215 research outputs found
Reductio ad discrimen: Where features come from
This paper addresses two fundamental questions about the nature of formal features in phonology and morphosyntax: what is their expressive power, and where do they come from? To answer these questions, we begin with the most restrictive possible hypothesis (all features are privative, and are wholly dictated by Universal Grammar, with no room for cross-linguistic variation), and examine the extent to which empirical evidence from a variety of languages compels a retreat from this position. We argue that there is little to be gained by positing a universal set of specific features, and propose instead that the crucial contribution of UG is the language learner's ability to construct features by identifying correlations between contrasts at different levels of linguistic structure. This view resonates with current research on how the interaction between UG and external 'third factors' shapes the structure of language, while at the same time harking back to the Saussurean notion that contrast is the central function of linguistic representations
Marginal contrasts and the contrastivist hypothesis
Publisher's Version/PDFThe Contrastivist Hypothesis (CH; Hall 2007; Dresher 2009) holds that the only features that can be phonologically active in any language are those that serve to distinguish phonemes, which presupposes that phonemic status is categorical. Many researchers, however, demonstrate the existence of gradient relations. For instance, Hall (2009) quantifies these using the information-theoretic measure of entropy (unpredictability of distribution) and shows that a pair of sounds may have an entropy between 0 (totally predictable) and 1 (totally unpredictable). We argue that the existence of such intermediate degrees of contrastiveness does not make the CH untenable, but rather offers insight into contrastive hierarchies. The existence of a continuum does not preclude categorical distinctions: a categorical line can be drawn between zero entropy (entirely predictable, and thus by the CH phonologically inactive) and non-zero entropy (at least partially contrastive, and thus potentially phonologically active). But this does not mean that intermediate degrees of surface contrastiveness are entirely irrelevant to the CH; rather, we argue, they can shed light on how deeply ingrained a phonemic distinction is in the phonological system. As an example, we provide a case study from Pulaar [ATR] harmony, which has previously been claimed to be problematic for the CH
Planet formation: The case for large efforts on the computational side
Modern astronomy has finally been able to observe protoplanetary disks in
reasonable resolution and detail, unveiling the processes happening during
planet formation. These observed processes are understood under the framework
of disk-planet interaction, a process studied analytically and modeled
numerically for over 40 years. Long a theoreticians' game, the wealth of
observational data has been allowing for increasingly stringent tests of the
theoretical models. Modeling efforts are crucial to support the interpretation
of direct imaging analyses, not just for potential detections but also to put
meaningful upper limits on mass accretion rates and other physical quantities
in current and future large-scale surveys. This white paper addresses the
questions of what efforts on the computational side are required in the next
decade to advance our theoretical understanding, explain the observational
data, and guide new observations. We identified the nature of accretion, ab
initio planet formation, early evolution, and circumplanetary disks as major
fields of interest in computational planet formation. We recommend that
modelers relax the approximations of alpha-viscosity and isothermal equations
of state, on the grounds that these models use flawed assumptions, even if they
give good visual qualitative agreement with observations. We similarly
recommend that population synthesis move away from 1D hydrodynamics. The
computational resources to reach these goals should be developed during the
next decade, through improvements in algorithms and the hardware for hybrid
CPU/GPU clusters. Coupled with high angular resolution and great line
sensitivity in ground based interferometers, ELTs and JWST, these advances in
computational efforts should allow for large strides in the field in the next
decade.Comment: White paper submitted to the Astro2020 decadal surve
Childhood asthma exacerbations and the Arg16 b2-receptor polymorphism: a meta-analysis stratified by treatment
Background: The Gly-to-Arg substitution at the 16 position
(rs1042713) in the b2-adrenoceptor gene (ADRB2) is associated with enhanced downregulation and uncoupling of b2-receptors.
Objectives: We sought to undertake a meta-analysis to test the hypothesis that there is an interaction between the A allele of rs1042713 (Arg16 amino acid) and long-acting b-agonist (LABA) exposure for asthma exacerbations in children.
Methods: Children with diagnosed asthma were recruited in 5
populations (BREATHE, Genes-Environments and Admixture
in Latino Americans II, PACMAN, the Paediatric Asthma Gene
Environment Study, and the Pharmacogenetics of Adrenal
Suppression with Inhaled Steroid Study). A history of recent
exacerbation and asthma treatment was determined from
questionnaire data. DNA was extracted, and the Gly16Arg
genotype was determined.
Results: Data from 4226 children of white Northern European
and Latino origin were analyzed, and the odds ratio for
exacerbation increased by 1.52 (95% CI, 1.17-1.99; P 5 .0021) for each copy of the A allele among the 637 children treated with inhaled corticosteroids (ICSs) plus LABAs but not for treatment with ICSs alone (n 5 1758) or ICSs plus leukotriene receptor antagonist (LTRAs; n 5 354) or ICSs plus LABAs plus LTRAs (n 5 569). Conclusions: The use of a LABA but not an LTRA as an ‘‘addon controller’’ is associated with increased risk of asthma exacerbation in children carrying 1 or 2 A alleles at rs1042713. Prospective genotype-stratified clinical trials are now required to explore the potential role of rs1042713 genotyping for personalized asthma therapy in children. (J Allergy Clin Immunol 201
Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires
The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of , and is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 0.02 \mbox{fb}^{-1}. The bosons are reconstructed in the decays , where denotes muon or electron, while the and quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions
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