The effects of the geosynchronous energetic particle radiation environment on spacecraft charging phenomena

The energetic electron environment at the geosynchronous orbit is responsible for a variety of adverse charging effects on spacecraft components. The most serious of these is the degradation and failure of a complementary-metal-oxide-semiconductor (CMOS) electronic components as a result of internal charge-buildup induced by the energetic electrons. Efforts to accurately determine the expected lifetime of these components in this orbit are hampered by the lack of detailed knowledge of the electron spectrum and intensity, particularly of the more penetrating energies greater than 1.5 MeV. This problem is illustrated through the calculation of the dose received by a CMOS device from the energetic electrons and associated bremsstrahlung as a function of aluminum shielding thickness using the NASA AE-6 and the Aerospace measured electron environments. Two computational codes which were found to be in good agreement were used to perform the calculations. For a given shielding thickness the dose received with the two radiation environments differ by as much as a factor of seven with a corresponding variation in lifetime of the CMOS

Mortality problems in Brazil and in Germany: past-present-future. Learning from each other?

This article was written by a Swiss-German historical demographer after having visited different Brazilian Universities in 1984 as a guest-professor. It aims at promoting a real dialog between developed and developing countries, commencing the discussion with the question: Can we learn from each other? An affirmative answer is given, but not in the superficial manner in which the discussion partners simply want to give each other some "good advice" or in which the one declares his country's own development to be the solely valid standard. Three points are emphasized: 1. Using infant mortality in S. Paulo from 1908 to 1983 as an example, it is shown that Brazil has at its disposal excellent, highly varied research literature that is unjustifiably unknown to us (in Europe) for the most part. Brazil by no means needs our tutoring lessons as regards the causal relationships; rather, we could learn two things from Brazil about this. For one, it becomes clear that our almost exclusively medical-biological view is inappropriate for passing a judgment on the present-day problems in Brazil and that any conclusions so derived are thus only transferable to a limited extent. For another, we need to reinterpret the history of infant mortality in our own countries up to the past few decades in a much more encompassing "Brazilian" sense. 2. A fruitful dialog can only take place if both partners frankly present their problems. For this reason, the article refers with much emprasis to our present problems in dealing with death and dying - problems arising near the end of the demographic and epidemiologic transitions: the superanuation of the population, chronic-incurable illnesses as the main causes of death, the manifold dependencies of more and more elderly and really old people at the end of a long life. Brazil seems to be catching up to us in this and will be confronted with these problems sooner or later. A far-sighted discussion already at this time seems thus to be useful. 3. The article, however, does not want to conclude with the rather depressing state of affairs of problems alternatingly superseding each other. Despite the caution which definitely has a place when prognoses are being made on the basis of extrapolations from historical findings, the foreseeable development especially of the epidemiologic transition in the direction of a rectangular survival curve does nevertheless provide good reason for being rather optimistic towards the future: first in regards to the development in our own countries, but then - assuming that the present similar tendencies of development are stuck to - also in regard to Brazil.Estudo realizado em 1984, por um professor suiço-alemão, especializado em demografia histórica, com a finalidade de promover diálogo mútuo entre países desenvolvidos e em desenvolvimento, sobre demografia. Três pontos são destacados: 1. Tomando a mortalidade infantil de São Paulo no período de 1908 a 1983, como exemplo, é mostrado que o Brasil tem ao seu dispor excelente e variada literatura de pesquisa sobre o assunto, que é injustificavelmente desconhecida pela maioria dos europeus. É enfatizado que o Brasil não depende do conhecimento dos autores europeus para explicações concernentes aos fatores que, sob vários aspectos, estão implicados: podem ser considerados, pelos europeus, dois aspectos do Brasil, a este respeito. No primeiro torna-se evidente que o conhecimento do europeu, do ponto de vista médico-biológico, não é apropriado para se chegar a conclusões sobre os problemas atuais do Brasil e que quaisquer conclusões poderão ser extrapoladas em apenas alguns poucos casos. O segundo aspecto refere-se à reinterpretação da história da mortalidade infantil nos países europeus, até as últimas décadas, que em sentido mais abrangente mostra uma situação semelhante à brasileira. 2. Um diálogo frutífero só poderia ser realizado se ambos os interessados apresentassem francamente seus problemas. Por este motivo, o estudo faz referências enfáticas aos atuais problemas do europeu em relação a estudos da morte e do morrer - problemas que surgem perto da fronteira das transições demográfica e epidemiológica: o envelhecimento da população, as doenças crônicas incuráveis como as principais causas de morte e o problema do idoso. O Brasil parece estar se aproximando da situação européia, neste particular, e há de se defrontar com estes problemas mais cedo ou mais tarde. Uma discussão já com vistas ao futuro, parece ser proveitosa. 3. O estudo não pretende apresentar um quadro deprimente de problemas que se alternam sucessivamente. Apesar da cautela que se deve ter quando se faz prognósticos, há boas razões para um certo otimismo quanto ao futuro: em primeiro lugar, em relação ao desenvolvimento dos países europeus - presumindo que se continui a seguir as tendências atuais de desenvolvimento - e mesmo em relação ao Brasil

An Algorithmic Framework for Labeling Road Maps

Given an unlabeled road map, we consider, from an algorithmic perspective, the cartographic problem to place non-overlapping road labels embedded in their roads. We first decompose the road network into logically coherent road sections, e.g., parts of roads between two junctions. Based on this decomposition, we present and implement a new and versatile framework for placing labels in road maps such that the number of labeled road sections is maximized. In an experimental evaluation with road maps of 11 major cities we show that our proposed labeling algorithm is both fast in practice and that it reaches near-optimal solution quality, where optimal solutions are obtained by mixed-integer linear programming. In comparison to the standard OpenStreetMap renderer Mapnik, our algorithm labels 31% more road sections in average.Comment: extended version of a paper to appear at GIScience 201

Reconstructing biological frameworks of populations in the past

Die historische Abteilung der Freien Universität Berlin hat mit Unterstützung der Deutschen Forschungsgemeinschaft eine Datenbank über 7000 Familien in acht hessischen Gemeinden über den Zeitraum von 1700 bis zum 20. Jahrhundert angelegt. Der Autor berichtet über die Ergebnisse und Probleme der Datenerhebung und Bearbeitung. Kernproblem war die Scheidung von rein biologisch bedingten Daten von sozial beeinflußten. Vermittelt werden die Ergebnisse im Bereich der Periodisierung des untersuchten Zeitraums und Daten über Sterblichkeit, Geburten. (BG

Possíveis conseqüências da crescente longevidade no Brasil: perspectiva de um demógrafo

Those over sixty years of age accounted for 6.6% of the total population of Brazil in 1985, in the Federal Republic of Germany this proportion was 20.3% in 1984. As early as 1950 it had been 14.5%. This proportion will not even be reached in Brazil in the year 2000 when persons aged sixty years and older are only projected to make up 8.8% of the total population. Similarly, in 1982/84 life expectancy at birth in the Federal Republic was 70.8 years for men and 77.5 for women; in Brazil the figures for 1980/85 were, by contrast, "only" 61.0 and 66.0. Against this background it is easy to understand why the discussion concerning an ageing society with its many related medical, economic, individual and social problems has been so slow in coming into its own in Brazil. As important as a more intensive consideration of these aspects may be in Brazil at present, they are, nevertheless, only one side of the story. For a European historical demographer with a long-term perspective of three of four hundred years, the other side of the story is just as important. The life expectancy which is almost ten years lower in Brazil is not a result of the fact that no one in Brazil lives to old age. In 1981 people sixty-five years and older accounted for 34.4% of all deaths! At the same time infants accounted for only 22.1% of total mortality. They are responsible, along with the "premature" deaths among youths and adults, for the low, "average" life expectancy figure. In Europe, by contrast, these "premature" deaths no longer play much of a role. In 1982/84 more than half of the women (52.8%) in the Federal Republic of Germany lived to see their eightieth birthdays and almost half of the men (47.3%) lived to see their seventy-fifth. Our biological existence is guaranteed to an extent today that would have been unthinkable a few generations ago. Then, the classic troika of "plague, hunger and war" threatened our forefathers all the time and everywhere. The radical transition from the formerly uncertain to a present-day certain lifetime, which is the result of the repression of "plague, hunger and war", led to unexpected consequences for our living together. Our forefathers were forced to live in closely knit Gemeinschaften in the interest of physical survival and to subordinate their egoistic goals to a common value, but now these pressures have, for the most part, fallen away. Correspondingly, this much more certain EGO has taken center stage. An ever greater number of us chooses to live life as single beings: the number of marriages is lower every year; the number of divorces is on the increase; in Berlin (West) more than half (sic! 52.3%) of all households are already composed on only one person. For the last dozen years the annual number of births in the Federal Republic has been insufficient to ensure population replacement. Not a population explosion but rather the opposite, a population implosion, is our problem. Human beings do not appear to be "social animals", as was axiomatically assumed for so long. They were only forced to behave as such for as long as "plague, hunger and war" forced them to do so. When these life endangering conditions no longer exist and life becomes certain even without their being integrated into a Gemeinschaft then humans suddenly show themselves more and more to be independent single beings. It is not the percentage of the population that is over sixty or sixty-five that is decisive in this context but rather how certain adults perceive their biological lives to be, since they are the ones who organize their lives, who build communities or who are ever more often willing only to enter into means-to-an-end personal unions without lasting or close ties and mutual responsibilities. There are many signs which seem to point to a development in this direction in Brazil as well. More and more adults in Brazil are caught up in the deep-seated transition from an uncertain to a certain lifetime. A third of them die after having reached their sixty-fifth birthday. It therefore seems to me to be high time that one began to give more consideration to the other side of the story in Brazil as well. And who is more suited intensively to consider the long-term perspectives than those engaged in the public health sector in whose competence, after all, such aspects, as "life certainty", "life expectancy" and "age at death" belong?Em 1985, as pessoas com mais de 60 anos de idade representavam 6,6% da população total do Brasil, enquanto na República Federativa da Alemanha esta proporção era, em 1984, de 20,3%; em 1950 havia chegado aos 14,5%. Esta proporção não será alcançada no Brasil, nem mesmo no ano 2000, pois se prevê que as pessoas acima de 60 anos comporão 8,8% da população total. Da mesma forma, no período 1982/84 a expectativa de vida ao nascer na República Federativa da Alemanha era de 70,8 anos, para homens, e de 77,5, para mulheres. No Brasil, para 1980/85, foi de 61,0 e 66,0, respectivamente. Com este pano de fundo entende-se porque o debate sobre o envelhecimento da sociedade com os seus múltiplos problemas - médicos, econômicos, individuais e sociais - tem demorado a assumir qualquer destaque no Brasil. Embora sejam importantes no Brasil estas considerações, elas constituem, no entanto, presentemente, apenas um lado da história. Para um europeu estudioso de demografia histórica com a vantagem de uma visão de 300 ou 400 anos, o outro lado da história é igualmente importante. O fato de a longevidade estar 10 anos mais baixa no Brasil não significa que ninguém nesse país viva até a idade avançada. Em 1981, pessoas de 65 anos ou mais representaram 34,4% do total de óbitos; ao mesmo tempo a mortalidade infantil representou 22,1% da mortalidade geral. Estas e as mortes "prematuras" entre jovens e adultos são responsáveis pela baixa cifra da vida média. Na Europa, por outro lado, as mortes "prematuras" já não desempenham importante papel. Mais da metade das mulheres (52,8%) da Alemanha sobreviveram até 80 anos de idade, de 1982/84, e quase metade dos homens (47,3%) sobreviveram até 75 anos. A durabilidade da vida é hoje garantida de tal forma que teria sido inconcebível há poucas gerações. O tripé clássico de "peste, fome e guerra" ameaçava os nossos antepassados em todos os lugares e todo tempo. A transição radical de uma vida anteriormente incerta para a vida segura atual, resultado da repressão daquele tripé, levou a conseqüências imprevistas para o convívio em comunidade. Nossos antepassados eram obrigados a viver em sociedade, bem integrados na busca de sua sobrevivência física, e subordinar seus dejetos pessoais aos valores comuns; mas, agora, ao menos na sua maior parte, estas pressões desapareceram. O ego, com muito mais segurança, passou a ocupar lugar de destaque. Um número crescente de pessoas tem optado por uma vida solitária: o número de casamentos diminui a cada ano, o número de divórcios aumenta; em Berlim Ocidental, mais da metade (52,3%) das "famílias" já se compõe de uma só pessoa. Durante os últimos 6 anos o número anual de nascimentos foi insuficiente para assegurar a reposição da população. O problema da Alemanha não é de explosão demográfica e, sim, de implosão. Os seres humanos já não parecem ser "animais sociais", como se supunha. Na verdade, a "peste, fome e guerra" os obrigavam a este comportamento. Quando estas condições ameaçadoras se modificaram e a vida se tornou mais segura, mesmo sem estarem integrados numa sociedade, os seres humanos vêm se tornando cada vez mais solitários. Não é a existência de população acima de 60 ou 65 anos que se constituiu um fator decisivo neste contexto, mas, sim, a percepção dos adultos de sua condição humana, desde que são eles que organizam suas vidas, que constroem comunidades e que com freqüência cada vez maior contraem uniões pessoais como um fim em si mesmo, sem laços chegados ou duradouros ou responsabilidades mútuas. Uniões estas que fazem com que as pessoas convivam sem um verdadeiro relacionamento mútuo. Há vários sinais que parecem indicar tendência nesta direção, também no Brasil. Mais e mais adultos estão envolvidos nesta profunda transição de uma vida incerta para outra mais segura. Um terço deles morre depois de ter alcançado seu 65.º aniversário. Já é tempo, pois, de levar em consideração este outro lado da história no Brasil. E quem melhor para estudar estas perspectivas, a longo prazo, do que aqueles da área da Saúde Pública, a quem compete, afinal, lidar com aspectos tais como "certeza de vida", expectativa de vida e "idade ao morrer"

Competition, Proprietary Costs of Financial Reporting, and Financial Statement Comparability

Competitors often pay close attention to rivals’ financial reports. For firms with high levels of proprietary information, competition may increase the costs of public disclosure. Theory suggests that such costs, which we refer to as the proprietary costs of financial reporting, may lead to strategic financial reporting. We find that financial statement comparability is decreasing in the proprietary costs of financial reporting. Our results are robust to the use of alternative measures of comparability and alternative measures of proprietary costs of financial reporting. In addition, theory suggests that financial reports will contain stronger signals of managers’ private information when information asymmetry is high. We show that the negative relation between the proprietary costs of financial reporting and financial statement comparability is stronger for firms with poorer information environments. Together, our findings suggest that through the discretion afforded in Generally Accepted Accounting Principles (GAAP), managers of firms with high levels of proprietary information report in a way that reduces the comparability of their financial statements, particularly when information asymmetry is high

A vida prolongada . Consequências para nossa vida cotidiana

(parágrafo do artigo)A vida cotidiana nos seus aspectos sociais, políticos e econômicos de uma população com uma idade média de vinte anos é bem diferente da de uma de quarenta . Para melhor sentir essa diferença podemos, por exemplo, comparar a sociedade européia do século XVI com a do fim do século XX, ou a vida nos países em desenvolvimento com a das nações industrializadas

Efficacy, safety, and tolerance of piperacillin/tazobactam compared to co-amoxiclav plus an aminoglycoside in the treatment of severe pneumonia

An open, randomized, multicenter study was conducted to compare the efficacy and safety of piperacillin/tazobactam and co-amoxiclav plus aminoglycoside in the treatment of hospitalized patients with severe community-acquired or nosocomial pneumonia. Of the 89 patients who entered the study, 84 (94%) were clinically evaluable. A favorable clinical response was observed in 90% of the piperacillin/ tazobactam group and in 84% of the co-amoxiclav/aminoglycoside group (not significant). The bacteriological efficacy was comparable in both groups (96% vs. 92%; not significant). There was only one fatal outcome in the piperacillin/tazobactam group compared to six in the co-amoxiclav/aminoglycoside group regimenP=0.058). The adverse event rate was non-significantly lower in the piperacillin/ tazobactam group compared to the co-amoxiclav/aminoglycoside group (2% vs. 7%;P=0.32). Piperacillin/tazobactam is safe and highly efficacious in the treatment of serious pneumonia in hospitalized patients. It compares favorably with the combination of co-amoxiclav/aminoglycosid