61 research outputs found
A Separation Logic for a Promising Semantics
We present SLR, the first expressive program logic for reason- ing about concurrent programs under a weak memory model addressing the out-of-thin-air problem. Our logic includes the standard features from existing logics, such as RSL and GPS, that were previously known to be sound only under stronger memory models: (1) separation, (2) per-location invariants, and (3) ownership transfer via release-acquire synchronisationâas well as novel features for reasoning about (4) the absence of out-of-thin-air behaviours and (5) coherence. The logic is proved sound over the recent âpromisingâ memory model of Kang et al., using a substantially different argument to soundness proofs of logics for simpler memory models.The research was supported in part by the Danish Council for Independent Research (project DFF â 4181-00273), by a European Research Council Consolidator Grant for the project âRustBeltâ (grant agreement no. 683289), and by Len Blavatnik and the Blavatnik Family foundation
Transfinite Step-Indexing: Decoupling Concrete and Logical Steps
International audienceStep-indexing has proven to be a powerful technique for defining logical relations for languages with advanced type systems and models of expressive program logics. In both cases, the model is stratified using natural numbers to solve a recursive equation that has no naive solutions. As a result of this stratification, current models require that each unfolding of the recursive equation â each logical step â must coincide with a concrete reduction step. This tight coupling is problematic for applications where the number of logical steps cannot be statically bounded. In this paper we demonstrate that this tight coupling between logical and concrete steps is artificial and show how to loosen it using transfinite step-indexing. We present a logical relation that supports an arbitrary but finite number of logical steps for each concrete step
Risk factors Associated with <em>Mycoplasma bovis</em> disease in Danish dairy herds 2010-2014
The Danish respiratory society guideline for long-term high flow nasal cannula treatment, with or without supplementary oxygen
Myocardial Work in Patients Hospitalized With COVIDâ19:Relation to Biomarkers, COVIDâ19 Severity, and AllâCause Mortality
BACKGROUND: COVIDâ19 infection has been hypothesized to affect left ventricular function; however, the underlying mechanisms and the association to clinical outcome are not understood. The global work index (GWI) is a novel echocardiographic measure of systolic function that may offer insights on cardiac dysfunction in COVIDâ19. We hypothesized that GWI was associated with disease severity and allâcause death in patients with COVIDâ19. METHODS AND RESULTS: In a multicenter study of patients admitted with COVIDâ19 (n=305), 249 underwent pressureâstrain loop analyses to quantify GWI at a median time of 4âdays after admission. We examined the association of GWI to cardiac biomarkers (troponin and NTâproBNP [Nâterminal proâBâtype natriuretic peptide]), disease severity (oxygen requirement and CRP [Câreactive protein]), and allâcause death. Patients with elevated troponin (n=71) exhibited significantly reduced GWI (1508 versus 1707âmmâHg%; P=0.018). A curvilinear association to NTâproBNP was observed, with increasing NTâproBNP once GWI decreased below 1446âmmâHg%. Moreover, GWI was significantly associated with a higher oxygen requirement (relative increase of 6% per 100âmmâHg% decrease). No association was observed with CRP. Of the 249 patients, 37 died during followâup (median, 58âdays). In multivariable Cox regression, GWI was associated with allâcause death (hazard ratio, 1.08 [95% CI, 1.01â1.15], per 100âmmâHg% decrease), but did not increase Câstatistics when added to clinical parameters. CONCLUSIONS: In patients admitted with COVIDâ19, our findings indicate that NTâproBNP and troponin may be associated with lower GWI, whereas CRP is not. GWI was independently associated with allâcause death, but did not provide prognostic information beyond readily available clinical parameters. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04377035
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