University of Nice Sophia Antipolis

About: University of Nice Sophia Antipolis is a education organization based out in Nice, France. It is known for research contribution in the topics: Population & Stars. The organization has 10291 authors who have published 19964 publications receiving 680762 citations. The organization is also known as: UNS & University of Nice-Sophia Antipolis.

Automatic test data generation using constraint solving techniques

Abstract: Automatic test data generation leads to identify input values on which a selected point in a procedure is executed. This paper introduces a new method for this problem based on constraint solving techniques. First, we statically transform a procedure into a constraint system by using well-known "Static Single Assignment" form and control-dependencies. Second, we solve this system to check whether at least one feasible control flow path going through the selected point exists and to generate test data that correspond to one of these paths.The key point of our approach is to take advantage of current advances in constraint techniques when solving the generated constraint system. Global constraints are used in a preliminary step to detect some of the non feasible paths. Partial consistency techniques are employed to reduce the domains of possible values of the test data. A prototype implementation has been developped on a restricted subset of the C language. Advantages of our approach are illustrated on a non-trivial example.

Ecological genetics of invasive alien species

Abstract: There is growing realisation that integrating genetics and ecology is critical in the context of biological invasions, since the two are explicitly linked. So far, the focus of ecological genetics of invasive alien species (IAS) has been on determining the sources and routes of invasions, and the genetic make-up of founding populations, which is critical for defining and testing ecological and evolutionary hypotheses. However an ecological genetics approach can be extended to investigate questions about invasion success and impacts on native, recipient species. Here, we discuss recent progress in the field, provide overviews of recent methodological advances, and highlight areas that we believe are of particular interest for future research. First, we discuss the main insights from studies that have inferred source populations and invasion routes using molecular genetic data, with particular focus on the role of genetic diversity, adaptation and admixture in invasion success. Second, we consider how genetic tools can lead to a better understanding of patterns of dispersal, which is critical to predicting the spread of invasive species, and how studying invasions can shed light on the evolution of dispersal. Finally, we explore the potential for combining molecular genetic data and ecological network modelling to investigate community interactions such as those between predator and prey, and host and parasite. We conclude that invasions are excellent model systems for understanding the role of natural selection in shaping phenotypes and that an ecological genetics approach offers great potential for addressing fundamental questions in invasion biology.

Capital Structure and Firm Efficiency

Abstract: This paper investigates the relationship between firm efficiency and leverage. We consider both the effect of leverage on firm performance as well as the reverse causality relationship. In particular, we address the following questions: Does higher leverage lead to better firm performance? Does efficiency exert a significant effect on leverage over and above that of traditional financial measures of capital structure? Is the effect of efficiency on leverage similar across different capital structures? What is the signalling role of efficiency to creditors or investors? Using a sample of 12,240 New Zealand firms we find evidence supporting the theoretical predictions of the Jensen and Meckling (1976) agency cost model. Efficiency measured as the distance from the industry's ‘best practice’ production frontier is positively related to leverage over the entire range of observed data. The frontier is constructed using the non-parametric Data Envelopment Analysis (DEA) method. Using quantile regression analysis we show that the reverse causality effect of efficiency on leverage is positive at low to mid-leverage levels and negative at high leverage ratios. Firm size also has a non-monotonic effect on leverage: negative at low debt ratios and positive at mid to high debt ratios. The effect of tangibles and profitability on leverage is positive while intangibles and other assets are negatively related to leverage.

Significant and persistent impact of timber harvesting on soil microbial communities in Northern coniferous forests

Abstract: Forest ecosystems have integral roles in climate stability, biodiversity and economic development. Soil stewardship is essential for sustainable forest management. Organic matter (OM) removal and soil compaction are key disturbances associated with forest harvesting, but their impacts on forest ecosystems are not well understood. Because microbiological processes regulate soil ecology and biogeochemistry, microbial community structure might serve as indicator of forest ecosystem status, revealing changes in nutrient and energy flow patterns before they have irreversible effects on long-term soil productivity. We applied massively parallel pyrosequencing of over 4.6 million ribosomal marker sequences to assess the impact of OM removal and soil compaction on bacterial and fungal communities in a field experiment replicated at six forest sites in British Columbia, Canada. More than a decade after harvesting, diversity and structure of soil bacterial and fungal communities remained significantly altered by harvesting disturbances, with individual taxonomic groups responding differentially to varied levels of the disturbances. Plant symbionts, like ectomycorrhizal fungi, and saprobic taxa, such as ascomycetes and actinomycetes, were among the most sensitive to harvesting disturbances. Given their significant ecological roles in forest development, the fate of these taxa might be critical for sustainability of forest ecosystems. Although abundant bacterial populations were ubiquitous, abundant fungal populations often revealed a patchy distribution, consistent with their higher sensitivity to the examined soil disturbances. These results establish a comprehensive inventory of bacterial and fungal community composition in northern coniferous forests and demonstrate the long-term response of their structure to key disturbances associated with forest harvesting.

Mitochondrial control of caspase-dependent and -independent cell death.

Abstract: Mitochondria control whether a cell lives or dies. The role mitochondria play in deciding the fate of a cell was first identified in the mid-1990s, because mitochondria-enriched fractions were found to be necessary for activation of death proteases, the caspases, in a cell-free model of apoptotic cell death. Mitochondrial involvement in apoptosis was subsequently shown to be regulated by Bcl-2, a protein that was known to contribute to cancer in specific circumstances. The important role of mitochondria in promoting caspase activation has therefore been a major focus of apoptosis research; however, it is also clear that mitochondria contribute to cell death by caspase-independent mechanisms. In this review, we will highlight recent findings and discuss the mechanism underlying the mitochondrial control of apoptosis and caspase-independent cell death.