932 resultados para Research associations
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v. 17, no. 4-5 (1998)
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v. 16 (1997)
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v. 18 (1999)
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The work reported here was carried-out on the invitation of Dr. Henry Kumm, Director of the Rockefeller Foundation, and by appointment from Dr. Henrique Aragão, Director of the Instituto Oswaldo Cruz. It was done during the investigation of sylvan yellow fever, in June 1947, with a view to establishing the phyto-ecological conditions of the county of Passos. The pe¬riod was, however, too short for definite conclusions to be reached. Thanks are due to Dr. O. R. Causey, Chief of Research on Yellow Fever for transpor¬tation and other help. THE REGIONAL VEGETATION. Aerial photographs of the county of Passos shoto that it is covered by three great types of vegetation: Rain Forest, Secondary Pasture Land and Scrub.1 Detailed investigation, however, brings out the fact that these correspond to different seres; furthermore, each type presents not only the specific, characteristics of the biological form dominant for the climate, but also are at various stages, which express HABITATS differing from those of the normal sere. The phytogeographic survey of the region shows that most of it is now covered by secondary pasture land (disclimax) in which Melinis minutiflora, v. "fat grass" (fig. 1), predominates. The mosaic of Rain Forest and of small patches of Scrub reveals the effects of human intervention (BARRETO, H. L. de Mello 1); consequently, all the formations have to be regarded as secon¬dary, though some of them probably include relicts of the primitive climax (WARMING, E. 2). On close examination, the Scrub cannot be considered as the climax, because of the following facts: 1. In the zone of Rain-Forest stretches of forest are present in very varied topographic conditions and the reconstitution of the associations show that man has destroyed an ecological unit (fig. 2). 2. In the zone of Scrub the characteristic patches are small. The banks of rivers and brooks, the valleys and ravine and whatever the soil has retained some humidity, is being invaded fry Rain Forest, which seems to be growing under optimum conditions. The Scrub is thus limited to small belts on the calcareous mountains and on sandy soils with alcaline depths (pH abo¬ve 7) which do not retain enough moisture for the Rain Forest that is progres¬sively restricting the area occupied by Scrub. In view of the topographic and present climatic conditions the Rain Forest must consequently be regarded as the regional climax. The presence of ecologically contradictory elements and associations shows that the real problem is that of the fluctuations of the climate of Passos or even of Minas Geraes during the quaternary and recent periods (DAN-SEREAU, P. : 3), a subject on which little is known and which is tied to the evolution of the climate of Brazil (OLIVEIRA, E. : 4) . The transformation of Scrub into Rain Forest has been - observed by the author before, in other parts of Brazil (VELOSO, PL P.: 5) . It seems probable that the Rio Grande has also greatly influenced the change of the regional vegetation, by invading areas of Scrub and dislocating the limit of the Pluvial climate towards the Canastra Range, though there are remnants of Scrub (postclimax) transfor¬med into secondary open country (disclimax, fig. 5) by human devastation and the setting of fire to the land. VEGETATION GROUPS OF THE PLUVIAL TYPE. The map of the region also shows that at the present time the small patches of forest (whether devasted or intact) occupy the least accessible places, such as valleys, peaks and abrupt slopes (fig. 2). Even these are now being destroyed, so that in the near future this forested region will be en¬tirely reduced to poor pasture land unless energetic measures of conservation are undertaken in time. The Special Service for Prophylaxis against Yellow Fever installed two of their four Stations for the Capture of Mosquitos in this area, one of them at Batatal and the other at Cachoeira, which have separate formations each of them composed of several associations. Other vegetation formations were also analysed, from the synecological point of view, so as to ascertain of which degree of succession their associations belong. These phytosociological sur¬veys give an idea of the principal characteristics of each station. BATATAL FORMATION. The abrupt nature of the valley has rendered this location inappropriate for agricultural purposes since colonial times. The relict of the primitive forest climax saved by this circumstance has expanded gradually to zones whose paedologic conditions favour the eatablishment of mesophilous species. The aerial photograph shows two small stretches of forest, one apparently primi¬tive, the other composed of associations belonging to the subclimax of the subsere. CACHOEIRA FORMATION. Aerial photographs show that this station is crossed by a small river, which divides it into two separate parts. The first, which presents ecological conditions similar, though not identical to those of Batatal, is favoured by topography and apparently remains primitive forest. Though the topography of the other, on the whole, favours the establishment of groups belonging to the normal sere of the climax, is has been partly devastated recently and the aspect of the associations has been completely modified. It was is this part that the four posts for the capturing of mosquitos were set up. The first forest is favoured by deposition of organic matter, washed out from the nearby devasted areas by torrential rains, and thus provides, an appropriate HABITAT for the climax species with certain hygrophilous trends of the ecological quasiclimax type. This association seems to have reached a biological equilibrium, as the dominates. Gallesia gorarema and Cariniana legalis (fig. 10), present an optimum vitality with a vigorous habit and a normal evolutionary cycle. The Cariniantum legalis Gallesiosum equilibrium, corresponds however, to a provisory association, because if the moving of soil by torrential rains should cease it would become possible
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190712
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This paper studies the effects of different types of research policy on economic growth. We find that while tax incentives to private research, public funding of private projects, and basic research performed at public institutions have unambiguously positive effects on economic growth, performing applied research at public institutions could have negative growth effects. This is due to the large crowding out of private research caused by public R\&D when it competes with private firms in the "patent race". Concerning the effects of these policies on welfare, it is found that research policy can either improve or reduce consumer welfare depending on the characteristics of the policy and that an excessively high research subsidy will reduce it.
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In several instances, third-party payers negotiate prices of health care services with providers. We show that a third-party payer may prefer to deal with a professional association than with the sub-set constituted by the more efficient providers, and then apply the same price to all providers. The reason for it is the increase in the bargaining position of providers. The more efficient providers are also the ones with higher profits in the event of negotiation failure. This allows them to ext act a higher surplus from the third-party payer.
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Research carried out in Tokyo Institute of Technology. The objective is to determine the influence of Interfacial Transition Zone (ITZ) around Lightweight aggregate in concrete on Chloride ion diffusivity. The ITZ of conventional concretes is the weakest point of concrete. The accumulating water on ITZ zone forms the most permeable area inside the concrete. Hence ITZ paves the way for chloride ion diffusion. The quality of ITZ depends on type and quality of aggregates used, water-cement ratio and also the method used for the production of concrete. It has been used two types of lightweight aggregates will be used, Chinese and Japanese, with different absorption capacities. The idea is to produce concrete with same effective water - cement ratio, using the same aggregates in two different conditions, dry and saturated, and compare the chloride ion diffusivity in these concretes (by diffusion test). A comparison of ITZ thickness of these concretes by SEM and EDAX-maps is also proposed. The chloride ion diffusion of concretes produced with the same effective water – cement ratio and same aggregates (dry and ssd) will depend, mainly, on ITZ.
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This paper investigates the effects of monetary rewards on the pattern of research. We build a simple repeated model of a researcher capable to obtain innovative ideas. We analyse how the legal environment affects the allocation of researcher's time between research and development. Although technology transfer objectives reduce the time spent in research, they might also induce researchers to conduct research that is more basic in nature, contrary to what the skewing problem would presage. We also show that our results hold even if development delays publication.
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Per a poder comprendre la dimensió de les possibles transformacions que Internet pot comportar, cal investigar els usos concrets de què es o ha estat objecte. En definitiva, cal realitzar investigacions empíriques que aportin informació sobre qui usa Internet, en quines circumstàncies i amb quins objectius. En aquest context, s’ha iniciat l’anàlisi en profunditat d’un cas específic de comunitat virtual de suport social creada per una persona afectada pel trastorn bipolar. L’objectiu d’una comunitat d’autoajuda virtual és proporcionar informació i recolzament emocional a través d’Internet. Mitjançant una metodologia qualitativa s’ha realitzat l’observació del fòrum virtual que penja de la pàgina web “Bipoloarweb.com”. En les investigacions del fenomen dels grups d’autoajuda a Internet, sovint s’ha destacat que a diferència dels grups ‘presencials’, aquests només poden aportar recolzament emocional i informatiu als seus membres. El tipus de recolzament instrumental o altre tipus d’assistència física, en canvi, no és possible en els casos virtuals. Els primers resultats de la recerca invaliden aquesta afirmació general ja que s’ha pogut observar episodis diferents d’ajut instrumental. En relació a la gestió d’informació i producció de coneixement, ja es pot avançar algunes qüestions interessants. En primer lloc, la quantitat i el detall de la informació que en el fòrum circula sobre el trastorn Bipolar. La majoria d’aquests coneixements, però, sorgeixen directament de compartir l’experiència diària entre els membres del grup. Tot això permet avançar la següent hipòtesi de treball pel futur: a més a més de suport emocional i instrumental, aquest grup ‘empodera’ el seus membres? Si la resposta fos positiva, el nostre cas tindria semblances amb altres fenòmens com son les associacions de malalts.
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This paper is a positive analysis of the driving forces in interdisciplinary research. I take the perspective of a research institution that has to decide how to apply its resources among the production of two types of knowledge: specialized or interdisciplinary. Using a prize mechanism of compensation, I show that the choice of interdisciplinarity is compatible with profit maximization when the requirement for the production is sufficiently demanding, and when the new interdisciplinary field is not too neutral. Productive gains due to complementarities of efforts is the main advantage of interdisciplinary organization.
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I analyze, in the context of business and science research collaboration, how the characteristics of partnership agreements are the result of an optimal contract between partners. The final outcome depends on the structure governing the partnership, and on the informational problems towards the efforts involved. The positive effect that the effort of each party has on the success of the other party, makes collaboration a preferred solution. Divergence in research goals may, however, create conflicts between partners. This paper shows how two different structures of partnership governance (a centralized, and a decentralized ones) may optimally use the type of project to motivate the supply of non-contractible efforts. Decentralized structure, however, always choose a project closer to its own preferences. Incentives may also come from monetary transfers, either from partners sharing each other benefits, or from public funds. I derive conditions under which public interventio
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BACKGROUND: Highway maintenance workers are constantly and simultaneously exposed to traffic-related particle and noise emissions, and both have been linked to increased cardiovascular morbidity and mortality in population-based epidemiology studies. OBJECTIVES: We aimed to investigate short-term health effects related to particle and noise exposure. METHODS: We monitored 18 maintenance workers, during as many as five 24-hour periods from a total of 50 observation days. We measured their exposure to fine particulate matter (PM2.5), ultrafine particles, noise, and the cardiopulmonary health endpoints: blood pressure, pro-inflammatory and pro-thrombotic markers in the blood, lung function and fractional exhaled nitric oxide (FeNO) measured approximately 15 hours post-work. Heart rate variability was assessed during a sleep period approximately 10 hours post-work. RESULTS: PM2.5 exposure was significantly associated with C-reactive protein and serum amyloid A, and negatively associated with tumor necrosis factor α. None of the particle metrics were significantly associated with von Willebrand factor or tissue factor expression. PM2.5 and work noise were associated with markers of increased heart rate variability, and with increased HF and LF power. Systolic and diastolic blood pressure on the following morning were significantly associated with noise exposure after work, and non-significantly associated with PM2.5. We observed no significant associations between any of the exposures and lung function or FeNO. CONCLUSIONS: Our findings suggest that exposure to particles and noise during highway maintenance work might pose a cardiovascular health risk. Actions to reduce these exposures could lead to better health for this population of workers.