检索结果-南通市图书馆

维普期刊数据库

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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

Synthesis,sintering,and thermoelectric properties of the solid solution La_(1–x)Sr_(x)CoO_(3±δ)(0≤x≤1)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2018年第2期7卷 160-168页

作者： M.A.BOUSNINA R.DUJARDIN L.PERRIERE F.GIOVANNELLI G.GUEGAN F.DELORME Universitéfrancois rabelais de tours CNRSINSA CVLGREMAN UMR7347IUT de Blois ICMPE ST Microelectronics

In this work, we synthesized cubic perovskite ceramics of the whole La_(1–x)Sr_xCoO_3(0 ≤ x ≤ 1) solid solution for the first time. Synthesis was carried out by solid state reaction and conventional sintering to reach dense ceramics. For x > 0.8, it was necessary to substitute 3% cobalt by silicon to stabilize the cubic perovskite structure. Electrical conductivity increased with Sr content to reach 3×10~5 S·m^(–1) at 330 K for x = 0.3. However, the optimum electrical properties have been found for x = 0.05 at 330 K with PF_(max) = 3.11×10^(–4)W·m^(–1)·K^(–2). Indeed, the Seebeck coefficient was decreasing when x increased to reach values close to 0 for x ≥ 0.3. Thermal conductivity was low at low temperature(≈ 2.5 W×m^(–1)·K^(–1)) and increased up to 6.5 W·m^(–1)·K^(–1) when temperature increased. As the highest power factor was reached at low temperature as well as the lowest thermal conductivity, La_(1–x)Sr_xCoO_3 compounds with low x values appeared as very promising thermoelectric materials around room temperature, on the contrary to layered cobalt oxides. For high x values, Seebeck coefficient values close to zero made these materials unsuitable for thermoelectric applications.

关键词： perovskite cobalt oxide solid solution electrical conductivity thermoelectric

维普期刊数据库

Earwig mothers consume the feces of their juveniles during family life

在线全文

学校读者我要写书评

暂无评论

Insect Science 2022年第2期29卷 595-602页

作者： Sophie Van Meyel Séverine Devers Joël Meunier Institut de Recherche sur la Biologie de l'Insecte UMR 7261CNRSUniversity of ToursToursFrance

Many animals consume the feces of their *** allo-coprophagy can have benefits,such as access to nutrients and symbionts,but also risks for consumers,mainly due to direct contact with pathogens that develop on *** the European earwig Forficula auricularia,mothers and juveniles live in nests lined with their *** surprising habit allows juveniles to consume the feces of their siblings during family life and provides them with nutritional benefits when mothers provide low ***,it was unclear whether earwig mothers also practice allo-coprophagy,and whether this behavior is motivated by their nutritional ***,we set up four types of experimental families in which we manipulated the nutritional needs of mothers and/or juveniles and measured the effects on the production of feces by the juveniles,and the consumption of these feces by the *** results first show that fed juveniles produced more feces pellet in presence of fed compared to food-deprived *** also found that,overall,about 50%of the mothers consumed juveniles *** consumption was both more likely and larger when the feces were produced by fed compared to food-deprived juveniles,while the proportion of feces pellets eaten was larger in food-deprived compared to fed ***,our results reveal that allo-coprophagy involves every family member and suggest that it can have both nutritional and non-nutritional benefits for earwig ***-coprophagy could thus favor the maintenance of mothers in the nest and,more generally,promote the early evolution of family life.

关键词： cooperation coprophagy dermaptera family life parental care

Hyperhomocysteinemia and Associated Biological Markers in a Congolese Population of Type 2 Diabetes Mellitus in Brazzaville

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Endocrine and Metabolic Diseases 2024年第6期14卷 123-134页

作者： V. R. Ikia Monde A. L. M. Boumba E. Mokondjimobe H. Poaty G. Loubano-Voumbi W. F. Ondongo A. G. Mayindou Kimbangu K. Onanga F. Elilie Mawa Ongoth E. Bouenizabila C. Andres H. G. Monabeka Biochemistry Laboratory Service University Hospital Center Brazzaville Congo Faculty of Health Sciences Marien NGOUABI University Brazzaville Congo Research Area of Pointe-Noire National Institute for Research in Health Sciences (IRSSA) Pointe-Noire Congo Microbiology and Molecular Biology Department Loandjili General Hospital Pointe-Noire Congo LOMO Research university Kinshasa DRC Department of Statistics Health Information and Epidemiology Surveillance Departmental Directorate of Health Care and Services Brazzaville Congo Department of Endocrinology University Hospital Center Brazzaville Congo Department of Biochemistry and Molecular Biology Bretonneau Regional University Hospital Tours France

The search for new biomarkers predictive of type 2 diabetes currently constitutes a research avenue in Bioclinical. Total homocysteine remains a preferred target due to its involvement in the occurrence of degenerative complications in type 2 diabetics. The aim of this work was to study hyperhomocysteinemia and other biochemical markers associated with T2D in the Congolese population. This was an analytical case-control study carried out between October 2022 and October 2023. The study population consisted of 150 subjects including 100 T2D patients and 50 control subjects. The main clinical data were collected on a pre-established form. Homocysteine determination was carried out by the sandwich ELISA method. The other biochemical markers were measured by colorimetric enzymatic methods. Hyperhomocysteinemia was present in 27.3% (41/150) of the entire study population. Type 2 diabetics had a frequency of hyperhomocysteinemia of 36% (36/100) and control 10% (5/50) (p = 0.001). The mean hyperhomocysteinemia concentration was 31.9 μmol/l with extremes ranging from 18 to 103 μmol/l. Means of biological markers between diabetics and controls showed a statistically significant difference (p = 0.01). The risk factors associated with this HHcy were: sex (OR = 3.5), age (OR = 9.4), sedentary lifestyle (OR = 3.4) and glycosylated hemoglobin (OR = 12) with a p-value <0.05 respectively. Our results suggest that hyperhomocysteinemia can be considered as a predictive biomarker in the bioclinic of Congolese type 2 diabetic patients.

关键词： Hyperhomocysteinemia Biological Markers T2DM Brazzaville

Delayed sexual maturity in males of Vespa velutina

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

A Novel Insertion Solution for the Travelling Salesman Problem

24th International Papillomavirus Conference and Clinical Workshop

作者： Eva Alvarez Latifa Bousarghin Antoine Touze Pierre Coursaget Inserm U618 Francois Rabelais UniversityToursFrance Inserm U618 Francois Rabelais UniversityToursFrance Inserm U618 Francois Rabelais UniversityToursFrance Inserm U618 Francois Rabelais UniversityToursFrance

＜正＞The aims of this study were to insert E7 and E7 peptides into the surface loops of the HPV-16 L1 protein,in order to create new chimeric HPV *** generated 7 mutants by insertion of 5 different HPV-16 E7 sequences within BC,DE,EF,and HI loops With the exception of two L1/E7 mutants containing the entire E7 sequence,all these L1 mutants were able to self- assemble into ***,the insertion of heterologous sequences was accompanied by a reduction in the yield of VLP

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第4期79卷 1581-1597页

作者： Emmanuel Oluwatobi Asani Aderemi Elisha Okeyinka Sunday Adeola Ajagbe Ayodele Ariyo Adebiyi Roseline Oluwaseun Ogundokun Temitope Samson Adekunle Pragasen Mudali Matthew Olusegun Adigun Department of Computer Science Landmark UniversityOmu Aran251103Nigeria SDG 11 Group Landmark UniversityOmu Aran251103Nigeria Department of Computing MiVA UniversityAbuja900211Nigeria Department of Computer Science Ibrahim Badamasi Babangida UniversityLapai911101Nigeria Department of Computer Science University of ZululandKwadlangezwa3886South Africa Department of Computer&Industrial Production Engineering First Technical UniversityIbadan200243Nigeria Department of Multimedia Engineering Kaunas University of TechnologyKaunasLT-44249Lithuania Department of Computer Science Colorado State UniversityFort Collins80523USA

The studypresents theHalfMax InsertionHeuristic (HMIH) as a novel approach to solving theTravelling SalesmanProblem (TSP). The goal is to outperform existing techniques such as the Farthest Insertion Heuristic (FIH) andNearest Neighbour Heuristic (NNH). The paper discusses the limitations of current construction tour heuristics,focusing particularly on the significant margin of error in FIH. It then proposes HMIH as an alternative thatminimizes the increase in tour distance and includes more nodes. HMIH improves tour quality by starting withan initial tour consisting of a ‘minimum’ polygon and iteratively adding nodes using our novel Half Max *** paper thoroughly examines and compares HMIH with FIH and NNH via rigorous testing on standard TSPbenchmarks. The results indicate that HMIH consistently delivers superior performance, particularly with respectto tour cost and computational efficiency. HMIH’s tours were sometimes 16% shorter than those generated by FIHand NNH, showcasing its potential and value as a novel benchmark for TSP solutions. The study used statisticalmethods, including Friedman’s Non-parametric Test, to validate the performance of HMIH over FIH and *** guarantees that the identified advantages are statistically significant and consistent in various situations. Thiscomprehensive analysis emphasizes the reliability and efficiency of the heuristic, making a compelling case for itsuse in solving TSP issues. The research shows that, in general, HMIH fared better than FIH in all cases studied,except for a few instances (pr439, eil51, and eil101) where FIH either performed equally or slightly better thanHMIH. HMIH’s efficiency is shown by its improvements in error percentage (δ) and goodness values (g) comparedto FIH and NNH. In the att48 instance, HMIH had an error rate of 6.3%, whereas FIH had 14.6% and NNH had20.9%, indicating that HMIH was closer to the optimal solution. HMIH consistently showed superior performanceacross many benchmarks,

关键词： Nearest neighbour heuristic farthest insertion heuristic half max insertion heuristic tour construction travelling salesman problem

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

维普期刊数据库