Search results for "Trait"

Cocaine addiction and personality: a mathematical model.

2010

The existence of a close relation between personality and drug consumption is recognized, but the corresponding causal connection is not well known. Neither is it well known whether personality exercises an influence predominantly at the beginning and development of addiction, nor whether drug consumption produces changes in personality. This paper presents a dynamic mathematical model of personality and addiction based on the unique personality trait theory (UPTT) and the general modelling methodology. This model attempts to integrate personality, the acute effect of drugs, and addiction. The UPTT states the existence of a unique trait of personality called extraversion, understood as a di…

Building up adjusted indicators of students' evaluation of university courses using generalized item response models

2012

This article advances a proposal for building up adjusted composite indicators of the quality of university courses from students’ assessments. The flexible framework of Generalized Item Response Models is adopted here for controlling the sources of heterogeneity in the data structure that make evaluations across courses not directly comparable. Specifically, it allows us to: jointly model students’ ratings to the set of items which define the quality of university courses; explicitly consider the dimensionality of the items composing the evaluation form; evaluate and remove the effect of potential confounding factors which may affect students’ evaluation; model the intra-cluster variabilit…

A note on alternative parameterizations of a model for evaluating agreement between two tests.

2004

The agreement between two competing tests which purport to measure the same trait is a common concern in test development. In this paper three alternative parameterizations of the measurement model useful in this context are presented. Both one-factor and two-factor approaches are applied. Lord's classic example, where the main problem is to investigate whether time limits represent an extra speed component in a vocabulary test, is used to illustrate the ideas.

Flexible latent trait aggregation to analyze employability after the Ph.D. in Italy

2015

The analysis of satisfaction, employability and economic perspectives after the Ph.D. in Italy has not received adequate attention in the past, especially in terms of comparison among universities. To analyze these aspects, in this paper we consider data from the survey ‘Statistica in TEma di Laureati e LAvoro’ on doctors who achieved the title on 2007, 2008 and 2009 [CILEA, Laureati STELLA, indagine occupazionale post-dottorato, dottori di ricerca 2007–2008, Tech. Rep., CILEA, Segrate, 2010; CILEA,Laureati STELLA, indagine occupazionale post-dottorato, dottori di ricerca 2008–2009, Tech. Rep., CILEA, Segrate, 2011]. To deal with the complex, multidimensional nature of the concept, we propo…

New records of leatherback sea turtle, Dermochelys coriacea (Vandelli, 1761) (Testudines: Dermochelyidae) in the Strait of Sicily

2017

We report three new records of leatherback sea turtle, Dermochelys coriacea (Vandelli, 1761) recovered in February 2011 and in spring-summer 2016 in the Strait of Sicily. The individuals were handed over dead to the IZS of Palermo for necropsy. The first specimen measured 139 and 91 cm of CCL and CCW respectively and was found beached and alive but died a few hours later for septicemia. The second measured 110 cm of CCL and 83 cm of CCW and showed a deep wound on its head probably due to contact with a boat propeller. The third individual measured 134 cm of CCL and 96 cm of CCW and had plastic bags, a piece of fishing net and debris of various nature in the stomach. For the second individua…

Genetic and morphometric variation of Mediterranean hake, Merluccius merluccius, in the Strait of Sicily (Central Mediterranean)

2004

Allozyme, morphometric and growth analyses were applied to samples collected in the Strait of Sicily (central Mediterranean Sea) to test the hypothesis of the existence of a unique hake stock (Merluccius merluccius) in the study area. The level of genetic variation was detected from five polymorphic loci (ADH*, PGI-1*, PGI-2*, PGM*, SOD-1*). The average observed heterozygosity amounted to 0.421, while the average expected was 0.353. Weir & Cockerham statistics showed no heterogeneity, except for the single PGI? locus (theta = 0.011; P 0.05). Morphometric analyses revealed some differentiation. Females showed different relationships in six out of eight morphometric indices with total length,…

Use of Hydroacoustic Methods for the Identification of Potential Seabed Habitats for Small Pelagic Fish Schools in the Strait of Sicily

2011

Larval fish assemblages in the central Mediterranean Sea: spatio-temporal dynamics and biological effects on early life stage of Sardinella aurita (P…

Subjective Perception of Time: Research Applied on Dynamic Psychology

2017

The time marked by the clock hands, the so-called “objective time,” is deeply different from the one perceived by the individual. Starting from this hypothesis, directly connected to the subjective...

Plant trait‐environment relationships in tundra are consistent across spatial scales

2023

Patterns and processes shaping ecosystems vary across spatiotemporal scales. As plant functional traits reflect ecosystem properties, investigating their relationships with environment provides an important tool to understand and predict ecosystem structure and functioning. This is particularly important in the tundra where a changing climate may trigger severe alterations in plant communities as both summer and winter conditions are changing. Here, we investigate the relationships between key environmental drivers including summer temperature, snow persistence, topographic position and soil pH, and species height, specific leaf area (SLA) and seed mass as plant traits. The study is carried…