Spatio-temporal distribution of the infestations of Coelaenomenodera lameensis Berti and Mariau (Coleoptera, Chrysomelidae) an oil palm tree (Elaeis guineensis Jacq.) pest in Toumanguié (Côte d’Ivoire)

Spatio-temporal distribution of Coelaenomenodera lameensis Berti and Mariau, 1999, pest of palm oil tree (Elaeis guineensis Jacquin, 1963) was carried out on 1226 ha of an industrial plantation at Toumanguié (south-east of Côte d’Ivoire). Temporal distribution of population established the existence, according to the years, of favorable periods of Coelaenomenodera lameensis infestations. Eight peaks of infestation were observed during 24 months. Infestation cycles proceeds each 90 days. Spatial distribution of the infestations revealed experimental plots having recorded between 0 and 8 months of infestation during the 2 years of investigation. This distribution proved to be independent of the age of the plots. Infestations were also independent of abiotic factors (rainfall, temperature and relative humidity). Larvae at stages 1, 2, 3 and 4 are mostly responsible of the damages observed in the fields.Key words: Coelaenomenodera lameensis; Elaeis guineensis; spatio-temporal distribution; Côte d’Ivoir

Impact de la Cochenille Phenacoccus manihoti (Homoptera, Pseudococcidae) sur les rendements du manioc (Manihot esculenta) au Gabon

La cochenille Phenacoccus manihoti est l’une des causes de la chute des rendements du manioc au Gabon. Par la randomisation, nous avons étudié  son impact sur la croissance de la plante et sur les rendements du manioc. P. manihoti réduit la croissance des plants à 40%, la distance entrenoeuds  des tiges à 45%. Il diminue le nombre, la longueur et le diamètre des tubercules ; respectivement pour le nombre de 7 à 4, de 34 à 9  cm pour la longueur et de 10 à 5 cm pour le diamètre en moyenne. L’action de la cochenille P. manihoti induit ainsi la dimunition de la croissance des  plants et la baisse des rendements du manioc au Gabon. Pour protéger le manioc contre la cochenille, nous pensons que l’utilisation des  techniques de lutte efficaces est indispensable. Elles pourraient même être associées, dans le cadre d’une lutte intégrée, excluant complètement la  lutte chimique, à l’origine de beaucoup de problèmes environnementaux. Les auteurs ont enfin attiré l’attention des gouvernements africains sur la  nécessité de promouvoir les politiques de développement agricole dans leurs pays. English title: Impact of the mealybug Phenacoccus manihoti (homoptera, pseudococcidae) on the yields of the cassava (Manihot esculenta) in Gabon The mealybug Phenacoccus manihoti is one of the causes in the drop of cassava yields in Gabon. Through the randomization, we have studied its  impact on the growth of the plant and on the yields of the cassava. P. manihoti reduces the growth of the plants to 40%, the interval among knots of  the stems to 45%. Its diminishes the number, the length and the diameter of the tubercules, respectively for the number of 7 to 4; of 34 to 9cm for  the length and for 10 to 5cm for the average diameter. Thus, the share of the mealybug P. manihoti induces the lessening of the growth of the plants  and the drop of the cassava yields in Gabon. For protect the cassava against the mealybug we think that the using of the efficient fight  techniques is indispensable. They must even be assoociated in integrated fight excuding completely the chemical fight which induces meny  environemental problems. At last the authors have attracted the car of the african governments abut the necessity to upgrade the agricultural  development politics in theirs contries.&nbsp

Different environmental variables predict distribution and cover of the introduced red seaweed Eucheuma denticulatum in two geographical locations

In this study we examined abiotic and biotic factors that could potentially influence the presence of a non-indigenous seaweed, Eucheuma denticulatum, in two locations, one outside (Kane'ohe Bay, Hawai'i, USA) and one within (Mafia Island, Tanzania) its natural geographical range. We hypothesized that the availability of hard substrate and the amount of wave exposure would explain distribution patterns, and that higher abundance of herbivorous fishes in Tanzania would exert stronger top-down control than in Hawai'i. To address these hypotheses, we surveyed E. denticulatum in sites subjected to different environmental conditions and used generalized linear mixed models (GLMM) to identify predictors of E. denticulatum presence. We also estimated grazing intensity on E. denticulatum by surveying the type and the amount of grazing scars. Finally, we used molecular tools to distinguish between indigenous and non-indigenous strains of E. denticulatum on Mafia Island. In Kane'ohe Bay, the likelihood of finding E. denticulatum increased with wave exposure, whereas on Mafia Island, the likelihood increased with cover of coral rubble, and decreased with distance from areas of introduction (AOI), but this decrease was less pronounced in the presence of coral rubble. Grazing intensity was higher in Kane'ohe Bay than on Mafia Island. However, we still suggest that efforts to reduce non-indigenous E. denticulatum should include protection of important herbivores in both sites because of the high levels of grazing close to AOI. Moreover, we recommend that areas with hard substrate and high structural complexity should be avoided when farming non-indigenous strains of E. denticulatum

Direct penetration of spin-triplet superconductivity into a ferromagnet in Au/SrRuO3/Sr2RuO4 junctions

Efforts have been ongoing to establish superconducting spintronics utilizing ferromagnet/superconductor heterostructures1. Previously reported devices are based on spin-singlet superconductors (SSCs), where the spin degree of freedom is lost. Spin-polarized supercurrent induction in ferromagnetic metals (FMs) is achieved even with SSCs, but only with the aid of interfacial complex magnetic structures, which severely affect information imprinted to the electron spin. Use of spin-triplet superconductors (TSCs) with active spins potentially overcomes this difficulty and further leads to novel functionalities. Here, we report spin-triplet superconductivity induction into a FM SrRuO3 from a leading TSC candidate Sr2RuO4, by fabricating microscopic devices using an epitaxial SrRuO3/Sr2RuO4 hybrid. The differential conductance, exhibiting Andreev-reflection features with multiple energy scales up to around half tesla, indicates the penetration of superconductivity over a considerable distance of 15 nm across the SrRuO3 layer without help of interfacial complex magnetism. This demonstrates the first FM/TSC device exhibiting the spin-triplet proximity effect

Growth inhibition of oral mutans streptococci and candida by commercial probiotic lactobacilli - an in vitro study

<p>Abstract</p> <p>Background</p> <p>Probiotic bacteria are suggested to play a role in the maintenance of oral health. Such health promoting bacteria are added to different commercial probiotic products. The aim of the study was to investigate the ability of a selection of lactobacilli strains, used in commercially available probiotic products, to inhibit growth of oral mutans streptococci and <it>C. albicans in vitro</it>.</p> <p>Methods</p> <p>Eight probiotic lactobacilli strains were tested for growth inhibition on three reference strains and two clinical isolates of mutans streptococci as well as two reference strains and three clinical isolates of <it>Candida albicans </it>with an agar overlay method.</p> <p>Results</p> <p>At concentrations ranging from 10⁹to 10⁵CFU/ml, all lactobacilli strains inhibited the growth of the mutans streptococci completely with the exception of <it>L. acidophilus </it>La5 that executed only a slight inhibition of some strains at concentrations corresponding to 10⁷and 10⁵CFU/ml. At the lowest cell concentration (10³CFU/ml), only <it>L. plantarum </it>299v and <it>L. plantarum </it>931 displayed a total growth inhibition while a slight inhibition was seen for all five mutans streptococci strains by <it>L. rhamnosus </it>LB21, <it>L. paracasei </it>F19, <it>L. reuteri </it>PTA 5289 and <it>L. reuteri </it>ATCC 55730. All the tested lactobacilli strains reduced candida growth but the effect was generally weaker than for mutans streptococci. The two <it>L. plantarum </it>strains and <it>L. reuteri </it>ATCC 55730 displayed the strongest inhibition on <it>Candida albicans</it>. No significant differences were observed between the reference strains and the clinical isolates.</p> <p>Conclusion</p> <p>The selected probiotic strains showed a significant but somewhat varying ability to inhibit growth of oral mutans streptococci and <it>Candida albicans in vitro</it>.</p

Multiple Interactions and the Structure of Beam Remnants

Recent experimental data have established some of the basic features of multiple interactions in hadron-hadron collisions. The emphasis is therefore now shifting, to one of exploring more detailed aspects. Starting from a brief review of the current situation, a next-generation model is developed, wherein a detailed account is given of correlated flavour, colour, longitudinal and transverse momentum distributions, encompassing both the partons initiating perturbative interactions and the partons left in the beam remnants. Some of the main features are illustrated for the Tevatron and the LHC.Comment: 69pp, 33 figure