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Petrography of alluvial sands as a past and present environmental indicator:Case of the Loire River(France)

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International Journal of Sediment Research 2013年第3期28卷 285-303页

作者： Jean-Jacques MACAIRE Isabelle GAY-OVEJERO Michel BACCHI Constantin COCIRTA Luc PATRYL Stéphane RODRIGUES university Franqois-rabelais of tours university francois-rabelais of tours SARL RIVE 4. Commissariat a l'Energie Atomique-CEA DAMDIF

Four sample sets of the Upper and Middle Loire river sands were analyzed in order to study the impact of natural and anthropogenic factors on their petrographic composition in space(on an 800 km stretch) and *** was determined by modal analysis of three sand-size fractions using a polarizing optical microscope and calculated for each sample("standard sand" = Sst).The watershed is composed mainly of endogenic(Massif Central) and sedimentary(southern Parisian Basin) rocks.B-set sands collected in channels for different water flows in 1996 show that Sst compositions vary by only 5%.Present-day sands in the Upper Loire and Middle Loire have very high petrographic immaturity comparing to others worldwide fluvial sands,although bio-climatic conditions favor sand maturation by source-rock weathering in the *** shows the strong impact of the Massif Central on sediment yield due to relief rejuvenation as a consequence of the formation of the Alps during the *** sands stored during the Weichselian and the Holocene in the Middle Loire floodplain,although partly weathered since their deposition,show higher inputs from the endogenic rocks of the Massif Central than present-day *** can be explained by Weichselian periglacial conditions and the development of crop farming since the Neolithic,which favored mechanical erosion,particularly in the Massif Central which is characterized by a cold,humid climate and steep *** upstream-downstream change in the composition of presently deposited sand is low in the diked *** shows however that basalt and some heavy mineral grains are vulnerable to abrasion during transport and indicates a marked sediment yield from ancient sediment stored in the *** is in line with the high incision of the river bed over the last 150 years partly due to dam construction and aggregate mining.

关键词： Fluvial sand Sand petrography Sediment source Tectonics impact Human impact Loire river

Do males choose their mates in the lekking moth Achroia grisella？ Influence of female body mass and male reproductive status on male mate choice

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Insect Science 2018年第5期25卷 861-868页

作者： Marlene Goubault Rebecca Burlaud Institut de Recherche sur la Biologie de I'Insecte UMR 7261 CNRS-Universite Francois-Rabelais Tours France

Lekking males aggregate to attract females and contribute solely to egg fer- tilization, without any further parental care. Evolutionary theory therefore predicts them to be nonchoosy toward their mates, because any lost mating opportunities would out- weigh the benefits associated with such preferences. Nevertheless, due to time costs, the production of energetically costly sexual displays, and potential sperm limitation, the mat- ing effort of lekking males is often considerable. These factors, combined with the fact that many females of varying quality are likely to visit leks, could favor the evolution of male mate preferences. Here, we show that males of the lekking lesser wax moth, Achroia grisella, were indeed more likely to mate with heavier females in choice experiments, even at their virgin mating （i.e., when their reproductive resources have not yet been depleted by previous matings）. This differential female mating success could not be attributed to female behavior as heavy and light females showed similar motivation to mate （i.e., la- tency to approach the males） and time to copulate. Males seem to benefit from mating with heavier females, as fecundity positively correlated with female mass. This new em- pirical evidence shows that male mate choice may have been tmderestimated in lekking species

关键词： fecundity lek lesser wax moth mate choice mating status sexual behavior

Acromyrmex ameliae sp. n. （Hymenoptera： Formicidae）： A new social parasite of leaf-cutting ants in Brazil

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Insect Science 2007年第3期14卷 251-257页

作者： DANIVAL JOSE de SOUZA ILKA MARIA FERNANdeS SOARES TEREZINHA MARIA CASTRO deLLA LUCIA Institut de Recherche sur la Biologie de 1'Insecte Université Francois Rabelais Tours France departamento de Biologia Animal Laboratório de Ecologia de Comunidades Departamento de Biologia Geral Universidade Federal de Vicosa MG 36570-000 Brazil

The fungus-growing ants （Tribe Attini） are a New World group of〉 200 species, all obligate symbionts with a fungus they use for food. Four attine taxa are known to be social parasites of other attines. Acromyrmex （ Pseudoatta） argentina argentina and Acromyrmex （Pseudoatta） argentina platensis （parasites of Acromyrmex lundi）, and Acromyrmex sp. （a parasite of Acromyrmex rugosus） produce no worker caste. In contrast, the recently discovered Acromyrmex insinuator （a parasite of Acromyrmex echinatior） does produce workers. Here, we describe a new species, Acromyrmex ameliae, a social parasite of Acromyrmex subterraneus subterraneus and Acromyrmex subterraneus brunneus in Minas Gerais, Brasil. Like A. insinuator, it produces workers and appears to be closely related to its hosts. Similar social parasites may be fairly common in the fungus-growing ants, but overlooked due to the close resemblance between parasite and host workers.

关键词： Acromyrmex leaf-cutting ants social evolution social parasitism

Therapeutic potential of α7 nicotinic receptor agonists to regulate neuroinflammation in neurodegenerative diseases

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Neural Regeneration Research 2017年第9期12卷 1418-1421页

作者： Laura Foucault-Fruchard Daniel Antier UMR INSERM U930 Université Fran?ois Rabelais CHRU de tours H?pital Bretonneau

Neurodegenerative diseases, such as Alzheimer＇s, Parkinson＇s and Huntington＇s diseases, are all character- ized by a component of innate immunity called neuroinflammation. Neuronal loss and neuroinflammation are two phenomena closely linked. Hence, the neuroinflammation is a relevant target for the management of the neurodegenerative diseases given that, to date, there is no treatment to stop neuronal loss. Several studies have investigated the potential effects of activators of alpha 7 nicotinic acetylcholine receptors in animal models of neurodegenerative diseases. These receptors are widely distributed in the central nervous system. After activation, they seem to mediate the cholinergic anti-inflammatory pathway in the brain. This anti-inflammatory pathway, first described in periphery, regulates activation of microglial cells considered as the resident macrophage population of the central nervous system. In this article, we shortly review the agonists of the alpha 7 nicotinic acetylcholine receptors that have been evaluated in vivo and we focused on the selective positive allosteric modulators of these receptors. These compounds represent a key element to enhance receptor activity only in the presence of the endogenous agonist.

关键词： α7 nicotinic receptors cholinergic anti-inflammatory pathway Alzheimer's disease Huntington's disease Parkinson's disease neuroinflammation neurodegeneration positive allosteric modulators

Genetic diversity of the hepatitis C virus: Impact and issues inthe antiviral therapy

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World Journal of Gastroenterology 2007年第17期13卷 2416-2426页

作者： H Le Guillou-Guillemette S Vallet C Gaudy-Graffin C Payan A Pivert A Goudeau F Lunel-Fabiani Laboratory of Virology University Hospital of Angers France and Laboratory HIFI UPRES EA 3859 University of Angers France department of Microbiology EA 3882 CHU Morvan University Hospital of Brest France université francois rabelais INSERM ERI 19 et CHRU de Tours Tours France

The hepatitis C Virus (HCV) presents a high degree of genetic variability which is explained by the combination of a lack of proof reading by the RNA dependant RNA polymerase and a high level of viral replication. The re- sulting genetic polymorphism defines a classification in clades, genotypes, subtypes, isolates and quasispecies. This diversity is known to reflect the range of responses to Interferon therapy. The genotype is one of the pre- dictive parameters currently used to define the antiviral treatment strategy and the chance of therapeutic suc- cess. Studies have also reported the potential impact of the viral genetic polymorphism in the outcome of antivi- ral therapy in patients infected by the same HCV geno- type. Both structural and non structural genomic regions of HCV have been suggested to be involved in the Inter- feron pathway and the resistance to antiviral therapy. In this review, we first detail the viral basis of HCV diversity. Then, the HCV genetic regions that may be implicated in resistance to therapy are described, with a focus on the structural region encoded by the E2 gene and the non- structural genes NS3, NS5A and NS5B. Both mechanisms of the Interferon resistance and of the new antiviral drugs are described in this review.

关键词： Hepatitis C virus Genetic diversity Therapyresistance E2 NS3 NSSA NSSB

delayed sexual maturity in males of Vespa velutina

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Insect Science 2018年第4期25卷 679-689页

作者： Juliette Poidatz Christophe Bressac Olivier Bonnard denis Thiery INRA UMR1065 Santé et Agroecologie du Vignoble ISVV Bordeaux Sciences Agro Villenave d'Omon France IRBI Universite Francois Rabelais UMR CNRS 7261 Tours France

Vespa velutina var nigrithorax （Lepelletier, 1835） is an invasive predator of bees accidentally introduced in France in 2004, and it is having a serious impact on apiculture and ecosystems. Studying the reproduction of an invasive species is key to assess its population dynamic. This study explores the sexual maturation of IT. velutina males and the evolution of their fertility. The main studied parameters were physiologic （spermiogenesis, spermatogenesis） and anatomic （testes size and structure, head width）. Two populations of males were described based on their emergence period： early males in early summer or classic males in autumn. Each testis has an average of 108 testicular follicles. Spermatogenesis is synchronous, with only 1 sperm production wave, and completed, on average, at 10.3 d after emergence with the degeneration of the testes. The sperm counts in seminal vesicles of mature males are 3 x 106 in October/November and 0.8 ~ 106 in June. In com- parison, females store 0.1 x 106 sperm in their spermathecae. The early males emerged from colonies made by fertilized queens. The reproductive potential of these early males seemed limited, and their fimction in the colony is discussed. The sperm stock evolution in autumn males suggests the occurrence of a reproductive pattern of male competition for the access to females and a single copulation per male. The synchronicity of male and foundress emergences and sexual maturation is of primary importance for the mating success and the future colony development.

关键词： male fertility seminal vesicles spermiogenesis sperm stock testis Vespidae yellow-legged hornet

Dynamics and origin of cytokinins involved in plant manipulation by a leaf-mining insect

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Insect Science 2017年第6期24卷 1065-1078页

作者： Hui Zhang Antoine Guiguet Geraldine Dubreuil Anna Kisiala Peter Andreas R. J. Neil Emery Elisabeth Huguet Melanie Body David Giron Institut de Recherche sur la Biologie de I'lnsecte UMR 7261 CNRSIUniversite Francois-Rabelais de Tours Tours France departement de Biologie Ecole Normale Superieure de Lyon Lyon France department of Life and Environmental Sciences Kyoto Prefectural University Kyoto Japan department of Biology Trent University Peterborough Canada Division of Plant Sciences Christopher S. Bond Life Sciences Center University of Missouri Columbia USA

Several herbivorous insects and plant-associated microorganisms control the phytohormonal balance, thus enabling them to successfully exploit the plant by inhibiting plant defenses and withdrawing plant resources for their own benefit. The leaf-mining moth Phyllonorycter blancardella modifies the cytokinin （CK） profile of mined leaf-tissues, and the insect symbiotic bacteria Wolbachia is involved in the plant manipulation to the benefit of the insect host. To gain a deeper understanding into the possible origin and dynamics of CKs, we conducted an extensive characterization of CKs in larvae and in infected apple leaves. Our results show the enhanced CK levels in mines, both on green and yellow leaves, allowing insects to control their nutritional supply under fluctuating environmental conditions. The spatial distribution of CKs within the mined leaves shows that hormone manipulation is strictly limited to the mine suggesting the absence of CK translocation from distant leaf areas toward the insect feeding site. Mass spectrometry analyses reveal that major CK types accumulating in mines and larvae are similar to what is observed for most gall-inducers, suggesting that strategies underlying the plant manipulation may be shared between herbivorous insects with distinct life histories. Results further show that CKs are detected in the highest levels in larvae, reinforcing our hypothesis that CKs accumulating in the mines originate from the insect itself. Presence of bacteria- specific methylthio-CKs is consistent with previous results suggesting that insect bacterial symbionts contribute to the observed phenotype. Our study provides key findings toward the understanding of molecular mechanisms underlying this intricate plant-insect-microbe interaction.

关键词： cytokinins insect bacterial symbionts leaf-miners phytohormones plantinsect-microbe interactions plant manipulation

Towards a simple acoustic method to evaluate the nonlinear parameter B/A of fluids

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Towards a simple acoustic method to evaluate the nonlinear p...

Insertion Of E7 Into External Loops Of Hpv-16 L1 Vlps For The Production Of Chimeric Vaccines

2008 IEEE International Ultrasonics Symposium

作者： francois Vander Meulen Lionel Haumesser université francois rabelais de tours INSERM U930/CNRS FRE 2448Blois

＜正＞Background,Motivation and Objective The nonlinearity parameter is known to be an indicator of great interest in the medical field and for non destructive evaluation in industrial *** and industrial constraints o...

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Insertion Of E7 Into External Loops Of Hpv-16 L1 Vlps For Th...