Search results for "multivariate"

MULTIVARIATE STATISTICAL TOOLS FOR THE RADIOMETRIC FEATURES OF VOLCANIC ISLANDS

2009

The Aeolian Islands represents a Quaternary volcanic arc related to the subduction of the Ionian plate beneath the Calabrian Arc. The geochemical variability of the islands has led to a broad spectrum of magma rocks. Volcanic products from calc-alkaline (CA) to calc-alkaline high in potassium (HKCA) are present throughout the Archipelago, but products belonging to shoshonitic (SHO) and potassium (KS) series characterize the southern portion of Lipari, Vulcano and Stromboli. Tectonics also plays an important role in the process of the islands differentiation. In this work, we want to review and cross-analyze the data on Lipari, Stromboli and Vulcano, collected in measurement and sampling cam…

Discovery of recurring behavioural sequences in Wistar rat social activity: Possible support to studies on Autism Spectrum Disorders.

2017

This study was undertaken to investigate whether, in rat interactive activities, recurring sequences of behavioural events might be identified and how and to what extent each component of the pair is involved. To this aim, the multivariate temporal-pattern (t-pattern) analysis was applied to the social interactions of 9 pairs of male Wistar rats tested in open field. Interactive activities were classified into intra- and inter-subjects. Quantitative evaluations showed that intra-subject behavioural elements represented 62.37% and inter-subject ones 37.63% of the comprehensive behaviour. T-pattern analysis revealed the presence of 221 different t-patterns organized in four different categori…

Application of multivariate T-pattern analysis in the study of social interaction in rats

2015

ABSTRACT NON PREVISTO DALLA PUBBLICAZIONE

Prognostic significance of p16INK4a alterations and 9p21 loss of heterozigosity in locally advanced laryngeal squamous cell carcinoma

2002

The p16INK4a gene, localized within chromosome 9p21, has been identified as a cyclin-dependent kinase inhibitor and may negatively regulate the cell cycle acting as a tumor suppressor. Genetic alterations involving the 9p21 region are common in human cancers. A consecutive series of 64 untreated patients (median of follow up 53 months) undergoing surgical resection for locally advanced laryngeal squamous-cell carcinomas (LSCCs) has been studied prospectively. Our purpose was to investigate p16 alterations (9p21 allelic loss, hypermethylation and point mutations) and their possible association with clinico-pathological data and flow cytometric variables (DNA-ploidy and S-phase fraction (SPF)…

Testing for Asymmetric Information in Insurance Markets: A Multivariate Ordered Regression Approach

2018

The positive correlation (PC) test is the standard procedure used in the empirical literature to detect the existence of asymmetric information in insurance markets. This article describes a new tool to implement an extension of the PC test based on a new family of regression models, the multivariate ordered logit, designed to study how the joint distribution of two or more ordered response variables depends on exogenous covariates. We present an application of our proposed extension of the PC test to the Medigap health insurance market in the United States. Results reveal that the risk–coverage association is not homogeneous across coverage and risk categories, and depends on individual so…

Discrete Time Portfolio Selection with Lévy Processes

2007

This paper analyzes discrete time portfolio selection models with Lévy processes. We first implement portfolio models under the hypotheses the vector of log-returns follow or a multivariate Variance Gamma model or a Multivariate Normal Inverse Gaussian model or a Brownian Motion. In particular, we propose an ex-ante and an ex-post empirical comparisons by the point of view of different investors. Thus, we compare portfolio strategies considering different term structure scenarios and different distributional assumptions when unlimited short sales are allowed.

The silver collection of San Gennaro treasure (Neaples): A multivariate statistic approach applied to X-ray fluorescence data

2021

Abstract In this work we report an X-ray fluorescence spectroscopy (XRF) study combined with a multivariate approach allowing to detect compositional differences and similarities among the alloys used in realization of silver collection of San Gennaro items collection. The San Gennaro treasure in Naples (Italy) represents, in fact, one of the most important silver collections in the world. The classification of the collection items is very complex, not only for the large number of objects, but also in consideration that between 1600 and 1700, in Naples, more than 350 laboratories were active, most of them specialized in specific art of work. As a consequence, a given collection object could…

P0792 : Baseline factors associated with increased SVR rates in 123 treatment-naïve chronic HCV genotype 1 patients treated with a shortened 12-week …

2015

An exponential spline interpolation for unequally spaced data points

1982

Effectiveness of a mobile app intervention to prevent dating violence in residential child care

2020

ABSTRACT This study focuses on the effectiveness of an app-based, monitored intervention using the Liad@s app in a residential youth-care setting. The aim of this intervention is to reduce maladaptive beliefs and attitudes linked to dating violence: distortions or myths about romantic love and hostile and benevolent dimensions of sexism. A quasi-experimental pre-post study with a control group was carried out. Participants were 71 adolescents from 9 group homes in Valencia (Spain). The outcomes measures were hostile and benevolent sexism (Ambivalent Sexism Inventory - ASI), ambivalence and prejudice towards men (Ambivalence toward Men Inventory - AMI), and myths about romantic love. The res…