Search results for "InSe"
showing 10 items of 3069 documents
Surviving in a warmer world: environmental and genetic responses
2012
There are numerous reports in the literature of advancing trends in phenophases of plants, insects and birds attributed to rising temperature resulting from human-driven climate warming. One mechanism that enables a population to respond rapidly to changes in the environ- ment is termed phenotypic plasticity. This plasticity grants a degree of flexibility to enable the tim- ing of developmental stages to coincide with resource availability. If, however, environmental con- ditions exceed the plastic limits of an organism, evolutionary change may be necessary in order to ensure continued survival of their populations. We review evidence for phenotypic plasticity and genetic adaptation in phen…
Graphene as a tunable resistor
2014
We present the design of a graphene-based electronically tuneable microstrip attenuator operating at a frequency of 5 GHz. The use of graphene as a variable resistor is discussed and the modelling of its electromagnetic properties at microwave frequencies is fully addressed. The design of the graphene-based attenuator is described. The structure integrates a patch of graphene, whose characteristics can range from being a fairly good conductor to a highly lossy material, depending on the applied voltage. By applying the proper voltage through two high-impedance bias lines, the surface resistivity of graphene can be modified, thereby changing the insertion loss of the microstrip attenuator.
L'enseignement agricole entre l'attraction de l'urbain et le retour à la ferme : une vue transversale
1985
International audience
Regards croisés sur les étudiants et les jeunes diplômés : déterminants individuels et migrations régionales
2006
This paper aims at comparing individual and regional factors of young people's migrations. Especially these linked with French High Education ; entering University, students in training and graduates integrating labour market. Do they mirgrate the same way ? Do regions influence the way they migrate ? Do individual and social factors interfere in the same way ? This paper aims at answering all these questions.
An integrated approach to evaluating the tribo-contact for coated cutting inserts
2000
Abstract The orthogonal machining process when end turning medium carbon and austenitic stainless steels with cemented WC-Co tools coated with single-layer (TiC), two-layer (TiC/TiN), and three-layer (TiC/Al2O3/TiN) hard thin films was investigated. Extensive experimental investigations including the thermal, mechanical and tribological responses of the tribo-contact between the coating–substrate system and the chip, under different cutting conditions, were carried out. The study sheds light on the cutting forces, the interface temperatures and the tribo-contact conditions, including the friction energy dissipated at the tool–chip interface, the frictional heat flux conducting into either t…
Multiple-chromosome sex systems in the darkling beetles Blaps gigas and Blaps gibba (Coleoptera, Tenebrionidae)
1996
We have studied mitotic and meiotic chromosomes in the males of two species of Blaps: B. gigas and B. gibba. Karyological characteristics such as the occurrence of a multivalent configuration at diakinesis and two types of metaphase-II spreads support the notion that multiple-chromosome sex systems involving five chromosomes in B. gigas and eight chromosomes in B. gibba have developed in these species. Results obtained by means of silver staining and C-banding techniques suggest that the complex sex systems occurring in B. gigas and B. gibba may have originated from exchanges of terminal ribosomal genes among the Y chromosome and some autosomes.
Lifetime egg production of captive libellulids (Odonata)
2015
The estimation of lifetime egg production (LEP) is a central question in ecology, since the number of eggs produced determines the potential size of the following generation. In this study, I tried to obtain a rough estimation of the LEPs in libellulids in outdoor cages. The main questions were: (1) does hand feeding influence females’ life history traits; (2) how long is the maturation period and the lifespan; (3) does the quality/quantity of eggs vary with female age or size; and (4) how many eggs do females lay in their lifetime? I installed two outdoor cages and kept individually marked specimens of Orthetrum coerulescens and Sympetrum striolatum under semi-natural circumstances. Orthet…
Association between haematozoan infections and reproduction in the Pied Flycatcher
1997
1. Parasites may affect breeding success of their host since they compete for the same resources as their hosts. Reproduction may also increase the susceptibility of a host to parasite infections owing to lowered resistance to parasites during breeding. 2. We studied the association between breeding performance and haematozoan parasite infection in the Pied Flycatcher (Ficedula hypoleuca) by using both natural data on reproduction and data from clutch size manipulations. 3. The most frequent blood parasites of the Pied Flycatcher in central Finland were Haemoproteus pallidus, Haemoproteus balmorali and Trypanosoma avium complex. 4. We did not find evidence that these haematozoan parasites h…
Duck Hepatitis B Virus Requires Cholesterol for Endosomal Escape during Virus Entry
2008
ABSTRACT The identity and functionality of biological membranes are determined by cooperative interaction between their lipid and protein constituents. Cholesterol is an important structural lipid that modulates fluidity of biological membranes favoring the formation of detergent-resistant microdomains. In the present study, we evaluated the functional role of cholesterol and lipid rafts for entry of hepatitis B viruses into hepatocytes. We show that the duck hepatitis B virus (DHBV) attaches predominantly to detergent-soluble domains on the plasma membrane. Cholesterol depletion from host membranes and thus disruption of rafts does not affect DHBV infection. In contrast, depletion of chole…
Formation et insertion des apprentis de niveau V, quelle relation rétablir ?
1990
International audience