422 research outputs found

    Nonconventional averages along arithmetic progressions and lattice spin systems

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    We study the so-called nonconventional averages in the context of lattice spin systems, or equivalently random colourings of the integers. For i.i.d. colourings, we prove a large deviation principle for the number of monochromatic arithmetic progressions of size two in the box [1,N]∩N[1,N]\cap \N, as N→∞N\to\infty, with an explicit rate function related to the one-dimensional Ising model. For more general colourings, we prove some bounds for the number of monochromatic arithmetic progressions of arbitrary size, as well as for the maximal progression inside the box [1,N]∩N[1,N]\cap \N. Finally, we relate nonconventional sums along arithmetic progressions of size greater than two to statistical mechanics models in dimension larger than one.Comment: 18 pages, 3 figures. A new section was added on arithmetic progressions of length larger than 2 and statistical mechanics models on Z^d, d>1. To appear in Indagationes Mathematicae (2012

    Prevalence of Enterococci and Vancomycin Resistance in the Throat of Non-Hospitalized Individuals Randomly Selected in Central Italy

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    Enterococci are commonly found in the environment and humans as a part of the normal microbiota. Among these, Enterococcus faecalis and Enterococcus faecium can convert into opportunistic pathogens, making them a major cause of nosocomial infections. The rapid diffusion of vancomycin-resistant strains and their impact on nosocomial settings is of considerable concern. Approximately one-third of the E. faecium infections in Italy are caused by vancomycin-resistant strains. This study explored the hypothesis that the oral cavity could represent a silent reservoir of virulent enterococci. A sample of 862 oral flora specimens collected from healthy human volunteers in Central Italy was investigated by real-time PCR to detect E. faecalis and E. faecium, as well as the genetic elements that most frequently determine vancomycin resistance. The prevalence of E. faecalis was 19%, a value that was not associated with alcohol consumption, tobacco smoking, or age of the subjects. Less frequently detected, with an overall prevalence of 0.7%, E. faecium was more common among people older than 49 years of age. The genes conferring vancomycin resistance were detected in only one sample. The results indicate that the oral cavity can be considered a reservoir of clinically relevant enterococci; however, our data suggest that healthy individuals rarely carry vancomycin-resistant strains

    Association between oral cleft and transcobalamin 2 polymorphism in a sample study from Nassiriya, Iraq

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    Orofacial clefts are common congenital defects whose prevalence differs between geographical regions and ethnic groups. The inheritance is complex, involving the contribution of both genetic and environmental factors. The involvement of genes belonging to the folate pathway is still matter of debate, with strong evidences of association and conflicting results. After demonstrating the contribution, for a sample from the Italian population, of common mutations mapping on three genes of the folate pathway, our group tried to unravel their contribution in independent sample studies with different ethnicity. In the present investigation a set of 34 triads with oral cleft from Nassiriya, Iraq, has been genotyped for rs1801133 of MTHFR, rs1801198 of TCN2, and rs4920037 of CBS polymorphisms. Association analysis evidenced a decreased risk of cleft for children carrying the 667G allele at TCN2 gene (P = 0.02). This evidence further supported the relationship between polymorphisms of folate related genes and oral clefts, and outlined the relevance of studying populations having different ethnicity

    Nonconventional Large Deviations Theorems

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    We obtain large deviations theorems for nonconventional sums with underlying process being a Markov process satisfying the Doeblin condition or a dynamical system such as subshift of finite type or hyperbolic or expanding transformation

    Ultra-Rare Variants Identify Biological Pathways and Candidate Genes in the Pathobiology of Non-Syndromic Cleft Palate Only

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    : In recent decades, many efforts have been made to elucidate the genetic causes of non-syndromic cleft palate (nsCPO), a complex congenital disease caused by the interaction of several genetic and environmental factors. Since genome-wide association studies have evidenced a minor contribution of common polymorphisms in nsCPO inheritance, we used whole exome sequencing data to explore the role of ultra-rare variants in this study. In a cohort of 35 nsCPO cases and 38 controls, we performed a gene set enrichment analysis (GSEA) and a hypergeometric test for assessing significant overlap between genes implicated in nsCPO pathobiology and genes enriched in ultra-rare variants in our cohort. GSEA highlighted an enrichment of ultra-rare variants in genes principally belonging to cytoskeletal protein binding pathway (Probability Density Function corrected p-value = 1.57 × 10-4); protein-containing complex binding pathway (p-value = 1.06 × 10-2); cell adhesion molecule binding pathway (p-value = 1.24 × 10-2); ECM-receptor interaction pathway (p-value = 1.69 × 10-2); and in the Integrin signaling pathway (p-value = 1.28 × 10-2). Two genes implicated in nsCPO pathobiology, namely COL2A1 and GLI3, ranked among the genes (n = 34) with nominal enrichment in the ultra-rare variant collapsing analysis (Fisher's exact test p-value < 0.05). These genes were also part of an independent list of genes highly relevant to nsCPO biology (n = 25). Significant overlap between the two sets of genes (hypergeometric test p-value = 5.86 × 10-3) indicated that enriched genes are likely to be implicated in physiological palate development and/or the pathological processes of oral clefting. In conclusion, ultra-rare variants collectively impinge on biological pathways crucial to nsCPO pathobiology and point to candidate genes that may contribute to the individual risk of disease. Sequencing can be an effective approach to identify candidate genes and pathways for nsCPO

    Stochastic Duality and Orthogonal Polynomials

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    For a series of Markov processes we prove stochastic duality relations with duality functions given by orthogonal polynomials. This means that expectations with respect to the original process (which evolves the variable of the orthogonal polynomial) can be studied via expectations with respect to the dual process (which evolves the index of the polynomial). The set of processes include interacting particle systems, such as the exclusion process, the inclusion process and independent random walkers, as well as interacting diffusions and redistribution models of Kipnis–Marchioro–Presutti type. Duality functions are given in terms of classical orthogonal polynomials, both of discrete and continuous variable, and the measure in the orthogonality relation coincides with the process stationary measure

    Aging and oral care: An observational study of characteristics and prevalence of oral diseases in an Italian cohort

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    Background: Poor oral health is a common condition in patients suffering from dementia. Several aspects of this systemic pathology contribute to causing oral problems: cognitive impairment, behavior disorders, communication and, motor skills deterioration, low levels of cooperation and medical-nursing staff incompetency in the dental field. Objectives: The objectives of this study were to evaluate the prevalence and the characteristics of oral pathology in a demented elderly population, as well as to check the association between the different degree of dementia and the oral health condition of each patient. Materials and Methods: In this observational study (with cross-sectional design) two groups of elderly patients suffering from dementia, living in two different residential care institutions were recruited. The diagnosis of dementia of each included patient was performed using the Clinical Dementia Rating Scale. In order to evaluate the oral health condition of the included subjects, each patient underwent a physical examination of the oral cavity, during which different clinical parameters were analyzed (number of remaining teeth, oral mucosa, periodontal tissues, bone crests). To each parameter, a score was assigned. Spearman’s Rho test was used. Results: Regarding the prevalence of oral pathology in elderly suffering from dementia, it emerged that 20.58% of the included patients had mucosal lesions and/or new mucosal formations (in most cases undiagnosed and therefore untreated). The prevalence of periodontal disease was equal to 82.35% and a marked clinically detectable reabsorption of bone crests was found in almost all patients (88.23%). 24.13% of patients, who underwent the oral examination, had totally edentulous maxillae and/or with retained roots, without prosthetic rehabilitations. The correlation index r showed the presence of a linear correlation (inverse relationship) between the degree of dementia and the state of health of the oral cavity of each patient. Conclusions: Several factors contribute to poor oral health in the elderly suffering from dementia: cognitive functions deterioration, behavioral disorders and inadequate medical-staff nursing training on oral hygiene. This study also demonstrated that the lower the dementia degree is, the lower tends to be the oral health status. In order to guarantee a complete assistance to these patients, residential care institutions should include in their healthcare program specific dental protocols

    Non-syndromic cleft palate: Association analysis on three gene polymorphisms of the folate pathway in Asian and Italian populations

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    Periconceptional folic acid supplementation can reduce the risk of inborn malformations, including orofacial clefts. Polymorphisms of MTHFR, TCN2, and CBS folate-related genes seem to modulate the risk of cleft lip with or without cleft palate (CL/P) in some populations. CL/P and cleft palate only (CPO) are different malformations that share several features and possibly etiological causes. In the present investigation, we conducted a family-based, candidate gene association study of non-syndromic CPO. Three single nucleotide polymorphisms, namely, rs1801133 of MTHFR, rs1801198 of TCN2, and rs4920037 of CBS, were investigated in a sample that included 129 Italian and 65 Asian families. No evidence of association between the three genotyped polymorphisms and CPO was found in the Italian and Asian cases, indeed the transmission disequilibrium test did not detect any asymmetry of transmission of alleles. This investigation, although with some limitation, further supports that CL/P and CPO diverge in their genetic background

    Quality in Emergency Departments: a study on 3,285,440 admissions

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    INTRODUCTION: A multi-centre study has been conducted, during 2005, by means of a questionnaire posted on the Italian Society of Emergency Medicine (SIMEU) web page. Our intention was to carry out an organisational and functional analysis of Italian Emergency Departments (ED) in order to pick out some macro-indicators of the activities performed. Participation was good, in that 69 ED (3,285,440 admissions to emergency services) responded to the questionnaire. METHODS: The study was based on 18 questions: 3 regarding the personnel of the ED, 2 regarding organisational and functional aspects, 5 on the activity of the ED, 7 on triage and 1 on the assessment of the quality perceived by the users of the ED. RESULTS AND CONCLUSION: The replies revealed that 91.30% of the ED were equipped with data-processing software, which, in 96.83% of cases, tracked the entire itinerary of the patient. About 48,000 patients/year used the ED: 76.72% were discharged and 18.31% were hospitalised. Observation Units were active in 81.16% of the ED examined. Triage programmes were in place in 92.75% of ED: in 75.81% of these, triage was performed throughout the entire itinerary of the patient; in 16.13% it was performed only symptom-based, and in 8.06% only on-call. Of the patients arriving at the ED, 24.19% were assigned a non-urgent triage code, 60.01% a urgent code, 14.30% a emergent code and 1.49% a life-threatening code. Waiting times were: 52.39 min for non-urgent patients, 40.26 min for urgent, 12.08 for emergent, and 1.19 for life-threatening patients

    A standard set of person-centred outcomes for diabetes mellitus: results of an international and unified approach

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    AIMS To select a core list of standard outcomes for diabetes to be routinely applied internationally, including patient-reported outcomes. METHODS We conducted a structured systematic review of outcome measures, focusing on adults with either type 1 or type 2 diabetes. This process was followed by a consensus-driven modified Delphi panel, including a multidisciplinary group of academics, health professionals and people with diabetes. External feedback to validate the set of outcome measures was sought from people with diabetes and health professionals. RESULTS The panel identified an essential set of clinical outcomes related to diabetes control, acute events, chronic complications, health service utilisation, and survival that can be measured using routine administrative data and/or clinical records. Three instruments were recommended for annual measurement of patient-reported outcome measures: the WHO Well-Being Index for psychological well-being; the depression module of the Patient Health Questionnaire for depression; and the Problem Areas in Diabetes scale for diabetes distress. A range of factors related to demographic, diagnostic profile, lifestyle, social support and treatment of diabetes were also identified for case-mix adjustment. CONCLUSIONS We recommend the standard set identified in this study for use in routine practice to monitor, benchmark and improve diabetes care. The inclusion of patient-reported outcomes enables people living with diabetes to report directly on their condition in a structured way
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