|
|
|
| Registros recuperados: 1.923 | |
|
|
| Le Hir, Pierre; Breton, M; L'Yavanc, J.. |
| Afin de préciser les rejets où il est préférable d'intervenir pour réduire les contaminations des secteurs conchylicoles de l'Elorn et du Nord de la rade de Brest, un calcul de dilution de chacun des rejets a été mené à l'aide d'un modèle mathématique. Après une description des courants de marée calculés dans tout le secteur d'étude, des figures de dilution sont présentées. L'impact de chaque rejet se déduit facilement. |
| Tipo: Text |
|
| Ano: 1987 |
URL: http://archimer.ifremer.fr/doc/00103/21460/19041.pdf |
| |
|
|
| Berthome, Jean-paul; Le Mao, Patrick; Rey, H.; Nguyen, D.. |
| Le développement d'un élevage nouveau peut entrainer des conséquences biologiques et économiques, dans un secteur conchylicole traditionnel. Après une présentation de la baie du Mont Saint-Michel et de ses activités, l’étude fournit une évaluation du niveau de nourriture pour les bivalves. Les possibilités biologiques de développement de l’élevage de la palourde sans impact sur les cultures existantes sont montrées. Enfin, la faisabilité économique du projet est analysée de même que la sensibilité des résultats selon différentes hypothèses. |
| Tipo: Text |
|
| Ano: 1987 |
URL: http://archimer.ifremer.fr/doc/00091/20271/17915.pdf |
| |
|
|
| Dintheer, Christian; Cadiou, Yvon; Leroy, Claude. |
| Pour améliorer la gestion de la pêcherie crevettière de Guyane française a été développée et expérimentée une application halieutique du système ARGOS. Deux prototypes TMA 85 ont été mis au point en tenant compte des conditions particulières de cette exploitation puis embarquée sur deux chalutiers. Ils se composent d'une balise BA 10 et de son antenne, et d'un microcalculateur sur lequel les capitaines enregistrent des données de pêche grâce à un logiciel spécifique calqué sur les fiches de pêche traditionnelles. Après un an d'utilisation dans des conditions commerciales, ce nouveau moyen de collecte d'informations apparaît performant. Robuste, facile d'emploi, il permet la mise à disposition rapide des armements et des scientifiques de messages complets,... |
| Tipo: Text |
Palavras-chave: Stâtistiques de pêche; Crevettes; Utilisation satellitaire; Gestiondes stocks; Guyane. |
| Ano: 1987 |
URL: https://archimer.ifremer.fr/doc/00501/61255/64839.pdf |
| |
|
|
| Herbst, Hans-Volkmar. |
| In two wells on the island Barbados (West Indies) females and males of two species of Cyclopidae were found that are apparently new to science. One of them, Halicyclops laciniatus n. sp., belongs to the group of Halicyclops bearing elongated hyaline appendages on the distal margin of the third abdominal segment, and the spine formula 3 4 4 3. The second new species possesses a fifth leg as found in the genera Microcyclops and Cryptocyclops, whereas the structure of the swimming legs approaches that of the genus Apocyclops, viz. the distal segment of the endopodites bears an apical spine and a longer, plumose seta. Typical of the new species is also the expression of the furcal armature (absence of medioterminal seta, lateral seta particularly long and... |
| Tipo: Article / Letter to the editor |
|
| Ano: 1987 |
URL: http://www.repository.naturalis.nl/record/504126 |
| |
|
| |
|
| |
|
|
| Hardy, William E., Jr.; Spurlock, Stanley R.; Parrish, Donnie R.; Benoist, Lee A.. |
| Financial conditions existing in agriculture are placing severe pressure on lenders as well as borrowers. Data from both good and foreclosed Federal Land Bank loans were analyzed to determine the most important characteristics leading to the failure of loans. The analysis was completed by comparing means through t-tests and the development of a discriminant model. The ratio of total debt service to total income, the debt to asset ratio, the ratio of total loan amount to appraised value, and the ratio of acres in security to acres owned were determined to be the most important discriminating variables. |
| Tipo: Journal Article |
Palavras-chave: Agricultural Finance. |
| Ano: 1987 |
URL: http://purl.umn.edu/30200 |
| |
|
|
| Hickson, A.B.; Carter, Colin A.. |
| This paper examines changes in the welfare of Canadian barley and livestock producers attributable to a substantial alteration of Canadian domestic feed grain policy in 1974. Three welfare effects are determined institutional, destabilization, and risk response. Generally, the analytical results confirmed initial hypotheses, with the exclusion of a positive relationship between price risk and barley production on the Prairies. This positive relationship, theorized to result from the risk reduction effect of yearly stabilized Canadian Wheat Board initial prices, enhanced the welfare benefits of the policy change. |
| Tipo: Journal Article |
Palavras-chave: Agricultural and Food Policy. |
| Ano: 1987 |
URL: http://purl.umn.edu/32225 |
| |
|
|
| Becker,Miriam; Frieiro Costa,Fernando Antonio. |
| Randomly sampled oothecae of a natural population of Gratiana spadicea from the outskirts of Porto Alegre, RS, were dissected. The overlapping of the egg membranes makes possible to enumerate the eggs in a batch and therefore to relate mortality to position in the ootheca. The ootheca of this cassid provides a spatial refuge for some of its eggs. Successful eggs of G. spadicea amounted to less than one fifth of the total in each batch. Parasitoids and predators were responsible for a high mortality of eggs whatever the size of the ootheca. The main cause of mortality was the eulophid wasp Emersonella ooecia De Santis, 1983. A large proportion of eggs were sucked dry by the mirid Tupiocoris cincticornis (Stal, 1860). The sucked eggs could have contained... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1987 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751987000300003 |
| |
|
|
| Grabemeyer, June C.. |
| The 1970's were characterized by growth in agriculture. There were increases in agricultural exports and prices received by farmers. Cash and feed grain production expanded in response to these price signals. Gross farm income rose from $58.8 billion in 1970 to $167.9 billion in 1981. In Michigan, the value of farmland and buildings grew from $326 per acre in 1970 to a peak of $1,289 per acre in 1981. Increasing asset values enabled farmers to use unrealized capital gains on assets as collateral for loans. Farm real estate debt in Michigan increased from $667 million in 1970 to $2,058 million in 1981. Total U.S. farm debt increased from $48,928 million in 1970 to $170,030 million in 1981. The rationale for the increased use of debt financing in the... |
| Tipo: Thesis or Dissertation |
Palavras-chave: Agricultural Finance; Crop Production/Industries. |
| Ano: 1987 |
URL: http://purl.umn.edu/11072 |
| |
|
|
| Thomas, P.L.L.. |
| The primary types of 48 species of Symphyta (Hymenoptera), described by Van Achterberg & Van Aartsen (2), Benson (7), Cameron (1), Forsius (13), Koornneef (1) and Snellen van Vollenhoven (24), housed in the collections of the Rijksmuseum van Natuurlijke Historie (Leiden), the Instituut voor Taxonomische Zoologie (Universiteit van Amsterdam) and the Laboratorium voor Entomologie (Landbouw Universiteit Wageningen) are listed. Lectotypes are designated for 16 species group names. The synonymy has been checked. One new combination, Gilpinia verticalis (Snellen van Vollenhoven, 1858), and two new synonymys are proposed: Gilpinia verticalis Gussakovskij, 1947 = G. catocala (Snellen van Vollenhoven, 1858) and Nematus trimaculatus Snellen van Vollenhoven, 1862... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Argidae; Cephidae; Diprionidae; Orussidae; Pamphiliidae; Siricidae; Tenthredinidae; Xiphydriidae; Types; 42.75. |
| Ano: 1987 |
URL: http://www.repository.naturalis.nl/record/319292 |
| |
|
| |
|
|
| Bardsley, Peter; Harris, Michael. |
| A simple model is developed relating the debt and asset portfolio of the farm to the production decision, which leads to a small non-linear system of equations. The system is estimated with time-series cross-sectional data from Australian broadacre agriculture using non-linear three-stage least squares. This gives a new method of estimating risk aversion coefficients by using actual behaviour of farmers in a realistic economic environment, rather than games played in artificial situations. Australian farmers are found to be risk averse, and the partial coefficient of risk aversion decreases with wealth and increases with income. The results are consistent with the results of studies by Binswanger in India and elsewhere using a completely different method.... |
| Tipo: Journal Article |
Palavras-chave: Research Methods/ Statistical Methods; Risk and Uncertainty. |
| Ano: 1987 |
URL: http://purl.umn.edu/22447 |
| |
|
|
| Felixson, Tryggvi; Allen, P. Geoffrey; Storey, David A.. |
| Most econometric studies of the groundfish sector have suggested that either imports are not sensitive to U.S. prices, or that domestic prices are not much affected by imports, or both. Using a six equation model of the domestic fresh groundfish market we obtained contrasting results. For example, a 5.82 percent tariff of the type proposed by the U.S. International Trade Commission in 1986 would, if it applied to both whole fish and fillets, lower imports of fresh fish 3.7 percent and raise domestic ex-vessel prices 2.6 percent in the long run. The main reasons for the different results appear to be our inclusion of exchange rate effects and a more accurate measure of total fresh imports. |
| Tipo: Journal Article |
Palavras-chave: International Relations/Trade. |
| Ano: 1987 |
URL: http://purl.umn.edu/28889 |
| |
|
|
| Chopak, Charles John. |
| One of the goals emphasized in Senegal's new Agricultural Policy is to intensify agricultural production with aim of approaching food self-sufficiency. This thesis examines the potential of animal traction to evaluate if it represents an appropriate technology to achieve this goal. Animal traction was evaluated to observe if the potential benefits- improvement in yield, cropping intensity, area, profits, human drudgery, and labor productivity- were being accrued to farmers in two zones in the Lower Casamance Region of Senegal. The main conclusion of the study is that farmers who have access to animal traction chose to expand upland production rather than production per unit area. The benefits, therefore, were due to expansion rather then intensification. |
| Tipo: Thesis or Dissertation |
Palavras-chave: Farm Management. |
| Ano: 1987 |
URL: http://purl.umn.edu/11060 |
| |
|
|
| Reid, Donald W.; Tew, Bernard V.. |
| This article evaluates the performance of expected value and expected value-variance criteria in achieving risk efficiency in crop selection. Results indicate that the expected returns criterion achieves risk efficiency in many situations because of constraints. However, in the absence of many constraints the expected returns criterion performs poorly except when highly mean-dominant activities are present. The expected value-variance criterion achieves a high degree of risk efficiency for all situations examined. This result implies that criteria more complex than expected value-variance are not necessary for crop selection analysis, given empirical returns distributions. |
| Tipo: Journal Article |
Palavras-chave: Crop Production/Industries. |
| Ano: 1987 |
URL: http://purl.umn.edu/28985 |
| |
|
|
| Willemstein, S.C.. |
| In the introduction and chapter 2 the incentives and way of reasoning are given for the description of an evolutionary basis of pollination ecology. Starting from the until recently rather anecdotical character of the study of pollination ecology as a whole, and in the absence of large-scale correlations of flowerecologically important character states with angiosperm and insect phylogeny (in the sense of Hennig, 1966), an attempt is made to derive directed evolutionary lines (transformation series) of floral character states. Because the fossil record of flowers is very restricted and the study of angiosperm phylogeny in the sense of Hennig (1966) is only at its very beginning, the only possibilities to achieve this, can be based on the comparatively... |
| Tipo: Article / Letter to the editor |
|
| Ano: 1987 |
URL: http://www.repository.naturalis.nl/record/508219 |
| |
|
| |
| Registros recuperados: 1.923 | |
|
|
|
