Search results for "discriminant function"
showing 10 items of 25 documents
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…
Discriminating uniparental and biparental breeding strategies by monitoring nest temperature
2017
10 pages; International audience; Birds exhibit a wide diversity of breeding strategies. During incubation or chick-rearing, parental care can be either uniparental, by either the male or the female, or biparental. Understanding the selective pressures that drive these different strategies represents an exciting challenge for ecologists. In this context, assigning the type of parental care at the nest (e.g. biparental or uniparental incubation strategy) is often a prerequisite to answering questions in evolutionary ecology. The aim of this study was to produce a standardized method unequivocally to assign an incubation strategy to any Sanderling Calidris alba nest found in the field by moni…
Computer-assisted sperm morphometry fluorescence-based analysis has potential to determine progeny sex
2016
This study was designed to determine the ability of computer-assisted sperm morphometry analysis (CASA-Morph) with fluorescence to discriminate between spermatozoa carrying different sex chromosomes from the nuclear morphometrics generated and different statistical procedures in the bovine species. The study was divided into two experiments. The first was to study the morphometric differences between X- and Y-chromosome-bearing spermatozoa (SX and SY, respectively). Spermatozoa from eight bulls were processed to assess simultaneously the sex chromosome by FISH and sperm morphometry by fluorescence-based CASA-Morph. SX cells were larger than SY cells on average (P < 0.001) although with impo…
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…
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…
Discrimination and selection of new potential antibacterial compounds using simple topological descriptors.
2003
Abstract The aim of the work was to discriminate between antibacterial and non-antibacterial drugs by topological methods and to select new potential antibacterial agents from among new structures. The method used for antibacterial activity selection was a linear discriminant analysis (LDA). It is possible to obtain a QSAR interpretation of the information contained in the discriminant function. We make use of the pharmacological distribution diagrams (PDDs) as a visualizing technique for the identification and selection of new antibacterial agents.
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 …
Search compounds with antimicrobial activity by applying molecular topology to selected quinolones.
2003
Molecular topology was used to obtain substances with antimicrobial activity. Selected quinolones were employed to develop the corresponding connectivity functions and discriminant equation. Limiting functions were selected that allowed the discriminant function to more efficiently distinguish substances with and without antibacterial activity. Antibacterial tests were run to confirm the theoretically established activity.
Distribution of Brachionus species in Spanish mediterranean wetlands
1987
In this study 200 zooplankton samples were Burjassotcollected (1979–1980), from 57 different wetlands in coastal Mediterranean Spain (CMS) and examined for the occurrence of Brachionus species. Data on 17 separate physical and chemical features of these water bodies were obtained from samples collected at the same time. Ten different Brachionus species were found in these wetlands, but only six occurred frequently enough to allow further examination of their distributional patterns using multivariate discriminant analysis. To separate these species, three analyses were performed using the 17 physical and chemical parameters, or their ratios. Three discriminant functions accounted for 80% or…
Distinctive amino acid residue periodicities in terminal sequences of type III and type I secreted proteins from proteobacteria
2007
AbstractThe Fourier transform (FT) method was applied to specify the distribution of 14 predefined groups of amino acids (64 residues) at both termini of annotated type III and type I secreted proteins from proteobacteria. Type I proteins displayed a higher occurrence of significant periodicities at both C-and N-termini, indicating potent features to discriminate between secretion types, particularly by the use of variables selected from the full periodicity profiles at 19 orders of FT. The Fishers linear discriminant analysis, together with the stepwise selection of variables throughout equal pairs of combinations for all predefined groups of residues, revealed the C-terminal harmonics of …