebih dingin selama 5 menit dan dikembalikan lagi ke wadah mula-mula. Perlakuan stres perubahan suhu dingin tersebut adalah A (Δ 0°C, B (Δ- 3°C, C (Δ-6°C dan D (Δ-9°C. Glukosa darah diukur dari 5 ekor ikan pada jam ke 0, 1, 2, 3, 4 dan 5 jam pascastres. Kelangsungan hidup dihitung pada saat perlakuan stres. Untuk melihat peran aktivasi insulin dalam menekan efek stres, ikan sebanyak 30 ekor diinjeksi insulin 2 iu/100 g bobot badan sebelum diberi stres. Kadar glukosa darah ikan gurame

  19. Evaluation of lacI mutation in germ cells and micronuclei in peripheral blood after treatment of male lacI transgenic mice with ethylnitrosourea, isopropylmethane sulfonate or methylmethane sulfonate.

    Science.gov (United States)

    Gorelick, N J; Andrews, J L; Gibson, D P; Carr, G J; Aardema, M J

    1997-02-14

    Male C57B1/6 lacI transgenic mice were used to evaluate germ cell mutagenesis in vivo as part of a collaborative study. Groups of 10 mice were administered single intraperitoneal doses of ethylnitrosourea (ENU; 150 mg/kg), isopropyl methanesulfonate (IPMS; 200 mg/kg), methyl methanesulfonate (MMS; 40 mg/kg) or vehicle. Epididymal spermatozoa and testes were recovered 3 days later and DNA isolated subsequently from epididymal spermatozoa and seminiferous tubules were analyzed for lacI mutations. The mutant frequency in seminiferous tubules (average +/- SEM) increased significantly compared with untreated controls (7.2 +/- 0.7 x 10(-5) following treatment with ENU (11.7 +/- 0.8 x 10(-5), p = 0.003) or with IPMS (9.6 +/- 0.5 x 10(-5), p = 0.018) but not following treatment with MMS (8.1 +/- 0.8 x 10(-5), p = 0.213). Group mutant frequencies were not determined for epididymal spermatozoa from MMS- or IPMS-treated mice because of poor DNA recoveries. As another indicator of the genotoxicity of these alkylating agents, the frequencies of micronuclei were determined in the peripheral blood 48 h after carcinogen administration in the same transgenic mice. The micronuclei frequencies were elevated significantly (p < 0.05) by each treatment (IPMS: 1.0%; MMS: 0.94%) compared to vehicle controls (0.3%). In a separate experiment, 40 mg/kg ENU was previously found to increase the frequency of micronuclei in peripheral blood of lacI transgenic mice 48 h after treatment (3.2%; Gibson et al., 1995). These results demonstrate that the lacI transgenic mouse male germ cells are sensitive to some, but not all, mutagens under the conditions used in this experiment. Investigation of other experimental designs would offer additional perspective on the usefulness of this transgenic model for routine mutagenicity testing in germ cells.

  20. Bistable behavior of the lac operon in E. coli when induced with a mixture of lactose and TMG.

    Science.gov (United States)

    Díaz-Hernández, Orlando; Santillán, Moisés

    2010-01-01

    In this work we investigate multistability in the lac operon of Escherichia coli when it is induced by a mixture of lactose and the non-metabolizable thiomethyl galactoside (TMG). In accordance with previously published experimental results and computer simulations, our simulations predict that: (1) when the system is induced by TMG, the system shows a discernible bistable behavior while, (2) when the system is induced by lactose, bistability does not disappear but excessively high concentrations of lactose would be required to observe it. Finally, our simulation results predict that when a mixture of lactose and TMG is used, the bistability region in the extracellular glucose concentration vs. extracellular lactose concentration parameter space changes in such a way that the model predictions regarding bistability could be tested experimentally. These experiments could help to solve a recent controversy regarding the existence of bistability in the lac operon under natural conditions.

  1. Bistable behavior of the lac operon in E. coli when induced with a mixture of lactose and TMG

    Directory of Open Access Journals (Sweden)

    Orlando Díaz-Hernández

    2010-07-01

    Full Text Available In this work we investigate multistability in the lac operon of Escherichia coli when it is induced by a mixture of lactose and the non-metabolizable thiomethyl galactoside (TMG. In accordance with previously published experimental results and computer simulations, our simulations predict that: (1 when the system is induced by TMG, the system shows a discernible bistable behavior while, (2 when the system is induced by lactose, bistability does not disappear but excessively high concentrations of lactose would be required to observe it. Finally, our simulation results predict that when a mixture of lactose and TMG is used, the bistability region in the extracellular glucose concentration vs. extracellular lactose concentration parameter space changes in such a way that the model predictions regarding bistability could be tested experimentally. These experiments could help to solve a recent controversy regarding the existence of bistability in the lac operon under natural conditions.

  2. A LacI-family regulator activates maltodextrin metabolism of Enterococcus faecium.

    Directory of Open Access Journals (Sweden)

    Xinglin Zhang

    Full Text Available Enterococcus faecium is a gut commensal of humans and animals. In the intestinal tract, E. faecium will have access to a wide variety of carbohydrates, including maltodextrins and maltose, which are the sugars that result from the enzymatic digestion of starch by host-derived and microbial amylases. In this study, we identified the genetic determinants for maltodextrin utilization of E. faecium E1162. We generated a deletion mutant of the mdxABCD-pulA gene cluster that is homologous to maltodextrin uptake genes in other Gram-positive bacteria, and a deletion mutant of the mdxR gene, which is predicted to encode a LacI family regulator of mdxABCD-pulA. Both mutations impaired growth on maltodextrins but had no effect on the growth on maltose and glucose. Comparative transcriptome analysis showed that eight genes (including mdxABCD-pulA were expressed at significantly lower levels in the isogenic ΔmdxR mutant strain compared to the parental strain when grown on maltose. Quantitative real-time RT-PCR confirmed the results of transcriptome analysis and showed that the transcription of a putative maltose utilization gene cluster is induced in a semi-defined medium supplemented with maltose but is not regulated by MdxR. Understanding the maltodextrin metabolism of E. faecium could yield novel insights into the underlying mechanisms that contribute to the gut commensal lifestyle of E. faecium.

  3. The physical properties and orbital parameters of the triple system V402 Lac

    Science.gov (United States)

    Hoyman, B.; Kalomeni, B.; Yakut, K.

    2018-04-01

    We present first ground-based multi-colors photometric study of an eccentric, double-lined eclipsing binary system V402 Lac. Analyzing the data obtained in this study together with earlier studies in the literature we derived the orbital and physical parameters of this detached binary system of considerable interest. Derived physical parameters of the components are as follows; M1 = 2.95 ± 0.06M⊙ , M2 = 2.86 ± 0.06M⊙ , R1 = 2.61 ± 0.04R⊙ , R2 = 2.16 ± 0.03R⊙ , L1 = 98 ± 5L⊙ and L2 = 69 ± 3L⊙ . Using the newly obtained parameters the distance of the binary is determined to be 262 ± 33 pc. In addition, the system show apsidal motion whose period is determined to be 213 years. A possible third star (M3 sin i = 1.9M⊙) orbiting the binary system in an eccentric orbit (e = 0.23) with an orbital period of 20.5 years has been detected in this study with LTT.

  4. NEW MEGALOCYTIVIRUS INFECTED TO THE CULTURED FRESH WATER GIANT GOURAMI, Osphronemus gouramy Lac. IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Isti Koesharyani

    2013-06-01

    Full Text Available Giant gourami (Osphronemus gouramy Lac. is one of freshwater fish having high economic value and very popular in Indonesian food restaurant. This fish have been cultured throughout Indonesia. Since two years ago, cultured fish in ponds infected by unknown pathogenic agent and may cause diseased fish and mass mortality. Mass mortality of pond cultured giant gourami occurred in West Java, Central Java, and Bali-Indonesia. The symptoms of diseased fish are the body color becomes darker, resting on the water surface, and internal organs of fish characterized by enlargement of spleen. In the present study diseased fish samples were diagnose by Polymerase Chain Reaction (PCR techniques using specific primers of red sea bream iridovirus (RSIV and histopathologically analysis to determine the causative agent of mortality. Based on PCR analysis, show that all fish sampled were positive infected by megalocytivirus and infected fish mostly died. This is a new and first time reported virus infection in cultured giant gourami in Indonesia and it is proposed to be named as giant gourami iridovirus (GGIV.

  5. Genotype to phenotype mapping and the fitness landscape of the E. coli lac promoter.

    Directory of Open Access Journals (Sweden)

    Jakub Otwinowski

    Full Text Available Genotype-to-phenotype maps and the related fitness landscapes that include epistatic interactions are difficult to measure because of their high dimensional structure. Here we construct such a map using the recently collected corpora of high-throughput sequence data from the 75 base pairs long mutagenized E. coli lac promoter region, where each sequence is associated with its phenotype, the induced transcriptional activity measured by a fluorescent reporter. We find that the additive (non-epistatic contributions of individual mutations account for about two-thirds of the explainable phenotype variance, while pairwise epistasis explains about 7% of the variance for the full mutagenized sequence and about 15% for the subsequence associated with protein binding sites. Surprisingly, there is no evidence for third order epistatic contributions, and our inferred fitness landscape is essentially single peaked, with a small amount of antagonistic epistasis. There is a significant selective pressure on the wild type, which we deduce to be multi-objective optimal for gene expression in environments with different nutrient sources. We identify transcription factor (CRP and RNA polymerase binding sites in the promotor region and their interactions without difficult optimization steps. In particular, we observe evidence for previously unexplored genetic regulatory mechanisms, possibly kinetic in nature. We conclude with a cautionary note that inferred properties of fitness landscapes may be severely influenced by biases in the sequence data.

  6. Variable quasi-stellar sources with particular emphasis on objects of the BL Lac type

    International Nuclear Information System (INIS)

    Kinman, T.D.

    1975-01-01

    The optically variable quasars tend to have steep optical spectra and to show variable polarization; they tend to be associated with compact radio sources which have flat radio spectra at GHz frequencies. Objects are known which have continuous spectra (like BL Lac and OJ 287), but whose other properties closely parallel those of the variable quasars and N galaxies; in fact no sharp distinction can be drawn between them. The variation in the visibility of emission lines in quasars and N galaxies could be due to variations in the strength and spectral index of the radiation from the non-thermal source and from the differences in the amount and disposition of the material around it; it does not seem likely that a combination of these factors accounts for the observed range in emission line strength. The systematic difference in optical spectral index between continuous-spectrum objects (and OVV variables) on the one hand and those with emission lines on the other will produce a difference in K term between them, which may be expected to affect their distributions with respect to apparent magnitude. (Auth.)

  7. THE 2001-2003 LOW STATE OF NOVA LACERTAE 1950 (DK LAC)

    International Nuclear Information System (INIS)

    Honeycutt, R. K.; Jacobson, H.; Hoffman, D.; Maxwell, T.; Croxall, K.; Kafka, S.; Henden, A. A.; Robertson, J. W.

    2011-01-01

    We report on extensive photometry of DK Lac obtained during the interval 1990-2009, which includes a 2 mag low state during 2001-2003. Much of the photometry consists of exposures obtained with a typical spacing of several days, but also includes 26 sequences of continuous photometry each lasting 2-7 hr. We find no evidence for periodicities in our data. We do find that the random variations in the low state are approximately twice those in the high state, when expressed in magnitudes. The lack of orbital-timescale variations is attributed to the nearly face-on presentation of the disk. There is a 0.2 mag decline in the high-state brightness of the system over 19 years, which is consistent with the behavior of other old novae in the decades following outburst. High-state spectra are also presented and discussed. We find that the equivalent width of Hα falls by about double from 1991 to 2008. The photometric properties are discussed in the context of the hibernation scenario for the behavior of novae between outbursts, in which we conclude that low states in old novae are probably unrelated to their possible entrance into hibernation.

  8. Le Milton de Toland

    Directory of Open Access Journals (Sweden)

    James C. BROWN

    2003-10-01

    Full Text Available Alors que l’œuvre de John Milton suscite encore de nombreuses critiques et interprétations, je vous propose un retour en arrière afin d’étudier l’un des premiers écrits biographiques dédié à la vie et à l’œuvre du poète anglais signé par le philosophe irlandais John Toland. Paru en 1698, Life of John Milton dresse un portrait plus complet que ceux que l’on trouve dans les précédentes biographies du poète anglais (Darbishire xxix. Ayant été l’un des premiers biographes de Milton, Toland a pub...

  9. Le Baratze (ou

    Directory of Open Access Journals (Sweden)

    Jacques Blot

    1998-01-01

    Full Text Available El círculo de piedras Mendizabal 7, de 8 metros de diámetro,   presenta una corona externa constituida de grandes bloques   hincados en la tierra, y otra interna y tangente, de elementos idénticos sólo puestos en el suelo. El cajón central está compuesto de cuatro losas y una tapa. No hay depósito de huesos ni de carbón de leña ; sólo se encuentran dos herraduras, entre las cuales una completa de tipo medieval, que podrían permitir de pensar en una construcción del círculo en el periodo histórico.

  10. Le tourisme alpin

    Directory of Open Access Journals (Sweden)

    Andrea Macchiavelli

    2009-06-01

    Full Text Available La forte croissance qu’ont connue les pays alpins dans les dernières décennies a surtout été fondée sur l’offre des activités du ski, avec comme conséquence, un massif développement immobilier, la multiplication d’infrastructures et l’extension des domaines. Aujourd’hui, le marché du ski semble arriver à saturation, la Convention alpine a mis un frein à la poursuite du développement des domaines skiables et on observe donc avec intérêt la diversification de l’offre soutenue par l’innovation. Après avoir rappelé les facteurs de changement en cours les plus significatifs dans le tourisme montagnard, l’article présente une grille interprétative de l’évolution des destinations touristiques alpines, identifiant les phases qui ont caractérisé son développement. Puis il propose une réflexion sur certaines conditions qui peuvent favoriser l’innovation dans le tourisme alpin, ainsi que sur les contradictions qui les accompagnent souvent. Dans la plupart des cas l’innovation est le résultat d’un processus qui a été lancé et qui s’est développé au sein de la communauté alpine, souvent favorisé et soutenu par des institutions nationales et internationales, et grâce auquel les difficultés structurelles qui ont déjà été abordées précédemment ont pu être surmontées avec succès.The spectacular increase in tourism in the Alps in recent decades has been founded mainly on the boom in skiing, resulting in both strong real estate development and an increasing array of infrastructures and ski runs. Today the ski market seems to have virtually reached saturation point and the winter sports sector needs to diversify its offer through innovation. After a review of the main factors of change in mountain tourism, the paper presents a grid for interpreting the life cycle of alpine destinations, identifying the phases that characterize their evolution. The conditions that may favour innovation in alpine

  11. Le grand inventaire

    Directory of Open Access Journals (Sweden)

    Michel Melot

    2012-05-01

    Full Text Available Depuis quarante ans qu’il existe, l’Inventaire général des monuments et des richesses artistiques de la France n’a pas seulement progressé, couvrant près de dix mille communes, documentant plus de vingt mille dans cinq millions de pages, trois millions de photographies, et cent mille dessins. Il est devenu ce que ses fondateurs désiraient qu’il fût. Il n’est pas une liste d’objets plus ou moins singuliers qu’on aurait oubliés, mais l’observation méthodique de l’émergence dans le monde de l’ar...

  12. Le citoyen rieur

    Directory of Open Access Journals (Sweden)

    Anna Rycman

    2009-11-01

    Full Text Available Dans la Pologne d’aujourd’hui, l’évolution des modèles d’engagement civique et politique s’opère plus particulièrement auprès des jeunes générations. Parmi les expériences nouvelles de participation politique, les nouvelles technologies de l’information et de la communication offrent des opportunités radicales de reconfigurer l’espace public. La jeunesse polonaise investit en masse le Web. Dans le flux de paroles affranchies circulant et dialoguant dans le cyberespace, nous nous intéressons ici au développement d’un discours qui emprunte au registre de la dérision et de la satire politiques. Une multitude de sites critiques, de nature apparemment contestataire, des sites d’opposition fondés sur le genre satirique, ont émergé comme réponse apportée à la situation politique. Cet espace public électronique représente une forme moderne de « folklore politique », contribuant au processus de socialisation des jeunes citoyens polonais.The laughing citizen. A modern form of civic commitment in democratic Poland?In present day Poland, the evolution of civic and political commitment models is above all the affaire of the younger generations. Among the current opportunities for political participation, the new information and communication technologies offer radical opportunities to reconfigure the public arena. Polish youth are flocking to the Web. Amongst the flux of frank points of views circulating and dialoguing in cyberspace, our interest here is the development of a discourse inspired by political and satirical derision. A multitude of critical, apparently anti-establishment, sites and general opposition sites using the satirical style have emerged as a response to the political situation. This public electronic space represents a modern form of « political folklore », contributing to the socialising processes of young polish citizens.El ciudadano que rie. ¿Nueva forma del compromiso cívico en la

  13. INVESTIR DANS LE SAVOIR : le soutien que le CRDI consent à des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    5 nov. 2010 ... ... 40 ans, le Cenre de recherches pour le développement international (CRDI), en plus d'appuyer des travaux de recherche dans l'ensemble des pays en développement, encourage des générations successives de jeunes chercheurs par l'entremise de son Programme de formation et de bourses (PFB).

  14. Lele des chefs traditionnels au Ghana : un modèle inspirant ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    … en Afrique. À l'université, Ray pouvait étudier la politique canadienne ou la politique africaine. « J'ai cru que je comprendrais mieux mon pays si j'allais voir ce qui se passe ailleurs dans le monde, puis en tirais des leçons ...

  15. DNA adducts, mutant frequencies and mutation spectra in λlacZ transgenic mice treated with N-nitrosodimethylamine

    NARCIS (Netherlands)

    Souliotis, V.L.; Delft, J.H.M. van; Steenwinkel, M.-J.S.T.; Baan, R.A.; Kyrtopoulos, S.A.

    1998-01-01

    Groups of λlacZ transgenic mice were treated i.p. with N-nitrosodimethylamine (NDMA) as single doses of 5 mg/kg or 10 mg/kg or as 10 daily doses of 1 mg/kg and changes in DNA N7- or O6-methylguanine or the repair enzyme O6-alkylguanine-DNA alkyltransferase (AGT) were followed for up to 14 days in

  16. Bistable Behavior of the Lac Operon in E. Coli When Induced with a Mixture of Lactose and TMG

    OpenAIRE

    Díaz-Hernández, Orlando; Santillán, Moisés

    2010-01-01

    In this work we investigate multistability in the lac operon of Escherichia coli when it is induced by a mixture of lactose and the non-metabolizable thiomethyl galactoside (TMG). In accordance with previously published experimental results and computer simulations, our simulations predict that: (1) when the system is induced by TMG, the system shows a discernible bistable behavior while, (2) when the system is induced by lactose, bistability does not disappear but excessively high concentrat...

  17. Optimization of lignin peroxidase, manganese peroxidase, and Lac production from Ganoderma lucidum under solid state fermentation of pineapple leaf

    OpenAIRE

    Sudha Hariharan; Padma Nambisan

    2013-01-01

    This study was undertaken to isolate ligninase-producing white-rot fungi for use in the extraction of fibre from pineapple leaf agriwaste. Fifteen fungal strains were isolated from dead tree trunks and leaf litter. Ligninolytic enzymes (lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac)), were produced by solid-state fermentation (SSF) using pineapple leaves as the substrate. Of the isolated strains, the one showing maximum production of ligninolytic enzymes was identified...

  18. Données préliminaires sur la diversité du zooplancton du lac Nokoué

    African Journals Online (AJOL)

    SARAH

    31 juil. 2017 ... RESUME. Objectif : L'étude de diversité et la répartition des organismes zooplanctoniques du Lac Nokoué a été menée. Méthodologie et résultats : Pour la compréhension de cette composante importante de l'écosystème, un échantillonnage mensuel a été effectué sur 4 mois (juin à septembre 2015).

  19. The extent of co-metabolism of glucose and galactose by L. lactis changes with the expression of the lacSZ operon from Streptococcus thermophilus

    DEFF Research Database (Denmark)

    Solem, Christian; Købmann, Brian Jensen; Jensen, Peter Ruhdal

    2008-01-01

    The lactose transporter and β-galactosidase from Streptococcus thermophilus, encoded by the lacSZ operon, were introduced into the lactose-negative strain Lactococcus lactis MG1363 and the expression of the lacSZ operon was modulated by substitution of the native promoter with randomized synthetic...... promoters. A series of strains with various expression levels of lacSZ were examined for their fermentation of lactose. Strains with a high expression level were found to metabolize lactose in a similar manner to S. thermophilus, i.e. the galactose moiety of lactose was excreted to the growth medium...... and only glucose was metabolized in glycolysis. Interestingly, strains with low expression of the operon showed a mixed acid metabolism and co-metabolism of galactose and glucose. The lactose flux increased gradually with increasing expression of the lacSZ operon until an optimum was observed...

  20. Distinct roles of two ceramide synthases, CaLag1p and CaLac1p, in the morphogenesis of Candida albicans

    DEFF Research Database (Denmark)

    Cheon, Seon Ah; Bal, Jyotiranjan; Song, Yunkyoung

    2012-01-01

    Lag1p and Lac1p catalyse ceramide synthesis in Saccharomyces cerevisiae. This study shows that Lag1 family proteins are generally required for polarized growth in hemiascomycetous yeast. However, in contrast to S. cerevisiae where these proteins are functionally redundant, C. albicans Lag1p (CaLag1......p) and Lac1p (CaLac1p) are functionally distinct. Lack of CaLag1p, but not CaLac1p, caused severe defects in the growth and hyphal morphogenesis of C. albicans. Deletion of CaLAG1 decreased expression of the hypha-specific HWP1 and ECE1 genes. Moreover, overexpression of CaLAG1 induced pseudohyphal....... albicans....

  1. Excrétion de carbone organique par le phytoplancton lémanique

    OpenAIRE

    Feuillade, M.; Dufour, Philippe; Feuillade, J.; Pelletier, J.P.

    1986-01-01

    L'excrétion du carbone organique dissous par le phytoplancton du lac Léman a été évaluée par la méthode du 14C entre mars et novembre 1984. Elle varie entre 0,01 et 0,5 mgC.m-3.h-1 et dépend en premier lieu de la vitesse d'assimilation photosynthétique. L'excrétion carbonée oscille généralement entre 2 et 5% de l'assimilation carbonée et n'excède qu'exceptionnellement 6%. Les valeurs sont sous-estimées par la réassimilation hétérotrophe. L'excrétion nocturne représente moins de 10% des pertes...

  2. Dans le tourbillon des particules

    CERN Document Server

    Zito, Marco

    2015-01-01

    Accélérateurs géants, détecteurs complexes, particules énigmatiques... La physique subatomique peut sembler bien intimidante pour le novice. Et pourtant, qui n a jamais entendu parler du boson de Higgs et du CERN, le laboratoire européen où il a été découvert en 2012 ? Nul besoin d être un spécialiste pour comprendre de quoi il s agit. Aujourd hui, une théorie extraordinairement élégante, le Modèle Standard, décrit tous les résultats des expériences dans le domaine. Trente-sept particules élémentaires et quatre forces fondamentales : c est tout ce dont nous avons besoin pour expliquer la matière et l Univers ! Ce livre, destiné à un large public, raconte sans équations le long parcours qui a abouti au Modèle Standard. Ce parcours, parfois sinueux, a été entamé lorsque les Grecs anciens, et peut-être d autres avant eux, ont imaginé que la matière est composée de petites « billes ». Il faudra attendre plusieurs siècles pour qu on réalise que la matière, à l échelle micros...

  3. Contamination en métaux traces des sédiments du lac Fouarat ...

    African Journals Online (AJOL)

    La comparaison entre les teneurs en métaux dans les sédiments du fond et ceux de surface d\\'une carotte montre que les teneurs en zinc, en chrome et en cadmium diminuent de la surface vers la profondeur. L\\'intensité de cette pollution est traduite par le facteur et l\\'indice de contamination qui montrent une nette ...

  4. Rapport sur le développement dans le monde

    International Development Research Centre (IDRC) Digital Library (Canada)

    Parlement International Development Research Centre Centre de recherches pour le développement international Centro Internacional de Investigaciones ..... Other donors include the Swedish International Development Cooperation Agency (Sida), the Norwegian Agency for Development Cooperation (Norad) and the ...

  5. Effect of the partial NaCl substitution by other chloride salts on the volatile profile during the ripening of dry-cured lacón

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, R.; Munekata, P.E.; Cittadini, A.; Lorenzo, J.M.

    2016-07-01

    The influence of three salting treatments (treatment II: 50% NaCl-50% KCl; III: 45% NaCl-25% KCl-20% CaCl2-10% MgCl2; IV: 30% NaCl-50% KCl-15% CaCl2-5% MgCl2) on the formation of volatile compounds throughout the process was studied and compared to those of a control “lacón” (treatment I: 100% NaCl). There was an intense formation of volatile compounds throughout the processing, particularly during the dry-ripening stage. The most abundant chemical family in all the formulations, in the final product was hydrocarbons followed by aldehydes. The total volatile compound release was more intense in the control “lacóns” (1164 AU×106 ·g–1dry matter) than in “lacóns” from formulations II, III and IV (817–891 AU×106 ·g−1dry matter). The “lacóns” from formulation I showed the highest amounts of aldehydes. The “lacóns” from formulations I and II presented the highest amounts of hydrocarbons. The main conclusion is that the replacement of NaCl produces changes in the volatile profile and could be affect the aroma of “lacón”. (Author)

  6. Complete genome sequence of hypervirulent and outbreak-associated Acinetobacter baumannii strain LAC-4: epidemiology, resistance genetic determinants and potential virulence factors

    Science.gov (United States)

    Ou, Hong-Yu; Kuang, Shan N.; He, Xinyi; Molgora, Brenda M.; Ewing, Peter J.; Deng, Zixin; Osby, Melanie; Chen, Wangxue; Xu, H. Howard

    2015-01-01

    Acinetobacter baumannii is an important human pathogen due to its multi-drug resistance. In this study, the genome of an ST10 outbreak A. baumannii isolate LAC-4 was completely sequenced to better understand its epidemiology, antibiotic resistance genetic determinants and potential virulence factors. Compared with 20 other complete genomes of A. baumannii, LAC-4 genome harbors at least 12 copies of five distinct insertion sequences. It contains 12 and 14 copies of two novel IS elements, ISAba25 and ISAba26, respectively. Additionally, three novel composite transposons were identified: Tn6250, Tn6251 and Tn6252, two of which contain resistance genes. The antibiotic resistance genetic determinants on the LAC-4 genome correlate well with observed antimicrobial susceptibility patterns. Moreover, twelve genomic islands (GI) were identified in LAC-4 genome. Among them, the 33.4-kb GI12 contains a large number of genes which constitute the K (capsule) locus. LAC-4 harbors several unique putative virulence factor loci. Furthermore, LAC-4 and all 19 other outbreak isolates were found to harbor a heme oxygenase gene (hemO)-containing gene cluster. The sequencing of the first complete genome of an ST10 A. baumannii clinical strain should accelerate our understanding of the epidemiology, mechanisms of resistance and virulence of A. baumannii. PMID:25728466

  7. Mathematical model of the lac operon: inducer exclusion, catabolite repression, and diauxic growth on glucose and lactose.

    Science.gov (United States)

    Wong, P; Gladney, S; Keasling, J D

    1997-01-01

    A mathematical model of the lactose (lac) operon was developed to study diauxic growth on glucose and lactose. The model includes catabolite repression, inducer exclusion, lactose hydrolysis to glucose and galactose, and synthesis and degradation of allolactose. Two models for catabolite repression were tested: (i) cyclic AMP (cAMP) synthesis inversely correlated with the external glucose concentration and (ii) synthesis inversely correlated with the glucose transport rate. No significant differences in the two models were observed. In addition to synthesis, degradation and secretion of cAMP were also included in the model. Two models for the phosphorylation of the glucose produced from lactose hydrolysis were also tested: (i) phosphorylation by intracellular hexokinase and (ii) secretion of glucose and subsequent phosphorylation upon transport back into the cell. The latter model resulted in weak catabolite repression when the glucose produced from lactose was transported out of the cell, whereas the former model showed no catabolite repression during growth on lactose. Parameter sensitivity analysis indicates the importance of key parameters to lac operon expression and cell growth: the lactose and allolactose transformation rates by beta-galactosidase and the glucose concentrations that affect catabolite repression and inducer exclusion. Large values of the allolactose hydrolysis rate resulted in low concentrations of allolactose, low-level expression of the lac operon, and slow growth due to limited import and metabolism of lactose; small values resulted in a high concentration of allolactose, high-level expression of the lac operon, and slow growth due to a limiting concentration of glucose 6-phosphate formed from allolactose. Changes in the rates of all beta-galactosidase-catalyzed reactions showed similar behavior, but had more drastic effects on the growth rate. Changes in the glucose concentration that inhibited lactose transport could extend or contract

  8. Le FIVB annonce le financement de huit autres projets | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    5 avr. 2018 ... Découvrez les derniers récents projets soutenus par le Fonds d'innovation en matière de vaccins pour le bétail : Maladie de Newcastle · Pleuropneumonie contagieuse caprine – cowdriose · Plateforme de modification génétique CRISPR/cas9 · Entérotoxémie, la bactérie Pasteurella et la fièvre de la vallée ...

  9. Un exemple de sedimentation biodetritique holocene en climat tropical humide le ``lac'' Ahémé (Bénin, Afrique de l'Ouest)

    Science.gov (United States)

    Oyede, L. M.; Lang, J.; Tsawlassou, G.

    The coastal atlantic margins of the Benin Republic presents an excellent example of a margino-littoral coastline with lagoons and vertically oriented river valleys. One of these is the river Couffo which runs out from the "lake" Aheme in the SW portion of the country. Hydrodynamic analysis shows that its alimentation principally downstream from sea waters and fresh waters originating from the Mono river. In this case, supplies or contributions are less important and the rate of feeling up is low. About one hundred superficial samples distributed across the entire bottom of the lake were colleced from depths that do not exceed 2,35m. Eight small bore-hole samples from 0,7 to 1,5m and two deep borehole samples from 7m depth are collected. Sedimentologic analysis (granulometry, exoscopy, heavy minerals, X-RAY diffractometry) suggest that the actual sedimentation conditions which are relatively calm, permitted the deposition of mud and sandy mud. This calm environment was followed up by a high energy environment which led to the deposition of coarse sands. The sands essentially originated from the neighbouring "Continental terminal" beds and were deposited before the nouakchottian transgression whose maximum was attained about 5700 years. The accumulation of vegetal materials in this mangrove surrounding at the edge of the lake within the margino-littoral environment was probably related to some exceptional events which disturbed the environmental conditions as well as the processes of sedimentation and hydrology. The emergence in anaerobic surrounding and neotectonic movements in relation with subsidence and epeirogenesis favour the evolution of vegetation and the formation of peat.

  10. Production algale et consommation par le Tilapia, Oreochromis niloticus L., au Lac Muhazi (Rwanda. Résumé de thèse de doctorat

    Directory of Open Access Journals (Sweden)

    Mukankomeje, R.

    1992-01-01

    Full Text Available Algal production and consumption by the Tilapia Oreochromis niloticus L., in Lake Muhazi (Rwanda. The article describes shortly the objectives of a Food Early Warning System (FEWS project, as well as its organisation. The specifie case of Somalia, where the project had to evolve in increasingly difficult situations, and the solutions used so as to preserve the output, are described.

  11. Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Léman) in France

    Science.gov (United States)

    Certad, Gabriela; Dupouy-Camet, Jean; Gantois, Nausicaa; Hammouma-Ghelboun, Ourida; Pottier, Muriel; Guyot, Karine; Benamrouz, Sadia; Osman, Marwan; Delaire, Baptiste; Creusy, Colette; Viscogliosi, Eric; Aliouat-Denis, Cecile Marie; Follet, Jérôme

    2015-01-01

    Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman) in France, 41 entire fish and 100 fillets (cuts of fish flesh) were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%), distributed as follows: 13 (87%) C. parvum, 1 (7%) C. molnari, and 1 (7%) mixed infection (C. parvum and C. molnari). C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60) was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by the

  12. End of life care preferences among people of advanced age: LiLACS NZ.

    Science.gov (United States)

    Gott, Merryn; Frey, Rosemary; Wiles, Janine; Rolleston, Anna; Teh, Ruth; Moeke-Maxwell, Tess; Kerse, Ngaire

    2017-12-19

    Understanding end of life preferences amongst the oldest old is crucial to informing appropriate palliative and end of life care internationally. However, little has been reported in the academic literature about the end of life preferences of people in advanced age, particularly the preferences of indigenous older people, including New Zealand Māori. Data on end of life preferences were gathered from 147 Māori (aged >80 years) and 291 non- Māori aged (>85 years), during three waves of Te Puawaitangi O Nga Tapuwae Kia Ora Tonu, Life and Living in Advanced Age (LiLACs NZ). An interviewer-led questionnaire using standardised tools and including Māori specific subsections was used. The top priority for both Māori and non-Māori participants at end of life was 'not being a burden to my family'. Interestingly, a home death was not a high priority for either group. End of life preferences differed by gender, however these differences were culturally contingent. More female Māori participants wanted spiritual practices at end of life than male Māori participants. More male non-Māori participants wanted to be resuscitated than female non- Māori participants. That a home death was not in the top three end of life priorities for our participants is not consistent with palliative care policy in most developed countries where place of death, and particularly home death, is a central concern. Conversely our participants' top concern - namely not being a burden - has received little research or policy attention. Our results also indicate a need to pay attention to diversity in end of life preferences amongst people of advanced age, as well as the socio-cultural context within which preferences are formulated.

  13. Attachment to place in advanced age: A study of the LiLACS NZ cohort.

    Science.gov (United States)

    Wiles, Janine L; Rolleston, Anna; Pillai, Avinesh; Broad, Joanna; Teh, Ruth; Gott, Merryn; Kerse, Ngaire

    2017-07-01

    An extensive body of research theorises that attachment to place is positively associated with health, particularly for older people. Building on this, we measure how indicators of attachment to place are associated with health for in people of advanced age in New Zealand. We use data from a cohort study (LiLACS NZ), which includes an indigenous Māori cohort aged 80-90 years and a non-Māori cohort aged 85 years from a mixed urban/rural region in New Zealand. Each cohort undertook a comprehensive interview and health assessment (n = 267 Māori and n = 404 non-Māori). Using multivariate regression analyses, we explore participants' feelings for and connectedness with their home, community and neighbourhood; nature and the outdoors; expectations about and enthusiasm for residential mobility; and how all these are associated with measures of health (e.g., SF-12 physical and mental health related quality of life) and functional status (e.g., NEADL). We demonstrate that people in advanced age hold strong feelings of attachment to place. We also establish some positive associations between attachment to place and health in advanced age, and show how these differ for the indigenous and non-indigenous cohorts. For older Māori there were strong associations between various health measures and the importance of nature and the outdoors, and connectedness to neighbourhood and community. For older non-Māori, there were strong associations between health and liking home and neighbourhood, and feeling connected to their community and neighbourhood. Place attachment, and particularly its relationship to health, operates in different ways for different groups. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Le Valais et ses Reines

    Directory of Open Access Journals (Sweden)

    Alberto Campi

    2012-06-01

    Full Text Available Combat de ReinesAu premier plan (la corde dans la main, un propriétaire de vaches. Dans l'arène se trouve le rabatteur. Les Reines sur la photo sont des reines de première catégorie (ainsi que le montre le « I » sur leur cuisse .Dimanche 6 mai 2012, « Schakira », la vache numéro 42, a gagné, non sans polémique, le titre de Reine. Elle peut donc être considérée comme la Reine des Reines, titre qu’elle a gagné en se battant contre ses rivales dans différents combats, qui ont commencé pour Sch...

  15. Sur le chemin de Buchenwald

    OpenAIRE

    Bessière, Bernard

    2017-01-01

    En 1963, âgé de 37 ans, l’activiste communiste Jorge Semprún publie en français le roman Le Grand Voyage dans lequel il raconte le périple de 800 km qui l’avait conduit en train de Compiègne jusqu’à Buchenwald en septembre 1943. Il avait alors 19 ans. C’est dans ce camp de la mort situé près de Weimar – cité de Goethe, que Semprún admirait – qu’il sera interné jusqu’à sa libération par les troupes américaines en avril  1945. Pendant les quatre jours et cinq nuits de ce « grand voyage », le dé...

  16. Le bal du loup

    CERN Multimedia

    Happy Children's Home

    2013-01-01

    The Bord'eau amateur theatre group will graciously perform a play of their creation Le bal du loup Saturday 19 October 2013 at 20:00 Sunday 20 October at 17:00 in the Théâtre des Grottes Rue Louis Favre 43, 1201 Genève Children from age 12 upwards. Summary: The new-elected mayoress of a small village would like to clean up the town by prohibiting alcohol and getting rid of its prostitutes. Then along comes « Massimo Lupo » the pimp... The performances will be given to support the Happy Children's Home charity, which runs a foster-home in Pokhara for Nepali children:  http://www.happychildrenshome.org/ Admission : minimum charge of 10 CHF per person requested, to cover the cost of technical assistance and theatre rental. Any profit will be used solely for the foster-home. At the end of each performance members of the HCH charity will be happy to answer any questions you may have. The theatre has 86 seats, thank you for reserv...

  17. Le CRDI dans les Philippines

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le CRDI appuie la recherche dans les. Philippines depuis 1972. Le travail qu'y ont accompli des universités et des instituts de recherche vigoureux et la participation active de la société civile ont entraîné d'importantes améliorations dans les domaines de l'agriculture, du suivi de la pauvreté et de la gestion des forêts.

  18. Un oiseau "sabote" le CERN

    CERN Multimedia

    Colson, Sébastien

    2009-01-01

    Un oiseau, un simple oiseau, est parvenu à bloquer à lui tout seul l'accélérateur à particules à 3,7 milliards d'euros. UNe histoire quasiment bulresque qui a toutefois impacté le fonctionnement de la machine durant près de cinq jours, puisque c'est le système de refroidissement qui a été affecté. (1 page)

  19. Le cas de la Chine

    International Development Research Centre (IDRC) Digital Library (Canada)

    pwust

    Des changements récents dans le milieu de l'élaboration des politiques du pays semblent propices à la ... centrale, la Chine fait l'expérience de nouveaux partenariats d'aide au développement où .... 2 Le Service des prêts à des conditions libérales de la Banque d'import-export de Chine gère les prêts assortis de.

  20. Le livre sur le livre traité de documentation

    CERN Document Server

    Otlet, Paul

    2015-01-01

    Paul Otlet est considéré comme le père des sciences de l'information. Ouvrage fondateur et fondamental, le Traité de documentation. Le livre sur le livre (1934) est l'aboutissement de son travail inlassable pour rassembler, classer et partager les connaissances. Otlet y propose une remarquable synthèse du savoir sur le livre et le document en même temps qu'il anticipe Internet et l'hypertexte. La réédition du Traité de documentation, 70 ans après la disparition de son auteur, coïncide avec la réouverture du Mundaneum à Mons, où le fabuleux héritage documentaire légué par Paul Otlet et Henri La Fontaine est conservé. « Ici, la table de travail n'est plus chargée d'aucun livre. À leur place se dresse un écran et à portée un téléphone. Là-bas, au loin, dans un édifice immense, sont tous les livres et tous les renseignements. De là, on fait apparaître sur l'écran la page à lire pour connaître la réponse aux questions posées par téléphone. » Préfaces de Benoît Peeters (éc...

  1. Le modèle spatial de la capitale allemande

    Directory of Open Access Journals (Sweden)

    Antoine Laporte

    2013-06-01

    Full Text Available En Allemagne, en 1999, le Chancelier fédéral et son gouvernement ont quitté Bonn pour Berlin. Ce transfert du pouvoir est accompagné de celui d’une grande partie de l’appareil d’État et de la haute administration, et des fonctions qui leur sont traditionnellement attribuées comme la presse, les lobbys ou encore la diplomatie. Le déplacement du statut de capitale effective de l’Allemagne de Bonn à Berlin est le résultat des évolutions géopolitiques d’un pays ayant recouvré son unité et sa pleine et entière souveraineté. Installer le pouvoir exécutif et législatif à Berlin était une démarche hautement symbolique, visant à normaliser la position de l’ancienne capitale de la RDA et du IIIe Reich comme véritable centre politique de l’Allemagne. Or le déplacement des institutions fédérales n’est pas qu’un acte symbolique. Il entraîne également à l’échelle intra-urbaine des dynamiques très concrètes sur le tissu urbain et participe à la mise en place de nouvelles centralités dans la ville. En effet, le statut de capitale d’État prédestine l’agglomération à la coprésence de nombreuses fonctions urbaines spécifiques plus ou moins directement liées à l’exercice ou à la symbolique du pouvoir.

  2. 3. Le moraliste, le sociologue et le juge : objectivation et production de la connaissance

    OpenAIRE

    Noreau, Pierre

    2018-01-01

    Commedia del diritto Œuvre spécialement réalisée pour cet ouvrage par Maya Pankalla Le rapport qu’entretiennent les sciences sociales et le monde des valeurs est traversé par l’ambiguïté. Ce que nous pourrions appeler ici l’« engagement sociologique » de Guy Rocher témoigne de cette tension continue ; il exemplifie les relations complexes qui lient le mouvement de la pensée au monde de l’action. Comme il le rappelle lui-même dans ses entretiens avec Georges Khal, à la fin d’u...

  3. Le plomb, le cadmium et le mercure dans les produits de la mer

    OpenAIRE

    Thibaud, Yves

    1987-01-01

    Trois contaminants métalliques, toxiques vis-à-vis de l'homme : le plomb, le cadmium et le mercure, sont considérés sous l'angle de leur cheminement dans l'environnement, en particulier celui de l'accès au consommateur par les aliments d'origine marine. En plus des réglementations visant au contrôle des produits de la pêche destinés à la consommation et des mesures visant à limiter lés disséminations, il existe en France un système de surveillance continue des niveaux de contamination du litt...

  4. Le nouveau modèle africain | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    22 juil. 2011 ... Or, ce serait rater le bateau que de ne pas s'engager dans la voie tout autre que les Africains proposent maintenant — à savoir se défaire du syndrome de la dépendance qui afflige l'Afrique depuis des décennies. Le Canada et les autres pays riches du Nord reconnaissent généralement qu'ils ne peuvent ...

  5. Lele des intervenants non gouvernementaux dans le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Ce projet servira à déterminer les facteurs stratégiques et réglementaires qui ont contribué ou nui aux efforts visant à permettre aux fournisseurs non gouvernementaux de participer au renforcement des systèmes de santé. Lele des fournisseurs de ... Climate Change and Water Adaptation Options. The impacts of climate ...

  6. Insight into the nature of the candidate Extreme BL Lac object RBS 0723 with the MAGIC telescopes

    Science.gov (United States)

    Carosi, A.; Lombardi, S.; Tavecchio, F.; Bonnoli, G.; Stamerra, A.

    2017-01-01

    In the past years, the MAGIC Telescopes have performed observation campaigns on candidates Extreme BL Lac objects (EHBL). These sources are known to show an extreme frequency of their synchrotron and inverse Compton peaks in the spectral energy distribution (in the hard X-ray and TeV bands respectively). Furthermore, they are characterized by the extreme hardness of the UV-X-ray and (de-absorbed) TeV continua. These characteristics are usually explained in a leptonic synchrotron+SSC emission model under the assumption that the energy distribution of the emitting relativistic electrons has a large value of the minimum Lorentz factor (˜ 105) coupled with a rather low magnetic field intensity (˜ 10-2 G); although alternative models including contributions from hadrons in the jet are also proposed. This aspect points out a significant difference with respect to the parameters usually used in 'classical' TeV BL Lacs modelling. Thus, EHBL are important and very interesting targets as their observation allows to investigate the properties of blazars belonging to a poorly known category of sources described by peculiar values of the relevant physical quantities of their jets. Despite the remarkable scientific interest, observations of the hard but faint high energy emission from EHBLs are still sparse, and only a handful of these has been discovered at TeV energies. The BL Lac object RBS 0723 fits quite well within the EHBL subclass. The source was detected on January 2014 by the MAGIC telescopes with a statistical significance of more than 5 standard deviations. Although with large uncertainties, the source shows a relatively soft spectrum. Furthermore, the non-detection in the earlier data taken in December and in the subsequent months points to a possible VHE flux variability at variance with the general view of these sources, commonly thought to be relatively steady objects.

  7. Various mutations compensate for a deleterious lacZα insert in the replication enhancer of M13 bacteriophage.

    Science.gov (United States)

    Zygiel, Emily M; Noren, Karen A; Adamkiewicz, Marta A; Aprile, Richard J; Bowditch, Heather K; Carroll, Christine L; Cerezo, Maria Abigail S; Dagher, Adelle M; Hebert, Courtney R; Hebert, Lauren E; Mahame, Gloria M; Milne, Stephanie C; Silvestri, Kelly M; Sutherland, Sara E; Sylvia, Alexandria M; Taveira, Caitlyn N; VanValkenburgh, David J; Noren, Christopher J; Hall, Marilena Fitzsimons

    2017-01-01

    M13 and other members of the Ff class of filamentous bacteriophages have been extensively employed in myriad applications. The Ph.D. series of phage-displayed peptide libraries were constructed from the M13-based vector M13KE. As a direct descendent of M13mp19, M13KE contains the lacZα insert in the intergenic region between genes IV and II, where it interrupts the replication enhancer of the (+) strand origin. Phage carrying this 816-nucleotide insert are viable, but propagate in E. coli at a reduced rate compared to wild-type M13 phage, presumably due to a replication defect caused by the insert. We have previously reported thirteen compensatory mutations in the 5'-untranslated region of gene II, which encodes the replication initiator protein gIIp. Here we report several additional mutations in M13KE that restore a wild-type propagation rate. Several clones from constrained-loop variable peptide libraries were found to have ejected the majority of lacZα gene in order to reconstruct the replication enhancer, albeit with a small scar. In addition, new point mutations in the gene II 5'-untranslated region or the gene IV coding sequence have been spontaneously observed or synthetically engineered. Through phage propagation assays, we demonstrate that all these genetic modifications compensate for the replication defect in M13KE and restore the wild-type propagation rate. We discuss the mechanisms by which the insertion and ejection of the lacZα gene, as well as the mutations in the regulatory region of gene II, influence the efficiency of replication initiation at the (+) strand origin. We also examine the presence and relevance of fast-propagating mutants in phage-displayed peptide libraries.

  8. Le clerc et le ménestrel

    OpenAIRE

    Szkilnik, Michelle

    2007-01-01

    Quand au début du XIVe siècle, un auteur inconnu imagine de raconter l’histoire d’un roi d’Angleterre tout aussi inconnu, Perceforest, il choisit « naturellement » la prose. « Naturellement » parce que le Perceforest se veut la pré-histoire du monde arthurien, qu’il prétend donc se rattacher, comme l’avait fait L’Estoire del Saint Graal, à l’avant des grands cycles en prose du XIIIe siècle, le Lancelot-Graal en particulier. Il opte donc pour le même mode d’écriture que les œuvres qu’il vient ...

  9. Voyages dans le temps et dans l’espace d’un mot marin : « batture ». Ce qu’en dévoilent les mises en relief métalinguistiques dans les grands corpus

    Directory of Open Access Journals (Sweden)

    Wissner Inka

    2014-07-01

    C’est la confrontation des données lexicographiques et textuelles, métalinguistiques et ordinaires, contemporaines et anciennes, qui permet de retracer le voyage du diatopisme « batture », à l’origine un terme du vocabulaire des marins, sans doute formé en moyen français tardif dans le grand Ouest de la France. Suite à divers glissements de sens, il connaît en français moderne plusieurs emplois techniques et usuels, notamment en Amérique du Nord. Ayant suivi les grandes voies d’eau outre-mer, le type lexical a pu se répandre au Canada (au Québec et autour des Grands Lacs surtout, mais aussi vers plusieurs régions aux États-Unis, pour s’établir dans l’usage contemporain non seulement au Canada, mais aussi en Acadie et en Louisiane.

  10. Induction of lacI- mutations in Escherichia coli cells after single and split-dose irradiation

    International Nuclear Information System (INIS)

    Kozubek, S.; Ryznar, L.

    1992-01-01

    In the lacI system of Escherichia coli, X-ray mutagenesis follows a linear-quadratic curve with suppression; the survival curve is exponential. Dose fractionation leads to nearly complete repair of premutational lesions during an incubation interval of 3.5 h. Repair starts with a delay of 1.5-2 h, suggesting the involvement of an inducible repair/mutation fixation system. The dose-dependence of mutagenesis is described by a simple model assuming two hits being required. A probable explanation might be that the premutagenic lesions consist of two closely spaced lesions on the opposite strands of the DNA molecule. (author)

  11. Structural evidence for induced fit and a mechanism for sugar/H+ symport in LacY

    DEFF Research Database (Denmark)

    Mirza, Osman Asghar; Guan, Lan; Verner, Gill

    2006-01-01

    Cation-coupled active transport is an essential cellular process found ubiquitously in all living organisms. Here, we present two novel ligand-free X-ray structures of the lactose permease (LacY) of Escherichia coli determined at acidic and neutral pH, and propose a model for the mechanism...... of coupling between lactose and H+ translocation. No sugar-binding site is observed in the absence of ligand, and deprotonation of the key residue Glu269 is associated with ligand binding. Thus, substrate induces formation of the sugar-binding site, as well as the initial step in H+ transduction....

  12. Le sacré sauvage

    Directory of Open Access Journals (Sweden)

    Roger Bastide

    2010-09-01

    Full Text Available Conférence prononcée le 13 septembre 1973 dans le cadre des Rencontres Internationales de Genève qui avaient pour thème cette année-là « Le besoin religieux ». Cette conférence figure dans les Actes de cette rencontre (Le Besoin religieux, Éditions de la Baconnière, Neuchâtel, 1974, pp. 123-145. Elle a été republiée dans un ouvrage posthume dont elle est l’éponyme, ouvrage édité par Henri Desroche (Paris, éditions Stock, 1975. Nous reproduisons ici le texte intégral original, avec l’aimable autorisation des Rencontres Internationales de Genève auxquelles SociologieS adresse ses remerciements.The wild sacredText of a lecture taken on November the 13th 1973 during the Rencontres Internationales de Genève whom theme was "The religious need". This lecture was first published in: Le Besoin religieux (La Baconnière Editions, Neuchâtel, 1974, pp. 123-145, and published once again in a posthumous book: Le sacré sauvage ("The wild sacred" edited by Henri Desroche (Paris, Stock Editions, 1975. It is reproduced here with the kind authorization of the Rencontres Internationales de Genève. SociologieS gives them sincere thanks.Le Sacré sauvage (Lo sagrado en el mundo primitivoConferencia efectuada el 13 de septiembre de 1973 en el marco de las Rencontres Internationales de Genève (Encuentros Internacionales de Ginebra que tenia como tema general la necesidad de la experiencia religiosa (“Le besoin religieux”, Éditions de la Baconnière, Neuchâtel, 1974, pp. 123-145. Esta conferencia fue publicada de nuevo en un trabajo póstumo que lleva el mismo título, editado por Henri Desroche (Paris, Éditions Stock, 1975. Reproducimos aquí la integralidad del texto original con la amable autorización de las Rencontres Internationales de Genève, a las cuales la revista SociologieS expresa su agradecimiento.

  13. Le LHC, un tunnel cosmique

    CERN Document Server

    CERN. Geneva

    2009-01-01

    Et si la lumière au bout du tunnel du LHC était cosmique ? En d’autres termes, qu’est-ce que le LHC peut nous apporter dans la connaissance de l’Univers ? Car la montée en énergie des accélérateurs de particules nous permet de mieux appréhender l’univers primordial, chaud et dense. Mais dans quel sens dit-on que le LHC reproduit des conditions proches du Big bang ? Quelles informations nous apporte-t-il sur le contenu de l’Univers ? La matière noire est-elle détectable au LHC ? L’énergie noire ? Pourquoi l’antimatière accumulée au CERN est-elle si rare dans l’Univers ? Et si le CERN a bâti sa réputation sur l’exploration des forces faibles et fortes qui opèrent au sein des atomes et de leurs noyaux, est-ce que le LHC peut nous apporter des informations sur la force gravitationnelle qui gouverne l’évolution cosmique ? Depuis une trentaine d’années, notre compréhension de l’univers dans ses plus grandes dimensions et l’appréhension de son comportement aux plus peti...

  14. Le paludisme, le tsunami silencieux d'Afrique | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    12 janv. 2011 ... Dans un élan de compassion fort justifié, le monde s'est porté au secours des victimes du tsunami qui a touché récemment la région de l'océan Indien. Mais il ignore qu'un « tsunami silencieux », le paludisme, s'abat sans cesse sur l'Afrique et y fait chaque année plus de 1,5 million de victimes, surtout de ...

  15. Le même et le différent

    OpenAIRE

    Tixier, Nicolas

    2015-01-01

    À partir de Smoke de Paul Auster et Wayne Wang; International audience; Auggie Wren (joué par Harvey Keitel) tient un débit de tabac à Brooklyn au coin de la 16e rue et de Prospect Park West. Chaque matin il traverse le carrefour face à sa boutique et dispose avec attention, toujours au même endroit, son appareil photo sur un trépied. Il regarde sa montre, attend la bonne heure et appuie sur le déclencheur. Cette photo rejoindra un album où jour après jour, page après page, depuis de nombreus...

  16. activite photosynthetique du phytoplancton dans le barrage ...

    African Journals Online (AJOL)

    AISA

    Biomasses, peuplements phytoplanctoniques et production primaire du lac Titicaca. Rev. Hydrobiol. trop. 14 (4) : 349 - 380. Mason C. F. 1991. Biology of freshwater pollution. Second edition, Longman Scientific and. Technical, New York, 350 p. Melack J. M. 1976. Primary productivity and fish yields in tropical lakes. Trans.

  17. The extent of co-metabolism of glucose and galactose by Lactococcus lactis changes with the expression of the lacSZ operon from Streptococcus thermophilus.

    Science.gov (United States)

    Solem, Christian; Koebmann, Brian; Jensen, Peter R

    2008-05-01

    The lactose transporter and beta-galactosidase from Streptococcus thermophilus, encoded by the lacSZ operon, were introduced into the lactose-negative strain Lactococcus lactis MG1363 and the expression of the lacSZ operon was modulated by substitution of the native promoter with randomized synthetic promoters. A series of strains with various expression levels of lacSZ were examined for their fermentation of lactose. Strains with a high expression level were found to metabolize lactose in a similar manner to S. thermophilus, i.e. the galactose moiety of lactose was excreted to the growth medium and only glucose was metabolized in glycolysis. Interestingly, strains with low expression of the operon showed a mixed acid metabolism and co-metabolism of galactose and glucose. The lactose flux increased gradually with increasing expression of the lacSZ operon until an optimum was observed at intermediate beta-galactosidase activities of 2000-3000 Miller units. At higher expression levels, the flux decreased. These strains had a glycolytic flux comparable with those of reference strains with the standard lactococcal PTS(lac) (lactose phosphotransferase transport system) lactose transporter, which indicates that lactose transport is not rate-limiting for glycolysis in Lactococcus. Finally, an additional ATP drain was introduced into the fastest growing strain, CS2004, to test whether the ATP demand controlled glycolysis under these conditions, but in fact no increase in glycolytic flux was observed.

  18. Pre-induced Lac Operon Effect on Non Specific Sugars: Pre-culture Effect is Dependent on Strength of Induction, Exponential Phase and Substrate Concentration.

    Science.gov (United States)

    Malakar, Pushkar

    2015-01-01

    The source and history of the cell plays an important role in influencing the phenotypic properties of the organism in a particular environmental condition. Pre-induced lac operon provides benefit on lactose environment. During metabolism lactose is broken down into glucose and galactose. The fate of cells with pre-induced lac operon on glucose and galactose milieu is not known. The influence of nutritional status of the medium, level of pre-induction and growth phase on pre-culture effect is not investigated. Effect of pre-induced lac operon on non specific sugars along with the factors that influence this effect was enumerated in the present study. Results of this present study indicate that pre-induced lac operon provide benefit in terms of growth on galactose milieu. This study also suggests that Pre induced lac operon effect depends on the (i) strength of induction in the pre-culture, (ii) nutritional content of the environment and (iii) exponential growth phase of the organism. The above study will help in the better characterization of the pre culture effect. It will also help in the better understanding of the relation between gene expression and growth physiology.

  19. Production of giant gourami Osphronemus goramy Lac. juvenile with different rate of water exchange

    Directory of Open Access Journals (Sweden)

    Tatag Budiardi

    2015-03-01

    Full Text Available ABSTRACTGiant gourami Osphronemus goramy Lac. is one of the most important fresh water fish commodities with increasing production level every year. Water quality management through a proper water exchange both in quantity and quality can be one of the alternatives to support the elevating production. This research was conducted from July to August 2010 at the Aquaculture Production Technology and Management Laboratory, Department of Aquaculture, Faculty of Fisheries and Marine Science, Bogor Agricultural University. The juvenile used was 0.84±0.011 cm in length and 0.017±0.001 cm in weight which reared in nine units of aquaria with a size of 60×29×33 cm3. Silk worm was used as the feed and provided daily at satiation. Water exchange was performed twice a day at a level depending on the treatment, namely 75% (50% at morning and 25% at evening, 100% (50% at morning and evening and 125% (75% at morning and 50% at evening of total water volume. Water exchange at 75%, 100%, and 125%/day resulted in survival rates of 94.11±0.63%; 91.89±2.02%; and 93.89±0.75%; specific growth rates of 7.43±0.15%, 8.58±0.24%, and 9.97±0.18%. Growth rate in length of 1.06±0.06 cm, 1.33±0.04 cm, and 1.55±0.01 cm; coefficient of variation in length of 11.31±1.43%, 9.35±1.46%, and 6.90±2.30%; feed efficiency of 12.47±0.30%, 14.32±1.05%, and 19.67±0.54%. The financial benefits resulted of the process were worth of IDR.351,903.00; IDR.402,302.00; and IDR.464,715.00; whereas R/C ratio of 1.71; 1.80; dan 1.90; BEP of 1,845 unit, 1,645 unit, and 1,517 unit; payback period (PP of 0.97 years, 0.85 years, and 0.74 years; and the cost production as much as IDR.79.90; IDR.82.70; and IDR.82.90/individual, respectively. The treatments were significantly different on several parameters, such as specific growth rate, length of growth rate, feed efficiency at p<0.05. The results of this experiment showed that 125% daily water exchange improved the production

  20. L'algue alimentaire Spirulina sp. Découverte de lacs naturels à Wadi el Natroun en République Arabe d'Egypte Spirulina Sp. Food Alga. Discovery of Natural Lakes At Wadi El Natrun in the Arab Republic of Egypt

    Directory of Open Access Journals (Sweden)

    Abdin El Sherif S. A.

    2006-11-01

    Full Text Available Bien que connue depuis les temps les plus anciens, la dépression de Wadi el Natroun n'avait jamais été prospectée autrement que pour sa richesse en sels minéraux. C'est en 1977 que les auteurs, cherchant à savoir s'il existait des lacs naturels à Spirulines en République Arabe d'Égypte, découvrirent dans la dépression de Wadi el Natroun certains lacs comme Abou Gobara et El Khadra où croissaient spontanément les algues spirulines. Le climat du site, l'origine et la composition des eaux, ainsi que la concentration en algues, ont été étudiés afin d'estimer la productivité du site en vue d'une éventuelle exploitation industrielle. L'exploitation de ces lacs permettrait de mettre en valeur le site de Wadi el Natroun par la production d'une substance très riche en protéine pour l'alimentation humaine dont à tant besoin la République Arabe d'Égypte. Even though it has been known from olden days, the depression of Wadi el Natrun had never been prospected other than for its wealth of mineral salts. It was in 1977 that the authors began searching for natural lakes with Spirulina algae in the Arab Republic of Egypt and, in the depression of Wadi el Natrun, discovered varions lakes such as Abu Gobara and El Khadra where Spirulina algae grew in a natural state. The climate of the site, the original and composition of the water as well as the algae concentration were analyzed to evaluate the productivity of the site for eventual industrial exploitation. The exploitation of these lakes would give value to the Wadi el Natrun site by producing a very protein-rich substance for human nourishment which the Arab Republic of Egypt needs so badly.

  1. Le Fleix – Bourg Ouest

    OpenAIRE

    Gineste, Marie-Christine

    2013-01-01

    Date de l'opération : 2009 (EX) Le projet d’extension d’une cantine scolaire est à l’origine de cette prescription. Il concerne une parcelle de 1 438 m2 située sur un replat de la terrasse holocène, en bordure d’un affluent de la Dordogne ; le Lasolle du Bost, dans le périmètre supposé de l’agglomération antique appelée « ville de Meille ». L’assiette du projet correspond au XIXe siècle à un secteur agricole non bâti. Deux tranchées ont été réalisées, occasionnant la découverte, surtout au no...

  2. Le Corbusier’s Dioramas

    Directory of Open Access Journals (Sweden)

    José Ramón Alonso Pereira

    2013-10-01

    Full Text Available AbstractLe Corbusier symbolizes the modern rational urbanism, whose rigorous effort of town planning demands a parallel effort of comprehension. It opposes to these contemporary urbanism that wish to perceive and to enjoy cities in a sensible way. Nevertheless, sentiment and reason are not adverses and Le Corbusier gives us at his  moment keys to intent a synthesis, joined them in a singular way by means of his ‘boîtes à miracles’ or ‘magic boxes’: those "architectural spectacles of synthesis" that he defined in 1951 Ciam. Here we try to approach to the first of those ‘spectacles’: the ‘diorama’, considering it as a corbusean strategy of mediation between rational and sensible in modern and contemporary city.Key wordsLe Corbusier, diorama, Ville Contemporaine, Plan Voisin, Plan Maciá

  3. La preuve par le nombre

    Directory of Open Access Journals (Sweden)

    Hélène Verdier

    2012-04-01

    Full Text Available S’il en était besoin, la question des usages et de la finalité des résultats de l’inventaire général pourrait être abordée par le nombre : nombre d’œuvres répertoriées, de communes inventoriées, de clichés photographiques réalisés, de dossiers, de consultations des notices dans les bases de données… Les additions aujourd’hui sont éloquentes, mais elles laissent dans l’ombre lele de l’inventaire qui, en mettant en œuvre une démarche systématique de connaissance, participe à l’ identificatio...

  4. Le front oriental de Lille

    Directory of Open Access Journals (Sweden)

    Étienne Poncelet

    2011-06-01

    Full Text Available De la porte d’eau de la Basse Deûle jusqu’au fort Saint-Sauveur, le front oriental de Lille, fortifié à l’époque espagnole, glisse ses courtines dans les entrelacs du périphérique et des gares. L’enjeu urbain actuel consiste à s’appuyer sur ces murs historiques pour « passer malgré tout » à travers cet écheveau urbain et retisser les fils de la continuité des promenades au cœur de la ville. Moins connus que le front occidental de la reine des citadelles, ces anciens espaces militaires sont une chance pour l’urbanisme de demain dont les opérations en cours de la Porte de Gand et de la Basse Deûle témoignent déjà.The east wall, at Lille, fortified during the period of Spanish occupation, extends from the Porte d'Eau de la Basse-Deûle to the Saint-Sauveur fort. Its curtain walls emerge today in a landscape of ring roads and railway territories. The issue today is to profit from these historic walls in order to make some sense of the urban chaos and to reinstate some urban continuity in the city-centre walkways. Although they are not as well known as the western wall of this major fortified city, these former military properties are an exciting opportunity for tomorrow's town-planners, as the operations already underway at the Porte de Gand et de la Basse Deûle suggest.

  5. Ligeti, Le Grand Macabre (1978)

    OpenAIRE

    Amaral, Pedro

    2011-01-01

    Le Grand Macabre, de Györgi Ligeti, uma obra que, em plenos anos setenta, retoma e reinventa a grande tradição da ópera de repertório. Escrita para a Ópera de Estocolmo, estreada em Abril de 1978, Le Grand Macabre é uma das obras mais marcantes e uma das mais consagradas, internacionalmente, no plano da música dramática da segunda metade do século XX. Escrita a partir de uma peça do dramaturgo belga Michel de Ghelderode, “A Balada do Grande Macabro”, de 1934, a obra de Ligeti retoma um...

  6. Agir sur le gaspillage alimentaire

    OpenAIRE

    Jan, Sophie; Baron, Florence

    2016-01-01

    On estime aujourd'hui à 25% les pertes d'aliments post-récolte et en aval, en raison de leur altération par des microorganismes. L'étude menée ici illustre le risque d'altération engendré par une rupture dans la chaîne du froid, en prenant comme modèle un aliment liquide pasteurisé et réfrigéré, riche en nutriments et dont la température ne doit pas dépasser 4°C.

  7. Le developpement autocentre avec integration dans le marche ...

    African Journals Online (AJOL)

    -arabe, que l'Europe accepterait à cause de son intérêt à stabiliser les pays du sud de la Méditerranée sur le plan social et politique. Mots Clés: Industrialisation, Rente, Exportation de produits manufacturés, Coopération euro-arabe ...

  8. Quantitative comparison of DNA detection by GFP-lac repressor tagging, fluorescence in situ hybridization and immunostaining

    Directory of Open Access Journals (Sweden)

    Rohr Karl

    2007-12-01

    Full Text Available Abstract Background GFP-fusion proteins and immunostaining are methods broadly applied to investigate the three-dimensional organization of cells and cell nuclei, the latter often studied in addition by fluorescence in situ hybridization (FISH. Direct comparisons of these detection methods are scarce, however. Results We provide a quantitative comparison of all three approaches. We make use of a cell line that contains a transgene array of lac operator repeats which are detected by GFP-lac repressor fusion proteins. Thus we can detect the same structure in individual cells by GFP fluorescence, by antibodies against GFP and by FISH with a probe against the transgene array. Anti-GFP antibody detection was repeated after FISH. Our results show that while all four signals obtained from a transgene array generally showed qualitative and quantitative similarity, they also differed in details. Conclusion Each of the tested methods revealed particular strengths and weaknesses, which should be considered when interpreting respective experimental results. Despite the required denaturation step, FISH signals in structurally preserved cells show a surprising similarity to signals generated before denaturation.

  9. Vibrational Relaxation of the Backbone and Base Modes in LacDNA Complexes by UV Resonance Raman Spectroscopy.

    Science.gov (United States)

    Muntean, Cristina M; Bratu, Ioan; Hernanz, Antonio

    2017-07-20

    Vibrational band shape analysis through time correlation function concept is widely used to obtain experimental information on the molecular dynamics of medium-size molecules in different environments. Interesting details are revealed by extending this technique to biomolecules such as functional groups of the nucleic acids in media approaching the physiological conditions. In this work a study into the UV resonance Raman (UVRR) vibrational half bandwidths of functional groups in LacDNA, upon lowering the pH (pH 6.4, pH 3.45) and in the presence of Mn 2+ and Ca 2+ ions, respectively, was of interest. The corresponding global relaxation times have been derived. Also, the 793 cm -1 UVRR band, corresponding to ν (backbone O-P-O, dT) oscillator of LacDNA in aqueous solutions, was selected for band shape-analysis. Vibrational relaxation appears as the dominant relaxation process for this mode, with vibrational dephasing being the most efficient for this oscillator. Current theories developed for vibrational dephasing have been applied to this profile, and relevant relaxation parameters have been obtained and discussed. To our knowledge this is the first study on DNA oligomers vibrational band shape analysis through time correlation function concept.

  10. An Analysis of Light Periods of BL Lac Object S5 0716+714 with the MUSIC Algorithm

    Science.gov (United States)

    Tang, Jie

    2012-07-01

    The multiple signal classification (MUSIC) algorithm is introduced to the estimation of light periods of BL Lac objects. The principle of the MUSIC algorithm is given, together with a testing on its spectral resolution by using a simulative signal. From a lot of literature, we have collected a large number of effective observational data of the BL Lac object S5 0716+714 in the three optical wavebands V, R, and I from 1994 to 2008. The light periods of S5 0716+714 are obtained by means of the MUSIC algorithm and average periodogram algorithm, respectively. It is found that there exist two major periodic components, one is the period of (3.33±0.08) yr, another is the period of (1.24±0.01) yr. The comparison of the performances of periodicity analysis of two algorithms indicates that the MUSIC algorithm has a smaller requirement on the sample length, as well as a good spectral resolution and anti-noise ability, to improve the accuracy of periodicity analysis in the case of short sample length.

  11. Lactose carrier protein of Escherichia coli. Structure and expression of plasmids carrying the Y gene of the lac operon.

    Science.gov (United States)

    Teather, R M; Bramhall, J; Riede, I; Wright, J K; Fürst, M; Aichele, G; Wilhelm, U; Overath, P

    1980-01-01

    The previously described hybrid plasmid pC7 which carries lacI+O+delta(Z)Y+A+ on a 12.3 X 10(6)-Mr DNA fragment [Teather et al. (1978) Mol. Gen. Genet. 159, 239-248] was partially digested with the restriction endonuclease EcoRI under conditions reducing the recognition sequence to d(A-A-T-T) and ligated to the vector pB322. lac Y-carrying inserts of various sized (Mr 1.5-4.7 X 10(6)) were obtained. Hybrid plasmid pTE18 (2300-base-pair insert) carries part of the I (repressor) gene, the promotor-operator region, part of the Z (beta-galactosidase) gene, the Y (lactose carrier) gene and part of the A (transacetylase) gene. Upon induction of pTE18-harbouring strains the Y-gene product is expressed at a nearly constant rate for several generations and accumulates to a level of 12-16% of the total cytoplasmic membrane protein. Integration into the membrane leads to active carrier as judged by binding and transport measurements.

  12. Hydrogen production by Escherichia coli {delta}hycA {delta}lacI using cheese whey as substrate

    Energy Technology Data Exchange (ETDEWEB)

    Rosales-Colunga, Luis Manuel; Ordonez, Leandro G.; De Leon-Rodriguez, Antonio (Division de Biologia Molecular, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la Presa San Jose 2055, Col. Lomas 4a secc. CP 78216, San Luis Potosi, SLP. Mexico); Razo-Flores, Elias; Alatriste-Mondragon, Felipe (Division de Ciencias Ambientales, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la Presa San Jose 2055, Col. Lomas 4a secc. CP 78216, San Luis Potosi, SLP. Mexico)

    2010-01-15

    This study reports a fermentative hydrogen production by Escherichia coli using cheese whey as substrate. To improve the biohydrogen production, an E. coli {delta}hycA {delta}lacI strain (WDHL) was constructed. The absence of hycA and lacI genes had a positive effect on the biohydrogen production. The strain produced 22% more biohydrogen in a shorter time than the wild-type (WT) strain. A Box-Behnken experimental design was used to optimize pH, temperature and substrate concentration. The optimal initial conditions for biohydrogen production by WDHL strain were pH 7.5, 37 C and 20 g/L of cheese whey. The specific production rate was improved from 3.29 mL H{sub 2}/optical density at 600 nm (OD{sub 600nm}) unit-h produced by WDHL under non-optimal conditions to 5.88 mL H{sub 2}/OD{sub 600nm} unit-h under optimal conditions. Using optimal initial conditions, galactose can be metabolized by WDHL strain. The maximum yield obtained was 2.74 mol H{sub 2}/mol lactose consumed, which is comparable with the yield reached in other hydrogen production processes with Clostridium sp. or mixed cultures. (author)

  13. Lac-L-TTA, a novel lactose-based amino acid-sugar conjugate for anti-metastatic applications.

    Science.gov (United States)

    Roviello, Giovanni N; Iannitti, Roberta; Palumbo, Rosanna; Simonyan, Hayarpi; Vicidomini, Caterina; Roviello, Valentina

    2017-08-01

    Here we describe the synthesis, chromatographic purification, MS and NMR characterization of a new lactosyl-derivative, i.e. a lactosyl thiophenyl-substituted triazolyl-thione L-alanine (Lac-L-TTA). This amino acid-sugar conjugate was prepared by solution synthesis in analogy to the natural fructosyl-amino acids. Furthermore, we investigated the inhibition of PC-3 prostate cancer cell colony formation by this lactose derivative in comparison with the less polar fructose-based derivative, Fru-L-TTA. This let us to compare the properties of the artificial derivative, object of the present work, with the monosaccharide-based counterpart and to obtain a preliminary information on the influence of polarity on such biological activity. A significantly higher anticancer effect of Lac-L-TTA with respect to the fructose analogue emerged from our study suggesting that the anti-metastatic potential of fructosyl-amino acids can be enhanced by increasing the polarity of the compounds, for example by introducing disaccharide moieties in place of fructose.

  14. Dissemination in athymic nude mice of lacZ transfected small cell lung cancer cells identified by X-gal staining

    DEFF Research Database (Denmark)

    Rømer, M U; Christiansen, J; Brünner, N

    1995-01-01

    The small cell lung cancer cell lines GLC-2 and DMS 456 were genetically labeled with the lacZ gene and examined for invasive and metastatic potential in META/Bom nude mice. The lacZ gene encodes the enzyme beta-D- galactosidase, and cells expressing this enzyme were identified by staining...... with the chromogenic substrate X-gal. lacZ expressing cells were investigated after subcutaneous (s.c.) inoculation and intravenous (i.v.) injection. The X-gal detection of beta-D-galactosidase activity proved to be a rapid and easy means for specific and highly sensitive identification of metastases. All primary s.......c. tumors stained by X-gal. The primary tumors of GLC-2 regularly demonstrated local invasive growth and produced multiple metastases in several organs. In contrast, primary DMS 456 tumors only occasionally demonstrated local invasion and very rarely generated secondary foci. No experimental metastases were...

  15. DYNAMIQUE DES PEUPLEMENTS DE POISSONS DANS LE RÉSERVOIR DE PETIT-SAUT (FLEUVE SINNAMARY, GUYANE FRANÇAISE.

    Directory of Open Access Journals (Sweden)

    DE MÉRONA B.

    2002-01-01

    Full Text Available La modélisation des effets des barrages hydroélectriques nécessite un grand nombre de données d’observation dans chacune des situations concrètes. En zone tropicale ces données sont souvent incomplètes et de nature hétérogène rendant difficile la comparaison entre des situations différentes. En janvier 1994, Electricité de France (EDF : Compagnie Nationale française d’Electricité a procédé à la fermeture du barrage de Petit-Saut sur le fleuve Sinnamary en Guyane française. A cette occasion, un suivi environnemental a été mené sur une période s’étendant depuis 5 années avant la fermeture jusqu’à 7 années après. En ce qui concerne les poissons, trois phases successives dans le processus de colonisation du lac ont été identifiées. Pendant la phase de mise en eau, les captures de poissons ont rapidement augmenté alors que la richesse spécifique diminuait. Une espèce dominait le peuplement. Durant les 2 années qui ont suivi, les captures se sont maintenues à un niveau élevé alors que la richesse spécifique continuait à diminuer. Le peuplement était dominé par deux espèces capables de tirer avantage des nouvelles ressources offertes par le lac. Enfin, au cours des 4 années suivantes, les captures diminuaient lentement et régulièrement et la composition spécifique se modifiait profondément. Ce schéma semble conforme à ce qui a été observé dans plusieurs grandes retenues en zone tropicale.

  16. p53 deficiency alters the yield and spectrum of radiation-induced lacZ mutants in the brain of transgenic mice

    Science.gov (United States)

    Chang, P. Y.; Kanazawa, N.; Lutze-Mann, L.; Winegar, R. A.

    2001-01-01

    Exposure to heavy particle radiation in the galacto-cosmic environment poses a significant risk in space exploration and the evaluation of radiation-induced genetic damage in tissues, especially in the central nervous system, is an important consideration in long-term manned space missions. We used a plasmid-based transgenic mouse model system, with the pUR288 lacZ transgene integrated in the genome of every cell of C57Bl/6(lacZ) mice, to evaluate the genetic damage induced by iron particle radiation. In order to examine the importance of genetic background on the radiation sensitivity of individuals, we cross-bred p53 wild-type lacZ transgenic mice with p53 nullizygous mice, producing lacZ transgenic mice that were either hemizygous or nullizygous for the p53 tumor suppressor gene. Animals were exposed to an acute dose of 1 Gy of iron particles and the lacZ mutation frequency (MF) in the brain was measured at time intervals from 1 to 16 weeks post-irradiation. Our results suggest that iron particles induced an increase in lacZ MF (2.4-fold increase in p53+/+ mice, 1.3-fold increase in p53+/- mice and 2.1-fold increase in p53-/- mice) and that this induction is both temporally regulated and p53 genotype dependent. Characterization of mutants based on their restriction patterns showed that the majority of the mutants arising spontaneously are derived from point mutations or small deletions in all three genotypes. Radiation induced alterations in the spectrum of deletion mutants and reorganization of the genome, as evidenced by the selection of mutants containing mouse genomic DNA. These observations are unique in that mutations in brain tissue after particle radiation exposure have never before been reported owing to technical limitations in most other mutation assays.

  17. Rapport sur le développement dans le monde sur le thème du rôle ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... rural et sont tributaires principalement de l'agriculture pour assurer leur subsistance. Ce projet permettra de veiller à ce qu'une place soit accordée aux travaux de recherche financés par le CRDI, aux points de vue différents et aux auteurs de l'hémisphère Sud dans le Rapport sur le développement dans le monde 2008.

  18. Le profil entrepreneurial : Facteur discriminant du developpement ...

    African Journals Online (AJOL)

    Le développement économique est un objectif majeur pour tout pays. Selon le classement établi par le Forum économique mondial, le développement économique dépend du niveau du PIB per capita et de la part des exportations des biens minéraux dans l'exportation totale. A partir de la base de données GEM Algérie, ...

  19. Quand le dentier devient danger!

    Science.gov (United States)

    Sadak, Nouzha; Herrak, Laila; Achachi, Leila; El Ftouh, Mustapha

    2017-01-01

    Bien que rare chez l'adulte, l'inhalation de corps étranger (CE) est un accident grave pouvant mettre en jeu le pronostic vital ou entrainer des séquelles importantes. Nous rapportons l'observation d'un patient de 50 ans, sans antécédents pathologiques particuliers, qui s'est présentée aux urgences pour douleur thoracique, toux intermittente et dyspnée d'effort, six jours après avoir inhalé, accidentellement, sa prothèse dentaire en plastique lors d'un repas. L'examen clinique était sans particularités. La radiographie thoracique ainsi que l'ASP ne montraient pas d'anomalie. Une bronchoscopie souple sous anesthésie générale a permis de visualiser le CE au niveau du tronc intermédiaire et l'extraction a été réalisée avec succès évitant ainsi le recours à un geste beaucoup plus invasif. La radiographie standard peut s'avérer utile en visualisant les CE radio-opaque ou par des signes indirects évoquant la présence d'un CE, mais le recours à la bronchoscopie à visée diagnostique et thérapeutique est primordial. PMID:28904706

  20. Nanostructures pour le développement de vaccins contre le virus de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Institut national de la recherche agronomique (France). Ce projet est financé par le fonds d'innovation en vaccins pour le bétail, un partenariat entre la fondation Bill et Melinda Gates, Affaires Mondiales Canada et le Centre de recherches pour le ...

  1. Le Kenya nomme le titulaire de sa première chaire de recherche

    International Development Research Centre (IDRC) Digital Library (Canada)

    14 avr. 2016 ... De concert avec le CRDI, la National Commission for Science, Technology and Innovation (NACOSTI) du Kenya a inauguré sa première chaire de recherche à Nairobi, le 31 mars 2015. Le professeur Fabian Omoding Esamai, qui dirige actuellement le College of Health Sciences de la Moi University, a été ...

  2. Dissemination in athymic nude mice of lacZ transfected small cell lung cancer cells identified by X-gal staining

    DEFF Research Database (Denmark)

    Rømer, M U; Christiansen, J; Brünner, N

    1995-01-01

    The small cell lung cancer cell lines GLC-2 and DMS 456 were genetically labeled with the lacZ gene and examined for invasive and metastatic potential in META/Bom nude mice. The lacZ gene encodes the enzyme beta-D- galactosidase, and cells expressing this enzyme were identified by staining...... found after i.v. injection of the examined tumor lines. The results indicate an intratumoral heterogeneity among individual SCLC tumors in the capacity for invasion and metastatic spread. The different metastatic pattern of GLC-2 after s.c. and i.v. inoculation supports the hypothesis that initial steps...

  3. Le LHC, priorité absolue

    CERN Multimedia

    Huet, S

    2002-01-01

    Le LHC, sa mise en est repoussee a 2007 quand les physiciens esperaient 2006. Le CERN a sous-estime les couts, environ 11% pour les 1 200 aimants supraconducteurs. Les Etats membres n'augmenteront pas leurs subventions, il propose donc cette semaine un plan drastique : tout pour le LHC (1/2 page).

  4. Le CERN ouvre ses entrailles au public

    CERN Multimedia

    2004-01-01

    "Le CERN se lance dans une grande opération de relations publiques pour son cinquantième anniversaire. Le centre de recherche organisera une journée portes ouvertes le 16 octobre. Quelque 50 sites pourrant être visités" (1/2 page)

  5. LE CORBUSIER: CONCURSOS Y PALACIOS / Le Corbusier: competitions and palaces

    Directory of Open Access Journals (Sweden)

    Fernando Zaparaín Hernández

    2012-11-01

    Full Text Available RESUMEN Cuando Le Corbusier ya había pasado de los cuarenta años se enfrentó a dos concursos internacionales: el Palacio de las Naciones en Ginebra (1926–31 y el Palacio de los Soviets en Moscú (1931–32 con los que intentaba acceder a grandes encargos de estado con mayor escala urbana en los que poner a prueba su ideario moderno sobre arquitectura y urbanismo. En ambos casos estuvo entre los vencedores pero por conveniencia e indecisión, los poderes políticos optaron por soluciones academicistas. Al conocer las decisiones definitivas, Le Corbusier y todos sus contactos del Movimiento Moderno orquestaron diversas polémicas ante los medios de comunicación y los gobernantes por entender que el progreso se veía lastrado por el triunfo de propuestas reaccionarias. Mediante el estudio de la correspondencia con personas particulares como Moser, Giedion, Colly o Stonorov, conservada en la Fundación Le Corbusier, se analizan las relaciones y el tono ideológico en torno a aquellas protestas. En esos textos quedan reflejados los principales rasgos que caracterizan la modernidad como su internacionalización, la seguridad en la propia misión, la defensa de lo nuevo o el método dialéctico. SUMMARY When Le Corbusier had already passed the age of forty he confronted two international competitions: the Palais des Nations in Geneva (1926–1931 and the Palace of the Soviets in Moscow (1931–32, with which he attempted to access large state commissions, with greater urban scale, in which to test his ideas about modern architecture and urbanism. In both cases he was among the winners, but through convenience and indecision the political powers opted for solutions from academicians. Upon knowing the final decisions, Le Corbusier and all his contacts in the Modern Movement orchestrated several controversies with the media, and the people in power, to convey that progress seemed burdened by the triumph of reactionary proposals. The relationships

  6. LE CORBUSIER: CONCURSOS Y PALACIOS / Le Corbusier: competitions and palaces

    Directory of Open Access Journals (Sweden)

    Fernando Zaparaín Hernández

    2012-11-01

    Full Text Available RESUMEN Cuando Le Corbusier ya había pasado de los cuarenta años se enfrentó a dos concursos internacionales: el Palacio de las Naciones en Ginebra (1926–31 y el Palacio de los Soviets en Moscú (1931–32 con los que intentaba acceder a grandes encargos de estado con mayor escala urbana en los que poner a prueba su ideario moderno sobre arquitectura y urbanismo. En ambos casos estuvo entre los vencedores pero por conveniencia e indecisión, los poderes políticos optaron por soluciones academicistas. Al conocer las decisiones definitivas, Le Corbusier y todos sus contactos del Movimiento Moderno orquestaron diversas polémicas ante los medios de comunicación y los gobernantes por entender que el progreso se veía lastrado por el triunfo de propuestas reaccionarias. Mediante el estudio de la correspondencia con personas particulares como Moser, Giedion, Colly o Stonorov, conservada en la Fundación Le Corbusier, se analizan las relaciones y el tono ideológico en torno a aquellas protestas. En esos textos quedan reflejados los principales rasgos que caracterizan la modernidad como su internacionalización, la seguridad en la propia misión, la defensa de lo nuevo o el método dialéctico.SUMMARY When Le Corbusier had already passed the age of forty he confronted two international competitions: the Palais des Nations in Geneva (1926–1931 and the Palace of the Soviets in Moscow (1931–32, with which he attempted to access large state commissions, with greater urban scale, in which to test his ideas about modern architecture and urbanism. In both cases he was among the winners, but through convenience and indecision the political powers opted for solutions from academicians. Upon knowing the final decisions, Le Corbusier and all his contacts in the Modern Movement orchestrated several controversies with the media, and the people in power, to convey that progress seemed burdened by the triumph of reactionary proposals. The relationships and

  7. Files de pierres dressées dans le sud de l'Éthiopie et au nord du Kenya

    OpenAIRE

    Joussaume, Roger

    2015-01-01

    Les travaux de deux équipes américaines dans les années 1970 et 2000 ont fait connaître plusieurs sites à lignes de pierres dressées près du lac Turkana au nord du Kenya. Les plus anciens sont datés du début du IIIe millénaire avant notre ère, d’autres de la deuxième moitié du premier millénaire avant J.-C. Ils furent l’œuvre d’une société de pasteurs qui aurait connu la céramique. Dans le Sidamo, au sud de l’Éthiopie, les stèles phalliques des pays Gedeo et Sidama forment fréquemment des ali...

  8. Publications | Page 95 | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le CRDI et la lutte contre le paludisme. DOCUMENT D'INFORMATION. Le paludisme tue un enfant africain toutes les 30 secondes. Avec le VIH/sida et la tuberculose, le paludisme est l'un des principaux problèmes de santé publique menaçant le.

  9. pour le trimestre qui a pris fin le 30 septembre 2017

    International Development Research Centre (IDRC) Digital Library (Canada)

    Sophie Comeau

    30 sept. 2017 ... Régi par la Loi sur le Centre de recherches pour le développement international (1970), le Centre de recherches pour le développement international (le Centre ou CRDI) vise à « lancer, encourager, appuyer et mener des recherches sur les problèmes des régions du monde en voie de développement et ...

  10. Reflexion sur le climat, l'effet de serre et le rechauffement global ...

    African Journals Online (AJOL)

    Le climat de la Terre est largement influencé par l'état de son atmosphère. Le rayonnement solaire jouerait un rôle primordial dans la climatologie terrestre certes, néanmoins, il n'est plus en mesure à lui tout seul d'expliquer le climat qui prédomine, en moyenne, à la surface de la terre. L'effet de serre serait le phénomène ...

  11. Rapport financier trimestriel pour le trimestre qui a pris fin le 31 ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Office 2004 Test Drive User

    31 déc. 2016 ... Lʼinformation et les divulgations contenues dans le Rapport annuel 2015-2016 sʼappliquent au trimestre sur lequel porte le présent rapport trimestriel, sauf indication contraire. Budget 2016-2017 révisé. Le Conseil des gouverneurs a approuvé le budget 2016-2017 avant le début de lʼexercice. Cʼest.

  12. Le contrôle de gestion des entreprises familiales : un contrôle non-financiarisé ?

    OpenAIRE

    Barbelivien, Dominique

    2016-01-01

    Nous examinons la tendance décrite dans la littérature quant à la financiarisation de la fonction de contrôle de gestion en nous appuyant sur le cas d’une entreprise de taille intermédiaire familiale. Nous constatons que le contrôle de gestion dans le cas étudié correspond à une rationalisation des décisions opérationnelles et développons les raisons qui peuvent expliquer la persistance d’un contrôle de gestion très opérationnel. Le contexte d’entreprise familiale dans laquelle il y a confusi...

  13. Comparaison de la variabilité génétique de deux espèces de poissons, l'ombre commun et le gardon, dans un fleuve aménagé

    Directory of Open Access Journals (Sweden)

    BOUVET Y.

    1992-01-01

    Full Text Available Les deux espèces habitent le bassin du Haut-Rhône français, en amont de Lyon. Mais leur variabilité génétique est très différente. La variabilité intra-populations de l'ombre ne représente qu'un tiers de la variation totale, mais celle du gardon en représente 86 %, avec une plus grande diversité dans les annexes du fleuve (Lac du Bourget, bras mort que dans le chenal. Ces différences sont discutées dans le cadre de l'étendue et de la structure de l'habitat de chaque espèce, ainsi que de l'impact de la gestion piscicole et des aménagements récents. L'ombre constitue de petites communautés autonomes accrochées au terrain et dont la diversité optimale se situe vers le milieu du gradient amont-aval du bassin. Les annexes semblent constituer, pour le gardon, des réservoirs de diversité génétique à partir desquels un flux génique important mais sélectionné dévale le fleuve.

  14. Bulletin #109 | CRDI - Le Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... offres d'emploi. Appel à propositions de recherche sur les villes résilientes en Amérique latine. Date butoir : 13 juin 2016. Programme de recherche sur le virus Zika Canada-Amérique latine et Caraïbes Date butoir : 12 juillet 2016. POSSIBILITÉS D'EMPLOIS Agent de ressources humaines · Analyste des opérations de TI.

  15. Le cosmos et le lotus confessions d'un astrophysicien

    CERN Document Server

    Trinh, Xuan Thuan

    2011-01-01

    Que nous dit vraiment la science sur la nature de l'univers, sur son origine et son avenir ? Par quel mystère le langage mathématique, pure création de l'esprit humain, se révèle-t-il aussi performant pour nous décrire les phénomènes physiques, de l'infiniment petit à l'infiniment grand ? S'il existe un ordre du monde, ce que nous en disent la physique quantique et la théorie de la relativité est-il compatible avec ce qu'enseigne le bouddhisme ? Et que peut-on en conclure concernant notre propre vie ? A ces questions passionnantes et à beaucoup d'autres, le célèbre astrophysicien Trinh Xuan Thuan répond ici d'une façon personnelle, en s'appuyant sur son expérience. Son itinéraire l'a placé d'emblée à la confluence de trois cultures : issu d'une famille de lettrés vietnamiens imprégnée de traditions bouddhiste et confucéenne, il a reçu une éducation à la française puis une formation scientifique à l'américaine. Une telle richesse de points de vue lui permet d'apporter, non pas de...

  16. Le futur du travail | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    12 juin 2017 ... Une base de données probantes est nécessaire afin de trouver des solutions stratégiques et sociales appropriées aux divers défis que posent ces nouveaux modes de travail. La recherche sur l'innovation en matière d'éducation et le renforcement des capacités seront également essentiels pour assurer la ...

  17. WHAT IS THE REDSHIFT OF THE GAMMA-RAY BL LAC SOURCE S4 0954+65?

    Energy Technology Data Exchange (ETDEWEB)

    Landoni, M. [INAF—Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807 Merate (Italy); Falomo, R. [INAF—Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy); Treves, A. [Universita’ degli Studi dell’Insubria, Via Valleggio 11, I-22100 (Italy); Scarpa, R.; Payá, D. Reverte, E-mail: marco.landoni@brera.inaf.it [Instituto de Astrofsica de Canarias, C/O Via Lactea, s/n E38205—La Laguna (Tenerife) (Spain)

    2015-12-15

    High signal-to-noise ratio spectroscopic observations of the BL Lac object S4 0954+65 at the alleged redshift z = 0.367 are presented. This source was detected at gamma frequencies by the MAGIC (TeV) and FERMI (GeV) telescopes during a remarkable outburst that occurred in 2015 February, making the determination of its distance particularly relevant for our understanding of the properties of the extragalactic background light. Contrary to previous reports on the redshift, we found that the optical spectrum is featureless at an equivalent width limit of ∼0.1 Å. A critical analysis of the existing observations indicates that the redshift is still unknown. Based on the new data we estimate a lower limit to the redshift at z ≥ 0.45.

  18. The cost of expression of Escherichia coli lac operon proteins is in the process, not in the products.

    Science.gov (United States)

    Stoebel, Daniel M; Dean, Antony M; Dykhuizen, Daniel E

    2008-03-01

    Transcriptional regulatory networks allow bacteria to express proteins only when they are needed. Adaptive hypotheses explaining the evolution of regulatory networks assume that unneeded expression is costly and therefore decreases fitness, but the proximate cause of this cost is not clear. We show that the cost in fitness to Escherichia coli strains constitutively expressing the lactose operon when lactose is absent is associated with the process of making the lac gene products, i.e., associated with the acts of transcription and/or translation. These results reject the hypotheses that regulation exists to prevent the waste of amino acids in useless protein or the detrimental activity of unnecessary proteins. While the cost of the process of protein expression occurs in all of the environments that we tested, the expression of the lactose permease could be costly or beneficial, depending on the environment. Our results identify the basis of a single selective pressure likely acting across the entire E. coli transcriptome.

  19. Complete Genomes of Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, Two Phylogenetically Distinct Probiotics

    Science.gov (United States)

    Ramya, T. N. C.; Subramanian, Srikrishna

    2016-01-01

    Several spore-forming strains of Bacillus are marketed as probiotics due to their ability to survive harsh gastrointestinal conditions and confer health benefits to the host. We report the complete genomes of two commercially available probiotics, Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, and compare them with the genomes of other Bacillus and Lactobacillus. The taxonomic position of both organisms was established with a maximum-likelihood tree based on twenty six housekeeping proteins. Analysis of all probiotic strains of Bacillus and Lactobacillus reveal that the essential sporulation proteins are conserved in all Bacillus probiotic strains while they are absent in Lactobacillus spp. We identified various antibiotic resistance, stress-related, and adhesion-related domains in these organisms, which likely provide support in exerting probiotic action by enabling adhesion to host epithelial cells and survival during antibiotic treatment and harsh conditions. PMID:27258038

  20. Complete Genomes of Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, Two Phylogenetically Distinct Probiotics.

    Directory of Open Access Journals (Sweden)

    Indu Khatri

    Full Text Available Several spore-forming strains of Bacillus are marketed as probiotics due to their ability to survive harsh gastrointestinal conditions and confer health benefits to the host. We report the complete genomes of two commercially available probiotics, Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, and compare them with the genomes of other Bacillus and Lactobacillus. The taxonomic position of both organisms was established with a maximum-likelihood tree based on twenty six housekeeping proteins. Analysis of all probiotic strains of Bacillus and Lactobacillus reveal that the essential sporulation proteins are conserved in all Bacillus probiotic strains while they are absent in Lactobacillus spp. We identified various antibiotic resistance, stress-related, and adhesion-related domains in these organisms, which likely provide support in exerting probiotic action by enabling adhesion to host epithelial cells and survival during antibiotic treatment and harsh conditions.

  1. Complete Genomes of Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, Two Phylogenetically Distinct Probiotics.

    Science.gov (United States)

    Khatri, Indu; Sharma, Shailza; Ramya, T N C; Subramanian, Srikrishna

    2016-01-01

    Several spore-forming strains of Bacillus are marketed as probiotics due to their ability to survive harsh gastrointestinal conditions and confer health benefits to the host. We report the complete genomes of two commercially available probiotics, Bacillus coagulans S-lac and Bacillus subtilis TO-A JPC, and compare them with the genomes of other Bacillus and Lactobacillus. The taxonomic position of both organisms was established with a maximum-likelihood tree based on twenty six housekeeping proteins. Analysis of all probiotic strains of Bacillus and Lactobacillus reveal that the essential sporulation proteins are conserved in all Bacillus probiotic strains while they are absent in Lactobacillus spp. We identified various antibiotic resistance, stress-related, and adhesion-related domains in these organisms, which likely provide support in exerting probiotic action by enabling adhesion to host epithelial cells and survival during antibiotic treatment and harsh conditions.

  2. Novel strategies to overcome expression problems encountered with toxic proteins: application to the production of Lac repressor proteins for NMR studies

    NARCIS (Netherlands)

    Romanuka, J.; van den Bulke, H.; Kaptein, R.; Boelens, R.; Folkers, G.E.

    2009-01-01

    NMR studies of structural aspects of allosteric regulation by the Lac repressor requires overexpression and isotope labeling of the protein. The size of the repressor makes it a challenging target, putting constraints on both expression conditions and sample preparation methods to overcome problems

  3. Specificity and affinity of Lac repressor for the auxiliary operators O2 and O3 are explained by the structures of their protein–DNA complexes

    NARCIS (Netherlands)

    Romanuka, J.|info:eu-repo/dai/nl/30483761X; Folkers, G.E.|info:eu-repo/dai/nl/162277202; Biris, N.; Tishchenko, E.; Wienk, H.L.J.|info:eu-repo/dai/nl/203884884; Bonvin, A.M.J.J.|info:eu-repo/dai/nl/113691238; Kaptein, R.|info:eu-repo/dai/nl/074334603; Boelens, R.|info:eu-repo/dai/nl/070151407

    2009-01-01

    The structures of a dimeric mutant of the Lac repressor DNA-binding domain complexed with the auxiliary operators O2 and O3 have been determined using NMR spectroscopy and compared to the structures of the previously determined Lac–O1 and Lac–nonoperator complexes. Structural analysis of the Lac–O1

  4. Methyl bromide causes DNA methylation in rats and mice but fails to induce somatic mutations in λlacZ transgenic mice

    NARCIS (Netherlands)

    Pletsa, V.; Steenwinkel, M.-J.S.T.; Delft, J.H.M. van; Baan, R.A.; Kyrtopoulos, S.A.

    1998-01-01

    Following single or multiple oral treatments of rats or λlacZ transgenic mice with methyl bromide, methylated DNA adducts (N7- and/or O6-methylguanine) were found at comparable levels in various tissues, including among others the glandular stomach, the forestomach and the liver. Multiple rat

  5. Subcellular localization of a PhoE-LacZ fusion protein in E. coli by protease accessibility experiments reveals an inner-membrane-spanning form of the protein

    NARCIS (Netherlands)

    Tommassen, J.P.M.; Kroon, T. de

    1987-01-01

    Protease accessibility experiments were employed to localize a PhoE-LacZ hybrid protein, encompassing a large N-terminal fragment of the outer membrane PhoE protein of E. coli, fused to β-galactosidase, at the subcellular level. In previous studies, this protein was shown to co-fractionate with the

  6. Tunable Control of an Escherichia coli Expression System for the Overproduction of Membrane Proteins by Titrated Expression of a Mutant lac Repressor.

    Science.gov (United States)

    Kim, Seong Keun; Lee, Dae-Hee; Kim, Oh Cheol; Kim, Jihyun F; Yoon, Sung Ho

    2017-09-15

    Most inducible expression systems suffer from growth defects, leaky basal induction, and inhomogeneous expression levels within a host cell population. These difficulties are most prominent with the overproduction of membrane proteins that are toxic to host cells. Here, we developed an Escherichia coli inducible expression system for membrane protein production based on titrated expression of a mutant lac repressor (mLacI). Performance of the mLacI inducible system was evaluated in conjunction with commonly used lac operator-based expression vectors using a T7 or tac promoter. Remarkably, expression of a target gene can be titrated by the dose-dependent addition of l-rhamnose, and the expression levels were homogeneous in the cell population. The developed system was successfully applied to overexpress three membrane proteins that were otherwise difficult to produce in E. coli. This gene expression control system can be easily applied to a broad range of existing protein expression systems and should be useful in constructing genetic circuits that require precise output signals.

  7. Pollen and plant macrofossils at Lac de Fully (2135 m a.s.l.): Holocene forest dynamics on a highland plateau in the Valais, Switzerland

    NARCIS (Netherlands)

    Finsinger, W.; Tinner, W.

    2007-01-01

    We use pollen, stomata and plant-macrofossil records to infer Holocene timberline fluctuations and changes in forest composition at Lac Supérieur de Fully (2135 m a.s.l.), a small lake located near the modern regional timberline on a highland plateau in the Central Alps. Our records suggest that

  8. Deposition mechanism and microstructure of laser-assisted cold-sprayed (LACS) Al-12 wt.%Si coatings: effects of laser power

    CSIR Research Space (South Africa)

    Olakanmi, EO

    2013-06-01

    Full Text Available at the substrate and build up a coating. To circumvent the processing problems associated with cold-spray (CS) deposition of low-temperature, corrosion-resistant Al-12 wt.%Si coatings, a preliminary investigation detailing the effect of laser power on its LACS...

  9. Characterization of platelet-derived growth factor-A expression in mouse tissues using a lacZ knock-in approach.

    Directory of Open Access Journals (Sweden)

    Johanna Andrae

    Full Text Available Expression of the platelet-derived growth factor A-chain gene (Pdgfa occurs widely in the developing mouse, where it is mainly localized to various epithelial and neuronal structures. Until now, in situ mRNA hybridization (ISH has been the only reliable method to identify Pdgfa expression in tissue sections or whole mount preparations. Validated protocols for in situ detection of PDGF-A protein by immunohistochemistry is lacking. In particular, this has hampered understanding of Pdgfa expression pattern in adult tissues, where ISH is technically challenging. Here, we report a gene targeted mouse Pdgfa allele, Pdgfaex4COIN, which is a combined conditional knockout and reporter allele. Cre-mediated inversion of the COIN cassette inactivates Pdgfa coding while simultaneously activating a beta-galactosidase (lacZ reporter under endogenous Pdgfa transcription control. The generated Pdgfaex4COIN-INV-lacZ allele can next be used to identify cells carrying a Pdgfa null allele, as well as to map endogenous Pdgfa expression. We evaluated the Pdgfaex4COIN-INV-lacZ allele as a reporter for endogenous Pdgfa expression patterns in mouse embryos and adults. We conclude that the expression pattern of Pdgfaex4COIN-INV-lacZ recapitulates known expression patterns of Pdgfa. We also report on novel embryonic and adult Pdgfa expression patterns in the mouse and discuss their implications for Pdgfa physiology.

  10. Contrasting expression of canonical Wnt signaling reporters TOPGAL, BATGAL and Axin2(LacZ during murine lung development and repair.

    Directory of Open Access Journals (Sweden)

    Denise Al Alam

    Full Text Available Canonical WNT signaling plays multiple roles in lung organogenesis and repair by regulating early progenitor cell fates: investigation has been enhanced by canonical Wnt reporter mice, TOPGAL, BATGAL and Axin2(LacZ. Although widely used, it remains unclear whether these reporters convey the same information about canonical Wnt signaling. We therefore compared beta-galactosidase expression patterns in canonical Wnt signaling of these reporter mice in whole embryo versus isolated prenatal lungs. To determine if expression varied further during repair, we analyzed comparative pulmonary expression of beta-galactosidase after naphthalene injury. Our data show important differences between reporter mice. While TOPGAL and BATGAL lines demonstrate Wnt signaling well in early lung epithelium, BATGAL expression is markedly reduced in late embryonic and adult lungs. By contrast, Axin2(LacZ expression is sustained in embryonic lung mesenchyme as well as epithelium. Three days into repair after naphthalene, BATGAL expression is induced in bronchial epithelium as well as TOPGAL expression (already strongly expressed without injury. Axin2(LacZ expression is increased in bronchial epithelium of injured lungs. Interestingly, both TOPGAL and Axin2(LacZ are up regulated in parabronchial smooth muscle cells during repair. Therefore the optimal choice of Wnt reporter line depends on whether up- or down-regulation of canonical Wnt signal reporting in either lung epithelium or mesenchyme is being compared.

  11. A specific and efficient photoreaction between E. coli RNA polymerase and T+1 in the lacUV5 or deoP1 promoter

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Jensen, Kaj Frank; Nielsen, Peter E.

    1988-01-01

    Upon irradiation of the RNA polymerase-lacUV5 or deoP1 promoter complex with short wavelength ultraviolet light (lambda less than or equal to 300 nm) the polymerase is covalently crosslinked at an efficiency of greater than 10% to the first transcribed base of the template DNA strand when...

  12. Additional new species of Hypostomus Lacépède, 1803, from Surinam; with remarks on the apparent „gymnorhynchus-complex” (Siluriformes, Loricariidae)

    NARCIS (Netherlands)

    Boeseman, M.

    1969-01-01

    Two new Surinam species of Hypostomus Lacépède are described, and their relationship is discussed; a group of three forms from eastern Surinam and (French) Guyane (gymnorhynchus-complex) is reconsidered; the species H. plecostomus (Linnaeus) is reported to hitherto survive in the lacustrine

  13. Mutant frequencies and spectra depend on growth state and passage number in cells cultured from transgenic lacZ-plasmid reporter mice.

    NARCIS (Netherlands)

    Busuttil, Rita A; Rubio, Miguel; Dollé, Martijn E T; Campisi, Judith; Vijg, Jan

    2006-01-01

    Transgenic mice harboring the lacZ gene within a plasmid that can be recovered and amplified in Escherichia coli, to establish mutant frequencies and spectra, have provided crucial insights into the relationships between mutations, cancer and aging in vivo. Here, we use embryonic fibroblasts from

  14. Lanthanum-mediated dehydrogenation of 1- and 2-butynes: Spectroscopy and formation of La(C4H4) isomers.

    Science.gov (United States)

    Cao, Wenjin; Hewage, Dilrukshi; Yang, Dong-Sheng

    2017-08-14

    La atom reactions with 1-butyne and 2-butyne are carried out in a laser-vaporization molecular beam source. Both reactions yield the same La-hydrocarbon products from the dehydrogenation and carbon-carbon bond cleavage and coupling of the butynes. The dehydrogenated species La(C 4 H 4 ) is characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectra of La(C 4 H 4 ) produced from the two reactions exhibit two identical transitions, each consisting of a strong origin band and several vibrational intervals. The two transitions are assigned to the ionization of two isomers: La(η 4 -CH 2 CCCH 2 ) (Iso A) and La(η 4 -CH 2 CHCCH) (Iso B). The ground electronic states are 2 A 1 (C 2v ) for Iso A and 2 A (C 1 ) for Iso B. The ionization of the doublet state of each isomer removes a La 6s-based electron and results in a 1 A 1 ion of Iso A and a 1 A ion of Iso B. The formation of Iso A from 2-butyne and Iso B from 1-butyne involves the addition of La to the C≡C triple bond, the activation of two C(sp 3 )-H bonds, and concerted elimination of a H 2 molecule. The formation of Iso A from 1-butyne and Iso B from 2-butyne involves the isomerization of the two butynes to 1,2-butadiene in addition to the concerted H 2 elimination.

  15. Water in the Cratonic Mantle: Insights from FTIR Data on Lac De Gras Xenoliths (Slave Craton, Canada)

    Science.gov (United States)

    Peslier, Anne H.; Brandon, Alan D.; Schaffer, Lillian Aurora; O'Reilly, Suzanne Yvette; Griffin, William L.; Morris, Richard V.; Graff, Trevor G.; Agresti, David G.

    2014-01-01

    The mantle lithosphere beneath the cratonic part of continents is the deepest (> 200 km) and oldest (>2-3 Ga) on Earth, remaining a conundrum as to how these cratonic roots could have resisted delamination by asthenospheric convection over time. Water, or trace H incorporated in mineral defects, could be a key player in the evolution of continental lithosphere because it influences melting and rheology of the mantle. Mantle xenoliths from the Lac de Gras kimberlite in the Slave craton were analyzed by FTIR. The cratonic mantle beneath Lac de Gras is stratified with shallow (<145 km) oxidized ultradepleted peridotites and pyroxenites with evidence for carbonatitic metasomatism, underlain by reduced and less depleted peridotites metasomatized by kimberlite melts. Peridotites analyzed so far have H O contents in ppm weight of 7-100 in their olivines, 58 to 255 in their orthopyroxenes (opx), 11 to 84 in their garnet, and 139 in one clinopyroxene. A pyroxenite contains 58 ppm H2O in opx and 5 ppm H2O in its olivine and garnet. Olivine and garnet from the deep peridotites have a range of water contents extending to higher values than those from the shallow ones. The FTIR spectra of olivines from the shallow samples have more prominent Group II OH bands compared to the olivines from the deep samples, consistent with a more oxidized mantle environment. The range of olivine water content is similar to that observed in Kaapvaal craton peridotites at the same depths (129-184 km) but does not extend to as high values as those from Udachnaya (Siberian craton). The Slave, Kaapvaal and Siberian cratons will be compared in terms of water content distribution, controls and role in cratonic root longevity.

  16. Lanthanum-mediated dehydrogenation of 1- and 2-butynes: Spectroscopy and formation of La(C4H4) isomers

    Science.gov (United States)

    Cao, Wenjin; Hewage, Dilrukshi; Yang, Dong-Sheng

    2017-08-01

    La atom reactions with 1-butyne and 2-butyne are carried out in a laser-vaporization molecular beam source. Both reactions yield the same La-hydrocarbon products from the dehydrogenation and carbon-carbon bond cleavage and coupling of the butynes. The dehydrogenated species La(C4H4) is characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectra of La(C4H4) produced from the two reactions exhibit two identical transitions, each consisting of a strong origin band and several vibrational intervals. The two transitions are assigned to the ionization of two isomers: La(η4-CH2CCCH2) (Iso A) and La(η4-CH2CHCCH) (Iso B). The ground electronic states are 2A1 (C2v) for Iso A and 2A (C1) for Iso B. The ionization of the doublet state of each isomer removes a La 6s-based electron and results in a 1A1 ion of Iso A and a 1A ion of Iso B. The formation of Iso A from 2-butyne and Iso B from 1-butyne involves the addition of La to the C≡C triple bond, the activation of two C(sp3)-H bonds, and concerted elimination of a H2 molecule. The formation of Iso A from 1-butyne and Iso B from 2-butyne involves the isomerization of the two butynes to 1,2-butadiene in addition to the concerted H2 elimination.

  17. Le glaive de la parole

    Directory of Open Access Journals (Sweden)

    Luce Marchal-Albert

    2006-09-01

    Full Text Available Chacun sait, selon le mot de Pierre Viret, « en quelle confusion est la Chrestienté » au xvie siècle en Europe. C’est le deuxième quart du siècle qui nous intéressera ici, et en particulier l’année 1545, qui constitue une année charnière qui voit vaciller l’Église romaine, flamber et culminer la chasse aux hérétiques en même temps qu’elle voit la jeune Église réformée se renforcer et se positionner avec succès dans un champ religieux plus que chaotique. Les ouvrages polémiques réformés écrits...

  18. Prendre le pli des techniques

    OpenAIRE

    Latour, Bruno

    1983-01-01

    À partir de la notion de mode d’existence développée par Gilbert Simondon et surtout par Etienne Souriau, il est possible d’aborder la question de la technique sans se laisser arrêter par la présence excessive de l’un de ses résultats : les objets techniques. On peut alors essayer de définir le mode propre de la technique comme un mouvement, un projet, un plissage, une forme très particulière de transcendance, qui n’a pas reçu en philosophie le traitement que mérite son importance et son ubiq...

  19. Le sette meraviglie del cosmo

    CERN Document Server

    Narlikar, Jayant V

    2004-01-01

    Tra giganti, "nane" e stelle che esplodono in cielo, un vademecum per scoprire il cosmo e i misteri che lo abitano. Lasciati alle spalle i confini sicuri della Terra e del Sistema solare, assistiamo a un'esplosione continua di fenomeni inaspettati. L'universo si svela nel suo continuo mutamento, cresce in fascino e complessità via via che ci addentriamo nei suoi spazi profondi. Tramite esempi semplici, aneddoti umoristici e una prosa cristallina, Vishnu Narkilar racconta l'emozione di fronte alle sorprese del cosmo. Le "sette meraviglie" sono i fenomeni misteriosi che si nascondono dietro le stelle che punteggiano il cielo, una schiera di eventi spettacolari che per secoli hanno sfidato la curiosità umana ed eluso ogni spiegazione.

  20. Le CRDI au Sri Lanka

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le CRDI appuie la recherche au Sri. Lanka depuis 1973. Il s'est d'abord concentré sur l'amélioration des pratiques agricoles. Par exemple, grâce à la mise au point d'un système de rizi - culture permettant d'exploiter les pluies de mousson, les riziculteurs ont triplé leurs rendements en quatre ans. Ils ont été nombreux à ...

  1. Le jumelage de journalistes scientifiques

    International Development Research Centre (IDRC) Digital Library (Canada)

    Cathy Egan

    Les questions scientifiques suscitent de plus en plus de doutes, d'angoisse et de discorde chez le grand public. Les profanes, peut-être plus encore que les scientifiques, s'interrogent et s'obstinent sur les causes du réchauffement planétaire, l'innocuité des organismes génétiquement modifiés (OGM) dans les aliments ou ...

  2. Georges et le big bang

    CERN Document Server

    Hawking, Lucy; Parsons, Gary

    2011-01-01

    Georges et Annie, sa meilleure amie, sont sur le point d'assister à l'une des plus importantes expériences scientifiques de tous les temps : explorer les premiers instants de l'Univers, le Big Bang ! Grâce à Cosmos, leur super ordinateur, et au Grand Collisionneur de hadrons créé par Éric, le père d'Annie, ils vont enfin pouvoir répondre à cette question essentielle : pourquoi existons nous ? Mais Georges et Annie découvrent qu'un complot diabolique se trame. Pire, c'est toute la recherche scientifique qui est en péril ! Entraîné dans d'incroyables aventures, Georges ira jusqu'aux confins de la galaxie pour sauver ses amis...Une plongée passionnante au coeur du Big Bang. Les toutes dernières théories de Stephen Hawking et des plus grands scientifiques actuels.

  3. An MSC2 Promoter-lacZ Fusion Gene Reveals Zinc-Responsive Changes in Sites of Transcription Initiation That Occur across the Yeast Genome.

    Directory of Open Access Journals (Sweden)

    Yi-Hsuan Wu

    Full Text Available The Msc2 and Zrg17 proteins of Saccharomyces cerevisiae form a complex to transport zinc into the endoplasmic reticulum. ZRG17 is transcriptionally induced in zinc-limited cells by the Zap1 transcription factor. In this report, we show that MSC2 mRNA also increases (~1.5 fold in zinc-limited cells. The MSC2 gene has two in-frame ATG codons at its 5' end, ATG1 and ATG2; ATG2 is the predicted initiation codon. When the MSC2 promoter was fused at ATG2 to the lacZ gene, we found that unlike the chromosomal gene this reporter showed a 4-fold decrease in lacZ mRNA in zinc-limited cells. Surprisingly, β-galactosidase activity generated by this fusion gene increased ~7 fold during zinc deficiency suggesting the influence of post-transcriptional factors. Transcription of MSC2ATG2-lacZ was found to start upstream of ATG1 in zinc-replete cells. In zinc-limited cells, transcription initiation shifted to sites just upstream of ATG2. From the results of mutational and polysome profile analyses, we propose the following explanation for these effects. In zinc-replete cells, MSC2ATG2-lacZ mRNA with long 5' UTRs fold into secondary structures that inhibit translation. In zinc-limited cells, transcripts with shorter unstructured 5' UTRs are generated that are more efficiently translated. Surprisingly, chromosomal MSC2 did not show start site shifts in response to zinc status and only shorter 5' UTRs were observed. However, the shifts that occur in the MSC2ATG2-lacZ construct led us to identify significant transcription start site changes affecting the expression of ~3% of all genes. Therefore, zinc status can profoundly alter transcription initiation across the yeast genome.

  4. Assessment of the hydraulic properties of fractured aquifers in crystalline and metamorphic formations in the region of Lacs (Central Côte d’Ivoire

    Directory of Open Access Journals (Sweden)

    Soro, G.

    2010-12-01

    Full Text Available Groundwater is the main source of water supply for rural populations in the Region des Lacs area in central Côte d’Ivoire (West Africa. The area is underlain by the metamorphic and crystalline fractured hard rock aquifers. This paper focuses on the assessment of their hydraulic properties. To this end, a data base comprising pumping tests data and the technical reports were gathered. 105 values of transmissivity (T and specific capacity (Q/s have been deduced after pumping tests interpretation by the Jacob recovery method. Statistical analyses of all these data have been done. Depth of wells range from 49.50 to 99 m with an average of 69 m. The thickness of the weathered zone has averaged 16.52 m and lies between 1.90 and 63.10 m. Wells average rate is 2.32 m3/s. The depths of open fractures are significantly in the first 60 meters of hard rock drilling and averaged 42.94 m. The transmissivity and specific capacity of each aquifer span over several orders of magnitude revealing the strong heterogeneity of the aquifer. Both variables are lognormal variables A significant empirical relationship between T and Q/s was found T = 0,937(Q/s^1.118 with a coefficient of determination (R^2 = 0.82. This relationship enabled the transmissivity data to be supplemented with the 95% prediction interval in order to assess the uncertainty associated with the estimates of transmissivity in the area of the study. These results are significant and can be used as an input in forthcoming modeling these aquifers and facilitate groundwater management policy.

    [fr] Dans la région des Lacs, centre de la Côte d’Ivoire (Afrique de l’Ouest, l’alimentation en eau potable des populations rurales est assurée en majorité par les eaux souterraines contenues dans les aquifères discontinus cristallin et cristallophyllien. L’objet de cet article est d’évaluer les propriétés hydrauliques de ces aquifères afin d’entreprendre des études pour la gestion

  5. Le principe non bis in idem et le droit communautaire

    OpenAIRE

    Hedabou, Aziz

    2018-01-01

    Le principe non bis in idem est une garantie fondamentale qui interdit que les mêmes faits soit poursuivi et puni deux fois. Il est reconnu par tous les droits internes et “appartient aux droit universel des nations”. Dès lors, sa lettre et son esprit ne sont plus cantonnés au droit interne et ont tendance à s’internationaliser. En droit communautaire, l’étude du principe non bis in idem peut être envisagée sous trois angles différents. D’abord en droit pénal international unilatéral où chaqu...

  6. Essai d'optimisation de la capacite de retenue d'eau d'un lac par ...

    African Journals Online (AJOL)

    L'appareil de mesure de la résistivité apparente est le résistivimètre GTR-2 à sommation de signaux et à compensation automatique de la polarisation spontanée de Geotrade Instruments. Le traitement des données de résistivités apparentes mesurées a été réalisé à l'aide du logiciel WinSev 3.3 de Geosoft. Les sondages ...

  7. Contester le mariage forcé : mettre en place la ligne de défense et le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le droit civil en matière de mariage est la Loi spéciale sur le mariage, qui permet aux parties de différentes religions de se marier sans changer de religion. Elle exige le consentement explicite des deux partenaires pour que le mariage soit possible. Le consentement demeure le point central de la loi sur le mariage; ...

  8. LE SECTEUR INFORMEL EN ALGERIE : APPROCHES, ACTEURS ...

    African Journals Online (AJOL)

    du respect des lois et des règlements et de l'Etat de droit de façon générale. 1.4. L'approche du secteur informel selon le Bureau International du Travail (BIT) ... qui ne tiennent pas une comptabilité complète et dont la person- l'importation…) mais également dans le secteur immobilier dont le fonctionnement est informel.

  9. Peut-on voyager dans le temps ?

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    La possibilité de voyager dans le temps est régulièrement évoquée par les magazines scientifiques (et parfois même par les scientifiques). Elle est également le sujet de nombreux romans de science-fiction. Nous discuterons d’abord du sens qu’on peut donner à l’expression « voyager dans le temps », puis nous expliciterons ce que la physique contemporaine dit à ce propos.

  10. Télécharger le PDF

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le CRDI finance la recherche dans les pays en développement afin de réduire la pauvreté, soutenant ainsi l'objectif des activités de dévelop- pement international du Canada. Le Centre favorise la croissance et le développement et encourage la communication des connaissances aux responsables des politiques, aux ...

  11. Le CRDI en Égypte

    International Development Research Centre (IDRC) Digital Library (Canada)

    afin d'y favoriser la croissance et le développement. Il en résulte des solutions locales, novatrices et durables, qui offrent des choix aux personnes qui en ont le plus besoin et font changer les choses. Centre de recherches pour le développement international. CP 8500, Ottawa (Ontario) Canada K1G 3H9. 1012 alexandrie.

  12. Le CRDI en Éthiopie

    International Development Research Centre (IDRC) Digital Library (Canada)

    'une crise. À long terme, toutefois, elle peut entraîner la dépendance et saper le système local de production de semences. Dans le cadre d'une étude menée de 2005 à 2008, des chercheurs s ubventionnés par le CRDI ont constaté que l'on ...

  13. Le corps dans l'Antiquité

    Directory of Open Access Journals (Sweden)

    Sophie Lalanne

    2008-06-01

    Full Text Available Ouvrages générauxLaqueur Thomas, La fabrique du sexe. Essai sur le corps et le genre en Occident, trad. fr., Paris, Gallimard, 1992.Feher Michel, Naddaff Ramona, Tazi Nadia, Fragments for a History of the Human Body, 3 volumes, New York, Zone Books, 1989.Le Corps dans l’AntiquitéBodiou Lydie, Frère Dominique, Mehl Véronique dir., L’expression des corps. Gestes, attitudes, regards dans l’iconographie antique, Rennes, Presses Universitaires de Rennes, 2006.Bonnard Jean-Baptiste, Le complexe de ...

  14. Le marketing : quelle contribution au bien commun ?

    OpenAIRE

    Béji-Bécheur, Amina

    2015-01-01

    National audience; Partons d'un constat : le marketing est né pour servir l'entreprise capitaliste et le développement de ses marchés. Le but ultime étant la création de richesses et par ricochet le bien-être des populations. Un ensemble d'outils marketing ont été créés pour accompagner les enjeux de performance économique des entreprises. Reprenant les travaux de Jean-Claude Moisdon (Du mode d'existence des outils de gestion, les instruments de gestion à l'épreuve de l'organisation 1), ces o...

  15. Le marketing cherche ses marques

    OpenAIRE

    Hentschel, Dieter

    2018-01-01

    Voici maintenant dix ans que, dans le cadre d’une politique continue de diversification des formations offertes aux germanistes, l’IAA a mis en place un enseignement de marketing. Cette innovation n’est pas restée sans suite, puisqu’elle a abouti au repositionnement du DESS « économie et Société dans les pays de langue allemande » qui s’appelle désormais « Gestion et marketing franco-allemands ». L’objectif a été de proposer aux étudiants une formation professionnalisante qui corresponde aux ...

  16. Le CRDI et la lutte contre le paludisme | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    22 juil. 2011 ... D'autres interventions luttent également contre le paludisme, notamment les moustiquaires imprégnées d'insecticide et les médicaments visant à prévenir le ... Le CRDI appuie le GCRAI depuis les années 1970 et participe avec SIMA au financement de la recherche sur les interactions complexes entre ...

  17. Lele du langage de programmation dans la réalisation de code ...

    African Journals Online (AJOL)

    Lele du langage de programmation dans la réalisation de code de qualité, les cas de Delphi et C++ Nous discutons dans ce papier lele du langage de programmation dans la production d'un code de qualité. La qualité d'un code peut être atteinte en respectant certains critères simples au niveau de la programmation ...

  18. Le

    NARCIS (Netherlands)

    de Beer, P.T.; Luttikhuizen, R.; Barbier, J.C.; Gautii, J.

    1998-01-01

    Interventions ` visie ` la fois iconomique et sociale, les politiques publiques de l'emploi (PPE) de chaque pays trouvent leur logique dans une relation itroite avec chacun des systhmes nationaux de protection sociale. La premihre partie de cet ouvrage est consacrie ` la prisentation de cas

  19. Nutrient, trace-element, and ecological history of Musky Bay, Lac Courte Oreilles, Wisconsin, as inferred from sediment cores

    Science.gov (United States)

    Fitzpatrick, Faith A.; Garrison, Paul J.; Fitzgerald, Sharon A.; Elder, John F.

    2003-01-01

    Sediment cores were collected from Musky Bay, Lac Courte Oreilles, and from surrounding areas in 1999 and 2001 to determine whether the water quality of Musky Bay has declined during the last 100 years or more as a result of human activity, specifically cottage development and cranberry farming. Selected cores were analyzed for sedimentation rates, nutrients, minor and trace elements, biogenic silica, diatom assemblages, and pollen over the past several decades. Two cranberry bogs constructed along Musky Bay in 1939 and the early 1950s were substantially expanded between 1950?62 and between 1980?98. Cottage development on Musky Bay has occurred at a steady rate since about 1930, although currently housing density on Musky Bay is one-third to one-half the housing density surrounding three other Lac Courte Oreilles bays. Sedimentation rates were reconstructed for a core from Musky Bay by use of three lead radioisotope models and the cesium-137 profile. The historical average mass and linear sedimentation rates for Musky Bay are 0.023 grams per square centimeter per year and 0.84 centimeters per year, respectively, for the period of about 1936?90. There is also limited evidence that sedimentation rates may have increased after the mid-1990s. Historical changes in input of organic carbon, nitrogen, phosphorus, and sulfur to Musky Bay could not be directly identified from concentration profiles of these elements because of the potential for postdepositional migration and recycling. Minor- and trace-element profiles from the Musky Bay core possibly reflect historical changes in the input of clastic material over time, as well as potential changes in atmospheric deposition inputs. The input of clastic material to the bay increased slightly after European settlement and possibly in the 1930s through 1950s. Concentrations of copper in the Musky Bay core increased steadily through the early to mid-1900s until about 1980 and appear to reflect inputs from atmospheric

  20. Le CRDI participe à la lutte mondiale contre le VIH/sida | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    15 juil. 2014 ... Le Centre de recherches pour le développement international (CRDI), organisme canadien, a été l'un des premiers bailleurs de fonds à vocation internationale à reconnaître que le VIH/sida constituait un problème de développement important.

  1. Le CRDI participe à la lutte mondiale contre le VIH/sida | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    15 juil. 2014 ... Le Centre de recherches pour le développement international (CRDI), organisme canadien, a été l'un des premiers bailleurs de fonds à vocation internationale à reconnaître que le VIH/sida constituait un problème de développement important.

  2. Lanthanum-mediated dehydrogenation of butenes: Spectroscopy and formation of La(C4H6) isomers.

    Science.gov (United States)

    Cao, Wenjin; Hewage, Dilrukshi; Yang, Dong-Sheng

    2018-01-28

    La atom reactions with 1-butene, 2-butene, and isobutene are carried out in a laser-vaporization molecular beam source. The three reactions yield the same La-hydrocarbon products from the dehydrogenation and carbon-carbon bond cleavage and coupling of the butenes. The dehydrogenated species La(C 4 H 6 ) is the major product, which is characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectrum of La(C 4 H 6 ) produced from the La+1-butene reaction exhibits two band systems, whereas the MATI spectra produced from the La+2-butene and isobutene reactions display only a single band system. Each of these spectra shows a strong origin band and several vibrational progressions. The two band systems from the spectrum of the 1-butene reaction are assigned to the ionization of two isomers: La[C(CH 2 ) 3 ] (Iso A) and La(CH 2 CHCHCH 2 ) (Iso B), and the single band system from the spectra of the 2-butene and isobutene reactions is attributed to Iso B and Iso A, respectively. The ground electronic states are 2 A 1 (C 3v ) for Iso A and 2 A' (C s ) for Iso B. The ionization of the doublet state of each isomer removes a La 6s-based electron and leads to the 1 A 1 ion of Iso A and the 1 A' ion of Iso B. The formation of both isomers consists of La addition to the C=C double bond, La insertion into two C(sp 3 )-H bonds, and H 2 elimination. In addition to these steps, the formation of Iso A from the La+1-butene reaction may involve the isomerization of 1-butene to isobutene prior to the C-H bond activation, whereas the formation of Iso B from the La+trans-2-butene reaction may include the trans- to cis-butene isomerization after the C-H bond activation.

  3. Lanthanum-mediated dehydrogenation of butenes: Spectroscopy and formation of La(C4H6) isomers

    Science.gov (United States)

    Cao, Wenjin; Hewage, Dilrukshi; Yang, Dong-Sheng

    2018-01-01

    La atom reactions with 1-butene, 2-butene, and isobutene are carried out in a laser-vaporization molecular beam source. The three reactions yield the same La-hydrocarbon products from the dehydrogenation and carbon-carbon bond cleavage and coupling of the butenes. The dehydrogenated species La(C4H6) is the major product, which is characterized with mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical computations. The MATI spectrum of La(C4H6) produced from the La+1-butene reaction exhibits two band systems, whereas the MATI spectra produced from the La+2-butene and isobutene reactions display only a single band system. Each of these spectra shows a strong origin band and several vibrational progressions. The two band systems from the spectrum of the 1-butene reaction are assigned to the ionization of two isomers: La[C(CH2)3] (Iso A) and La(CH2CHCHCH2) (Iso B), and the single band system from the spectra of the 2-butene and isobutene reactions is attributed to Iso B and Iso A, respectively. The ground electronic states are 2A1 (C3v) for Iso A and 2A' (Cs) for Iso B. The ionization of the doublet state of each isomer removes a La 6s-based electron and leads to the 1A1 ion of Iso A and the 1A' ion of Iso B. The formation of both isomers consists of La addition to the C=C double bond, La insertion into two C(sp3)—H bonds, and H2 elimination. In addition to these steps, the formation of Iso A from the La+1-butene reaction may involve the isomerization of 1-butene to isobutene prior to the C—H bond activation, whereas the formation of Iso B from the La+trans-2-butene reaction may include the trans- to cis-butene isomerization after the C—H bond activation.

  4. L'analyse des semences d'arachide fermières pour le contrôle de ...

    African Journals Online (AJOL)

    Le manque de semences sélectionnées en qualité satisfaisante et en quantités suffisantes est une contrainte majeure à la production de l'arachide (Arachis hypogea L.) en Afrique centrale. La multiplication de semences en milieu paysan est le moyen de propagation le plus rapide, le moins cher et le plus durable.

  5. Aharon Appelfeld et Philip Roth : le réel, l’imaginaire, le double et le fantastique

    OpenAIRE

    Toren, Orly

    2014-01-01

    C’est la marge étroite entre « le réel et l’imaginaire » selon le titre de l’essai de Masha Itzhaki sur Appelfeld que nous souhaiterions explorer à partir de la relation entre Le Temps des prodiges d’Appelfeld et Opération Shylock de Philip Roth. Si la vrai/fausse « confession » de Roth se présente comme le détournement vertigineux des codes du fantastique, de l’autobiographie et de l’autofiction, le roman d’Appelfeld pousse les limites du réalisme par l’interrogation que suscite son titre én...

  6. L’Association du personnel, le TREF, le Comité des Finances et le Conseil du CERN

    CERN Multimedia

    Staff Association

    2016-01-01

    L’Association du personnel, forte de son approche participative et consensuelle, recherche toujours le meilleur accord possible pour l’Organisation et son personnel. Pour ce faire, discussions et concertation avec la Direction, travail d’explication et de persuasion au TREF et ailleurs auprès des délégués des États membres sont nos principaux atouts. TREF (Tripartite Employment Conditions Forum), un Forum d’échanges, de discussions « L’objectif du Forum est d’améliorer le processus de prise de décision  en donnant aux personnes concernées la possibilité et le temps de comprendre pleinement la position de tous les participants. » (CERN/RTG/8) Le Forum tripartite sur les conditions d’emploi (TREF), créé par le Conseil du CERN en juin 1994, est composé de r...

  7. Le contrôle de gestion environnementale d'une entreprise

    OpenAIRE

    Marquet-Pondeville, Sophie

    2001-01-01

    Dans cette recherche, nous étudions comment s’opère le contrôle de gestion environnementale. Cette problématique est abordée dans une perspective contingente et nous proposons un modèle théorique qui met en évidence l’impact de certaines variables sur les systèmes de contrôle de la gestion environnementale. Certains liens présents dans ce modèle sont discutés à travers une étude de cas.

  8. Le facteur humain et la sûreté de fonctionnement dans le ...

    African Journals Online (AJOL)

    Notre contribution porte sur lele fondamental du facteur humain dans le management intégré des risques d'une part et du rôle déterminant qu'il peut avoir à jouer pour que la sûreté de fonctionnement réponde à sa propriété d'autre part. Un rôle illustré à travers une analyse de risque dans un complexe de Gaz Naturel ...

  9. Effect of the partial NaCl substitution by other chloride salts on the volatile profile during the ripening of dry-cured lacón

    Directory of Open Access Journals (Sweden)

    Domínguez, R.

    2016-06-01

    Full Text Available The influence of three salting treatments (treatment II: 50% NaCl-50% KCl; III: 45% NaCl-25% KCl-20% CaCl2-10% MgCl2; IV: 30% NaCl-50% KCl-15% CaCl2-5% MgCl2 on the formation of volatile compounds throughout the process was studied and compared to those of a control “lacón” (treatment I: 100% NaCl. There was an intense formation of volatile compounds throughout the processing, particularly during the dry-ripening stage. The most abundant chemical family in all the formulations, in the final product was hydrocarbons followed by aldehydes. The total volatile compound release was more intense in the control “lacóns” (1164 AU_106·g-1dry matter than in “lacóns” from formulations II, III and IV (817-891 AUx106·g-1dry matter. The “lacóns” from formulation I showed the highest amounts of aldehydes. The “lacóns” from formulations I and II presented the highest amounts of hydrocarbons. The main conclusion is that the replacement of NaCl produces changes in the volatile profile and could be affect the aroma of “lacón”.Se estudió la influencia de tres tratamientos de salado (tratamiento II: 50 % NaCl-50 % KCl; III: 45 % NaCl-25 % KCl-20 % CaCl2-10 % MgCl2; IV: 30 % NaCl-50 % KCl-15 % CaCl2-5 % MgCl2 en la formación de compuestos volátiles durante la elaboración de lacón, en comparación con un control (tratamiento I: 100 % NaCl. Hubo una intensa formación de compuestos volátiles durante el procesado, principalmente durante la fase de secado-maduración. La familia química más abundante en el producto final fueron los hidrocarbonos, seguidos por los aldehídos. La liberación de volátiles fue más intensa en los lacones control (1164 AU_106·g-1 materia seca que en los otros lacones (817-891 AUx106· g-1 materia seca. Los lacones de la formulación I mostraron las mayores cantidades de aldehídos, y los lacones de las formulaciones I y II presentaron los mayores contenidos de hidrocarburos. La principal conclusi

  10. Le Hodler d'Iéna

    OpenAIRE

    2017-01-01

    Suites de la protestation contre le bombardement de la cathédrale de Reims. Nouvelle proposition de M. Gunsburger pour le rachat du tableau de Hodler "Départ des étudiants d'Iéna pour la guerre de libération contre Napoléon en 1813".

  11. L'astronomie dans le monde

    Science.gov (United States)

    Manfroid, J.

    2008-09-01

    Fragmentation et astéroïdes binaires; Astéroïde géocroiseur triple; Rosetta sort de son hibernation; Messenger; Transit lunaire vu par Deep Impact; Titan; Phobos; Phoenix; Einstein avait raison; Le ballet des taches rouges; Le poids des lentilles;

  12. Sources of variability in data from a positive selection lacZ transgenic mouse mutation assay: an interlaboratory study.

    Science.gov (United States)

    Piegorsch, W W; Lockhart, A C; Carr, G J; Margolin, B H; Brooks, T; Douglas, G R; Liegibel, U M; Suzuki, T; Thybaud, V; van Delft, J H; Gorelick, N J

    1997-02-14

    Experimental features of a positive selection transgenic mouse mutation assay based on a lambda lacZ transgene are considered in detail, with emphasis on results using germ cells as the target tissue. Sources of variability in the experimental protocol that can affect the statistical nature of the observations are examined, with the goal of identifying sources of excess variation in the observed mutant frequencies. The sources include plate-to-plate (within packages), package-to-package (within animals), and animal-to-animal variability. Data from five laboratories are evaluated in detail. Results suggest only scattered patterns of excess variability below the animal-to-animal level, but, generally, significant excess variability at the animal-to-animal level. Using source of variability analyses to guide the choice of statistical methods, control-vs-treatment comparisons are performed for assessing the male germ cell mutagenicity of ethylnitrosourea (ENU), isopropyl methanesulfonate (iPMS), and methyl methanesulfonate (MMS). Results on male germ cell mutagenesis of ethyl methanesulfonate (EMS) and methylnitrosourea (MNU) are also reported.

  13. Advances in the graphitization protocol at the Radiocarbon Laboratory of the Universidade Federal Fluminense (LAC-UFF) in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Macario, Kita D., E-mail: kitamacario@gmail.com [Departamento de Física, Instituto deFísica, Universidade Federal Fluminense, Campus da Praia Vermelha, Av. Gal. Milton Tavares de Souza s/n°, Niterói, RJ, 24210-346 (Brazil); Oliveira, Fabiana M. [Departamento de Física, Instituto deFísica, Universidade Federal Fluminense, Campus da Praia Vermelha, Av. Gal. Milton Tavares de Souza s/n°, Niterói, RJ, 24210-346 (Brazil); Carvalho, Carla [Departamento de Geoquímica, Instituto de Química, Universidade Federal Fluminense, Campus do Valonguinho, Outeiro São João Batista, s/n°, Niterói, RJ, 24020-150 (Brazil); Santos, Guaciara M.; Xu, Xiaomei [Department of Earth System Science, B321 Croul Hall, University of California Irvine, Irvine, CA, 92697-3100 (United States); Chanca, Ingrid S.; Alves, Eduardo Q.; Jou, Renata M.; Oliveira, Maria Isabela; Pereira, Bruna B.; Moreira, Vinicius; Muniz, Marcelo C.; Linares, Roberto; Gomes, Paulo Roberto Silveira; Meigikos dos Anjos, Roberto [Departamento de Física, Instituto deFísica, Universidade Federal Fluminense, Campus da Praia Vermelha, Av. Gal. Milton Tavares de Souza s/n°, Niterói, RJ, 24210-346 (Brazil); and others

    2015-10-15

    In this paper, we summarize the sample preparation methods currently used at the Radiocarbon Laboratory of the Universidade Federal Fluminense (LAC-UFF) in Brazil. We also report on a series of results with regards to the graphitization protocol. Tests with different temperatures and baking times were performed, and carbon stable isotope ratios of graphite were measured by an EA–IRMS (elemental analyzer coupled with an isotopic ratio mass spectrometer) to infer the completeness of the graphitization reaction. We monitored the muffle furnace temperature using an independent thermocouple and found a −60 °C offset, which may have caused the lower graphitization yields (detected from the large isotopic fractionation on several reference materials targets). At a temperature of 520 °C, the isotopic fractionation in the graphitization reaction was systematically lower (−5‰ in average) and the overall scattering was reduced. As long as isotopic fractionation corrections are made using the online stable isotopes ratios provided by the AMS system, the accuracy of the {sup 14}C results should be maintained.

  14. Mutagenicity of the peroxisome proliferators clofibrate, Wyeth 14,643 and di-2-ethylhexyl phthalate in the lacZ plasmid-based transgenic mouse mutation assay

    Directory of Open Access Journals (Sweden)

    Boerrigter Michaël

    2004-01-01

    Full Text Available Abstract Background Peroxisome proliferators are considered rodent carcinogens that are putative human non-carcinogens based on the presumed absence of direct genetic toxicity in rodent and human cells and the resistance of human cells to the induction of peroxisomes by peroxisome proliferators. The highly sensitive lacZ plasmid-based transgenic mouse mutation assay was employed to investigate the mutagenicity of several peroxisome proliferators based on several lines of evidence suggesting that these agents may in fact exert a genotoxic effect. Methods Male and female lacZ-plasmid based transgenic mice were treated at 4 months of age with 6 doses of 2,333 mg di-2-ethylhexyl phthalate (DHEP, 200 mg Wyeth-14,643, or 90 mg clofibrate per kg of bodyweight, respectively, over a two-week period. Control animals were treated with the respective vehicles only (35% propyl glycol for DEHP and Wyeth-14,643 treatment controls and sterile water for clofibrate treatment controls. The mutant frequency in liver, kidney and spleen DNA was determined as the proportion of retrieved mutant and wild-type lacZ plasmids expressed in Escherichia Coli C host cells employing a positive selection system for mutant plasmids. Results Exposure to DEHP or Wyeth-14,643 significantly increased the mutant frequency in liver, but not in kidney or spleen, of both female and male mice. Treatment with clofibrate did not lead to an increased mutant frequency in any of the organs studied. Conclusion The results indicate that some peroxisome proliferators display an organ-specific mutagenicity in lacZ plasmid-based transgenic mice consistent with historical observations of organ- and compound-specific carcinogenicity.

  15. A new pale-spotted species of Hypostomus Lacépède (Siluriformes: Loricariidae from the rio Tocantins and rio Xingu basins in central Brazil

    Directory of Open Access Journals (Sweden)

    Cláudio H. Zawadzki

    Full Text Available A new species of the genus Hypostomus Lacépède (Siluriformes, Loricariidae from rio Tocantins and rio Xingu basins in central Brazil, is described. The new species is distinguished from its congeners by a unique combination of pale blotches over a darker background on head, body and fins, and conspicuous keels on head, predorsal region and lateral plates. Comments on the pale-spotted species of Hypostomus are provided.

  16. ENDOR determination of the proton positions around Gd3+ in La(C2H5SO4)3.9H2O

    International Nuclear Information System (INIS)

    Beer, R. de; Biesboer, F.; Ormondt, D. van

    1976-01-01

    The water proton positions around Gd 3+ in La(C 2 H 5 SO 4 ) 3 .9H 2 O have been determined by means of ENDOR. The positions of the nearest neighbour water oxygens are discussed on the basis of a superposition model analysis of the ratios b 2 0 /A 2 0 2 >, b 6 6 /b 6 0 and mod(A 6 6 )modA 6 0 . (Auth.)

  17. Le barrage des trois Gorges (Chine

    Directory of Open Access Journals (Sweden)

    Luc Merchez

    1999-09-01

    Full Text Available Le barrage des Trois Gorges, en construction sur le Yangzijiang, sera le plus grand barrage au monde. Le gigantisme du projet et sa médiatisation croissante en Occident permettent d'en saisir les enjeux environnementaux et humains. On analyse les grandes caractéristiques du projet et ses conséquences premières avant d'aborder le travail de recherche de l'équipe SIG de l'IGA de Grenoble qui vise à préparer la relocalisation de plus d'un million d'habitants, et à modéliser les impacts démographiques et sociaux.

  18. Le Premier Amendement : un mythe

    Directory of Open Access Journals (Sweden)

    Claude‑Jean Bertrand

    2006-03-01

    Full Text Available Ce papier, plein de verve, d’humeur et d’humour, pose, comme sait si bien le faire l’auteur, des questions profondes sous une apparence paradoxale. Il a été présenté lors d’un colloque sur le Premier amendement organisé à l’Université Lumière-Lyon 2 les 17 et 18 janvier 2003. Certaines communications ont été publiées dans le volume XXIV, n°1 (2003, « Le premier amendement : un modèle américain des libertés » (sous la direction de Vincent Michelot de la Revue Tocqueville.

  19. Cisjordanie et Gaza | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le conflit qui perdure et la violence politique ont aggravé le stress chez les adolescents, qui constituent près de la moitié de la population de la Cisjordanie. La violence politique et le conflit qui perdure ont aggravé le stress chez les adolescents. Le problème a été analysé dans le cadre de travaux menés en collaboration ...

  20. Louisiana SIP: LAC 33:III Ch 2147. Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 2011-08-04 (LAd34) to 2017-09-27

    Science.gov (United States)

    Louisiana SIP: LAC 33:III Ch 2147. Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 2011-08-04 (LAd34) to 2017-09-27

  1. Characterization of stress-responsive behavior in Pseudomonas aeruginosa PAO: isolation of Tn3-lacZYA fusions with novel damage-inducible (din) promoters.

    Science.gov (United States)

    Warner-Bartnicki, A L; Miller, R V

    1992-03-01

    Although the pervasive soil and water microorganism Pseudomonas aeruginosa demonstrates heightened sensitivity to UV radiation, this species possesses a recA gene that, based on structural and functional properties, could mediate a DNA damage-responsive regulon similar to the SOS regulon of Escherichia coli. To determine whether P. aeruginosa encodes such stress-inducible genes, the response of P. aeruginosa to DNA-damaging agents including far-UV radiation (UVC) and the quinolone antimicrobial agent norfloxacin was investigated by monitoring the expression of fusions linking P. aeruginosa promoters to a beta-galactosidase reporter gene. These fusions were obtained by Tn3-HoHoI insertional mutagenesis of a P. aeruginosa genomic library. Eight different damage-inducible (din) gene fusions were isolated which lack homology to the P. aeruginosa recA gene. Expression of the three gene fusions studied, dinA::lacZYA, dinB::lacZYA, and dinC::lacZYA, increased following UVC and quinolone exposure but not following heat shock. Similar to E. coli SOS genes, the din genes were induced to different extents and with dissimilar kinetics following UVC irradiation.

  2. Assessment of aquifer properties, evapotranspiration, and the effects of ditching in the Stoney Brook watershed, Fond du Lac Reservation, Minnesota, 2006-9

    Science.gov (United States)

    Jones, Perry M.; Tomasek, Abigail A.

    2015-01-01

    The U.S. Geological Survey, in cooperation with the Fond du Lac Band of Lake Superior Chippewa, assessed hydraulic properties of geologic material, recharge, and evapotranspiration, and the effects of ditching on the groundwater resources in the Stoney Brook watershed in the Fond du Lac Reservation. Geologic, groundwater, and surface-water data were collected during 2006–9 to estimate hydrologic properties in the watershed. Streamflow and groundwater levels in the shallow glacial deposits in the Stoney Brook watershed were analyzed to estimate groundwater-flow directions, groundwater recharge, and evapotranspiration within the watershed and to assess the effect of ditches on surrounding groundwater resources. Groundwater, streamflow, and precipitation data collected during the study (2006–9) can be used to update the U.S. Department of Agriculture’s Natural Resource Conservation Service and Fond du Lac Resource Management Division surface-water models, which are used to evaluate the effect of proposed adjustments to the ditching system on streamflow on wild rice production and aquatic habitats.

  3. Le lien retrouvé

    Directory of Open Access Journals (Sweden)

    Luis Antonio Bittar Venturi

    2009-06-01

    Full Text Available Les ressources naturelles sont les principales médiatrices de la relation homme-nature, se situant à l´interface entre les dimensions sociale et naturelle. Cette thématique favorise donc la ré-intégration entre la géographie physique et humaine, dans la mesure où elle amène le chercheur à une vraie analyse géographique, celle qui considère, en même temps, les aspects humains et naturels pour la compréhension du territoire ou, si l’on préfère, de l´espace géographique. C´est dans ce contexte i...

  4. Comprendre le territoire de Venise

    Directory of Open Access Journals (Sweden)

    Lorena Rocca

    2013-05-01

    Full Text Available Le projet de recherche PANDORA - PArticipatory Networks and Databases fOr sustainable Research and Assessment (www.feempandora.it – de la Fondation Eni Enrico Mattei repose sur une démarche innovante de recherche action invitant à la participation de tous grâce aux Nouvelles Technologies de l’Information et de la Communication (TIC. A partir de l’analyse des pratiques collaboratives sur Internet, un espace en ligne a été créé afin de diffuser des informations et des données sur la ville mais surtout, de recueillir des avis, des idées et des solutions alternatives permettant d’atteindre les objectifs d’un développement urbain durable et co-construit.

  5. Le Point sur... Astronomie IV

    Science.gov (United States)

    Pecker, J.-C.

    Cet ouvrage regroupe des articles de mise au point sollicités par le rédacteur en chef de la rubrique Astronomie des Comptes rendus de l'Académie des sciences. Les textes se proposent de faire découvrir aux lecteurs, dans les principales disciplines de l'astronomie, les résultats les plus remarquables des dernières années.Leurs auteurs sont des spécialistes participant activement à l'accroissement des connaissances dans des domaines faisant l'objet de recherches intensives. Ces mises au point sur des questions particulièrement importantes de l'astronomie sont rédigées soit en français, soit en anglais et accompagnées d'une bibliographie détaillée.

  6. Le Point sur... Astronomie III

    Science.gov (United States)

    Pecker, J.-C.

    Ce fascicule contient l'ensemble des textes du débat sur la cosmologie du big-bang entre Joseph Silk, Jayant V. Narlikar, arbitrés par Jean-Claude Pecker. Il regroupe également des articles de mise au point sollicités par le rédacteur en chef de la rubrique Astronomie des Comptes rendus de l'Académie des sciences. Les textes se proposent de faire découvrir aux lecteurs, dans les principales disciplines de l'astronomie, les résultats les plus remarquables des dernières années. Ces mises au point sur des questions particulièrement importantes de l'astronomie sont rédigées soit en francais, soit en anglais et accompagnèes d'une bibliographie dètaillèe.

  7. Two Paired "Le Chatelier" Reactions

    Science.gov (United States)

    Cawley, John J.

    1995-07-01

    We have created a two-week, two hour-per-week cyclic experiment, which pairs two reactions. These reactions, the acid catalyzed esterification to yield n-amyl acetate and the base catalyzed hydrolysis of n-amyl acetate are intended to serve as a first and last experiment respectively, of the second-semester laboratory for liberal arts students. Because of time constraints, we have modified these experiments so that no distillation is performed as a purification step. The notion of achieving yields beyond the equilibrium value is discussed in terms of the pragmatics of removing one of the products of an equilibrium. Because of this "Le Chatelier" aspect of each reaction, each of them may be pushed in practicality to completion, which is well beyond the equilibrium value expectation. Because of the cycle, the chemistry may be done on a scale well beyond the microscale approach with little loss of material.

  8. Le Squatteur, le Gentrifieur et le Promoteur. Une leçon de la géographie

    Directory of Open Access Journals (Sweden)

    Laurent Matthey

    2005-03-01

    Full Text Available Posées sur mon bureau : deux photos. Je les regarde. Silencieusement, je les décris et les commente. La première a été prise en novembre 1997. Angle rue Jean-Violette, rue Prévost-Martin, à Genève. On y voit un immeuble, ancien, des échafaudages. Entre cet immeuble et celui qui lui fait face, on a tendu des fanions verts, bleus, orange. Son rez-de-chaussée a été repeint dans une teinte un peu brique. La seconde date d’avril 2005. C’est le même immeuble, presque dix ans plus tard, rénové. Jaun...

  9. Des maux pour le taire

    OpenAIRE

    Dussy, Dorothée; Caisne, Léonore Le

    2011-01-01

    Cette enquête ethnographique effectuée dans une association parisienne d’entraide aux victimes d’inceste montre que les enfants sexuellement abusés par un familier doivent se construire sur une double approche de la réalité sociale : d’un côté un discours dominant qui prône l’interdit de l’inceste et le respect des valeurs ordinaires, de l’autre l’expérience quotidienne des viols perpétrés par un de ceux qui transmettent ces valeurs. Grâce à un annonciateur, l’inceste perd son caractère anomi...

  10. Le surpoids, l'obésité et le contrôle glycémique chez les diabétiques ...

    African Journals Online (AJOL)

    utilisation et du stockage des sucres apportés par l'alimentation, sa prise en charge est assurée par le suivi du surpoids et l'obésité et le contrôle glycémique régulier. L'objectif de ce travail était l'étude du surpoids, l'obésité et le contrôle glycémique ...

  11. Le Mahdi dans le Maghreb médiéval

    Directory of Open Access Journals (Sweden)

    Michael Brett

    2009-05-01

    Full Text Available Dans le monde islamique médiéval, l'Afrique du Nord fut le centre principal du mahdisme, qui y inspira deux des trois grandes révolutions qui unifièrent le Maghreb entre le IV/Xe et le Vl/XIIe siècles : celle des Fatimides au Xe et celle des Almohades au XIIe siècle. La forme islamique du messianisme judéo-chrétien, le mahdisme, attendait l'arrivée d'un second Muhammad pour inaugurer un âge d'or ; mais il souffrait aussi d'une hésitation entre un royaume de ce monde ou du monde à venir, entre un homme envoyé par Dieu ou un être divin. Son succès au Maghreb était le fruit de son appel aux fidèles à conquérir le monde, moyennant une prédication militante adressée à des populations tribales pour les persuader de se soumettre à la discipline militaire imposée par un prophète. Dans les deux cas, néanmoins, la prédication et son accomplissement se divisèrent entre un annonciateur comparable à Saint Jean-Baptiste et « l'homme né pour être roi ». Dans le cas des Fatimides, le roi fut le mahdi lui-même ; mais dans le cas des Almohades, le mahdi fut le prophète qui ouvrit la voie à son calife, destiné au gouvernement du monde. Après la désintégration de l'empire almohade au XIIIe siècle, le mahdisme se réduisit au Maghreb à un millénarisme inefficace, mais revint au pouvoir au XVIe avec la dynastie saadienne au Maroc. Ici encore, comme dans le cas d'Abdelkader en Algérie au XIXe siècle, le mahdisme se fonda sur la même distinction entre prophète et roi ; mais, au cours du XXe siècle, il a été remplacé par le nationalisme comme force politique efficace.

  12. Analyse et modélisation de la précipitation de struvite : vers le traitement d'effluents aqueux industriels

    OpenAIRE

    Hanhoun, Mary

    2011-01-01

    La réduction des apports phosphorés des eaux usées régie par la Directive Européenne de 1991 (91/271/EEC) est considérée comme le facteur clé de la lutte contre la pollution des rivières et des lacs. Ces travaux concernent exclusivement l'étude de la formation maîtrisée de struvite (MgNH4PO4.6H2O) par précipitation comme alternative originale de récupération du phosphore et, par voie de conséquence, de l'ammonium à partir d'eaux usées. Un atout de ce procédé concerne la valorisation du précip...

  13. : Le Goff, Annales and National Historical Traditions:

    OpenAIRE

    Rucquoi, Adeline

    1994-01-01

    Version originale de l'article traduit en anglais (mal) et publié sous le titre (dû à l'éditeur) "Spanish Medieval History and the Annales: Between Franco and Marx"; International audience; Influencia ejercida por las obras de Jacques Le Goff y la llamada "escuela de los Annales" sobre la historiografía española (1950-1990); Influence des travaux de Jacques Le Goff et de l'"école" des Annales sur l'historiographie espagnole (1950-1990)

  14. Le Corbusier, Alfred Roth y el color

    Directory of Open Access Journals (Sweden)

    Angelica Fernández-Morales

    2014-07-01

    Full Text Available This article discusses the relationship between Le Corbusier and Alfred Roth, a member of the Paris office between 1927 and 1928. It also deals with the influence that this period had with reference to an important factor in Roth’s professional development, as in Le Corbusier’s later works: the use of colour in his architecture. This article takes the position that Roth, given his close friendship with Mondrian, was an important figure in turning Le Corbusier’s work towards greater use of primary colours and aesthetic neoplasticism.

  15. Use of EDTA in modified kinetic testing for contaminated drainage prediction from waste rocks: case of the Lac Tio mine.

    Science.gov (United States)

    Plante, Benoît; Benzaazoua, Mostafa; Bussière, Bruno; Kandji, El-Hadji-Babacar; Chopard, Aurélie; Bouzahzah, Hassan

    2015-05-01

    The tools developed for acid mine drainage (AMD) prediction were proven unsuccessful to predict the geochemical behavior of mine waste rocks having a significant chemical sorption capacity, which delays the onset of contaminated neutral drainage (CND). The present work was performed in order to test a new approach of water quality prediction, by using a chelating agent solution (0.03 M EDTA, or ethylenediaminetetraacetic acid) in kinetic testing used for the prediction of the geochemical behavior of geologic material. The hypothesis underlying the proposed approach is that the EDTA solution should chelate the metals as soon as they are released by sulfide oxidation, inhibiting their sorption or secondary precipitation, and therefore reproduce a worst-case scenario where very low metal attenuation mechanisms are present in the drainage waters. Fresh and weathered waste rocks from the Lac Tio mine (Rio tinto, Iron and Titanium), which are known to generate Ni-CND at the field scale, were submitted to small-scale humidity cells in control tests (using deionized water) and using an EDTA solution. Results show that EDTA effectively prevents the metals to be sorbed or to precipitate as secondary minerals, therefore enabling to bypass the delay associated with metal sorption in the prediction of water quality from these materials. This work shows that the use of a chelating agent solution is a promising novel approach of water quality prediction and provides general guidelines to be used in further studies, which will help both practitioners and regulators to plan more efficient management and disposal strategies of mine wastes.

  16. Multiwavelength Variability Study of the Classical BL Lac Object PKS 0735+178 on Timescales Ranging from Decades to Minutes

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, Arti; Stawarz, Łukasz; Ostrowski, Michał; Soida, Marian [Astronomical Observatory of Jagiellonian University, ul. Orla 171, 30-244 Kraków (Poland); Larionov, Valeri [Astronomical Institute of St. Petersburg State University, Petrodvorets 198504 (Russian Federation); Gopal-Krishna [Centre for Excellence in Basic Sciences (CEBS), University of Mumbai campus (Kalina), Mumbai 400098 (India); Wiita, Paul J. [Department of Physics, The College of New Jersey, 2000 Pennington Road, Ewing, NJ 08628-0718 (United States); Joshi, Santosh [Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital 263002 (India); Agudo, Iván, E-mail: arti@oa.uj.edu.pl [Instituto de Astrofísica de Andalucía (CSIC), Apartado 3004, E–18080 Granada (Spain)

    2017-03-10

    We present the results of our power spectral analysis for the BL Lac object PKS 0735+178, utilizing the Fermi -LAT survey at high-energy γ -rays, several ground-based optical telescopes, and single-dish radio telescopes operating at GHz frequencies. The novelty of our approach is that, by combining long-term and densely sampled intra-night light curves in the optical regime, we were able to construct for the first time the optical power spectrum of the blazar for a time domain extending from 23 years down to minutes. Our analysis reveals that: (1) the optical variability is consistent with a pure red noise, for which the power spectral density can be well approximated by a single power law throughout the entire time domain probed; (2) the slope of power spectral density at high-energy γ -rays (∼1) is significantly flatter than that found at radio and optical frequencies (∼2) within the corresponding time variability range; (3) for the derived power spectra, we did not detect any low-frequency flattening, nor do we see any evidence for cutoffs at the highest frequencies down to the noise floor levels due to measurement uncertainties. We interpret our findings in terms of a model where the blazar variability is generated by the underlying single stochastic process (at radio and optical frequencies), or a linear superposition of such processes (in the γ -ray regime). Along with the detailed PSD analysis, we also present the results of our extended (1998–2015) intra-night optical monitoring program and newly acquired optical photo-polarimetric data for the source.

  17. Waist circumference (WC), body mass index (BMI), and disability among older adults in Latin American and the Caribbean (LAC).

    Science.gov (United States)

    Nam, Sanggon; Kuo, Yong-Fang; Markides, Kyriakos S; Al Snih, Soham

    2012-01-01

    To examine the association between WC and BMI on disability among older adults from LAC. Cross-sectional, multicenter city study of 5786 subjects aged 65 years and older from the Health, Well-Being and Aging in Latin America and the Caribbean (SABE) study (1999-2000). Sociodemographic variables, smoking status, medical conditions, BMI, WC, and activities of daily living (ADL) were obtained. Prevalence of high WC (HWC) (> 88 cm) in women ranged from 48.5% (Havana) to 72.7% (Mexico City), while among men (> 102 cm) it ranged from 12.5% (Bridgetown) to 32.5% (Santiago). The associations between WC and ADL disability were "J" shaped, with higher risks of ADL disability observed above 110 cm for women in Bridgetown, Santiago, Havana, and Montevideo. The association in Sao Paulo is plateau with higher risk above 100 cm, and the association in Mexico City is closer to linear. Among men the associations were "U" (Bridgetown, Sao Paulo, and Havana), "J" shaped (Montevideo), plateau (Santiago), and closer to linear in Mexico City. When WC and BMI were analyzed together, we found that participants from Sao Paulo, Santiago, Havana, and Montevideo in the overweight or obese category with HWC were significantly more likely to report ADL disability after adjusting for all covariates. The findings of this study suggest that both general and abdominal adiposity are associated with disability and support the use of WC in addition to BMI to assess risk of disability in older adults. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  18. Mutational spectrum of the lacI gene in Escherichia coli K12 induced by low-energy ion beam

    International Nuclear Information System (INIS)

    Tang Mingli; Wang Shun Chang; Wang Tao; Zhao Shiguang; Wu Yaojing; Wu Lijun; Yu Zengliang

    2006-01-01

    The mutational spectrum of the genomic lacI gene induced by low-energy nitrogen ion irradiation in wild type Escherichia coli strain W3110 were compared with the spontaneous and the vacuum controls. The mutant frequency of irradiated group was dose-dependent and reached 26.3 x 10 -6 at dose of 31.2 x 10 14 ions/cm 2 , which was about 18-fold over the background (1.5 x 10 -6 ) and 10-fold over the vacuum controls (2.6 x 10 -6 ). This result indicated that the low-energy ion irradiation was one of many effective mutagens, though the vacuum condition of low-energy ions contributed some low-level gene mutations. It was found that the difference between the spontaneous and the vacuum control was the increases of base-pair substitutions in the vacuum control group. The spectra of irradiated group were quite similar to that of oxygen free-radical induced in the same strain, suggesting free-radicals and other adducts generated by low-energy ions might play an important role in the mutagenesis in vivo. When the spontaneous and the vacuum control group were compared, base-pair substitutions, deletions and additions of the irradiated group were significantly increased, and the +TGGC or -TGGC at hot spot was decreased from 82 to 48%. But the remarkable increase in absolute MF of the +TGGC or -TGGC at hot spot in the irradiated group suggested that low-energy ions did induce the mutations of this type. The spectra of our irradiated group had relative low-level base-pair substitutions, high-level ±TGGC and high proportion additions than those of γ-radiation induced, implying there were some different effects or processes between them

  19. Karakterisasi Molekuler Ikan Gurami Soang (Osphronemus goramy Lac. berbeda uuran menggunakan Pcr-Rflp Gen Sitokrom C Oksidase 1

    Directory of Open Access Journals (Sweden)

    Siti Nur Azizah

    2017-01-01

    Full Text Available Gourami (Osprhronemus goramy Lac. is a  freshwater fish that is  widely cultivated in Indonesia, particularly by fish farmer in Java. Soang strain has a faster growth rate than other strains. However, the fry that derived from a single cohort (generated from a single spawning shows various sizes even in the same age because they have different growth rate. Differences in growth rate may occur due to differences in metabolic capabilities especially cellular respiration. Different rate of respiration can be assumed to be due to differences in the genetic component, especially on their cytochrome c oxidase 1 gene (CO1. Therefore this study aimed to determine whether there are differences in PCR-RFLP marker CO1 gene among different sizes of gourami soang strain from the same cohort so that can be used to analyze genetic diversity. This study used survey method by applying purposive random sampling. Four restriction enzymes were used  during the  research. Molecular characters were defined descriptively based on the appearance of restriction fragment on agarose gel. The result showed that soang strain which used in this study had monomorphics allele on their CO1-HindIII. PstI, BamHI, and EcoRI, could not cut the PCR products and results no RFLP markers. So that genetic variation in the used CO1 gene fragment could not be detected using HindIII, Pst1, BamH1 and EcoR1 enzymes. The three different sizes of soang strain had similar alleles or homozygous, meaning that heterozigocity value was 0 (zero. Therefore, the CO1 gene in this study could not be used as molecular character to differentiate different sizes of gourami soang strain from the same cohort.

  20. Le Great Limpopo Transfrontier Park

    Directory of Open Access Journals (Sweden)

    Nadia Belaidi

    2008-10-01

    Full Text Available Cet article a pour objet de présenter quelques problématiques d'une recherche sur la construction d’un mécanisme de valorisation sociale de la protection de l’environnement : l’ordre public écologique. Cette étude s’appuie sur une expérience récente et originale en Afrique australe : la création de Parcs pour la Paix dont relève le Great Limpopo Transfrontier Park. Ces parcs sont officiellement consacrés à la protection et à la conservation de la diversité biologique, des ressources naturelles et culturelles qui y sont associées, ainsi qu’à la promotion de la coopération et de la Paix qu’elle soit civile, sociale, économique ou culturelle. La logique de construction de ces parcs repose sur l’idée que l’articulation des zones de conservation facilite la résolution de conflits territoriaux – de toutes sortes – en transformant les préoccupations environnementales en objet de coopération entre des juridictions politiques diverses. C’est précisément le schéma du concept juridique objet de nos travaux : l’ordre public écologique. Aussi peut-on se demander si le GLTP, en particulier, (peut constitue(r une illustration concrète de ce mécanisme et permettre d’atteindre la Paix recherchée, favorisant ainsi les processus de développement ?This article aims to present some problems of researches on the construction of a mechanism of social valorisation of the environmental protection: ecological public order. This study leans on a recent and original experience in southern Africa: the creation of Peace Park like the Great Limpopo Transfrontier Park (GLTP. These parks are officially dedicated to the protection and to the preservation of biological diversity, natural and cultural resources which are associated with it, as well as in the promotion of the cooperation and the peace. The peace looked for in these parks is not only the opposite of the war but it is also social, economic and cultural peace

  1. Simulation of groundwater flow and interaction of groundwater and surface water on the Lac du Flambeau Reservation, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.; Fienen, Michael N.; Hunt, Randall J.

    2014-01-01

    The Lac du Flambeau Band of Lake Superior Chippewa and Indian Health Service are interested in improving the understanding of groundwater flow and groundwater/surface-water interaction on the Lac du Flambeau Reservation (Reservation) in southwest Vilas County and southeast Iron County, Wisconsin, with particular interest in an understanding of the potential for contamination of groundwater supply wells and the fate of wastewater that is infiltrated from treatment lagoons on the Reservation. This report describes the construction, calibration, and application of a regional groundwater flow model used to simulate the shallow groundwater flow system of the Reservation and water-quality results for groundwater and surface-water samples collected near a system of waste-water-treatment lagoons. Groundwater flows through a permeable glacial aquifer that ranges in thickness from 60 to more than 200 feet (ft). Seepage and drainage lakes are common in the area and influence groundwater flow patterns on the Reservation. A two-dimensional, steady-state analytic element groundwater flow model was constructed using the program GFLOW. The model was calibrated by matching target water levels and stream base flows through the use of the parameter-estimation program, PEST. Simulated results illustrate that groundwater flow within most of the Reservation is toward the Bear River and the chain of lakes that feed the Bear River. Results of analyses of groundwater and surface-water samples collected downgradient from the wastewater infiltration lagoons show elevated levels of ammonia and dissolved phosphorus. In addition, wastewater indicator chemicals detected in three downgradient wells and a small downgradient stream indicate that infiltrated wastewater is moving southwest of the lagoons toward Moss Lake. Potential effects of extended wet and dry periods (within historical ranges) were evaluated by adjusting precipitation and groundwater recharge in the model and comparing the

  2. Le soleil devient un mythe

    Directory of Open Access Journals (Sweden)

    Ildikó Lőrinszky

    2009-01-01

    Full Text Available Partant d’une phrase énigmatique datant de 1858 et puisée dans la Correspondance de Flaubert, cet article s’interroge sur la relation entre soleil et mythe, qui constituera l’un des éléments clefs de la dimension mythologique de Salammbô. Il se propose d’examiner la façon dont cette question apparaît dans deux ouvrages représentatifs des études mythographiques : d’une part, L’Origine de tous les cultes de Charles-François Dupuis, d’autre part, Les Religions de l’Antiquité..., publié sous les noms de Frédéric Creuzer et de son adaptateur français, Joseph-Daniel Guigniault. La version française de la grande synthèse de Creuzer, assortie d’une série importante de planches, a été richement exploitée par Flaubert au cours de la genèse du roman carthaginois. Dans Salammbô, le mythe apparaît sous de multiples formes. L’analyse de ce texte peut nous amener à réfléchir sur le « bon usage » du mythe auquel chaque créateur (et chaque lecteur se trouve nécessairement confronté.Starting from an enigmatic phrase in Flaubert’s correspondence, dating from 1858, this article examines the relation between the Sun and myth, which constitutes one of the key elements of the mythological dimension of Salammbô. It especially focuses on the treatment of this question in two representative works of mythographic studies, The Origin of All Religious Worship by Charles-François Dupuis, and Les Religions de l’Antiquité..., the French adaptation of Frédéric Creuzer’s Symbolik und Mythologie der alten Völker by Joseph-Daniel Guigniault. The French version of Creuzer’s great synthesis, supplied with a remarkable set of prints, was abundantly consulted by Flaubert when writing his Carthaginian novel. In Salammbô, myth takes on various forms. Analyzing this text might lead one to reconsider “the right way” to use myths — a problem all writers (and readers find themselves confronted with.

  3. Les ERP changent-ils le contrôle de gestion ?

    OpenAIRE

    Meyssonnier, François; Pourtier, Frédéric

    2005-01-01

    L'intégration de l'information de gestion dans le cadre d'ERP se généralise et le contrôle de gestion s'effectue maintenant la plupart du temps en environnement ERP dans les grandes entreprises. Un état de l'art est effectué relativement à l'impact des ERP aussi bien sur les concepts et les outils du contrôle de gestion que sur la fonction et lele des contrôleurs de gestion. La démarche de recherche, fondée sur dix études de cas dans une approche intermédiaire entre les monographies qualit...

  4. Vers une plus grande collaboration régionale — le CRDI appuie le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    26 janv. 2011 ... Bien qu'ils aient souvent de la difficulté à se démarquer face à la véritable dynamo économique qu'est la Chine, des pays tels que le Laos, le Cambodge et le Vietnam, qui tentaient d'échapper à la guerre il y a à peine 25 ans, connaissent une croissance explosive encore plus remarquable. Renaissance ...

  5. Démocratie et le développement dans le monde arabe | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Extrants. Rapports. Democracy and development in the Arab world : final technical report, Sep. 15, 2006 - Sep. 15, 2009. Téléchargez le PDF. Contenus connexes. Le CRDI « analyse l'autonomisation des femmes » lors d'une conférence à l'Université McGill. Les conclusions d'un programme financé par le CRDI au ...

  6. ÉTUDE DE CAS — Cuba : Le logement et le capital humain à Cuba ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    10 janv. 2011 ... ÉTUDE DE CAS — Cuba : Le logement et le capital humain à Cuba .... Elle reconnaît qu'il existe des liens inéluctables entre les humains et les milieux biophysique, social et économique qui ont des répercussions sur la santé des gens », explique le Dr Mariano Bonet, l'un des chercheurs de l'équipe et ...

  7. pour le trimestre qui a pris fin le 30 juin 2014

    International Development Research Centre (IDRC) Digital Library (Canada)

    Office 2004 Test Drive User

    30 juin 2014 ... d'information financière (normes IFRS). Toutes les sommes sont exprimées en dollars canadiens. Le CRDI recommande de lire ce rapport en parallèle avec les états financiers intermédiaires résumés, non audités (qui débutent à la page 11). L'information et les divulgations contenues dans le Rapport ...

  8. pour le trimestre qui a pris fin le 30 septembre 2014

    International Development Research Centre (IDRC) Digital Library (Canada)

    Office 2004 Test Drive User

    30 sept. 2014 ... d'information financière (normes IFRS). Toutes les sommes sont exprimées en dollars canadiens. Le CRDI recommande de lire ce rapport en parallèle avec les états financiers intermédiaires résumés, non audités (qui débutent à la page 11). L'information et les divulgations contenues dans le Rapport ...

  9. pour le trimestre qui a pris fin le 30 juin 2012

    International Development Research Centre (IDRC) Digital Library (Canada)

    Office 2004 Test Drive User

    30 juin 2012 ... dans le Rapport annuel 2011-2012 du CRDI s'appliquent au trimestre sur lequel porte le présent rapport trimestriel à moins d'une mise à jour fournie aux présentes. Résultats. Aperçu de la situation financière. (pour la période de trois mois qui a pris fin le 30 juin 2012). 0. 10. 20. 30. 40. 50. 60. 70. Produits.

  10. Rapport financier trimestriel pour le trimestre qui a pris fin le 31 ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Sophie Comeau

    31 déc. 2011 ... Le Centre de recherches pour le développement international. CRDI , qui est un élément clé de l'aide internationale du. Canada depuis 1970, appuie des travaux de recherche dans les pays en développement afin d'y favoriser la croissance et le développement. Il veille aussi à promouvoir la diffusion.

  11. Le « modèle germanique » Français

    OpenAIRE

    Lefebvre , Armelle

    2009-01-01

    Resume Le concept d?Allemagne permet de reveler, selon une approche , l?ampleur des desaccords ayant preside a la definition du concept d?Etat en France. De ce dernier, l?on aborde divers emplois qu?illustrent des modeles d?Etat. Le opere ainsi dans un debat qui est le creuset de la connaissance politique moderne, avec ses apories: celles de la souverainete externe, de l?ordre interetatique, de la confederation. L?article expose alo...

  12. 205 Le Role de la Litterature dans le Developpement de la Nation ...

    African Journals Online (AJOL)

    Ike Odimegwu

    du plaisir en même temps qu'il le moralise. Elle fait naître dans ses lecteurs ou dans son audience des .... développement de l'esprit>>(319)Par cette définition nous comprenons que le développement signale qu'il du progrès ... qu'elle est une œuvre de l'imagination qui aide l'homme à transcender le monde physique.

  13. Droits d'auteur | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Droits d'auteur détenus par le CRDI Sauf indication contraire, les droits d'auteur relatifs aux documents mis en ligne sur le présent site Web sont détenus par le Centre de recherches pour le développement international (CRDI).

  14. Publications | Page 200 | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le CRDI collabore avec les chercheurs et les établissements des pays en développement au renforcement des capacités locales par le truchement du financement, de la mise en commun des connaissances et de la ... Le partage de l''information et des techniques de la communication favorise le développement durable.

  15. Publications | Page 103 | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le FIE 2008 fait avancer le cadre écobiosocial de l'OMS. Le Programme spécial de recherche et de formation concernant les maladies tropicales (TDR) de l'OMS a élaboré le concept du champ « écobiosocial », qui combine les perspectives écologiques, biologiques et sociales « pour mieux.

  16. Publications | Page 17 | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Publication du rapport de BSR sur le travail des enfants en Birmanie. Le CRDI finance plusieurs projets de recherche sur les facteurs expliquant le travail des enfants, incluant le rapport intitulé 'Child labor in Myanmar's Garment Sector' écrit récemment par l'organisme Business for Social Responsibility (BSR).

  17. Jan Potocki et le "Gothic Novel"

    Science.gov (United States)

    Finne, Jacques

    1970-01-01

    Establishes a parallel between the supernatural and fantastic qualities of Le Comte Jan Potocki's literary works, and the English gothic novels by comparing the elements of terror, mysterious atmosphere, and the supernatural beings involved. (DS)

  18. Savoir gérer le mal

    Directory of Open Access Journals (Sweden)

    Michel Maffesoli

    2015-09-01

    Full Text Available Le sens commun, conservatoire immémorial de la sagesse humaine « sait », de savoir incorporé, que le mal, l’ombre, la mort, la douleur sont des caractéristiques essentielles de l’existence en son entièreté. Dès lors les créatures quelles qu’elles soient, sont des manifestations de la vie et, dès lors, méritent une attitude « compassionnelle », fraternelle, parce qu’ensemble elles constituent le flux vital. C’est ainsi que l’on peut comprendre l’utilité sociale de ces divers « mondes intermédiaires » que sont les croyances, religieuses ou philosophiques, au « double », au « daimon », aux esprits et autres figures tutélaires ou effrayantes. Elles aident à vivre, au jour le jour, la souffrance en la communalisant.

  19. Nuevo León

    Directory of Open Access Journals (Sweden)

    Laura Nelly Medellín Mendoza

    2006-01-01

    Full Text Available El ensayo analiza la transición política nuevoleonesa a partir de un contexto de liberalización política. En Nuevo León el régimen político autoritario fue cediendo en el plano electoral, dada la presión que conjuntamente la sociedad política y la sociedad civil ejercieron por lograr reglas democráticas. Este avance gradual permitió garantizar un organismo electoral confiable y que determinó en buena medida la garantía de la alternancia en 1997. El pan fue el partido que capitalizó el bono democrático, pero una vez en la responsabilidad de gobierno, no pudo ampliar el proceso de liberalización política al mediatizar las reformas electorales y no comprometerse para sacar del atolladero legislativo las iniciativas que garantizaban mecanismos de participación ciudadana: referéndum y plebiscito.

  20. le des universités dans le renforcement des technologies de l ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    le des universités dans le renforcement des technologies de l'information et de la communication au service du développement (TIC-D) en Asie. Jusqu'à maintenant, les efforts déployés dans le secteur de l'enseignement supérieur ont surtout été axés sur le téléapprentissage, l'apprentissage électronique et différentes ...

  1. Rapport financier trimestriel pour le trimestre qui a pris fin le 31 ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Office 2004 Test Drive User

    31 déc. 2015 ... Budget 2015-2016 révisé. Le Conseil a approuvé le budget 2015-2016 avant le début de lʼexercice. Cʼest sur ce budget que sont fondées les sommes budgétaires qui ont été présentés dans le Rapport annuel. 2014-2015. En octobre, on a revu les prévisions budgétaires initiales en tenant compte des.

  2. Le modèle de l’erreur humaine de James Reason

    OpenAIRE

    Larouzée, Justin; Guarnieri, Franck; Besnard, Denis

    2014-01-01

    Ce papier de recherche a pour objet de revenir en détail sur les travaux de recherche du psychologue anglais James Reason, mondialement célèbre pour sa taxonomie de l’erreur humaine et son modèle étiologique de l’accident immensément connu sous le nom de Swiss Cheese Model (SCM) ou Modèle du Fromage Suisse. Ce papier de recherche est une synthèse du parcours scientifique de Reason, il revient aussi sur la conception du modèle et ses évolutions, il traite de ses usages, apports et limites. Il ...

  3. la lutte contre le SIDA au Cameroun

    African Journals Online (AJOL)

    Chantel

    à une action efficace et courageuse, à la mesure de l'enjeu. De nombreuses ..... des médicaments à un niveau toujours prohibitif. Tableau 2 indique les ... Les femmes et les jeunes paient le plus lourd tribut à l'épidémie (Kuate Defo, 1998). En effet, les 3/5 des personnes infectées sont des femmes et le tiers des personnes ...

  4. Le déficit de filles

    International Development Research Centre (IDRC) Digital Library (Canada)

    qui veulent former un couple idéal. D'autre part, les chercheuses indiquent que le céli- bat des femmes est perçu comme une « aberration totale ». Tous les répondants ont fait, à ce sujet, des remarques semblables : même la personne la plus riche du monde, disent-ils, ne peut assumer le far- deau financier qu'impose une ...

  5. Quand la musique donne le ton

    DEFF Research Database (Denmark)

    Reeh, Henrik

    2017-01-01

    Le lycée Sainte-Anne de Copenhague est un établissement réputé pour les résultats de ses élèves et pour être le foyer d’une intense tradition chorale et musicologique. L’article interroge les parcours de 32 élèves d’une même classe, tous reçus au baccalauréat 2014 avec une option musique et...

  6. Le désordre du monde

    African Journals Online (AJOL)

    sulaiman.adebowale

    interfère dans le désordre du monde. Globalement, une négligence des aspects collectifs planétaires par rap- port à des intérêts nationaux toujours surdéterminés conduit à l'entropie. Cela débouche sur le désordre, au regard des questions qui nécessitent un consensus, un accord et une démarche collective sans (auto) ...

  7. Le Chatelier principle in replicator dynamics

    OpenAIRE

    Allahverdyan, Armen E.; Galstyan, Aram

    2011-01-01

    The Le Chatelier principle states that physical equilibria are not only stable, but they also resist external perturbations via short-time negative-feedback mechanisms: a perturbation induces processes tending to diminish its results. The principle has deep roots, e.g., in thermodynamics it is closely related to the second law and the positivity of the entropy production. Here we study the applicability of the Le Chatelier principle to evolutionary game theory, i.e., to perturbations of a Nas...

  8. Le CRDI au Népal

    International Development Research Centre (IDRC) Digital Library (Canada)

    Les chercheurs ont aidé les agriculteurs de Kulekhani à adopter la pisciculture en cage. CRDI. Centre De reCherChes pour le Développement internAtionAl. Le CRDI au Népal. Grâce à l'appui du CRDI. □ les collectivités s'adaptent aux changements climatiques. □ les agriculteurs de l'Himalaya améliorent leurs moyens.

  9. Le cas du Brésil

    International Development Research Centre (IDRC) Digital Library (Canada)

    pwust

    de biocarburants (particulièrement l'éthanol et le biodiesel). Les tendances actuelles donnent à croire que les projets reliés à l'énergie et aux biocarburants deviendront particulièrement importants sous peu. Outre ces domaines traditionnels, les projets en Afrique ont ciblé l'éducation, le développement des entreprises, les ...

  10. Transparence | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    La transparence est un élément clé de l'engagement du gouvernement du Canada envers le gouvernement ouvert, dont l'objectif est d'améliorer l'accès aux données, aux renseignements et aux échanges. Le CRDI s'emploie à la transparence en fournissant des renseignements sur son site Web, dans ses publications, ...

  11. Le CRDI en Cisjordanie et à Gaza

    International Development Research Centre (IDRC) Digital Library (Canada)

    Stress des adolescents et conflit qui perdure. En Cisjordanie, la violence politique et le conflit qui perdure ont aggravé le stress chez les adolescents, qui constituent près de la moitié de la population. À Ramallah, plus de 3 000 adolescents de 15 à 17 ans ont été interrogés par des chercheurs de l'Université de Birzeit et de ...

  12. Le cas de l'Inde

    International Development Research Centre (IDRC) Digital Library (Canada)

    pwust

    le développement, l'Inde doit réduire la proportion de personnes vivant en deçà du seuil de pauvreté de 37,5 %, en. 1990, à 18,75 % ... exemple, à la suite du tsunami en Asie, en 2004, c'est le premier ministre qui a décidé de porter assistance. Pour ces types d'opérations, les forces militaires et paramilitaires indiennes.

  13. dynamiques migratoires et rapport avec le

    African Journals Online (AJOL)

    qui s'était illustré sur le campus par sa violence, notamment l'agression des étudiants au restaurant et en cité universitaires (sans aucune réaction de ... venant de l'extérieur), dans des actions de parrainage (le président du Tocsin a été choisi comme parrain par la promotion 2002 de l'École nationale du service social de ...

  14. Le juge administratif et le sens des images. Les mutations des techniques contentieuses du contrôle des visas d’exploitation

    OpenAIRE

    Mercier, Jérémy

    2017-01-01

    A la suite des affaires Nymphomaniac, La Vie d'Adèle, Antichrist, Love, SAW 3D Chapitre final, Cinquante Nuances de Grey, Bang Gang : une histoire d'amour moderne, Les Huit Salopards et Salafistes, l'affaire Sausage Party a mis en évidence un élément central dans le raisonnement du juge administratif : l'argumentation sur les images et sur le sens de leur contenu, impliquant un affinement progressif de son contrôle théorique de l'effet produit sur le spectateur. Le contentieux relatif au syst...

  15. Le patrimoine et ses outils de gestion

    CERN Document Server

    Garcin, J

    2001-01-01

    Les principale taches de gestion du Patrimoine immobilier du CERN sont la saisie des données, leur mise à jour, l'archivage et la mise à disposition des informations. Les outils de gestion actuels : Le Système de Gestion de Base de Données Relationnelles alphanumérique ORACLE permet de gérer toutes les informations du Patrimoine, sur le réseau du CERN. Le logiciel de dessin Graphique MICROSTATION (Bentley) a été installé dans la division ST depuis fin 1991. Les plans de situation des sites, des bâtiments et locaux, des espaces confinés ont été réalisés avec ce logiciel. Les outils de demain : La mise en place du SIG (Système d'Information Graphique) STAR a été réalisée en 1993. Le transfert des plans de locaux de MICROSTATION vers STAR est en cours depuis une année environ. Le dessin de la cartographie des réseaux de canalisations Eaux Usées et Eaux Pluviales est en cours de réalisation. Le Web est l'outil de consultation de l'information par les utilisateurs.

  16. Dans le grand collisionneur du CERN

    CERN Document Server

    AUTHOR|(CDS)2051256

    2014-01-01

    Ce livre fait pénétrer le lecteur non initié dans l’instrument scientifique le plus grand du monde. D’ailleurs, le web fut précisément inventé à Genève en vue d’une collaboration aussi gigantesque. Résultat de vingt ans de recherche, le LHC, Grand collisionneur de hadrons, est l’anneau de 26,7 km creusé sous la frontière francosuisse, où sont accélérés, en sens opposés, des paquets de particules jusqu’à des vitesses et des énergies extrêmes. Ainsi la physique s’est-elle engagée dans une étape nouvelle de nos connaissances. Après les grandes découvertes de l’univers et de la réalité microscopique du siècle dernier, le collisionneur nous fait progresser aujourd’hui dans un «nuage de probabilités» aux frontières de l’antimatière. Dans une bousculade de particules, voici le champ convoité du boson de Higgs. Mario Campanelli, professeur associé à l’Université de Londres et collaborateur au projet ATLAS du LHC, propose, dans cet ouvrage, de s’introduire pas �...

  17. Activité antérieure – Le Kenya nomme le titulaire de sa première ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    14 avr. 2016 ... De concert avec le CRDI, la National Commission for Science, Technology and Innovation (NACOSTI) du Kenya a inauguré sa première chaire de recherche à Nairobi, le 31 mars 2015. Le professeur Fabian Omoding Esamai, qui dirige actuellement le College of Health Sciences de la Moi University, a été ...

  18. Mef2c-F10N enhancer driven β-galactosidase (LacZ) and Cre recombinase mice facilitate analyses of gene function and lineage fate in neural crest cells.

    Science.gov (United States)

    Aoto, Kazushi; Sandell, Lisa L; Butler Tjaden, Naomi E; Yuen, Kobe C; Watt, Kristin E Noack; Black, Brian L; Durnin, Michael; Trainor, Paul A

    2015-06-01

    Neural crest cells (NCC) comprise a multipotent, migratory stem cell and progenitor population that gives rise to numerous cell and tissue types within a developing embryo, including craniofacial bone and cartilage, neurons and glia of the peripheral nervous system, and melanocytes within the skin. Here we describe two novel stable transgenic mouse lines suitable for lineage tracing and analysis of gene function in NCC. Firstly, using the F10N enhancer of the Mef2c gene (Mef2c-F10N) linked to LacZ, we generated transgenic mice (Mef2c-F10N-LacZ) that express LacZ in the majority, if not all migrating NCC that delaminate from the neural tube. Mef2c-F10N-LacZ then continues to be expressed primarily in neurogenic, gliogenic and melanocytic NCC and their derivatives, but not in ectomesenchymal derivatives. Secondly, we used the same Mef2c-F10N enhancer together with Cre recombinase to generate transgenic mice (Mef2c-F10N-Cre) that can be used to indelibly label, or alter gene function in, migrating NCC and their derivatives. At early stages of development, Mef2c-F10N-LacZ and Mef2c-F10N-Cre label NCC in a pattern similar to Wnt1-Cre mice, with the exception that Mef2c-F10N-LacZ and Mef2c-F10N-Cre specifically label NCC that have delaminated from the neural plate, while premigratory NCC are not labeled. Thus, our Mef2c-F10N-LacZ and Mef2c-F10N-Cre transgenic mice provide new resources for tracing migratory NCC and analyzing gene function in migrating and differentiating NCC independently of NCC formation. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Livres | Page 21 | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ISBN: 190239142X. Le débat des semences volume 2 : Solutions pour les lois nationales régissant le contrôle des ressources génétiques et des innovations biologiques. Le Débat des semences met les lecteurs au courant de ce qui a changé — sur le plan scientifique, politique et environnemental — depuis la publication ...

  20. Le Projet d’Ole Lando sur les Contrats

    DEFF Research Database (Denmark)

    Holle, Marie-Louise

    2017-01-01

    En 2016 le projet de recherche le plus important jusqu’à présent sur le droit nordique des contrats a pris fin et un livre, de presque 400 pages, en a marqué l’aboutissement. Le résultat du projet est un « restatement » tel qu’il existe aux États-Unis. Le Restatement porte sur les règles et les...