1,538 research outputs found
Do we need dynamic semantics?
I suspect the answer to the question in the title of this paper is no. But
the scope of my paper will be considerably more limited: I will be concerned
with whether certain types of considerations that are commonly cited in
favor of dynamic semantics do in fact push us towards a dynamic semantics.
Ultimately, I will argue that the evidence points to a dynamics of discourse
that is best treated pragmatically, rather than as part of the semantics
Dynamic Semantics
This article focuses on foundational issues in dynamic and static semantics, specifically on what is conceptually at stake between the dynamic framework and the truth-conditional framework, and consequently what kinds of evidence support each framework. The article examines two questions. First, it explores the consequences of taking the proposition as central semantic notion as characteristic of static semantics, and argues that this is not as limiting in accounting for discourse dynamics as many think. Specifically, it explores what it means for a static semantics to incorporate the notion of context change potential in a dynamic pragmatics and denies that this conception of static semantics requires that all updates to the context be eliminative and distributive. Second, it argues that the central difference between the two frameworks is whether semantics or pragmatics accounts for dynamics, and explores what this means for the oft-heard claim that dynamic semantics blurs the semantics/pragmatics distinction
Community health club and its application for health promotion and community building in Matazano, Guatemala
This article was published in the Spring 2014 issue of the Journal of Undergraduate Researc
Telomerase and Telomere-Associated Proteins: Structural Insights into Mechanism and Evolution
SummaryRecent advances in our structural understanding of telomerase and telomere-associated proteins have contributed significantly to elucidating the molecular mechanisms of telomere maintenance. The structures of telomerase TERT domains have provided valuable insights into how experimentally identified conserved motifs contribute to the telomerase reverse transcriptase reaction. Additionally, structures of telomere-associated proteins in a variety of organisms have revealed that, across evolution, telomere-maintenance mechanisms employ common structural elements. For example, the single-stranded 3′ overhang of telomeric DNA is specifically and tightly bound by an OB-fold in nearly all species, including ciliates (TEBP and Pot1a), fission yeast (SpPot1), budding yeast (Cdc13), and humans (hPOT1). Structures of the yeast Cdc13, Stn1, and Ten1 proteins demonstrated that telomere maintenance is regulated by a complex that bears significant similarity to the RPA heterotrimer. Similarly, proteins that specifically bind double-stranded telomeric DNA in divergent species use homeodomains to execute their functions (human TRF1 and TRF2 and budding yeast ScRap1). Likewise, the conserved protein Rap1, which is found in budding yeast, fission yeast, and humans, contains a structural motif that is known to be critical for protein-protein interaction. In addition to revealing the common underlying themes of telomere maintenance, structures have also elucidated the specific mechanisms by which many of these proteins function, including identifying a telomere-specific domain in Stn1 and how the human TRF proteins avoid heterodimerization. In this review, we summarize the high-resolution structures of telomerase and telomere-associated proteins and discuss the emergent common structural themes among these proteins. We also address how these high-resolution structures complement biochemical and cellular studies to enhance our understanding of telomere maintenance and function
Protocol for the effective feedback to improve primary care prescribing safety (EFIPPS) study : a cluster randomised controlled trial using ePrescribing data
High-risk prescribing in primary care is common and causes considerable harm. Feedback interventions to improve care are attractive because they are relatively cheap to widely implement. There is good evidence that feedback has small to moderate effects, but the most recent Cochrane review called for more high-quality, large trials that explicitly test different forms of feedback. The study is a three-arm cluster-randomised trial with general practices being randomised and outcomes measured at patient level. 262 practices in three Scottish Health Board areas have been randomised (94% of all possible practices). The two active arms receive different forms of prescribing safety data feedback, with rates of high-risk prescribing compared with a ‘usual care’ arm. Sample size estimation used baseline data from participating practices. With 85 practices randomised to each arm, then there is 93% power to detect a 25% difference in the percentage of high-risk prescribing (from 6.1% to 4.5%) between the usual care arm and each intervention arm. The primary outcome is a composite of six high-risk prescribing measures (antipsychotic prescribing to people aged ≥75 years; non-steroidal anti-inflammatory drug (NSAID) prescribing to people aged ≥75 without gastroprotection; NSAID prescribing to people prescribed aspirin/clopidogrel without gastroprotection; NSAID prescribing to people prescribed an ACE inhibitor/angiotensin receptor blocker and a diuretic; NSAID prescription to people prescribed an oral anticoagulant without gastroprotection; aspirin/clopidogrel prescription to people prescribed an oral anticoagulant without gastroprotection). The primary analysis will use multilevel modelling to account for repeated measurement of outcomes in patients clustered within practices. The study was reviewed and approved by the NHS Tayside Committee on Medical Research Ethics B (11/ES/0001). The study will be disseminated via a final report to the funder with a publicly available research summary, and peer reviewed publications
Determination of the Corrosive Conditions Present within Aircraft Lap-Splice Joints
The complexity of airframe structure lends itself to damage resulting from crevice corrosion. Fuselage lap-splice joints are a particularly important structural detail in this regard because of the difficulty associated with detection and measurement of corrosion in these occluded regions. The objective of this work is to develop a laboratory corrosion test protocol to identify the chemistry to which lap joints are exposed and to develop a model of the corrosion within the joints. A protocol for collecting and identifying the chemistry of airframe crevice corrosion has been developed. Capillary electrophoresis (CE) is used to identify the ionic species contained in corrosion product samples removed from fuselage lap splice joints. CE analysis has been performed on over sixty corrosion product samples removed from both civilian and military aircraft. Over twenty different ions have been detected. Measurements of pH of wetted corroded surfaces indicated an alkaline occluded solution. After determining the species present and their relative concentrations, the resultant solution was reproduced in bulk and electrochemical tests were performed to determine the corrosion rate. Electrochemical analyses of the behavior of AA2024-T3 in these solutions gave corrosion rates of up to 250 microns per year (10 mpy). Additional tests have determined the relative importance of each of the detected ions in model solutions used for future predictive tests. The statistically significant ions have been used to create a second generation solution. Laboratory studies have also included exposure tests involving artificial lap joints exposed to various simulated bulk and crevice environments. The extent and morphology of the attack in artificial lap joints has been compared to studies of corroded samples from actual aircraft. Other effects, such as temperature and potential, as well as the impact of the environment on fatigue crack growth have also been studied
On the Substitution of Identicals in Counterfactual Reasoning
It is widely held that counterfactuals, unlike attitude ascriptions, preserve the referential transparency of their constituents, i.e., that counterfactuals validate the substitution of identicals when their constituents do. The only putative counterexamples in the literature come from counterpossibles, i.e., counterfactuals with impossible antecedents. Advocates of counterpossibilism, i.e., the view that counterpossibles are not all vacuous, argue that counterpossibles can generate referential opacity. But in order to explain why most substitution inferences into counterfactuals seem valid, counterpossibilists also often maintain that counterfactuals with possible antecedents are transparency‐preserving. I argue that if counterpossibles can generate opacity, then so can ordinary counterfactuals with possible antecedents. Utilizing an analogy between counterfactuals and attitude ascriptions, I provide a counterpossibilist‐friendly explanation for the apparent validity of substitution inferences into counterfactuals. I conclude by suggesting that the debate over counterpossibles is closely tied to questions concerning the extent to which counterfactuals are more like attitude ascriptions and epistemic operators than previously recognized
Rapid Population Decline of the Pillar Coral Dendrogyra cylindrus Along the Florida Reef Tract
Coral reefs worldwide are in a state of decline, but the population status and impacts of stressors for rare species are generally not well documented using broad-scale monitoring protocols. We fate-tracked all known colonies of the pillar coral, Dendrogyra cylindrus, on the Florida Reef Tract (FRT) from 2013 to 2020 to assess population condition and trend, and to document the relative impacts of chronic and acute stressors. Large average colony size, an absence of juveniles, and large geographic distances between genotypes suggest that the Florida D. cylindrus population has been reproductively extinct for decades. During the study period, low-intensity chronic stressors were balanced by regrowth, while back-to-back years of coral bleaching and thermally-exacerbated disease led to declines that the subsequent recovery rates suggest would require 11 uninterrupted years to overcome. The most recent stressor on Florida’s D. cylindrus population is “stony coral tissue loss disease” (SCTLD). Following the appearance of the disease in Florida in 2014, unrecoverable losses occurred within the D. cylindrus population as tissue, colonies, and whole genotypes suffered complete mortality. Losses of 94% of coral tissue, 93% of colonies, and 86% of genotypes between 2014 and the end of 2020 have led to functional extinction of D. cylindrus on the FRT
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