Consulta: subjectFacets:"Poisson"
Registros recuperados: 27
Data/hora: 09/06/2024 05:25:22

Evaluation par vidéo (STAVIRO) de l’état des peuplements ichtyologiques d’intérêt halieutique du Parc Naturel Marin de Mayotte
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Roos, David; Gaboriau, Matthias; Giannasi, Paul; Maurel, Laurence; Pelletier, Dominique.
Les diagnostics des peuplements de poisson d’intérêt halieutique et des principaux stocks mettent en évidence des états contrastés à Mayotte en 2017. A l’échelle des peuplements, toutes espèces confondues, aucun signe patent d’un état non satisfaisant lié à la pression de pêche exercée n’a été observé. Cette situation s’explique en grande partie par les familles les plus diversifiées et les plus abondantes, souvent herbivores, tels que les poissons chirurgiens et les perroquets, dont l’état est jugé satisfaisant. En revanche, l’état des quatre principales familles de grands carnivores (les mérous, les vivaneaux, les capitaines et les carangues) est qualifié de non satisfaisant. La raréfaction des grandes espèces, voire la perte de diversité dans les...
Tipo: Text
Palavras-chave: État initial; Évaluation; Peuplement ichtyologique; Stock; Vidéo; STAVIRO; Abondance; Richesse spécifique; Ressources halieutiques; Poisson; Habitat corallien; Lagon; Récif; Mayotte.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00485/59659/71413.pdf

Recherche et caractérisation d'immunoglobulines dans les oeufs du loup (Dicentrarchus labrax)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Pepin, Jean-francois; Breuil, Gilles; Rigobert, P; Romestand, Bernard.
The occurrence of maternal immunity transfer in Sea bass (Dicentrarchus labrax) was investigated using ELISA and Western blot technics. In order to determine the possible presence of immunoglobulin (Ig), egg proteins obtained from fertilized eggs were analyzed. After several extraction protocol assays (precipitation, chromatography), monoclonal and polyclonal antibody probes specific to Sea bass Ig allowed to confirm the presence of an immunoglobulin-like protein in eggs with very low level. Biochemical characterization was carried out using SDS-PAGE. Results indicated that egg Ig had a molecular weight of 206 kDa. They were smaller than seric IgM (800 kDa). The heavy (H) and light (L) chains of the egg Ig and of the seric IgM had similar molecular weight,...
Tipo: Text
Palavras-chave: Immunoglobuline; Transfert immunité maternelle; ELISA; Œuf; Poisson; Immunoglobulin; Maternal immunity transfer; ELISA; Eggs; Fish.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00272/38275/36458.pdf

Recherche et élimination des facteurs inhibiteurs de croissance dans les élevages piscicoles en circuit fermé
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Leonard, Noemie.
Recirculation of the water of fish rearing systems requires a biological treatment based on the nitrifying activity of autotrophic bacteria. In parallel heterotrophic bacterial populations utilise the organic substrate, produced by the fish, to grow. Opposite to the autotrophic populations, the heterotrophic bacteria (1) have a quick growth and (2) might contain fish pathogenic strains. The main aim was to characterise the heterotrophic bacteria populations ?.nd to understand (1) which parameters do control the dynamics of their populations and (2) their influence on the quality of the recirculating water. In a rearing system, the heterotrophic bacterial populations are stable in number and in genus, for a given operating mode. The bacteria are either...
Tipo: Text
Palavras-chave: Carbon; Gills; Bacterium; Humics substances; Fish; Ozone; Aquiculture; Carbone; Branchies; Bacterie; Substances humiques; Poisson; Ozone; Aquaculture.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/these-1728.pdf

Utilisation d’espèces halieutiques exploitées comme indicateurs de la contamination chimique en zone littorale
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Abarnou, Alain.
The concept of biological indicator relies upon the assumption that the contamination measured in biological tissues reflects that of the aquatic environment. This study aims to update the knowledge on contamination levels of various chemical contaminants in a few exploited fish species from various areas along the French coastline. The objective of the work is to evaluate the possibility of differentiating the various coastal zones according to the contamination levels measured in fish living there. Several groups of contaminants were followed: PCBs (marker PCBs and dioxin-like PCBs), dioxins (PCCDs and PCDFs), PBDEs, PFCs and total mercury). These contaminants were mainly measured in four fish species: the sea bass (Dicentrarchus labrax), the mackerel...
Tipo: Text
Palavras-chave: Espèces indicatrices; Poisson; Environnement marin; POP; PCB; Dioxines; PBDE; PFC; Biological indicators; Fishes; Marine environment; POPs; PCBs; Dioxins; PBDEs; PFCs.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00014/12475/9315.pdf

Synthèse française des procédures d'estimation d'âge
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Mahe, Kelig; Bellail, Robert; Dufour, Jean-louis; Boiron-leroy, Anne; Dimeet, Joel; Duhamel, Erwan; Elleboode, Romain; Felix, Jerome; Grellier, Patrick; Huet, Jerome; Labastie, Jacques; Le Roy, Didier; Lizaud, Oceann; Manten, Marie-line; Martin, Stephane; Metral, Luisa; Nedelec, Daniel; Verin, Yves; Badts, Vincent.
This document presents all the techniques used in routine by Ifremer to estimate the age of fish from the calcified piece. The procedure for estimating age describes each technical stage from the taking of the calcified piece through to the supplying of key sizes/ages to the European work groups. This procedure is specific to each species and even each population of fish.
Tipo: Text
Palavras-chave: Poisson; TNPC; Préparation; Procédure; Age; Ecaille; Illicium; Otolithe; Sclérochronologie; Fish; TNPC; Preparation; Procedure; Age; Scale; Illicium; Otolith; Sclerochronology.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00000/7294/rapport-7294.pdf

Fiches d’aide à l’identification. Poissons et céphalopodes de Manche et de mer du Nord
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Garren, Francois; Verin, Yves; Dufour, Jean-louis; Mahe, Kelig; Le Roy, Didier; Rostiaux, Emilie.
This document present identification fact sheets of fishes and cephalopods species frequently captured during scientific surveys in the English Channel and the North Sea. Simple and concise description of the morphological criteria enable a fast and easy discrimination between species that may be confused.
Tipo: Text
Palavras-chave: Identification; Poisson; Céphalopode; Manche; Mer du Nord; Identification; Fish; Cephalopod; English Channel; North Sea.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/00326/43758/43302.pdf

Fish faunal and habitat analyses using trawls, camera sleds and submersibles in benthic deep-sea habitats off central California
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Cailliet, Gm; Andrews, Ah; Wakefield, Ww; Moreno, G; Rhodes, Kl.
Beam trawl, camera sled and submersible data from 2 000-3 300 m off central California produced similar fish faunal composition, but different density estimates. All species caught in trawls were observed in camera-sled and submersible observations. However, some rare species that were observed were not caught in trawls. The fish fauna was dominated by the families Macrouridae, Zoarcidae, Moridae, and Rajidae. Fishes both trawled and observed were the macrourids Coryphaenoides armatus, C. filifer and C. leptolepis; the zoarcids Bothrocara spp., Pachycara lepinium and Lycenchelys spp.; the morid Antimora microlepis; the rajid Bathyraja trachura, the ophidiid Spectrunculus grandis, and the liparidid Careproctus ovigerum. One unidentified liparidid...
Tipo: Text
Palavras-chave: Benthos; Poisson; Habitat; Chalutage; Submersible; Deep-sea; Fishes; Habitat; Sampling; Submersibles.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/00325/43583/44022.pdf

Méthode de dosage du cadmium, du cuivre, du plomb et du zinc dans la chair de poissons
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Auger, Dominique.
An analytical technique for cadmium, copper, lead and zinc determination in fish tissue used in monitoring programmes is described. Atomic absorption spectrophotometry on nitric digested samples is performed.
Tipo: Text
Palavras-chave: Cadmium; Cuivre; Poisson; Plomb; Zinc; Analyse; Cadmium; Copper; Lead; Zinc; Fish; Determination.
Ano: 1989
URL: https://archimer.ifremer.fr/doc/00489/60059/63343.pdf

Effect of temperature, volume of ova batches, and addition of a diluent, an antibiotic, oxygen and a protein inhibitor on short-term storage capacities of turbot, Psetta maxima, ova
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Suquet, Marc; Chereguini, Olvido; Omnes, Marie-helene; Rasines, Inmaculada; Normant, Yvon; Souto, Isabel; Quemener, Loic.
The effect of different parameters on shea-term storage capacity of turbot ova was assessed over a 45-h period after ova collection for fertilization rates and over a 9-h period after ova collection for hatching rates. Increasing the volume of ova sampling from 0.5 to 2.5 mt, as well as adding an antibiotic-antimicotic solution or oxygen did not significantly change the storage capacity of ova. Regarding the hatching rates, a higher storage ability was recorded at 8 and 13 degrees C, compared to 3 degrees C. The mean composition of the ovarian fluid was determined (n = 57 spawns). Use of a diluent mimicking the ovarian fluid significantly decreased the storage ability as assessed by the fertilization rates but did not modify the hatching rates. Diluting...
Tipo: Text
Palavras-chave: Psetta maxima; Turbot; Calcium; Ovarian fluid; Short term storage; Ova; Fish; Psetta maxima; Turbot; Calcium; Liquide ovarien; Conservation à court terme; Ovules; Poisson.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/1999/publication-857.pdf

Traitement par lagunage a haut rendement algal (LHRA) des effluents piscicoles marins recycles: évaluation chimique et écotoxicologique
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Deviller, Genevieve.
World aquaculture is a fast growing activity and the control of its waste becomes a key issue. Compared to traditional systems, recirculating systems allow to reduce replacement water and waste volumes. Nevertheless their effluents are more concentrated in dissolved nutrients (nitrate, phosphate). The high rate algae pond (HRAP) is one of the possible treatment technique to remove those nutrients. During this work, three rearing systems: one recycled, one recycled with HRAP and one open as a standard, were operated for one year to assess the impact of: (1) the reuse of treated effluent on survival, growth and nutrition of sea bass (2) the rearing system on fish health using multibiomarkers and trace metals accumulation responses and (3) best conditions for...
Tipo: Text
Palavras-chave: Aquaculture; Fish; Growth; Metals; Biomarker; Water treatment; Recirculating effluent; High rate algal pond; Aquaculture; Poisson; Croissance; Métaux; Biomarqueur; Epuration; Effluent recyclé; Lagunage à haut rendement algal.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2004/these-163.pdf

Caractérisation du comportement chimique du complexe otosac-otolithe et réaction à des perturbations induites.
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Edeyer, Anaick.
Teleost fish have the capacity to record in their otoliths, calcareous concretions located in the inner ear, the principal events (environmental and physiological) which punctuate their life. Otolith is made of CaC03 deposits on a protein matrix according to a circadian rhythm. Due to the quasi irreversibility of this process, otoliths can be compared to biological archives largely used to apprehend the fish ecology.   The otolith bathes in the endolymph, a medium in which all the precursors of otolith formation forward. The endolymph chemical analysis revealed a heterogeneity of its principal components (proteins, total C02 and total Ca) which origin lies in the non uniform spatial distribution of the ionocytes in the saccular epithelium. Thus, in...
Tipo: Text
Palavras-chave: Environmental disturbances; Microchemistry; Biomineralisation; Psetta maxima; Fish; Calcification; Endolymph; Otolith; Perturbations environnementales; Microchimie; Biominéralisation; Psetta maxima; Poisson; Calcification; Endolymphe; Otolithe.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/rapport-1123.pdf

Expédition antarctique française (1903-1905) commandée par le Dr Jean Charcot. Poissons
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Vaillant, Léon.
La connaissance des Poissons de la Région antarctique est de date relativement récente, ces contrées, d'un accès difficile, où la navigation est particulièrement pénible et périlleuse, n'ayant été explorées avec quelques succès qu'au commencement du XIXè siècle. Il est toutefois important de définir d'abord, autant que le permettent nos connaissances, ce que l'on doit regarder comme Région polaire australe ou Région antarctique. [OCR NON CONTRÔLE]
Tipo: Text
Palavras-chave: Poisson; Antarctique; Expédition; Campagne; Histoire.
Ano: 1908
URL: http://archimer.ifremer.fr/doc/1908/publication-6964.pdf

Courantométrie du site d'élevage de salmonides en grande rade de Cherbourg
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Merceron, Michel; Gaffet, Jean-dominique.
Current recordings were performed near the middle of the great breakwater of Cherbourg ("Grande Digue", inner side) during two months of the 1993 summer. The data show that, in this site, the currents drive mostly westwards. They are driving eastwards only during the first half of flood. In the tidal cycle, there is only one current slack, at law tide. The most important velocities are observed during the high tides : 0.5 to 0.6 m.s-1• The fish net pens, which are located there, tend to speed up the undemeath currents and, thus, contribute to scatter the farm effluents. The temperature and salinity records are also displayed. _
Tipo: Text
Palavras-chave: Courant; Cage; Élevage; Poisson; Cherbourg; Current; Net pen; Farm; Fish; Cherbourg.
Ano: 1994
URL: http://archimer.ifremer.fr/doc/00082/19330/16924.pdf

L'éthoxyrésorufine-o-déethylase, les adduits à l'ADN et les mocronuclei dans les organismes marins. Application à la surveillance des effets biologiques sur les côtes françaises
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Burgeot, Thierry.
Three biomarkers [ethoxyresorufm-o-deethylase (EROD), DNA adducts and micronuclei (MN) were studied for biomonitoring applications along French coasts. EROD was developed at an experirnental stage in two pilot sites, Seine Bay and Fos sur Mer, using the dab (Limanda limanda), dragon et (Callionymus lyra), red mullet (Mullus barbatus) and comber (Serranus hepatus) as target species. Higbest EROD activity was observed in the subestuarial part of Seine Bay and at the stations closest to sources of pollution from Cortiou and Fos sur Mer. The suitable number of fish for detection of a significant difference between two EROD activities was deterrnined as a function of sampling variance and a preselected statistical power. A preliminary study on hepatocytes in a...
Tipo: Text
Palavras-chave: Ethoxyrésorufine-o-déethylase; Adduits à l'ADN; Micronuclei; Poisson; Moule; Huître; Biosurveillance; Ethoryresorufin-o-deethylase; DNA adducts; Micronuclei; Fish; Mussel; Oyster; Biomonitoring.
Ano: 1994
URL: http://archimer.ifremer.fr/doc/00443/55462/56984.pdf

Méthode de dosage du Methylmercure dans la chair de poisson
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Averty, Bernard.
The methyl mercury determination techniqu~ .used for .fish tissue in monitoring programmes is described. Chromatographie measurement with electron capture detector is performed on purified toluen extract .
Tipo: Text
Palavras-chave: Méthylmercure; Dosage; Poisson; Methyl mercury; Analysis; Fish tissue.
Ano: 1989
URL: https://archimer.ifremer.fr/doc/00679/79114/81606.pdf

Liste des « poissons » capturés dans les Pertuis charentais de 2005 à 2012. Cartes de distribution annuelles pour 18 espèces
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Leaute, Jean-pierre; Quero, Jean-claude.
From 2005 to 2012, during the 8 annual summer beam trawl fishing surveys in the Pertuis charentais to assess the abundance of young soles, 59 species of fish were caught : 2 Elasmobranchii and 57 Actinopterygii. The list of these and the annual distribution maps of the more or less 18 plentiful species are given.
Tipo: Text
Palavras-chave: Poisson; Cartes de repartition; Pertuis charentais; Fish; Distribution maps; Pertuis charentais.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00240/35119/36067.pdf

Managing fleet capacity effectively under second-hand market redistribution
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Quillerou, Emmanuelle; Roudaut, Nolwenn; Guyader, Olivier.
Fishing capacity management policies have been traditionally implemented at national level with national targets for capacity reduction. More recently, capacity management policies have increasingly targeted specific fisheries. French fisheries spatially vary along the French coastline and are associated to specific regions. Capacity management policies however ignore the capital mobility associated with second-hand vessel trade between regions. This is not an issue for national policies but could limit the effectiveness of regional capacity management policies. A gravity model and a random-effect Poisson regression model are used to analyse the determinants and spatial extent of the second-hand market in France. This study is based on panel data from the...
Tipo: Text
Palavras-chave: Gravity model; Fishing vessels; Second-hand markets; Poisson; French Atlantic.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00102/21288/19569.pdf

Définition d'un modèle d'élevage larvaire intensif pour la daurade Sparus auratus
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Ounais-guschemann, Nadia.
This study defines rearing parameters for mass products of 30-day old post larvae. Continuous lighting (600 lux) optimizes the predatory activity and suppresses the feeding rhythm. For 4-5 mm larvae (15 days), food ingestion slows down if the prey concentration in the tank is below 5 rotifers/ml, while there is no such threshold for 6-7 mm larvae (22 days). The rotifer Brachionus plicatilis , between 100 and 200 mu m, is an adequate initial prey, it can be replaced by Artemia salina for 7-8 mm larvae (30 days). It is observed that free amino acids and essential fatty acids contents have a prominent role in larvae growth; docosahexaenoic acid (C22:6n-3) content could be determined. Finally, the development of the swim bladder is facilitated by the renewal...
Tipo: Text
Palavras-chave: Sparus auratus; Pisces; Marine fish; Environmental diseases; Fatty acids; Amino acids; Controlled conditions; Juveniles; Culture tanks; Growth; Light effects; Nutritional requirements; Fish larvae; Syndrome de paroi; Nutrition; Alimentation; Lumière; Inflation primaire de la vessie natatoire; Sparus auratus; Elevage larvaire intensif; Poisson.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/1989/these-1679.pdf

Guide de la mensuration des espèces en halieutique, poissons, mollusques, crustacés, reptiles marins, mammifères marins
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Badts, Vincent; Bertrand, Jacques.
This guide presents the rules for measuring fi shes, mollusks, shellfi shes, reptiles and marine mammals applicable to the fisheries surveys coordinated by Ifremer, including tasks carried out at the international level, in particular within the European regulation related to the fishery data collection.
Tipo: Text
Palavras-chave: Mensuration; Taille; Poisson; Mollusque; Crustacé; Reptile marin; Mammifère marin; Halieutique; Protocole; Measurement; Size; Fishe; Mollusk; Shellfishe; Marine reptile; Marine mammal; Fishery; Guideline.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00001/6237/7655.pdf

Les Dentés (poissons Sparidés) des côtes tunisiennes : Étude éco-biologique et dynamique des populations
Provedor de dados: Ocean Docs: e-repository of  publications
Autores: CHemmam, B.
Le présent travail sur les Dentés des côtes tunisiennes comporte trois parties principales. La première partie a été consacrée à la présentation des milieux prospectés et des trois espèces de Dentés étudiées. En effet, l’analyse des différents milieux prospectés montre deux facteurs principaux caractérisant les côtes de la Tunisie: la variabilité des fonds rocheux et sableux et les courants qui entraînent le mélange de l’eau de l’Atlantique et de la Méditerranée caractérisant les côtes tunisiennes. Ceci pourrait expliquer la richesse en faune benthique de cette région méditerranéenne. De plus ces fonds variables constituent l’habitat préféré pour les Sparidés. En effet, parmi les 22 espèces méditerranéennes 19 espèces sont mentionnées sur les côtes...
Tipo: Theses and Dissertations
Palavras-chave: Dentex dentex; Dentex gibbosus; Dentex maroccanus; Poisson; Sparidae; Eco-Biologie; Dynamique population; Systematique.
Ano: 2002
URL: http://hdl.handle.net/1834/4612

A TWO-STEP ESTIMATOR FOR A SPATIAL LAG MODEL OF COUNTS: THEORY, SMALL SAMPLE PERFORMANCE AND AN APPLICATION
Provedor de dados: Research in Agricultural & Applied Economics (AgEcon Searh)
Autores: Lambert,   Dayton M.; Brown,   Jason P.; Florax,   Raymond J.G.M.
Several spatial econometric approaches are available to model spatially correlated disturbances in count models, but there are at present no structurally consistent count models incorporating spatial lag autocorrelation. A two-step, limited information maximum likelihood estimator is proposed to fill this gap. The estimator is developed assuming a Poisson distribution, but can be extended to other count distributions. The small sample properties of the estimator are evaluated with Monte Carlo experiments. Simulation results suggest that the spatial lag count estimator achieves gains in terms of bias over the aspatial version as spatial lag autocorrelation and sample size increase. An empirical example deals with the location choice of single-unit start-up...
Tipo: Working or Discussion Paper
Palavras-chave: Count model; Location choice; Manufacturing; Poisson; Spatial econometrics; Community/Rural/Urban Development; Land Economics/Use; Research and Development/Tech Change/Emerging Technologies; C21; C25; D21; R12; R30.
Ano: 2010
URL: http://purl.umn.edu/59780

Precision Agriculture Technology Adoption for Cotton Production
Provedor de dados: Research in Agricultural & Applied Economics (AgEcon Searh)
Autores: Paxton,   Kenneth W.; Mishra,   Ashok K.; Chintawar,   Sachin; Larson,   James A.; Roberts,   Roland K.; English,   Burton C.; Lambert,   Dayton M.; Marra,   Michele C.; Larkin,   Sherry L.; Reeves,   Jeanne M.; Martin,   Steven W.
Many studies on the adoption of precision technologies have generally used logit models to explain the adoption behavior of individuals. This study investigates factors affecting the number of specific types of precision agriculture technologies adopted by cotton farmers. Particular attention is given to the influence of spatial yield variability on the number of precision farming technologies adopted, using a Count data estimation procedure and farm-level data. Results indicate that farmers with more within-field yield variability adopted a larger number of precision agriculture technologies. Younger and better educated producers and the number of precision agriculture technologies were significantly correlated. Finally, farmers using computers for...
Tipo: Conference Paper or Presentation
Palavras-chave: Precision technologies; Poisson; Negative Binomial; Count-data method; GIS; Education; Cotton; Agricultural and Food Policy; Farm Management; Labor and Human Capital; Land Economics/Use; Productivity Analysis; Resource /Energy Economics and Policy.
Ano: 2010
URL: http://purl.umn.edu/56486

Do Leader and Organizational Characteristics Affect Scientist's Productivity? A Multilevel Analysis of Nigerian Agricultural Research System
Provedor de dados: Research in Agricultural & Applied Economics (AgEcon Searh)
Autores: Ragasa,   Catherine; Babu,   Suresh Chandra; Abdullahi,   Aliyu Sabi.
Organizations offer employees with opportunities to cultivate their innovativeness and facilitate greater productivity. In this paper we analyze preconditions for individual productivity of agricultural researchers in Nigeria, measured in terms of the self-reported number of scholarly publications and technologies produced; presence of external collaborators; number of dissemination events for publications produced; and perceived adoption level of technologies developed. It utilizes a multilevel analysis to systematically examine what characteristics of individual scientists and organizations promote greater individual productivity. The statistically significant random-effect estimates show that there is considerable variance across the 47 organizations...
Tipo: Conference Paper or Presentation
Palavras-chave: Organizational culture; Multilevel analysis; Poisson; Productivity; Research; Motivation; Institutional and Behavioral Economics; Productivity Analysis; Research and Development/Tech Change/Emerging Technologies; Q16; L32; D23.
Ano: 2011
URL: http://purl.umn.edu/103723

Intensity of Precision Agriculture Technology Adoption by Cotton Producers
Provedor de dados: Research in Agricultural & Applied Economics (AgEcon Searh)
Autores: Paxton,   Kenneth W.; Mishra,   Ashok K.; Chintawar,   Sachin; Roberts,   Roland K.; Larson,   James A.; English,   Burton C.; Lambert,   Dayton M.; Marra,   Michele C.; Larkin,   Sherry L.; Reeves,   Jeanne M.; Martin,   Steven W.
Many studies on the adoption of precision technologies have generally used logit models to explain the adoption behavior of individuals. This study investigates factors affecting the intensity of precision agriculture technologies adopted by cotton farmers. Particular attention is given to the role of spatial yield variability on the number of precision farming technologies adopted, using a count data estimation procedure and farm-level data. Results indicate that farmers with more within-field yield variability adopted a higher number of precision agriculture technologies. Younger and better educated producers and the number of precision agriculture technologies used were significantly correlated. Finally, farmers using computers for management decisions...
Tipo: Journal Article
Palavras-chave: Precision technologies; Poisson; Negative binomial count data method; GPS; Education; Cotton; Crop Production/Industries; Farm Management; Production Economics; Research and Development/Tech Change/Emerging Technologies.
Ano: 2011
URL: http://purl.umn.edu/105464

Caracterização da distribuição espacial das fezes por bovinos em uma pastagem de Brachiaria decumbens
Provedor de dados: Revista Brasileira de Zootecnia
Autores: Braz,Sérgio Pereira; Nascimento Júnior,Domicio do; Cantarutti,Reinaldo Bertola; Martins,Carlos Eugênio; Fonseca,Dilermando Miranda da; Barbosa,Rodrigo Amorim.
O experimento foi conduzido no campo Experimental de Coronel Pacheco pertencente à EMBRAPA Gado de Leite, na Zona da Mata de Minas Gerais, com o objetivo de avaliar a distribuição espacial das fezes depositadas por bovinos na pastagem. Foi demarcado um piquete de forma quadrada com 110 m de lado numa pastagem de Brachiaria decumbens, com boa disponibilidade de forragem e cobertura homogênea. A área foi dividida em bordadura (faixa de 5 m em toda periferia) e área útil de avaliação (região central com 1 ha), onde se estudou a distribuição e cobertura das placas de fezes pelos animais na pastagem. As placas de fezes produzidas pelos três animais que permaneceram na área por 10 semanas cobriram 0,81% da superfície da área experimental. Os dados obtidos...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Binomial negativa; Poisson; Índice de Morisita.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982003000400002

Effect of air pollution on pediatric respiratory emergency room visits and hospital admissions
Provedor de dados: Brazilian Journal of Medical and Biological Research
Autores: Farhat,S.C.L.; Paulo,R.L.P.; Shimoda,T.M.; Conceição,G.M.S.; Lin,C.A.; Braga,A.L.F.; Warth,M.P.N.; Saldiva,P.H.N.
In order to assess the effect of air pollution on pediatric respiratory morbidity, we carried out a time series study using daily levels of PM10, SO2, NO2, ozone, and CO and daily numbers of pediatric respiratory emergency room visits and hospital admissions at the Children's Institute of the University of São Paulo Medical School, from August 1996 to August 1997. In this period there were 43,635 hospital emergency room visits, 4534 of which were due to lower respiratory tract disease. The total number of hospital admissions was 6785, 1021 of which were due to lower respiratory tract infectious and/or obstructive diseases. The three health end-points under investigation were the daily number of emergency room visits due to lower respiratory tract diseases,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Time-series; Poisson; Air pollution; Children; Respiratory morbidity.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000200011

Eucalyptus cloeziana seed count data: a comparative analysis of statistical models
Provedor de dados: Ciência e Agrotecnologia
Autores: Michelon,Thomas Bruno; Taconeli,Cesar Augusto; Vieira,Elisa Serra Negra; Panobianco,Maristela.
ABSTRACT Generalized linear models (GLMs) are an extension of the linear model and include the normal, Poisson, and negative binomial distributions. Although GLMs were introduced in 1972, most seed technology studies, especially those involving count data, such as germination tests of seeds from the genus Eucalyptus, still using the analysis of variance, without analysis of the fit of other models. Thus, this study aimed to evaluate the most appropriate model in the GLM class for seed count data of Eucalyptus cloeziana. Data were obtained from a germination test using seeds from three lots of E. cloeziana. Each lot was separated by sieving into three material fractions based on size: small (&lt;0.84 mm), medium (from 1.18 to 1.00 mm), and large (&gt;1.18...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Generalized linear models; Poisson; ANOVA; Germination test.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542019000100243