Limit theorems for von Mises statistics of a measure preserving transformation

For a measure preserving transformation $T$ of a probability space $(X,\mathcal F,\mu)$ we investigate almost sure and distributional convergence of random variables of the form $$x \to \frac{1}{C_n} \sum_{i_1<n,...,i_d<n} f(T^{i_1}x,...,T^{i_d}x),\, n=1,2,...,$$ where $f$ (called the \emph{kernel}) is a function from $X^d$ to $\R$ and $C_1, C_2,...$ are appropriate normalizing constants. We observe that the above random variables are well defined and belong to $L_r(\mu)$ provided that the kernel is chosen from the projective tensor product $$L_p(X_1,\mathcal F_1, \mu_1) \otimes_{\pi}...\otimes_{\pi} L_p(X_d,\mathcal F_d, \mu_d)\subset L_p(\mu^d)$$ with $p=d\,r,\, r\ \in [1, \infty).$ We establish a form of the individual ergodic theorem for such sequences. Next, we give a martingale approximation argument to derive a central limit theorem in the non-degenerate case (in the sense of the classical Hoeffding's decomposition). Furthermore, for $d=2$ and a wide class of canonical kernels $f$ we also show that the convergence holds in distribution towards a quadratic form $\sum_{m=1}^{\infty} \lambda_m\eta^2_m$ in independent standard Gaussian variables $\eta_1, \eta_2,...$. Our results on the distributional convergence use a $T$--\,invariant filtration as a prerequisite and are derived from uni- and multivariate martingale approximations

Possible thermochemical disequilibrium in the atmosphere of the exoplanet GJ 436b

The nearby extrasolar planet GJ 436b--which has been labelled as a 'hot Neptune'--reveals itself by the dimming of light as it crosses in front of and behind its parent star as seen from Earth. Respectively known as the primary transit and secondary eclipse, the former constrains the planet's radius and mass, and the latter constrains the planet's temperature and, with measurements at multiple wavelengths, its atmospheric composition. Previous work using transmission spectroscopy failed to detect the 1.4-\mu m water vapour band, leaving the planet's atmospheric composition poorly constrained. Here we report the detection of planetary thermal emission from the dayside of GJ 436b at multiple infrared wavelengths during the secondary eclipse. The best-fit compositional models contain a high CO abundance and a substantial methane (CH4) deficiency relative to thermochemical equilibrium models for the predicted hydrogen-dominated atmosphere. Moreover, we report the presence of some H2O and traces of CO2. Because CH4 is expected to be the dominant carbon-bearing species, disequilibrium processes such as vertical mixing and polymerization of methane into substances such as ethylene may be required to explain the hot Neptune's small CH4-to-CO ratio, which is at least 10^5 times smaller than predicted

Mechanisms of Psychological Distress following War in the Former Yugoslavia: The Role of Interpersonal Sensitivity

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This study was funded by a grant from the European Commission, contract number INCO-CT-2004-509176. AN was supported by a Clinical Early Career Research Fellowship (113295) and a Project Grant (104288

Characteristics of maxillofacial injuries resulting from road traffic accidents – a 5 year review of the case records from Department of Maxillofacial Surgery in Katowice, Poland

BACKGROUND: In spite of employing numerous devices improving the safety in motor vehicles, traffic accidents are still among the main reasons of maxillofacial injuries. The maxillofacial injuries remain the serious clinical problem because of the specificity of this anatomical region. The knowledge of etiologic factors and mechanisms of injuries can be helpful in a satisfactory trauma prevention. The aim of this study was to find out the incidence and the pattern of maxillofacial injuries resulting from traffic accidents in the patients treated in the Department of Maxillofacial Surgery (Silesian Medical Academy in Katowice, Poland) from January 2001 to December 2005. METHODS: The material consisted of 1024 case records of patients with maxillofacial injuries treated in the Maxillofacial Surgery Department of Silesian Medical Academy. The detailed analysis was carried out on the case records of 198 patients in the age of 3 to 68 with maxillofacial injuries resulting from traffic accidents. On the basis of data from a history, examination on admission, consultations and radiological examinations, patients' age and gender, we obtained the information on a pattern of injury and detailed description of an accident (the date and the time of an accident, the role of the patient in an accident). RESULTS: The traffic accidents were the cause of 19,93% maxillofacial injuries in the analyzed period of time. Most of the patients had injuries to the soft tissues of the face (22,21%), followed by tooth and alveolar process injuries (20,71%) and mandibular fractures (18,69%). All the types of injuries were more common in men than in women. The majority of the patients were car drivers followed by car passengers, pedestrians, cyclists and motor cyclists. The peak age of the patients was between 18 to 25 years. The prevalent number of accidents resulting in injuries to this region took place in spring, especially between noon and 4 PM. CONCLUSION: Our results exhibit that road traffic accidents remain among the main reasons of maxillofacial injuries following the traumas resulting from assaults and interpersonal violence. This succession of etiologic factors is in accordance with the data from the most developed countries. The relatively high incidence of injuries resulting from traffic accidents indicates the necessity to reinforce legislation aimed to prevent road traffic crashes and thus to reduce maxillofacial injuries among children and adults

Genome-wide signatures of convergent evolution in echolocating mammals

Evolution is typically thought to proceed through divergence of genes, proteins, and ultimately phenotypes(1-3). However, similar traits might also evolve convergently in unrelated taxa due to similar selection pressures(4,5). Adaptive phenotypic convergence is widespread in nature, and recent results from a handful of genes have suggested that this phenomenon is powerful enough to also drive recurrent evolution at the sequence level(6-9). Where homoplasious substitutions do occur these have long been considered the result of neutral processes. However, recent studies have demonstrated that adaptive convergent sequence evolution can be detected in vertebrates using statistical methods that model parallel evolution(9,10) although the extent to which sequence convergence between genera occurs across genomes is unknown. Here we analyse genomic sequence data in mammals that have independently evolved echolocation and show for the first time that convergence is not a rare process restricted to a handful of loci but is instead widespread, continuously distributed and commonly driven by natural selection acting on a small number of sites per locus. Systematic analyses of convergent sequence evolution in 805,053 amino acids within 2,326 orthologous coding gene sequences compared across 22 mammals (including four new bat genomes) revealed signatures consistent with convergence in nearly 200 loci. Strong and significant support for convergence among bats and the dolphin was seen in numerous genes linked to hearing or deafness, consistent with an involvement in echolocation. Surprisingly we also found convergence in many genes linked to vision: the convergent signal of many sensory genes was robustly correlated with the strength of natural selection. This first attempt to detect genome-wide convergent sequence evolution across divergent taxa reveals the phenomenon to be much more pervasive than previously recognised

Evaluation of a standard provision versus an autonomy promotive exercise referral programme: rationale and study design

Background The National Institute of Clinical Excellence in the UK has recommended that the effectiveness of ongoing exercise referral schemes to promote physical activity should be examined in research trials. Recent empirical evidence in health care and physical activity promotion contexts provides a foundation for testing the utility of a Self Determination Theory (SDT) -based exercise referral consultation. Methods/Design Design: An exploratory cluster randomised controlled trial comparing standard provision exercise on prescription with a Self Determination Theory-based (SDT) exercise on prescription intervention. Participants: 347 people referred to the Birmingham Exercise on Prescription scheme between November 2007 and July 2008. The 13 exercise on prescription sites in Birmingham were randomised to current practice (n=7) or to the SDT-based intervention (n=6). Outcomes measured at 3 and 6-months: Minutes of moderate or vigorous physical activity per week assessed using the 7-day Physical Activity Recall; physical health: blood pressure and weight; health status measured using the Dartmouth CO-OP charts; anxiety and depression measured by the Hospital Anxiety and Depression Scale and vitality measured by the subjective vitality score; motivation and processes of change: perceptions of autonomy support from the advisor, satisfaction of the needs for competence, autonomy, and relatedness via physical activity, and motivational regulations for exercise. Discussion This trial will determine whether an exercise referral programme based on Self Determination Theory increases physical activity and other health outcomes compared to a standard programme and will test the underlying SDT-based process model (perceived autonomy support, need satisfaction, motivation regulations, outcomes) via structural equation modelling. Trial registration The trial is registered as Current Controlled trials ISRCTN07682833

Perceptions of Teachers’ Interpersonal Styles and Well-Being and Ill-Being in Secondary School Physical Education Students: The Role of Need Satisfaction and Need Frustration

This study examined the associations among physical education students’ perceptions of their teachers’ autonomy-supportive and controlling interpersonal styles, need satisfaction and need frustration, and indices of psychological well-being (subjective vitality) and ill-being (negative affect). The results from 591 Chinese secondary school students in Hong Kong indicated that the relationship between students’ perceptions of autonomy-supportive teaching behaviors and subjective vitality was primarily mediated by need satisfaction, whereas the relationship between perceived controlling teaching behaviors and negative affect was primarily mediated by need frustration. The results obtained from the multi-group structural equation model also suggested that these relationships were invariant across sex

Statistical estimates of absenteeism attributable to seasonal and pandemic influenza from the Canadian Labour Force Survey

<p>Abstract</p> <p>Background</p> <p>As many respiratory viruses are responsible for influenza like symptoms, accurate measures of the disease burden are not available and estimates are generally based on statistical methods. The objective of this study was to estimate absenteeism rates and hours lost due to seasonal influenza and compare these estimates with estimates of absenteeism attributable to the two H1N1 pandemic waves that occurred in 2009.</p> <p>Methods</p> <p>Key absenteeism variables were extracted from Statistics Canada's monthly labour force survey (LFS). Absenteeism and the proportion of hours lost due to own illness or disability were modelled as a function of trend, seasonality and proxy variables for influenza activity from 1998 to 2009.</p> <p>Results</p> <p>Hours lost due to the H1N1/09 pandemic strain were elevated compared to seasonal influenza, accounting for a loss of 0.2% of potential hours worked annually. In comparison, an estimated 0.08% of hours worked annually were lost due to seasonal influenza illnesses. Absenteeism rates due to influenza were estimated at 12% per year for seasonal influenza over the 1997/98 to 2008/09 seasons, and 13% for the two H1N1/09 pandemic waves. Employees who took time off due to a seasonal influenza infection took an average of 14 hours off. For the pandemic strain, the average absence was 25 hours.</p> <p>Conclusions</p> <p>This study confirms that absenteeism due to seasonal influenza has typically ranged from 5% to 20%, with higher rates associated with multiple circulating strains. Absenteeism rates for the 2009 pandemic were similar to those occurring for seasonal influenza. Employees took more time off due to the pandemic strain than was typical for seasonal influenza.</p

Six weeks of home enteral nutrition versus standard care after esophagectomy or total gastrectomy for cancer: study protocol for a randomized controlled trial

Background: Each year approximately 3000 patients in the United Kingdom undergo surgery for esophagogastric cancer. Jejunostomy feeding tubes, placed at the time of surgery for early postoperative nutrition, have been shown to have a positive impact on clinical outcomes in the short term. Whether feeding out of hospital is of benefit is unknown. Local experience has identified that between 15 and 20% of patients required ‘rescue’ jejunostomy feeding for nutritional problems and weight loss while at home. This weight loss and poor nutrition may contribute to the detrimental effect on the overall quality of life (QoL) reported in these patients. Methods/Design: This randomized pilot and feasibility study will provide preliminary information on the routine use of jejunostomy feeding after hospital discharge in terms of clinical benefits and QoL. Sixty participants undergoing esophagectomy or total gastrectomy will be randomized to receive either a planned program of six weeks of home jejunostomy feeding after discharge from hospital (intervention) or treatment-as-usual (control). The intention of this study is to inform a multi-centre randomized controlled trial. The primary outcome measures will be recruitment and retention rates at six weeks and six months. Secondary outcome measures will include disease specific and general QoL measures, nutritional parameters, total and oral nutritional intake, hospital readmission rates, and estimates of healthcare costs. Up to 20 participants will also be enrolled in a qualitative sub-study that will explore participants’ and carers’ experiences of home tube feeding. The results will be disseminated by presentation at surgical, gastroenterological and dietetic meetings and publication in appropriate peer review journals. A patient-friendly lay summary will be made available on the University of Leicester and the University Hospitals of Leicester NHS Trust websites. The study has full ethical and institutional approval and started recruitment in July 2012. Trial registration: UKClinical Research Network ID #12447 (Main study); UKCRN ID#13361 (Qualitative sub study); ClinicalTrials.gov #NCT01870817 (First registered 28 May 2013

Individual Recognition in Domestic Cattle (Bos taurus): Evidence from 2D-Images of Heads from Different Breeds

BACKGROUND: In order to maintain cohesion of groups, social animals need to process social information efficiently. Visual individual recognition, which is distinguished from mere visual discrimination, has been studied in only few mammalian species. In addition, most previous studies used either a small number of subjects or a few various views as test stimuli. Dairy cattle, as a domestic species allow the testing of a good sample size and provide a large variety of test stimuli due to the morphological diversity of breeds. Hence cattle are a suitable model for studying individual visual recognition. This study demonstrates that cattle display visual individual recognition and shows the effect of both familiarity and coat diversity in discrimination. [br/]METHODOLOGY/PRINCIPAL FINDINGS: We tested whether 8 Prim'Holstein heifers could recognize 2D-images of heads of one cow (face, profiles, (3/4) views) from those of other cows. Experiments were based on a simultaneous discrimination paradigm through instrumental conditioning using food rewards. In Experiment 1, all images represented familiar cows (belonging to the same social group) from the Prim'Holstein breed. In Experiments 2, 3 and 4, images were from unfamiliar (unknown) individuals either from the same breed or other breeds. All heifers displayed individual recognition of familiar and unfamiliar individuals from their own breed. Subjects reached criterion sooner when recognizing a familiar individual than when recognizing an unfamiliar one (Exp 1: 3.1+/-0.7 vs. Exp 2: 5.2+/-1.2 sessions; Z = 1.99, N = 8, P = 0.046). In addition almost all subjects recognized unknown individuals from different breeds, however with greater difficulty. [br/] CONCLUSIONS/SIGNIFICANCE: Our results demonstrated that cattle have efficient individual recognition based on categorization capacities. Social familiarity improved their performance. The recognition of individuals with very different coat characteristics from the subjects was the most difficult task. These results call for studies exploring the mechanisms involved in face recognition allowing interspecies comparisons, including humans