Search results for "Cluster Analysis"
showing 10 items of 848 documents
Sensitization to dust mite defines different phenotypes of asthma: A multicenter study
2017
Background Indoor allergens are risk factors for asthma: Thus, the characterization of indoor air quality is important for studying environment–health relationships in children. In particular, Dermatophagoides pteronyssinus is the dominant allergen for asthma. We cross-sectionally investigated the relationships among respiratory symptoms and function, airway inflammation, allergen sensitization, and indoor allergen concentration. Methods One hundred and thirty-two children aging 10-14 years and living in a Southern Mediterranean area were evaluated by parental questionnaires. Spirometry, exhaled nitric oxide (FeNO), skin prick tests, total, and specific serum IgE analyses were performed alo…
Traits that define the different alcohol intensive consume type during the practice of "botellon".
2012
Un fenómeno que en España favorece el actual patrón de consumo de alcohol juvenil es el conocido como botellón. A partir de una investigación financiada por el Plan Nacional sobre Drogas (2004-2007), se recogieron datos de 6009 jóvenes entre 14 y 25 años en tres ciudades españolas, considerando para este trabajo a quienes realizan episodios de consumo intensivo de alcohol (n = 2807). El objetivo ha sido identificar los distintos tipos de consumidores de riesgo intensivos mediante un análisis de conglomerados y establecer el perfil característico de cada uno. Se diferencian cuatro grupos en función de la edad, sexo, cantidad de alcohol y años de consumo. Los estudiantes de secundaria ingiere…
Breed, sex, and litter effects in 2-month old puppies’ behaviour in a standardised open-field test
2017
AbstractA considerable number of studies have reported differences among dog breeds with respect to their genetic profile, cognitive abilities or personality traits. Each dog breed is normally treated as a homogeneous group, however, researchers have recently questioned whether the behavioural profile of modern breeds still reflects their historical function or if the intense divergent selective pressures and geographical barriers have created a more fragmented picture. The majority of studies attempting to assess and compare modern breeds’ personality focused on the evaluation of adult dogs where the potential effects of environmental/human factors on the dogs’ behaviour are hard to discer…
Disentangling the Association of Hydroxychloroquine Treatment with Mortality in Covid-19 Hospitalized Patients through Hierarchical Clustering
2021
The efficacy of hydroxychloroquine (HCQ) in treating SARS-CoV-2 infection is harshly debated, with observational and experimental studies reporting contrasting results. To clarify the role of HCQ in Covid-19 patients, we carried out a retrospective observational study of 4,396 unselected patients hospitalized for Covid-19 in Italy (February–May 2020). Patients’ characteristics were collected at entry, including age, sex, obesity, smoking status, blood parameters, history of diabetes, cancer, cardiovascular and chronic pulmonary diseases, and medications in use. These were used to identify subtypes of patients with similar characteristics through hierarchical clustering based on Gower distan…
Genomic response of the rat brain to global ischemia and reperfusion
2008
To identify genes that are involved in ischemia response of the brain, we have evaluated changes of gene expression in rat cerebrum after 15 min complete global ischemia, followed by reperfusion for 1 h, 6 h or 24 h. The expression profiles of approximately 30,000 transcripts from three subjects in each group (including sham-operated controls) were monitored employing oligonucleotide microarrays. About 20,000 transcripts were detectable in rat brains. The levels of 576 transcripts (approximately 2.9%) were significantly altered in response to experimental ischemia. 419 transcripts were up- and 157 downregulated; 39 transcripts changed after 1 h reperfusion, 174 after 6 h and 462 after 24 h.…
Escherichia coli of human and avian origin: detection of clonal groups associated with fluoroquinolone and multidrug resistance in Italy
2012
Objectives: Poultry have been suggested as a reservoir for fluoroquinolone-resistant extraintestinal pathogenic Escherichia coli (ExPEC). Our aim was to investigate whether genotypes associated with ciprofloxacin and multidrug resistance were shared among human and avian E. coli. Methods: We compared 277 human ExPEC isolates from urinary tract infection (UTI) and sepsis (142 susceptible and 135 ciprofloxacin resistant) and 101 avian isolates (68 susceptible and 33 ciprofloxacin resistant) by antimicrobial resistance phenotype, phylogenetic group and multilocus sequence type (ST). Results: Most ciprofloxacin-resistant isolates from both human and avian sources were multidrug resistant. Human…
Emerging Trends in CRF02_AG Variants Transmission Among Men Who Have Sex With Men in Spain
2013
Structure of rat behavior in hole-board: I) multivariate analysis of response to anxiety
2008
Aim of present paper was to carry out an analysis of rat behavior in hole-board following different multivariate approaches. Thirty male Wistar rats were observed in a hole-board apparatus and their behavior recorded for 10 min through a digital videocamera for a following frame-by-frame analysis. Both descriptive and multivariate analyses were used. Descriptive analysis showed that roughly 85% of the whole behavioral structure encompassed six patterns appearing during the first minute of observation: walking, climbing, rearing, immobile-sniffing, edge-sniff and head-dip. As to multivariate approach, cluster analysis showed three main dyadic associations: [edge-sniff/head-dip], [walking/cli…
Multivariate analysis of the modifications induced by an environmental acoustic cue on rat exploratory behavior.
2007
The aim of the present paper is to study by means of a multivariate analysis the modifications induced by an environmental acoustic cue on the structure of rat exploratory behavior. Adult male Wistar rats were observed during the exploration of a soundproof observation box. Each rat was acoustically stimulated after 150 s from the beginning of the experimental session, lasting 300 s, and recorded through a digital videocamera. A frame by frame analysis was thereafter carried out using a professional video-recording system. Thirteen behavioral patterns were selected: immobility, immobile-sniffing, walking, rearing, climbing, chewing, paw-licking, face-grooming, body-grooming, head-turning, t…
Comparison of different statistical approaches to evaluate morphometric sperm subpopulations in men.
2016
This study was designed to characterize morphometric sperm subpopulations in normozoospermic men by using different statistical methods and examining their suitability to classify correctly different sperm nuclear morphologies present in human ejaculates. Ejaculates from 21 normozoospermic men were collected for the study. After semen collection and analysis, samples were prepared for morphometric determination. At least 200 spermatozoa per sample were assessed for sperm morphometry by computer-assisted sperm morphometry analysis (CASA-Morph) using fluorescence. Clustering and discriminant procedures were performed to identify sperm subpopulations from the morphometric data obtained. Cluste…