5,244 research outputs found
A stochastic movement simulator improves estimates of landscape connectivity
Acknowledgments This publication issued from the project TenLamas funded by the French Ministère de l'Energie, de l'Ecologie, du Développement Durable et de la Mer through the EU FP6 BiodivERsA Eranet; by the Agence Nationale de la Recherche (ANR) through the open call INDHET and 6th extinction MOBIGEN to V. M. Stevens, M. Baguette, and A. Coulon, and young researcher GEMS (ANR-13-JSV7-0010-01) to V. M. Stevens and M. Baguette; and by a VLIR-VLADOC scholarship awarded to J. Aben. L. Lens, J. Aben, D. Strubbe, and E. Matthysen are grateful to the Research Foundation Flanders (FWO) for financial support of fieldwork and genetic analysis (grant G.0308.13). V. M. Stevens and M. Baguette are members of the “Laboratoire d'Excellence” (LABEX) entitled TULIP (ANR-10-LABX-41). J. M. J. Travis and S. C. F. Palmer also acknowledge the support of NERC. A. Coulon and J. Aben contributed equally to the work.Peer reviewedPublisher PD
Empirical research on youth transitions to and within the labour market
The research project aimed to provide research outcomes on the magnitude of youth transitions, the main drivers and barriers of youth transitions and potential long-term outcomes (‘scarring’) on people’s subsequent employment trajectories. This report summarises the evidence obtained by making use of a range of individual-level data sets and methods, in particular:
• An analysis of Labour Force Survey (LFS) data creating pseudo-cohorts to examine long-term education and labour market trends affecting 16-to-24 year olds from 39 different birth cohorts and subsequent employment trajectories.
• An analysis of the ‘Ad Hoc module’ of 2009 from the European Labour Force Survey (EU:LFS) on ‘Youth Transitions’ on individual long-term outcomes of particular youth labour market transitions.
• An analysis of various cohort studies (National Child Development Study [NCDS], British Cohort Study [BCS], Youth Cohort Study [YCS], Longitudinal Study of Young People in England [LSYPE]) comparing the episodes young people experience when making transitions into the labour market in youth and early adulthood. This study uses sequential analysis for individual monthly panel data to describe biographies of young people until the age of 25 (based on BCS and NCDS) and until the age of 19 (for YCS and LSYPE).
• An analysis of the transition from secondary schooling to further destinations using a recent cohort of School Leavers National Pupil Data (NPD) merged to records of National Client Casework Information System (NCCIS) on young people’s activities after the end of compulsory education including econometric models on drivers and barriers of particular transitions
SENSE: A comparison of photon detection efficiency and optical crosstalk of various SiPM devices
This paper describes a comparison of photon detection efficiency and optical
crosstalk measurements performed by three partners: Geneva University, Catania
Observatory and Nagoya University. The measurements were compared for three
different SiPM devices with different active areas: from 9 up to 93.6
produced by Hamamatsu. The objective of this work is to establish the
measurements and analysis procedures for calculating the main SiPM parameters
and their precision. This work was done in the scope of SENSE project which
aims to build roadmap for the last developments in field of sensors for low
light level detection
The ferroelectric Mott-Hubbard phase of organic (TMTTF)2X conductors
We present experimental evidences for a ferro-electric transition in the
family of quasi one- dimensional conductors (TMTTF)2X. We interpret this new
transition in the frame of the combined Mott-Hubbard state taking into account
the double action of the spontaneous charge disproportionation on the TMTTF
molecular stacks and of the X anionic potentials
Analysis of Farmland Abandonment and the Extent and Location of Agricultural Areas that are Actually Abandoned or are in Risk to be Abandoned
Farmland abandonment (FLA) can be defined as the cessation of agricultural activities on a given surface of land and not taken by another activity (such as urbanisation or afforestation). This process attracts the attention of policy-makers both at national and EU level, in particular within the context of the Rural Development Policy. And, considering its importance in environmental and socio-economic terms, it is necessary to better understand the geographic distribution and strength of farmland abandonment trends in the EU-27, and to develop indicators to identify the most important farmland abandonment tendencies.
The first aim of this study was to establish the state of the art concerning farmland abandonment (definition, type) and methodologies for identifying/quantifying this phenomenon (dataset, period of analysis, scale). Then, it was about contributing to a new definition of Less Favoured Areas by assessing the driving forces of farmland abandonment and preparing the guidelines for agri-environmental indicator Nr 14 [COM2006 (508final)] by evaluating the state and risk of farmland abandonment.
The proposed methodology was based on two main elements: the variation of the UAA and the definition of rural areas. After identifying clear definitions for each variable, the way to consider the main flows of land use changes was studied. Due to a lack of accurate data at the appropriate scale, farmland afforestation could not be separated from the flow of FLA and the flow from farmland to sealed soil was estimated based on the hypothesis that it was mainly located in urban areas where the population density is high or increases very fast.
The methodology was tested in three of the main agricultural countries in the EU-27 in terms of surface (France, Spain and Poland). Then, five regions were chosen to cover different contexts where a high level of FLA was observed and interviews of experts and stakeholders completed the study. Based on the results on the main causes of FLA, indicators of risk were proposed and recommendations were formulated to improve the methodology and datasets.JRC.H.5-Rural, water and ecosystem resource
Superconductivity and Antiferromagnetism in Quasi-one-dimensional Organic Conductors
We review the current understanding of superconductivity in the
quasi-one-dimensional organic conductors of the Bechgaard and Fabre salt
families. We discuss the interplay between superconductivity,
antiferromagnetism, and charge-density-wave fluctuations. The connection to
recent experimental observations supporting unconventional pairing and the
possibility of a triplet-spin order parameter for the superconducting phase is
also presented.Comment: (v1) 30 pages, 13 figures; Review article for the 20th anniversary of
high-Tc superconductivity, to appear in J. Low Temp. Phys. (v2) 1 Ref. adde
Elongation mechanism of the ion shaping of embedded gold nanoparticles under swift heavy ion irradiation
The elongation process under swift heavy ion irradiation (74 MeV Kr ions) of gold NPs, with a diameter in the range 10-30 nm, and embedded in a silica matrix has been investigated by combining experiment and simulation techniques: three-dimensional thermal spike (3DTS), molecular dynamics (MD) and a phenomenological simulation code specially developed for this study. 3DTS simulations evidence the formation of a track in the host matrix and the melting of the NP after the passage of the impinging ion. MD simulations demonstrate that melted NPs have enough time to expand after each ion impact. Our phenomenological simulation relies on the expansion of the melted NP, which flows in the track in silica with modified (lower) density, followed by its recrystallization upon cooling. Finally, the elongation of the spherical NP into a cylindrical one, with a length proportional to its initial size and a width close to the diameter of the track, is the result of the superposition of the independent effects of each expansion/recrystallization process occurring for each ion impact. In agreement with experiment, the simulation shows the gradual elongation of spherical NPs in the ion-beam direction until their widths saturate in the steady state and reach a value close to the track diameter. Moreover, the simulations indicate that the expansion of the gold NP is incomplete at each ion impact.Peer reviewe
Polarization-mode interferometry in birefringent single-mode fibers
An interferometric technique was used to investigate the relative phase delay between polarization modes in birefringent single-mode fibers. Polarization-mode dispersion is directly deduced from the measurements of relative phase delay at different wavelengths. Relative group delays of 20 fsec can be measured in meter-length samples without the need for light-polarizing device
Towards testing a two-Higgs-doublet model with maximal CP symmetry at the LHC: construction of a Monte Carlo event generator
A Monte Carlo event generator is constructed for a two-Higgs-doublet model
with maximal CP symmetry, the MCPM. The model contains five physical Higgs
bosons; the , behaving similarly to the standard-model Higgs boson, two
extra neutral bosons and , and a charged pair . The special
feature of the MCPM is that, concerning the Yukawa couplings, the bosons ,
and couple directly only to the second generation fermions but
with strengths given by the third-generation-fermion masses. Our event
generator allows the simulation of the Drell-Yan-type production processes of
, and in proton-proton collisions at LHC energies. Also the
subsequent leptonic decays of these bosons into the , and channels are studied as well as the dominant
background processes. We estimate the integrated luminosities needed in
collisions at center-of-mass energies of 8 TeV and 14 TeV for significant
observations of the Higgs bosons , and in these muonic
channels
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