391 research outputs found
Speciation‐by‐Depth on Coral Reefs: Sympatric Divergence with Gene Flow or Cryptic Transient Isolation?
The distributions of many sister species in the sea overlap geographically but are partitioned along depth gradients. The genetic changes leading to depth segregation may evolve in geographic isolation as a prerequisite to coexistence or may emerge during primary divergence leading to new species. These alternatives can now be distinguished via the power endowed by the thousands of scorable loci provided by second‐generation sequence data. Here, we revisit the case of two depth‐segregated, genetically isolated ecotypes of the nominal Caribbean candelabrum coral Eunicea flexuosa. Previous analyses based on a handful of markers could not distinguish between models of genetic exchange after a period of isolation (consistent with secondary contact) and divergence with gene flow (consistent with primary divergence). Analyses of the history of isolation, genetic exchange and population size based on 15,640 new SNP markers derived from RNAseq data best support models where divergence began 800K BP and include epochs of divergence with gene flow, but with an intermediate period of transient isolation. Results also supported the previous conclusion that recent exchange between the ecotypes occurs asymmetrically from the Shallow lineage to the Deep. Parallel analyses of data from two other corals with depth‐segregated populations (Agaricia fragilis and Pocillopora damicornis) suggest divergence leading to depth‐segregated populations may begin with a period of symmetric exchange, but that an epoch of population isolation precedes more complete isolation marked by asymmetric introgression. Thus, while divergence‐with‐gene flow may account for much of the differentiation that separates closely related, depth‐segregated species, it remains to be seen whether any critical steps in the speciation process only occur when populations are isolated
POPLMark reloaded: Mechanizing proofs by logical relations
We propose a new collection of benchmark problems in mechanizing the metatheory of programming languages, in order to compare and push the state of the art of proof assistants. In particular, we focus on proofs using logical relations (LRs) and propose establishing strong normalization of a simply typed calculus with a proof by Kripke-style LRs as a benchmark. We give a modern view of this well-understood problem by formulating our LR on well-typed terms. Using this case study, we share some of the lessons learned tackling this problem in different dependently typed proof environments. In particular, we consider the mechanization in Beluga, a proof environment that supports higher-order abstract syntax encodings and contrast it to the development and strategies used in general-purpose proof assistants such as Coq and Agda. The goal of this paper is to engage the community in discussions on what support in proof environments is needed to truly bring mechanized metatheory to the masses and engage said community in the crafting of future benchmarks
The deindustrialisation/tertiarisation hypothesis reconsidered: a subsystem application to the OECD7
The diffusion of outsourcing, both national and international, and
vertical FDIs among manufacturing firms, along with the higher integra-
tion of business services in manufacturing, has recently led to question
the empirical evidence supporting the Deindustrialisation/Tertiarisation
(DT) hypothesis. Rather than a \real" phenomenon, it has been argued,
DT would be an \apparent" one, mainly due to the reorganization of
production across national and sectoral boundaries.
The empirical studies that have dealt with the topic so far have
not been able to effectively rule out such possibility, because of two
main limitations: the sectoral level of the analysis and/or the national
focus. In order to overcome them, the paper carries out an appreciative
investigation of the actual extent of the DT occurred in the OECD
area over the '80s and the '90s by moving from a sector to a subsystem
perspective, thus retaining both direct and indirect relations, and by
referring to a \pseudo-World" of 7 OECD countries, thus taking into
account the \global" dimension of the phenomenon.
The results strongly support the DT hypothesis: although the weight
of business sector services in the manufacturing subsystem increased,
acting as a counterbalancing tendency to the manufacturing decline,
subsystem shares significantly decreased, thus confirming DT as a more
fundamental trend of modern economies
Outsourcing and structural change: shifting firm and sectoral boundaries
The paper aims at investigating the structural change implications of
outsourcing. In trying to bridge the organizational/industrial and the
sectoral/structural analysis of outsourcing, it discusses the rational and
the methodological pros and cons of a “battery” of outsourcing measurements
for structural change analysis. Their functioning is then illustrated
through a concise application of them to the OECD area over the ’80s and
the early ’90s. A combined used of them emerges as recommendable in
checking for the role of outsourcing with respect to that of other structural
change determinants
Mobile resource guarantees (evaluation paper)
This paper summarises the main outcomes of the Mobile Resource Guarantees (MRG) project, which focused on a proof-carrying-code (PCC) infrastructure for resources to be applied to mobile code. MRG was a three year project funded by the EC under the FET proactive initiative on Global Computing. We give an overview of the projects\u2019 results, discuss the lessons learnt from it and introduce follow-up work in new projects that will build on these results
HLA-class I markers and multiple sclerosis susceptibility in the Italian population
Previous studies reported an association with multiple sclerosis (MS) of distinct HLA-class I markers, namely HLA-A*02, HLA-Cw*05 and MOG-142L. In this work, we tested the association with MS of A*02 and Cw*05 in 1273 Italian MS patients and 1075 matched controls, which were previously analyzed for MOG-142, and explored the relationship among these three markers in modulating MS risk. HLA-A*02 conferred a statistically robust MS protection (odds ratio, OR=0.61; 95% confidence intervals, CI=0.51–0.72, P<10−9), which was independent of DRB1*15 and of any other DRB1* allele and remained similar after accounting for the other two analyzed class I markers. Conversely, the protective effect we previously observed for MOG-142L was secondary to its linkage disequilibrium with A*02. Cw*05 was not associated considering the whole sample, but its presence significantly enhanced the protection in the HLA-A*02-positive group, independently of DRB1: the OR conferred by A*02 in Cw*05-positive individuals (0.22, 95% CI=0.13–0.38) was significantly lower than in Cw*05-negative individuals (0.69, 95% CI=0.58–0.83) with a significant (P=4.94 × 10−5) multiplicative interaction between the two markers. In the absence of A*02, Cw*05 behaved as a risk factor, particularly in combination with DRB1*03 (OR=3.89, P=0.0006), indicating that Cw*05 might be a marker of protective or risk haplotypes, respectively
Processos de subjetivação e relações micropolíticas do modo de atenção psicossocial
This article aims to problematize the micropolitical relationships produced in the Psychosocial Care Center (caps), Alegrete-RS, focusing on ethical principles in relation with customers and teamwork, identifying similarities and differences with the propositions of psychosocial care. This study follows a qualitative, descriptive and analytical approach. Interviews were conducted with users and workers, as well as participant observation. Aspects of subjective mobilization, innovation and the creation of relationships that produce ruptures in institutional practices were found, increasing subjectivation, negotiation, agency, resistance, and invention of various relationship and interaction devices in society, producing existential territories in the psychosocial care perspective. Micropolitical relations serve as agents for the production of meaning and the valorization of knowledges and enhancement of knowledge meaning, featuring an ethical stance regarding relationsEl artículo tiene como objetivo problematizar las relaciones micropolíticas producidas en el Centro de Atención Psicosocial (caps) de Alegrete-RS, enfoncando los principios éticos de las relaciones de los trabajadores con la clientela y en el trabajo en equipo, identificando las aproximaciones y los distanciamientos con las propuestas de atención psicosocial. Se trata de un estudio de abordaje cualitativo, descriptivo y analítico. Se realizaron entrevistas con los usuarios y trabajadores, y observación participante. Se encontraron aspectos de movilización subjetiva, innovación y creación de relaciones que producen rupturas en las prácticas institucionales, potencializando la subjetivación, los agenciamientos, las resistencias y la invención de diversos dispositivos de relación e interacción en la sociedad, produciendo territorios existenciales en la perspectiva de la atención psicosocial. Las relaciones micropolíticas trabajan para agenciar procesos de producción de sentido y valorización de los saberes, caracterizando una postura ética en el ámbito de las relacionesO artigo objetiva problematizar as relações micropolíticas produzidas no Centro de Atenção Psicossocial (caps), de Alegrete-RS, com foco nos princípios éticos da relação dos trabalhadores com a clientela e no trabalho em equipe, identificando aproximações e distanciamentos com as proposições da atenção psicossocial. Trata-se de um estudo de abordagem qualitativa, descritiva e analítica. Realizaram-se entrevistas com usuários e trabalhadores, e observação participante. Encontraram-se aspectos de mobilização subjetiva, inovação e criação de relações que produzem rupturas nas práticas institucionais, potencializando subjetivação, agenciamentos, resistências e invenção de dispositivos diversos de relação e interação na sociedade, produzindo territórios existenciais, na perspectiva da atenção psicossocial. As relações micropolíticas trabalham para agenciar processos de produção de sentido e valorização de saberes, caracterizando uma postura ética no âmbito das relaçõe
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