955 resultados para historical perspective
Resumo:
The objective of this paper is to present the evolution and the state-of-the-art in the area of legged locomotion systems. In a first phase different possibilities for implementing mobile robots are discussed, namely the case of artificial legged locomotion systems, while emphasizing their advantages and limitations. In a second phase a historical overview of the evolution of these systems is presented, bearing in mind several particular cases often considered as milestones of technological and scientific progress. After this historical timeline, some of the present-day systems are examined and their performance is analyzed. In a third phase the major areas of research and development that are presently being followed in the construction of legged robots are pointed out. Finally, some still unsolved problems that remain defying robotics research, are also addressed.
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We all hope that biotechnology will answer some social and economical unavoidable requirements of the modern life. It is necessary to improve agriculture production, food abundance and health quality in a sustainable development. It is indeed a hard task to keep the progress on taking into account the rational use of genetic resources and the conservation of biodiversity. In this context, a historical perspective and prospects of the biomedical research on parasitic diseases is described in a view of three generations of investigators. This work begins with a picture of the scientific progress on biomedical research and human health over the last centuries. This black-and-white picture is painted by dissecting current advancements of molecular biology and modern genetics, which are outlined at the meaning of prospecting achievements in health science for this new millenium.
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The filamentous fungus Ashbya gossypii has been safely and successfully used for more than two decades in the commercial production of riboflavin (vitamin B2). Its industrial relevance combined with its high genetic similarity with Saccharomyces cerevisiae together promoted the accumulation of fundamental knowledge that has been efficiently converted into a significant molecular and in silico toolbox for its genetic engineering. This synergy has enabled a directed and sustained exploitation of A. gossypii as an industrial riboflavin producer. Although there is still room for optimizing riboflavin production, the recent years have seen an abundant advance in the exploration of A. gossypii for other biotechnological applications, such as the production of recombinant proteins, single cell oil and flavour compounds. Here, we will address the biotechnological potential of A. gossypii beyond riboflavin production by presenting (a) a physiological and metabolic perspective over this fungus; (b) the molecular toolbox available for its manipulation; and (c) commercial and emerging biotechnological applications for this industrially important fungus, together with the approaches adopted for its engineering.
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This article aims to describe important points in the history of panic disorder concept, as well as to highlight the importance of its diagnosis for clinical and research developments. Panic disorder has been described in several literary reports and folklore. One of the oldest examples lies in Greek mythology - the god Pan, responsible for the term panic. The first half of the 19th century witnessed the culmination of medical approach. During the second half of the 19th century came the psychological approach of anxiety. The 20th century associated panic disorder to hereditary, organic and psychological factors, dividing anxiety into simple and phobic anxious states. Therapeutic development was also observed in psychopharmacological and psychotherapeutic fields. Official classifications began to include panic disorder as a category since the third edition of the American Classification Manual (1980). Some biological theories dealing with etiology were widely discussed during the last decades of the 20th century. They were based on laboratory studies of physiological, cognitive and biochemical tests, as the false suffocation alarm theory and the fear network. Such theories were important in creating new diagnostic paradigms to modern psychiatry. That suggests the need to consider a wide range of historical variables to understand how particular features for panic disorder diagnosis have been developed and how treatment has emerged.
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Ecological economics has five good reasons to consider that economic globalisation, spurred by commercial and financial fluxes, to be one of the main driving forces responsible for causing environmental degradation to our planet. The first, is the energy consumption and the socio-environmental impacts which long-distance haulage entails. The second, is the ever-increasing flow of goods to far-away destinations which renders their recycling practically impossible. This is particularly significant, because it prevents the metabolic lock of the nutrients present in food and other agrarian products from taking place. The third, is that the high degree of specialization attained in agriculture, forestry, cattle, mining and industry in each region, generates deleterious effects not only on the eco-landscape structure of the uses of the soil, but on the capability to provide habitat and environmental functions to maintain biodiversity as well
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Institutions, and more speci cally private property rights, have come to be seen as a major determinant of long-run economic development. We evaluate the case for property rights as an explanatory factor of the Industrial Revolution and derive some lessons for the analysis of developing countries today. We pay particular attention to the role of property rights in the accumulation of physical capital and the production of new ideas. The evidence that we review from the economic history literature does not support the institutional thesis.
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Although it might have been expected that, by this point in time, the unacceptability of the marginal productivity theory of the return on capital would be universally agreed, that is evidently not the case. Popular textbooks still propound the dogma to the innocent. This note is presented in the hope that a succinct indication of the origins of the theory it will contribute to a more general appreciation of the unrealistic and illogical nature of this doctrine.
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Malaria has always been an important public health problem in Brazil. The early history of Brazilian malaria and its control was powered by colonisation by Europeans and the forced relocation of Africans as slaves. Internal migration brought malaria to many regions in Brazil where, given suitableAnopheles mosquito vectors, it thrived. Almost from the start, officials recognised the problem malaria presented to economic development, but early control efforts were hampered by still developing public health control and ignorance of the underlying biology and ecology of malaria. Multiple regional and national malaria control efforts have been attempted with varying success. At present, the Amazon Basin accounts for 99% of Brazil’s reported malaria cases with regional increases in incidence often associated with large scale public works or migration. Here, we provide an exhaustive summary of primary literature in English, Spanish and Portuguese regarding Brazilian malaria control. Our goal was not to interpret the history of Brazilian malaria control from a particular political or theoretical perspective, but rather to provide a straightforward, chronological narrative of the events that have transpired in Brazil over the past 200 years and identify common themes.
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In this paper we compare two historical scenarios very different one to each other bothin institutional and geographical terms. What they have in common is the situation ofrelative poverty of most of the population. On the one side we are dealing withhistorical industrializing Catalonia in the North East of Spain, a country exhibiting pooreconomic yields in the context of European and non European industrializing nations inthe 19th century. We compare children s work patterns in 19th century Catalonia withthose of current developing countries in Latin America, Africa and South and East Asia.This kind of exercise in which the nexus of the comparison are the levels of wealth ofcountries that are unsuccessful to achieve high standards of economic growth allows usto combine the micro historical analysis (in the Catalan case) with the macrocomparative approach in current developing countries. By means of both, the microhistorical analysis and the macro regression analysis we obtain the result that adultwomen s skills and real wages are a key factor when we want to explain the patterns ofchildren work. While female real wages increased a sharp rate in 19th century Cataloniawe obtain very different results in the case of developing countries. This differentgender bias helps to explain why in some cases children continue to work and also whysome parts of the world continue to be poor according to our regression analysis.
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This article examines the debt history of two contenders for European hegemony: 16th-centurySpain and 18th-century Britain. We analyze their fiscal behavior using measures of overborrowingand fiscal policy functions. Our results suggest that stringency was not key for Britain ssuccess in avoiding default. Instead, fiscal repression allowed the United Kingdom to borrowat below-market rates, thereby outspending its continental rivals.
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In the late 19th century, it was already known that severe infections could be associated with cardiovascular collapse, a fact essentially attributed to cardiac failure. A major experimental work in the rabbit, published by Romberg and Pässler in 1899, shifted attention to disturbed peripheral vascular tone as the mechanism of hypotension in these conditions. In the first half of the 20th century, great progresses were made in the pathophysiologic understanding of hemorrhagic and traumatic shocks, while researchers devoted relatively little attention to septic shock. Progress in the hemodynamic understanding of septic shock resumed with the advent of critical care units. The hyperdynamic state was recognized in the late fifties and early sixties. The present short review ends with landmark studies by Max Harry Weil, demonstrating the importance of venous pooling, and John H. Siegel, which introduced the concept of deficient peripheral utilization of oxygen, inspiring later work on the microvascular disturbances of septic shock.
Resumo:
Finnish Defence Studies is published under the auspices of the National Defence College, and the contributions reflect the fields of research and teaching of the College. Finnish Defence Studies will occasionally feature documentation on Finnish Security Policy. Views expressed are those of the authors and do not necessarily imply endorsement by the National Defence College.
Resumo:
Mann–Kendall non-parametric test was employed for observational trend detection of monthly, seasonal and annual precipitation of five meteorological subdivisions of Central Northeast India (CNE India) for different 30-year normal periods (NP) viz. 1889–1918 (NP1), 1919–1948 (NP2), 1949–1978 (NP3) and 1979–2008 (NP4). The trends of maximum and minimum temperatures were also investigated. The slopes of the trend lines were determined using the method of least square linear fitting. An application of Morelet wavelet analysis was done with monthly rainfall during June– September, total rainfall during monsoon season and annual rainfall to know the periodicity and to test the significance of periodicity using the power spectrum method. The inferences figure out from the analyses will be helpful to the policy managers, planners and agricultural scientists to work out irrigation and water management options under various possible climatic eventualities for the region. The long-term (1889–2008) mean annual rainfall of CNE India is 1,195.1 mm with a standard deviation of 134.1 mm and coefficient of variation of 11%. There is a significant decreasing trend of 4.6 mm/year for Jharkhand and 3.2 mm/day for CNE India. Since rice crop is the important kharif crop (May– October) in this region, the decreasing trend of rainfall during themonth of July may delay/affect the transplanting/vegetative phase of the crop, and assured irrigation is very much needed to tackle the drought situation. During themonth of December, all the meteorological subdivisions except Jharkhand show a significant decreasing trend of rainfall during recent normal period NP4. The decrease of rainfall during December may hamper sowing of wheat, which is the important rabi crop (November–March) in most parts of this region. Maximum temperature shows significant rising trend of 0.008°C/year (at 0.01 level) during monsoon season and 0.014°C/year (at 0.01 level) during post-monsoon season during the period 1914– 2003. The annual maximum temperature also shows significant increasing trend of 0.008°C/year (at 0.01 level) during the same period. Minimum temperature shows significant rising trend of 0.012°C/year (at 0.01 level) during postmonsoon season and significant falling trend of 0.002°C/year (at 0.05 level) during monsoon season. A significant 4– 8 years peak periodicity band has been noticed during September over Western UP, and 30–34 years periodicity has been observed during July over Bihar subdivision. However, as far as CNE India is concerned, no significant periodicity has been noticed in any of the time series.