A good leaf order on simplicial trees

Using the existence of a good leaf in every simplicial tree, we order the facets of a simplicial tree in order to find combinatorial information about the Betti numbers of its facet ideal. Applications include an Eliahou-Kervaire splitting of the ideal, as well as a refinement of a recursive formula of H\`a and Van Tuyl for computing the graded Betti numbers of simplicial trees.Comment: 17 pages, to appear; Connections Between Algebra and Geometry, Birkhauser volume (2013

Analyzing capacitance-voltage measurements of vertical wrapped-gated nanowires

The capacitance of arrays of vertical wrapped-gate InAs nanowires are analyzed. With the help of a Poisson-Schr"odinger solver, information about the doping density can be obtained directly. Further features in the measured capacitance-voltage characteristics can be attributed to the presence of surface states as well as the coexistence of electrons and holes in the wire. For both scenarios, quantitative estimates are provided. It is furthermore shown that the difference between the actual capacitance and the geometrical limit is quite large, and depends strongly on the nanowire material.Comment: 15 pages, 6 Figures included, to appear in Nanotechnolog

Regularity of Edge Ideals and Their Powers

We survey recent studies on the Castelnuovo-Mumford regularity of edge ideals of graphs and their powers. Our focus is on bounds and exact values of $\text{ reg } I(G)$ and the asymptotic linear function $\text{ reg } I(G)^q$, for $q \geq 1,$ in terms of combinatorial data of the given graph $G.$Comment: 31 pages, 15 figure

Gender and Responsible Gambling in Spain. The Social Gambling Questionnaire for Women (SGQW-47), a new screening instrument

Objective: The aim of this study is to develop a questionnaire to assess responsible gambling habits in females of the general population, to explore its psychometric properties and to compare the results between a community sample and a clinical sample of patients with gambling disorder. We also aim at providing empirical evidence of the gambling habits among Spanish females. Method: Two samples were selected to develop the questionnaire and to explore gambling habits in female Spanish population. The clinical sample was recruited from the Pathological Gambling Unit at the University Hospital of Bellvitge (Barcelona, Spain), comprising 30 patients. The community sample was recruited from individuals visiting the hospital for the Dentistry and Chiropody Departments, placed at the same university hospital and it comprised 316 females. Results: The questionnaire showed high values for sensitivity and specificity, discriminating between patients with gambling disorder and healthy controls. More than a 3% of the females from the community sample presented a problematic gambling behavior. In relation to predictors of gambling behavior, low socioeconomic status emerged as the unique socio-demographic factor for problematic gambling. Moreover, the illusion of winning money through gambling or feeling better by gambling were powerful stimulators of gambling behavior. Conclusions: Despite being male is strongly associated with the development of problem gambling, females can also be considered "at risk gamblers" themselves. To explore gambling habits of this population, identifying potentially harmful behaviors, in order to maintain responsible gambling habits, may contribute to the development of prevention and education programs promoting the general health of the community

Typologies of young pathological gamblers based on sociodemographic and clinical characteristics

Objective: the aim of this study is to explore empirical clusters within the population of young Spanish individuals attending outpatient pathological gambling treatment. Method: the South Oaks Gambling Screen (SOGS), the Symptom Checklist (SCL-90-R), the Temperament and Character Inventory-R (TCI-R) and other clinical and psychopathological measures were administered to 154 patients (between 17 and 25 years old). The two-step cluster analysis explored the presence of empirical heterogeneous groups based on clinical and socio-demographic characteristics. Results: three clusters of young pathological gambling patients emerged. Type I showed less psychopathology and more functional personality traits. Type II showed a profile characterized by major emotional distress, shame, immaturity, hostility and negative feelings. Type III showed the most severe psychopathological profile and most psychopathological disturbances and schizotypal traits. Conclusions: these results suggest that three distinct endophenotypes exist, and that environmental factors have a stronger influence in the first, while in the second and third, individual factors related to deficits of emotional regulation stand out

Four lectures on secant varieties

This paper is based on the first author's lectures at the 2012 University of Regina Workshop "Connections Between Algebra and Geometry". Its aim is to provide an introduction to the theory of higher secant varieties and their applications. Several references and solved exercises are also included.Comment: Lectures notes to appear in PROMS (Springer Proceedings in Mathematics & Statistics), Springer/Birkhause

Comparative analysis of distinct phenotypes in gambling disorder based on gambling preferences

Background: studies examining gambling preferences have identified the importance of the type of gambling practiced on distinct individual profiles. The objectives were to compare clinical, psychopathological and personality variables between two different groups of individuals with a gambling disorder (strategic and non-strategic gamblers) and to evaluate the statistical prediction capacity of these preferences with respect to the severity of the disorder. Method: a total sample of 2010 treatment-seeking patients with a gambling disorder participated in this stand-alone study. All were recruited from a single Pathological Gambling Unit in Spain (1709 strategic and 301 non-strategic gamblers). The design of the study was cross-sectional and data were collected at the start of treatment. Data was analysed using logistic regression for binary outcomes and analysis of variance (ANOVA) for quantitative responses. Results: there were significant differences in several socio-demographic and clinical variables, as well as in personality traits (novelty seeking and cooperativeness). Multiple regression analysis showed harm avoidance and self-directedness were the main predictors of gambling severity and psychopathology, while age at assessment and age of onset of gambling behaviour were predictive of gambling severity. Strategic gambling (as opposed to non-strategic) was significantly associated with clinical outcomes, but the effect size of the relationships was small. Conclusions: it is possible to identify distinct phenotypes depending on the preference of gambling. While these phenotypes differ in relation to the severity of the gambling disorder, psychopathology and personality traits, they can be useful from a clinical and therapeutic perspective in enabling risk factors to be identified and prevention programs targeting specific individual profiles to be developed

Human papillomavirus ‘reflex' testing as a screening method in cases of minor cytological abnormalities

The aim was to evaluate human papillomavirus (HPV) ‘reflex genotyping' in cases of minor cytological abnormalities detected in the gynaecological screening programme in Stockholm, Sweden. Liquid-based cytology samples showing minor cytological abnormalities were analysed using HPV genotyping (Linear Array, Roche diagnostics). Colposcopically directed cervical biopsies were obtained and the HPV test results were correlated with the histological results. In all, 63% (70/112) of the samples were high-risk (HR) HPV (HR-HPV) positive. A statistically significant correlation was found between high-grade cervical lesions and HR-HPV (P=0.019), among which HPV 16, 18, and 31 were the most important. The negative predictive value of HR-HPV detection for histologically confirmed high-grade lesions was 100%. An age limit for HPV reflex testing may be motivated in cases of low-grade squamous intraepithelial neoplasia (LSIL), because of high HR-HPV prevalence among younger women. By using HPV reflex genotyping, additional extensive workup can safely be avoided in about 50% of all cases of atypical squamous cells of undetermined significance (ASCUS) and LSIL among women ⩾30 years. This screening strategy could potentially reduce the total abnormal cytology-reporting rate in the Swedish screening programme by about 1% and provide more accurately directed follow-up, guided by cytological appearance and HPV test results