262 research outputs found
Fragments of ML decidable by nested data class memory automata
The call-by-value language RML may be viewed as a canonical restriction of Standard ML to ground-type references, augmented by a “bad variable” construct in the sense of Reynolds. We consider the fragment of (finitary) RML terms of order at most 1 with free variables of order at most 2, and identify two subfragments of this for which we show observational equivalence to be decidable. The first subfragment, RMLP−Str2⊢1, consists of those terms in which the P-pointers in the game semantic representation are determined by the underlying sequence of moves. The second subfragment consists of terms in which the O-pointers of moves corresponding to free variables in the game semantic representation are determined by the underlying moves. These results are shown using a reduction to a form of automata over data words in which the data values have a tree-structure, reflecting the tree-structure of the threads in the game semantic plays. In addition we show that observational equivalence is undecidable at every third- or higher-order type, every second-order type which takes at least two first-order arguments, and every second-order type (of arity greater than one) that has a first-order argument which is not the final argument
Fragments of ML Decidable by Nested Data Class Memory Automata
The call-by-value language RML may be viewed as a canonical restriction of
Standard ML to ground-type references, augmented by a "bad variable" construct
in the sense of Reynolds. We consider the fragment of (finitary) RML terms of
order at most 1 with free variables of order at most 2, and identify two
subfragments of this for which we show observational equivalence to be
decidable. The first subfragment consists of those terms in which the
P-pointers in the game semantic representation are determined by the underlying
sequence of moves. The second subfragment consists of terms in which the
O-pointers of moves corresponding to free variables in the game semantic
representation are determined by the underlying moves. These results are shown
using a reduction to a form of automata over data words in which the data
values have a tree-structure, reflecting the tree-structure of the threads in
the game semantic plays. In addition we show that observational equivalence is
undecidable at every third- or higher-order type, every second-order type which
takes at least two first-order arguments, and every second-order type (of arity
greater than one) that has a first-order argument which is not the final
argument
A mixed-methods evaluation of a dementia education program for hospital staff and volunteers in Melbourne, Australia
People with dementia have a high likelihood of being hospitalized at some point during the disease process. Recent research has found that more can be done to improve dementia care in hospitals. One of the strategies suggested to help achieve this objective is to provide dementia education programs to hospital staff. Such programs have the potential to improve the knowledge, attitudes, and skills of staff in caring for people with dementia to optimize their in-hospital experiences and clinical outcomes. This paper reports a mixed-methods evaluation of a dementia education program delivered to staff at a hospital in Melbourne, Australia. The quantitative evaluation found significant improvements in participant’s knowledge of dementia but did not show significant improvements in “social comfort,” a measure of how comfortable respondents are around people with dementia. Qualitative interview data supported the quantitative finding regarding improvements in knowledge about dementia and demonstrated participants were largely satisfied with the content of the education program. However, qualitative data also indicated a problem with engagement with some non-clinical staff. There is a need to improve the quality of care for patients with dementia in hospitals, and this study shows that a dementia education program can be effective in improving staff knowledge about people with dementia
Kolmogorov Complexity, Circuits, and the Strength of Formal Theories of Arithmetic
Can complexity classes be characterized in terms of efficient reducibility to the (undecidable) set of Kolmogorov-random strings? Although this might seem improbable, a series of papers has recently provided evidence that this may be the case. In particular, it is known that there is a class of problems C defined in terms of polynomial-time truth-table reducibility to RK (the set of Kolmogorov-random strings) that lies between BPP and PSPACE [4, 3]. In this paper, we investigate improving this upper bound from PSPACE to PSPACE ∩ P/poly. More precisely, we present a collection of true statements in the language of arithmetic, (each provable in ZF) and show that if these statements can be proved in certain extensions of Peano arithmetic, then BPP ⊆C⊆PSPACE ∩ P/poly. We conjecture that C is equal to P, and discuss the possibility this might be an avenue for trying to prove the equality of BPP and P
Household reporting of childhood respiratory health and air pollution in rural Alaska Native communities
Background. Air pollution is an important contributor to respiratory disease in children.
Objective. To examine associations between household reporting of childhood respiratory conditions and household characteristics related to air pollution in Alaska Native communities.
Design. In-home surveys were administered in 2 rural regions of Alaska. The 12-month prevalence of respiratory conditions was summarized by region and age. Odds ratios (ORs) were calculated to describe associations between respiratory health and household and air quality characteristics.
Results. Household-reported respiratory health data were collected for 561 children in 328 households. In 1 region, 33.6% of children aged/or bronchitis. Children with these conditions were 2 times more likely to live in a wood-heated home, but these findings were imprecise. Resident concern with mould was associated with elevated prevalence of respiratory infections in children (ORs 1.6–2.5), while reported wheezing was associated with 1 or more smokers living in the household. Reported asthma in 1 region (7.6%) was lower than national prevalence estimates.
Conclusions. Findings suggest that there may be preventable exposures, including wood smoke and mould that affect childhood respiratory disease in these rural areas. Additional research is needed to quantify particulate matter 2.5 microns in aerodynamic diameter or less and mould exposures in these communities, and to objectively evaluate childhood respiratory health
Congestive Heart Failure Patient Education Intervention to Address 30 Day CHF Readmission
Introduction. The ACA Hospital Readmissions Reduction Program recently cut reimbursement for 30 day readmissions. Risk-adjusted congestive heart failure (CHF) 30-day readmission rate at Fletcher Allen Health Care (FAHC) in 2012 approached 22.2% among Medicare patients.https://scholarworks.uvm.edu/comphp_gallery/1203/thumbnail.jp
Sexual Signal Evolution Outpaces Ecological Divergence during Electric Fish Species Radiation
Natural selection arising from resource competition and environmental heterogeneity can drive adaptive radiation. Ecological opportunity facilitates this process, resulting in rapid divergence of ecological traits in many celebrated radiations. In other cases, sexual selection is thought to fuel divergence in mating signals ahead of ecological divergence. Comparing divergence rates between naturally and sexually selected traits can offer insights into processes underlying species radiations, but to date such comparisons have been largely qualitative. Here, we quantitatively compare divergence rates for four traits in African mormyrid fishes, which use an electrical communication system with few extrinsic constraints on divergence. We demonstrate rapid signal evolution in the Paramormyrops species flock compared to divergence in morphology, size, and trophic ecology. This disparity in the tempo of trait evolution suggests that sexual selection is an important early driver of species radiation in these mormyrids. We also found slight divergence in ecological traits among closely related species, consistent with a supporting role for natural selection in Paramormyrops diversification. Our results highlight the potential for sexual selection to drive explosive signal divergence when innovations in communication open new opportunities in signal space, suggesting that opportunity can catalyze species radiations through sexual selection, as well as natural selection
Egalitarianism in surgical training: let equity prevail
This study aimed to quantify core surgical trainee (CST) differential attainment (DA) related to three cohorts; white UK graduate (White UKG) versus black and minority ethnic UKG (BME UKG) versus international medical graduates (IMGs). The primary outcome measures were annual review of competence progression (ARCP) outcome, intercollegiate Membership of the Royal College of Surgeons (iMRCS) examination pass and national training number (NTN) selection. Intercollegiate Surgical Curriculum Programme (ISCP) portfolios of 264 consecutive CSTs (2010–2017, 168 white UKG, 66 BME UKG, 30 IMG) from a single UK regional post graduate medical region (Wales) were examined. Data collected prospectively over an 8-year time period was analysed retrospectively. ARCP outcomes were similar irrespective of ethnicity or nationality (ARCP outcome 1, white UKG 60.7% vs BME UKG 62.1% vs IMG 53.3%, p=0.395). iMRCS pass rates for white UKG vs BME UKG vs IMG were 71.4% vs 71.2% vs 50.0% (p=0.042), respectively. NTN success rates for white UKG vs BME UKG vs IMG were 36.9% vs 36.4% vs 6.7% (p=0.023), respectively. On multivariable analysis, operative experience (OR 1.002, 95% CI 1.001 to 1.004, p=0.004), bootcamp attendance (OR 2.615, 95% CI 1.403 to 4.871, p=0.002), and UKG (OR 7.081, 95% CI 1.556 to 32.230, p=0.011), were associated with NTN appointment. Although outcomes related to BME DA were equitable, important DA variation was apparent among IMGs, with iMRCS pass 21.4% lower and NTN success sixfold less likely than UKG. Targeted counter measures are required to let equity prevail in UK CST programmes
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