872 resultados para [JEL:O10] Economic Development, Technological Change, and Growth - Economic Development - General
Resumo:
This research project aimed the following goal: promote the creation, use and disclosure of OER in a Group of Schools, involving schools and teachers from different learning levels, expecting to test and validate the use of OER, in a learning-teaching model towards curricular innovation. Defining as a starting point different subjects and teachers from distinct academic areas, we have implemented a set of activities leading to the creation of OER supported, when possible, in FLOSS tools. We adopted an action research methodology with a dual purpose: to act within a community of teachers and students, while increasing at the same time their knowledge, as well as the researcher's. The activity was developed cooperatively in order to process a certain reality of the teaching-learning process, through practical/reflective action towards it and inducing its implementation by others in the Portuguese School System, based on the production and sharing OER.
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Latin medical texts transmit medical theories and practices that originated mainly in Greece. This interaction took place through juxtaposition, assimilation and transformation of ideas. 'Greek' and 'Roman' in Latin Medical Texts studies the ways in which this cultural interaction influenced the development of the medical profession and the growth of knowledge of human and animal bodies, and especially how it provided the foundations for innovations in the areas of anatomy, pathology and pharmacology, from the earliest Latin medical texts until well into the medieval world.
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This paper studies the effects of financial liberalization and banking crises on growth. It shows that financial liberalization spurs on average economic growth. Banking crises are harmful for growth, but to a lesser extent in countries with open financial systems and good institutions. The positive effect of financial liberalization is robust to different definitions. While the removal of capital account restrictions is effective by increasing financial depth, equity market liberalization affects growth directly. The empirical analysis is performed through GMM dynamic panel data estimations on a panel of 90 countries observed in the period 1975-1999.
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This paper presents empirical support for the existence of wealth effects in the contribution of financial intermediation to economic growth, and offers a theoretical explanation for these effects. Using GMM dynamic panel data techniques applied to study the growth-promoting effects of financial intermediation, we show that the exogenous contribution of financial development on economic growth has different effects for different levels of income per capita. We find that this contribution is generally increasing with thelevel of income per capita of the economy, up to a relatively high level of income. This contribution is consistently lower for poor countries; and for some low levels of income per capita it can be negative. We provide a model to account for these wealth effects. The model is a overlapping generations growth model where financial intermediaries implement liquidity risk sharing among depositors. We show that at early stages of economic development, a bank can increase welfare of its depositors only at the cost of lowering investment and growth. However, once the economy has crossed certain wealth threshold, the liquidity role of banks becomes unambiguously growth enhancing. As wealth increases, banks offer improving liquidity insurance, and higher growth; however, for high levels of wealth, growth generated byfinancial intermediation declines as the economy attains the optimal level of consumption risk sharing.
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This paper argues that a large technological innovation may lead to a merger wave by inducing entrepreneurs to seek funds from technologically knowledgeable firms -experts. When a large technological innovation occurs, the ability of non-experts (banks) to discriminate between good and bad quality projects is reduced. Experts can continue to charge a low rate of interest for financing because their expertise enables them to identify good quality projects and to avoid unprofitable investments. On the other hand, non-experts now charge a higher rate of interest in order to screen bad projects. More entrepreneurs, therefore, disclose their projects to experts to raise funds from them. Such experts are, however, able to copy the projects and disclosure to them invites the possibility of competition. Thus the entrepreneur and the expert may merge so as to achieve product market collusion. As well as rationalizing mergers, the model can also explain various forms of venture financing by experts such as corporate investors and business angels.
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We employ a non-parametrical approach to growth accounting (Data Envelopment Analysis,DEA) to disentangle the proximate sources of labour productivity growth in 41 nationsbetween 1929 and 1950 by decomposing productivity growth into four components:technological change; efficiency catch-up (movements towards the production frontier),capital accumulation and human capital accumulation. We show that efficiency catch-upgenerally explains productivity growth, whereas technological change and factoraccumulation were limited and distorted by the effects of war. War clearly hamperedefficiency. Moreover, an unbalanced ratio of human capital to physical capital (a gap to thetechnological leader) was crucial for efficiency catching-up.
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This article analyses the varying influence across time of the "epistemic community" of free-market economists on immigration policy making in Switzerland. To this end, a framework for the analysis of the impact of economic expertise is provided, and then used in an historical analysis comparing the 1960s with the 1990s. Whereas this influence can be considered to have been weak in the 1960s, it gained significantly in importance in the 1990s, when a period of economic unrest seriously challenged previous immigration policies. It is argued that economic experts played an important role in framing the reforms undertaken during this latter period, notably by providing a "credible causal story" about the links between the existing immigration policy and the social problems which arose in the country in the 1990s. As compared to the 1960s, economic expertise in the 1990s enjoyed more credibility, more political support and took full advantage of a more uncertain social and economic context
Resumo:
La pression exercée par les activités humaines menace pratiquement tous les écosystèmes aquatiques du globe. Ainsi, sous l'effet de divers facteurs tels que la pollution, le réchauffement climatique ou encore la pêche industrielle, de nombreuses populations de poissons ont vu leurs effectifs chuter et divers changements morphologiques ont été observés. Dans cette étude, nous nous sommes intéressés à une menace particulière: la sélection induite par la pêche sur la croissance des poissons. En effet, la génétique des populations prédit que la soustraction régulière des individus les plus gros peut entraîner des modifications rapides de certains traits physiques comme la croissance individuelle. Cela a par ailleurs été observé dans de nombreuses populations marines ou lacustres, dont les populations de féras, bondelles et autres corégones des lacs suisses. Toutefois, malgré un nombre croissant d'études décrivant ce phénomène, peu de plans de gestion en tiennent compte, car l'importance des effets génétiques liés à la pêche est le plus souvent négligée par rapport à l'impact des changements environnementaux. Le but premier de cette étude a donc été de quantifier l'importance des facteurs génétiques et environnementaux. Dans le premier chapitre, nous avons étudié la population de palée du lac de Joux (Coregonus palaea). Nous avons déterminé les différentiels de sélection dus à la pêche, c'est-à-dire l'intensité de la sélection sur le taux de croissance, ainsi que les changements nets de croissance au cours du temps. Nous avons observé une baisse marquée de croissance et un différentiel de sélection important indiquant qu'au moins 30% de la diminution de croissance observée était due à la pression de sélection induite par la pêche. Dans le deuxième chapitre, nous avons effectué les mêmes analyses sur deux espèces proches du lac de Brienz (C. albellus et C. fatioi) et avons observé des effets similaires dont l'intensité était spécifique à chaque espèce. Dans le troisième chapitre, nous avons analysé deux autres espèces : C. palaea et C. confusus du lac de Bienne, et avons constaté que le lien entre la pression de sélection et la diminution de croissance était influencé par des facteurs environnementaux. Finalement, dans le dernier chapitre, nous avons étudié les effets potentiels de différentes modifications de la taille des mailles des filets utilisés pour la pêche à l'aide de modèles mathématiques. Nous concluons que la pêche a un effet génétique non négligeable (et donc peu réversible) sur la croissance individuelle dans les populations observée, que cet effet est lié à la compétition pour la nourriture et à la qualité de l'environnement, et que certaines modifications simples de la taille des mailles des filets de pêche pourraient nettement diminuer l'effet de sélection et ainsi ralentir, voir même renverser la diminution de croissance observée.
Resumo:
The objective of this work was to compare phyllochron and leaf area on individual stalks of selected sugarcane (Saccharum officinarum) clones grown in a subtropical environment. A two-year field experiment was carried out in Santa Maria, RS, Brazil, during the 2007/2008 and 2008/2009 growing seasons. Three sugarcane clones were used: IAC 822045 (early), SP 711406 (median) and CB 4176 (late), in a complete randomized block design, with four replications. Expanded leaf and total leaf (tips) number were determined, and expanded leaf area was measured. The phyllochron (ºC day leaf-1) based on expanded and tip leaf number was estimated, using 10ºC as base temperature. Allometric relationships between individual area and number of expanded leaves were fitted. Phyllochron was analysed as a four-factor experiment: clone, growing season, phyllochron phase, and phyllochron type. The early clone had the greatest potential for growing in a subtropical climate because of higher leaf output and leaf area.
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Cordia curassavica (Jacq.) Roem. & Schult. (Boraginaceae), also referred to as Cordia verbenacea DC, has been traditionally used for medicinal purposes. This study was driven to verify the behavior of the species in similar conditions to its natural environment, such as high light intensity and sandbank soil, and in conditions of low light intensity and fertilized substratum (dystroferric red nitosoil plus earthworm humus). The growth of the plant, the income of leaf crude extracts and, in the alcoholic extract, the number of substances found in thin layer cromatography and the toxicity of the substratum was observed. The results indicated that the growth of the root biomass, stem and leaves in discharge or lower light intensity was similar, but smaller in sandbank soil than in fertilized soil. The relative income of extracts in ether of petroleum and alcohol was larger in high light intensity and fertilized substratum. The light intensity and the substratum type didn't affect the number of substances detected in the alcoholic extract or the toxicity of this extract. Stains corresponding to the rosmarinic acid were only evidenced in some samples of the alcoholic extract, not allowing the verification of the effect of the treatments about its production.
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Concerns about the sustainability of large-scale, direct-drilled RR-soybeans (Glycine max), and RR-maize (Zea mays) under monoculture in central Argentina are growing steadily. An experiment was conducted during three consecutive years to determine the effects of crops and systems (monocultures and strips) and herbicide strategy on weed density, population rate of change (l), b community diversity (H´), crop yields and Land Equivalent Ratio (LER). Not only crops but also crop systems differentially influenced weed densities along their growth and development. For crop harvests, weed densities increased in both maize crop systems as compared to in the one for soybeans, but the lowest increase occurred in soybean strips. Differences were leveled by both herbicide strategies, which achieved 73% efficacy during the critical periods in both crops. l of annual monocotyledonous increased, thus shifting the weed community composition. Species richness and H´ were not affected by crop systems, but both herbicide strategies, particularly POST, either in soybeans in monoculture or in maize strips, significantly enhanced H´. Crop yields significantly increased in the maize-strip system with POST (Year 1) or PRE (Years 2 and 3) strategies, thus increasing LER above 1. Herbicide Environmental Load treatments fall within very low or low field use rating.
Resumo:
The objective of this study was to determine the effects of GDF-9, IGF-I, and GH alone or combined on preantral follicle survival, activation and development after 1 and 7 days of in vitro culture. Either fresh (non-cultured) or cultured ovarian tissue was processed for histological and fluorescence analysis. For all media tested, the percent of normal follicles was greater when compared to minimum essential medium supplemented (MEM+) alone, except when ovarian tissue was cultured with GDF-9/IGF-I or GDF-9/GH (P < 0.05). Fluorescence analysis showed that the percent of viable follicles after 7 days of culture was similar for non-cultured tissue and for all treatments tested. The percent of primordial follicles was reduced (P < 0.05) and there was a significant and concomitant increase in the percent of intermediate and primary follicles in all treatments tested after 7 days of culture when compared to non-cultured tissue. After 7 days of culture, the highest percent of intermediate follicles was observed with IGF-I/GH (61.3%), and the highest percent of primary follicles was achieved with IGF-I (57.7%). After 7 days of culture in MEM+ containing GDF-9, IGF-I and GH alone or in all associations, a significant increase in follicular diameter was observed when compared to MEM+ alone and non-cultured tissue. In conclusion, GDF-9, IGF-I and GH alone or in combination maintain preantral follicle survival and promote primordial follicle activation. Nevertheless, the data showed that IGF-I/GH and IGF-I alone are efficient in promoting the transition from primordial to intermediate follicles and from intermediate to primary follicles, respectively.