72 research outputs found

    Integration of monoterpenoids with low pressure simulating vacuum for control of diapausing Indian meal moth larvae and red flour beetle adults

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    Monoterpenoids as well as low pressure simulating vacuum, when applied alone have been demonstrated to cause mortality of stored-product insect pests. The current report explored the possibility of integrating these two control methods in the management of stored-product insects. The insects used for this study were the adults of the red flour beetle, Tribolium castaneum, and diapausing larvae of the Indian meal moth, Plodia interpunctella. The monoterpenoids investigated were E-anethole, estragole, S-carvone, linalool, L-fenchone, geraniol, Îł-terpinene and DL-camphor. Exposure of the insects to all the monoterpenoids alone, with the exception of camphor, at a concentration of 66.7ÎŒL/1L of volume required more than 24 h to generate 100% mortality at 28.0 ± 0.8°C and 70 ± 2.5 r.h. However, exposure of the insects to camphor alone generated 100% mortality with 3 h exposure in T. castaneum. Exposure of the insects to low pressure at 36.5 mm Hg generated 100% mortlity in beetles with 24 h exposure and in the diapausing P. interpunctella larvae with 48 h exposure. However, combination of the monoterpenoids with low pressure reduced exposure periods (3-24 h) required to generate 100% mortality in both diapausing larvae of P. interpunctella and the adult beetles of T. castaneum. In all cases T. castaneum showed signs of weakness faster than diapausing P. interpunctella larvae. Keywords: Low pressure, DL-camphor, Estragole, Îł-terpinene, Carvon

    Analysis of monoterpenoids in inclusion complexes with ÎČ-cyclodextrin and study on ratio effect in these microcapsules.

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    In recent studies, the insecticide activity against some stored products pests of monoterpenoids, such as linalool, S-carvone, camphor, geraniol, Îł-terpinene and fenchone, and phenylpropanoids, like E-anethole and estragole, has been proved. Currently, applications of these volatile compounds are complicated due to their chemical and physical properties. This is one of the major problems for their use as insecticides; therefore, microencapsulation could be the solution to problems of stability, evaporation and release. Microencapsulation of these chemicals was carried out with ÎČ-cyclodextrin using a chemical precipitation method at four different ratios (ÎČ-cyclodextrin: monoterpenoids), 1.33:1, 3.33:1, 4.66:1 and 6.66:1 (w/w) in order to determine the ratio effect. This study establishes that encapsulation at the ratio of 3.33:1 to linalool and Îł-terpinene was higher, whereas S-carvone, camphor, E-anethole, geraniol, estragole and fenchone showed the greatest encapsulation when the ratio was 6.66:1. Furthermore, the efficiency of encapsulation was estimated by measuring the content of the compounds in the powder by gas chromatography. The maximum inclusion efficiency of ÎČ-cyclodextrin was reached by camphor (52%) followed by geraniol (34%) using 10 g of ÎČ-cyclodextrin and linalool (31%) using 5 g of this matrix. The present study indicates that natural products such as monoterpenoids or phenylpropanoids could be microencapsulated in an efficient way using an appropriate amount of ÎČ-cyclodextrin. Keywords: Microencapsulation, ÎČ-cyclodextrin, Camphor, Geraniol and Linaloo

    Nematicidal activity of essential oils and organic amendments from Asteraceae against root-knot nematodes

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    The essential oil of Chrysanthemum coronarium flowerheads showed strong nematicidal activity in vitro and in growthchamber experiments. Essential oil concentrations of 2, 4, 8 and 16 ÎŒL mL−1, significantly reduced hatch, J2 survival (determined by final value and area under curves of cumulative percentage hatch or mortality) and reproduction rate of Meloidogyne artiellia in vitro, with the lowest values occurring at 16 ÎŒL mL−1. In pot trials with chickpea cv. PV 61, essential oil concentrations of 10–40 ÎŒL per 500 cm3 soil, applied on sterile cotton pellets, also significantly reduced the nematode’s reproduction rate. The biological processes of mortality and hatching/reproduction were adequately described by the monomolecular and expanded negative exponential models, respectively. Effectiveness of soil amendment with either flowers, leaves, roots or seeds of C. coronarium, and flowers from several species of Asteraceae (Chrysanthemum segetum, Calendula maritima, Calendula officinalis and Calendula suffruticosa) at 5 g per 500 cm3 soil was tested for suppression of M. artiellia and growth of chickpea cv. PV 61 under growth-chamber conditions. In these tests, flowers of all five Asteraceae species and various parts of C. coronarium significantly reduced reproduction rates of M. artiellia, by 83·0–95·9%, with the minimum rates occurring in infected chickpea plants amended with flowers of C. officinalis and C. suffruticosa. The in vitro and in planta results suggest that the essential oil of C. coronarium and organic amendments from Asteraceae species may serve as nematicides.This research, part of a PhD study by P.P., was supported by grant SC98-022 and a fellowship from the Instituto Nacional de TecnologĂ­as Agroalimentarias (INIA).Peer reviewe

    La familia Euphorbiaceae como fuente de aceites vegetales para la industria tecnoquĂ­mica

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    The family Euphorbiaceae includes a huge number of species some of which provide important raw materials such as rubber, cassava, waxes and oils. In this study, the general botanical and chemical characteristics of this family are described firstly together with the chemical composition of their seed oils and a comparison with those of other families. Secondly, other chemical constituents of economic interest are reviewed and compared with the species already used for food, industry and medicine purposes. A further revision is included on some of its genus with potential interest and on current industrial oil crops such as Ridnus, Euphorbia, Aleurites, Sapium, Jatropha, etc. Finally, from an economic point of view, future prospects of some of these oils as raw materials for the chemical industry are given.La familia Euphorbiaceae contiene gran nĂșmero de especies de las que se pueden obtener productos de interĂ©s econĂłmico como el caucho, la tapioca, ceras y aceites. En este trabajo se estudian en primer lugar las caracterĂ­sticas botĂĄnicas y quĂ­micas de la familia y las peculiaridades de los aceites de sus semillas y se comparan con los de otras familias. En segundo lugar, se revisan otros compuestos quĂ­micos asĂ­ como especies de interĂ©s econĂłmico utilizadas en alimentaciĂłn, medicina o industria, incluyendo gĂ©neros con potencial interĂ©s y los actuales cultivos oleaginosos industriales como Ridnus, Euphorbia, Aleurites, Sapium, Jatropha, etc. Finalmente, desde un punto de vista de mercado, se apuntan las perspectivas de estos aceites como materias primas para la industria quĂ­mica

    Genetic Variation in Safflower (Carthamus tinctorious L.) for Seed Quality-Related Traits and Inter-Simple Sequence Repeat (ISSR) Markers

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    Safflower (Carthamus tinctorious L.) is an oilseed crop that is valued as a source of high quality vegetable oil. The genetic diversity of 16 safflower genotypes originated from different geographical regions of Iran and some with exotic origin were evaluated. Eight different seed quality-related traits including fatty acid composition of seed oil (stearic acid, palmitic acid, oleic acid and linoleic acid), the contents of, oil, protein, fiber and ash in its seeds, as well as 20 inter-simple sequence repeat (ISSR) polymorphic primers were used in this study. Analysis of variance showed significant variation in genotypes for the seed quality-related traits. Based on ISSR markers, a total of 204 bands were amplified and 149 bands (about 70%) of these were polymorphic. Cluster analysis based on either biochemical or molecular markers classified the genotypes into four groups, showing some similarities between molecular and biochemical markers for evaluated genotypes. A logical similarity between the genotype clusters based on molecular data with their geographical origins was observed

    ICAR: endoscopic skull‐base surgery

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    From Computer Metaphor to Computational Modeling: The Evolution of Computationalism

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    In this paper, I argue that computationalism is a progressive research tradition. Its metaphysical assumptions are that nervous systems are computational, and that information processing is necessary for cognition to occur. First, the primary reasons why information processing should explain cognition are reviewed. Then I argue that early formulations of these reasons are outdated. However, by relying on the mechanistic account of physical computation, they can be recast in a compelling way. Next, I contrast two computational models of working memory to show how modeling has progressed over the years. The methodological assumptions of new modeling work are best understood in the mechanistic framework, which is evidenced by the way in which models are empirically validated. Moreover, the methodological and theoretical progress in computational neuroscience vindicates the new mechanistic approach to explanation, which, at the same time, justifies the best practices of computational modeling. Overall, computational modeling is deservedly successful in cognitive (neuro)science. Its successes are related to deep conceptual connections between cognition and computation. Computationalism is not only here to stay, it becomes stronger every year
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