Search results for "Function analysis"
showing 10 items of 28 documents
Sexing birds using discriminant function analysis: a critical appraisal.
2011
9 pages; International audience; Discriminant function analysis (DFA) based on morphological measurements is a quick, inexpensive, and efficient method for sex determination in field studies on cryptically monomorphic bird species. However, behind the apparent standardization and relative simplicity of DFA lie subtle differences and pitfalls that have been neglected in some studies. Most of these concerns directly affect assessment of the discriminant performance, a parameter of crucial importance in practice because it provides a measure of the quality of an equation that may be used in later field studies. Using results from 141 published studies and simulations based on a large data set …
Relationship between eating styles and temperament in an Anorexia Nervosa, Healtlhy Control, and Morbid Obesity female sample.
2014
Contains fulltext : 127209.pdf (Publisher’s version ) (Closed access) Objectives: Eating styles have been studied in both Obesity (OB) and Eating Disorders (ED), but they have not been examined in these two weight conditions together. The present study explores differences in eating styles in an Anorexia Nervosa (AN) and OB sample, compared to Healthy Controls (HC), and it analyses their relationship with Body Mass Index (BMI) and personality traits. Method: The total sample consisted of 291 female participants (66 AN, 79 OB and 146 HC). Evaluation: Assessment measures included the Dutch Eating Behaviour Questionnaire-DEBQ- and the Temperament and Character Inventory-Revised-TCI-R-. Results…
Artificial Neural Networks and Linear Discriminant Analysis: A Valuable Combination in the Selection of New Antibacterial Compounds
2004
A set of topological descriptors has been used to discriminate between antibacterial and nonantibacterial drugs. Topological descriptors are simple integers calculated from the molecular structure represented in SMILES format. The methods used for antibacterial activity discrimination were linear discriminant analysis (LDA) and artificial neural networks of a multilayer perceptron (MLP) type. The following plot frequency distribution diagrams were used: a function of the number of drugs within a value interval of the discriminant function and the output value of the neural network versus these values. Pharmacological distribution diagrams (PDD) were used as a visualizing technique for the i…
Evaluation of intraocular pressure and other biomechanical parameters to distinguish between subclinical keratoconus and healthy corneas
2021
(1) Purpose: To assess the main corneal response differences between normal and subclinical keratoconus (SCKC) with a Corvis® ST device. (2) Material and Methods: We selected 183 eyes of normal patients, of a mean age of 33 ± 9 years and 16 eyes of patients with SCKC of a similar mean age. We measured best corrected visual acuity (BCVA) and corneal topography with a Pentacam HD device to select the SCKC group. Biomechanical measurements were performed using the Corvis® ST device. We carried out a non-parametric analysis of the data with SPSS software (Wilcoxon signed rank-test). (3) Results: We found statistically significant differences between the control and SCKC groups in some corneal b…
Pharmacological distribution diagrams: a tool for de novo drug design.
1996
Abstract Discriminant analysis applied to SAR studies using topological descriptors allows us to plot frequency distribution diagrams: a function of the number of drugs within an interval of values of discriminant function vs. these values. We make use of these representations, pharmacological distribution diagrams (PDDs), in structurally heterogeneous groups where generally they adopt skewed Gaussian shapes or present several maxima. The maxima afford intervals of discrimianant function in which exists a good expectancy to find new active drugs. A set of β-blockers with contrasted activity has been selected to test the ability of PDDs as a visualizing technique, for the identification of n…
The Role of Individual and Relational Characteristics on Alcohol Consumption among Italian Adolescents: A Discriminant Function Analysis
2013
The aim of the present study was to explore the association between family functioning, coping strategies, peer influences and alcohol use among Italian adolescents. Nine hundred and sixty-three Italian adolescents, aged from 14 to 17 years, completed self-report measures assessing alcohol use, family functioning, and coping strategies. According to previous research, adolescents were categorized into non-drinkers, social, binge and heavy drinkers. Results showed that adolescents belonging to groups characterized by alcohol misuse differ in terms of coping strategies, family functioning dimensions, and typology of friends. In particular, heavy drinkers appeared to have more friends who drin…
Multiple morphological characters needed for field identification of cryptic long‐eared bat species around the Swiss Alps
2010
The identification of cryptic species may significantly change our view about their distribution, abundance, ecology and therefore conservation status. In the European Alps, molecular studies have revealed the existence of three sibling species of plecotine bats Plecotus auritus, Plecotus austriacus and, very recently, Plecotus macrobullaris. Knowledge of the ecological niche partitioning of cryptic species is a requisite to develop sound conservation policies. Yet, this requests the development of unambiguous identification methods easily applicable in the field. This study investigates the reliability of several morphological methods used for species recognition and proposes a new identif…
Correspondence between regional delineations and spatial patterns in macroinvertebrate assemblages of boreal headwater streams
2002
AbstractGeographical stratification may provide a useful framework for stream management programs, yet most studies testing the utility of such stratifications have been conducted in temperate regions. We studied the correspondence between regional delineations (5 ecoregions, 11 subecoregions), environmental characteristics, and benthic macroinvertebrate assemblages in 156 boreal headwater streams in Finland, using a combination of principal components analysis, nonmetric multidimensional scaling, and discriminant function analysis (DFA). Both stream characteristics and macroinvertebrate assemblage structure showed a closer correspondence to ecoregions than to subecoregions, a pattern partl…
A comparison of three statistical methods for analysing extinction threat status
2013
SUMMARYThe International Union for Conservation of Nature (IUCN) Red List provides a globally-recognized evaluation of the conservation status of species, with the aim of catalysing appropriate conservation action. However, in some parts of the world, species data may be lacking or insufficient to predict risk status. If species with shared ecological or life history characteristics also tend to share their risk of extinction, then ecological or life history characteristics may be used to predict which species may be at risk, although perhaps not yet classified as such by the IUCN. Statistical models may be a means to determine whether there are non-threatened or unclassified species that s…
Two distinct pathways for Developmental Coordination Disorder: Persistence and resolution
2003
This article describes the perceptual motor, educational and social outcome of early motor delay in a group of 17-18 year old Finnish adolescents who were originally evaluated at age 5. The study group consisted of 65 adolescents: 22 with significant motor problems (or developmental coordination disorder, DCD), 23 with minor motor problems (intermediate group) and 20 controls. The goal of this study was to reassess the results obtained when they were age 15 and to determine whether the variables used earlier could still discriminate the adolescents at age 17. The results showed that at age 17 all perceptual motor tasks differentiated the three groups. The DCD group performed less well than …