Search results for "dance"
showing 10 items of 2075 documents
Efectos conductuales y neuroquímicos del consumo de éxtasis y cocaína en ratones adolescentes.
2009
La 3,4-metilendioximetanfetamina (MDMA), una sustancia popularmente conocida como éxtasis, es una droga ilícita consumida habitualmente por adolescentes y adultos jóvenes. Además, el policonsumo es una práctica habitual entre los usuarios de la MDMA, siendo la cocaína una de las drogas más frecuentemente asociadas a esta sustancia. El objetivo del presente trabajo fue evaluar los efectos a corto y largo plazo que se producen tras la administración de la MDMA (5, 10, o 20 mg/kg) sola o en combinación con cocaína (25 mg/kg) en ratones adolescentes. En el estudio sobre el efecto agudo, observamos que ambas drogas administradas individual o simultáneamente incrementan la actividad motora. La do…
Rice fields as facilitators of freshwater invasions in protected wetlands: the case of Ostracoda (Crustacea) in the Albufera Natural Park (E Spain)
2014
Background: Previous studies have identified rice fields in the Mediterranean region as ‘hot spots’ for the introduction of alien freshwater organisms. Consequently, special attention should be paid when rice fields are located inside or near protected areas for the conservation of native, endangered species. To analyse the relationship between rice field environmental traits and the ecology of aquatic invaders, a study of zoobenthic communities was carried out in JulySeptember 2008 and May-August 2009 in ten rice fields located in the Albufera Natural Park (E Spain), with focus on Ostracoda. Results: A total of nine ostracod species were found including four considered exotic: Candonocypri…
Species Diversity and Distribution of Mammals in Riga
2003
The aim of this study was to investigate the species diversity and distribution of mammals in the territory of Riga. Our specific aims were to create a zonal division of Riga, and to classify habitats in unbuilt areas of the city. Riga was divided into four zones according to historical, economic and geographical features. Criteria of habitat classification were as follows: the size of a territory, anthropogenic load, soil and vegetation types and age. Sixteen types of habitats were distinguished. In the period 1999–2002, 27 mammal species of six orders were registered in the investigated territory of Riga. The number of animals and the diversity of species increased towards the periphery o…
The Factorization Method for Electrical Impedance Tomography in the Half-Space
2008
We consider the inverse problem of electrical impedance tomography in a conducting half-space, given electrostatic measurements on its boundary, i.e., a hyperplane. We first provide a rigorous weak analysis of the corresponding forward problem and then develop a numerical algorithm to solve an associated inverse problem. This inverse problem consists of the reconstruction of certain inclusions within the half-space which have a different conductivity than the background. To solve the inverse problem we employ the so-called factorization method of Kirsch, which so far has only been considered for the impedance tomography problem in bounded domains. Our analysis of the forward problem makes u…
Microwave Response of Ceramic MgB2 Samples
2009
The microwave response of ceramic MgB2 has been investigated as a function of temperature and external magnetic field by two different techniques: microwave surface impedance and second-harmonic emission measurements. The measurements of the surface resistance have shown that microwave losses in MgB2 are strongly affected by the magnetic field in the whole range of temperatures below Tc, even for relatively low field values. The results have been accounted for in the framework of the Coffey and Clem model hypothesizing that in different temperature ranges the microwave current induces fluxons to move in different regimes. In particular, the results at temperatures close to Tc have been quan…
Identification of ELF3 as an early transcriptional regulator of human urothelium
2014
AbstractDespite major advances in high-throughput and computational modelling techniques, understanding of the mechanisms regulating tissue specification and differentiation in higher eukaryotes, particularly man, remains limited. Microarray technology has been explored exhaustively in recent years and several standard approaches have been established to analyse the resultant datasets on a genome-wide scale. Gene expression time series offer a valuable opportunity to define temporal hierarchies and gain insight into the regulatory relationships of biological processes. However, unless datasets are exactly synchronous, time points cannot be compared directly.Here we present a data-driven ana…
Pesticide doses, landscape structure and their relative effects on farmland birds
2014
International audience; tAgricultural changes related to the intensification of farming practices and the simplification of land-scape elements often occur simultaneously. Their respective effects on biodiversity are thus difficult todisentangle and are poorly understood. This study assessed the relative contribution of each componentof agricultural intensification on taxonomic and functional bird communities.The bird communities studied were composed of 70 species, both farmland and non-farmland birds,found in 66 fields covering three main cereal departments of France. Herbicide dose was related to mea-surable negative effects on the Community Specialization Index (CSI). Overall, the propo…
Adaptive Collision Avoidance through Implicit Acknowledgments in WSNs
2008
The large number of nodes, typical of many sensor network deployments, and the well-known hidden terminal problem make collision avoidance an essential goal for the actual employment of WSN technology. Collision avoidance is traditionally dealt with at the MAC Layer and plenty of different solutions have been proposed, which however have encountered limited diffusion because of their incompatibility with commonly available devices.In this paper we propose an approach to collision avoidance which is designed to work over a standard MAC Layer, namely the IEEE 802.15.4 MAC, and is based on application-controlled delays of packet transmission times. The proposed scheme is simple, decentralized …
Cooperative RTS/CTS MAC with relay selection in distributed wireless networks
2009
This paper proposes a cooperative multiple access protocol based on the Distributed Coordination Function (DCF) Request-To-Send/Clear-To-Send (RTS/CTS) scheme for distributed wireless networks. It answers three key questions concerning cooperation from the network perspective, namely when to cooperate, whom to cooperate with and how to protect cooperative transmissions. According to our protocol, the cooperation is initiated only if the direct transmission fails. An optimal relay node is selected in a distributed manner according to instantaneous relay channel conditions without prior information or extra signaling among relay candidates in the network. An additional three-way handshake is …
Revisit of RTS/CTS Exchange in High-Speed IEEE 802.11 Networks
2005
IEEE 802.11 medium access control (MAC), called distributed coordination function (DCF), provides two different access modes, namely, 2-way (basic access) and 4-way (RTS/CTS) handshaking. The 4-way handshaking has been introduced in order to combat the hidden terminal phenomenon. It has been also proved that such a mechanism can be beneficial even in the absence of hidden terminals, because of the collision time reduction. We analyze the effectiveness of the RTS/CTS access mode, in current 802.11b and 802.11a networks. Since the rates employed for control frame transmissions can be much lower than the rate employed for data frames, the assumption on the basis of the 4-way handshaking introd…