Search results for "Location"
showing 10 items of 1480 documents
The price of safety: food deprivation in early life influences the efficacy of chemical defence in an aposematic moth
2018
Aposematism is the combination of a primary signal with a secondary defence that predators must learn to associate with one another. However, variation in the level of defence, both within and between species, is very common. As secondary defences influence individual fitness, this variation in quality and quantity requires an evolutionary explanation, particularly as it may or may not correlate with variation in primary signals. The costs of defence production are expected to play a considerable role in generating this variation, yet studies of the cost of chemical defence have focused on species that sequester their defences, while studies in species that produce them de novo are scarce. …
Assembly and Translocation of Papillomavirus Capsid Proteins
2002
ABSTRACT The major and minor capsid proteins of polyomavirus are preassembled in the cytoplasm and translocated to the nucleus only as a VP1-VP2/VP3 complex. In this study, we describe independent nuclear translocation of the L1 major protein and the L2 minor capsid protein of human papillomavirus type 33 by several approaches. First, we observed that expression and nuclear translocation of L2 in natural lesions precede expression of L1. Second, using a cell culture system for coexpression, we found that accumulation of L2 in nuclear domain 10 (ND10) subnuclear structures precedes L1 by several hours. In contrast, complexes of L2 and mutants of L1 forced to assemble in the cytoplasm are tra…
Visual working memory resource allocation mechanism in consolidation and maintenance phase
2018
Visual working memory (VWM) is a system for actively maintaining visual information to meet the needs of an ongoing task. It allows individuals to store visual input information from a complex outside environment and provides storage space as an information buffer platform to help integrate information into a continuous visual experience. This research examined the consolidation and maintenance phase of the VWM resource allocation mechanism. Four aspects of this issue were investigated. First, resource allocation in VWM consolidation was investigated for different materials, and it was determined whether VWM resources were allocated in a serial manner for orientation materials but in a limi…
Negative emotional state modulates visual working memory in the late consolidation phase
2020
Although a considerable literature has grown up around the interactions between emotional state and visual working memory (VWM) performance, the mechanism underlying the impact of the negative emotional state on VWM remains unclear. The present study aimed to test whether the influence of emotional state is related to the early phase or late phase of VWM consolidation process. Across three experiments, we found that the negative emotional state did not affect VWM performance when the presentation time of stimuli was short. However, when the presentation time was long, the negative emotional state increased the VWM precision and reduced the VWM number. According to the two-phase model propos…
Les types de temps associés aux risques d’inondations et d’érosions en Camargue : éléments de diagnostic et de prospectives pour le 21e siècle (1993-…
2010
Les fortes surcotes marines et les fortes vagues sont les principaux aléas météo-marins associés aux risques de submersion et d’érosion du littoral camarguais. Sur la période 1993-2002, une forte fréquence mensuelle de très hautes surcotes marégraphiques est généralement associée à une forte fréquence de très hautes vagues. Ces deux phénomènes locaux se produisent principalement lorsqu'une dépression autour du Golfe de Gascogne est associée à des hautes pressions sur l’Europe Centrale. La fréquence mensuelle de ce type de temps nous renseigne sur la probabilité d’occurrence de fortes surcotes marégraphiques et vagues en Camargue. Au 21e siècle, la fréquence du type de temps associé aux plus…
A Double Auction Mechanism for Virtual Resource Allocation in SDN-based Cellular Network
2016
The explosively growing demands for mobile traffic service bring both challenges and opportunities to wireless net- works, among which, wireless network virtualization is proposed as the main evolution towards 5G. In this paper, we first propose a Software Defined Network (SDN) based wireless virtualization architecture for enabling multi-flow transmission in order to save capital expenses (CapEx) and operation expenses (OpEx) significantly with multiple Infrastructures Providers (InPs) and multiple Mobile Virtual Network Operators (MVNOs). We for- mulate the virtual resource allocation problem with diverse QoS requirements as a social welfare maximization problem with transaction cost. Due…
Energy Efficient Optimization for Wireless Virtualized Small Cell Networks With Large-Scale Multiple Antenna
2017
Wireless network virtualization is envisioned as a promising framework to provide efficient and customized services for next-generation wireless networks. In wireless virtualized networks (WVNs), limited radio resources are shared among different services providers for providing services to different users with heterogeneous demands. In this paper, we propose a resource allocation scheme for an orthogonal frequency division multiplexing-based WVN, where one small cell base station equipped with a large number of antennas serves the users with different service requirements. In particular, with the objective to obtain the energy efficiency in the uplink, a joint power, subcarrier, and antenn…
Resource Allocation and Computation Offloading for Wireless Powered Mobile Edge Computing
2022
In this paper, we investigate a resource allocation and computation offloading problem in a heterogeneous mobile edge computing (MEC) system. In the considered system, a wireless power transfer (WPT) base station (BS) with an MEC sever is able to deliver wireless energy to the mobile devices (MDs), and the MDs can utilize the harvested energy for local computing or task offloading to the WPT BS or a Macro BS (MBS) with a stronger computing server. In particular, we consider that the WPT BS can utilize full- or half-duplex wireless energy transmission mode to empower the MDs. The aim of this work focuses on optimizing the offloading decision, full/half-duplex energy harvesting mode and energ…
L'allocation de ressources par élève dans le système éducatif français : point de vue d'un économiste
1993
This article examines why it is interesting to have a better knowledge of unit costs in educational systems, and to analyse differences between levels of education, between schools and between countries. It underlines the fact that few studies have been carried out up to now, and that little agreement exists among specialists concerning the methodologies for estimating costs. In spite or these deficiencies in available information, the author reviews existing case studies in France and in the world, and shows that extensive possibilities of improving the cost-effectiveness of ressources allocation still exist. Comparisons between France and its economic partners show that French unit costs …
Izglītības ģeogrāfija Saldus novadā: bērnu un jauniešu izvietojuma iezīmes
2022
Bakalaura darbā “Izglītības ģeogrāfija Saldus novadā: bērnu un jauniešu izvietojuma iezīmes” tiek analizētas pārmaiņas bērnu un jauniešu izvietojumā Saldus novada pagastos un ciemos. Bērnu un jauniešu izvietojumam raksturīga augsta koncentrācija novada centrālajā daļā, īpaši izglītības iestāžu tiešā tuvumā. Visos novada ciemos un pagastos jauniešu vecumā līdz 24 gadiem vidū dominē skolas vecuma bērni vecumā no 7 līdz 17 gadiem. Izvietojuma izmaiņās būtisks faktors ir iedzīvotāju sastāva novecošanās un depopulācija. Viskrasākās atšķirības novadā redzamas Vadakstes pagastā, Blīdenes pagastā, Nīgrandes pagastā un citos Saldus novada perifērijā esošajos pagastos. Darbā apskatīta pieejamā litera…