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Separate Cluster (separate + cluster)
Selected AbstractsSimilar breakdown rates and benthic macroinvertebrate assemblages on native and Eucalyptus globulus leaf litter in Californian streamsFRESHWATER BIOLOGY, Issue 4 2010IGOR LA Summary 1.,Eucalyptus globulus, a tree species planted worldwide in many riparian zones, has been reported to affect benthic macroinvertebrates negatively. Although there is no consensus about the effects of Eucalyptus on aquatic macrobenthos, its removal is sometimes proposed as a means of ecological restoration. 2.,We combined the sampling of macroinvertebrates with measurement of the colonisation of leaf packs in mesh bags, to examine the effects of riparian Eucalyptus and its litter on benthic macroinvertebrates in three small streams in California, U.S.A. Each stream included one reach bordered by Eucalyptus (E-site) and a second bordered by native vegetation (N-site). 3.,The macrobenthos was sampled and two sets of litter bags were deployed at each site: one set with Eucalyptus litter (Euc-bags) and one with mixed native tree litter (Nat-bags) containing Quercus, Umbellularia, Acer and Alnus. Bags were exposed for 28, 56 and 90 days and this experiment was repeated in the autumn, winter and spring to account for effects of changing stream flow and insect phenology. 4.,Litter input (average dry mass: 950 g m,2 year,1 in E-sites versus 669 g m,2 year,1 in N-sites) was similar, although in-stream litter composition differed between E- and N-sites. Litter broke down at similar rates in Euc-bags and Nat-bags (0.0193 day,1 versus 0.0134 day,1), perhaps reflecting the refractory nature of some of the leaves of the native trees (Quercus agrifolia). 5.,Summary metrics for macroinvertebrates (taxon richness, Shannon diversity, pollution tolerance index) did not differ significantly between the E and N sites, or between Euc-bags and Nat-bags. No effect of exposure time or site was detected by ordination of the taxa sampled. However, distinct seasonal ordination clusters were observed in winter, spring and autumn, and one of the three streams formed a separate cluster. 6.,The presence of Eucalyptus was less important in explaining the taxonomic composition of the macrobenthos than either ,season' or ,stream'. Similarly, these same two factors (but not litter species) also helped explain the variation in leaf breakdown. We conclude that patches of riparian Eucalyptus and its litter have little effect on stream macrobenthos in this region. [source] Clustering of Saccharomyces boulardii strains within the species S. cerevisiae using molecular typing techniquesJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2002G. Mitterdorfer Aims: This study was undertaken to characterize and differentiate therapeutically relevant Saccharomyces yeasts. Among the isolates were so-called Saccharomyces boulardii strains, which are considered as probiotic agents, but whose taxonomic assignment is controversial. Moreover, the discriminative power of the applied molecular typing techniques should be evaluated. Methods and Results: Genotyping was performed using species-specific polymerase chain reaction (PCR), randomly amplified polymorphic DNA-PCR, restriction fragment length polymorphism analysis of rDNA spacer regions and pulsed-field gel electrophoresis. Species-specific PCR assigned all of the product isolates to the species S. cerevisiae. By combining the other techniques, all isolates could be discriminated. Moreover, it could be demonstrated that probiotic S. boulardii strains form a separate cluster located within the species. Conclusions: With the exception of species-specific PCR, all of the applied methodologies were suitable for subspecies typing and indicated a close relationship between the probiotic strains. Significance and Impact of the Study: The methods applied in this study are considered powerful tools for quality control of therapeutically relevant yeasts. It is of crucial importance, especially regarding S. boulardii yeasts, to verify the identity of the correct strain, since the beneficial properties are considered to be strain-specific. [source] A new genotype 2 subcluster identified among GBV-C strains circulating in the Lisbon metropolitan area of PortugalJOURNAL OF MEDICAL VIROLOGY, Issue 3 2010Cristina Branco Abstract The rate of infection by the GBV-C virus was investigated in a group of 214 individuals at high risk of infection with parenterally transmitted viruses, and all living in the Lisbon metropolitan area (Portugal). RNA was extracted from plasma samples, and a fragment of the 5,-UTR was amplified by RT-PCR, disclosing a high prevalence of infection (40.7%). Most probably due to similar modes of viral transmission, the majority of GBV-C (+) individuals were found to be coinfected with HIV and/or HCV. A genomic region covering part of the E1/E2 glycoprotein coding sequence was amplified from approximately half of the GBV-C positive samples (44/87). Phylogenetic analysis of nucleotide sequences showed segregation of Portuguese GBV-C strains with genotype 1 (G1, n,=,10) and genotype 2 (G2, n,=,24) references. Genotype 1 was significantly associated with the African descent of those infected. Curiously, some of the strains assigned to genotype 2 were shown to form a separate cluster (designated G2*) in both neighbor-joining and Bayesian phylogenetic trees, which was confirmed by multivariate principal coordinate analysis. However, analysis of the distribution of intra- and intergenotype genetic distances support the hypothesis that rather than corresponding to a new viral genotype, G2* is a geographical subcluster within the genotype 2 radiation. J. Med. Virol. 82:452,459, 2010. © 2010 Wiley-Liss, Inc. [source] Immunohistopathological re-evaluation of adenocarcinoma of the lung with mixed subtypes using a tissue microarray technique and hierarchical clustering analysisPATHOLOGY INTERNATIONAL, Issue 12 2007Gehan Gamal To re-evaluate adenocarcinoma, mixed subtypes (ADMIX) of the lung, a total of 201 cases were classified into three main subgroups according to the most differentiated histological growth pattern; namely bronchioloalveolar carcinoma (BAC)-mixed, which was the most predominant (73.1%), papillary (PAP)-mixed (21.9%), and acinar-mixed (5%). The PAP-mixed was significantly male predominant and had more progressed clinicopathological features. A significant cytological difference was observed among the three subgroups. A tissue microarray was constructed and immunohistochemistry was undertaken using 15 biomarkers. Hierarchical clustering analysis was separately applied to the immunohistochemical results of ADMIX and ADMIX subgroups, and it was found that most acinar-mixed cases were placed in a separate cluster, while the BAC-mixed and PAP-mixed failed to form significant independent clusters. The antibody clustering profile for the acinar-mixed was clearly different from that for the BAC-mixed or PAP-mixed, but the PAP-mixed shared a dendrogram profile with the other two subgroups. Statistically, approximately half of the 15 biomarkers were significant for differentiating between ADMIX subgroups and between different histological growth patterns. In conclusion, ADMIX can be classified into three histopathological subgroups according to the most differentiated growth pattern, of which a PAP growth pattern might indicate more aggressive behavior than that of a BAC growth pattern. [source] Epidemiological evidence that vegetatively propagated, solanaceous plant species act as sources of Potato spindle tuber viroid inoculum for tomatoPLANT PATHOLOGY, Issue 1 2010J. Th. In autumn 2006 in the Netherlands, Potato spindle tuber viroid (PSTVd) infections were detected in 42·3 and 71·9% of professionally grown lots of Brugmansia spp. and Solanum jasminoides respectively. The infected lots contained 73 985 and 431 374 plants, respectively, demonstrating the presence of many potential viroid sources for tomato (Solanum lycopersicum). PSTVd was identified in cultivars of Brugmansia × candida, B. × flava, B. sanguinea, B. suaveolens and unspecified Brugmansia species/cultivars. Most infected lots of Brugmansia spp. originated from a single Dutch nursery; most infected lots of S. jasminoides originated abroad. Sequence analysis revealed that the PSTVd genomes from Brugmansia spp. contained an average of 360 nt, whereas all genomes from S. jasminoides except one consisted of 357 nt. Furthermore, the collective PSTVd genotypes showed polymorphism at four or more positions, except for two cases in which genotypes from Brugmansia spp. and S. jasminoides were identical. Phylogenetic studies showed that PSTVd genotypes from Brugmansia spp. and S. jasminoides grouped apart from each other and from PSTVd isolates from potato (Solanum tuberosum) and Physalis peruviana. The PSTVd genotypes from tomato did not form a separate cluster, but were dispersed over clusters of vegetatively or partly vegetatively propagated plant species, i.e. potato, P. peruviana and S. jasminoides. Moreover, mechanical inoculation of the predominant PSTVd genotypes from S. jasminoides to tomato was successful. These results provide evidence that vegetatively propagated, solanaceous plant species have been sources of infection for tomato crops in the past. [source] Usefulness of Nonlinear Analysis of ECG Signals for Prediction of Inducibility of Sustained Ventricular Tachycardia by Programmed Ventricular Stimulation in Patients with Complex Spontaneous Ventricular ArrhythmiasANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 3 2008Ornella Durin M.D. Introduction: The aim of our study was to assess the effectiveness of the nonlinear analysis (NLA) of ECG in predicting the results of invasive electrophysiologic study (EPS) in patients with ventricular arrhythmias. Methods: We evaluated 25 patients with history of cardiac arrest, syncope, sustained, or nonsustained ventricular tachycardia (VT). All patients underwent electrophysiologic study (EPS) and nonlinear analysis (NLA) of ECG. The study group was compared with a control group of 25 healthy subjects, in order to define the normal range of NLA. ECG was processed in order to obtain numerical values, which were analyzed by nonlinear mathematical functions. Patients were classified through the application of a clustering procedure to the whole set of functions, and the correlation between the results of nonlinear analysis of ECG and EPS was tested. Results: NLA assigned all patients with negative EPS to the same class of healthy subjects, whereas the patients in whom VT was inducible had been correctly and clearly isolated into a separate cluster. In our study, the result of NLA with application of the clustering technique was significantly correlated to that of EPS (P < 0.001), and was able to predict the result of EPS, with a negative predictive value of 100% and a positive predictive value of 100%. Conclusions: NLA can predict the results of EPS with good negative and positive predictive value. However, further studies are needed in order to verify the usefulness of this noninvasive tool for sudden death risk stratification in patients with ventricular arrhythmias. [source] Prospective Follow-Up of Empirically Derived Alcohol Dependence Subtypes in Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC): Recovery Status, Alcohol Use Disorders and Diagnostic Criteria, Alcohol Consumption Behavior, Health Status, and Treatment SeekingALCOHOLISM, Issue 6 2010Howard B. Moss Background:, We have previously reported on an empirical classification of Alcohol Dependence (AD) individuals into subtypes using nationally representative general population data from the 2001 to 2002 Wave 1 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) and latent class analysis. Our results suggested a typology of 5 separate clusters based upon age of onset of AD, multigenerational familial AD, rates of antisocial personality disorder (ASPD), endorsement of specific AD and Alcohol Abuse (AA) criteria, and the presence of comorbid mood, anxiety, and substance use disorders (SUD). In this report, we focus on the clinical follow-up of these cluster members in Wave 2 of the NESARC (2004 to 2005). Methods:, The mean interval between NESARC Wave 1 and NESARC Wave 2 interviews was 36.6 (SD = 2.6) months. For these analyses, we utilized a Wave 2 NESARC sample that was comprised of a total of 1,172 individuals who were initially ascertained as having past-year AD at NESARC Wave 1 and initially subtyped into one of 5 groupings using latent class analysis. We identified these subtypes as: (i) Young Adult, characterized by very early age of onset, minimal family history, and low rates of psychiatric and SUD comorbidity; (ii) Functional, characterized by older age of onset, higher psychosocial functioning, minimal family history, and low rates of psychiatric and SUD comorbidity; (iii) Intermediate Familial, characterized by older age of onset, significant familial AD, and elevated comorbid rates of mood disorders SUD; (iv) Young Antisocial, characterized by early age of onset and elevated rates of ASPD, significant familial AD, and elevated rates of comorbid mood disorders and SUD; (v) Chronic Severe, characterized by later onset, elevated rates of ASPD, significant familial AD, and elevated rates of comorbid mood disorders and SUD. In this report, we examine Wave 2 recovery status, health status, alcohol consumption behavior, and treatment episodes based upon these subtypes. Results:, Significantly fewer of the Young Adult and Functional subtypes continued to meet full DSM-IV AD criteria in Wave 2 than did the Intermediate Familial, the Young Antisocial, and the Chronic Severe subtypes. However, we did not find that treatment seeking for alcohol problems increased over Wave 1 reports. In Wave 2, Young Antisocial and Chronic Severe subtypes had highest rates of past-year treatment seeking. In terms of health status, the Intermediate Familial, the Young Antisocial, and the Chronic Severe subtypes had significantly worse mental health scores than the Young Adult and Functional subtypes. For physical health status, the Functional, Intermediate Familial, Young Antisocial, and the Chronic Severe subtypes had significantly worse scores than the Young Adult subtype. In terms of alcohol consumption behavior, the Young Adult, Functional, and Young Antisocial subtypes significantly reduced their risk drinking days between Wave 1 and Wave 2, whereas the Intermediate Familial and the Chronic Severe subtypes did not. Discussion:, The results suggest that the empirical AD typology predicts differential clinical outcomes 3 years later. Persistence of full AD, treatment seeking, and worse mental health status were associated most strongly with those subtypes manifesting the greatest degree of psychiatric comorbidity. Reductions in alcohol consumption behavior and good physical health status were seen among the 2 younger subtypes. Overall, the least prevalent subtype, the Chronic Severe, showed the greatest stability in the manifestations of AD, despite having the highest rate of treatment seeking. [source] Chemical study of triterpenoid resinous materials in archaeological findings by means of direct exposure electron ionisation mass spectrometry and gas chromatography/mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2006Francesca Modugno A systematic study of standard triterpenes (, -amyrine, oleanolic acid, betulin, lupeol, betulinic acid and lupenone) and of raw resinous materials (frankincense resin, mastic resin and birch bark pitch) was performed using direct exposure electron ionisation mass spectrometry (DE-MS) and gas chromatography/mass spectrometry (GC/MS). DE-MS provides a mass spectral fingerprint of organic materials in a few minutes which highlights the compounds that are the main components in the sample. The application of principal component analysis (PCA) on DE-MS data in the mass ranges m/z 181,260 and m/z 331,500, corresponding to the fragmentation of triterpenoid molecules, enabled us to distinguish between different triterpenoid materials such as mastic resin, frankincense resin and birch bark pitch, and to graphically plot the resinous substances in three separate clusters, retaining 89% of the total variance. GC/MS analysis of the same materials has permitted us to elucidate in detail the molecular composition and to identify minor components and species that act as markers of the degradation undergone by the materials. The paper also reports the results for the organic residues contained in an Egyptian censer (5th,7th century AD) which was recovered in the excavation of the Necropolis of Antinoe (Egypt), and for the hafting material found on a Palaeolithic tool recovered at the site of Campitello (Arezzo, Tuscany), dating back to the Mid-Pleistocene period. Although DE-MS was found to be a fast analytical tool, it failed to give any information on the presence of less abundant compounds when applied to mixtures of different materials: only mastic resin was found in the residues from the Roman censer, whereas GC/MS analysis identified the presence of a vegetable oil from Brassicaceae seeds and Pinaceae resin. Birch bark pitch as a pure material was identified in the sample from the Palaeolithic flint flake using both procedures. Copyright © 2006 John Wiley & Sons, Ltd. [source] | |||||||||||||