Combinatorial Games with a Pass: A dynamical systems approach

By treating combinatorial games as dynamical systems, we are able to address a longstanding open question in combinatorial game theory, namely, how the introduction of a "pass" move into a game affects its behavior. We consider two well known combinatorial games, 3-pile Nim and 3-row Chomp. In the case of Nim, we observe that the introduction of the pass dramatically alters the game's underlying structure, rendering it considerably more complex, while for Chomp, the pass move is found to have relatively minimal impact. We show how these results can be understood by recasting these games as dynamical systems describable by dynamical recursion relations. From these recursion relations we are able to identify underlying structural connections between these "games with passes" and a recently introduced class of "generic (perturbed) games." This connection, together with a (non-rigorous) numerical stability analysis, allows one to understand and predict the effect of a pass on a game.Comment: 39 pages, 13 figures, published versio

P2519: The Impact of Transcatheter Aortic Valve Implantation on Quality of Life: A Mixed Methods Study

Objective: To provide an in-depth understanding of patients' views about the impact of transcatheter aortic valve implantation on self-reported quality of life. Background: Transcatheter aortic valve implantation is considered to be the gold standard of care for inoperable patients diagnosed with severe symptomatic aortic stenosis. Mid- to long-term clinical outcomes are favourable and questionnaire data indicates improvements in quality of life but an in-depth understanding of how quality of life is altered by the intervention is missing. Methods: A mixed methods study design with a total of 89 in-depth qualitative interviews conducted with participants (39% male; mean age 81.7 years), 1 and 3 months post TAVI, recruited from a regional centre in England. Data were triangulated with questionnaire data (SF-36 and EQ5D-VAS) collected, pre, 1 and 3 months post implantation. Results: Participants' accounts were characterised by four key themes; shortened life, extended life, limited life and changed life. Quality of life was changed through two mechanisms. Most participants reported a reduced symptom burden and all explained that their life expectancy was improved. Questionnaire data supported interview data with gradual improvements in mean EQ-5D scores and SF-36 physical and mental domain scores at 1 and 3 months compared to baseline. Conclusion: Findings suggest that TAVI was of variable benefit, producing considerable improvements in either mental or physical health in many participants, while a smaller proportion continued to deteriorate

Knowledge representation on the web

Exploiting the full potential of the World Wide Web will require semantic as well as syntactic interoperability. This can best be achieved by providing a further representation and inference layer that builds on existing and proposed web standards. The OIL language extends the RDF schema standard to provide just such a layer. It combines the most attractive features of frame based languages with the expressive power, formal rigour and reasoning services of a very expressive description logic.

The Mineral Composition of Wild Type and Cultivated Varieties of Pasture Species

Mineral deficiencies in livestock are often prevented by using prophylactic supplementation, which is imprecise and inefficient. Instead, the trend for increased species diversity in swards is an opportunity to improve mineral concentrations in the basal diet. Currently there are limited data on the mineral concentrations of different species and botanical groups, particularly for I and Se, which are among the most deficient minerals in livestock diets. We grew 21 pasture species, including some cultivar/wild type comparisons, of grasses, legumes and forbs, as single species stands in a pot study in a standard growth medium. Herbage concentrations of Co, Cu, I, Mn, Se, Zn, S, Mo and Fe showed no consistent differences between the wild and cultivated types. There were significant differences between botanical groups for many minerals tested. Forbs were highest in I and Se, grasses in Mn, and legumes in Cu, Co, Zn and Fe. Comparing species concentrations to recommended livestock intakes, the forbs Achillea millefolium, Cichorium intybus and Plantago lanceolate, and the legumes Medicago lupulina, Trifolium hybridum, and Lotus corniculatus, appear good sources of Co, Cu, I, Se and Zn. Further work is required to ensure these results are consistent in multispecies mixtures, in different soil types, and in field trials

No downregulation of immune function during breeding in two year-round breeding bird species in an equatorial East African environment

Some equatorial environments exhibit substantial within-location variation in environmental conditions throughout the year and yet have year-round breeding birds. This implies that breeding in such systems are potentially unrelated to the variable environmental conditions. By breeding not being influenced by environmental conditions, we become sure that any differences in immune function between breeding and non-breeding birds do not result from environmental variation, therefore allowing for exclusion of the confounding effect of variation in environmental conditions. This create a unique opportunity to test if immune function is down-regulated during reproduction compared to non-breeding periods. We compared the immune function of sympatric male and female chick-feeding and non-breeding red-capped Calandrella cinerea and rufous-naped larks Mirafra africana in equatorial East Africa. These closely-related species occupy different niches and have different breeding strategies in the same grassland habitat. Red-capped larks prefer areas with short grass or almost bare ground, and breed during low rainfall periods. Rufous-naped larks prefer areas of tall grass and scattered shrubs and breed during high rainfall. We measured the following immune indices: nitric oxide, haptoglobin, agglutination and lysis, and measured total monthly rain, monthly average minimum (T-min) and maximum (T-max) temperatures. Contrary to our predictions, we found no down-regulation of immune function during breeding; breeding birds had higher nitric oxide than non-breeding ones in both species, while the other three immune indices did not differ between breeding phases. Red-capped larks had higher nitric oxide concentrations than Rufous-naped larks, which in turn had higher haptoglobin levels than red-capped larks. T-max was higher during breeding than during non-breeding for red-capped larks only, suggesting potential confounding effect of T-max on the comparison of immune function between breeding and non-breeding birds for this species. Overall, we conclude that in the two year-round breeding equatorial larks, immune function is not down-regulated during breeding

Implementing a 48 h EWTD-compliant rota for junior doctors in the UK does not compromise patients’ safety : assessor-blind pilot comparison

Background: There are currently no field data about the effect of implementing European Working Time Directive (EWTD)-compliant rotas in a medical setting. Surveys of doctors’ subjective opinions on shift work have not provided reliable objective data with which to evaluate its efficacy. Aim: We therefore studied the effects on patient's safety and doctors’ work-sleep patterns of implementing an EWTD-compliant 48 h work week in a single-blind intervention study carried out over a 12-week period at the University Hospitals Coventry & Warwickshire NHS Trust. We hypothesized that medical error rates would be reduced following the new rota. Methods: Nineteen junior doctors, nine studied while working an intervention schedule of <48 h per week and 10 studied while working traditional weeks of <56 h scheduled hours in medical wards. Work hours and sleep duration were recorded daily. Rate of medical errors (per 1000 patient-days), identified using an established active surveillance methodology, were compared for the Intervention and Traditional wards. Two senior physicians blinded to rota independently rated all suspected errors. Results: Average scheduled work hours were significantly lower on the intervention schedule [43.2 (SD 7.7) (range 26.0–60.0) vs. 52.4 (11.2) (30.0–77.0) h/week; P < 0.001], and there was a non-significant trend for increased total sleep time per day [7.26 (0.36) vs. 6.75 (0.40) h; P = 0.095]. During a total of 4782 patient-days involving 481 admissions, 32.7% fewer total medical errors occurred during the intervention than during the traditional rota (27.6 vs. 41.0 per 1000 patient-days, P = 0.006), including 82.6% fewer intercepted potential adverse events (1.2 vs. 6.9 per 1000 patient-days, P = 0.002) and 31.4% fewer non-intercepted potential adverse events (16.6 vs. 24.2 per 1000 patient-days, P = 0.067). Doctors reported worse educational opportunities on the intervention rota. Conclusions: Whilst concerns remain regarding reduced educational opportunities, our study supports the hypothesis that a 48 h work week coupled with targeted efforts to improve sleep hygiene improves patient safety

Characterization of breast tissue using energy-dispersive X-ray diffraction computed tomography

Abstract A method for sample characterization using energy-dispersive X-ray diffraction computed tomography (EDXRDCT) is presented. The procedures for extracting diffraction patterns from the data and the corrections applied are discussed. The procedures were applied to the characterization of breast tissue samples, 6 mm in diameter. Comparison with histological sections of the samples confirmed the possibility of grouping the patterns into five families, corresponding to adipose tissue, fibrosis, poorly differentiated cancer, well differentiated cancer, and benign tumour

Cataract, abnormal electroretinogram and visual evoked potentials in a child with SMA-LED2 - extending the phenotype.

This case report describes a girl who presented antenatal arthrogryposis and postnatal hypotonia, generalized and respiratory weakness, joint deformities particularly affecting the lower limbs and poor swallow. By 5 months, cataracts, abnormal electroretinograms, visual evoked potentials and global developmental impairments were recognized. No causative variants were identified on targeted gene panels. After her unexpected death at 11 months, gene-agnostic trio whole exome sequencing revealed a likely pathogenic de novo BICD2 missense variant, NM_001003800.1, c.593T>C, p.(Leu198Pro), confirming the diagnosis of spinal muscular atrophy lower extremity predominant type 2 (SMA-LED2). We propose that cataracts and abnormal electroretinograms are novel features of SMA-LED2

Effects of nitroethane and 2-nitropropanol against Campylobacter jejuni

Campylobacter jejuni is an important foodborne pathogen that colonizes the gut of swine. In this study, the effects of nitroethane and 2-nitropropanol (0, 10 and 20 mM) on growth of C. jejuni were tested during culture in Bolton broth adjusted to pH of 5.6, 7.0 or 8.2. Viable cell counts of samples taken at intervals during incubation revealed main effects (P\u3c0.0001) of nitroethane or 2-nitropropanol on mean specific growth rates thus demonstrating that these were inhibitory to C. jejuni. By 48 h of incubation, C. jejuni concentrations had increased by 1.9 log10 CFU/ml or higher in cultures containing no added nitrocompound