The Complexity of Reasoning for Fragments of Autoepistemic Logic

Autoepistemic logic extends propositional logic by the modal operator L. A formula that is preceded by an L is said to be "believed". The logic was introduced by Moore 1985 for modeling an ideally rational agent's behavior and reasoning about his own beliefs. In this paper we analyze all Boolean fragments of autoepistemic logic with respect to the computational complexity of the three most common decision problems expansion existence, brave reasoning and cautious reasoning. As a second contribution we classify the computational complexity of counting the number of stable expansions of a given knowledge base. To the best of our knowledge this is the first paper analyzing the counting problem for autoepistemic logic

The costs and benefits of European immigration

In the early 21st century Europe is confronted with an ageing population, stagnating or even declining native populations, high unemployment and in the most key countries also with slow economic growth. At the same time Europe remains one of the prime destinations of international migration. Free movement of people is a means of creating an integrated Europe. Geographic mobility also helps on establishing a more efficient labour market, to the long-term benefit of workers, employers, taxpayers and EU Member States. Thus, our paper quantifies current migration patterns (see pp. 14-15); it recollects theoretical (see pp. 16-27) and empirical arguments (see pp. 28-47) on why immigration is so important, to what extent labour mobility allows individuals to improve their job prospects and employers to recruit people with adequate skills. The paper also discusses what kind of common European policies should be undertaken to optimise benefits of international migration. All our findings might not only avail understanding the economic impact of immigration. But they have policy implications for migrant receiving countries in Europe as well. The aim is to develop a better understanding of how the EU and its Member States could use availability and skills of today's and future immigrant populations in order to cope with economic and demographic challenges. --

Secondary instability of stratified Ekman layer roll vortices

see pdf fil

CIARD Activities in the CGIAR: Final Report on activities, outputs and lessons from the implementation of the CIARD grant to the CGIAR

CIARD activities for the CGIAR have been led by the CGIAR ICT-KM program, which has worked closely with scientists, researchers, research managers and information and communication specialists across the CGIAR: Centers, Programs and projects. This document reports on activities implemented by the CGIAR ICT-KM program through a grant (PO245548) from FAO, originally from the DFID CIARD grant, but is based on activities being undertaken by Centres, Programs and projects of the CGIAR. Special acknowledgement and appreciation is given to ILRI for hosting the CIARD CGIAR grant coordinator and its great support to learning, documentation and promotion of CIARD principles and pathways

Dramatic expansion of the black widow toxin arsenal uncovered by multi-tissue transcriptomics and venom proteomics.

BackgroundAnimal venoms attract enormous interest given their potential for pharmacological discovery and understanding the evolution of natural chemistries. Next-generation transcriptomics and proteomics provide unparalleled, but underexploited, capabilities for venom characterization. We combined multi-tissue RNA-Seq with mass spectrometry and bioinformatic analyses to determine venom gland specific transcripts and venom proteins from the Western black widow spider (Latrodectus hesperus) and investigated their evolution.ResultsWe estimated expression of 97,217 L. hesperus transcripts in venom glands relative to silk and cephalothorax tissues. We identified 695 venom gland specific transcripts (VSTs), many of which BLAST and GO term analyses indicate may function as toxins or their delivery agents. ~38% of VSTs had BLAST hits, including latrotoxins, inhibitor cystine knot toxins, CRISPs, hyaluronidases, chitinase, and proteases, and 59% of VSTs had predicted protein domains. Latrotoxins are venom toxins that cause massive neurotransmitter release from vertebrate or invertebrate neurons. We discovered ≥ 20 divergent latrotoxin paralogs expressed in L. hesperus venom glands, significantly increasing this biomedically important family. Mass spectrometry of L. hesperus venom identified 49 proteins from VSTs, 24 of which BLAST to toxins. Phylogenetic analyses showed venom gland specific gene family expansions and shifts in tissue expression.ConclusionsQuantitative expression analyses comparing multiple tissues are necessary to identify venom gland specific transcripts. We present a black widow venom specific exome that uncovers a trove of diverse toxins and associated proteins, suggesting a dynamic evolutionary history. This justifies a reevaluation of the functional activities of black widow venom in light of its emerging complexity

Investigating long-term lifestyles changes in France: a statistical and modelling approach

International audienceAs lifestyles relate to our ways of "doing" , "having" , "using" and "displaying" , our behaviour and all of the related products, objects and infrastructures (Røpke, 2009), they are both a broad and complex object of thought and a key determinant of the sustainability of our societies. Conducted in a qualitative way, the analysis of future lifestyles offers great freedom to imagine dramatic changes of societies and to explore paradigm shifts. These changes could result from the widespread of various existing behaviours considered today as weak signals or from the emergence of social movements of great magnitude. Performing a quantitative analysis is less straightforward and could be conceptually questioned. Yet for the specific problem of sustainable lifestyles a quantitative approach can help ground the scenarios not only on technical solutions but also on elements of lifestyles change. What is missing is a quantitative method to define the possible long term impact of lifestyle change on mobility, housing and consumption patterns. In this paper we introduce a statistical model that we developed especially to address long-term lifestyles changes and their consequences on the consumption of goods and services and on the energy services demand in France. We make use of national mobility housing and consumption surveys to identify significant patterns. We propose a model of their diffusion in the long term according while also taking into account the demographic changes. Our contribution is organised as follows: we first describe the statistical model and the surveys; then an application to future societal trends is proposed in a prospective approach. A set of lifestyles anticipated for France in 2050 that explore various changes are considered. Finally we aim to discuss the contributions and limitations of the proposed quantitative model and how it can fit into futures thinking