Search results for "values."
showing 10 items of 1353 documents
PT-symmetry and Schrödinger operators. The double well case
2015
We study a class of $PT$-symmetric semiclassical Schrodinger operators, which are perturbations of a selfadjoint one. Here, we treat the case where the unperturbed operator has a double-well potential. In the simple well case, two of the authors have proved in [6] that, when the potential is analytic, the eigenvalues stay real for a perturbation of size $O(1)$. We show here, in the double-well case, that the eigenvalues stay real only for exponentially small perturbations, then bifurcate into the complex domain when the perturbation increases and we get precise asymptotic expansions. The proof uses complex WKB-analysis, leading to a fairly explicit quantization condition.
Circular law for sparse random regular digraphs
2020
Fix a constant $C\geq 1$ and let $d=d(n)$ satisfy $d\leq \ln^{C} n$ for every large integer $n$. Denote by $A_n$ the adjacency matrix of a uniform random directed $d$-regular graph on $n$ vertices. We show that, as long as $d\to\infty$ with $n$, the empirical spectral distribution of appropriately rescaled matrix $A_n$ converges weakly in probability to the circular law. This result, together with an earlier work of Cook, completely settles the problem of weak convergence of the empirical distribution in directed $d$-regular setting with the degree tending to infinity. As a crucial element of our proof, we develop a technique of bounding intermediate singular values of $A_n$ based on studyi…
A Widrow–Hoff Learning Rule for a Generalization of the Linear Auto-associator
1996
Abstract A generalization of the linear auto-associator that allows for differential importance and nonindependence of both the stimuli and the units has been described previously by Abdi (1988). This model was shown to implement the general linear model of multivariate statistics. In this note, a proof is given that the Widrow–Hoff learning rule can be similarly generalized and that the weight matrix will converge to a generalized pseudo-inverse when the learning parameter is properly chosen. The value of the learning parameter is shown to be dependent only upon the (generalized) eigenvalues of the weight matrix and not upon the eigenvectors themselves. This proof provides a unified framew…
Polymorphism of Alcohol Dehydrogenase Genes in Alcoholic and Nonalcoholic Individuals from Valencia (Spain)
2004
Polymorphisms in the two variable ADH loci (ADH2 and ADH3) were analyzed in two groups (alcoholics and nonalcoholics) from a Spanish population. The frequencies were similar to those reported for other Causcasian groups. ADH2-1 and ADH3-1 genotypes were more frequent in alcoholics than in nonalcoholics, but the differences were not significant.
MHC class II genes influence the susceptibility to chronic active hepatitis C
1997
Chronic hepatitis C develops in more than 70% of hepatitis C virus infected subjects. Viral factors influence the disease course, but little is known about the importance of host factors.Frequencies of major histocompatibility complex (MHC) class I and class II antigens were analyzed in two groups of patients with chronic hepatitis C virus infection and in control subjects. MHC class I typing was done by standard microlymphocytotoxicity assays. DRB1 and DQA1 genotyping was done by PCR based typing methods.DRB1*0301 was found in 26 of 75 patients with chronic hepatitis C virus infection (34.7%) and in 12 of 101 control subjects (11.9%) (relative risk 3.9; p0.001). Homozygosity for this allel…
The EU'S Explicit and Implicit Heritage Politics
2014
During the past couple of decades, heritage has become topical in a new way in Europe as the concept has been utilized for political purposes in the EU cultural policy. The EU currently administrates or supports three initiatives – the European Heritage Days, the European Union Prize for Cultural Heritage, and the European Heritage Label – that address the fostering of the transnational European cultural heritage. The article discusses the explicit and implicit heritage politics included in these initiatives. In order to understand the constructive and generative nature of the EU heritage politics, it is approached in the article as a discursive meaning-making process consisting of several …
Culinary tourism experiences in agri-tourism destinations and sustainable consumption-Understanding Italian tourists' motivations
2019
Culinary tourism represents an emerging component of the tourism industry and encompasses all the traditional values associated with the new trends in tourism: respect for culture and tradition, authenticity and sustainability. Italy is known worldwide for the richness and variety of its gastronomy, and agri-tourism represents one of the most important places where culinary tourists can experience local food and beverages. By using a modified version of Kim and Eves&rsquo
Laboratory parameters in centenarians of Italian ancestry
2008
Studies aimed at collecting reference parameters for haematochemical analysis in the elderly are scarce and for the oldest old subjects even more rare. In order to establish the reference values for the most common laboratory text in long living individuals, we measured haematochemical parameters in >100 years old subjects and in aged subjects as control. Six hundred and two centenarians accepted to be enrolled in the study. A case history containing the complete anamnesis, clinical examinations, evaluation of the clinical cognitive and functional tests, was prepared for each centenarian. Blood samples from 120 > 100 years old subjects free of chronic or acute Illness (i.e. Alzheimer’s dise…
Validation study of the Italian Addenbrooke’s Cognitive Examination Revised in a young-old and old-old population
2011
<i>Aims:</i> The main aims of the study were the translation and the subsequent validation in Italian of the Addenbrooke’s Cognitive Examination Revised (ACE-R), and the evaluation of its usefulness in discriminating cognitively normal subjects from patients with mild dementia in an elderly population. <i>Methods:</i> The ACE-R was translated and adapted into Italian. The Italian ACE-R was administered to a group of 179 elderly subjects (72 cognitively healthy and 107 subjects with mild dementia, mean age 75.4 ± 6.4 years). The group was stratified into two subsamples according to age, i.e. a young-old (<75 years) and an old-old (≧75 years) group, in order to eval…
Normative data of BMI and physical fitness in a Norwegian sample of early adolescents.
2013
Aim: The purpose of the present study was to 1) provide normative data quantifying the physical fitness level and body mass index of 13–15-year-old Norwegian adolescents using a multi-component fitness assessment, and 2) compare the physical fitness of Norwegian teenagers with available European and International fitness data. Methods: 1059 adolescents (529 males, 530 females) from 12 public schools in Kristiansand were invited to testing at age 13, 14, and 15 years (Grades 8–10). Test participation was 75%–80%. The participants performed objectively anthropometrical measures (height and weight) and six field-based physical fitness tests. Results and Conclusions: As expected, sex differenc…