Search results for "Cluster Analysis"
showing 10 items of 848 documents
Cluster analysis of mrna expression levels identifies multiple sequential patterns following focal cerebral ischemia
2012
AIM The purpose of this study is to detect gene expression patterns following focal cerebral ischemia. MATERIAL AND METHODS 25 male Wistar rats were divided into control (n = 8) and ischemic (n = 17) groups. In the ischemic group, slowly progressing focal ischemia was simulated by two-vein occlusion with spreading depression (SD) a cortical microinjection of KCl induced. Ischemic tissue was removed at 2, 8, 24, or 72 h postischemia. Using semiquantitative reverse transcription polymerase chain reaction, we investigated mRNA expression levels of 13 representative genes related to cerebral ischemia. Cluster analysis of the gene expression levels was done. RESULTS In the ischemic group, the ex…
Goal orientation profile differences on perceived motivational climate, perceived peer relationships, and motivation-related responses of youth athle…
2006
The aims of this study were twofold: (a) to determine if dispositional achievement goal orientation profiles that are reported in the literature would be observed in a sample of youth athletes, and (b) to examine potential achievement goal orientation profile differences on perceptions of the motivational climate, perceptions of peer relationships, and motivation-related responses. Male soccer players (n=223) aged 9-12 years (mean=10.9, s=0.6) completed a multi-section questionnaire containing assessments of dispositional goal (task, ego) orientations, the perceived task- and ego-involving features of the motivational climate, perceived peer acceptance and friendship quality (positive frien…
Reproducibility of CT Radiomic Features within the Same Patient: Influence of Radiation Dose and CT Reconstruction Settings.
2019
Background Results of recent phantom studies show that variation in CT acquisition parameters and reconstruction techniques may make radiomic features largely nonreproduceable and of limited use for prognostic clinical studies. Purpose To investigate the effect of CT radiation dose and reconstruction settings on the reproducibility of radiomic features, as well as to identify correction factors for mitigating these sources of variability. Materials and Methods This was a secondary analysis of a prospective study of metastatic liver lesions in patients who underwent staging with single-energy dual-source contrast material-enhanced staging CT between September 2011 and April 2012. Technique p…
Cluster of cases of Salmonella enterica serotype Rissen infection in a general hospital, Italy, 2007.
2009
In 2007, three strains of Salmonella enterica serotype Rissen (S. Rissen) were isolated in the laboratory of diagnostic microbiology of the General Hospital of Prato, Tuscany, Italy, over a 1 month and half interval of time. The first isolate was recovered on January 26 from an outpatient with enteritis. Then, two strains were isolated on February 16 and March 11 respectively, from central venous catheters of patients who were being hospitalized in two departments of the Hospital. An epidemiologically linked cluster of cases of salmonellosis was suspected. The three strains were submitted to single enzyme-amplified fragment length polymorphism (SE-AFLP) and XbaI macrorestriction and pulsed-…
Screen media usage, sleep time and academic performance in adolescents: clustering a self-organizing maps analysis.
2014
Screen media usage, sleep time and socio-demographic features are related to adolescents' academic performance, but interrelations are little explored. This paper describes these interrelations and behavioral profiles clustered in low and high academic performance. A nationally representative sample of 3,095 Spanish adolescents, aged 12 to 18, was surveyed on 15 variables linked to the purpose of the study. A Self-Organizing Maps analysis established non-linear interrelationships among these variables and identified behavior patterns in subsequent cluster analyses. Topological interrelationships established from the 15 emerging maps indicated that boys used more passive videogames and compu…
Prevalence of diphtheria toxin antibodies in human sera from a cross-section of the Italian population.
1999
Abstract A polycentric study was carried out between 1993 and 1995 in order to evaluate diphtheria immunity on a representative sample of population from different areas of Italy. To determine diphtheria antitoxin, sera from 5187 apparently healthy subjects, divided according to sex and age groups, were titrated using an ELISA indirect method. A basic protective titre of diphtheria antitoxin (>0.01 IU ml −1 ) was found in 4080 (78.6%) subjects. No statistically significant differences between males and females were observed. Our findings show that the proportion of susceptibles increases with age and a high proportion of adults no longer has diphtheria antitoxin at protective levels since t…
Limited cross-border infections in patients newly diagnosed with HIV in Europe
2013
Background: International travel plays a role in the spread of HIV-1 across Europe. It is, however, not known whether international travel is more important for spread of the epidemic as compared to endogenous infections within single countries. In this study, phylogenetic associations among HIV of newly diagnosed patients were determined across Europe.Results: Data came from the SPREAD programme which collects samples of newly diagnosed patients that are representative for national HIV epidemics. 4260 pol sequences from 25 European countries and Israel collected in 2002-2007 were included.We identified 457 clusters including 1330 persons (31.2% of all patients). The cluster size ranged bet…
Dog sperm swimming parameters analysed by computer-assisted semen analysis of motility reveal major breed differences
2019
Dogs have undergone an intensive artificial selection process ever since the beginning of their relationship with humans. As a consequence, a wide variety of well-defined breeds exist today. Due to the enormous variation in dog phenotypes and the unlikely chance of gene exchange between them, the question arises as to whether they should still be regarded as a single species or, perhaps, they be considered as different taxa that possess different reproductive traits. The aim of this study was therefore to characterize some male reproductive traits, focusing on kinematic characteristics of dog spermatozoa from several breeds. Thirty-seven dogs from the following breeds were used: Staffordshi…
Association of tenacious goal pursuit and flexible goal adjustment with out-of-home mobility among community-dwelling older people
2018
Background As people age, functional losses may limit the potential to get outside the home and participate in desired activities and community life. Coping with age-related losses has been reported to be important for psychological well-being. Hitherto is not known whether active use of coping strategies also helps maintain out-of-home mobility. Aims We investigated how two coping strategies, tenacious goal pursuit (TGP; persistency in reaching one’s goals) and flexible goal adjustment (FGA; adjusting one’s goals to changed circumstances), are associated with life-space mobility and perceived autonomy in participation outdoors among community-dwelling older people. Methods Participants (n …
Cross-species transcriptomic analysis elucidates constitutive aryl hydrocarbon receptor activity
2014
Background Research on the aryl hydrocarbon receptor (AHR) has largely focused on variations in toxic outcomes resulting from its activation by halogenated aromatic hydrocarbons. But the AHR also plays key roles in regulating pathways critical for development, and after decades of research the mechanisms underlying physiological regulation by the AHR remain poorly characterized. Previous studies identified several core genes that respond to xenobiotic AHR ligands across a broad range of species and tissues. However, only limited inferences have been made regarding its role in regulating constitutive gene activity, i.e. in the absence of exogenous ligands. To address this, we profiled transc…