3,092 research outputs found
Croissance de la thonine Euthynnus alletteratus (Rafinesque, 1810), Ă©tablie Ă partir de coupes transversales du premier rayon de la nageoire dorsale
Etat des stocks de listao (Katsuwonus pelamis) de l'Atlantique Est par l'analyse des cohortes et modèle de production par recrue
Sausu - Malonas - Tolai ou les leçons d'une transmigration réussie : étude agro-économique de 3 Centres de Transmigration dans la Province de Sulawesi Tengah
Cette étude concerne 3 centres de transmigration situés à Sulawesi Centre : Sausu,Malonas,Tolai.L'essentiel des données de base a été obtenu auprès des transmigrants.Un échantillon de 160 familles de colons a été suivi par enquête en quatre passages répétés espacés de 2 mois et observation sur le terrain.En Indonésie,les transferts de population commencés sous l'administration coloniale hollandaise avaient pour objectifs de réduire les déséquilibres démographiques entre les différentes iles.En 1980,la densité de population était de 690 habitants au km2 à Java et de 18 km2 à Sulawesi Centre.Dans la première partie de cette étude,les auteurs analysent l'origine,les motivations des transmigrants,ce qui fait l'originalité des 3 Centres qui jouissent d'un environnement favorable du point de vue de la pluviométrie,du relief,de la fertilité du sol.Pour chacun des centres,il est signalé les surfaces cultivées,les cultures adoptées (riz,soja) et les revenus dont bénéficient les transmigrants grace aux activités agricoles et non agricoles.Dans la dernière partie,les auteurs analysent les causes de certains échecs et des succès de l'opération en signalant le nombre trés important des transmigrants spontanés dans cette région et présentent des recommandations pour l'avenir
Grapevine European catalogue: towards a comprehensive list
Starting from the 1950’s, different European countries have established official lists of grapevine varieties authorized to be cultivated. The objectives of such lists were to limit ambiguous denomination of varieties and the related trade conflicts, as well as the implementation of viticulture
recovery politics through the support of certain varieties and the limitation of others. In the same direction, in 1968
the European Union (EU) decided to create a “common catalogue of varieties”, defined as the sum of current national catalogues (Council Directive of 9 April 1968 “on
the marketing of material for the vegetative propagation of the vine”, 68/193/EEC, modified). These catalogues (also called “registers”) include all the wine varieties “classified” by each Member State within the framework of the Common Organisation of the Market in wine (Council Directive No 479/2008), as well as all the non-classified
varieties (table grape, rootstocks, etc.).
For this work, we took the opportunity of the European research program “GrapeGen06”, focused on the study and the preservation of grapevine genetic resources, to contribute to the establishment and improvement of such
an European catalogue. The comprehensive survey aims at two objectives: to support the implementation of European regulations on propagation of grapevine plants within
the EU, and to assess priority actions, by technical and research institutes, for the conservation of grapevine genetic
resources.Peer reviewe
Urban challenges to food and nutrition security
This review of recent literature explores the urban face of food and nutrition security in a more comprehensive, integrated way than most previous efforts. The review is organized around a conceptual framework that identifies food insecurity, inadequate caring behaviors, and poor health as the primary causes of malnutrition. It discusses current knowledge in eight areas that require the special attention of policymakers, development practitioners, and program administrators who wish to improve urban food and nutrition security: the sources and cost of food; incomes and employment; urban agriculture; urban diets; child caregiving practices; childhood mortality, morbidity, and malnutrition; health and environment; and social assistance programs, or safety nets. The review also reports on the magnitude of rural-urban and intra-urban health differences in mortality, morbidity, and malnutrition. In conclusion, the review indicates which policy issues and knowledge gaps remain for future research to address.Urban health. ,Urban poor Services for. ,Food security. ,Malnutrition. ,Child care. ,
Simplified extended Kalman filter phase noise estimation for CO-OFDM transmissions
We propose a flexible simplified extended Kalman filter (S-EKF) scheme that can be applied in both pilot-aided and blind modes for phase noise compensation in 16-QAM CO-OFDM transmission systems employing a small-to-moderate number of subcarriers. The performance of the proposed algorithm is evaluated and compared with conventional pilot-aided (PA) and blind phase search (BPS) methods via extensive an Monte Carlo simulation in a back-to-back configuration and with a dual polarization fiber transmission. For 64 subcarrier 32 Gbaud 16-QAM CO-OFDM systems with 200 kHz combined laser linewidths, an optical signal-to-noise ratio penalty as low as 1 dB can be achieved with the proposed S-EKF scheme using only 2 pilots in the pilot-aided mode and just 4 inputs in the blind mode, resulting in a spectrally efficient enhancement by a factor of 3 and a computational effort reduction by a factor of more than 50 in comparison with the conventional PA and the BPS methods, respectively
Chandra HRC Localization of the Low Mass X-ray Binaries X1624-490 and X1702-429: The Infrared Counterparts
We report on the precise localization of the low mass X-ray binaries
X1624-490 and X1702-429 with the Chandra HRC-I. We determine the best positions
to be 16:28:02.825 -49:11:54.61 (J2000) and 17:06:15.314 -43:02:08.69 (J2000)
for X1624-490 and X1702-429, respectively, with the nominal Chandra positional
uncertainty of 0.6". We also obtained deep IR observations of the fields of
these sources in an effort to identify the IR counterparts. A single, faint
(Ks=18.3 +/- 0.1) source is visible inside the Chandra error circle of
X1624-490, and we propose this source as its IR counterpart. For X1702-429, a
Ks=16.5 +/- 0.07 source is visible at the edge of the Chandra error circle. The
brightness of both counterpart candidates is comparable to that of other low
mass X-ray binary IR counterparts when corrected for extinction and distance.Comment: 5 pages, 2 figures, accepted for publication in Ap
The Mid-Infrared Instrument for the James Webb Space Telescope, VII: The MIRI Detectors
The MIRI Si:As IBC detector arrays extend the heritage technology from the
Spitzer IRAC arrays to a 1024 x 1024 pixel format. We provide a short
discussion of the principles of operation, design, and performance of the
individual MIRI detectors, in support of a description of their operation in
arrays provided in an accompanying paper (Ressler et al. (2015)). We then
describe modeling of their response. We find that electron diffusion is an
important component of their performance, although it was omitted in previous
models. Our new model will let us optimize the bias voltage while avoiding
avalanche gain. It also predicts the fraction of the IR-active layer that is
depleted (and thus contributes to the quantum efficiency) as signal is
accumulated on the array amplifier. Another set of models accurately predicts
the nonlinearity of the detector-amplifier unit and has guided determination of
the corrections for nonlinearity. Finally, we discuss how diffraction at the
interpixel gaps and total internal reflection can produce the extended
cross-like artifacts around images with these arrays at short wavelengths, ~ 5
microns. The modeling of the behavior of these devices is helping optimize how
we operate them and also providing inputs to the development of the data
pipeline
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