The purpose of this paper is to analyze the competition among mobile app stores for smart mobile media devices. Therefore, the business models of seven mobile app stores are analyzed with a special focus on Apple and Google. We use e3-value modelling - a formal business modelling technique - for analyzing the critical elements of these mobile ecosystems. The analysis of the app store ecosystems allows a differentiated view on the different strategies of the app store owners. Additionally, we look at the impact of network effects, economies of scale, platform differentiation, quality assurance, and transaction costs on the design of mobile application markets. This theoretical model allows a deeper discussion about the design choices and success factors in the different app store cases. Based on our analysis, we expect that the open versus closed models discussion becomes less relevant - so-called open platforms have closed aspects as well as the other way around - and that competitive differentiation and segmentation strategies will become increasingly critical in order to strengthen the competitive positioning of the different app store platforms.

A ocorrência e abundância de ostrácodes darwinulídeos, bem como os fatores ambientais que influenciam estes padrões, foram investigadas no vale aluvial do alto rio Paraná. Os ostrácodes foram coletados em vários substratos, como sedimentos litorâneos e plêuston, o qual incluiu várias espécies de macrófitas aquáticas, de 31 ambientes (lênticos e lóticos) pertencentes a diferentes sistemas fluviais. Oito espécies de darwinulídeos foram encontradas, representando todos os gêneros desta família. Alicenula serricaudata, Vestalenula pagliolii e Penthesilenula brasiliensis foram as espécies mais comuns. A análise de agrupamento, baseada na composição e abundância das comunidades de darwinulídeos, revelou a presença de cinco associações. Darwinula stevensoni, Vestalenula botocuda e Penthesilenula aotearoa foram praticamente exclusivas de ambientes lóticos. O teste de Mantel múltiplo evidenciou que a ocorrência e distribuição de ostrácodes estiveram significantemente relacionadas aos tipos de hábitat e sistema, mas não às variáveis abióticas. Desta forma, parece que as flutuações hidrodinâmicas destes ambientes atuam mais fortemente na distribuição de darwinulídeos que as características limnológicas.

The occurrence and abundance of darwinulid ostracods, as well as environmental factors influencing these patterns, were investigated in the alluvial valley of the upper Paraná River. Ostracods were sampled from several substrates, like littoral sediments and pleuston, which included several aquatic macrophytes species, from 31 localities (lentic and lotic) belonging to different riverine systems. Eight darwinulid species were found, representing all genera from this family. Alicenula serricaudata, Vestalenula pagliolii, and Penthesilenula brasiliensis were the most common species. Cluster analysis based on the composition and abundance of darwinulid communities revealed the presence of five associations. Darwinula stevensoni, Vestalenula botocuda, and Penthesilenula aotearoa were almost exclusive to lotic environments. A Mantel multiple test showed that the occurrence and distribution of darwinulid ostracods were significantly related to types of habitat and systems, but not to abiotic variables. It thus seems that the hydrodynamic fluctuations of these environments are probably more important to darwinulid distribution than the limnological characteristics.

Human-induced climate change threatens ecosystems and human health on a global scale. In order to withstand the worldwide threats to ecosystems, the concept of sustainable development was introduced during the 1980s. Since then, this concept has been widely applied to guide and focus policy-making. The present article reviews the health consequences of human-induced climate change on sustainable development, particularly the potential impact of such change on food supply, natural disasters, infectious diseases, ecosystems, and sea level rise. Discussed is an integrated model containing the key indicators of sustainable development. The relevance of climate change, human health, and sustainable development for international climate change policy is also examined.

El cambio climático debido a actividades humanas pone en peligro los ecosistemas y la salud humana a escala mundial. Con el fin de hacer frente a las amenazas que se ciernen sobre los ecosistemas en todo el mundo, en el decenio de 1980 se introdujo el concepto del desarrollo sostenible. Desde entonces, ese concepto se ha aplicado ampliamente para guiar y enfocar la formulación de políticas. En el presente artículo se examinan las consecuencias sanitarias que tiene el cambio climático debido a actividades humanas para el desarrollo sostenible, en particular su posible efecto en el abastecimiento de alimentos, los desastres naturales, las enfermedades infecciosas, los ecosistemas y la elevación del nivel del mar. Se discute un modelo integrado que contiene los principales indicadores del desarrollo sostenible. También se examina la importancia que tienen el cambio climático, la salud humana y el desarrollo sostenible para las políticas internacionales pertinentes.