Search results for " Correspondence Analysi"
showing 10 items of 44 documents
Application of the new multimetric MMI_PL index for biological water quality assessment in reference and human-impacted streams (Poland, the Slovak R…
2014
Abstract A new multimetric MMI_PL index, which is based on the macroinvertebrate composition and combines six single key metrics, has already been implemented in Poland according to the requirements of the EU Water Framework Directive. The objectives of our survey were to assess the biological water quality using the new multimetric MMI_PL index in both reference and human-impacted streams, to analyze whether the values of the new multimetric index properly reflect the ecological status of the water in upland and mountain streams as well as to determine which environmental factors influence the distribution of benthic macroinvertebrates and the values of the metrics. The study was carried o…
Ordination analysis and bioindices based on zoobenthos communities used to assess pollution of a lake in southern Finland
1990
The suitability of an ordination method, detrended correspondence analysis (DCA), was tested in assessing the degree of pollution of a large lake on the basis of the zoobenthos communities. Lake Etela-Saimaa, in southern Finland, was originally oligotrophic but is now heavily loaded by effluents from the wood-processing industry. Comparison between areas was complicated by variation in the water depths of the lake sub-basins. A horizontal pollution gradient could, however, easily be detected by means of the DCA in both the profundal and sublittoral zones. The benthic quality index (BQI) based on the composition of the profundal chironomid fauna failed at some stations because the indicator …
Supervised vs Unsupervised Latent DirichletAllocation: topic detection in lyrics.
2020
Topic modeling is a type of statistical modeling for discovering the abstract ``topics'' that occur in a collection of documents. Latent Dirichlet Allocation (LDA) is an example of topic model and is used to classify text in a document to a particular topic. It builds a fixed number of topics starting from words in each document modeled according to a Dirichlet distribution. In this work we are going to apply LDA to a set of songs from four famous Italian songwriters and split them into topics. This work studies the use of themes in lyrics using statistical analysis to detect topics. Aim of the work is to underline the main limits of the standard unsupervised LDA and to propose a supervised…
European public perceptions of homelessness: A knowledge, attitudes and practices survey
2019
peer-reviewed Background Addressing Citizen’s perspectives on homelessness is crucial for the design of effective and durable policy responses, and available research in Europe is not yet substantive. We aim to explore citizens’ opinions about homelessness and to explain the differences in attitudes within the general population of eight European countries: France, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, and Sweden. Methods A nationally representative telephone survey of European citizens was conducted in 2017. Three domains were investigated: Knowledge, Attitudes, and Practices about homelessness. Based on a multiple correspondence analysis (MCA), a generalized linear mod…
Combined effect of different factors on weight status and cardiometabolic risk in Italian adolescents
2019
Background The observed increase in body weight and cardiometabolic risk (CR) in youth from developed countries contributes to the global burden of chronic diseases in adult age. The aim of this work is to provide a patterning of the associations between different factors and the weight status and CR of the subjects involved in the Italian ministerial ASSO project. Methods This study involved 919 students from high schools in Palermo. Weight, height and waist circumference were collected by trained teachers; weight status was estimated by the BMI cut-offs for adolescents and CR through the waist-to-height ratio. Questionnaires were administered through the web-based ASSO-NutFit software. Ch…
Effects of environmental and spatial variables on lotic ostracod metacommunity structure in the Iberian Peninsula
2015
The heterogeneous distribution of aquatic species in lotic environments has been studied little in terms of metacommunity theory. Previous empirical tests have found significant spatial and environmental effects in pond and lake communities, but this has not yet been clearly established for stream networks. We conducted a multi-season survey of mountain streams in the Iberian Peninsula. We recorded GIS and in situ environmental data and collected biological samples to determine ostracods and macroinvertebrates and identified 41 ostracod species, the most common belonging to genera Herpetocypris , Sarscypridopsis , and Ilyocypris . A generalized linear model analysis showed that thermal rang…
An extended Benthic Quality Index for assessment of lake profundal macroinvertebrates: addition of indicator taxa by multivariate ordination and weig…
2014
AbstractThe chironomid Benthic Quality Index (BQI) is a widely used metric in assessments of lake status. The BQI is based on 7 indicator taxa, which like most profundal fauna, often occur sporadically in low densities. Hence, a major weakness of the index is that it cannot be calculated when indicator taxa are not captured. Thus, an extension of the BQI that incorporates more macroinvertebrate taxa is desirable. We used 2 statistical approaches (Detrended Correspondence Analysis and Weighted Averaging) to estimate new benthic quality indicator scores for profundal macroinvertebrate taxa and to construct modified BQIs called Profundal Invertebrate Community Metrics (PICMs). We calibrated th…
Subfossil chironomid assemblages in deep, stratified European lakes: relationships with temperature, trophic state and oxygen
2010
Summary 1. The distributions of subfossil remains of chironomid larvae in 28 large, deep and stratified lakes in Europe were examined in surface sediments along a latitudinal transect ranging from northern Sweden to southern Italy. 2. Canonical correspondence analysis (CCA) showed that summer surface water and July air temperature, as well as total phosphorus (TP) concentrations, hypolimnetic oxygen availability and conductivity were statistically significant (P < 0.05) explanatory variables explaining between 11 and 14% of the variance in the chironomid data. 3. Owing to the spatial scale covered by our study, many environmental variables were covarying. Temperature, TP concentration and o…
Distribution and habitat selection of wintering birds in urban environments
1998
Habitat selection of wintering land-birds was studied in 31 human settlements in Finland. A total of 26 wintering bird species representing 5155 individuals were observed. Between-year variation (CVB%) and short-term fluctuation within one winter (CVW%) in species richness (CVB=10% CVW=15%) were low, as were total numbers of birds (CVB=22% CVW=24%) and populations of the most common bird species (CVB=20–40% CVW=15–47%). The most abundant bird species (e.g., Passer domesticus, Parus major and Pica pica) occurred in most of the study sites. The total densities of omnivorous birds, sedentary birds and bird species that commonly use feeding tables were higher in a heavily urbanized areas than i…
Revista electrónica de investigación y evaluación educativa
2016
Este estudio evalúa un procedimiento nuevo para el análisis “micro-sociométrico” de los patrones relacionales de género en el alumnado adolescente, lo que se analiza aplicando Análisis de Correspondencias Múltiples (ACM). El propósito del estudio es desarrollar y validar la Escala de Preferencias Relacionales de Género (EPRG), con el fin de obtener datos válidos y fiables que permitan reconocer la predisposición de las chicas y los chicos adolescentes a relacionarse con sus iguales; y, si las relaciones que establecen están condicionadas por la socialización diferencial de género que propone el patriarcado (Bosch, Ferrer & Alzamora, 2006; Lagarde, 1996; Lomas, 2007; Lorente, 2007; Rodríguez…