147 research outputs found

    Climate and soil type together explain the distribution of microendemic species in a biodiversity hotspot

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    The grasshopper genus Caledonula, endemic to New Caledonia, was studied to understand the evolution of species distributions in relation to climate and soil types. Based on a comprehensive sampling of 80 locations throughout the island, the genus was represented by five species, four of which are new to science, of which three are described here. All the species have limited distributions in New Caledonia. Bioclimatic niche modelling shows that all the species were found in association with a wet climate and reduced seasonality, explaining their restriction to the southern half of the island. The results suggest that the genus was ancestrally constrained by seasonality. A molecular phylogeny was reconstructed using two mitochondrial and two nuclear markers. The partially resolved tree showed monophyly of the species found on metalliferous soils, and molecular dating indicated a rather recent origin for the genus. Adaptation to metalliferous soils is suggested by both morphological changes and radiation on these soils. The genus Caledonula is therefore a good model to understand the origin of microendemism in the context of recent and mixed influences of climate and soil type

    RESULTADOS PRELIMINARES DA DISTRIBUIÇÃO DE FÓSFORO E SUAS FORMAS NOS SEDIMENTOS DA PLATAFORMA CONTINENTAL DO ESTADO DE SANTA CATARINA

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    Distribuition of phosphorus in marine sediments have been recognized as a useful tool for the knowledgement of its geochemical cicle, that have been undergoing chances by human actions. Marine sediments represents the major reservoir of this constituint, where processes take place and control its disponibility to water column. Differents forms of phosphorus were determined by sequencial extrations in 27 samples of bottom sediment collected in the inner shelf off Santa Catarina. The aim of this study was to investigate the distribuition of phosphorus in the sequencial extrated frations and the relationship with sediment facies. The highest total phosphorus concentrations have been related to fine grained sediments. Although, there were some differences between samples with similar sedimentar patterns. Iron plus aluminium phosphate has been showed high concentrations in the neigborhood of river mounths, declining off shore. Calcium phosphate was the predominant form in most samples.O estudo de fósforo em sedimentos marinhos tem sido utilizado como importante ferramenta para compreensão do ciclo geoquímico deste nutriente, o qual vem sendo alterado pela ação antropogênica. Os sedimentos marinhos representam o depósito final deste constituinte e, dependendo dos processos de interação química que ali ocorrem, podem ser responsáveis por sua maior ou menor disponibilidade para a coluna d’água. Neste estudo foram determinadas as diferentes formas de fósforo, através do método de extração sequencial (modificado de SILVEIRA, 1993), em 27 amostras de sedimentos superficiais coletados na plataforma interna do litoral centro-norte catarinense. O objetivo era verificar a distribuição de fósforo e suas formas de acordo com as fácies sedimentares encontradas na área de estudo. As concentrações de fósforo total variaram entre 1,27 a 18,77 µmol/g, com as mais elevadas estando associadas aos sedimentos finos, embora tenham ocorrido diferenças entre fácies com características granolumétricas similares. O fosfato de ferro + alumínio apresentou concentrações mais altas próximo as desembocaduras dos rios diminuindo com o aumento da distância da linha de costa, indicando o aporte continental. A forma predominante na maioria das amostras foi o fosfato de cálcio que apresentou uma relação direta com a profundidade

    Deep-ultraviolet-microelectromechanicaI systems stencils for high-throughput resistless. patterning of mesoscopic structures

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    We describe a combination of 100-mm wafer scale deep-ultraviolet (DUV) exposure and a microelectromechanical systems (MEMS) process to fabricate silicon nitride membranes with submicrometer apertures to be used as miniature shadow masks or nanostencils. Apertures down to a lateral resolution of 200 nm were made in a 500-nm-thick membrane by DUV exposure and dry plasma etching. The membranes were released by a combination of wet silicon etching using potassium hydroxide (KOH) and dry silicon etching using a plasma process. The millimeter-size stencils were used for single-step, local deposition of metal micro- and nano-patterns without the need for photoresist process steps. We have performed stencil deposition on full wafer scale for micro- and nano-patterns in a variety of metals (e.g. Al, Au, Ni, etc.). Dry under-etching of the nanowires resulted in free-standing cantilevered nanoelectromechanical systems (NEMS) structures with resonance frequencies in the megahertz range. The resistless method allows us to pattern micrometer and nanometer scale patterns in a single step without any further processing. It is promising for the surface processing of MEMS/NEMS devices having sensitive or fragile surfaces, such as biochips, organic polymer layers, and self-assembled monolayers. (C) 2004 American Vacuum Society

    THE UTILISATION OF VALUE BASED MANAGEMENT IN THE STRATEGIC MANAGEMENT OF GERMAN’S AUTOMOTIVE INDUSTRY

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    The purpose of this research paper is to analyse the value-based management commitment of automotive enterprises and to examine the factors that explain the control parameters in automotive industry. There have been a few empirical studies published in the German’s automotive sector but most of the existing studies failed to provide evidence of utilisation of value-based management in the strategic management in the automotive sector. The German automotive industry’s development is closely related to global economic developments. Previous research work has considered control parameters of enterprises but there is little evidence on the factors that explain which control parameters are used in automotive industry. A survey based on annual reports from the year 2008 to 2011 is used. In total, 20 annual reports of automotive companies were analysed. The results show that automotive companies, especially Original Equipment Manufacturers (OEMs) and listed suppliers, have committed to value-oriented management and have implemented value-oriented approaches. However, not all of the suppliers are communicating this in their reports. The results also show that Economic Value Added (EVA) is the leading key indicator in the automotive industry

    Separation – integration – and now …? - An historical perspective on the relationship between German management accounting and financial accounting

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    German accounting has traditionally followed a dual ledger approach with strictly separated internal cost accounting, as the basis for management information, and external financial accounting focusing on creditor protection and based on the commercial law. However, the increased adoption of integrated accounting system implies a significant change in the relationship between financial and management accounting systems. We use Hegelian dialectic to trace the historical development of German accounting from separated systems towards antithetical propositions of full integration, and the emergence of partial integration as the synthesis of this transformation process. For this reason, our paper provides a comprehensive analysis of the literature on the relationship between financial and management accounting in Germany. On this basis, we elaborate how financial accounting in Germany has been shaped by its economic context and legislation, and how financial accounting – accompanied by institutional pressures – in turn influenced management accounting. We argue that the changing relationship between management and financial accounting in the German context illustrates how current accounting practice is shaped not only by its environment, but also by its historical path. Based on this reasoning, we discuss several avenues for future research

    Gender-Specific Modulation of the Response to Arterial Injury by Soluble Guanylate Cyclase α1

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    Objective: Soluble guanylate cyclase (sGC), a heterodimer composed of α and β subunits, synthesizes cGMP in response to nitric oxide (NO). NO modulates vascular tone and structure but the relative contributions of cGMP-dependent versus cGMP-independent mechanisms remain uncertain. We studied the response to vascular injury in male (M) and female (F) mice with targeted deletion of exon 6 of the sGCα1 subunit (sGCα1-/-), resulting in a non-functional heterodimer. Methods: We measured aortic cGMP levels and mRNA transcripts encoding sGC α1, α2, and β1 subunits in wild type (WT) and sGCa1-/- mice. To study the response to vascular injury, BrdU-incorporation and neointima formation (maximum intima to media (I/M) ratio) were determined 5 and 28 days after carotid artery ligation, respectively. Results: Aortic cGMP levels were 4-fold higher in F than in M mice in both genotypes, and, within each gender, 4-fold higher in WT than in sGCa1-/-. In contrast, sGCα1, sGCα2, and sGCβ1 mRNA expression did not differ between groups. 3H-thymidine incorporation in cultured sGCa1-/- smooth muscle cells (SMC) was 27%±12% lower than in WT SMC and BrdU-incorporation in carotid arteries 5 days after ligation was significantly less in sGCa1-/- M than in WT M. Neointima area and I/M 28 days after ligation were 65% and 62% lower in sGCa1-/- M than in WT M mice (p<0,05 for both) but were not different in F mice. Conclusion: Functional deletion of sGCa1 resulted in reduced cGMP levels in male sGCa1-/- mice and a gender-specific effect on the adaptive response to vascular injury

    Who Uses Financial Reports and for What Purpose? Evidence from Capital Providers

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