WorldWideScience

Sample records for twelve distinct clusters

  1. The SLUGGS Survey: Kinematics for over 2500 Globular Clusters in Twelve Early-type Galaxies

    CERN Document Server

    Pota, Vincenzo; Romanowsky, Aaron J; Brodie, Jean P; Spitler, Lee R; Strader, Jay; Foster, Caroline; Arnold, Jacob A; Benson, Andrew; Blom, Christina; Hargis, Jonathan R; Rhode, Katherine L; Usher, Christopher

    2012-01-01

    We present a spectro-photometric survey of 2522 extragalactic globular clusters (GCs) around twelve early-type galaxies, nine of which have not been published previously. Combining space-based and multi-colour wide field ground-based imaging, with spectra from the Keck DEIMOS instrument, we obtain an average of 160 GC radial velocities per galaxy, with a high velocity precision of 15 km/s per GC. After studying the photometric properties of the GC systems, such as their spatial and colour distributions, we focus on the kinematics of metal-poor (blue) and metal-rich (red) GC subpopulations to an average distance of ~8 effective radii from the galaxy centre. Our results show that for some systems the bimodality in GC colour is also present in GC kinematics. The kinematics of the red GC subpopulations are strongly coupled with the host galaxy stellar kinematics. The blue GC subpopulations are more dominated by random motions, especially in the outer regions, and decoupled from the red GCs. Peculiar GC kinematic ...

  2. The OCCASO survey: Presentation and radial velocities of twelve Milky Way Open Clusters

    CERN Document Server

    Casamiquela, L; Jordi, C; Balaguer-Núñez, L; Pancino, E; Hidalgo, S L; Martínez-Vázquez, C E; Murabito, S; del Pino, A; Aparicio, A; Blanco-Cuaresma, S; Gallart, C

    2016-01-01

    Open clusters (OCs) are crucial for studying the formation and evolution of the Galactic disc. However, the lack of a large number of OCs analyzed homogeneously hampers the investigations about chemical patterns and the existence of Galactocentric radial and vertical gradients, or an age-metallicity relation. To overcome this, we have designed the Open Cluster Chemical Abundances from Spanish Observatories survey (OCCASO). We aim to provide homogeneous radial velocities, physical parameters and individual chemical abundances of six or more Red Clump stars for a sample of 25 old and intermediate-age OCs visible from the Northern hemisphere. To do so, we use high resolution spectroscopic facilities (R> 62,000) available at Spanish observatories. We present the motivation, design and current status of the survey, together with the first data release of radial velocities for 77 stars in 12 OCs, which represents about 50% of the survey. We include clusters never studied with high-resolution spectroscopy before (NG...

  3. Distinct Phenotypes of Cigarette Smokers Identified by Cluster Analysis of Patients with Severe Asthma.

    Science.gov (United States)

    Konno, Satoshi; Taniguchi, Natsuko; Makita, Hironi; Nakamaru, Yuji; Shimizu, Kaoruko; Shijubo, Noriharu; Fuke, Satoshi; Takeyabu, Kimihiro; Oguri, Mitsuru; Kimura, Hirokazu; Maeda, Yukiko; Suzuki, Masaru; Nagai, Katsura; Ito, Yoichi M; Wenzel, Sally E; Nishimura, Masaharu

    2015-12-01

    Smoking may have multifactorial effects on asthma phenotypes, particularly in severe asthma. Cluster analysis has been applied to explore novel phenotypes, which are not based on any a priori hypotheses. To explore novel severe asthma phenotypes by cluster analysis when including cigarette smokers. We recruited a total of 127 subjects with severe asthma, including 59 current or ex-smokers, from our university hospital and its 29 affiliated hospitals/pulmonary clinics. Twelve clinical variables obtained during a 2-day hospital stay were used for cluster analysis. After clustering using clinical variables, the sputum levels of 14 molecules were measured to biologically characterize the clinical clusters. Five clinical clusters were identified, including two characterized by high pack-year exposure to cigarette smoking and low FEV1/FVC. There were marked differences between the two clusters of cigarette smokers. One had high levels of circulating eosinophils, high IgE levels, and a high sinus disease score. The other was characterized by low levels of the same parameters. Sputum analysis revealed increased levels of IL-5 in the former cluster and increased levels of IL-6 and osteopontin in the latter. The other three clusters were similar to those previously reported: young onset/atopic, nonsmoker/less eosinophilic, and female/obese. Key clinical variables were confirmed to be stable and consistent 1 year later. This study reveals two distinct phenotypes of severe asthma in current and former cigarette smokers with potentially different biological pathways contributing to fixed airflow limitation. Clinical trial registered with www.umin.ac.jp (000003254).

  4. Distinct ADHD Symptom Clusters Differentially Associated with Personality Traits

    Science.gov (United States)

    McKinney, Ashley A.; Canu, Will H.; Schneider, H. G.

    2013-01-01

    Objective: ADHD has been linked to various constructs, yet there is a lack of focus on how its symptom clusters differentially associate with personality, which this study addresses. Method: The current study examines the relationship between impulsive and inattentive ADHD traits and personality, indexed by the Revised NEO Personality Inventory…

  5. Cu6S4 cluster based twelve-connected face-centered cubic and Cu19I4S12 cluster based fourteen-connected body-centered cubic topological coordination polymers.

    Science.gov (United States)

    Hao, Zheng-Ming; Fang, Rui-Qin; Wu, Hai-Shun; Zhang, Xian-Ming

    2008-09-15

    Hydrothermal reaction of Cu(MeCO2)2, (4-pyridylthio)acetic acid and NH4SCN resulted in a twelve-connected face-centered cubic topological metal-organic framework [Cu3(pdt)2(CN)] (pdt = pyridinethiolate) in which Cu6S4 clusters act as twelve-connected nodes and pyridine rings and cyanides act as connectors. As an extension, an unprecedented fourteen-connected body-centered cubic coordination polymer [Cu19I4(pdt)12(SH)3] has been synthesized by three methods, in which nanosized chiral Cu19I4S12 clusters act as fourteen-connected nodes and triple pyridine rings and hydrosulfides act as connectors. The in situ S-C(sp(3)), S-C(sp(2)), and S-C(sp) cleavage reactions have been observed in the work.

  6. Identifying Two Groups of Entitled Individuals: Cluster Analysis Reveals Emotional Stability and Self-Esteem Distinction.

    Science.gov (United States)

    Crowe, Michael L; LoPilato, Alexander C; Campbell, W Keith; Miller, Joshua D

    2016-12-01

    The present study hypothesized that there exist two distinct groups of entitled individuals: grandiose-entitled, and vulnerable-entitled. Self-report scores of entitlement were collected for 916 individuals using an online platform. Model-based cluster analyses were conducted on the individuals with scores one standard deviation above mean (n = 159) using the five-factor model dimensions as clustering variables. The results support the existence of two groups of entitled individuals categorized as emotionally stable and emotionally vulnerable. The emotionally stable cluster reported emotional stability, high self-esteem, more positive affect, and antisocial behavior. The emotionally vulnerable cluster reported low self-esteem and high levels of neuroticism, disinhibition, conventionality, psychopathy, negative affect, childhood abuse, intrusive parenting, and attachment difficulties. Compared to the control group, both clusters reported being more antagonistic, extraverted, Machiavellian, and narcissistic. These results suggest important differences are missed when simply examining the linear relationships between entitlement and various aspects of its nomological network.

  7. Different disease subtypes with distinct clinical expression in familial Mediterranean fever: results of a cluster analysis.

    Science.gov (United States)

    Akar, Servet; Solmaz, Dilek; Kasifoglu, Timucin; Bilge, Sule Yasar; Sari, Ismail; Gumus, Zeynep Zehra; Tunca, Mehmet

    2016-02-01

    The aim of this study was to evaluate whether there are clinical subgroups that may have different prognoses among FMF patients. The cumulative clinical features of a large group of FMF patients [1168 patients, 593 (50.8%) male, mean age 35.3 years (s.d. 12.4)] were studied. To analyse our data and identify groups of FMF patients with similar clinical characteristics, a two-step cluster analysis using log-likelihood distance measures was performed. For clustering the FMF patients, we evaluated the following variables: gender, current age, age at symptom onset, age at diagnosis, presence of major clinical features, variables related with therapy and family history for FMF, renal failure and carriage of M694V. Three distinct groups of FMF patients were identified. Cluster 1 was characterized by a high prevalence of arthritis, pleuritis, erysipelas-like erythema (ELE) and febrile myalgia. The dosage of colchicine and the frequency of amyloidosis were lower in cluster 1. Patients in cluster 2 had an earlier age of disease onset and diagnosis. M694V carriage and amyloidosis prevalence were the highest in cluster 2. This group of patients was using the highest dose of colchicine. Patients in cluster 3 had the lowest prevalence of arthritis, ELE and febrile myalgia. The frequencies of M694V carriage and amyloidosis were lower in cluster 3 than the overall FMF patients. Non-response to colchicine was also slightly lower in cluster 3. Patients with FMF can be clustered into distinct patterns of clinical and genetic manifestations and these patterns may have different prognostic significance. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. EVIDENCE FOR TWO DISTINCT STELLAR INITIAL MASS FUNCTIONS: REVISITING THE EFFECTS OF CLUSTER DYNAMICAL EVOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Zaritsky, Dennis [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Colucci, Janet E.; Bernstein, Rebecca A. [Department of Astronomy and Astrophysics, 1156 High Street, UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Pessev, Peter M. [Gemini South Observatory, c/o AURA Inc., Casilla 603, La Serena (Chile); Chandar, Rupali, E-mail: dzaritsky@as.arizona.edu [Department of Physics and Astronomy, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States)

    2013-06-20

    We measure the velocity dispersions of six galactic globular clusters using spatially integrated spectra, to test for the effects of internal dynamical evolution in the stellar mass-to-light ratios, Y{sub *}, of star clusters. In particular, we revisit whether the low values of Y{sub *} that we found in our previous study, from which we concluded that there are at least two population of stellar clusters with distinct stellar initial mass functions, are artificially depressed by relaxation driven mass loss. The combination of our previous sample of five old clusters and these six now provide an order of magnitude range in cluster mass with which to explore this issue. We find no relationship between cluster mass, or relaxation time, and Y{sub *}. Because relaxation is mass dependent, we conclude that the values of Y{sub *} for these clusters are not strongly affected by dynamical effects, and so confirm the presence of the population of clusters with low Y{sub *}.

  9. Observation of two distinct spatial-temporal BOLD clusters during sensory stimulation in rats.

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    Goelman, Gadi; Pelled, Galit; Dodd, Steve; Koretsky, Alan

    2007-02-01

    Neuronal activity evokes changes in local CBF and CBV, whose spatial differences are not fully known. We use the Radial Correlation Contrast (RCC) analysis method with high spatial resolution 100 x 100 x 1000 microm3 data collected with an 11.7 T magnet to differentiate two spatial-temporal BOLD clusters during sensory rat forepaw stimulation and hypothesize that each corresponds to either the CBF or the CBV processes. One cluster, obtained during the time segment of stimulation onset, is characterized by a high positive BOLD signal whereas the other, obtained during the simulation decline time segment, is characterized by a lower positive signal and strong post stimulus undershoot. The average volume of stimulation onset clusters is embedded in the stimulation decline clusters with the latter significantly larger and shifted towards deeper cortical layers. Comparison of amplitude-RCC and cross-correlation analyses performed on equivalent time segments (30 s, 40 images) revealed no differences in cluster size or location, demonstrating that temporal locality is more important than spatial locality in distinguishing between stimulation onset and stimulation decline clusters. We hypothesize that clusters characterized by stimulation onset are highly weighted by local changes in CBF whereas clusters characterized by stimulation decline are more CBV weighted. Moreover, the data suggest that the locations of the highest CBF changes are distinct from the locations of the highest CBV changes. While the former located within stimulation decline clusters and its weight is gradually reduced towards cluster's periphery (mainly ventrally), the highest changes in CBV occur in the cluster's periphery with only modest changes towards its center.

  10. Two distinct sequences of blue straggler stars in the globular cluster M30

    CERN Document Server

    Ferraro, F R; Dalessandro, E; Lanzoni, B; Sills, A; Rood, R T; Pecci, F Fusi; Karakas, A I; Miocchi, P; Bovinelli, S; 10.1038/nature08607

    2010-01-01

    Stars in globular clusters are generally believed to have all formed at the same time, early in the Galaxy's history. 'Blue stragglers' are stars massive enough that they should have evolved into white dwarfs long ago. Two possible mechanisms have been proposed for their formation: mass transfer between binary companions and stellar mergers resulting from direct collisions between two stars. Recently, the binary explanation was claimed to be dominant. Here we report that there are two distinct parallel sequences of blue stragglers in M30. This globular cluster is thought to have undergone 'core collapse', during which both the collision rate and the mass transfer activity in binary systems would have been enhanced. We suggest that the two observed sequences arise from the cluster core collapse, with the bluer population arising from direct stellar collisions and the redder one arising from the evolution of close binaries that are probably still experiencing an active phase of mass transfer.

  11. Neuro- and social-cognitive clustering highlights distinct profiles in adults with anorexia nervosa.

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    Renwick, Beth; Musiat, Peter; Lose, Anna; DeJong, Hannah; Broadbent, Hannah; Kenyon, Martha; Loomes, Rachel; Watson, Charlotte; Ghelani, Shreena; Serpell, Lucy; Richards, Lorna; Johnson-Sabine, Eric; Boughton, Nicky; Treasure, Janet; Schmidt, Ulrike

    2015-01-01

    This study aimed to explore the neuro- and social-cognitive profile of a consecutive series of adult outpatients with anorexia nervosa (AN) when compared with widely available age and gender matched historical control data. The relationship between performance profiles, clinical characteristics, service utilization, and treatment adherence was also investigated. Consecutively recruited outpatients with a broad diagnosis of AN (restricting subtype AN-R: n = 44, binge-purge subtype AN-BP: n = 33 or Eating Disorder Not Otherwise Specified-AN subtype EDNOS-AN: n = 23) completed a comprehensive set of neurocognitive (set-shifting, central coherence) and social-cognitive measures (Emotional Theory of Mind). Data were subjected to hierarchical cluster analysis and a discriminant function analysis. Three separate, meaningful clusters emerged. Cluster 1 (n = 45) showed overall average to high average neuro- and social- cognitive performance, Cluster 2 (n = 38) showed mixed performance characterized by distinct strengths and weaknesses, and Cluster 3 (n = 17) showed poor overall performance (Autism Spectrum disorder (ASD) like cluster). The three clusters did not differ in terms of eating disorder symptoms, comorbid features or service utilization and treatment adherence. A discriminant function analysis confirmed that the clusters were best characterized by performance in perseveration and set-shifting measures. The findings suggest that considerable neuro- and social-cognitive heterogeneity exists in patients with AN, with a subset showing ASD-like features. The value of this method of profiling in predicting longer term patient outcomes and in guiding development of etiologically targeted treatments remains to be seen. © 2014 Wiley Periodicals, Inc.

  12. Scientific-educational clusters: the distinctive features and preconditions of development

    Directory of Open Access Journals (Sweden)

    G.T. Piatnytska

    2016-09-01

    Full Text Available The aim of the article. The aim of our study was following: to determine the preconditions for the development of scientific-educational cluster and to evaluate presence of this conditions in Ukraine now. The results of the analysis. On the bases of analysis of the different interpretations of such concepts as «educational cluster», «scientific (or research cluster», «scientific-educational cluster» and cores of all this clusters, we improved the definition and allocated distinctive features of the scientific-educational cluster. In our opinion, scientific-educational cluster is one of the cluster’s types, which combines research institutions (scientific centers, institutes, laboratories, etc. and educational institutions with strong scientific and educational bases and high intellectual potential. Members of these clusters are capable to produce, promote and facilitate the practical implementation and dissemination of innovation; solve complex social, economic, technical and other problems; develop good relationships with businesses. The key tasks of the scientific-educational cluster’s development are qualified personnel (staff training and retraining according to the needs of the country / region / local area, etc. It was established that the main preconditions for the scientific-educational cluster development are: 1 existence the educational institution(s or scientific-educational center with a strong scientific and educational bases; 2 financial resources for the development and effective work of the cluster’s members; 3 sufficient human resources with high intellectual potential; 4 close contacts for cooperation between scientific-educational center and business; 5 stimulus and motivational factors for increasing innovation activity at the enterprises, their absorption of innovations, increasing demand for high quality educational services. Conclusions and directions of further researches. The study demonstrated that today in

  13. Chemical tagging of three distinct populations of red giants in the globular cluster NGC 6752

    CERN Document Server

    Carretta, Eugenio; Gratton, Raffaele; Lucatello, Sara; D'Orazi, Valentina

    2012-01-01

    We present aluminium, magnesium, and silicon abundances in the metal-poor globular cluster NGC 6752 for a sample of more than 130 red giants with homogeneous oxygen and sodium abundances. We find that [Al/Fe] shows a spread of about 1.4 dex among giants in NGC 6752 and is anticorrelated with [Mg/Fe] and [O/Fe] and correlated with [Na/Fe] and [Si/Fe]. These relations are not continuous in nature, but the distribution of stars is clearly clustered around three distinct Al values, low, intermediate, and high. These three groups nicely correspond to the three distinct sequences previously detected using Stromgren photometry along the red giant branch. These two independent findings strongly indicate the existence of three distinct stellar populations in NGC 6752. Comparing the abundances of O and Mg, we find that the population with intermediate chemical abundances cannot originate from material with the same composition of the most O- and Mg-poor population, diluted by material with that of the most O- and Mg-ri...

  14. Zucchini shoestring virus: a distinct potyvirus in the papaya ringspot virus cluster.

    Science.gov (United States)

    Ibaba, J D; Laing, M D; Gubba, A

    2016-08-01

    Zucchini shoestring virus (ZSSV) has been proposed to be a putative potyvirus in the papaya ringspot virus (PRSV) cluster, based on the sequence similarity of its coat protein to those of related potyviruses. ZSSV has been associated with the outbreak of a damaging disease of baby marrow (Cucurbita pepo L.) that had been observed throughout the province of KwaZulu-Natal, in the Republic of South Africa (RSA). We report the genome sequence of ZSSV, determined by next-generation sequencing of total RNA extracted from an infected baby marrow (Cucurbita pepo L.). The ZSSV genome is 10,295 nucleotides long excluding the poly(A) tail and displays a typical potyvirus organization. Algerian watermelon mosaic virus (AWMV; EU410442.1) was identified as the closest relative of ZSSV, sharing the highest nucleotide sequence identity of 65.68%. The nucleotide and amino acid sequence identity values for each protein support the differentiation of ZSSV as a member of a distinct species in the genus Potyvirus. This taxonomic position was also confirmed using the Pairwise Sequence Comparison online tool from the National Center for Biotechnology Information. Phylogenetic analysis of the polyprotein coding sequence of ZSSV grouped ZSSV together with AWMV and Moroccan watermelon mosaic virus, but in different clusters. ZSSV is the second cucurbit-infecting virus in the PRSV cluster present in RSA.

  15. Five groups of red giants with distinct chemical composition in the globular cluster NGC 2808

    CERN Document Server

    Carretta, Eugenio

    2015-01-01

    The chemical composition of multiple populations in the massive globular cluster (GC) NGC~2808 is addressed with the homogeneous abundance re-analysis of 140 red giant branch (RGB) stars. UVES spectra for 31 stars and GIRAFFE spectra for the other giants were analysed with the same procedures used for about 2500 giants in 23 GCs in our FLAMES survey, deriving abundances of Fe, O, Na, Mg, Si, Ca, Ti, Sc, Cr, Mn, and Ni. Iron, elements from alpha-capture, and in the Fe-group do not show intrinsic scatter. On our UVES scale the metallicity of NGC~2808 is [Fe/H]=-1.129+/-0.005+/-0.034$ (+/-statistical +/-systematic error) with sigma=0.030 (31 stars). Main features related to proton-capture elements are retrieved, but the improved statistics and the smaller associated internal errors allow to uncover five distinct groups of stars along the Na-O anticorrelation. We observe large depletions in Mg, anticorrelated with enhancements of Na and also Si, suggestive of unusually high temperatures for proton-captures. About...

  16. Methylome sequencing in triple-negative breast cancer reveals distinct methylation clusters with prognostic value.

    Science.gov (United States)

    Stirzaker, Clare; Zotenko, Elena; Song, Jenny Z; Qu, Wenjia; Nair, Shalima S; Locke, Warwick J; Stone, Andrew; Armstong, Nicola J; Robinson, Mark D; Dobrovic, Alexander; Avery-Kiejda, Kelly A; Peters, Kate M; French, Juliet D; Stein, Sandra; Korbie, Darren J; Trau, Matt; Forbes, John F; Scott, Rodney J; Brown, Melissa A; Francis, Glenn D; Clark, Susan J

    2015-02-02

    Epigenetic alterations in the cancer methylome are common in breast cancer and provide novel options for tumour stratification. Here, we perform whole-genome methylation capture sequencing on small amounts of DNA isolated from formalin-fixed, paraffin-embedded tissue from triple-negative breast cancer (TNBC) and matched normal samples. We identify differentially methylated regions (DMRs) enriched with promoters associated with transcription factor binding sites and DNA hypersensitive sites. Importantly, we stratify TNBCs into three distinct methylation clusters associated with better or worse prognosis and identify 17 DMRs that show a strong association with overall survival, including DMRs located in the Wilms tumour 1 (WT1) gene, bi-directional-promoter and antisense WT1-AS. Our data reveal that coordinated hypermethylation can occur in oestrogen receptor-negative disease, and that characterizing the epigenetic framework provides a potential signature to stratify TNBCs. Together, our findings demonstrate the feasibility of profiling the cancer methylome with limited archival tissue to identify regulatory regions associated with cancer.

  17. Theoretical characterization of four distinct isomer types in hydrated-electron clusters, and proposed assignments for photoelectron spectra of water cluster anions.

    Science.gov (United States)

    Jacobson, Leif D; Herbert, John M

    2011-12-14

    Water cluster anions, (H(2)O)(N)(-), are examined using mixed quantum/classical molecular dynamics based on a one-electron pseudopotential model that incorporates many-body polarization and predicts vertical electron detachment energies (VDEs) with an accuracy of ~0.1 eV. By varying the initial conditions under which the clusters are formed, we are able to identify four distinct isomer types that exhibit different size-dependent VDEs. On the basis of a strong correlation between the electron's radius of gyration and its optical absorption maximum, and extrapolating to the bulk limit (N → ∞), our analysis supports the assignment of the "isomer Ib" data series, observed in photoelectron spectra of very cold clusters, as arising from cavity-bound (H(2)O)(N)(-) cluster isomers. The "isomer I" data reported in warmer experiments are assigned to surface-bound isomers in smaller clusters, transitioning to partially embedded isomers in larger clusters. The partially embedded isomers are characterized by a partially formed solvent cavity at the cluster surface, and they are spectroscopically quite similar to internalized cavity isomers. These assignments are consistent with various experimental data, and our theoretical characterization of these isomers sheds new light on a long-standing assignment problem. © 2011 American Chemical Society

  18. Quantitative computed tomographic imaging-based clustering differentiates asthmatic subgroups with distinctive clinical phenotypes.

    Science.gov (United States)

    Choi, Sanghun; Hoffman, Eric A; Wenzel, Sally E; Castro, Mario; Fain, Sean; Jarjour, Nizar; Schiebler, Mark L; Chen, Kun; Lin, Ching-Long

    2017-09-01

    Imaging variables, including airway diameter, wall thickness, and air trapping, have been found to be important metrics when differentiating patients with severe asthma from those with nonsevere asthma and healthy subjects. The objective of this study was to identify imaging-based clusters and to explore the association of the clusters with existing clinical metrics. We performed an imaging-based cluster analysis using quantitative computed tomography-based structural and functional variables extracted from the respective inspiration and expiration scans of 248 asthmatic patients. The imaging-based metrics included a broader set of multiscale variables, such as inspiratory airway dimension, expiratory air trapping, and registration-based lung deformation (inspiration vs expiration). Asthma subgroups derived from a clustering method were associated with subject demographics, questionnaire results, medication history, and biomarker variables. Cluster 1 was composed of younger patients with early-onset nonsevere asthma and reversible airflow obstruction and normal airway structure. Cluster 2 was composed of patients with a mix of patients with nonsevere and severe asthma with marginal inflammation who exhibited airway luminal narrowing without wall thickening. Clusters 3 and 4 were dominated by patients with severe asthma. Cluster 3 patients were obese female patients with reversible airflow obstruction who exhibited airway wall thickening without airway narrowing. Cluster 4 patients were late-onset older male subjects with persistent airflow obstruction who exhibited significant air trapping and reduced regional deformation. Cluster 3 and 4 patients also showed decreased lymphocyte and increased neutrophil counts, respectively. Four image-based clusters were identified and shown to be correlated with clinical characteristics. Such clustering serves to differentiate asthma subgroups that can be used as a basis for the development of new therapies. Copyright © 2017

  19. The distinction of 'psychosomatogenic family types' based on parents' self reported questionnaire information: a cluster analysis.

    Science.gov (United States)

    Rousseau, Sofie; Grietens, Hans; Vanderfaeillie, Johan; Ceulemans, Eva; Hoppenbrouwers, Karel; Desoete, Annemie; Van Leeuwen, Karla

    2014-06-01

    The theory of 'psychosomatogenic family types' is often used in treatment of somatizing adolescents. This study investigated the validity of distinguishing 'psychosomatogenic family types' based on parents' self-reported family features. The study included a Flemish general population sample of 12-year olds (n = 1428). We performed cluster analysis on 3 variables concerning parents' self-reported problems in family functioning. The distinguished clusters were examined for differences in marital problems, parental emotional problems, professional help for family members, demographics, and adolescents' somatization. Results showed the existence of 5 family types: 'chaotic family functioning,' 'average amount of family functioning problems,' 'few family functioning problems,' 'high amount of support and communication problems,' and 'high amount of sense of security problems' clusters. Membership of the 'chaotic family functioning' and 'average amount of family functioning problems' cluster was significantly associated with higher levels of somatization, compared with 'few family functioning problems' cluster membership. Among additional variables, only marital and parental emotional problems distinguished somatization relevant from non relevant clusters: parents in 'average amount of family functioning problems' and 'chaotic family functioning' clusters reported higher problems. The data showed that 'apparently perfect' or 'enmeshed' patterns of family functioning may not be assessed by means of parent report as adopted in this study. In addition, not only adolescents from 'extreme' types of family functioning may suffer from somatization. Further, professionals should be careful assuming that families in which parents report average to high amounts of family functioning problems also show different demographic characteristics.

  20. NGC6362: the least massive globular cluster with chemically distinct multiple populations

    CERN Document Server

    Mucciarelli, A; Massari, D; Bellazzini, M; Ferraro, F R; Lanzoni, B; Lardo, C; Salaris, M; Cassisi, S

    2016-01-01

    We present the first measure of Fe and Na abundances in NGC 6362, a low-mass globular cluster where first and second generation stars are fully spatially mixed. A total of 160 member stars (along the red giant branch and the red horizontal branch) have been observed with the multi-object spectrograph FLAMES at the Very Large Telescope. We find that the cluster has an iron abundance of [Fe/H]=--1.09$\\pm$0.01 dex, without evidence of intrinsic dispersion. On the other hand, the [Na/Fe] distribution turns out to be intrinsically broad and bimodal. The Na-poor and Na-rich stars populate, respectively, the bluest and the reddest red giant branches detected in the color-magnitude diagrams including the U filter. The red giant branch is composed of a mixture of first and second generation stars in a similar proportion, while almost all the red horizontal branch stars belong to the first cluster generation. Until now, NGC 6362 is the least massive globular cluster where both the photometric and spectroscopic signatur...

  1. Distinct Short-Range Order Is Inherent to Small Amorphous Calcium Carbonate Clusters (<2 nm)

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Shengtong [Physical Chemistry, University of Konstanz, Universitätsstrasse 10 78457 Konstanz Germany; School of Chemical Engineering, State Key Laboratory of Chemical Engineering, Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, 130 Meilong Road Shanghai 200237 P.R. China; Chevrier, Daniel M. [Department of Chemistry and Institute for Research in Materials, Dalhousie University, Halifax Nova Scotia B3H 4R2 Canada; Zhang, Peng [Department of Chemistry and Institute for Research in Materials, Dalhousie University, Halifax Nova Scotia B3H 4R2 Canada; Gebauer, Denis [Physical Chemistry, University of Konstanz, Universitätsstrasse 10 78457 Konstanz Germany; Cölfen, Helmut [Physical Chemistry, University of Konstanz, Universitätsstrasse 10 78457 Konstanz Germany

    2016-09-09

    Amorphous intermediate phases are vital precursors in the crystallization of many biogenic minerals. While inherent short-range orders have been found in amorphous calcium carbonates (ACCs) relating to different crystalline forms, it has never been clarified experimentally whether such orders already exist in very small clusters less than 2 nm in size. Here, we studied the stability and structure of 10,12-pentacosadiynoic acid (PCDA) protected ACC clusters with a core size of ca. 1.4 nm consisting of only seven CaCO3 units. Ligand concentration and structure are shown to be key factors in stabilizing the ACC clusters. More importantly, even in such small CaCO3 entities, a proto-calcite short-range order can be identified but with a relatively high degree of disorder that arises from the very small size of the CaCO3 core. Our findings support the notion of a structural link between prenucleation clusters, amorphous intermediates, and final crystalline polymorphs, which appears central to the understanding of polymorph selection.

  2. Promoting chondrocyte cell clustering through tuning of a poly(ethylene glycol)-poly(peptide) thermosensitive hydrogel with distinctive microarchitecture.

    Science.gov (United States)

    Peng, Sydney; Wu, Chih-Wei; Lin, Ji-Yu; Yang, Chin-Yu; Cheng, Ming-Huei; Chu, I-Ming

    2017-07-01

    Hydrogels are considered to be attractive cell-matrix for chondrocytes due to their similarity in properties to the natural cartilage. However, the formation of chondrocyte cell clusters in hydrogels has been mostly limited to naturally-derived or relatively fast degrading materials. In this study, a series of diblock copolymer poly(ethylene glycol)-poly(alanine) (mPEG-PA) was synthesized and investigated as injectable biomimic hydrogels for the culturing of chondrocytes. Depending on the poly(alanine) chain length, afforded hydrogels exhibited variable mechanical property and microarchitecture due to difference in secondary structure arrangement. After 21days of culture, cell clusters were observed in all hydrogels with longer PA chains and these hydrogels supported more homogenous and established clustering as well as significantly higher glycosaminoglycan and collagen deposition. Interestingly, scanning electron microscopy revealed a distinct micron range fibrillar-like microarchitecture that may be responsible for maintaining chondrocyte phenotype and matrix production. In addition, micrographs revealed the presence of collagen fibrils and an extensive extracellular matrix network. Therefore, it is reasonable to conclude that mPEG-PA hydrogels possess the desirable properties for chondrocyte cluster formation and serve as potential candidate in cartilage tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Identifying Distinct Geographic Health Service Environments in British Columbia, Canada: Cluster Analysis of Population-Based Administrative Data.

    Science.gov (United States)

    Lavergne, M Ruth

    2016-08-01

    Definitions of "urban" and "rural" developed for general purposes may not reflect the organization and delivery of healthcare. This research used cluster analysis to group Local Health Areas based on the distribution of healthcare spending across service categories. Though total spending was similar, the metropolitan areas of Vancouver and Victoria were identified as distinct from non-metropolitan and remote communities, based on the distribution of healthcare spending alone. Non-metropolitan communities with large community hospitals and greater physician supply were further distinguished from those with fewer healthcare resources. This approach may be useful to other researchers and service planners.

  4. Multiple populations in globular clusters: the distinct kinematic imprints of different formation scenarios

    CERN Document Server

    Hénault-Brunet, Vincent; Agertz, Oscar; Read, Justin I

    2015-01-01

    Several scenarios have been proposed to explain the presence of multiple stellar populations in globular clusters. Many of them invoke multiple generations of stars to explain the observed chemical abundance anomalies, but it has also been suggested that self-enrichment could occur via accretion of ejecta from massive stars onto the circumstellar disc of low-mass pre-main sequence stars. These scenarios imply different initial conditions for the kinematics of the various stellar populations. Given some net angular momentum initially, models for which a second generation forms from gas that collects in a cooling flow into the core of the cluster predict an initially larger rotational amplitude for the polluted stars compared to the pristine stars. This is opposite to what is expected from the accretion model, where the polluted stars are the ones crossing the core and are on preferentially radial (low-angular momentum) orbits, such that their rotational amplitude is lower. Here we present the results of a suit...

  5. Molecular epidemiological analysis of Mycoplasma bovis isolates from the United Kingdom shows two genetically distinct clusters

    DEFF Research Database (Denmark)

    McAuliffe, Laura; Kokotovic, Branko; Ayling, Roger D.

    2004-01-01

    Mycoplasma bovis is an important veterinary pathogen causing pneumonia, arthritis, and mastitis in infected cattle. We investigated the genetic diversity of 53 isolates collected in the United Kingdom between 1996 and 2002 with pulsed-field gel electrophoresis (PFGE), amplified fragment length...... polymorphism (AFLP), and random amplified polymorphic DNA (RAPD) analysis. In addition, the influence of variable surface protein (Vsp) profiles on the profiles generated with molecular typing techniques was studied. Both AFLP and RAPD separated the isolates into two distinct groups, but PFGE showed less...

  6. Substrate-Trapped Interactors of PHD3 and FIH Cluster in Distinct Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Javier Rodriguez

    2016-03-01

    Full Text Available Amino acid hydroxylation is a post-translational modification that regulates intra- and inter-molecular protein-protein interactions. The modifications are regulated by a family of 2-oxoglutarate- (2OG dependent enzymes and, although the biochemistry is well understood, until now only a few substrates have been described for these enzymes. Using quantitative interaction proteomics, we screened for substrates of the proline hydroxylase PHD3 and the asparagine hydroxylase FIH, which regulate the HIF-mediated hypoxic response. We were able to identify hundreds of potential substrates. Enrichment analysis revealed that the potential substrates of both hydroxylases cluster in the same pathways but frequently modify different nodes of signaling networks. We confirm that two proteins identified in our screen, MAPK6 (Erk3 and RIPK4, are indeed hydroxylated in a FIH- or PHD3-dependent mechanism. We further determined that FIH-dependent hydroxylation regulates RIPK4-dependent Wnt signaling, and that PHD3-dependent hydroxylation of MAPK6 protects the protein from proteasomal degradation.

  7. Two-year outcome of alcohol interventions in Swedish university halls of residence: a cluster randomized trial of a brief skills training program, twelve-step-influenced intervention, and controls.

    Science.gov (United States)

    Ståhlbrandt, Henriettae; Johnsson, Kent O; Berglund, Mats

    2007-03-01

    High-risk alcohol consumption among university students is well documented. Several types of intervention have proved to be effective in reducing alcohol consumption. This study examines the 2-year outcome of 2 different alcohol intervention programs at university halls of residence. Ninety-eight university halls of residence (with 556 students) were cluster randomized to 2 different intervention groups: a brief skills training program (BSTP) with interactive lectures and discussions, a twelve-step-influenced (TSI) program with didactic lectures by therapists trained in the 12-step approach, and a control group. All students completing the baseline assessment received personalized feedback by mail. Students responded to mailed follow-up questionnaires after 1, 2, and 3 years, including alcohol use disorders identification test (AUDIT; years 2 and 3), short index of problems (SIP), and estimated blood alcohol concentration (eBAC). All groups significantly reduced their AUDIT scores from baseline to the second year follow-up, with no significant differences between the groups. Seventy-seven percent of the students belonged to a population with high-risk consumption, using the AUDIT cut-off scores of 8 and 4 for men and women, respectively. Students with high-risk alcohol consumption showed significant differences in AUDIT score reduction in favor of the BSTP compared with controls, and had a tendency to show better results than the TSI intervention (p=0.06). Similar trends could be seen using SIP and eBAC. The TSI did not differ significantly from the control group within the group of students with high-risk alcohol consumption. This study suggests that a BSTP is effective as an intervention in students with high-risk alcohol consumption.

  8. Zucchini tigré mosaic virus is a distinct potyvirus in the papaya ringspot virus cluster: molecular and biological insights.

    Science.gov (United States)

    Romay, G; Lecoq, H; Desbiez, C

    2014-02-01

    In recent years, three new potyviruses have been described in the papaya ringspot virus (PRSV) cluster. In addition, two types of PRSV are recognized, type W, infecting cucurbit plants, and type P, infecting papaya and also cucurbits. A third type, PRSV-T, was also partially described in Guadeloupe. Complete genome sequencing of four PRSV-T isolates showed that this virus is a related virus that is distinct from PRSV, and the name zucchini tigré mosaic virus (ZTMV) is proposed, in reference to the typical symptoms observed in zucchini squash. Eleven other viral isolates from different geographic origins were confirmed as ZTMV isolates using the complete sequence of the cylindrical inclusion (CI) coding region, whereas pairwise sequence similarities in the coat protein (CP) coding region did not unambiguously distinguish ZTMV isolates from PRSV isolates. The use of the CI coding region for species demarcation appears more suitable than the CP coding region for closely related viruses. Principal coordinates analysis based on the biological behavior of the viral isolates studied clustered PRSV-P, PRSV-W and ZTMV isolates into three different groups. Therefore, ZTMV is different from PRSV in its molecular and biological properties.

  9. Distinct cell clusters touching islet cells induce islet cell replication in association with over-expression of Regenerating Gene (REG protein in fulminant type 1 diabetes.

    Directory of Open Access Journals (Sweden)

    Kaoru Aida

    Full Text Available BACKGROUND: Pancreatic islet endocrine cell-supporting architectures, including islet encapsulating basement membranes (BMs, extracellular matrix (ECM, and possible cell clusters, are unclear. PROCEDURES: The architectures around islet cell clusters, including BMs, ECM, and pancreatic acinar-like cell clusters, were studied in the non-diabetic state and in the inflamed milieu of fulminant type 1 diabetes in humans. RESULT: Immunohistochemical and electron microscopy analyses demonstrated that human islet cell clusters and acinar-like cell clusters adhere directly to each other with desmosomal structures and coated-pit-like structures between the two cell clusters. The two cell-clusters are encapsulated by a continuous capsule composed of common BMs/ECM. The acinar-like cell clusters have vesicles containing regenerating (REG Iα protein. The vesicles containing REG Iα protein are directly secreted to islet cells. In the inflamed milieu of fulminant type 1 diabetes, the acinar-like cell clusters over-expressed REG Iα protein. Islet endocrine cells, including beta-cells and non-beta cells, which were packed with the acinar-like cell clusters, show self-replication with a markedly increased number of Ki67-positive cells. CONCLUSION: The acinar-like cell clusters touching islet endocrine cells are distinct, because the cell clusters are packed with pancreatic islet clusters and surrounded by common BMs/ECM. Furthermore, the acinar-like cell clusters express REG Iα protein and secrete directly to neighboring islet endocrine cells in the non-diabetic state, and the cell clusters over-express REG Iα in the inflamed milieu of fulminant type 1 diabetes with marked self-replication of islet cells.

  10. Abraham's children in the genome era: major Jewish diaspora populations comprise distinct genetic clusters with shared Middle Eastern Ancestry.

    Science.gov (United States)

    Atzmon, Gil; Hao, Li; Pe'er, Itsik; Velez, Christopher; Pearlman, Alexander; Palamara, Pier Francesco; Morrow, Bernice; Friedman, Eitan; Oddoux, Carole; Burns, Edward; Ostrer, Harry

    2010-06-11

    For more than a century, Jews and non-Jews alike have tried to define the relatedness of contemporary Jewish people. Previous genetic studies of blood group and serum markers suggested that Jewish groups had Middle Eastern origin with greater genetic similarity between paired Jewish populations. However, these and successor studies of monoallelic Y chromosomal and mitochondrial genetic markers did not resolve the issues of within and between-group Jewish genetic identity. Here, genome-wide analysis of seven Jewish groups (Iranian, Iraqi, Syrian, Italian, Turkish, Greek, and Ashkenazi) and comparison with non-Jewish groups demonstrated distinctive Jewish population clusters, each with shared Middle Eastern ancestry, proximity to contemporary Middle Eastern populations, and variable degrees of European and North African admixture. Two major groups were identified by principal component, phylogenetic, and identity by descent (IBD) analysis: Middle Eastern Jews and European/Syrian Jews. The IBD segment sharing and the proximity of European Jews to each other and to southern European populations suggested similar origins for European Jewry and refuted large-scale genetic contributions of Central and Eastern European and Slavic populations to the formation of Ashkenazi Jewry. Rapid decay of IBD in Ashkenazi Jewish genomes was consistent with a severe bottleneck followed by large expansion, such as occurred with the so-called demographic miracle of population expansion from 50,000 people at the beginning of the 15th century to 5,000,000 people at the beginning of the 19th century. Thus, this study demonstrates that European/Syrian and Middle Eastern Jews represent a series of geographical isolates or clusters woven together by shared IBD genetic threads.

  11. Conserved piRNA Expression from a Distinct Set of piRNA Cluster Loci in Eutherian Mammals.

    Science.gov (United States)

    Chirn, Gung-Wei; Rahman, Reazur; Sytnikova, Yuliya A; Matts, Jessica A; Zeng, Mei; Gerlach, Daniel; Yu, Michael; Berger, Bonnie; Naramura, Mayumi; Kile, Benjamin T; Lau, Nelson C

    2015-11-01

    The Piwi pathway is deeply conserved amongst animals because one of its essential functions is to repress transposons. However, many Piwi-interacting RNAs (piRNAs) do not base-pair to transposons and remain mysterious in their targeting function. The sheer number of piRNA cluster (piC) loci in animal genomes and infrequent piRNA sequence conservation also present challenges in determining which piC loci are most important for development. To address this question, we determined the piRNA expression patterns of piC loci across a wide phylogenetic spectrum of animals, and reveal that most genic and intergenic piC loci evolve rapidly in their capacity to generate piRNAs, regardless of known transposon silencing function. Surprisingly, we also uncovered a distinct set of piC loci with piRNA expression conserved deeply in Eutherian mammals. We name these loci Eutherian-Conserved piRNA cluster (ECpiC) loci. Supporting the hypothesis that conservation of piRNA expression across ~100 million years of Eutherian evolution implies function, we determined that one ECpiC locus generates abundant piRNAs antisense to the STOX1 transcript, a gene clinically associated with preeclampsia. Furthermore, we confirmed reduced piRNAs in existing mouse mutations at ECpiC-Asb1 and -Cbl, which also display spermatogenic defects. The Asb1 mutant testes with strongly reduced Asb1 piRNAs also exhibit up-regulated gene expression profiles. These data indicate ECpiC loci may be specially adapted to support Eutherian reproduction.

  12. Two distinct energetic electron populations of different origin in the Earth's magnetotail: a Cluster case study

    Directory of Open Access Journals (Sweden)

    I. I. Vogiatzis

    2006-08-01

    Full Text Available Energetic electrons (E≥30 keV travelling along and perpendicular to the magnetic field lines have been observed in the magnetotail at L~17:00 and 22:00 MLT during the recovery phase of a storm-time substorm on 7 October 2002. Three-dimensional electron distributions of the full unit sphere obtained from the IES/RAPID sensor system demonstrated a rather complicated and random behavior of the energetic electrons. Occasionally these electrons were appearing to travel parallel, perpendicular, or in both directions, relative to the magnetic field direction, forming in this way bi-directional, perpendicular-peaked, and mixed distributions. The electron enhancements occurred while the Cluster spacecraft were on closed field lines in the central plasma sheet approaching the neutral sheet from the northern tail lobe. Magnetic field and energetic particle measurements have been used from geosynchronous and Cluster satellites, in order to describe the general context of the event and then give a possible interpretation regarding the occurrence of the electron anisotropies observed by the IES/RAPID spectrometer on board Cluster. According to geosynchronous measurements an electron dispersionless ejection is very well correlated with a dipolar re-configuration of the magnetic field. The latter fact supports the idea that electrons and, in general, particle ejections at geosynchronous altitude are directly related to electric fields arising from field dipolarization caused by current disruption. Also, having as a main objective the understanding of the way 3-D electron distributions are formed, we have analyzed electron energy spectra along and perpendicular to the magnetic field direction, demonstrating the fact that the electron population consists of two distinct components acting independently and in a random manner relative to each other. This leads to the conclusion that these two electron populations along and perpendicular to the field are

  13. The Twelve Hotel, Barna : Video

    OpenAIRE

    Irish Food Channel

    2014-01-01

    Fergus O'Halloran, Managing Director of The Twelve Hotel in Barna in County Galway, talks about his philosophy in running this unique boutique hotel. Reproduced with kind permission from John & Sally McKenna. 3.35 mins

  14. Distinct functional domains within the acidic cluster of tegument protein pp28 required for trafficking and cytoplasmic envelopment of human cytomegalovirus.

    Science.gov (United States)

    Seo, Jun-Young; Jeon, Hyejin; Hong, Sookyung; Britt, William J

    2016-10-01

    Human cytomegalovirus UL99-encoded tegument protein pp28 contains a 16 aa acidic cluster that is required for pp28 trafficking to the assembly compartment (AC) and the virus assembly. However, functional signals within the acidic cluster of pp28 remain undefined. Here, we demonstrated that an acidic cluster rather than specific sorting signals was required for trafficking to the AC. Recombinant viruses with chimeric pp28 proteins expressing non-native acidic clusters exhibited delayed viral growth kinetics and decreased production of infectious virus, indicating that the native acidic cluster of pp28 was essential for wild-type virus assembly. These results suggested that the acidic cluster of pp28 has distinct functional domains required for trafficking and for efficient virus assembly. The first half (aa 44-50) of the acidic cluster was sufficient for pp28 trafficking, whereas the native acidic cluster consisting of aa 51-59 was required for the assembly of wild-type levels of infectious virus.

  15. Comparative Genomic Analyses of Multiple Pseudomonas Strains Infecting Corylus avellana Trees Reveal the Occurrence of Two Genetic Clusters with Both Common and Distinctive Virulence and Fitness Traits.

    Directory of Open Access Journals (Sweden)

    Simone Marcelletti

    Full Text Available The European hazelnut (Corylus avellana is threatened in Europe by several pseudomonads which cause symptoms ranging from twig dieback to tree death. A comparison of the draft genomes of nine Pseudomonas strains isolated from symptomatic C. avellana trees was performed to identify common and distinctive genomic traits. The thorough assessment of genetic relationships among the strains revealed two clearly distinct clusters: P. avellanae and P. syringae. The latter including the pathovars avellanae, coryli and syringae. Between these two clusters, no recombination event was found. A genomic island of approximately 20 kb, containing the hrp/hrc type III secretion system gene cluster, was found to be present without any genomic difference in all nine pseudomonads. The type III secretion system effector repertoires were remarkably different in the two groups, with P. avellanae showing a higher number of effectors. Homologue genes of the antimetabolite mangotoxin and ice nucleation activity clusters were found solely in all P. syringae pathovar strains, whereas the siderophore yersiniabactin was only present in P. avellanae. All nine strains have genes coding for pectic enzymes and sucrose metabolism. By contrast, they do not have genes coding for indolacetic acid and anti-insect toxin. Collectively, this study reveals that genomically different Pseudomonas can converge on the same host plant by suppressing the host defence mechanisms with the use of different virulence weapons. The integration into their genomes of a horizontally acquired genomic island could play a fundamental role in their evolution, perhaps giving them the ability to exploit new ecological niches.

  16. Cluster Analysis in the COPDGene Study Identifies Subtypes of Smokers with Distinct Patterns of Airway Disease and Emphysema

    Science.gov (United States)

    Castaldi, Peter J; Dy, Jennifer; Ross, James; Chang, Yale; Washko, George R; Curran-Everett, Douglas; Williams, Andre; Lynch, David A; Make, Barry J; Crapo, James D; Bowler, Russ P; Regan, Elizabeth A; Hokanson, John E; Kinney, Greg L; Han, Meilan K; Soler, Xavier; Ramsdell, Joseph W; Barr, R Graham; Foreman, Marilyn; van Beek, Edwin; Casaburi, Richard; Criner, Gerald J; Lutz, Sharon M; Rennard, Steven I; Santorico, Stephanie; Sciurba, Frank C; DeMeo, Dawn L; Hersh, Craig P; Silverman, Edwin K; Cho, Michael H

    2014-01-01

    Background There is notable heterogeneity in the clinical presentation of patients with COPD. To characterize this heterogeneity, we sought to identify subgroups of smokers by applying cluster analysis to data from the COPDGene Study. Methods We applied a clustering method, k-means, to data from 10,192 smokers in the COPDGene Study. After splitting the sample into a training and validation set, we evaluated three sets of input features across a range of k (user-specified number of clusters). Stable solutions were tested for association with four COPD-related measures and five genetic variants previously associated with COPD at genome-wide significance. The results were confirmed in the validation set. Findings We identified four clusters that can be characterized as 1) relatively resistant smokers (i.e. no/mild obstruction and minimal emphysema despite heavy smoking), 2) mild upper zone emphysema predominant, 3) airway disease predominant, and 4) severe emphysema. All clusters are strongly associated with COPD-related clinical characteristics, including exacerbations and dyspnea (pCluster analysis identifies four subgroups of smokers that show robust associations with clinical characteristics of COPD and known COPD-associated genetic variants. PMID:24563194

  17. A distinct Bemisia tabaci (Gennadius) (Hemiptera: Sternorrhyncha: Aleyrodidae) genotype cluster is associated with the epidemic of severe cassava mosaic virus disease in Uganda.

    Science.gov (United States)

    Legg, J P; French, R; Rogan, D; Okao-Okuja, G; Brown, J K

    2002-07-01

    During the 1990s, an epidemic of cassava mosaic virus disease caused major losses to cassava production in Uganda. Two factors associated with the epidemic were the occurrence of a novel recombinant begomovirus, EACMV-Ug, and unusually high populations of the whitefly vector, Bemisia tabaci. Here we present molecular evidence for the occurrence of two cassava-colonizing B. tabaci genotype clusters, Ug1 and Ug2, one of which, Ug2, can be consistently associated with the CMD epidemic in Uganda at the time of collection in 1997. By contrast, a second genotype cluster, Ug1, only occurred 'at' or 'ahead of' the epidemic 'front', sometimes in mixtures with Ug2. Comparison of mitochondrial cytochrome oxidase I gene sequences for Ug1 and Ug2 and well-studied B. tabaci reference populations indicated that the two Ugandan populations exhibited approximately 8% divergence, suggesting they represent distinct sub-Saharan African lineages. Neither Ugandan genotype cluster was identified as the widely distributed, polyphagous, and highly fecund B biotype of Old World origin, with which they both diverged by approximately 8%. Within genotype cluster divergence of Ug1 at 0.61 +/- 0.1% was twice that of Ug2 at 0.35 +/- 0.1%. Mismatch analysis suggested that Ug2 has undergone a recent population expansion and may be of nonUgandan origin, whereas Ug1 has diverged more slowly, and is likely to be an indigenous genotype cluster.

  18. Distinct Loci in the CHRNA5/CHRNA3/CHRNB4 Gene Cluster Are Associated With Onset of Regular Smoking

    Science.gov (United States)

    Stephens, Sarah H.; Hartz, Sarah M.; Hoft, Nicole R.; Saccone, Nancy L.; Corley, Robin C.; Hewitt, John K.; Hopfer, Christian J.; Breslau, Naomi; Coon, Hilary; Chen, Xiangning; Ducci, Francesca; Dueker, Nicole; Franceschini, Nora; Frank, Josef; Han, Younghun; Hansel, Nadia N.; Jiang, Chenhui; Korhonen, Tellervo; Lind, Penelope A.; Liu, Jason; Lyytikäinen, Leo-Pekka; Michel, Martha; Shaffer, John R.; Short, Susan E.; Sun, Juzhong; Teumer, Alexander; Thompson, John R.; Vogelzangs, Nicole; Vink, Jacqueline M.; Wenzlaff, Angela; Wheeler, William; Yang, Bao-Zhu; Aggen, Steven H.; Balmforth, Anthony J.; Baumeister, Sebastian E.; Beaty, Terri H.; Benjamin, Daniel J.; Bergen, Andrew W.; Broms, Ulla; Cesarini, David; Chatterjee, Nilanjan; Chen, Jingchun; Cheng, Yu-Ching; Cichon, Sven; Couper, David; Cucca, Francesco; Dick, Danielle; Foroud, Tatiana; Furberg, Helena; Giegling, Ina; Gillespie, Nathan A.; Gu, Fangyi; Hall, Alistair S.; Hällfors, Jenni; Han, Shizhong; Hartmann, Annette M.; Heikkilä, Kauko; Hickie, Ian B.; Hottenga, Jouke Jan; Jousilahti, Pekka; Kaakinen, Marika; Kähönen, Mika; Koellinger, Philipp D.; Kittner, Stephen; Konte, Bettina; Landi, Maria-Teresa; Laatikainen, Tiina; Leppert, Mark; Levy, Steven M.; Mathias, Rasika A.; McNeil, Daniel W.; Medland, Sarah E.; Montgomery, Grant W.; Murray, Tanda; Nauck, Matthias; North, Kari E.; Paré, Peter D.; Pergadia, Michele; Ruczinski, Ingo; Salomaa, Veikko; Viikari, Jorma; Willemsen, Gonneke; Barnes, Kathleen C.; Boerwinkle, Eric; Boomsma, Dorret I.; Caporaso, Neil; Edenberg, Howard J.; Francks, Clyde; Gelernter, Joel; Grabe, Hans Jörgen; Hops, Hyman; Jarvelin, Marjo-Riitta; Johannesson, Magnus; Kendler, Kenneth S.; Lehtimäki, Terho; Magnusson, Patrik K.E.; Marazita, Mary L.; Marchini, Jonathan; Mitchell, Braxton D.; Nöthen, Markus M.; Penninx, Brenda W.; Raitakari, Olli; Rietschel, Marcella; Rujescu, Dan; Samani, Nilesh J.; Schwartz, Ann G.; Shete, Sanjay; Spitz, Margaret; Swan, Gary E.; Völzke, Henry; Veijola, Juha; Wei, Qingyi; Amos, Chris; Cannon, Dale S.; Grucza, Richard; Hatsukami, Dorothy; Heath, Andrew; Johnson, Eric O.; Kaprio, Jaakko; Madden, Pamela; Martin, Nicholas G.; Stevens, Victoria L.; Weiss, Robert B.; Kraft, Peter; Bierut, Laura J.; Ehringer, Marissa A.

    2014-01-01

    Neuronal nicotinic acetylcholine receptor (nAChR) genes (CHRNA5/CHRNA3/CHRNB4) have been reproducibly associated with nicotine dependence, smoking behaviors, and lung cancer risk. Of the few reports that have focused on early smoking behaviors, association results have been mixed. This meta-analysis examines early smoking phenotypes and SNPs in the gene cluster to determine: (1) whether the most robust association signal in this region (rs16969968) for other smoking behaviors is also associated with early behaviors, and/or (2) if additional statistically independent signals are important in early smoking. We focused on two phenotypes: age of tobacco initiation (AOI) and age of first regular tobacco use (AOS). This study included 56,034 subjects (41 groups) spanning nine countries and evaluated five SNPs including rs1948, rs16969968, rs578776, rs588765, and rs684513. Each dataset was analyzed using a centrally generated script. Meta-analyses were conducted from summary statistics. AOS yielded significant associations with SNPs rs578776 (beta = 0.02, P = 0.004), rs1948 (beta = 0.023, P = 0.018), and rs684513 (beta = 0.032, P = 0.017), indicating protective effects. There were no significant associations for the AOI phenotype. Importantly, rs16969968, the most replicated signal in this region for nicotine dependence, cigarettes per day, and cotinine levels, was not associated with AOI (P = 0.59) or AOS (P = 0.92). These results provide important insight into the complexity of smoking behavior phenotypes, and suggest that association signals in the CHRNA5/A3/B4 gene cluster affecting early smoking behaviors may be different from those affecting the mature nicotine dependence phenotype. PMID:24186853

  19. High-throughput bacterial SNP typing identifies distinct clusters of Salmonella Typhi causing typhoid in Nepalese children

    LENUS (Irish Health Repository)

    Holt, Kathryn E

    2010-05-31

    Abstract Background Salmonella Typhi (S. Typhi) causes typhoid fever, which remains an important public health issue in many developing countries. Kathmandu, the capital of Nepal, is an area of high incidence and the pediatric population appears to be at high risk of exposure and infection. Methods We recently defined the population structure of S. Typhi, using new sequencing technologies to identify nearly 2,000 single nucleotide polymorphisms (SNPs) that can be used as unequivocal phylogenetic markers. Here we have used the GoldenGate (Illumina) platform to simultaneously type 1,500 of these SNPs in 62 S. Typhi isolates causing severe typhoid in children admitted to Patan Hospital in Kathmandu. Results Eight distinct S. Typhi haplotypes were identified during the 20-month study period, with 68% of isolates belonging to a subclone of the previously defined H58 S. Typhi. This subclone was closely associated with resistance to nalidixic acid, with all isolates from this group demonstrating a resistant phenotype and harbouring the same resistance-associated SNP in GyrA (Phe83). A secondary clone, comprising 19% of isolates, was observed only during the second half of the study. Conclusions Our data demonstrate the utility of SNP typing for monitoring bacterial populations over a defined period in a single endemic setting. We provide evidence for genotype introduction and define a nalidixic acid resistant subclone of S. Typhi, which appears to be the dominant cause of severe pediatric typhoid in Kathmandu during the study period.

  20. Stable isotope phenotyping via cluster analysis of NanoSIMS data as a method for characterizing distinct microbial ecophysiologies and sulfur-cycling in the environment

    Directory of Open Access Journals (Sweden)

    Katherine S Dawson

    2016-05-01

    Full Text Available Stable isotope probing (SIP is a valuable tool for gaining insights into ecophysiology and biogeochemical cycling of environmental microbial communities by tracking isotopically labeled compounds into cellular macromolecules as well as into byproducts of respiration. SIP, in conjunction with nanoscale secondary ion mass spectrometry (NanoSIMS, allows for the visualization of isotope incorporation at the single cell level. In this manner, both active cells within a diverse population as well as heterogeneity in metabolism within a homogeneous population can be observed. The ecophysiological implications of these single cell stable isotope measurements are often limited to the taxonomic resolution of paired fluorescence in situ hybridization (FISH microscopy. Here we introduce a taxonomy-independent method using multi-isotope SIP and NanoSIMS for identifying and grouping phenotypically similar microbial cells by their chemical and isotopic fingerprint. This method was applied to SIP experiments in a sulfur-cycling biofilm collected from sulfidic intertidal vents amended with 13C-acetate, 15N-ammonium, and 33S-sulfate. Using a cluster analysis technique based on fuzzy c-means to group cells according to their isotope (13C/12C, 15N/14N, and 33S/32S and elemental ratio (C/CN and S/CN profiles, our analysis partitioned ~2200 cellular regions of interest (ROIs into 5 distinct groups. These isotope phenotype groupings are reflective of the variation in labeled substrate uptake by cells in a multispecies metabolic network dominated by Gamma- and Deltaproteobacteria. Populations independently grouped by isotope phenotype were subsequently compared with paired FISH data, demonstrating a single coherent deltaproteobacterial cluster and multiple gammaproteobacterial groups, highlighting the distinct ecophysiologies of spatially-associated microbes within the sulfur-cycling biofilm from White Point Beach, CA.

  1. Stable isotope phenotyping via cluster analysis of NanoSIMS data as a method for characterizing distinct microbial ecophysiologies and sulfur-cycling in the environment

    Science.gov (United States)

    Dawson, K.; Scheller, S.; Dillon, J. G.; Orphan, V. J.

    2016-12-01

    Stable isotope probing (SIP) is a valuable tool for gaining insights into ecophysiology and biogeochemical cycling of environmental microbial communities by tracking isotopically labeled compounds into cellular macromolecules as well as into byproducts of respiration. SIP, in conjunction with nanoscale secondary ion mass spectrometry (NanoSIMS), allows for the visualization of isotope incorporation at the single cell level. In this manner, both active cells within a diverse population as well as heterogeneity in metabolism within a homogeneous population can be observed. The ecophysiological implications of these single cell stable isotope measurements are often limited to the taxonomic resolution of paired fluorescence in situ hybridization (FISH) microscopy. Here we introduce a taxonomy-independent method using multi-isotope SIP and NanoSIMS for identifying and grouping phenotypically similar microbial cells by their chemical and isotopic fingerprint. This method was applied to SIP experiments in a sulfur-cycling biofilm collected from sulfidic intertidal vents amended with 13C-acetate, 15N-ammonium, and 33S-sulfate. Using a cluster analysis technique based on fuzzy c-means to group cells according to their isotope (13C/12C, 15N/14N, and 33S/32S) and elemental ratio (C/CN and S/CN) profiles, our analysis partitioned 2200 cellular regions of interest (ROIs) into 5 distinct groups. These isotope phenotype groupings are reflective of the variation in labeled substrate uptake by cells in a multispecies metabolic network dominated by Gamma- and Deltaproteobacteria. Populations independently grouped by isotope phenotype were subsequently compared with paired FISH data, demonstrating a single coherent deltaproteobacterial cluster and multiple gammaproteobacterial groups, highlighting the distinct ecophysiologies of spatially-associated microbes within the sulfur-cycling biofilm from White Point Beach, CA.

  2. Transanal rectopexy - twelve case studies

    Directory of Open Access Journals (Sweden)

    Rubens Henrique Oleques Fernandes

    2012-06-01

    Full Text Available OBJECTIVES: This study analyzed the results of transanal rectopexy and showed the benefits of this surgical technique. METHOD: Twelve patients were submitted to rectopexy between 1997 and 2011. The surgical technique used was transanal rectopexy, where the mesorectum was fixed to the sacrum with nonabsorbable suture. Three patients had been submitted to previous surgery, two by the Delorme technique and one by the Thiersch technique. RESULTS: Postoperative hospital stay ranged from 1 to 4 days. One patient (8.3% had intraoperative hematoma, which was treated with local compression and antibiotics. One patient (8.3% had residual mucosal prolapse, which was resected. Prolapse recurrence was seen in one case (8.3%. Improved incontinence occurred in 75% of patients and one patient reported obstructed evacuation in the first month after surgery. No death occurred. CONCLUSION: Transanal rectopexy is a simple, low cost technique, which has shown good efficacy in rectal prolapse control.OBJETIVO: O presente estudo analisou os resultados da retopexia pela via transanal e expôs os benefícios desta técnica cirúrgica. MÉTODO: Doze pacientes com prolapso foram operados no período de 1997 a 2011. A técnica cirúrgica usada foi a retopexia transanal, onde o mesorreto foi fixado ao sacro com fio inabsorvível. Três pacientes tinham cirurgia prévia, dois pela técnica de Delorme e um pela técnica de Thiersch. RESULTADOS: A permanência hospitalar pós-operatória variou de 1- 4 dias. Uma paciente (8,3% apresentou hematoma transoperatório que foi tratado com compressão local e antibioticoterapia. Um paciente apresentou prolapso mucoso residual (8,3%, que foi ressecado. Houve recidiva da procidência em um caso (8,3%. A melhora da incontinência ocorreu em 75% dos pacientes e uma paciente apresentou bloqueio evacuatório no primeiro mês após a cirurgia. Não houve mortalidade entre os pacientes operados. CONCLUSÃO: A retopexia transanal é uma t

  3. MicroRNA-Target Network Inference and Local Network Enrichment Analysis Identify Two microRNA Clusters with Distinct Functions in Head and Neck Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Steffen Sass

    2015-12-01

    clusters of miRNAs that were predicted to mediate HPV-associated dysregulation in HNSCC. Our novel approach was able to characterize distinct pathway regulations from matched miRNA and mRNA data. An R package of miRlastic was made available through: http://icb.helmholtz-muenchen.de/mirlastic.

  4. Mythematics Solving the Twelve Labors of Hercules

    CERN Document Server

    Huber, Michael

    2009-01-01

    How might Hercules, the most famous of the Greek heroes, have used mathematics to complete his astonishing Twelve Labors? From conquering the Nemean Lion and cleaning out the Augean Stables, to capturing the Erymanthean Boar and entering the Underworld to defeat the three-headed dog Cerberus, Hercules and his legend are the inspiration for this book of fun and original math puzzles. While Hercules relied on superhuman strength to accomplish the Twelve Labors, Mythematics shows how math could have helped during his quest. How does Hercules defeat the Lernean Hydra and stop its heads from multip

  5. Degradation of Benzene by Pseudomonas veronii 1YdBTEX2 and 1YB2 Is Catalyzed by Enzymes Encoded in Distinct Catabolism Gene Clusters

    Science.gov (United States)

    de Lima-Morales, Daiana; Chaves-Moreno, Diego; Wos-Oxley, Melissa L.; Jáuregui, Ruy; Vilchez-Vargas, Ramiro

    2015-01-01

    Pseudomonas veronii 1YdBTEX2, a benzene and toluene degrader, and Pseudomonas veronii 1YB2, a benzene degrader, have previously been shown to be key players in a benzene-contaminated site. These strains harbor unique catabolic pathways for the degradation of benzene comprising a gene cluster encoding an isopropylbenzene dioxygenase where genes encoding downstream enzymes were interrupted by stop codons. Extradiol dioxygenases were recruited from gene clusters comprising genes encoding a 2-hydroxymuconic semialdehyde dehydrogenase necessary for benzene degradation but typically absent from isopropylbenzene dioxygenase-encoding gene clusters. The benzene dihydrodiol dehydrogenase-encoding gene was not clustered with any other aromatic degradation genes, and the encoded protein was only distantly related to dehydrogenases of aromatic degradation pathways. The involvement of the different gene clusters in the degradation pathways was suggested by real-time quantitative reverse transcription PCR. PMID:26475106

  6. A DNA-Encapsulated and Fluorescent Ag 10 6+ Cluster with a Distinct Metal-Like Core

    Energy Technology Data Exchange (ETDEWEB)

    Petty, Jeffrey T.; Ganguly, Mainak; Rankine, Ian J.; Chevrier, Daniel M.; Zhang, Peng (Dalhousie U.); (Furman)

    2017-06-29

    Silver cluster–DNA complexes are optical chromophores, and pairs of these conjugates can be toggled from fluorescently dim to bright states using DNA hybridization. This paper highlights spectral and structural differences for a specific cluster pair. We have previously characterized a cluster with low emission and violet absorption that forms a compact structure with single-stranded oligonucleotides. We now consider its counterpart with blue absorption and strong green emission. This cluster develops with a single-stranded/duplex DNA construct and is favored by low silver concentrations with ≲8 Ag+:DNA, an oxygen atmosphere, and neutral pH. The resulting cluster displays key signatures of a molecular metal with well-defined absorption/emission bands at 490/550 nm, and with a fluorescence quantum yield of 15% and lifetime of 2.4 ns. The molecular cluster conjugates with the larger DNA host because it chromatographically elutes with the DNA and it exhibits circular dichroism. The silver cluster is identified as Ag106+ using two modes of mass spectrometry and elemental analysis. Our key finding is that it adopts a low-dimensional shape, as determined from a Ag K-edge extended X-ray absorption fine structure analysis. The Ag0 in this oxidized cluster segregates from the Ag+ via a sparse number of metal-like bonds and a denser network of silver–DNA bonds. This structure contrasts with the compact, octahedral-like shape of the violet counterpart to the blue cluster, which is also a Ag106+ species. We consider that the blue- and violet-absorbing clusters may be isomers with shapes that are controlled by the secondary structures of their DNA templates.

  7. Comparative analysis of twelve Dothideomycete plant pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Ohm, Robin; Aerts, Andrea; Salamov, Asaf; Goodwin, Stephen B.; Grigoriev, Igor

    2011-03-11

    The Dothideomycetes are one of the largest and most diverse groups of fungi. Many are plant pathogens and pose a serious threat to agricultural crops grown for biofuel, food or feed. Most Dothideomycetes have only a single host and related Dothideomycete species can have very diverse host plants. Twelve Dothideomycete genomes have currently been sequenced by the Joint Genome Institute and other sequencing centers. They can be accessed via Mycocosm which has tools for comparative analysis

  8. Cluster-cluster clustering

    Science.gov (United States)

    Barnes, J.; Dekel, A.; Efstathiou, G.; Frenk, C. S.

    1985-01-01

    The cluster correlation function xi sub c(r) is compared with the particle correlation function, xi(r) in cosmological N-body simulations with a wide range of initial conditions. The experiments include scale-free initial conditions, pancake models with a coherence length in the initial density field, and hybrid models. Three N-body techniques and two cluster-finding algorithms are used. In scale-free models with white noise initial conditions, xi sub c and xi are essentially identical. In scale-free models with more power on large scales, it is found that the amplitude of xi sub c increases with cluster richness; in this case the clusters give a biased estimate of the particle correlations. In the pancake and hybrid models (with n = 0 or 1), xi sub c is steeper than xi, but the cluster correlation length exceeds that of the points by less than a factor of 2, independent of cluster richness. Thus the high amplitude of xi sub c found in studies of rich clusters of galaxies is inconsistent with white noise and pancake models and may indicate a primordial fluctuation spectrum with substantial power on large scales.

  9. Cluster-cluster clustering

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, J.; Dekel, A.; Efstathiou, G.; Frenk, C.S.

    1985-08-01

    The cluster correlation function xi sub c(r) is compared with the particle correlation function, xi(r) in cosmological N-body simulations with a wide range of initial conditions. The experiments include scale-free initial conditions, pancake models with a coherence length in the initial density field, and hybrid models. Three N-body techniques and two cluster-finding algorithms are used. In scale-free models with white noise initial conditions, xi sub c and xi are essentially identical. In scale-free models with more power on large scales, it is found that the amplitude of xi sub c increases with cluster richness; in this case the clusters give a biased estimate of the particle correlations. In the pancake and hybrid models (with n = 0 or 1), xi sub c is steeper than xi, but the cluster correlation length exceeds that of the points by less than a factor of 2, independent of cluster richness. Thus the high amplitude of xi sub c found in studies of rich clusters of galaxies is inconsistent with white noise and pancake models and may indicate a primordial fluctuation spectrum with substantial power on large scales. 30 references.

  10. Twelve tips for peer observation of teaching.

    Science.gov (United States)

    Siddiqui, Zarrin Seema; Jonas-Dwyer, Diana; Carr, Sandra E

    2007-05-01

    This paper outlines twelve tips for undertaking peer observation of teaching in medical education, using the peer review model and the experiences of the authors. An accurate understanding of teaching effectiveness is required by individuals, medical schools, and universities to evaluate the learning environment and to substantiate academic and institutional performance. Peer Observation of Teaching is one tool that provides rich, qualitative evidence for teachers, quite different from closed-ended student evaluations. When Peer Observation of Teaching is incorporated into university practice and culture, and is conducted in a mutually respectful and supportive way, it has the potential to facilitate reflective change and growth for teachers.

  11. A First Assessment of Mycobacterium tuberculosis Genetic Diversity and Drug-Resistance Patterns in Twelve Caribbean Territories

    Directory of Open Access Journals (Sweden)

    Julie Millet

    2014-01-01

    Full Text Available With the exception of some French-speaking islands, data on tuberculosis (TB in the Caribbean are scarce. In this study, we report a first assessment of genetic diversity of a convenience sample of Mycobacterium tuberculosis strains received from twelve Caribbean territories by spoligotyping and describe their drug-resistance patterns. Of the 480 isolates, 40 (8.3% isolates showed resistance to at least one anti-TB drug. The proportion of drug-resistant strains was significantly higher in The Bahamas (21.4%; P=0.02, and Guyana (27.5%; P<0.0001, while it was significantly lower in Jamaica (2.4%; P=0.03 than in other countries of the present study. Regarding genetic diversity, 104 distinct spoligotype patterns were observed: 49 corresponded to clustered strains (2 to 93 strains per cluster, while 55 remained unclustered among which 16 patterns were not reported previously. Combining the study results with regional data retrieved from the international SITVIT2 database underlined a connection between frequency of certain M. tuberculosis phylogenetic lineages and the language spoken, suggesting historical (colonial and ongoing links (trade, tourism, and migratory flows with European countries with which they shared a common past.

  12. Oral papillary squamous cell carcinoma in twelve dogs.

    Science.gov (United States)

    Nemec, A; Murphy, B G; Jordan, R C; Kass, P H; Verstraete, F J M

    2014-01-01

    Papillary squamous cell carcinoma (PSCC) is a distinct histological subtype of oral squamous cell carcinoma (SCC), described in both dogs and man. In dogs, PSCC has long been considered a malignant oral tumour of very young animals, but it has recently been reported to occur in adult dogs as well. The aim of this study was to describe the major clinicopathological characteristics of canine oral PSCC (COPSCC). Twelve dogs diagnosed with COPSCC were included in this retrospective study (1990-2012). The majority (75%) of the dogs were >6 years of age (median age 9 years). All tumours were derived from the gingiva of dentate jaws, with 66.7% affecting the rostral aspects of the jaws. The gross appearance of the lesions varied, with one having an intraosseous component only. The majority (91.7%) of the tumours were advanced lesions (T2 and T3), but no local or distant metastases were noted. Microscopically, two patterns were seen: (1) invasion of bone forming a cup-shaped indentation in the bone or a deeply cavitating cyst within the bone (cavitating pattern), (2) histologically malignant growth, but lack of apparent bone invasion (non-cavitating pattern). The microscopical appearance corresponded to imaging findings in a majority of cases, with cavitating forms presenting with a cyst-like pattern of bone loss or an expansile mass on imaging and non-cavitating forms showing an infiltrative pattern of bone destruction on imaging. These features suggest two distinct biological behaviours of COPSCC.

  13. Combining ability of twelve maize populations

    Directory of Open Access Journals (Sweden)

    Vacaro Elton

    2002-01-01

    Full Text Available Genetic progress depends on germplasm quality and breeding methods. Twelve maize populations and their crosses were evaluated to estimate combining ability and potential to be included as source populations in breeding programs. Plant height, point of insertion of the first ear, number of ears per plant, number of grains per ear, root and stalk lodging and grain yield were studied in two locations in Brazil, during the 1997/98 season. Genotype sum of squares was divided into general (GCA and specific (SCA combining ability. Results indicated the existence of genetic divergence for all traits analyzed, where additive effects were predominant. The high heterosis levels observed, mainly in Xanxerê, suggested the environmental influence on the manifestation of this genetic phenomenon. Populations revealed potential to be used in breeding programs; however, those more intensively submitted to selection could provide larger genetic progress, showing the importance of population improvement for the increment of the heterosis in maize.

  14. Novel Method To Identify Source-Associated Phylogenetic Clustering Shows that Listeria monocytogenes Includes Niche-Adapted Clonal Groups with Distinct Ecological Preferences

    DEFF Research Database (Denmark)

    Nightingale, K. K.; Lyles, K.; Ayodele, M.

    2006-01-01

    While phylogenetic and cluster analyses are often used to define clonal groups within bacterial species, the identification of clonal groups that are associated with specific ecological niches or host species remains a challenge. We used Listeria monocytogenes, which causes invasive disease...... in humans and different animal species and which can be isolated from a number of environments including food, as a model organism to develop and implement a two-step statistical approach to the identification of phylogenetic clades that are significantly associated with different source populations...

  15. Two Groups of Red Giants with Distinct Chemical Abundances in the Bulge Globular Cluster NGC 6553 Through the Eyes of APOGEE

    CERN Document Server

    Tang, Baitian; Geisler, Doug; Schiavon, Ricardo; Majewski, Steven R; Villanova, Sandro; Carrera, Ricardo; Zamora, Olga; Garcia-Hernandez, D A; Shetrone, Matthew; Frinchaboy, Peter; Meza, Andres; Fernández-Trincado, J G; Muñoz, Ricardo R; Lin, Chien-Cheng; Lane, Richard R; Nitschelm, Christian; Pan, Kaike; Bizyaev, Dmitry; Oravetz, Daniel; Simmons, Audrey

    2016-01-01

    Multiple populations revealed in globular clusters (GCs) are important windows to the formation and evolution of these stellar systems. The metal-rich GCs in the Galactic bulge are an indispensable part of this picture, but the high optical extinction in this region has prevented extensive research. In this work, we use the high resolution near-infrared (NIR) spectroscopic data from APOGEE to study the chemical abundances of NGC 6553, which is one of the most metal-rich bulge GCs. We identify ten red giants as cluster members using their positions, radial velocities, iron abundances, and NIR photometry. Our sample stars show a mean radial velocity of $-0.14\\pm5.47$ km s$^{-1}$, and a mean [Fe/H] of $-0.15\\pm 0.05$. We clearly separate two populations of stars in C and N in this GC for the first time. NGC 6553 is the most metal-rich GC where the multiple stellar population phenomenon is found until now. Substantial chemical variations are also found in Na, O, and Al. However, the two populations show similar S...

  16. Two Groups of Red Giants with Distinct Chemical Abundances in the Bulge Globular Cluster NGC 6553 Through the Eyes of APOGEE

    Science.gov (United States)

    Tang, Baitian; Cohen, Roger; Geisler, Douglas; Schiavon, Ricardo P.; Majewski, Steven R.; Villanova, Sandro; Carrera, Ricardo; Zamora, Olga; Garcia-Hernandez, D.; Shetrone, Matthew D.; Frinchaboy, Peter M.; Fernandez Trincado, Jose Gregorio; APOGEE Team

    2017-01-01

    Multiple populations revealed in globular clusters (GCs) are important windows to the formation and evolution of these stellar systems. The metal-rich GCs in the Galactic bulge are an indispensable part of this picture, but the high optical extinction in this region has prevented extensive research. In this work, we use the high resolution near-infrared (NIR) spectroscopic data from APOGEE to study the chemical abundances of NGC 6553, which is one of the most metal-rich bulge GCs. We identify ten red giants as cluster members using their positions, radial velocities, iron abundances, and NIR photometry. Our sample stars show a mean radial velocity of -0.14 km/s, and a mean [Fe/H] of -0.15. We clearly separate two populations of stars in C and N in this GC for the first time. NGC 6553 is the most metal-rich GC where the multiple stellar population phenomenon is found until now. Substantial chemical variations are also found in Na, O, and Al. However, the two populations show similar Si, Ca, and iron-peak element abundances. Therefore, we infer that the CNO, NeNa, and MgAl cycles have been activated, but the MgAl cycle is too weak to show its effect on Mg. The Si leakage from the MgAl cycle is negligible. Type Ia and Type II supernovae do not seem to have significantly polluted the second generation stars. Comparing the APOGEE results with other GC studies, we find that NGC 6553 shows similar chemical variations as other relatively metal-rich GCs. We also confront current GC formation theories with our results, and suggest possible avenues for improvement in the models.

  17. Two groups of red giants with distinct chemical abundances in the bulge globular cluster NGC 6553 through the eyes of APOGEE

    Science.gov (United States)

    Tang, Baitian; Cohen, Roger E.; Geisler, Doug; Schiavon, Ricardo P.; Majewski, Steven R.; Villanova, Sandro; Carrera, Ricardo; Zamora, Olga; Garcia-Hernandez, D. A.; Shetrone, Matthew; Frinchaboy, Peter; Meza, Andres; Fernández-Trincado, J. G.; Muñoz, Ricardo R.; Lin, Chien-Cheng; Lane, Richard R.; Nitschelm, Christian; Pan, Kaike; Bizyaev, Dmitry; Oravetz, Daniel; Simmons, Audrey

    2017-02-01

    Multiple populations revealed in globular clusters (GCs) are important windows to the formation and evolution of these stellar systems. The metal-rich GCs in the Galactic bulge are an indispensable part of this picture, but the high optical extinction in this region has prevented extensive research. In this work, we use the high-resolution near-infrared (NIR) spectroscopic data from Apache Point Observatory Galactic Evolution Experiment (APOGEE) to study the chemical abundances of NGC 6553, which is one of the most metal-rich bulge GCs. We identify 10 red giants as cluster members using their positions, radial velocities, iron abundances, and NIR photometry. Our sample stars show a mean radial velocity of -0.14 ± 5.47 km s-1, and a mean [Fe/H] of -0.15 ± 0.05. We clearly separate two populations of stars in C and N in this GC for the first time. NGC 6553 is the most metal-rich GC where the multiple stellar population phenomenon is found until now. Substantial chemical variations are also found in Na, O, and Al. However, the two populations show similar Si, Ca, and iron-peak element abundances. Therefore, we infer that the CNO, NeNa, and MgAl cycles have been activated, but the MgAl cycle is too weak to show its effect on Mg. Type Ia and Type II supernovae do not seem to have significantly polluted the second generation stars. Comparing with other GC studies, NGC 6553 shows similar chemical variations as other relatively metal-rich GCs. We also confront current GC formation theories with our results, and suggest possible avenues for improvement in the models.

  18. Twelve tips for getting your manuscript published.

    Science.gov (United States)

    Cook, David A

    2016-01-01

    The author shares twelve practical tips on how to navigate the process of getting a manuscript published. These tips, which apply to all fields of academic writing, advise that during the initial preparation phase authors should: (1) plan early to get it out the door; (2) address authorship and writing group expectations up front; (3) maintain control of the writing; (4) ensure complete reporting; (5) use electronic reference management software; (6) polish carefully before they submit; (7) select the right journal; and (8) follow journal instructions precisely. Rejection after the first submission is likely, and when this occurs authors should (9) get it back out the door quickly, but first (10) take seriously all reviewer and editor suggestions. Finally, when the invitation comes to revise and resubmit, authors should (11) respond carefully to every reviewer suggestion, even if they disagree, and (12) get input from others as they revise. The author also shares detailed suggestions on the creation of effective tables and figures, and on how to respond to reviewer critiques.

  19. Antifouling activity of twelve demosponges from Brazil

    Directory of Open Access Journals (Sweden)

    SM. Ribeiro

    Full Text Available Benthic marine organisms are constantly exposed to fouling, which is harmful to most host species. Thus, the production of secondary metabolites containing antifouling properties is an important ecological advantage for sessile organisms and may also provide leading compounds for the development of antifouling paints. High antifouling potential of sponges has been demonstrated in the Indian and Pacific oceans and in the Caribbean and Mediterranean seas. Brazilian sponges remain understudied concerning antifouling activities. Only two scientific articles reported this activity in sponges of Brazil. The objective of this study was to test crude extracts of twelve species of sponges from Brazil against the attachment of the mussel Perna perna through laboratorial assays, and highlight promising species for future studies. The species Petromica citrina, Amphimedon viridis, Desmapsamma anchorata, Chondrosia sp., Polymastia janeirensis, Tedania ignis, Aplysina fulva, Mycale angulosa, Hymeniacidon heliophila, Dysidea etheria, Tethya rubra, and Tethya maza were frozen and freeze-dried before extraction with acetone or dichloromethane. The crude extract of four species significantly inhibited the attachment of byssus: Tethya rubra (p = 0.0009, Tethya maza (p = 0.0039, Petromica citrina (p = 0.0277, and Hymeniacidon heliophila (p = 0.00003. These species, specially, should be the target of future studies to detail the substances involved in the ability antifouling well as to define its amplitude of action.

  20. Twelve Elastic Constants of Betula platyphylla Suk.

    Institute of Scientific and Technical Information of China (English)

    Wang Liyu; Lu Zhenyou

    2004-01-01

    Wood elastic constants are needed to describe the elastic behaviors of wood and be taken as an important design parameter for wood-based composite materials and structural materials. This paper clarified the relationships between compliance coefficients and engineering elastic constants combined with orthotropic properties of wood, and twelve elastic constants of Betula platyphylla Suk. were measured by electrical strain gauges. Spreading the adhesive quantity cannot be excessive or too little when the strain flakes were glued. If excessive, the glue layer was too thick which would influence the strain flakes' performance, and if too little, glues plastered were not firm, which could not accurately transmit the strain. Wood as an orthotropic material, its modulus of elasticity and poisson's ratios are related by two formulas:μij /Ei =μji /Ej and μij 0.95) between the reciprocal of elastic modulus MOE-1 and the square of the ratio of depth to length (h/l)2, which indicate that shear modulus values measured were reliable by three point bending experiment.

  1. Distinct core and halo stellar populations and the formation history of the bright Coma cluster early-type galaxy NGC 4889

    CERN Document Server

    Coccato, Lodovico; Arnaboldi, Magda

    2010-01-01

    We study the stellar population far into the halo of one of the two brightest galaxies in the Coma cluster, NGC 4889, based on deep medium resolution spectroscopy with FOCAS at the Subaru 8.2m telescope. We fit single stellar population models to the measured line-strength (Lick) indices (Hbeta, Mgb, [MgFe]' and ). Combining with literature data, we construct radial profiles of metallicity, [alpha/Fe] element abundance ratio and age for NGC 4889, from the center out to ~60 kpc (~4Re). We find evidence for different chemical and star formation histories for stars inside and outside 1.2Re = 18 kpc radius. The inner regions are characterized by a steep [Z/H] gradient and high [alpha/Fe] at ~2.5 times solar value. In the halo, between 18 and 60 kpc, the [Z/H] is near-solar with a shallow gradient, while [alpha/Fe] shows a strong negative gradient, reaching solar values at ~60 kpc. We interpret these data in terms of different formation histories for both components. The data for the inner galaxy are consistent wi...

  2. Recursive Distinctioning

    CERN Document Server

    Isaacson, Joel

    2016-01-01

    Recursive distinctioning (RD) is a name coined by Joel Isaacson in his original patent document describing how fundamental patterns of process arise from the systematic application of operations of distinction and description upon themselves. Recursive distinctioning means just what it says. A pattern of distinctions is given in a space based on a graphical structure (such as a line of print or a planar lattice or given graph). Each node of the graph is occupied by a letter from some arbitrary alphabet. A specialized alphabet is given that can indicate distinctions about neighbors of a given node. The neighbors of a node are all nodes that are connected to the given node by edges in the graph. The letters in the specialized alphabet (call it SA) are used to describe the states of the letters in the given graph and at each stage in the recursion, letters in SA are written at all nodes in the graph, describing its previous state. The recursive structure that results from the iteration of descriptions is called ...

  3. Sequence-based Screening for Rare Enzymes: New Insights into the World of AMDases Reveal a Conserved Motif and 58 Novel Enzymes Clustering in Eight Distinct Families.

    Directory of Open Access Journals (Sweden)

    Janine Maimanakos

    2016-08-01

    Full Text Available Arylmalonate-Decarboxylases (AMDases, EC 4.1.1.76 are very rare and mostly underexplored enzymes. Currently only four known and biochemically characterized representatives exist. However, their ability to decarboxylate α-disubstituted malonic acid derivatives to optically pure products without cofactors makes them attractive and promising candidates for the use as biocatalysts in industrial processes. Until now, AMDases could not be separated from other members of the aspartate/glutamate racemase superfamily based on their gene sequences. Within this work, a search algorithm was developed that enables a reliable prediction of AMDase activity for potential candidates. Based on specific sequence patterns and screening methods 58 novel AMDase candidate genes could be identified in this work. Thereby, AMDases with the conserved sequence pattern of Bordetella bronchiseptica’s prototype appeared to be limited to the classes of Alpha-, Beta- and Gammaproteobacteria. Amino acid homologies and comparison of gene surrounding sequences enabled the classification of eight enzyme clusters. Particularly striking is the accumulation of genes coding for different transporters of the TTT family, TRAP transporters and ABC transporters as well as genes coding for mandelate racemases/muconate lactonizing enzymes that might be involved in substrate uptake or degradation of AMDase products. Further, three novel AMDases were characterized which showed a high enantiomeric excess (>99% of the (R-enantiomer of flurbiprofen. These are the recombinant AmdA and AmdV from Variovorax sp. strains HH01 and HH02, originated from soil, and AmdP from Polymorphum gilvum found by a data base search. Altogether our findings give new insights into the class of AMDases and reveal many previously unknown enzyme candidates with high potential for bioindustrial processes.

  4. Sequence-Based Screening for Rare Enzymes: New Insights into the World of AMDases Reveal a Conserved Motif and 58 Novel Enzymes Clustering in Eight Distinct Families

    Science.gov (United States)

    Maimanakos, Janine; Chow, Jennifer; Gaßmeyer, Sarah K.; Güllert, Simon; Busch, Florian; Kourist, Robert; Streit, Wolfgang R.

    2016-01-01

    Arylmalonate Decarboxylases (AMDases, EC 4.1.1.76) are very rare and mostly underexplored enzymes. Currently only four known and biochemically characterized representatives exist. However, their ability to decarboxylate α-disubstituted malonic acid derivatives to optically pure products without cofactors makes them attractive and promising candidates for the use as biocatalysts in industrial processes. Until now, AMDases could not be separated from other members of the aspartate/glutamate racemase superfamily based on their gene sequences. Within this work, a search algorithm was developed that enables a reliable prediction of AMDase activity for potential candidates. Based on specific sequence patterns and screening methods 58 novel AMDase candidate genes could be identified in this work. Thereby, AMDases with the conserved sequence pattern of Bordetella bronchiseptica’s prototype appeared to be limited to the classes of Alpha-, Beta-, and Gamma-proteobacteria. Amino acid homologies and comparison of gene surrounding sequences enabled the classification of eight enzyme clusters. Particularly striking is the accumulation of genes coding for different transporters of the tripartite tricarboxylate transporters family, TRAP transporters and ABC transporters as well as genes coding for mandelate racemases/muconate lactonizing enzymes that might be involved in substrate uptake or degradation of AMDase products. Further, three novel AMDases were characterized which showed a high enantiomeric excess (>99%) of the (R)-enantiomer of flurbiprofen. These are the recombinant AmdA and AmdV from Variovorax sp. strains HH01 and HH02, originated from soil, and AmdP from Polymorphum gilvum found by a data base search. Altogether our findings give new insights into the class of AMDases and reveal many previously unknown enzyme candidates with high potential for bioindustrial processes. PMID:27610105

  5. Twelve novel Atm mutations identified in Chinese ataxia telangiectasia patients.

    Science.gov (United States)

    Huang, Yu; Yang, Lu; Wang, Jianchun; Yang, Fan; Xiao, Ying; Xia, Rongjun; Yuan, Xianhou; Yan, Mingshan

    2013-09-01

    Ataxia telangiectasia (A-T) is an autosomal recessive disease characterized mainly by progressive cerebellar ataxia, oculocutaneous telangiectasia, and immunodeficiency. This disease is caused by mutations of the ataxia telangiectasia mutated (Atm) gene. More than 500 Atm mutations that are responsible for A-T have been identified so far. However, there have been very few A-T cases reported in China, and only two Chinese A-T patients have undergone Atm gene analysis. In order to systemically investigate A-T in China and map their Atm mutation spectrum, we recruited eight Chinese A-T patients from six unrelated families nationwide. Using direct sequencing of genomic DNA and the multiplex ligation-dependent probe amplification, we identified twelve pathogenic Atm mutations, including one missense, four nonsense, five frameshift, one splicing, and one large genomic deletion. All the Atm mutations we identified were novel, and no homozygous mutation and founder-effect mutation were found. These results suggest that Atm mutations in Chinese populations are diverse and distinct largely from those in other ethnic areas.

  6. Hepatic Angiosarcoma: a Review of Twelve Cases

    Institute of Scientific and Technical Information of China (English)

    Qiang Li; Xishan Hao

    2005-01-01

    OBJECTIVE Hepatic angiosarcoma (HAS), a lethal disease, is the most common sarcoma arising in the liver. Little information about the epidemiology, etiology, diagnosis and management of HAS has been reported. Increased familiarity with this disease will facilitate correct diagnosis and help to improve management of this condition in the future.The objective of this study was to describe cases of hepatic angiosarcoma and to discuss the etiologic, diagnostic, therapeutic features and prognosis of this tumor. This report not only serves to give more evidence of the relationship between hepatic angiosarcoma and carcinogenic exposure, but also demonstrates the key points in different methods of diagnosis and the optimal treatment of hepatic angiosarcoma.METHODS Twelve cases of hepatic angiosareoma were analyzed retrospectively, representing the different character in clinical presentations and laboratory computed tomographical scans; pathological data and treatment are described. Clinical and biologic follow-up was carried out for two years after surgical treatment.RESULTS There were nine men and three women varying in ages from 57 to 71 years with an average of 64.3 years. Ten patientshad a history of exposure to vinyl chloride or thorotrast. Mild or moderate abdominal pain and bloating, abdominal mass and fever were the common clinical presentations. Tumors were visualized by ultrasonography and CT scans in all patients. Biochemical profiles yielded variable results and proved to be of little value in detection or diagnosis. Surgical resection was feasible for each patient who was treated as follows: two wedge resections, six segementectomies and four bisegmentectomies. Five patients received Neoadjuvant chemotherapy postoperatively. The survival rate of those cases was poor. The maximum survival time was fourteen months. The mean survival time for this chemotherapeutic group was 11 months. The difference between the survival time of those treated with an operation

  7. Most cases of cryptococcal meningitis in HIV-uninfected patients in Vietnam are due to a distinct amplified fragment length polymorphism-defined cluster of Cryptococcus neoformans var. grubii VN1.

    Science.gov (United States)

    Day, Jeremy N; Hoang, Thu N; Duong, Anh V; Hong, Chau T T; Diep, Pham T; Campbell, James I; Sieu, Tran P M; Hien, Tran T; Bui, Tien; Boni, Maciej F; Lalloo, David G; Carter, Dee; Baker, Stephen; Farrar, Jeremy J

    2011-02-01

    Cryptococcal disease most commonly occurs in patients with an underlying immune deficit, most commonly HIV infection, and is due to Cryptococcus neoformans var. grubii. Occasionally disease due to this variety occurs in apparently immunocompetent patients. The relationship between strains infecting immunosuppressed and immunocompetent patients is not clear. Amplified fragment length polymorphism (AFLP) analysis was used to characterize the relationship between strains infecting HIV-infected and uninfected patients. Isolates from 51 HIV-uninfected patients and 100 HIV-infected patients with cryptococcal meningitis were compared. C. neoformans var. grubii VNI was responsible for infections in 73% of HIV-uninfected and 100% of HIV-infected patients. AFLP analysis defined two distinct clusters, VNIγ and VNIδ. The majority (84%) of isolates from HIV-uninfected patients were VNIγ, compared with only 38% of isolates from HIV-infected patients (odds ratio, 8.30; 95% confidence interval [CI], 3.04 to 26.6; P cryptococcal meningitis in Vietnam. The distribution of these clusters differs according to the immune status of the host.

  8. Structural models of human eEF1A1 and eEF1A2 reveal two distinct surface clusters of sequence variation and potential differences in phosphorylation.

    Directory of Open Access Journals (Sweden)

    Dinesh C Soares

    Full Text Available BACKGROUND: Despite sharing 92% sequence identity, paralogous human translation elongation factor 1 alpha-1 (eEF1A1 and elongation factor 1 alpha-2 (eEF1A2 have different but overlapping functional profiles. This may reflect the differential requirements of the cell-types in which they are expressed and is consistent with complex roles for these proteins that extend beyond delivery of tRNA to the ribosome. METHODOLOGY/PRINCIPAL FINDINGS: To investigate the structural basis of these functional differences, we created and validated comparative three-dimensional (3-D models of eEF1A1 and eEF1A2 on the basis of the crystal structure of homologous eEF1A from yeast. The spatial location of amino acid residues that vary between the two proteins was thereby pinpointed, and their surface electrostatic and lipophilic properties were compared. None of the variations amongst buried amino acid residues are judged likely to have a major structural effect on the protein fold, or to affect domain-domain interactions. Nearly all the variant surface-exposed amino acid residues lie on one face of the protein, in two proximal but distinct sub-clusters. The result of previously performed mutagenesis in yeast may be interpreted as confirming the importance of one of these clusters in actin-bundling and filament disorganization. Interestingly, some variant residues lie in close proximity to, and in a few cases show differences in interactions with, residues previously inferred to be directly involved in binding GTP/GDP, eEF1Balpha and aminoacyl-tRNA. Additional sequence-based predictions, in conjunction with the 3-D models, reveal likely differences in phosphorylation sites that could reconcile some of the functional differences between the two proteins. CONCLUSIONS: The revelation and putative functional assignment of two distinct sub-clusters on the surface of the protein models should enable rational site-directed mutagenesis, including homologous reverse

  9. Data Clustering

    Science.gov (United States)

    Wagstaff, Kiri L.

    2012-03-01

    On obtaining a new data set, the researcher is immediately faced with the challenge of obtaining a high-level understanding from the observations. What does a typical item look like? What are the dominant trends? How many distinct groups are included in the data set, and how is each one characterized? Which observable values are common, and which rarely occur? Which items stand out as anomalies or outliers from the rest of the data? This challenge is exacerbated by the steady growth in data set size [11] as new instruments push into new frontiers of parameter space, via improvements in temporal, spatial, and spectral resolution, or by the desire to "fuse" observations from different modalities and instruments into a larger-picture understanding of the same underlying phenomenon. Data clustering algorithms provide a variety of solutions for this task. They can generate summaries, locate outliers, compress data, identify dense or sparse regions of feature space, and build data models. It is useful to note up front that "clusters" in this context refer to groups of items within some descriptive feature space, not (necessarily) to "galaxy clusters" which are dense regions in physical space. The goal of this chapter is to survey a variety of data clustering methods, with an eye toward their applicability to astronomical data analysis. In addition to improving the individual researcher’s understanding of a given data set, clustering has led directly to scientific advances, such as the discovery of new subclasses of stars [14] and gamma-ray bursts (GRBs) [38]. All clustering algorithms seek to identify groups within a data set that reflect some observed, quantifiable structure. Clustering is traditionally an unsupervised approach to data analysis, in the sense that it operates without any direct guidance about which items should be assigned to which clusters. There has been a recent trend in the clustering literature toward supporting semisupervised or constrained

  10. Experimental and theoretical investigation of the magnetization dynamics of an artificial square spin ice cluster

    Energy Technology Data Exchange (ETDEWEB)

    Pohlit, Merlin, E-mail: pohlit@physik.uni-frankfurt.de; Porrati, Fabrizio; Huth, Michael; Müller, Jens [Institute of Physics, Goethe-University Frankfurt, Frankfurt/Main (Germany); Stockem, Irina; Schröder, Christian [Bielefeld Institute for Applied Materials Research, FH Bielefeld-University of Applied Sciences, Bielefeld (Germany)

    2016-10-14

    We study the magnetization dynamics of a spin ice cluster which is a building block of an artificial square spin ice fabricated by focused electron-beam-induced deposition both experimentally and theoretically. The spin ice cluster is composed of twelve interacting Co nanoislands grown directly on top of a high-resolution micro-Hall sensor. By employing micromagnetic simulations and a macrospin model, we calculate the magnetization and the experimentally investigated stray field emanating from a single nanoisland. The parameters determined from a comparison with the experimental hysteresis loop are used to derive an effective single-dipole macrospin model that allows us to investigate the dynamics of the spin ice cluster. Our model reproduces the experimentally observed non-deterministic sequences in the magnetization curves as well as the distinct temperature dependence of the hysteresis loop.

  11. Experimental and theoretical investigation of the magnetization dynamics of an artificial square spin ice cluster

    Science.gov (United States)

    Pohlit, Merlin; Stockem, Irina; Porrati, Fabrizio; Huth, Michael; Schröder, Christian; Müller, Jens

    2016-10-01

    We study the magnetization dynamics of a spin ice cluster which is a building block of an artificial square spin ice fabricated by focused electron-beam-induced deposition both experimentally and theoretically. The spin ice cluster is composed of twelve interacting Co nanoislands grown directly on top of a high-resolution micro-Hall sensor. By employing micromagnetic simulations and a macrospin model, we calculate the magnetization and the experimentally investigated stray field emanating from a single nanoisland. The parameters determined from a comparison with the experimental hysteresis loop are used to derive an effective single-dipole macrospin model that allows us to investigate the dynamics of the spin ice cluster. Our model reproduces the experimentally observed non-deterministic sequences in the magnetization curves as well as the distinct temperature dependence of the hysteresis loop.

  12. The twelve dimensional super (2+2)-brane

    CERN Document Server

    Hewson, S F

    1996-01-01

    We discuss supersymmetry in twelve dimensions and present a covariant supersymmetric action for a brane with worldsheet signature (2,2), called a super (2+2)-brane, propagating in the osp(64,12) superspace. This superspace is explicitly constructed, and is trivial in the sense that the spinorial part is a trivial bundle over spacetime, unlike the twisted superspace of usual Poincare supersymmetry. For consistency, it is necessary to take a projection of the superspace. This is the same as the projection required for worldvolume supersymmetry. Upon compactification of this superspace, a torsion is naturally introduced and we produce the membrane and type IIB string actions in 11 and 10 dimensional Minkowski spacetimes. In addition, the compactification of the twelve dimensional supersymmetry algebra produces the correct algebras for these theories, including central charges. These considerations thus give the type IIB string and M-theory a single twelve dimensional origin.

  13. Alcoholics anonymous and other twelve-step programs in recovery.

    Science.gov (United States)

    Detar, D Todd

    2011-03-01

    Recovery is a new way of life for many patients; a life without substances to alter their moods but with a major change improving the physical, psychological, and emotional stability with improved overall health outcomes. The Twelve Steps of the Alcoholics Anonymous (AA) are the foundation of the AA, describing both the necessary actions and the spiritual basis for the recovery program of the AA. The Twelve Steps of the AA provide a structure for which a patient with alcoholism may turn for an answer to their problem of alcohol use, abuse, or dependence. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. The strong coupling regime of twelve flavors QCD

    NARCIS (Netherlands)

    Silva, Tiago Nunes da; Pallante, Elisabetta

    2012-01-01

    We summarize the results recently reported in Ref.[1] [A. Deuzeman, M.P. Lombardo, T. Nunes da Silva and E. Pallante,"The bulk transition of QCD with twelve flavors and the role of improvement"] for the SU(3) gauge theory with Nf=12 fundamental flavors, and we add some numerical evidence and theoret

  15. EFFORTS Technical annex for the twelve month progress report

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Eriksen, Morten; Thomas christensen, Thomas Vennick;

    The present report is documentation for the work carried out at DTU during the second year of project activity. The report describes the work completed by DTU in general as well as on the active sub-tasks within materials properties, friction modelling and physical modelling, over the last twelve...

  16. Human Evolution in Science Textbooks from Twelve Different Countries

    Science.gov (United States)

    Quessada, Marie-Pierre; Clement, Pierre; Oerke, Britta; Valente, Adriana

    2008-01-01

    What kinds of images of human beings illustrate human evolution in school textbooks? A comparison between the textbooks of eighteen different countries (twelve European countries and six non-European countries) was attempted. In six countries (Algeria, Malta, Morocco, Mozambique, Portugal, and Tunisia), we did not find any chapter on the topic of…

  17. Bibliography of Spanish Materials for Students, Grades Seven through Twelve.

    Science.gov (United States)

    California State Dept. of Education, Sacramento.

    This annotated bibliography of Spanish materials for students in grades seven through twelve is divided into the following categories: (1) Art, Drama, Music, and Poetry; (2) Books in Series; (3) Culture; (4) Dictionaries and Encyclopedias; (5) Literature; (6) Mathematics; (7) Physical Education, Health, and Recreation; (8) Reading and Language…

  18. Super computer made with Linux cluster

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Hun; Oh, Yeong Eun; Kim, Jeong Seok

    2002-01-15

    This book consists of twelve chapters, which introduce super computer made with Linux cluster. The contents of this book are Linux cluster, the principle of cluster, design of Linux cluster, general things for Linux, building up terminal server and client, Bear wolf cluster by Debian GNU/Linux, cluster system with red hat, Monitoring system, application programming-MPI, on set-up and install application programming-PVM, with PVM programming and XPVM application programming-open PBS with composition and install and set-up and GRID with GRID system, GSI, GRAM, MDS, its install and using of tool kit.

  19. Transfer of eleven species of the genus Burkholderia to the genus Paraburkholderia and proposal of Caballeronia gen. nov. to accommodate twelve species of the genera Burkholderia and Paraburkholderia.

    Science.gov (United States)

    Dobritsa, Anatoly P; Samadpour, Mansour

    2016-08-01

    It has been proposed to split the genus Burkholderia into two genera according to phylogenetic clustering: (1) a genus retaining this name and consisting mainly of animal and plant pathogens and (2) the genus Paraburkholderia including so-called environmental bacteria. The latter genus name has been validly published recently. During the period between the effective and valid publications of the genus name Paraburkholderia, 16 novel species of the genus Burkholderiawere described, but only two of them can be classified as members of this genus based on the emended genus description. Analysis of traits and phylogenetic positions of the other 11 species shows that they belong to the genus Paraburkholderia, and we propose to transfer them to this genus. The reclassified species names are proposed as Paraburkholderia dipogonis comb. nov., Paraburkholderia ginsengiterrae comb. nov., Paraburkholderia humisilvae comb. nov., Paraburkholderia insulsa comb. nov., Paraburkholderia kirstenboschensis comb. nov., Paraburkholderia metalliresistens comb. nov., Paraburkholderia monticola comb. nov., Paraburkholderia panaciterrae comb. nov., Paraburkholderia rhizosphaerae comb. nov., Paraburkholderia solisilvae comb. nov. and Paraburkholderia susongensis comb. nov. The remaining three species are transferred to the new genus Caballeronia gen. nov. proposed to accommodate twelve species of the genera Burkholderia and Paraburkholderia forming a distinctive clade in phylogenetic trees. The new genus members are Caballeronia choica comb. nov., Caballeronia cordobensis comb. nov., Caballeronia glathei comb. nov., Caballeronia grimmiae comb. nov., Caballeronia humi comb. nov., Caballeronia megalochromosomata comb. nov., Caballeronia jiangsuensis comb. nov., Caballeronia sordidicola comb. nov., Caballeronia telluris comb. nov., Caballeronia terrestris comb. nov., Caballeronia udeis comb. nov., and Caballeronia zhejiangensis comb. nov.

  20. Twelve Theses on Reactive Rules for the Web

    OpenAIRE

    Bry, François; Eckert, Michael

    2007-01-01

    Reactivity, the ability to detect and react to events, is an essential functionality in many information systems. In particular, Web systems such as online marketplaces, adaptive (e.g., recommender) sys- tems, and Web services, react to events such as Web page updates or data posted to a server. This article investigates issues of relevance in designing high-level programming languages dedicated to reactivity on the Web. It presents twelve theses on features desira...

  1. Twelve Tips for teaching medical professionalism at all levels of medical education.

    Science.gov (United States)

    Al-Eraky, Mohamed Mostafa

    2015-01-01

    Review of studies published in medical education journals over the last decade reveals that teaching medical professionalism is essential, yet challenging. According to a recent Best Evidence in Medical Education (BEME) guide, there is no consensus on a theoretical or practical model to integrate the teaching of professionalism into medical education. The aim of this article is to outline a practical manual for teaching professionalism at all levels of medical education. Drawing from research literature and author's experience, Twelve Tips are listed and organised in four clusters with relevance to (1) the context, (2) the teachers, (3) the curriculum, and (4) the networking. With a better understanding of the guiding educational principles for teaching medical professionalism, medical educators will be able to teach one of the most challenging constructs in medical education.

  2. Comparative analysis and supragenome modeling of twelve Moraxella catarrhalis clinical isolates

    Directory of Open Access Journals (Sweden)

    Hermans Peter WM

    2011-01-01

    Full Text Available Abstract Background M. catarrhalis is a gram-negative, gamma-proteobacterium and an opportunistic human pathogen associated with otitis media (OM and exacerbations of chronic obstructive pulmonary disease (COPD. With direct and indirect costs for treating these conditions annually exceeding $33 billion in the United States alone, and nearly ubiquitous resistance to beta-lactam antibiotics among M. catarrhalis clinical isolates, a greater understanding of this pathogen's genome and its variability among isolates is needed. Results The genomic sequences of ten geographically and phenotypically diverse clinical isolates of M. catarrhalis were determined and analyzed together with two publicly available genomes. These twelve genomes were subjected to detailed comparative and predictive analyses aimed at characterizing the supragenome and understanding the metabolic and pathogenic potential of this species. A total of 2383 gene clusters were identified, of which 1755 are core with the remaining 628 clusters unevenly distributed among the twelve isolates. These findings are consistent with the distributed genome hypothesis (DGH, which posits that the species genome possesses a far greater number of genes than any single isolate. Multiple and pair-wise whole genome alignments highlight limited chromosomal re-arrangement. Conclusions M. catarrhalis gene content and chromosomal organization data, although supportive of the DGH, show modest overall genic diversity. These findings are in stark contrast with the reported heterogeneity of the species as a whole, as wells as to other bacterial pathogens mediating OM and COPD, providing important insight into M. catarrhalis pathogenesis that will aid in the development of novel therapeutic regimens.

  3. Twelve tips for developing and delivering a massive open online course in medical education.

    Science.gov (United States)

    Pickering, James D; Henningsohn, Lars; DeRuiter, Marco C; de Jong, Peter G M; Reinders, Marlies E J

    2017-07-01

    Massive open online courses (MOOCs) are a novel mode of online learning. They are typically based on higher education courses and can attract a high number of learners, often in the thousands. They are distinct from on-campus education and deliver the learning objectives through a series of short videos, recommended readings and discussion fora, alongside automated assessments. Within medical education the role of MOOCs remains unclear, with recent proposals including continuing professional development, interprofessional education or integration into campus-based blended learning curricula. In this twelve tips article, we aim to provide a framework for readers to use when developing, delivering and evaluating a MOOC within medical education based on the literature and our own experience. Practical advice is provided on how to design the appropriate curriculum, engage with learners on the platform, select suitable assessments, and comprehensively evaluate the impact of your course.

  4. The twelve theses: a call to a new reformation

    Directory of Open Access Journals (Sweden)

    John Shelby Spong

    2015-03-01

    Full Text Available With every discovery emerging from the world of science over the last 500 years concerning the origins of the universe and of life itself, the traditional explanations offered by the Christian Church appeared to be more and more dated and irrelevant.  Christian leaders, unable to embrace the knowledge revolution seemed to believe  that the only way to save Christianity was not to disturb the old patterns either by listening to, much less by entertaining the new knowledge. I tried to articulate this challenge in a book entitled: Why Christianity Must Change or Die, published in 1998.  In that book I examined in detail the issues that I was convinced Christianity must address. Shortly after that book was published I reduced its content to twelve theses, which I attached in Luther-like fashion to the great doors on the Chapel of Mansfield College at Oxford University in the United Kingdom. I then mailed copies of those Twelve Theses to every acknowledged Christian leader of the world. It was an attempt to call them into a debate on the real issues that I was certain the Christian Church now faced.  I framed my twelve theses in the boldest, most provocative language possible, designed primarily to elicit response and debate. I welcome responses from Christians everywhere.  I claim no expertise or certainty in developing answers, but I am quite confident that I do understand the problems we are facing as Christians who are seeking to relate to the 21st century.

  5. Melting of sodium clusters

    CERN Document Server

    Reyes-Nava, J A; Beltran, M R; Michaelian, K

    2002-01-01

    Thermal stability properties and the melting-like transition of Na_n, n=13-147, clusters are studied through microcanonical molecular dynamics simulations. The metallic bonding in the sodium clusters is mimicked by a many-body Gupta potential based on the second moment approximation of a tight-binding Hamiltonian. The characteristics of the solid-to-liquid transition in the sodium clusters are analyzed by calculating physical quantities like caloric curves, heat capacities, and root-mean-square bond length fluctuations using simulation times of several nanoseconds. Distinct melting mechanisms are obtained for the sodium clusters in the size range investigated. The calculated melting temperatures show an irregular variation with the cluster size, in qualitative agreement with recent experimental results. However, the calculated melting point for the Na_55 cluster is about 40 % lower than the experimental value.

  6. Whole-Proteome Analysis of Twelve Species of Alphaproteobacteria Links Four Pathogens

    Directory of Open Access Journals (Sweden)

    Yunyun Zhou

    2013-11-01

    Full Text Available Thousands of whole-genome and whole-proteome sequences have been made available through advances in sequencing technology, and sequences of millions more organisms will become available in the coming years. This wealth of genetic information will provide numerous opportunities to enhance our understanding of these organisms including a greater understanding of relationships among species. Researchers have used 16S rRNA and other gene sequences to study the evolutionary origins of bacteria, but these strategies do not provide insight into the sharing of genes among bacteria via horizontal transfer. In this work we use an open source software program called pClust to cluster proteins from the complete proteomes of twelve species of Alphaproteobacteria and generate a dendrogram from the resulting orthologous protein clusters. We compare the results with dendrograms constructed using the 16S rRNA gene and multiple sequence alignment of seven housekeeping genes. Analysis of the whole proteomes of these pathogens grouped Rickettsia typhi with three other animal pathogens whereas conventional sequence analysis failed to group these pathogens together. We conclude that whole-proteome analysis can give insight into relationships among species beyond their phylogeny, perhaps reflecting the effects of horizontal gene transfer and potentially providing insight into the functions of shared genes by means of shared phenotypes.

  7. Twelve tips for teaching medical students with dyslexia.

    Science.gov (United States)

    Shaw, Sebastian Charles Keith; Anderson, John Leeds

    2017-07-01

    Dyslexia is a common learning difficulty. As a result of SS' own experiences as a medical student with dyslexia, we have been researching and teaching on this topic for the past two years. Here, we present twelve tips for teaching medical students with dyslexia. These are gathered from our personal experiences and research, discussions with other educators, and wider literature on the topic. This article aims to shed some light on dyslexia, and also to make practical suggestions. Teaching students with dyslexia should not be a daunting experience. Small changes to existing methods, at minor effort, can make a difference - for example, adding pastel colors to slide backgrounds or avoiding Serif fonts. These tips can help educators gain more insight into dyslexia and incorporate small, beneficial adaptations into their teaching.

  8. Antibacterial activities of extracts from twelve Centaurea species from Turkey

    Directory of Open Access Journals (Sweden)

    Tekeli Yener

    2011-01-01

    Full Text Available Members of the genus Centaurea (Asteraceae have been used in traditional plant-based medicine. The methanol extracts of twelve Centaurea species, of which five are endemic to Turkey flora, were screened for antibacterial activity against four bacteria (Escherichia coli, Bacillus cereus, Salmonella enteritidis, Staphylococcus aureus. The antibacterial activity was evaluated by the microdilution method and the minimum inhibition concentrations (MIC of the extracts were determined. C. cariensis subsp. microlepis exhibited an antimicrobial effect on all tested microorganisms. The extracts from eight Centaurea species (C. balsamita, C. calolepis, C. cariensis subsp. maculiceps, C. cariensis subsp. microlepis, C. kotschyi var. kotschyi, C. solstitialis subsp. solstitialis, C. urvillei subsp. urvillei and C. virgata possessed antibacterial activity against several of the tested microorganisms.

  9. Twelve tips on how to compile a medical educator's portfolio.

    Science.gov (United States)

    Dalton, Claudia Lucy; Wilson, Anthony; Agius, Steven

    2017-09-17

    Medical education is an expanding area of specialist interest for medical professionals. Whilst most doctors will be familiar with the compilation of clinical portfolios for scrutiny of their clinical practice and provision of public accountability, teaching portfolios used specifically to gather and demonstrate medical education activity remain uncommon in many non-academic settings. For aspiring and early career medical educators in particular, their value should not be underestimated. Such a medical educator's portfolio (MEP) is a unique compendium of evidence that is invaluable for appraisal, revalidation, and promotion. It can stimulate and provide direction for professional development, and is a rich source for personal reflection and learning. We recommend that all new and aspiring medical educators prepare an MEP, and suggest twelve tips on how to skillfully compile one.

  10. Spectroscopy of twelve Type Ia supernovae at intermediate redshift

    CERN Document Server

    Balland, C; Pain, R; Walton, N A; Amanullah, R; Astier, Pierre; Ellis, Richard S; Fabbro, S; Goobar, A; Hardin, D; Hook, I M; Irwin, M J; McMahon, R M; Mendez, J M; Ruiz-Lapuente, P; Sainton, G; Schahmaneche, K; Stanishev, V

    2005-01-01

    We present spectra of twelve Type Ia supernovae obtained in 1999 at the William Herschel Telescope and the Nordic Optical Telescope during a search for Type Ia supernovae (SN Ia) at intermediate redshift. The spectra range from z=0.178 to z=0.493, including five high signal-to-noise ratio SN Ia spectra in the still largely unexplored range 0.15 < z < 0.3. Most of the spectra were obtained before or around restframe B-band maximum light. None of them shows the peculiar spectral features found in low-redshift over- or under-luminous SN Ia. Expansion velocities of characteristic spectral absorption features such as SiII at 6355 angs., SII at 5640 angs. and CaII at 3945 angs. are found consistent with their low-z SN Ia counterparts.

  11. RUGBY GAME-RELATED STATISTICS THAT DISCRIMINATE BETWEEN WINNING AND LOSING TEAMS IN IRB AND SUPER TWELVE CLOSE GAMES

    Directory of Open Access Journals (Sweden)

    Luis Vaz

    2010-03-01

    Full Text Available The aim of the current study was to identify the Rugby game- related statistics that discriminated between winning and losing teams in IRB and S12 close games. Archival data reported to game-related statistics from 120 IRB games and 204 Super Twelve games played between 2003 and 2006. Afterwards, a cluster analysis was conducted to establish, according to game final score differences, three different match groups. Only the close games group was selected for further analysis (IRB n = 64 under 15 points difference and Super Twelve n = 95 under 11 points difference. An analysis to the structure coefficients (SC obtained through a discriminant analysis allowed to identify the most powerful game-related statistics in discriminating between winning and losing teams. The discriminant functions were statistically significant for Super Twelve games (Chi-square = 33.8, p < 0.01, but not for IRB games (Chi- square = 9.4, p = n.s.. In the first case, winners and losers were discriminated by possessions kicked (SC = 0.48, tackles made (SC = 0.45, rucks and pass (SC = -0.40, passes completed (SC = 0. 39, mauls won (SC = -0.36, turnovers won (SC = -0.33, kicks to touch (SC = 0.32 and errors made (SC = -0.32. The minus sign denotes higher values in losing teams. Rugby game-related statistics were able to discriminate between winners and losers in Super Twelve close games and suggest that a kicking based game supported by an effective defensive structure is more likely to win matches than a possession based one

  12. Quantum Distinction: Quantum Distinctiones!

    OpenAIRE

    Zeps, Dainis

    2009-01-01

    10 pages; How many distinctions, in Latin, quantum distinctiones. We suggest approach of anthropic principle based on anthropic reference system which should be applied equally both in theoretical physics and in mathematics. We come to principle that within reference system of life subject of mathematics (that of thinking) should be equated with subject of physics (that of nature). For this reason we enter notions of series of distinctions, quantum distinction, and argue that quantum distinct...

  13. Quartile Clustering: A quartile based technique for Generating Meaningful Clusters

    CERN Document Server

    Goswami, Saptarsi

    2012-01-01

    Clustering is one of the main tasks in exploratory data analysis and descriptive statistics where the main objective is partitioning observations in groups. Clustering has a broad range of application in varied domains like climate, business, information retrieval, biology, psychology, to name a few. A variety of methods and algorithms have been developed for clustering tasks in the last few decades. We observe that most of these algorithms define a cluster in terms of value of the attributes, density, distance etc. However these definitions fail to attach a clear meaning/semantics to the generated clusters. We argue that clusters having understandable and distinct semantics defined in terms of quartiles/halves are more appealing to business analysts than the clusters defined by data boundaries or prototypes. On the samepremise, we propose our new algorithm named as quartile clustering technique. Through a series of experiments we establish efficacy of this algorithm. We demonstrate that the quartile clusteri...

  14. Cluster headache

    Science.gov (United States)

    Histamine headache; Headache - histamine; Migrainous neuralgia; Headache - cluster; Horton's headache; Vascular headache - cluster ... A cluster headache begins as a severe, sudden headache. The headache commonly strikes 2 to 3 hours after you fall ...

  15. Cluster Forests

    CERN Document Server

    Yan, Donghui; Jordan, Michael I

    2011-01-01

    Inspired by Random Forests (RF) in the context of classification, we propose a new clustering ensemble method---Cluster Forests (CF). Geometrically, CF randomly probes a high-dimensional data cloud to obtain "good local clusterings" and then aggregates via spectral clustering to obtain cluster assignments for the whole dataset. The search for good local clusterings is guided by a cluster quality measure $\\kappa$. CF progressively improves each local clustering in a fashion that resembles the tree growth in RF. Empirical studies on several real-world datasets under two different performance metrics show that CF compares favorably to its competitors. Theoretical analysis shows that the $\\kappa$ criterion is shown to grow each local clustering in a desirable way---it is "noise-resistant." A closed-form expression is obtained for the mis-clustering rate of spectral clustering under a perturbation model, which yields new insights into some aspects of spectral clustering.

  16. Star Clusters

    OpenAIRE

    Gieles, M.

    1993-01-01

    Star clusters are observed in almost every galaxy. In this thesis we address several fundamental problems concerning the formation, evolution and disruption of star clusters. From observations of (young) star clusters in the interacting galaxy M51, we found that clusters are formed in complexes of stars and star clusters. These complexes share similar properties with giant molecular clouds, from which they are formed. Many (70%) of the young clusters will not survive the fist 10 Myr, due to t...

  17. Sensitivity and growth of twelve Elatior begonia cultivars to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Reinert, R.A.; Nelson, P.V.

    1979-12-01

    Twelve cultivars of Elatior begonia (Begonia X hiemalis Fotsch.) were exposed to O/sub 3/ at 25 and 50 pphM. The 'Schwabenland' group, 'Whisper 'O' Pink', and 'Improved Krefeld Orange' were the most sensitive, whereas 'Ballerina', 'Mikkell Limelight', and 'Turo' were the least sensitive. 'Rennaisance', 'Heirloom' 'Nixe', and 'Fantasy' were intermediate in sensitivity. The dry weight of foliage (stems plus leaves) of 9 cultivars exposed to O/sub 3/ was significantly less than that of control plants. Ozone at 25 and 50 pphM inhibited flower growth (including peduncles) and development in 4 and 8 of the 12 cultivars, respectively. Differences in flower weight ranged from 43 to 105% of the control at 25 pphM and from 25 to 98% of the control at 50 pphM, depending on cultivar. 1 table.

  18. Twelve tips for designing and running longitudinal integrated clerkships.

    Science.gov (United States)

    Ellaway, Rachel; Graves, Lisa; Berry, Sue; Myhre, Doug; Cummings, Beth-Ann; Konkin, Jill

    2013-12-01

    Longitudinal integrated clerkships (LICs) involve learners spending an extended time in a clinical setting (or a variety of interlinked clinical settings) where their clinical learning opportunities are interwoven through continuities of patient contact and care, continuities of assessment and supervision, and continuities of clinical and cultural learning. Our twelve tips are grounded in the lived experiences of designing, implementing, maintaining, and evaluating LICs, and in the extant literature on LICs. We consider: general issues (anticipated benefits and challenges associated with starting and running an LIC); logistical issues (how long each longitudinal experience should last, where it will take place, the number of learners who can be accommodated); and integration issues (how the LIC interfaces with the rest of the program, and the need for evaluation that aligns with the dynamics of the LIC model). Although this paper is primarily aimed at those who are considering setting up an LIC in their own institutions or who are already running an LIC we also offer our recommendations as a reflection on the broader dynamics of medical education and on the priorities and issues we all face in designing and running educational programs.

  19. Commercializing Government-sponsored Innovations: Twelve Successful Buildings Case Studies

    Science.gov (United States)

    Brown, M. A.; Berry, L. G.; Goel, R. K.

    1989-01-01

    This report examines the commercialization and use of R and D results funded by DOE's Office of Buildings and Community Systems (OBCS), an office that is dedicated to improving the energy efficiency of the nation's buildings. Three goals guided the research described in this report: to improve understanding of the factors that hinder or facilitate the transfer of OBCS R and D results, to determine which technology transfer strategies are most effective and under what circumstances each is appropriate, and to document the market penetration and energy savings achieved by successfully-commercialized innovations that have received OBCS support. Twelve successfully-commercialized innovations are discussed here. The methodology employed involved a review of the literature, interviews with innovation program managers and industry personnel, and data collection from secondary sources. Six generic technology transfer strategies are also described. Of these, contracting R and D to industrial partners is found to be the most commonly used strategy in our case studies. The market penetration achieved to date by the innovations studied ranges from less than 1% to 100%. For the three innovations with the highest predicted levels of energy savings (i.e., the flame retention head oil burner, low-E windows, and solid-state ballasts), combined cumulative savings by the year 2000 are likely to approach 2 quads. To date the energy savings for these three innovations have been about 0.2 quads. Our case studies illustrate the important role federal agencies can play in commercializing new technologies.

  20. The strong coupling regime of twelve flavors QCD

    CERN Document Server

    da Silva, Tiago Nunes

    2012-01-01

    We summarize the results recently reported in Ref.[1] [A. Deuzeman, M.P. Lombardo, T. Nunes da Silva and E. Pallante,"The bulk transition of QCD with twelve flavors and the role of improvement"] for the SU(3) gauge theory with Nf=12 fundamental flavors, and we add some numerical evidence and theoretical discussion. In particular, we study the nature of the bulk transition that separates a chirally broken phase at strong coupling from a chirally restored phase at weak coupling. When a non-improved action is used, a rapid crossover is observed at small bare quark masses. Our results confirm a first order nature for this transition, in agreement with previous results we obtained using an improved action. As shown in Ref.[1], when improvement of the action is used, the transition is preceded by a second rapid crossover at weaker coupling and an exotic phase emerges, where chiral symmetry is not yet broken. This can be explained [1] by the non hermiticity of the improved lattice Transfer matrix, arising from the c...

  1. Computational study of the structural and vibrational properties of ten and twelve vertex closo-carboranes

    Energy Technology Data Exchange (ETDEWEB)

    Salam, A.; Deleuze, M.S.; Francois, J.-P

    2003-01-01

    Calculations using ab initio Hartree-Fock and Density Functional theories, the latter employing the B3LYP functional, in combination with a number of large standard basis sets ranging from 6-31G** to cc-pVDZ, have been performed on a series of ten and twelve vertex closo-carborane isomer species. Results obtained for optimized structural parameters and molecular properties are presented for 1,2-, 1,6- and 1,10-C{sub 2}B{sub 8}H{sub 10} and 1,2-, 1,7- and 1,12-C{sub 2}B{sub 10}H{sub 12} and compared, where possible, with both earlier theoretical data and experiment. Irrespective of the model chemistry chosen, the para-isomer in each class of carborane cluster is found to be the most stable species, corresponding to a structure in which the cage carbon atoms are positioned at diametrically opposed ends of the respective polyhedron. Boron-hydrogen and carbon-hydrogen bond lengths are found to change little on going from isomers of one particular cage size to another, supporting analogous conclusions previously established for small closo-carborane cages possessing five, six and seven vertices. The calculated vibrational spectra of the isomers of both decacarborane and dodecacarborane are seen to be similar to each other and reflect a high degree of rigidity within each cluster. Key polyhedral skeletal breathing modes along with characteristic boron-hydrogen and carbon-hydrogen stretching frequencies are identified in the spectra and compared with experiment. Thermochemical data relating to each species are also analyzed.

  2. The Synthesis and Antitumor Activity of Twelve Galloyl Glucosides

    Directory of Open Access Journals (Sweden)

    Chang-Wei Li

    2015-01-01

    Full Text Available Twelve galloyl glucosides 1–12, showing diverse substitution patterns with two or three galloyl groups, were synthesized using commercially available, low-cost D-glucose and gallic acid as starting materials. Among them, three compounds, methyl 3,6-di-O-galloyl-α-D-glucopyranoside (9, ethyl 2,3-di-O-galloyl-α-D-glucopyranoside (11 and ethyl 2,3-di-O-galloyl-β-D-glucopyranoside (12, are new compounds and other six, 1,6-di-O-galloyl-β-D-glucopyranose (1, 1,4,6-tri-O-galloyl-β-D-glucopyranose (2, 1,2-di-O-galloyl-β-D-glucopyranose (3, 1,3-di-O-galloyl-β-D-glucopyranose (4, 1,2,3-tri-O-galloyl-α-D-glucopyranose (6 and methyl 3,4,6-tri-O-galloyl-α-D-glucopyranoside (10, were synthesized for the first time in the present study. In in vitro MTT assay, 1–12 inhibited human cancer K562, HL-60 and HeLa cells with inhibition rates ranging from 64.2% to 92.9% at 100 μg/mL, and their IC50 values were determined to be varied in 17.2–124.7 μM on the tested three human cancer cell lines. In addition, compounds 1–12 inhibited murine sarcoma S180 cells with inhibition rates ranging from 38.7% to 52.8% at 100 μg/mL in the in vitro MTT assay, and in vivo antitumor activity of 1 and 2 was also detected in murine sarcoma S180 tumor-bearing Kunming mice using taxol as positive control.

  3. [Twelve years of working of Brazzaville cancer registry].

    Science.gov (United States)

    Nsondé Malanda, Judith; Nkoua Mbon, Jean Bernard; Bambara, Augustin Tozoula; Ibara, Gérard; Minga, Benoît; Nkoua Epala, Brice; Gombé Mbalawa, Charles

    2013-02-01

    The Brazzaville cancer registry was created in 1996 with the support of the International Agency Research against Cancer (IARC) which is located in Lyon, France. The Brazzaville cancer registry is a registry which is based on population which records new cancer cases occurring in Brazzaville by using Canreg 4.0 Software. Its aim is to supply useful information to fight against cancer to physicians and to decision makers. We conducted this study whose target was to determine the incidence of cancer in Brazzaville during twelve years, from January 1st, 1998 to December 31, 2009. During that period 6,048 new cancer cases were recorded: 3,377 women (55.8%), 2,384 men (39.4%), and 287 children (4.8%) from 0 to 14 years old with an annual average of 504 cases. Middle age to the patient's diagnosis was 49.5 years in female sex and 505.5 years old for male sex. The incidence rate of cancers in Brazzaville was 39.8 or 100.000 inhabitants per year and by sex we observed 49 to female sex and 35.2 for male sex. The first cancers localizations observed to women were in order of frequency: breast, cervix uterine, liver ovaries, hematopoietic system, to men : liver, prostate, hematopoietic system, colon and stomach; to children : retina, kidney, hematopoietic system, liver and bones. These rates are the basis to know the burden of cancer among all pathologies of Brazzaville and the achievement of a national cancer control program.

  4. Hyperinsulinism and hyperammonemia syndrome: report of twelve unrelated patients.

    Science.gov (United States)

    De Lonlay, P; Benelli, C; Fouque, F; Ganguly, A; Aral, B; Dionisi-Vici, C; Touati, G; Heinrichs, C; Rabier, D; Kamoun, P; Robert, J J; Stanley, C; Saudubray, J M

    2001-09-01

    Hyperinsulinism and hyperammonemia syndrome has been reported as a cause of moderately severe hyperinsulinism with diffuse involvement of the pancreas. The disorder is caused by gain of function mutations in the GLUD1 gene, resulting in a decreased inhibitory effect of guanosine triphosphate on the glutamate dehydrogenase (GDH) enzyme. Twelve unrelated patients (six males, six females) with hyperinsulinism and hyperammonemia syndrome have been investigated. The phenotypes were clinically heterogeneous, with neonatal and infancy-onset hypoglycemia and variable responsiveness to medical (diazoxide) and dietary (leucine-restricted diet) treatment. Hyperammonemia (90-200 micromol/L, normal carbamylglutamate administration. The patients had mean basal GDH activity (18.3 +/- 0.9 nmol/min/mg protein) not different from controls (17.9 +/- 1.8 nmol/min/mg protein) in cultured lymphoblasts. The sensitivity of GDH activity to inhibition by guanosine triphosphate was reduced in all patient lymphoblast cultures (IC(50), or concentrations required for 50% inhibition of GDH activity, ranging from 140 to 580 nM, compared with control IC(50) value of 83 +/- 1.0 nmol/L). The allosteric effect of ADP was within the normal range. The activating effect of leucine on GDH activity varied among the patients, with a significant decrease of sensitivity that was correlated with the negative clinical response to a leucine-restricted diet in plasma glucose levels in four patients. Molecular studies were performed in 11 patients. Heterozygous mutations were localized in the antenna region (four patients in exon 11, two patients in exon 12) as well as in the guanosine triphosphate binding site (two patients in exon 6, two patients in exon 7) of the GLUD1 gene. No mutation has been found in one patient after sequencing the exons 5-13 of the gene.

  5. Commercializing government-sponsored innovations: Twelve successful buildings case studies

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M.A.; Berry, L.G.; Goel, R.K.

    1989-01-01

    This report examines the commercialization and use of R and D results funded by DOE's Office of Buildings and Community Systems (OBCS), an office that is dedicated to improving the energy efficiency of the nation's buildings. Three goals guided the research described in this report: to improve understanding of the factors that hinder or facilitate the transfer of OBCS R and D results, to determine which technology transfer strategies are most effective and under what circumstances each is appropriate, and to document the market penetration and energy savings achieved by successfully-commercialized innovations that have received OBCS support. Twelve successfully-commercialized innovations are discussed here. The methodology employed involved a review of the literature, interviews with innovation program managers and industry personnel, and data collection from secondary sources. Six generic technology transfer strategies are also described. Of these, contracting R and D to industrial partners is found to be the most commonly used strategy in our case studies. The market penetration achieved to date by the innovations studied ranges from less than 1% to 100%. For the three innovations with the highest predicted levels of energy savings (i.e., the flame retention head oil burner, low-E windows, and solid-state ballasts), combined cumulative savings by the year 2000 are likely to approach 2 quads. To date the energy savings for these three innovations have been about 0.2 quads. Our case studies illustrate the important role federal agencies can play in commercializing new technologies. 27 refs., 21 figs., 4 tabs.

  6. Site-directed mutagenesis of HIV-1 vpu gene demonstrates two clusters of replication-defective mutants with distinct ability to down-modulate cell surface CD4 and tetherin

    Directory of Open Access Journals (Sweden)

    Masako Nomaguchi

    2010-11-01

    Full Text Available HIV-1 Vpu acts positively on viral infectivity by mediating CD4 degradation in endoplasmic reticulum and enhances virion release by counteracting a virion release restriction factor, tetherin. In order to define the impact of Vpu activity on HIV-1 replication, we have generated a series of site-specific proviral vpu mutants. Of fifteen mutants examined, seven exhibited a replication-defect similar to that of a vpu-deletion mutant in a lymphocyte cell line H9. These mutations clustered in narrow regions within transmembrane domain (TMD and cytoplasmic domain (CTD. Replication-defective mutants displayed the reduced ability to enhance virion release from a monolayer cell line HEp2 without exception. Upon transfection with Vpu expression vectors, neither TMD mutants nor CTD mutants blocked CD4 expression at the cell surface in another monolayer cell line MAGI. While TMD mutants were unable to down-modulate cell surface tetherin in HEp2 cells, CTD mutants did quite efficiently. Confocal microscopy analysis revealed the difference of intracellular localization between TMD and CTD mutants. In total, replication capability of HIV-1 carrying vpu mutations correlates well with the ability of Vpu to enhance virion release and to impede the cell surface expression of CD4 but not with the ability to down-modulate cell surface tetherin. Our results here suggest that efficient viral replication requires not only down-regulation of cell surface tetherin but also its degradation.

  7. Weighted Clustering

    DEFF Research Database (Denmark)

    Ackerman, Margareta; Ben-David, Shai; Branzei, Simina

    2012-01-01

    We investigate a natural generalization of the classical clustering problem, considering clustering tasks in which different instances may have different weights.We conduct the first extensive theoretical analysis on the influence of weighted data on standard clustering algorithms in both...... the partitional and hierarchical settings, characterizing the conditions under which algorithms react to weights. Extending a recent framework for clustering algorithm selection, we propose intuitive properties that would allow users to choose between clustering algorithms in the weighted setting and classify...

  8. Peer teaching in medical education: twelve reasons to move from theory to practice.

    Science.gov (United States)

    Ten Cate, Olle; Durning, Steven

    2007-09-01

    To provide an estimation of how often peer teaching is applied in medical education, based on reports in the literature and to summarize reasons that support the use of this form of teaching. We surveyed the 2006 medical education literature and categorised reports of peer teaching according to educational distance between students teaching and students taught, group size, and level of formality of the teaching. Subsequently, we analysed the rationales for applying peer teaching. Most reports were published abstracts in either Medical Education's annual feature 'Really Good Stuff' or the AMEE's annual conference proceedings. We identified twelve distinct reasons to apply peer teaching, including 'alleviating faculty teaching burden', 'providing role models for junior students', 'enhancing intrinsic motivation' and 'preparing physicians for their future role as educators'. Peer teaching appears to be practiced often, but many peer teaching reports do not become full length journal articles. We conclude that specifically 'near-peer teaching' appears beneficial for student teachers and learners as well as for the organisation. The analogy of the 'journeyman', as intermediate between 'apprentice' and 'master', with both learning and teaching tasks, is a valuable but yet under-recognized source of education in the medical education continuum.

  9. Computational visual distinctness metric

    NARCIS (Netherlands)

    Martínez-Baena, J.; Toet, A.; Fdez-Vidal, X.R.; Garrido, A.; Rodríguez-Sánchez, R.

    1998-01-01

    A new computational visual distinctness metric based on principles of the early human visual system is presented. The metric is applied to quantify (1) the visual distinctness of targets in complex natural scenes and (2) the perceptual differences between compressed and uncompressed images. The new

  10. Are clusters of dietary patterns and cluster membership stable over time? Results of a longitudinal cluster analysis study.

    Science.gov (United States)

    Walthouwer, Michel Jean Louis; Oenema, Anke; Soetens, Katja; Lechner, Lilian; de Vries, Hein

    2014-11-01

    Developing nutrition education interventions based on clusters of dietary patterns can only be done adequately when it is clear if distinctive clusters of dietary patterns can be derived and reproduced over time, if cluster membership is stable, and if it is predictable which type of people belong to a certain cluster. Hence, this study aimed to: (1) identify clusters of dietary patterns among Dutch adults, (2) test the reproducibility of these clusters and stability of cluster membership over time, and (3) identify sociodemographic predictors of cluster membership and cluster transition. This study had a longitudinal design with online measurements at baseline (N=483) and 6 months follow-up (N=379). Dietary intake was assessed with a validated food frequency questionnaire. A hierarchical cluster analysis was performed, followed by a K-means cluster analysis. Multinomial logistic regression analyses were conducted to identify the sociodemographic predictors of cluster membership and cluster transition. At baseline and follow-up, a comparable three-cluster solution was derived, distinguishing a healthy, moderately healthy, and unhealthy dietary pattern. Male and lower educated participants were significantly more likely to have a less healthy dietary pattern. Further, 251 (66.2%) participants remained in the same cluster, 45 (11.9%) participants changed to an unhealthier cluster, and 83 (21.9%) participants shifted to a healthier cluster. Men and people living alone were significantly more likely to shift toward a less healthy dietary pattern. Distinctive clusters of dietary patterns can be derived. Yet, cluster membership is unstable and only few sociodemographic factors were associated with cluster membership and cluster transition. These findings imply that clusters based on dietary intake may not be suitable as a basis for nutrition education interventions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. The distinctive features for standard Chinese (Putonghua)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jialu

    2006-01-01

    The distinctive features, which are one of the important research subjects in Phonetics and Phonology and in speech technology also, are the ultimate units of speech. Firstly a phoneme system of the standard Chinese-Putonghua was determined based on the results of cluster analysis of perceptual confusion of speech sounds of Putonghua. Then according to the principle of choice between the two opposites proposed by Jakobson, Fant and Halle, considering the characteristics of Putonghua the distinctive feature values for Initials, Finals and Tones were determined in this paper. And the features have been formulated at both acoustic level and genetic level. The distinctive feature trees of Chinese initials and finals were drawn in addition to the feature tables, in order to understand the distinctive features for individual phoneme easily.

  12. Distinct subtypes of knee osteoarthritis : data from the Osteoarthritis Initiative

    NARCIS (Netherlands)

    Waarsing, Jan H; Bierma-Zeinstra, Sita M A; Weinans, Harrie

    OBJECTIVE: OA is suspected to be a collection of distinct subtypes, each with different aetiology and clinical characteristics. We aimed to explore the existence of different subtypes of knee OA, using cluster analysis of the data of the OA Initiative. METHODS: We used latent class cluster analysis

  13. Distinct subtypes of knee osteoarthritis : data from the Osteoarthritis Initiative

    NARCIS (Netherlands)

    Waarsing, Jan H; Bierma-Zeinstra, Sita M A; Weinans, Harrie

    2015-01-01

    OBJECTIVE: OA is suspected to be a collection of distinct subtypes, each with different aetiology and clinical characteristics. We aimed to explore the existence of different subtypes of knee OA, using cluster analysis of the data of the OA Initiative. METHODS: We used latent class cluster analysis

  14. An Experiment in Humanistic Management within Community College District Twelve, Centralia/Olympia, Washington.

    Science.gov (United States)

    Miller, Dale A.; Hurley, John A.

    Community College District Twelve, a multi-college district serving a two-county area in southwestern Washington, has attempted to incorporate at administrative levels many of the humanistic, process-oriented principles of management discussed by Maslow and Maccoby. A concept of the ideal leadership style for District Twelve guides the selection…

  15. Photoionization of rare gas clusters

    Science.gov (United States)

    Zhang, Huaizhen

    This thesis concentrates on the study of photoionization of van der Waals clusters with different cluster sizes. The goal of the experimental investigation is to understand the electronic structure of van der Waals clusters and the electronic dynamics. These studies are fundamental to understand the interaction between UV-X rays and clusters. The experiments were performed at the Advanced Light Source at Lawrence Berkeley National Laboratory. The experimental method employs angle-resolved time-of-flight photoelectron spectrometry, one of the most powerful methods for probing the electronic structure of atoms, molecules, clusters and solids. The van der Waals cluster photoionization studies are focused on probing the evolution of the photoelectron angular distribution parameter as a function of photon energy and cluster size. The angular distribution has been known to be a sensitive probe of the electronic structure in atoms and molecules. However, it has not been used in the case of van der Waals clusters. We carried out outer-valence levels, inner-valence levels and core-levels cluster photoionization experiments. Specifically, this work reports on the first quantitative measurements of the angular distribution parameters of rare gas clusters as a function of average cluster sizes. Our findings for xenon clusters is that the overall photon-energy-dependent behavior of the photoelectrons from the clusters is very similar to that of the corresponding free atoms. However, distinct differences in the angular distribution point at cluster-size-dependent effects were found. For krypton clusters, in the photon energy range where atomic photoelectrons have a high angular anisotropy, our measurements show considerably more isotropic angular distributions for the cluster photoelectrons, especially right above the 3d and 4p thresholds. For the valence electrons, a surprising difference between the two spin-orbit components was found. For argon clusters, we found that the

  16. Meaningful Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Sanfilippo, Antonio P.; Calapristi, Augustin J.; Crow, Vernon L.; Hetzler, Elizabeth G.; Turner, Alan E.

    2004-05-26

    We present an approach to the disambiguation of cluster labels that capitalizes on the notion of semantic similarity to assign WordNet senses to cluster labels. The approach provides interesting insights on how document clustering can provide the basis for developing a novel approach to word sense disambiguation.

  17. Cluster Lenses

    CERN Document Server

    Kneib, Jean-Paul; 10.1007/s00159-011-0047-3

    2012-01-01

    Clusters of galaxies are the most recently assembled, massive, bound structures in the Universe. As predicted by General Relativity, given their masses, clusters strongly deform space-time in their vicinity. Clusters act as some of the most powerful gravitational lenses in the Universe. Light rays traversing through clusters from distant sources are hence deflected, and the resulting images of these distant objects therefore appear distorted and magnified. Lensing by clusters occurs in two regimes, each with unique observational signatures. The strong lensing regime is characterized by effects readily seen by eye, namely, the production of giant arcs, multiple-images, and arclets. The weak lensing regime is characterized by small deformations in the shapes of background galaxies only detectable statistically. Cluster lenses have been exploited successfully to address several important current questions in cosmology: (i) the study of the lens(es) - understanding cluster mass distributions and issues pertaining...

  18. Substance, Reality, and Distinctness

    Directory of Open Access Journals (Sweden)

    Boris Hennig

    2008-04-01

    Full Text Available Descartes claims that God is a substance, and that mind and body are two different and separable substances. This paper provides some background that renders these claims intelligible. For Descartes, that something is real means it can exist in separation, and something is a substance if it does not depend on other substances for its existence. Further, separable objects are correlates of distinct ideas, for an idea is distinct (in an objective sense if its object may be easily and clearly separated from everything that is not its object. It follows that if our idea of God is our most distinct idea, as Descartes claims, then God must be a substance in the Cartesian sense of the term. Also, if we can have an idea of a thinking subject which does not in any sense refer to bodily things, and if bodily things are substances, then mind and body must be two different substances.

  19. The impact of alcoholics anonymous on other substance abuse-related twelve-step programs.

    Science.gov (United States)

    Laudet, Alexandre B

    2008-01-01

    This chapter explores the influence of the AA model on self-help fellowships addressing problems of drug dependence. Fellowships that have adapted the twelve-step recovery model to other substances of abuse are reviewed; next similarities and differences between AA and drug-recovery twelve-step organizations are examined; finally, we present empirical findings on patterns of attendance and perceptions of AA and Narcotics Anonymous (NA) among polydrug-dependent populations, many of whom are cross-addicted to alcohol. Future directions in twelve-step research are noted in closing.

  20. Cluster Chemistry

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ Cansisting of eight scientists from the State Key Laboratory of Physical Chemistry of Solid Surfaces and Xiamen University, this creative research group is devoted to the research of cluster chemistry and creation of nanomaterials.After three-year hard work, the group scored a series of encouraging progresses in synthesis of clusters with special structures, including novel fullerenes, fullerene-like metal cluster compounds as well as other related nanomaterials, and their properties study.

  1. CLINICAL APPLICATION OF “TWELVE WELL-POINTS” IN EMERGENCY TREATMENT

    Institute of Scientific and Technical Information of China (English)

    段功保

    2000-01-01

    In many years' clinical practice, I used blood-letting method of “Twelve Well-points” to treat emergencies as coma, syncope, acute infantile convulsion, wind-stroke syndrome, hysteria, epilepsy, etc. and have achieved immediate results.

  2. Clustered regression with unknown clusters

    CERN Document Server

    Barman, Kishor

    2011-01-01

    We consider a collection of prediction experiments, which are clustered in the sense that groups of experiments ex- hibit similar relationship between the predictor and response variables. The experiment clusters as well as the regres- sion relationships are unknown. The regression relation- ships define the experiment clusters, and in general, the predictor and response variables may not exhibit any clus- tering. We call this prediction problem clustered regres- sion with unknown clusters (CRUC) and in this paper we focus on linear regression. We study and compare several methods for CRUC, demonstrate their applicability to the Yahoo Learning-to-rank Challenge (YLRC) dataset, and in- vestigate an associated mathematical model. CRUC is at the crossroads of many prior works and we study several prediction algorithms with diverse origins: an adaptation of the expectation-maximization algorithm, an approach in- spired by K-means clustering, the singular value threshold- ing approach to matrix rank minimization u...

  3. Subspace clustering through attribute clustering

    Institute of Scientific and Technical Information of China (English)

    Kun NIU; Shubo ZHANG; Junliang CHEN

    2008-01-01

    Many recently proposed subspace clustering methods suffer from two severe problems. First, the algorithms typically scale exponentially with the data dimensionality or the subspace dimensionality of clusters. Second, the clustering results are often sensitive to input parameters. In this paper, a fast algorithm of subspace clustering using attribute clustering is proposed to over-come these limitations. This algorithm first filters out redundant attributes by computing the Gini coefficient. To evaluate the correlation of every two non-redundant attributes, the relation matrix of non-redundant attributes is constructed based on the relation function of two dimensional united Gini coefficients. After applying an overlapping clustering algorithm on the relation matrix, the candidate of all interesting subspaces is achieved. Finally, all subspace clusters can be derived by clustering on interesting subspaces. Experiments on both synthesis and real datasets show that the new algorithm not only achieves a significant gain of runtime and quality to find subspace clusters, but also is insensitive to input parameters.

  4. Hydrogen-bonded clusters of ferrocenecarboxylic acid on Au(111).

    Science.gov (United States)

    Quardokus, Rebecca C; Wasio, Natalie A; Christie, John A; Henderson, Kenneth W; Forrest, Ryan P; Lent, Craig S; Corcelli, Steven A; Kandel, S Alex

    2014-09-14

    Self-assembled monolayers of ferrocenecarboxylic acid (FcCOOH) contain two fundamental units, both stabilized by intermolecular hydrogen bonding: dimers and cyclic five-membered catemers. At surface coverages below a full monolayer, however, there is a significantly more varied structure that includes double-row clusters containing two to twelve FcCOOH molecules. Statistical analysis shows a distribution of cluster sizes that is sharply peaked compared to a binomial distribution. This rules out simple nucleation-and-growth mechanisms of cluster formation, and strongly suggests that clusters are formed in solution and collapse into rows when deposited on the Au(111) surface.

  5. Cluster editing

    DEFF Research Database (Denmark)

    Böcker, S.; Baumbach, Jan

    2013-01-01

    . The problem has been the inspiration for numerous algorithms in bioinformatics, aiming at clustering entities such as genes, proteins, phenotypes, or patients. In this paper, we review exact and heuristic methods that have been proposed for the Cluster Editing problem, and also applications......The Cluster Editing problem asks to transform a graph into a disjoint union of cliques using a minimum number of edge modifications. Although the problem has been proven NP-complete several times, it has nevertheless attracted much research both from the theoretical and the applied side...

  6. Weighted Clustering

    CERN Document Server

    Ackerman, Margareta; Branzei, Simina; Loker, David

    2011-01-01

    In this paper we investigate clustering in the weighted setting, in which every data point is assigned a real valued weight. We conduct a theoretical analysis on the influence of weighted data on standard clustering algorithms in each of the partitional and hierarchical settings, characterising the precise conditions under which such algorithms react to weights, and classifying clustering methods into three broad categories: weight-responsive, weight-considering, and weight-robust. Our analysis raises several interesting questions and can be directly mapped to the classical unweighted setting.

  7. Cluster analysis

    CERN Document Server

    Everitt, Brian S; Leese, Morven; Stahl, Daniel

    2011-01-01

    Cluster analysis comprises a range of methods for classifying multivariate data into subgroups. By organizing multivariate data into such subgroups, clustering can help reveal the characteristics of any structure or patterns present. These techniques have proven useful in a wide range of areas such as medicine, psychology, market research and bioinformatics.This fifth edition of the highly successful Cluster Analysis includes coverage of the latest developments in the field and a new chapter dealing with finite mixture models for structured data.Real life examples are used throughout to demons

  8. Clustering Teachers' Motivations for Teaching

    Science.gov (United States)

    Visser-Wijnveen, Gerda J.; Stes, Ann; Van Petegem, Peter

    2014-01-01

    The motivation to teach is a powerful, yet neglected, force in teaching at institutes of higher education. A better understanding of academics' motivations for teaching is necessary. The aim of this mixed-method study was to identify groups with distinctively different motivations for teaching. Six clusters were identified: expertise, duty,…

  9. Fuzzy Clustering

    DEFF Research Database (Denmark)

    Berks, G.; Keyserlingk, Diedrich Graf von; Jantzen, Jan

    2000-01-01

    A symptom is a condition indicating the presence of a disease, especially, when regarded as an aid in diagnosis.Symptoms are the smallest units indicating the existence of a disease. A syndrome on the other hand is an aggregate, set or cluster of concurrent symptoms which together indicate...... and clustering are the basic concerns in medicine. Classification depends on definitions of the classes and their required degree of participant of the elements in the cases' symptoms. In medicine imprecise conditions are the rule and therefore fuzzy methods are much more suitable than crisp ones. Fuzzy c......-mean clustering is an easy and well improved tool, which has been applied in many medical fields. We used c-mean fuzzy clustering after feature extraction from an aphasia database. Factor analysis was applied on a correlation matrix of 26 symptoms of language disorders and led to five factors. The factors...

  10. Touch communicates distinct emotions.

    Science.gov (United States)

    Hertenstein, Matthew J; Keltner, Dacher; App, Betsy; Bulleit, Brittany A; Jaskolka, Ariane R

    2006-08-01

    The study of emotional signaling has focused almost exclusively on the face and voice. In 2 studies, the authors investigated whether people can identify emotions from the experience of being touched by a stranger on the arm (without seeing the touch). In the 3rd study, they investigated whether observers can identify emotions from watching someone being touched on the arm. Two kinds of evidence suggest that humans can communicate numerous emotions with touch. First, participants in the United States (Study 1) and Spain (Study 2) could decode anger, fear, disgust, love, gratitude, and sympathy via touch at much-better-than-chance levels. Second, fine-grained coding documented specific touch behaviors associated with different emotions. In Study 3, the authors provide evidence that participants can accurately decode distinct emotions by merely watching others communicate via touch. The findings are discussed in terms of their contributions to affective science and the evolution of altruism and cooperation. (c) 2006 APA, all rights reserved

  11. Bringing distinctive TV drama?

    DEFF Research Database (Denmark)

    Jensen, Pia Majbritt; Raats, Tim

    roles of PSB. (2) Comparing public service media strategies for TV drama financing and distribution in two markets: the Flemish (i.e. Dutch-speaking part of Belgium) and the Danish market. Both cases are characterized by huge popularity of domestic tv drama and both markets are non......-Anglophone with a limited market size and hence, theoretically, limited capacity for production and export. Both cases furthermore show a crucial role of the public broadcasters as part of developing and sustaining tv drama in those markets. However, the underlying policy impetus reflect clearly different views on TV drama...... strategies, with policymakers employing TV drama in Flanders as a driver for a ‘healthy’ independent production sector (especially in VRT’s most recent management contract) and DR drama clearly driven by distinct public service characteristics. Having the said that, the latter case in recently proved its...

  12. Chapter Twelve

    African Journals Online (AJOL)

    User

    dissemination in Nigeria· Some local jingles from Radio Nigeria Purity F.M. .... Indigenous Language in Advertisement: Problems and Prospects – Thecla ... the rural newspapers from performing their role of rural development· The ..... Sharma Raman, M· and, S (2004), Technical Communication Principle and Practice· India:.

  13. Evolution of homeobox gene clusters in animals: the Giga-cluster and primary versus secondary clustering.

    Directory of Open Access Journals (Sweden)

    David Ellard Keith Ferrier

    2016-04-01

    Full Text Available The Hox gene cluster has been a major focus in evolutionary developmental biology. This is because of its key role in patterning animal development and widespread examples of changes in Hox genes being linked to the evolution of animal body plans and morphologies. Also, the distinctive organisation of the Hox genes into genomic clusters in which the order of the genes along the chromosome corresponds to the order of their activity along the embryo, or during a developmental process, has been a further source of great interest. This is known as Colinearity, and it provides a clear link between genome organisation and the regulation of genes during development, with distinctive changes marking evolutionary transitions. The Hox genes are not alone, however. The homeobox genes are a large super-class, of which the Hox genes are only a small subset, and an ever-increasing number of further gene clusters besides the Hox are being discovered. This is of great interest because of the potential for such gene clusters to help understand major evolutionary transitions, both in terms of changes to development and morphology as well as evolution of genome organisation. However, there is uncertainty in our understanding of homeobox gene cluster evolution at present. This relates to our still rudimentary understanding of the dynamics of genome rearrangements and evolution over the evolutionary timescales being considered when we compare lineages from across the animal kingdom. A major goal is to deduce whether particular instances of clustering are primary (conserved from ancient ancestral clusters or secondary (reassortment of genes into clusters in lineage-specific fashion. The following summary of the various instances of homeobox gene clusters in animals, and the hypotheses about their evolution, provides a framework for the future resolution of this uncertainty.

  14. Star Cluster Formation and Feedback

    CERN Document Server

    Krumholz, Mark R; Arce, Hector G; Dale, James E; Gutermuth, Robert; Klein, Richard I; Li, Zhi-Yun; Nakamura, Fumitaka; Zhang, Qizhou

    2014-01-01

    Stars do not generally form in isolation. Instead, they form in clusters, and in these clustered environments newborn stars can have profound effects on one another and on their parent gas clouds. Feedback from clustered stars is almost certainly responsible for a number of otherwise puzzling facts about star formation: that it is an inefficient process that proceeds slowly when averaged over galactic scales; that most stars disperse from their birth sites and dissolve into the galactic field over timescales $\\ll 1$ Gyr; and that newborn stars follow an initial mass function (IMF) with a distinct peak in the range $0.1 - 1$ $M_\\odot$, rather than an IMF dominated by brown dwarfs. In this review we summarize current observational constraints and theoretical models for the complex interplay between clustered star formation and feedback.

  15. Cluster forcing

    DEFF Research Database (Denmark)

    Christensen, Thomas Budde

    .g. sustainability or quality of life. The purpose of this paper is to explore how and to what extent public sector interventions that aim at forcing cluster development in industries can support sustainable development as defined in the Brundtland tradition and more recently elaborated in such concepts as eco......, Portugal and New Zealand have adopted the concept. Public sector interventions that aim to support cluster development in industries most often focus upon economic policy goals such as enhanced employment and improved productivity, but rarely emphasise broader societal policy goals relating to e...... to the automotive sector in Wales. Specifically, the paper evaluates the "Accelerates" programme initiated by the Welsh Development Agency and elaborates on how and to what extent the Accelerate programme supports the development of a sustainable automotive industry cluster. The Accelerate programme was set up...

  16. 5S rDNA characterization in twelve Sciaenidae fish species (Teleostei, Perciformes: depicting gene diversity and molecular markers

    Directory of Open Access Journals (Sweden)

    Fernanda A. Alves-Costa

    2008-01-01

    Full Text Available In order to extend the genetic data on the Sciaenidae fish family, the present study had the purpose to characterize PCR-generated 5S rDNA repeats of twelve species of this group through PAGE (Polyacrylamide Gel Electrophoresis analysis. The results showed the occurrence of at least two different 5S rDNA size classes in all the species. Moreover, 5S rDNA repeats of one of the studied species - Isopisthus parvipinnis - were cloned and subjected to nucleotide sequencing and Southern blot membrane hybridization analyses, which permitted to confirm the existence of two major 5S rDNA classes. Phylogenetic analysis based on the nucleotide sequences of different 5S rDNA repeats of I. parvipinnis lead to their separation into two major clusters. These results may reflect the high dynamism that rules the evolution rate of 5S rDNA repeats. The obtained data suggest that 5S rDNA can be useful in genetic analyses to identify species-specific markers and determine relationships among species of the Sciaenidae group.

  17. Distinct subtypes of knee osteoarthritis: Data from the Osteoarthritis Initiative

    NARCIS (Netherlands)

    J.H. Waarsing (Jan); S.M. Bierma-Zeinstra (Sita); H.H. Weinans (Harrie)

    2015-01-01

    textabstractObjective. OA is suspected to be a collection of distinct subtypes, each with different aetiology and clinical characteristics. We aimed to explore the existence of different subtypes of knee OA, using cluster analysis of the data of the OA Initiative. Methods. We used latent class

  18. Isolation and characterization of twelve microsatellite loci for the Japanese Devilray (Mobula japanica)

    NARCIS (Netherlands)

    Poortvliet, Marloes; Galvan-Magana, Felipe; Bernardi, Giacomo; Croll, Donald A.; Olsen, Jeanine L.

    2011-01-01

    Twelve polymorphic microsatellites loci were characterized for Mobula japanica (Japanese Devilray) using an enrichment protocol. All but two loci were in Hardy-Weinberg equilibrium with no evidence of linkage disequilibrium or null-alleles for a sample of 40 individuals from two populations. The num

  19. 17 CFR 210.3-06 - Financial statements covering a period of nine to twelve months.

    Science.gov (United States)

    2010-04-01

    ... ACT OF 1933, SECURITIES EXCHANGE ACT OF 1934, PUBLIC UTILITY HOLDING COMPANY ACT OF 1935, INVESTMENT COMPANY ACT OF 1940, INVESTMENT ADVISERS ACT OF 1940, AND ENERGY POLICY AND CONSERVATION ACT OF 1975... to twelve months. Except with respect to registered investment companies, the filing of...

  20. Twelve new species of Triplocania Roesler (Psocodea: 'Psocoptera': Ptiloneuridae), from South America.

    Science.gov (United States)

    Silva Neto, Alberto Moreira Da; Aldrete, Alfonso N García; Rafael, José Albertino

    2016-05-09

    Twelve species of Triplocania, seven based on male and female specimens and five based on male specimens, are here described and illustrated; nine species are Brazilian, three are Ecuadorian, and one of the latter is shared with Peru. Comments on sexes known and distribution of the species are included.

  1. Portrayal of Life Form in Selected Biographies for Children Eight to Twelve Years of Age.

    Science.gov (United States)

    Koch, Shirley Lois

    This study describes and analyzes, in a critical literary manner, selected biographies for children eight to twelve years of age. Biographies of Jane Addams, Cesar Chavez, Mohandas Gandhi, Toyohiko Kagawa, Martin Luther King, Jr., and Albert Schweitzer are viewed from the perspective of a literary criterion based on the principles of design to…

  2. Premarital sex in the last twelve months and its predictors among ...

    African Journals Online (AJOL)

    Premarital sex in the last twelve months and its predictors among students of ... Statistical significance was determined through a 95% confidence level. ... having comprehensive knowledge of HIV [AOR(95% CI)=1.5(1.01-2.10)], alcohol use ...

  3. Portrayal of Life Form in Selected Biographies for Children Eight to Twelve Years of Age.

    Science.gov (United States)

    Koch, Shirley Lois

    This study describes and analyzes, in a critical literary manner, selected biographies for children eight to twelve years of age. Biographies of Jane Addams, Cesar Chavez, Mohandas Gandhi, Toyohiko Kagawa, Martin Luther King, Jr., and Albert Schweitzer are viewed from the perspective of a literary criterion based on the principles of design to…

  4. A novel double quad-inverter configuration for multilevel twelve-phase open-winding converter

    DEFF Research Database (Denmark)

    Padmanaban, Sanjeevi Kumar; Blaabjerg, Frede; Wheeler, Patrick William

    2016-01-01

    This paper describes a novel proposal of double quad-inverter configuration for multilevel twelve-phase open-winding ac converter. Modular power units are developed from reconfigured eight classical three-phase voltage source inverters (VSIs). Each VSI has one additional bi-directional switching ...

  5. Ameloblastoma Phenotypes Reflected in Distinct Transcriptome Profiles

    Science.gov (United States)

    Hu, Shijia; Parker, Joel; Divaris, Kimon; Padilla, Ricardo; Murrah, Valerie; Wright, John Timothy

    2016-01-01

    Ameloblastoma is a locally invasive benign neoplasm derived from odontogenic epithelium and presents with diverse phenotypes yet to be characterized molecularly. High recurrence rates of 50–80% with conservative treatment in some sub-types warrants radical surgical resections resulting in high morbidity. The objective of the study was to characterize the transcriptome of ameloblastoma and identify relevant genes and molecular pathways using normal odontogenic tissue (human “dentome”) for comparison. Laser capture microdissection was used to obtain neoplastic epithelial tissue from 17 tumors which were examined using the Agilent 44 k whole genome microarray. Ameloblastoma separated into 2 distinct molecular clusters that were associated with pre-secretory ameloblast and odontoblast. Within the pre-secretory cluster, 9/10 of samples were of the follicular type while 6/7 of the samples in the odontoblast cluster were of the plexiform type (p ameloblastoma sub-types and have implications for the use of tailored treatment. PMID:27491308

  6. Cluster forcing

    DEFF Research Database (Denmark)

    Christensen, Thomas Budde

    The cluster theory attributed to Michael Porter has significantly influenced industrial policies in countries across Europe and North America since the beginning of the 1990s. Institutions such as the EU, OECD and the World Bank and governments in countries such as the UK, France, The Netherlands...

  7. Quotients of cluster categories

    OpenAIRE

    Jorgensen, Peter

    2007-01-01

    Higher cluster categories were recently introduced as a generalization of cluster categories. This paper shows that in Dynkin types A and D, half of all higher cluster categories are actually just quotients of cluster categories. The other half can be obtained as quotients of 2-cluster categories, the "lowest" type of higher cluster categories. Hence, in Dynkin types A and D, all higher cluster phenomena are implicit in cluster categories and 2-cluster categories. In contrast, the same is not...

  8. Regional Innovation Clusters

    Data.gov (United States)

    Small Business Administration — The Regional Innovation Clusters serve a diverse group of sectors and geographies. Three of the initial pilot clusters, termed Advanced Defense Technology clusters,...

  9. Cluster Radioactivity

    Science.gov (United States)

    Poenaru, Dorin N.; Greiner, Walter

    One of the rare examples of phenomena predicted before experimental discovery, offers the opportunity to introduce fission theory based on the asymmetric two center shell model. The valleys within the potential energy surfaces are due to the shell effects and are clearly showing why cluster radioactivity was mostly detected in parent nuclei leading to a doubly magic lead daughter. Saddle point shapes can be determined by solving an integro-differential equation. Nuclear dynamics allows us to calculate the half-lives. The following cluster decay modes (or heavy particle radioactivities) have been experimentally confirmed: 14C, 20O, 23F, 22,24-26Ne, 28,30Mg, 32,34Si with half-lives in good agreement with predicted values within our analytical superasymmetric fission model. The preformation probability is calculated as the internal barrier penetrability. An universal curve is described and used as an alternative for the estimation of the half-lives. The macroscopic-microscopic method was extended to investigate two-alpha accompanied fission and true ternary fission. The methods developed in nuclear physics are also adapted to study the stability of deposited atomic clusters on the planar surfaces.

  10. Anatomical studies on twelve clones of Camellia species with reference to their taxonomic significance

    Directory of Open Access Journals (Sweden)

    Rajanna L

    2010-10-01

    Full Text Available Anatomical studies of leaf and stem of twelve clones of Camellia were investigated. Cross sections of the stem of all the clones exhibited a typical pattern of arrangement of tissues characteristics of woody plants. Two types of idioblastic sclereids were found in the medullary parenchyma of the taxa studied. While astrosclereids werepresent in 10 of the twelve clones, the vesciculose sclereids were found only in the four clones belonging to C. sinensis. Leaves of the clones show variations in the number of palisade layers. Astro sclereids, brachy sclereids, and dendritic forms were observed in the leaves, their distribution varying in the different clones. A few other micromorphological features are also recorded. Our study forms a basis for answering uncertainties in taxonomic revision in the genus Camellia.

  11. Cluster beam visualization with MCPs

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, Esperanza; Grieser, Silke; Hergemoeller, Ann-Katrin; Taeschner, Alexander; Ortjohann, Hans-Werner; Bonaventura, Daniel; Khoukaz, Alfons [Muenster Univ. (Germany). Inst. fuer Kernphysik

    2013-07-01

    A cluster-jet target will be the first installed internal target for the PANDA experiment at HESR/FAIR. For performance studies a cluster-jet target prototype in complete PANDA geometry was already built up and set successfully into operation at the University of Muenster. At present this target prototype is routinely operated with hydrogen and the use of other materials such as deuterium is also possible. The observation of distinct density structures within the jet beam behind the nozzle and the use of a new tilting system lead to areal target densities of more than 2 x 10{sup 15} atoms/cm{sup 2} at a distance of 2.1 m. The thickness is reproducible, constant in time, and variable over several orders of magnitude. Depending on the experimental program the target beam size and shape is variable. This can be visualized by a new monitoring system based on a Micro Channel Plate (MCP), which allows for a direct observation of an ionized cluster beam. Therefore, the cluster beam is ionized by an electron beam and the signals in the MCP are observed by a phosphor screen in combination with a CCD camera. In this talk the performance of the cluster-jet target and MCP images of the cluster beam are presented and discussed.

  12. Multiple Clustering Views via Constrained Projections

    DEFF Research Database (Denmark)

    Dang, Xuan-Hong; Assent, Ira; Bailey, James

    2012-01-01

    Clustering, the grouping of data based on mutual similarity, is often used as one of principal tools to analyze and understand data. Unfortunately, most conventional techniques aim at finding only a single clustering over the data. For many practical applications, especially those being described...... in high dimensional data, it is common to see that the data can be grouped into different yet meaningful ways. This gives rise to the recently emerging research area of discovering alternative clusterings. In this preliminary work, we propose a novel framework to generate multiple clustering views....... The framework relies on a constrained data projection approach by which we ensure that a novel alternative clustering being found is not only qualitatively strong but also distinctively different from a reference clustering solution. We demonstrate the potential of the proposed framework using both synthetic...

  13. Descriptions of twelve new species of ochyroceratids (Araneae, Ochyroceratidae) from mainland Ecuador.

    Science.gov (United States)

    Dupérré, Nadine

    2015-05-12

    Twelve new species in three different genera from the spider family Ochyroceratidae are described from mainland Ecuador: Speocera bioforestae sp. n., Speocera violacea sp. n., Speocera musgo sp. n., Ochyrocera rinocerotos sp. n., Ochyrocera callaina sp. n., Ochyrocera italoi sp. n., Ochyrocera minotaure sp. n., Ochyrocera losrios sp. n., Ochyrocera zabaleta sp. n., Ochyrocera otonga sp. n., Ochyrocera cashcatotoras sp. n. and Psiloochyrocera tortilis sp. n. Speocera machadoi Gertsch 1977 is transferred to Ochyrocera.

  14. A Hidden Twelve-Dimensional SuperPoincare Symmetry In Eleven Dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Bars, Itzhak; Deliduman, Cemsinan; Pasqua, Andrea; Zumino, Bruno

    2003-12-13

    First, we review a result in our previous paper, of how a ten-dimensional superparticle, taken off-shell, has a hidden eleven-dimensional superPoincare symmetry. Then, we show that the physical sector is defined by three first-class constraints which preserve the full eleven-dimensional symmetry. Applying the same concepts to the eleven dimensional superparticle, taken off-shell, we discover a hidden twelve dimensional superPoincare symmetry that governs the theory.

  15. Premarital Sex in the Last Twelve Months and Its Predictors among Students of Wollega University, Ethiopia.

    Science.gov (United States)

    Regassa, Tesfaye; Chala, Dereje; Adeba, Emiru

    2016-07-01

    Premarital sex increases the risk of unintended pregnancy and sexually transmitted infections including HIV if unprotected and contraception is not used. Thus, the objective of this study was to assess premarital sex in the last twelve months and its predictors among regular undergraduate students of Wollega University. A cross-sectional survey using pretested, structured questionnaire was conducted on a total of 704 regular undergraduate students of Wollega University from February to March, 2014. We used multistage sampling technique to recruit study participants. Binary and multivariable logistic regressions were performed using SPSS version 20 to assess predictors of premarital sex. Statistical significance was determined through a 95% confidence level. Wollega University youths who had premarital sex in the last twelve months were 28.4%; 55.5% of them did not use condom during last sex while 31.3% engaged in multiple sex. Being male [Adjusted Odds Ratio (AOR)(95% Confidence Interval(CI))=2.7(1.58-4.75)], age 20-24 years [AOR(95%CI)=2.8(1.13-7.20)], training on how to use condom [AOR(95%CI)=1.7(1.17-2.46)], being tested for HIV [AOR(95%CI)=2.3(1.48-3.53)], using social media frequently [AOR(95%CI)=1.8(1.14-2.88)], having comprehensive knowledge of HIV [AOR(95% CI)=1.5(1.01-2.10)], alcohol use [AOR (95%CI)=2.2(1.31-3.56)] were associated with increased odds of premarital sex in the last twelve months. Nearly one-third of regular undergraduate students of the university were engaged in premarital sex in the last twelve months. Being male, using social media frequently and alcohol use were associated with increased odds of premarital sex in the stated period. Thus, higher institutions have to deliver abstinence messages alongside information about self-protection.

  16. Hidden twelve-dimensional super Poincaré symmetry in eleven dimensions

    CERN Document Server

    Bars, Itzhak; Pasqua, A; Zumino, B; Bars, Itzhak; Deliduman, Cemsinan; Pasqua, Andrea; Zumino, Bruno

    2004-01-01

    First, we review a result in our previous paper, of how a ten-dimensional superparticle, taken off-shell, has a hidden eleven-dimensional superPoincare symmetry. Then, we show that the physical sector is defined by three first-class constraints which preserve the full eleven-dimensional symmetry. Applying the same concepts to the eleven dimensional superparticle, taken off-shell, we discover a hidden twelve dimensional superPoincare symmetry that governs the theory.

  17. Distinctiveness of Ugandapithecus from Proconsul

    Directory of Open Access Journals (Sweden)

    Gommery, D.

    2009-12-01

    variation of male cheek teeth. All other known male and female hominoid species possess cheek teeth whose ranges of variation overlap strongly. Bivariate plots of the teeth attributed to Ugandapithecus reveal three consistent non-overlapping clusters of points among the Early Miocene specimens, which we interpret to represent three distinct species. A fourth species of the genus, U. gitongai, was previously defined at the Middle Miocene site of Kipsaraman, Kenya. We conclude that Ugandapithecus was a lineage of great ape distinct from Proconsul, and its main evolutionary trend was an increase in dimensions from basal Early Miocene Ugandapithecus meswae (21.5-19 Ma to late Early Miocene species Ugandapithecus legetetensis nov. sp. (20-19 Ma and Ugandapithecus major (19-18 Ma, and culminating in late Middle Miocene Ugandapithecus gitongai (ca. 14.5 Ma.La decisión de crear el género Ugandapithecus por Senut et al. (2000 ha sido criticada, tanto directamente y en detalle por Maclatchy & Rossie (2005b que argumentan que es una sinonimia de Proconsul, o indirectamente sin ninguna argumentación, primero por Harrison (2001 que no lo considera como distinto de Proconsul, y después por Suwa et al. (2007 que emplean el nombre de “Ugandapithecus” entre comillas, implicando algún grado de duda sobre su validez como género. Recientemente Harrison & Andrews (2009 han reconocido la muestra de Meswa como una especie diferente, pero argumentando que debería ser mantenida en Proconsul, a pesar de las diferencias morfológicas que posee con respecto a otras especies del género. En este trabajo reexaminamos el problema, por un lado comparando, el maxilar holotipo de Proconsul africanus, especie tipo del género, con la dentición superior de Ugandapithecus major y por otro lado, con la dentición inferior y mandíbulas previamente atribuidas a Proconsul africanus. La conclusión de estas comparaciones es que las diferencias entre las denticiones superiores e inferiores conocidas de

  18. Counselor Identity: Conformity or Distinction?

    Science.gov (United States)

    McLaughlin, Jerry E.; Boettcher, Kathryn

    2009-01-01

    The authors explore 3 debates in other disciplines similar to counseling's identity debate in order to learn about common themes and outcomes. Conformity, distinction, and cohesion emerged as common themes. They conclude that counselors should retain their distinctive, humanistic approach rather than conforming to the dominant, medical approach.

  19. Counselor Identity: Conformity or Distinction?

    Science.gov (United States)

    McLaughlin, Jerry E.; Boettcher, Kathryn

    2009-01-01

    The authors explore 3 debates in other disciplines similar to counseling's identity debate in order to learn about common themes and outcomes. Conformity, distinction, and cohesion emerged as common themes. They conclude that counselors should retain their distinctive, humanistic approach rather than conforming to the dominant, medical approach.

  20. Is Face Distinctiveness Gender Based?

    Science.gov (United States)

    Baudouin, Jean-Yves; Gallay, Mathieu

    2006-01-01

    Two experiments were carried out to study the role of gender category in evaluations of face distinctiveness. In Experiment 1, participants had to evaluate the distinctiveness and the femininity-masculinity of real or artificial composite faces. The composite faces were created by blending either faces of the same gender (sexed composite faces,…

  1. Optimal Distinctiveness Signals Membership Trust.

    Science.gov (United States)

    Leonardelli, Geoffrey J; Loyd, Denise Lewin

    2016-07-01

    According to optimal distinctiveness theory, sufficiently small minority groups are associated with greater membership trust, even among members otherwise unknown, because the groups are seen as optimally distinctive. This article elaborates on the prediction's motivational and cognitive processes and tests whether sufficiently small minorities (defined by relative size; for example, 20%) are associated with greater membership trust relative to mere minorities (45%), and whether such trust is a function of optimal distinctiveness. Two experiments, examining observers' perceptions of minority and majority groups and using minimal groups and (in Experiment 2) a trust game, revealed greater membership trust in minorities than majorities. In Experiment 2, participants also preferred joining minorities over more powerful majorities. Both effects occurred only when minorities were 20% rather than 45%. In both studies, perceptions of optimal distinctiveness mediated effects. Discussion focuses on the value of relative size and optimal distinctiveness, and when membership trust manifests.

  2. Advances in molecular vibrations and collision dynamics molecular clusters

    CERN Document Server

    Bacic, Zatko

    1998-01-01

    This volume focuses on molecular clusters, bound by van der Waals interactions and hydrogen bonds. Twelve chapters review a wide range of recent theoretical and experimental advances in the areas of cluster vibrations, spectroscopy, and reaction dynamics. The authors are leading experts, who have made significant contributions to these topics.The first chapter describes exciting results and new insights in the solvent effects on the short-time photo fragmentation dynamics of small molecules, obtained by combining heteroclusters with femtosecond laser excitation. The second is on theoretical work on effects of single solvent (argon) atom on the photodissociation dynamics of the solute H2O molecule. The next two chapters cover experimental and theoretical aspects of the energetics and vibrations of small clusters. Chapter 5 describes diffusion quantum Monte Carlo calculations and non additive three-body potential terms in molecular clusters. The next six chapters deal with hydrogen-bonded clusters, refle...

  3. Poikiloderma Vasculare Atrophicans: A Distinct Clinical Entity?

    Science.gov (United States)

    Mahajan, Vikram K; Chauhan, Pushpinder S; Mehta, Karaninder S; Sharma, Anju Lath

    2015-01-01

    This paper describes a typical case of poikiloderma vasculare atrophicans (PVA) in a 48-year-old female. Histologically, the features were suggestive of PVA with the absence of Pautrier's microabscess or atypical lymphoid cells. The biopsy specimen was positive for cluster of differentiation (CD) 8 on immunohistochemical staining. Its exact pathogenesis remains obscure, and it remains unclear whether PVA actually is mycosis fungoides (MF), a forme fruste of MF, or a distinct and benign dermatosis with CD8+ phenotype that can perhaps be labeled as PVA. However, it has a long benign clinical course without progression to tumor stage of MF in most cases, and its status within the spectrum of cutaneous T-cell lymphoma remains poorly understood. Yet it is imperative to distinguish PVA from poikilodermic MF. PMID:25814753

  4. Poikiloderma vasculare atrophicans: A distinct clinical entity?

    Directory of Open Access Journals (Sweden)

    Vikram K Mahajan

    2015-01-01

    Full Text Available This paper describes a typical case of poikiloderma vasculare atrophicans (PVA in a 48-year-old female. Histologically, the features were suggestive of PVA with the absence of Pautrier′s microabscess or atypical lymphoid cells. The biopsy specimen was positive for cluster of differentiation (CD 8 on immunohistochemical staining. Its exact pathogenesis remains obscure, and it remains unclear whether PVA actually is mycosis fungoides (MF, a forme fruste of MF, or a distinct and benign dermatosis with CD8+ phenotype that can perhaps be labeled as PVA. However, it has a long benign clinical course without progression to tumor stage of MF in most cases, and its status within the spectrum of cutaneous T-cell lymphoma remains poorly understood. Yet it is imperative to distinguish PVA from poikilodermic MF.

  5. Toward an Empirical Taxonomy of Suicide Ideation: A Cluster Analysis of the Youth Risk Behavior Survey

    Science.gov (United States)

    Flannery, William Peter; Sneed, Carl D.; Marsh, Penny

    2003-01-01

    In this study we examined adolescent risk behaviors, giving special attention to suicide ideation. Cluster analysis was used to classify adolescents ( N = 2,730) on the Youth Risk Behavior Survey. Six clusters of adolescent risk behavior were identified. Although each risk cluster was distinct, some clusters shared overlapping risk behaviors.…

  6. Hot Populations in M87 Globular Clusters

    CERN Document Server

    Sohn, S T; Kundu, A; Landsman, W B; Burstein, D; Bohlin, R C; Frogel, J A; Rose, J A

    2005-01-01

    We have obtained HST/STIS far- and near-UV photometry of globular clusters in four fields in the gE galaxy M87. To a limit of m(FUV) = 25 we detect a total of 66 globular clusters (GCs) in common with the deep HST optical-band study of Kundu et al. (1999). Despite strong overlap in V- and I-band properties, the M87 GCs have UV/optical properties that are distinct from clusters in the Milky Way and in M31. M87 clusters, especially metal-poor ones, produce larger hot HB populations than do Milky Way analogues. Cluster mass is probably not a factor in these distinctions. The most metal-rich M87 GCs in our sample are near Z_sun and overlap the local E galaxy sample in estimated Mg_2 line indices. Nonetheless, the clusters produce much more UV light at a given Mg_2, being up to 1 mag bluer than any gE galaxy in (FUV-V) color. The M87 GCs do not appear to represent a transition between Milky Way-type clusters and E galaxies. The differences are in the correct sense if the clusters are significantly older than the E...

  7. Anticancer properties of distinct antimalarial drug classes.

    Directory of Open Access Journals (Sweden)

    Rob Hooft van Huijsduijnen

    Full Text Available We have tested five distinct classes of established and experimental antimalarial drugs for their anticancer potential, using a panel of 91 human cancer lines. Three classes of drugs: artemisinins, synthetic peroxides and DHFR (dihydrofolate reductase inhibitors effected potent inhibition of proliferation with IC50s in the nM- low µM range, whereas a DHODH (dihydroorotate dehydrogenase and a putative kinase inhibitor displayed no activity. Furthermore, significant synergies were identified with erlotinib, imatinib, cisplatin, dasatinib and vincristine. Cluster analysis of the antimalarials based on their differential inhibition of the various cancer lines clearly segregated the synthetic peroxides OZ277 and OZ439 from the artemisinin cluster that included artesunate, dihydroartemisinin and artemisone, and from the DHFR inhibitors pyrimethamine and P218 (a parasite DHFR inhibitor, emphasizing their shared mode of action. In order to further understand the basis of the selectivity of these compounds against different cancers, microarray-based gene expression data for 85 of the used cell lines were generated. For each compound, distinct sets of genes were identified whose expression significantly correlated with compound sensitivity. Several of the antimalarials tested in this study have well-established and excellent safety profiles with a plasma exposure, when conservatively used in malaria, that is well above the IC50s that we identified in this study. Given their unique mode of action and potential for unique synergies with established anticancer drugs, our results provide a strong basis to further explore the potential application of these compounds in cancer in pre-clinical or and clinical settings.

  8. An Automatic Clustering Technique for Optimal Clusters

    CERN Document Server

    Pavan, K Karteeka; Rao, A V Dattatreya; 10.5121/ijcsea.2011.1412

    2011-01-01

    This paper proposes a simple, automatic and efficient clustering algorithm, namely, Automatic Merging for Optimal Clusters (AMOC) which aims to generate nearly optimal clusters for the given datasets automatically. The AMOC is an extension to standard k-means with a two phase iterative procedure combining certain validation techniques in order to find optimal clusters with automation of merging of clusters. Experiments on both synthetic and real data have proved that the proposed algorithm finds nearly optimal clustering structures in terms of number of clusters, compactness and separation.

  9. Clustervision: Visual Supervision of Unsupervised Clustering.

    Science.gov (United States)

    Kwon, Bum Chul; Eysenbach, Ben; Verma, Janu; Ng, Kenney; deFilippi, Christopher; Stewart, Walter F; Perer, Adam

    2017-08-29

    Clustering, the process of grouping together similar items into distinct partitions, is a common type of unsupervised machine learning that can be useful for summarizing and aggregating complex multi-dimensional data. However, data can be clustered in many ways, and there exist a large body of algorithms designed to reveal different patterns. While having access to a wide variety of algorithms is helpful, in practice, it is quite difficult for data scientists to choose and parameterize algorithms to get the clustering results relevant for their dataset and analytical tasks. To alleviate this problem, we built Clustervision, a visual analytics tool that helps ensure data scientists find the right clustering among the large amount of techniques and parameters available. Our system clusters data using a variety of clustering techniques and parameters and then ranks clustering results utilizing five quality metrics. In addition, users can guide the system to produce more relevant results by providing task-relevant constraints on the data. Our visual user interface allows users to find high quality clustering results, explore the clusters using several coordinated visualization techniques, and select the cluster result that best suits their task. We demonstrate this novel approach using a case study with a team of researchers in the medical domain and showcase that our system empowers users to choose an effective representation of their complex data.

  10. Cluster analysis in phenotyping a Portuguese population.

    Science.gov (United States)

    Loureiro, C C; Sa-Couto, P; Todo-Bom, A; Bousquet, J

    2015-09-03

    Unbiased cluster analysis using clinical parameters has identified asthma phenotypes. Adding inflammatory biomarkers to this analysis provided a better insight into the disease mechanisms. This approach has not yet been applied to asthmatic Portuguese patients. To identify phenotypes of asthma using cluster analysis in a Portuguese asthmatic population treated in secondary medical care. Consecutive patients with asthma were recruited from the outpatient clinic. Patients were optimally treated according to GINA guidelines and enrolled in the study. Procedures were performed according to a standard evaluation of asthma. Phenotypes were identified by cluster analysis using Ward's clustering method. Of the 72 patients enrolled, 57 had full data and were included for cluster analysis. Distribution was set in 5 clusters described as follows: cluster (C) 1, early onset mild allergic asthma; C2, moderate allergic asthma, with long evolution, female prevalence and mixed inflammation; C3, allergic brittle asthma in young females with early disease onset and no evidence of inflammation; C4, severe asthma in obese females with late disease onset, highly symptomatic despite low Th2 inflammation; C5, severe asthma with chronic airflow obstruction, late disease onset and eosinophilic inflammation. In our study population, the identified clusters were mainly coincident with other larger-scale cluster analysis. Variables such as age at disease onset, obesity, lung function, FeNO (Th2 biomarker) and disease severity were important for cluster distinction. Copyright © 2015. Published by Elsevier España, S.L.U.

  11. Analyses of Twelve New Whole Genome Sequences of Cassava Brown Streak Viruses and Ugandan Cassava Brown Streak Viruses from East Africa: Diversity, Supercomputing and Evidence for Further Speciation.

    Directory of Open Access Journals (Sweden)

    Joseph Ndunguru

    Full Text Available Cassava brown streak disease is caused by two devastating viruses, Cassava brown streak virus (CBSV and Ugandan cassava brown streak virus (UCBSV which are frequently found infecting cassava, one of sub-Saharan Africa's most important staple food crops. Each year these viruses cause losses of up to $100 million USD and can leave entire families without their primary food source, for an entire year. Twelve new whole genomes, including seven of CBSV and five of UCBSV were uncovered in this research, doubling the genomic sequences available in the public domain for these viruses. These new sequences disprove the assumption that the viruses are limited by agro-ecological zones, show that current diagnostic primers are insufficient to provide confident diagnosis of these viruses and give rise to the possibility that there may be as many as four distinct species of virus. Utilizing NGS sequencing technologies and proper phylogenetic practices will rapidly increase the solution to sustainable cassava production.

  12. Distinction

    OpenAIRE

    2010-01-01

    Pr Serge Haroche La Médaille d’or 2009 du CNRS est décernée au Pr Serge Haroche, titulaire de la chaire de Physique quantique depuis 2001. Serge Haroche est spécialiste de physique atomique et d’optique quantique. Il est l’un des fondateurs de l’électrodynamique quantique en cavité, domaine qui permet, par des expériences conceptuellement simples, d’éclairer les fondements de la théorie quantique et de réaliser des prototypes de systèmes de traitement quantique de l’information. Serge Haroche...

  13. The Bright SHARC Survey The Cluster Catalog

    CERN Document Server

    Romer, A K; Holden, B P; Ulmer, M P; Pildis, R A; Merrelli, A J; Adami, C; Burke, D J; Collins, C A; Metevier, A J; Kron, Richard G; Commons, K

    1999-01-01

    We present the Bright SHARC (Serendipitous High-Redshift Archival ROSAT Cluster) Survey, which is an objective search for serendipitously detected extended X-ray sources in 460 deep ROSAT PSPC pointings. The Bright SHARC Survey covers an area of 178.6 sq.deg and has yielded 374 extended sources. We discuss the X-ray data reduction, the candidate selection and present results from our on-going optical follow-up campaign. The optical follow-up concentrates on the brightest 94 of the 374 extended sources and is now 97% complete. We have identified thirty-seven clusters of galaxies, for which we present redshifts and luminosities. The clusters span a redshift range of 0.0696Twelve of the clusters have redshifts greater than z=0.3, eight of which are at luminosities brighter than Lx=3e44 erg/s. Seventeen of the 37 optically confirmed Bright SHARC clusters have not been listed in any previously ...

  14. Definition of a Twelve-Point Polygonal SAA Boundaryfor the GLAST Mission

    Energy Technology Data Exchange (ETDEWEB)

    Djomehri, Sabra I.; /UC, Santa Cruz /SLAC

    2007-08-29

    The Gamma-Ray Large Area Space Telescope (GLAST), set to launch in early 2008, detects gamma rays within a huge energy range of 100 MeV - 300 GeV. Background cosmic radiation interferes with such detection resulting in confusion over distinguishing cosmic from gamma rays encountered. This quandary is resolved by encasing GLAST's Large Area Telescope (LAT) with an Anti-Coincidence Detector (ACD), a device which identifies and vetoes charged particles. The ACD accomplishes this through plastic scintillator tiles; when cosmic rays strike, photons produced induce currents in Photomultiplier Tubes (PMTs) attached to these tiles. However, as GLAST orbits Earth at altitudes {approx}550km and latitudes between -26 degree and 26 degree, it will confront the South Atlantic Anomaly (SAA), a region of high particle flux caused by trapped radiation in the geomagnetic field. Since the SAA flux would degrade the sensitivity of the ACD's PMTs over time, a determined boundary enclosing this region need be attained, signaling when to lower the voltage on the PMTs as a protective measure. The operational constraints on such a boundary require a convex SAA polygon with twelve edges, whose area is minimal ensuring GLAST has maximum observation time. The AP8 and PSB97 models describing the behavior of trapped radiation were used in analyzing the SAA and defining a convex SAA boundary of twelve sides. The smallest possible boundary was found to cover 14.58% of GLAST's observation time. Further analysis of defining a boundary safety margin to account for inaccuracies in the models reveals if the total SAA hull area is increased by {approx}20%, the loss of total observational area is < 5%. These twelve coordinates defining the SAA flux region are ready for implementation by the GLAST satellite.

  15. Hydrophobic mismatch sorts SNARE proteins into distinct membrane domains

    Science.gov (United States)

    Milovanovic, Dragomir; Honigmann, Alf; Koike, Seiichi; Göttfert, Fabian; Pähler, Gesa; Junius, Meike; Müllar, Stefan; Diederichsen, Ulf; Janshoff, Andreas; Grubmüller, Helmut; Risselada, Herre J.; Eggeling, Christian; Hell, Stefan W.; van den Bogaart, Geert; Jahn, Reinhard

    2015-01-01

    The clustering of proteins and lipids in distinct microdomains is emerging as an important principle for the spatial patterning of biological membranes. Such domain formation can be the result of hydrophobic and ionic interactions with membrane lipids as well as of specific protein-protein interactions. Here using plasma membrane-resident SNARE proteins as model, we show that hydrophobic mismatch between the length of transmembrane domains (TMDs) and the thickness of the lipid membrane suffices to induce clustering of proteins. Even when the TMDs differ in length by only a single residue, hydrophobic mismatch can segregate structurally closely homologous membrane proteins in distinct membrane domains. Domain formation is further fine-tuned by interactions with polyanionic phosphoinositides and homo and heterotypic protein interactions. Our findings demonstrate that hydrophobic mismatch contributes to the structural organization of membranes.

  16. Heavy hitters via cluster-preserving clustering

    DEFF Research Database (Denmark)

    Larsen, Kasper Green; Nelson, Jelani; Nguyen, Huy L.

    2016-01-01

    , providing correctness whp. In fact, a simpler version of our algorithm for p = 1 in the strict turnstile model answers queries even faster than the "dyadic trick" by roughly a log n factor, dominating it in all regards. Our main innovation is an efficient reduction from the heavy hitters to a clustering...... problem in which each heavy hitter is encoded as some form of noisy spectral cluster in a much bigger graph, and the goal is to identify every cluster. Since every heavy hitter must be found, correctness requires that every cluster be found. We thus need a "cluster-preserving clustering" algorithm......, that partitions the graph into clusters with the promise of not destroying any original cluster. To do this we first apply standard spectral graph partitioning, and then we use some novel combinatorial techniques to modify the cuts obtained so as to make sure that the original clusters are sufficiently preserved...

  17. The correlation between reading and mathematics ability at age twelve has a substantial genetic component.

    Science.gov (United States)

    Davis, Oliver S P; Band, Gavin; Pirinen, Matti; Haworth, Claire M A; Meaburn, Emma L; Kovas, Yulia; Harlaar, Nicole; Docherty, Sophia J; Hanscombe, Ken B; Trzaskowski, Maciej; Curtis, Charles J C; Strange, Amy; Freeman, Colin; Bellenguez, Céline; Su, Zhan; Pearson, Richard; Vukcevic, Damjan; Langford, Cordelia; Deloukas, Panos; Hunt, Sarah; Gray, Emma; Dronov, Serge; Potter, Simon C; Tashakkori-Ghanbaria, Avazeh; Edkins, Sarah; Bumpstead, Suzannah J; Blackwell, Jenefer M; Bramon, Elvira; Brown, Matthew A; Casas, Juan P; Corvin, Aiden; Duncanson, Audrey; Jankowski, Janusz A Z; Markus, Hugh S; Mathew, Christopher G; Palmer, Colin N A; Rautanen, Anna; Sawcer, Stephen J; Trembath, Richard C; Viswanathan, Ananth C; Wood, Nicholas W; Barroso, Ines; Peltonen, Leena; Dale, Philip S; Petrill, Stephen A; Schalkwyk, Leonard S; Craig, Ian W; Lewis, Cathryn M; Price, Thomas S; Donnelly, Peter; Plomin, Robert; Spencer, Chris C A

    2014-07-08

    Dissecting how genetic and environmental influences impact on learning is helpful for maximizing numeracy and literacy. Here we show, using twin and genome-wide analysis, that there is a substantial genetic component to children's ability in reading and mathematics, and estimate that around one half of the observed correlation in these traits is due to shared genetic effects (so-called Generalist Genes). Thus, our results highlight the potential role of the learning environment in contributing to differences in a child's cognitive abilities at age twelve.

  18. New Eyes on the Universe Twelve Cosmic Mysteries and the Tools We Need to Solve Them

    CERN Document Server

    Webb, Stephen

    2012-01-01

    "New Eyes on the Universe -- Twelve Cosmic Mysteries and the Tools We Need to Solve Them" gives an up-to-date broad overview of some of the key issues in modern astronomy and cosmology. It describes the vast amount of observational data that the new generation of observatories and telescopes are currently producing, and how that data might solve some of the outstanding puzzles inherent in our emerging world view. Included are questions such as: What is causing the Universe to blow itself apart? What could be powering the luminous gamma-ray bursters? Where is all the matter in the Uni

  19. DETECTION OF CHROMOSOME ABERRATIONS IN TWELVE PRIMARY GASTRIC CANCERS BY DIRECT CHROMOSOME ANALYSIS AND FISH

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Direct chromosome analysis and FISH were performed on twelve primary gastric carcinomas. Two of them had simple chromosome changes: 48,XX, +8, +20, and 49, XY, +2, +8, +9, and the others had complicated chromosome changes, which includes much more numerical and structural chromosome aberrations. Frequent structural changes in the complicated types involved chromosome 7, 3, 1, 5 and 12 etc. The del 7q was noted in eight cases. The del (3p) and del (1p) were noted in six and five cases, respectively. The results provide some important clues for isolation of the genes related to gastric cancer.

  20. Developing a learning culture: twelve tips for individuals, teams and organizations.

    Science.gov (United States)

    Stinson, Lynn; Pearson, David; Lucas, Beverley

    2006-06-01

    A culture of learning in providing health services and education for health professionals is a constant challenge for individuals, team and organizations. The importance of such a culture was highlighted by the findings of the Bristol Royal Infirmary Inquiry (2001). This was discussed in the context of the literature on the Learning Organization (Senge, 1990) at the 2004 Association of Medical Education in Europe (AMEE) conference, and reviewed a year later at the 2005 AMEE conference. This paper outlines twelve tips for educational and health service organizations in facilitating a culture of learning for their members and also offers specific advice to individual students and professionals.

  1. Mitochondria Maintain Distinct Ca(2+) Pools in Cone Photoreceptors.

    Science.gov (United States)

    Giarmarco, Michelle M; Cleghorn, Whitney M; Sloat, Stephanie R; Hurley, James B; Brockerhoff, Susan E

    2017-02-22

    Ca(2+) ions have distinct roles in the outer segment, cell body, and synaptic terminal of photoreceptors. We tested the hypothesis that distinct Ca(2+) domains are maintained by Ca(2+) uptake into mitochondria. Serial block face scanning electron microscopy of zebrafish cones revealed that nearly 100 mitochondria cluster at the apical side of the inner segment, directly below the outer segment. The endoplasmic reticulum surrounds the basal and lateral surfaces of this cluster, but does not reach the apical surface or penetrate into the cluster. Using genetically encoded Ca(2+) sensors, we found that mitochondria take up Ca(2+) when it accumulates either in the cone cell body or outer segment. Blocking mitochondrial Ca(2+) uniporter activity compromises the ability of mitochondria to maintain distinct Ca(2+) domains. Together, our findings indicate that mitochondria can modulate subcellular functional specialization in photoreceptors.SIGNIFICANCE STATEMENT Ca(2+) homeostasis is essential for the survival and function of retinal photoreceptors. Separate pools of Ca(2+) regulate phototransduction in the outer segment, metabolism in the cell body, and neurotransmitter release at the synaptic terminal. We investigated the role of mitochondria in compartmentalization of Ca(2+) We found that mitochondria form a dense cluster that acts as a diffusion barrier between the outer segment and cell body. The cluster is surprisingly only partially surrounded by the endoplasmic reticulum, a key mediator of mitochondrial Ca(2+) uptake. Blocking the uptake of Ca(2+) by mitochondria causes redistribution of Ca(2+) throughout the cell. Our results show that mitochondrial Ca(2+) uptake in photoreceptors is complex and plays an essential role in normal function. Copyright © 2017 the authors 0270-6474/17/372061-12$15.00/0.

  2. Cluster headache

    Directory of Open Access Journals (Sweden)

    Ducros Anne

    2008-07-01

    Full Text Available Abstract Cluster headache (CH is a primary headache disease characterized by recurrent short-lasting attacks (15 to 180 minutes of excruciating unilateral periorbital pain accompanied by ipsilateral autonomic signs (lacrimation, nasal congestion, ptosis, miosis, lid edema, redness of the eye. It affects young adults, predominantly males. Prevalence is estimated at 0.5–1.0/1,000. CH has a circannual and circadian periodicity, attacks being clustered (hence the name in bouts that can occur during specific months of the year. Alcohol is the only dietary trigger of CH, strong odors (mainly solvents and cigarette smoke and napping may also trigger CH attacks. During bouts, attacks may happen at precise hours, especially during the night. During the attacks, patients tend to be restless. CH may be episodic or chronic, depending on the presence of remission periods. CH is associated with trigeminovascular activation and neuroendocrine and vegetative disturbances, however, the precise cautive mechanisms remain unknown. Involvement of the hypothalamus (a structure regulating endocrine function and sleep-wake rhythms has been confirmed, explaining, at least in part, the cyclic aspects of CH. The disease is familial in about 10% of cases. Genetic factors play a role in CH susceptibility, and a causative role has been suggested for the hypocretin receptor gene. Diagnosis is clinical. Differential diagnoses include other primary headache diseases such as migraine, paroxysmal hemicrania and SUNCT syndrome. At present, there is no curative treatment. There are efficient treatments to shorten the painful attacks (acute treatments and to reduce the number of daily attacks (prophylactic treatments. Acute treatment is based on subcutaneous administration of sumatriptan and high-flow oxygen. Verapamil, lithium, methysergide, prednisone, greater occipital nerve blocks and topiramate may be used for prophylaxis. In refractory cases, deep-brain stimulation of the

  3. NEO-FFI personality clusters in trichotillomania.

    Science.gov (United States)

    Keuthen, Nancy J; Tung, Esther S; Tung, Matthew G; Curley, Erin E; Flessner, Christopher A

    2016-05-30

    The purpose of this study was to determine whether personality prototypes exist among hair pullers and if these groups differ in hair pulling (HP) characteristics, clinical correlates, and quality of life. 164 adult hair pullers completed the NEO-Five Factor Inventory (NEO-FFI; Costa and McCrae, 1992) and self-report measures of HP severity, HP style, affective state, and quality of life. A latent class cluster analysis using NEO-FFI scores was performed to separate participants into clusters. Bonferroni-corrected t-tests were used to compare clusters on HP, affective, and quality of life variables. Multiple regression was used to determine which variables significantly predicted quality of life. Two distinct personality prototypes were identified. Cluster 1 (n=96) had higher neuroticism and lower extraversion, agreeableness, and conscientiousness when compared to cluster 2 (n=68). No significant differences in demographics were reported for the two personality clusters. The clusters differed on extent of focused HP, severity of depression, anxiety, and stress, as well as quality of life. Those in cluster 1 endorsed greater depression, anxiety, and stress, and worse quality of life. Additionally, only depression and cluster membership (based on NEO scores) significantly predicted quality of life. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. DNA-Protected Silver Clusters for Nanophotonics

    Directory of Open Access Journals (Sweden)

    Elisabeth Gwinn

    2015-02-01

    Full Text Available DNA-protected silver clusters (AgN-DNA possess unique fluorescence properties that depend on the specific DNA template that stabilizes the cluster. They exhibit peak emission wavelengths that range across the visible and near-IR spectrum. This wide color palette, combined with low toxicity, high fluorescence quantum yields of some clusters, low synthesis costs, small cluster sizes and compatibility with DNA are enabling many applications that employ AgN-DNA. Here we review what is known about the underlying composition and structure of AgN-DNA, and how these relate to the optical properties of these fascinating, hybrid biomolecule-metal cluster nanomaterials. We place AgN-DNA in the general context of ligand-stabilized metal clusters and compare their properties to those of other noble metal clusters stabilized by small molecule ligands. The methods used to isolate pure AgN-DNA for analysis of composition and for studies of solution and single-emitter optical properties are discussed. We give a brief overview of structurally sensitive chiroptical studies, both theoretical and experimental, and review experiments on bringing silver clusters of distinct size and color into nanoscale DNA assemblies. Progress towards using DNA scaffolds to assemble multi-cluster arrays is also reviewed.

  5. Work environment perceptions following relocation to open-plan offices: A twelve-month longitudinal study.

    Science.gov (United States)

    Bergström, Jessica; Miller, Michael; Horneij, Eva

    2015-01-01

    A workplace's design can have various positive or negative effects on the employees and since the 1970s the advantages and disadvantages of open-plan offices have been discussed. The aim of this study was to investigate perceived health, work environment and self-estimated productivity one month before and at three, six and twelve months after relocation from individual offices to an open-plan office environment. Employees from three departments within the same company group and who worked with relatively similar tasks and who were planned to be relocated from private offices to open-plan offices were invited to participate. Questionnaires comprising items from The Salutogenic Health Indicator Scale, The Work Experience Measurement Scale, the questionnaire by Brennan et al. about perceived performance and one question from the Work Ability Index were sent to participants one month before relocation (baseline) to open-plan offices and then at three, six and twelve months after relocation. At baseline, 82 questionnaires were sent out. The response rate was 85%. At the follow-ups 77-79 questionnaires were sent out and the response-rate was 70%-81%. At follow-ups, perceived health, job satisfaction and performance had generally deteriorated. The results of the study indicate that employees' perception of health, work environment and performance decreased during a 12 month period following relocation from individual offices to open-plan offices.

  6. Approximate analytic method for high-apogee twelve-hour orbits of artificial Earth's satellites

    Science.gov (United States)

    Vashkovyaka, M. A.; Zaslavskii, G. S.

    2016-09-01

    We propose an approach to the study of the evolution of high-apogee twelve-hour orbits of artificial Earth's satellites. We describe parameters of the motion model used for the artificial Earth's satellite such that the principal gravitational perturbations of the Moon and Sun, nonsphericity of the Earth, and perturbations from the light pressure force are approximately taken into account. To solve the system of averaged equations describing the evolution of the orbit parameters of an artificial satellite, we use both numeric and analytic methods. To select initial parameters of the twelve-hour orbit, we assume that the path of the satellite along the surface of the Earth is stable. Results obtained by the analytic method and by the numerical integration of the evolving system are compared. For intervals of several years, we obtain estimates of oscillation periods and amplitudes for orbital elements. To verify the results and estimate the precision of the method, we use the numerical integration of rigorous (not averaged) equations of motion of the artificial satellite: they take into account forces acting on the satellite substantially more completely and precisely. The described method can be applied not only to the investigation of orbit evolutions of artificial satellites of the Earth; it can be applied to the investigation of the orbit evolution for other planets of the Solar system provided that the corresponding research problem will arise in the future and the considered special class of resonance orbits of satellites will be used for that purpose.

  7. Global surface temperature change analysis based on MODIS data in recent twelve years

    Science.gov (United States)

    Mao, K. B.; Ma, Y.; Tan, X. L.; Shen, X. Y.; Liu, G.; Li, Z. L.; Chen, J. M.; Xia, L.

    2017-01-01

    Global surface temperature change is one of the most important aspects in global climate change research. In this study, in order to overcome shortcomings of traditional observation methods in meteorology, a new method is proposed to calculate global mean surface temperature based on remote sensing data. We found that (1) the global mean surface temperature was close to 14.35 °C from 2001 to 2012, and the warmest and coldest surface temperatures of the global in the recent twelve years occurred in 2005 and 2008, respectively; (2) the warmest and coldest surface temperatures on the global land surface occurred in 2005 and 2001, respectively, and on the global ocean surface in 2010 and 2008, respectively; and (3) in recent twelve years, although most regions (especially the Southern Hemisphere) are warming, global warming is yet controversial because it is cooling in the central and eastern regions of Pacific Ocean, northern regions of the Atlantic Ocean, northern regions of China, Mongolia, southern regions of Russia, western regions of Canada and America, the eastern and northern regions of Australia, and the southern tip of Africa. The analysis of daily and seasonal temperature change indicates that the temperature change is mainly caused by the variation of orbit of celestial body. A big data model based on orbit position and gravitational-magmatic change of celestial body with the solar or the galactic system should be built and taken into account for climate and ecosystems change at a large spatial-temporal scale.

  8. Distinctive personality profiles of fibromyalgia and chronic fatigue syndrome patients

    Science.gov (United States)

    Zohar, Ada H.; Zaraya-Blum, Reut; Buskila, Dan

    2016-01-01

    Objective The current study is an innovative exploratory investigation, aiming at identifying differences in personality profiles within Fibromyalgia Syndrome (FMS) and Chronic Fatigue Syndrome (CFS) patients. Method In total, 344 participants (309 female, 35 male) reported suffering from FMS and/or CFS and consented to participate in the study. Participants were recruited at an Israeli FM/CFS patient meeting held in May 2013, and through an announcement posted on several social networks. Participants were asked to complete a research questionnaire, which included FMS criteria and severity scales, and measures of personality, emotional functioning, positivity, social support and subjective assessment of general health. In total, 204 participants completed the research questionnaire (40.7% attrition rate). Results A cluster analysis produced two distinct clusters, which differed significantly on psychological variables, but did not differ on demographic variables or illness severity. As compared to cluster number 2 (N = 107), participants classified into cluster number 1 (N = 97) showed a less adaptive pattern, with higher levels of Harm Avoidance and Alexithymia; higher prevalence of Type D personality; and lower levels of Persistence (PS), Reward dependence (RD), Cooperation, Self-directedness (SD), social support and positivity. Conclusion The significant pattern of results indicates at least two distinct personality profiles of FM and CFS patients. Findings from this research may help improve the evaluation and treatment of FM and CFS patients, based on each patient’s unique needs, psychological resources and weaknesses, as proposed by the current trend of personalized medicine. PMID:27672497

  9. Distinctive personality profiles of fibromyalgia and chronic fatigue syndrome patients

    Directory of Open Access Journals (Sweden)

    Jacob N. Ablin

    2016-09-01

    Full Text Available Objective The current study is an innovative exploratory investigation, aiming at identifying differences in personality profiles within Fibromyalgia Syndrome (FMS and Chronic Fatigue Syndrome (CFS patients. Method In total, 344 participants (309 female, 35 male reported suffering from FMS and/or CFS and consented to participate in the study. Participants were recruited at an Israeli FM/CFS patient meeting held in May 2013, and through an announcement posted on several social networks. Participants were asked to complete a research questionnaire, which included FMS criteria and severity scales, and measures of personality, emotional functioning, positivity, social support and subjective assessment of general health. In total, 204 participants completed the research questionnaire (40.7% attrition rate. Results A cluster analysis produced two distinct clusters, which differed significantly on psychological variables, but did not differ on demographic variables or illness severity. As compared to cluster number 2 (N = 107, participants classified into cluster number 1 (N = 97 showed a less adaptive pattern, with higher levels of Harm Avoidance and Alexithymia; higher prevalence of Type D personality; and lower levels of Persistence (PS, Reward dependence (RD, Cooperation, Self-directedness (SD, social support and positivity. Conclusion The significant pattern of results indicates at least two distinct personality profiles of FM and CFS patients. Findings from this research may help improve the evaluation and treatment of FM and CFS patients, based on each patient’s unique needs, psychological resources and weaknesses, as proposed by the current trend of personalized medicine.

  10. Comparative assay of fluorescent antibody test results among twelve European National Reference Laboratories using various anti-rabies conjugates

    DEFF Research Database (Denmark)

    Robardet, E.; Andrieu, S.; Rasmussen, Thomas Bruun

    2013-01-01

    Twelve National Reference Laboratories (NRLs) for rabies have undertaken a comparative assay to assess the comparison of fluorescent antibody test (FAT) results using five coded commercial anti-rabies conjugates (Biorad, Bioveta, Fujirebio, Millipore, and SIFIN conjugates). Homogenized positive...

  11. Partitional clustering algorithms

    CERN Document Server

    2015-01-01

    This book summarizes the state-of-the-art in partitional clustering. Clustering, the unsupervised classification of patterns into groups, is one of the most important tasks in exploratory data analysis. Primary goals of clustering include gaining insight into, classifying, and compressing data. Clustering has a long and rich history that spans a variety of scientific disciplines including anthropology, biology, medicine, psychology, statistics, mathematics, engineering, and computer science. As a result, numerous clustering algorithms have been proposed since the early 1950s. Among these algorithms, partitional (nonhierarchical) ones have found many applications, especially in engineering and computer science. This book provides coverage of consensus clustering, constrained clustering, large scale and/or high dimensional clustering, cluster validity, cluster visualization, and applications of clustering. Examines clustering as it applies to large and/or high-dimensional data sets commonly encountered in reali...

  12. Clustering and Community Detection with Imbalanced Clusters

    OpenAIRE

    Aksoylar, Cem; Qian, Jing; Saligrama, Venkatesh

    2016-01-01

    Spectral clustering methods which are frequently used in clustering and community detection applications are sensitive to the specific graph constructions particularly when imbalanced clusters are present. We show that ratio cut (RCut) or normalized cut (NCut) objectives are not tailored to imbalanced cluster sizes since they tend to emphasize cut sizes over cut values. We propose a graph partitioning problem that seeks minimum cut partitions under minimum size constraints on partitions to de...

  13. Defining poverty as distinctively human

    Directory of Open Access Journals (Sweden)

    H.P.P. Lötter

    2007-05-01

    Full Text Available While it is relatively easy for most people to identify human beings suffering from poverty, it is rather more difficult to come to a proper understanding of poverty. In this article the author wants to deepen our understanding of poverty by interpreting the conventional definitions of poverty in a new light. The article starts with a defence of a claim that poverty is a concept uniquely applicable to humans. It then present a critical discussion of the distinction between absolute and relative poverty and it is then argued that a revision of this distinction can provide general standards applicable to humans everywhere.

  14. Cluster headaches.

    Science.gov (United States)

    Ryan, R E; Ryan, R E

    1989-12-01

    The patient with cluster headaches will be afflicted with the most severe type of pain that one will encounter. If the physician can do something to help this patient either by symptomatic or, more importantly, prophylactic treatment, he or she will have a most thankful patient. This type of headache is seen most frequently in men, and occurs in a cyclic manner. During an acute cycle, the patient will experience a daily type of pain that may occur many times per day. The pain is usually unilateral and may be accompanied by unilateral lacrimation, conjunctivitis, and clear rhinorrhea. Prednisone is the first treatment we employ. Patients are seen for follow-up approximately twice a week, and their medication is lowered in an appropriate manner, depending on their response to the treatment. Regulation of dosage has to be individualized, and when one reaches the lower dose such as 5 to 10 mg per day, the drug may have to be tapered more slowly, or even maintained at that level for a period of time to prevent further recurrence of symptoms. We frequently will use an intravenous histamine desensitization technique to prevent further attacks. We will give the patient an ergotamine preparation to use for symptomatic relief. As these patients often have headaches during the middle of the night, we will place the patient on a 2-mg ergotamine preparation to take prior to going to bed in the evening. This often works in a prophylactic nature, and prevents the nighttime occurrence of a headache. We believe that following these principles to make the accurate diagnosis and institute the proper therapy will help the practicing otolaryngologist recognize and treat patients suffering from this severe pain.

  15. Clustering Teachers' Motivations for Teaching

    Science.gov (United States)

    Visser-Wijnveen, Gerda J.; Stes, Ann; Van Petegem, Peter

    2014-01-01

    The motivation to teach is a powerful, yet neglected, force in teaching at institutes of higher education. A better understanding of academics' motivations for teaching is necessary. The aim of this mixed-method study was to identify groups with distinctively different motivations for teaching. Six clusters were identified: expertise, duty,…

  16. Module Cluster: UG - 001.00 (GSC) Urban Geography.

    Science.gov (United States)

    Currier, Wade R.

    This is one of several module clusters developed for the Camden Teacher Corps project. This module cluster is designed to introduce students to urban studies through the application of a geographic approach. Although geography shares with other social sciences many concepts and methods, it has contributed a distinctive set of viewpoints and a…

  17. Educational Psychology: The Distinctive Contribution

    Science.gov (United States)

    Cameron, R. J.

    2006-01-01

    This paper, written in the twenty-first anniversary year of the journal "Educational Psychology in Practice", attempts to uncover those distinctive aspects of the discipline and the practice of applied psychology in general and educational psychology in particular. After considering some of the reasons for attempting this task at this point in…

  18. Educational Psychology: The Distinctive Contribution

    Science.gov (United States)

    Cameron, R. J.

    2006-01-01

    This paper, written in the twenty-first anniversary year of the journal "Educational Psychology in Practice", attempts to uncover those distinctive aspects of the discipline and the practice of applied psychology in general and educational psychology in particular. After considering some of the reasons for attempting this task at this point in…

  19. Factorial PD-Clustering

    CERN Document Server

    Tortora, Cristina; Summa, Mireille Gettler

    2011-01-01

    Factorial clustering methods have been developed in recent years thanks to the improving of computational power. These methods perform a linear transformation of data and a clustering on transformed data optimizing a common criterion. Factorial PD-clustering is based on Probabilistic Distance clustering (PD-clustering). PD-clustering is an iterative, distribution free, probabilistic, clustering method. Factorial PD-clustering make a linear transformation of original variables into a reduced number of orthogonal ones using a common criterion with PD-Clustering. It is demonstrated that Tucker 3 decomposition allows to obtain this transformation. Factorial PD-clustering makes alternatively a Tucker 3 decomposition and a PD-clustering on transformed data until convergence. This method could significantly improve the algorithm performance and allows to work with large dataset, to improve the stability and the robustness of the method.

  20. Possibilistic Exponential Fuzzy Clustering

    Institute of Scientific and Technical Information of China (English)

    Kiatichai Treerattanapitak; Chuleerat Jaruskulchai

    2013-01-01

    Generally,abnormal points (noise and outliers) cause cluster analysis to produce low accuracy especially in fuzzy clustering.These data not only stay in clusters but also deviate the centroids from their true positions.Traditional fuzzy clustering like Fuzzy C-Means (FCM) always assigns data to all clusters which is not reasonable in some circumstances.By reformulating objective function in exponential equation,the algorithm aggressively selects data into the clusters.However noisy data and outliers cannot be properly handled by clustering process therefore they are forced to be included in a cluster because of a general probabilistic constraint that the sum of the membership degrees across all clusters is one.In order to improve this weakness,possibilistic approach relaxes this condition to improve membership assignment.Nevertheless,possibilistic clustering algorithms generally suffer from coincident clusters because their membership equations ignore the distance to other clusters.Although there are some possibilistic clustering approaches that do not generate coincident clusters,most of them require the right combination of multiple parameters for the algorithms to work.In this paper,we theoretically study Possibilistic Exponential Fuzzy Clustering (PXFCM) that integrates possibilistic approach with exponential fuzzy clustering.PXFCM has only one parameter and not only partitions the data but also filters noisy data or detects them as outliers.The comprehensive experiments show that PXFCM produces high accuracy in both clustering results and outlier detection without generating coincident problems.

  1. Exploring Content Schemata Influence on L2 Reading: The Hunted Fox and Twelve and Not Stupid

    Directory of Open Access Journals (Sweden)

    Amizura Hanadi Mohd Radzi

    2014-10-01

    Full Text Available This paper will discuss the aspects of content schemata in second language reading among diploma level students who were taking a reading course in Universiti Teknologi MARA Perlis. In this qualitative case study, the researcher had selected two short stories that are categorized as content-familiar texts, i.e. The Hunted Fox and Twelve and Not Stupid. Six participants were asked to write a 150-word entry response on the short story and a grading criteria was used to assess the participants’ level of comprehension. An in-depth interview was also conducted on each participant. The entry responses and the interview patterns were analyzed to determine whether content schemata had contributed to the learners’ understanding of the text. This study discovered that content schemata had contributed to the learners’ understanding of the text because the learners’ comprehension was facilitated by their background knowledge on the content-familiar texts.

  2. Development and characterization of twelve microsatellite markers for Porphyra linearis Greville.

    Science.gov (United States)

    Varela-Álvarez, Elena; Paulino, Cristina; Serrão, Ester A

    2017-02-01

    The genus Porphyra (and its sister genus Pyropia) contains important red algal species that are cultivated and/or harvested for human consumption, sustaining a billion-dollar aquaculture industry. A vast amount of research has been focused on species of this genus, including studies on genetics and genomics among other areas. Twelve novel microsatellite markers were developed here for Porphyra linearis. Markers were characterized using 32 individuals collected from four natural populations of P. linearis with total heterozygosity varying from 0.098 to 0.916. The number of alleles per locus ranged from 2 to 18. All markers showed cross amplification with Porphyra umbilicalis and/or Porphyra dioica. These polymorphic microsatellite markers are useful for investigating population genetic diversity and differentiation in P. linearis and may become useful for other genetic research on the reproductive biology of this important species.

  3. Proteomic characterization of human milk whey proteins during a twelve-month lactation period.

    Science.gov (United States)

    Liao, Yalin; Alvarado, Rudy; Phinney, Brett; Lönnerdal, Bo

    2011-04-01

    Human milk is a rich source of bioactive proteins that support the early growth and development of the newborn. Although the major components of the protein fraction in human milk have been studied, the expression and relative abundance of minor components have received limited attention. We examined the expression of low-abundance proteins in the whey fraction of human milk and their dynamic changes over a twelve-month lactation period. The low-abundance proteins were enriched by ProteoMiner beads, and protein identification was performed by liquid chromatography tandem mass spectrometry. One hundred and fifteen proteins were identified, thirty-eight of which have not been previously reported in human colostrum or milk. We also for the first time described differences in protein patterns among the low-abundance proteins during lactation. These results enhance our knowledge about the complexity of the human milk proteome, which constitutes part of the advantages to the breast-fed infant.

  4. Fate of the conformal fixed point with twelve massless fermions and SU(3) gauge group

    CERN Document Server

    Fodor, Zoltan; Kuti, Julius; Mondal, Santanu; Nogradi, Daniel; Wong, Chik Him

    2016-01-01

    We report new results on the conformal properties of an important strongly coupled gauge theory, a building block of composite Higgs models beyond the Standard Model. With twelve massless fermions in the fundamental representation of the SU(3) color gauge group, an infrared fixed point of the $\\beta$-function was recently reported in the theory (Cheng:2014jba) with uncertainty in the location of the critical gauge coupling inside the narrow $[ 6.0

  5. Twelve Years of Education and Public Outreach with the Fermi Gamma-ray Space Telescope

    CERN Document Server

    Cominsky, Lynn; Simonnet, Aurore; Education, the Fermi

    2013-01-01

    During the past twelve years, NASA's Fermi Gamma-ray Space Telescope has supported a wide range of Education and Public Outreach (E/PO) activities, targeting K-14 students and the general public. The purpose of the Fermi E/PO program is to increase student and public understanding of the science of the high-energy Universe, through inspiring, engaging and educational activities linked to the mission's science objectives. The E/PO program has additional more general goals, including increasing the diversity of students in the Science, Technology, Engineering and Mathematics (STEM) pipeline, and increasing public awareness and understanding of Fermi science and technology. Fermi's multi-faceted E/PO program includes elements in each major outcome category: Higher Education; Elementary and Secondary Education; Informal Education and Public Outreach.

  6. Hepatoprotective activity of twelve novel 7'-hydroxy lignan glucosides from Arctii Fructus.

    Science.gov (United States)

    Yang, Ya-Nan; Huang, Xiao-Ying; Feng, Zi-Ming; Jiang, Jian-Shuang; Zhang, Pei-Cheng

    2014-09-17

    Twelve novel 7'-hydroxy lignan glucosides (1-12), including two benzofuran-type neolignans, two 8-O-4' neolignans, two dibenzylbutyrolactone lignans, and six tetrahydrofuranoid lignans, together with six known lignan glucosides (13-18), were isolated from the fruit of Arctium lappa L. (Asteraceae), commonly known as Arctii Fructus. Their structures were elucidated using spectroscopy (1D and 2D NMR, MS, IR, ORD, and UV) and on the basis of chemical evidence. The absolute configurations of compounds 1-12 were confirmed using rotating frame nuclear overhauser effect spectroscopy (ROESY), the circular dichroic (CD) exciton chirality method, and Rh2(OCOCF3)4-induced CD spectrum analysis. All of the isolated compounds were tested for hepatoprotective effects against D-galactosamine-induced cytotoxicity in HL-7702 hepatic cells. Compounds 1, 2, 7-12, and 17 showed significantly stronger hepatoprotective activity than the positive control bicyclol at a concentration of 1 × 10(-5) M.

  7. Parallel algorithms and cluster computing

    CERN Document Server

    Hoffmann, Karl Heinz

    2007-01-01

    This book presents major advances in high performance computing as well as major advances due to high performance computing. It contains a collection of papers in which results achieved in the collaboration of scientists from computer science, mathematics, physics, and mechanical engineering are presented. From the science problems to the mathematical algorithms and on to the effective implementation of these algorithms on massively parallel and cluster computers we present state-of-the-art methods and technology as well as exemplary results in these fields. This book shows that problems which seem superficially distinct become intimately connected on a computational level.

  8. Structures of Mn clusters

    Indian Academy of Sciences (India)

    Tina M Briere; Marcel H F Sluiter; Vijay Kumar; Yoshiyuki Kawazoe

    2003-01-01

    The geometries of several Mn clusters in the size range Mn13–Mn23 are studied via the generalized gradient approximation to density functional theory. For the 13- and 19-atom clusters, the icosahedral structures are found to be most stable, while for the 15-atom cluster, the bcc structure is more favoured. The clusters show ferrimagnetic spin configurations.

  9. Dissolution of Globular Clusters

    OpenAIRE

    Baumgardt, Holger

    2006-01-01

    Globular clusters are among the oldest objects in galaxies, and understanding the details of their formation and evolution can bring valuable insight into the early history of galaxies. This review summarises the current knowledge about the dissolution of star clusters and discusses the implications of star cluster dissolution for the evolution of the mass function of star cluster systems in galaxies.

  10. Clustering of correlated networks

    OpenAIRE

    Dorogovtsev, S. N.

    2003-01-01

    We obtain the clustering coefficient, the degree-dependent local clustering, and the mean clustering of networks with arbitrary correlations between the degrees of the nearest-neighbor vertices. The resulting formulas allow one to determine the nature of the clustering of a network.

  11. Simple versus complex PTSD: a cluster analytic investigation.

    Science.gov (United States)

    Taylor, Steven; Asmundson, Gordon J G; Carleton, R Nicholas

    2006-01-01

    A cluster analytic investigation was conducted on measures of PTSD associated features (e.g., personality pathology, dissociative tendencies) to investigate whether empirically-defined clusters correspond to Herman's [1992, Complex PTSD: a syndrome in survivors of prolonged and repeated trauma. Journal of Traumatic Stress, 5, 377-391; 1997, Trauma and recovery (Rev. ed.). New York: Basic Books] distinction between simple and complex PTSD. Results from a sample of 60 PTSD patients were broadly consistent with this distinction, although some inconsistencies were observed. Treatment outcome generally did not differ between the two clusters. Implications for classifying and treating PTSD are discussed.

  12. Contextualizing the Cluster

    DEFF Research Database (Denmark)

    Giacomin, Valeria

    This dissertation examines the case of the palm oil cluster in Malaysia and Indonesia, today one of the largest agricultural clusters in the world. My analysis focuses on the evolution of the cluster from the 1880s to the 1970s in order to understand how it helped these two countries to integrate......-researched topic in the cluster literature – the emergence of clusters, their governance and institutional change, and competition between rival cluster locations – through the case of the Southeast Asian palm oil cluster....

  13. Contextualizing the Cluster

    DEFF Research Database (Denmark)

    Giacomin, Valeria

    This dissertation examines the case of the palm oil cluster in Malaysia and Indonesia, today one of the largest agricultural clusters in the world. My analysis focuses on the evolution of the cluster from the 1880s to the 1970s in order to understand how it helped these two countries to integrate......-researched topic in the cluster literature – the emergence of clusters, their governance and institutional change, and competition between rival cluster locations – through the case of the Southeast Asian palm oil cluster....

  14. Grima: A Distinct Emotion Concept?

    Science.gov (United States)

    Schweiger Gallo, Inge; Fernández-Dols, José-Miguel; Gollwitzer, Peter M.; Keil, Andreas

    2017-01-01

    People experience an unpleasant sensation when hearing a scratch on a board or plate. The present research focuses on this aversive experience known in Spanish as ‘grima’ with no equivalent term in English and German. We hypothesized that this aversive experience constitutes a distinctive, separate emotional concept. In Study 1, we found that the affective meaning of ‘grima’ was closer to disgust than to other emotion concepts. Thus, in Study 2 we explored the features of grima and compared them with disgust. As grima was reported to be predominantly elicited by certain auditory stimuli and associated with a distinctive physiological pattern, Study 3 used direct measures of physiological arousal to test the assumption of a distinctive pattern of physiological responses elicited by auditory stimuli of grima and disgust, and found different effects on heart rate but not on skin conductance. In Study 4, we hypothesized that only participants with an implementation intention geared toward down-regulating grima would be able to successfully weaken the grima- but not disgust- experience. Importantly, this effect was specific as it held true for the grima-eliciting sounds only, but did not affect disgust-related sounds. Finally, Study 5 found that English and German speakers lack a single accessible linguistic label for the pattern of aversive reactions termed by Spanish speaking individuals as ‘grima’, whereas the elicitors of other emotions were accessible and accurately identified by German, English, as well as Spanish speakers. PMID:28217102

  15. Unsupervised analysis of classical biomedical markers: robustness and medical relevance of patient clustering using bioinformatics tools.

    Directory of Open Access Journals (Sweden)

    Michal Markovich Gordon

    Full Text Available MOTIVATION: It has been proposed that clustering clinical markers, such as blood test results, can be used to stratify patients. However, the robustness of clusters formed with this approach to data pre-processing and clustering algorithm choices has not been evaluated, nor has clustering reproducibility. Here, we made use of the NHANES survey to compare clusters generated with various combinations of pre-processing and clustering algorithms, and tested their reproducibility in two separate samples. METHOD: Values of 44 biomarkers and 19 health/life style traits were extracted from the National Health and Nutrition Examination Survey (NHANES. The 1999-2002 survey was used for training, while data from the 2003-2006 survey was tested as a validation set. Twelve combinations of pre-processing and clustering algorithms were applied to the training set. The quality of the resulting clusters was evaluated both by considering their properties and by comparative enrichment analysis. Cluster assignments were projected to the validation set (using an artificial neural network and enrichment in health/life style traits in the resulting clusters was compared to the clusters generated from the original training set. RESULTS: The clusters obtained with different pre-processing and clustering combinations differed both in terms of cluster quality measures and in terms of reproducibility of enrichment with health/life style properties. Z-score normalization, for example, dramatically improved cluster quality and enrichments, as compared to unprocessed data, regardless of the clustering algorithm used. Clustering diabetes patients revealed a group of patients enriched with retinopathies. This could indicate that routine laboratory tests can be used to detect patients suffering from complications of diabetes, although other explanations for this observation should also be considered. CONCLUSIONS: Clustering according to classical clinical biomarkers is a robust

  16. Globular Cluster Systems in Brightest Cluster Galaxies. III: Beyond Bimodality

    Science.gov (United States)

    Harris, William E.; Ciccone, Stephanie M.; Eadie, Gwendolyn M.; Gnedin, Oleg Y.; Geisler, Douglas; Rothberg, Barry; Bailin, Jeremy

    2017-01-01

    We present new deep photometry of the rich globular cluster (GC) systems around the Brightest Cluster Galaxies UGC 9799 (Abell 2052) and UGC 10143 (Abell 2147), obtained with the Hubble Space Telescope (HST) ACS and WFC3 cameras. For comparison, we also present new reductions of similar HST/ACS data for the Coma supergiants NGC 4874 and 4889. All four of these galaxies have huge cluster populations (to the radial limits of our data, comprising from 12,000 to 23,000 clusters per galaxy). The metallicity distribution functions (MDFs) of the GCs can still be matched by a bimodal-Gaussian form where the metal-rich and metal-poor modes are separated by ≃ 0.8 dex, but the internal dispersions of each mode are so large that the total MDF becomes very broad and nearly continuous from [Fe/H] ≃ ‑2.4 to solar. There are, however, significant differences between galaxies in the relative numbers of metal-rich clusters, suggesting that they underwent significantly different histories of mergers with massive gas-rich halos. Last, the proportion of metal-poor GCs rises especially rapidly outside projected radii R≳ 4 {R}{eff}, suggesting the importance of accreted dwarf satellites in the outer halo. Comprehensive models for the formation of GCs as part of the hierarchical formation of their parent galaxies will be needed to trace the systematic change in structure of the MDF with galaxy mass, from the distinctly bimodal form in smaller galaxies up to the broad continuum that we see in the very largest systems.

  17. Clustering in analytical chemistry.

    Science.gov (United States)

    Drab, Klaudia; Daszykowski, Michal

    2014-01-01

    Data clustering plays an important role in the exploratory analysis of analytical data, and the use of clustering methods has been acknowledged in different fields of science. In this paper, principles of data clustering are presented with a direct focus on clustering of analytical data. The role of the clustering process in the analytical workflow is underlined, and its potential impact on the analytical workflow is emphasized.

  18. Bayesian Analysis of Two Stellar Populations in Galactic Globular Clusters III: Analysis of 30 Clusters

    CERN Document Server

    Wagner-Kaiser, R; Sarajedini, A; von Hippel, T; van Dyk, D A; Robinson, E; Stein, N; Jefferys, W H

    2016-01-01

    We use Cycle 21 Hubble Space Telescope (HST) observations and HST archival ACS Treasury observations of 30 Galactic Globular Clusters to characterize two distinct stellar populations. A sophisticated Bayesian technique is employed to simultaneously sample the joint posterior distribution of age, distance, and extinction for each cluster, as well as unique helium values for two populations within each cluster and the relative proportion of those populations. We find the helium differences among the two populations in the clusters fall in the range of ~0.04 to 0.11. Because adequate models varying in CNO are not presently available, we view these spreads as upper limits and present them with statistical rather than observational uncertainties. Evidence supports previous studies suggesting an increase in helium content concurrent with increasing mass of the cluster and also find that the proportion of the first population of stars increases with mass as well. Our results are examined in the context of proposed g...

  19. Globular cluster systems in low-luminosity early-type galaxies near the Fornax Cluster centre

    CERN Document Server

    Bassino, L P; Dirsch, B; Bassino, Lilia P.; Richtler, Tom; Dirsch, Boris

    2006-01-01

    We present a photometric study of the globular cluster systems of the Fornax cluster galaxies NGC 1374, NGC 1379, and NGC 1387. The data consists of images from the wide-field MOSAIC Imager of the CTIO 4-m telescope, obtained with Washington C and Kron-Cousins R filters. The images cover a field of 36 x 36 arcmin, corresponding to 200 x 200 kpc at the Fornax distance. Two of the galaxies, NGC 1374 and NGC 1379, are low-luminosity ellipticals while NGC 1387 is a low-luminosity lenticular. Their cluster systems are still embedded in the cluster system of NGC 1399. Therefore the use of a large field is crucial and some differences to previous work can be explained by this. The colour distributions of all globular cluster systems are bimodal. NGC 1387 presents a particularly distinct separation between red and blue clusters and an overproportionally large population of red clusters. The radial distribution is different for blue and red clusters, red clusters being more concentrated towards the respective galaxies...

  20. Galaxy Cluster Baryon Fractions Revisited

    CERN Document Server

    Gonzalez, Anthony H; Zabludoff, Ann I; Zaritsky, Dennis

    2013-01-01

    We measure the baryons contained in both the stellar and hot gas components for twelve galaxy clusters and groups at z~0.1 with M=1-5e14 Msun. This paper improves upon our previous work through the addition of XMM data, enabling measurements of the total mass and masses of each major baryonic component --- ICM, intracluster stars, and stars in galaxies --- for each system. We recover a relation for the stellar mass versus halo mass consistent with our previous result. We confirm that the partitioning of baryons between the stellar and hot gas components is a strong function of M500; the fractions of total mass in stars and X-ray gas within r500 scale as M500^-0.45 and M500^0.26, respectively. We also confirm that the combination of the BCG and intracluster stars is an increasingly important contributor to the stellar baryon budget in lower halo masses. We find a weak, but statistically significant, dependence of the total baryon fraction upon halo mass, scaling as M500^0.16. For M500>2e14, the total baryon fr...

  1. Cluster analysis of residential heat load profiles and the role of technical and household characteristics

    DEFF Research Database (Denmark)

    Carmo, Carolina; Christensen, Toke Haunstrup

    2016-01-01

    segments; a main cluster with a relatively constant load profile and a minor cluster with a more distinct variation during the day. The difference between the clusters is primarily correlated with building characteristics like floor area, building year and type of space heating distribution system, while...

  2. Twelve-year cyclic surging episode at Donjek Glacier in Yukon, Canada

    Science.gov (United States)

    Furuya, M.; Abe, T.; Sakakibara, D.

    2015-12-01

    Surge-type glaciers exhibit several-fold to orders-of-magnitude speed-up during the short active phase, resulting in km-scale terminus advance. Although there are many surge-type glaciers near the border of Alaska and the Yukon, the generation mechanisms remain uncertain because of limited and few continuous observations. To better understand the surge dynamics and predict the next event, it is essential to examine the entire surge cycles. Here we use Landsat optical imageries to reveal the long-term evolutions, and report three surging episodes at Donjek Glacier in Yukon, Canada. Using the Landsat images, we found three surging events in 1989, 2001, and 2013. In the 2001 event, the surface speed significantly increased by up to 4.5 m/d; during the quiescent phases it was ~0.5 m/d at the terminus. While the duration of active phase is about 4~5 and 2~3 year in the 2001 and 2013 events, the period in the 1989 event is unclear because of the lack of high temporal resolution data. Remarkably, the surging area is limited to the ~20-km section from the terminus instead of the entire glacier. Moreover, we examined the terminus area changes from 1975 to 2014. Although the area has been secularly decreasing probably due to the tread of global warming, it has also revealed four significant fluctuations during the nearly forty years. Comparing the speed and the area changes, the three speed-up events correspond to the terminus area fluctuations with a few time lags. It turns out that the surge event has been quite regularly repeating every twelve years. Although the behavior is rather similar to that in Svalbard glaciers in terms of maximum speed and unclear initiation season, the recurrence interval is much shorter than other nearby surges. Considering that the surge events seem to have initiated around significantly narrower area than upstream, the strong valley constriction may control the regularity as well as the twelve-year recurrence time.

  3. Analyzing Patients' Values by Applying Cluster Analysis and LRFM Model in a Pediatric Dental Clinic in Taiwan

    Science.gov (United States)

    Lin, Shih-Yen; Liu, Chih-Wei

    2014-01-01

    This study combines cluster analysis and LRFM (length, recency, frequency, and monetary) model in a pediatric dental clinic in Taiwan to analyze patients' values. A two-stage approach by self-organizing maps and K-means method is applied to segment 1,462 patients into twelve clusters. The average values of L, R, and F excluding monetary covered by national health insurance program are computed for each cluster. In addition, customer value matrix is used to analyze customer values of twelve clusters in terms of frequency and monetary. Customer relationship matrix considering length and recency is also applied to classify different types of customers from these twelve clusters. The results show that three clusters can be classified into loyal patients with L, R, and F values greater than the respective average L, R, and F values, while three clusters can be viewed as lost patients without any variable above the average values of L, R, and F. When different types of patients are identified, marketing strategies can be designed to meet different patients' needs. PMID:25045741

  4. Analyzing Patients’ Values by Applying Cluster Analysis and LRFM Model in a Pediatric Dental Clinic in Taiwan

    Directory of Open Access Journals (Sweden)

    Hsin-Hung Wu

    2014-01-01

    Full Text Available This study combines cluster analysis and LRFM (length, recency, frequency, and monetary model in a pediatric dental clinic in Taiwan to analyze patients’ values. A two-stage approach by self-organizing maps and K-means method is applied to segment 1,462 patients into twelve clusters. The average values of L, R, and F excluding monetary covered by national health insurance program are computed for each cluster. In addition, customer value matrix is used to analyze customer values of twelve clusters in terms of frequency and monetary. Customer relationship matrix considering length and recency is also applied to classify different types of customers from these twelve clusters. The results show that three clusters can be classified into loyal patients with L, R, and F values greater than the respective average L, R, and F values, while three clusters can be viewed as lost patients without any variable above the average values of L, R, and F. When different types of patients are identified, marketing strategies can be designed to meet different patients’ needs.

  5. The Distinction Between English Synonyms

    Institute of Scientific and Technical Information of China (English)

    段佳

    2012-01-01

      A large number of new words and terms flock in the English vocabulary and English has a variety of expressive methods making it possible to express the same meaning by different words. Therefore English synonyms are so abundant that it is possible to describe the colorful world and to express the complicated, delicate human thought and emotions. But they bring people many problems such as the correct choice of words from synonyms. The reason for this problem is the insufficient knowledge of the distinction of English synonyms, which have differences in many aspects. This paper offers three main aspects in distinguishing English synonyms that include words’ meaning, coloring and usage.

  6. Cluster Analysis and Clinical Asthma Phenotypes

    Science.gov (United States)

    Shaw, Dominic E.; Berry, Michael A.; Thomas, Michael; Brightling, Christopher E.; Wardlaw, Andrew J.

    2014-01-01

    Rationale Heterogeneity in asthma expression is multidimensional, including variability in clinical, physiologic, and pathologic parameters. Classification requires consideration of these disparate domains in a unified model. Objectives To explore the application of a multivariate mathematical technique, k-means cluster analysis, for identifying distinct phenotypic groups. Methods We performed k-means cluster analysis in three independent asthma populations. Clusters of a population managed in primary care (n = 184) with predominantly mild to moderate disease, were compared with a refractory asthma population managed in secondary care (n = 187). We then compared differences in asthma outcomes (exacerbation frequency and change in corticosteroid dose at 12 mo) between clusters in a third population of 68 subjects with predominantly refractory asthma, clustered at entry into a randomized trial comparing a strategy of minimizing eosinophilic inflammation (inflammation-guided strategy) with standard care. Measurements and Main Results Two clusters (early-onset atopic and obese, noneosinophilic) were common to both asthma populations. Two clusters characterized by marked discordance between symptom expression and eosinophilic airway inflammation (early-onset symptom predominant and late-onset inflammation predominant) were specific to refractory asthma. Inflammation-guided management was superior for both discordant subgroups leading to a reduction in exacerbation frequency in the inflammation-predominant cluster (3.53 [SD, 1.18] vs. 0.38 [SD, 0.13] exacerbation/patient/yr, P = 0.002) and a dose reduction of inhaled corticosteroid in the symptom-predominant cluster (mean difference, 1,829 μg beclomethasone equivalent/d [95% confidence interval, 307–3,349 μg]; P = 0.02). Conclusions Cluster analysis offers a novel multidimensional approach for identifying asthma phenotypes that exhibit differences in clinical response to treatment algorithms. PMID:18480428

  7. Soft Uncoupling of Markov Chains for Permeable Language Distinction: A New Algorithm

    OpenAIRE

    Nock, Richard; Vaillant, Pascal; Nielsen, Frank; Henry, Claudia

    2008-01-01

    Without prior knowledge, distinguishing different languages may be a hard task, especially when their borders are permeable. We develop an extension of spectral clustering -- a powerful unsupervised classification toolbox -- that is shown to resolve accurately the task of soft language distinction. At the heart of our approach, we replace the usual hard membership assignment of spectral clustering by a soft, probabilistic assignment, which also presents the advantage to bypass a well-known co...

  8. Margalef revisited: A new phytoplankton mandala incorporating twelve dimensions, including nutritional physiology.

    Science.gov (United States)

    Glibert, Patricia M

    2016-05-01

    Building on the classic depiction of the progression from a diatom to a dinoflagellate bloom as a function of nutrients and turbulence, known as the "Margalef mandala", a new conceptual model or mandala is presented here. The new mandala maps twelve response or effects traits, or environmental characteristics, related to different phytoplankton functional types: (1) relative preference for chemically reduced vs chemically oxidized forms of nitrogen; (2) relative availability of inorganic nitrogen and phosphorus; (3) adaptation to high vs low light and the tendency to be autotrophic vs mixotrophic; (4) cell motility; (5) environmental turbulence; (6) pigmentation quality; (7) temperature; (8) cell size; (9) relative growth rate; (10) relative production of bioactive compounds such as toxins or reactive oxygen species (ROS); (11) r vs K strategy; and (12) fate of the production in terms of grazing. The new mandala serves to highlight the differences and trade-offs between traits and/or environmental conditions, and illustrates some traits tend to track each other, a concept that may be helpful in trait-based modeling approaches and in understanding environmental factors associated with harmful algal blooms. It is hoped that this new mandala captures some of our recent insight into phytoplankton physiology and functional traits, and has contemporary relevance in light of anthropogenic changes in nutrient form and ratio. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Margalef revisited: A new phytoplankton mandala incorporating twelve dimensions, including nutrient ratios and forms

    Science.gov (United States)

    Glibert, P. M.

    2016-02-01

    Building on the classic depiction of the progression from a diatom to a dinoflagellate bloom as a function of nutrients and turbulence, known as the "Margalef mandala", a new conceptual model or mandala is presented here. The new mandala maps twelve traits or environmental characteristics related to different phytoplankton functional types: (1) relative preference for chemically reduced vs chemically oxidized forms of nitrogen; (2) relative availability of inorganic nitrogen and phosphorus; (3) adaptation to high vs low light and the tendency to be autotrophic vs mixotrophic; (4) cell motility; (5) environmental turbulence; (6) pigmentation quality; (7) temperature; (8) cell size; (9) relative growth rate; (10) relative production of bioactive compounds such as toxins or reactive oxygen species (ROS); (11) r vs K strategy; and (12) fate of the production in terms of grazing. The new mandala serves to highlight the differences and trade-offs between traits and/or environmental conditions, and illustrates some traits tend to track each other, a concept that may be helpful in trait-based modeling approaches. It is hoped that this new mandala captures some of our recent insight into phytoplankton physiology and functional traits, and has contemporary relevance in light of anthropogenic changes in nutrient form and ratio.

  10. Evolution and potential function of fibrinogen-like domains across twelve Drosophila species

    Directory of Open Access Journals (Sweden)

    Middha Sumit

    2008-05-01

    Full Text Available Abstract Background The fibrinogen-like (FBG domain consists of approximately 200 amino acid residues, which has high sequence similarity to the C-terminal halves of fibrinogen β and γ chains. Fibrinogen-related proteins (FREPs containing one or more FBG domains are found universally in vertebrates and invertebrates. In invertebrates, FREPs are involved in immune responses and other aspects of physiology. To understand the complexity of this gene family in Drosophila, we analyzed FREPs in twelve Drosophila species. Results Using the genome data from 12 Drosophila species, we identified FBG domains in each species. The results show that the gene numbers in each species vary from 14 genes up to 43 genes. Using sequence profile analysis, we found that FBG domains have high sequence similarity and are highly conserved throughout. By comparison of structure and sequence conservation, some of the FBG domains in Drosophila melanogaster are predicted to function in recognition of carbohydrates and their derivatives on the surface of microorganisms in innate immunity. Conclusion Sequence and structural analyses show that FREP family across 12 Drosophila species contains conserved FBG domains. Expansion of the FREP families in Drosophila is mainly accounted by a major expansion of FBG domains.

  11. Twelve-Year Trends of PM10 and Visibility in the Hefei Metropolitan Area of China

    Directory of Open Access Journals (Sweden)

    Lin Huang

    2016-01-01

    Full Text Available China has been experiencing severe air pollution and previous studies have mostly focused on megacities and a few hot spot regions. Hefei, the provincial capital city of Anhui province, has a population of near 5 million in its metropolitan area, but its air quality has not been reported in literature. In this study, daily PM10 and visibility data in 2001–2012 were analyzed to investigate the air quality status as well as the twelve-year pollution trends in Hefei. The results reveal that Hefei has been suffering high PM10 pollution and low visibility during the study period. The annual average PM10 concentrations are 2~3 times of the Chinese Ambient Air Quality Standard. PM10 shows fluctuating variation in 2001–2007 and has a slightly decreasing trend after 2008. The annual average visibility range is generally lower than 7 km and shows a worsening trend from 2001 to 2006 followed by an improving trend from 2007 to 2012. Wind speed, precipitation, and relative humidity have negative effects on PM10 concentrations in Hefei, while temperature could positively or negatively affect PM10. The results provide a general understanding of the status and long-term trends of PM10 pollution and visibility in a typical second-tier city in China.

  12. Validation of Twelve Small Kepler Transiting Planets in the Habitable Zone

    CERN Document Server

    Torres, Guillermo; Fressin, Francois; Caldwell, Douglas A; Twicken, Joseph D; Ballard, Sarah; Batalha, Natalie M; Bryson, Stephen T; Ciardi, David R; Henze, Christopher E; Howell, Steve B; Isaacson, Howard T; Jenkins, Jon M; Muirhead, Philip S; Newton, Elisabeth R; Petigura, Erik A; Barclay, Thomas; Borucki, William J; Crepp, Justin R; Everett, Mark E; Horch, Elliott P; Howard, Andrew W; Kolbl, Rea; Marcy, Geoffrey W; McCauliff, Sean; Quintana, Elisa V

    2015-01-01

    We present an investigation of twelve candidate transiting planets from Kepler with orbital periods ranging from 34 to 207 days, selected from initial indications that they are small and potentially in the habitable zone (HZ) of their parent stars. The expected Doppler signals are too small to confirm them by demonstrating that their masses are in the planetary regime. Here we verify their planetary nature by validating them statistically using the BLENDER technique, which simulates large numbers of false positives and compares the resulting light curves with the Kepler photometry. This analysis was supplemented with new follow-up observations (high-resolution optical and near-infrared spectroscopy, adaptive optics imaging, and speckle interferometry), as well as an analysis of the flux centroids. For eleven of them (KOI-0571.05, 1422.04, 1422.05, 2529.02, 3255.01, 3284.01, 4005.01, 4087.01, 4622.01, 4742.01, and 4745.01) we show that the likelihood they are true planets is far greater than that of a false po...

  13. Measurement and analysis of angular velocity variations of twelve-cylinder diesel engine crankshaft

    Science.gov (United States)

    Bulatović, Ž. M.; Štavljanin, M. S.; Tomić, M. V.; Knežević, D. M.; Biočanin, S. Lj.

    2011-11-01

    This paper presents the procedures for measuring and analyzing the angular velocity variation of twelve-cylinder diesel engine crankshaft on its free end and on the power-output end. In addition, the paper deals with important aspects of the measurement of crankshaft torsional oscillations. The method is based on digital encoders placed at two distances, and one of them is a sensor not inserted directly on the shaft, i.e. a non-contact method with a toothed disc is used. The principle based on toothed disc is also used to measure the actual camshaft angular velocity of in-line compact high-pressure pump the engine is equipped with, and this paper aims to demonstrate the possibility of measuring the actual angular velocity of any rotating shaft in the engine, on which it is physically possible to mount a toothed disc. The method was created completely independently during long-range development and research tests of V46 family engines. This method is specific for its particular adaptability for use on larger engines with extensive vibrations and torsional oscillations. The main purpose of this paper is a practical contribution to all the more interesting research of the use of engine crankshaft angular velocity as a diagnostic tool for identifying the engine irregular running.

  14. Access to oral health services in children under twelve years of age in Peru, 2014

    Directory of Open Access Journals (Sweden)

    Akram Hernández-Vásquez

    2016-10-01

    Full Text Available The aim of the study was to explore the patterns of dental health services access in children under twelve years of age in Peru. Data from 25,285 children under 12 years who participated in the Demographic and Family Health Survey of 2014 were reviewed. An exploratory spatial analysis was performed to project the proportions of children with access to dental health services, according to national regions, type of health service and urban or rural place of residence. The results show that of the total sample, 26.7% had access to dental health services in the last six months, 39.6% belonged to the age group 0-4 years, 40.6% lived in the Andean region and 58.3% lived in urban areas. The regions of Huancavelica, Apurimac, Ayacucho, Lima and Pasco had the highest percentages of access nationwide. In conclusion, there is low access to dental health services in the population under 12 years of age in Peru. The spatial distribution of access to dental health services allows regions to be identified and grouped according to similar access patterns, in order to better focus public health actions.

  15. Synergy between Seeking Safety and Twelve-Step Affiliation on Substance Use Outcomes for Women

    Science.gov (United States)

    Morgan-Lopez, Antonio A.; Saavedra, Lissette M.; Hien, Denise A.; Campbell, Aimee N.; Wu, Elwin; Ruglass, Lesia

    2014-01-01

    Objective The Recovery Management paradigm provides a conceptual framework for the examination of joint impact of a focal treatment and post-treatment service utilization on substance abuse treatment outcomes. We test this framework by examining the interactive effects of a treatment for comorbid PTSD and substance use, Seeking Safety, and post-treatment Twelve-Step Affiliation (TSA) on alcohol and cocaine use. Method Data from 353 women in a six-site, randomized controlled effectiveness trial within the NIDA Clinical Trials Network were analyzed under latent class pattern mixture modeling. LCPMM was used to model variation in Seeking Safety by TSA interaction effects on alcohol and cocaine use. Results Significant reductions in alcohol use among women in Seeking Safety (compared to Health Education) were observed; women in the Seeking Safety condition who followed up with TSA had the greatest reductions over time in alcohol use. Reductions in cocaine use over time were also observed but did not differ between treatment conditions nor were there interactions with post-treatment TSA. Conclusions Findings advance understanding of the complexities for treatment and continuing recovery processes for women with PTSD and SUDs, and further support the chronic disease model of addiction. PMID:23558158

  16. Coréia aguda na gravidez Acute chorea in pregnancy: comments on twelve consecutive cases

    Directory of Open Access Journals (Sweden)

    Walter C. Pereira

    1967-12-01

    Full Text Available São apresentados doze casos de coréia aguda observados entre 150.000 gestantes (1/12.500. A maioria dos surtos ocorreu no segundo trimestre da primeira gravidez. A duração média dos sintomas foi de três meses, não tendo sido registrado caso algum de óbito materno. Todos os partos foram espontâneos e normais. Houve apenas um óbito fetal conseqüente a choque hemorrágico. São tecidas considerações a propósito dos aspectos clínico, laboratorial e prognóstico da coréia gravídica, sendo focalizado mais pormenorizadamente o problema fisiopatogênico dessa afecção.Twelve consecutive cases of acute chorea occurring among 150.000 pregnant women (1/12.500 are reported. Most of the cases occurred from the fourth do the sixth month of the first pregnancy. The average duration of the symptoms was of three months and no one case of maternal death was verified in the group. The deliveries were spontaneous and normal in all the patients. Only one case of fetal death occurred in consequence of a hemorragic shock. Comments are made on the clinical, laboratorial and prognostic features of chorea gravidarum, being particulary focused the physiopathogenic problem of this condtion.

  17. TRANSIT TIMING OBSERVATIONS FROM KEPLER. VIII. CATALOG OF TRANSIT TIMING MEASUREMENTS OF THE FIRST TWELVE QUARTERS

    Energy Technology Data Exchange (ETDEWEB)

    Mazeh, Tsevi; Nachmani, Gil; Holczer, Tomer; Sokol, Gil [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of Chicago, 5640 Ellis Ave., Chicago, IL 60637 (United States); Ford, Eric B.; Ragozzine, Darin [Astronomy Department, University of Florida, Gainesville, FL 32111 (United States); Sanchis-Ojeda, Roberto [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Rowe, Jason F.; Lissauer, Jack J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Zucker, Shay [Department of Geophysical, Atmospheric and Planetary Sciences, Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv University, 69978 Tel Aviv (Israel); Agol, Eric [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Carter, Joshua A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Quintana, Elisa V. [SETI Institute, 189 Bernardo Ave, Suite 100, Mountain View, CA 94043 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Welsh, William [Astronomy Department, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182 (United States)

    2013-10-01

    Following the works of Ford et al. and Steffen et al. we derived the transit timing of 1960 Kepler objects of interest (KOIs) using the pre-search data conditioning light curves of the first twelve quarters of the Kepler data. For 721 KOIs with large enough signal-to-noise ratios, we obtained also the duration and depth of each transit. The results are presented as a catalog for the community to use. We derived a few statistics of our results that could be used to indicate significant variations. Including systems found by previous works, we have found 130 KOIs that showed highly significant times of transit variations (TTVs) and 13 that had short-period TTV modulations with small amplitudes. We consider two effects that could cause apparent periodic TTV—the finite sampling of the observations and the interference with the stellar activity, stellar spots in particular. We briefly discuss some statistical aspects of our detected TTVs. We show that the TTV period is correlated with the orbital period of the planet and with the TTV amplitude.

  18. Heterochromatic banding patterns on chromosomes of twelve weevil species (Insecta, Coleoptera, Curculionoidea: Apionidae, Curculionidae).

    Science.gov (United States)

    Holecová, Milada; Rozek, Maria; Lachowska, Dorota

    2002-01-01

    The C-banding patterns of twelve weevil species are presented. The obtained results confirm the existence of two groups of species: with a small or large amount of heterochromatin in the karyotype. The first group comprises seven species (Apionidae: Holotrichapion pisi; Curculionidae: Phyllobius urticae, Ph. pyri, Ph. maculicornis, Tanymecus palliatus, Larinodontes turbinatus, Cionus tuberculosus). In weevils with a small amount of heterochromatin, tiny grains on the nucleus in interphase are visible, afterwards in mitotic and meiotic prophase appearing as dark dots. The absence of C-bands does not indicate a lack of heterochromatin but heterochromatic regions are sometimes so small that the condensation is not visible during the cell cycle. The second group comprises five species (Otiorhynchus niger, O. morio, Polydrusus corruscus, Barypeithes chevrolati, Nedyus quadrimaculatus) which possess much larger heteropicnotic parts of chromosomes visible during all nuclear divisions. The species examined have paracentromeric C-bands on autosomes and the sex chromosome X, except for Otiorhynchus niger, which also has an intercalary bands on one pair of autososomes. All the species examined differ in the size of segments of constitutive heterochromatin. The y heterochromosome is dot-like and wholly euchromatic in all the studied species.

  19. In vitro antibacterial and antifungal activities of twelve sponges collected from the Anambas Islands, Indonesia

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    Masteria Yunovilsa Putra

    2016-09-01

    Full Text Available Objective: To evaluate antimicrobial activities in methanolic extracts of twelve sponges collected from the Anambas Islands, Indonesia. Methods: The antibacterial activity of methanolic extracts was tested against two Grampositive bacteria, viz. Bacillus subtilis (ATCC 6633 and Staphylococcus aureus (ATCC 25923, and two Gram-negative bacteria, viz. Eschericia coli (ATCC 25922 and Vibrio anguillarum (ATCC 19264 using the disk diffusion assay. The antifungal activity was similarly tested against Candida albicans (ATCC 10231 and Aspergillus niger (ATCC 16404. The minimum inhibitory concentrations of promising sponges extracts were determined by the microdilution technique. Results: All the sponge species in this study showed antimicrobial activities against at least one of the test strains. Antibacterial activities were observed in 66.7% of the sponges extracts, while 30.0% of the extracts exhibited antifungal activities. Among them, the extracts of the sponges Stylissa massa and Axinyssa sp. were the most active against four tested bacteria and the yeast Candida albicans. The sponge Theonella swinhoei and two species of Xestospongia also displayed significant activities against two fungal pathogens Candida albicans and Aspergillus niger. Conclusions: Antimicrobial activities were demonstrated in extracts from various marine sponges collected from the Anambas Islands, Indonesia. The most promising sponges among them were Stylissa massa and Axinyssa sp. This is the first report of antimicrobial activity in extracts of marine sponges from the Indonesian Anambas Islands.

  20. INCIDENCE AND SURVIVAL OF LIPOLYTIC ORGANISMS MONITORED FOR TWELVE MONTHS IN DOMESTIC WASTEWATER AND RECEIVING STREAM

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    Adebowale Odeyemi

    2013-10-01

    Full Text Available The incidence and survival of lipolytic organisms in domestic wastewater and receiving stream were monitored over 12 months. The average total bacterial count in the wastewater samples reduced in April and November by 24.2% and 41.6% respectively. There was also a reduction of 42.3% and 60.1% in the load in the receiving stream in August and July. Subsequently, at 5m downstream from the entry of the wastewater the microbial load reduced in March (19.2% and June (19.2%. However, the occurrence of coliforms was more affected in the months of May (53% to July (87.2%. At 5m and 10m downstream the coliform population reduced by 27.9% and 30.1% respectively. Of the twelve (12 bacterial isolates obtained at the exit of the wastewater into the receiving stream, only four (4 were found to possess lipolytic activity. These include the species of Enterococcus, Klebsiella, Pseudomonas and Staphylococcus. There was no significant difference in the amount of nutrients found in the domestic wastewater and receiving stream during the months. This paper also discusses the implication of disposing large amounts of wastewater effluents into the receiving water and the need to remedy and minimize the overall impact of such pollution on the environment.

  1. Interaction and cooperative effort among scientific societies. Twelve years of COSCE.

    Science.gov (United States)

    Martín, Nazario; Andradas, Carlos

    2015-12-01

    The evolution of knowledge and technology in recent decades has brought profound changes in science policy, not only in the countries but also in the supranational organizations. It has been necessary, therefore, to adapt the scientific institutions to new models in order to achieve a greater and better communication between them and the political counterparts responsible for defining the general framework of relations between science and society. The Federationon of Scientific Societies of Spain (COSCE, Confederación de Sociedades Científicas de España) was founded in October 2003 to respond to the urgent need to interact with the political institutions and foster a better orientation in the process of making decisions about the science policy. Currently COSCE consists of over 70 Spanish scientific societies and more than 40,000 scientists. During its twelve years of active life, COSCE has developed an intense work of awareness of the real situation of science in Spain by launching several initiatives (some of which have joined other organizations) or by joining initiatives proposed from other groups related to science both at the Spanish level and at the European and non-European scenarios. [Int Microbiol 18(4): 245-251 (2015)].

  2. Ecological conversion efficiency and its influencers in twelve species of fish in the Yellow Sea Ecosystem

    Science.gov (United States)

    Tang, Qisheng; Guo, Xuewu; Sun, Yao; Zhang, Bo

    2007-09-01

    The ecological conversion efficiencies in twelve species of fish in the Yellow Sea Ecosystem, i.e., anchovy ( Engraulis japonicus), rednose anchovy ( Thrissa kammalensis), chub mackerel ( Scomber japonicus), halfbeak ( Hyporhamphus sajori), gizzard shad ( Konosirus punctatus), sand lance ( Ammodytes personatus), red seabream ( Pagrus major), black porgy ( Acanthopagrus schlegeli), black rockfish ( Sebastes schlegeli), finespot goby ( Chaeturichthys stigmatias), tiger puffer ( Takifugu rubripes), and fat greenling ( Hexagrammos otakii), were estimated through experiments conducted either in situ or in a laboratory. The ecological conversion efficiencies were significantly different among these species. As indicated, the food conversion efficiencies and the energy conversion efficiencies varied from 12.9% to 42.1% and from 12.7% to 43.0%, respectively. Water temperature and ration level are the main factors influencing the ecological conversion efficiencies of marine fish. The higher conversion efficiency of a given species in a natural ecosystem is acquired only under the moderate environment conditions. A negative relationship between ecological conversion efficiency and trophic level among ten species was observed. Such a relationship indicates that the ecological efficiency in the upper trophic levels would increase after fishing down marine food web in the Yellow Sea ecosystem.

  3. Differences in antimicrobial activity of chlorine against twelve most prevalent poultry-associated Salmonella serotypes.

    Science.gov (United States)

    Paul, Narayan C; Sullivan, Tarah S; Shah, Devendra H

    2017-06-01

    Chlorine is the most widely used carcass sanitizer in poultry processing in the USA. The objective of this study was to determine the effects of varying concentrations of organic matter on the susceptibility of twelve most prevalent poultry-associated Salmonella serotypes (MPPSTs) to chlorine. To mimic the microenvironment of the water used for immersion chilling, we manipulated organic matter contamination levels in pre-chilled (pH∼6, T∼4 °C) chlorinated (50 ppm) water using varying concentrations (0, 1, 2, 3, 4, and 5%) of chicken-meat-extract (CME) produced from frozen chicken carcasses. This CME-based in vitro model was challenged with ∼1 × 10(5) CFUs of each MPPST isolate and the bacterial survival was tested at 5, 30, 60 and 90 min post-challenge. In this model, the decimal reduction time (D90-values) of each MPPST was linearly correlated with the concentration of CME. Significant inter-serotype differences in the D90-values were observed. The results show that the pH, concentration of total- and free-chlorine were also linearly correlated with the presence of CME in a concentration-dependent manner. The findings of this study indicate that the serotype and the levels of organic matter contamination significantly influence Salmonella survival and that both variables should be included in models that predict effectiveness of chlorine treatment in immersion chilling.

  4. Alcoholics Anonymous and twelve-step recovery: a model based on social and cognitive neuroscience.

    Science.gov (United States)

    Galanter, Marc

    2014-01-01

    In the course of achieving abstinence from alcohol, longstanding members of Alcoholics Anonymous (AA) typically experience a change in their addiction-related attitudes and behaviors. These changes are reflective of physiologically grounded mechanisms which can be investigated within the disciplines of social and cognitive neuroscience. This article is designed to examine recent findings associated with these disciplines that may shed light on the mechanisms underlying this change. Literature review and hypothesis development. Pertinent aspects of the neural impact of drugs of abuse are summarized. After this, research regarding specific brain sites, elucidated primarily by imaging techniques, is reviewed relative to the following: Mirroring and mentalizing are described in relation to experimentally modeled studies on empathy and mutuality, which may parallel the experiences of social interaction and influence on AA members. Integration and retrieval of memories acquired in a setting like AA are described, and are related to studies on storytelling, models of self-schema development, and value formation. A model for ascription to a Higher Power is presented. The phenomena associated with AA reflect greater complexity than the empirical studies on which this article is based, and certainly require further elucidation. Despite this substantial limitation in currently available findings, there is heuristic value in considering the relationship between the brain-based and clinical phenomena described here. There are opportunities for the study of neuroscientific correlates of Twelve-Step-based recovery, and these can potentially enhance our understanding of related clinical phenomena. © American Academy of Addiction Psychiatry.

  5. Deathly silence and apocalyptic noise: Observations on the soundscape of the Book of the Twelve

    Directory of Open Access Journals (Sweden)

    Aaron Schart

    2010-03-01

    Full Text Available This paper proposes a reading of the Book of the Twelve (used interchangeably with �Twelve� and �Book� for convenience that concentrates on the sound that is included in the description of the world of the text. Three onomatopoeic devices are singled out. First, the mourning cry h�y is considered. This interjection is used differently in several of the writings: in Amos (5:18; 6:1 the prophet cries out in compassion with the addressees. By contrast, in Nahum 3:1 and Habakkuk 2:6�19, h�y is uttered in a mood of mockery. In Zechariah 2:10 a third, joyful h�y is used. It appears that the different usages cohere nicely with the overall structure of the Book of the Twelve. Secondly, the interjection has likewise shows different usages. In Amos 6:10 and 8:3, it simulates the last breath of Israelites dying when the land is devastated. By contrast, in Habakkuk 2:20, Zephaniah 1:7 and Zechariah 2:17, the addressees are directed to be silent before YHWH. This command should be perceived as an act of reverence. Again, the sequence of the occurrences coheres with the overall structure of the Book of the Twelve. Of special relevance is that the last three instances build a frame around the Babylonian exile, which lies between Zephaniah and Haggai. The third example is the phrase ham�n�m, ham�n�m in Joel 4:14. The author employs an irregular double plural to construe this place as the loudest spot (�apocalyptic noise� within the Twelve.Setu sa go tiba le modumo wa aphokhaliptiki: Ditemogo ka medumo ya Puku ya ba LesomepediPampiri ye e �i�inya go balwa ga Puku ya ba Lesomepedi (yeo e ka nogo bit�wa �Lesomepedi� goba �Puku� go bebofat�a ditaba ka go gatelela modumo wo o lego ka gare ga tlhaloso ya lefase la go tswala dingwalo t�e. Ditsela t�e tharo t�a onomathopoiki di bewa pepeneng. La mathomo, go �et�wa sello sa mahloko sa h?y. Lelahlelwa le le �omi�wa ka go fapana mo dingwalong t�e mmalwa: go Amosi

  6. Fate of the conformal fixed point with twelve massless fermions and SU(3) gauge group

    Science.gov (United States)

    Fodor, Zoltan; Holland, Kieran; Kuti, Julius; Mondal, Santanu; Nogradi, Daniel; Wong, Chik Him

    2016-11-01

    We report new results on the conformal properties of an important strongly coupled gauge theory, a building block of composite Higgs models beyond the Standard Model. With twelve massless fermions in the fundamental representation of the SU(3) color gauge group, an infrared fixed point (IRFP) of the β -function was recently reported in the theory [A. Cheng, A. Hasenfratz, Y. Liu, G. Petropoulos, and D. Schaich, J. High Energy Phys. 05 (2014) 137] with uncertainty in the location of the critical gauge coupling inside the narrow [6.0 fixed point and scale invariance in the theory with model-building implications. Using the exact same renormalization scheme as the previous study, we show that no fixed point of the β -function exists in the reported interval. Our findings eliminate the only seemingly credible evidence for conformal fixed point and scale invariance in the Nf=12 model whose infrared properties remain unresolved. The implications of the recently completed 5-loop QCD β -function for arbitrary flavor number are discussed with respect to our work.

  7. Twelve tips for creating trigger images for problem-based learning cases.

    Science.gov (United States)

    Azer, Samy A

    2007-03-01

    A trigger is the starting point of problem-based learning (PBL) cases. It is usually in the form of 5-6 text lines that provide the key information about the main character (usually the patient), including 3-4 of patient's presenting problems. In addition to the trigger text, most programs using PBL include a visual trigger. This might be in the form of a single image, a series of images, a video clip, a cartoon, or even one of the patient's investigation results (e.g. chest X-ray, pathology report, or urine sample analysis). The main educational objectives of the trigger image are as follows: (1) to introduce the patient to the students; (2) to enhance students' observation skills; (3) to provide them with new information to add to the cues obtained from the trigger text; and (4) to stimulate students to ask questions as they develop their enquiry plan. When planned and delivered effectively, trigger images should be engaging and stimulate group discussion. Understanding the educational objectives of using trigger images and choosing appropriate images are the keys for constructing successful PBL cases. These twelve tips highlight the key steps in the successful creation of trigger images.

  8. What Makes Clusters Decline?

    DEFF Research Database (Denmark)

    Østergaard, Christian Richter; Park, Eun Kyung

    2015-01-01

    Most studies on regional clusters focus on identifying factors and processes that make clusters grow. However, sometimes technologies and market conditions suddenly shift, and clusters decline. This paper analyses the process of decline of the wireless communication cluster in Denmark....... The longitudinal study on the high-tech cluster reveals that technological lock-in and exit of key firms have contributed to decline. Entrepreneurship has a positive effect on the cluster’s adaptive capabilities, while multinational companies have contradicting effects by bringing in new resources to the cluster...

  9. Data clustering in C++ an object-oriented approach

    CERN Document Server

    Gan, Guojun

    2011-01-01

    Data clustering is a highly interdisciplinary field, the goal of which is to divide a set of objects into homogeneous groups such that objects in the same group are similar and objects in different groups are quite distinct. Thousands of theoretical papers and a number of books on data clustering have been published over the past 50 years. However, few books exist to teach people how to implement data clustering algorithms. This book was written for anyone who wants to implement or improve their data clustering algorithms. Using object-oriented design and programming techniques, Data Clusterin

  10. Abnormal brain functional connectivity of the hypothalamus in cluster headaches.

    Directory of Open Access Journals (Sweden)

    Enchao Qiu

    Full Text Available The aim of this study was to detect the abnormality of the brain functional connectivity of the hypothalamus during acute spontaneous cluster headache (CH attacks ('in attack' and headache-free intervals ('out of attack' using resting-state functional magnetic resonance imaging (RS-fMRI technique. The RS-fMRI data from twelve male CH patients during 'in attack' and 'out of attack' periods and twelve age- and sex-matched normal controls were analyzed by the region-of-interest -based functional connectivity method using SPM5 software. Abnormal brain functional connectivity of the hypothalamus is present in CH, which is located mainly in the pain system during the spontaneous CH attacks. It extends beyond the pain system during CH attack intervals.

  11. Comprehensive cluster analysis with Transitivity Clustering.

    Science.gov (United States)

    Wittkop, Tobias; Emig, Dorothea; Truss, Anke; Albrecht, Mario; Böcker, Sebastian; Baumbach, Jan

    2011-03-01

    Transitivity Clustering is a method for the partitioning of biological data into groups of similar objects, such as genes, for instance. It provides integrated access to various functions addressing each step of a typical cluster analysis. To facilitate this, Transitivity Clustering is accessible online and offers three user-friendly interfaces: a powerful stand-alone version, a web interface, and a collection of Cytoscape plug-ins. In this paper, we describe three major workflows: (i) protein (super)family detection with Cytoscape, (ii) protein homology detection with incomplete gold standards and (iii) clustering of gene expression data. This protocol guides the user through the most important features of Transitivity Clustering and takes ∼1 h to complete.

  12. The Cluster Substructure - Alignment Connection

    OpenAIRE

    Plionis, Manolis

    2001-01-01

    Using the APM cluster data we investigate whether the dynamical status of clusters is related to the large-scale structure of the Universe. We find that cluster substructure is strongly correlated with the tendency of clusters to be aligned with their nearest neighbour and in general with the nearby clusters that belong to the same supercluster. Furthermore, dynamically young clusters are more clustered than the overall cluster population. These are strong indications that cluster develop in ...

  13. Nuclear Clusters in Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Kubono, S.; Binh, Dam N.; Hayakawa, S.; Hashimoto, H.; Kahl, D.; Wakabayashi, Y.; Yamaguchi, H. [Center for Nuclear Study (CNS), University of Tokyo, Wako Branch at RIKEN 2-1 Hirosawa, Wako, Saitama, 351-0198 (Japan); Teranishi, T. [Department of Physics, Kyushu University, Fukuoka, 812-8581 (Japan); Iwasa, N. [Department of Physics, Tohoku University, Sendai, 980-8578 (Japan); Komatsubara, T. [Department of Physics, Tsukuba University, Ibaraki, 305-8571 (Japan); Kato, S. [Department of Physics, Yamagata University, Yamagata, 990-8560 (Japan); Khiem, Le H. [Institute of Physics, Vietnam Academy for Science and Technology, Hanoi (Viet Nam)

    2010-03-01

    The role of nuclear clustering is discussed for nucleosynthesis in stellar evolution with Cluster Nucleosynthesis Diagram (CND) proposed before. Special emphasis is placed on alpha-induced stellar reactions together with molecular states for O and C burning.

  14. A theoretical study of water clusters: the relation between hydrogen-bond topology and interaction energy from quantum-chemical computations for clusters with up to 22 molecules.

    Science.gov (United States)

    Lenz, Annika; Ojamäe, Lars

    2005-05-07

    Quantum-chemical calculations of a variety of water clusters with eight, ten and twelve molecules were performed, as well as for selected clusters with up to 22 water molecules. Geometry optimizations were carried out at the B3LYP/cc-pVDZ level and single-point energies were calculated at the B3LYP/aug-cc-pVDZ level for selected clusters. The electronic energies were studied with respect to the geometry of the oxygen arrangement and six different characteristics of the hydrogen-bond arrangement in the cluster. Especially the effect of the placement of the non-hydrogen bonding hydrogens on the interaction energy was studied. Models for the interaction energy with respect to different characteristics of the hydrogen-bond arrangement were derived through least-square fits. The results from the study of the clusters with eight, ten and twelve molecules are used to predict possible low-energy structures for various shapes of clusters with up to 22 molecules.

  15. Branding your practice: twelve practical steps to creating lifelong patient relationships.

    Science.gov (United States)

    Neely, Melinda Hinson

    2005-01-01

    The concept of branding is not limited to large companies. It can be successfully applied in medical practices to those individuals or groups that wish to establish a distinct identity in the marketplace. Branding a medical practice establishes a competitive advantage, ensures a more predictable flow of patients, and ultimately enhances patient satisfaction. This article conceptualizes the branding process and provides guidelines for implementation that are applicable to a variety of budgets.

  16. Improving Comparability Of Survey Results Through Ex-Post Harmonisation A Case Study With Twelve European National Travel Surveys

    DEFF Research Database (Denmark)

    Christensen, Linda; Hubert, Jean-Paul; Järvi, Tuuli

    that reflect behavioural differences rather than methodological ones, in the context of the COST Action SHANTI (Survey Harmonisation with New Technologies Improvement, TUD0804) an ex-post harmonisation approach was developed using microdata from twelve European NTS’s. The paper presents both concept and basic...

  17. [Pathophysiology of cluster headache].

    Science.gov (United States)

    Donnet, Anne

    2015-11-01

    The aetiology of cluster headache is partially unknown. Three areas are involved in the pathogenesis of cluster headache: the trigeminal nociceptive pathways, the autonomic system and the hypothalamus. The cluster headache attack involves activation of the trigeminal autonomic reflex. A dysfunction located in posterior hypothalamic gray matter is probably pivotal in the process. There is a probable association between smoke exposure, a possible genetic predisposition and the development of cluster headache.

  18. Distinct cellular states determine calcium signaling response.

    Science.gov (United States)

    Yao, Jason; Pilko, Anna; Wollman, Roy

    2016-12-15

    The heterogeneity in mammalian cells signaling response is largely a result of pre-existing cell-to-cell variability. It is unknown whether cell-to-cell variability rises from biochemical stochastic fluctuations or distinct cellular states. Here, we utilize calcium response to adenosine trisphosphate as a model for investigating the structure of heterogeneity within a population of cells and analyze whether distinct cellular response states coexist. We use a functional definition of cellular state that is based on a mechanistic dynamical systems model of calcium signaling. Using Bayesian parameter inference, we obtain high confidence parameter value distributions for several hundred cells, each fitted individually. Clustering the inferred parameter distributions revealed three major distinct cellular states within the population. The existence of distinct cellular states raises the possibility that the observed variability in response is a result of structured heterogeneity between cells. The inferred parameter distribution predicts, and experiments confirm that variability in IP3R response explains the majority of calcium heterogeneity. Our work shows how mechanistic models and single-cell parameter fitting can uncover hidden population structure and demonstrate the need for parameter inference at the single-cell level. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

  19. Cluster Physics with Merging Galaxy Clusters

    Directory of Open Access Journals (Sweden)

    Sandor M. Molnar

    2016-02-01

    Full Text Available Collisions between galaxy clusters provide a unique opportunity to study matter in a parameter space which cannot be explored in our laboratories on Earth. In the standard LCDM model, where the total density is dominated by the cosmological constant ($Lambda$ and the matter density by cold dark matter (CDM, structure formation is hierarchical, and clusters grow mostly by merging.Mergers of two massive clusters are the most energetic events in the universe after the Big Bang,hence they provide a unique laboratory to study cluster physics.The two main mass components in clusters behave differently during collisions:the dark matter is nearly collisionless, responding only to gravity, while the gas is subject to pressure forces and dissipation, and shocks and turbulenceare developed during collisions. In the present contribution we review the different methods used to derive the physical properties of merging clusters. Different physical processes leave their signatures on different wavelengths, thusour review is based on a multifrequency analysis. In principle, the best way to analyze multifrequency observations of merging clustersis to model them using N-body/HYDRO numerical simulations. We discuss the results of such detailed analyses.New high spatial and spectral resolution ground and space based telescopeswill come online in the near future. Motivated by these new opportunities,we briefly discuss methods which will be feasible in the near future in studying merging clusters.

  20. The Durban Auto Cluster

    DEFF Research Database (Denmark)

    Lorentzen, Jochen; Robbins, Glen; Barnes, Justin

    2004-01-01

    The paper describes the formation of the Durban Auto Cluster in the context of trade liberalization. It argues that the improvement of operational competitiveness of firms in the cluster is prominently due to joint action. It tests this proposition by comparing the gains from cluster activities i...

  1. The Durban Auto Cluster

    DEFF Research Database (Denmark)

    Lorentzen, Jochen; Robbins, Glen; Barnes, Justin

    2004-01-01

    The paper describes the formation of the Durban Auto Cluster in the context of trade liberalization. It argues that the improvement of operational competitiveness of firms in the cluster is prominently due to joint action. It tests this proposition by comparing the gains from cluster activities i...

  2. Marketing research cluster analysis

    Directory of Open Access Journals (Sweden)

    Marić Nebojša

    2002-01-01

    Full Text Available One area of applications of cluster analysis in marketing is identification of groups of cities and towns with similar demographic profiles. This paper considers main aspects of cluster analysis by an example of clustering 12 cities with the use of Minitab software.

  3. Cluster Correspondence Analysis

    NARCIS (Netherlands)

    M. van de Velden (Michel); A. Iodice D' Enza; F. Palumbo

    2014-01-01

    markdownabstract__Abstract__ A new method is proposed that combines dimension reduction and cluster analysis for categorical data. A least-squares objective function is formulated that approximates the cluster by variables cross-tabulation. Individual observations are assigned to clusters

  4. Twelve Years of Education and Public Outreach with the Fermi Gamma-ray Space Telescope

    Science.gov (United States)

    Cominsky, Lynn R.; McLin, K. M.; Simonnet, A.; Fermi E/PO Team

    2013-04-01

    During the past twelve years, NASA's Fermi Gamma-ray Space Telescope has supported a wide range of Education and Public Outreach (E/PO) activities, targeting K-14 students and the general public. The purpose of the Fermi E/PO program is to increase student and public understanding of the science of the high-energy Universe, through inspiring, engaging and educational activities linked to the mission’s science objectives. The E/PO program has additional more general goals, including increasing the diversity of students in the Science, Technology, Engineering and Mathematics (STEM) pipeline, and increasing public awareness and understanding of Fermi science and technology. Fermi's multi-faceted E/PO program includes elements in each major outcome category: ● Higher Education: Fermi E/PO promotes STEM careers through the use of NASA data including research experiences for students and teachers (Global Telescope Network), education through STEM curriculum development projects (Cosmology curriculum) and through enrichment activities (Large Area Telescope simulator). ● Elementary and Secondary education: Fermi E/PO links the science objectives of the Fermi mission to well-tested, customer-focused and NASA-approved standards-aligned classroom materials (Black Hole Resources, Active Galaxy Education Unit and Pop-up book, TOPS guides, Supernova Education Unit). These materials have been distributed through (Educator Ambassador and on-line) teacher training workshops and through programs involving under-represented students (after-school clubs and Astro 4 Girls). ● Informal education and public outreach: Fermi E/PO engages the public in sharing the experience of exploration and discovery through high-leverage multi-media experiences (Black Holes planetarium and PBS NOVA shows), through popular websites (Gamma-ray Burst Skymap, Epo's Chronicles), social media (Facebook, MySpace), interactive web-based activities (Space Mysteries, Einstein@Home) and activities by

  5. Relative peripheral refraction in children: twelve-month changes in eyes with different ametropias.

    Science.gov (United States)

    Lee, Tsui-Tsui; Cho, Pauline

    2013-05-01

    To determine the peripheral refraction of children with different types of ametropias and to evaluate the relationship between central refractive changes, baseline relative peripheral refraction (RPR) and changes in RPR over a 12-month monitoring period. Cycloplegic central and peripheral refraction were performed biannually on the right eyes of children aged 6-9 for 12 months, using an open-view autorefractor. Peripheral refraction were measured along 10°, 20° and 30° from central fixation in both nasal and temporal fields. Refractive data were transposed into M, J0 and J45 vectors for analyses. RPR was determined by subtracting the central measurement from each peripheral measurement. Hyperopic eyes showed relative peripheral myopia while myopic eyes had relative hyperopia across the central 60° horizontal field at baseline. Emmetropic eyes had relative myopia within but showed relative hyperopia beyond the central 30° field. However, there was no significant correlation between central refractive changes and baseline RPR or between changes in central refraction and RPR over twelve months in any refractive groups. Correlations between changes in PR and central myopic shift were found mainly in the nasal field in different groups. In the subgroup analysis on the initially emmetropic and the initially myopic groups, the subgroups with faster myopic progression did not have significantly different RPR from the subgroups with slower progression. The RPR pattern of the initially emmetropic and the initially myopic groups became more asymmetric at the end of the study period with a larger increase in relative hyperopia in the temporal field. RPR patterns were different among hyperopic, emmetropic and myopic eyes. However, baseline RPR and changes in RPR cannot predict changes in central refraction over time. Our results did not provide evidence to support the hypothesis of RPR as a causative factor for myopic central refractive changes in children. Ophthalmic

  6. Indifference to pain syndrome in a twelve-year-old boy (case report

    Directory of Open Access Journals (Sweden)

    Baghdadi T

    2007-08-01

    Full Text Available Background: People vary greatly in their response to painful stimuli, from those with a low pain threshold to those with indifference to pain. However, insensitivity to pain is a rare disorder, characterized by the lack of usual subjective and objective responses to noxious stimuli. Patients who have congenital indifference to pain sustain painless injuries beginning in infancy, but have sensory responses that are otherwise normal on examination. Perception of passive movement, joint position, and vibration is normal in these patients, as are tactile thresholds and light touch perception. Case report: A twelve-year-old boy was admitted to the hospital for a painless deformity, degeneration in both knees and a neglected femoral neck fracture that was inappropriately painless. Further examination revealed normal sensory responses, perception of passive movement, joint position, vibration tactile thresholds and light touch perception. Spinal cord and brain MRI were normal as was the electromyography and nerve conduction velocity (EMG/NCV examination. There was no positive family history for this disorder. Conclusion: The deficits present in the different pain insensitivity syndromes provide insight into the complex anatomical and physiological nature of pain perception. Reports on pain asymbolia, in which pain is perceived but does not cause suffering, and related cortical conditions illustrate that there can be losses that independently involve either the sensory-discriminative component or the affective-motivational component of pain perception, thus highlighting their different anatomical localization. The paucity of experience with this entity and the resultant diagnostic problems, the severity of the associated disabling arthropathy and underscore the importance of this case report of indifference to pain.

  7. Removal of trace level amounts of twelve sulfonamides from drinking water by UV-activated peroxymonosulfate.

    Science.gov (United States)

    Cui, Changzheng; Jin, Lei; Jiang, Lei; Han, Qi; Lin, Kuangfei; Lu, Shuguang; Zhang, Dong; Cao, Guomin

    2016-12-01

    Trace levels of residual antibiotics in drinking water may threaten public health and become a serious problem in modern society. In this work, we investigated the degradation of twelve sulfonamides (SAs) at environmentally relevant trace level concentrations by three different methods: ultraviolet (UV) photolysis, peroxymonosulfate (PMS) oxidation, and UV-activated PMS (UV/PMS). Sulfaguanidine, sulfadiazine, sulfamerazine, sulfamethazine, sulfathiazole, sulfamethoxydiazine, and sulfadimethoxine were be effectively removed by direct UV photolysis and PMS oxidation. However, sulfanilamide, sulfamethizole, sulfamethoxazole, sulfisoxazole, and sulfachloropyridazine were not completely degraded, despite prolonging the UV irradiation time to 30min or increasing the PMS concentration to 5.0mg·L(-1). UV/PMS provided more thorough elimination of SAs, as demonstrated by the complete removal of 200ng·L(-1) of all SAs within 5min at an initial PMS concentration of 1.0mg·L(-1). UV/PMS promoted SA decomposition more efficiently than UV photolysis or PMS oxidation alone. Bicarbonate concentration and pH had a negligible effect on SA degradation by UV/PMS. However, humic acid retarded the process. Removal of 200ng·L(-1) of each SA from a sample of sand-filtered effluent from a drinking water treatment plant (DWTPs) was quickly and completely achieved by UV/PMS. Meanwhile, about 41% of the total organic carbon (TOC) was eliminated. Scavenging experiments showed that sulfate radical (SO4(-)) was the predominant species involved in the degradation. It is concluded that UV/PMS is a rapid and efficient method for removing trace-level SAs from drinking water. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. A survey of innovation through duplication in the reduced genomes of twelve parasites.

    Directory of Open Access Journals (Sweden)

    Jeremy D DeBarry

    Full Text Available We characterize the prevalence, distribution, divergence, and putative functions of detectable two-copy paralogs and segmental duplications in the Apicomplexa, a phylum of parasitic protists. Apicomplexans are mostly obligate intracellular parasites responsible for human and animal diseases (e.g. malaria and toxoplasmosis. Gene loss is a major force in the phylum. Genomes are small and protein-encoding gene repertoires are reduced. Despite this genomic streamlining, duplications and gene family amplifications are present. The potential for innovation introduced by duplications is of particular interest. We compared genomes of twelve apicomplexans across four lineages and used orthology and genome cartography to map distributions of duplications against genome architectures. Segmental duplications appear limited to five species. Where present, they correspond to regions enriched for multi-copy and species-specific genes, pointing toward roles in adaptation and innovation. We found a phylum-wide association of duplications with dynamic chromosome regions and syntenic breakpoints. Trends in the distribution of duplicated genes indicate that recent, species-specific duplicates are often tandem while most others have been dispersed by genome rearrangements. These trends show a relationship between genome architecture and gene duplication. Functional analysis reveals: proteases, which are vital to a parasitic lifecycle, to be prominent in putative recent duplications; a pair of paralogous genes in Toxoplasma gondii previously shown to produce the rate-limiting step in dopamine synthesis in mammalian cells, a possible link to the modification of host behavior; and phylum-wide differences in expression and subcellular localization, indicative of modes of divergence. We have uncovered trends in multiple modes of duplicate divergence including sequence, intron content, expression, subcellular localization, and functions of putative recent duplicates that

  9. Characterizing gene-gene interactions in a statistical epistasis network of twelve candidate genes for obesity.

    Science.gov (United States)

    De, Rishika; Hu, Ting; Moore, Jason H; Gilbert-Diamond, Diane

    2015-01-01

    Recent findings have reemphasized the importance of epistasis, or gene-gene interactions, as a contributing factor to the unexplained heritability of obesity. Network-based methods such as statistical epistasis networks (SEN), present an intuitive framework to address the computational challenge of studying pairwise interactions between thousands of genetic variants. In this study, we aimed to analyze pairwise interactions that are associated with Body Mass Index (BMI) between SNPs from twelve genes robustly associated with obesity (BDNF, ETV5, FAIM2, FTO, GNPDA2, KCTD15, MC4R, MTCH2, NEGR1, SEC16B, SH2B1, and TMEM18). We used information gain measures to identify all SNP-SNP interactions among and between these genes that were related to obesity (BMI > 30 kg/m(2)) within the Framingham Heart Study Cohort; interactions exceeding a certain threshold were used to build an SEN. We also quantified whether interactions tend to occur more between SNPs from the same gene (dyadicity) or between SNPs from different genes (heterophilicity). We identified a highly connected SEN of 709 SNPs and 1241 SNP-SNP interactions. Combining the SEN framework with dyadicity and heterophilicity analyses, we found 1 dyadic gene (TMEM18, P-value = 0.047) and 3 heterophilic genes (KCTD15, P-value = 0.045; SH2B1, P-value = 0.003; and TMEM18, P-value = 0.001). We also identified a lncRNA SNP (rs4358154) as a key node within the SEN using multiple network measures. This study presents an analytical framework to characterize the global landscape of genetic interactions from genome-wide arrays and also to discover nodes of potential biological significance within the identified network.

  10. Thermal environment in eight low-energy and twelve conventional Finnish houses.

    Science.gov (United States)

    Kähkönen, Erkki; Salmi, Kari; Holopainen, Rauno; Pasanen, Pertti; Reijula, Kari

    2015-11-01

    We assessed the thermal environment of eight recently built low-energy houses and twelve conventional Finnish houses. We monitored living room, bedroom and outdoor air temperatures and room air relative humidity from June 2012 to September 2013. Perceived thermal environment was evaluated using a questionnaire survey during the heating, cooling and interim seasons. We compared the measured and perceived thermal environments of the low-energy and conventional houses. The mean air temperature was 22.8 °C (21.9-23.8 °C) in the low-energy houses, and 23.3 °C (21.4-26.5 °C) in the conventional houses during the summer (1. June 2013-31. August 2013). In the winter (1. December 2012-28. February 2013), the mean air temperature was 21.3 °C (19.8-22.5 °C) in the low-energy houses, and 21.6 °C (18.1-26.4 °C) in the conventional houses. The variation of the air temperature was less in the low-energy houses than that in the conventional houses. In addition, the occupants were on average slightly more satisfied with the indoor environment in the low-energy houses. However, there was no statistically significant difference between the mean air temperature and relative humidity of the low-energy and conventional houses. Our measurements and surveys showed that a good thermal environment can be achieved in both types of houses.

  11. Phytochemical screening of twelve species of phytoplankton isolated from Arabian Sea coast

    Directory of Open Access Journals (Sweden)

    Sushanth Vishwanath Rai

    2015-11-01

    Full Text Available Objective: To analyze the phytochemicals in twelve species of marine phytoplankton. Methods: Total phenolic content of methanol extract was estimated by the Folin-Ciocalteu method. Total flavonoid content of the methanol extarct was determined by aluminium chloride method. Chlorophylls, β-carotene and astaxanthin were estimated by acetone extraction method. Vitamin C was determined by dinitrophenyl-hydrazine method. Phycobiliproteins such as allophycocyanin, phycocyanin and phycoerythrin in the aqueous extracts were determined. Results: Total phenolics varied from 5.41 mg gallic acid equivalents/g dry weight (DW in Phormidium corium (P. corium to 17.37 mg gallic acid equivalents/g DW in Oscillatoria fremyii (O. fremyii. Total flavonoids ranged between 0.74 mg quercetin equivalent/g DW in P. corium and 9.87 mg quercetin equivalent/g DW in Nannochloropsis oceanica. Chlorophyll-a pigment was high in Chaetoceros calcitrans (C. calcitrans (15.51 mg/g DW and low in P. corium (1.08 mg/g DW. Chlorophyll-c ranged between 0.07 mg/g DW in Nannochloropsis oceanica and 4.62 mg/g DW in C. calcitrans. High contents of β-carotene and astaxanthin were found in C. calcitrans and low in P. corium which ranged from 0.33 to 10.03 mg/g DW and 0.18 to 3.85 mg/g DW, respectively. Vitamin C content varied from 0.50 mg/g DW in C. calcitrans to 1.51 mg/g DW in Phormidium tenue. O. fremyii showed highest total phycobiliproteins of 317.05 mg/g DW. High contents of allophycocyanin and phycocyanin were found in O. fremyii, whereas high contents of phycoerythrin were found in Oscillatoria sancta. All the three phycobiliproteins were low in Chroococcus turgidus. Conclusions: Marine phytoplankton are one of the natural sources providing novel biologically active compounds with potential for pharmaceutical applications.

  12. Segregation of PIP2 and PIP3 into distinct nanoscale regions within the plasma membrane

    Directory of Open Access Journals (Sweden)

    Jie Wang

    2012-07-01

    PIP2 and PIP3 are implicated in a wide variety of cellular signaling pathways at the plasma membrane. We have used STORM imaging to localize clusters of PIP2 and PIP3 to distinct nanoscale regions within the plasma membrane of PC12 cells. With anti-phospholipid antibodies directly conjugated with AlexaFluor 647, we found that PIP2 clusters in membrane domains of 64.5±27.558 nm, while PIP3 clusters had a size of 125.6±22.408 nm. With two color direct STORM imaging we show that >99% of phospholipid clusters have only one or other phospholipid present. These results indicate that lipid nano-domains can be readily identified using super-resolution imaging techniques, and that the lipid composition and size of clusters is tightly regulated.

  13. Profiles of exercise motivation, physical activity, exercise habit, and academic performance in Malaysian adolescents: A cluster analysis

    OpenAIRE

    Hairul Anuar Hashim; Freddy Golok; Rosmatunisah Ali

    2011-01-01

    Objectives: This study examined Malaysian adolescents’ profiles of exercise motivation, exercise habit strength, academic performance, and levels of physical activity (PA) using cluster analysis.Methods: The sample (n = 300) consisted of 65.6% males and 34.4% females with a mean age of 13.40 ± 0.49. Statistical analysis was performed using cluster analysis.Results: Cluster analysis revealed three distinct cluster groups. Cluster 1 is characterized by a moderate level of PA, relatively high in...

  14. Cluster analysis for applications

    CERN Document Server

    Anderberg, Michael R

    1973-01-01

    Cluster Analysis for Applications deals with methods and various applications of cluster analysis. Topics covered range from variables and scales to measures of association among variables and among data units. Conceptual problems in cluster analysis are discussed, along with hierarchical and non-hierarchical clustering methods. The necessary elements of data analysis, statistics, cluster analysis, and computer implementation are integrated vertically to cover the complete path from raw data to a finished analysis.Comprised of 10 chapters, this book begins with an introduction to the subject o

  15. Range-Clustering Queries

    OpenAIRE

    Abrahamsen, Mikkel; de Berg, Mark; Buchin, Kevin; Mehr, Mehran; Mehrabi, Ali D.

    2017-01-01

    In a geometric $k$-clustering problem the goal is to partition a set of points in $\\mathbb{R}^d$ into $k$ subsets such that a certain cost function of the clustering is minimized. We present data structures for orthogonal range-clustering queries on a point set $S$: given a query box $Q$ and an integer $k>2$, compute an optimal $k$-clustering for $S\\setminus Q$. We obtain the following results. We present a general method to compute a $(1+\\epsilon)$-approximation to a range-clustering query, ...

  16. Cluster Decline and Resilience

    DEFF Research Database (Denmark)

    Østergaard, Christian Richter; Park, Eun Kyung

    -2011. Our longitudinal study reveals that technological lock-in and exit of key firms have contributed to impairment of the cluster’s resilience in adapting to disruptions. Entrepreneurship has a positive effect on cluster resilience, while multinational companies have contradicting effects by bringing......Most studies on regional clusters focus on identifying factors and processes that make clusters grow. However, sometimes technologies and market conditions suddenly shift, and clusters decline. This paper analyses the process of decline of the wireless communication cluster in Denmark, 1963...

  17. Management of cluster headache

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Peer C; Jensen, Rigmor H

    2012-01-01

    and agitation. Patients may have up to eight attacks per day. Episodic cluster headache (ECH) occurs in clusters of weeks to months duration, whereas chronic cluster headache (CCH) attacks occur for more than 1 year without remissions. Management of cluster headache is divided into acute attack treatment....... In drug-resistant CCH, neuromodulation with either occipital nerve stimulation or deep brain stimulation of the hypothalamus is an alternative treatment strategy. For most cluster headache patients there are fairly good treatment options both for acute attacks and for prophylaxis. The big problem...

  18. Myofascial trigger points in cluster headache patients: a case series

    Directory of Open Access Journals (Sweden)

    Rico-Villademoros Fernando

    2008-12-01

    Full Text Available Abstract Active myofascial trigger points (MTrPs have been found to contribute to chronic tension-type headache and migraine. The purpose of this case series was to examine if active trigger points (TrPs provoking cluster-type referred pain could be found in cluster headache patients and, if so, to evaluate the effectiveness of active TrPs anaesthetic injections both in the acute and preventive headache's treatment. Twelve patients, 4 experiencing episodic and 8 chronic cluster headache, were studied. TrPs were found in all of them. Abortive infiltrations could be done in 2 episodic and 4 chronic patients, and preemptive infiltrations could be done in 2 episodic and 5 chronic patients, both kind of interventions being successful in 5 (83.3% and in 6 (85.7% of the cases respectively. When combined with prophylactic drug therapy, injections were associated with significant improvement in 7 of the 8 chronic cluster patients. Our data suggest that peripheral sensitization may play a role in cluster headache pathophysiology and that first neuron afferent blockade can be useful in cluster headache management.

  19. Clustering Time Series Data Stream - A Literature Survey

    CERN Document Server

    Kavitha, V

    2010-01-01

    Mining Time Series data has a tremendous growth of interest in today's world. To provide an indication various implementations are studied and summarized to identify the different problems in existing applications. Clustering time series is a trouble that has applications in an extensive assortment of fields and has recently attracted a large amount of research. Time series data are frequently large and may contain outliers. In addition, time series are a special type of data set where elements have a temporal ordering. Therefore clustering of such data stream is an important issue in the data mining process. Numerous techniques and clustering algorithms have been proposed earlier to assist clustering of time series data streams. The clustering algorithms and its effectiveness on various applications are compared to develop a new method to solve the existing problem. This paper presents a survey on various clustering algorithms available for time series datasets. Moreover, the distinctiveness and restriction ...

  20. Cluster headache and sleep, is there a connection?

    DEFF Research Database (Denmark)

    Barløse, Mads; Jennum, P; Knudsen, S

    2012-01-01

    PURPOSE OF REVIEW: Sleep and the chronobiological disease cluster headache are believed to be interconnected. Despite efforts, the precise nature of the relationship remains obscured. A better understanding of this relation may lead to more effective therapeutic regimes for patients suffering from...... this debilitating disease. This review aims to evaluate the existing literature on the subject of cluster headache and sleep. LATEST FINDINGS: Several previous studies describe an association between episodic cluster headache and distinct macrostructural sleep phases. This association was not confirmed in a recent...... study of seven episodic cluster headache patients, but it was suggested that further studies into the correlation between cluster headache attacks and the microstructure of sleep are relevant. The connection between cluster headache and the hypocretins is currently under investigation. SUMMARY...

  1. Ab initio Calculations of Optical Properties of Clusters

    CERN Document Server

    Shinde, Ravindra

    2016-01-01

    We have performed systematic large-scale all-electron correlated calculations on boron Bn, aluminum Aln and magnesium Mgn clusters (n=2--5), to study their linear optical absorption spectra. Several possible isomers of each cluster were considered, and their geometries were optimized at the coupled-cluster singles doubles (CCSD) level of theory. Using the optimized ground-state geometries, excited states of different clusters were computed using the multi-reference singles-doubles configuration interaction (MRSDCI) approach, which includes electron correlation effects at a sophisticated level. These CI wavefunctions were used to compute the transition dipole matrix elements connecting the ground and various excited states of different clusters, eventually leading to their linear absorption spectra. The convergence of our results with respect to the basis sets, and the size of the CI expansion was carefully examined. Isomers of a given cluster show a distinct signature spectrum, indicating a strong structure p...

  2. Clusters in nuclei

    CERN Document Server

    Following the pioneering discovery of alpha clustering and of molecular resonances, the field of nuclear clustering is today one of those domains of heavy-ion nuclear physics that faces the greatest challenges, yet also contains the greatest opportunities. After many summer schools and workshops, in particular over the last decade, the community of nuclear molecular physicists has decided to collaborate in producing a comprehensive collection of lectures and tutorial reviews covering the field. This third volume follows the successful Lect. Notes Phys. 818 (Vol. 1) and 848 (Vol. 2), and comprises six extensive lectures covering the following topics:  - Gamma Rays and Molecular Structure - Faddeev Equation Approach for Three Cluster Nuclear Reactions - Tomography of the Cluster Structure of Light Nuclei Via Relativistic Dissociation - Clustering Effects Within the Dinuclear Model : From Light to Hyper-heavy Molecules in Dynamical Mean-field Approach - Clusterization in Ternary Fission - Clusters in Light N...

  3. Spatial cluster modelling

    CERN Document Server

    Lawson, Andrew B

    2002-01-01

    Research has generated a number of advances in methods for spatial cluster modelling in recent years, particularly in the area of Bayesian cluster modelling. Along with these advances has come an explosion of interest in the potential applications of this work, especially in epidemiology and genome research. In one integrated volume, this book reviews the state-of-the-art in spatial clustering and spatial cluster modelling, bringing together research and applications previously scattered throughout the literature. It begins with an overview of the field, then presents a series of chapters that illuminate the nature and purpose of cluster modelling within different application areas, including astrophysics, epidemiology, ecology, and imaging. The focus then shifts to methods, with discussions on point and object process modelling, perfect sampling of cluster processes, partitioning in space and space-time, spatial and spatio-temporal process modelling, nonparametric methods for clustering, and spatio-temporal ...

  4. Unconventional methods for clustering

    Science.gov (United States)

    Kotyrba, Martin

    2016-06-01

    Cluster analysis or clustering is a task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more similar (in some sense or another) to each other than to those in other groups (clusters). It is the main task of exploratory data mining and a common technique for statistical data analysis used in many fields, including machine learning, pattern recognition, image analysis, information retrieval, and bioinformatics. The topic of this paper is one of the modern methods of clustering namely SOM (Self Organising Map). The paper describes the theory needed to understand the principle of clustering and descriptions of algorithm used with clustering in our experiments.

  5. Penoscrotal porokeratosis: A distinct entity

    Directory of Open Access Journals (Sweden)

    Rajiv Joshi

    2015-01-01

    Full Text Available A 26-year-old man presented with five months history of redness associated with itching and burning over the scrotum and shaft of the penis with a persistent rash on those sites. There had been no response to topical steroid and antifungal creams. Clinical examination revealed a large well-circumscribed erythematous plaque with a thready raised border with a tiny groove at its summit that involved almost two-thirds of the ventral part of the shaft of the penis. Ill-defined erythema with a granular surface was seen over the anterior scrotal skin. A 4 mm punch biopsy of the plaque on the penile shaft revealed multiple cornoid lamellae located adjacent to one another. The patient was treated with topical emollients. Follow up after four months revealed almost complete resolution of the plaque on the penile shaft. Penoscrotal porokeratosis appears to be a distinct entity in the family of porokeratotic diseases, described only in young males in their twenties with involvement of the penile shaft and anterior scrotum with severe burning and itching and histologically associated with multiple cornoid lamellae. It may represent an unusual epidermal porokeratotic reaction pattern and may be a self-resolving condition.

  6. Combined Mapping of Multiple clUsteriNg ALgorithms (COMMUNAL): A Robust Method for Selection of Cluster Number, K.

    Science.gov (United States)

    Sweeney, Timothy E; Chen, Albert C; Gevaert, Olivier

    2015-11-19

    In order to discover new subsets (clusters) of a data set, researchers often use algorithms that perform unsupervised clustering, namely, the algorithmic separation of a dataset into some number of distinct clusters. Deciding whether a particular separation (or number of clusters, K) is correct is a sort of 'dark art', with multiple techniques available for assessing the validity of unsupervised clustering algorithms. Here, we present a new technique for unsupervised clustering that uses multiple clustering algorithms, multiple validity metrics, and progressively bigger subsets of the data to produce an intuitive 3D map of cluster stability that can help determine the optimal number of clusters in a data set, a technique we call COmbined Mapping of Multiple clUsteriNg ALgorithms (COMMUNAL). COMMUNAL locally optimizes algorithms and validity measures for the data being used. We show its application to simulated data with a known K, and then apply this technique to several well-known cancer gene expression datasets, showing that COMMUNAL provides new insights into clustering behavior and stability in all tested cases. COMMUNAL is shown to be a useful tool for determining K in complex biological datasets, and is freely available as a package for R.

  7. CLEAN: CLustering Enrichment ANalysis

    Directory of Open Access Journals (Sweden)

    Medvedovic Mario

    2009-07-01

    Full Text Available Abstract Background Integration of biological knowledge encoded in various lists of functionally related genes has become one of the most important aspects of analyzing genome-wide functional genomics data. In the context of cluster analysis, functional coherence of clusters established through such analyses have been used to identify biologically meaningful clusters, compare clustering algorithms and identify biological pathways associated with the biological process under investigation. Results We developed a computational framework for analytically and visually integrating knowledge-based functional categories with the cluster analysis of genomics data. The framework is based on the simple, conceptually appealing, and biologically interpretable gene-specific functional coherence score (CLEAN score. The score is derived by correlating the clustering structure as a whole with functional categories of interest. We directly demonstrate that integrating biological knowledge in this way improves the reproducibility of conclusions derived from cluster analysis. The CLEAN score differentiates between the levels of functional coherence for genes within the same cluster based on their membership in enriched functional categories. We show that this aspect results in higher reproducibility across independent datasets and produces more informative genes for distinguishing different sample types than the scores based on the traditional cluster-wide analysis. We also demonstrate the utility of the CLEAN framework in comparing clusterings produced by different algorithms. CLEAN was implemented as an add-on R package and can be downloaded at http://Clusteranalysis.org. The package integrates routines for calculating gene specific functional coherence scores and the open source interactive Java-based viewer Functional TreeView (FTreeView. Conclusion Our results indicate that using the gene-specific functional coherence score improves the reproducibility of the

  8. Survey on Text Document Clustering

    OpenAIRE

    M.Thangamani; Dr.P.Thangaraj

    2010-01-01

    Document clustering is also referred as text clustering, and its concept is merely equal to data clustering. It is hardly difficult to find the selective information from an ‘N’number of series information, so that document clustering came into picture. Basically cluster means a group of similar data, document clustering means segregating the data into different groups of similar data. Clustering can be of mathematical, statistical or numerical domain. Clustering is a fundamental data analysi...

  9. Phytochemical screening of twelve species of phytoplankton isolated from Arabian Sea coast

    Institute of Scientific and Technical Information of China (English)

    Sushanth Vishwanath Rai; Madaiah Rajashekhar

    2015-01-01

    Objective:To analyze the phytochemicals in twelve species of marine phytoplankton. Methods: Total phenolic content of methanol extract was estimated by the Folin-Ciocalteu method. Total flavonoid content of the methanol extarct was determined by aluminium chloride method. Chlorophylls,β-carotene and astaxanthin were estimated by acetone extraction method. Vitamin C was determined by dinitrophenyl-hydrazine method. Phycobiliproteins such as allophycocyanin, phycocyanin and phycoerythrin in the aqueous extracts were determined. Results: Total phenolics varied from 5.41 mg gallic acid equivalents/g dry weight (DW) in Phormidium corium (P. corium) to 17.37 mg gallic acid equivalents/g DW inOscillatoria fremyii(O. fremyii). Total flavonoids ranged between 0.74 mg quercetin equivalent/g DW inP. corium and 9.87 mg quercetin equivalent/g DW inNannochloropsis oceanica. Chlorophyll-a pigment was high inChaetoceros calcitrans(C. calcitrans)(15.51 mg/g DW) and low inP. corium (1.08 mg/g DW). Chlorophyll-c ranged between 0.07 mg/g DW inNannochloropsis oceanica and 4.62 mg/g DW inC. calcitrans. High contents ofβ-carotene and astaxanthin were found inC. calcitrans and low inP. corium which ranged from 0.33 to 10.03 mg/g DW and 0.18 to 3.85 mg/g DW, respectively. Vitamin C content varied from 0.50 mg/g DW inC. calcitrans to 1.51 mg/g DW inPhormidium tenue.O. fremyii showed highest total phycobiliproteins of 317.05 mg/g DW. High contents of allophycocyanin and phycocyanin were found inO. fremyii, whereas high contents of phycoerythrin were found inOscillatoria sancta. All the three phycobiliproteins were low inChroococcus turgidus. Conclusions: Marine phytoplankton are one of the natural sources providing novel biologically active compounds with potential for pharmaceutical applications.

  10. Nutrient Contents per Serving of Twelve Varieties of Cooked Rice Marketed in Jordan

    Directory of Open Access Journals (Sweden)

    Jafar M. El-Qudah

    2008-01-01

    Full Text Available Jordan imports rice from different countries without any quality preferences. Twelve varieties of cooked rice marketed in Jordan were analyzed. The content per serving of these varieties were computed for energy, protein, carbohydrates, fat, calcium, sodium, potassium, magnesium, manganese, copper, iron and phosphorous. The protein content per serving found to range from 0.49 g for La Cigala rice to 6.2 g for Harvest rice. The fat content for all rice brands was less than 0.37 g per serving. The energy content ranged from 172.12 g/serving for Basmati rice to 212.25 g/serving for Sun White rice. Generally, all rice varieties contain significant amounts of minerals per serving. Ruzzana found to contain the highest level of calcium (38.2 mg/serving and Amber the lowest calcium content (6.7 mg/serving. Magnesium content found to range from 5.7 mg/serving for Royal Umberella rice to 16.3 mg/serving for Ruzzana rice. Consumption of one serving of Harvest cooked rice will cover 13.5% of the daily requirement of protein for females and 11.1% for males. Manganese content of one serving of Harvest, Sun White, Abu bent and La Cigala will cover 22.2% of the daily requirements for females and 14.7% for males, while consumption of one of Basmati, Sos rice or Amber will cover only 11.1% and 8.75 of requirement for females and males respectively. Planning a healthful diet is not a simple task. Dietary Reference Intake planning and assessing the diets of individuals or groups of healthy individuals according to their stage of life and sex. Food choice is a function of many factors, including personal preferences, habits, ethnic heritage and tradition. Dietary guidelines for Americans, consider whole grain products like rice are among the food groups that form the basis of a healthy diet. Including rice as part of a healthy, balanced diet can be linked to overall healthier eating patterns. Rice eaters are more likely to eat a diet consistent with the 2005 Dietary

  11. Risk factors for chronic noncontiguous diseases: Twelve-week prospective study

    Directory of Open Access Journals (Sweden)

    Lapčević Mirjana

    2004-01-01

    basis of RF number and combination for genesis and development of CND in our sample, 74.7% of variability (development or risk may be accounted for angina pectoris (AP, 74.2% for DM+HTA, 70.0% for DM, 79.9% for HTA, 80.8% for myocardial infarction (Ml, and 85.8% of variability (development or risk for cerebrovascular insult (CVI. Twelve-week intervention resulted in reduction of HTA, HLP, glucose, and PC (p<0.001 levels as well as lower BMI and PA (p<0.5. To accomplish the aforementioned goals, continuous mutual activity of an individual, his/her family, health service and community is required, along with occasional evaluation of the obtained results.

  12. Experiencing a constructivist museum exhibit: A case study of twelve children and their families

    Science.gov (United States)

    Hill, Martha Anne Leech

    2002-04-01

    The American Association for the Advancement of Science and the National Research Council have called for the creation of a scientifically literate populace and introduced science standards and guidelines to direct this process. Science education in traditional school settings plays a key role in reaching this goal, but individuals over their lifetimes will have more exposure to science ideas through informal science experiences such as visits to museums and through diverse media sources. The purpose of this study was to explore the role museums play in this journey to science literacy. This qualitative collective case study examined the experience of 12 children and their families in a children's museum as they interacted with an exhibit designed along the tenets of constructivist theory to introduce children to ideas of science. Twelve children and their families were videotaped interacting with a model of a watershed that included the stream, surrounding land, gravel, and dam building and erosion abatement manipulatives. Children were interviewed to ascertain their stream-related ideas and conceptual understanding prior to and after using the exhibit. Parents completed demographic and post-exhibit experience questionnaires. Two museum staff members who played key roles in the development of the exhibit and surrounding gallery were also interviewed. Individual and cross-case analyses were done to describe the experience of each child and family, and to elucidate the commonalities of these experiences to describe the phenomenon of using a constructivist-based science exhibit. Results of the study indicate (1) the type of experience children and families had at the exhibit depended on child and parent interactions and roles each assumed, and (2) experience with the exhibit encouraged children to think more deeply about water topics, past experiences, and ideas they had previously constructed. Implications of this research include (1) parents should engage children

  13. [Risk factors for chronic noncontiguous diseases: twelve-week prospective study].

    Science.gov (United States)

    Lapcević, Mirjana; Vuković, Mira

    2004-01-01

    RF number and combination for genesis and development of CND in our sample, 74.7% of variability (development or risk) may be accounted for angina pectoris (AP), 74.2% for DM+HTA, 70.0% for DM, 79.9% for HTA, 80.8% for myocardial infarction (MI), and 85.8% of variability (development or risk) for cerebrovascular insult (CVI). Twelve-week intervention resulted in reduction of HTA, HLP, glucose, and PC (p<0.001) levels as well as lower BMI and PA (p<0.5). To accomplish the aforementioned goals, continuous mutual activity of an individual, his/her family, health service and community is required, along with occasional evaluation of the obtained results.

  14. Clustering analysis of seismicity and aftershock identification.

    Science.gov (United States)

    Zaliapin, Ilya; Gabrielov, Andrei; Keilis-Borok, Vladimir; Wong, Henry

    2008-07-01

    We introduce a statistical methodology for clustering analysis of seismicity in the time-space-energy domain and use it to establish the existence of two statistically distinct populations of earthquakes: clustered and nonclustered. This result can be used, in particular, for nonparametric aftershock identification. The proposed approach expands the analysis of Baiesi and Paczuski [Phys. Rev. E 69, 066106 (2004)10.1103/PhysRevE.69.066106] based on the space-time-magnitude nearest-neighbor distance eta between earthquakes. We show that for a homogeneous Poisson marked point field with exponential marks, the distance eta has the Weibull distribution, which bridges our results with classical correlation analysis for point fields. The joint 2D distribution of spatial and temporal components of eta is used to identify the clustered part of a point field. The proposed technique is applied to several seismicity models and to the observed seismicity of southern California.

  15. Agricultural Clusters in the Netherlands

    NARCIS (Netherlands)

    Schouten, M.A.; Heijman, W.J.M.

    2012-01-01

    Michael Porter was the first to use the term cluster in an economic context. He introduced the term in The Competitive Advantage of Nations (1990). The term cluster is also known as business cluster, industry cluster, competitive cluster or Porterian cluster. This article aims at determining and

  16. Agricultural Clusters in the Netherlands

    NARCIS (Netherlands)

    Schouten, M.A.; Heijman, W.J.M.

    2012-01-01

    Michael Porter was the first to use the term cluster in an economic context. He introduced the term in The Competitive Advantage of Nations (1990). The term cluster is also known as business cluster, industry cluster, competitive cluster or Porterian cluster. This article aims at determining and mea

  17. Agricultural Clusters in the Netherlands

    NARCIS (Netherlands)

    Schouten, M.A.; Heijman, W.J.M.

    2012-01-01

    Michael Porter was the first to use the term cluster in an economic context. He introduced the term in The Competitive Advantage of Nations (1990). The term cluster is also known as business cluster, industry cluster, competitive cluster or Porterian cluster. This article aims at determining and mea

  18. The Impact of the Financial Crisis on the Content of Twelve Bestselling US Principles of Economics Textbooks

    DEFF Research Database (Denmark)

    Madsen, Poul Thøis

    2013-01-01

    How have authors of twelve bestselling introductory US textbooks in economics responded to the traumatizing financial crisis? In general the financial crisis is described with a couple of lines here and there or it is dealt with in boxes, separate sections, or specific isolated chapters. Some...... of the textbooks distinguish themselves by also having made some modest qualitative changes of content as a reaction to the financial crisis (especially Colander 2010 and Krugman and Wells 2013). Applying my general analysis of the changes being made already in the twelve textbooks seen as a whole, I discuss how...... any introductory textbook could integrate the financial crisis more adequately into the general presentation, thereby hopefully contributing to enhancing the interest of the students....

  19. Spectroscopic Constraints on the Form of the Stellar Cluster Mass Function

    CERN Document Server

    Bastian, N; Trancho, G; Weisz, D R; Larsen, S S; Fouesneau, M; Kaschinski, C B; Gieles, M

    2012-01-01

    This contribution addresses the question of whether the initial cluster mass function (ICMF) has a fundamental limit (or truncation) at high masses. The shape of the ICMF at high masses can be studied using the most massive young (<10 Myr) clusters, however this has proven difficult due to low-number statistics. In this contribution we use an alternative method based on the luminosities of the brightest clusters, combined with their ages. If a truncation is present, a generic prediction (nearly independent of the cluster disruption law adopted) is that the median age of bright clusters should be younger than that of fainter clusters. In the case of an non-truncated ICMF, the median age should be independent of cluster luminosity. Here, we present optical spectroscopy of twelve young stellar clusters in the face-on spiral galaxy NGC 2997. The spectra are used to estimate the age of each cluster, and the brightness of the clusters is taken from the literature. The observations are compared with the model exp...

  20. CSR in Industrial Clusters

    DEFF Research Database (Denmark)

    Lund-Thomsen, Peter; Pillay, Renginee G.

    2012-01-01

    Purpose – The paper seeks to review the literature on CSR in industrial clusters in developing countries, identifying the main strengths, weaknesses, and gaps in this literature, pointing to future research directions and policy implications in the area of CSR and industrial cluster development...... in this field and their comments incorporated in the final version submitted to Corporate Governance. Findings – The article traces the origins of the debate on industrial clusters and CSR in developing countries back to the early 1990s when clusters began to be seen as an important vehicle for local economic...... development in the South. At the turn of the millennium the industrial cluster debate expanded as clusters were perceived as a potential source of poverty reduction, while their role in promoting CSR among small and medium-sized enterprises began to take shape from 2006 onwards. At present, there is still...

  1. Cosmology with cluster surveys

    Indian Academy of Sciences (India)

    Subhabrata Majumdar

    2004-10-01

    Surveys of clusters of galaxies provide us with a powerful probe of the density and nature of the dark energy. The red-shift distribution of detected clusters is highly sensitive to the dark energy equation of state parameter . Upcoming Sunyaev–Zel'dovich (SZ) surveys would provide us large yields of clusters to very high red-shifts. Self-calibration of cluster scaling relations, possible for such a huge sample, would be able to constrain systematic biases on mass estimators. Combining cluster red-shift abundance with limited mass follow-up and cluster mass power spectrum can then give constraints on , as well as on 8 and to a few per cents.

  2. Disentangling Porterian Clusters

    DEFF Research Database (Denmark)

    Jagtfelt, Tue

    This dissertation investigates the contemporary phenomenon of industrial clusters based on the work of Michael E. Porter, the central progenitor and promoter of the cluster notion. The dissertation pursues two central questions: 1) What is a cluster? and 2) How could Porter’s seemingly fuzzy......, contested theory become so widely disseminated and applied as a normative and prescriptive strategy for economic development? The dissertation traces the introduction of the cluster notion into the EU’s Lisbon Strategy and demonstrates how its inclusion originates from Porter’s colleagues: Professor Örjan...... Sölvell, Dr. Christian Ketels and Dr. Göran Lindqvist. Taking departure in Porter’s works and the cluster literature, the dissertations shows a considerable paradigmatic shift has occurred from the first edition of Nations to the present state of cluster cooperation. To elaborate on this change...

  3. Online Correlation Clustering

    CERN Document Server

    Mathieu, Claire; Schudy, Warren

    2010-01-01

    We study the online clustering problem where data items arrive in an online fashion. The algorithm maintains a clustering of data items into similarity classes. Upon arrival of v, the relation between v and previously arrived items is revealed, so that for each u we are told whether v is similar to u. The algorithm can create a new cluster for v and merge existing clusters. When the objective is to minimize disagreements between the clustering and the input, we prove that a natural greedy algorithm is O(n)-competitive, and this is optimal. When the objective is to maximize agreements between the clustering and the input, we prove that the greedy algorithm is .5-competitive; that no online algorithm can be better than .834-competitive; we prove that it is possible to get better than 1/2, by exhibiting a randomized algorithm with competitive ratio .5+c for a small positive fixed constant c.

  4. Cluster Management Institutionalization

    DEFF Research Database (Denmark)

    Normann, Leo; Agger Nielsen, Jeppe

    2015-01-01

    This article explores a new management form – cluster management – in Danish public sector day care. Although cluster management has been widely adopted in Danish day care at the municipality level, it has attracted only sparse research attention. We use theoretical insights from Scandinavian...... institutionalism together with a longitudinal case-based inquiry into how cluster management has entered and penetrated the management practices of day care in Denmark. We demonstrate how cluster management became widely adopted in the day care field not only because of its intrinsic properties but also because...... of how it was legitimized as a “ready-to-use” management model. Further, our account reveals how cluster management translated into considerably different local variants as it travelled into specific organizations. However, these processes have not occurred sequentially with cluster management first...

  5. Cluster Correspondence Analysis.

    Science.gov (United States)

    van de Velden, M; D'Enza, A Iodice; Palumbo, F

    2017-03-01

    A method is proposed that combines dimension reduction and cluster analysis for categorical data by simultaneously assigning individuals to clusters and optimal scaling values to categories in such a way that a single between variance maximization objective is achieved. In a unified framework, a brief review of alternative methods is provided and we show that the proposed method is equivalent to GROUPALS applied to categorical data. Performance of the methods is appraised by means of a simulation study. The results of the joint dimension reduction and clustering methods are compared with the so-called tandem approach, a sequential analysis of dimension reduction followed by cluster analysis. The tandem approach is conjectured to perform worse when variables are added that are unrelated to the cluster structure. Our simulation study confirms this conjecture. Moreover, the results of the simulation study indicate that the proposed method also consistently outperforms alternative joint dimension reduction and clustering methods.

  6. Cluster Management Institutionalization

    DEFF Research Database (Denmark)

    Normann, Leo; Agger Nielsen, Jeppe

    2015-01-01

    of how it was legitimized as a “ready-to-use” management model. Further, our account reveals how cluster management translated into considerably different local variants as it travelled into specific organizations. However, these processes have not occurred sequentially with cluster management first......This article explores a new management form – cluster management – in Danish public sector day care. Although cluster management has been widely adopted in Danish day care at the municipality level, it has attracted only sparse research attention. We use theoretical insights from Scandinavian...... institutionalism together with a longitudinal case-based inquiry into how cluster management has entered and penetrated the management practices of day care in Denmark. We demonstrate how cluster management became widely adopted in the day care field not only because of its intrinsic properties but also because...

  7. Roche volume filling of star clusters in the Milky Way

    Science.gov (United States)

    Ernst, A.; Just, A.

    2013-03-01

    We examine the ratios rh/rJ of projected half-mass and Jacobi radius as well as rt/rJ of tidal and Jacobi radius for open and globular clusters in the Milky Way using data of both observations and simulations. We applied an improved calculation of rJ for eccentric orbits of globular clusters. A sample of 236 open clusters of Piskunov et al. within the nearest kiloparsec around the Sun has been used. For the Milky Way globular clusters, data are taken from the Harris catalogue. We particularly use the subsample of 38 Milky Way globular clusters for which orbits have been integrated by Dinescu et al. We aim to quantify the differences between open and globular clusters and to understand, why they form two intrinsically distinct populations. We find under certain assumptions, or, in other words, in certain approximations (i) that globular clusters are presently Roche volume underfilling, (ii) with at least 3σ confidence that the ratio rh/rJ of half-mass and Jacobi radius is three to five times larger at present for an average open cluster in our sample than for an average globular cluster in our sample and (iii) that a significant fraction of globular clusters may be Roche volume overfilling at pericentre with rt > rJ. Another aim of this paper is to throw light on the underlying theoretical reason for the existence of the van den Bergh correlation between half-mass and Galactocentric radius.

  8. Clustering Categorical Data:A Cluster Ensemble Approach

    Institute of Scientific and Technical Information of China (English)

    He Zengyou(何增友); Xu Xiaofei; Deng Shengchun

    2003-01-01

    Clustering categorical data, an integral part of data mining,has attracted much attention recently. In this paper, the authors formally define the categorical data clustering problem as an optimization problem from the viewpoint of cluster ensemble, and apply cluster ensemble approach for clustering categorical data. Experimental results on real datasets show that better clustering accuracy can be obtained by comparing with existing categorical data clustering algorithms.

  9. Spatial Scan Statistic: Selecting clusters and generating elliptic clusters

    DEFF Research Database (Denmark)

    Christiansen, Lasse Engbo; Andersen, Jens Strodl

    2004-01-01

    The spatial scan statistic is widely used to search for clusters. This paper shows that the usually applied elimination of overlapping clusters to find secondary clusters is sensitive to smooth changes in the shape of the clusters. We present an algorithm for generation of set of confocal elliptic...... clusters. In addition, we propose a new way to present the information in a given set of clusters based on the significance of the clusters....

  10. Clustering of Absorbers

    CERN Document Server

    Cristiani, S; D'Odorico, V; Fontana, A; Giallongo, E; Moscardini, L; Savaglio, S

    1997-01-01

    The observed clustering of Lyman-$\\alpha$ lines is reviewed and compared with the clustering of CIV systems. We argue that a continuity of properties exists between Lyman-$\\alpha$ and metal systems and show that the small-scale clustering of the absorbers is consistent with a scenario of gravitationally induced correlations. At large scales statistically significant over and under-densities (including voids) are found on scales of tens of Mpc.

  11. Clustering Techniques in Bioinformatics

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Masood

    2015-01-01

    Full Text Available Dealing with data means to group information into a set of categories either in order to learn new artifacts or understand new domains. For this purpose researchers have always looked for the hidden patterns in data that can be defined and compared with other known notions based on the similarity or dissimilarity of their attributes according to well-defined rules. Data mining, having the tools of data classification and data clustering, is one of the most powerful techniques to deal with data in such a manner that it can help researchers identify the required information. As a step forward to address this challenge, experts have utilized clustering techniques as a mean of exploring hidden structure and patterns in underlying data. Improved stability, robustness and accuracy of unsupervised data classification in many fields including pattern recognition, machine learning, information retrieval, image analysis and bioinformatics, clustering has proven itself as a reliable tool. To identify the clusters in datasets algorithm are utilized to partition data set into several groups based on the similarity within a group. There is no specific clustering algorithm, but various algorithms are utilized based on domain of data that constitutes a cluster and the level of efficiency required. Clustering techniques are categorized based upon different approaches. This paper is a survey of few clustering techniques out of many in data mining. For the purpose five of the most common clustering techniques out of many have been discussed. The clustering techniques which have been surveyed are: K-medoids, K-means, Fuzzy C-means, Density-Based Spatial Clustering of Applications with Noise (DBSCAN and Self-Organizing Map (SOM clustering.

  12. Structures in Galaxy Clusters

    CERN Document Server

    Escalera, E; Girardi, M; Giuricin, G; Mardirossian, F; Mazure, A; Mezzetti, M

    1993-01-01

    The analysis of the presence of substructures in 16 well-sampled clusters of galaxies suggests a stimulating hypothesis: Clusters could be classified as unimodal or bimodal, on the basis of to the sub-clump distribution in the {\\em 3-D} space of positions and velocities. The dynamic study of these clusters shows that their fundamental characteristics, in particular the virial masses, are not severely biased by the presence of subclustering if the system considered is bound.

  13. Radicular anatomy of twelve representatives of the Catasetinae subtribe (Orchidaceae: Cymbidieae

    Directory of Open Access Journals (Sweden)

    Cristiano Pedroso-de-Moraes

    2012-06-01

    Full Text Available Considering that the root structure of the Brazilian genera belonging to the Catasetinae subtribe is poorly known, we describe the roots of twelve representatives from this subtribe. For anatomical analysis, the roots were fixed in FAA 50, preserved in ethanol 70% and sectioned at its medium region using razor blades. The sections were stained with 0.05% astra blue and safranin and mounted in glycerin. For the identification of starch we used Lugol's solution; for lignin, floroglucin chloridric; for lipids, Sudan III, and for flavanoids, potassium hydroxide. The relevant aspects were registered using a digital camera joined with an Olympus microspope (BX51 model. The structural similarities of all roots support the placement of the subtribe Catasetinae into the monophyletic tribe Cymbidieae. Some root features are restricted to one or two taxa and can be useful in the systematics of the subtribe. For example, the occurrence of flavonoidic crystals characterizes the genera Catasetum and Cychnodes, and the number of the velamen layers and the shape of the epivelamen cells are useful to confirm the taxonomic position of Clowesia amazonica. The presence of velamen and flavonoidic crystals was interpreted as an adaptation to the epiphytic habit.Considerando que a estrutura das raízes de gêneros brasileiros pertencentes à subtribo Catasetinae é pouco conhecida, descrevemos as raízes de doze representantes desta subtribo. Para análise anatômica, as raízes foram fixadas em FAA 50, preservadas em álcool 70% e seccionadas na sua região média usando lâminas de barbear. Os cortes foram corados com astra blue e Safrablau 0,05% e montados em glicerina. Para a identificação do amido, utilizou-se a solução de Lugol; da lignina, floroglucina clorídrica, dos lipídios, Sudan III e dos flavonóides, hidróxido de potássio. Os aspectos relevantes foram registrados usando câmera digital acoplada a um microscópio Olympus (modelo BX51. As semelhan

  14. The Youngest Globular Clusters

    CERN Document Server

    Beck, Sara

    2014-01-01

    It is likely that all stars are born in clusters, but most clusters are not bound and disperse. None of the many protoclusters in our Galaxy are likely to develop into long-lived bound clusters. The Super Star Clusters (SSCs) seen in starburst galaxies are more massive and compact and have better chances of survival. The birth and early development of SSCs takes place deep in molecular clouds, and during this crucial stage the embedded clusters are invisible to optical or UV observations but are studied via the radio-infared supernebulae (RISN) they excite. We review observations of embedded clusters and identify RISN within 10 Mpc whose exciting clusters have a million solar masses or more in volumes of a few cubic parsecs and which are likely to not only survive as bound clusters, but to evolve into objects as massive and compact as Galactic globulars. These clusters are distinguished by very high star formation efficiency eta, at least a factor of 10 higher than the few percent seen in the Galaxy, probably...

  15. Star Clusters within FIRE

    Science.gov (United States)

    Perez, Adrianna; Moreno, Jorge; Naiman, Jill; Ramirez-Ruiz, Enrico; Hopkins, Philip F.

    2017-01-01

    In this work, we analyze the environments surrounding star clusters of simulated merging galaxies. Our framework employs Feedback In Realistic Environments (FIRE) model (Hopkins et al., 2014). The FIRE project is a high resolution cosmological simulation that resolves star forming regions and incorporates stellar feedback in a physically realistic way. The project focuses on analyzing the properties of the star clusters formed in merging galaxies. The locations of these star clusters are identified with astrodendro.py, a publicly available dendrogram algorithm. Once star cluster properties are extracted, they will be used to create a sub-grid (smaller than the resolution scale of FIRE) of gas confinement in these clusters. Then, we can examine how the star clusters interact with these available gas reservoirs (either by accreting this mass or blowing it out via feedback), which will determine many properties of the cluster (star formation history, compact object accretion, etc). These simulations will further our understanding of star formation within stellar clusters during galaxy evolution. In the future, we aim to enhance sub-grid prescriptions for feedback specific to processes within star clusters; such as, interaction with stellar winds and gas accretion onto black holes and neutron stars.

  16. Galaxy Clusters with Chandra

    CERN Document Server

    Forman, W; Markevitch, M L; Vikhlinin, A A; Churazov, E

    2002-01-01

    We discuss Chandra results related to 1) cluster mergers and cold fronts and 2) interactions between relativistic plasma and hot cluster atmospheres. We describe the properties of cold fronts using NGC1404 in the Fornax cluster and A3667 as examples. We discuss multiple surface brightness discontinuities in the cooling flow cluster ZW3146. We review the supersonic merger underway in CL0657. Finally, we summarize the interaction between plasma bubbles produced by AGN and hot gas using M87 and NGC507 as examples.

  17. 15th Cluster workshop

    CERN Document Server

    Laakso, Harri; Escoubet, C. Philippe; The Cluster Active Archive : Studying the Earth’s Space Plasma Environment

    2010-01-01

    Since the year 2000 the ESA Cluster mission has been investigating the small-scale structures and processes of the Earth's plasma environment, such as those involved in the interaction between the solar wind and the magnetospheric plasma, in global magnetotail dynamics, in cross-tail currents, and in the formation and dynamics of the neutral line and of plasmoids. This book contains presentations made at the 15th Cluster workshop held in March 2008. It also presents several articles about the Cluster Active Archive and its datasets, a few overview papers on the Cluster mission, and articles reporting on scientific findings on the solar wind, the magnetosheath, the magnetopause and the magnetotail.

  18. Grape cluster microclimate influences the aroma composition of Sauvignon blanc wine.

    Science.gov (United States)

    Martin, Damian; Grose, Claire; Fedrizzi, Bruno; Stuart, Lily; Albright, Abby; McLachlan, Andrew

    2016-11-01

    New Zealand Sauvignon blanc (SB) wines are characterised by a distinctive combination of tropical-fruity and green-herbaceous aromatic compounds. The influence of sunlight exposure of grape clusters on juice and wine composition was investigated, with the aim of manipulating aromatic compounds in SB wine. In the absence of basal leaf removal SB clusters naturally exposed to sunlight were riper than shaded clusters, evidenced by higher total soluble solids (TSS) and proline, and lower malic acid, 3-isobutyl-2-methoxypyrazine (IBMP) and arginine. Volatile thiols in wines did not differ between shaded and exposed clusters. At equivalent TSS, cluster exposure had little or no effect on malic acid concentration. Conversely, wine from shaded clusters had almost double the IBMP concentration of wine from exposed clusters at equivalent TSS. The effects on SB juice and wine composition of natural variations in cluster microclimate are not comparable with the effects of cluster exposure created through leaf removal.

  19. Motivational Spiral Models (MSM): common and distinct motivations in context.

    Science.gov (United States)

    Fisher, Laurel J

    2013-01-01

    Motivational Spiral Models (MSM) show links over time among self concepts, feelings, strategies, skills and participation in everyday activities. In theory, MSM have many common features, with distinct features in particular contexts. This project examined children's motivation to participate in literacy (MSM-L), social (MSM-S) and physical activities (MSM-P). The participants in Study 1 (N = 32) were 9 to 11 years old, and in Study 2 (N = 73) were 4 to 12 year old children. Locations were close to the Australian national average in socio-economic indicators, and initial screening showed these were representative samples. Analyses used variable-oriented correlational models as well as person-oriented clusters that suggest the standard and alternative motivational pathways. The results of Study 1 suggested bi-directional links between children's self concepts and participation in activities. Study 2 identified the common features as: openness and stability over time; and self concepts that motivate and justify participation in activities. Distinct features of MSM-L show the few negative feelings that may limit reading. In MSM-S, self concepts support the positive feelings, and in MSM-P, positive feelings support the task strategies. In conclusion, findings support MSM theory with common features based on self concepts and distinct features of developing motivations in particular contexts. MSM provide a sound base for future research in the contexts of everyday activities for children. In addition, there are practical applications of the findings to prevention, monitoring and intervention programmes.

  20. Testing the Large-scale Environments of Cool-core and Non-cool-core Clusters with Clustering Bias

    Science.gov (United States)

    Medezinski, Elinor; Battaglia, Nicholas; Coupon, Jean; Cen, Renyue; Gaspari, Massimo; Strauss, Michael A.; Spergel, David N.

    2017-02-01

    There are well-observed differences between cool-core (CC) and non-cool-core (NCC) clusters, but the origin of this distinction is still largely unknown. Competing theories can be divided into internal (inside-out), in which internal physical processes transform or maintain the NCC phase, and external (outside-in), in which the cluster type is determined by its initial conditions, which in turn leads to different formation histories (i.e., assembly bias). We propose a new method that uses the relative assembly bias of CC to NCC clusters, as determined via the two-point cluster-galaxy cross-correlation function (CCF), to test whether formation history plays a role in determining their nature. We apply our method to 48 ACCEPT clusters, which have well resolved central entropies, and cross-correlate with the SDSS-III/BOSS LOWZ galaxy catalog. We find that the relative bias of NCC over CC clusters is b = 1.42 ± 0.35 (1.6σ different from unity). Our measurement is limited by the small number of clusters with core entropy information within the BOSS footprint, 14 CC and 34 NCC clusters. Future compilations of X-ray cluster samples, combined with deep all-sky redshift surveys, will be able to better constrain the relative assembly bias of CC and NCC clusters and determine the origin of the bimodality.

  1. Sun Protection Belief Clusters: Analysis of Amazon Mechanical Turk Data.

    Science.gov (United States)

    Santiago-Rivas, Marimer; Schnur, Julie B; Jandorf, Lina

    2016-12-01

    This study aimed (i) to determine whether people could be differentiated on the basis of their sun protection belief profiles and individual characteristics and (ii) explore the use of a crowdsourcing web service for the assessment of sun protection beliefs. A sample of 500 adults completed an online survey of sun protection belief items using Amazon Mechanical Turk. A two-phased cluster analysis (i.e., hierarchical and non-hierarchical K-means) was utilized to determine clusters of sun protection barriers and facilitators. Results yielded three distinct clusters of sun protection barriers and three distinct clusters of sun protection facilitators. Significant associations between gender, age, sun sensitivity, and cluster membership were identified. Results also showed an association between barrier and facilitator cluster membership. The results of this study provided a potential alternative approach to developing future sun protection promotion initiatives in the population. Findings add to our knowledge regarding individuals who support, oppose, or are ambivalent toward sun protection and inform intervention research by identifying distinct subtypes that may best benefit from (or have a higher need for) skin cancer prevention efforts.

  2. Motivational typologies of drinkers: do enhancement and coping drinkers form two distinct groups?

    Science.gov (United States)

    Littlefield, Andrew K; Vergés, Alvaro; Rosinski, Jenny M; Steinley, Douglas; Sher, Kenneth J

    2013-03-01

    This study used a person-centered approach to test whether drinking motive typologies could be identified. Longitudinal study of college students within the intensive multivariate prospective alcohol college-transitions (IMPACTS) data set. University campus in the United States. University students (baseline n reporting alcohol motives = 2158; baseline age = 18.60 years old). The drinking motives questionnaire-revised (DMQ-R). Using Steinley & Brusco's cluster analysis approach [based on the theoretical ratio expected between the within sum of squares and the total sum of squares when the data are divided into two clusters when no cluster structure is present; the cut-off for the ratio is 0.25 for uniform (multivariate uniform) distributions and 0.36 for normal (multivariate normal) distributions], we examined whether there was evidence for distinct clusters of individuals that differed on their overall level of motives to drink. We tested the fit of a one-group (cluster) solution compared to multi-cluster solutions. Both cross-sectionally and prospectively, the data could not be partitioned into two or more clusters [regardless of whether the cut-off assuming a multivariate uniform distribution (i.e. 0.25) or the more liberal multivariate normal distribution (i.e., 0.36) was used]. These findings showed that enhancement and coping drinkers do not form two distinct groups but, rather, these motives exist on a continuum such that individuals who are high in one internal motive tend to be high in the other motive. Coping and enhancement drinkers do not form two distinct groups. Variable-centered approaches to drinking motives may be a better alternative to classifying all drinkers as either enhancement or coping drinkers for both clinical and research endeavors. © 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.

  3. Statistical properties of convex clustering

    OpenAIRE

    Tan, Kean Ming; Witten, Daniela

    2015-01-01

    In this manuscript, we study the statistical properties of convex clustering. We establish that convex clustering is closely related to single linkage hierarchical clustering and $k$-means clustering. In addition, we derive the range of the tuning parameter for convex clustering that yields a non-trivial solution. We also provide an unbiased estimator of the degrees of freedom, and provide a finite sample bound for the prediction error for convex clustering. We compare convex clustering to so...

  4. Document Clustering Based on Semi-Supervised Term Clustering

    Directory of Open Access Journals (Sweden)

    Hamid Mahmoodi

    2012-05-01

    Full Text Available The study is conducted to propose a multi-step feature (term selection process and in semi-supervised fashion, provide initial centers for term clusters. Then utilize the fuzzy c-means (FCM clustering algorithm for clustering terms. Finally assign each of documents to closest associated term clusters. While most text clustering algorithms directly use documents for clustering, we propose to first group the terms using FCM algorithm and then cluster documents based on terms clusters. We evaluate effectiveness of our technique on several standard text collections and compare our results with the some classical text clustering algorithms.

  5. Distinct metal-exchange pathways of doped Ag25 nanoclusters

    KAUST Repository

    Bootharaju, Megalamane Siddaramappa

    2016-09-09

    Atomically precise metal nanoclusters (NCs) containing more than one type of metal atom (i.e., doped or alloyed), due to synergistic effects, open new avenues for engineering the catalytic and optical properties of NCs in a manner that homometal NCs cannot. Unfortunately, it is still a major challenge to controllably introduce multimetallic dopants in NCs, understanding the dopants\\' positions, mechanism, and synergistic effects. To overcome these challenges, we designed a metal-exchange approach involving NCs as molecular templates and metal ions as the source of the incoming dopant. In particular, two structurally similar monodoped silver-rich NCs, [MAg24(SR)(18)](2-) (M = Pd/Pt and SR: thiolate), were synthesized as templates to study their mechanistic transformation in response to the introduction of gold atoms. The controllable incorporation of Au atoms into the MAg24 framework facilitated the elucidation of distinct doping pathways through high-resolution mass spectrometry, optical spectroscopy and elemental analysis. Interestingly, gold replaced the central Pd atom of [PdAg24(SR)(18)](2-) clusters to produce predominantly bimetallic [AuAg24(SR)(18)](-) clusters along with a minor product of an [Au2Ag23(SR)(18)](-) cluster. In contrast, the central Pt atom remained intact in [PtAg24(SR)(18)](2-) clusters, and gold replaced the noncentral Ag atoms to form trimetallic [AuxPtAg24-x(SR)(18)](2-) NCs, where x = 1-2, with a portion of the starting [PtAg24(SR)(18)](2-) NCs remaining. This study reveals some of the unusual metal-exchange pathways of doped NCs and the important role played by the initial metal dopant in directing the position of a second dopant in the final product.

  6. Twelve automated thresholding methods for segmentation of PET images: a phantom study.

    Science.gov (United States)

    Prieto, Elena; Lecumberri, Pablo; Pagola, Miguel; Gómez, Marisol; Bilbao, Izaskun; Ecay, Margarita; Peñuelas, Iván; Martí-Climent, Josep M

    2012-06-21

    Tumor volume delineation over positron emission tomography (PET) images is of great interest for proper diagnosis and therapy planning. However, standard segmentation techniques (manual or semi-automated) are operator dependent and time consuming while fully automated procedures are cumbersome or require complex mathematical development. The aim of this study was to segment PET images in a fully automated way by implementing a set of 12 automated thresholding algorithms, classical in the fields of optical character recognition, tissue engineering or non-destructive testing images in high-tech structures. Automated thresholding algorithms select a specific threshold for each image without any a priori spatial information of the segmented object or any special calibration of the tomograph, as opposed to usual thresholding methods for PET. Spherical (18)F-filled objects of different volumes were acquired on clinical PET/CT and on a small animal PET scanner, with three different signal-to-background ratios. Images were segmented with 12 automatic thresholding algorithms and results were compared with the standard segmentation reference, a threshold at 42% of the maximum uptake. Ridler and Ramesh thresholding algorithms based on clustering and histogram-shape information, respectively, provided better results that the classical 42%-based threshold (p < 0.05). We have herein demonstrated that fully automated thresholding algorithms can provide better results than classical PET segmentation tools.

  7. Spatial separation of molecular conformers and clusters.

    Science.gov (United States)

    Horke, Daniel; Trippel, Sebastian; Chang, Yuan-Pin; Stern, Stephan; Mullins, Terry; Kierspel, Thomas; Küpper, Jochen

    2014-01-09

    Gas-phase molecular physics and physical chemistry experiments commonly use supersonic expansions through pulsed valves for the production of cold molecular beams. However, these beams often contain multiple conformers and clusters, even at low rotational temperatures. We present an experimental methodology that allows the spatial separation of these constituent parts of a molecular beam expansion. Using an electric deflector the beam is separated by its mass-to-dipole moment ratio, analogous to a bender or an electric sector mass spectrometer spatially dispersing charged molecules on the basis of their mass-to-charge ratio. This deflector exploits the Stark effect in an inhomogeneous electric field and allows the separation of individual species of polar neutral molecules and clusters. It furthermore allows the selection of the coldest part of a molecular beam, as low-energy rotational quantum states generally experience the largest deflection. Different structural isomers (conformers) of a species can be separated due to the different arrangement of functional groups, which leads to distinct dipole moments. These are exploited by the electrostatic deflector for the production of a conformationally pure sample from a molecular beam. Similarly, specific cluster stoichiometries can be selected, as the mass and dipole moment of a given cluster depends on the degree of solvation around the parent molecule. This allows experiments on specific cluster sizes and structures, enabling the systematic study of solvation of neutral molecules.

  8. Assessment on knowledge network sharing capability of industrial cluster based on dempster-shafer theory of evidence.

    Science.gov (United States)

    Dai, Shengli; Zhang, Hailin

    2014-01-01

    Based on Theory of Evidence and reviewing research papers concerned, a concept model of knowledge sharing network among industrial cluster firms, which can be applied to assess knowledge sharing capacity, has been built. Next, the authors create a set of assessment index systems including twelve subindexes under four principle indexes. In this study, ten experts in the same field were invited to score all the indexes of knowledge sharing capacity concerning one certain industrial cluster. The research result shows relatively high knowledge network sharing capacity among the certain industrial cluster firms. Another conclusion is that the assessment method with Theory of Evidence is feasible to conduct such a research.

  9. Assessment on Knowledge Network Sharing Capability of Industrial Cluster Based on Dempster-Shafer Theory of Evidence

    Directory of Open Access Journals (Sweden)

    Shengli Dai

    2014-01-01

    Full Text Available Based on Theory of Evidence and reviewing research papers concerned, a concept model of knowledge sharing network among industrial cluster firms, which can be applied to assess knowledge sharing capacity, has been built. Next, the authors create a set of assessment index systems including twelve subindexes under four principle indexes. In this study, ten experts in the same field were invited to score all the indexes of knowledge sharing capacity concerning one certain industrial cluster. The research result shows relatively high knowledge network sharing capacity among the certain industrial cluster firms. Another conclusion is that the assessment method with Theory of Evidence is feasible to conduct such a research.

  10. Cost-Effective Clustering

    CERN Document Server

    Gottlieb, S

    2001-01-01

    Small Beowulf clusters can effectively serve as personal or group supercomputers. In such an environment, a cluster can be optimally designed for a specific problem (or a small set of codes). We discuss how theoretical analysis of the code and benchmarking on similar hardware lead to optimal systems.

  11. [Cluster headache differential diagnosis].

    Science.gov (United States)

    Guégan-Massardier, Evelyne; Laubier, Cécile

    2015-11-01

    Cluster headache is characterized by disabling stereotyped headache. Early diagnosis allows appropriate treatment, unfortunately diagnostic errors are frequent. The main differential diagnoses are other primary or essential headaches. Migraine, more frequent and whose diagnosis is carried by excess, trigeminal neuralgia or other trigemino-autonomic cephalgia. Vascular or tumoral underlying condition can mimic cluster headache, neck and brain imaging is recommended, ideally MRI.

  12. Coma cluster of galaxies

    Science.gov (United States)

    1999-01-01

    Atlas Image mosaic, covering 34' x 34' on the sky, of the Coma cluster, aka Abell 1656. This is a particularly rich cluster of individual galaxies (over 1000 members), most prominently the two giant ellipticals, NGC 4874 (right) and NGC 4889 (left). The remaining members are mostly smaller ellipticals, but spiral galaxies are also evident in the 2MASS image. The cluster is seen toward the constellation Coma Berenices, but is actually at a distance of about 100 Mpc (330 million light years, or a redshift of 0.023) from us. At this distance, the cluster is in what is known as the 'Hubble flow,' or the overall expansion of the Universe. As such, astronomers can measure the Hubble Constant, or the universal expansion rate, based on the distance to this cluster. Large, rich clusters, such as Coma, allow astronomers to measure the 'missing mass,' i.e., the matter in the cluster that we cannot see, since it gravitationally influences the motions of the member galaxies within the cluster. The near-infrared maps the overall luminous mass content of the member galaxies, since the light at these wavelengths is dominated by the more numerous older stellar populations. Galaxies, as seen by 2MASS, look fairly smooth and homogeneous, as can be seen from the Hubble 'tuning fork' diagram of near-infrared galaxy morphology. Image mosaic by S. Van Dyk (IPAC).

  13. Mixed-Initiative Clustering

    Science.gov (United States)

    Huang, Yifen

    2010-01-01

    Mixed-initiative clustering is a task where a user and a machine work collaboratively to analyze a large set of documents. We hypothesize that a user and a machine can both learn better clustering models through enriched communication and interactive learning from each other. The first contribution or this thesis is providing a framework of…

  14. Cluster Synchronization Algorithms

    NARCIS (Netherlands)

    Xia, Weiguo; Cao, Ming

    2010-01-01

    This paper presents two approaches to achieving cluster synchronization in dynamical multi-agent systems. In contrast to the widely studied synchronization behavior, where all the coupled agents converge to the same value asymptotically, in the cluster synchronization problem studied in this paper,

  15. Neurostimulation in cluster headache

    DEFF Research Database (Denmark)

    Pedersen, Jeppe L; Barloese, Mads; Jensen, Rigmor H

    2013-01-01

    PURPOSE OF REVIEW: Neurostimulation has emerged as a viable treatment for intractable chronic cluster headache. Several therapeutic strategies are being investigated including stimulation of the hypothalamus, occipital nerves and sphenopalatine ganglion. The aim of this review is to provide...... effective strategy must be preferred as first-line therapy for intractable chronic cluster headache....

  16. Securing personal network clusters

    NARCIS (Netherlands)

    Jehangir, Assed; Heemstra de Groot, Sonia M.

    2007-01-01

    A Personal Network is a self-organizing, secure and private network of a user’s devices notwithstanding their geographic location. It aims to utilize pervasive computing to provide users with new and improved services. In this paper we propose a model for securing Personal Network clusters. Clusters

  17. Clustering Text Data Streams

    Institute of Scientific and Technical Information of China (English)

    Yu-Bao Liu; Jia-Rong Cai; Jian Yin; Ada Wai-Chee Fu

    2008-01-01

    Clustering text data streams is an important issue in data mining community and has a number of applications such as news group filtering, text crawling, document organization and topic detection and tracing etc. However, most methods are similarity-based approaches and only use the TF*IDF scheme to represent the semantics of text data and often lead to poor clustering quality. Recently, researchers argue that semantic smoothing model is more efficient than the existing TF.IDF scheme for improving text clustering quality. However, the existing semantic smoothing model is not suitable for dynamic text data context. In this paper, we extend the semantic smoothing model into text data streams context firstly. Based on the extended model, we then present two online clustering algorithms OCTS and OCTSM for the clustering of massive text data streams. In both algorithms, we also present a new cluster statistics structure named cluster profile which can capture the semantics of text data streams dynamically and at the same time speed up the clustering process. Some efficient implementations for our algorithms are also given. Finally, we present a series of experimental results illustrating the effectiveness of our technique.

  18. Relevant Subspace Clustering

    DEFF Research Database (Denmark)

    Müller, Emmanuel; Assent, Ira; Günnemann, Stephan;

    2009-01-01

    Subspace clustering aims at detecting clusters in any subspace projection of a high dimensional space. As the number of possible subspace projections is exponential in the number of dimensions, the result is often tremendously large. Recent approaches fail to reduce results to relevant subspace c...

  19. Structural transitions in clusters

    Science.gov (United States)

    Ghazali, A.; Lévy, J.-C. S.

    1997-02-01

    Monatomic clusters are studied by Monte Carlo relaxation using generalized Lennard-Jones potentials. A transition from an icosahedral symmetry to a crystalline symmetry with stacking faults is always observed. Bcc-based soft atom clusters are found to have a lower energy than the corresponding hcp and fcc ones below the melting point.

  20. Twelve tips for academic role and institutional change in distance learning.

    Science.gov (United States)

    Delgaty, Laura

    2015-01-01

    With the uptake of distance learning (DL), which has been marginal for most clinical academics, teaching contexts, traditional power structures and relationships have changed, leaving lecturers potentially disenfranchised. DL has caused a distinct change in academic roles, but academic and institutional routines have remained unchanged. Information surrounding the changes is confusing and lacks clear guidance. To provide a pragmatic outline of roles, responsibilities, obstacles and solutions for clinical academics involved in DL. A two-year action research project was carried out examining the academic role when developing and delivering a 20 credit post graduate DL module in Clinical Education at Newcastle University. It entailed three strands which were "active" for two weeks at a time in which all activities had to be completed. Sixteen students participated in the module consisting of independent activities, facilitated discussion forums, wikis, required reading, individual and group tasks. Pedagogically, it was based on heavily on Garrison's (2012) and Salmon's (2008) work on constructivism and online communities. Institutions need a clear plan and a change of culture. Roles have emerged including: administrator, manager, team leader knowledge expert, moderator and facilitator. Universities struggle to engage staff with DL due to its unrecognised and (many academics believe) unsustainable workload. These 12 tips provide academics and managers involved in clinical education with clear guidance surrounding strategies that inform practice. New roles have emerged, work habits must be revolutionised and changes in routine must be addressed.

  1. Mathematical classification and clustering

    CERN Document Server

    Mirkin, Boris

    1996-01-01

    I am very happy to have this opportunity to present the work of Boris Mirkin, a distinguished Russian scholar in the areas of data analysis and decision making methodologies. The monograph is devoted entirely to clustering, a discipline dispersed through many theoretical and application areas, from mathematical statistics and combina­ torial optimization to biology, sociology and organizational structures. It compiles an immense amount of research done to date, including many original Russian de­ velopments never presented to the international community before (for instance, cluster-by-cluster versions of the K-Means method in Chapter 4 or uniform par­ titioning in Chapter 5). The author's approach, approximation clustering, allows him both to systematize a great part of the discipline and to develop many in­ novative methods in the framework of optimization problems. The optimization methods considered are proved to be meaningful in the contexts of data analysis and clustering. The material presented in ...

  2. Neutrosophic Hierarchical Clustering Algoritms

    Directory of Open Access Journals (Sweden)

    Rıdvan Şahin

    2014-03-01

    Full Text Available Interval neutrosophic set (INS is a generalization of interval valued intuitionistic fuzzy set (IVIFS, whose the membership and non-membership values of elements consist of fuzzy range, while single valued neutrosophic set (SVNS is regarded as extension of intuitionistic fuzzy set (IFS. In this paper, we extend the hierarchical clustering techniques proposed for IFSs and IVIFSs to SVNSs and INSs respectively. Based on the traditional hierarchical clustering procedure, the single valued neutrosophic aggregation operator, and the basic distance measures between SVNSs, we define a single valued neutrosophic hierarchical clustering algorithm for clustering SVNSs. Then we extend the algorithm to classify an interval neutrosophic data. Finally, we present some numerical examples in order to show the effectiveness and availability of the developed clustering algorithms.

  3. Cool Cluster Correctly Correlated

    Energy Technology Data Exchange (ETDEWEB)

    Varganov, Sergey Aleksandrovich [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    Atomic clusters are unique objects, which occupy an intermediate position between atoms and condensed matter systems. For a long time it was thought that physical and chemical properties of atomic dusters monotonically change with increasing size of the cluster from a single atom to a condensed matter system. However, recently it has become clear that many properties of atomic clusters can change drastically with the size of the clusters. Because physical and chemical properties of clusters can be adjusted simply by changing the cluster's size, different applications of atomic clusters were proposed. One example is the catalytic activity of clusters of specific sizes in different chemical reactions. Another example is a potential application of atomic clusters in microelectronics, where their band gaps can be adjusted by simply changing cluster sizes. In recent years significant advances in experimental techniques allow one to synthesize and study atomic clusters of specified sizes. However, the interpretation of the results is often difficult. The theoretical methods are frequently used to help in interpretation of complex experimental data. Most of the theoretical approaches have been based on empirical or semiempirical methods. These methods allow one to study large and small dusters using the same approximations. However, since empirical and semiempirical methods rely on simple models with many parameters, it is often difficult to estimate the quantitative and even qualitative accuracy of the results. On the other hand, because of significant advances in quantum chemical methods and computer capabilities, it is now possible to do high quality ab-initio calculations not only on systems of few atoms but on clusters of practical interest as well. In addition to accurate results for specific clusters, such methods can be used for benchmarking of different empirical and semiempirical approaches. The atomic clusters studied in this work contain from a few atoms

  4. Job Oriented Monitoring Clusters

    Directory of Open Access Journals (Sweden)

    Vijayalaxmi Cigala,

    2011-03-01

    Full Text Available There has been a lot of development in the field of clusters and grids. Recently, the use of clusters has been on rise in every possible field. This paper proposes a system that monitors jobs onlarge computational clusters. Monitoring jobs is essential to understand how jobs are being executed. This helps us in understanding the complete life cycle of the jobs being executed on large clusters. Also, this paper describes how the information obtained by monitoring the jobs would help in increasing the overall throughput of clusters. Heuristics help in efficient job distribution among the computational nodes, thereby accomplishing fair job distribution policy. The proposed system would be capable of loadbalancing among the computational nodes, detecting failures, taking corrective actions after failure detection, job monitoring, system resource monitoring, etc.

  5. On TPC cluster reconstruction

    CERN Document Server

    Dydak, F; Nefedov, Y; Wotschack, J; Zhemchugov, A

    2004-01-01

    For a bias-free momentum measurement of TPC tracks, the correct determination of cluster positions is mandatory. We argue in particular that (i) the reconstruction of the entire longitudinal signal shape in view of longitudinal diffusion, electronic pulse shaping, and track inclination is important both for the polar angle reconstruction and for optimum r phi resolution; and that (ii) self-crosstalk of pad signals calls for special measures for the reconstruction of the z coordinate. The problem of 'shadow clusters' is resolved. Algorithms are presented for accepting clusters as 'good' clusters, and for the reconstruction of the r phi and z cluster coordinates, including provisions for 'bad' pads and pads next to sector boundaries, respectively.

  6. A Commodity Computing Cluster

    Science.gov (United States)

    Teuben, P. J.; Wolfire, M. G.; Pound, M. W.; Mundy, L. G.

    We have assembled a cluster of Intel-Pentium based PCs running Linux to compute a large set of Photodissociation Region (PDR) and Dust Continuum models. For various reasons the cluster is heterogeneous, currently ranging from a single Pentium-II 333 MHz to dual Pentium-III 450 MHz CPU machines. Although this will be sufficient for our ``embarrassingly parallelizable problem'' it may present some challenges for as yet unplanned future use. In addition the cluster was used to construct a MIRIAD benchmark, and compared to equivalent Ultra-Sparc based workstations. Currently the cluster consists of 8 machines, 14 CPUs, 50GB of disk-space, and a total peak speed of 5.83 GHz, or about 1.5 Gflops. The total cost of this cluster has been about $12,000, including all cabling, networking equipment, rack, and a CD-R backup system. The URL for this project is http://dustem.astro.umd.edu.

  7. Cross-entropy clustering framework for catchment classification

    Science.gov (United States)

    Tongal, Hakan; Sivakumar, Bellie

    2017-09-01

    There is an increasing interest in catchment classification and regionalization in hydrology, as they are useful for identification of appropriate model complexity and transfer of information from gauged catchments to ungauged ones, among others. This study introduces a nonlinear cross-entropy clustering (CEC) method for classification of catchments. The method specifically considers embedding dimension (m), sample entropy (SampEn), and coefficient of variation (CV) to represent dimensionality, complexity, and variability of the time series, respectively. The method is applied to daily streamflow time series from 217 gauging stations across Australia. The results suggest that a combination of linear and nonlinear parameters (i.e. m, SampEn, and CV), representing different aspects of the underlying dynamics of streamflows, could be useful for determining distinct patterns of flow generation mechanisms within a nonlinear clustering framework. For the 217 streamflow time series, nine hydrologically homogeneous clusters that have distinct patterns of flow regime characteristics and specific dominant hydrological attributes with different climatic features are obtained. Comparison of the results with those obtained using the widely employed k-means clustering method (which results in five clusters, with the loss of some information about the features of the clusters) suggests the superiority of the cross-entropy clustering method. The outcomes from this study provide a useful guideline for employing the nonlinear dynamic approaches based on hydrologic signatures and for gaining an improved understanding of streamflow variability at a large scale.

  8. The Clusters AgeS Experiment (CASE). Variable stars in the field of the globular cluster NGC 362

    CERN Document Server

    Rozyczka, M; Narloch, W; Pych, W; Czerny, A Schwarzenberg -

    2016-01-01

    The field of the globular cluster NGC 362 was monitored between 1997 and 2015 in a search for variable stars. BV light curves were obtained for 151 periodic or likely periodic variables, over a hundred of which are new detections. Twelve newly detected variables are proper motion members of the cluster: two SX Phe and two RR Lyr pulsators, one contact binary, three detached or semi-detached eclipsing binaries, and four spotted variables. The most interesting objects among these are the binary blue straggler V20 with an asymmetric light curve, and the 8.1 d semidetached binary V24 located on the red giant branch of NGC 362, which is a Chandra X-ray source. We also provide substantial new data for 24 previously known variables.

  9. Explaining ICT Infrastructure and E-Commerce Uses and Benefits in Industrial Clusters-Evidence from a Biotech Cluster

    DEFF Research Database (Denmark)

    Scupola, Ada; Steinfield, Charles

    2006-01-01

    in an industrial cluster might utilize and derive benefit from a public, broadband ICT infrastructure, particularly in support of e-commerce applications. A case study of a successful biotech cluster in Denamrk and Sweden-The Medicon Valley-provides a preliminary test of these expectations. Distinctions in uses...... and benefits based upon firm size are considered. A key finding is that small firms that would not otherwise be expected to gain from global e-commerce can rely on the cluster "brand" to enable trade with unknown and distant partners....

  10. CHANDRA OBSERVATION OF ABELL 1142: A COOL-CORE CLUSTER LACKING A CENTRAL BRIGHTEST CLUSTER GALAXY?

    Energy Technology Data Exchange (ETDEWEB)

    Su, Yuanyuan; Weeren, Reinout van [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Buote, David A. [Department of Physics and Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697 (United States); Gastaldello, Fabio, E-mail: yuanyuan.su@cfa.harvard.edu [INAF-IASF-Milano, Via E. Bassini 15, I-20133 Milano (Italy)

    2016-04-10

    Abell 1142 is a low-mass galaxy cluster at low redshift containing two comparable brightest cluster galaxies (BCGs) resembling a scaled-down version of the Coma Cluster. Our Chandra analysis reveals an X-ray emission peak, roughly 100 kpc away from either BCG, which we identify as the cluster center. The emission center manifests itself as a second beta-model surface brightness component distinct from that of the cluster on larger scales. The center is also substantially cooler and more metal-rich than the surrounding intracluster medium (ICM), which makes Abell 1142 appear to be a cool-core cluster. The redshift distribution of its member galaxies indicates that Abell 1142 may contain two subclusters, each of which contain one BCG. The BCGs are merging at a relative velocity of ≈1200 km s{sup −1}. This ongoing merger may have shock-heated the ICM from ≈2 keV to above 3 keV, which would explain the anomalous L{sub X}–T{sub X} scaling relation for this system. This merger may have displaced the metal-enriched “cool core” of either of the subclusters from the BCG. The southern BCG consists of three individual galaxies residing within a radius of 5 kpc in projection. These galaxies should rapidly sink into the subcluster center due to the dynamical friction of a cuspy cold dark matter halo.

  11. Bayesian analysis of two stellar populations in Galactic globular clusters- III. Analysis of 30 clusters

    Science.gov (United States)

    Wagner-Kaiser, R.; Stenning, D. C.; Sarajedini, A.; von Hippel, T.; van Dyk, D. A.; Robinson, E.; Stein, N.; Jefferys, W. H.

    2016-12-01

    We use Cycle 21 Hubble Space Telescope (HST) observations and HST archival ACS Treasury observations of 30 Galactic globular clusters to characterize two distinct stellar populations. A sophisticated Bayesian technique is employed to simultaneously sample the joint posterior distribution of age, distance, and extinction for each cluster, as well as unique helium values for two populations within each cluster and the relative proportion of those populations. We find the helium differences among the two populations in the clusters fall in the range of ˜0.04 to 0.11. Because adequate models varying in carbon, nitrogen, and oxygen are not presently available, we view these spreads as upper limits and present them with statistical rather than observational uncertainties. Evidence supports previous studies suggesting an increase in helium content concurrent with increasing mass of the cluster and we also find that the proportion of the first population of stars increases with mass as well. Our results are examined in the context of proposed globular cluster formation scenarios. Additionally, we leverage our Bayesian technique to shed light on the inconsistencies between the theoretical models and the observed data.

  12. Chandra Observation of Abell 1142: A Cool-Core Cluster Lacking a Central Brightest Cluster Galaxy?

    CERN Document Server

    Su, Yuanyuan; Gastaldello, Fabio; van Weeren, Reinout

    2016-01-01

    Abell~1142 is a low-mass galaxy cluster at low redshift containing two comparable Brightest Cluster Galaxies (BCG) resembling a scaled-down version of the Coma Cluster. Our Chandra analysis reveals an X-ray emission peak, roughly 100 kpc away from either BCG, which we identify as the cluster center. The emission center manifests itself as a second beta-model surface brightness component distinct from that of the cluster on larger scales. The center is also substantially cooler and more metal rich than the surrounding intracluster medium (ICM), which makes Abell 1142 appear to be a cool core cluster. The redshift distribution of its member galaxies indicates that Abell 1142 may contain two subclusters with each containing one BCG. The BCGs are merging at a relative velocity of ~1200 km/s. This ongoing merger may have shock-heated the ICM from ~ 2 keV to above 3 keV, which would explain the anomalous L_X--T_X scaling relation for this system. This merger may have displaced the metal-enriched "cool core" of eith...

  13. Pillared-layer cluster organic frameworks constructed from nanoscale Ln10 and Cu16 clusters.

    Science.gov (United States)

    Fang, Wei-Hui; Yang, Guo-Yu

    2014-06-02

    Two pillared-layer cluster organic frameworks, [Ln5(μ3-OH)4(μ-H2O)Cu8I8L11]·H2O (L = 4-pyridin-4-yl-benzoate; Ln = Dy(1), Eu(2)), have been made by employing lanthanide oxide and copper(I) halide as the source of lanthanide and transitional metal under hydrothermal condition. Compared to the pillared-layer frameworks constructed from heterometallic layers and organic pillars, these two compounds are derived from lanthanide cluster organic layers and copper(I) halide cluster motifs. Thus, there are two distinct types of inorganic metal connectors in the structure, one is hydroxo lanthanide [Ln10(μ3-OH)8](22+) (Ln10) cluster, and the other is copper(I) halide [Cu16I16] (Cu16) cluster. The rational assembly of these two inorganic connectors and organic linear linkers leads to the formation of the two complexes here. To the best of our knowledge, they appear to be the first 3D frameworks constructed from decanuclear hydroxo lanthanide clusters. From the topological point of view, these compounds represent an intriguing example of a binodal (8,14)-connected net considering the Ln10 and Cu16 connectors as the nodes, revealing that they are typical high dimensional frameworks with high connected net based on high nuclearity nodes. Furthermore, elemental analysis, IR, TGA, PXRD, and UV-vis properties are also studied.

  14. Properties of He clustering in α-Fe grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lei, E-mail: zhang_lei@iapcm.ac.cn [CEA, DEN, Service de Recherches de Métallurgie Physique, F-91191 Gif-sur-Yvette (France); Department of Physics, Beihang University, Beijing 100191 (China); Fu, Chu-Chun, E-mail: chuchun.fu@cea.fr [CEA, DEN, Service de Recherches de Métallurgie Physique, F-91191 Gif-sur-Yvette (France); Hayward, Erin [CEA, DEN, Service de Recherches de Métallurgie Physique, F-91191 Gif-sur-Yvette (France); Lu, Guang-Hong [Department of Physics, Beihang University, Beijing 100191 (China)

    2015-04-15

    Classical molecular dynamics and density functional theory calculations are performed to study the impact of two distinct Fe grain boundaries (GBs) on the clustering properties of helium (He) and the possible He effect on GB decohesion. Several He concentrations are considered. Common properties of He clustering are found for the both GBs, which are visibly different from the bcc bulk. In particular, He clusters in the GBs are always elongated in the directions parallel to the interface and contracted in the direction normal to the GB plane, while they are isotropic in the bcc bulk. When the He number in the clusters is sufficiently large, the strong local pressure promotes the occurrence of loop punching, which is easier to trigger in the GBs than in the bulk, resulting in a lower He-to-vacancy ratio in the GB clusters. The emitted self-interstitial atoms (SIAs) can more easily dissociate from the clusters in the GBs than in the bulk, leading to relatively lower local pressures around the clusters in the GBs, and facilitating the clusters growth. He is found to decrease GB cohesion, and the embrittling effect of He increases with its concentration. But interestingly, this effect decreases with He clustering. The present findings are fully compatible with existing experimental evidence, for instance, for a stronger GB embrittlement due to He at rather low temperatures than at higher temperatures.

  15. Ananke: temporal clustering reveals ecological dynamics of microbial communities

    Directory of Open Access Journals (Sweden)

    Michael W. Hall

    2017-09-01

    Full Text Available Taxonomic markers such as the 16S ribosomal RNA gene are widely used in microbial community analysis. A common first step in marker-gene analysis is grouping genes into clusters to reduce data sets to a more manageable size and potentially mitigate the effects of sequencing error. Instead of clustering based on sequence identity, marker-gene data sets collected over time can be clustered based on temporal correlation to reveal ecologically meaningful associations. We present Ananke, a free and open-source algorithm and software package that complements existing sequence-identity-based clustering approaches by clustering marker-gene data based on time-series profiles and provides interactive visualization of clusters, including highlighting of internal OTU inconsistencies. Ananke is able to cluster distinct temporal patterns from simulations of multiple ecological patterns, such as periodic seasonal dynamics and organism appearances/disappearances. We apply our algorithm to two longitudinal marker gene data sets: faecal communities from the human gut of an individual sampled over one year, and communities from a freshwater lake sampled over eleven years. Within the gut, the segregation of the bacterial community around a food-poisoning event was immediately clear. In the freshwater lake, we found that high sequence identity between marker genes does not guarantee similar temporal dynamics, and Ananke time-series clusters revealed patterns obscured by clustering based on sequence identity or taxonomy. Ananke is free and open-source software available at https://github.com/beiko-lab/ananke.

  16. Two Populations of Young Massive Star Clusters in Arp 220

    CERN Document Server

    Wilson, C D; Longden, R; Scoville, N Z; Wilson, Christine D.; Harris, William E.; Longden, Rebecca

    2006-01-01

    We present new optical observations of young massive star clusters in Arp 220, the nearest ultraluminous infrared galaxy, taken in UBVI with the Hubble Space Telescope ACS/HRC camera. We find a total of 206 probable clusters whose spatial distribution is centrally concentrated toward the nucleus of Arp 220. We use model star cluster tracks to determine ages, luminosities, and masses for 14 clusters with complete UBVI indices or previously published near-infrared data. We estimate rough masses for 24 additional clusters with I < 24 mag from BVI indices alone. The clusters with useful ages fall into two distinct groups: a ``young'' population (< 10 Myr) and an intermediate-age population (~300 Myr). There are many clusters with masses clearly above 10^6 Msun and possibly even above 10^7 Msun in the most extreme instances. These masses are high enough that the clusters being formed in the Arp 220 starburst can be considered as genuine young globular clusters. In addition, this study allows us to extend the...

  17. Enhancing digital driver models: identification of distinct postural strategies used by drivers.

    Science.gov (United States)

    Kyung, Gyouhyung; Nussbaum, Maury A; Babski-Reeves, Kari L

    2010-03-01

    Driver workspace design and evaluation is, in part, based on assumed driving postures of users and determines several ergonomic aspects of a vehicle, such as reach, visibility and postural comfort. Accurately predicting and specifying standard driving postures, hence, are necessary to improve the ergonomic quality of the driver workspace. In this study, a statistical clustering approach was employed to reduce driving posture simulation/prediction errors, assuming that drivers use several distinct postural strategies when interacting with automobiles. 2-D driving postures, described by 16 joint angles, were obtained from 38 participants with diverse demographics (age, gender) and anthropometrics (stature, body mass) and in two vehicle classes (sedans and SUVs). Based on the proximity of joint angle sets, cluster analysis yielded three predominant postural strategies in each vehicle class (i.e. 'lower limb flexed', 'upper limb flexed' and 'extended'). Mean angular differences between clusters ranged from 3.8 to 52.4 degrees for the majority of joints, supporting the practical relevance of the distinct clusters. The existence of such postural strategies should be considered when utilising digital human models (DHMs) to enhance and evaluate driver workspace design ergonomically and proactively. STATEMENT OF RELEVANCE: This study identified drivers' distinct postural strategies, based on actual drivers' behaviours. Such strategies can facilitate accurate positioning of DHMs and hence help design ergonomic driver workspaces.

  18. Document clustering methods, document cluster label disambiguation methods, document clustering apparatuses, and articles of manufacture

    Science.gov (United States)

    Sanfilippo, Antonio [Richland, WA; Calapristi, Augustin J [West Richland, WA; Crow, Vernon L [Richland, WA; Hetzler, Elizabeth G [Kennewick, WA; Turner, Alan E [Kennewick, WA

    2009-12-22

    Document clustering methods, document cluster label disambiguation methods, document clustering apparatuses, and articles of manufacture are described. In one aspect, a document clustering method includes providing a document set comprising a plurality of documents, providing a cluster comprising a subset of the documents of the document set, using a plurality of terms of the documents, providing a cluster label indicative of subject matter content of the documents of the cluster, wherein the cluster label comprises a plurality of word senses, and selecting one of the word senses of the cluster label.

  19. Evidence for a Distinct Kind of Noun.

    Science.gov (United States)

    Soja, Nancy N.

    1994-01-01

    Examined the spontaneous speech of four children and their parents for use of determiners with NP-type nouns and count nouns. Found that the parents made a clear distinction between the two kinds of nouns, omitting determiners with the NP-type nouns but not with the count nouns. The children all made the same distinction by four years of age. (HTH)

  20. Killing and letting die: a defensible distinction.

    Science.gov (United States)

    Cartwright, W

    1996-04-01

    The distinction between killing and letting die is investigated and clarified. It is then argued that in most cases, though not in all, it is worse to kill than to let die. In euthanasia the significance of the distinction is diminished, but still important.

  1. Directed networks' different link formation mechanisms causing degree distribution distinction

    Science.gov (United States)

    Behfar, Stefan Kambiz; Turkina, Ekaterina; Cohendet, Patrick; Burger-Helmchen, Thierry

    2016-11-01

    Within undirected networks, scientists have shown much interest in presenting power-law features. For instance, Barabási and Albert (1999) claimed that a common property of many large networks is that vertex connectivity follows scale-free power-law distribution, and in another study Barabási et al. (2002) showed power law evolution in the social network of scientific collaboration. At the same time, Jiang et al. (2011) discussed deviation from power-law distribution; others indicated that size effect (Bagrow et al., 2008), information filtering mechanism (Mossa et al., 2002), and birth and death process (Shi et al., 2005) could account for this deviation. Within directed networks, many authors have considered that outlinks follow a similar mechanism of creation as inlinks' (Faloutsos et al., 1999; Krapivsky et al., 2001; Tanimoto, 2009) with link creation rate being the linear function of node degree, resulting in a power-law shape for both indegree and outdegree distribution. Some other authors have made an assumption that directed networks, such as scientific collaboration or citation, behave as undirected, resulting in a power-law degree distribution accordingly (Barabási et al., 2002). At the same time, we claim (1) Outlinks feature different degree distributions than inlinks; where different link formation mechanisms cause the distribution distinctions, (2) in/outdegree distribution distinction holds for different levels of system decomposition; therefore this distribution distinction is a property of directed networks. First, we emphasize in/outlink formation mechanisms as causal factors for distinction between indegree and outdegree distributions (where this distinction has already been noticed in Barker et al. (2010) and Baxter et al. (2006)) within a sample network of OSS projects as well as Java software corpus as a network. Second, we analyze whether this distribution distinction holds for different levels of system decomposition: open

  2. Ocular hypotensive effect, preservation of visual fields, and safety of adding dorzolamide to prostaglandin therapy for twelve months

    Directory of Open Access Journals (Sweden)

    Kenji Inoue

    2011-03-01

    Full Text Available Kenji Inoue1,3, Mieko Masumoto1,3, Masato Wakakura1, Goji Tomita2, On behalf of the Ochanomizu Ophthalmology Study Group31Inouye Eye Hospital, Tokyo, Japan; 2Department of Ophthalmology, Toho University School of Medicine, Tokyo, Japan; 3Ochanomizu Ophthalmology, Tokyo, JapanPurpose: To prospectively evaluate the safety, hypotensive effect, and preservation of visual fields of dorzolamide when added to latanoprost.Subjects and methods: This study included 46 patients (46 eyes with primary open-angle glaucoma who had been treated with latanoprost. Dorzolamide (1% was added to latanoprost, and the intraocular pressure (IOP was monitored before and after 3, 6, and 12 months. The mean deviation shown by Humphrey perimetry was compared before and after twelve months of treatment. Adverse reactions were monitored over the 12-month study period.Results: The mean baseline IOP was 17.2 ± 3.0 mmHg while those after 3, 6 and 12 months of treatment were 14.9 ± 3.0 mmHg, 14.5 ± 3.2 mmHg, and 14.6 ± 2.6 mmHg respectively (P < 0.0001, 1-ß(power = 0.9999571. The absolute reduction of IOP and the percent reduction were similar after 3, 6, and 12 months of treatment. The mean deviation on Humphrey perimetry was similar before and after twelve months of treatment. Three patients discontinued dorzolamide therapy due to elevation of IOP and one patient discontinued it because of adverse reactions.Conclusion: Dorzolamide is safe and effective when used for twelve months as add-on therapy to latanoprost for open-angle glaucoma.Keywords: dorzolamide, primary open-angle glaucoma, latanoprost 

  3. Do supervised weekly exercise programs maintain functional exercise capacity and quality of life, twelve months after pulmonary rehabilitation in COPD?

    Directory of Open Access Journals (Sweden)

    Alison Jennifer A

    2007-05-01

    Full Text Available Abstract Background Pulmonary rehabilitation programs have been shown to increase functional exercise capacity and quality of life in COPD patients. However, following the completion of pulmonary rehabilitation the benefits begin to decline unless the program is of longer duration or ongoing maintenance exercise is followed. Therefore, the aim of this study is to determine if supervised, weekly, hospital-based exercise compared to home exercise will maintain the benefits gained from an eight-week pulmonary rehabilitation program in COPD subjects to twelve months. Methods Following completion of an eight-week pulmonary rehabilitation program, COPD subjects will be recruited and randomised (using concealed allocation in numbered envelopes into either the maintenance exercise group (supervised, weekly, hospital-based exercise or the control group (unsupervised home exercise and followed for twelve months. Measurements will be taken at baseline (post an eight-week pulmonary rehabilitation program, three, six and twelve months. The exercise measurements will include two six-minute walk tests, two incremental shuttle walk tests, and two endurance shuttle walk tests. Oxygen saturation, heart rate and dyspnoea will be monitored during all these tests. Quality of life will be measured using the St George's Respiratory Questionnaire and the Hospital Anxiety and Depression Scale. Participants will be excluded if they require supplemental oxygen or have neurological or musculoskeletal co-morbidities that will prevent them from exercising independently. Discussion Pulmonary rehabilitation plays an important part in the management of COPD and the results from this study will help determine if supervised, weekly, hospital-based exercise can successfully maintain functional exercise capacity and quality of life following an eight-week pulmonary rehabilitation program in COPD subjects in Australia.

  4. Social conformity despite individual preferences for distinctiveness.

    Science.gov (United States)

    Smaldino, Paul E; Epstein, Joshua M

    2015-03-01

    We demonstrate that individual behaviours directed at the attainment of distinctiveness can in fact produce complete social conformity. We thus offer an unexpected generative mechanism for this central social phenomenon. Specifically, we establish that agents who have fixed needs to be distinct and adapt their positions to achieve distinctiveness goals, can nevertheless self-organize to a limiting state of absolute conformity. This seemingly paradoxical result is deduced formally from a small number of natural assumptions and is then explored at length computationally. Interesting departures from this conformity equilibrium are also possible, including divergence in positions. The effect of extremist minorities on these dynamics is discussed. A simple extension is then introduced, which allows the model to generate and maintain social diversity, including multimodal distinctiveness distributions. The paper contributes formal definitions, analytical deductions and counterintuitive findings to the literature on individual distinctiveness and social conformity.

  5. Misty Mountain clustering: application to fast unsupervised flow cytometry gating

    Directory of Open Access Journals (Sweden)

    Sealfon Stuart C

    2010-10-01

    Full Text Available Abstract Background There are many important clustering questions in computational biology for which no satisfactory method exists. Automated clustering algorithms, when applied to large, multidimensional datasets, such as flow cytometry data, prove unsatisfactory in terms of speed, problems with local minima or cluster shape bias. Model-based approaches are restricted by the assumptions of the fitting functions. Furthermore, model based clustering requires serial clustering for all cluster numbers within a user defined interval. The final cluster number is then selected by various criteria. These supervised serial clustering methods are time consuming and frequently different criteria result in different optimal cluster numbers. Various unsupervised heuristic approaches that have been developed such as affinity propagation are too expensive to be applied to datasets on the order of 106 points that are often generated by high throughput experiments. Results To circumvent these limitations, we developed a new, unsupervised density contour clustering algorithm, called Misty Mountain, that is based on percolation theory and that efficiently analyzes large data sets. The approach can be envisioned as a progressive top-down removal of clouds covering a data histogram relief map to identify clusters by the appearance of statistically distinct peaks and ridges. This is a parallel clustering method that finds every cluster after analyzing only once the cross sections of the histogram. The overall run time for the composite steps of the algorithm increases linearly by the number of data points. The clustering of 106 data points in 2D data space takes place within about 15 seconds on a standard laptop PC. Comparison of the performance of this algorithm with other state of the art automated flow cytometry gating methods indicate that Misty Mountain provides substantial improvements in both run time and in the accuracy of cluster assignment. Conclusions

  6. Software-Defined Cluster

    Institute of Scientific and Technical Information of China (English)

    聂华; 杨晓君; 刘淘英

    2015-01-01

    The cluster architecture has played an important role in high-end computing for the past 20 years. With the advent of Internet services, big data, and cloud computing, traditional clusters face three challenges: 1) providing flexible system balance among computing, memory, and I/O capabilities;2) reducing resource pooling overheads;and 3) addressing low performance-power efficiency. This position paper proposes a software-defined cluster (SDC) architecture to deal with these challenges. The SDC architecture inherits two features of traditional cluster: its architecture is multicomputer and it has loosely-coupled interconnect. SDC provides two new mechanisms: global I/O space (GIO) and hardware-supported native access (HNA) to remote devices. Application software can define a virtual cluster best suited to its needs from resources pools provided by a physical cluster, and traditional cluster ecosystems need no modification. We also discuss a prototype design and implementation of a 32-processor cloud server utilizing the SDC architecture.

  7. Cluster knockout reactions

    Indian Academy of Sciences (India)

    Arun K Jain; B N Joshi

    2014-04-01

    Cluster knockout reactions are expected to reveal the amount of clustering (such as that of , d and even of heavier clusters such as 12C, 16O etc.) in the target nucleus. In simple terms, incident medium high-energy nuclear projectile interacts strongly with the cluster (present in the target nucleus) as if it were existing as a free entity. Theoretically, the relatively softer interactions of the two outgoing particles with the residual nucleus lead to optical distortions and are treated in terms of distorted wave (DW) formalism. The long-range projectile–cluster interaction is accounted for, in terms of the finite range (FR) direct reaction formalism, as against the more commonly adopted zero-range (ZR) distorted wave impulse approximation (DWIA) formalism. Comparison of the DWIA calculations with the observed data provide information about the momentum distribution and the clustering spectroscopic factor of the target nucleus. Interesting results and some recent advancements in the area of (, 2) reactions and heavy cluster knockout reactions are discussed. Importance of the finite-range vertex and the final-state interactions are brought out.

  8. Textile Industrial Clusters in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    "National Textile Industry Cluster Development Seminar" convened, held by China National Textile and Apparel Council, 23 cities and towns were awarded as China’s Textile Industry Cluster Pilot District. By far, China’s textile industrial clusters have grown

  9. Spanning Tree Based Attribute Clustering

    DEFF Research Database (Denmark)

    Zeng, Yifeng; Jorge, Cordero Hernandez

    2009-01-01

    inconsistent edges from a maximum spanning tree by starting appropriate initial modes, therefore generating stable clusters. It discovers sound clusters through simple graph operations and achieves significant computational savings. We compare the Star Discovery algorithm against earlier attribute clustering...

  10. A Comparison of Algorithms for the Construction of SZ Cluster Catalogues

    CERN Document Server

    Melin, J -B; Bartelmann, M; Bartlett, J G; Betoule, M; Bobin, J; Carvalho, P; Chon, G; Delabrouille, J; Diego, J M; Harrison, D L; Herranz, D; Hobson, M; Kneissl, R; Lasenby, A N; Jeune, M Le; Lopez-Caniego, M; Mazzotta, P; Rocha, G M; Schaefer, B M; Starck, J -L; Waizmann, J -C; Yvon, D

    2012-01-01

    We evaluate the construction methodology of an all-sky catalogue of galaxy clusters detected through the Sunyaev-Zel'dovich (SZ) effect. We perform an extensive comparison of twelve algorithms applied to the same detailed simulations of the millimeter and submillimeter sky based on a Planck-like case. We present the results of this "SZ Challenge" in terms of catalogue completeness, purity, astrometric and photometric reconstruction. Our results provide a comparison of a representative sample of SZ detection algorithms and highlight important issues in their application. In our study case, we show that the exact expected number of clusters remains uncertain (about a thousand cluster candidates at |b|> 20 deg with 90% purity) and that it depends on the SZ model and on the detailed sky simulations, and on algorithmic implementation of the detection methods. We also estimate the astrometric precision of the cluster candidates which is found of the order of ~2 arcmins on average, and the photometric uncertainty of...

  11. Allodynia in Cluster Headache.

    Science.gov (United States)

    Wilbrink, Leopoldine A; Louter, Mark A; Teernstra, Onno Pm; van Zwet, Erik W; Huygen, Frank Jpm; Haan, Joost; Ferrari, Michel D; Terwindt, Gisela M

    2017-03-04

    Cutaneous allodynia is an established marker for central sensitization in migraine. There is debate whether cutaneous allodynia may also occur in cluster headache, another episodic headache disorder. Here we examined the presence and severity of allodynia in a large well-defined nation-wide population of people with cluster headache.Using validated questionnaires we assessed, cross-sectionally, ictal allodynia and comorbid depression and migraine in the nation-wide "Leiden University Cluster headache neuro-Analysis" (LUCA) study. Participants with cluster headache were diagnosed according to the International Classification of Headache Disorders criteria. Multivariate regression models were used, with correction for demographic factors and cluster headache subtype (chronic vs. episodic; recent attacks cluster headache responded of whom 218/606 (36%) had allodynia during attacks. Female gender (OR 2.05, 95% CI 1.28-3.29), low age at onset (OR 0.98, 95% CI 0.96- 0.99), lifetime depression (OR 1.63; 95% CI 1.06-2.50), comorbid migraine (OR 1.96; 95% CI 1.02-3.79), and having recent attacks (OR 1.80; 95% CI 1.13-2.86), but not duration of attacks and chronic cluster headache, were independent risk factors for allodynia.The high prevalence of cutaneous allodynia with similar risk factors for allodynia as found for migraine suggests that central sensitization, like in migraine, also occurs in cluster headache. In clinical practice, awareness that people with cluster headache may suffer from allodynia can in the future be an important feature in treatment options.

  12. The myrmicine ant genus Metapone Forel (Hymenoptera: Formicidae): a global taxonomic review with descriptions of twelve new species.

    Science.gov (United States)

    Taylor, Robert W; Alpert, Gary D

    2016-04-26

    The 28 known species of Metapone are monographed and illustrated. Twelve are described as new: M. africana, Gabon; M. balinensis, Bali, Indonesia; M. enigmatica, northeast New Guinea; M. hoelldobleri, northeast Queensland, Australia; M. javana, Java, Indonesia; M. manni, Viti Levu, Fiji; M. mathinnae, Flinders Island, Tasmania, Australia; M. philwardi, northeast New Guinea; M. salomonis, Guadalcanal, Solomon Islands; M. tecklini, northeast Queensland; M. titan, New Ireland, Papua New Guinea; M. wallaceana, Lombok, Indonesia; spp.n. New synonymies include M. greeni Forel = M. johni Karavaiev (Sri Lanka) syn.n, and M. jacobsoni Crawley (Sumatra) = M. nicobarensis Tiwari & Jonathan (Great Nicobar Island) syn.n.

  13. The Asthma Phenotype in the Obese: Distinct or Otherwise?

    Directory of Open Access Journals (Sweden)

    Sherry Farzan

    2013-01-01

    Full Text Available Asthma is a heterogenous disorder that can be classified into several different phenotypes. Recent cluster analyses have identified an “obese-asthma” phenotype which is characterized by late onset, female predominance and lack of atopy. In addition, obesity among early-onset asthmatics clearly exists and heightens the clinical presentation. Observational studies have demonstrated that asthma among the obese has a clinical presentation that is more severe, harder to control, and is not as responsive to standard controller therapies. While weight loss studies have demonstrated improvement in asthma outcomes, further studies need to be performed. The current knowledge of the existence of two obesity-asthma phenotypes (early- versus late-onset asthma should encourage investigators to study these entities separately since just as they have distinct presentations, their course, response to therapies, and weight loss strategies may be different as well.

  14. Raspberry Pi super cluster

    CERN Document Server

    Dennis, Andrew K

    2013-01-01

    This book follows a step-by-step, tutorial-based approach which will teach you how to develop your own super cluster using Raspberry Pi computers quickly and efficiently.Raspberry Pi Super Cluster is an introductory guide for those interested in experimenting with parallel computing at home. Aimed at Raspberry Pi enthusiasts, this book is a primer for getting your first cluster up and running.Basic knowledge of C or Java would be helpful but no prior knowledge of parallel computing is necessary.

  15. Cluster modular autocontenido

    OpenAIRE

    2009-01-01

    Desde hace años es común en organizaciones educativas y de investigación el desarrollo de actividades que requieren grandes capacidades de cálculo. La solución más común a estas necesidades es la compra o construcción de un cluster HPC (High Performance Computing), pero construir un cluster acarrea problemas y costos inesperados problemas al momento de utilizarlo y mantenerlo en operaciones. Nuestro proyecto busca desarrollar y documentar técnicas para construir un cluster HPC que sea fácilme...

  16. Extending Beowulf Clusters

    Science.gov (United States)

    Steinwand, Daniel R.; Maddox, Brian; Beckmann, Tim; Hamer, George

    2003-01-01

    Beowulf clusters can provide a cost-effective way to compute numerical models and process large amounts of remote sensing image data. Usually a Beowulf cluster is designed to accomplish a specific set of processing goals, and processing is very efficient when the problem remains inside the constraints of the original design. There are cases, however, when one might wish to compute a problem that is beyond the capacity of the local Beowulf system. In these cases, spreading the problem to multiple clusters or to other machines on the network may provide a cost-effective solution.

  17. Introduction to cluster dynamics

    CERN Document Server

    Reinhard, Paul-Gerhard

    2008-01-01

    Clusters as mesoscopic particles represent an intermediate state of matter between single atoms and solid material. The tendency to miniaturise technical objects requires knowledge about systems which contain a ""small"" number of atoms or molecules only. This is all the more true for dynamical aspects, particularly in relation to the qick development of laser technology and femtosecond spectroscopy. Here, for the first time is a highly qualitative introduction to cluster physics. With its emphasis on cluster dynamics, this will be vital to everyone involved in this interdisciplinary subje

  18. ClusterAlive

    Science.gov (United States)

    Caruso, G.; Arezzini, S.; Ciampa, A.; Formuso, A.; Mazzoni, E.

    2015-12-01

    INFN-Pisa Scientific Computing Center is working from many years both in GRID and HPC computing. The monitoring and managing tools have been key components of the center's successful operation. The lessons learned from the use of standard tools, such as Ganglia, have been starting points for the development of new tools specific for our infrastructure. In this note we will illustrate the integration of many different monitoring tools in one single platform called ClusterAlive. Aim of ClusterAlive is to increase the HPC cluster performance and simplify maintenance operations, possibly in a proactive approach.

  19. From collisions to clusters

    DEFF Research Database (Denmark)

    Loukonen, Ville; Bork, Nicolai; Vehkamaki, Hanna

    2014-01-01

    -principles molecular dynamics collision simulations of (sulphuric acid)1(water)0, 1 + (dimethylamine) → (sulphuric acid)1(dimethylamine)1(water)0, 1 cluster formation processes. The simulations indicate that the sticking factor in the collisions is unity: the interaction between the molecules is strong enough...... to overcome the possible initial non-optimal collision orientations. No post-collisional cluster break up is observed. The reasons for the efficient clustering are (i) the proton transfer reaction which takes place in each of the collision simulations and (ii) the subsequent competition over the proton...

  20. Negotiating Cluster Boundaries

    DEFF Research Database (Denmark)

    Giacomin, Valeria

    2017-01-01

    Palm oil was introduced to Malay(si)a as an alternative to natural rubber, inheriting its cluster organizational structure. In the late 1960s, Malaysia became the world’s largest palm oil exporter. Based on archival material from British colonial institutions and agency houses, this paper focuses...... on the governance dynamics that drove institutional change within this cluster during decolonization. The analysis presents three main findings: (i) cluster boundaries are defined by continuous tug-of-war style negotiations between public and private actors; (ii) this interaction produces institutional change...

  1. Combining cluster number counts and galaxy clustering

    Science.gov (United States)

    Lacasa, Fabien; Rosenfeld, Rogerio

    2016-08-01

    The abundance of clusters and the clustering of galaxies are two of the important cosmological probes for current and future large scale surveys of galaxies, such as the Dark Energy Survey. In order to combine them one has to account for the fact that they are not independent quantities, since they probe the same density field. It is important to develop a good understanding of their correlation in order to extract parameter constraints. We present a detailed modelling of the joint covariance matrix between cluster number counts and the galaxy angular power spectrum. We employ the framework of the halo model complemented by a Halo Occupation Distribution model (HOD). We demonstrate the importance of accounting for non-Gaussianity to produce accurate covariance predictions. Indeed, we show that the non-Gaussian covariance becomes dominant at small scales, low redshifts or high cluster masses. We discuss in particular the case of the super-sample covariance (SSC), including the effects of galaxy shot-noise, halo second order bias and non-local bias. We demonstrate that the SSC obeys mathematical inequalities and positivity. Using the joint covariance matrix and a Fisher matrix methodology, we examine the prospects of combining these two probes to constrain cosmological and HOD parameters. We find that the combination indeed results in noticeably better constraints, with improvements of order 20% on cosmological parameters compared to the best single probe, and even greater improvement on HOD parameters, with reduction of error bars by a factor 1.4-4.8. This happens in particular because the cross-covariance introduces a synergy between the probes on small scales. We conclude that accounting for non-Gaussian effects is required for the joint analysis of these observables in galaxy surveys.

  2. Identification of asthma clusters in two independent Korean adult asthma cohorts.

    Science.gov (United States)

    Kim, Tae-Bum; Jang, An-Soo; Kwon, Hyouk-Soo; Park, Jong-Sook; Chang, Yoon-Seok; Cho, Sang-Heon; Choi, Byoung Whui; Park, Jung-Won; Nam, Dong-Ho; Yoon, Ho-Joo; Cho, Young-Joo; Moon, Hee-Bom; Cho, You Sook; Park, Choon-Sik

    2013-06-01

    Asthma is a heterogeneous airway disease with various clinical phenotypes. It is crucial to clearly identify clinical phenotypes to achieve better asthma management. We used cluster analysis to classify the clinical groups of 724 asthmatic patients from the Cohort for Reality and Evolution of Adult Asthma in Korea (COREA), and in 1843 subjects from another independent Korean asthma cohort of Soonchunhyang University Asthma Genome Research Centre (SCH) (Bucheon, Republic of Korea). Hierarchical cluster analysis was performed by Ward's method, followed by κ-means cluster analysis. Cluster analysis of the COREA cohort indicated four asthma subtypes: 1) smoking asthma; 2) severe obstructive asthma; 3) early-onset atopic asthma; and 4) late-onset mild asthma. An independent cluster analysis of the SCH cohort also indicated four clusters that were similar to the COREA clusters. Our results indicate that adult Korean asthma patients can be classified into four distinct clusters.

  3. Distinct properties of the triplet pair state from singlet fission.

    Science.gov (United States)

    Trinh, M Tuan; Pinkard, Andrew; Pun, Andrew B; Sanders, Samuel N; Kumarasamy, Elango; Sfeir, Matthew Y; Campos, Luis M; Roy, Xavier; Zhu, X-Y

    2017-07-01

    Singlet fission, the conversion of a singlet exciton (S1) to two triplets (2 × T1), may increase the solar energy conversion efficiency beyond the Shockley-Queisser limit. This process is believed to involve the correlated triplet pair state (1)(TT). Despite extensive research, the nature of the (1)(TT) state and its spectroscopic signature remain actively debated. We use an end-connected pentacene dimer (BP0) as a model system and show evidence for a tightly bound (1)(TT) state. It is characterized in the near-infrared (IR) region (~1.0 eV) by a distinct excited-state absorption (ESA) spectral feature, which closely resembles that of the S1 state; both show vibronic progressions of the aromatic ring breathing mode. We assign these near-IR spectra to (1)(TT)→Sn and S1→Sn' transitions; Sn and Sn' likely come from the antisymmetric and symmetric linear combinations, respectively, of the S2 state localized on each pentacene unit in the dimer molecule. The (1)(TT)→Sn transition is an indicator of the intertriplet electronic coupling strength, because inserting a phenylene spacer or twisting the dihedral angle between the two pentacene chromophores decreases the intertriplet electronic coupling and diminishes this ESA peak. In addition to spectroscopic signature, the tightly bound (1)(TT) state also shows chemical reactivity that is distinctively different from that of an individual T1 state. Using an electron-accepting iron oxide molecular cluster [Fe8O4] linked to the pentacene or pentacene dimer (BP0), we show that electron transfer to the cluster occurs efficiently from an individual T1 in pentacene but not from the tightly bound (1)(TT) state. Thus, reducing intertriplet electronic coupling in (1)(TT) via molecular design might be necessary for the efficient harvesting of triplets from intramolecular singlet fission.

  4. Hopelessness depression as a distinct dimension of depressive symptoms among clinical and non-clinical samples.

    Science.gov (United States)

    Joiner, T E; Steer, R A; Abramson, L Y; Alloy, L B; Metalsky, G I; Schmidt, N B

    2001-05-01

    Subtyping depression has been an interest of theorists and clinicians for at least four centuries. In this paper, we examined the validity of the symptom cluster component of the hopelessness theory of depression. We used structural equation modeling analyses on large samples of psychiatric outpatients (N=1604, 844, and 680) and Air Force cadets (N=1404) who completed the items of the Beck Depression Inventory (BDI). Findings were supportive of the hopelessness depression cluster as a distinct depressive syndrome. Implications for the nosology of depression and for depression theory were discussed.

  5. Sources of inter-firm heterogeneity in accessing knowledge-creation benefits within technology clusters

    NARCIS (Netherlands)

    Arikan, A.; Knoben, J.

    2014-01-01

    We build on recent literature to highlight the distinction between knowledge-diffusion and knowledge-creation benefits of technology clustering and argue that firms located in technology clusters will have differential access to the latter. To explain the antecedents of such differential access, we

  6. Identifying At-Risk Students in General Chemistry via Cluster Analysis of Affective Characteristics

    Science.gov (United States)

    Chan, Julia Y. K.; Bauer, Christopher F.

    2014-01-01

    The purpose of this study is to identify academically at-risk students in first-semester general chemistry using affective characteristics via cluster analysis. Through the clustering of six preselected affective variables, three distinct affective groups were identified: low (at-risk), medium, and high. Students in the low affective group…

  7. Identifying At-Risk Students in General Chemistry via Cluster Analysis of Affective Characteristics

    Science.gov (United States)

    Chan, Julia Y. K.; Bauer, Christopher F.

    2014-01-01

    The purpose of this study is to identify academically at-risk students in first-semester general chemistry using affective characteristics via cluster analysis. Through the clustering of six preselected affective variables, three distinct affective groups were identified: low (at-risk), medium, and high. Students in the low affective group…

  8. Evolution of clustered storage

    CERN Document Server

    CERN. Geneva; Van de Vyvre, Pierre

    2007-01-01

    The session actually featured two presentations: * Evolution of clustered storage by Lance Hukill, Quantum Corporation * ALICE DAQ - Usage of a Cluster-File System: Quantum StorNext by Pierre Vande Vyvre, CERN-PH the second one prepared at short notice by Pierre (thanks!) to present how the Quantum technologies are being used in the ALICE experiment. The abstract to Mr Hukill's follows. Clustered Storage is a technology that is driven by business and mission applications. The evolution of Clustered Storage solutions starts first at the alignment between End-users needs and Industry trends: * Push-and-Pull between managing for today versus planning for tomorrow * Breaking down the real business problems to the core applications * Commoditization of clients, servers, and target devices * Interchangeability, Interoperability, Remote Access, Centralized control * Oh, and yes, there is a budget and the "real world" to deal with This presentation will talk through these needs and trends, and then ask the question, ...

  9. Improved graph clustering

    Science.gov (United States)

    2013-01-01

    on Facebook , one would like to detect tightly connected communities, which is useful for subsequent tasks like customized recommendation and... advertisement . Graphs in modern applications have several characteristics that complicate graph clustering: • Small density gap: the edge density across

  10. Clustering of Emerging Flux

    Science.gov (United States)

    Ruzmaikin, A.

    1997-01-01

    Observations show that newly emerging flux tends to appear on the Solar surface at sites where there is flux already. This results in clustering of solar activity. Standard dynamo theories do not predict this effect.

  11. How Clusters Work

    Science.gov (United States)

    Technology innovation clusters are geographic concentrations of interconnected companies, universities, and other organizations with a focus on environmental technology. They play a key role in addressing the nation’s pressing environmental problems.

  12. Clustering in Ethiopia

    African Journals Online (AJOL)

    Information Systems (GIS) that can process the data may not be available and accessible where ... Methods: An example of space-time clustering of malaria cases around a dam in Ethiopia (106 .... was prepared for publication using mapping.

  13. APROACHES TOWARDS CLUSTER ANALYSIS

    National Research Council Canada - National Science Library

    Manuela Tvaronaviciene; Kristina Razminiene; Leonardo Piccinetti

    2015-01-01

    .... The findings indicate that case study is used in many articles refering to cluster research. Other methods, such as analysis, interview, survey, research, equation and others are used to support case study...

  14. Parallel Wolff Cluster Algorithms

    Science.gov (United States)

    Bae, S.; Ko, S. H.; Coddington, P. D.

    The Wolff single-cluster algorithm is the most efficient method known for Monte Carlo simulation of many spin models. Due to the irregular size, shape and position of the Wolff clusters, this method does not easily lend itself to efficient parallel implementation, so that simulations using this method have thus far been confined to workstations and vector machines. Here we present two parallel implementations of this algorithm, and show that one gives fairly good performance on a MIMD parallel computer.

  15. Magnetic cluster excitations

    Science.gov (United States)

    Furrer, Albert; Waldmann, Oliver

    2013-01-01

    Magnetic clusters, i.e., assemblies of a finite number (between two or three and several hundred) of interacting spin centers which are magnetically decoupled from their environment, can be found in many materials ranging from inorganic compounds and magnetic molecules to artificial metal structures formed on surfaces and metalloproteins. Their magnetic excitation spectra are determined by the nature of the spin centers and of the magnetic interactions, and the particular arrangement of the mutual interaction paths between the spin centers. Small clusters of up to four magnetic ions are ideal model systems in which to examine the fundamental magnetic interactions, which are usually dominated by Heisenberg exchange, but often complemented by anisotropic and/or higher-order interactions. In large magnetic clusters, which may potentially deal with a dozen or more spin centers, there is the possibility of novel many-body quantum states and quantum phenomena. In this review the necessary theoretical concepts and experimental techniques to study the magnetic cluster excitations and the resulting characteristic magnetic properties are introduced, followed by examples of small clusters, demonstrating the enormous amount of detailed physical information that can be retrieved. The current understanding of the excitations and their physical interpretation in the molecular nanomagnets which represent large magnetic clusters is then presented, with a section devoted to the subclass of single-molecule magnets, distinguished by displaying quantum tunneling of the magnetization. Finally, there is a summary of some quantum many-body states which evolve in magnetic insulators characterized by built-in or field-induced magnetic clusters. The review concludes by addressing future perspectives in the field of magnetic cluster excitations.

  16. Cauchy cluster process

    DEFF Research Database (Denmark)

    Ghorbani, Mohammad

    2013-01-01

    In this paper we introduce an instance of the well-know Neyman–Scott cluster process model with clusters having a long tail behaviour. In our model the offspring points are distributed around the parent points according to a circular Cauchy distribution. Using a modified Cramér-von Misses test st...... statistic and the simulated pointwise envelopes it is shown that this model fits better than the Thomas process to the frequently analyzed long-leaf pine data-set....

  17. Globular clusters with Gaia

    Science.gov (United States)

    Pancino, E.; Bellazzini, M.; Giuffrida, G.; Marinoni, S.

    2017-01-01

    The treatment of crowded fields in Gaia data will only be a reality in a few years from now. In particular, for globular clusters, only the end-of-mission data (public in 2022-2023) will have the necessary full crowding treatment and will reach sufficient quality for the faintest stars. As a consequence, the work on the deblending and decontamination pipelines is still ongoing. We describe the present status of the pipelines for different Gaia instruments, and we model the end-of-mission crowding errors on the basis of available information. We then apply the nominal post-launch Gaia performances, appropriately worsened by the estimated crowding errors, to a set of 18 simulated globular clusters with different concentration, distance, and field contamination. We conclude that there will be 103-104 stars with astrometric performances virtually untouched by crowding (contaminated by <1 mmag) in the majoritiy of clusters. The most limiting factor will be field crowding, not cluster crowding: the most contaminated clusters will only contain 10-100 clean stars. We also conclude that: (i) the systemic proper motions and parallaxes will be determined to 1% or better up to ≃15 kpc, and the nearby clusters will have radial velocities to a few km s-1 ; (ii) internal kinematics will be of unprecendented quality, cluster masses will be determined to ≃10% up to 15 kpc and beyond, and it will be possible to identify differences of a few km s-1 or less in the kinematics (if any) of cluster sub-populations up to 10 kpc and beyond; (iii) the brightest stars (V≃17 mag) will have space-quality, wide-field photometry (mmag errors), and all Gaia photometry will have 1-3% errors on the absolute photometric calibration.

  18. The Effect o f Twelve - Week Recreation Act i v ities on the Anxiety Level of Female Pri soners

    Directory of Open Access Journals (Sweden)

    Zekiye B AŞARAN

    2015-07-01

    Full Text Available T h e a i m o f t h e s t u d y w a s to examine the effect of twelve - weeks recreation activities on the trait anxiety level of female prisoners in the prisons. The sampling of this study consists of 45 female prisoners who are in the Open Prison in Kandira, 22 of whom are in the experimental group and 23 of whom are in the control group. Different activities, such as music, dance, meditatio n, sportive activities, movies and videos, fun and entertainment activities and competitions, were performed one and half hours a day and two days a week. This lasted for twelve weeks. The data were collected by pre - tests and post - tests that were given bo th at the beginning and at the end of this program. Personal information form and Spielberger anxiety inventory were used as the data collecting tool. The reliability coefficient (Cronbach Alpha was calculated as ,873. The data were analysed with SPSS Win dows 18 programme. Descriptive statistics and Wilcoxon test were conducted. A si gnificant statistical correlation was determined between the prisoners’ pre - tests and post - tests scores in the experimental group (p <0.05. A s c o n c l u s i o n , a positive impact on trait anxiety levels of prisoners w a s f o u n d a f t e r 12 weeks o f recreational activities.

  19. Risk assessment of K basin twelve-inch drain valve failure from a postulated seismic initiating event

    Energy Technology Data Exchange (ETDEWEB)

    MORGAN, R.G.

    1999-04-06

    The Spent Nuclear Fuel (SNF) Project will transfer metallic SNF from the Hanford 105 K-East and 105 K-West Basins to safe interim storage in the Canister Storage Building in the 200 Area. The initial basis for design, fabrication, installation, and operation of the fuel removal systems was that the basin leak rates which could result from a postulated accident condition would not be excessive relative to reasonable recovery operations. However, an additional potential K Basin water leak path is through the K Basin drain valves. Three twelve-inch drain valves are located in the main basin bays along the north wall. The sumps containing the valves are filled with concrete which covers the drain valve body. Visual observations suggest that only the valve's bonnet and stem are exposed above the basin concrete floor. It was recognized, however, that damage of the drain valve bonnet or stem during a seismic initiating event could provide a potential K Basin water leak path. The objectives of this activity are to: (1) evaluate the risk of damaging the three twelve-inch drain valves located along the north wall of the main basin from a seismic initiating event, and (2) determine the associated potential leak rate from a damaged valve.

  20. Twelve new species and fifty-three new provincial distribution records of Aleocharinae rove beetles of Saskatchewan, Canada (Coleoptera, Staphylinidae).

    Science.gov (United States)

    Klimaszewski, Jan; Larson, David J; Labrecque, Myriam; Bourdon, Caroline

    2016-01-01

    One hundred twenty species of aleocharine beetles (Staphylinidae) are recognized in the province of Saskatchewan. Sixty-five new provincial records, including twelve new species and one new North American record, are presented. Oligota inflata (Mannerheim), a Palearctic species, is newly recorded for North America. The following twelve species are described as new to science: Acrotona pseudopygmaea Klimaszewski & Larson, sp. n., Agaricomorpha pulchra Klimaszewski & Larson, sp. n. (new genus record for Canadian fauna), Aleochara elisabethae Klimaszewski & Larson, sp. n., Atheta (Dimetrota) larsonae Klimaszewski & Larson, sp. n., Atheta (Microdota) pseudopittionii Klimaszewski & Larson, sp. n., Atheta (Microdota) spermathecorum Klimaszewski & Larson, sp. n., Atheta (sensu lato) richardsoni Klimaszewski & Larson, sp. n., Brachyusa saskatchewanae Klimaszewski & Larson, sp. n., Dochmonota langori Klimaszewski & Larson, sp. n., Dochmonota simulans Klimaszewski & Larson, sp. n., Dochmonota websteri Klimaszewski & Larson, sp. n., and Oxypoda domestica Klimaszewski & Larson, sp. n. Colour images of habitus and black and white images of the median lobe of the aedeagus, spermatheca, and tergite and sternite VIII are presented for all new species, Oligota inflata Mannerheim and Dochmonota rudiventris (Eppelsheim). A new synonymy is established: Tetralina filitarsus Casey, syn. n. = Tetralina helenae Casey, now placed in the genus Brachyusa Mulsant & Rey.

  1. Risk assessment of K basin twelve-inch drain valve failure from a postulated seismic initiating event

    Energy Technology Data Exchange (ETDEWEB)

    MORGAN, R.G.

    1999-04-06

    The Spent Nuclear Fuel (SNF) Project will transfer metallic SNF from the Hanford 105 K-East and 105 K-West Basins to safe interim storage in the Canister Storage Building in the 200 Area. The initial basis for design, fabrication, installation, and operation of the fuel removal systems was that the basin leak rates which could result from a postulated accident condition would not be excessive relative to reasonable recovery operations. However, an additional potential K Basin water leak path is through the K Basin drain valves. Three twelve-inch drain valves are located in the main basin bays along the north wall. The sumps containing the valves are filled with concrete which covers the drain valve body. Visual observations suggest that only the valve's bonnet and stem are exposed above the basin concrete floor. It was recognized, however, that damage of the drain valve bonnet or stem during a seismic initiating event could provide a potential K Basin water leak path. The objectives of this activity are to: (1) evaluate the risk of damaging the three twelve-inch drain valves located along the north wall of the main basin from a seismic initiating event, and (2) determine the associated potential leak rate from a damaged valve.

  2. Hypervalence in monoxides and dioxides of superalkali clusters

    Science.gov (United States)

    Cochran, Elizabeth; Meloni, Giovanni

    2014-05-01

    F2Li3, a superalkali cluster, is characterized as having a lower adiabatic ionization energy than its elemental alkali counterpart and, coupled with the presence of complex molecular orbitals, suggests promise for novel bonding possibilities. CBS-QB3 composite method was used to study three distinct cluster isomers, as well as their cationic (+1) and anionic (-1) species, to identify energetic trends and observe geometric changes. Oxides were then generated from these clusters, of which three distinct monoxides and nine dioxides were obtained upon structure optimization. Identical calculations were performed for the oxide species and their charged counterparts. Some of the most stable oxides produced appear to possess hypervalent lithium and oxygen atoms, forming unique structures with exceptional stability.

  3. A class III archaeological survey of twelve region wide fencing upgrade locations in Eagle, Grand, Gunnison, Jackson, Moffat, Pitkin, and Routt counties, Colorado

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Colorado Department of Transportation proposes to upgrade existing right-of-way fencing along roadways at twelve separate locations in northwestern Colorado. To...

  4. Cosmography with Galaxy Clusters

    CERN Document Server

    Soares-Santos, M; La Barbera, F; Lopes, P A A; Annis, J

    2008-01-01

    In the present work we focus on future experiments using cluster abundance observations to constraint the Dark Energy equation of state parameter, w. To obtain tight constraints from this kind of experiment, a reliable sample of galaxy clusters must be obtained from deep and wide-field images. We therefore present the computational environment (2DPHOT) that allow us to build the galaxy catalog from the images and the Voronoi Tessellation cluster finding algorithm that we use to identify the galaxy clusters on those catalogs. To test our pipeline with data similar in quality to what will be gathered by future wide field surveys, we process images from the Deep fields obtained as part of the LEGACY Survey (four fields of one square degree each, in five bands, with depth up to r'=25). We test our cluster finder by determining the completeness and purity of the finder when applied to mock galaxy catalogs made for the Dark Energy Survey cluster finder comparison project by Risa Wechsler and Michael Busha. This pro...

  5. Galaxy cluster's rotation

    CERN Document Server

    Manolopoulou, Maria

    2016-01-01

    We study the possible rotation of cluster galaxies, developing, testing and applying a novel algorithm which identifies rotation, if such does exits, as well as its rotational centre, its axis orientation, rotational velocity amplitude and, finally, the clockwise or counterclockwise direction of rotation on the plane of the sky. To validate our algorithms we construct realistic Monte-Carlo mock rotating clusters and confirm that our method provides robust indications of rotation. We then apply our methodology on a sample of Abell clusters with z<~0.1 with member galaxies selected from the SDSS DR10 spectroscopic database. We find that ~35% of our clusters are rotating when using a set of strict criteria, while loosening the criteria we find this fraction increasing to ~48%. We correlate our rotation indicators with the cluster dynamical state, provided either by their Bautz-Morgan type or by their X-ray isophotal shape and find for those clusters showing rotation that the significance and strength of their...

  6. Cluster functional renormalization group

    Science.gov (United States)

    Reuther, Johannes; Thomale, Ronny

    2014-01-01

    Functional renormalization group (FRG) has become a diverse and powerful tool to derive effective low-energy scattering vertices of interacting many-body systems. Starting from a free expansion point of the action, the flow of the RG parameter Λ allows us to trace the evolution of the effective one- and two-particle vertices towards low energies by taking into account the vertex corrections between all parquet channels in an unbiased fashion. In this work, we generalize the expansion point at which the diagrammatic resummation procedure is initiated from a free UV limit to a cluster product state. We formulate a cluster FRG scheme where the noninteracting building blocks (i.e., decoupled spin clusters) are treated exactly, and the intercluster couplings are addressed via RG. As a benchmark study, we apply our cluster FRG scheme to the spin-1/2 bilayer Heisenberg model (BHM) on a square lattice where the neighboring sites in the two layers form the individual two-site clusters. Comparing with existing numerical evidence for the BHM, we obtain reasonable findings for the spin susceptibility, the spin-triplet excitation energy, and quasiparticle weight even in coupling regimes close to antiferromagnetic order. The concept of cluster FRG promises applications to a large class of interacting electron systems.

  7. Cluster bomb ocular injuries

    Directory of Open Access Journals (Sweden)

    Ahmad M Mansour

    2012-01-01

    Full Text Available Purpose: To present the visual outcomes and ocular sequelae of victims of cluster bombs. Materials and Methods: This retrospective, multicenter case series of ocular injury due to cluster bombs was conducted for 3 years after the war in South Lebanon (July 2006. Data were gathered from the reports to the Information Management System for Mine Action. Results: There were 308 victims of clusters bombs; 36 individuals were killed, of which 2 received ocular lacerations and; 272 individuals were injured with 18 receiving ocular injury. These 18 surviving individuals were assessed by the authors. Ocular injury occurred in 6.5% (20/308 of cluster bomb victims. Trauma to multiple organs occurred in 12 of 18 cases (67% with ocular injury. Ocular findings included corneal or scleral lacerations (16 eyes, corneal foreign bodies (9 eyes, corneal decompensation (2 eyes, ruptured cataract (6 eyes, and intravitreal foreign bodies (10 eyes. The corneas of one patient had extreme attenuation of the endothelium. Conclusions: Ocular injury occurred in 6.5% of cluster bomb victims and 67% of the patients with ocular injury sustained trauma to multiple organs. Visual morbidity in civilians is an additional reason for a global ban on the use of cluster bombs.

  8. Cluster analysis of autoantibodies in 852 patients with systemic lupus erythematosus from a single center.

    Science.gov (United States)

    Artim-Esen, Bahar; Çene, Erhan; Şahinkaya, Yasemin; Ertan, Semra; Pehlivan, Özlem; Kamali, Sevil; Gül, Ahmet; Öcal, Lale; Aral, Orhan; Inanç, Murat

    2014-07-01

    Associations between autoantibodies and clinical features have been described in systemic lupus erythematosus (SLE). Herein, we aimed to define autoantibody clusters and their clinical correlations in a large cohort of patients with SLE. We analyzed 852 patients with SLE who attended our clinic. Seven autoantibodies were selected for cluster analysis: anti-DNA, anti-Sm, anti-RNP, anticardiolipin (aCL) immunoglobulin (Ig)G or IgM, lupus anticoagulant (LAC), anti-Ro, and anti-La. Two-step clustering and Kaplan-Meier survival analyses were used. Five clusters were identified. A cluster consisted of patients with only anti-dsDNA antibodies, a cluster of anti-Sm and anti-RNP, a cluster of aCL IgG/M and LAC, and a cluster of anti-Ro and anti-La antibodies. Analysis revealed 1 more cluster that consisted of patients who did not belong to any of the clusters formed by antibodies chosen for cluster analysis. Sm/RNP cluster had significantly higher incidence of pulmonary hypertension and Raynaud phenomenon. DsDNA cluster had the highest incidence of renal involvement. In the aCL/LAC cluster, there were significantly more patients with neuropsychiatric involvement, antiphospholipid syndrome, autoimmune hemolytic anemia, and thrombocytopenia. According to the Systemic Lupus International Collaborating Clinics damage index, the highest frequency of damage was in the aCL/LAC cluster. Comparison of 10 and 20 years survival showed reduced survival in the aCL/LAC cluster. This study supports the existence of autoantibody clusters with distinct clinical features in SLE and shows that forming clinical subsets according to autoantibody clusters may be useful in predicting the outcome of the disease. Autoantibody clusters in SLE may exhibit differences according to the clinical setting or population.

  9. How clustering dark energy affects matter perturbations

    CERN Document Server

    Mehrabi, A; Pace, F

    2015-01-01

    The rate of structure formation in the Universe is different in homogeneous and clustered dark energy models. The degree of dark energy clustering depends on the magnitude of its effective sound speed $c^{2}_{\\rm eff}$ and for $c_{\\rm eff}=0$ dark energy clusters in a similar fashion to dark matter while for $c_{\\rm eff}=1$ it stays (approximately) homogeneous. In this paper we consider two distinct equations of state for the dark energy component, $w_{\\rm d}=const$ and $w_{\\rm d}=w_0+w_1\\left(\\frac{z}{1+z}\\right)$ with $c_{\\rm eff}$ as a free parameter and we try to constrain the dark energy effective sound speed using current available data including SnIa, Baryon Acoustic Oscillation, CMB shift parameter ({\\em Planck} and {\\em WMAP}), Hubble parameter, Big Bang Nucleosynthesis and the growth rate of structures $f\\sigma_{8}(z)$. At first we derive the most general form of the equations governing dark matter and dark energy clustering under the assumption that $c_{\\rm eff}=const$. Finally we constrain the mod...

  10. Determination of atomic cluster structure with cluster fusion algorithm

    DEFF Research Database (Denmark)

    Obolensky, Oleg I.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2005-01-01

    We report an efficient scheme of global optimization, called cluster fusion algorithm, which has proved its reliability and high efficiency in determination of the structure of various atomic clusters.......We report an efficient scheme of global optimization, called cluster fusion algorithm, which has proved its reliability and high efficiency in determination of the structure of various atomic clusters....

  11. Four phenotypically and phylogenetically distinct lineages in Phytophthora lateralis.

    Science.gov (United States)

    Brasier, Clive M; Franceschini, Selma; Vettraino, Anna Maria; Hansen, Everett M; Green, Sarah; Robin, Cecile; Webber, Joan F; Vannini, Andrea

    2012-12-01

    Until recently Phytophthora lateralis was known only as the cause of dieback and mortality of Chamaecyparis lawsoniana in its native range in the Pacific Northwest (PNW). Since the 1990s however disease outbreaks have occurred increasingly on ornamental C. lawsoniana in Europe; and in 2007 the pathogen was discovered in soil around old growth Chamaecyparis obtusa in Taiwan, where it may be endemic. When the phenotypes of over 150 isolates of P. lateralis from Taiwan, across the PNW (British Columbia to California) and from France, the Netherlands and the UK were compared three growth rate groups were resolved: one slow growing from Taiwan, one fast growing from the PNW and Europe, and one of intermediate growth from a small area of the UK. Within these growth groups distinct subtypes were identified based on colony patterns and spore metrics and further discriminated in a multivariate analysis. The assumption that the three main growth groups represented phylogenetic units was tested by comparative sequencing of two mitochondrial and three nuclear genes. This assumption was confirmed. In addition two phenotype clusters within the Taiwan growth group were also shown to be phylogenetically distinct. These four phenotypically and genotypically unique populations are informally designated as the PNW lineage, the UK lineage, the Taiwan J lineage, and the Taiwan K lineage. Their characteristics and distribution are described and their evolution, taxonomic, and plant health significance is discussed.

  12. Modest validity and fair reproducibility of dietary patterns derived by cluster analysis.

    Science.gov (United States)

    Funtikova, Anna N; Benítez-Arciniega, Alejandra A; Fitó, Montserrat; Schröder, Helmut

    2015-03-01

    Cluster analysis is widely used to analyze dietary patterns. We aimed to analyze the validity and reproducibility of the dietary patterns defined by cluster analysis derived from a food frequency questionnaire (FFQ). We hypothesized that the dietary patterns derived by cluster analysis have fair to modest reproducibility and validity. Dietary data were collected from 107 individuals from population-based survey, by an FFQ at baseline (FFQ1) and after 1 year (FFQ2), and by twelve 24-hour dietary recalls (24-HDR). Repeatability and validity were measured by comparing clusters obtained by the FFQ1 and FFQ2 and by the FFQ2 and 24-HDR (reference method), respectively. Cluster analysis identified a "fruits & vegetables" and a "meat" pattern in each dietary data source. Cluster membership was concordant for 66.7% of participants in FFQ1 and FFQ2 (reproducibility), and for 67.0% in FFQ2 and 24-HDR (validity). Spearman correlation analysis showed reasonable reproducibility, especially in the "fruits & vegetables" pattern, and lower validity also especially in the "fruits & vegetables" pattern. κ statistic revealed a fair validity and reproducibility of clusters. Our findings indicate a reasonable reproducibility and fair to modest validity of dietary patterns derived by cluster analysis. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Recent Insights Into the Prenucleation Cluster Pathway

    Science.gov (United States)

    Gebauer, D.; Kellermeier, M.; Berg, J. K.

    2012-12-01

    Stable calcium carbonate pre-nucleation clusters (PNCs) form in aqueous solution prior to nucleation of CaCO3 (1). Computer simulations suggest that the thermodynamic stability of PNCs is based upon strong hydration in combination with a distinct entropic contribution (2). In this way, PNCs can compete enthalpically with ion pairs and entropically with amorpous calcium carbonate (ACC). The clue is a high degree of structural disorder in highly dynamic, liquid- and chain-like polymeric structures of calcium carbonate ion pairs (2). Nucleation of solid calcium carbonate from these polymeric species proceeds via PNC aggregation rather than via ion-by-ion additions to un-/metastable nuclei (3). Owing to these basic characteristics, the pre-nucleation cluster pathway has been referred to as "non-classical nucleation" (4). Non-classical nucleation leads to distinct short-range structural features in ACC, and depending on pH they relate to the crystalline long-range order of calcite or vaterite (5). This suggests that calcium carbonate exhibits polyamorphism, and that distinct polyamorphs may play a central role during polymorph selection. In this contribution, we outline the scenario described above, and focus on recent insights into the pre-nucleation cluster pathway. 1. D. Gebauer, A. Völkel & H. Cölfen, Science 322, 1819-1822 (2008). 2. R. Demichelis, P. Raiteri, J.D. Gale, D. Quigley, D. Gebauer, Nat. Commun. 2, 590 (2011). 3. M. Kellermeier et al., Adv. Funct. Mater., DOI: 10.1002/adfm.201200953 (2012). 4. D. Gebauer, H. Cölfen, Nano Today 6, 564-584 (2011). 5. D. Gebauer et al., Angew. Chem. Int. Ed. 49, 8889-8891 (2010).

  14. Obstructive Sleep Apnea: A Cluster Analysis at Time of Diagnosis

    Science.gov (United States)

    Grillet, Yves; Richard, Philippe; Stach, Bruno; Vivodtzev, Isabelle; Timsit, Jean-Francois; Lévy, Patrick; Tamisier, Renaud; Pépin, Jean-Louis

    2016-01-01

    Background The classification of obstructive sleep apnea is on the basis of sleep study criteria that may not adequately capture disease heterogeneity. Improved phenotyping may improve prognosis prediction and help select therapeutic strategies. Objectives: This study used cluster analysis to investigate the clinical clusters of obstructive sleep apnea. Methods An ascending hierarchical cluster analysis was performed on baseline symptoms, physical examination, risk factor exposure and co-morbidities from 18,263 participants in the OSFP (French national registry of sleep apnea). The probability for criteria to be associated with a given cluster was assessed using odds ratios, determined by univariate logistic regression. Results: Six clusters were identified, in which patients varied considerably in age, sex, symptoms, obesity, co-morbidities and environmental risk factors. The main significant differences between clusters were minimally symptomatic versus sleepy obstructive sleep apnea patients, lean versus obese, and among obese patients different combinations of co-morbidities and environmental risk factors. Conclusions Our cluster analysis identified six distinct clusters of obstructive sleep apnea. Our findings underscore the high degree of heterogeneity that exists within obstructive sleep apnea patients regarding clinical presentation, risk factors and consequences. This may help in both research and clinical practice for validating new prevention programs, in diagnosis and in decisions regarding therapeutic strategies. PMID:27314230

  15. Validity of Sensory Systems as Distinct Constructs

    OpenAIRE

    2014-01-01

    Confirmatory factor analysis testing whether sensory questionnaire items represented distinct sensory system constructs found, using data from two age groups, that such constructs can be measured validly using questionnaire data.

  16. Cluster fusion algorithm: application to Lennard-Jones clusters

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    2008-01-01

    paths up to the cluster size of 150 atoms. We demonstrate that in this way all known global minima structures of the Lennard-Jones clusters can be found. Our method provides an efficient tool for the calculation and analysis of atomic cluster structure. With its use we justify the magic number sequence...... for the clusters of noble gas atoms and compare it with experimental observations. We report the striking correspondence of the peaks in the dependence of the second derivative of the binding energy per atom on cluster size calculated for the chain of the Lennard-Jones clusters based on the icosahedral symmetry......We present a new general theoretical framework for modelling the cluster structure and apply it to description of the Lennard-Jones clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing...

  17. Cluster fusion algorithm: application to Lennard-Jones clusters

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Solov'yov, Andrey V.; Greiner, Walter

    2006-01-01

    paths up to the cluster size of 150 atoms. We demonstrate that in this way all known global minima structures of the Lennard-Jones clusters can be found. Our method provides an efficient tool for the calculation and analysis of atomic cluster structure. With its use we justify the magic number sequence...... for the clusters of noble gas atoms and compare it with experimental observations. We report the striking correspondence of the peaks in the dependence of the second derivative of the binding energy per atom on cluster size calculated for the chain of the Lennard-Jones clusters based on the icosahedral symmetry......We present a new general theoretical framework for modelling the cluster structure and apply it to description of the Lennard-Jones clusters. Starting from the initial tetrahedral cluster configuration, adding new atoms to the system and absorbing its energy at each step, we find cluster growing...

  18. The structures of small gold cluster anions as determined by a combination of ion mobility measurements and density functional calculations

    Science.gov (United States)

    Furche, Filipp; Ahlrichs, Reinhart; Weis, Patrick; Jacob, Christoph; Gilb, Stefan; Bierweiler, Thomas; Kappes, Manfred M.

    2002-10-01

    A combined experimental and theoretical study of small gold cluster anions is performed. The experimental effort consists of ion mobility measurements that lead to the assignment of the collision cross sections for the different cluster sizes at room temperature. The theoretical study is based on ab initio molecular dynamics calculations with the goal to find energetically favorable candidate structures. By comparison of the theoretical results with the measured collision cross sections as well as vertical detachment energies (VDEs) from the literature, we assign structures for the small Aun- ions (nVDEs alone is generally not possible, the collision cross sections provide a direct and rather sensitive measure of the cluster structure. In contrast to what was expected from other metal clusters and previous theoretical studies, the structural transition occurs at an unusually large cluster size of twelve atoms.

  19. The Extension of The Twelve-Point Sphere Theorem for a Tetrahedron%四面体的十二点二次曲面

    Institute of Scientific and Technical Information of China (English)

    王奇志; 王东生

    2012-01-01

    垂心四面体中四条高的垂足,四个面的重心及从各顶点与四面体的垂心连线的三等分点,共十二个点共球.试图把垂心改为四面体内的任意点,相应地把四条高线改换为过该点与每个顶点连线的共点直线组时,则将把垂心四面体的十二点球有趣地推广为四面体的十二点二次曲面.%The four feet of four altitudes for an orthocenter tetrahedron, the centers of gravity of the four faces, the trisection of the line segments from the orthocenter to four summits, total twelve points lie on same sphere, which is known as twelve-point sphere. If the orthocenter can be changed into any point within a tetrahedron in this paper, and corresponding the four perpendiculars also can be changed into the four lines segment passing through the given point to the summits of the tetrahedron, the twelve-point sphere can be changed into twelve-point quadric surface. Twelve point sphere of an orthocenter tetrahedron can be generalized to the twelve-point quadratic surface of a tetrahedron.

  20. Cluster Size Statistic and Cluster Mass Statistic: Two Novel Methods for Identifying Changes in Functional Connectivity Between Groups or Conditions

    Science.gov (United States)

    Ing, Alex; Schwarzbauer, Christian

    2014-01-01

    Functional connectivity has become an increasingly important area of research in recent years. At a typical spatial resolution, approximately 300 million connections link each voxel in the brain with every other. This pattern of connectivity is known as the functional connectome. Connectivity is often compared between experimental groups and conditions. Standard methods used to control the type 1 error rate are likely to be insensitive when comparisons are carried out across the whole connectome, due to the huge number of statistical tests involved. To address this problem, two new cluster based methods – the cluster size statistic (CSS) and cluster mass statistic (CMS) – are introduced to control the family wise error rate across all connectivity values. These methods operate within a statistical framework similar to the cluster based methods used in conventional task based fMRI. Both methods are data driven, permutation based and require minimal statistical assumptions. Here, the performance of each procedure is evaluated in a receiver operator characteristic (ROC) analysis, utilising a simulated dataset. The relative sensitivity of each method is also tested on real data: BOLD (blood oxygen level dependent) fMRI scans were carried out on twelve subjects under normal conditions and during the hypercapnic state (induced through the inhalation of 6% CO2 in 21% O2 and 73%N2). Both CSS and CMS detected significant changes in connectivity between normal and hypercapnic states. A family wise error correction carried out at the individual connection level exhibited no significant changes in connectivity. PMID:24906136

  1. Cluster size statistic and cluster mass statistic: two novel methods for identifying changes in functional connectivity between groups or conditions.

    Science.gov (United States)

    Ing, Alex; Schwarzbauer, Christian

    2014-01-01

    Functional connectivity has become an increasingly important area of research in recent years. At a typical spatial resolution, approximately 300 million connections link each voxel in the brain with every other. This pattern of connectivity is known as the functional connectome. Connectivity is often compared between experimental groups and conditions. Standard methods used to control the type 1 error rate are likely to be insensitive when comparisons are carried out across the whole connectome, due to the huge number of statistical tests involved. To address this problem, two new cluster based methods--the cluster size statistic (CSS) and cluster mass statistic (CMS)--are introduced to control the family wise error rate across all connectivity values. These methods operate within a statistical framework similar to the cluster based methods used in conventional task based fMRI. Both methods are data driven, permutation based and require minimal statistical assumptions. Here, the performance of each procedure is evaluated in a receiver operator characteristic (ROC) analysis, utilising a simulated dataset. The relative sensitivity of each method is also tested on real data: BOLD (blood oxygen level dependent) fMRI scans were carried out on twelve subjects under normal conditions and during the hypercapnic state (induced through the inhalation of 6% CO2 in 21% O2 and 73%N2). Both CSS and CMS detected significant changes in connectivity between normal and hypercapnic states. A family wise error correction carried out at the individual connection level exhibited no significant changes in connectivity.

  2. Recent advances in coupled-cluster methods

    CERN Document Server

    Bartlett, Rodney J

    1997-01-01

    Today, coupled-cluster (CC) theory has emerged as the most accurate, widely applicable approach for the correlation problem in molecules. Furthermore, the correct scaling of the energy and wavefunction with size (i.e. extensivity) recommends it for studies of polymers and crystals as well as molecules. CC methods have also paid dividends for nuclei, and for certain strongly correlated systems of interest in field theory.In order for CC methods to have achieved this distinction, it has been necessary to formulate new, theoretical approaches for the treatment of a variety of essential quantities

  3. The Distinction of 'Psychosomatogenic Family Types' Based on Parents' Self Reported Questionnaire Information : A Cluster Analysis

    NARCIS (Netherlands)

    Rousseau, Sofie; Grietens, Hans; Vanderfaeillie, Johan; Ceulemans, Eva; Hoppenbrouwers, Karel; Desoete, Annemie; Van Leeuwen, Karla

    2014-01-01

    The theory of 'psychosomatogenic family types' is often used in treatment of somatizing adolescents. This study investigated the validity of distinguishing 'psychosomatogenic family types' based on parents' self-reported family features. The study included a Flemish general population sample of 12-y

  4. Molecular epidemiological analysis of Mycoplasma bovis isolates from the United Kingdom shows two genetically distinct clusters

    DEFF Research Database (Denmark)

    McAuliffe, Laura; Kokotovic, Branko; Ayling, Roger D.;

    2004-01-01

    Mycoplasma bovis is an important veterinary pathogen causing pneumonia, arthritis, and mastitis in infected cattle. We investigated the genetic diversity of 53 isolates collected in the United Kingdom between 1996 and 2002 with pulsed-field gel electrophoresis (PFGE), amplified fragment length...

  5. Are There Distinctive Clusters of Higher and Lower Status Universities in the UK?

    Science.gov (United States)

    Boliver, Vikki

    2015-01-01

    In 1992 the binary divide between universities and polytechnics was dismantled to create a nominally unitary system of higher education for the UK. Just a year later, the first UK university league table was published, and the year after that saw the formation of the Russell Group of self-proclaimed "leading" universities. This paper…

  6. Are There Distinctive Clusters of Higher and Lower Status Universities in the UK?

    Science.gov (United States)

    Boliver, Vikki

    2015-01-01

    In 1992 the binary divide between universities and polytechnics was dismantled to create a nominally unitary system of higher education for the UK. Just a year later, the first UK university league table was published, and the year after that saw the formation of the Russell Group of self-proclaimed "leading" universities. This paper…

  7. Genetic analysis of Israel Acute Paralysis Virus: distinct clusters are circulating into the United States.

    Science.gov (United States)

    Israel acute paralysis virus (IAPV) is associated with colony collapse disorder of honey bees. Nonetheless, its role in the pathogenesis of the disorder and its geographic distribution are unclear. Here, we report phylogenetic analysis of IAPV obtained from bees in the United States, Canada, Austral...

  8. The Distinction of 'Psychosomatogenic Family Types' Based on Parents' Self Reported Questionnaire Information : A Cluster Analysis

    NARCIS (Netherlands)

    Rousseau, Sofie; Grietens, Hans; Vanderfaeillie, Johan; Ceulemans, Eva; Hoppenbrouwers, Karel; Desoete, Annemie; Van Leeuwen, Karla

    The theory of 'psychosomatogenic family types' is often used in treatment of somatizing adolescents. This study investigated the validity of distinguishing 'psychosomatogenic family types' based on parents' self-reported family features. The study included a Flemish general population sample of

  9. Searching for globular cluster-like abundance patterns in young massive clusters - II. Results from the Antennae galaxies

    Science.gov (United States)

    Lardo, C.; Cabrera-Ziri, I.; Davies, B.; Bastian, N.

    2017-06-01

    The presence of multiple populations (MPs) with distinctive light element abundances is a widespread phenomenon in clusters older than 6 Gyr. Clusters with masses, luminosities, and sizes comparable to those of ancient globulars are still forming today. None the less, the presence of light element variations has been poorly investigated in such young systems, even if the knowledge of the age at which this phenomenon develops is crucial for theoretical models on MPs. We use J-band integrated spectra of three young (7-40 Myr) clusters in NGC 4038 to look for Al variations indicative of MPs. Assuming that the large majority (≥70 per cent) of stars are characterized by high Al content - as observed in Galactic clusters with comparable mass; we find that none of the studied clusters show significant Al variations. Small Al spreads have been measured in all the six young clusters observed in the near-infrared. While it is unlikely that young clusters only show low Al whereas old ones display different levels of Al variations; this suggests the possibility that MPs are not present at such young ages at least among the high-mass stellar component. Alternatively, the fraction of stars with field-like chemistry could be extremely large, mimicking low Al abundances in the integrated spectrum. Finally, since the near-infrared stellar continuum of young clusters is almost entirely due to luminous red supergiants, we can also speculate that MPs only manifest themselves in low-mass stars due to some evolutionary mechanism.

  10. Cluster Based Text Classification Model

    DEFF Research Database (Denmark)

    2011-01-01

    We propose a cluster based classification model for suspicious email detection and other text classification tasks. The text classification tasks comprise many training examples that require a complex classification model. Using clusters for classification makes the model simpler and increases th...... datasets. Our model also outperforms A Decision Cluster Classification (ADCC) and the Decision Cluster Forest Classification (DCFC) models on the Reuters-21578 dataset....

  11. FINDCLUS : Fuzzy INdividual Differences CLUStering

    NARCIS (Netherlands)

    Giordani, Paolo; Kiers, Henk A. L.

    ADditive CLUStering (ADCLUS) is a tool for overlapping clustering of two-way proximity matrices (objects x objects). In Simple Additive Fuzzy Clustering (SAFC), a variant of ADCLUS is introduced providing a fuzzy partition of the objects, that is the objects belong to the clusters with the so-called

  12. Subspace K-means clustering

    NARCIS (Netherlands)

    Timmerman, Marieke E.; Ceulemans, Eva; De Roover, Kim; Van Leeuwen, Karla

    2013-01-01

    To achieve an insightful clustering of multivariate data, we propose subspace K-means. Its central idea is to model the centroids and cluster residuals in reduced spaces, which allows for dealing with a wide range of cluster types and yields rich interpretations of the clusters. We review the existi

  13. Soft Uncoupling of Markov Chains for Permeable Language Distinction: A New Algorithm

    CERN Document Server

    Nock, Richard; Nielsen, Frank; Henry, Claudia

    2008-01-01

    Without prior knowledge, distinguishing different languages may be a hard task, especially when their borders are permeable. We develop an extension of spectral clustering -- a powerful unsupervised classification toolbox -- that is shown to resolve accurately the task of soft language distinction. At the heart of our approach, we replace the usual hard membership assignment of spectral clustering by a soft, probabilistic assignment, which also presents the advantage to bypass a well-known complexity bottleneck of the method. Furthermore, our approach relies on a novel, convenient construction of a Markov chain out of a corpus. Extensive experiments with a readily available system clearly display the potential of the method, which brings a visually appealing soft distinction of languages that may define altogether a whole corpus.

  14. Distinct gene expression profiles in ovarian cancer linked to Lynch syndrome

    DEFF Research Database (Denmark)

    Jönsson, Jenny-Maria; Bartuma, Katarina; Dominguez-Valentin, Mev

    2014-01-01

    Ovarian cancer linked to Lynch syndrome represents a rare subset that typically presents at young age as early-stage tumors with an overrepresentation of endometrioid and clear cell histologies. We investigated the molecular profiles of Lynch syndrome-associated and sporadic ovarian cancer...... ovarian cancers. Lynch syndrome-associated and sporadic ovarian cancers differed by 349 significantly deregulated genes, including PTPRH, BIRC3, SHH and TNFRSF6B. The genes involved were predominantly linked to cell growth, proliferation, and cell-to-cell signaling and interaction. When stratified...... for histologic subtype, hierarchical clustering confirmed distinct differences related to heredity in the endometrioid and serous subtypes. Furthermore, separate clustering was achieved in an independent, publically available data set. The distinct genetic signatures in Lynch syndrome-associated and sporadic...

  15. Cluster Implantation and Deposition Apparatus

    DEFF Research Database (Denmark)

    Hanif, Muhammad; Popok, Vladimir

    2015-01-01

    In the current report, a design and capabilities of a cluster implantation and deposition apparatus (CIDA) involving two different cluster sources are described. The clusters produced from gas precursors (Ar, N etc.) by PuCluS-2 can be used to study cluster ion implantation in order to develop...... contributions to the theory of cluster stopping in matter as well as for practical applications requiring ultra-shallow implantation and modification of surfaces on the nanoscale. Metal clusters from the magnetron cluster source are of interest for the production of optical sensors to detect specific biological...

  16. Stellar populations in star clusters

    CERN Document Server

    Li, Chengyuan; Deng, Licai

    2016-01-01

    Stellar populations contain the most important information about star clus- ter formation and evolution. Until several decades ago, star clusters were believed to be ideal laboratories for studies of simple stellar populations (SSPs). However, discoveries of multiple stellar populations in Galactic globular clusters have expanded our view on stellar populations in star clusters. They have simultaneously generated a number of controversies, particularly as to whether young star clusters may have the same origin as old globular clusters. In addition, extensive studies have revealed that the SSP scenario does not seem to hold for some intermediate-age and young star clusters either, thus making the origin of multiple stellar populations in star clusters even more complicated. Stellar population anomalies in numerous star clusters are well-documented, implying that the notion of star clusters as true SSPs faces serious challenges. In this review, we focus on stellar populations in massive clusters with different ...

  17. Selections of data preprocessing methods and similarity metrics for gene cluster analysis

    Institute of Scientific and Technical Information of China (English)

    YANG Chunmei; WAN Baikun; GAO Xiaofeng

    2006-01-01

    Clustering is one of the major exploratory techniques for gene expression data analysis. Only with suitable similarity metrics and when datasets are properly preprocessed, can results of high quality be obtained in cluster analysis. In this study, gene expression datasets with external evaluation criteria were preprocessed as normalization by line, normalization by column or logarithm transformation by base-2, and were subsequently clustered by hierarchical clustering, k-means clustering and self-organizing maps (SOMs) with Pearson correlation coefficient or Euclidean distance as similarity metric. Finally, the quality of clusters was evaluated by adjusted Rand index. The results illustrate that k-means clustering and SOMs have distinct advantages over hierarchical clustering in gene clustering, and SOMs are a bit better than k-means when randomly initialized. It also shows that hierarchical clustering prefers Pearson correlation coefficient as similarity metric and dataset normalized by line. Meanwhile, k-means clustering and SOMs can produce better clusters with Euclidean distance and logarithm transformed datasets. These results will afford valuable reference to the implementation of gene expression cluster analysis.

  18. Clustering by Pattern Similarity

    Institute of Scientific and Technical Information of China (English)

    Hai-xun Wang; Jian Pei

    2008-01-01

    The task of clustering is to identify classes of similar objects among a set of objects. The definition of similarity varies from one clustering model to another. However, in most of these models the concept of similarity is often based on such metrics as Manhattan distance, Euclidean distance or other Lp distances. In other words, similar objects must have close values in at least a set of dimensions. In this paper, we explore a more general type of similarity. Under the pCluster model we proposed, two objects are similar if they exhibit a coherent pattern on a subset of dimensions. The new similarity concept models a wide range of applications. For instance, in DNA microarray analysis, the expression levels of two genes may rise and fall synchronously in response to a set of environmental stimuli. Although the magnitude of their expression levels may not be close, the patterns they exhibit can be very much alike. Discovery of such clusters of genes is essential in revealing significant connections in gene regulatory networks. E-commerce applications, such as collaborative filtering, can also benefit from the new model, because it is able to capture not only the closeness of values of certain leading indicators but also the closeness of (purchasing, browsing, etc.) patterns exhibited by the customers. In addition to the novel similarity model, this paper also introduces an effective and efficient algorithm to detect such clusters, and we perform tests on several real and synthetic data sets to show its performance.

  19. Chemical evolution of star clusters

    OpenAIRE

    van Loon, Jacco Th.

    2009-01-01

    I discuss the chemical evolution of star clusters, with emphasis on old globular clusters, in relation to their formation histories. Globular clusters clearly formed in a complex fashion, under markedly different conditions from any younger clusters presently known. Those special conditions must be linked to the early formation epoch of the Galaxy and must not have occurred since. While a link to the formation of globular clusters in dwarf galaxies has been suggested, present-day dwarf galaxi...

  20. Maximum-likelihood cluster recontruction

    CERN Document Server

    Bartelmann, M; Seitz, S; Schneider, P J; Bartelmann, Matthias; Narayan, Ramesh; Seitz, Stella; Schneider, Peter

    1996-01-01

    We present a novel method to recontruct the mass distribution of galaxy clusters from their gravitational lens effect on background galaxies. The method is based on a least-chisquare fit of the two-dimensional gravitational cluster potential. The method combines information from shear and magnification by the cluster lens and is designed to easily incorporate possible additional information. We describe the technique and demonstrate its feasibility with simulated data. Both the cluster morphology and the total cluster mass are well reproduced.

  1. No sign (yet) of intergalactic globular clusters in the Local Group

    CERN Document Server

    Mackey, Dougal; Leaman, Ryan

    2016-01-01

    We present Gemini/GMOS imaging of twelve candidate intergalactic globular clusters (IGCs) in the Local Group, identified in a recent survey of the SDSS footprint by di Tullio Zinn & Zinn (2015). Our image quality is sufficiently high, at $\\sim 0.4^{\\prime\\prime} - 0.7^{\\prime\\prime}$, that we are able to unambiguously classify all twelve targets as distant galaxies. To reinforce this conclusion we use GMOS images of globular clusters in the M31 halo, taken under very similar conditions, to show that any genuine clusters in the putative IGC sample would be straightforward to distinguish. Based on the stated sensitivity of the di Tullio Zinn & Zinn (2015) search algorithm, we conclude that there cannot be a significant number of IGCs with $M_V \\le -6$ lying unseen in the SDSS area if their properties mirror those of globular clusters in the outskirts of M31 -- even a population of $4$ would have only a $\\approx 1\\%$ chance of non-detection.

  2. Femtosecond Excited State Dynamics of Size Selected Neutral Molecular Clusters.

    Science.gov (United States)

    Montero, Raúl; León, Iker; Fernández, José A; Longarte, Asier

    2016-07-21

    The work describes a novel experimental approach to track the relaxation dynamics of an electronically excited distribution of neutral molecular clusters formed in a supersonic expansion, by pump-probe femtosecond ionization. The introduced method overcomes fragmentation issues and makes possible to retrieve the dynamical signature of a particular cluster from each mass channel, by associating it to an IR transition of the targeted structure. We have applied the technique to study the nonadiabatic relaxation of pyrrole homoclusters. The results obtained exciting at 243 nm, near the origin of the bare pyrrole electronic absorption, allow us to identify the dynamical signature of the dimer (Py)2, which exhibits a distinctive lifetime of τ1 ∼ 270 fs, considerably longer than the decays recorded for the monomer and bigger size clusters (Py)n>2. A possible relationship between the measured lifetime and the clusters geometries is tentatively discussed.

  3. Automatic script identification from images using cluster-based templates

    Energy Technology Data Exchange (ETDEWEB)

    Hochberg, J.; Kerns, L.; Kelly, P.; Thomas, T.

    1995-02-01

    We have developed a technique for automatically identifying the script used to generate a document that is stored electronically in bit image form. Our approach differs from previous work in that the distinctions among scripts are discovered by an automatic learning procedure, without any handson analysis. We first develop a set of representative symbols (templates) for each script in our database (Cyrillic, Roman, etc.). We do this by identifying all textual symbols in a set of training documents, scaling each symbol to a fixed size, clustering similar symbols, pruning minor clusters, and finding each cluster`s centroid. To identify a new document`s script, we identify and scale a subset of symbols from the document and compare them to the templates for each script. We choose the script whose templates provide the best match. Our current system distinguishes among the Armenian, Burmese, Chinese, Cyrillic, Ethiopic, Greek, Hebrew, Japanese, Korean, Roman, and Thai scripts with over 90% accuracy.

  4. The complex star cluster system of NGC 1316 (Fornax A)

    Science.gov (United States)

    Sesto, Leandro A.; Faifer, Favio R.; Forte, Juan C.

    2016-10-01

    This paper presents Gemini-gri' high-quality photometry for cluster candidates in the field of NGC 1316 (Fornax A) as part of a study that also includes GMOS spectroscopy. A preliminary discussion of the photometric data indicates the presence of four stellar cluster populations with distinctive features in terms of age, chemical abundance and spatial distribution. Two of them seem to be the usually old (metal poor and metal rich) populations typically found in elliptical galaxies. In turn, an intermediate-age (5 Gyr) globular cluster population is the dominant component of the sample (as reported by previous papers). We also find a younger cluster population with a tentative age of ≈ 1 Gyr.

  5. The complex star cluster system of NGC 1316 (Fornax A)

    CERN Document Server

    Sesto, Leandro A; Forte, Juan C

    2016-01-01

    This paper presents Gemini-$gri'$ high quality photometry for cluster candidates in the field of NGC 1316 (Fornax A) as part of a study that also includes GMOS spectroscopy. A preliminary discussion of the photometric data indicates the presence of four stellar cluster populations with distinctive features in terms of age, chemical abundance and spatial distribution. Two of them seem to be the usually old (metal poor and metal rich) populations typically found in elliptical galaxies. In turn, an intermediate-age (5 Gyr) globular cluster population is the dominant component of the sample (as reported by previous papers). We also find a younger cluster population with a tentative age of $\\approx$ 1 Gyr.

  6. Long-Range Correlations in Small Atomic Clusters

    Science.gov (United States)

    Nayak, Saroj K.; Ramaswamy, R.

    We study the power spectrum of fluctuations in the potential energy of atoms in small rare-gas clusters. At temperatures when the cluster is in a liquid-like state the spectra have a “1/f” dependence over a wide range of frequency f. This behavior is distinctly different from both the solid phase of clusters or bulk liquid, and is indicative of long-range temporal correlations. The origins of this phenomenon is explored by studying the individual potential-energy distributions in pure and mixed rare-gas clusters, Xe55 and ArXe54, via molecular dynamics simulations. Substitution of atomic impurities acts as an effective probe of the dynamics, and we observe that long-lived memory effects have their origins in hierarchical relaxation processes arising in the motion of the atoms from the surface to the core and vice-versa.

  7. Twelve reasons to refuse the nuclear in the MDP; Douze raisons pour refuser le nucleaire dans le MDP

    Energy Technology Data Exchange (ETDEWEB)

    Bonduelle, A

    2000-07-01

    The author presents twelve reasons which show that the nuclear energy has not a place in the MDP Mechanism of Clean Development: a main loophole for the developed countries, the doubtful ''additionality'' of the nuclear, the treaty ratification is more difficult with the nuclear, the domestic energy conservation is more efficient in Europe than the nuclear development, the nuclear white elephants facing the South debts, the technology transfers are doubtful, the developing countries and the sustainable development policies are evicted from the MDP, some options are more powerful in the South, the reactors and transport networks size are unsuited, the absence of democratic control, the nuclear proliferation, the nuclear safety and the wastes. (A.L.B.)

  8. Scanning Electron Microscopy Reveals Two Distinct Classes of Erythroblastic Island Isolated from Adult Mammalian Bone Marrow.

    Science.gov (United States)

    Yeo, Jia Hao; McAllan, Bronwyn M; Fraser, Stuart T

    2016-04-01

    Erythroblastic islands are multicellular clusters in which a central macrophage supports the development and maturation of red blood cell (erythroid) progenitors. These clusters play crucial roles in the pathogenesis observed in animal models of hematological disorders. The precise structure and function of erythroblastic islands is poorly understood. Here, we have combined scanning electron microscopy and immuno-gold labeling of surface proteins to develop a better understanding of the ultrastructure of these multicellular clusters. The erythroid-specific surface antigen Ter-119 and the transferrin receptor CD71 exhibited distinct patterns of protein sorting during erythroid cell maturation as detected by immuno-gold labeling. During electron microscopy analysis we observed two distinct classes of erythroblastic islands. The islands varied in size and morphology, and the number and type of erythroid cells interacting with the central macrophage. Assessment of femoral marrow isolated from a cavid rodent species (guinea pig, Cavis porcellus) and a marsupial carnivore species (fat-tailed dunnarts, Sminthopsis crassicaudata) showed that while the morphology of the central macrophage varied, two different types of erythroblastic islands were consistently identifiable. Our findings suggest that these two classes of erythroblastic islands are conserved in mammalian evolution and may play distinct roles in red blood cell production.

  9. Clustering Game Behavior Data

    DEFF Research Database (Denmark)

    Bauckhage, C.; Drachen, Anders; Sifa, Rafet

    2015-01-01

    Recent years have seen a deluge of behavioral data from players hitting the game industry. Reasons for this data surge are many and include the introduction of new business models, technical innovations, the popularity of online games, and the increasing persistence of games. Irrespective...... of the causes, the proliferation of behavioral data poses the problem of how to derive insights therefrom. Behavioral data sets can be large, time-dependent and high-dimensional. Clustering offers a way to explore such data and to discover patterns that can reduce the overall complexity of the data. Clustering...... and other techniques for player profiling and play style analysis have, therefore, become popular in the nascent field of game analytics. However, the proper use of clustering techniques requires expertise and an understanding of games is essential to evaluate results. With this paper, we address game data...

  10. Exotic cluster structures on

    CERN Document Server

    Gekhtman, M; Vainshtein, A

    2017-01-01

    This is the second paper in the series of papers dedicated to the study of natural cluster structures in the rings of regular functions on simple complex Lie groups and Poisson-Lie structures compatible with these cluster structures. According to our main conjecture, each class in the Belavin-Drinfeld classification of Poisson-Lie structures on \\mathcal{G} corresponds to a cluster structure in \\mathcal{O}(\\mathcal{G}). The authors have shown before that this conjecture holds for any \\mathcal{G} in the case of the standard Poisson-Lie structure and for all Belavin-Drinfeld classes in SL_n, n<5. In this paper the authors establish it for the Cremmer-Gervais Poisson-Lie structure on SL_n, which is the least similar to the standard one.

  11. Twelve positions in a β-lactamase that can expand its substrate spectrum with a single amino acid substitution.

    Directory of Open Access Journals (Sweden)

    Hyojeong Yi

    Full Text Available The continuous evolution of β-lactamases resulting in bacterial resistance to β-lactam antibiotics is a major concern in public health, and yet the underlying molecular basis or the pattern of such evolution is largely unknown. We investigated the mechanics of the substrate fspectrum expansion of the class A β-lactamase using PenA of Burkholderia thailandensis as a model. By analyzing 516 mutated enzymes that acquired the ceftazidime-hydrolyzing activity, we found twelve positions with single amino acid substitutions (altogether twenty-nine different substitutions, co-localized at the active-site pocket area. The ceftazidime MIC (minimum inhibitory concentration levels and the relative frequency in the occurrence of substitutions did not correlate well with each other, and the latter appeared be largely influenced by the intrinsic mutational biases present in bacteria. Simulation studies suggested that all substitutions caused a congruent effect, expanding the space in a conserved structure called the omega loop, which in turn increased flexibility at the active site. A second phase of selection, in which the mutants were placed under increased antibiotic pressure, did not result in a second mutation in the coding region, but a mutation that increased gene expression arose in the promoter. This result suggests that the twelve amino acid positions and their specific substitutions in PenA may represent a comprehensive repertoire of the enzyme's adaptability to a new substrate. These mapped substitutions represent a comprehensive set of general mechanical paths to substrate spectrum expansion in class A β-lactamases that all share a functional evolutionary mechanism using common conserved residues.

  12. Distinctiveness of Saudi Arabian EFL Learners

    Directory of Open Access Journals (Sweden)

    Manssour Habbash

    2016-04-01

    Full Text Available In view of the increasing concern among English language teachers dealing with students from Saudi Arabia, as it manifests in TESOL community discussions, about the uniqueness of Saudi Arabian EFL learners, this paper attempts to document the outcome of a study of their distinctiveness from the perspective of expatriate teachers working for PYPs (Preparatory Year Programs in Saudi Arabia. This study examines the distinctiveness with regard to the learning attitudes of Saudi students that are often cultivated by the culture and academic environment in their homeland. Employing an emic approach for collecting the required data an analysis was carried out in light of the other studies on ‘education’ in Saudi Arabia that have particular reference to the factors that can positively influence student motivation, student success and the academic environment. The findings were used in constructing the rationale behind such distinctiveness. Assuming that the outcome of the discussion on the findings of this exploration can be helpful for teachers in adapting their teaching methodology and improving their teacher efficacy in dealing with students both from the kingdom and in the kingdom, some recommendations are made. Keywords: China Distinctiveness, Saudi Arabian University context, Expatriate teachers’ perspective, Distinctiveness Theory

  13. Kinematics of Clustering

    CERN Document Server

    Wang, Steven; Metcalfe, Guy; Wu, Jie

    2014-01-01

    The dynamical system for inertial particles in fluid flow has both attracting and repelling regions, the interplay of which can localize particles. In laminar flow experiments we find that particles, initially moving throughout the fluid domain, can undergo an instability and cluster into subdomains of the fluid when the flow Reynolds number exceeds a critical value that depends on particle and fluid inertia. We derive an expression for the instability boundary and for a universal curve that describes the clustering rate for all particles.

  14. Clustering via Kernel Decomposition

    DEFF Research Database (Denmark)

    Have, Anna Szynkowiak; Girolami, Mark A.; Larsen, Jan

    2006-01-01

    Methods for spectral clustering have been proposed recently which rely on the eigenvalue decomposition of an affinity matrix. In this work it is proposed that the affinity matrix is created based on the elements of a non-parametric density estimator. This matrix is then decomposed to obtain...... posterior probabilities of class membership using an appropriate form of nonnegative matrix factorization. The troublesome selection of hyperparameters such as kernel width and number of clusters can be obtained using standard cross-validation methods as is demonstrated on a number of diverse data sets....

  15. South Asian Cluster

    Directory of Open Access Journals (Sweden)

    Ionel Sergiu Pirju

    2014-12-01

    Full Text Available This article aims at presenting the South Asian cluster composed of India, Indonesia, Iran and Malaysia, the intercultural values that characterizes it, the supported leadership style and tracing the main macroeconomic considerations which characterizes them. The research is synchronic, analysing the contemporary situation of these countries without reference to their evolution in time, by using the positivist paradigm that explains the reality at one point. It will be analysed the overall cluster with the existing interactions between the countries that composes it, while the article being one of information will avoid building recommendation, or new theories.

  16. Cluster-tilting theory

    OpenAIRE

    Simões, Raquel Coelho Guardado

    2008-01-01

    Tese de mestado em Matemática (Álgebra, Lógica e Fundamentos) apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2008 Resumo alargado disponível em português The notion of Cluster Algebra first appeared in 2001, in a paper by S. Fomin and A. Zelevinsky, studying the dual canonical basis of the quantum group of a finite dimensional simple Lie algebra over the complex numbers, and also total positivity for algebraic groups. Cluster categories, introduced by A. Buan, R...

  17. I Cluster geografici

    Directory of Open Access Journals (Sweden)

    Maurizio Rosina

    2010-03-01

    Full Text Available Geographic ClustersOver the past decade, public alphanumeric database have been growing at exceptional rate. Most of data can be georeferenced, so that is possible gaining new knowledge from such databases. The contribution of this paper is two-fold. We first present a model of geographic clusters, which uses only geographic and functionally data properties. The model is useful to process huge amount of public/government data, even daily upgrading. After that, we merge the model into the framework GEOPOI (GEOcoding Points Of Interest, and show some graphic map results.

  18. Clustering high dimensional data

    DEFF Research Database (Denmark)

    Assent, Ira

    2012-01-01

    High-dimensional data, i.e., data described by a large number of attributes, pose specific challenges to clustering. The so-called ‘curse of dimensionality’, coined originally to describe the general increase in complexity of various computational problems as dimensionality increases, is known...... to render traditional clustering algorithms ineffective. The curse of dimensionality, among other effects, means that with increasing number of dimensions, a loss of meaningful differentiation between similar and dissimilar objects is observed. As high-dimensional objects appear almost alike, new approaches...

  19. Spherically-symmetric Accretion onto a Black Hole at the Center of a Young Stellar Cluster

    CERN Document Server

    Silich, Sergiy; Hueyotl-Zahuantitla, Filiberto

    2008-01-01

    We present a self-consistent, bimodal stationary solution for spherically symmetric flows driven by young massive stellar clusters with a central supermassive black hole. We demonstrate that the hydrodynamic regime of the flow depends on the location of the cluster in the 3D (star cluster mechanical luminosity - BH mass - star cluster radius) parameter space. We show that a threshold mechanical luminosity (L_crit) separates clusters which evolve in the BH dominated regime frome those whose internal structure is strongly affected by the radiative cooling. In the first case(below the threshold energy) gravity of the BH separates the flow into two distinct zones: the inner accretion zone and the outer zone where the star cluster wind is formed. In the second case (above the critical luminosity), catastrophic cooling sets in inside the cluster. In this case the injected plasma becomes thermally unstable that inhibits a complete stationary solution. We compared the calculated accretion rates and the BH luminositie...

  20. An Emerge Approach in Inter Cluster Similarity for Quality Clusters

    Directory of Open Access Journals (Sweden)

    H. Venkateswara Reddy

    2013-04-01

    Full Text Available Relationship between the datasets is one most important issue in recent years. The recent methods are based mostly on the numerical data, but these methods are not suitable for real time data such as web pages, business transactions etc., which are known as Categorical data. It is difficult to find relationship in categorical data. In this paper, a new approach is proposed for finding the relationshipbetween the categorical data, hence to find relationship between the clusters. The main aim is to identify the quality clusters based on the relationship between clusters. If there is no relationship between clusters then those clusters are treated as quality clusters.

  1. On Hobbes’s distinction of accidents

    Directory of Open Access Journals (Sweden)

    Lupoli Agostino

    2012-06-01

    Full Text Available An interpolation introduced by K. Schuhmann in his critical edition of "De corpore" (chap. VI, § 13 diametrically overturns the meaning of Hobbes’s doctrine of distinction of accidents in comparison with all previous editions. The article focuses on the complexity of this crucial juncture in "De corpore" argument on which depends the interpretation of Hobbes’s whole conception of science. It discusses the reasons pro and contra Schuhmann’s interpolation and concludes against it, because it is not compatible with the rationale underlying the complex architecture of "De corpore", which involves a symmetry between the ‘logical’ distinction of accidents and the ‘metaphysical’ distinction of phantasms.

  2. Distinctive Dynamic Capabilities for New Business Creation

    DEFF Research Database (Denmark)

    Rosenø, Axel; Enkel, Ellen; Mezger, Florian

    2013-01-01

    This study examines the distinctive dynamic capabilities for new business creation in established companies. We argue that these are very different from those for managing incremental innovation within a company's core business. We also propose that such capabilities are needed in both slow...... and fast-paced industries, and that similarities exist across industries. Hence, the study contributes to dynamic capabilities literature by: 1) identifying the distinctive dynamic capabilities for new business creation; 2) shifting focus away from dynamic capabilities in environments characterised by high...... clock-speed and uncertainty towards considering dynamic capabilities for the purpose of developing new businesses, which also implies a high degree of uncertainty. Based on interviews with 33 companies, we identify distinctive dynamic capabilities for new business creation, find that dynamic...

  3. Combining cluster number counts and galaxy clustering

    CERN Document Server

    Lacasa, Fabien

    2016-01-01

    We present a detailed modelling of the joint covariance matrix between cluster number counts and the galaxy angular power spectrum. To this end, we use a Halo Model framework complemented by a Halo Occupation Distribution model (HOD), and we work in full-sky. We demonstrate the importance of accounting for non-Gaussianity to produce accurate covariance predictions, as the Gaussian part of the covariance can in fact become subdominant in certain configurations. We discuss in particular the case of the super-sample covariance (SSC), including the effects of galaxy shot-noise, halo second order bias and non-local bias, and demonstrating interesting mathematical properties. Using the joint covariance matrix and a Fisher matrix methodology, we examine the prospects of combining these two probes to constrain cosmological and HOD parameters. We find that the combination indeed results in noticeable better constraints, in particular because the cross-covariance introduces a synergy between the probes on small scales....

  4. Localized attack on clustering networks

    CERN Document Server

    Dong, Gaogao; Du, Ruijin; Shao, Shuai; Stanley, H Eugene; Shlomo, Havlin

    2016-01-01

    Clustering network is one of which complex network attracting plenty of scholars to discuss and study the structures and cascading process. We primarily analyzed the effect of clustering coefficient to other various of the single clustering network under localized attack. These network models including double clustering network and star-like NON with clustering and random regular (RR) NON of ER networks with clustering are made up of at least two networks among which exist interdependent relation among whose degree of dependence is measured by coupling strength. We show both analytically and numerically, how the coupling strength and clustering coefficient effect the percolation threshold, size of giant component, critical coupling point where the behavior of phase transition changes from second order to first order with the increase of coupling strength between the networks. Last, we study the two types of clustering network: one type is same with double clustering network in which each subnetwork satisfies ...

  5. Clustering of resting state networks.

    Directory of Open Access Journals (Sweden)

    Megan H Lee

    Full Text Available BACKGROUND: The goal of the study was to demonstrate a hierarchical structure of resting state activity in the healthy brain using a data-driven clustering algorithm. METHODOLOGY/PRINCIPAL FINDINGS: The fuzzy-c-means clustering algorithm was applied to resting state fMRI data in cortical and subcortical gray matter from two groups acquired separately, one of 17 healthy individuals and the second of 21 healthy individuals. Different numbers of clusters and different starting conditions were used. A cluster dispersion measure determined the optimal numbers of clusters. An inner product metric provided a measure of similarity between different clusters. The two cluster result found the task-negative and task-positive systems. The cluster dispersion measure was minimized with seven and eleven clusters. Each of the clusters in the seven and eleven cluster result was associated with either the task-negative or task-positive system. Applying the algorithm to find seven clusters recovered previously described resting state networks, including the default mode network, frontoparietal control network, ventral and dorsal attention networks, somatomotor, visual, and language networks. The language and ventral attention networks had significant subcortical involvement. This parcellation was consistently found in a large majority of algorithm runs under different conditions and was robust to different methods of initialization. CONCLUSIONS/SIGNIFICANCE: The clustering of resting state activity using different optimal numbers of clusters identified resting state networks comparable to previously obtained results. This work reinforces the observation that resting state networks are hierarchically organized.

  6. Intraosseous myoepithelioma: A rare, distinct tumor entity

    Directory of Open Access Journals (Sweden)

    Bharat Rekhi

    2014-01-01

    Full Text Available Primary musculoskeletal myoepithelial tumors (METs are distinctly rare tumors and are being increasingly recognized as a result of improved diagnostic criteria and objective confirmation with immunohistochemical markers, including epithelial markers. Recent studies have unraveled distinct molecular mechanisms underlying these tumors. Herein, we present our second diagnosed case of an intraosseous MET that occurred in the tibia of a 37-year-old lady. The case is discussed with regards to current clinicopathological perspectives on these rather uncommon tumors, including our personal experience.

  7. Fermionic bound states in distinct kinklike backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, Paraiba (Brazil); Mohammadi, A. [Universidade Federal de Campina Grande, Departamento de Fisica, Caixa Postal 10071, Campina Grande, Paraiba (Brazil)

    2017-04-15

    This work deals with fermions in the background of distinct localized structures in the two-dimensional spacetime. Although the structures have a similar topological character, which is responsible for the appearance of fractionally charged excitations, we want to investigate how the geometric deformations that appear in the localized structures contribute to the change in the physical properties of the fermionic bound states. We investigate the two-kink and compact kinklike backgrounds, and we consider two distinct boson-fermion interactions, one motivated by supersymmetry and the other described by the standard Yukawa coupling. (orig.)

  8. Analysis of breast cancer progression using principal component analysis and clustering

    Indian Academy of Sciences (India)

    G Alexe; G S Dalgin; S Ganesan; C DeLisi; G Bhanot

    2007-08-01

    We develop a new technique to analyse microarray data which uses a combination of principal components analysis and consensus ensemble -clustering to find robust clusters and gene markers in the data. We apply our method to a public microarray breast cancer dataset which has expression levels of genes in normal samples as well as in three pathological stages of disease; namely, atypical ductal hyperplasia or ADH, ductal carcinoma in situ or DCIS and invasive ductal carcinoma or IDC. Our method averages over clustering techniques and data perturbation to find stable, robust clusters and gene markers. We identify the clusters and their pathways with distinct subtypes of breast cancer (Luminal, Basal and Her2+). We confirm that the cancer phenotype develops early (in early hyperplasia or ADH stage) and find from our analysis that each subtype progresses from ADH to DCIS to IDC along its own specific pathway, as if each was a distinct disease.

  9. X-ray archaeology in the Coma cluster

    Science.gov (United States)

    White, Simon D. M.; Briel, Ulrich G.; Henry, J. P.

    1993-01-01

    We present images of X-ray emission from hot gas within the Coma cluster of galaxies. These maps, made with the ROSAT satellite, have much higher SNR than any previous X-ray image of a galaxy cluster, and allow cluster structure to be analyzed in unprecedented detail. They show greater structural irregularity than might have been anticipated from earlier observations of Coma. Emission is detected from a number of bright cluster galaxies in addition to the two known previously. In four cases, there is evidence that these galaxies lie at the center of an extended subconcentration within the cluster, possibly the remnant of their associated groups. For at least two galaxies, the images show direct evidence for ongoing disruption of their gaseous atmosphere. The luminosity associated with these galaxies is comparable to that detected around similar ellipticals in much poorer environments. Emission is easily detected to the limit of our field, about 1 deg from the cluster center, and appears to become more regular at large radii. The data show clearly that this archetype of a rich and regular galaxy cluster was, in fact, formed by the merging of several distinct subunits which are not yet fully destroyed.

  10. Survey of Young Stellar Clusters in the North Hemisphere

    Science.gov (United States)

    Costado, M. T.; Alfaro, E. J.; Delgado, A. A.; Djupvik, A. A.; Michel, R.

    2017-03-01

    Five years ago, the Stellar Systems Group of the IAA began an observational programme of young stellar clusters containing massive stars, whose main objective is the characterization of their stellar population using optical (UBV RI + Hα) and NIR (JHK) photometry. With these data, we can obtain the physical parameters of the clusters and determine the mass function of the cluster members, their spatial distribution by mass range, as well as a census of populations at different masses and evolutionary states for two distinct environments: a) isolated clusters, and b) clusters contained within a larger star-forming region. So far, we have observed around 40 clusters, which are at different stages of analysis. The optical data were secured from the 1.5m telescope at Sierra Nevada Observatory (OSN), while the NIR data were taken using the Nordic Optical Telescope (NOT) at Roque de los Muchachos Observatory. The last year, we began the optical observations of the survey with a larger field of view (13' size) at the 0.9m telescope (OSN). The analysis of the set of standard stars observed along the whole project enabled us to determine a reliable estimation of the atmospheric extinction as well as to analyze the stability of the photometric transformations at OSN to calibrate the data. In this poster, we present the results of the calibration analysis and the preliminary study for a subsample of the clusters.

  11. Roche volume filling of star clusters in the Milky Way

    CERN Document Server

    Ernst, A

    2012-01-01

    We examine the ratios $r_h/r_J$ of projected half-mass and Jacobi radius as well as $r_t/r_J$ of tidal and Jacobi radius for open and globular clusters in the Milky Way using data of both observations and simulations. We applied an improved calculation of $r_J$ for eccentric orbits of globular clusters. A sample of 236 open clusters of Piskunov et al. within the nearest kiloparsec around the Sun has been used. For the Milky Way globular clusters, data are taken from the Harris catalogue. We particularly use the subsample of 38 Milky Way globular clusters for which orbits have been integrated by Dinescu et al. We aim to quantify the differences between open and globular clusters and to understand, why they form two intrinsically distinct populations. We find under certain assumptions, or, in other words, in certain approximations, (i) that globular clusters are presently Roche volume underfilling and (ii) with at least $3\\sigma$ confidence that the ratio $r_h/r_J$ of half-mass and Jacobi radius is $3 - 5$ time...

  12. X-ray archaeology in the Coma cluster

    Science.gov (United States)

    White, Simon D. M.; Briel, Ulrich G.; Henry, J. P.

    1993-01-01

    We present images of X-ray emission from hot gas within the Coma cluster of galaxies. These maps, made with the ROSAT satellite, have much higher SNR than any previous X-ray image of a galaxy cluster, and allow cluster structure to be analyzed in unprecedented detail. They show greater structural irregularity than might have been anticipated from earlier observations of Coma. Emission is detected from a number of bright cluster galaxies in addition to the two known previously. In four cases, there is evidence that these galaxies lie at the center of an extended subconcentration within the cluster, possibly the remnant of their associated groups. For at least two galaxies, the images show direct evidence for ongoing disruption of their gaseous atmosphere. The luminosity associated with these galaxies is comparable to that detected around similar ellipticals in much poorer environments. Emission is easily detected to the limit of our field, about 1 deg from the cluster center, and appears to become more regular at large radii. The data show clearly that this archetype of a rich and regular galaxy cluster was, in fact, formed by the merging of several distinct subunits which are not yet fully destroyed.

  13. Detecting alternative graph clusterings.

    Science.gov (United States)

    Mandala, Supreet; Kumara, Soundar; Yao, Tao

    2012-07-01

    The problem of graph clustering or community detection has enjoyed a lot of attention in complex networks literature. A quality function, modularity, quantifies the strength of clustering and on maximization yields sensible partitions. However, in most real world networks, there are an exponentially large number of near-optimal partitions with some being very different from each other. Therefore, picking an optimal clustering among the alternatives does not provide complete information about network topology. To tackle this problem, we propose a graph perturbation scheme which can be used to identify an ensemble of near-optimal and diverse clusterings. We establish analytical properties of modularity function under the perturbation which ensures diversity. Our approach is algorithm independent and therefore can leverage any of the existing modularity maximizing algorithms. We numerically show that our methodology can systematically identify very different partitions on several existing data sets. The knowledge of diverse partitions sheds more light into the topological organization and helps gain a more complete understanding of the underlying complex network.

  14. Clustering under Perturbation Resilience

    CERN Document Server

    Balcan, Maria Florina

    2011-01-01

    Recently, Bilu and Linial \\cite{BL} formalized an implicit assumption often made when choosing a clustering objective: that the optimum clustering to the objective should be preserved under small multiplicative perturbations to distances between points. They showed that for max-cut clustering it is possible to circumvent NP-hardness and obtain polynomial-time algorithms for instances resilient to large (factor $O(\\sqrt{n})$) perturbations, and subsequently Awasthi et al. \\cite{ABS10} considered center-based objectives, giving algorithms for instances resilient to O(1) factor perturbations. In this paper, we greatly advance this line of work. For the $k$-median objective, we present an algorithm that can optimally cluster instances resilient to $(1 + \\sqrt{2})$-factor perturbations, solving an open problem of Awasthi et al.\\cite{ABS10}. We additionally give algorithms for a more relaxed assumption in which we allow the optimal solution to change in a small $\\epsilon$ fraction of the points after perturbation. ...

  15. Resolved SZE Cluster Count

    Institute of Scientific and Technical Information of China (English)

    Jia-Yu Tang; Zu-Hui Fan

    2003-01-01

    We study the counts of resolved SZE (Sunyaev-Zel'dovich effect) clus-ters expected from an interferometric survey in different cosmological models underdifferent conditions. The self-similar universal gas model and Press-Schechter massfunction are used. We take the observing frequency to be 90 GHz, and consider twodish diameters, 1.2 m and 2.5 m. We calculate the number density of the galaxyclusters dN/(dΩdz) at a high flux limit Slimv = 100mJy and at a relative lowSlimv = 10 mJy. The total numbers of SZE clusters N in two low-Ω0 models arecompared. The results show that the influence of the resolved effect depends notonly on D, but also on Slimv: at a given D, the effect is more significant for a highthan for a low Slim Also, the resolved effect for a flat universe is more impressivethan that for an open universe. For D = 1.2m and Slimv= 10mJy, the resolvedeffect is very weak. Considering the designed interferometers which will be used tosurvey SZE clusters, we find that the resolved effect is insignificant when estimatingthe expected yield of the SZE cluster surveys.

  16. Relevant Subspace Clustering

    DEFF Research Database (Denmark)

    Müller, Emmanuel; Assent, Ira; Günnemann, Stephan

    2009-01-01

    . We prove that computation of this model is NP-hard. For RESCU, we propose an approximative solution that shows high accuracy with respect to our relevance model. Thorough experiments on synthetic and real world data show that RESCU successfully reduces the result to manageable sizes. It reliably...... achieves top clustering quality while competing approaches show greatly varying performance....

  17. Cluster headaches simulating parasomnias.

    Science.gov (United States)

    Isik, Ugur; D'Cruz, O 'Neill F

    2002-09-01

    Nocturnal episodes of agitated arousal in otherwise healthy young children are often related to nonrapid eye movement parasomnias (night terrors). However, in patients with acute onset or increased frequency of parasomnias, organic causes of discomfort must be excluded. We report four young children whose parasomnias were caused by nocturnal cluster headaches and who responded to indomethacin dramatically.

  18. Fuzzy clustering of mechanisms

    Indian Academy of Sciences (India)

    Amitabha Ghosh; Dilip Kumar Pratihar; M V V Amarnath; Guenter Dittrich; Jorg Mueller

    2012-10-01

    During the course of development of Mechanical Engineering, a large number of mechanisms (that is, linkages to perform various types of tasks) have been conceived and developed. Quite a few atlases and catalogues were prepared by the designers of machines and mechanical systems. However, often it is felt that a clustering technique for handling the list of large number of mechanisms can be very useful,if it is developed based on a scientific principle. In this paper, it has been shown that the concept of fuzzy sets can be conveniently used for this purpose, if an adequate number of properly chosen attributes (also called characteristics) are identified. Using two clustering techniques, the mechanisms have been classified in the present work and in future, it may be extended to develop an expert system, which can automate type synthesis phase of mechanical design. To the best of the authors’ knowledge, this type of clustering of mechanisms has not been attempted before. Thus, this is the first attempt to cluster the mechanisms based on some quantitative measures. It may help the engineers to carry out type synthesis of the mechanisms.

  19. Emergence of regional clusters

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Østergaard, Christian Richter; Dalum, Bent

    2010-01-01

    The literature on regional clusters has increased considerably during the last decade. The emergence and growth patterns are usually explained by such factors as unique local culture, regional capabilities, tacit knowledge or the existence of location-specific externalities (knowledge spillovers,...

  20. Hybrid cluster identification

    Science.gov (United States)

    Martín-Herrero, J.

    2004-10-01

    I present a hybrid method for the labelling of clusters in two-dimensional lattices, which combines the recursive approach with iterative scanning to reduce the stack size required by the pure recursive technique, while keeping its benefits: single pass and straightforward cluster characterization and percolation detection parallel to the labelling. While the capacity to hold the entire lattice in memory is usually regarded as the major constraint for the applicability of the recursive technique, the required stack size is the real limiting factor. Resorting to recursion only for the transverse direction greatly reduces the recursion depth and therefore the required stack. It also enhances the overall performance of the recursive technique, as is shown by results on a set of uniform random binary lattices and on a set of samples of the Ising model. I also show how this technique may replace the recursive technique in Wolff's cluster algorithm, decreasing the risk of stack overflow and increasing its speed, and the Hoshen-Kopelman algorithm in the Swendsen-Wang cluster algorithm, allowing effortless characterization during generation of the samples and increasing its speed.

  1. Dettagli utilizzo cluster INTEL

    OpenAIRE

    2012-01-01

    Dall'inizio dell'anno 2004 il CILEA ospita e gestisce un cluster di processori Intel a 32 bit denominato avogadro. Esso é costituito da 128 nodi biprocessori Intel Xeon 3.06 GHz. L'articolo intende presentare le problematiche relative all'utilizzo della macchina processore fornendo le istruzioni operative necessarie all'uso più efficace.

  2. PVM Support for Clusters

    Science.gov (United States)

    Springer, P.

    2000-01-01

    The latest version of PVM (3.4.3) now contains support for a PC cluster running Linux, also known as a Beowulf system. A PVM user of a computer outside the Beowulf system can add the Beowulf as a single machine.

  3. Large Crater Clustering tool

    Science.gov (United States)

    Laura, Jason; Skinner, James A.; Hunter, Marc A.

    2017-08-01

    In this paper we present the Large Crater Clustering (LCC) tool set, an ArcGIS plugin that supports the quantitative approximation of a primary impact location from user-identified locations of possible secondary impact craters or the long-axes of clustered secondary craters. The identification of primary impact craters directly supports planetary geologic mapping and topical science studies where the chronostratigraphic age of some geologic units may be known, but more distant features have questionable geologic ages. Previous works (e.g., McEwen et al., 2005; Dundas and McEwen, 2007) have shown that the source of secondary impact craters can be estimated from secondary impact craters. This work adapts those methods into a statistically robust tool set. We describe the four individual tools within the LCC tool set to support: (1) processing individually digitized point observations (craters), (2) estimating the directional distribution of a clustered set of craters, back projecting the potential flight paths (crater clusters or linearly approximated catenae or lineaments), (3) intersecting projected paths, and (4) intersecting back-projected trajectories to approximate the local of potential source primary craters. We present two case studies using secondary impact features mapped in two regions of Mars. We demonstrate that the tool is able to quantitatively identify primary impacts and supports the improved qualitative interpretation of potential secondary crater flight trajectories.

  4. Clustering Techniques in Bioinformatics

    National Research Council Canada - National Science Library

    Muhammad Ali Masood; M. N. A. Khan

    2015-01-01

    ... according to well-defined rules. Data mining, having the tools of data classification and data clustering, is one of the most powerful techniques to deal with data in such a manner that it can help researchers identify the required information...

  5. Extended Fuzzy Clustering Algorithms

    NARCIS (Netherlands)

    U. Kaymak (Uzay); M. Setnes

    2000-01-01

    textabstractFuzzy clustering is a widely applied method for obtaining fuzzy models from data. It has been applied successfully in various fields including finance and marketing. Despite the successful applications, there are a number of issues that must be dealt with in practical applications of fuz

  6. Disentangling Porterian Clusters

    DEFF Research Database (Denmark)

    Jagtfelt, Tue

    intertwined and that Porter’s consciously paradigmatic textbook very likely gained worldwide influence due to two interrelated factors. The first factor is the deliberately holistic gestalt figure propounded in Nations, which prompted scientific communities to pursue cluster research; the second factor...

  7. European freshwater VHSV genotype Ia isolates divide into two distinct subpopulations

    DEFF Research Database (Denmark)

    Kahns, Søren; Skall, Helle Frank; Kaas, Rolf Sommer;

    2012-01-01

    Viral haemorrhagic septicaemia (VHS), caused by the novirhabdovirus VHSV, often leads to significant economic losses to European rainbow trout production. The virus isolates are divided into 4 distinct genotypes with additional subgroups including sublineage Ia, isolates of which are the main...... detected in Denmark since January 2009. Full-length G-genes of all Danish VHSV isolates that were submitted for diagnostic analyses in the period 2004−2009 were sequenced and analysed. All 58 Danish isolates from rainbow trout grouped with sublineage Ia isolates. Furthermore, VHSV isolates from infected...... Danish freshwater catchments appear to have evolved into a distinct clade within sublineage Ia, herein designated clade Ia-1, whereas trout isolates originating from other continental European countries cluster in another distinct clade, designated clade Ia-2. In addition, phylogenetic analyses indicate...

  8. Twelve-Month Effects of the COPE Healthy Lifestyles TEEN Program on Overweight and Depressive Symptoms in High School Adolescents

    Science.gov (United States)

    Melnyk, Bernadette M.; Jacobson, Diana; Kelly, Stephanie A.; Belyea, Michael J.; Shaibi, Gabriel Q.; Small, Leigh; O'Haver, Judith A.; Marsiglia, Flavio F.

    2015-01-01

    Background: We evaluated the 12-month effects of the COPE (Creating Opportunities for Personal Empowerment) Healthy Lifestyles TEEN (Thinking, Emotions, Exercise, Nutrition) program versus an attention control program (Healthy Teens) on overweight/obesity and depressive symptoms in high school adolescents. Methods: A cluster randomized controlled…

  9. Data clustering algorithms and applications

    CERN Document Server

    Aggarwal, Charu C

    2013-01-01

    Research on the problem of clustering tends to be fragmented across the pattern recognition, database, data mining, and machine learning communities. Addressing this problem in a unified way, Data Clustering: Algorithms and Applications provides complete coverage of the entire area of clustering, from basic methods to more refined and complex data clustering approaches. It pays special attention to recent issues in graphs, social networks, and other domains.The book focuses on three primary aspects of data clustering: Methods, describing key techniques commonly used for clustering, such as fea

  10. The Massive and Distant Clusters of WISE Survey (MaDCoWS): Stellar mass fractions in a sample of infrared-selected galaxy clusters at z~1

    Science.gov (United States)

    Decker, Bandon; Brodwin, Mark

    2017-01-01

    Galaxy clusters are the largest gravitationally bound objects in the universe. In addition to being interesting objects in their own right, they are excellent laboratories in which to study galaxy evolution and the properties and abundance of galaxy clusters provide important tests for cosmology. The Massive and Distant Clusters of WISE Survey (MaDCoWS) is a high-redshift (z~1) survey that selects galaxy clusters in the infrared over nearly the full extragalactic sky using the Wide-field Infrared Survey Explorer (WISE) AllWISE data release. We have measured Sunyaev-Zel'dovich (SZ) masses for twelve of the MaDCoWS clusters lying in the range 0.9 Research in Millimeter-wave Astronomy (CARMA) and used follow-up Spitzer/IRAC rest-frame near-infrared observations to measure the stellar mass of these clusters. With these data, we have measured the stellar mass fraction, f_star, and it's relation to total mass for a sample of infrared-selected clusters at z~1. We repeated our analysis of stellar mass fraction on a sample of SZ-selected clusters from the South Pole Telescope (SPT)-SZ survey that lie in a comparable range of mass and redshift to our MaDCoWS clusters to compare the selection methods. We found no significant difference in the trend of stellar mass fraction-to-total mass between infrared and radio selections. Comparing to similar measurements in the local Universe, we find no evidence of strong evolution in the trend over the last 8 Gyr.

  11. Experiments on individual alumina-supported adatoms and clusters

    Science.gov (United States)

    Nilius, N.; Cörper, A.; Bozdech, G.; Ernst, N.; Freund, H.-J.

    2001-08-01

    To contribute to an understanding of growth conditions and electronic properties of metal clusters on technologically relevant oxides we have examined the mobility of individual, alumina-supported Pt-adatoms and the optical properties of single supported Ag-clusters. Using field-ion microscopy (FIM) we have prepared and imaged an individual Pt-adatom at approximately 40 K, both on the apex plane of a [1 1 0]-oriented NiAl tip and on a thin alumina film, grown on the same NiAl specimen by oxidation. On the alumina film, the onset temperature for Pt surface diffusion approaches 100 K being distinctively lower than the value 165 K measured on NiAl(1 1 0). Employing the tip of a scanning tunneling microscope (STM) as a local electron source, photon emission from individual, alumina-supported Ag-clusters was spectroscopically analyzed. The occurrence of a distinct emission line is explained by the decay of a collective electron oscillation (Mie-plasmon resonance). For decreasing Ag-cluster diameter, the emission lines (i) shift to higher energies and (ii) their widths increase. To explain these observations, we discuss (i) the reduced screening of the plasmon oscillation due to the Ag 4d electrons and (ii) an enhanced electron surface scattering rate in small clusters.

  12. A discriminative approach for unsupervised clustering of DNA sequence motifs.

    Directory of Open Access Journals (Sweden)

    Philip Stegmaier

    Full Text Available Algorithmic comparison of DNA sequence motifs is a problem in bioinformatics that has received increased attention during the last years. Its main applications concern characterization of potentially novel motifs and clustering of a motif collection in order to remove redundancy. Despite growing interest in motif clustering, the question which motif clusters to aim at has so far not been systematically addressed. Here we analyzed motif similarities in a comprehensive set of vertebrate transcription factor classes. For this we developed enhanced similarity scores by inclusion of the information coverage (IC criterion, which evaluates the fraction of information an alignment covers in aligned motifs. A network-based method enabled us to identify motif clusters with high correspondence to DNA-binding domain phylogenies and prior experimental findings. Based on this analysis we derived a set of motif families representing distinct binding specificities. These motif families were used to train a classifier which was further integrated into a novel algorithm for unsupervised motif clustering. Application of the new algorithm demonstrated its superiority to previously published methods and its ability to reproduce entrained motif families. As a result, our work proposes a probabilistic approach to decide whether two motifs represent common or distinct binding specificities.

  13. The life-cycle of young star-clusters; the role of the galactic environment on cluster formation and evolution

    Science.gov (United States)

    Adamo, Angela

    2015-08-01

    Our understanding of star formation on galactic scales has been fairly grasped (e.g. the rate at which stars form scales proportionally to the molecular gas content) both in the local and high redshift universe. However, our knowledge on how star formation proceeds at small scales (e.g. the fraction of star formation happening in stellar clusters, the time-scales for star-forming regions to dissolve, the impact of the galactic environment on star and cluster formation) remains a challenge. Gravitationally bound young stellar clusters appear to be a commune product of star formation. There are tantalizing similarities between young star clusters and globular clusters, the latter formed by gravitationally bound ancient stellar populations. However, the young and globular cluster populations show statistical properties (mass functions, formation efficiencies, and survival times) that have been claimed incompatible, leaving the two populations being the results of distinct processes of formation. In my contribution, I will discuss the latest results produced with the analysis of the young cluster populations in several nearby galaxies. The use of new statistical methods, the link with dense gas fueling star formation, the access to homogenous datasets show, for the first time, clear evidence of the influence of the galactic environment in shaping the properties of young star cluster populations. After all, the differences between the two cluster populations may not be so pronounced, suggesting that the same physical formation process under different environmental conditions has been (and currently is) at work at high redshift (when globular clusters were formed) and in the local universe.

  14. Testing Haldane's conjecture in the O(3) model by a meron cluster simulation

    CERN Document Server

    Bietenholz, W; Wiese, U J

    1995-01-01

    Twelve years ago, Haldane formulated his famous conjecture for 1-d antiferromagnetic quantum spin chains. In the context of the 2-d O(3) model with a \\theta term, it predicts a phase transition at \\theta = \\pi, which has not yet been verified reliably. To simulate this we use the Wolff cluster algorithm together with an improved estimator for the topological charge distribution. Each cluster carries integer or half integer charge. Clusters with charge 1/2 are identified with merons. At \\theta = \\pi they are inactive, such that the mass gap vanishes. We obtain critical exponents which are consistent with predictions from the k=1 WZNW model, therefore confirming a second order phase transition.

  15. Testing Haldane's Conjecture in the O(3) Model by a Meron Cluster Simulation

    Science.gov (United States)

    Bietenholz, W.; Pochinsky, A.; Wiese, U.-J.

    1996-03-01

    Twelve years ago, Haldane formulated his famous conjecture for 1-d antiferromagnetic quantum spin chains. In the context of the 2-d O(3) σ model with a θ term, it predicts a phase transition as θ → π, which has not yet been verified reliably. To simulate this we use the Wolff cluster algorithm together with an improved estimator for the charge distribution. Each cluster carries integer or half integer charge. Clusters with charge 1/2 are identified with merons. At θ = π they are inactive, such that the mass gap vanishes. We obtain critical exponents which are consistent with predictions from the k = 1 WZNW model, therefore confirming a second order phase transition.

  16. nIFTy galaxy cluster simulations I: dark matter & non-radiative models

    CERN Document Server

    Sembolini, Federico; Pearce, Frazer R; Knebe, Alexander; Kay, Scott T; Power, Chris; Cui, Weiguang; Beck, Alexander M; Borgani, Stefano; Vecchia, Claudio Dalla; Davé, Romeel; Elahi, Pascal Jahan; February, Sean; Huang, Shuiyao; Hobbs, Alex; Katz, Neal; Lau, Erwin; McCarthy, Ian G; Murante, Giuseppe; Nagai, Daisuke; Nelson, Kaylea; Newton, Richard D A; Puchwein, Ewald; Read, Justin I; Saro, Alexandro; Schaye, Joop; Thacker, Robert J

    2015-01-01

    We have simulated the formation of a galaxy cluster in a $\\Lambda$CDM universe using twelve different codes modeling only gravity and non-radiative hydrodynamics (\\art, \\arepo, \\hydra\\ and 9 incarnations of GADGET). This range of codes includes particle based, moving and fixed mesh codes as well as both Eulerian and Lagrangian fluid schemes. The various GADGET implementations span traditional and advanced smoothed-particle hydrodynamics (SPH) schemes. The goal of this comparison is to assess the reliability of cosmological hydrodynamical simulations of clusters in the simplest astrophysically relevant case, that in which the gas is assumed to be non-radiative. We compare images of the cluster at $z=0$, global properties such as mass, and radial profiles of various dynamical and thermodynamical quantities. The underlying gravitational framework can be aligned very accurately for all the codes allowing a detailed investigation of the differences that develop due to the various gas physics implementations employ...

  17. On the Relationship Between Belief and Acceptance of Evolution as Goals of Evolution Education. Twelve Years Later

    Science.gov (United States)

    Smith, Mike U.; Siegel, Harvey

    2016-08-01

    The issue of the proper goals of science education and science teacher education have been a focus of the science education and philosophy of science communities in recent years. More particularly, the issue of whether belief/acceptance of evolution and/or understanding are the appropriate goals for evolution educators and the issue of the precise nature of the distinctions among the terms knowledge, understanding, belief, and acceptance have received increasing attention in the 12 years since we first published our views on these subjects. During that time, our own views about these issues have evolved, and this article presents a reconsideration of both these distinctions and the propriety of these goals. In particular, the present paper continues our discussion of the nature of belief as it relates to science education, and more specifically to evolution education. We extend that work to consider the import of the distinction between belief and acceptance.

  18. Neurobiology and sleep disorders in cluster headache.

    Science.gov (United States)

    Barloese, Mads Christian Johannes

    2015-01-01

    Cluster headache is characterized by unilateral attacks of severe pain accompanied by cranial autonomic features. Apart from these there are also sleep-related complaints and strong chronobiological features. The interaction between sleep and headache is complex at any level and evidence suggests that it may be of critical importance in our understanding of primary headache disorders. In cluster headache several interactions between sleep and the severe pain attacks have already been proposed. Supported by endocrinological and radiological findings as well as the chronobiological features, predominant theories revolve around central pathology of the hypothalamus. We aimed to investigate the clinical presentation of chronobiological features, the presence of concurrent sleep disorders and the relationship with particular sleep phases or phenomena, the possible role of hypocretin as well as the possible involvement of cardiac autonomic control. We conducted a questionnaire survey on 275 cluster headache patients and 145 controls as well an in-patient sleep study including 40 CH-patients and 25 healthy controls. The findings include: A distinct circannual connection between cluster occurrence and the amount of daylight, substantially poorer sleep quality in patients compared to controls which was present not only inside the clusters but also outside, affected REM-sleep in patients without a particular temporal connection to nocturnal attacks, equal prevalence of sleep apnea in both patient and control groups, reduced levels of hypocretin-1 in the cerebrospinal fluid of patients and finally a blunted response to the change from supine to tilted position in the head-up tilt table test indicating a weakened sympathoexcitatory or stronger parasympathetic drive. Overall, these findings support a theory of involvement of dysregulation in hypothalamic and brainstem nuclei in cluster headache pathology. Further, it is made plausible that the headache attacks are but one

  19. A Note on Two Basic Semantic Distinctions.

    Science.gov (United States)

    Celce, Marianne; Schwarcz, Robert M.

    This paper discusses the nature of two basic semantic distinctions--intensional/extensional, and mental/physical (mental/physical being similar to abstract/concrete but more concrete)--and how an understanding of their interaction is an essential preliminary to writing a semantically motivated grammar of English. (Author/FWB)

  20. Simultaneous occurrence of distinct symmetries in nuclei

    CERN Document Server

    Leviatan, A

    2015-01-01

    We show that distinct emergent symmetries, such as partial dynamical symmetry and quasi dynamical symmetry, can occur simultaneously in the same or different eigenstates of the Hamiltonian. Implications for nuclear spectroscopy in the rare-earth region and for first-order quantum phase transitions between spherical and deformed shapes, are considered.