WorldWideScience

Sample records for two-level risk cluster

  1. A spatial scan statistic for nonisotropic two-level risk cluster.

    Science.gov (United States)

    Li, Xiao-Zhou; Wang, Jin-Feng; Yang, Wei-Zhong; Li, Zhong-Jie; Lai, Sheng-Jie

    2012-01-30

    Spatial scan statistic methods are commonly used for geographical disease surveillance and cluster detection. The standard spatial scan statistic does not model any variability in the underlying risks of subregions belonging to a detected cluster. For a multilevel risk cluster, the isotonic spatial scan statistic could model a centralized high-risk kernel in the cluster. Because variations in disease risks are anisotropic owing to different social, economical, or transport factors, the real high-risk kernel will not necessarily take the central place in a whole cluster area. We propose a spatial scan statistic for a nonisotropic two-level risk cluster, which could be used to detect a whole cluster and a noncentralized high-risk kernel within the cluster simultaneously. The performance of the three methods was evaluated through an intensive simulation study. Our proposed nonisotropic two-level method showed better power and geographical precision with two-level risk cluster scenarios, especially for a noncentralized high-risk kernel. Our proposed method is illustrated using the hand-foot-mouth disease data in Pingdu City, Shandong, China in May 2009, compared with two other methods. In this practical study, the nonisotropic two-level method is the only way to precisely detect a high-risk area in a detected whole cluster. Copyright © 2011 John Wiley & Sons, Ltd.

  2. Two-level Robust Measurement Fusion Kalman Filter for Clustering Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng; QI Wen-Juan; DENG Zi-Li

    2014-01-01

    This paper investigates the distributed fusion Kalman filtering over clustering sensor networks. The sensor network is partitioned as clusters by the nearest neighbor rule and each cluster consists of sensing nodes and cluster-head. Using the minimax robust estimation principle, based on the worst-case conservative system with the conservative upper bounds of noise variances, two-level robust measurement fusion Kalman filter is presented for the clustering sensor network systems with uncertain noise variances. It can significantly reduce the communication load and save energy when the number of sensors is very large. A Lyapunov equation approach for the robustness analysis is presented, by which the robustness of the local and fused Kalman filters is proved. The concept of the robust accuracy is presented, and the robust accuracy relations among the local and fused robust Kalman filters are proved. It is proved that the robust accuracy of the two-level weighted measurement fuser is equal to that of the global centralized robust fuser and is higher than those of each local robust filter and each local weighted measurement fuser. A simulation example shows the correctness and effectiveness of the proposed results.

  3. Risk Analysis of a Two-Level Supply Chain Subject to Misplaced Inventory

    Directory of Open Access Journals (Sweden)

    Lijing Zhu

    2017-06-01

    Full Text Available Misplaced inventory is prevalent in retail stores and may lead to the overall poor performance of the supply chain. We explore the impact of misplaced inventory on a two-level supply chain, which consists of a risk-neutral supplier and a risk-averse retailer. The supplier decides the wholesale price to maximize her profit, whereas the retailer decides the order quantity to maximize his utility. Under the Conditional Value-at-Risk (CVaR criterion, we formulate the problem as a Stackelberg game model and obtain the equilibrium solutions in three cases: (i information asymmetry about inventory errors exists; (ii the retailer shares information about inventory errors with the supplier; and (iii in order to reduce misplaced inventory, the supply chain deploys Radio-Frequency Identification (RFID technology. The benefits of information sharing and RFID implementation are explored. A revenue and cost sharing contract is proposed to coordinate the supply chain and to allocate the cost savings from RFID implementation among supply chain participants. Finally, we provide managerial insights for risk-averse decision makers that are considering investing in the RFID technology.

  4. Problem of two-level hierarchical minimax program control the final state of regional social and economic system in the presence of risks

    International Nuclear Information System (INIS)

    Shorikov, A. F.

    2015-01-01

    This article discusses a discrete-time dynamical system consisting of a set a controllable objects (region and forming it municipalities). The dynamics each of these is described by the corresponding vector nonlinear discrete-time recurrent vector equations and its control system consist from two levels: basic (control level I) that is dominating and subordinate level (control level II). Both levels have different criterions of functioning and united a priori by determined informational and control connections defined in advance. In this paper we study the problem of optimization of guaranteed result for program control by the final state of regional social and economic system in the presence of risks. For this problem we proposed in this work an economical and mathematical model of two-level hierarchical minimax program control the final state of regional social and economic system in the presence of risks and the general scheme for its solving

  5. Problem of two-level hierarchical minimax program control the final state of regional social and economic system in the presence of risks

    Energy Technology Data Exchange (ETDEWEB)

    Shorikov, A. F., E-mail: afshorikov@mail.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002, Russia Institute of Mathematics and Mechanics, Ural Branch of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation)

    2015-11-30

    This article discusses a discrete-time dynamical system consisting of a set a controllable objects (region and forming it municipalities). The dynamics each of these is described by the corresponding vector nonlinear discrete-time recurrent vector equations and its control system consist from two levels: basic (control level I) that is dominating and subordinate level (control level II). Both levels have different criterions of functioning and united a priori by determined informational and control connections defined in advance. In this paper we study the problem of optimization of guaranteed result for program control by the final state of regional social and economic system in the presence of risks. For this problem we proposed in this work an economical and mathematical model of two-level hierarchical minimax program control the final state of regional social and economic system in the presence of risks and the general scheme for its solving.

  6. Cardiovascular Risk Factors in Cluster Headache.

    Science.gov (United States)

    Lasaosa, S Santos; Diago, E Bellosta; Calzada, J Navarro; Benito, A Velázquez

    2017-06-01

     Patients with cluster headache tend to have a dysregulation of systemic blood pressure such as increased blood pressure variability and decreased nocturnal dipping. This pattern of nocturnal nondipping is associated with end-organ damage and increased risk of cardiovascular disease.  To determine if cluster headache is associated with a higher risk of cardiovascular disease.  Cross-sectional study of 33 cluster headache patients without evidence of cardiovascular disease and 30 age- and gender-matched healthy controls. Ambulatory blood pressure monitoring was performed in all subjects. We evaluate anthropometric, hematologic, and structural parameters (carotid intima-media thickness and ankle-brachial index).  Of the 33 cluster headache patients, 16 (48.5%) were nondippers, a higher percentage than expected. Most of the cluster headache patients (69.7%) also presented a pathological ankle-brachial index. In terms of the carotid intima-media thickness values, 58.3% of the patients were in the 75th percentile, 25% were in the 90th percentile, and 20% were in the 95th percentile. In the control group, only five of the 30 subjects (16.7%) had a nondipper pattern ( P  =   0.004), with 4.54% in the 90th and 95th percentiles ( P  =   0.012 and 0.015).  Compared with healthy controls, patients with cluster headache presented a high incidence (48.5%) of nondipper pattern, pathological ankle-brachial index (69.7%), and intima-media thickness values above the 75th percentile. These findings support the hypothesis that patients with cluster headache present increased risk of cardiovascular disease. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  7. Optimal replenishment and credit policy in supply chain inventory model under two levels of trade credit with time- and credit-sensitive demand involving default risk

    Science.gov (United States)

    Mahata, Puspita; Mahata, Gour Chandra; Kumar De, Sujit

    2018-03-01

    Traditional supply chain inventory modes with trade credit usually only assumed that the up-stream suppliers offered the down-stream retailers a fixed credit period. However, in practice the retailers will also provide a credit period to customers to promote the market competition. In this paper, we formulate an optimal supply chain inventory model under two levels of trade credit policy with default risk consideration. Here, the demand is assumed to be credit-sensitive and increasing function of time. The major objective is to determine the retailer's optimal credit period and cycle time such that the total profit per unit time is maximized. The existence and uniqueness of the optimal solution to the presented model are examined, and an easy method is also shown to find the optimal inventory policies of the considered problem. Finally, numerical examples and sensitive analysis are presented to illustrate the developed model and to provide some managerial insights.

  8. Forming homogeneous clusters for differential risk information

    International Nuclear Information System (INIS)

    Maardberg, B.

    1996-01-01

    Latent risk situations are always present in society. General information on these risk situations is supposed to be received differently by different groups of people in the population. In the aftermath of specific accidents different groups presumably have need of specific information about how to act to survive, to avoid injuries, to find more information, to obtain facts about the accidents etc. As targets for information these different groups could be defined in different ways. The conventional way is to divide the population according to demographic variables, such as age, sex, occupation etc. Another way would be to structure the population according to dependent variables measured in different studies. They may concern risk perception, emotional reactions, specific technical knowledge of the accidents, and belief in the information sources. One procedure for forming such groupings of people into homogeneous clusters would be by statistical clustering methods on dependent variables. Examples of such clustering procedures are presented and discussed. Data are from a Norwegian study on the perception of radiation from nuclear accidents and other radiation sources. Speculations are made on different risk information strategies. Elements of a research programme are proposed. (author)

  9. Suicide Clusters: A Review of Risk Factors and Mechanisms

    Science.gov (United States)

    Haw, Camilla; Hawton, Keith; Niedzwiedz, Claire; Platt, Steve

    2013-01-01

    Suicide clusters, although uncommon, cause great concern in the communities in which they occur. We searched the world literature on suicide clusters and describe the risk factors and proposed psychological mechanisms underlying the spatio-temporal clustering of suicides (point clusters). Potential risk factors include male gender, being an…

  10. Risk Evaluation for Cyclic Aliphatic Bromide Cluster (HBCD Cluster)

    Science.gov (United States)

    EPA's existing chemicals programs address pollution prevention, risk assessment, hazard and exposure assessment and/or characterization, and risk management for chemicals substances in commercial use.

  11. Risk Probability Estimating Based on Clustering

    DEFF Research Database (Denmark)

    Chen, Yong; Jensen, Christian D.; Gray, Elizabeth

    2003-01-01

    of prior experiences, recommendations from a trusted entity or the reputation of the other entity. In this paper we propose a dynamic mechanism for estimating the risk probability of a certain interaction in a given environment using hybrid neural networks. We argue that traditional risk assessment models...... from the insurance industry do not directly apply to ubiquitous computing environments. Instead, we propose a dynamic mechanism for risk assessment, which is based on pattern matching, classification and prediction procedures. This mechanism uses an estimator of risk probability, which is based...

  12. Cytokines and clustered cardiovascular risk factors in children

    DEFF Research Database (Denmark)

    Andersen, Lars Bo; Müller, Klaus; Eiberg, Stig

    2010-01-01

    pronounced in fat and unfit children based on the association with CRP levels. The association between fitness and fatness variables, insulin resistance, and clustered risk could be caused by other mechanisms related to these exposures. The role of IL-6 remains unclear.......The aim was to evaluate the possible role of tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), C-reactive protein (CRP), low fitness, and fatness in the early development of clustering of cardiovascular disease (CVD) risk factors and insulin resistance. Subjects for this cross......-sectional study were obtained from 18 schools near Copenhagen, Denmark. Two hundred ten 9-year-old children were selected for cytokine analysis from 434 third-grade children with complete CVD risk profiles. The subgroup was selected according to the CVD risk factor profile (upper and lower quartile of a composite...

  13. Darboux transformation for two-level system

    Energy Technology Data Exchange (ETDEWEB)

    Bagrov, V.; Baldiotti, M.; Gitman, D.; Shamshutdinova, V. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318-CEP, 05315-970 Sao Paulo, S.P. (Brazil)

    2005-06-01

    We develop the Darboux procedure for the case of the two-level system. In particular, it is demonstrated that one can construct the Darboux intertwining operator that does not violate the specific structure of the equations of the two-level system, transforming only one real potential into another real potential. We apply the obtained Darboux transformation to known exact solutions of the two-level system. Thus, we find three classes of new solutions for the two-level system and the corresponding new potentials that allow such solutions. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  14. Clinical fracture risk evaluated by hierarchical agglomerative clustering

    DEFF Research Database (Denmark)

    Kruse, C; Eiken, P; Vestergaard, P

    2017-01-01

    reimbursement, primary healthcare sector use and comorbidity of female subjects were combined. Standardized variable means, Euclidean distances and Ward's D2 method of hierarchical agglomerative clustering (HAC), were used to form the clustering object. K number of clusters was selected with the lowest cluster...

  15. Prioritizing the risk of plant pests by clustering methods; self-organising maps, k-means and hierarchical clustering

    Directory of Open Access Journals (Sweden)

    Susan Worner

    2013-09-01

    Full Text Available For greater preparedness, pest risk assessors are required to prioritise long lists of pest species with potential to establish and cause significant impact in an endangered area. Such prioritization is often qualitative, subjective, and sometimes biased, relying mostly on expert and stakeholder consultation. In recent years, cluster based analyses have been used to investigate regional pest species assemblages or pest profiles to indicate the risk of new organism establishment. Such an approach is based on the premise that the co-occurrence of well-known global invasive pest species in a region is not random, and that the pest species profile or assemblage integrates complex functional relationships that are difficult to tease apart. In other words, the assemblage can help identify and prioritise species that pose a threat in a target region. A computational intelligence method called a Kohonen self-organizing map (SOM, a type of artificial neural network, was the first clustering method applied to analyse assemblages of invasive pests. The SOM is a well known dimension reduction and visualization method especially useful for high dimensional data that more conventional clustering methods may not analyse suitably. Like all clustering algorithms, the SOM can give details of clusters that identify regions with similar pest assemblages, possible donor and recipient regions. More important, however SOM connection weights that result from the analysis can be used to rank the strength of association of each species within each regional assemblage. Species with high weights that are not already established in the target region are identified as high risk. However, the SOM analysis is only the first step in a process to assess risk to be used alongside or incorporated within other measures. Here we illustrate the application of SOM analyses in a range of contexts in invasive species risk assessment, and discuss other clustering methods such as k

  16. Identifying Children at Risk of Problematic Development: Latent Clusters Among Childhood Arrestees

    NARCIS (Netherlands)

    Geluk, C.A.M.L.; van Domburgh, L.; Doreleijers, T.A.H.; Jansen, L.M.C.; Bouwmeester, S.; Galindo Garre, F.; Vermeiren, R.R.J.M.

    2014-01-01

    The presence of clusters characterized by distinct profiles of individual, family and peer characteristics among childhood arrestees was investigated and cluster membership stability after 2 years was determined. Identification of such clusters in this heterogeneous at-risk group can extend insight

  17. A clustering approach to segmenting users of internet-based risk calculators.

    Science.gov (United States)

    Harle, C A; Downs, J S; Padman, R

    2011-01-01

    Risk calculators are widely available Internet applications that deliver quantitative health risk estimates to consumers. Although these tools are known to have varying effects on risk perceptions, little is known about who will be more likely to accept objective risk estimates. To identify clusters of online health consumers that help explain variation in individual improvement in risk perceptions from web-based quantitative disease risk information. A secondary analysis was performed on data collected in a field experiment that measured people's pre-diabetes risk perceptions before and after visiting a realistic health promotion website that provided quantitative risk information. K-means clustering was performed on numerous candidate variable sets, and the different segmentations were evaluated based on between-cluster variation in risk perception improvement. Variation in responses to risk information was best explained by clustering on pre-intervention absolute pre-diabetes risk perceptions and an objective estimate of personal risk. Members of a high-risk overestimater cluster showed large improvements in their risk perceptions, but clusters of both moderate-risk and high-risk underestimaters were much more muted in improving their optimistically biased perceptions. Cluster analysis provided a unique approach for segmenting health consumers and predicting their acceptance of quantitative disease risk information. These clusters suggest that health consumers were very responsive to good news, but tended not to incorporate bad news into their self-perceptions much. These findings help to quantify variation among online health consumers and may inform the targeted marketing of and improvements to risk communication tools on the Internet.

  18. Perceived risk and benefit of nuclear waste repositories: four opinion clusters.

    Science.gov (United States)

    Seidl, Roman; Moser, Corinne; Stauffacher, Michael; Krütli, Pius

    2013-06-01

    Local public resistance can block the site-selection process, construction, and operation of nuclear waste repositories. Social science has established that the perception of risks and benefits, trust in authorities, and opinion on nuclear energy play important roles in acceptance. In particular, risk and benefit evaluations seem critical for opinion formation. However, risks and benefits have rarely been studied independently and, most often, the focus has been on the two most salient groups of proponents and opponents. The aim of this exploratory study is to examine the often-neglected majority of people holding ambivalent or indifferent opinions. We used cluster analysis to examine the sample (N = 500, mailed survey in German-speaking Switzerland) in terms of patterns of risk and benefit perception. We reveal four significantly different and plausible clusters: one cluster with high-benefit ratings in favor of a repository and one cluster with high-risk ratings opposing it; a third cluster shows ambivalence, with high ratings on both risk and benefit scales and moderate opposition, whereas a fourth cluster seems indifferent, rating risks and benefits only moderately compared to the ambivalent cluster. We conclude that a closer look at the often neglected but considerable number of people with ambivalent or indifferent opinions is necessary. Although the extreme factions of the public will most probably not change their opinion, we do not yet know how the opinion of the ambivalent and indifferent clusters might develop over time. © 2012 Society for Risk Analysis.

  19. 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…

  20. Social and Behavioral Risk Marker Clustering Associated with Biological Risk Factors for Coronary Heart Disease: NHANES 2001–2004

    Directory of Open Access Journals (Sweden)

    Nicholas J. Everage

    2014-01-01

    Full Text Available Background. Social and behavioral risk markers (e.g., physical activity, diet, smoking, and socioeconomic position cluster; however, little is known whether clustering is associated with coronary heart disease (CHD risk. Objectives were to determine if sociobehavioral clustering is associated with biological CHD risk factors (total cholesterol, HDL cholesterol, systolic blood pressure, body mass index, waist circumference, and diabetes and whether associations are independent of individual clustering components. Methods. Participants included 4,305 males and 4,673 females aged ≥20 years from NHANES 2001–2004. Sociobehavioral Risk Marker Index (SRI included a summary score of physical activity, fruit/vegetable consumption, smoking, and educational attainment. Regression analyses evaluated associations of SRI with aforementioned biological CHD risk factors. Receiver operator curve analyses assessed independent predictive ability of SRI. Results. Healthful clustering (SRI = 0 was associated with improved biological CHD risk factor levels in 5 of 6 risk factors in females and 2 of 6 risk factors in males. Adding SRI to models containing age, race, and individual SRI components did not improve C-statistics. Conclusions. Findings suggest that healthful sociobehavioral risk marker clustering is associated with favorable CHD risk factor levels, particularly in females. These findings should inform social ecological interventions that consider health impacts of addressing social and behavioral risk factors.

  1. Two-Level Semantics and Code Generation

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis

    1988-01-01

    A two-level denotational metalanguage that is suitable for defining the semantics of Pascal-like languages is presented. The two levels allow for an explicit distinction between computations taking place at compile-time and computations taking place at run-time. While this distinction is perhaps...... not absolutely necessary for describing the input-output semantics of programming languages, it is necessary when issues such as data flow analysis and code generation are considered. For an example stack-machine, the authors show how to generate code for the run-time computations and still perform the compile...

  2. Clustering of Multiple Lifestyle Behaviours and Its Association to Cardiovascular Risk Factors in Children

    DEFF Research Database (Denmark)

    Bel-Serrat, Silvia; Mouratidou, Theodora; Santaliestra-Pasías, Alba María

    2013-01-01

    ratio, triglycerides, sum of two skinfolds and systolic blood pressure (SBP) z-scores were summed to compute a CVD risk score. Cluster analyses stratified by sex and age groups (2 to ...) consumption, PA performance and television video/DVD viewing. RESULTS: Five clusters were identified. Associations between CVD risk factors and score, and clusters were obtained by multiple linear regression using cluster 5 (‘low beverages consumption and low sedentary’) as the reference cluster. SBP...... association was observed between CVD risk score and clusters 2 (β=0.60; 95% CI: 0.20, 1.01), 3 (β=0.55; 95% CI: 0.14, 0.97) and 4 (β=0.60, 95% CI: 0.18, 1.02) in older boys. CONCLUSIONS: Low television/video/DVD viewing levels and low SSB consumption may result in a healthier CVD profile rather than having...

  3. A two-stage approach to estimate spatial and spatio-temporal disease risks in the presence of local discontinuities and clusters.

    Science.gov (United States)

    Adin, A; Lee, D; Goicoa, T; Ugarte, María Dolores

    2018-01-01

    Disease risk maps for areal unit data are often estimated from Poisson mixed models with local spatial smoothing, for example by incorporating random effects with a conditional autoregressive prior distribution. However, one of the limitations is that local discontinuities in the spatial pattern are not usually modelled, leading to over-smoothing of the risk maps and a masking of clusters of hot/coldspot areas. In this paper, we propose a novel two-stage approach to estimate and map disease risk in the presence of such local discontinuities and clusters. We propose approaches in both spatial and spatio-temporal domains, where for the latter the clusters can either be fixed or allowed to vary over time. In the first stage, we apply an agglomerative hierarchical clustering algorithm to training data to provide sets of potential clusters, and in the second stage, a two-level spatial or spatio-temporal model is applied to each potential cluster configuration. The superiority of the proposed approach with regard to a previous proposal is shown by simulation, and the methodology is applied to two important public health problems in Spain, namely stomach cancer mortality across Spain and brain cancer incidence in the Navarre and Basque Country regions of Spain.

  4. Clustering of Mycobacterium tuberculosis Cases in Acapulco: Spoligotyping and Risk Factors

    Directory of Open Access Journals (Sweden)

    Elizabeth Nava-Aguilera

    2011-01-01

    Full Text Available Recurrence and reinfection of tuberculosis have quite different implications for prevention. We identified 267 spoligotypes of Mycobacterium tuberculosis from consecutive tuberculosis patients in Acapulco, Mexico, to assess the level of clustering and risk factors for clustered strains. Point cluster analysis examined spatial clustering. Risk analysis relied on the Mantel Haenszel procedure to examine bivariate associations, then to develop risk profiles of combinations of risk factors. Supplementary analysis of the spoligotyping data used SpolTools. Spoligotyping identified 85 types, 50 of them previously unreported. The five most common spoligotypes accounted for 55% of tuberculosis cases. One cluster of 70 patients (26% of the series produced a single spoligotype from the Manila Family (Clade EAI2. The high proportion (78% of patients infected with cluster strains is compatible with recent transmission of TB in Acapulco. Geomatic analysis showed no spatial clustering; clustering was associated with a risk profile of uneducated cases who lived in single-room dwellings. The Manila emerging strain accounted for one in every four cases, confirming that one strain can predominate in a hyperendemic area.

  5. Internal validation of risk models in clustered data: a comparison of bootstrap schemes

    NARCIS (Netherlands)

    Bouwmeester, W.; Moons, K.G.M.; Kappen, T.H.; van Klei, W.A.; Twisk, J.W.R.; Eijkemans, M.J.C.; Vergouwe, Y.

    2013-01-01

    Internal validity of a risk model can be studied efficiently with bootstrapping to assess possible optimism in model performance. Assumptions of the regular bootstrap are violated when the development data are clustered. We compared alternative resampling schemes in clustered data for the estimation

  6. Health in police officers: Role of risk factor clusters and police divisions.

    Science.gov (United States)

    Habersaat, Stephanie A; Geiger, Ashley M; Abdellaoui, Sid; Wolf, Jutta M

    2015-10-01

    Law enforcement is a stressful occupation associated with significant health problems. To date, most studies have focused on one specific factor or one domain of risk factors (e.g., organizational, personal). However, it is more likely that specific combinations of risk factors are differentially health relevant and further, depend on the area of police work. A self-selected group of officers from the criminal, community, and emergency division (N = 84) of a Swiss state police department answered questionnaires assessing personal and organizational risk factors as well as mental and physical health indicators. In general, few differences were observed across divisions in terms of risk factors or health indicators. Cluster analysis of all risk factors established a high-risk and a low-risk cluster with significant links to all mental health outcomes. Risk cluster-by-division interactions revealed that, in the high-risk cluster, Emergency officers reported fewer physical symptoms, while community officers reported more posttraumatic stress symptoms. Criminal officers in the high-risk cluster tended to perceived more stress. Finally, perceived stress did not mediate the relationship between risk clusters and posttraumatic stress symptoms. In summary, our results support the notion that police officers are a heterogeneous population in terms of processes linking risk factors and health indicators. This heterogeneity thereby appeared to be more dependent on personal factors and individuals' perception of their own work conditions than division-specific work environments. Our findings further suggest that stress-reduction interventions that do not target job-relevant sources of stress may only show limited effectiveness in reducing health risks associated with police work. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Surviving a cluster collapse: risk aversion as a core value

    NARCIS (Netherlands)

    Schiele, Holger; Hospers, Gerrit J.; van der Zee, D.J.

    2012-01-01

    Purpose – This paper analyses firms, which survived in a collapsed regional cluster. The target is to analyze whether the principles for enduring success identified researching success factors of very old firms also apply in such an environment. Design/methodology/approach – The authors conduct a

  8. clusters

    Indian Academy of Sciences (India)

    2017-09-27

    Sep 27, 2017 ... Author for correspondence (zh4403701@126.com). MS received 15 ... lic clusters using density functional theory (DFT)-GGA of the DMOL3 package. ... In the process of geometric optimization, con- vergence thresholds ..... and Postgraduate Research & Practice Innovation Program of. Jiangsu Province ...

  9. clusters

    Indian Academy of Sciences (India)

    environmental as well as technical problems during fuel gas utilization. ... adsorption on some alloys of Pd, namely PdAu, PdAg ... ried out on small neutral and charged Au24,26,27, Cu,28 ... study of Zanti et al.29 on Pdn (n = 1–9) clusters.

  10. Local bladder cancer clusters in southeastern Michigan accounting for risk factors, covariates and residential mobility.

    Directory of Open Access Journals (Sweden)

    Geoffrey M Jacquez

    Full Text Available In case control studies disease risk not explained by the significant risk factors is the unexplained risk. Considering unexplained risk for specific populations, places and times can reveal the signature of unidentified risk factors and risk factors not fully accounted for in the case-control study. This potentially can lead to new hypotheses regarding disease causation.Global, local and focused Q-statistics are applied to data from a population-based case-control study of 11 southeast Michigan counties. Analyses were conducted using both year- and age-based measures of time. The analyses were adjusted for arsenic exposure, education, smoking, family history of bladder cancer, occupational exposure to bladder cancer carcinogens, age, gender, and race.Significant global clustering of cases was not found. Such a finding would indicate large-scale clustering of cases relative to controls through time. However, highly significant local clusters were found in Ingham County near Lansing, in Oakland County, and in the City of Jackson, Michigan. The Jackson City cluster was observed in working-ages and is thus consistent with occupational causes. The Ingham County cluster persists over time, suggesting a broad-based geographically defined exposure. Focused clusters were found for 20 industrial sites engaged in manufacturing activities associated with known or suspected bladder cancer carcinogens. Set-based tests that adjusted for multiple testing were not significant, although local clusters persisted through time and temporal trends in probability of local tests were observed.Q analyses provide a powerful tool for unpacking unexplained disease risk from case-control studies. This is particularly useful when the effect of risk factors varies spatially, through time, or through both space and time. For bladder cancer in Michigan, the next step is to investigate causal hypotheses that may explain the excess bladder cancer risk localized to areas of

  11. Prevalence and risk factors of seizure clusters in adult patients with epilepsy.

    Science.gov (United States)

    Chen, Baibing; Choi, Hyunmi; Hirsch, Lawrence J; Katz, Austen; Legge, Alexander; Wong, Rebecca A; Jiang, Alfred; Kato, Kenneth; Buchsbaum, Richard; Detyniecki, Kamil

    2017-07-01

    In the current study, we explored the prevalence of physician-confirmed seizure clusters. We also investigated potential clinical factors associated with the occurrence of seizure clusters overall and by epilepsy type. We reviewed medical records of 4116 adult (≥16years old) outpatients with epilepsy at our centers for documentation of seizure clusters. Variables including patient demographics, epilepsy details, medical and psychiatric history, AED history, and epilepsy risk factors were then tested against history of seizure clusters. Patients were then divided into focal epilepsy, idiopathic generalized epilepsy (IGE), or symptomatic generalized epilepsy (SGE), and the same analysis was run. Overall, seizure clusters were independently associated with earlier age of seizure onset, symptomatic generalized epilepsy (SGE), central nervous system (CNS) infection, cortical dysplasia, status epilepticus, absence of 1-year seizure freedom, and having failed 2 or more AEDs (Pepilepsy (16.3%) and IGE (7.4%; all Pepilepsy type showed that absence of 1-year seizure freedom since starting treatment at one of our centers was associated with seizure clustering in patients across all 3 epilepsy types. In patients with SGE, clusters were associated with perinatal/congenital brain injury. In patients with focal epilepsy, clusters were associated with younger age of seizure onset, complex partial seizures, cortical dysplasia, status epilepticus, CNS infection, and having failed 2 or more AEDs. In patients with IGE, clusters were associated with presence of an aura. Only 43.5% of patients with seizure clusters were prescribed rescue medications. Patients with intractable epilepsy are at a higher risk of developing seizure clusters. Factors such as having SGE, CNS infection, cortical dysplasia, status epilepticus or an early seizure onset, can also independently increase one's chance of having seizure clusters. Copyright © 2017. Published by Elsevier B.V.

  12. Risk Profiles of Children Entering Residential Care: A Cluster Analysis

    Science.gov (United States)

    Hagaman, Jessica L.; Trout, Alexandra L.; Chmelka, M. Beth; Thompson, Ronald W.; Reid, Robert

    2010-01-01

    Children in residential care are a heterogeneous population, presenting various combinations of risks. Existing studies on these children suggest high variability across multiple domains (e.g., academics, behavior). Given this heterogeneity, it is important to begin to identify the combinations and patterns of multiple risks, or risk profiles,…

  13. Fascioliasis risk factors and space-time clusters in domestic ruminants in Bangladesh.

    Science.gov (United States)

    Rahman, A K M Anisur; Islam, S K Shaheenur; Talukder, Md Hasanuzzaman; Hassan, Md Kumrul; Dhand, Navneet K; Ward, Michael P

    2017-05-08

    A retrospective observational study was conducted to identify fascioliasis hotspots, clusters, potential risk factors and to map fascioliasis risk in domestic ruminants in Bangladesh. Cases of fascioliasis in cattle, buffalo, sheep and goats from all districts in Bangladesh between 2011 and 2013 were identified via secondary surveillance data from the Department of Livestock Services' Epidemiology Unit. From each case report, date of report, species affected and district data were extracted. The total number of domestic ruminants in each district was used to calculate fascioliasis cases per ten thousand animals at risk per district, and this was used for cluster and hotspot analysis. Clustering was assessed with Moran's spatial autocorrelation statistic, hotspots with the local indicator of spatial association (LISA) statistic and space-time clusters with the scan statistic (Poisson model). The association between district fascioliasis prevalence and climate (temperature, precipitation), elevation, land cover and water bodies was investigated using a spatial regression model. A total of 1,723,971 cases of fascioliasis were reported in the three-year study period in cattle (1,164,560), goats (424,314), buffalo (88,924) and sheep (46,173). A total of nine hotspots were identified; one of these persisted in each of the three years. Only two local clusters were found. Five space-time clusters located within 22 districts were also identified. Annual risk maps of fascioliasis cases correlated with the hotspots and clusters detected. Cultivated and managed (P fascioliasis in Bangladesh, respectively. Results indicate that due to land use characteristics some areas of Bangladesh are at greater risk of fascioliasis. The potential risk factors, hot spots and clusters identified in this study can be used to guide science-based treatment and control decisions for fascioliasis in Bangladesh and in other similar geo-climatic zones throughout the world.

  14. Clustering of risk factors for noncommunicable diseases in Brazilian adolescents: prevalence and correlates.

    Science.gov (United States)

    Cureau, Felipe Vogt; Duarte, Paola; dos Santos, Daniela Lopes; Reichert, Felipe Fossati

    2014-07-01

    Few studies have investigated the prevalence and correlates of risk factors for noncommunicable diseases among Brazilian adolescents. We evaluated the clustering of risk factors and their associations with sociodemographic variables. We used a cross-sectional study carried out in 2011 comprising 1132 students aged 14-19 years from Santa Maria, Brazil. The cluster index was created as the sum of the risk factors. For the correlates analysis, a multinomial logistic regression was used. Furthermore, the observed/expected ratio was calculated. Prevalence of individual risk factors studied was as follows: 85.8% unhealthy diets, 53.5% physical inactivity, 31.3% elevated blood pressure, 23.9% overweight, 22.3% excessive drinking alcohol, and 8.6% smoking. Only 2.8% of the adolescents did not present any risk factor, while 21.7%, 40.9%, 23.1%, and 11.5% presented 1, 2, 3, and 4 or more risk factors, respectively. The most prevalent combination was between unhealthy diets and physical inactivity (observed/expected ratio =1.32; 95% CI: 1.16-1.49). Clustering of risk factors was directly associated with age and inversely associated with socioeconomic status. Clustering of risk factors for noncommunicable diseases is high in Brazilian adolescents. Preventive strategies are more likely to be successful if focusing on multiple risk factors, instead of a single one.

  15. Behavioral Health Risk Profiles of Undergraduate University Students in England, Wales, and Northern Ireland: A Cluster Analysis.

    Science.gov (United States)

    El Ansari, Walid; Ssewanyana, Derrick; Stock, Christiane

    2018-01-01

    Limited research has explored clustering of lifestyle behavioral risk factors (BRFs) among university students. This study aimed to explore clustering of BRFs, composition of clusters, and the association of the clusters with self-rated health and perceived academic performance. We assessed (BRFs), namely tobacco smoking, physical inactivity, alcohol consumption, illicit drug use, unhealthy nutrition, and inadequate sleep, using a self-administered general Student Health Survey among 3,706 undergraduates at seven UK universities. A two-step cluster analysis generated: Cluster 1 (the high physically active and health conscious) with very high health awareness/consciousness, good nutrition, and physical activity (PA), and relatively low alcohol, tobacco, and other drug (ATOD) use. Cluster 2 (the abstinent) had very low ATOD use, high health awareness, good nutrition, and medium high PA. Cluster 3 (the moderately health conscious) included the highest regard for healthy eating, second highest fruit/vegetable consumption, and moderately high ATOD use. Cluster 4 (the risk taking) showed the highest ATOD use, were the least health conscious, least fruit consuming, and attached the least importance on eating healthy. Compared to the healthy cluster (Cluster 1), students in other clusters had lower self-rated health, and particularly, students in the risk taking cluster (Cluster 4) reported lower academic performance. These associations were stronger for men than for women. Of the four clusters, Cluster 4 had the youngest students. Our results suggested that prevention among university students should address multiple BRFs simultaneously, with particular focus on the younger students.

  16. Spatial clustering and local risk of leprosy in São Paulo, Brazil.

    Directory of Open Access Journals (Sweden)

    Antônio Carlos Vieira Ramos

    2017-02-01

    Full Text Available Although the detection rate is decreasing, the proportion of new cases with WHO grade 2 disability (G2D is increasing, creating concern among policy makers and the Brazilian government. This study aimed to identify spatial clustering of leprosy and classify high-risk areas in a major leprosy cluster using the SatScan method.Data were obtained including all leprosy cases diagnosed between January 2006 and December 2013. In addition to the clinical variable, information was also gathered regarding the G2D of the patient at diagnosis and after treatment. The Scan Spatial statistic test, developed by Kulldorff e Nagarwalla, was used to identify spatial clustering and to measure the local risk (Relative Risk-RR of leprosy. Maps considering these risks and their confidence intervals were constructed.A total of 434 cases were identified, including 188 (43.31% borderline leprosy and 101 (23.28% lepromatous leprosy cases. There was a predominance of males, with ages ranging from 15 to 59 years, and 51 patients (11.75% presented G2D. Two significant spatial clusters and three significant spatial-temporal clusters were also observed. The main spatial cluster (p = 0.000 contained 90 census tracts, a population of approximately 58,438 inhabitants, detection rate of 22.6 cases per 100,000 people and RR of approximately 3.41 (95%CI = 2.721-4.267. Regarding the spatial-temporal clusters, two clusters were observed, with RR ranging between 24.35 (95%CI = 11.133-52.984 and 15.24 (95%CI = 10.114-22.919.These findings could contribute to improvements in policies and programming, aiming for the eradication of leprosy in Brazil. The Spatial Scan statistic test was found to be an interesting resource for health managers and healthcare professionals to map the vulnerability of areas in terms of leprosy transmission risk and areas of underreporting.

  17. Spatial clustering and local risk of leprosy in São Paulo, Brazil.

    Science.gov (United States)

    Ramos, Antônio Carlos Vieira; Yamamura, Mellina; Arroyo, Luiz Henrique; Popolin, Marcela Paschoal; Chiaravalloti Neto, Francisco; Palha, Pedro Fredemir; Uchoa, Severina Alice da Costa; Pieri, Flávia Meneguetti; Pinto, Ione Carvalho; Fiorati, Regina Célia; Queiroz, Ana Angélica Rêgo de; Belchior, Aylana de Souza; Dos Santos, Danielle Talita; Garcia, Maria Concebida da Cunha; Crispim, Juliane de Almeida; Alves, Luana Seles; Berra, Thaís Zamboni; Arcêncio, Ricardo Alexandre

    2017-02-01

    Although the detection rate is decreasing, the proportion of new cases with WHO grade 2 disability (G2D) is increasing, creating concern among policy makers and the Brazilian government. This study aimed to identify spatial clustering of leprosy and classify high-risk areas in a major leprosy cluster using the SatScan method. Data were obtained including all leprosy cases diagnosed between January 2006 and December 2013. In addition to the clinical variable, information was also gathered regarding the G2D of the patient at diagnosis and after treatment. The Scan Spatial statistic test, developed by Kulldorff e Nagarwalla, was used to identify spatial clustering and to measure the local risk (Relative Risk-RR) of leprosy. Maps considering these risks and their confidence intervals were constructed. A total of 434 cases were identified, including 188 (43.31%) borderline leprosy and 101 (23.28%) lepromatous leprosy cases. There was a predominance of males, with ages ranging from 15 to 59 years, and 51 patients (11.75%) presented G2D. Two significant spatial clusters and three significant spatial-temporal clusters were also observed. The main spatial cluster (p = 0.000) contained 90 census tracts, a population of approximately 58,438 inhabitants, detection rate of 22.6 cases per 100,000 people and RR of approximately 3.41 (95%CI = 2.721-4.267). Regarding the spatial-temporal clusters, two clusters were observed, with RR ranging between 24.35 (95%CI = 11.133-52.984) and 15.24 (95%CI = 10.114-22.919). These findings could contribute to improvements in policies and programming, aiming for the eradication of leprosy in Brazil. The Spatial Scan statistic test was found to be an interesting resource for health managers and healthcare professionals to map the vulnerability of areas in terms of leprosy transmission risk and areas of underreporting.

  18. Tracking of clustered cardiovascular disease risk factors from childhood to adolescence

    DEFF Research Database (Denmark)

    Bugge, Anna; El-Naaman, Bianca; McMurray, Robert G

    2013-01-01

    samples were analyzed for CVD risk factors. A clustered risk-score (z-score) was constructed by adding sex-specific z-scores for blood pressure, homeostatic model assessment (HOMA-IR), triglyceride, skinfolds and negative values of high-density lipoprotein cholesterol (HDLc) and VO(2peak...

  19. Fitness, fatness and clustering of cardiovascular risk factors in children from Denmark, Estonia and Portugal

    DEFF Research Database (Denmark)

    Andersen, Lars B; Sardinha, Luis B; Froberg, Karsten

    2008-01-01

    BACKGROUND: Levels of overweight have increased and fitness has decreased in children. Potentially, these changes may be a threat to future health. Numerous studies have measured changes in body mass index (BMI), but few have assessed the independent effects of low fitness, overweight and physical...... inactivity on cardiovascular (CVD) risk factors. METHODS: A cross-sectional multi-center study including 1 769 children from Denmark, Estonia and Portugal. The main outcome was clustering of CVD risk factors. Independent variables were waist circumference, skinfolds, physical activity and cardio......-respiratory fitness. RESULTS: Both waist circumference and skinfolds were associated with clustered CVD risk. Odds ratios for clustered CVD risk for the upper quartiles compared with the lowest quartile were 9.13 (95% CI: 5.78-14.43) and 11.62 (95% CI: 7.11-18.99) when systolic blood pressure, triglyceride, insulin...

  20. Risk Assessment for Bridges Safety Management during Operation Based on Fuzzy Clustering Algorithm

    Directory of Open Access Journals (Sweden)

    Xia Hanyu

    2016-01-01

    Full Text Available In recent years, large span and large sea-crossing bridges are built, bridges accidents caused by improper operational management occur frequently. In order to explore the better methods for risk assessment of the bridges operation departments, the method based on fuzzy clustering algorithm is selected. Then, the implementation steps of fuzzy clustering algorithm are described, the risk evaluation system is built, and Taizhou Bridge is selected as an example, the quantitation of risk factors is described. After that, the clustering algorithm based on fuzzy equivalence is calculated on MATLAB 2010a. In the last, Taizhou Bridge operation management departments are classified and sorted according to the degree of risk, and the safety situation of operation departments is analyzed.

  1. Development of innovative methods for risk assessment in high-rise construction based on clustering of risk factors

    Science.gov (United States)

    Okolelova, Ella; Shibaeva, Marina; Shalnev, Oleg

    2018-03-01

    The article analyses risks in high-rise construction in terms of investment value with account of the maximum probable loss in case of risk event. The authors scrutinized the risks of high-rise construction in regions with various geographic, climatic and socio-economic conditions that may influence the project environment. Risk classification is presented in general terms, that includes aggregated characteristics of risks being common for many regions. Cluster analysis tools, that allow considering generalized groups of risk depending on their qualitative and quantitative features, were used in order to model the influence of the risk factors on the implementation of investment project. For convenience of further calculations, each type of risk is assigned a separate code with the number of the cluster and the subtype of risk. This approach and the coding of risk factors makes it possible to build a risk matrix, which greatly facilitates the task of determining the degree of impact of risks. The authors clarified and expanded the concept of the price risk, which is defined as the expected value of the event, 105 which extends the capabilities of the model, allows estimating an interval of the probability of occurrence and also using other probabilistic methods of calculation.

  2. Case-control geographic clustering for residential histories accounting for risk factors and covariates

    Science.gov (United States)

    2006-01-01

    Background Methods for analyzing space-time variation in risk in case-control studies typically ignore residential mobility. We develop an approach for analyzing case-control data for mobile individuals and apply it to study bladder cancer in 11 counties in southeastern Michigan. At this time data collection is incomplete and no inferences should be drawn – we analyze these data to demonstrate the novel methods. Global, local and focused clustering of residential histories for 219 cases and 437 controls is quantified using time-dependent nearest neighbor relationships. Business address histories for 268 industries that release known or suspected bladder cancer carcinogens are analyzed. A logistic model accounting for smoking, gender, age, race and education specifies the probability of being a case, and is incorporated into the cluster randomization procedures. Sensitivity of clustering to definition of the proximity metric is assessed for 1 to 75 k nearest neighbors. Results Global clustering is partly explained by the covariates but remains statistically significant at 12 of the 14 levels of k considered. After accounting for the covariates 26 Local clusters are found in Lapeer, Ingham, Oakland and Jackson counties, with the clusters in Ingham and Oakland counties appearing in 1950 and persisting to the present. Statistically significant focused clusters are found about the business address histories of 22 industries located in Oakland (19 clusters), Ingham (2) and Jackson (1) counties. Clusters in central and southeastern Oakland County appear in the 1930's and persist to the present day. Conclusion These methods provide a systematic approach for evaluating a series of increasingly realistic alternative hypotheses regarding the sources of excess risk. So long as selection of cases and controls is population-based and not geographically biased, these tools can provide insights into geographic risk factors that were not specifically assessed in the case

  3. Case-control geographic clustering for residential histories accounting for risk factors and covariates

    Directory of Open Access Journals (Sweden)

    Goovaerts Pierre

    2006-08-01

    Full Text Available Abstract Background Methods for analyzing space-time variation in risk in case-control studies typically ignore residential mobility. We develop an approach for analyzing case-control data for mobile individuals and apply it to study bladder cancer in 11 counties in southeastern Michigan. At this time data collection is incomplete and no inferences should be drawn – we analyze these data to demonstrate the novel methods. Global, local and focused clustering of residential histories for 219 cases and 437 controls is quantified using time-dependent nearest neighbor relationships. Business address histories for 268 industries that release known or suspected bladder cancer carcinogens are analyzed. A logistic model accounting for smoking, gender, age, race and education specifies the probability of being a case, and is incorporated into the cluster randomization procedures. Sensitivity of clustering to definition of the proximity metric is assessed for 1 to 75 k nearest neighbors. Results Global clustering is partly explained by the covariates but remains statistically significant at 12 of the 14 levels of k considered. After accounting for the covariates 26 Local clusters are found in Lapeer, Ingham, Oakland and Jackson counties, with the clusters in Ingham and Oakland counties appearing in 1950 and persisting to the present. Statistically significant focused clusters are found about the business address histories of 22 industries located in Oakland (19 clusters, Ingham (2 and Jackson (1 counties. Clusters in central and southeastern Oakland County appear in the 1930's and persist to the present day. Conclusion These methods provide a systematic approach for evaluating a series of increasingly realistic alternative hypotheses regarding the sources of excess risk. So long as selection of cases and controls is population-based and not geographically biased, these tools can provide insights into geographic risk factors that were not specifically

  4. Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.

    Science.gov (United States)

    Bi, Qifang; Azman, Andrew S; Satter, Syed Moinuddin; Khan, Azharul Islam; Ahmed, Dilruba; Riaj, Altaf Ahmed; Gurley, Emily S; Lessler, Justin

    2016-02-01

    Close interpersonal contact likely drives spatial clustering of cases of cholera and diarrhea, but spatial clustering of risk factors may also drive this pattern. Few studies have focused specifically on how exposures for disease cluster at small spatial scales. Improving our understanding of the micro-scale clustering of risk factors for cholera may help to target interventions and power studies with cluster designs. We selected sets of spatially matched households (matched-sets) near cholera case households between April and October 2013 in a cholera endemic urban neighborhood of Tongi Township in Bangladesh. We collected data on exposures to suspected cholera risk factors at the household and individual level. We used intra-class correlation coefficients (ICCs) to characterize clustering of exposures within matched-sets and households, and assessed if clustering depended on the geographical extent of the matched-sets. Clustering over larger spatial scales was explored by assessing the relationship between matched-sets. We also explored whether different exposures tended to appear together in individuals, households, and matched-sets. Household level exposures, including: drinking municipal supplied water (ICC = 0.97, 95%CI = 0.96, 0.98), type of latrine (ICC = 0.88, 95%CI = 0.71, 1.00), and intermittent access to drinking water (ICC = 0.96, 95%CI = 0.87, 1.00) exhibited strong clustering within matched-sets. As the geographic extent of matched-sets increased, the concordance of exposures within matched-sets decreased. Concordance between matched-sets of exposures related to water supply was elevated at distances of up to approximately 400 meters. Household level hygiene practices were correlated with infrastructure shown to increase cholera risk. Co-occurrence of different individual level exposures appeared to mostly reflect the differing domestic roles of study participants. Strong spatial clustering of exposures at a small spatial scale in a cholera endemic

  5. Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.

    Directory of Open Access Journals (Sweden)

    Qifang Bi

    2016-02-01

    Full Text Available Close interpersonal contact likely drives spatial clustering of cases of cholera and diarrhea, but spatial clustering of risk factors may also drive this pattern. Few studies have focused specifically on how exposures for disease cluster at small spatial scales. Improving our understanding of the micro-scale clustering of risk factors for cholera may help to target interventions and power studies with cluster designs. We selected sets of spatially matched households (matched-sets near cholera case households between April and October 2013 in a cholera endemic urban neighborhood of Tongi Township in Bangladesh. We collected data on exposures to suspected cholera risk factors at the household and individual level. We used intra-class correlation coefficients (ICCs to characterize clustering of exposures within matched-sets and households, and assessed if clustering depended on the geographical extent of the matched-sets. Clustering over larger spatial scales was explored by assessing the relationship between matched-sets. We also explored whether different exposures tended to appear together in individuals, households, and matched-sets. Household level exposures, including: drinking municipal supplied water (ICC = 0.97, 95%CI = 0.96, 0.98, type of latrine (ICC = 0.88, 95%CI = 0.71, 1.00, and intermittent access to drinking water (ICC = 0.96, 95%CI = 0.87, 1.00 exhibited strong clustering within matched-sets. As the geographic extent of matched-sets increased, the concordance of exposures within matched-sets decreased. Concordance between matched-sets of exposures related to water supply was elevated at distances of up to approximately 400 meters. Household level hygiene practices were correlated with infrastructure shown to increase cholera risk. Co-occurrence of different individual level exposures appeared to mostly reflect the differing domestic roles of study participants. Strong spatial clustering of exposures at a small spatial scale in a

  6. Research on the method of information system risk state estimation based on clustering particle filter

    Science.gov (United States)

    Cui, Jia; Hong, Bei; Jiang, Xuepeng; Chen, Qinghua

    2017-05-01

    With the purpose of reinforcing correlation analysis of risk assessment threat factors, a dynamic assessment method of safety risks based on particle filtering is proposed, which takes threat analysis as the core. Based on the risk assessment standards, the method selects threat indicates, applies a particle filtering algorithm to calculate influencing weight of threat indications, and confirms information system risk levels by combining with state estimation theory. In order to improve the calculating efficiency of the particle filtering algorithm, the k-means cluster algorithm is introduced to the particle filtering algorithm. By clustering all particles, the author regards centroid as the representative to operate, so as to reduce calculated amount. The empirical experience indicates that the method can embody the relation of mutual dependence and influence in risk elements reasonably. Under the circumstance of limited information, it provides the scientific basis on fabricating a risk management control strategy.

  7. Research on the method of information system risk state estimation based on clustering particle filter

    Directory of Open Access Journals (Sweden)

    Cui Jia

    2017-05-01

    Full Text Available With the purpose of reinforcing correlation analysis of risk assessment threat factors, a dynamic assessment method of safety risks based on particle filtering is proposed, which takes threat analysis as the core. Based on the risk assessment standards, the method selects threat indicates, applies a particle filtering algorithm to calculate influencing weight of threat indications, and confirms information system risk levels by combining with state estimation theory. In order to improve the calculating efficiency of the particle filtering algorithm, the k-means cluster algorithm is introduced to the particle filtering algorithm. By clustering all particles, the author regards centroid as the representative to operate, so as to reduce calculated amount. The empirical experience indicates that the method can embody the relation of mutual dependence and influence in risk elements reasonably. Under the circumstance of limited information, it provides the scientific basis on fabricating a risk management control strategy.

  8. Examining Subtypes of Behavioral/Emotional Risk Using Cluster Analysis

    Science.gov (United States)

    Dever, Bridget V.; Gallagher, Emily K.; Hochbein, Craig D.; Loukas, Austin; Dai, Chenchen

    2017-01-01

    Behavioral and emotional problems among children and adolescents can lead to numerous negative outcomes without intervention. From a prevention standpoint, screening for behavioral and emotional risk is an important step toward identifying such problems before the point of diagnosis or referral. The present study conducted a k-means cluster…

  9. Clustering of chronic disease risk factors with tobacco smoking ...

    African Journals Online (AJOL)

    Methods: A cross-sectional study was derived from an initial assessment in workplaces which was part of a community-based intervention to prevent chronic disease risk ... The main items assessed socio-demographics characteristics, smoking status, eating habits, level of physical activity and alcohol use of the participants.

  10. Directed clustering coefficient as a measure of systemic risk in complex banking networks

    Science.gov (United States)

    Tabak, Benjamin M.; Takami, Marcelo; Rocha, Jadson M. C.; Cajueiro, Daniel O.; Souza, Sergio R. S.

    2014-01-01

    Recent literature has focused on the study of systemic risk in complex networks. It is clear now, after the crisis of 2008, that the aggregate behavior of the interaction among agents is not straightforward and it is very difficult to predict. Contributing to this debate, this paper shows that the directed clustering coefficient may be used as a measure of systemic risk in complex networks. Furthermore, using data from the Brazilian interbank network, we show that the directed clustering coefficient is negatively correlated with domestic interest rates.

  11. Performance of the modified Poisson regression approach for estimating relative risks from clustered prospective data.

    Science.gov (United States)

    Yelland, Lisa N; Salter, Amy B; Ryan, Philip

    2011-10-15

    Modified Poisson regression, which combines a log Poisson regression model with robust variance estimation, is a useful alternative to log binomial regression for estimating relative risks. Previous studies have shown both analytically and by simulation that modified Poisson regression is appropriate for independent prospective data. This method is often applied to clustered prospective data, despite a lack of evidence to support its use in this setting. The purpose of this article is to evaluate the performance of the modified Poisson regression approach for estimating relative risks from clustered prospective data, by using generalized estimating equations to account for clustering. A simulation study is conducted to compare log binomial regression and modified Poisson regression for analyzing clustered data from intervention and observational studies. Both methods generally perform well in terms of bias, type I error, and coverage. Unlike log binomial regression, modified Poisson regression is not prone to convergence problems. The methods are contrasted by using example data sets from 2 large studies. The results presented in this article support the use of modified Poisson regression as an alternative to log binomial regression for analyzing clustered prospective data when clustering is taken into account by using generalized estimating equations.

  12. Cardiometabolic risk clustering in spinal cord injury: results of exploratory factor analysis.

    Science.gov (United States)

    Libin, Alexander; Tinsley, Emily A; Nash, Mark S; Mendez, Armando J; Burns, Patricia; Elrod, Matt; Hamm, Larry F; Groah, Suzanne L

    2013-01-01

    Evidence suggests an elevated prevalence of cardiometabolic risks among persons with spinal cord injury (SCI); however, the unique clustering of risk factors in this population has not been fully explored. The purpose of this study was to describe unique clustering of cardiometabolic risk factors differentiated by level of injury. One hundred twenty-one subjects (mean 37 ± 12 years; range, 18-73) with chronic C5 to T12 motor complete SCI were studied. Assessments included medical histories, anthropometrics and blood pressure, and fasting serum lipids, glucose, insulin, and hemoglobin A1c (HbA1c). The most common cardiometabolic risk factors were overweight/obesity, high levels of low-density lipoprotein (LDL-C), and low levels of high-density lipoprotein (HDL-C). Risk clustering was found in 76.9% of the population. Exploratory principal component factor analysis using varimax rotation revealed a 3-factor model in persons with paraplegia (65.4% variance) and a 4-factor solution in persons with tetraplegia (73.3% variance). The differences between groups were emphasized by the varied composition of the extracted factors: Lipid Profile A (total cholesterol [TC] and LDL-C), Body Mass-Hypertension Profile (body mass index [BMI], systolic blood pressure [SBP], and fasting insulin [FI]); Glycemic Profile (fasting glucose and HbA1c), and Lipid Profile B (TG and HDL-C). BMI and SBP formed a separate factor only in persons with tetraplegia. Although the majority of the population with SCI has risk clustering, the composition of the risk clusters may be dependent on level of injury, based on a factor analysis group comparison. This is clinically plausible and relevant as tetraplegics tend to be hypo- to normotensive and more sedentary, resulting in lower HDL-C and a greater propensity toward impaired carbohydrate metabolism.

  13. Types of Obesity and Its Association with the Clustering of Cardiovascular Disease Risk Factors in Jilin Province of China

    OpenAIRE

    Zhang, Peng; Wang, Rui; Gao, Chunshi; Song, Yuanyuan; Lv, Xin; Jiang, Lingling; Yu, Yaqin; Wang, Yuhan; Li, Bo

    2016-01-01

    Cardiovascular disease (CVD) has become a serious public health problem in recent years in China. Aggregation of CVD risk factors in one individual increases the risk of CVD and the risk increases substantially with each additional risk factor. This study aims to explore the relationship between the number of clustered CVD risk factors and different types of obesity. A multistage stratified random cluster sampling design was used in this population-based cross-sectional study in 2012. Informa...

  14. Sedentary behaviour and clustered metabolic risk in adolescents: the HELENA study.

    Science.gov (United States)

    Rey-López, J P; Bel-Serrat, S; Santaliestra-Pasías, A; de Moraes, A C; Vicente-Rodríguez, G; Ruiz, J R; Artero, E G; Martínez-Gómez, D; Gottrand, F; De Henauw, S; Huybrechts, I; Polito, A; Molnar, D; Manios, Y; Moreno, L A

    2013-10-01

    Although sedentary behaviours are linked with mortality for cardiovascular reasons, it is not clear whether they are negatively related with cardio-metabolic risk factors. The aim was to examine the association between time engaged in television (TV) viewing or playing with videogames and a clustered cardio-metabolic risk in adolescents. Sedentary behaviours and physical activity were assessed in 769 adolescents (376 boys, aged 12.5-17.5 years) from the HELENA-CSS study. We measured systolic blood pressure, HOMA index, triglycerides, TC/HDL-c, VO₂max and the sum of four skinfolds, and a clustered metabolic risk index was computed. A multilevel regression model (by Poisson) was performed to calculate the prevalence ratio of having a clustered metabolic risk. In boys, playing >4 h/day with videogames (weekend) and moderate to vigorous PA (MVPA) was associated with cardio-metabolic risk after adjustment for age, maternal education and MVPA. In contrast, TV viewing was not associated with the presence of cardio-metabolic risk. In boys, playing with videogames may impair cardio-metabolic health during the adolescence. Adolescents should be encouraged to increase their participation in physical activity of at least moderate intensity to obtain a more favourable risk factor profile. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Risk factors associated with cluster size of Mycobacterium tuberculosis (Mtb) of different RFLP lineages in Brazil.

    Science.gov (United States)

    Peres, Renata Lyrio; Vinhas, Solange Alves; Ribeiro, Fabíola Karla Correa; Palaci, Moisés; do Prado, Thiago Nascimento; Reis-Santos, Bárbara; Zandonade, Eliana; Suffys, Philip Noel; Golub, Jonathan E; Riley, Lee W; Maciel, Ethel Leonor

    2018-02-08

    Tuberculosis (TB) transmission is influenced by patient-related risk, environment and bacteriological factors. We determined the risk factors associated with cluster size of IS6110 RFLP based genotypes of Mycobacterium tuberculosis (Mtb) isolates from Vitoria, Espirito Santo, Brazil. Cross-sectional study of new TB cases identified in the metropolitan area of Vitoria, Brazil between 2000 and 2010. Mtb isolates were genotyped by the IS6110 RFLP, spoligotyping and RD Rio . The isolates were classified according to genotype cluster sizes by three genotyping methods and associated patient epidemiologic characteristics. Regression Model was performed to identify factors associated with cluster size. Among 959 Mtb isolates, 461 (48%) cases had an isolate that belonged to an RFLP cluster, and six clusters with ten or more isolates were identified. Of the isolates spoligotyped, 448 (52%) were classified as LAM and 412 (48%) as non-LAM. Our regression model found that 6-9 isolates/RFLP cluster were more likely belong to the LAM family, having the RD Rio genotype and to be smear-positive (adjusted OR = 1.17, 95% CI 1.08-1.26; adjusted OR = 1.25, 95% CI 1.14-1.37; crude OR = 2.68, 95% IC 1.13-6.34; respectively) and living in a Serra city neighborhood decrease the risk of being in the 6-9 isolates/RFLP cluster (adjusted OR = 0.29, 95% CI, 0.10-0.84), than in the others groups. Individuals aged 21 to 30, 31 to 40 and > 50 years were less likely of belonging the 2-5 isolates/RFLP cluster than unique patterns compared to individuals cluster group (adjustment OR = 0.45, 95% CI 0.24-0.85) than unique patterns. We found that a large proportion of new TB infections in Vitoria is caused by prevalent Mtb genotypes belonging to the LAM family and RD Rio genotypes. Such information demonstrates that some genotypes are more likely to cause recent transmission. Targeting interventions such as screening in specific areas and social risk groups, should be a priority

  16. Insulin sensitivity and clustering of coronary heart disease risk factors in young adults. The Northern Ireland Young Hearts Study

    DEFF Research Database (Denmark)

    Andersen, Lars Bo; Boreham, Colin A.G.; Young, Ian S.

    2006-01-01

    risk factor. Subjects with clustered risk were defined as those displaying four or more risk factors. Blood glucose and insulin were measured in the fasting state and 2 h after ingestion of a 75 g glucose load. Results. Fasting insulin and the homeostasis model assessment insulin resistance score (HOMA......) were strong, graded predictors of clustered risk. The odds ratio (OR) for having clustered risk was 10.8 (95% CI: 3.6-32.4) for the upper quartile of fasting insulin compared to the lowest quartile, and the corresponding OR for HOMA was 23.2 (95% CI: 5.3-101.6). Conclusion. HOMA score predicts...

  17. Behavioral Health Risk Profiles of Undergraduate University Students in England, Wales, and Northern Ireland: A Cluster Analysis

    Directory of Open Access Journals (Sweden)

    Walid El Ansari

    2018-05-01

    Full Text Available BackgroundLimited research has explored clustering of lifestyle behavioral risk factors (BRFs among university students. This study aimed to explore clustering of BRFs, composition of clusters, and the association of the clusters with self-rated health and perceived academic performance.MethodWe assessed (BRFs, namely tobacco smoking, physical inactivity, alcohol consumption, illicit drug use, unhealthy nutrition, and inadequate sleep, using a self-administered general Student Health Survey among 3,706 undergraduates at seven UK universities.ResultsA two-step cluster analysis generated: Cluster 1 (the high physically active and health conscious with very high health awareness/consciousness, good nutrition, and physical activity (PA, and relatively low alcohol, tobacco, and other drug (ATOD use. Cluster 2 (the abstinent had very low ATOD use, high health awareness, good nutrition, and medium high PA. Cluster 3 (the moderately health conscious included the highest regard for healthy eating, second highest fruit/vegetable consumption, and moderately high ATOD use. Cluster 4 (the risk taking showed the highest ATOD use, were the least health conscious, least fruit consuming, and attached the least importance on eating healthy. Compared to the healthy cluster (Cluster 1, students in other clusters had lower self-rated health, and particularly, students in the risk taking cluster (Cluster 4 reported lower academic performance. These associations were stronger for men than for women. Of the four clusters, Cluster 4 had the youngest students.ConclusionOur results suggested that prevention among university students should address multiple BRFs simultaneously, with particular focus on the younger students.

  18. Prevalence, Co-Occurrence and Clustering of Lifestyle Risk Factors Among UK Men

    Directory of Open Access Journals (Sweden)

    Stephen Zwolinsky

    2017-01-01

    Full Text Available Objective: Men – more than women - engage in unhealthy lifestyle practices that place them at greater risk of developing non-communicable disease. This paper aims to explore the prevalence, co-occurrence and clustering of four core lifestyle risk factors and examine the socio demographic variation of their distribution, among men living in two central London boroughs. Method: A stratified street survey was undertaken with N=859 men. Prevalence odds ratios calculated risk factor clustering and a multinomial logistic regression model examined the socio-demographic variation. Results: Over 72% of men presented with combinations of lifestyle risk factors. Physical inactivity combined with a lack of fruit and vegetables was the most common combination. Co-occurrence was more prominent for unemployed, widowed, divorced/separated and white British men. Clustering was evident for adherence and non-adherence to UK health recommendations. Conclusion: Men may benefit from targeted health interventions that address multiple – rather than single – health related behaviours.

  19. Patient clusters in acute, work-related back pain based on patterns of disability risk factors.

    Science.gov (United States)

    Shaw, William S; Pransky, Glenn; Patterson, William; Linton, Steven J; Winters, Thomas

    2007-02-01

    To identify subgroups of patients with work-related back pain based on disability risk factors. Patients with work-related back pain (N = 528) completed a 16-item questionnaire of potential disability risk factors before their initial medical evaluation. Outcomes of pain, functional limitation, and work disability were assessed 1 and 3 months later. A K-Means cluster analysis of 5 disability risk factors (pain, depressed mood, fear avoidant beliefs, work inflexibility, and poor expectations for recovery) resulted in 4 sub-groups: low risk (n = 182); emotional distress (n = 103); severe pain/fear avoidant (n = 102); and concerns about job accommodation (n = 141). Pain and disability outcomes at follow-up were superior in the low-risk group and poorest in the severe pain/fear avoidant group. Patients with acute back pain can be discriminated into subgroups depending on whether disability is related to pain beliefs, emotional distress, or workplace concerns.

  20. The Metabolic Syndrome in Children and Adolescents: Shifting the Focus to Cardiometabolic Risk Factor Clustering.

    Science.gov (United States)

    Magge, Sheela N; Goodman, Elizabeth; Armstrong, Sarah C

    2017-07-24

    Metabolic syndrome (MetS) was developed by the National Cholesterol Education Program Adult Treatment Panel III, identifying adults with at least 3 of 5 cardiometabolic risk factors (hyperglycemia, increased central adiposity, elevated triglycerides, decreased high-density lipoprotein cholesterol, and elevated blood pressure) who are at increased risk of diabetes and cardiovascular disease. The constellation of MetS component risk factors has a shared pathophysiology and many common treatment approaches grounded in lifestyle modification. Several attempts have been made to define MetS in the pediatric population. However, in children, the construct is difficult to define and has unclear implications for clinical care. In this Clinical Report, we focus on the importance of screening for and treating the individual risk factor components of MetS. Focusing attention on children with cardiometabolic risk factor clustering is emphasized over the need to define a pediatric MetS. Copyright © 2017 by the American Academy of Pediatrics.

  1. Clustering of modifiable biobehavioral risk factors for chronic disease in US adults: a latent class analysis.

    Science.gov (United States)

    Leventhal, Adam M; Huh, Jimi; Dunton, Genevieve F

    2014-11-01

    Examining the co-occurrence patterns of modifiable biobehavioral risk factors for deadly chronic diseases (e.g. cancer, cardiovascular disease, diabetes) can elucidate the etiology of risk factors and guide disease-prevention programming. The aims of this study were to (1) identify latent classes based on the clustering of five key biobehavioral risk factors among US adults who reported at least one risk factor and (2) explore the demographic correlates of the identified latent classes. Participants were respondents of the National Epidemiologic Survey of Alcohol and Related Conditions (2004-2005) with at least one of the following disease risk factors in the past year (N = 22,789), which were also the latent class indicators: (1) alcohol abuse/dependence, (2) drug abuse/dependence, (3) nicotine dependence, (4) obesity, and (5) physical inactivity. Housing sample units were selected to match the US National Census in location and demographic characteristics, with young adults oversampled. Participants were administered surveys by trained interviewers. Five latent classes were yielded: 'obese, active non-substance abusers' (23%); 'nicotine-dependent, active, and non-obese' (19%); 'active, non-obese alcohol abusers' (6%); 'inactive, non-substance abusers' (50%); and 'active, polysubstance abusers' (3.7%). Four classes were characterized by a 100% likelihood of having one risk factor coupled with a low or moderate likelihood of having the other four risk factors. The five classes exhibited unique demographic profiles. Risk factors may cluster together in a non-monotonic fashion, with the majority of the at-risk population of US adults expected to have a high likelihood of endorsing only one of these five risk factors. © Royal Society for Public Health 2013.

  2. Comparison of cluster-based and source-attribution methods for estimating transmission risk using large HIV sequence databases.

    Science.gov (United States)

    Le Vu, Stéphane; Ratmann, Oliver; Delpech, Valerie; Brown, Alison E; Gill, O Noel; Tostevin, Anna; Fraser, Christophe; Volz, Erik M

    2018-06-01

    Phylogenetic clustering of HIV sequences from a random sample of patients can reveal epidemiological transmission patterns, but interpretation is hampered by limited theoretical support and statistical properties of clustering analysis remain poorly understood. Alternatively, source attribution methods allow fitting of HIV transmission models and thereby quantify aspects of disease transmission. A simulation study was conducted to assess error rates of clustering methods for detecting transmission risk factors. We modeled HIV epidemics among men having sex with men and generated phylogenies comparable to those that can be obtained from HIV surveillance data in the UK. Clustering and source attribution approaches were applied to evaluate their ability to identify patient attributes as transmission risk factors. We find that commonly used methods show a misleading association between cluster size or odds of clustering and covariates that are correlated with time since infection, regardless of their influence on transmission. Clustering methods usually have higher error rates and lower sensitivity than source attribution method for identifying transmission risk factors. But neither methods provide robust estimates of transmission risk ratios. Source attribution method can alleviate drawbacks from phylogenetic clustering but formal population genetic modeling may be required to estimate quantitative transmission risk factors. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Inflammatory Markers and Clustered Cardiovascular Disease Risk Factors in Danish Adolescents

    DEFF Research Database (Denmark)

    Bugge, Anna; El-Naaman, Bianca; McMurray, Robert G

    2012-01-01

    Aims: To evaluate the associations between inflammatory markers and clustering of cardiovascular disease (CVD) risk factors, and to examine how inflammatory markers and CVD risk are related to fatness and cardiorespiratory fitness (VO(2peak)) in adolescents. Methods: Body mass and height, skinfolds...... and blood pressure of 413 adolescents (mean age 13.4 ± 0.3 years) were measured. Circulating fasting levels of glucose, insulin, lipids, adiponectin, C-reactive protein (CRP), tumor necrosis factor (TNF)α, soluble TNF receptor-1 (sTNFR1), interleukin (IL)-6 and IL-1 receptor antagonist (IL-1Ra) were...

  4. Cardiovascular risk factor clustering and its association with fitness in nine-year-old rural Norwegian children

    DEFF Research Database (Denmark)

    Resaland, G K; Mamen, A; Boreham, C

    2010-01-01

    of those in the other quartiles. Finally, subjects were cross-tabulated into different fat-fit groups. For both sexes, the unfit and overweight/obese group had a significantly higher CVD risk factor score than the fit and normal weight group. Clustering of CVD risk factors was present in this group......This paper describes cardiovascular disease (CVD) risk factor levels in a population-representative sample of healthy, rural Norwegian children and examines the association between fitness and clustering of CVD risk factors. Final analyses included 111 boys and 116 girls (mean age 9.3 +/- 0.......3). To determine the degree of clustering, six CVD risk factors were selected: homeostasis model assessment score, waist circumference, triglycerides, systolic blood pressure, total cholesterol to high-density lipoprotein ratio and fitness (VO(2peak)). Clustering was observed in 9.9% of the boys and 13...

  5. Cardiorespiratory fitness, cardiovascular workload and risk factors among cleaners; a cluster randomized worksite intervention

    DEFF Research Database (Denmark)

    Korshøj, Mette; Krustrup, Peter; Jørgensen, Marie Birk

    2012-01-01

    . The clusters will be balanced on the following criteria: Geographical work location, gender, age and seniority. Cleaners are randomized to either I) a reference group, receiving lectures concerning healthy living, or II) an intervention group, performing worksite aerobic exercise. Data collection......ABSTRACT: BACKGROUND: Prevalence of cardiovascular risk factors is unevenly distributed among occupational groups. The working environment, as well as lifestyle and socioeconomic status contribute to the disparity and variation in prevalence of these risk factors. High physical work demands have...... been shown to increase the risk for cardiovascular disease and mortality, contrary to leisure time physical activity. High physical work demands in combination with a low cardiorespiratory fitness infer a high relative workload and an excessive risk for cardiovascular mortality. Therefore, the aim...

  6. Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990–2016

    DEFF Research Database (Denmark)

    Moesgaard Iburg, Kim

    2017-01-01

    surveillance and inform policy debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs......), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2016. This study included 481 risk-outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk (RR......) and exposure estimates from 22 717 randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources, according to the GBD 2016 source counting methods. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated...

  7. Cluster analysis of cardiovascular and metabolic risk factors in women of reproductive age.

    Science.gov (United States)

    Tzeng, Chii-Ruey; Chang, Yuan-chin Ivan; Chang, Yu-chia; Wang, Chia-Woei; Chen, Chi-Huang; Hsu, Ming-I

    2014-05-01

    To study the association between endocrine disturbances and metabolic complications in women seeking gynecologic care. Retrospective study, cluster analysis. Outpatient clinic, university medical center. 573 women, including 384 at low risk and 189 at high risk of cardiometabolic disease. None. Cardiovascular and metabolic parameters and clinical and biochemical characteristics. Risk factors for metabolic disease are associated with a low age of menarche, high levels of high-sensitivity C-reactive protein and liver enzymes, and low levels of sex hormone-binding globulin. Overweight/obese status, polycystic ovary syndrome, oligo/amenorrhea, and hyperandrogenism were found to increase the risk of cardiometabolic disease. However, hyperprolactinemia and premature ovarian failure were not associated with the risk of cardiometabolic disease. In terms of androgens, the serum total testosterone level and free androgen index but not androstenedione or dehydroepiandrosterone sulfate (DHEAS) were associated with cardiometabolic risk. Although polycystic ovary syndrome is associated with metabolic risk, obesity was the major determinant of cardiometabolic disturbances in reproductive-aged women. Hyperprolactinemia and premature ovarian failure were not associated with the risk of cardiovascular and metabolic diseases. NCT01826357. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  8. Impaired Fasting Glucose in Nondiabetic Range: Is It a Marker of Cardiovascular Risk Factor Clustering?

    Directory of Open Access Journals (Sweden)

    Giovanna Valentino

    2015-01-01

    Full Text Available Background. Impaired fasting glucose (IFG through the nondiabetic range (100–125 mg/dL is not considered in the cardiovascular (CV risk profile. Aim. To compare the clustering of CV risk factors (RFs in nondiabetic subjects with normal fasting glucose (NFG and IFG. Material and Methods. Cross-sectional study in 3739 nondiabetic subjects. Demographics, medical history, and CV risk factors were collected and lipid profile, fasting glucose levels (FBG, C-reactive protein (hsCRP, blood pressure (BP, anthropometric measurements, and aerobic capacity were determined. Results. 559 (15% subjects had IFG: they had a higher mean age, BMI, waist circumference, non-HDL cholesterol, BP, and hsCRP (p<0.0001 and lower HDL (p<0.001 and aerobic capacity (p<0.001. They also had a higher prevalence of hypertension (34% versus 25%; p<0.001, dyslipidemia (79% versus 74%; p<0.001, and obesity (29% versus 16%; p<0.001 and a higher Framingham risk score (8% versus 6%; p<0.001. The probability of presenting 3 or more CV RFs adjusted by age and gender was significantly higher in the top quintile of fasting glucose (≥98 mg/dL; OR = 2.02; 1.62–2.51. Conclusions. IFG in the nondiabetic range is associated with increased cardiovascular RF clustering.

  9. Clustering of Risk Factors for Non-Communicable Diseases among Adolescents from Southern Brazil.

    Directory of Open Access Journals (Sweden)

    Heloyse Elaine Gimenes Nunes

    Full Text Available The aim of this study was to investigate the simultaneous presence of risk factors for non-communicable diseases and the association of these risk factors with demographic and economic factors among adolescents from southern Brazil.The study included 916 students (14-19 years old enrolled in the 2014 school year at state schools in São José, Santa Catarina, Brazil. Risk factors related to lifestyle (i.e., physical inactivity, excessive alcohol consumption, smoking, sedentary behaviour and unhealthy diet, demographic variables (sex, age and skin colour and economic variables (school shift and economic level were assessed through a questionnaire. Simultaneous behaviours were assessed by the ratio between observed and expected prevalences of risk factors for non-communicable diseases. The clustering of risk factors was analysed by multinomial logistic regression. The clusters of risk factors that showed a higher prevalence were analysed by binary logistic regression.The clustering of two, three, four, and five risk factors were found in 22.2%, 49.3%, 21.7% and 3.1% of adolescents, respectively. Subgroups that were more likely to have both behaviours of physical inactivity and unhealthy diet simultaneously were mostly composed of girls (OR = 3.03, 95% CI = 1.57-5.85 and those with lower socioeconomic status (OR = 1.83, 95% CI = 1.05-3.21; simultaneous physical inactivity, excessive alcohol consumption, sedentary behaviour and unhealthy diet were mainly observed among older adolescents (OR = 1.49, 95% CI = 1.05-2.12. Subgroups less likely to have both behaviours of sedentary behaviour and unhealthy diet were mostly composed of girls (OR = 0.58, 95% CI = 0.38-0.89; simultaneous physical inactivity, sedentary behaviour and unhealthy diet were mainly observed among older individuals (OR = 0.66, 95% CI = 0.49-0.87 and those of the night shift (OR = 0.59, 95% CI = 0.43-0.82.Adolescents had a high prevalence of simultaneous risk factors for NCDs

  10. Clustering of Risk Factors for Non-Communicable Diseases among Adolescents from Southern Brazil.

    Science.gov (United States)

    Nunes, Heloyse Elaine Gimenes; Gonçalves, Eliane Cristina de Andrade; Vieira, Jéssika Aparecida Jesus; Silva, Diego Augusto Santos

    2016-01-01

    The aim of this study was to investigate the simultaneous presence of risk factors for non-communicable diseases and the association of these risk factors with demographic and economic factors among adolescents from southern Brazil. The study included 916 students (14-19 years old) enrolled in the 2014 school year at state schools in São José, Santa Catarina, Brazil. Risk factors related to lifestyle (i.e., physical inactivity, excessive alcohol consumption, smoking, sedentary behaviour and unhealthy diet), demographic variables (sex, age and skin colour) and economic variables (school shift and economic level) were assessed through a questionnaire. Simultaneous behaviours were assessed by the ratio between observed and expected prevalences of risk factors for non-communicable diseases. The clustering of risk factors was analysed by multinomial logistic regression. The clusters of risk factors that showed a higher prevalence were analysed by binary logistic regression. The clustering of two, three, four, and five risk factors were found in 22.2%, 49.3%, 21.7% and 3.1% of adolescents, respectively. Subgroups that were more likely to have both behaviours of physical inactivity and unhealthy diet simultaneously were mostly composed of girls (OR = 3.03, 95% CI = 1.57-5.85) and those with lower socioeconomic status (OR = 1.83, 95% CI = 1.05-3.21); simultaneous physical inactivity, excessive alcohol consumption, sedentary behaviour and unhealthy diet were mainly observed among older adolescents (OR = 1.49, 95% CI = 1.05-2.12). Subgroups less likely to have both behaviours of sedentary behaviour and unhealthy diet were mostly composed of girls (OR = 0.58, 95% CI = 0.38-0.89); simultaneous physical inactivity, sedentary behaviour and unhealthy diet were mainly observed among older individuals (OR = 0.66, 95% CI = 0.49-0.87) and those of the night shift (OR = 0.59, 95% CI = 0.43-0.82). Adolescents had a high prevalence of simultaneous risk factors for NCDs. Demographic

  11. Risk perception of aquatic pollution originated from chemical industry clusters in the coastal area of Jiangsu province, China.

    Science.gov (United States)

    Yao, Hong; Liu, Bo; You, Zhen; Zhao, Li

    2018-02-01

    According to "the Layout Scheme of the Chemical Industry in Jiangsu Province From 2016 to 2030" and "the Development Planning in the Coastal Area of Jiangsu Province, China," several chemical industry clusters will be located in the coastal area of Jiangsu province, China, and the risk of surface water pollution will be inevitably higher in the densely populated region. To get to know the risk acceptance level of the residents near the clusters, public perception was analyzed from the five risk factors: the basic knowledge about the pollution, the negative effects on aquatic environment imposed by the clusters, the positive effects brought by the clusters, the trust of controlling aquatic pollution, and the acceptance of the clusters. Twenty-four statements were screened out to describe the five factors, and about 600 residents were covered in three typical clusters surveyed. On the whole, the youth showed a higher interest on the survey, and middle-aged people were likely to be more concerned about aquatic pollution incident. There was no significant difference on risk perception of the three clusters. The respondents investigated had good knowledge background on aquatic pollution and the residents identified with the benefits brought by the clusters. They were weak in risk awareness of pollution originated from the chemical enterprises' groups. Although the respondents regarded that chemical industry clusters did not expose all points of pollutants' generation to the public, they inclined to trust the administration agencies on controlling the pollution and welcome the construction of chemical clusters in their dwelling cities. Besides, risk perception showed obvious spatial distribution. The closer were the samples' sites to the clusters and the rivers receiving pollutants, the higher were the residents' perceived risk, benefit, and trust. However, there was no identical spatial difference on risk acceptance, which might be comprehensively influenced by various

  12. The triply troubled teenager--chronic conditions associated with fewer protective factors and clustered risk behaviours.

    Science.gov (United States)

    Nylander, Charlotte; Seidel, Carina; Tindberg, Ylva

    2014-02-01

    This study aimed to measure protective factors and risk behaviour among adolescents with chronic conditions (CCs) and to evaluate the impact of protective factors on risk-taking. A population-based study of 7262 students aged 15 and 17 years old was performed in Sörmland, Sweden 2008 (response rate 82%). The questionnaire explored background factors, CCs, risk behaviours and protective factors. CCs were reported by 8%, while 58% had no health problems. Girls with CCs encompassed less individual protective factors, while boys with CCs tended to over-report all individual risk behaviours compared with healthy peers. Both boys and girls with CCs were more likely to report few protective factors and co-occurrence of risk behaviours. The adjOR for clustered health risk behaviours was 1.6 (1.0-2.5) in youths with CCs and ≥4 protective factors and 6.3 (3.6-10.9) in youths with CCs and 0-3 protective factors, as compared to healthy peers with ≥4 protective factors. Adolescents with CCs reported fewer protective factors and more risk behaviours than their healthy peers. The vulnerability of adolescents with CCs and few protective factors is important to acknowledge. Professionals should provide stronger protection for these adolescents, to prevent risky behaviour. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  13. Time-dependent risks of cancer clustering among couples: a nationwide population-based cohort study in Taiwan.

    Science.gov (United States)

    Wang, Jong-Yi; Liang, Yia-Wen; Yeh, Chun-Chen; Liu, Chiu-Shong; Wang, Chen-Yu

    2018-02-21

    Spousal clustering of cancer warrants attention. Whether the common environment or high-age vulnerability determines cancer clustering is unclear. The risk of clustering in couples versus non-couples is undetermined. The time to cancer clustering after the first cancer diagnosis is yet to be reported. This study investigated cancer clustering over time among couples by using nationwide data. A cohort of 5643 married couples in the 2002-2013 Taiwan National Health Insurance Research Database was identified and randomly matched with 5643 non-couple pairs through dual propensity score matching. Factors associated with clustering (both spouses with tumours) were analysed by using the Cox proportional hazard model. Propensity-matched analysis revealed that the risk of clustering of all tumours among couples (13.70%) was significantly higher than that among non-couples (11.84%) (OR=1.182, 95% CI 1.058 to 1.321, P=0.0031). The median time to clustering of all tumours and of malignant tumours was 2.92 and 2.32 years, respectively. Risk characteristics associated with clustering included high age and comorbidity. Shared environmental factors among spouses might be linked to a high incidence of cancer clustering. Cancer incidence in one spouse may signal cancer vulnerability in the other spouse. Promoting family-oriented cancer care in vulnerable families and preventing shared lifestyle risk factors for cancer are suggested. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  14. Moderation analysis using a two-level regression model.

    Science.gov (United States)

    Yuan, Ke-Hai; Cheng, Ying; Maxwell, Scott

    2014-10-01

    Moderation analysis is widely used in social and behavioral research. The most commonly used model for moderation analysis is moderated multiple regression (MMR) in which the explanatory variables of the regression model include product terms, and the model is typically estimated by least squares (LS). This paper argues for a two-level regression model in which the regression coefficients of a criterion variable on predictors are further regressed on moderator variables. An algorithm for estimating the parameters of the two-level model by normal-distribution-based maximum likelihood (NML) is developed. Formulas for the standard errors (SEs) of the parameter estimates are provided and studied. Results indicate that, when heteroscedasticity exists, NML with the two-level model gives more efficient and more accurate parameter estimates than the LS analysis of the MMR model. When error variances are homoscedastic, NML with the two-level model leads to essentially the same results as LS with the MMR model. Most importantly, the two-level regression model permits estimating the percentage of variance of each regression coefficient that is due to moderator variables. When applied to data from General Social Surveys 1991, NML with the two-level model identified a significant moderation effect of race on the regression of job prestige on years of education while LS with the MMR model did not. An R package is also developed and documented to facilitate the application of the two-level model.

  15. Risk Assessment of Nautical Navigational Environment Based on Grey Fixed Weight Cluster

    Directory of Open Access Journals (Sweden)

    Yanfei Tian

    2017-06-01

    Full Text Available In order to set up a mathematical model suitable for nautical navigational environment risk evaluation and systematically master the navigational environment risk characteristics of the Qiongzhou Strait in a quantitative way, a risk assessment model with approach steps is set up based on the grey fixed weight cluster (GFWC. The evaluation index system is structured scientifically through both literature review and expert investigation. The relative weight of each index is designed to be obtained via fuzzy analytic hierarchy process (FAHP; Index membership degree of every grey class is proposed to be achieved by fuzzy statistics (FS to avoid the difficulty of building whiten weight functions. By using the model, nautical navigational environment risk of the Qiongzhou Strait is determined at a “moderate” level according to the principle of maximum membership degree. The comprehensive risk evaluation of the Qiongzhou Strait nautical navigational environment can provide theoretical reference for implementing targeted risk control measures. It shows that the constructed GFWC risk assessment model as well as the presented steps are workable in case of incomplete information. The proposed strategy can excavate the collected experts’ knowledge mathematically, quantify the weight of each index and risk level, and finally lead to a comprehensive risk evaluation result. Besides, the adoptions of probability and statistic theory, fuzzy theory, aiming at solving the bottlenecks in case of uncertainty, will give the model a better adaptability and executability.

  16. Improving cluster-based methods for investigating potential for insect pest species establishment: region-specific risk factors

    Directory of Open Access Journals (Sweden)

    Michael J. Watts

    2011-09-01

    Full Text Available Existing cluster-based methods for investigating insect species assemblages or profiles of a region to indicate the risk of new insect pest invasion have a major limitation in that they assign the same species risk factors to each region in a cluster. Clearly regions assigned to the same cluster have different degrees of similarity with respect to their species profile or assemblage. This study addresses this concern by applying weighting factors to the cluster elements used to calculate regional risk factors, thereby producing region-specific risk factors. Using a database of the global distribution of crop insect pest species, we found that we were able to produce highly differentiated region-specific risk factors for insect pests. We did this by weighting cluster elements by their Euclidean distance from the target region. Using this approach meant that risk weightings were derived that were more realistic, as they were specific to the pest profile or species assemblage of each region. This weighting method provides an improved tool for estimating the potential invasion risk posed by exotic species given that they have an opportunity to establish in a target region.

  17. Cluster-cluster clustering

    International Nuclear Information System (INIS)

    Barnes, J.; Dekel, A.; Efstathiou, G.; Frenk, C.S.; Yale Univ., New Haven, CT; California Univ., Santa Barbara; Cambridge Univ., England; Sussex Univ., Brighton, England)

    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. 30 references

  18. Experimental Hamiltonian identification for controlled two-level systems

    International Nuclear Information System (INIS)

    Schirmer, S.G.; Kolli, A.; Oi, D.K.L.

    2004-01-01

    We present a strategy to empirically determine the internal and control Hamiltonians for an unknown two-level system (black box) subject to various (piecewise constant) control fields when direct readout by measurement is limited to a single, fixed observable

  19. Genomic and Metabolomic Profile Associated to Clustering of Cardio-Metabolic Risk Factors.

    Science.gov (United States)

    Marrachelli, Vannina G; Rentero, Pilar; Mansego, María L; Morales, Jose Manuel; Galan, Inma; Pardo-Tendero, Mercedes; Martinez, Fernando; Martin-Escudero, Juan Carlos; Briongos, Laisa; Chaves, Felipe Javier; Redon, Josep; Monleon, Daniel

    2016-01-01

    To identify metabolomic and genomic markers associated with the presence of clustering of cardiometabolic risk factors (CMRFs) from a general population. One thousand five hundred and two subjects, Caucasian, > 18 years, representative of the general population, were included. Blood pressure measurement, anthropometric parameters and metabolic markers were measured. Subjects were grouped according the number of CMRFs (Group 1: profile was assessed by 1H NMR spectra using a Brucker Advance DRX 600 spectrometer. From the total population, 1217 (mean age 54±19, 50.6% men) with high genotyping call rate were analysed. A differential metabolomic profile, which included products from mitochondrial metabolism, extra mitochondrial metabolism, branched amino acids and fatty acid signals were observed among the three groups. The comparison of metabolomic patterns between subjects of Groups 1 to 3 for each of the genotypes associated to those subjects with three or more CMRFs revealed two SNPs, the rs174577_AA of FADS2 gene and the rs3803_TT of GATA2 transcription factor gene, with minimal or no statistically significant differences. Subjects with and without three or more CMRFs who shared the same genotype and metabolomic profile differed in the pattern of CMRFS cluster. Subjects of Group 3 and the AA genotype of the rs174577 had a lower prevalence of hypertension compared to the CC and CT genotype. In contrast, subjects of Group 3 and the TT genotype of the rs3803 polymorphism had a lower prevalence of T2DM, although they were predominantly males and had higher values of plasma creatinine. The results of the present study add information to the metabolomics profile and to the potential impact of genetic factors on the variants of clustering of cardiometabolic risk factors.

  20. Arterial stiffness and its association with clustering of metabolic syndrome risk factors

    Directory of Open Access Journals (Sweden)

    Wanda R. P. Lopes-Vicente

    2017-10-01

    Full Text Available Abstract Background Metabolic syndrome (MetS is associated with structural and functional vascular abnormalities, which may lead to increased arterial stiffness, more frequent cardiovascular events and higher mortality. However, the role played by clustering of risk factors and the combining pattern of MetS risk factors and their association with the arterial stiffness have yet to be fully understood. Age, hypertension and diabetes mellitus seem to be strongly associated with increased pulse wave velocity (PWV. This study aimed at determining the clustering and combining pattern of MetS risk factors and their association with the arterial stiffness in non-diabetic and non-hypertensive patients. Methods Recently diagnosed and untreated patients with MetS (n = 64, 49 ± 8 year, 32 ± 4 kg/m2 were selected, according to ATP III criteria and compared to a control group (Control, n = 17, 49 ± 6 year, 27 ± 2 kg/m2. Arterial stiffness was evaluated by PWV in the carotid-femoral segment. Patients were categorized and analyzed according MetS risk factors clustering (3, 4 and 5 factors and its combinations. Results Patients with MetS had increased PWV when compared to Control (7.8 ± 1.1 vs. 7.0 ± 0.5 m/s, p < 0.001. In multivariate analysis, the variables that remained as predictors of PWV were age (β = 0.450, p < 0.001, systolic blood pressure (β = 0.211, p = 0.023 and triglycerides (β = 0.212, p = 0.037. The increased number of risk factors reflected in a progressive increase in PWV. When adjusted to systolic blood pressure, PWV was greater in the group with 5 risk factors when compared to the group with 3 risk factors and Control (8.5 ± 0.4 vs. 7.5 ± 0.2, p = 0.011 and 7.2 ± 0.3 m/s, p = 0.012. Similarly, the 4 risk factors group had higher PWV than the Control (7.9 ± 0.2 vs. 7.2 ± 0.3, p = 0.047. Conclusions The number of risk factors seems to increase arterial stiffness. Notably, besides

  1. Clustering of Major Cardiovascular Risk Factors and the Association with Unhealthy Lifestyles in the Chinese Adult Population.

    Directory of Open Access Journals (Sweden)

    Bixia Gao

    Full Text Available Previous studies indicated that lifestyle-related cardiovascular risk factors tend to be clustered in certain individuals. However, population-based studies, especially from developing countries with substantial economic heterogeneity, are extremely limited. Our study provides updated data on the clustering of cardiovascular risk factors, as well as the impact of lifestyle on those factors in China.A representative sample of adult population in China was obtained using a multistage, stratified sampling method. We investigated the clustering of four cardiovascular disease (CVD risk factors (defined as two or more of the following: hypertension, diabetes, dyslipidemia and overweight and their association with unhealthy lifestyles (habitual drinking, physical inactivity, chronic use of non-steroidal anti-inflammatory drugs (NSAIDs and a low modified Dietary Approaches to Stop Hypertension (DASH score.Among the 46,683 participants enrolled in this study, only 31.1% were free of any pre-defined CVD risk factor. A total of 20,292 subjects had clustering of CVD risk factors, and 83.5% of them were younger than 65 years old. The adjusted prevalence of CVD risk factor clustering was 36.2%, and the prevalence was higher among males than among females (37.9% vs. 34.5%. Habitual drinking, physical inactivity, and chronic use of NSAIDs were positively associated with the clustering of CVD risk factors, with ORs of 1.60 (95% confidence interval [CI] 1.40 to1.85, 1.20 (95%CI 1.11 to 1.30 and 2.17 (95%CI 1.84 to 2.55, respectively. The modified DASH score was inversely associated with the clustering of CVD risk factors, with an OR of 0.73 (95%CI 0.67 to 0.78 for those with modified DASH scores in the top tertile. The lifestyle risk factors were more prominent among participants with low socioeconomic status.Clustering of CVD risk factors was common in China. Lifestyle modification might be an effective strategy to control CVD risk factors.

  2. The geometric phase in two-level atomic systems

    International Nuclear Information System (INIS)

    Tian Mingzhen; Barber, Zeb W.; Fischer, Joe A.; Randall Babbitt, Wm.

    2004-01-01

    We report the observation of the geometric phase in a closed two-level atomic system using stimulated photon echoes. The two-level system studied consists of the two-electronic energy levels ( 3 H 4 and 3 H 6 ) of Tm 3+ doped in YAG crystal. When a two-level atom at an arbitrary superposition state is excited by a pair of specially designed laser pulses, the excited state component gains a relative phase with respect to the ground state component. We identified the phase shift to be of pure geometric nature. The dynamic phase associated to the driving Hamiltonian is unchanged. The experiment results of the phase change agree with the theory to the extent of the measurement limit

  3. Cohort study on clustering of lifestyle risk factors and understanding its association with stress on health and wellbeing among school teachers in Malaysia (CLUSTer)--a study protocol.

    Science.gov (United States)

    Moy, Foong Ming; Hoe, Victor Chee Wai; Hairi, Noran Naqiah; Buckley, Brian; Wark, Petra A; Koh, David; Bueno-de-Mesquita, H Bas; Bulgiba, Awang M

    2014-06-17

    The study on Clustering of Lifestyle risk factors and Understanding its association with Stress on health and wellbeing among school Teachers in Malaysia (CLUSTer) is a prospective cohort study which aims to extensively study teachers in Malaysia with respect to clustering of lifestyle risk factors and stress, and subsequently, to follow-up the population for important health outcomes. This study is being conducted in six states within Peninsular Malaysia. From each state, schools from each district are randomly selected and invited to participate in the study. Once the schools agree to participate, all teachers who fulfilled the inclusion criteria are invited to participate. Data collection includes a questionnaire survey and health assessment. Information collected in the questionnaire includes socio-demographic characteristics, participants' medical history and family history of chronic diseases, teaching characteristics and burden, questions on smoking, alcohol consumption and physical activities (IPAQ); a food frequency questionnaire, the job content questionnaire (JCQ); depression, anxiety and stress scale (DASS21); health related quality of life (SF12-V2); Voice Handicap Index 10 on voice disorder, questions on chronic pain, sleep duration and obstetric history for female participants. Following blood drawn for predefined clinical tests, additional blood and urine specimens are collected and stored for future analysis. Active follow up of exposure and health outcomes will be carried out every two years via telephone or face to face contact. Data collection started in March 2013 and as of the end of March 2014 has been completed for four states: Kuala Lumpur, Selangor, Melaka and Penang. Approximately 6580 participants have been recruited. The first round of data collection and blood sampling is expected to be completed by the end of 2014 with an expected 10,000 participants recruited. Our study will provide a good basis for exploring the clustering of

  4. Resting Heart Rate Is Not a Good Predictor of a Clustered Cardiovascular Risk Score in Adolescents: The HELENA Study.

    Directory of Open Access Journals (Sweden)

    Augusto César Ferreira de Moraes

    Full Text Available Resting heart rate (RHR reflects sympathetic nerve activity a significant association between RHR and all-cause and cardiovascular mortality has been reported in some epidemiologic studies.To analyze the predictive power and accuracy of RHR as a screening measure for individual and clustered cardiovascular risk in adolescents. The study comprised 769 European adolescents (376 boys participating in the HELENA cross-sectional study (2006-2008 were included in this study. Measurements on systolic blood pressure, HOMA index, triglycerides, TC/HDL-c, VO2máx and the sum of four skinfolds were obtained, and a clustered cardiovascular disease (CVD risk index was computed. The receiver operating characteristics curve was applied to calculate the power and accuracy of RHR to predict individual and clustered CVD risk factors.RHR showed low accuracy for screening CVD risk factors in both sexes (range 38.5%-54.4% in boys and 45.5%-54.3% in girls. Low specificity's (15.6%-19.7% in boys; 18.1%-20.0% in girls were also found. Nevertheless, the sensitivities were moderate-to-high (61.4%-89.1% in boys; 72.9%-90.3% in girls.RHR is a poor predictor of individual CVD risk factors and of clustered CVD and the estimates based on RHR are not accurate. The use of RHR as an indicator of CVD risk in adolescents may produce a biased screening of cardiovascular health in both sexes.

  5. Two-level convolution formula for nuclear structure function

    Science.gov (United States)

    Ma, Boqiang

    1990-05-01

    A two-level convolution formula for the nuclear structure function is derived in considering the nucleus as a composite system of baryon-mesons which are also composite systems of quark-gluons again. The results show that the European Muon Colaboration effect can not be explained by the nuclear effects as nucleon Fermi motion and nuclear binding contributions.

  6. Two-level convolution formula for nuclear structure function

    International Nuclear Information System (INIS)

    Ma Boqiang

    1990-01-01

    A two-level convolution formula for the nuclear structure function is derived in considering the nucleus as a composite system of baryon-mesons which are also composite systems of quark-gluons again. The results show that the European Muon Colaboration effect can not be explained by the nuclear effects as nucleon Fermi motion and nuclear binding contributions

  7. Stationary states of two-level open quantum systems

    International Nuclear Information System (INIS)

    Gardas, Bartlomiej; Puchala, Zbigniew

    2011-01-01

    A problem of finding stationary states of open quantum systems is addressed. We focus our attention on a generic type of open system: a qubit coupled to its environment. We apply the theory of block operator matrices and find stationary states of two-level open quantum systems under certain conditions applied on both the qubit and the surrounding.

  8. Cardiovascular disease risk factor clustering among rural adult population in West Bengal, India.

    Science.gov (United States)

    Nag, Tanmay; Ghosh, Arnab

    2016-01-01

    This study aimed to find out the prevalence of cardiovascular disease (CVD) risk factor clustering in a rural adult population of West Bengal, India. This cross-sectional study was carried out among 1007 participants (645 males and 362 females) aged ≥20 years in a rural community. All participants were grouped: Group I (20-39 years); Group II (40-59 years); Group III (≥60 years). Anthropometric measures were collected using standard techniques. Metabolic profiles and blood pressure were also measured. Mean of minimum waist circumference (MWC), waist-hip ratio (WHR), trunk-extremity ratio (TER), fat free mass (FFM), basal metabolic rate (BMR), intra-abdominal visceral fat (IVF) and arm muscle area (AMA) was found to be higher among males in comparison to females, whereas, the mean of body mass index (BMI), maximum hip circumference (MHC), waist-height ratio (WHtR), sum of four skinfolds (∑SF4), percentage of body fat (%BF), fat mass (FM), insulin, HOMA-IR and arm fat area (AFA) was higher in females. 37% of individuals (males 25% and females 49%) with high triglyceride (TG) also had low high density lipoprotein (HDL), whereas, 25% individuals (males 25% and females 24%) with overweight also had high fasting blood glucose (FBG). The prevalence of high systolic blood pressure (SBP) among individuals having high %BF was higher in the age groups of 40-59 years for both sexes. The study showed that prevalence of CVD risk factor clustering is high in the study population and warranted early intervention to safeguard the cardiovascular health of the nation. Copyright © 2015 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

  9. Neck circumference and clustered cardiovascular risk factors in children and adolescents: cross-sectional study.

    Science.gov (United States)

    Castro-Piñero, José; Delgado-Alfonso, Alvaro; Gracia-Marco, Luis; Gómez-Martínez, Sonia; Esteban-Cornejo, Irene; Veiga, Oscar L; Marcos, Ascensión; Segura-Jiménez, Víctor

    2017-09-11

    Early detection of cardiovascular disease (CVD) risk factors, such as obesity, is crucial to prevent adverse long-term effects on individuals' health. Therefore, the aims were: (1) to explore the robustness of neck circumference (NC) as a predictor of CVD and examine its association with numerous anthropometric and body composition indices and (2) to release sex and age-specific NC cut-off values to classify youths as overweight/obese. Cross-sectional study. 23 primary schools and 17 secondary schools from Spain. 2198 students (1060 girls), grades 1-4 and 7-10. Pubertal development, anthropometric and body composition indices, systolic and diastolic blood pressure (SBP and DBP, respectively), cardiorespiratory fitness, blood sampling triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), glucose and inflammatory markers. Homoeostasis model assessment (HOMA-IR) and cluster of CVD risk factors were calculated. NC was negatively associated with maximum oxygen consumption (R2=0.231, P<0.001 for boys; R2=0.018, P<0.001 for girls) and adiponectin (R2=0.049, P<0.001 for boys; R2=0.036, P<0.001 for girls); and positively associated with SBP, DBP, TC/HDL-c, TG, HOMA, complement factors C-3 and C-4, leptin and clustered CVD risk factor in both sexes (R2 from 0.035 to 0.353, P<0.01 for boys; R2 from 0.024 to 0.215, P<0.001 for girls). Moreover, NC was positively associated with serum C reactive protein and LDL-c only in boys (R2 from 0.013 to 0.055, P<0.05). NC is a simple, low-cost and practical screening tool of excess of upper body obesity and CVD risk factors in children and adolescents. Paediatricians can easily use it as a screening tool for overweight/obesity in children and adolescents. For this purpose, sex and age-specific thresholds to classify children and adolescents as normal weight or overweight/obese are provided. © Article author(s) (or their employer(s) unless otherwise stated

  10. Supplier Risk Assessment Based on Best-Worst Method and K-Means Clustering: A Case Study

    Directory of Open Access Journals (Sweden)

    Merve Er Kara

    2018-04-01

    Full Text Available Supplier evaluation and selection is one of the most critical strategic decisions for developing a competitive and sustainable organization. Companies have to consider supplier related risks and threats in their purchasing decisions. In today’s competitive and risky business environment, it is very important to work with reliable suppliers. This study proposes a clustering based approach to group suppliers based on their risk profile. Suppliers of a company in the heavy-machinery sector are assessed based on 17 qualitative and quantitative risk types. The weights of the criteria are determined by using the Best-Worst method. Four factors are extracted by applying Factor Analysis to the supplier risk data. Then k-means clustering algorithm is applied to group core suppliers of the company based on the four risk factors. Three clusters are created with different risk exposure levels. The interpretation of the results provides insights for risk management actions and supplier development programs to mitigate supplier risk.

  11. Memory Effects in the Two-Level Model for Glasses

    Science.gov (United States)

    Aquino, Gerardo; Allahverdyan, Armen; Nieuwenhuizen, Theo M.

    2008-07-01

    We study an ensemble of two-level systems interacting with a thermal bath. This is a well-known model for glasses. The origin of memory effects in this model is a quasistationary but nonequilibrium state of a single two-level system, which is realized due to a finite-rate cooling and slow thermally activated relaxation. We show that single-particle memory effects, such as negativity of the specific heat under reheating, vanish for a sufficiently disordered ensemble. In contrast, a disordered ensemble displays a collective memory effect [similar to the Kovacs effect], where nonequilibrium features of the ensemble are monitored via a macroscopic observable. An experimental realization of the effect can be used to further assess the consistency of the model.

  12. Two-level method with coarse space size independent convergence

    Energy Technology Data Exchange (ETDEWEB)

    Vanek, P.; Brezina, M. [Univ. of Colorado, Denver, CO (United States); Tezaur, R.; Krizkova, J. [UWB, Plzen (Czech Republic)

    1996-12-31

    The basic disadvantage of the standard two-level method is the strong dependence of its convergence rate on the size of the coarse-level problem. In order to obtain the optimal convergence result, one is limited to using a coarse space which is only a few times smaller than the size of the fine-level one. Consequently, the asymptotic cost of the resulting method is the same as in the case of using a coarse-level solver for the original problem. Today`s two-level domain decomposition methods typically offer an improvement by yielding a rate of convergence which depends on the ratio of fine and coarse level only polylogarithmically. However, these methods require the use of local subdomain solvers for which straightforward application of iterative methods is problematic, while the usual application of direct solvers is expensive. We suggest a method diminishing significantly these difficulties.

  13. Risk factors and clusters of Highly Pathogenic Avian Influenza H5N1 outbreaks in Bangladesh

    Science.gov (United States)

    Loth, Leo; Gilbert, Marius; Osmani, Mozaffar G.; Kalam, Abul M.; Xiao, Xiangming

    2016-01-01

    Between March 2007 and July 2009, 325 Highly Pathogenic Avian Influenza (HPAI, subtype H5N1) outbreaks in poultry were reported in 154 out of a total of 486 sub-districts in Bangladesh. This study analyzed the temporal and spatial patterns of HPAI H5N1 outbreaks and quantified the relationship between several spatial risk factors and HPAI outbreaks in sub-districts in Bangladesh. We assessed spatial autocorrelation and spatial dependence, and identified clustering sub-districts with disease statistically similar to or dissimilar from their neighbors. Three significant risk factors associated to HPAI H5N1 virus outbreaks were identified; the quadratic log-transformation of human population density [humans per square kilometer, P = 0.01, OR 1.15 (95% CI: 1.03–1.28)], the log-transformation of the total commercial poultry population [number of commercial poultry per sub-district, P Bangladesh to target surveillance and to concentrate response efforts in areas where disease is likely to occur. Concentrating response efforts may help to combat HPAI more effectively, reducing the environmental viral load and so reducing the number of disease incidents. PMID:20554337

  14. Franson Interference Generated by a Two-Level System

    Science.gov (United States)

    Peiris, M.; Konthasinghe, K.; Muller, A.

    2017-01-01

    We report a Franson interferometry experiment based on correlated photon pairs generated via frequency-filtered scattered light from a near-resonantly driven two-level semiconductor quantum dot. In contrast to spontaneous parametric down-conversion and four-wave mixing, this approach can produce single pairs of correlated photons. We have measured a Franson visibility as high as 66%, which goes beyond the classical limit of 50% and approaches the limit of violation of Bell's inequalities (70.7%).

  15. Mixing phases of unstable two-level systems

    International Nuclear Information System (INIS)

    Sokolov, V.V.; Brentano, P. von.

    1993-01-01

    An unstable two-level system decaying into an arbitrary number of channels is considered. It is shown that the mixing phases of the two overlapping resonances can be expressed in the terms of their partial widths and one additional universal mixing parameter. Some applications to a doublet of 2 + resonances in 8 Be and to the ρ-ω systems are considered. 18 refs

  16. Two-level systems driven by large-amplitude fields

    Science.gov (United States)

    Nori, F.; Ashhab, S.; Johansson, J. R.; Zagoskin, A. M.

    2009-03-01

    We analyze the dynamics of a two-level system subject to driving by large-amplitude external fields, focusing on the resonance properties in the case of driving around the region of avoided level crossing. In particular, we consider three main questions that characterize resonance dynamics: (1) the resonance condition, (2) the frequency of the resulting oscillations on resonance, and (3) the width of the resonance. We identify the regions of validity of different approximations. In a large region of the parameter space, we use a geometric picture in order to obtain both a simple understanding of the dynamics and quantitative results. The geometric approach is obtained by dividing the evolution into discrete time steps, with each time step described by either a phase shift on the basis states or a coherent mixing process corresponding to a Landau-Zener crossing. We compare the results of the geometric picture with those of a rotating wave approximation. We also comment briefly on the prospects of employing strong driving as a useful tool to manipulate two-level systems. S. Ashhab, J.R. Johansson, A.M. Zagoskin, F. Nori, Two-level systems driven by large-amplitude fields, Phys. Rev. A 75, 063414 (2007). S. Ashhab et al, unpublished.

  17. Clustering of health and risk behaviour in immigrant and indigenous Dutch residents aged 19–40 years

    NARCIS (Netherlands)

    Reijneveld, S.A.; Nieuwenhuijzen, M. van; Klein Velderman, M.; Paulussen, T.W.G.M.; Junger, M.

    2012-01-01

    Objectives Studies on the co-occurrence, ‘clustering’ of health and other risk behaviours among immigrants from non-industrialised countries lack until now. The aim of this study was to compare this clustering in immigrant and indigenous adults. Methods A representative sample (N = 2,982; response

  18. Malaria prevalence, spatial clustering and risk factors in a low endemic area of Eastern Rwanda: a cross sectional study

    NARCIS (Netherlands)

    Rulisa, Stephen; Kateera, Fredrick; Bizimana, Jean Pierre; Agaba, Steven; Dukuzumuremyi, Javier; Baas, Lisette; de Dieu Harelimana, Jean; Mens, Petra F.; Boer, Kimberly R.; de Vries, Peter J.

    2013-01-01

    Rwanda reported significant reductions in malaria burden following scale up of control intervention from 2005 to 2010. This study sought to; measure malaria prevalence, describe spatial malaria clustering and investigate for malaria risk factors among health-centre-presumed malaria cases and their

  19. Detection of major climatic and environmental predictors of liver fluke exposure risk in Ireland using spatial cluster analysis.

    Science.gov (United States)

    Selemetas, Nikolaos; de Waal, Theo

    2015-04-30

    Fasciolosis caused by Fasciola hepatica (liver fluke) can cause significant economic and production losses in dairy cow farms. The aim of the current study was to identify important weather and environmental predictors of the exposure risk to liver fluke by detecting clusters of fasciolosis in Ireland. During autumn 2012, bulk-tank milk samples from 4365 dairy farms were collected throughout Ireland. Using an in-house antibody-detection ELISA, the analysis of BTM samples showed that 83% (n=3602) of dairy farms had been exposed to liver fluke. The Getis-Ord Gi* statistic identified 74 high-risk and 130 low-risk significant (Pclimatic variables (monthly and seasonal mean rainfall and temperatures, total wet days and rain days) and environmental datasets (soil types, enhanced vegetation index and normalised difference vegetation index) were used to investigate dissimilarities in the exposure to liver fluke between clusters. Rainfall, total wet days and rain days, and soil type were the significant classes of climatic and environmental variables explaining the differences between significant clusters. A discriminant function analysis was used to predict the exposure risk to liver fluke using 80% of data for modelling and the remaining subset of 20% for post hoc model validation. The most significant predictors of the model risk function were total rainfall in August and September and total wet days. The risk model presented 100% sensitivity and 91% specificity and an accuracy of 95% correctly classified cases. A risk map of exposure to liver fluke was constructed with higher probability of exposure in western and north-western regions. The results of this study identified differences between clusters of fasciolosis in Ireland regarding climatic and environmental variables and detected significant predictors of the exposure risk to liver fluke. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. The relationship between physical fitness and clustered risk, and tracking of clustered risk from adolescence to young adulthood: eight years follow-up in the Danish Youth and Sport Study

    Directory of Open Access Journals (Sweden)

    Grønfeldt Vivian

    2004-03-01

    Full Text Available Abstract Introduction Cardiovascular disease (CVD is usually caused by high levels of many risk factors simultaneously over many years. Therefore, it is of great interest to study if subjects stay within rank order over time in both the biological risk factors and the behaviour that influences these risk factors. Many studies have described stability (tracking in single risk factors, especially in children where hard endpoints are lacking, but few have analysed tracking in clustered risk. Methods Two examinations were conducted 8 years apart. The first time, 133 males and 172 females were 16–19 years of age. Eight years later, 98 males and 137 females participated. They were each time ranked into quartiles by sex in four CVD risk factors all related to the metabolic syndrome. Risk factors were the ratio between total cholesterol and HDL, triglyceride, systolic BP and body fat. The upper quartile was defined as being at risk, and if a subject had two or more risk factors, he/she was defined as a case (15–20 % of the subjects. Odds ratios (OR for being a case was calculated between quartiles of fitness in both cross-sectional studies. The stability of combined risk was calculated as the OR between cases and non-cases at the first examination to be a case at the second examination. Results ORs for having two or more risk factors between quartiles of fitness were 3.1, 3.8 and 4.9 for quartiles two to four, respectively. At the second examination, OR were 0.7, 3.5 and 4.9, respectively. The probability for "a case" at the first examination to be "a case" at the second was 6.0. Conclusions The relationship between an exposure like physical fitness and CVD risk factors is much stronger when clustering of risk factors are analysed compared to the relationship to single risk factors. The stability over time in multiple risk factors analysed together is strong. This relationship should be seen in the light of moderate or weak tracking of single risk

  1. Risk Factors and Spatial Clusters of Cryptosporidium Infection among School-Age Children in a Rural Region of Eastern China.

    Science.gov (United States)

    Zheng, Hao; He, Jianfeng; Wang, Li; Zhang, Rong; Ding, Zhen; Hu, Wenbiao

    2018-05-06

    The epidemiological features of Cryptosporidium infection among school-age children in China still remain unclear. Hereby, a cross-sectional study of 1637 children aged 3⁻9 years was designed to investigate the risk factors and spatial clusters of Cryptosporidium infection in a rural region of Eastern China. Stool specimens collected from participants were examined using the auramine-phenol and modified acid-fast staining. Univariable and multivariable analyses were performed to identify the risk factors of Cryptospordium infection. The spatial clusters were analyzed by a discrete Poisson model using SaTScan software. Our results showed that the overall prevalence of Cryptosporidium infection was 11‰ in the research region. At the age of 3⁻6 years (odds ratios (OR) = 3.072, 95% confidence intervals (CI) : 1.001⁻9.427), not washing hands before eating and after defecation (OR = 3.003, 95% CI: 1.060⁻8.511) were recognized as risk factors. Furthermore, a high-risk spatial cluster (relative risk = 4.220, p = 0.025) was identified. These findings call for effective sustainable interventions including family and school-based hygienic education to reduce the prevalence of Cryptosporidium infection. Therefore, an early warning system based spatiotemporal models with risk factors is required to further improve the effectiveness and efficiency of cryptosporidiosis control in the future.

  2. Perturbation Theory for Open Two-Level Nonlinear Quantum Systems

    International Nuclear Information System (INIS)

    Zhang Zhijie; Jiang Dongguang; Wang Wei

    2011-01-01

    Perturbation theory is an important tool in quantum mechanics. In this paper, we extend the traditional perturbation theory to open nonlinear two-level systems, treating decoherence parameter γ as a perturbation. By this virtue, we give a perturbative solution to the master equation, which describes a nonlinear open quantum system. The results show that for small decoherence rate γ, the ratio of the nonlinear rate C to the tunneling coefficient V (i.e., r = C/V) determines the validity of the perturbation theory. For small ratio r, the perturbation theory is valid, otherwise it yields wrong results. (general)

  3. Modal intersection types, two-level languages, and staged synthesis

    DEFF Research Database (Denmark)

    Henglein, Fritz; Rehof, Jakob

    2016-01-01

    -linguistic framework for staged program synthesis, where metaprograms are automatically synthesized which, when executed, generate code in a target language. We survey the basic theory of staged synthesis and illustrate by example how a two-level language theory specialized from λ∩ ⎕ can be used to understand......A typed λ-calculus, λ∩ ⎕, is introduced, combining intersection types and modal types. We develop the metatheory of λ∩ ⎕, with particular emphasis on the theory of subtyping and distributivity of the modal and intersection type operators. We describe how a stratification of λ∩ ⎕ leads to a multi...... the process of staged synthesis....

  4. Cohort study on clustering of lifestyle risk factors and understanding its association with stress on health and wellbeing among school teachers in Malaysia (CLUSTer) – a study protocol

    Science.gov (United States)

    2014-01-01

    Background The study on Clustering of Lifestyle risk factors and Understanding its association with Stress on health and wellbeing among school Teachers in Malaysia (CLUSTer) is a prospective cohort study which aims to extensively study teachers in Malaysia with respect to clustering of lifestyle risk factors and stress, and subsequently, to follow-up the population for important health outcomes. Method/design This study is being conducted in six states within Peninsular Malaysia. From each state, schools from each district are randomly selected and invited to participate in the study. Once the schools agree to participate, all teachers who fulfilled the inclusion criteria are invited to participate. Data collection includes a questionnaire survey and health assessment. Information collected in the questionnaire includes socio-demographic characteristics, participants’ medical history and family history of chronic diseases, teaching characteristics and burden, questions on smoking, alcohol consumption and physical activities (IPAQ); a food frequency questionnaire, the job content questionnaire (JCQ); depression, anxiety and stress scale (DASS21); health related quality of life (SF12-V2); Voice Handicap Index 10 on voice disorder, questions on chronic pain, sleep duration and obstetric history for female participants. Following blood drawn for predefined clinical tests, additional blood and urine specimens are collected and stored for future analysis. Active follow up of exposure and health outcomes will be carried out every two years via telephone or face to face contact. Data collection started in March 2013 and as of the end of March 2014 has been completed for four states: Kuala Lumpur, Selangor, Melaka and Penang. Approximately 6580 participants have been recruited. The first round of data collection and blood sampling is expected to be completed by the end of 2014 with an expected 10,000 participants recruited. Discussion Our study will provide a good basis

  5. Cluster analysis to estimate the risk of preeclampsia in the high-risk Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction (PREDO) study

    Science.gov (United States)

    Marttinen, Pekka; Gillberg, Jussi; Lokki, A. Inkeri; Majander, Kerttu; Ordén, Maija-Riitta; Taipale, Pekka; Pesonen, Anukatriina; Räikkönen, Katri; Hämäläinen, Esa; Kajantie, Eero; Laivuori, Hannele

    2017-01-01

    Objectives Preeclampsia is divided into early-onset (delivery before 34 weeks of gestation) and late-onset (delivery at or after 34 weeks) subtypes, which may rise from different etiopathogenic backgrounds. Early-onset disease is associated with placental dysfunction. Late-onset disease develops predominantly due to metabolic disturbances, obesity, diabetes, lipid dysfunction, and inflammation, which affect endothelial function. Our aim was to use cluster analysis to investigate clinical factors predicting the onset and severity of preeclampsia in a cohort of women with known clinical risk factors. Methods We recruited 903 pregnant women with risk factors for preeclampsia at gestational weeks 12+0–13+6. Each individual outcome diagnosis was independently verified from medical records. We applied a Bayesian clustering algorithm to classify the study participants to clusters based on their particular risk factor combination. For each cluster, we computed the risk ratio of each disease outcome, relative to the risk in the general population. Results The risk of preeclampsia increased exponentially with respect to the number of risk factors. Our analysis revealed 25 number of clusters. Preeclampsia in a previous pregnancy (n = 138) increased the risk of preeclampsia 8.1 fold (95% confidence interval (CI) 5.7–11.2) compared to a general population of pregnant women. Having a small for gestational age infant (n = 57) in a previous pregnancy increased the risk of early-onset preeclampsia 17.5 fold (95%CI 2.1–60.5). Cluster of those two risk factors together (n = 21) increased the risk of severe preeclampsia to 23.8-fold (95%CI 5.1–60.6), intermediate onset (delivery between 34+0–36+6 weeks of gestation) to 25.1-fold (95%CI 3.1–79.9) and preterm preeclampsia (delivery before 37+0 weeks of gestation) to 16.4-fold (95%CI 2.0–52.4). Body mass index over 30 kg/m2 (n = 228) as a sole risk factor increased the risk of preeclampsia to 2.1-fold (95%CI 1.1–3

  6. Clustering of metabolic and cardiovascular risk factors in the polycystic ovary syndrome: a principal component analysis.

    Science.gov (United States)

    Stuckey, Bronwyn G A; Opie, Nicole; Cussons, Andrea J; Watts, Gerald F; Burke, Valerie

    2014-08-01

    Polycystic ovary syndrome (PCOS) is a prevalent condition with heterogeneity of clinical features and cardiovascular risk factors that implies multiple aetiological factors and possible outcomes. To reduce a set of correlated variables to a smaller number of uncorrelated and interpretable factors that may delineate subgroups within PCOS or suggest pathogenetic mechanisms. We used principal component analysis (PCA) to examine the endocrine and cardiometabolic variables associated with PCOS defined by the National Institutes of Health (NIH) criteria. Data were retrieved from the database of a single clinical endocrinologist. We included women with PCOS (N = 378) who were not taking the oral contraceptive pill or other sex hormones, lipid lowering medication, metformin or other medication that could influence the variables of interest. PCA was performed retaining those factors with eigenvalues of at least 1.0. Varimax rotation was used to produce interpretable factors. We identified three principal components. In component 1, the dominant variables were homeostatic model assessment (HOMA) index, body mass index (BMI), high density lipoprotein (HDL) cholesterol and sex hormone binding globulin (SHBG); in component 2, systolic blood pressure, low density lipoprotein (LDL) cholesterol and triglycerides; in component 3, total testosterone and LH/FSH ratio. These components explained 37%, 13% and 11% of the variance in the PCOS cohort respectively. Multiple correlated variables from patients with PCOS can be reduced to three uncorrelated components characterised by insulin resistance, dyslipidaemia/hypertension or hyperandrogenaemia. Clustering of risk factors is consistent with different pathogenetic pathways within PCOS and/or differing cardiometabolic outcomes. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Two-level schemes for the advection equation

    Science.gov (United States)

    Vabishchevich, Petr N.

    2018-06-01

    The advection equation is the basis for mathematical models of continuum mechanics. In the approximate solution of nonstationary problems it is necessary to inherit main properties of the conservatism and monotonicity of the solution. In this paper, the advection equation is written in the symmetric form, where the advection operator is the half-sum of advection operators in conservative (divergent) and non-conservative (characteristic) forms. The advection operator is skew-symmetric. Standard finite element approximations in space are used. The standard explicit two-level scheme for the advection equation is absolutely unstable. New conditionally stable regularized schemes are constructed, on the basis of the general theory of stability (well-posedness) of operator-difference schemes, the stability conditions of the explicit Lax-Wendroff scheme are established. Unconditionally stable and conservative schemes are implicit schemes of the second (Crank-Nicolson scheme) and fourth order. The conditionally stable implicit Lax-Wendroff scheme is constructed. The accuracy of the investigated explicit and implicit two-level schemes for an approximate solution of the advection equation is illustrated by the numerical results of a model two-dimensional problem.

  8. Two-level systems driven by large-amplitude fields

    International Nuclear Information System (INIS)

    Ashhab, S.; Johansson, J. R.; Zagoskin, A. M.; Nori, Franco

    2007-01-01

    We analyze the dynamics of a two-level system subject to driving by large-amplitude external fields, focusing on the resonance properties in the case of driving around the region of avoided level crossing. In particular, we consider three main questions that characterize resonance dynamics: (1) the resonance condition (2) the frequency of the resulting oscillations on resonance, and (3) the width of the resonance. We identify the regions of validity of different approximations. In a large region of the parameter space, we use a geometric picture in order to obtain both a simple understanding of the dynamics and quantitative results. The geometric approach is obtained by dividing the evolution into discrete time steps, with each time step described by either a phase shift on the basis states or a coherent mixing process corresponding to a Landau-Zener crossing. We compare the results of the geometric picture with those of a rotating wave approximation. We also comment briefly on the prospects of employing strong driving as a useful tool to manipulate two-level systems

  9. Effect of Cardio-Metabolic Risk Factors Clustering with or without Arterial Hypertension on Arterial Stiffness: A Narrative Review

    Directory of Open Access Journals (Sweden)

    Vasilios G. Athyros

    2013-11-01

    Full Text Available The clustering of cardio-metabolic risk factors, either when called metabolic syndrome (MetS or not, substantially increases the risk of cardiovascular disease (CVD and causes mortality. One of the possible mechanisms for this clustering's adverse effect is an increase in arterial stiffness (AS, and in high central aortic blood pressure (CABP, which are significant and independent CVD risk factors. Arterial hypertension was connected to AS long ago; however, other MetS components (obesity, dyslipidaemia, dysglycaemia or MetS associated abnormalities not included in MetS diagnostic criteria (renal dysfunction, hyperuricaemia, hypercoaglutability, menopause, non alcoholic fatty liver disease, and obstructive sleep apnea have been implicated too. We discuss the evidence connecting these cardio-metabolic risk factors, which negatively affect AS and finally increase CVD risk. Furthermore, we discuss the impact of possible lifestyle and pharmacological interventions on all these cardio-metabolic risk factors, in an effort to reduce CVD risk and identify features that should be taken into consideration when treating MetS patients with or without arterial hypertension.

  10. Atomistic study of two-level systems in amorphous silica

    Science.gov (United States)

    Damart, T.; Rodney, D.

    2018-01-01

    Internal friction is analyzed in an atomic-scale model of amorphous silica. The potential energy landscape of more than 100 glasses is explored to identify a sample of about 700 two-level systems (TLSs). We discuss the properties of TLSs, particularly their energy asymmetry and barrier as well as their deformation potential, computed as longitudinal and transverse averages of the full deformation potential tensors. The discrete sampling is used to predict dissipation in the classical regime. Comparison with experimental data shows a better agreement with poorly relaxed thin films than well relaxed vitreous silica, as expected from the large quench rates used to produce numerical glasses. The TLSs are categorized in three types that are shown to affect dissipation in different temperature ranges. The sampling is also used to discuss critically the usual approximations employed in the literature to represent the statistical properties of TLSs.

  11. Two-level modelling of real estate taxtation

    DEFF Research Database (Denmark)

    Gall, Jaroslav; Stubkjær, Erik

    2006-01-01

    Real estate taxes recurrently attract attention, because they are a source of potentially increased revenue for local and national government. Most experts agree that it is necessary to switch from using normative values for taxation to a market-value-based taxation of real property with computer......-assisted mass valuation, witch benefit from use of value maps. In Czech Republic, efforts have been made to adopt current tax policy goals, but improvements are still needed. The paper aims at supporting the current improvement process towards a market based system. It presents models, which describe aspects...... of the present Czech property tax system. A proposal for the future system focuses on the value map component. The described change depends on political involvement. This political activity is modelled as well. The hypothesis is that the two-level modelling effort enhances the change process by providing...

  12. Cluster analysis of fasciolosis in dairy cow herds in Munster province of Ireland and detection of major climatic and environmental predictors of the exposure risk.

    Science.gov (United States)

    Selemetas, Nikolaos; Phelan, Paul; O'Kiely, Padraig; de Waal, Theo

    2015-03-19

    Fasciolosis caused by Fasciola hepatica is a widespread parasitic disease in cattle farms. The aim of this study was to detect clusters of fasciolosis in dairy cow herds in Munster Province, Ireland and to identify significant climatic and environmental predictors of the exposure risk. In total, 1,292 dairy herds across Munster was sampled in September 2012 providing a single bulk tank milk (BTM) sample. The analysis of samples by an in-house antibody-detection enzyme-linked immunosorbent assay (ELISA), showed that 65% of the dairy herds (n = 842) had been exposed to F. hepatica. Using the Getis-Ord Gi* statistic, 16 high-risk and 24 low-risk (P <0.01) clusters of fasciolosis were identified. The spatial distribution of high-risk clusters was more dispersed and mainly located in the northern and western regions of Munster compared to the low-risk clusters that were mostly concentrated in the southern and eastern regions. The most significant classes of variables that could reflect the difference between high-risk and low-risk clusters were the total number of wet-days and rain-days, rainfall, the normalized difference vegetation index (NDVI), temperature and soil type. There was a bigger proportion of well-drained soils among the low-risk clusters, whereas poorly drained soils were more common among the high-risk clusters. These results stress the role of precipitation, grazing, temperature and drainage on the life cycle of F. hepatica in the temperate Irish climate. The findings of this study highlight the importance of cluster analysis for identifying significant differences in climatic and environmental variables between high-risk and low-risk clusters of fasciolosis in Irish dairy herds.

  13. Cluster analysis of fasciolosis in dairy cow herds in Munster province of Ireland and detection of major climatic and environmental predictors of the exposure risk

    Directory of Open Access Journals (Sweden)

    Nikolaos Selemetas

    2015-03-01

    Full Text Available Fasciolosis caused by Fasciola hepatica is a widespread parasitic disease in cattle farms. The aim of this study was to detect clusters of fasciolosis in dairy cow herds in Munster Province, Ireland and to identify significant climatic and environmental predictors of the exposure risk. In total, 1,292 dairy herds across Munster was sampled in September 2012 providing a single bulk tank milk (BTM sample. The analysis of samples by an in-house antibody-detection enzyme-linked immunosorbent assay (ELISA, showed that 65% of the dairy herds (n = 842 had been exposed to F. hepatica. Using the Getis-Ord Gi* statistic, 16 high-risk and 24 low-risk (P <0.01 clusters of fasciolosis were identified. The spatial distribution of high-risk clusters was more dispersed and mainly located in the northern and western regions of Munster compared to the low-risk clusters that were mostly concentrated in the southern and eastern regions. The most significant classes of variables that could reflect the difference between high-risk and low-risk clusters were the total number of wet-days and rain-days, rainfall, the normalized difference vegetation index (NDVI, temperature and soil type. There was a bigger proportion of well-drained soils among the low-risk clusters, whereas poorly drained soils were more common among the high-risk clusters. These results stress the role of precipitation, grazing, temperature and drainage on the life cycle of F. hepatica in the temperate Irish climate. The findings of this study highlight the importance of cluster analysis for identifying significant differences in climatic and environmental variables between high-risk and low-risk clusters of fasciolosis in Irish dairy herds.

  14. Physical activity and not sedentary time per se influences on clustered metabolic risk in elderly community-dwelling women.

    Directory of Open Access Journals (Sweden)

    Andreas Nilsson

    Full Text Available Whether amount of time spent in sedentary activities influences on clustered metabolic risk in elderly, and to what extent such an influence is independent of physical activity behavior, remain unclear. Therefore, the aim of the study was to examine cross-sectional associations of objectively assessed physical activity and sedentary behavior on metabolic risk outcomes in a sample of elderly community-dwelling women.Metabolic risk outcomes including waist circumference, systolic and diastolic blood pressures, fasting levels of plasma glucose, HDL-cholesterol and triglycerides were assessed in 120 community-dwelling older women (65-70 yrs. Accelerometers were used to retrieve daily sedentary time, breaks in sedentary time, daily time in light (LPA and moderate-to-vigorous physical activity (MVPA, and total amount of accelerometer counts. Multivariate regression models were used to examine influence of physical activity and sedentary behavior on metabolic risk outcomes including a clustered metabolic risk score.When based on isotemporal substitution modeling, replacement of a 10-min time block of MVPA with a corresponding time block of either LPA or sedentary activities was associated with an increase in clustered metabolic risk score (β = 0.06 to 0.08, p < 0.05, and an increase in waist circumference (β = 1.78 to 2.19 p < 0.01. All associations indicated between sedentary time and metabolic risk outcomes were lost once variation in total accelerometer counts was adjusted for.Detrimental influence of a sedentary lifestyle on metabolic health is likely explained by variations in amounts of physical activity rather than amount of sedentary time per se. Given our findings, increased amounts of physical activity with an emphasis on increased time in MVPA should be recommended in order to promote a favorable metabolic health profile in older women.

  15. Group Music Therapy as a Preventive Intervention for Young People at Risk: Cluster-Randomized Trial.

    Science.gov (United States)

    Gold, Christian; Saarikallio, Suvi; Crooke, Alexander Hew Dale; McFerran, Katrina Skewes

    2017-07-01

    Music forms an important part of the lives and identities of adolescents and may have positive or negative mental health implications. Music therapy can be effective for mental disorders such as depression, but its preventive potential is unknown. The aim of this study was to examine whether group music therapy (GMT) is an effective intervention for young people who may be at risk of developing mental health problems, as indicated via unhealthy music use. The main question was whether GMT can reduce unhealthy uses of music and increase potentials for healthy uses of music, compared to self-directed music listening (SDML). We were also interested in effects of GMT on depressive symptoms, psychosocial well-being, rumination, and reflection. In an exploratory cluster-randomized trial in Australian schools, 100 students with self-reported unhealthy music use were invited to GMT (weekly sessions over 8 weeks) or SDML. Changes in the Healthy-Unhealthy Music Scale (HUMS) and mental health outcomes were measured over 3 months. Both interventions were well accepted. No effects were found between GMT and SDML (all p > 0.05); both groups tended to show small improvements over time. Younger participants benefited more from GMT, and older ones more from SDML (p = 0.018). GMT was associated with similar changes as SDML. Further research is needed to improve the processes of selecting participants for targeted interventions; to determine optimal dosage; and to provide more reliable evidence of effects of music-based interventions for adolescents. © the American Music Therapy Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  16. Clustering of risk factors in parents of patients with type 1 diabetes and nephropathy.

    Science.gov (United States)

    Thorn, Lena M; Forsblom, Carol; Fagerudd, Johan; Pettersson-Fernholm, Kim; Kilpikari, Riika; Groop, Per-Henrik

    2007-05-01

    To assess the impact of parental risk factors for diabetic nephropathy. This cross-sectional study included 2,355 type 1 diabetic patients from the FinnDiane (Finnish Diabetic Nephropathy) study. Diabetic nephropathy was defined as macroalbuminuria (urinary albumin excretion rate >200 microg/min or >300 mg/24 h) or end-stage renal disease. Information was available from 4,676 parents. Parental scores were calculated based on the number of various traits in the parents. Patients with diabetic nephropathy, compared with those without diabetic nephropathy, had a higher prevalence of maternal (41 vs. 35%, P = 0.046) and parental (62 vs. 55%, P = 0.044) hypertension, maternal stroke (7.6 vs. 5.1%, P = 0.044), and maternal (1.4 vs. 0.7%, P = 0.058) and parental (4.3 vs. 2.9%, P = 0.030) type 1 diabetes. If both, compared with none, of the parents had hypertension, the adjusted odds ratio (OR) for diabetic nephropathy in offspring was 1.56 (95% CI 1.13-2.15). The adjusted OR for diabetic nephropathy was 2.13 (1.36-3.33) for the parental hypertension-diabetes score (3-4 vs. 0 points) and 2.13 (1.37-3.33) for the parental hypertension-cardiovascular disease (CVD)-diabetes score (4-6 vs. 0 points). Fathers of patients with diabetic nephropathy, compared with those without diabetic nephropathy, had reduced overall survival (log-rank P = 0.04) and reduced cardiovascular survival (log-rank P = 0.03). A cluster of parental hypertension, CVD, and diabetes is associated with diabetic nephropathy in type 1 diabetes, as is paternal mortality.

  17. Analyzing Dynamic Probabilistic Risk Assessment Data through Topology-Based Clustering

    Energy Technology Data Exchange (ETDEWEB)

    Diego Mandelli; Dan Maljovec; BeiWang; Valerio Pascucci; Peer-Timo Bremer

    2013-09-01

    We investigate the use of a topology-based clustering technique on the data generated by dynamic event tree methodologies. The clustering technique we utilizes focuses on a domain-partitioning algorithm based on topological structures known as the Morse-Smale complex, which partitions the data points into clusters based on their uniform gradient flow behavior. We perform both end state analysis and transient analysis to classify the set of nuclear scenarios. We demonstrate our methodology on a dataset generated for a sodium-cooled fast reactor during an aircraft crash scenario. The simulation tracks the temperature of the reactor as well as the time for a recovery team to fix the passive cooling system. Combined with clustering results obtained previously through mean shift methodology, we present the user with complementary views of the data that help illuminate key features that may be otherwise hidden using a single methodology. By clustering the data, the number of relevant test cases to be selected for further analysis can be drastically reduced by selecting a representative from each cluster. Identifying the similarities of simulations within a cluster can also aid in the drawing of important conclusions with respect to safety analysis.

  18. Clustering of risk factors for non-communicable disease and healthcare expenditure in employees with private health insurance presenting for health risk appraisal: a cross-sectional study.

    Science.gov (United States)

    Kolbe-Alexander, Tracy L; Conradie, Jaco; Lambert, Estelle V

    2013-12-21

    The global increase in the prevalence of NCD's is accompanied by an increase in risk factors for these diseases such as insufficient physical activity and poor nutritional habits. The main aims of this research study were to determine the extent to which insufficient physical activity (PA) clustered with other risk factors for non-communicable disease (NCD) in employed persons undergoing health risk assessment, and whether these risk factors were associated with higher healthcare costs. Employees from 68 companies voluntarily participated in worksite wellness days, that included an assessment of self-reported health behaviors and clinical measures, such as: blood pressure (BP), Body Mass Index (BMI), as well as total cholesterol concentrations from capillary blood samples. A risk-related age, 'Vitality Risk Age' was calculated for each participant using an algorithm that incorporated multiplicative pooled relative risks for all cause mortality associated with smoking, PA, fruit and vegetable intake, BMI, BP and cholesterol concentration. Healthcare cost data were obtained for employees (n = 2 789). Participants were 36±10 years old and the most prevalent risk factors were insufficient PA (67%) and BMI ≥ 25 (62%). Employees who were insufficiently active also had a greater number of other NCD risk factors, compared to those meeting PA recommendations (chi2 = 43.55; p employees meeting PA guidelines had significantly fewer visits to their family doctor (GP) (2.5 versus 3.11; p Physical inactivity was associated with clustering of risk factors for NCD in SA employees. Employees with lower BMI, better self-reported health status and readiness to change were more likely to meet the PA guidelines. These employees might therefore benefit from physical activity intervention programs that could result in improved risk profile and reduced healthcare expenditure.

  19. Two-level tunneling systems in amorphous alumina

    Science.gov (United States)

    Lebedeva, Irina V.; Paz, Alejandro P.; Tokatly, Ilya V.; Rubio, Angel

    2014-03-01

    The decades of research on thermal properties of amorphous solids at temperatures below 1 K suggest that their anomalous behaviour can be related to quantum mechanical tunneling of atoms between two nearly equivalent states that can be described as a two-level system (TLS). This theory is also supported by recent studies on microwave spectroscopy of superconducting qubits. However, the microscopic nature of the TLS remains unknown. To identify structural motifs for TLSs in amorphous alumina we have performed extensive classical molecular dynamics simulations. Several bistable motifs with only one or two atoms jumping by considerable distance ~ 0.5 Å were found at T=25 K. Accounting for the surrounding environment relaxation was shown to be important up to distances ~ 7 Å. The energy asymmetry and barrier for the detected motifs lied in the ranges 0.5 - 2 meV and 4 - 15 meV, respectively, while their density was about 1 motif per 10 000 atoms. Tuning of motif asymmetry by strain was demonstrated with the coupling coefficient below 1 eV. The tunnel splitting for the symmetrized motifs was estimated on the order of 0.1 meV. The discovered motifs are in good agreement with the available experimental data. The financial support from the Marie Curie Fellowship PIIF-GA-2012-326435 (RespSpatDisp) is gratefully acknowledged.

  20. Sample size estimation to substantiate freedom from disease for clustered binary data with a specific risk profile

    DEFF Research Database (Denmark)

    Kostoulas, P.; Nielsen, Søren Saxmose; Browne, W. J.

    2013-01-01

    and power when applied to these groups. We propose the use of the variance partition coefficient (VPC), which measures the clustering of infection/disease for individuals with a common risk profile. Sample size estimates are obtained separately for those groups that exhibit markedly different heterogeneity......, thus, optimizing resource allocation. A VPC-based predictive simulation method for sample size estimation to substantiate freedom from disease is presented. To illustrate the benefits of the proposed approach we give two examples with the analysis of data from a risk factor study on Mycobacterium avium...

  1. Analysis of risk factors for cluster behavior of dental implant failures.

    Science.gov (United States)

    Chrcanovic, Bruno Ramos; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

    2017-08-01

    Some studies indicated that implant failures are commonly concentrated in few patients. To identify and analyze cluster behavior of dental implant failures among subjects of a retrospective study. This retrospective study included patients receiving at least three implants only. Patients presenting at least three implant failures were classified as presenting a cluster behavior. Univariate and multivariate logistic regression models and generalized estimating equations analysis evaluated the effect of explanatory variables on the cluster behavior. There were 1406 patients with three or more implants (8337 implants, 592 failures). Sixty-seven (4.77%) patients presented cluster behavior, with 56.8% of all implant failures. The intake of antidepressants and bruxism were identified as potential negative factors exerting a statistically significant influence on a cluster behavior at the patient-level. The negative factors at the implant-level were turned implants, short implants, poor bone quality, age of the patient, the intake of medicaments to reduce the acid gastric production, smoking, and bruxism. A cluster pattern among patients with implant failure is highly probable. Factors of interest as predictors for implant failures could be a number of systemic and local factors, although a direct causal relationship cannot be ascertained. © 2017 Wiley Periodicals, Inc.

  2. Co-variations and clustering of chronic disease behavioral risk factors in China: China Chronic Disease and Risk Factor Surveillance, 2007.

    Directory of Open Access Journals (Sweden)

    Yichong Li

    Full Text Available BACKGROUND: Chronic diseases have become the leading causes of mortality in China and related behavioral risk factors (BRFs changed dramatically in past decades. We aimed to examine the prevalence, co-variations, clustering and the independent correlates of five BRFs at the national level. METHODOLOGY/PRINCIPAL FINDINGS: We used data from the 2007 China Chronic Disease and Risk Factor Surveillance, in which multistage clustering sampling was adopted to collect a nationally representative sample of 49,247 Chinese aged 15 to 69 years. We estimated the prevalence and clustering (mean number of BRFs of five BRFs: tobacco use, excessive alcohol drinking, insufficient intake of vegetable and fruit, physical inactivity, and overweight or obesity. We conducted binary logistic regression models to examine the co-variations among five BRFs with adjustment of demographic and socioeconomic factors, chronic conditions and other BRFs. Ordinal logistic regression was constructed to investigate the independent associations between each covariate and the clustering of BRFs within individuals. Overall, 57.0% of Chinese population had at least two BRFs and the mean number of BRFs is 1.80 (95% confidence interval: 1.78-1.83. Eight of the ten pairs of bivariate associations between the five BRFs were found statistically significant. Chinese with older age, being a male, living in rural areas, having lower education level and lower yearly household income experienced increased likelihood of having more BRFs. CONCLUSIONS/SIGNIFICANCE: Current BRFs place the majority of Chinese aged 15 to 69 years at risk for the future development of chronic disease, which calls for urgent public health programs to reduce these risk factors. Prominent correlations between BRFs imply that a combined package of interventions targeting multiple BRFs might be appropriate. These interventions should target elder population, men, and rural residents, especially those with lower SES.

  3. Pixel detector readout electronics with two-level discriminator scheme

    International Nuclear Information System (INIS)

    Pengg, F.

    1998-01-01

    In preparation for a silicon pixel detector with more than 3,000 readout channels per chip for operation at the future large hadron collider (LHC) at CERN the analog front end of the readout electronics has been designed and measured on several test-arrays with 16 by 4 cells. They are implemented in the HP 0.8 microm process but compatible with the design rules of the radiation hard Honeywell 0.8 microm bulk process. Each cell contains bump bonding pad, preamplifier, discriminator and control logic for masking and testing within a layout area of only 50 microm by 140 microm. A new two-level discriminator scheme has been implemented to cope with the problems of time-walk and interpixel cross-coupling. The measured gain of the preamplifier is 900 mV for a minimum ionizing particle (MIP, about 24,000 e - for a 300 microm thick Si-detector) with a return to baseline within 750 ns for a 1 MIP input signal. The full readout chain (without detector) shows an equivalent noise charge to 60e - r.m.s. The time-walk, a function of the separation between the two threshold levels, is measured to be 22 ns at a separation of 1,500 e - , which is adequate for the 40 MHz beam-crossing frequency at the LHC. The interpixel cross-coupling, measured with a 40fF coupling capacitance, is less than 3%. A single cell consumes 35 microW at 3.5 V supply voltage

  4. The relationship between physical fitness and clustered risk, and tracking of clustered risk from adolescence to young adulthood: eight years follow-up in the Danish Youth and Sport Study

    DEFF Research Database (Denmark)

    Andersen, Lars Bo; Hasselstrøm, Henriette; Hansen, Stig Eiberg

    2004-01-01

    was defined as being at risk, and if a subject had two or more risk factors, he/she was defined as a case (15-20 % of the subjects). Odds ratios (OR) for being a case was calculated between quartiles of fitness in both cross-sectional studies. The stability of combined risk was calculated as the OR between...... cases and non-cases at the first examination to be a case at the second examination. RESULTS: ORs for having two or more risk factors between quartiles of fitness were 3.1, 3.8 and 4.9 for quartiles two to four, respectively. At the second examination, OR were 0.7, 3.5 and 4.9, respectively....... The probability for "a case" at the first examination to be "a case" at the second was 6.0. CONCLUSIONS: The relationship between an exposure like physical fitness and CVD risk factors is much stronger when clustering of risk factors are analysed compared to the relationship to single risk factors. The stability...

  5. [High risk groups in health behavior defined by clustering of smoking, alcohol, and exercise habits: National Heath and Nutrition Examination Survey].

    Science.gov (United States)

    Kang, Kiwon; Sung, Joohon; Kim, Chang Yup

    2010-01-01

    We investigated the clustering of selected lifestyle factors (cigarette smoking, heavy alcohol consumption, lack of physical exercise) and identified the population characteristics associated with increasing lifestyle risks. Data on lifestyle risk factors, sociodemographic characteristics, and history of chronic diseases were obtained from 7,694 individuals >/=20 years of age who participated in the 2005 Korea National Health and Nutrition Examination Survey (KNHANES). Clustering of lifestyle risks involved the observed prevalence of multiple risks and those expected from marginal exposure prevalence of the three selected risk factors. Prevalence odds ratio was adopted as a measurement of clustering. Multiple correspondence analysis, Kendall tau correlation, Man-Whitney analysis, and ordinal logistic regression analysis were conducted to identify variables increasing lifestyle risks. In both men and women, increased lifestyle risks were associated with clustering of: (1) cigarette smoking and excessive alcohol consumption, and (2) smoking, excessive alcohol consumption, and lack of physical exercise. Patterns of clustering for physical exercise were different from those for cigarette smoking and alcohol consumption. The increased unhealthy clustering was found among men 20-64 years of age with mild or moderate stress, and among women 35-49 years of age who were never-married, with mild stress, and increased body mass index (>30 kg/m(2)). Addressing a lack of physical exercise considering individual characteristics including gender, age, employment activity, and stress levels should be a focus of health promotion efforts.

  6. Potential risks of atracting direct foreign investments to the formation of regional clusters

    Directory of Open Access Journals (Sweden)

    Galina Dmitrievna Boush

    2012-03-01

    Full Text Available This paper discussesthe role ofdirectforeign investmentsin the processes of regionalclusters’ creation. The new type of clusters was identified - clusters that are created bytransnational corporations (TNCsinvitedinto the territory.The authors analyzedthe globalexperience of creatingclusters byforeign direct investmentof transnational corporations and found out thatthere is much evidence thatindicatesa weakeconomic potentialof such projects.A statisticalanalysis of economic indicators of several foreign regional clusters (of this type showed that clustersof this typeare developedmainly due tomarket conditionsrather thanfrom its own resources. Correlationandregression analysisconfirmed the hypothesisofweak influence ofdirectforeign investment on economicpotentialof clustersin the early stagesof its development. The authors offer a set ofindicators to assessthe effectiveness ofclusters’ performancein case of a highdependency on a foreigninvestment

  7. Is the cluster risk model of parental adversities better than the cumulative risk model as an indicator of childhood physical abuse?: findings from two representative community surveys.

    Science.gov (United States)

    Fuller-Thomson, E; Sawyer, J-L

    2014-01-01

    Screening strategies for childhood physical abuse (CPA) need to be improved in order to identify those most at risk. This study uses two regionally representative community samples to examine whether a cluster or cumulative model of risk indicators (i.e. parental divorce, parental unemployment, and parental addictions) explains a larger proportion of the variation in CPA. Data were drawn from Statistics Canada's National Population Health Survey (1994-1995) and Canadian Community Health Survey 3.1 (2005). Response rates were greater than 80% in both samples. Each survey had approximately 13,000 respondents aged 18 and over who answered questions about the above adverse childhood experiences. A gradient was shown with similar outcomes in each data set. Only 3.4% of adults who experienced none of the three risk indicators reported they had been physically abused during childhood or adolescence. The prevalence of CPA was greater among those who experienced parental divorce alone (8.3%-10.7%), parental unemployment alone (8.9%-9.7%) or parental addictions alone (18.0%-19.5%). When all three risk indicators were present, the prevalence of CPA ranged from 36.0%-41.0% and the age-sex-race adjusted odds were greater than 15 times that of individuals with none of the three risk indicators. The cluster model explained a statistically significantly larger proportion of the variation than the cumulative model although the difference between the two models was modest. For the purposes of parsimony, the cumulative model may be the better alternative. Adults who were exposed to two or more childhood risk indicators were much more likely to report that they were physically abused during their childhood than those with only one or no risk factors. Medical professionals may use this information on cumulative risk factors to more effectively target screening for potential CPA. Future research should include prospective studies. © 2012 John Wiley & Sons Ltd.

  8. Change in cardiovascular risk factors following early diagnosis of type 2 diabetes: a cohort analysis of a cluster-randomised trial

    OpenAIRE

    Black, James A; Sharp, Stephen J; Wareham, Nicholas J; Sandbæk, Annelli; Rutten, Guy EHM; Lauritzen, Torsten; Khunti, Kamlesh; Davies, Melanie J; Borch-Johnsen, Knut; Griffin, Simon J; Simmons, Rebecca K

    2014-01-01

    Background There is little evidence to inform the targeted treatment of individuals found early in the diabetes disease trajectory. Aim To describe cardiovascular disease (CVD) risk profiles and treatment of individual CVD risk factors by modelled CVD risk at diagnosis; changes in treatment, modelled CVD risk, and CVD risk factors in the 5 years following diagnosis; and how these are patterned by socioeconomic status. Design and setting Cohort analysis of a cluster-randomised trial (ADDITION-...

  9. Assessing a risk tailored intervention to prevent disabling low back pain - protocol of a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Marnitz Ulf

    2010-01-01

    Full Text Available Abstract Background Although most patients with low back pain (LBP recover within a few weeks a significant proportion has recurrent episodes or will develop chronic low back pain. Several mainly psychosocial risk factors for developing chronic LBP have been identified. However, effects of preventive interventions aiming at behavioural risk factors and unfavourable cognitions have yielded inconsistent results. Risk tailored interventions may provide a cost efficient and effective means to take systematic account of the individual risk factors but evidence is lacking. Methods/Design This study will be a cluster-randomised controlled trial comparing screening and a subsequent risk tailored intervention for patients with low back pain to prevent chronic low back pain compared to treatment as usual in primary care. A total of 600 patients from 20 practices in each study arm will be recruited in Berlin and Goettingen. The intervention comprises the following elements: Patients will be assigned to one of four risk groups based on a screening questionnaire. Subsequently they receive an educational intervention including information and counselling tailored to the risk group. A telephone/email consulting service for back pain related problems are offered independent of risk group assignment. The primary outcomes will be functional capacity and sick leave. Discussion This trial will evaluate the effectiveness of screening for risk factors for chronic low back pain followed by a risk tailored intervention to prevent chronic low back pain. This trial will contribute new evidence regarding the flexible use of individual physical and psychosocial risk factors in general practice. Trial registration ISRCTN 68205910

  10. Mortality in Danish Swine herds: Spatio-temporal clusters and risk factors

    DEFF Research Database (Denmark)

    Lopes Antunes, Ana Carolina; Ersbøll, Annette Kjær; Bihrmann, Kristine

    2017-01-01

    -temporal analysis included data description for spatial, temporal, and spatio-temporal cluster analysis for three age groups: weaners (up to 30 kg), sows and finishers. Logistic regression models were used to assess the potential factors associated with finisher and weaner herds being included within multiple...

  11. Global, regional, and national comparative risk assessment of 79 behavioral, environmental and occupational, and metabolic risks or clusters of risks, 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015

    DEFF Research Database (Denmark)

    Moesgaard Iburg, Kim

    2016-01-01

    inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group......, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk...... pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood...

  12. Clustering of Risk Factors for Non-Communicable Diseases among Adolescents from Southern Brazil

    OpenAIRE

    Nunes, Heloyse Elaine Gimenes; Gon?alves, Eliane Cristina de Andrade; Vieira, J?ssika Aparecida Jesus; Silva, Diego Augusto Santos

    2016-01-01

    Introduction The aim of this study was to investigate the simultaneous presence of risk factors for non-communicable diseases and the association of these risk factors with demographic and economic factors among adolescents from southern Brazil. Methods The study included 916 students (14?19 years old) enrolled in the 2014 school year at state schools in S?o Jos?, Santa Catarina, Brazil. Risk factors related to lifestyle (i.e., physical inactivity, excessive alcohol consumption, smoking, sede...

  13. Comparing 3 dietary pattern methods--cluster analysis, factor analysis, and index analysis--With colorectal cancer risk: The NIH-AARP Diet and Health Study.

    Science.gov (United States)

    Reedy, Jill; Wirfält, Elisabet; Flood, Andrew; Mitrou, Panagiota N; Krebs-Smith, Susan M; Kipnis, Victor; Midthune, Douglas; Leitzmann, Michael; Hollenbeck, Albert; Schatzkin, Arthur; Subar, Amy F

    2010-02-15

    The authors compared dietary pattern methods-cluster analysis, factor analysis, and index analysis-with colorectal cancer risk in the National Institutes of Health (NIH)-AARP Diet and Health Study (n = 492,306). Data from a 124-item food frequency questionnaire (1995-1996) were used to identify 4 clusters for men (3 clusters for women), 3 factors, and 4 indexes. Comparisons were made with adjusted relative risks and 95% confidence intervals, distributions of individuals in clusters by quintile of factor and index scores, and health behavior characteristics. During 5 years of follow-up through 2000, 3,110 colorectal cancer cases were ascertained. In men, the vegetables and fruits cluster, the fruits and vegetables factor, the fat-reduced/diet foods factor, and all indexes were associated with reduced risk; the meat and potatoes factor was associated with increased risk. In women, reduced risk was found with the Healthy Eating Index-2005 and increased risk with the meat and potatoes factor. For men, beneficial health characteristics were seen with all fruit/vegetable patterns, diet foods patterns, and indexes, while poorer health characteristics were found with meat patterns. For women, findings were similar except that poorer health characteristics were seen with diet foods patterns. Similarities were found across methods, suggesting basic qualities of healthy diets. Nonetheless, findings vary because each method answers a different question.

  14. Clustering of near clusters versus cluster compactness

    International Nuclear Information System (INIS)

    Yu Gao; Yipeng Jing

    1989-01-01

    The clustering properties of near Zwicky clusters are studied by using the two-point angular correlation function. The angular correlation functions for compact and medium compact clusters, for open clusters, and for all near Zwicky clusters are estimated. The results show much stronger clustering for compact and medium compact clusters than for open clusters, and that open clusters have nearly the same clustering strength as galaxies. A detailed study of the compactness-dependence of correlation function strength is worth investigating. (author)

  15. Domain decomposition method of stochastic PDEs: a two-level scalable preconditioner

    International Nuclear Information System (INIS)

    Subber, Waad; Sarkar, Abhijit

    2012-01-01

    For uncertainty quantification in many practical engineering problems, the stochastic finite element method (SFEM) may be computationally challenging. In SFEM, the size of the algebraic linear system grows rapidly with the spatial mesh resolution and the order of the stochastic dimension. In this paper, we describe a non-overlapping domain decomposition method, namely the iterative substructuring method to tackle the large-scale linear system arising in the SFEM. The SFEM is based on domain decomposition in the geometric space and a polynomial chaos expansion in the probabilistic space. In particular, a two-level scalable preconditioner is proposed for the iterative solver of the interface problem for the stochastic systems. The preconditioner is equipped with a coarse problem which globally connects the subdomains both in the geometric and probabilistic spaces via their corner nodes. This coarse problem propagates the information quickly across the subdomains leading to a scalable preconditioner. For numerical illustrations, a two-dimensional stochastic elliptic partial differential equation (SPDE) with spatially varying non-Gaussian random coefficients is considered. The numerical scalability of the the preconditioner is investigated with respect to the mesh size, subdomain size, fixed problem size per subdomain and order of polynomial chaos expansion. The numerical experiments are performed on a Linux cluster using MPI and PETSc parallel libraries.

  16. Gender differences on effectiveness of a school-based physical activity intervention for reducing cardiometabolic risk: a cluster randomized trial.

    Science.gov (United States)

    Martínez-Vizcaíno, Vicente; Sánchez-López, Mairena; Notario-Pacheco, Blanca; Salcedo-Aguilar, Fernando; Solera-Martínez, Montserrat; Franquelo-Morales, Pablo; López-Martínez, Sara; García-Prieto, Jorge C; Arias-Palencia, Natalia; Torrijos-Niño, Coral; Mora-Rodríguez, Ricardo; Rodríguez-Artalejo, Fernando

    2014-12-10

    Studies that have examined the impact of a physical activity intervention on cardiometabolic risk factors have yielded conflicting results. The objective of this study was to assess the impact of a standardized physical activity program on adiposity and cardiometabolic risk factors in schoolchildren. Cluster randomized trial study of 712 schoolchildren, 8-10 years, from 20 public schools in the Province of Cuenca, Spain. The intervention (MOVI-2) consisted of play-based and non-competitive activities. MOVI-2 was conducted during two 90-minute sessions on weekdays and one 150-minute session on Saturday mornings every week between September 2010 and May 2011. We measured changes in adiposity (overweight/obesity prevalence, body mass index [BMI], triceps skinfold thickness [TST], body fat %, fat-free mass, waist circumference) and other cardiometabolic risk factors (LDL-cholesterol, triglycerides/HDL-cholesterol ratio, insulin, C-reactive protein and blood pressure). The analyses used mixed regression models to adjust for baseline covariates under cluster randomization. Among girls, we found a reduction of adiposity in intervention versus control schools, with a decrease in TST (-1.1 mm; 95% confidence interval [CI] -2.3 to -0.7), body fat % (-0.9%; 95% CI -1.3 to -0.4), waist circumference (-2.7 cm; 95% CI -4.5 to -0.9), and an increase in fat-free mass (0.3 kg; 95% CI 0.01 to 0.6). The intervention also led to lower serum LDL-cholesterol and insulin levels. Among boys, a reduction in waist circumference (-1.4 cm; 95% CI -2.6 to -0.1; P = 0.03), and an increase in fat-free mass (0.5 kg; 95% CI 0.2 to 0.9; P = 0.003) was associated with the intervention versus control schools. The prevalence of overweight/obesity or underweight, BMI, and other cardiometabolic risk factors was not modified by the intervention. No important adverse events were registered. An extracurricular intervention of non-competitive physical activity during an academic year, targeting all

  17. Risk moderation of a parent and student preventive alcohol intervention by adolescent and family factors: a cluster randomized trial.

    Science.gov (United States)

    Verdurmen, Jacqueline E E; Koning, Ina M; Vollebergh, Wilma A M; van den Eijnden, Regina J J M; Engels, Rutger C M E

    2014-03-01

    To examine risk moderation of an alcohol intervention targeting parents and adolescents. A cluster randomized trial including 2937 Dutch early adolescents (m=12.68years, SD=0.51) and their parents randomized over four conditions: parent intervention, student intervention, combined parent-student intervention, and control group. 152 classes of 19 high schools in The Netherlands (2006). Moderators at baseline (adolescent: gender, educational level and externalizing behavior; parent: educational level and heavy alcohol use) were used to examine the differential effects of the interventions on onset of (heavy) weekly drinking at 22-month follow-up. The combined intervention effectively delayed the onset of weekly drinking in the general population of adolescents, and was particularly effective in delaying the onset of heavy weekly drinking in a higher-risk subsample of adolescents (i.e. those attending lower levels of education and reporting higher levels of externalizing behavior). Present and previous results have established the combined intervention to be universally effective in postponing weekly alcohol use among Dutch adolescents, with an added effect on postponing heavy weekly drinking in high risk subgroups. Therefore, implementation of this intervention in the general population of schools in The Netherlands is advised. NTR649. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Meta Salud Diabetes study protocol: a cluster-randomised trial to reduce cardiovascular risk among a diabetic population of Mexico

    Science.gov (United States)

    Cornejo Vucovich, Elsa; Ingram, Maia; Valenica, Celina; Castro Vasquez, Maria del Carmen; Gonzalez-Fagoaga, Eduardo; Geurnsey de Zapien, Jill

    2018-01-01

    Introduction Northern Mexico has among the highest rates of cardiovascular disease (CVD) and diabetes in the world. This research addresses core gaps in implementation science to develop, test and scale-up CVD risk-reduction interventions in diabetics through a national primary care health system. Methods and analysis The Meta Salud Diabetes (MSD) research project is a parallel two-arm cluster-randomised clinical behavioural trial based in 22 (n=22) health centres in Sonora, Mexico. MSD aims to evaluate the effectiveness of the MSD intervention for the secondary prevention of CVD risk factors among a diabetic population (n=320) compared with the study control of usual care. The MSD intervention consists of 2-hour class sessions delivered over a 13-week period providing educational information to encourage sustainable behavioural change to prevent disease complications including the adoption of physical activity. MSD is delivered within the context of Mexico’s national primary care health centre system by health professionals, including nurses, physicians and community health workers via existing social support groups for individuals diagnosed with chronic disease. Mixed models are used to estimate the effect of MSD by comparing cardiovascular risk, as measured by the Framingham Risk Score, between the trial arms. Secondary outcomes include hypertension, behavioural risk factors and psychosocial factors. Ethics and dissemination This work is supported by the National Institutes of Health, National Heart Lung and Blood Institute (1R01HL125996-01) and approved by the University of Arizona Research Institutional Review Board (Protocol 1508040144) and the Research Bioethics Committee at the University of Sonora. The first Internal Review Board approval date was 31 August 2015 with five subsequent approved amendments. This article refers to protocol V.0.2, dated 30 January 2017. Results will be disseminated via peer-reviewed publication and presentation at

  19. Beyond Risk Compensation: Clusters of Antiretroviral Treatment (ART) Users in Sexual Networks Can Modify the Impact of ART on HIV Incidence.

    Science.gov (United States)

    Delva, Wim; Helleringer, Stéphane

    Concerns about risk compensation-increased risk behaviours in response to a perception of reduced HIV transmission risk-after the initiation of ART have largely been dispelled in empirical studies, but other changes in sexual networking patterns may still modify the effects of ART on HIV incidence. We developed an exploratory mathematical model of HIV transmission that incorporates the possibility of ART clusters, i.e. subsets of the sexual network in which the density of ART patients is much higher than in the rest of the network. Such clusters may emerge as a result of ART homophily-a tendency for ART patients to preferentially form and maintain relationships with other ART patients. We assessed whether ART clusters may affect the impact of ART on HIV incidence, and how the influence of this effect-modifying variable depends on contextual variables such as HIV prevalence, HIV serosorting, coverage of HIV testing and ART, and adherence to ART. ART homophily can modify the impact of ART on HIV incidence in both directions. In concentrated epidemics and generalized epidemics with moderate HIV prevalence (≈ 10%), ART clusters can enhance the impact of ART on HIV incidence, especially when adherence to ART is poor. In hyperendemic settings (≈ 35% HIV prevalence), ART clusters can reduce the impact of ART on HIV incidence when adherence to ART is high but few people living with HIV (PLWH) have been diagnosed. In all contexts, the effects of ART clusters on HIV epidemic dynamics are distinct from those of HIV serosorting. Depending on the programmatic and epidemiological context, ART clusters may enhance or reduce the impact of ART on HIV incidence, in contrast to serosorting, which always leads to a lower impact of ART on HIV incidence. ART homophily and the emergence of ART clusters should be measured empirically and incorporated into more refined models used to plan and evaluate ART programmes.

  20. Beyond Risk Compensation: Clusters of Antiretroviral Treatment (ART Users in Sexual Networks Can Modify the Impact of ART on HIV Incidence.

    Directory of Open Access Journals (Sweden)

    Wim Delva

    Full Text Available Concerns about risk compensation-increased risk behaviours in response to a perception of reduced HIV transmission risk-after the initiation of ART have largely been dispelled in empirical studies, but other changes in sexual networking patterns may still modify the effects of ART on HIV incidence.We developed an exploratory mathematical model of HIV transmission that incorporates the possibility of ART clusters, i.e. subsets of the sexual network in which the density of ART patients is much higher than in the rest of the network. Such clusters may emerge as a result of ART homophily-a tendency for ART patients to preferentially form and maintain relationships with other ART patients. We assessed whether ART clusters may affect the impact of ART on HIV incidence, and how the influence of this effect-modifying variable depends on contextual variables such as HIV prevalence, HIV serosorting, coverage of HIV testing and ART, and adherence to ART.ART homophily can modify the impact of ART on HIV incidence in both directions. In concentrated epidemics and generalized epidemics with moderate HIV prevalence (≈ 10%, ART clusters can enhance the impact of ART on HIV incidence, especially when adherence to ART is poor. In hyperendemic settings (≈ 35% HIV prevalence, ART clusters can reduce the impact of ART on HIV incidence when adherence to ART is high but few people living with HIV (PLWH have been diagnosed. In all contexts, the effects of ART clusters on HIV epidemic dynamics are distinct from those of HIV serosorting.Depending on the programmatic and epidemiological context, ART clusters may enhance or reduce the impact of ART on HIV incidence, in contrast to serosorting, which always leads to a lower impact of ART on HIV incidence. ART homophily and the emergence of ART clusters should be measured empirically and incorporated into more refined models used to plan and evaluate ART programmes.

  1. Polymorphisms of ST2-IL18R1-IL18RAP gene cluster: a new risk for autoimmune thyroid diseases.

    Science.gov (United States)

    Wang, X; Zhu, Y F; Li, D M; Qin, Q; Wang, Q; Muhali, F S; Jiang, W J; Zhang, J A

    2016-02-01

    Interleukin 33 (IL33) / ST2 pathway and ST2-interlukin18 receptor1-interlukin18 receptor accessory protein (ST2-IL18R1-IL18RAP) gene cluster have been involved in many autoimmune diseases but few report in autoimmune thyroid diseases (AITD). In this study, we investigated whether polymorphisms of IL33, ST2, IL18R1, and IL18RAP are associated with Graves' disease (GD) and Hashimoto's thyroiditis (HT), two major forms of AITD, among a Chinese population. A total of 11 SNPs were explored in a case-control study including 417 patients with GD, 250 HT patients and 301 controls, including rs1929992, rs10975519, rs10208293, rs6543116, rs1041973, rs3732127, rs11465597, rs1035130, rs2293225, rs1035127, rs917997 of IL 33, ST2-IL18R1-IL18RAP gene cluster. Genotyping of these SNPs was performed using matrix-assisted laser desorption / ionization-time-of-flight mass spectrometer (MALDI-TOF-MS) platform from Sequenom. The frequencies of allele A and AA+AG genotype of rs6543116 (ST2) in HT patients were significantly increased compared with those of the controls (P = 0.029/0.021, OR = 1.31/1.62). And in another SNP rs917997, AA+AG genotype presented an increased frequency in HT subjects compared with controls (P = 0.046, OR = 1.53). Furthermore, the haplotype GAGCCCG from ST2-IL18R1-IL18RAP gene cluster (rs6543116, rs1041973, rs1035130, rs3732127, rs1035127, rs2293225, rs917997) was associated with increased susceptibility to GD with an OR of 2.03 (P = 0.022, 95% CI = 1.07-3.86). Some SNPs of ST2-IL18R1-IL18RAP gene cluster might increase the risk of susceptibility of HT and GD in Chinese Han population. © 2015 John Wiley & Sons Ltd.

  2. A computational linguistic measure of clustering behavior on semantic verbal fluency task predicts risk of future dementia in the nun study.

    Science.gov (United States)

    Pakhomov, Serguei V S; Hemmy, Laura S

    2014-06-01

    Generative semantic verbal fluency (SVF) tests show early and disproportionate decline relative to other abilities in individuals developing Alzheimer's disease. Optimal performance on SVF tests depends on the efficiency of using clustered organization of semantically related items and the ability to switch between clusters. Traditional approaches to clustering and switching have relied on manual determination of clusters. We evaluated a novel automated computational linguistic approach for quantifying clustering behavior. Our approach is based on Latent Semantic Analysis (LSA) for computing strength of semantic relatedness between pairs of words produced in response to SVF test. The mean size of semantic clusters (MCS) and semantic chains (MChS) are calculated based on pairwise relatedness values between words. We evaluated the predictive validity of these measures on a set of 239 participants in the Nun Study, a longitudinal study of aging. All were cognitively intact at baseline assessment, measured with the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) battery, and were followed in 18-month waves for up to 20 years. The onset of either dementia or memory impairment were used as outcomes in Cox proportional hazards models adjusted for age and education and censored at follow-up waves 5 (6.3 years) and 13 (16.96 years). Higher MCS was associated with 38% reduction in dementia risk at wave 5 and 26% reduction at wave 13, but not with the onset of memory impairment. Higher [+1 standard deviation (SD)] MChS was associated with 39% dementia risk reduction at wave 5 but not wave 13, and association with memory impairment was not significant. Higher traditional SVF scores were associated with 22-29% memory impairment and 35-40% dementia risk reduction. SVF scores were not correlated with either MCS or MChS. Our study suggests that an automated approach to measuring clustering behavior can be used to estimate dementia risk in cognitively normal

  3. Injury patterns of child abuse: Experience of two Level 1 pediatric trauma centers.

    Science.gov (United States)

    Yu, Yangyang R; DeMello, Annalyn S; Greeley, Christopher S; Cox, Charles S; Naik-Mathuria, Bindi J; Wesson, David E

    2018-05-01

    This study examines non-accidental trauma (NAT) fatalities as a percentage of all injury fatalities and identifies injury patterns in NAT admissions to two level 1 pediatric trauma centers. We reviewed all children (<5years old) treated for NAT from 2011 to 2015. Patient demographics, injury sites, and survival were obtained from both institutional trauma registries. Of 4623 trauma admissions, 557 (12%) were due to NAT. However, 43 (46%) of 93 overall trauma fatalities were due to NAT. Head injuries were the most common injuries sustained (60%) and led to the greatest increased risk of death (RR 5.1, 95% CI 2.0-12.7). Less common injuries that increased the risk of death were facial injuries (14%, RR 2.9, 95% CI 1.6-5.3), abdominal injuries (8%, RR 2.8, 95% CI 1.4-5.6), and spinal injuries (3%, RR 3.9, 95% CI 1.8-8.8). Although 76% of head injuries occurred in infants <1year, children ages 1-4years old with head injuries had a significantly higher case fatality rate (27% vs. 6%, p<0.001). Child abuse accounts for a large proportion of trauma fatalities in children under 5years of age. Intracranial injuries are common in child abuse and increase the risk of death substantially. Preventing NAT in infants and young children should be a public health priority. Retrospective Review. II. Copyright © 2018. Published by Elsevier Inc.

  4. Replication of association of the apolipoprotein A1-C3-A4 gene cluster with the risk of gout.

    Science.gov (United States)

    Rasheed, Humaira; Phipps-Green, Amanda J; Topless, Ruth; Smith, Malcolm D; Hill, Catherine; Lester, Susan; Rischmueller, Maureen; Janssen, Matthijs; Jansen, Timothy L; Joosten, Leo A; Radstake, Timothy R; Riches, Philip L; Tausche, Anne-Kathrin; Lioté, Frederic; So, Alexander; van Rij, Andre; Jones, Gregory T; McCormick, Sally P; Harrison, Andrew A; Stamp, Lisa K; Dalbeth, Nicola; Merriman, Tony R

    2016-08-01

    Gout is associated with dyslipidaemia. Association of the apolipoprotein A1-C3-A4 gene cluster with gout has previously been reported in a small study. To investigate a possible causal role for this locus in gout, we tested the association of genetic variants from APOA1 (rs670) and APOC3 (rs5128) with gout. We studied data for 2452 controls and 2690 clinically ascertained gout cases of European and New Zealand Polynesian (Māori and Pacific) ancestry. Data were also used from the publicly available Atherosclerosis Risk in Communities study (n = 5367) and the Framingham Heart Study (n = 2984). Multivariate adjusted logistic and linear regression was used to test the association of single-nucleotide polymorphisms with gout risk, serum urate, triglyceride and high-density lipoprotein cholesterol (HDL-C). In Polynesians, the T-allele of rs670 (APOA1) increased (odds ratio, OR = 1.53, P = 4.9 × 10(-6)) and the G-allele of rs5128 (APOC3) decreased the risk of gout (OR = 0.86, P = 0.026). In Europeans, there was a strong trend to a risk effect of the T-allele for rs670 (OR = 1.11, P = 0.055), with a significant protective effect of the G-allele for rs5128 being observed after adjustment for triglycerides and HDL-C (OR = 0.81, P = 0.039). The effect at rs5128 was specific to males in both Europeans and Polynesians. Association in Polynesians was independent of any effect of rs670 and rs5128 on triglyceride and HDL-C levels. There was no evidence for association of either single-nucleotide polymorphism with serum urate levels (P ⩾ 0.10). Our data, replicating a previous study, supports the hypothesis that the apolipoprotein A1-C3-A4 gene cluster plays a causal role in gout. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Selenium Homeostasis and Clustering of Cardiovascular Risk Factors: A Systematic Review.

    Science.gov (United States)

    Gharipour, Mojgan; Sadeghi, Masoumeh; Behmanesh, Mehrdad; Salehi, Mansour; Nezafati, Pouya; Gharpour, Amin

    2017-10-23

      Selenium is a trace element required for a range of cellular functions. It is widely used for the biosynthesis of the unique amino acid selenocysteine [Sec], which is a structural element of selenoproteins. This systematic review focused on the possible relation between selenium and metabolic risk factors. The literature was searched via PubMed, Scopus, ISI Web of Science, and Google Scholar. Searches were not restricted by time or language. Relevant studies were selected in three phases. After an initial quality assessment, two reviewers extracted all the relevant data, whereas the third reviewer checked their extracted data. All evidence came from experimental and laboratory studies. Selenoprotein P is the best indicator for selenium nutritional levels. In addition, high levels of selenium may increase the risk of metabolic syndrome while the lack of sufficient selenium may also promote metabolic syndrome. selenium supplementation in subjects with sufficient serum selenium levels has a contrary effect on blood pressure, LDL, and total cholesterol. According to the bioavailability of different types of selenium supplementation such as selenomethionine, selenite and selenium-yeast, it seems that the best nutritional type of selenium is selenium-yeast. Regarding obtained results of longitudinal studies and randomized controlled trials, selenium supplementation should not be recommended for primary or secondary cardio-metabolic risk prevention in populations with adequate selenium status.

  6. Replicating Reducing the Risk: 12-Month Impacts of a Cluster Randomized Controlled Trial

    Science.gov (United States)

    Blocklin, Michelle; Layzer, Jean; Price, Cristofer; Juras, Randall; Freiman, Lesley

    2016-01-01

    Objectives. To test the effectiveness of Reducing the Risk, an evidence-based sexual health curriculum designed to help prevent adolescent pregnancy and sexually transmitted infections, on youth sexual behavior and intermediate outcomes thought to lead to these behaviors. Methods. Classes within schools in St. Louis, Missouri; Austin, Texas; and San Diego, California; were randomly assigned to receive Reducing the Risk or “business as usual.” Youths completed Web-based surveys at baseline (preintervention, August 2012–January 2014) and 12 months later (August 2013–January 2015). Intent-to-treat analyses were conducted across sites; we tested for differences in impacts between sites and other subgroups. Results. The program had no overall impact on sexual behaviors. However, at 1 site, program participants were significantly less likely to have engaged in recent sexual intercourse than were control group members. There were positive overall impacts on intermediate outcomes (e.g., knowledge, attitudes). Conclusions. After 12 months, Reducing the Risk was unsuccessful at changing sexual behaviors. Other results were mixed, but promising evidence (e.g., behavioral impacts at 1 site, impacts on intermediate outcomes) suggests potential for more widespread behavioral impacts over a longer term. PMID:27689492

  7. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013

    DEFF Research Database (Denmark)

    Forouzanfar, Mohammad H.; Alexander, Lily; Anderson, H. Ross

    2015-01-01

    Background The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the fi rst of a series of annual updates of the GBD. Risk factor quantifi cation, particularly of modifi able risk factors, can help to identify emerging threats to population health and opportunities for ...

  8. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013

    NARCIS (Netherlands)

    Forouzanfar, M.H.; Alexander, L.; Ross Anderson, H.; Geleijnse, J.M.

    2015-01-01

    Background The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for

  9. Task shifting of frontline community health workers for cardiovascular risk reduction: design and rationale of a cluster randomised controlled trial (DISHA study) in India.

    Science.gov (United States)

    Jeemon, Panniyammakal; Narayanan, Gitanjali; Kondal, Dimple; Kahol, Kashvi; Bharadwaj, Ashok; Purty, Anil; Negi, Prakash; Ladhani, Sulaiman; Sanghvi, Jyoti; Singh, Kuldeep; Kapoor, Deksha; Sobti, Nidhi; Lall, Dorothy; Manimunda, Sathyaprakash; Dwivedi, Supriya; Toteja, Gurudyal; Prabhakaran, Dorairaj

    2016-03-15

    Effective task-shifting interventions targeted at reducing the global cardiovascular disease (CVD) epidemic in low and middle-income countries (LMICs) are urgently needed. DISHA is a cluster randomised controlled trial conducted across 10 sites (5 in phase 1 and 5 in phase 2) in India in 120 clusters. At each site, 12 clusters were randomly selected from a district. A cluster is defined as a small village with 250-300 households and well defined geographical boundaries. They were then randomly allocated to intervention and control clusters in a 1:1 allocation sequence. If any of the intervention and control clusters were workers (mainly Anganwadi workers and ASHA workers) and a post intervention survey in a representative sample. The study staff had no information on intervention allocation until the completion of the baseline survey. In order to ensure comparability of data across sites, the DISHA study follows a common protocol and manual of operation with standardized measurement techniques. Our study is the largest community based cluster randomised trial in low and middle-income country settings designed to test the effectiveness of 'task shifting' interventions involving frontline health workers for cardiovascular risk reduction. CTRI/2013/10/004049 . Registered 7 October 2013.

  10. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013.

    Science.gov (United States)

    Forouzanfar, Mohammad H; Alexander, Lily; Anderson, H Ross; Bachman, Victoria F; Biryukov, Stan; Brauer, Michael; Burnett, Richard; Casey, Daniel; Coates, Matthew M; Cohen, Aaron; Delwiche, Kristen; Estep, Kara; Frostad, Joseph J; Astha, K C; Kyu, Hmwe H; Moradi-Lakeh, Maziar; Ng, Marie; Slepak, Erica Leigh; Thomas, Bernadette A; Wagner, Joseph; Aasvang, Gunn Marit; Abbafati, Cristiana; Abbasoglu Ozgoren, Ayse; Abd-Allah, Foad; Abera, Semaw F; Aboyans, Victor; Abraham, Biju; Abraham, Jerry Puthenpurakal; Abubakar, Ibrahim; Abu-Rmeileh, Niveen M E; Aburto, Tania C; Achoki, Tom; Adelekan, Ademola; Adofo, Koranteng; Adou, Arsène K; Adsuar, José C; Afshin, Ashkan; Agardh, Emilie E; Al Khabouri, Mazin J; Al Lami, Faris H; Alam, Sayed Saidul; Alasfoor, Deena; Albittar, Mohammed I; Alegretti, Miguel A; Aleman, Alicia V; Alemu, Zewdie A; Alfonso-Cristancho, Rafael; Alhabib, Samia; Ali, Raghib; Ali, Mohammed K; Alla, François; Allebeck, Peter; Allen, Peter J; Alsharif, Ubai; Alvarez, Elena; Alvis-Guzman, Nelson; Amankwaa, Adansi A; Amare, Azmeraw T; Ameh, Emmanuel A; Ameli, Omid; Amini, Heresh; Ammar, Walid; Anderson, Benjamin O; Antonio, Carl Abelardo T; Anwari, Palwasha; Argeseanu Cunningham, Solveig; Arnlöv, Johan; Arsenijevic, Valentina S Arsic; Artaman, Al; Asghar, Rana J; Assadi, Reza; Atkins, Lydia S; Atkinson, Charles; Avila, Marco A; Awuah, Baffour; Badawi, Alaa; Bahit, Maria C; Bakfalouni, Talal; Balakrishnan, Kalpana; Balalla, Shivanthi; Balu, Ravi Kumar; Banerjee, Amitava; Barber, Ryan M; Barker-Collo, Suzanne L; Barquera, Simon; Barregard, Lars; Barrero, Lope H; Barrientos-Gutierrez, Tonatiuh; Basto-Abreu, Ana C; Basu, Arindam; Basu, Sanjay; Basulaiman, Mohammed O; Batis Ruvalcaba, Carolina; Beardsley, Justin; Bedi, Neeraj; Bekele, Tolesa; Bell, Michelle L; Benjet, Corina; Bennett, Derrick A; Benzian, Habib; Bernabé, Eduardo; Beyene, Tariku J; Bhala, Neeraj; Bhalla, Ashish; Bhutta, Zulfiqar A; Bikbov, Boris; Bin Abdulhak, Aref A; Blore, Jed D; Blyth, Fiona M; Bohensky, Megan A; Bora Başara, Berrak; Borges, Guilherme; Bornstein, Natan M; Bose, Dipan; Boufous, Soufiane; Bourne, Rupert R; Brainin, Michael; Brazinova, Alexandra; Breitborde, Nicholas J; Brenner, Hermann; Briggs, Adam D M; Broday, David M; Brooks, Peter M; Bruce, Nigel G; Brugha, Traolach S; Brunekreef, Bert; Buchbinder, Rachelle; Bui, Linh N; Bukhman, Gene; Bulloch, Andrew G; Burch, Michael; Burney, Peter G J; Campos-Nonato, Ismael R; Campuzano, Julio C; Cantoral, Alejandra J; Caravanos, Jack; Cárdenas, Rosario; Cardis, Elisabeth; Carpenter, David O; Caso, Valeria; Castañeda-Orjuela, Carlos A; Castro, Ruben E; Catalá-López, Ferrán; Cavalleri, Fiorella; Çavlin, Alanur; Chadha, Vineet K; Chang, Jung-Chen; Charlson, Fiona J; Chen, Honglei; Chen, Wanqing; Chen, Zhengming; Chiang, Peggy P; Chimed-Ochir, Odgerel; Chowdhury, Rajiv; Christophi, Costas A; Chuang, Ting-Wu; Chugh, Sumeet S; Cirillo, Massimo; Claßen, Thomas K D; Colistro, Valentina; Colomar, Mercedes; Colquhoun, Samantha M; Contreras, Alejandra G; Cooper, Cyrus; Cooperrider, Kimberly; Cooper, Leslie T; Coresh, Josef; Courville, Karen J; Criqui, Michael H; Cuevas-Nasu, Lucia; Damsere-Derry, James; Danawi, Hadi; Dandona, Lalit; Dandona, Rakhi; Dargan, Paul I; Davis, Adrian; Davitoiu, Dragos V; Dayama, Anand; de Castro, E Filipa; De la Cruz-Góngora, Vanessa; De Leo, Diego; de Lima, Graça; Degenhardt, Louisa; del Pozo-Cruz, Borja; Dellavalle, Robert P; Deribe, Kebede; Derrett, Sarah; Des Jarlais, Don C; Dessalegn, Muluken; deVeber, Gabrielle A; Devries, Karen M; Dharmaratne, Samath D; Dherani, Mukesh K; Dicker, Daniel; Ding, Eric L; Dokova, Klara; Dorsey, E Ray; Driscoll, Tim R; Duan, Leilei; Durrani, Adnan M; Ebel, Beth E; Ellenbogen, Richard G; Elshrek, Yousef M; Endres, Matthias; Ermakov, Sergey P; Erskine, Holly E; Eshrati, Babak; Esteghamati, Alireza; Fahimi, Saman; Faraon, Emerito Jose A; Farzadfar, Farshad; Fay, Derek F J; Feigin, Valery L; Feigl, Andrea B; Fereshtehnejad, Seyed-Mohammad; Ferrari, Alize J; Ferri, Cleusa P; Flaxman, Abraham D; Fleming, Thomas D; Foigt, Nataliya; Foreman, Kyle J; Paleo, Urbano Fra; Franklin, Richard C; Gabbe, Belinda; Gaffikin, Lynne; Gakidou, Emmanuela; Gamkrelidze, Amiran; Gankpé, Fortuné G; Gansevoort, Ron T; García-Guerra, Francisco A; Gasana, Evariste; Geleijnse, Johanna M; Gessner, Bradford D; Gething, Pete; Gibney, Katherine B; Gillum, Richard F; Ginawi, Ibrahim A M; Giroud, Maurice; Giussani, Giorgia; Goenka, Shifalika; Goginashvili, Ketevan; Gomez Dantes, Hector; Gona, Philimon; Gonzalez de Cosio, Teresita; González-Castell, Dinorah; Gotay, Carolyn C; Goto, Atsushi; Gouda, Hebe N; Guerrant, Richard L; Gugnani, Harish C; Guillemin, Francis; Gunnell, David; Gupta, Rahul; Gupta, Rajeev; Gutiérrez, Reyna A; Hafezi-Nejad, Nima; Hagan, Holly; Hagstromer, Maria; Halasa, Yara A; Hamadeh, Randah R; Hammami, Mouhanad; Hankey, Graeme J; Hao, Yuantao; Harb, Hilda L; Haregu, Tilahun Nigatu; Haro, Josep Maria; Havmoeller, Rasmus; Hay, Simon I; Hedayati, Mohammad T; Heredia-Pi, Ileana B; Hernandez, Lucia; Heuton, Kyle R; Heydarpour, Pouria; Hijar, Martha; Hoek, Hans W; Hoffman, Howard J; Hornberger, John C; Hosgood, H Dean; Hoy, Damian G; Hsairi, Mohamed; Hu, Guoqing; Hu, Howard; Huang, Cheng; Huang, John J; Hubbell, Bryan J; Huiart, Laetitia; Husseini, Abdullatif; Iannarone, Marissa L; Iburg, Kim M; Idrisov, Bulat T; Ikeda, Nayu; Innos, Kaire; Inoue, Manami; Islami, Farhad; Ismayilova, Samaya; Jacobsen, Kathryn H; Jansen, Henrica A; Jarvis, Deborah L; Jassal, Simerjot K; Jauregui, Alejandra; Jayaraman, Sudha; Jeemon, Panniyammakal; Jensen, Paul N; Jha, Vivekanand; Jiang, Fan; Jiang, Guohong; Jiang, Ying; Jonas, Jost B; Juel, Knud; Kan, Haidong; Kany Roseline, Sidibe S; Karam, Nadim E; Karch, André; Karema, Corine K; Karthikeyan, Ganesan; Kaul, Anil; Kawakami, Norito; Kazi, Dhruv S; Kemp, Andrew H; Kengne, Andre P; Keren, Andre; Khader, Yousef S; Khalifa, Shams Eldin Ali Hassan; Khan, Ejaz A; Khang, Young-Ho; Khatibzadeh, Shahab; Khonelidze, Irma; Kieling, Christian; Kim, Daniel; Kim, Sungroul; Kim, Yunjin; Kimokoti, Ruth W; Kinfu, Yohannes; Kinge, Jonas M; Kissela, Brett M; Kivipelto, Miia; Knibbs, Luke D; Knudsen, Ann Kristin; Kokubo, Yoshihiro; Kose, M Rifat; Kosen, Soewarta; Kraemer, Alexander; Kravchenko, Michael; Krishnaswami, Sanjay; Kromhout, Hans; Ku, Tiffany; Kuate Defo, Barthelemy; Kucuk Bicer, Burcu; Kuipers, Ernst J; Kulkarni, Chanda; Kulkarni, Veena S; Kumar, G Anil; Kwan, Gene F; Lai, Taavi; Lakshmana Balaji, Arjun; Lalloo, Ratilal; Lallukka, Tea; Lam, Hilton; Lan, Qing; Lansingh, Van C; Larson, Heidi J; Larsson, Anders; Laryea, Dennis O; Lavados, Pablo M; Lawrynowicz, Alicia E; Leasher, Janet L; Lee, Jong-Tae; Leigh, James; Leung, Ricky; Levi, Miriam; Li, Yichong; Li, Yongmei; Liang, Juan; Liang, Xiaofeng; Lim, Stephen S; Lindsay, M Patrice; Lipshultz, Steven E; Liu, Shiwei; Liu, Yang; Lloyd, Belinda K; Logroscino, Giancarlo; London, Stephanie J; Lopez, Nancy; Lortet-Tieulent, Joannie; Lotufo, Paulo A; Lozano, Rafael; Lunevicius, Raimundas; Ma, Jixiang; Ma, Stefan; Machado, Vasco M P; MacIntyre, Michael F; Magis-Rodriguez, Carlos; Mahdi, Abbas A; Majdan, Marek; Malekzadeh, Reza; Mangalam, Srikanth; Mapoma, Christopher C; Marape, Marape; Marcenes, Wagner; Margolis, David J; Margono, Christopher; Marks, Guy B; Martin, Randall V; Marzan, Melvin B; Mashal, Mohammad T; Masiye, Felix; Mason-Jones, Amanda J; Matsushita, Kunihiro; Matzopoulos, Richard; Mayosi, Bongani M; Mazorodze, Tasara T; McKay, Abigail C; McKee, Martin; McLain, Abigail; Meaney, Peter A; Medina, Catalina; Mehndiratta, Man Mohan; Mejia-Rodriguez, Fabiola; Mekonnen, Wubegzier; Melaku, Yohannes A; Meltzer, Michele; Memish, Ziad A; Mendoza, Walter; Mensah, George A; Meretoja, Atte; Mhimbira, Francis Apolinary; Micha, Renata; Miller, Ted R; Mills, Edward J; Misganaw, Awoke; Mishra, Santosh; Mohamed Ibrahim, Norlinah; Mohammad, Karzan A; Mokdad, Ali H; Mola, Glen L; Monasta, Lorenzo; Montañez Hernandez, Julio C; Montico, Marcella; Moore, Ami R; Morawska, Lidia; Mori, Rintaro; Moschandreas, Joanna; Moturi, Wilkister N; Mozaffarian, Dariush; Mueller, Ulrich O; Mukaigawara, Mitsuru; Mullany, Erin C; Murthy, Kinnari S; Naghavi, Mohsen; Nahas, Ziad; Naheed, Aliya; Naidoo, Kovin S; Naldi, Luigi; Nand, Devina; Nangia, Vinay; Narayan, K M Venkat; Nash, Denis; Neal, Bruce; Nejjari, Chakib; Neupane, Sudan P; Newton, Charles R; Ngalesoni, Frida N; Ngirabega, Jean de Dieu; Nguyen, Grant; Nguyen, Nhung T; Nieuwenhuijsen, Mark J; Nisar, Muhammad I; Nogueira, José R; Nolla, Joan M; Nolte, Sandra; Norheim, Ole F; Norman, Rosana E; Norrving, Bo; Nyakarahuka, Luke; Oh, In-Hwan; Ohkubo, Takayoshi; Olusanya, Bolajoko O; Omer, Saad B; Opio, John Nelson; Orozco, Ricardo; Pagcatipunan, Rodolfo S; Pain, Amanda W; Pandian, Jeyaraj D; Panelo, Carlo Irwin A; Papachristou, Christina; Park, Eun-Kee; Parry, Charles D; Paternina Caicedo, Angel J; Patten, Scott B; Paul, Vinod K; Pavlin, Boris I; Pearce, Neil; Pedraza, Lilia S; Pedroza, Andrea; Pejin Stokic, Ljiljana; Pekericli, Ayfer; Pereira, David M; Perez-Padilla, Rogelio; Perez-Ruiz, Fernando; Perico, Norberto; Perry, Samuel A L; Pervaiz, Aslam; Pesudovs, Konrad; Peterson, Carrie B; Petzold, Max; Phillips, Michael R; Phua, Hwee Pin; Plass, Dietrich; Poenaru, Dan; Polanczyk, Guilherme V; Polinder, Suzanne; Pond, Constance D; Pope, C Arden; Pope, Daniel; Popova, Svetlana; Pourmalek, Farshad; Powles, John; Prabhakaran, Dorairaj; Prasad, Noela M; Qato, Dima M; Quezada, Amado D; Quistberg, D Alex A; Racapé, Lionel; Rafay, Anwar; Rahimi, Kazem; Rahimi-Movaghar, Vafa; Rahman, Sajjad Ur; Raju, Murugesan; Rakovac, Ivo; Rana, Saleem M; Rao, Mayuree; Razavi, Homie; Reddy, K Srinath; Refaat, Amany H; Rehm, Jürgen; Remuzzi, Giuseppe; Ribeiro, Antonio L; Riccio, Patricia M; Richardson, Lee; Riederer, Anne; Robinson, Margaret; Roca, Anna; Rodriguez, Alina; Rojas-Rueda, David; Romieu, Isabelle; Ronfani, Luca; Room, Robin; Roy, Nobhojit; Ruhago, George M; Rushton, Lesley; Sabin, Nsanzimana; Sacco, Ralph L; Saha, Sukanta; Sahathevan, Ramesh; Sahraian, Mohammad Ali; Salomon, Joshua A; Salvo, Deborah; Sampson, Uchechukwu K; Sanabria, Juan R; Sanchez, Luz Maria; Sánchez-Pimienta, Tania G; Sanchez-Riera, Lidia; Sandar, Logan; Santos, Itamar S; Sapkota, Amir; Satpathy, Maheswar; Saunders, James E; Sawhney, Monika; Saylan, Mete I; Scarborough, Peter; Schmidt, Jürgen C; Schneider, Ione J C; Schöttker, Ben; Schwebel, David C; Scott, James G; Seedat, Soraya; Sepanlou, Sadaf G; Serdar, Berrin; Servan-Mori, Edson E; Shaddick, Gavin; Shahraz, Saeid; Levy, Teresa Shamah; Shangguan, Siyi; She, Jun; Sheikhbahaei, Sara; Shibuya, Kenji; Shin, Hwashin H; Shinohara, Yukito; Shiri, Rahman; Shishani, Kawkab; Shiue, Ivy; Sigfusdottir, Inga D; Silberberg, Donald H; Simard, Edgar P; Sindi, Shireen; Singh, Abhishek; Singh, Gitanjali M; Singh, Jasvinder A; Skirbekk, Vegard; Sliwa, Karen; Soljak, Michael; Soneji, Samir; Søreide, Kjetil; Soshnikov, Sergey; Sposato, Luciano A; Sreeramareddy, Chandrashekhar T; Stapelberg, Nicolas J C; Stathopoulou, Vasiliki; Steckling, Nadine; Stein, Dan J; Stein, Murray B; Stephens, Natalie; Stöckl, Heidi; Straif, Kurt; Stroumpoulis, Konstantinos; Sturua, Lela; Sunguya, Bruno F; Swaminathan, Soumya; Swaroop, Mamta; Sykes, Bryan L; Tabb, Karen M; Takahashi, Ken; Talongwa, Roberto T; Tandon, Nikhil; Tanne, David; Tanner, Marcel; Tavakkoli, Mohammad; Te Ao, Braden J; Teixeira, Carolina M; Téllez Rojo, Martha M; Terkawi, Abdullah S; Texcalac-Sangrador, José Luis; Thackway, Sarah V; Thomson, Blake; Thorne-Lyman, Andrew L; Thrift, Amanda G; Thurston, George D; Tillmann, Taavi; Tobollik, Myriam; Tonelli, Marcello; Topouzis, Fotis; Towbin, Jeffrey A; Toyoshima, Hideaki; Traebert, Jefferson; Tran, Bach X; Trasande, Leonardo; Trillini, Matias; Trujillo, Ulises; Dimbuene, Zacharie Tsala; Tsilimbaris, Miltiadis; Tuzcu, Emin Murat; Uchendu, Uche S; Ukwaja, Kingsley N; Uzun, Selen B; van de Vijver, Steven; Van Dingenen, Rita; van Gool, Coen H; van Os, Jim; Varakin, Yuri Y; Vasankari, Tommi J; Vasconcelos, Ana Maria N; Vavilala, Monica S; Veerman, Lennert J; Velasquez-Melendez, Gustavo; Venketasubramanian, N; Vijayakumar, Lakshmi; Villalpando, Salvador; Violante, Francesco S; Vlassov, Vasiliy Victorovich; Vollset, Stein Emil; Wagner, Gregory R; Waller, Stephen G; Wallin, Mitchell T; Wan, Xia; Wang, Haidong; Wang, JianLi; Wang, Linhong; Wang, Wenzhi; Wang, Yanping; Warouw, Tati S; Watts, Charlotte H; Weichenthal, Scott; Weiderpass, Elisabete; Weintraub, Robert G; Werdecker, Andrea; Wessells, K Ryan; Westerman, Ronny; Whiteford, Harvey A; Wilkinson, James D; Williams, Hywel C; Williams, Thomas N; Woldeyohannes, Solomon M; Wolfe, Charles D A; Wong, John Q; Woolf, Anthony D; Wright, Jonathan L; Wurtz, Brittany; Xu, Gelin; Yan, Lijing L; Yang, Gonghuan; Yano, Yuichiro; Ye, Pengpeng; Yenesew, Muluken; Yentür, Gökalp K; Yip, Paul; Yonemoto, Naohiro; Yoon, Seok-Jun; Younis, Mustafa Z; Younoussi, Zourkaleini; Yu, Chuanhua; Zaki, Maysaa E; Zhao, Yong; Zheng, Yingfeng; Zhou, Maigeng; Zhu, Jun; Zhu, Shankuan; Zou, Xiaonong; Zunt, Joseph R; Lopez, Alan D; Vos, Theo; Murray, Christopher J

    2015-12-05

    The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for prevention. The GBD 2013 provides a timely opportunity to update the comparative risk assessment with new data for exposure, relative risks, and evidence on the appropriate counterfactual risk distribution. Attributable deaths, years of life lost, years lived with disability, and disability-adjusted life-years (DALYs) have been estimated for 79 risks or clusters of risks using the GBD 2010 methods. Risk-outcome pairs meeting explicit evidence criteria were assessed for 188 countries for the period 1990-2013 by age and sex using three inputs: risk exposure, relative risks, and the theoretical minimum risk exposure level (TMREL). Risks are organised into a hierarchy with blocks of behavioural, environmental and occupational, and metabolic risks at the first level of the hierarchy. The next level in the hierarchy includes nine clusters of related risks and two individual risks, with more detail provided at levels 3 and 4 of the hierarchy. Compared with GBD 2010, six new risk factors have been added: handwashing practices, occupational exposure to trichloroethylene, childhood wasting, childhood stunting, unsafe sex, and low glomerular filtration rate. For most risks, data for exposure were synthesised with a Bayesian meta-regression method, DisMod-MR 2.0, or spatial-temporal Gaussian process regression. Relative risks were based on meta-regressions of published cohort and intervention studies. Attributable burden for clusters of risks and all risks combined took into account evidence on the mediation of some risks such as high body-mass index (BMI) through other risks such as high systolic blood pressure and high cholesterol. All risks combined account for 57·2% (95% uncertainty interval

  11. Genetics of Cd36 and the clustering of multiple cardiovascular risk factors in spontaneous hypertension

    Czech Academy of Sciences Publication Activity Database

    Pravenec, Michal; Zídek, Václav; Šimáková, Miroslava; Křen, Vladimír; Křenová, D.; Horký, K.; Jáchymová, M.; Míková, B.; Kazdová, L.; Aitman, T. J.; Churchill, P. C.; Webb, R. C.; Hingarh, N. H.; Yang, Y.; Wang, J. M.; St.Lezin, E. M.; Kurtz, W. T.

    1999-01-01

    Roč. 103, č. 12 (1999), s. 1651-1657 ISSN 0021-9738 R&D Projects: GA ČR GA306/97/0521; GA ČR GV204/98/K015 Grant - others:NIH(US) ROI HL-56028; NIH(US) PO1 HL-35018; NIH(US) HL-18575 Institutional research plan: CEZ:AV0Z5011922 Keywords : Cd36 * cardiovascular risk factors * spontaneous hypertension Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 10.921, year: 1999

  12. Beyond Risk Compensation: Clusters of Antiretroviral Treatment (ART) Users in Sexual Networks Can Modify the Impact of ART on HIV Incidence

    Science.gov (United States)

    Delva, Wim; Helleringer, Stéphane

    2016-01-01

    Introduction Concerns about risk compensation—increased risk behaviours in response to a perception of reduced HIV transmission risk—after the initiation of ART have largely been dispelled in empirical studies, but other changes in sexual networking patterns may still modify the effects of ART on HIV incidence. Methods We developed an exploratory mathematical model of HIV transmission that incorporates the possibility of ART clusters, i.e. subsets of the sexual network in which the density of ART patients is much higher than in the rest of the network. Such clusters may emerge as a result of ART homophily—a tendency for ART patients to preferentially form and maintain relationships with other ART patients. We assessed whether ART clusters may affect the impact of ART on HIV incidence, and how the influence of this effect-modifying variable depends on contextual variables such as HIV prevalence, HIV serosorting, coverage of HIV testing and ART, and adherence to ART. Results ART homophily can modify the impact of ART on HIV incidence in both directions. In concentrated epidemics and generalized epidemics with moderate HIV prevalence (≈ 10%), ART clusters can enhance the impact of ART on HIV incidence, especially when adherence to ART is poor. In hyperendemic settings (≈ 35% HIV prevalence), ART clusters can reduce the impact of ART on HIV incidence when adherence to ART is high but few people living with HIV (PLWH) have been diagnosed. In all contexts, the effects of ART clusters on HIV epidemic dynamics are distinct from those of HIV serosorting. Conclusions Depending on the programmatic and epidemiological context, ART clusters may enhance or reduce the impact of ART on HIV incidence, in contrast to serosorting, which always leads to a lower impact of ART on HIV incidence. ART homophily and the emergence of ART clusters should be measured empirically and incorporated into more refined models used to plan and evaluate ART programmes. PMID:27657492

  13. Metabolic risk-factor clustering estimation in children: to draw a line across pediatric metabolic syndrome

    DEFF Research Database (Denmark)

    Brambilla, P; Lissau, I; Flodmark, C-E

    2007-01-01

    BACKGROUND: The diagnostic criteria of the metabolic syndrome (MS) have been applied in studies of obese adults to estimate the metabolic risk-associated with obesity, even though no general consensus exists concerning its definition and clinical value. We reviewed the current literature on the MS......, focusing on those studies that used the MS diagnostic criteria to analyze children, and we observed extreme heterogeneity for the sets of variables and cutoff values chosen. OBJECTIVES: To discuss concerns regarding the use of the existing definition of the MS (as defined in adults) in children...... derived from a child's family and personal history; the lack of consensus on insulin levels, lipid parameters, markers of inflammation or steato-hepatitis; the lack of an additive relevant effect of the MS definition to obesity per se. We propose the adoption of 10 evidence-based items from which...

  14. Participatory ergonomics to reduce exposure to psychosocial and physical risk factors for low back pain and neck pain: Results of a cluster randomised controlled trial

    NARCIS (Netherlands)

    Driessen, M.T.; Proper, K.I.; Anema, J.R.; Knol, D.L.; Bongers, P.M.; Beek, A.J. van der

    2011-01-01

    Objectives: This study investigated the effectiveness of the Stay@Work participatory ergonomics programme to reduce workers9 exposure to psychosocial and physical risk factors. Methods: 37 departments (n=3047 workers) from four Dutch companies participated in this cluster randomised controlled

  15. The Effect of Brief Interventions on the Drinking Behaviour of Pregnant Women in a High-Risk Rural South African Community: A Cluster Randomised Trial

    Science.gov (United States)

    Marais, Sandra; Jordaan, Esme; Viljoen, Dennis; Olivier, Leana; de Waal, Johanna; Poole, Caroline

    2011-01-01

    The purpose of this paper is to assess the impact of a series of brief interventions (BIs) on anti-natal alcohol consumption of women from a disadvantaged and high-risk background attending state health clinics in a rural district, Western Cape Province, South Africa. A pragmatic cluster randomised trial design was followed. All pregnant women,…

  16. Clustering of chronic disease risk factors with tobacco smoking habits among adults in the work place in Sousse, Tunisia.

    Science.gov (United States)

    Sonia, Hmad; Jihene, Maatoug; Imed, Harrabi; Rim, Ghammem; Mylene, Belkacem; Mounir, Saadi; Souad, Amimi; Khaoula, Knani; Mustafa, Al'Absi; Harry, Lando; Najib, Mrizak; Hassen, Ghannem

    2016-01-01

    The aim of our study was to explore the major non-communicable risk factors (unhealthy diet, sedentarily, alcohol consumption) of smokers and nonsmokers in workplaces. A cross-sectional study was derived from an initial assessment in workplaces which was part of a community-based intervention to prevent chronic disease risk factors conducted in 2009 in the region of Sousse, Tunisia. The surveyed subjects were employees in six factories spread across three delegations in the region. Overall, 1770 of 2250 employees participated in the assessment. In this study, the clustering of non-communicable diseases risk factors with smoking habits was made only for male employees including in this study 1099 among 2250. Data were collected at worksites by a questionnaire, via interview or self-report. The main items assessed socio-demographics characteristics, smoking status, eating habits, level of physical activity and alcohol use of the participants. The percentage of male smokers was 54.0%(n=594). Their average age of daily smoking initiation was 19.22 (±4.24 years). The percentage of male smokers consuming 5 fruits and vegetables per day was significantly lower than nonsmokers (57.2% vs 63.5%, p=0.04). The proportion of male smokers consuming alcohol was about three times that of nonsmokers (16.5% vs 5.8%, p=0.001). The proportion of male employees who agree with anti-smoking laws in work places was higher for nonsmokers than for smokers. A strong association existed between smoking and risky lifestyles factors in the work place. Such findings are potentially useful in directing intervention efforts regarding smoking cessation in occupational settings.

  17. Cluster Risk of Walking Scenarios Based on Macroscopic Flow Model and Crowding Force Analysis

    Directory of Open Access Journals (Sweden)

    Xiaohong Li

    2018-02-01

    Full Text Available In recent years, accidents always happen in confined space such as metro stations because of congestion. Various researchers investigated the patterns of dense crowd behaviors in different scenarios via simulations or experiments and proposed methods for avoiding accidents. In this study, a classic continuum macroscopic model was applied to simulate the crowded pedestrian flow in typical scenarios such as at bottlenecks or with an obstacle. The Lax–Wendroff finite difference scheme and artificial viscosity filtering method were used to discretize the model to identify high-density risk areas. Furthermore, we introduced a contact crowding force test of the interactions among pedestrians at bottlenecks. Results revealed that in the most dangerous area, the individual on the corner position bears the maximum pressure in such scenarios is 90.2 N, and there is an approximate exponential relationship between crowding force and density indicated by our data. The results and findings presented in this paper can facilitate more reasonable and precise simulation models by utilizing crowding force and crowd density and ensure the safety of pedestrians in high-density scenarios.

  18. Community risk factors for ocular Chlamydia infection in Niger: pre-treatment results from a cluster-randomized trachoma trial.

    Directory of Open Access Journals (Sweden)

    Abdou Amza

    Full Text Available Trachoma control programs utilize mass azithromycin distributions to treat ocular Chlamydia trachomatis as part of an effort to eliminate this disease world-wide. But it remains unclear what the community-level risk factors are for infection.This cluster-randomized, controlled trial entered 48 randomly selected communities in a 2×2 factorial design evaluating the effect of different treatment frequencies and treatment coverage levels. A pretreatment census and examination established the prevalence of risk factors for clinical trachoma and ocular chlamydia infection including years of education of household head, distance to primary water source, presence of household latrine, and facial cleanliness (ocular discharge, nasal discharge, and presence of facial flies. Univariate and multivariate associations were tested using linear regression and Bayes model averaging.There were a total of 24,536 participants (4,484 children aged 0-5 years in 6,235 households in the study. Before treatment in May to July 2010, the community-level prevalence of active trachoma (TF or TI utilizing the World Health Organization [WHO] grading system was 26.0% (95% CI: 21.9% to 30.0% and the mean community-level prevalence of chlamydia infection by Amplicor PCR was 20.7% (95% CI: 16.5% to 24.9% in children aged 0-5 years. Univariate analysis showed that nasal discharge (0.29, 95% CI: 0.04 to 0.54; P = 0.03, presence of flies on the face (0.40, 95% CI: 0.17 to 0.64; P = 0.001, and years of formal education completed by the head of household (0.07, 95% CI: 0.07 to 0.13; P = 0.03 were independent risk factors for chlamydia infection. In multivariate analysis, facial flies (0.26, 95% CI: 0.02 to 0.49; P = 0.03 and years of formal education completed by the head of household (0.06, 95% CI: 0.008 to 0.11; P = 0.02 were associated risk factors for ocular chlamydial infection.We have found that the presence of facial flies and years of education of the head

  19. Meta Salud Diabetes study protocol: a cluster-randomised trial to reduce cardiovascular risk among a diabetic population of Mexico.

    Science.gov (United States)

    Sabo, Samantha; Denman Champion, Catalina; Bell, Melanie L; Cornejo Vucovich, Elsa; Ingram, Maia; Valenica, Celina; Castro Vasquez, Maria Del Carmen; Gonzalez-Fagoaga, Eduardo; Geurnsey de Zapien, Jill; Rosales, Cecilia B

    2018-03-12

    Northern Mexico has among the highest rates of cardiovascular disease (CVD) and diabetes in the world. This research addresses core gaps in implementation science to develop, test and scale-up CVD risk-reduction interventions in diabetics through a national primary care health system. The Meta Salud Diabetes (MSD) research project is a parallel two-arm cluster-randomised clinical behavioural trial based in 22 (n=22) health centres in Sonora, Mexico. MSD aims to evaluate the effectiveness of the MSD intervention for the secondary prevention of CVD risk factors among a diabetic population (n=320) compared with the study control of usual care. The MSD intervention consists of 2-hour class sessions delivered over a 13-week period providing educational information to encourage sustainable behavioural change to prevent disease complications including the adoption of physical activity. MSD is delivered within the context of Mexico's national primary care health centre system by health professionals, including nurses, physicians and community health workers via existing social support groups for individuals diagnosed with chronic disease. Mixed models are used to estimate the effect of MSD by comparing cardiovascular risk, as measured by the Framingham Risk Score, between the trial arms. Secondary outcomes include hypertension, behavioural risk factors and psychosocial factors. This work is supported by the National Institutes of Health, National Heart Lung and Blood Institute (1R01HL125996-01) and approved by the University of Arizona Research Institutional Review Board (Protocol 1508040144) and the Research Bioethics Committee at the University of Sonora. The first Internal Review Board approval date was 31 August 2015 with five subsequent approved amendments. This article refers to protocol V.0.2, dated 30 January 2017. Results will be disseminated via peer-reviewed publication and presentation at international conferences and will be shared through meetings with health

  20. Association of Parental Overweight and Cardiometabolic Diseases and Pediatric Adiposity and Lifestyle Factors with Cardiovascular Risk Factor Clustering in Adolescents

    Directory of Open Access Journals (Sweden)

    Chun-Ying Lee

    2016-09-01

    Full Text Available Cardiometabolic risk factors or their precursors are observed in childhood and may continue into adulthood. We investigated the effects of parental overweight and cardiometabolic diseases and pediatric lifestyle factors on the clustering of cardiovascular risk factors among adolescents, and examined the mediating and modifying effects of pediatric adiposity on these associations. Representative adolescents (n = 2727; age, 12–16 years were randomly recruited through multistage stratified sampling from 36 schools in Southern Taiwan. Adolescent and parent surveys were conducted in schools and participant homes, respectively. Their demographic factors, diet patterns, and physical, anthropometric, and clinical parameters were collected and analyzed. Adolescents with 1–2 and ≥3 risk components for pediatric metabolic syndrome (MetS were defined as potential MetS (pot-MetS and MetS, respectively. Adolescents whose parents were overweight/obese, or with diabetes and hypertension had a higher prevalence ratio of pot-MetS and MetS (1.5–1.6 and 1.9–4.2-fold, respectively. Low physical activity (<952.4 MET·min/week, long screen time (≥3 h/day and high sugar-sweetened beverage intake (>500 mL/day were associated with a 3.3- (95% confidence intervals (CI = 1.5–7.3, 2.2- (95% CI = 1.1–4.4, and 26.9-fold (95% CI = 3.2–229.0 odds ratio (OR of MetS, respectively. Pediatric body mass index (BMI accounted for 18.8%–95.6% and 16.9%–60.3% increased prevalence ratios of these parental and pediatric risk factors for MetS. The OR of pot-MetS + MetS for sugar-sweetened beverage consumption was multiplicatively enhanced among adolescents with overweight/obesity (combined OR, 8.6-fold (95% CI = 4.3–17.3; p for multiplicative interaction, 0.009. The results suggest that parental overweight and cardiometabolic diseases and pediatric sedentary and high sugar-intake lifestyles correlate with the development of adolescent MetS, and an elevated child BMI

  1. Criteria of waist circumference according to computed tomography-measured visceral fat area and the clustering of cardiovascular risk factors

    International Nuclear Information System (INIS)

    Kashihara, Hidetoshi; Tamura, Masaki; Lee, J.S.; Akabayashi, Akira; Kawakubo, Kiyoshi

    2009-01-01

    The purpose of this study was to determine the discriminate gender-specific cutoff values of waist circumference (WC) for detecting the clustering of cardiovascular risk factors (CCRF), which reflects the intra-abdominal visceral fat area (VFA) using a large Japanese population. The study population consisted of 6,736 men and women who underwent a periodic health check-up and had a computed tomography scan for VFA measurement at the PL Tokyo Health Care Center in Tokyo, Japan. The CCRF was defined according to the Japanese Committee of the Criteria for Metabolic Syndrome. The discriminate values for detecting the CCRF were tested using receiver operating characteristics analysis. The discriminate values of VFA were 103.0 cm 2 with 68.7% sensitivity and 61.8% specificity for men and 69.0 cm 2 with 80.8% sensitivity and 70.0% specificity for women. The WC values corresponding to the VFA were 89.1 cm for men and 86.3 cm for women. The discriminate values of VFA and WC were not substantially different between people with or without raised blood pressure. For the early detection and management of the CCRF and VFA in the primary screening setting, the discriminate and convenient gender-specific WC criteria would be 90 cm for men and 85 cm for women. (author)

  2. A cluster randomized trial of alcohol prevention in small businesses: a cascade model of help seeking and risk reduction.

    Science.gov (United States)

    Reynolds, G Shawn; Bennett, Joel B

    2015-01-01

    The current study adapted two workplace substance abuse prevention programs and tested a conceptual model of workplace training effects on help seeking and alcohol consumption. Questionnaires were collected 1 month before, 1 month after, and 6 months within a cluster randomized field experiment. Texas small businesses in construction, transportation, and service industries. A total of 1510 employees from 45 businesses were randomly assigned to receive no training or one of the interventions. The interventions were 4-hour on-the-job classroom trainings that encouraged healthy lifestyles and seeking professional help (e.g., from the Employee Assistance Program [EAP]). The Team Awareness Program focused on peer referral and team building. The Choices in Health Promotion Program delivered various health topics based on a needs assessment. Questionnaires measured help-seeking attitudes and behavior, frequency of drinking alcohol, and job-related incidents. Mixed-model repeated-measures analyses of covariance were computed. Relative to the control group, training was associated with significantly greater reductions in drinking frequency, willingness to seek help, and seeking help from the EAP. After including help-seeking attitudes as a covariate, the correlation between training and help seeking becomes nonsignificant. Help-seeking behavior was not correlated with drinking frequency. Training improved help-seeking attitudes and behaviors and decreased alcohol risks. The reductions in drinking alcohol were directly correlated with training and independent from help seeking.

  3. Two-step values for games with two-level communication structure

    NARCIS (Netherlands)

    Béal, Silvain; Khmelnitskaya, Anna Borisovna; Solal, Philippe

    TU games with two-level communication structure, in which a two-level communication structure relates fundamentally to the given coalition structure and consists of a communication graph on the collection of the a priori unions in the coalition structure, as well as a collection of communication

  4. Clustering of risk-related modifiable behaviours and their association with overweight and obesity among a large sample of youth in the COMPASS study

    Directory of Open Access Journals (Sweden)

    Rachel E. Laxer

    2017-01-01

    Full Text Available Abstract Background Canadian youth exhibit a number of risky behaviours, some of which are associated with overweight and obesity. The purpose of this study was to examine the prevalence of 15 modifiable risk behaviours in a large sample of Canadian youth, to identify underlying subgroups based on patterns of health behaviours, and to examine the association between identified subgroups and overweight/obesity. Methods Data from 18,587 grades 9–12 students in Year 1 (2012–13 of the COMPASS study and latent class analysis were used to identify patterns and clustering among 15 health behaviours (e.g., physical inactivity, sedentary behaviour, unhealthy eating, substance use. A logistic regression model examined the associations between these clusters and overweight/obesity status. Results Four distinct classes were identified: traditional school athletes, inactive screenagers, health conscious, and moderately active substance users. Each behavioural cluster demonstrated a distinct pattern of behaviours, some with a greater number of risk factors than others. Traditional school athletes (odds ratio (OR 1.15, 95% CI 1.03–1.29, inactive screenagers (OR 1.33; 1.19–1.48, and moderately active substance users (OR 1.27; 1.14–1.43 were all significantly more likely to be overweight/obese compared to the health conscious group. Conclusions Four distinct subpopulations of youth were identified based on their patterns of health and risk behaviours. The three clusters demonstrating poorer health behaviour were all at an increased risk of being overweight/obese compared to their somewhat healthier peers. Obesity-related public health interventions and health promotion efforts might be more effective if consideration is given to population segments with certain behavioural patterns, targeting subgroups at greatest risk of overweight or obesity.

  5. Clustering of risk-related modifiable behaviours and their association with overweight and obesity among a large sample of youth in the COMPASS study.

    Science.gov (United States)

    Laxer, Rachel E; Brownson, Ross C; Dubin, Joel A; Cooke, Martin; Chaurasia, Ashok; Leatherdale, Scott T

    2017-01-21

    Canadian youth exhibit a number of risky behaviours, some of which are associated with overweight and obesity. The purpose of this study was to examine the prevalence of 15 modifiable risk behaviours in a large sample of Canadian youth, to identify underlying subgroups based on patterns of health behaviours, and to examine the association between identified subgroups and overweight/obesity. Data from 18,587 grades 9-12 students in Year 1 (2012-13) of the COMPASS study and latent class analysis were used to identify patterns and clustering among 15 health behaviours (e.g., physical inactivity, sedentary behaviour, unhealthy eating, substance use). A logistic regression model examined the associations between these clusters and overweight/obesity status. Four distinct classes were identified: traditional school athletes, inactive screenagers, health conscious, and moderately active substance users. Each behavioural cluster demonstrated a distinct pattern of behaviours, some with a greater number of risk factors than others. Traditional school athletes (odds ratio (OR) 1.15, 95% CI 1.03-1.29), inactive screenagers (OR 1.33; 1.19-1.48), and moderately active substance users (OR 1.27; 1.14-1.43) were all significantly more likely to be overweight/obese compared to the health conscious group. Four distinct subpopulations of youth were identified based on their patterns of health and risk behaviours. The three clusters demonstrating poorer health behaviour were all at an increased risk of being overweight/obese compared to their somewhat healthier peers. Obesity-related public health interventions and health promotion efforts might be more effective if consideration is given to population segments with certain behavioural patterns, targeting subgroups at greatest risk of overweight or obesity.

  6. Socio-demographic association of multiple modifiable lifestyle risk factors and their clustering in a representative urban population of adults: a cross-sectional study in Hangzhou, China

    Directory of Open Access Journals (Sweden)

    Wang Shengfeng

    2011-05-01

    Full Text Available Abstract Background To plan long-term prevention strategies and develop tailored intervention activities, it is important to understand the socio-demographic characteristics of the subpopulations at high risk of developing chronic diseases. This study aimed to examine the socio-demographic characteristics associated with multiple lifestyle risk factors and their clustering. Methods We conducted a simple random sampling survey to assess lifestyle risk factors in three districts of Hangzhou, China between 2008 and 2009. A two-step cluster analysis was used to identify different health-related lifestyle clusters based on tobacco use, physical activity, fruit and vegetable consumption, and out-of-home eating. Multinomial logistic regression was used to model the association between socio-demographic factors and lifestyle clusters. Results A total of 2016 eligible people (977 men and 1039 women, ages 18-64 years completed the survey. Three distinct clusters were identified from the cluster analysis: an unhealthy (UH group (25.7%, moderately healthy (MH group (31.1%, and healthy (H group (43.1%. UH group was characterised by a high prevalence of current daily smoking, a moderate or low level of PA, low FV consumption with regard to the frequency or servings, and more occurrences of eating out. H group was characterised by no current daily smoking, a moderate level of PA, high FV consumption, and the fewest times of eating out. MH group was characterised by no current daily smoking, a low or high level of PA, and an intermediate level of FV consumption and frequency of eating out. Men were more likely than women to have unhealthy lifestyles. Adults aged 50-64 years were more likely to live healthy lifestyles. Adults aged 40-49 years were more likely to be in the UH group. Adults whose highest level of education was junior high school or below were more likely to be in the UH group. Adults with a high asset index were more likely to be in the MH group

  7. Two levels decision system for efficient planning and implementation of bioenergy production

    International Nuclear Information System (INIS)

    Ayoub, Nasser; Martins, Ricardo; Wang, Kefeng; Seki, Hiroya; Naka, Yuji

    2007-01-01

    When planning bioenergy production from biomass, planners should take into account each and every stakeholder along the biomass supply chains, e.g. biomass resources suppliers, transportation, conversion and electricity suppliers. Also, the planners have to consider social concerns, environmental and economical impacts related with establishing the biomass systems and the specific difficulties of each country. To overcome these problems in a sustainable manner, a robust decision support system is required. For that purpose, a two levels general Bioenergy Decision System (gBEDS) for bioenergy production planning and implementation was developed. The core part of the gBEDS is the information base, which includes the basic bioenergy information and the detailed decision information. Basic bioenergy information include, for instance, the geographical information system (GIS) database, the biomass materials' database, the biomass logistic database and the biomass conversion database. The detailed decision information considers the parameters' values database with their default values and the variables database, values obtained by simulation and optimization. It also includes a scenario database, which is used for demonstration to new users and also for case based reasoning by planners and executers. Based on the information base, the following modules are included to support decision making: the simulation module with graph interface based on the unit process (UP) definition and the genetic algorithms (GAs) methods for optimal decisions and the Matlab module for applying data mining methods (fuzzy C-means clustering and decision trees) to the biomass collection points, to define the location of storage and bioenergy conversion plants based on the simulation and optimization model developed of the whole life cycle of bioenergy generation. Furthermore, Matlab is used to set up a calculation model with crucial biomass planning parameters (e.g. costs, CO 2 emissions), over

  8. [Effects of daily physical exercise at school on cardiovascular risk--results of a 2-year cluster-randomized study].

    Science.gov (United States)

    Walther, C; Mende, M; Gaede, L; Müller, U; Machalica, K; Schuler, G

    2011-11-01

    It was the aim of this study to measure the effects over two years of daily sport activity during the school-day on their physical fitness (primary endpoint), motor coordination and blood pressure (secondary endpoints). A total of 232 children from eleven different 6 (th) grade classes were enrolled after informed parental consent. Their mean age was 11.1  ±  0.6 years. Six classes were randomly assigned for intervention (n=141), five as control (n=91). Those of the intervention cohort undertook, for five days weekly during the school year one hour of regulated sport exercise, including 15 min of endurance training. The pupils of the control group undertook customary sport activity (two hours a week). Anthropometric data were recorded and maximal oxygen uptake measured in each pupil, as well as blood pressure and motor coordination at the beginning and at the end of each of the two years of the study. The data were analyzed using the cluster randomization method. Maximal oxygen uptake (VO (2)max) had improved among the intervention group after two years, compared with the controls (3.12 m/kg/min, 95% confindence interval [CI] 0.06-6.19), while improvement in motor coordination just failed to reach statistical significance (3.06, 95% CI -0.17-6.29). There was no significant difference in systolic and diastolic blood pressure, but a downward trend in the prevalence of overweight and obesity from 12.1% to 7.8% in the intervention group. The results indicate that daily physical exercise during school hours should be given greater importance. But it will require a long-term trial to determine whether promotion of increased physical activity at school influences the prevalence of cardiovascular risk factors when the pupils reach adulthood. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Prevalence and Risk Factors of Dengue Infection in Khanh Hoa Province, Viet Nam: A Stratified Cluster Sampling Survey.

    Science.gov (United States)

    Mai, Vien Quang; Mai, Trịnh Thị Xuan; Tam, Ngo Le Minh; Nghia, Le Trung; Komada, Kenichi; Murakami, Hitoshi

    2018-05-19

    Dengue is a clinically important arthropod-borne viral disease with increasing global incidence. Here we aimed to estimate the prevalence of dengue infections in Khanh Hoa Province, central Viet Nam, and to identify risk factors for infection. We performed a stratified cluster sampling survey including residents of 3-60 years of age in Nha Trang City, Ninh Hoa District and Dien Khanh District, Khanh Hoa Province, in October 2011. Immunoglobulin G (IgG) and immunoglobulin M (IgM) against dengue were analyzed using a rapid test kit. Participants completed a questionnaire exploring clinical dengue incidence, socio-economic status, and individual behavior. A household checklist was used to examine environment, mosquito larvae presence, and exposure to public health interventions. IgG positivity was 20.5% (urban, 16.3%; rural, 23.0%), IgM positivity was 6.7% (urban, 6.4%; rural, 6.9%), and incidence of clinically compatible dengue during the prior 3 months was 2.8 per 1,000 persons (urban, 1.7; rural, 3.4). For IgG positivity, the adjusted odds ratio (AOR) was 2.68 (95% confidence interval [CI], 1.24-5.81) for mosquito larvae presence in water pooled in old tires and was 3.09 (95% CI, 1.75-5.46) for proximity to a densely inhabited area. For IgM positivity, the AOR was 3.06 (95% CI, 1.50-6.23) for proximity to a densely inhabited area. Our results indicated rural penetration of dengue infections. Control measures should target densely inhabited areas, and may include clean-up of discarded tires and water-collecting waste.

  10. Risk assessment of water pollution sources based on an integrated k-means clustering and set pair analysis method in the region of Shiyan, China.

    Science.gov (United States)

    Li, Chunhui; Sun, Lian; Jia, Junxiang; Cai, Yanpeng; Wang, Xuan

    2016-07-01

    Source water areas are facing many potential water pollution risks. Risk assessment is an effective method to evaluate such risks. In this paper an integrated model based on k-means clustering analysis and set pair analysis was established aiming at evaluating the risks associated with water pollution in source water areas, in which the weights of indicators were determined through the entropy weight method. Then the proposed model was applied to assess water pollution risks in the region of Shiyan in which China's key source water area Danjiangkou Reservoir for the water source of the middle route of South-to-North Water Diversion Project is located. The results showed that eleven sources with relative high risk value were identified. At the regional scale, Shiyan City and Danjiangkou City would have a high risk value in term of the industrial discharge. Comparatively, Danjiangkou City and Yunxian County would have a high risk value in terms of agricultural pollution. Overall, the risk values of north regions close to the main stream and reservoir of the region of Shiyan were higher than that in the south. The results of risk level indicated that five sources were in lower risk level (i.e., level II), two in moderate risk level (i.e., level III), one in higher risk level (i.e., level IV) and three in highest risk level (i.e., level V). Also risks of industrial discharge are higher than that of the agricultural sector. It is thus essential to manage the pillar industry of the region of Shiyan and certain agricultural companies in the vicinity of the reservoir to reduce water pollution risks of source water areas. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Two level undercut-profile substrate for filamentary YBa2Cu3O7 coated conductors

    DEFF Research Database (Denmark)

    Wulff, Anders Christian; Solovyov, M.; Gömöry, Fedor

    2015-01-01

    A novel substrate design is presented for scalable industrial production of filamentary coated conductors (CCs). The new substrate, called ‘two level undercut-profile substrate (2LUPS)’, has two levels of plateaus connected by walls with an undercut profile. The undercuts are made to produce...... a shading effect during subsequent deposition of layers, thereby creating gaps in the superconducting layer deposited on the curved walls between the two levels. It is demonstrated that such 2LUPS-based CCs can be produced in a large-scale production system using standard deposition processes...

  12. From hypertension control to global cardiovascular risk management: an educational intervention in a cluster-randomised controlled trial.

    Science.gov (United States)

    Mortsiefer, Achim; Meysen, Tobias; Schumacher, Martin; Abholz, Heinz-Harald; Wegscheider, Karl; In der Schmitten, Jürgen

    2015-05-07

    Guidelines on hypertension management recommend adjusting therapeutic efforts in accordance with global cardiovascular risk (CVR) rather than by blood pressure levels alone. However, this paradigm change has not yet arrived in German General Practice. We have evaluated the effect of an educational outreach visit with general practitioners (GPs), encouraging them to consider CVR in treatment decisions for patients with hypertension. Prospective cluster-randomised trial comprising 3443 patients with known hypertension treated by 87 GPs. Practices were randomly assigned to complex (A) or simple (B) intervention. Both groups received a guideline by mail; group A also received complex peer intervention promoting the concept of global CVR. Clinical data were collected at baseline and 6-9 months after intervention. Main outcome was improvement of calculated CVR in the predefined subpopulation of patients with a high CVR (10-year mortality ≥5%), but no manifest cardiovascular disease. Adjusted for baseline the follow-up CVR were 13.1% (95% CI 12.6%-13.6%) (A) and 12.6% (95% CI 12.2%-13.1%) (B) with a group difference (A vs. B) of 0.5% (-0.2%-1.1%), p = 0.179. The group difference was -0.05% in patients of GPs familiar with global CVR and 1.1% in patients of GPs not familiar with with global CVR. However, this effect modification was not significant (p = 0.165). Pooled over groups, the absolute CVR reduction from baseline was 1.0%, p intervention group, and from 35.6 to 46.5% in the simple intervention group, with adjusted follow-up control rates of 46.7% (95% CI 40.4%-53.1%) (A) and 46.9% (95% CI 40.3%-53.5% (B) and an adjusted odds ratio (A vs B) of 0.99 (95% CI 0.68-1.45), p = 0.966. Our complex educational intervention, including a clinical outreach visit, had no significant effect on CVR of patients with known hypertension at high risk compared to a simple postal intervention. ISRCTN44478543 .

  13. Elucidating the underlying causes of oral cancer through spatial clustering in high-risk areas of Taiwan with a distinct gender ratio of incidence

    Directory of Open Access Journals (Sweden)

    Chi-Ting Chiang

    2010-05-01

    Full Text Available This study aimed to elucidate whether or not high-risk clusters of oral cancer (OC incidence spatially correlate with the prevalence rates of betel quid chewing (BQC and cigarette smoking (CS in Taiwan. The spatial autocorrelation and potential clusters of OC incidence among the 307 townships and heavy metal content of soil throughout Taiwan were identified using the Anselin’s local Moran test. Additionally, the spatial correlations among the incidence of OC, the prevalence of BQC and CS and heavy metal content of soil were determined based on a comparison of spatial clusters. High-risk OC (Moran’s I = 0.638, P <0.001 clusters were located in central and eastern Taiwan, while “hot spots” of BQC and CS prevalence were located mainly in eastern Taiwan. The distributions of BQC and CS lifestyle factors (P <0.001 were spatially autocorrelated. The “hot spots” of OC largely coincided with the “hot spots” of BQC, except for the Changhua and Yunlin counties, which are located in central Taiwan. However, high soil contents of nickel and chromium (P <0.001 in central Taiwan also coincided with the high-risk areas of OC incidence. In particular, Changhua county has incurred several decades of serious heavy-metal pollution, with inhabitants living in polluted areas having high-risk exposure to these metals. Results of this study suggest that, in addition to BQC and CS, anthropogenic pollution may profoundly impact the complexity of OC aetiology in central Taiwan.

  14. A climate-based prediction model in the high-risk clusters of the Mekong Delta region, Vietnam: towards improving dengue prevention and control.

    Science.gov (United States)

    Phung, Dung; Talukder, Mohammad Radwanur Rahman; Rutherford, Shannon; Chu, Cordia

    2016-10-01

    To develop a prediction score scheme useful for prevention practitioners and authorities to implement dengue preparedness and controls in the Mekong Delta region (MDR). We applied a spatial scan statistic to identify high-risk dengue clusters in the MDR and used generalised linear-distributed lag models to examine climate-dengue associations using dengue case records and meteorological data from 2003 to 2013. The significant predictors were collapsed into categorical scales, and the β-coefficients of predictors were converted to prediction scores. The score scheme was validated for predicting dengue outbreaks using ROC analysis. The north-eastern MDR was identified as the high-risk cluster. A 1 °C increase in temperature at lag 1-4 and 5-8 weeks increased the dengue risk 11% (95% CI, 9-13) and 7% (95% CI, 6-8), respectively. A 1% rise in humidity increased dengue risk 0.9% (95% CI, 0.2-1.4) at lag 1-4 and 0.8% (95% CI, 0.2-1.4) at lag 5-8 weeks. Similarly, a 1-mm increase in rainfall increased dengue risk 0.1% (95% CI, 0.05-0.16) at lag 1-4 and 0.11% (95% CI, 0.07-0.16) at lag 5-8 weeks. The predicted scores performed with high accuracy in diagnosing the dengue outbreaks (96.3%). This study demonstrates the potential usefulness of a dengue prediction score scheme derived from complex statistical models for high-risk dengue clusters. We recommend a further study to examine the possibility of incorporating such a score scheme into the dengue early warning system in similar climate settings. © 2016 John Wiley & Sons Ltd.

  15. Dynamical properties of a two-level system with arbitrary nonlinearities

    Indian Academy of Sciences (India)

    nication, information processing and quantum computing, such as in the investigation of quantum teleportation ... They con- sidered a two-level atom interacting with an undamped cavity initially in a coherent state. ... Because concurrence pro-.

  16. Two levels ARIMAX and regression models for forecasting time series data with calendar variation effects

    Science.gov (United States)

    Suhartono, Lee, Muhammad Hisyam; Prastyo, Dedy Dwi

    2015-12-01

    The aim of this research is to develop a calendar variation model for forecasting retail sales data with the Eid ul-Fitr effect. The proposed model is based on two methods, namely two levels ARIMAX and regression methods. Two levels ARIMAX and regression models are built by using ARIMAX for the first level and regression for the second level. Monthly men's jeans and women's trousers sales in a retail company for the period January 2002 to September 2009 are used as case study. In general, two levels of calendar variation model yields two models, namely the first model to reconstruct the sales pattern that already occurred, and the second model to forecast the effect of increasing sales due to Eid ul-Fitr that affected sales at the same and the previous months. The results show that the proposed two level calendar variation model based on ARIMAX and regression methods yields better forecast compared to the seasonal ARIMA model and Neural Networks.

  17. Efficiency analysis on a two-level three-phase quasi-soft-switching inverter

    DEFF Research Database (Denmark)

    Geng, Pan; Wu, Weimin; Huang, Min

    2013-01-01

    When designing an inverter, an engineer often needs to select and predict the efficiency beforehand. For the standard inverters, plenty of researches are analyzing the power losses and also many software tools are being used for efficiency calculation. In this paper, the efficiency calculation...... for non-conventional inverters with special shoot-through state is introduced and illustrated through the analysis on a special two-level three-phase quasi-soft-switching inverter. Efficiency comparison between the classical two-stage two-level three-phase inverter and the two-level three-phase quasi......-soft-switching inverter is carried out. A 10 kW/380 V prototype is constructed to verify the analysis. The experimental results show that the efficiency of the new inverter is higher than that of the traditional two-stage two- level three-phase inverter....

  18. Controlling the optical bistability and multistability in a two-level pumped-probe system

    International Nuclear Information System (INIS)

    Mahmoudi, Mohammad; Sahrai, Mostafa; Masoumeh Mousavi, Seyede

    2010-01-01

    We study the behavior of the optical bistability (OB) and multistability (OM) in a two-level pumped-probe atomic system by means of a unidirectional ring cavity. We show that the optical bistability in a two-level atomic system can be controlled by adjusting the intensity of the pump field and the detuning between two fields. We find that applying the pumping field decreases the threshold of the optical bistability.

  19. Excitation transfer in two two-level systems coupled to an oscillator

    International Nuclear Information System (INIS)

    Hagelstein, P L; Chaudhary, I U

    2008-01-01

    We consider a generalization of the spin-boson model in which two different two-level systems are coupled to an oscillator, under conditions where the oscillator energy is much less than the two-level system energies, and where the oscillator is highly excited. We find that the two-level system transition energy is shifted, producing a Bloch-Siegert shift in each two-level system similar to what would be obtained if the other were absent. At resonances associated with energy exchange between a two-level system and the oscillator, the level splitting is about the same as would be obtained in the spin-boson model at a Bloch-Siegert resonance. However, there occur resonances associated with the transfer of excitation between one two-level system and the other, an effect not present in the spin-boson model. We use a unitary transformation leading to a rotated system in which terms responsible for the shift and splittings can be identified. The level splittings at the anticrossings associated with both energy exchange and excitation transfer resonances are accounted for with simple two-state models and degenerate perturbation theory using operators that appear in the rotated Hamiltonian

  20. Cluster headache

    Science.gov (United States)

    Histamine headache; Headache - histamine; Migrainous neuralgia; Headache - cluster; Horton's headache; Vascular headache - cluster ... Doctors do not know exactly what causes cluster headaches. They ... (chemical in the body released during an allergic response) or ...

  1. Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016.

    Science.gov (United States)

    2017-09-16

    The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) provides a comprehensive assessment of risk factor exposure and attributable burden of disease. By providing estimates over a long time series, this study can monitor risk exposure trends critical to health surveillance and inform policy debates on the importance of addressing risks in context. We used the comparative risk assessment framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2016. This study included 481 risk-outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk (RR) and exposure estimates from 22 717 randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources, according to the GBD 2016 source counting methods. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. Finally, we explored four drivers of trends in attributable burden: population growth, population ageing, trends in risk exposure, and all other factors combined. Since 1990, exposure increased significantly for 30 risks, did not change significantly for four risks, and decreased significantly for 31 risks. Among risks that are leading causes of burden of disease, child growth failure and household air pollution showed the most significant declines, while metabolic risks, such as body-mass index and high fasting plasma glucose, showed significant increases. In 2016, at Level 3 of the hierarchy, the three leading risk factors in terms of attributable DALYs at the global level for men were smoking (124·1 million

  2. An investigation of war trauma types, symptom clusters, and risk-factors associated with post-traumatic stress disorder: where does gender fit?

    Science.gov (United States)

    Farhood, Laila; Fares, Souha; Hamady, Carmen

    2018-05-25

    The female-male ratio in the prevalence of post-traumatic stress disorder (PTSD) is approximately 2:1. Gender differences in experienced trauma types, PTSD symptom clusters, and PTSD risk factors are unclear. We aimed to address this gap using a cross-sectional design. A sample of 991 civilians (522 women, 469 men) from South Lebanon was randomly selected in 2007, after the 2006 war. Trauma types were grouped into disaster and accident, loss, chronic disease, non-malignant disease, and violence. PTSD symptom clusters involved re-experiencing, avoidance, negative cognitions and mood, and arousal. These were assessed using parts I and IV of the Arabic version of the Harvard Trauma Questionnaire (HTQ). Risk factors were assessed using data from a social support and life events questionnaire in multiple regression models. Females were twice as likely as males to score above PTSD threshold (24.3 vs. 10.4%, p ˂ 0.001). Total scores on all trauma types were similar across genders. Females scored higher on all symptom clusters (p < 0.001). Social support, social life events, witnessed traumas, and domestic violence significantly were associated with PTSD in both genders. Social support, social life events, witnessed traumas and domestic violence were significantly associated with PTSD in both genders. Conversely, gender difference in experienced traumas was not statistically significant. These findings accentuate the need to re-consider the role of gender in the assessment and treatment of PTSD.

  3. Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks

    Directory of Open Access Journals (Sweden)

    Fapojuwo Abraham O

    2007-01-01

    Full Text Available We propose a two-level call admission control (CAC scheme for direct sequence code division multiple access (DS-CDMA wireless networks supporting multimedia traffic and evaluate its performance. The first-level admission control assigns higher priority to real-time calls (also referred to as class 0 calls in gaining access to the system resources. The second level admits nonreal-time calls (or class 1 calls based on the resources remaining after meeting the resource needs for real-time calls. However, to ensure some minimum level of performance for nonreal-time calls, the scheme reserves some resources for such calls. The proposed two-level CAC scheme utilizes the delay-tolerant characteristic of non-real-time calls by incorporating a queue to temporarily store those that cannot be assigned resources at the time of initial access. We analyze and evaluate the call blocking, outage probability, throughput, and average queuing delay performance of the proposed two-level CAC scheme using Markov chain theory. The analytic results are validated by simulation results. The numerical results show that the proposed two-level CAC scheme provides better performance than the single-level CAC scheme. Based on these results, it is concluded that the proposed two-level CAC scheme serves as a good solution for supporting multimedia applications in DS-CDMA wireless communication systems.

  4. Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks

    Directory of Open Access Journals (Sweden)

    Abraham O. Fapojuwo

    2007-11-01

    Full Text Available We propose a two-level call admission control (CAC scheme for direct sequence code division multiple access (DS-CDMA wireless networks supporting multimedia traffic and evaluate its performance. The first-level admission control assigns higher priority to real-time calls (also referred to as class 0 calls in gaining access to the system resources. The second level admits nonreal-time calls (or class 1 calls based on the resources remaining after meeting the resource needs for real-time calls. However, to ensure some minimum level of performance for nonreal-time calls, the scheme reserves some resources for such calls. The proposed two-level CAC scheme utilizes the delay-tolerant characteristic of non-real-time calls by incorporating a queue to temporarily store those that cannot be assigned resources at the time of initial access. We analyze and evaluate the call blocking, outage probability, throughput, and average queuing delay performance of the proposed two-level CAC scheme using Markov chain theory. The analytic results are validated by simulation results. The numerical results show that the proposed two-level CAC scheme provides better performance than the single-level CAC scheme. Based on these results, it is concluded that the proposed two-level CAC scheme serves as a good solution for supporting multimedia applications in DS-CDMA wireless communication systems.

  5. Testing feedback message framing and comparators to address prescribing of high-risk medications in nursing homes: protocol for a pragmatic, factorial, cluster-randomized trial.

    Science.gov (United States)

    Ivers, Noah M; Desveaux, Laura; Presseau, Justin; Reis, Catherine; Witteman, Holly O; Taljaard, Monica K; McCleary, Nicola; Thavorn, Kednapa; Grimshaw, Jeremy M

    2017-07-14

    Audit and feedback (AF) interventions that leverage routine administrative data offer a scalable and relatively low-cost method to improve processes of care. AF interventions are usually designed to highlight discrepancies between desired and actual performance and to encourage recipients to act to address such discrepancies. Comparing to a regional average is a common approach, but more recipients would have a discrepancy if compared to a higher-than-average level of performance. In addition, how recipients perceive and respond to discrepancies may depend on how the feedback itself is framed. We aim to evaluate the effectiveness of different comparators and framing in feedback on high-risk prescribing in nursing homes. This is a pragmatic, 2 × 2 factorial, cluster-randomized controlled trial testing variations in the comparator and framing on the effectiveness of quarterly AF in changing high-risk prescribing in nursing homes in Ontario, Canada. We grouped homes that share physicians into clusters and randomized these clusters into the four experimental conditions. Outcomes will be assessed after 6 months; all primary analyses will be by intention-to-treat. The primary outcome (monthly number of high-risk medications received by each patient) will be analysed using a general linear mixed effects regression model. We will present both four-arm and factorial analyses. With 160 clusters and an average of 350 beds per cluster, assuming no interaction and similar effects for each intervention, we anticipate 90% power to detect an absolute mean difference of 0.3 high-risk medications prescribed. A mixed-methods process evaluation will explore potential mechanisms underlying the observed effects, exploring targeted constructs including intention, self-efficacy, outcome expectations, descriptive norms, and goal prioritization. An economic analysis will examine cost-effectiveness analysis from the perspective of the publicly funded health care system. This protocol

  6. Solutions of the two-level problem in terms of biconfluent Heun functions

    Energy Technology Data Exchange (ETDEWEB)

    Ishkhanyan, Artur [Engineering Center of Armenian National Academy of Sciences, Ashtarak (Armenia)]. E-mail: artur@ec.sci.am; Suominen, Kalle-Antti [Helsinki Institute of Physics, Helsinki (Finland); Department of Applied Physics, University of Turku, Turku (Finland)

    2001-08-17

    Five four-parametric classes of quantum mechanical two-level models permitting solutions in terms of the biconfluent Heun function are derived. Three of these classes are generalizations of the well known classes of Landau-Zener, Nikitin and Crothers. It is shown that two other classes describe super- and sublinear and essentially nonlinear level crossings, as well as processes with three crossing points. In particular, these classes include two-level models where the field amplitude is constant and the detuning varies as {delta}{sub 0}t+{delta}{sub 2}t{sup 3} or {approx}t{sup 1/3}. For the essentially nonlinear cubic-crossing model, {delta}{sub t}{approx}{delta}{sub 2}t{sup 3}, the general solution of the two-level problem is shown to be expressed as series of confluent hypergeometric functions. (author)

  7. Two-Level Solutions to Exponentially Complex Problems in Glass Science

    DEFF Research Database (Denmark)

    Mauro, John C.; Smedskjær, Morten Mattrup

    Glass poses an especially challenging problem for physicists. The key to making progress in theoretical glass science is to extract the key physics governing properties of practical interest. In this spirit, we discuss several two-level solutions to exponentially complex problems in glass science....... Topological constraint theory, originally developed by J.C. Phillips, is based on a two-level description of rigid and floppy modes in a glass network and can be used to derive quantitatively accurate and analytically solvable models for a variety of macroscopic properties. The temperature dependence...... that captures both primary and secondary relaxation modes. Such a model also offers the ability to calculate the distinguishability of particles during glass transition and relaxation processes. Two-level models can also be used to capture the distribution of various network-forming species in mixed...

  8. Crossing rule for a PT-symmetric two-level time-periodic system

    International Nuclear Information System (INIS)

    Moiseyev, Nimrod

    2011-01-01

    For a two-level system in a time-periodic field we show that in the non-Hermitian PT case the level crossing is of two quasistationary states that have the same dynamical symmetry property. At the field's parameters where the two levels which have the same dynamical symmetry cross, the corresponding quasienergy states coalesce and a self-orthogonal state is obtained. This situation is very different from the Hermitian case where a crossing of two quasienergy levels happens only when the corresponding two quasistationary states have different dynamical symmetry properties and, unlike the situation in the non-Hermitian case, the spectrum remains complete also when the two levels cross.

  9. Kir2.1 channels set two levels of resting membrane potential with inward rectification.

    Science.gov (United States)

    Chen, Kuihao; Zuo, Dongchuan; Liu, Zheng; Chen, Haijun

    2018-04-01

    Strong inward rectifier K + channels (Kir2.1) mediate background K + currents primarily responsible for maintenance of resting membrane potential. Multiple types of cells exhibit two levels of resting membrane potential. Kir2.1 and K2P1 currents counterbalance, partially accounting for the phenomenon of human cardiomyocytes in subphysiological extracellular K + concentrations or pathological hypokalemic conditions. The mechanism of how Kir2.1 channels contribute to the two levels of resting membrane potential in different types of cells is not well understood. Here we test the hypothesis that Kir2.1 channels set two levels of resting membrane potential with inward rectification. Under hypokalemic conditions, Kir2.1 currents counterbalance HCN2 or HCN4 cation currents in CHO cells that heterologously express both channels, generating N-shaped current-voltage relationships that cross the voltage axis three times and reconstituting two levels of resting membrane potential. Blockade of HCN channels eliminated the phenomenon in K2P1-deficient Kir2.1-expressing human cardiomyocytes derived from induced pluripotent stem cells or CHO cells expressing both Kir2.1 and HCN2 channels. Weakly inward rectifier Kir4.1 or inward rectification-deficient Kir2.1•E224G mutant channels do not set such two levels of resting membrane potential when co-expressed with HCN2 channels in CHO cells or when overexpressed in human cardiomyocytes derived from induced pluripotent stem cells. These findings demonstrate a common mechanism that Kir2.1 channels set two levels of resting membrane potential with inward rectification by balancing inward currents through different cation channels such as hyperpolarization-activated HCN channels or hypokalemia-induced K2P1 leak channels.

  10. A Two-Level Cache for Distributed Information Retrieval in Search Engines

    Directory of Open Access Journals (Sweden)

    Weizhe Zhang

    2013-01-01

    Full Text Available To improve the performance of distributed information retrieval in search engines, we propose a two-level cache structure based on the queries of the users’ logs. We extract the highest rank queries of users from the static cache, in which the queries are the most popular. We adopt the dynamic cache as an auxiliary to optimize the distribution of the cache data. We propose a distribution strategy of the cache data. The experiments prove that the hit rate, the efficiency, and the time consumption of the two-level cache have advantages compared with other structures of cache.

  11. A two-level cache for distributed information retrieval in search engines.

    Science.gov (United States)

    Zhang, Weizhe; He, Hui; Ye, Jianwei

    2013-01-01

    To improve the performance of distributed information retrieval in search engines, we propose a two-level cache structure based on the queries of the users' logs. We extract the highest rank queries of users from the static cache, in which the queries are the most popular. We adopt the dynamic cache as an auxiliary to optimize the distribution of the cache data. We propose a distribution strategy of the cache data. The experiments prove that the hit rate, the efficiency, and the time consumption of the two-level cache have advantages compared with other structures of cache.

  12. Strong nonlinearity-induced correlations for counterpropagating photons scattering on a two-level emitter

    DEFF Research Database (Denmark)

    Nysteen, Anders; McCutcheon, Dara; Mørk, Jesper

    2015-01-01

    We analytically treat the scattering of two counterpropagating photons on a two-level emitter embedded in an optical waveguide. We find that the nonlinearity of the emitter can give rise to significant pulse-dependent directional correlations in the scattered photonic state, which could be quanti......We analytically treat the scattering of two counterpropagating photons on a two-level emitter embedded in an optical waveguide. We find that the nonlinearity of the emitter can give rise to significant pulse-dependent directional correlations in the scattered photonic state, which could...

  13. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015.

    Science.gov (United States)

    2016-10-08

    The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors-the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56

  14. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010.

    Science.gov (United States)

    Lim, Stephen S; Vos, Theo; Flaxman, Abraham D; Danaei, Goodarz; Shibuya, Kenji; Adair-Rohani, Heather; Amann, Markus; Anderson, H Ross; Andrews, Kathryn G; Aryee, Martin; Atkinson, Charles; Bacchus, Loraine J; Bahalim, Adil N; Balakrishnan, Kalpana; Balmes, John; Barker-Collo, Suzanne; Baxter, Amanda; Bell, Michelle L; Blore, Jed D; Blyth, Fiona; Bonner, Carissa; Borges, Guilherme; Bourne, Rupert; Boussinesq, Michel; Brauer, Michael; Brooks, Peter; Bruce, Nigel G; Brunekreef, Bert; Bryan-Hancock, Claire; Bucello, Chiara; Buchbinder, Rachelle; Bull, Fiona; Burnett, Richard T; Byers, Tim E; Calabria, Bianca; Carapetis, Jonathan; Carnahan, Emily; Chafe, Zoe; Charlson, Fiona; Chen, Honglei; Chen, Jian Shen; Cheng, Andrew Tai-Ann; Child, Jennifer Christine; Cohen, Aaron; Colson, K Ellicott; Cowie, Benjamin C; Darby, Sarah; Darling, Susan; Davis, Adrian; Degenhardt, Louisa; Dentener, Frank; Des Jarlais, Don C; Devries, Karen; Dherani, Mukesh; Ding, Eric L; Dorsey, E Ray; Driscoll, Tim; Edmond, Karen; Ali, Suad Eltahir; Engell, Rebecca E; Erwin, Patricia J; Fahimi, Saman; Falder, Gail; Farzadfar, Farshad; Ferrari, Alize; Finucane, Mariel M; Flaxman, Seth; Fowkes, Francis Gerry R; Freedman, Greg; Freeman, Michael K; Gakidou, Emmanuela; Ghosh, Santu; Giovannucci, Edward; Gmel, Gerhard; Graham, Kathryn; Grainger, Rebecca; Grant, Bridget; Gunnell, David; Gutierrez, Hialy R; Hall, Wayne; Hoek, Hans W; Hogan, Anthony; Hosgood, H Dean; Hoy, Damian; Hu, Howard; Hubbell, Bryan J; Hutchings, Sally J; Ibeanusi, Sydney E; Jacklyn, Gemma L; Jasrasaria, Rashmi; Jonas, Jost B; Kan, Haidong; Kanis, John A; Kassebaum, Nicholas; Kawakami, Norito; Khang, Young-Ho; Khatibzadeh, Shahab; Khoo, Jon-Paul; Kok, Cindy; Laden, Francine; Lalloo, Ratilal; Lan, Qing; Lathlean, Tim; Leasher, Janet L; Leigh, James; Li, Yang; Lin, John Kent; Lipshultz, Steven E; London, Stephanie; Lozano, Rafael; Lu, Yuan; Mak, Joelle; Malekzadeh, Reza; Mallinger, Leslie; Marcenes, Wagner; March, Lyn; Marks, Robin; Martin, Randall; McGale, Paul; McGrath, John; Mehta, Sumi; Mensah, George A; Merriman, Tony R; Micha, Renata; Michaud, Catherine; Mishra, Vinod; Mohd Hanafiah, Khayriyyah; Mokdad, Ali A; Morawska, Lidia; Mozaffarian, Dariush; Murphy, Tasha; Naghavi, Mohsen; Neal, Bruce; Nelson, Paul K; Nolla, Joan Miquel; Norman, Rosana; Olives, Casey; Omer, Saad B; Orchard, Jessica; Osborne, Richard; Ostro, Bart; Page, Andrew; Pandey, Kiran D; Parry, Charles D H; Passmore, Erin; Patra, Jayadeep; Pearce, Neil; Pelizzari, Pamela M; Petzold, Max; Phillips, Michael R; Pope, Dan; Pope, C Arden; Powles, John; Rao, Mayuree; Razavi, Homie; Rehfuess, Eva A; Rehm, Jürgen T; Ritz, Beate; Rivara, Frederick P; Roberts, Thomas; Robinson, Carolyn; Rodriguez-Portales, Jose A; Romieu, Isabelle; Room, Robin; Rosenfeld, Lisa C; Roy, Ananya; Rushton, Lesley; Salomon, Joshua A; Sampson, Uchechukwu; Sanchez-Riera, Lidia; Sanman, Ella; Sapkota, Amir; Seedat, Soraya; Shi, Peilin; Shield, Kevin; Shivakoti, Rupak; Singh, Gitanjali M; Sleet, David A; Smith, Emma; Smith, Kirk R; Stapelberg, Nicolas J C; Steenland, Kyle; Stöckl, Heidi; Stovner, Lars Jacob; Straif, Kurt; Straney, Lahn; Thurston, George D; Tran, Jimmy H; Van Dingenen, Rita; van Donkelaar, Aaron; Veerman, J Lennert; Vijayakumar, Lakshmi; Weintraub, Robert; Weissman, Myrna M; White, Richard A; Whiteford, Harvey; Wiersma, Steven T; Wilkinson, James D; Williams, Hywel C; Williams, Warwick; Wilson, Nicholas; Woolf, Anthony D; Yip, Paul; Zielinski, Jan M; Lopez, Alan D; Murray, Christopher J L; Ezzati, Majid; AlMazroa, Mohammad A; Memish, Ziad A

    2012-12-15

    Quantification of the disease burden caused by different risks informs prevention by providing an account of health loss different to that provided by a disease-by-disease analysis. No complete revision of global disease burden caused by risk factors has been done since a comparative risk assessment in 2000, and no previous analysis has assessed changes in burden attributable to risk factors over time. We estimated deaths and disability-adjusted life years (DALYs; sum of years lived with disability [YLD] and years of life lost [YLL]) attributable to the independent effects of 67 risk factors and clusters of risk factors for 21 regions in 1990 and 2010. We estimated exposure distributions for each year, region, sex, and age group, and relative risks per unit of exposure by systematically reviewing and synthesising published and unpublished data. We used these estimates, together with estimates of cause-specific deaths and DALYs from the Global Burden of Disease Study 2010, to calculate the burden attributable to each risk factor exposure compared with the theoretical-minimum-risk exposure. We incorporated uncertainty in disease burden, relative risks, and exposures into our estimates of attributable burden. In 2010, the three leading risk factors for global disease burden were high blood pressure (7·0% [95% uncertainty interval 6·2-7·7] of global DALYs), tobacco smoking including second-hand smoke (6·3% [5·5-7·0]), and alcohol use (5·5% [5·0-5·9]). In 1990, the leading risks were childhood underweight (7·9% [6·8-9·4]), household air pollution from solid fuels (HAP; 7·0% [5·6-8·3]), and tobacco smoking including second-hand smoke (6·1% [5·4-6·8]). Dietary risk factors and physical inactivity collectively accounted for 10·0% (95% UI 9·2-10·8) of global DALYs in 2010, with the most prominent dietary risks being diets low in fruits and those high in sodium. Several risks that primarily affect childhood communicable diseases, including unimproved

  15. A community-based cluster randomized survey of noncommunicable disease and risk factors in a peri-urban shantytown in Lima, Peru.

    Science.gov (United States)

    Heitzinger, Kristen; Montano, Silvia M; Hawes, Stephen E; Alarcón, Jorge O; Zunt, Joseph R

    2014-05-21

    An estimated 863 million people-a third of the world's urban population-live in slums, yet there is little information on the disease burden in these settings, particularly regarding chronic preventable diseases. From March to May 2012, we conducted a cluster randomized survey to estimate the prevalence of noncommunicable diseases (NCDs) and associated risk factors in a peri-urban shantytown north of Lima, Peru. Field workers administered a questionnaire that included items from the WHO World Health Survey and the WHO STEPS survey of chronic disease risk factors. We used logistic regression to assess the associations of NCDs and related risk factors with age and gender. We accounted for sampling weights and the clustered sampling design using statistical survey methods. A total of 142 adults were surveyed and had a weighted mean age of 36 years (range 18-81). The most prevalent diseases were depression (12%) and chronic respiratory disease (8%), while lifetime prevalence of cancer, arthritis, myocardial infarction, and diabetes were all less than 5%. Fifteen percent of respondents were hypertensive and the majority (67%) was unaware of their condition. Being overweight or obese was common for both genders (53%), but abdominal obesity was more prevalent in women (54% vs. 10% in men, p Peru and suggests that prevention and treatment interventions could be optimized according to age and gender.

  16. A cross-sectional study of high-risk human papillomavirus clustering and cervical outcomes in HIV-infected women in Rio de Janeiro, Brazil

    International Nuclear Information System (INIS)

    Castilho, Jessica L.; Levi, José Eduardo; Luz, Paula M.; Cambou, Mary Catherine; Vanni, Tazio; Andrade, Angela de; Derrico, Mônica; Veloso, Valdiléa G.; Grinsztejn, Beatriz; Friedman, Ruth K.

    2015-01-01

    In Brazil, the rate of cervical cancer remains high despite the availability of screening programs. With ongoing vaccine development and implementation, information on the prevalence of specific HPV types is needed, particularly among high-risk populations, such as HIV-infected women. We performed a study of HIV-infected women in Rio de Janeiro, Brazil, who underwent cervical HPV genotype testing between 2005-2013. We examined the prevalence of high-risk HPV types and the patterns of high-risk HPV type clustering. Using logarithmic binomial regression, we estimated the risk of abnormal cytology by HPV genotype result. Of the 562 women included, 498 (89 %) had at least one HPV type detected. 364 women (65 %) had at least one high-risk HPV type detected and 181 (32 %) had more than one high-risk type detected. HPV 58 was the most frequent HPV type detected overall (prevalence 19.8 % [95 % confidence interval 16.4–23.1]), followed by HPV 53 (prevalence 15.5 % [12.5–18.5]) and HPV 16 (prevalence 13 % [10.2–15.8]). Women infected with more than one high-risk HPV type were younger, had lower CD4+ lymphocyte counts, and were more likely to be infected with HPV 16 or 18. In adjusted analyses, presence of more than one high-risk HPV type was associated with a two-fold increased risk of abnormal cytology after adjusting for presence of individual high-risk type, age, and CD4+ lymphocyte count (adjusted prevalence ratios 1.88–2.07, all p <0.001). No single high-risk HPV type was statistically associated with abnormal cytology after adjusting for the presence of more than one high-risk HPV type. In the largest study of cervical HPV genotypes among HIV-infected women in Latin America, infection by high-risk HPV types other than 16 or 18 and infection by more than one high-risk HPV types were common. Infection by more than one high-risk type was more strongly associated with abnormal cervical cytology than any individual high-risk HPV type, highlighting the need for

  17. Experimental Research into the Two-Level Cylindrical Cyclone with a Different Number of Channels

    Directory of Open Access Journals (Sweden)

    Egidijus Baliukas

    2014-10-01

    Full Text Available The multichannel two-level cyclone has been designed for separating solid particles from airflow and built at the Laboratory of Environmental Protection Technologies of Vilnius Gediminas Technical University. The conducted research is aimed at determining air flow distribution at two levels and channels of the multichannel cyclone. The multifunctional meter Testo-400 and the dynamic Pitot tube have been used form easuring air flow rates in the channels. The obtained results show that the equal volume of air gets into two levels installed inside the cyclone, and rates are distributed equally in the channels of these levels. The maximum air flow rate is recorded in the first channel and occurs when half-rings are set in such positions so that 75% of air flow returns to the previous channel. The biggest aerodynamic resistance is 1660 Pa and has been recorded in the cyclone having eight channels under air flow distribution ratio 75/25. The highest air purification efficiency has been observed in the two-level six-channel cyclone under air flow distribution ratio 75/25. The effectiveness of separating granite particles is 92.1% and that of wood particles – 91.1 when the particles are up to 20 μm in diameter.

  18. Polynomial pseudosupersymmetry underlying a two-level atom in an external electromagnetic field

    International Nuclear Information System (INIS)

    Samsonov, B.F.; Shamshutdinova, V.V.; Gitman, D.M.

    2005-01-01

    Chains of transformations introduced previously were studied in order to obtain electric fields with a time-dependent frequency for which the equation of motion of a two-level atom in the presence of these fields can be solved exactly. It is shown that a polynomial pseudosupersymmetry may be associated to such chains

  19. Ultimate temperature for laser cooling of two-level neutral atoms

    International Nuclear Information System (INIS)

    Bagnato, V.S.; Zilio, S.C.

    1989-01-01

    We present a simple pedagogical method to evaluate the minimum attainable temperature for laser cooling of two-level neutral atoms. Results are given as a function of the laser detuning and intensity. We also discuss the use of this approach to predict the minimum temperature of neutral atoms confined in magnetic traps. (author) [pt

  20. Resonant retuning of Rabi oscillations in a two-level system

    International Nuclear Information System (INIS)

    Leonov, A.V.; Feranchuk, I.D.

    2009-01-01

    The evolution of a two-level system in a single-mode quantum field is considered beyond the rotating wave approximation. The existence of quasi-degenerate energy levels is shown to influence the essential characteristics of temporal and amplitude Rabi oscillations of the system in a resonant manner. (authors)

  1. An Owen-type value for games with two-level communication structures

    NARCIS (Netherlands)

    van den Brink, René; Khmelnitskaya, Anna Borisovna; van der Laan, Gerard

    We introduce an Owen-type value for games with two-level communication structure, which is a structure where the players are partitioned into a coalition structure such that there exists restricted communication between as well as within the a priori unions of the coalition structure. Both types of

  2. Reactive Power Impact on Lifetime Prediction of Two-level Wind Power Converter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Lau, M.

    2013-01-01

    The influence of reactive power injection on the dominating two-level wind power converter is investigated and compared in terms of power loss and thermal behavior. Then the lifetime of both the partial-scale and full-scale power converter is estimated based on the widely used Coffin-Manson model...

  3. A two-level strategy to realize life-cycle production optimization in an operational setting

    NARCIS (Netherlands)

    Essen, van G.M.; Hof, Van den P.M.J.; Jansen, J.D.

    2012-01-01

    We present a two-level strategy to improve robustness against uncertainty and model errors in life-cycle flooding optimization. At the upper level, a physics-based large-scale reservoir model is used to determine optimal life-cycle injection and production profiles. At the lower level these profiles

  4. Random model of two-level atoms interacting with electromagnetic field

    International Nuclear Information System (INIS)

    Kireev, A.N.; Meleshko, A.N.

    1983-12-01

    A phase transition has been studied in a random system of two-level atoms interacting with an electromagnetic field. It is shown that superradiation can arise when there is short-range order in a spin-subsystem. The existence of long-range order is irrelevant for this phase transition

  5. Excitation of graphene plasmons as an analogy with the two-level system

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jiahui [Microwave and Electromagnetic Laboratory, Harbin Institute of Technology, No. 92, Xidazhi Street, Nangang District, Harbin City, Heilongjiang Province (China); Lv, Bo, E-mail: lb19840313@126.com [Microwave and Electromagnetic Laboratory, Harbin Institute of Technology, No. 92, Xidazhi Street, Nangang District, Harbin City, Heilongjiang Province (China); Li, Rujiang [College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027 (China); Ma, Ruyu; Chen, Wan; Meng, Fanyi [Microwave and Electromagnetic Laboratory, Harbin Institute of Technology, No. 92, Xidazhi Street, Nangang District, Harbin City, Heilongjiang Province (China)

    2016-02-15

    The excitation of graphene plasmons (GPs) is presented as an interaction between the GPs and the incident electromagnetic field. In this Letter, the excitation of GPs in a plasmonic system is interpreted as an analogy with the two-level system by taking the two-coupled graphene-covered gratings as an example. Based on the equivalent circuit theory, the excitation of GPs in the graphene-covered grating is equivalent to the resonance of an oscillator. Thus, according to the governing equation, the electric currents at the resonant frequencies for two-coupled graphene-covered gratings correspond to the energy states in a two-level system. In addition, the excitation of GPs in different two-coupled graphene-covered gratings is numerically studied to validate our theoretical model. Our work provides an intuitive understanding of the excitation of GPs using an analogy with the two-level system. - Highlights: • The excitation of graphene plasmons (GPs) in graphene-covered grating is equivalent to the resonance of an oscillator. • We establish the equivalent circuit of two-level system to analyze the resonant character. • The excitation of GPs in different two-coupled graphene-covered gratings are numerically studied to validate our theoretical model.

  6. Analysis of Two-Level Support Systems with Time-Dependent Overflow - A Banking Application

    DEFF Research Database (Denmark)

    Barth, Wolfgang; Manitz, Michael; Stolletz, Raik

    2010-01-01

    In this paper, we analyze the performance of call centers of financial service providers with two levels of support and a time-dependent overflow mechanism. Waiting calls from the front-office queue flow over to the back office if a waiting-time limit is reached and at least one back-office agent...

  7. Excitation of graphene plasmons as an analogy with the two-level system

    International Nuclear Information System (INIS)

    Fu, Jiahui; Lv, Bo; Li, Rujiang; Ma, Ruyu; Chen, Wan; Meng, Fanyi

    2016-01-01

    The excitation of graphene plasmons (GPs) is presented as an interaction between the GPs and the incident electromagnetic field. In this Letter, the excitation of GPs in a plasmonic system is interpreted as an analogy with the two-level system by taking the two-coupled graphene-covered gratings as an example. Based on the equivalent circuit theory, the excitation of GPs in the graphene-covered grating is equivalent to the resonance of an oscillator. Thus, according to the governing equation, the electric currents at the resonant frequencies for two-coupled graphene-covered gratings correspond to the energy states in a two-level system. In addition, the excitation of GPs in different two-coupled graphene-covered gratings is numerically studied to validate our theoretical model. Our work provides an intuitive understanding of the excitation of GPs using an analogy with the two-level system. - Highlights: • The excitation of graphene plasmons (GPs) in graphene-covered grating is equivalent to the resonance of an oscillator. • We establish the equivalent circuit of two-level system to analyze the resonant character. • The excitation of GPs in different two-coupled graphene-covered gratings are numerically studied to validate our theoretical model.

  8. A two-level strategy to realize life-cycle production optimization in an operational setting

    NARCIS (Netherlands)

    Essen, van G.M.; Hof, Van den P.M.J.; Jansen, J.D.

    2013-01-01

    We present a two-level strategy to improve robustness against uncertainty and model errors in life-cycle flooding optimization. At the upper level, a physics-based large-scale reservoir model is used to determine optimal life-cycle injection and production profiles. At the lower level these profiles

  9. Localization of a two-level atom via the absorption spectrum

    International Nuclear Information System (INIS)

    Xu, Jun; Hu, Xiang-Ming

    2007-01-01

    We show that it is possible to localize a two-level atom as it passes through a standing-wave field by measuring the probe-field absorption. There is 50% detecting probability of the atom at the nodes of the standing-wave field in the subwavelength domain when the probe field is tuned resonant with the atomic transition

  10. Efficient two-level preconditionined conjugate gradient method on the GPU

    NARCIS (Netherlands)

    Gupta, R.; Van Gijzen, M.B.; Vuik, K.

    2011-01-01

    We present an implementation of Two-Level Preconditioned Conjugate Gradient Method for the GPU. We investigate a Truncated Neumann Series based preconditioner in combination with deflation and compare it with Block Incomplete Cholesky schemes. This combination exhibits fine-grain parallelism and

  11. Two-Level Designs to Estimate All Main Effects and Two-Factor Interactions

    NARCIS (Netherlands)

    Eendebak, P.T.; Schoen, E.D.

    2017-01-01

    We study the design of two-level experiments with N runs and n factors large enough to estimate the interaction model, which contains all the main effects and all the two-factor interactions. Yet, an effect hierarchy assumption suggests that main effect estimation should be given more prominence

  12. Exact Solution of the Two-Level System and the Einstein Solid in the Microcanonical Formalism

    Science.gov (United States)

    Bertoldi, Dalia S.; Bringa, Eduardo M.; Miranda, E. N.

    2011-01-01

    The two-level system and the Einstein model of a crystalline solid are taught in every course of statistical mechanics and they are solved in the microcanonical formalism because the number of accessible microstates can be easily evaluated. However, their solutions are usually presented using the Stirling approximation to deal with factorials. In…

  13. Effect of a computer-guided, quality improvement program for cardiovascular disease risk management in primary health care: the treatment of cardiovascular risk using electronic decision support cluster-randomized trial.

    Science.gov (United States)

    Peiris, David; Usherwood, Tim; Panaretto, Kathryn; Harris, Mark; Hunt, Jennifer; Redfern, Julie; Zwar, Nicholas; Colagiuri, Stephen; Hayman, Noel; Lo, Serigne; Patel, Bindu; Lyford, Marilyn; MacMahon, Stephen; Neal, Bruce; Sullivan, David; Cass, Alan; Jackson, Rod; Patel, Anushka

    2015-01-01

    Despite effective treatments to reduce cardiovascular disease risk, their translation into practice is limited. Using a parallel arm cluster-randomized controlled trial in 60 Australian primary healthcare centers, we tested whether a multifaceted quality improvement intervention comprising computerized decision support, audit/feedback tools, and staff training improved (1) guideline-indicated risk factor measurements and (2) guideline-indicated medications for those at high cardiovascular disease risk. Centers had to use a compatible software system, and eligible patients were regular attendees (Aboriginal and Torres Strait Islander people aged ≥ 35 years and others aged ≥ 45 years). Patient-level analyses were conducted using generalized estimating equations to account for clustering. Median follow-up for 38,725 patients (mean age, 61.0 years; 42% men) was 17.5 months. Mean monthly staff support was improved overall risk factor measurements (62.8% versus 53.4% risk ratio; 1.25; 95% confidence interval, 1.04-1.50; P=0.02), but there was no significant differences in recommended prescriptions for the high-risk cohort (n=10,308; 56.8% versus 51.2%; P=0.12). There were significant treatment escalations (new prescriptions or increased numbers of medicines) for antiplatelet (17.9% versus 2.7%; Pquality improvement intervention, requiring minimal support, improved cardiovascular disease risk measurement but did not increase prescription rates in the high-risk group. Computerized quality improvement tools offer an important, albeit partial, solution to improving primary healthcare system capacity for cardiovascular disease risk management. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=336630. Australian New Zealand Clinical Trials Registry No. 12611000478910. © 2015 American Heart Association, Inc.

  14. 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...

  15. Cluster management.

    Science.gov (United States)

    Katz, R

    1992-11-01

    Cluster management is a management model that fosters decentralization of management, develops leadership potential of staff, and creates ownership of unit-based goals. Unlike shared governance models, there is no formal structure created by committees and it is less threatening for managers. There are two parts to the cluster management model. One is the formation of cluster groups, consisting of all staff and facilitated by a cluster leader. The cluster groups function for communication and problem-solving. The second part of the cluster management model is the creation of task forces. These task forces are designed to work on short-term goals, usually in response to solving one of the unit's goals. Sometimes the task forces are used for quality improvement or system problems. Clusters are groups of not more than five or six staff members, facilitated by a cluster leader. A cluster is made up of individuals who work the same shift. For example, people with job titles who work days would be in a cluster. There would be registered nurses, licensed practical nurses, nursing assistants, and unit clerks in the cluster. The cluster leader is chosen by the manager based on certain criteria and is trained for this specialized role. The concept of cluster management, criteria for choosing leaders, training for leaders, using cluster groups to solve quality improvement issues, and the learning process necessary for manager support are described.

  16. Can centralized sanctioning promote trust in social dilemmas? A two-level trust game with incomplete information.

    Science.gov (United States)

    Wang, Raymond Yu; Ng, Cho Nam

    2015-01-01

    The problem of trust is a paradigmatic social dilemma. Previous literature has paid much academic attention on effects of peer punishment and altruistic third-party punishment on trust and human cooperation in dyadic interactions. However, the effects of centralized sanctioning institutions on decentralized reciprocity in hierarchical interactions remain to be further explored. This paper presents a formal two-level trust game with incomplete information which adds an authority as a strategic purposive actor into the traditional trust game. This model allows scholars to examine the problem of trust in more complex game theoretic configurations. The analysis demonstrates how the centralized institutions might change the dynamics of reciprocity between the trustor and the trustee. Findings suggest that the sequential equilibria of the newly proposed two-level model simultaneously include the risk of placing trust for the trustor and the temptation of short-term defection for the trustee. Moreover, they have shown that even a slight uncertainty about the type of the newly introduced authority might facilitate the establishment of trust and reciprocity in social dilemmas.

  17. Can centralized sanctioning promote trust in social dilemmas? A two-level trust game with incomplete information.

    Directory of Open Access Journals (Sweden)

    Raymond Yu Wang

    Full Text Available The problem of trust is a paradigmatic social dilemma. Previous literature has paid much academic attention on effects of peer punishment and altruistic third-party punishment on trust and human cooperation in dyadic interactions. However, the effects of centralized sanctioning institutions on decentralized reciprocity in hierarchical interactions remain to be further explored. This paper presents a formal two-level trust game with incomplete information which adds an authority as a strategic purposive actor into the traditional trust game. This model allows scholars to examine the problem of trust in more complex game theoretic configurations. The analysis demonstrates how the centralized institutions might change the dynamics of reciprocity between the trustor and the trustee. Findings suggest that the sequential equilibria of the newly proposed two-level model simultaneously include the risk of placing trust for the trustor and the temptation of short-term defection for the trustee. Moreover, they have shown that even a slight uncertainty about the type of the newly introduced authority might facilitate the establishment of trust and reciprocity in social dilemmas.

  18. Analysis of stationary availability factor of two-level backbone computer networks with arbitrary topology

    Science.gov (United States)

    Rahman, P. A.

    2018-05-01

    This scientific paper deals with the two-level backbone computer networks with arbitrary topology. A specialized method, offered by the author for calculation of the stationary availability factor of the two-level backbone computer networks, based on the Markov reliability models for the set of the independent repairable elements with the given failure and repair rates and the methods of the discrete mathematics, is also discussed. A specialized algorithm, offered by the author for analysis of the network connectivity, taking into account different kinds of the network equipment failures, is also observed. Finally, this paper presents an example of calculation of the stationary availability factor for the backbone computer network with the given topology.

  19. Two-Level Iteration Penalty Methods for the Navier-Stokes Equations with Friction Boundary Conditions

    Directory of Open Access Journals (Sweden)

    Yuan Li

    2013-01-01

    Full Text Available This paper presents two-level iteration penalty finite element methods to approximate the solution of the Navier-Stokes equations with friction boundary conditions. The basic idea is to solve the Navier-Stokes type variational inequality problem on a coarse mesh with mesh size H in combining with solving a Stokes, Oseen, or linearized Navier-Stokes type variational inequality problem for Stokes, Oseen, or Newton iteration on a fine mesh with mesh size h. The error estimate obtained in this paper shows that if H, h, and ε can be chosen appropriately, then these two-level iteration penalty methods are of the same convergence orders as the usual one-level iteration penalty method.

  20. Dynamics of quantum Fisher information in a two-level system coupled to multiple bosonic reservoirs

    Science.gov (United States)

    Wang, Guo-You; Guo, You-Neng; Zeng, Ke

    2015-11-01

    We consider the optimal parameter estimation for a two-level system coupled to multiple bosonic reservoirs. By using quantum Fisher information (QFI), we investigate the effect of the Markovian reservoirs’ number N on QFI in both weak and strong coupling regimes for a two-level system surrounded by N zero-temperature reservoirs of field modes initially in the vacua. The results show that the dynamics of QFI non-monotonically decays to zero with revival oscillations at some time in the weak coupling regime depending on the reservoirs’ parameters. Furthermore, we also present the relations between the QFI flow, the flows of energy and information, and the sign of the decay rate to gain insight into the physical processes characterizing the dynamics. Project supported by the Hunan Provincial Innovation Foundation for Postgraduate, China (Grant No. CX2014B194) and the Scientific Research Foundation of Hunan Provincial Education Department, China (Grant No. 13C039).

  1. Minimax terminal approach problem in two-level hierarchical nonlinear discrete-time dynamical system

    Energy Technology Data Exchange (ETDEWEB)

    Shorikov, A. F., E-mail: afshorikov@mail.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002, Russia Institute of Mathematics and Mechanics, Ural Branch of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation)

    2015-11-30

    We consider a discrete–time dynamical system consisting of three controllable objects. The motions of all objects are given by the corresponding vector nonlinear or linear discrete–time recurrent vector relations, and control system for its has two levels: basic (first or I level) that is dominating and subordinate level (second or II level) and both have different criterions of functioning and united a priori by determined informational and control connections defined in advance. For the dynamical system in question, we propose a mathematical formalization in the form of solving a multistep problem of two-level hierarchical minimax program control over the terminal approach process with incomplete information and give a general scheme for its solving.

  2. A modified two-level three-phase quasi-soft-switching inverter

    DEFF Research Database (Denmark)

    Liu, Yusheng; Wu, Weimin; Blaabjerg, Frede

    2014-01-01

    A traditional Voltage Source Inverter (VSI) has higher efficiency than a Current Voltage Source (CSI) due to the less conduction power loss. However, the reverse recovery of the free-wheeling diode limits the efficiency improvement for the silicon devices based hard-switching VSI. The traditional...... quasi-soft-switching inverter can alternate between VSI and CSI by using a proper control scheme and thereby reduce the power losses caused by the reverse recovery of the free-wheeling diode. Nevertheless, slightly extra conduction power loss of the auxiliary switch is also introduced. In order...... to reduce the extra conduction power loss and the voltage stress across the DC-link capacitor, a modified two-level three-phase quasi-soft-switching inverter is proposed by using a SiC MOSFET instead of an IGBT. The principle of the modified two-level three-phase quasi-soft-switching inverter is analyzed...

  3. Revisional Surgery for Hallux Valgus with Serial Osteotomies at Two Levels

    Directory of Open Access Journals (Sweden)

    Jason B. T. Lim

    2011-01-01

    Full Text Available The aetiology and form of hallux valgus (HV is varied with many corrective procedures described. We report a 39-year-old woman, previously treated with a Chevron osteotomy, who presented with recurrent right HV, metatarsus primus varus, and associated bunion. Osteotomies were performed at two levels as a revisional procedure. This report highlights (1 limitations of the Chevron osteotomy and (2 the revisional procedure of the two level osteotomies: (i proximal opening-wedge basal osteotomy and (ii distal short Scarf with medial closing wedges. If a Chevron osteotomy is used inappropriately, for example, in an attempt to correct too large a deformity, it may angulate laterally causing a malunion with an increased distal metatarsal articular angle. Secondly, it is feasible to correct this combined deformity using a combination of proximal opening-wedge and distal short Scarf osteotomies.

  4. Risk-adapted monitoring is not inferior to extensive on-site monitoring: Results of the ADAMON cluster-randomised study.

    Science.gov (United States)

    Brosteanu, Oana; Schwarz, Gabriele; Houben, Peggy; Paulus, Ursula; Strenge-Hesse, Anke; Zettelmeyer, Ulrike; Schneider, Anja; Hasenclever, Dirk

    2017-12-01

    Background According to Good Clinical Practice, clinical trials must protect rights and safety of patients and make sure that the trial results are valid and interpretable. Monitoring on-site has an important role in achieving these objectives; it controls trial conduct at trial sites and informs the sponsor on systematic problems. In the past, extensive on-site monitoring with a particular focus on formal source data verification often lost sight of systematic problems in study procedures that endanger Good Clinical Practice objectives. ADAMON is a prospective, stratified, cluster-randomised, controlled study comparing extensive on-site monitoring with risk-adapted monitoring according to a previously published approach. Methods In all, 213 sites from 11 academic trials were cluster-randomised between extensive on-site monitoring (104) and risk-adapted monitoring (109). Independent post-trial audits using structured manuals were performed to determine the frequency of major Good Clinical Practice findings at the patient level. The primary outcome measure is the proportion of audited patients with at least one major audit finding. Analysis relies on logistic regression incorporating trial and monitoring arm as fixed effects and site as random effect. The hypothesis was that risk-adapted monitoring is non-inferior to extensive on-site monitoring with a non-inferiority margin of 0.60 (logit scale). Results Average number of monitoring visits and time spent on-site was 2.1 and 2.7 times higher in extensive on-site monitoring than in risk-adapted monitoring, respectively. A total of 156 (extensive on-site monitoring: 76; risk-adapted monitoring: 80) sites were audited. In 996 of 1618 audited patients, a total of 2456 major audit findings were documented. Depending on the trial, findings were identified in 18%-99% of the audited patients, with no marked monitoring effect in any of the trials. The estimated monitoring effect is -0.04 on the logit scale with two-sided 95

  5. Non-zero temperature two-mode squeezing for time-dependent two-level systems

    International Nuclear Information System (INIS)

    Aliaga, J.; Gruver, J.L.; Proto, A.N.; Cerdeira, H.A.

    1994-01-01

    A Maximum Entropy Principle density matrix method, valid for systems with temperature different from zero, is presented making it possible two-mode squeezed states in two-level systems with relevant operators and Hamiltonian connected with O(3,2). A method which allows one to relate the appearance of squeezing to the relevant operators, included in order to define the density matrix of the system is given. (author). 14 refs, 1 fig

  6. Urea metabolism in buffalo calves fed on rations containing two levels of crude protein

    International Nuclear Information System (INIS)

    Verma, D.N.; Singh, U.B.; Lal, M.; Varma, A.; Ranjhan, S.K.

    1974-01-01

    Urea entry rates into the body pools of Murrah Buffalo calves have been estimated using a single injection isotope dilution technique using 14 C-urea. The animals were fed two levels of crude proteins, namely, 13 percent lower and 19 percent higher than N.R.C. recommendations. Results show that the recycling of urea is significantly better in animals given low crude protein contents. (M.G.B.)

  7. Experiences of building a medical data acquisition system based on two-level modeling.

    Science.gov (United States)

    Li, Bei; Li, Jianbin; Lan, Xiaoyun; An, Ying; Gao, Wuqiang; Jiang, Yuqiao

    2018-04-01

    Compared to traditional software development strategies, the two-level modeling approach is more flexible and applicable to build an information system in the medical domain. However, the standards of two-level modeling such as openEHR appear complex to medical professionals. This study aims to investigate, implement, and improve the two-level modeling approach, and discusses the experience of building a unified data acquisition system for four affiliated university hospitals based on this approach. After the investigation, we simplified the approach of archetype modeling and developed a medical data acquisition system where medical experts can define the metadata for their own specialties by using a visual easy-to-use tool. The medical data acquisition system for multiple centers, clinical specialties, and diseases has been developed, and integrates the functions of metadata modeling, form design, and data acquisition. To date, 93,353 data items and 6,017 categories for 285 specific diseases have been created by medical experts, and over 25,000 patients' information has been collected. OpenEHR is an advanced two-level modeling method for medical data, but its idea to separate domain knowledge and technical concern is not easy to realize. Moreover, it is difficult to reach an agreement on archetype definition. Therefore, we adopted simpler metadata modeling, and employed What-You-See-Is-What-You-Get (WYSIWYG) tools to further improve the usability of the system. Compared with the archetype definition, our approach lowers the difficulty. Nevertheless, to build such a system, every participant should have some knowledge in both medicine and information technology domains, as these interdisciplinary talents are necessary. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Feedback controlled dephasing and population relaxation in a two-level system

    International Nuclear Information System (INIS)

    Wang Jin

    2009-01-01

    This Letter presents the maximum achievable stability and purity that can be obtained in a two-level system with both dephasing and population relaxation processes by using homodyne-mediated feedback control. An analytic formula giving the optimal amplitudes of the driving and feedback for the steady-state is also presented. Experimental examples are used to show the importance of controlling the dephasing process.

  9. FAST COMMUNICATION: A PDE Based Two Level Model of the Masking Property of the Human Ear

    OpenAIRE

    Xin, Jack; Qi, Yingyong

    2003-01-01

    Human ear has the masking property that certain audible sound becomes inaudible in the presence of another sound. Masking is quantified by the raised threshold from the absolute hearing threshold in quiet. It is of scientific and practical importance to compute masking thresholds. Empirical models on masking have applications in low bit rate digital music compression. A first principle based two level model is developed with partial differential equation (PDE) at the periphe...

  10. Effective Hamiltonians, two level systems, and generalized Maxwell-Bloch equations

    International Nuclear Information System (INIS)

    Sczaniecki, L.

    1981-02-01

    A new method is proposed involving a canonical transformation leading to the non-secular part of time-independent perturbation calculus. The method is used to derive expressions for effective Shen-Walls Hamiltonians which, taken in the two-level approximation and on the inclusion of non-Hamiltonian terms into the dynamics of the system, lead to generalized Maxwell-Bloch equations. The rotating wave approximation is written anew within the framework of our formalism. (author)

  11. Understanding of phase modulation in two-level systems through inverse scattering

    International Nuclear Information System (INIS)

    Hasenfeld, A.; Hammes, S.L.; Warren, W.S.

    1988-01-01

    Analytical and numerical calculations describe the effects of shaped radiation pulses on two-level systems in terms of quantum-mechanical scattering. Previous results obtained in the reduced case of amplitude modulation are extended to the general case of simultaneous amplitude and phase modulation. We show that an infinite family of phase- and amplitude-modulated pulses all generate rectangular inversion profiles. Experimental measurements also verify the theoretical analysis

  12. The simulation of the non-Markovian behaviour of a two-level system

    Science.gov (United States)

    Semina, I.; Petruccione, F.

    2016-05-01

    Non-Markovian relaxation dynamics of a two-level system is studied with the help of the non-linear stochastic Schrödinger equation with coloured Ornstein-Uhlenbeck noise. This stochastic Schrödinger equation is investigated numerically with an adapted Platen scheme. It is shown, that the memory effects have a significant impact to the dynamics of the system.

  13. Prediction of difficult mask ventilation using a systematic assessment of risk factors vs. existing practice - a cluster randomised clinical trial in 94,006 patients

    DEFF Research Database (Denmark)

    Nørskov, A K; Wetterslev, J; Rosenstock, C V

    2017-01-01

    We compared implementation of systematic airway assessment with existing practice of airway assessment on prediction of difficult mask ventilation. Twenty-six departments were cluster-randomised to assess eleven risk factors for difficult airway management (intervention) or to continue with their......We compared implementation of systematic airway assessment with existing practice of airway assessment on prediction of difficult mask ventilation. Twenty-six departments were cluster-randomised to assess eleven risk factors for difficult airway management (intervention) or to continue...... with their existing airway assessment (control). In both groups, patients predicted as a difficult mask ventilation and/or difficult intubation were registered in the Danish Anaesthesia Database, with a notational summary of airway management. The trial's primary outcome was the respective incidence of unpredicted...... difficult and easy mask ventilation in the two groups. Among 94,006 patients undergoing mask ventilation, the incidence of unpredicted difficult mask ventilation in the intervention group was 0.91% and 0.88% in the control group; (OR) 0.98 (95% CI 0.66-1.44), p = 0.90. The incidence of patients predicted...

  14. Minimum time control of a pair of two-level quantum systems with opposite drifts

    International Nuclear Information System (INIS)

    Romano, Raffaele; D’Alessandro, Domenico

    2016-01-01

    In this paper we solve two equivalent time optimal control problems. On one hand, we design the control field to implement in minimum time the SWAP (or equivalent) operator on a two-level system, assuming that it interacts with an additional, uncontrollable, two-level system. On the other hand, we synthesize the SWAP operator simultaneously, in minimum time, on a pair of two-level systems subject to opposite drifts. We assume that it is possible to perform three independent control actions, and that the total control strength is bounded. These controls either affect the dynamics of the target system, under the first perspective, or, simultaneously, the dynamics of both systems, in the second view. We obtain our results by using techniques of geometric control theory on Lie groups. In particular, we apply the Pontryagin maximum principle, and provide a complete characterization of singular and nonsingular extremals. Our analysis shows that the problem can be formulated as the motion of a material point in a central force, a well known system in classical mechanics. Although we focus on obtaining the SWAP operator, many of the ideas and techniques developed in this work apply to the time optimal implementation of an arbitrary unitary operator. (paper)

  15. Two-Level Micro-to-Nanoscale Hierarchical TiO2 Nanolayers on Titanium Surface

    Directory of Open Access Journals (Sweden)

    Elena G. Zemtsova

    2016-12-01

    Full Text Available Joint replacement is being actively developed within modern orthopedics. One novel material providing fast implantation is bioactive coatings. The synthesis of targeted nanocoatings on metallic nanotitanium surface is reported in this paper. TiO2-based micro- and nanocoatings were produced by sol-gel synthesis using dip-coating technology with subsequent fast (shock drying in hot plate mode at 400 °C. As a result of shock drying, the two-level hierarchical TiO2 nanolayer on the nanotitanium was obtained. This two-level hierarchy includes nanorelief of porous xerogel and microrelief of the micron-sized “defect” network (a crack network. The thickness of TiO2 nanolayers was controlled by repeating dip-coating process the necessary number of times after the first layer deposition. The state of the MS3T3-E1 osteoblast cell line (young cells that form bone tissue on the two-level hierarchical surface has been studied. Particularly, adhesion character, adhesion time and morphology have been studied. The reported results may serve the starting point for the development of novel bioactive coatings for bone and teeth implants.

  16. Isotopic clusters

    International Nuclear Information System (INIS)

    Geraedts, J.M.P.

    1983-01-01

    Spectra of isotopically mixed clusters (dimers of SF 6 ) are calculated as well as transition frequencies. The result leads to speculations about the suitability of the laser-cluster fragmentation process for isotope separation. (Auth.)

  17. Cluster Headache

    Science.gov (United States)

    ... a role. Unlike migraine and tension headache, cluster headache generally isn't associated with triggers, such as foods, hormonal changes or stress. Once a cluster period begins, however, drinking alcohol ...

  18. Rapid characterization of microscopic two-level systems using Landau-Zener transitions in a superconducting qubit

    International Nuclear Information System (INIS)

    Tan, Xinsheng; Yu, Haifeng; Yu, Yang; Han, Siyuan

    2015-01-01

    We demonstrate a fast method to detect microscopic two-level systems in a superconducting phase qubit. By monitoring the population leak after sweeping the qubit bias flux, we are able to measure the two-level systems that are coupled with the qubit. Compared with the traditional method that detects two-level systems by energy spectroscopy, our method is faster and more sensitive. This method supplies a useful tool to investigate two-level systems in solid-state qubits

  19. Socioeconomic risk factors for cholera in different transmission settings: An analysis of the data of a cluster randomized trial in Bangladesh.

    Science.gov (United States)

    Saha, Amit; Hayen, Andrew; Ali, Mohammad; Rosewell, Alexander; Clemens, John D; Raina MacIntyre, C; Qadri, Firdausi

    2017-09-05

    Cholera remains a threat globally, and socioeconomic factors play an important role in transmission of the disease. We assessed socioeconomic risk factors for cholera in vaccinated and non-vaccinated communities to understand whether the socioeconomic risk factors differ by transmission patterns for cholera. We used data from a cluster randomized control trial conducted in Dhaka, Bangladesh. There were 90 geographic clusters; 30 in each of the three arms of the study: vaccine (VAC), vaccine plus behavioural change (VBC), and non-intervention. The data were analysed for the three populations: (1) vaccinees in the vaccinated communities (VAC and VBC arms), (2) non-vaccinated individuals in the vaccinated communities and (3) all individuals in the non-vaccinated communities (non-intervention arm). A generalized estimating equation with logit link function was used to evaluate the risk factors for cholera among these different populations adjusting for household level correlation in the data. A total of 528 cholera and 226 cholera with severe dehydration (CSD) in 268,896 persons were observed during the two-year follow-up. For population 1, the cholera risk was not associated with any socioeconomic factors; however CSD was less likely to occur among individuals living in a household having ≤4 members (aOR=0.55, 95% CI=0.32-0.96). Among population 2, younger participants and individuals reporting diarrhoea during registration were more likely to have cholera. Females and individuals reporting diarrhoea during registration were at increased risk of CSD. Among population 3, individuals living in a household without a concrete floor, in an area with high population density, closer to the study hospital, or not treating drinking water were at significantly higher risk for both cholera and CSD. The profile of socioeconomic factors associated with cholera varies by individuals' vaccination status as well as the transmission setting. In a vaccinated community where

  20. Cluster Headache

    OpenAIRE

    Pearce, Iris

    1985-01-01

    Cluster headache is the most severe primary headache with recurrent pain attacks described as worse than giving birth. The aim of this paper was to make an overview of current knowledge on cluster headache with a focus on pathophysiology and treatment. This paper presents hypotheses of cluster headache pathophysiology, current treatment options and possible future therapy approaches. For years, the hypothalamus was regarded as the key structure in cluster headache, but is now thought to be pa...

  1. Categorias Cluster

    OpenAIRE

    Queiroz, Dayane Andrade

    2015-01-01

    Neste trabalho apresentamos as categorias cluster, que foram introduzidas por Aslak Bakke Buan, Robert Marsh, Markus Reineke, Idun Reiten e Gordana Todorov, com o objetivo de categoriíicar as algebras cluster criadas em 2002 por Sergey Fomin e Andrei Zelevinsky. Os autores acima, em [4], mostraram que existe uma estreita relação entre algebras cluster e categorias cluster para quivers cujo grafo subjacente é um diagrama de Dynkin. Para isto desenvolveram uma teoria tilting na estrutura triang...

  2. 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.

  3. Horticultural cluster

    OpenAIRE

    SHERSTIUK S.V.; POSYLAYEVA K.I.

    2013-01-01

    In the article there are the theoretical and methodological approaches to the nature and existence of the cluster. The cluster differences from other kinds of cooperative and integration associations. Was develop by scientific-practical recommendations for forming a competitive horticultur cluster.

  4. Group based prenatal care in a low-and high risk population in the Netherlands: a study protocol for a stepped wedge cluster randomized controlled trial.

    Science.gov (United States)

    van Zwicht, Birgit S; Crone, Matty R; van Lith, Jan M M; Rijnders, Marlies E B

    2016-11-15

    CenteringPregnancy (CP) is a multifaceted group based care-model integrated in routine prenatal care, combining health assessment, education, and support. CP has shown some positive results on perinatal outcomes. However, the effects are less obvious when limited to the results of randomized controlled trials: as there are few trials and there is a variation in reported outcomes. Furthermore, former research was mostly conducted in the United States of America and in specific (often high risk) populations. Our study aims to evaluate the effects of CP in the Netherlands in a general population of pregnant women (low and high risk). Furthermore we aim to explore the mechanisms leading to the eventual effects by measuring potential mediating factors. We will perform a stepped wedge cluster randomized controlled trial, in a Western region in the Netherlands. Inclusion criteria are care, women in the intervention period (starting at the randomized time-point) will be offered the choice between individual care or CP. Primary outcomes are maternal and neonatal morbidity, retrieved from a national routine database. Secondary outcomes are health behavior, psychosocial outcomes, satisfaction, health care utilization and process outcomes, collected through self-administered questionnaires, group-evaluations and individual interviews. We will conduct intention-to-treat analyses. Also a per protocol analysis will be performed comparing the three subgroups: control group, CP-participants and non-CP-participants, using multilevel techniques to account for clustering effects. This study contributes to the evidence regarding the effect of CP and gives a first indication of the effect and implementation of CP in both low and high-risk pregnancies in a high-income Western society other than the USA. Also, measuring factors that are hypothesized to mediate the effect of CP will enable to explain the mechanisms that lead to effects on maternal and neonatal outcomes. Dutch Trial

  5. Decreased expression of the APOA1–APOC3–APOA4 gene cluster is associated with risk of Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Lin Q

    2015-09-01

    Full Text Available Qiao Lin,1 Yunpeng Cao,2 Jie Gao3 1Department of Internal Medicine, Fourth Affiliated Hospital of China Medical University, 2Neural Department of Internal Medicine, 3Department of Anatomy, First Affiliated Hospital of China Medical University, Shenyang, People’s Republic of China Background: Apolipoprotein is genetically associated with the risk of Alzheimer’s disease (AD. The APOA1, APOC3, and APOA4 genes are closely linked and located on human chromosome 11. Therefore, this gene cluster may be related to the risk of AD.Patients and methods: A total of 147 AD patients and 160 healthy controls were randomly recruited from June 2013 to August 2014. APOA1, APOC3, and APOA4 levels were measured using real-time quantitative reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay.Results: APOA1, APOC3 and APOA4 levels were significantly lower in AD patients than controls (P<0.01. APOA1, APOC3, and APOA4 levels were negatively related with the severities of AD determined by Clinical Dementia Rating scores (P<0.01. APOA1, APOC3, and APOA4 levels showed a negative relation with Montgomery–Åsberg Depression Rating Scale scores and a positive relation with RAND 36-item health-survey scores (P<0.01. There was a decreased trend for levels of APOA1, APOC3, and APOA4 in AD patients.Conclusion: Low levels of APOA1, APOC3, and APOA4 are associated with risk of AD. APOA1, APOC3, and APOA4 should be developed as combined drugs for the therapy of AD. Keywords: Alzheimer’s disease, APOA1–APOC3–APOA4 gene cluster, enzyme-linked immunosorbent assay, Montgomery–Åsberg Depression Rating Scale, RAND 36-item health survey, real-time quantitative reverse-transcriptase PCR

  6. The association between serum brain-derived neurotrophic factor and a cluster of cardiovascular risk factors in adolescents

    DEFF Research Database (Denmark)

    Pedersen, Natascha Holbæk; Tarp, Jakob; Andersen, Lars Bo

    2017-01-01

    BACKGROUND AND OBJECTIVE: Cardiovascular disease and type 2 diabetes pose a global health burden. Therefore, clarifying the pathology of these risk factors is essential. Previous studies have found positive and negative associations between one or more cardiovascular risk factors and brain...... fitness (CRF), anthropometrics, pubertal status, blood pressure (BP), serum BDNF, high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), blood glucose and insulin were measured. Information about alcohol consumption and socio-economic status was collected via questionnaires. Associations were...

  7. Cluster Matters

    DEFF Research Database (Denmark)

    Gulati, Mukesh; Lund-Thomsen, Peter; Suresh, Sangeetha

    2018-01-01

    sell their products successfully in international markets, but there is also an increasingly large consumer base within India. Indeed, Indian industrial clusters have contributed to a substantial part of this growth process, and there are several hundred registered clusters within the country...... of this handbook, which focuses on the role of CSR in MSMEs. Hence we contribute to the literature on CSR in industrial clusters and specifically CSR in Indian industrial clusters by investigating the drivers of CSR in India’s industrial clusters....

  8. Renormalization of correlations in a quasiperiodically forced two-level system: quadratic irrationals

    International Nuclear Information System (INIS)

    Mestel, B D; Osbaldestin, A H

    2004-01-01

    Generalizing from the case of golden mean frequency to a wider class of quadratic irrationals, we extend our renormalization analysis of the self-similarity of correlation functions in a quasiperiodically forced two-level system. We give a description of all piecewise-constant periodic orbits of an additive functional recurrence generalizing that present in the golden mean case. We establish a criterion for periodic orbits to be globally bounded, and also calculate the asymptotic height of the main peaks in the correlation function

  9. Quantum averaging and resonances: two-level atom in a one-mode classical laser field

    Directory of Open Access Journals (Sweden)

    M. Amniat-Talab

    2007-06-01

    Full Text Available   We use a nonperturbative method based on quantum averaging and an adapted from of resonant transformations to treat the resonances of the Hamiltonian of a two-level atom interacting with a one-mode classical field in Floquet formalism. We illustrate this method by extraction of effective Hamiltonians of the system in two regimes of weak and strong coupling. The results obtained in the strong-coupling regime, are valid in the whole range of the coupling constant for the one-photon zero-field resonance.

  10. Aspects of two-level systems under external time-dependent fields

    Energy Technology Data Exchange (ETDEWEB)

    Bagrov, V.G.; Wreszinski, W.F. [Tomsk State University and Tomsk Institute of High Current Electronics (Russian Federation); Barata, J.C.A.; Gitman D.M. [Universidade de Sao Paulo, Instituto de Fisica (Brazil)]. E-mails: jbarata@fma.if.usp.br; gitman@fma.if.usp.br

    2001-12-14

    The dynamics of two-level systems in time-dependent backgrounds is under consideration. We present some new exact solutions in special backgrounds decaying in time. On the other hand, following ideas of Feynman et al, we discuss in detail the possibility of reducing the quantum dynamics to a classical Hamiltonian system. This, in particular, opens the possibility of directly applying powerful methods of classical mechanics (e.g. KAM methods) to study the quantum system. Following such an approach, we draw conclusions of relevance for 'quantum chaos' when the external background is periodic or quasi-periodic in time. (author)

  11. Characteristics of the 2011 Tohoku Tsunami and introduction of two level tsunamis for tsunami disaster mitigation.

    Science.gov (United States)

    Sato, Shinji

    2015-01-01

    Characteristics of the 2011 Tohoku Tsunami have been revealed by collaborative tsunami surveys extensively performed under the coordination of the Joint Tsunami Survey Group. The complex behaviors of the mega-tsunami were characterized by the unprecedented scale and the low occurrence frequency. The limitation and the performance of tsunami countermeasures were described on the basis of tsunami surveys, laboratory experiments and numerical analyses. These findings contributed to the introduction of two-level tsunami hazards to establish a new strategy for tsunami disaster mitigation, combining structure-based flood protection designed by the Level-1 tsunami and non-structure-based damage reduction planned by the Level-2 tsunami.

  12. Teleporting the one-qubit state via two-level atoms with spontaneous emission

    Energy Technology Data Exchange (ETDEWEB)

    Hu Mingliang, E-mail: mingliang0301@xupt.edu.cn, E-mail: mingliang0301@163.com [School of Science, Xi' an University of Posts and Telecommunications, Xi' an 710061 (China)

    2011-05-14

    We study quantum teleportation via two two-level atoms coupled collectively to a multimode vacuum field and prepared initially in different atomic states. We concentrated on the influence of the spontaneous emission, collective damping and dipole-dipole interaction of the atoms on fidelity dynamics of quantum teleportation and obtained the region of spatial distance between the two atoms over which the state can be teleported nonclassically. Moreover, we showed through concrete examples that entanglement of the channel state is the prerequisite but not the only essential quantity for predicting the teleportation fidelity.

  13. A January angular momentum balance in the OSU two-level atmospheric general circulation model

    Science.gov (United States)

    Kim, J.-W.; Grady, W.

    1982-01-01

    The present investigation is concerned with an analysis of the atmospheric angular momentum balance, based on the simulation data of the Oregon State University two-level atmospheric general circulation model (AGCM). An attempt is also made to gain an understanding of the involved processes. Preliminary results on the angular momentum and mass balance in the AGCM are shown. The basic equations are examined, and questions of turbulent momentum transfer are investigated. The methods of analysis are discussed, taking into account time-averaged balance equations, time and longitude-averaged balance equations, mean meridional circulation, the mean meridional balance of relative angular momentum, and standing and transient components of motion.

  14. Thermal analysis of two-level wind power converter under symmetrical grid fault

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede

    2013-01-01

    In this paper, the case of symmetrical grid fault when using the multi-MW wind turbine of partial-scale and full-scale two-level power converter are designed and investigated. Firstly, the different operation behaviors of the relevant power converters under the voltage dip will be described......) condition as well as the junction temperature. For the full-scale wind turbine system, the most thermal stressed power device in the grid-side converter will appear at the grid voltage below 0.5 pu, and for the partial-scale wind turbine system, the most thermal stressed power device in the rotor...

  15. Elimination of two level fluctuators in superconducting quantum bits by an epitaxial tunnel barrier

    International Nuclear Information System (INIS)

    Oh, Seongshik; Cicak, Katarina; Kline, Jeffrey S.; Sillanpaeae, Mika A.; Osborn, Kevin D.; Whittaker, Jed D.; Simmonds, Raymond W.; Pappas, David P.

    2006-01-01

    Quantum computing based on Josephson junction technology is considered promising due to its scalable architecture. However, decoherence is a major obstacle. Here, we report evidence for improved Josephson quantum bits (qubits) using a single-crystal Al 2 O 3 tunnel barrier. We have found an ∼80% reduction in the density of the spectral splittings that indicate the existence of two-level fluctators (TLFs) in amorphous tunnel barriers. The residual ∼20% TLFs can be attributed to interfacial effects that may be further reduced by different electrode materials. These results show that decoherence sources in the tunnel barrier of Josephson qubits can be identified and eliminated

  16. Geometric manipulation of the quantum states of two-level atoms

    International Nuclear Information System (INIS)

    Tian, Mingzhen; Barber, Zeb W.; Fischer, Joe A.; Babbitt, Wm. Randall

    2004-01-01

    Manipulation of the quantum states of two-level atoms has been investigated using laser-controlled geometric phase change, which has the potential to build robust quantum logic gates for quantum computing. For a qubit based on two electronic transition levels of an atom, two basic quantum operations that can make any universal single qubit gate have been designed employing resonant laser pulses. An operation equivalent to a phase gate has been demonstrated using Tm 3+ doped in a yttrium aluminum garnet crystal

  17. Oscillations of Doppler-Raby of two level atom moving in resonator

    International Nuclear Information System (INIS)

    Kozlovskij, A.V.

    2001-01-01

    The interaction of the two-level atom with the quantum mode of the high-quality resonator uniformly moving by the classic trajectory, is considered. The recurrent formula for the probability of the atom transition with the photon radiation is determined through the dressed states method. It is shown, that the ratio between the Doppler shift value of the atom transition and the Raby frequency value of the atom-field system qualitatively effects the dependence of the moving atom transition probability on its position in the resonator, as well as on its value [ru

  18. Limitations of two-level emitters as nonlinearities in two-photon controlled-PHASE gates

    DEFF Research Database (Denmark)

    Nysteen, Anders; McCutcheon, Dara P. S.; Heuck, Mikkel

    2017-01-01

    We investigate the origin of imperfections in the fidelity of a two-photon controlled-PHASE gate based on two-level-emitter nonlinearities. We focus on a passive system that operates without external modulations to enhance its performance. We demonstrate that the fidelity of the gate is limited...... by opposing requirements on the input pulse width for one-and two-photon-scattering events. For one-photon scattering, the spectral pulse width must be narrow compared with the emitter linewidth, while two-photon-scattering processes require the pulse width and emitter linewidth to be comparable. We find...

  19. Probe transparency in a two-level medium embedded by a squeezed vacuum

    International Nuclear Information System (INIS)

    Swain, S.; Zhou, P.

    1994-08-01

    Effect of the detuning on the probe absorption spectra of a two-level system with and without a classically driven field in a squeezed vacuum is investigated. For a strong squeezing, there is a threshold which determines the positions and widths of the absorption peaks, for the squeezed parameter M. In a large detuning, the spectra exhibit some resemblance to the Fano spectrum. The squeezing-induced transparency occurs at the frequency 2ω L - ω A in the minimum-uncertainty squeezed vacuum. This effect is not phase-sensitive. (author). 15 refs, 8 figs

  20. Participatory ergonomics to reduce exposure to psychosocial and physical risk factors for low back pain and neck pain: results of a cluster randomised controlled trial.

    Science.gov (United States)

    Driessen, Maurice T; Proper, Karin I; Anema, Johannes R; Knol, Dirk L; Bongers, Paulien M; van der Beek, Allard J

    2011-09-01

    This study investigated the effectiveness of the Stay@Work participatory ergonomics programme to reduce workers' exposure to psychosocial and physical risk factors. 37 departments (n=3047 workers) from four Dutch companies participated in this cluster randomised controlled trial; 19 (n=1472 workers) were randomised to an intervention group (participatory ergonomics) and 18 (n=1575 workers) to a control group (no participatory ergonomics). During a 6 h meeting guided by an ergonomist, working groups devised ergonomic measures to reduce psychosocial and physical workload and implemented them within 3months in their departments. Data on psychosocial and physical risk factors for low back pain and neck pain were collected at baseline and after 6 months. Psychosocial risk factors were measured using the Job Content Questionnaire and physical risk factors using the Dutch Musculoskeletal Questionnaire. Intervention effects were studied using multilevel analysis. Intervention group workers significantly increased on decision latitude (0.29 points; 95% CI 0.07 to 0.52) and decision authority (0.16 points; 95% CI 0.04 to 0.28) compared to control workers. However, exposure to awkward trunk working postures significantly increased in the intervention group (OR 1.86; 95% CI 1.15 to 3.01) compared to the control group. No significant differences between the intervention and control group were found for the remaining risk factors. After 6months, loss to follow-up was 35% in the intervention group and 29% in the control group. Participatory ergonomics was not effective in reducing exposure to psychosocial and physical risk factors for low back pain and neck pain among a large group of workers. ISRCTN27472278.

  1. Increasing young adults' condom use intentions and behaviour through changing chlamydia risk and coping appraisals: study protocol for a cluster randomised controlled trial of efficacy.

    Science.gov (United States)

    Newby, Katie V; French, David P; Brown, Katherine E; Lecky, Donna M

    2013-05-30

    Chlamydia is the most commonly diagnosed sexually transmitted infection (STI) in England and has serious public health consequences. Young people carry a disproportionate burden of infection. A number of social cognition models identify risk appraisal as a primary motivator of behaviour suggesting that changing risk appraisals for STIs may be an effective strategy in motivating protective behaviour. Meta-analytic evidence indicates that the relationship between risk appraisal and health behaviour is small, but studies examining this relationship have been criticised for their many conceptual and methodological weaknesses. The effect of risk appraisal on health behaviour may therefore be of larger size. The proposed study aims to examine the efficacy of an intervention to increase condom use intentions and behaviour amongst young people through changing chlamydia risk and coping appraisals. Coping appraisal is targeted to avoid the intervention being counterproductive amongst recipients who do not feel able to perform the behaviour required to reduce the threat. An experimental design with follow-up, a conditional measure of risk appraisal, and analysis which controls for past behaviour, enable the relationship between risk appraisal and protective behaviour to be accurately assessed. The proposed study is a two-arm cluster randomised controlled trial using a waiting-list control design to test the efficacy of the intervention compared to a control group. Participants will be school pupils aged 13-16 years old recruited from approximately ten secondary schools. Schools will be randomised into each arm. Participants will receive their usual teaching on STIs but those in the intervention condition will additionally receive a single-session sex education lesson on chlamydia. Measures will be taken at baseline, post-intervention and at follow-up three months later. The primary outcome measure is intention to use condoms with casual sexual partners. As far as the authors

  2. SCREENING OF MEDIUM COMPOUNDS USING A TWO-LEVEL FACTORIAL DESIGN FOR SACCHAROMYCES BOULARDII

    Directory of Open Access Journals (Sweden)

    GUOWEI SHU

    2016-04-01

    Full Text Available Even if the probiotic effect of Saccharomyces boulardii is has been reported, this yeast is rarely used in medium composition. Based on single factor experiment, two-level factorial design was employed to evaluate the effect of carbon sources (sucrose, glucose, nitrogen sources (soy peptone, beef extract, yeast extract, calf serum, malt extract and salts (K2HPO4, KH2PO4, MgSO4, Na2HPO4, NaH2PO4, CaCl2, sodium citrate, sodium glutamate on the growth of S. boulardii. At the same time, the optical density (OD in the medium was measured at 560 nm after 36 h of incubation. The result of two-level factorial design experiment showed that calf serum (p = 0.0214 and sodium citrate (p = 0.0045 are the significant growth factors of S. boulardii, sucrose (p = 0.0861 and malt extract (p = 0.0763 are important factors. In addition, sucrose and sodium citrate showed positive effect on the growth of S. boulardii. However, calf serum and malt extract showed negative effect on the growth. And we determined that the optimum medium composition for S. boulardii was as follow: 37.5 g·L-1 sucrose, 6 g·L-1 calf serum, 6 g·L-1 malt extract, 5 g·L-1 sodium citrate.

  3. Improved Genetic Algorithm with Two-Level Approximation for Truss Optimization by Using Discrete Shape Variables

    Directory of Open Access Journals (Sweden)

    Shen-yan Chen

    2015-01-01

    Full Text Available This paper presents an Improved Genetic Algorithm with Two-Level Approximation (IGATA to minimize truss weight by simultaneously optimizing size, shape, and topology variables. On the basis of a previously presented truss sizing/topology optimization method based on two-level approximation and genetic algorithm (GA, a new method for adding shape variables is presented, in which the nodal positions are corresponding to a set of coordinate lists. A uniform optimization model including size/shape/topology variables is established. First, a first-level approximate problem is constructed to transform the original implicit problem to an explicit problem. To solve this explicit problem which involves size/shape/topology variables, GA is used to optimize individuals which include discrete topology variables and shape variables. When calculating the fitness value of each member in the current generation, a second-level approximation method is used to optimize the continuous size variables. With the introduction of shape variables, the original optimization algorithm was improved in individual coding strategy as well as GA execution techniques. Meanwhile, the update strategy of the first-level approximation problem was also improved. The results of numerical examples show that the proposed method is effective in dealing with the three kinds of design variables simultaneously, and the required computational cost for structural analysis is quite small.

  4. Two-level method for unsteady Navier-Stokes equations based on a new projection

    International Nuclear Information System (INIS)

    Hou Yanren; Li Kaitai

    2004-12-01

    A two-level algorithm for the two dimensional unsteady Navier-Stokes equations based on a new projection is proposed and investigated. The approximate solution is solved as a sum of a large eddy component and a small eddy component, which are in the sense of the new projection, constructed in this paper. These two terms advance in time explicitly. Actually, the new algorithm proposed here can be regarded as a sort of postprocessing algorithm for the standard Galerkin method (SGM). The large eddy part is solved by SGM in the usual L 2 -based large eddy subspace while the small eddy part (the correction part) is obtained in its complement subspace in the sense of the new projection. The stability analysis indicates the improvement of the stability comparing with SGM of the same scale, and the L 2 -error estimate shows that the scheme can improve the accuracy of SGM approximation for half order. We also propose a numerical implementation based on Lagrange multiplier for this two-level algorithm. (author)

  5. Development and evaluation of a two-level functional structure for the thin film encapsulation

    International Nuclear Information System (INIS)

    Lee, Jae-Wung; Sharma, Jaibir; Singh, Navab; Kwong, Dim-Lee

    2013-01-01

    This paper reports a two level capping structure for encapsulating micro-electro-mechanical system (MEMS) devices. The two level capping solves the main issue of the longer release time as well as safe sealing in thin film encapsulation (TFE). In this technique, the first cap layer has many etch holes, which were uniformly distributed on it to enhance the removal of the sacrificial layer. The second cap layer forms a cap on every etch hole in the first cap layer to protect the mass loading on MEMS devices. This technique was found to be very effective in reducing the release time of the TFE. For the 1200 µm × 1200 µm sized cavity encapsulation, this technique decreases the release time of the TFE by a factor of 24 in comparison to the sidewall located channel scheme. The presented technique also helps in reducing the size of TFE as the etch holes are uniformly distributed on the TFE itself. Wide seal rings were not required to accommodate sidewall channels. (paper)

  6. Protecting quantum coherence of two-level atoms from vacuum fluctuations of electromagnetic field

    International Nuclear Information System (INIS)

    Liu, Xiaobao; Tian, Zehua; Wang, Jieci; Jing, Jiliang

    2016-01-01

    In the framework of open quantum systems, we study the dynamics of a static polarizable two-level atom interacting with a bath of fluctuating vacuum electromagnetic field and explore under which conditions the coherence of the open quantum system is unaffected by the environment. For both a single-qubit and two-qubit systems, we find that the quantum coherence cannot be protected from noise when the atom interacts with a non-boundary electromagnetic field. However, with the presence of a boundary, the dynamical conditions for the insusceptible of quantum coherence are fulfilled only when the atom is close to the boundary and is transversely polarizable. Otherwise, the quantum coherence can only be protected in some degree in other polarizable direction. -- Highlights: •We study the dynamics of a two-level atom interacting with a bath of fluctuating vacuum electromagnetic field. •For both a single and two-qubit systems, the quantum coherence cannot be protected from noise without a boundary. •The insusceptible of the quantum coherence can be fulfilled only when the atom is close to the boundary and is transversely polarizable. •Otherwise, the quantum coherence can only be protected in some degree in other polarizable direction.

  7. Ramsey interferometry with a two-level generalized Tonks-Girardeau gas

    International Nuclear Information System (INIS)

    Mousavi, S. V.; Campo, A. del; Lizuain, I.; Muga, J. G.

    2007-01-01

    We propose a solvable generalization of the Tonks-Girardeau model that describes a coherent one-dimensional (1D) gas of cold two-level bosons which interact with two external fields in a Ramsey interferometer. They also interact among themselves by idealized, infinitely strong contact potentials, with interchange of momentum and internal state. We study the corresponding Ramsey fringes and the quantum projection noise which, essentially unaffected by the interactions, remains that for ideal bosons. The dual system of this gas, an ideal gas of two-level fermions coupled by the interaction with the separated fields, produces the same fringes and noise fluctuations. The cases of time-separated and spatially separated fields are studied. For spatially separated fields the fringes may be broadened slightly by increasing the number of particles, but only for large particle numbers far from present experiments with Tonks-Girardeau gases. The uncertainty in the determination of the atomic transition frequency diminishes, essentially with the inverse root of the particle number. The difficulties to implement the model experimentally and possible shortcomings of strongly interacting 1D gases for frequency standards and atomic clocks are discussed

  8. A Weighted Two-Level Bregman Method with Dictionary Updating for Nonconvex MR Image Reconstruction

    Directory of Open Access Journals (Sweden)

    Qiegen Liu

    2014-01-01

    Full Text Available Nonconvex optimization has shown that it needs substantially fewer measurements than l1 minimization for exact recovery under fixed transform/overcomplete dictionary. In this work, two efficient numerical algorithms which are unified by the method named weighted two-level Bregman method with dictionary updating (WTBMDU are proposed for solving lp optimization under the dictionary learning model and subjecting the fidelity to the partial measurements. By incorporating the iteratively reweighted norm into the two-level Bregman iteration method with dictionary updating scheme (TBMDU, the modified alternating direction method (ADM solves the model of pursuing the approximated lp-norm penalty efficiently. Specifically, the algorithms converge after a relatively small number of iterations, under the formulation of iteratively reweighted l1 and l2 minimization. Experimental results on MR image simulations and real MR data, under a variety of sampling trajectories and acceleration factors, consistently demonstrate that the proposed method can efficiently reconstruct MR images from highly undersampled k-space data and presents advantages over the current state-of-the-art reconstruction approaches, in terms of higher PSNR and lower HFEN values.

  9. Detuning-induced stimulated Raman adiabatic passage in dense two-level systems

    Science.gov (United States)

    Deng, Li; Lin, Gongwei; Niu, Yueping; Gong, Shangqing

    2018-05-01

    We investigate the coherence generation in dense two-level systems under detuning-induced stimulated Raman adiabatic passage (D-STIRAP). In the dense two-level system, the near dipole-dipole (NDD) interaction should be taken into consideration. With the increase in the strength of the NDD interaction, it is found that a switchlike transition of the generated coherence from maximum value to zero appears. Meanwhile, the adiabatic condition of the D-STIRAP is destroyed in the presence of the NDD interaction. In order to avoid the sudden decrease in the generated coherence and maintain the maximum value, we can use stronger detuning pulse or pump pulse, between which increasing the intensity of the detuning pulse is of more efficiency. Except for taking advantage of such maximum coherence in the high density case into areas like enhancing the four-wave mixing process, we also point out that the phenomenon of the coherence transition can be applied as an optical switch.

  10. A novel two-level dynamic parallel data scheme for large 3-D SN calculations

    International Nuclear Information System (INIS)

    Sjoden, G.E.; Shedlock, D.; Haghighat, A.; Yi, C.

    2005-01-01

    We introduce a new dynamic parallel memory optimization scheme for executing large scale 3-D discrete ordinates (Sn) simulations on distributed memory parallel computers. In order for parallel transport codes to be truly scalable, they must use parallel data storage, where only the variables that are locally computed are locally stored. Even with parallel data storage for the angular variables, cumulative storage requirements for large discrete ordinates calculations can be prohibitive. To address this problem, Memory Tuning has been implemented into the PENTRAN 3-D parallel discrete ordinates code as an optimized, two-level ('large' array, 'small' array) parallel data storage scheme. Memory Tuning can be described as the process of parallel data memory optimization. Memory Tuning dynamically minimizes the amount of required parallel data in allocated memory on each processor using a statistical sampling algorithm. This algorithm is based on the integral average and standard deviation of the number of fine meshes contained in each coarse mesh in the global problem. Because PENTRAN only stores the locally computed problem phase space, optimal two-level memory assignments can be unique on each node, depending upon the parallel decomposition used (hybrid combinations of angular, energy, or spatial). As demonstrated in the two large discrete ordinates models presented (a storage cask and an OECD MOX Benchmark), Memory Tuning can save a substantial amount of memory per parallel processor, allowing one to accomplish very large scale Sn computations. (authors)

  11. Dynamical model of coherent circularly polarized optical pulse interactions with two-level quantum systems

    International Nuclear Information System (INIS)

    Slavcheva, G.; Hess, O.

    2005-01-01

    We propose and develop a method for theoretical description of circularly (elliptically) polarized optical pulse resonant coherent interactions with two-level atoms. The method is based on the time-evolution equations of a two-level quantum system in the presence of a time-dependent dipole perturbation for electric dipole transitions between states with total angular-momentum projection difference (ΔJ z =±1) excited by a circularly polarized electromagnetic field [Feynman et al., J. Appl. Phys. 28, 49 (1957)]. The adopted real-vector representation approach allows for coupling with the vectorial Maxwell's equations for the optical wave propagation and thus the resulting Maxwell pseudospin equations can be numerically solved in the time domain without any approximations. The model permits a more exact study of the ultrafast coherent pulse propagation effects taking into account the vector nature of the electromagnetic field and hence the polarization state of the optical excitation. We demonstrate self-induced transparency effects and formation of polarized solitons. The model represents a qualitative extension of the well-known optical Maxwell-Bloch equations valid for linearly polarized light and a tool for studying coherent quantum control mechanisms

  12. Achieving involvement: process outcomes from a cluster randomized trial of shared decision making skill development and use of risk communication aids in general practice.

    Science.gov (United States)

    Elwyn, G; Edwards, A; Hood, K; Robling, M; Atwell, C; Russell, I; Wensing, M; Grol, R

    2004-08-01

    A consulting method known as 'shared decision making' (SDM) has been described and operationalized in terms of several 'competences'. One of these competences concerns the discussion of the risks and benefits of treatment or care options-'risk communication'. Few data exist on clinicians' ability to acquire skills and implement the competences of SDM or risk communication in consultations with patients. The aims of this study were to evaluate the effects of skill development workshops for SDM and the use of risk communication aids on the process of consultations. A cluster randomized trial with crossover was carried out with the participation of 20 recently qualified GPs in urban and rural general practices in Gwent, South Wales. A total of 747 patients with known atrial fibrillation, prostatism, menorrhagia or menopausal symptoms were invited to a consultation to review their condition or treatments. Half the consultations were randomly selected for audio-taping, of which 352 patients attended and were audio-taped successfully. After baseline, participating doctors were randomized to receive training in (i) SDM skills or (ii) the use of simple risk communication aids, using simulated patients. The alternative training was then provided for the final study phase. Patients were allocated randomly to a consultation during baseline or intervention 1 (SDM or risk communication aids) or intervention 2 phases. A randomly selected half of the consultations were audio-taped from each phase. Raters (independent, trained and blinded to study phase) assessed the audio-tapes using a validated scale to assess levels of patient involvement (OPTION: observing patient involvement), and to analyse the nature of risk information discussed. Clinicians completed questionnaires after each consultation, assessing perceived clinician-patient agreement and level of patient involvement in decisions. Multilevel modelling was carried out with the OPTION score as the dependent variable, and

  13. Do Physical Activity, Body Mass Index, and Sleep Duration Predict Clustered Cardiovascular Disease Risk in Children?- A Part of the OPUS Study

    DEFF Research Database (Denmark)

    Hjorth, Mads F.; Damsgaard, Camilla T.; Dalskov, Stine-Mathilde

    Objective To investigate the single and combined associations of physical activity (PA), body mass index (BMI), and sleep duration with clustering of cardiovascular disease risk markers in healthy children. Methods We did a cross-sectional pilot-study of 74 Danish school children aged 8-11 years...... BMI was 17.1 (range 13.4-25.4) kg/m2, with 10.8% classified as overweight using isoBMI. Controlled for age and sex, P A was negatively associated with cMET-score (Standardised beta coefficients (sBeta)=-0.32); n=74; P=0.016) and BMI was positively associated with cMETscore (sBeta=0.49; n=74; P...

  14. Risk of cervical cancer associated with allergies and polymorphisms in genes in the chromosome 5 cytokine cluster.

    Science.gov (United States)

    Johnson, Lisa G; Schwartz, Stephen M; Malkki, Mari; Du, Qin; Petersdorf, Effie W; Galloway, Denise A; Madeleine, Margaret M

    2011-01-01

    Human papillomavirus is the acknowledged cause of cervical cancer. We hypothesized that allergies, characterized by hyperimmune reaction to common allergens and which have been associated with various cancers, may be related to cervical cancer, and that genetic variation in cytokine genes related to allergies might impact cervical cancer risk. We investigated the risk of invasive squamous cell cervical cancer (SCC) associated with self-reported allergies and with variation in allergy-related cytokine genes using data from a case-control study (561 cases, 1,258 controls) conducted in Washington State. Logistic regression models yielded odds ratios (OR) and 95% CI. Pollen allergy, the most commonly reported allergy, was associated with reduced SCC risk (OR: 0.6; 95% CI: 0.5-0.8). Of 60 tagging single-nucleotide polymorphisms covering eight genes (CSF2, IL3, IL4, IL13, CSF2RB, IL4R, IL13RA1, IL13RA2), several were related to pollen allergies among controls: IL4R rs3024647 (dominant OR: 1.5; 95% CI: 1.0-2.3; P = 0.04), CSF2RB rs16997517 (dominant OR: 2.2; 95% CI: 1.0-4.7; P = 0.04), and IL13 rs1800925 (per-allele OR: 1.7; 95% CI: 1.3-2.4; P = 0.0007). Two variants were inversely associated with SCC risk: IL4R rs3024656 (per-allele OR: 0.8; 95% CI: 0.6-1.0; P = 0.03) and CSF2RB rs16997517 (dominant OR: 0.4; 95% CI: 0.2-0.9; P = 0.04). Pollen allergies were related to reduced SCC risk. CSF2RB rs16997517 was directly related to pollen allergies in controls and to reduced SCC risk. If other studies confirm these results, the mechanism behind allergy-associated immune response associated with SCC risk may be worth exploring in the context of therapeutic or prophylactic vaccines. ©2011 AACR.

  15. 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

  16. SUBJECT «NUMBER SYSTEMS» IN TWO-LEVELED FORMAT PREPARATION TEACHERS OF MATHEMATICS

    Directory of Open Access Journals (Sweden)

    V. I. Igoshin

    2017-01-01

    Full Text Available The aim of this article is to analyze the format of a two-leveled training – bachelor and master – future teachers of mathematics from the point of view of the content of mathematical material, which is to develop prospective teachers of mathematics at those two levels, shaping their professional competence.Methods. The study involves the theoretical methods: the analysis of pedagogical and methodical literature, normative documents; historical, comparative and logical analysis of the content of pedagogical mathematical education; forecasting, planning and designing of two-leveled methodical system of training of future teachers of mathematics.Results and scientific novelty. The level differentiation of the higher education system requires developing the appropriate curricula for undergraduate and graduate programs. The fundamental principle must be the principle of continuity – the magister must continue to deepen and broaden knowledge and skills, along with competences acquired, developed and formed on the undergraduate level. From these positions, this paper examines the course «Number Systems» – the most important in terms of methodology course for future mathematics teachers, and shows what content should be filled with this course at the undergraduate level and the graduate level. At the undergraduate level it is proposed to study classical number systems – natural, integer, rational, real and complex. Further extensions of the number systems are studied at the graduate level. The theory of numeric systems is presented as a theory of algebraic systems, arising at the intersection of algebra and mathematical logic. Here we study algebras over a field, division algebra over a field, an alternative algebra with division over the field, Jordan algebra, Lie algebra. Comprehension of bases of the theory of algebras by the master of the «mathematical education» profile will promote more conscious

  17. Computer simulation of two-level pedicle subtraction osteotomy for severe thoracolumbar kyphosis in ankylosing spondylitis

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    2017-01-01

    Full Text Available Background: Advanced ankylosing spondylitis is often associated with thoracolumbar kyphosis, resulting in an abnormal spinopelvic balance and pelvic morphology. Different osteotomy techniques have been used to correct AS deformities, unfortunnaly, not all AS patients can gain spinal sagittal balance and good horizontal vision after osteotomy. Materials and Methods: Fourteen consecutive AS patients with severe thoracolumbar kyphosis who were treated with two-level PSO were studied retrospectively. All were male with a mean age of 34.9 ± 9.6 years. The followup ranged from 1–5 years. Preoperative computer simulations using the Surgimap Spinal software were performed for all patients, and the osteotomy level and angle determined from the computer simulation were used surgically. Spinal sagittal parameters were measured preoperatively, after the computer simulation, and postoperatively and included thoracic kyphosis (TK, lumbar lordosis (LL, sagittal vertical axis (SVA, pelvic incidence, pelvic tilt (PT, and sacral slope (SS. The level of correlation between the computer simulation and postoperative parameters was evaluated, and the differences between preoperative and postoperative parameters were compared. The visual analog scale (VAS for back pain and clinical outcome was also assessed. Results: Six cases underwent PSO at L1 and L3, five cases at L2 and T12, and three cases at L3 and T12. TK was corrected from 57.8 ± 15.2° preoperatively to 45.3 ± 7.7° postoperatively (P < 0.05, LL from 9.3 ± 17.5° to −52.3 ± 3.9° (P < 0.001, SVA from 154.5 ± 36.7 to 37.8 ± 8.4 mm (P < 0.001, PT from 43.3 ± 6.1° to 18.0 ± 0.9° (P < 0.001, and SS from 0.8 ± 7.0° to 26.5 ± 10.6° (P < 0.001. The LL, VAS, and PT of the simulated two-level PSO were highly consistent with, or almost the same as, the postoperative parameters. The correlations between the computer simulations and postoperative parameters were significant. The VAS decreased

  18. Comprehensive solutions to the Bloch equations and dynamical models for open two-level systems

    Science.gov (United States)

    Skinner, Thomas E.

    2018-01-01

    The Bloch equation and its variants constitute the fundamental dynamical model for arbitrary two-level systems. Many important processes, including those in more complicated systems, can be modeled and understood through the two-level approximation. It is therefore of widespread relevance, especially as it relates to understanding dissipative processes in current cutting-edge applications of quantum mechanics. Although the Bloch equation has been the subject of considerable analysis in the 70 years since its inception, there is still, perhaps surprisingly, significant work that can be done. This paper extends the scope of previous analyses. It provides a framework for more fully understanding the dynamics of dissipative two-level systems. A solution is derived that is compact, tractable, and completely general, in contrast to previous results. Any solution of the Bloch equation depends on three roots of a cubic polynomial that are crucial to the time dependence of the system. The roots are typically only sketched out qualitatively, with no indication of their dependence on the physical parameters of the problem. Degenerate roots, which modify the solutions, have been ignored altogether. Here the roots are obtained explicitly in terms of a single real-valued root that is expressed as a simple function of the system parameters. For the conventional Bloch equation, a simple graphical representation of this root is presented that makes evident the explicit time dependence of the system for each point in the parameter space. Several intuitive, visual models of system dynamics are developed. A Euclidean coordinate system is identified in which any generalized Bloch equation is separable, i.e., the sum of commuting rotation and relaxation operators. The time evolution in this frame is simply a rotation followed by relaxation at modified rates that play a role similar to the standard longitudinal and transverse rates. These rates are functions of the applied field, which

  19. Cluster evolution

    International Nuclear Information System (INIS)

    Schaeffer, R.

    1987-01-01

    The galaxy and cluster luminosity functions are constructed from a model of the mass distribution based on hierarchical clustering at an epoch where the matter distribution is non-linear. These luminosity functions are seen to reproduce the present distribution of objects as can be inferred from the observations. They can be used to deduce the redshift dependence of the cluster distribution and to extrapolate the observations towards the past. The predicted evolution of the cluster distribution is quite strong, although somewhat less rapid than predicted by the linear theory

  20. Canyon of current suppression in an interacting two-level quantum dot

    DEFF Research Database (Denmark)

    Karlström, O; Pedersen, Jonas Nyvold; Samuelsson, P

    2011-01-01

    Motivated by the recent discovery of a canyon of conductance suppression in a two-level equal-spin quantum dot system [Phys. Rev. Lett. 104, 186804 (2010)], the transport through this system is studied in detail. At low bias and low temperature a strong current suppression is found around...... the electron-hole symmetry point independent of the couplings, in agreement with previous results. By means of a Schrieffer–Wolff transformation we are able to give an intuitive explanation to this suppression in the low-energy regime. In the general situation, numerical simulations are carried out using...... for the current suppression. It is also shown how broadening, interference, and a finite interaction energy cause a shift of the current minimum away from degeneracy. Finally we see how an increased population of the upper level leads to current peaks on each side of the suppression line. At sufficiently high...

  1. Propagation of an attosecond pulse in a dense two-level medium

    International Nuclear Information System (INIS)

    Song Xiaohong; Gong Shangqing; Yang Weifeng; Xu Zhizhan

    2004-01-01

    We investigate the propagation of attosecond pulse in a dense two-level medium by using an iterative predictor-corrector finite-difference time-domain method. We find when attosecond pulse is considered, that the standard area theorem will break down even for small area pulses: ideal self-induced transparency cannot occur even for a 2π pulse, while the pulses whose areas are not integer multiples of 2π, such as 1.8π and 2.2π pulses, cannot evolve to 2π pulses as predicted by the standard area theorem. Significantly higher spectra components can occur on all these small area propagating pulses due to strong carrier reshaping. Furthermore, these higher spectral components dependent sensitively on the pulse area: the larger the pulse area is, the more evident are these higher spectral components

  2. Information Entropy Squeezing of a Two-Level Atom Interacting with Two-Mode Coherent Fields

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-Juan; FANG Mao-Fa

    2004-01-01

    From a quantum information point of view we investigate the entropy squeezing properties for a two-level atom interacting with the two-mode coherent fields via the two-photon transition. We discuss the influences of the initial state of the system on the atomic information entropy squeezing. Our results show that the squeezed component number,squeezed direction, and time of the information entropy squeezing can be controlled by choosing atomic distribution angle,the relative phase between the atom and the two-mode field, and the difference of the average photon number of the two field modes, respectively. Quantum information entropy is a remarkable precision measure for the atomic squeezing.

  3. Transmission-line resonators for the study of individual two-level tunneling systems

    Science.gov (United States)

    Brehm, Jan David; Bilmes, Alexander; Weiss, Georg; Ustinov, Alexey V.; Lisenfeld, Jürgen

    2017-09-01

    Parasitic two-level tunneling systems (TLS) emerge in amorphous dielectrics and constitute a serious nuisance for various microfabricated devices, where they act as a source of noise and decoherence. Here, we demonstrate a new test bed for the study of TLS in various materials which provides access to properties of individual TLS as well as their ensemble response. We terminate a superconducting transmission-line resonator with a capacitor that hosts TLS in its dielectric. By tuning TLS via applied mechanical strain, we observe the signatures of individual TLS strongly coupled to the resonator in its transmission characteristics and extract the coupling components of their dipole moments and energy relaxation rates. The strong and well-defined coupling to the TLS bath results in pronounced resonator frequency fluctuations and excess phase noise, through which we can study TLS ensemble effects such as spectral diffusion, and probe theoretical models of TLS interactions.

  4. Entanglement for a Bimodal Cavity Field Interacting with a Two-Level Atom

    International Nuclear Information System (INIS)

    Liu Jia; Chen Ziyu; Bu Shenping; Zhang Guofeng

    2009-01-01

    Negativity has been adopted to investigate the entanglement in a system composed of a two-level atom and a two-mode cavity field. Effects of Kerr-like medium and the number of photon inside the cavity on the entanglement are studied. Our results show that atomic initial state must be superposed, so that the two cavity field modes can be entangled. Moreover, we also conclude that the number of photon in the two cavity mode should be equal. The interaction between modes, namely, the Kerr effect, has a significant negative contribution. Note that the atom frequency and the cavity frequency have an indistinguishable effect, so a corresponding approximation has been made in this article. These results may be useful for quantum information in optics systems.

  5. Interacting two-level defects as sources of fluctuating high-frequency noise in superconducting circuits

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Clemens [ARC Centre of Excellence for Engineered Quantum Systems, The University of Queensland, Brisbane (Australia); Lisenfeld, Juergen [Physikalisches Institut, Karlsruhe Institute of Technology, Karlsruhe (Germany); Shnirman, Alexander [Institut fuer Theory der Kondensierten Materie, Karlsruhe Institute of Technology, Karlsruhe (Germany); LD Landau Institute for Theoretical Physics, Moscow (Russian Federation); Poletto, Stefano [IBM TJ Watson Research Centre, Yorktown Heights (United States)

    2016-07-01

    Since the very first experiments, superconducting circuits have suffered from strong coupling to environmental noise, destroying quantum coherence and degrading performance. In state-of-the-art experiments, it is found that the relaxation time of superconducting qubits fluctuates as a function of time. We present measurements of such fluctuations in a 3D-transmon circuit and develop a qualitative model based on interactions within a bath of background two-level systems (TLS) which emerge from defects in the device material. In our model, the time-dependent noise density acting on the qubit emerges from its near-resonant coupling to high-frequency TLS which experience energy fluctuations due to their interaction with thermally fluctuating TLS at low frequencies. We support the model by providing experimental evidence of such energy fluctuations observed in a single TLS in a phase qubit circuit.

  6. Two-Level Hierarchical FEM Method for Modeling Passive Microwave Devices

    Science.gov (United States)

    Polstyanko, Sergey V.; Lee, Jin-Fa

    1998-03-01

    In recent years multigrid methods have been proven to be very efficient for solving large systems of linear equations resulting from the discretization of positive definite differential equations by either the finite difference method or theh-version of the finite element method. In this paper an iterative method of the multiple level type is proposed for solving systems of algebraic equations which arise from thep-version of the finite element analysis applied to indefinite problems. A two-levelV-cycle algorithm has been implemented and studied with a Gauss-Seidel iterative scheme used as a smoother. The convergence of the method has been investigated, and numerical results for a number of numerical examples are presented.

  7. Estimation of Missing Observations in Two-Level Split-Plot Designs

    DEFF Research Database (Denmark)

    Almimi, Ashraf A.; Kulahci, Murat; Montgomery, Douglas C.

    2008-01-01

    Inserting estimates for the missing observations from split-plot designs restores their balanced or orthogonal structure and alleviates the difficulties in the statistical analysis. In this article, we extend a method due to Draper and Stoneman to estimate the missing observations from unreplicated...... two-level factorial and fractional factorial split-plot (FSP and FFSP) designs. The missing observations, which can either be from the same whole plot, from different whole plots, or comprise entire whole plots, are estimated by equating to zero a number of specific contrast columns equal...... to the number of the missing observations. These estimates are inserted into the design table and the estimates for the remaining effects (or alias chains of effects as the case with FFSP designs) are plotted on two half-normal plots: one for the whole-plot effects and the other for the subplot effects...

  8. Thermal analysis of multi-MW two-level wind power converter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Mogens, Lau

    2012-01-01

    In this paper, the multi-MW wind turbine of partial-scale and full-scale two-level power converter with DFIG and direct-drive PMSG are designed and compared in terms of their thermal performance. Simulations of different configurations regarding loss distribution and junction temperature...... in the power device in the whole range of wind speed are presented and analyzed. It is concluded that in both partial-scale and full-scale power converter the most thermal stressed power device in the generator-side converter will have higher mean junction temperature and larger junction temperature...... fluctuation compared to grid-side converter at the rated wind speed. Moreover, the thermal performance of the generator-side converter in the partial-scale power converter becomes crucial around the synchronous operating point and should be considered carefully....

  9. Two-Level Verification of Data Integrity for Data Storage in Cloud Computing

    Science.gov (United States)

    Xu, Guangwei; Chen, Chunlin; Wang, Hongya; Zang, Zhuping; Pang, Mugen; Jiang, Ping

    Data storage in cloud computing can save capital expenditure and relive burden of storage management for users. As the lose or corruption of files stored may happen, many researchers focus on the verification of data integrity. However, massive users often bring large numbers of verifying tasks for the auditor. Moreover, users also need to pay extra fee for these verifying tasks beyond storage fee. Therefore, we propose a two-level verification of data integrity to alleviate these problems. The key idea is to routinely verify the data integrity by users and arbitrate the challenge between the user and cloud provider by the auditor according to the MACs and ϕ values. The extensive performance simulations show that the proposed scheme obviously decreases auditor's verifying tasks and the ratio of wrong arbitration.

  10. Nonlinear Jaynes–Cummings model for two interacting two-level atoms

    International Nuclear Information System (INIS)

    Santos-Sánchez, O de los; González-Gutiérrez, C; Récamier, J

    2016-01-01

    In this work we examine a nonlinear version of the Jaynes–Cummings model for two identical two-level atoms allowing for Ising-like and dipole–dipole interplays between them. The model is said to be nonlinear in the sense that it can incorporate both a general intensity-dependent interaction between the atomic system and the cavity field and/or the presence of a nonlinear medium inside the cavity. As an example, we consider a particular type of atom-field coupling based upon the so-called Buck–Sukumar model and a lossless Kerr-like cavity. We describe the possible effects of such features on the evolution of some quantities of current interest, such as atomic excitation, purity, concurrence, the entropy of the field and the evolution of the latter in phase space. (paper)

  11. Two Level Versus Matrix Converters Performance in Wind Energy Conversion Systems Employing DFIG

    Science.gov (United States)

    Reddy, Gongati Pandu Ranga; Kumar, M. Vijaya

    2017-10-01

    Wind power capacity has received enormous growth during past decades. With substantial development of wind power, it is expected to provide a fifth of world's electricity by the end of 2030. In wind energy conversion system, the power electronic converters play an important role. This paper presents the two level and matrix converters performance in wind energy conversion system employing Doubly Fed Induction Generator (DFIG). The DFIG is a wound rotor induction generator. Because of the advantages of the DFIG over other generators it is being used for most of the wind applications. This paper also discusses control of converters using the space vector pulse width modulation technique. The MATLAB/SIMULINK ® software is used to study the performance of the converters.

  12. Phonon induced optical gain in a current carrying two-level quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Eskandari-asl, Amir, E-mail: amir.eskandari.asl@gmail.com [Department of Physics, Shahid Beheshti University, G.C. Evin, Tehran 1983963113 (Iran, Islamic Republic of); School of Nano Science, Institute for Research in Fundamental Sciences (IPM), P.O. Box: 19395-5531, Tehran, Iran (Iran, Islamic Republic of)

    2017-05-15

    In this work we consider a current carrying two level quantum dot (QD) that is coupled to a single mode phonon bath. Using self-consistent Hartree-Fock approximation, we obtain the I-V curve of QD. By considering the linear response of our system to an incoming classical light, we see that depending on the parametric regime, the system could have weak or strong light absorption or may even show lasing. This lasing occurs at high enough bias voltages and is explained by a population inversion considering side bands, while the total electron population in the higher level is less than the lower one. The frequency at which we have the most significant lasing depends on the level spacing and phonon frequency and not on the electron-phonon coupling strength.

  13. TWO-LEVEL HIERARCHICAL COORDINATION QUEUING METHOD FOR TELECOMMUNICATION NETWORK NODES

    Directory of Open Access Journals (Sweden)

    M. V. Semenyaka

    2014-07-01

    Full Text Available The paper presents hierarchical coordination queuing method. Within the proposed method a queuing problem has been reduced to optimization problem solving that was presented as two-level hierarchical structure. The required distribution of flows and bandwidth allocation was calculated at the first level independently for each macro-queue; at the second level solutions obtained on lower level for each queue were coordinated in order to prevent probable network link overload. The method of goal coordination has been determined for multilevel structure managing, which makes it possible to define the order for consideration of queue cooperation restrictions and calculation tasks distribution between levels of hierarchy. Decisions coordination was performed by the method of Lagrange multipliers. The study of method convergence has been carried out by analytical modeling.

  14. On Two-Level State-Dependent Routing Polling Systems with Mixed Service

    Directory of Open Access Journals (Sweden)

    Guan Zheng

    2015-01-01

    Full Text Available Based on priority differentiation and efficiency of the system, we consider an N+1 queues’ single-server two-level polling system which consists of one key queue and N normal queues. The novel contribution of the present paper is that we consider that the server just polls active queues with customers waiting in the queue. Furthermore, key queue is served with exhaustive service and normal queues are served with 1-limited service in a parallel scheduling. For this model, we derive an expression for the probability generating function of the joint queue length distribution at polling epochs. Based on these results, we derive the explicit closed-form expressions for the mean waiting time. Numerical examples demonstrate that theoretical and simulation results are identical and the new system is efficient both at key queue and normal queues.

  15. Intensity profiles of superdeformed bands in Pb isotopes in a two-level mixing model

    International Nuclear Information System (INIS)

    Wilson, A. N.; Szigeti, S. S.; Rogers, J. I.; Davidson, P. M.; Cardamone, D. M.

    2009-01-01

    A recently developed two-level mixing model of the decay out of superdeformed bands is applied to examine the loss of flux from the yrast superdeformed bands in 192 Pb, 194 Pb, and 196 Pb. Probability distributions for decay to states at normal deformations are calculated at each level. The sensitivity of the results to parameters describing the levels at normal deformation and their coupling to levels in the superdeformed well is explored. It is found that except for narrow ranges of the interaction strength coupling the states, the amount of intensity lost is primarily determined by the ratio of γ decay widths in the normal and superdeformed wells. It is also found that while the model can accommodate the observed fractional intensity loss profiles for decay from bands at relatively high excitation, it cannot accommodate the similarly abrupt decay from bands at lower energies if standard estimates of the properties of the states in the first minimum are employed

  16. Photon echo with a few photons in two-level atoms

    International Nuclear Information System (INIS)

    Bonarota, M; Dajczgewand, J; Louchet-Chauvet, A; Le Gouët, J-L; Chanelière, T

    2014-01-01

    To store and retrieve signals at the single photon level, various photon echo schemes have resorted to complex preparation steps involving ancillary shelving states in multi-level atoms. For the first time, we experimentally demonstrate photon echo operation at such a low signal intensity without any preparation step, which allows us to work with mere two-level atoms. This simplified approach relies on the so-coined ‘revival of silenced echo’ (ROSE) scheme. Low noise conditions are obtained by returning the atoms to the ground state before the echo emission. In the present paper we manage ROSE in photon counting conditions, showing that very strong control fields can be compatible with extremely weak signals, making ROSE consistent with quantum memory requirements. (paper)

  17. Dynamical Evolution of an Effective Two-Level System with {\\mathscr{P}}{\\mathscr{T}} Symmetry

    Science.gov (United States)

    Du, Lei; Xu, Zhihao; Yin, Chuanhao; Guo, Liping

    2018-05-01

    We investigate the dynamics of parity- and time-reversal (PT ) symmetric two-energy-level atoms in the presence of two optical and a radio-frequency (rf) fields. The strength and relative phase of fields can drive the system from unbroken to broken PT symmetric regions. Compared with the Hermitian model, Rabi-type oscillation is still observed, and the oscillation characteristics are also adjusted by the strength and relative phase in the region of unbroken PT symmetry. At exception point (EP), the oscillation breaks down. To better understand the underlying properties we study the effective Bloch dynamics and find the emergence of the z components of the fixed points is the feature of the PT symmetry breaking and the projections in x-y plane can be controlled with high flexibility compared with the standard two-level system with PT symmetry. It helps to study the dynamic behavior of the complex PT symmetric model.

  18. Faithful state transfer between two-level systems via an actively cooled finite-temperature cavity

    Science.gov (United States)

    Sárkány, Lőrinc; Fortágh, József; Petrosyan, David

    2018-03-01

    We consider state transfer between two qubits—effective two-level systems represented by Rydberg atoms—via a common mode of a microwave cavity at finite temperature. We find that when both qubits have the same coupling strength to the cavity field, at large enough detuning from the cavity mode frequency, quantum interference between the transition paths makes the swap of the excitation between the qubits largely insensitive to the number of thermal photons in the cavity. When, however, the coupling strengths are different, the photon-number-dependent differential Stark shift of the transition frequencies precludes efficient transfer. Nevertheless, using an auxiliary cooling system to continuously extract the cavity photons, we can still achieve a high-fidelity state transfer between the qubits.

  19. Two-level modulation scheme to reduce latency for optical mobile fronthaul networks.

    Science.gov (United States)

    Sung, Jiun-Yu; Chow, Chi-Wai; Yeh, Chien-Hung; Chang, Gee-Kung

    2016-10-31

    A system using optical two-level orthogonal-frequency-division-multiplexing (OFDM) - amplitude-shift-keying (ASK) modulation is proposed and demonstrated to reduce the processing latency for the optical mobile fronthaul networks. At the proposed remote-radio-head (RRH), the high data rate OFDM signal does not need to be processed, but is directly launched into a high speed photodiode (HSPD) and subsequently emitted by an antenna. Only a low bandwidth PD is needed to recover the low data rate ASK control signal. Hence, it is simple and provides low-latency. Furthermore, transporting the proposed system over the already deployed optical-distribution-networks (ODNs) of passive-optical-networks (PONs) is also demonstrated with 256 ODN split-ratios.

  20. Indoor Semantic Modelling for Routing: The Two-Level Routing Approach for Indoor Navigation

    Directory of Open Access Journals (Sweden)

    Liu Liu

    2017-11-01

    Full Text Available Humans perform many activities indoors and they show a growing need for indoor navigation, especially in unfamiliar buildings such as airports, museums and hospitals. Complexity of such buildings poses many challenges for building managers and visitors. Indoor navigation services play an important role in supporting these indoor activities. Indoor navigation covers extensive topics such as: 1 indoor positioning and localization; 2 indoor space representation for navigation model generation; 3 indoor routing computation; 4 human wayfinding behaviours; and 5 indoor guidance (e.g., textual directories. So far, a large number of studies of pedestrian indoor navigation have presented diverse navigation models and routing algorithms/methods. However, the major challenge is rarely referred to: how to represent the complex indoor environment for pedestrians and conduct routing according to the different roles and sizes of users. Such complex buildings contain irregular shapes, large open spaces, complicated obstacles and different types of passages. A navigation model can be very complicated if the indoors are accurately represented. Although most research demonstrates feasible indoor navigation models and related routing methods in regular buildings, the focus is still on a general navigation model for pedestrians who are simplified as circles. In fact, pedestrians represent different sizes, motion abilities and preferences (e.g., described in user profiles, which should be reflected in navigation models and be considered for indoor routing (e.g., relevant Spaces of Interest and Points of Interest. In order to address this challenge, this thesis proposes an innovative indoor modelling and routing approach – two-level routing. It specially targets the case of routing in complex buildings for distinct users. The conceptual (first level uses general free indoor spaces: this is represented by the logical network whose nodes represent the spaces and edges

  1. Segmental and global lordosis changes with two-level axial lumbar interbody fusion and posterior instrumentation

    Science.gov (United States)

    Melgar, Miguel A; Tobler, William D; Ernst, Robert J; Raley, Thomas J; Anand, Neel; Miller, Larry E; Nasca, Richard J

    2014-01-01

    Background Loss of lumbar lordosis has been reported after lumbar interbody fusion surgery and may portend poor clinical and radiographic outcome. The objective of this research was to measure changes in segmental and global lumbar lordosis in patients treated with presacral axial L4-S1 interbody fusion and posterior instrumentation and to determine if these changes influenced patient outcomes. Methods We performed a retrospective, multi-center review of prospectively collected data in 58 consecutive patients with disabling lumbar pain and radiculopathy unresponsive to nonsurgical treatment who underwent L4-S1 interbody fusion with the AxiaLIF two-level system (Baxano Surgical, Raleigh NC). Main outcomes included back pain severity, Oswestry Disability Index (ODI), Odom's outcome criteria, and fusion status using flexion and extension radiographs and computed tomography scans. Segmental (L4-S1) and global (L1-S1) lumbar lordosis measurements were made using standing lateral radiographs. All patients were followed for at least 24 months (mean: 29 months, range 24-56 months). Results There was no bowel injury, vascular injury, deep infection, neurologic complication or implant failure. Mean back pain severity improved from 7.8±1.7 at baseline to 3.3±2.6 at 2 years (p lordosis, defined as a change in Cobb angle ≤ 5°, was identified in 84% of patients at L4-S1 and 81% of patients at L1-S1. Patients with loss or gain in segmental or global lordosis experienced similar 2-year outcomes versus those with less than a 5° change. Conclusions/Clinical Relevance Two-level axial interbody fusion supplemented with posterior fixation does not alter segmental or global lordosis in most patients. Patients with postoperative change in lordosis greater than 5° have similarly favorable long-term clinical outcomes and fusion rates compared to patients with less than 5° lordosis change. PMID:25694920

  2. The social construction of real estate market risk. The case of a financial investments cluster in Mexico City

    Directory of Open Access Journals (Sweden)

    Louise David

    2012-11-01

    Full Text Available This article contributes to the study of the geographical concentration of financial investments in real estate markets. It demonstrates the social construction process at work in the evolution of real estate market risks. The objective is to highlight the conditions that allow or impede the implementation of ‘opportunistic’ and ‘conservative’ risk strategies. By analyzing the market entry of financial investors in the Cuautitlan industrial real estate market - an ‘emerging’ real estate market in Mexico City - this paper demonstrates that, due to the joint action of land developers, non-financial as well as financial real estate investors, this market moved from being ‘too risky’ to becoming an opportunistic market, and then a conservative one. There were two important phases in the transformation process. First, the contribution of land developers was fundamental to the transformation of the market from being too risky to being opportunistic from the perspective of financial investors. Two different types of land developers are evident: some are not willing to help financial investors’ entry in the market while others developed a business plan designed to facilitate financial investments. In the second phase of the market’s risks transformation, opportunistic financial investors enabled the conditions for the arrival of conservative financial investors, thanks to their presence in emerging markets and the diffusion of information.

  3. Effects of a complex intervention on fall risk in the general practitioner setting: a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Freiberger E

    2013-08-01

    Full Text Available Ellen Freiberger,1 Wolfgang A Blank,2 Johannes Salb,1 Barbara Geilhof,3 Christian Hentschke,1 Peter Landendoerfer,2 Martin Halle,3 Monika Siegrist31Institute of Sport Science and Sport Universität Erlangen-Nürnberg, Nuremberg, Germany; 2Institute of General Practice, Technische Universität München, Munich, Germany; 3Department of Prevention, Rehabilitation and Sports Medicine, Technische Universität München, Munich, GermanyPurpose: To study the feasibility of first, reaching functionally declined, but still independent older persons at risk of falls through their general practitioner (GP and second, to reduce their physiological and psychological fall risk factors with a complex exercise intervention. We investigated the effects of a 16-week exercise intervention on physiological (function, strength, and balance and psychological (fear of falling outcomes in community-dwelling older persons in comparison with usual care. In addition, we obtained data on adherence of the participants to the exercise program.Methods: Tests on physical and psychological fall risk were conducted at study inclusion, and after the 16-week intervention period in the GP office setting. The 16-week intervention included progressive and challenging balance, gait, and strength exercise as well as changes to behavioral aspects. To account for the hierarchical structure in the chosen study design, with patients nested in GPs and measurements nested in patients, a three-level linear mixed effects model was determined for analysis.Results: In total, 33 GPs recruited 378 participants (75.4% females. The mean age of the participants was 78.1 years (standard deviation 5.9 years. Patients in the intervention group showed an improvement in the Timed-Up-and-Go-test (TUG that was 1.5 seconds greater than that showed by the control group, equivalent to a small to moderate effect. For balance, a relative improvement of 0.8 seconds was accomplished, and anxiety about falls was

  4. Can an e-learning course improve nursing care for older people at risk of delirium: a stepped wedge cluster randomised trial.

    Science.gov (United States)

    van de Steeg, Lotte; IJkema, Roelie; Langelaan, Maaike; Wagner, Cordula

    2014-05-27

    Delirium occurs frequently in older hospitalised patients and is associated with several adverse outcomes. Ignorance among healthcare professionals and a failure to recognise patients suffering from delirium have been identified as the possible causes of poor care. The objective of the study was to determine whether e-learning can be an effective means of improving implementation of a quality improvement project in delirium care. This project aims primarily at improving the early recognition of older patients who are at risk of delirium. In a stepped wedge cluster randomised trial an e-learning course on delirium was introduced, aimed at nursing staff. The trial was conducted on general medical and surgical wards from 18 Dutch hospitals. The primary outcome measure was the delirium risk screening conducted by nursing staff, measured through monthly patient record reviews. Patient records from patients aged 70 and over admitted onto wards participating in the study were used for data collection. Data was also collected on the level of delirium knowledge of these wards' nursing staff. Records from 1,862 older patients were included during the control phase and from 1,411 patients during the intervention phase. The e-learning course on delirium had a significant positive effect on the risk screening of older patients by nursing staff (OR 1.8, p-value e-learning course also showed a significant positive effect on nurses' knowledge of delirium. Nurses who undertook a delirium e-learning course showed a greater adherence to the quality improvement project in delirium care. This improved the recognition of patients at risk and demonstrated that e-learning can be a valuable instrument for hospitals when implementing improvements in delirium care. The Netherlands National Trial Register (NTR). NTR2885.

  5. Can an e-learning course improve nursing care for older people at risk of delirium: a stepped wedge cluster randomised trial

    Science.gov (United States)

    2014-01-01

    Background Delirium occurs frequently in older hospitalised patients and is associated with several adverse outcomes. Ignorance among healthcare professionals and a failure to recognise patients suffering from delirium have been identified as the possible causes of poor care. The objective of the study was to determine whether e-learning can be an effective means of improving implementation of a quality improvement project in delirium care. This project aims primarily at improving the early recognition of older patients who are at risk of delirium. Methods In a stepped wedge cluster randomised trial an e-learning course on delirium was introduced, aimed at nursing staff. The trial was conducted on general medical and surgical wards from 18 Dutch hospitals. The primary outcome measure was the delirium risk screening conducted by nursing staff, measured through monthly patient record reviews. Patient records from patients aged 70 and over admitted onto wards participating in the study were used for data collection. Data was also collected on the level of delirium knowledge of these wards’ nursing staff. Results Records from 1,862 older patients were included during the control phase and from 1,411 patients during the intervention phase. The e-learning course on delirium had a significant positive effect on the risk screening of older patients by nursing staff (OR 1.8, p-value e-learning course also showed a significant positive effect on nurses’ knowledge of delirium. Conclusions Nurses who undertook a delirium e-learning course showed a greater adherence to the quality improvement project in delirium care. This improved the recognition of patients at risk and demonstrated that e-learning can be a valuable instrument for hospitals when implementing improvements in delirium care. Trial registration The Netherlands National Trial Register (NTR). Trial number: NTR2885. PMID:24884739

  6. Design and baseline characteristics of the PerfectFit study: a multicenter cluster-randomized trial of a lifestyle intervention in employees with increased cardiovascular risk.

    Science.gov (United States)

    Kouwenhoven-Pasmooij, Tessa A; Djikanovic, Bosiljka; Robroek, Suzan J W; Helmhout, Pieter; Burdorf, Alex; Hunink, M G Myriam

    2015-07-28

    The prevalence of unhealthy lifestyles and preventable chronic diseases is high. They lead to disabilities and sickness absence, which might be reduced if health promotion measures were applied. Therefore, we developed the PerfectFit health promotion intervention with a "blended care"-approach, which consists of a web-based health risk assessment (HRA) including tailored and personalized advice, followed by motivational interviewing (MI). We hypothesize that adding MI to a web-based HRA leads to better health outcomes. The objective is to describe the design and baseline characteristics of the PerfectFit study, which is being conducted among employees with high cardiovascular risk in the military workforce, the police organization and an academic hospital. PerfectFit is a cluster randomized controlled trial, consisting of two arms. Based on cardiovascular risk profiling, done between 2012 and 2014, we included employees based on one or more risk factors and motivation to participate. One arm is the 'limited' health program (control) that consists of: (a) an HRA as a decision aid for lifestyle changes, including tailored and personalized advice, and pros and cons of the options, and (b) a newsletter every 3 months. The other arm is the 'extensive' program (intervention), which is additionally offered MI-sessions by trained occupational physicians, 4 face-to-face and 3 by telephone, and is offered more choices of health promotion activities in the HRA. During the follow-up period, participants choose the health promotion activities they personally prefer. After six and twelve months, outcomes will be assessed by online questionnaires. After twelve months the cardiovascular risk profiling will be repeated. The primary outcome is self-reported general health. Secondary outcomes are self-reported work ability, CVD-risk score, sickness absence, productivity loss at work, participation in health promotion activities, changes in lifestyle (smoking, alcohol consumption

  7. The association between serum brain-derived neurotrophic factor and a cluster of cardiovascular risk factors in adolescents

    DEFF Research Database (Denmark)

    Pedersen, Natascha Holbæk; Tarp, Jakob; Andersen, Lars Bo

    2017-01-01

    .034) and HOMA-IR (Std. β = 0.19, P = 0.004), and negatively associated with CRF (Std. β = -0.15, P = 0.026). In females, BDNF was positively associated with TG (Std. β = 0.14, P = 0.030) and negatively associated with waist circumference (WC) (Std. β = -0.16, P = 0.012). Conclusion: Serum BDNF was positively...... associated with a composite z-score of cardiovascular risk factors. This association seems to be mainly driven by the association between TG, HOMA-IR and serum BDNF, and particularly for males. Further longitudinal research is warranted to determine the temporal relationship between BDNF and cardiovascular...

  8. Seizure clusters: characteristics and treatment.

    Science.gov (United States)

    Haut, Sheryl R

    2015-04-01

    Many patients with epilepsy experience 'clusters' or flurries of seizures, also termed acute repetitive seizures (ARS). Seizure clustering has a significant impact on health and quality of life. This review summarizes recent advances in the definition and neurophysiologic understanding of clustering, the epidemiology and risk factors for clustering and both inpatient and outpatient clinical implications. New treatments for seizure clustering/ARS are perhaps the area of greatest recent progress. Efforts have focused on creating a uniform definition of a seizure cluster. In neurophysiologic studies of refractory epilepsy, seizures within a cluster appear to be self-triggering. Clinical progress has been achieved towards a more precise prevalence of clustering, and consensus guidelines for epilepsy monitoring unit safety. The greatest recent advances are in the study of nonintravenous route of benzodiazepines as rescue medications for seizure clusters/ARS. Rectal benzodiazepines have been very effective but barriers to use exist. New data on buccal, intramuscular and intranasal preparations are anticipated to lead to a greater number of approved treatments. Progesterone may be effective for women who experience catamenial clusters. Seizure clustering is common, particularly in the setting of medically refractory epilepsy. Clustering worsens health and quality of life, and the field requires greater focus on clarifying of definition and clinical implications. Progress towards the development of nonintravenous routes of benzodiazepines has the potential to improve care in this area.

  9. Polymorphisms in IL-1 gene cluster and its association with the risk of perinatal HIV transmission, in an Indian cohort.

    Science.gov (United States)

    Ahir, Swati; Chaudhari, Deepali; Chavan, Vijay; Samant-Mavani, Padmaja; Nanavati, Ruchi; Mehta, Preeti; Mania-Pramanik, Jayanti

    2013-06-01

    Host genetic diversity plays a very important role in protecting infants exposed to HIV-1 through their mothers. IL-1 family genes are key mediators of inflammatory responses and no studies are available on its association with perinatal HIV transmission. We aimed to evaluate if single nucleotide polymorphisms in IL-1 family genes are associated with perinatal HIV transmission. Infants of HIV positive women were genotyped for five polymorphic loci in IL1 gene cluster namely; IL1R1 (rs2234650), IL1A (rs1800587), IL1B (rs16944), IL1B (rs1143634), and IL1RN (rs315952) using polymerase chain reaction with sequence specific primers (PCR-SSP) method. Haplotype block structure was determined using Haploview and statistical analysis was done using PyPop. In this cohort based observational study significantly increased frequency of CT genotype in IL1R1 (rs2234650) was observed in positive vs. negative children (76.4% vs. 42.2%, p = 0.023), while CC genotype was significantly (p = 0.022) high in exposed uninfected children compared to infected ones (51.1% vs. 17.6%). These significances, however, did not stand the Bonferroni corrections. Haplotypic analysis demonstrated that the TCCCT haplotype was significantly associated (p = 0.002) with HIV transmission and remained significant even after Bonferroni correction. The children who had the protective CC genotype at IL1R1 (rs2234650) and were still positive had the TTC haplotype for IL1A (rs1800587):IL1B (rs1143634):IL1R1 (rs2234650). In contrast, 16 out of 19 (84.2%) children who had the CT genotype and were still negative had the protective CTC haplotype for IL1A (rs1800587):IL1B (rs16944):IL1B (rs1143634). IL1R1 (rs2234650) polymorphisms CT/CC along the specific haplotypes of the IL-1 gene family can be exploited as possible markers for prediction of perinatal HIV transmission. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. INTroducing A Care bundle To prevent pressure injury (INTACT) in at-risk patients: A protocol for a cluster randomised trial.

    Science.gov (United States)

    Chaboyer, Wendy; Bucknall, Tracey; Webster, Joan; McInnes, Elizabeth; Banks, Merrilyn; Wallis, Marianne; Gillespie, Brigid M; Whitty, Jennifer A; Thalib, Lukman; Roberts, Shelley; Cullum, Nicky

    2015-11-01

    Pressure injuries are a significant clinical and economic issue, affecting both patients and the health care system. Many pressure injuries in hospitals are facility acquired, and are largely preventable. Despite growing evidence and directives for pressure injury prevention, implementation of preventative strategies is suboptimal, and pressure injuries remain a serious problem in hospitals. This study will test the effectiveness and cost-effectiveness of a patient-centred pressure injury prevention care bundle on the development of hospital acquired pressure injury in at-risk patients. This is a multi-site, parallel group cluster randomised trial. The hospital is the unit of randomisation. Adult medical and surgical patients admitted to the study wards of eight hospitals who are (a) deemed to be at risk of pressure injury (i.e. have reduced mobility), (b) expected to stay in hospital for ≥48h, (c) admitted to hospital in the past 36h; and (d) able to provide informed consent will be eligible to participate. Consenting patients will receive either the pressure injury prevention care bundle or standard care. The care bundle contains three main messages: (1) keep moving; (2) look after your skin; and (3) eat a healthy diet. Nurses will receive education about the intervention. Patients will exit the study upon development of a pressure injury, hospital discharge or 28 days, whichever comes first; transfer to another hospital or transfer to critical care and mechanically ventilated. The primary outcome is incidence of hospital acquired pressure injury. Secondary outcomes are pressure injury stage, patient participation in care and health care costs. A health economic sub-study and a process evaluation will be undertaken alongside the trial. Data will be analysed at the cluster (hospital) and patient level. Estimates of hospital acquired pressure injury incidence in each group, group differences and 95% confidence interval and p values will be reported. To our

  11. Improving Care for Patients With or at Risk for Chronic Kidney Disease Using Electronic Medical Record Interventions: A Pragmatic Cluster-Randomized Trial Protocol

    Science.gov (United States)

    Nash, Danielle M.; Ivers, Noah M.; Young, Jacqueline; Jaakkimainen, R. Liisa; Garg, Amit X.; Tu, Karen

    2017-01-01

    Background: Many patients with or at risk for chronic kidney disease (CKD) in the primary care setting are not receiving recommended care. Objective: The objective of this study is to determine whether a multifaceted, low-cost intervention compared with usual care improves the care of patients with or at risk for CKD in the primary care setting. Design: A pragmatic cluster-randomized trial, with an embedded qualitative process evaluation, will be conducted. Setting: The study population comes from the Electronic Medical Record Administrative data Linked Database®, which includes clinical data for more than 140 000 rostered adults cared for by 194 family physicians in 34 clinics across Ontario, Canada. The 34 primary care clinics will be randomized to the intervention or control group. Intervention: The intervention group will receive resources from the “CKD toolkit” to help improve care including practice audit and feedback, printed educational materials for physicians and patients, electronic decision support and reminders, and implementation support. Measurements: Patients with or at risk for CKD within participating clinics will be identified using laboratory data in the electronic medical records. Outcomes will be assessed after dissemination of the CKD tools and after 2 rounds of feedback on performance on quality indicators have been sent to the physicians using information from the electronic medical records. The primary outcome is the proportion of patients aged 50 to 80 years with nondialysis-dependent CKD who are on a statin. Secondary outcomes include process of care measures such as screening tests, CKD recognition, monitoring tests, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker prescriptions, blood pressure targets met, and nephrologist referral. Hierarchical analytic modeling will be performed to account for clustering. Semistructured interviews will be conducted with a random purposeful sample of physicians in the

  12. DNCON2: improved protein contact prediction using two-level deep convolutional neural networks.

    Science.gov (United States)

    Adhikari, Badri; Hou, Jie; Cheng, Jianlin

    2018-05-01

    Significant improvements in the prediction of protein residue-residue contacts are observed in the recent years. These contacts, predicted using a variety of coevolution-based and machine learning methods, are the key contributors to the recent progress in ab initio protein structure prediction, as demonstrated in the recent CASP experiments. Continuing the development of new methods to reliably predict contact maps is essential to further improve ab initio structure prediction. In this paper we discuss DNCON2, an improved protein contact map predictor based on two-level deep convolutional neural networks. It consists of six convolutional neural networks-the first five predict contacts at 6, 7.5, 8, 8.5 and 10 Å distance thresholds, and the last one uses these five predictions as additional features to predict final contact maps. On the free-modeling datasets in CASP10, 11 and 12 experiments, DNCON2 achieves mean precisions of 35, 50 and 53.4%, respectively, higher than 30.6% by MetaPSICOV on CASP10 dataset, 34% by MetaPSICOV on CASP11 dataset and 46.3% by Raptor-X on CASP12 dataset, when top L/5 long-range contacts are evaluated. We attribute the improved performance of DNCON2 to the inclusion of short- and medium-range contacts into training, two-level approach to prediction, use of the state-of-the-art optimization and activation functions, and a novel deep learning architecture that allows each filter in a convolutional layer to access all the input features of a protein of arbitrary length. The web server of DNCON2 is at http://sysbio.rnet.missouri.edu/dncon2/ where training and testing datasets as well as the predictions for CASP10, 11 and 12 free-modeling datasets can also be downloaded. Its source code is available at https://github.com/multicom-toolbox/DNCON2/. chengji@missouri.edu. Supplementary data are available at Bioinformatics online.

  13. Chronorisk in cluster headache

    DEFF Research Database (Denmark)

    Barloese, Mads; Haddock, Bryan; Lund, Nunu T

    2018-01-01

    and a spectral analysis identifying oscillations in risk. Results The Gaussian model fit for the chronorisk distribution for all patients reporting diurnal rhythmicity (n = 286) had a goodness of fit R2 value of 0.97 and identified three times of increased risk peaking at 21:41, 02:02 and 06:23 hours....... In subgroups, three to five modes of increased risk were found and goodness of fit values ranged from 0.85-0.99. Spectral analysis revealed multiple distinct oscillation frequencies in chronorisk in subgroups including a dominant circadian oscillation in episodic patients and an ultradian in chronic....... Conclusions Chronorisk in cluster headache can be characterised as a sum of individual, timed events of increased risk, each having a Gaussian distribution. In episodic cluster headache, attacks follow a circadian rhythmicity whereas, in the chronic variant, ultradian oscillations are dominant reflecting...

  14. Spectral density of Cooper pairs in two level quantum dot–superconductors Josephson junction

    Energy Technology Data Exchange (ETDEWEB)

    Dhyani, A., E-mail: archana.d2003@gmail.com [Department of Physics, University of Petroleum and Energy Studies, Dehradun 248007, Uttarakhand (India); Rawat, P.S. [Department of Nuclear Science and Technology, University of Petroleum and Energy Studies, Dehradun 248007, Uttarakhand (India); Tewari, B.S., E-mail: bstewari@ddn.upes.ac.in [Department of Physics, University of Petroleum and Energy Studies, Dehradun 248007, Uttarakhand (India)

    2016-09-15

    Highlights: • The present work deals with the study of the electronic spectral density of electron pairs and its effect in charge transport in superconductor-quantum dot-superconductor junctions. • The charge transfer across such junctions can be controlled by changing the positions of the dot level. • The Josephson supercurrent can also be tuned by controlling the position of quantum dot energy levels. - Abstract: In the present paper, we report the role of quantum dot energy levels on the electronic spectral density for a two level quantum dot coupled to s-wave superconducting leads. The theoretical arguments in this work are based on the Anderson model so that it necessarily includes dot energies, single particle tunneling and superconducting order parameter for BCS superconductors. The expression for single particle spectral function is obtained by using the Green's function equation of motion technique. On the basis of numerical computation of spectral function of superconducting leads, it has been found that the charge transfer across such junctions can be controlled by the positions and availability of the dot levels.

  15. Induced absorption and stimulated emission in a driven two-level atom

    International Nuclear Information System (INIS)

    Mavroyannis, C.

    1992-01-01

    We have considered the induced processes that occur in a driven two-level atom, where a laser photon is absorbed and emitted by the ground and by the excited states of the atom, respectively. In the low-intensity limit of the laser field, the induced spectra arising when a laser photon is absorbed by the ground state of the atom consist of two peaks describing induced absorption and stimulated-emission processes, respectively, where the former prevails over the latter. Asymmetry of the spectral lines occurs at off-resonance and its extent depends on the detuning of the laser field. The physical. process where a laser photon is emitted by the excited state is the reverse of that arising from the absorption of a laser photon by the ground state of the atom. The former differs from the latter in that the emission of a laser photon by the excited state occurs in the low frequency regime and that the stimulated-emission process prevails over that of the induced absorption. In this case, amplification of ultrashort pulses is likely to occur without the need of population inversion between the optical transitions. The computed spectra are graphically presented and discussed. (author)

  16. A distributed monitoring system for photovoltaic arrays based on a two-level wireless sensor network

    Science.gov (United States)

    Su, F. P.; Chen, Z. C.; Zhou, H. F.; Wu, L. J.; Lin, P. J.; Cheng, S. Y.; Li, Y. F.

    2017-11-01

    In this paper, a distributed on-line monitoring system based on a two-level wireless sensor network (WSN) is proposed for real time status monitoring of photovoltaic (PV) arrays to support the fine management and maintenance of PV power plants. The system includes the sensing nodes installed on PV modules (PVM), sensing and routing nodes installed on combiner boxes of PV sub-arrays (PVA), a sink node and a data management centre (DMC) running on a host computer. The first level WSN is implemented by the low-cost wireless transceiver nRF24L01, and it is used to achieve single hop communication between the PVM nodes and their corresponding PVA nodes. The second level WSN is realized by the CC2530 based ZigBee network for multi-hop communication among PVA nodes and the sink node. The PVM nodes are used to monitor the PVM working voltage and backplane temperature, and they send the acquired data to their PVA node via the nRF24L01 based first level WSN. The PVA nodes are used to monitor the array voltage, PV string current and environment irradiance, and they send the acquired and received data to the DMC via the ZigBee based second level WSN. The DMC is designed using the MATLAB GUIDE and MySQL database. Laboratory experiment results show that the system can effectively acquire, display, store and manage the operating and environment parameters of PVA in real time.

  17. Vorticity, backscatter and counter-gradient transport predictions using two-level simulation of turbulent flows

    Science.gov (United States)

    Ranjan, R.; Menon, S.

    2018-04-01

    The two-level simulation (TLS) method evolves both the large-and the small-scale fields in a two-scale approach and has shown good predictive capabilities in both isotropic and wall-bounded high Reynolds number (Re) turbulent flows in the past. Sensitivity and ability of this modelling approach to predict fundamental features (such as backscatter, counter-gradient turbulent transport, small-scale vorticity, etc.) seen in high Re turbulent flows is assessed here by using two direct numerical simulation (DNS) datasets corresponding to a forced isotropic turbulence at Taylor's microscale-based Reynolds number Reλ ≈ 433 and a fully developed turbulent flow in a periodic channel at friction Reynolds number Reτ ≈ 1000. It is shown that TLS captures the dynamics of local co-/counter-gradient transport and backscatter at the requisite scales of interest. These observations are further confirmed through a posteriori investigation of the flow in a periodic channel at Reτ = 2000. The results reveal that the TLS method can capture both the large- and the small-scale flow physics in a consistent manner, and at a reduced overall cost when compared to the estimated DNS or wall-resolved LES cost.

  18. Robust Methods for Moderation Analysis with a Two-Level Regression Model.

    Science.gov (United States)

    Yang, Miao; Yuan, Ke-Hai

    2016-01-01

    Moderation analysis has many applications in social sciences. Most widely used estimation methods for moderation analysis assume that errors are normally distributed and homoscedastic. When these assumptions are not met, the results from a classical moderation analysis can be misleading. For more reliable moderation analysis, this article proposes two robust methods with a two-level regression model when the predictors do not contain measurement error. One method is based on maximum likelihood with Student's t distribution and the other is based on M-estimators with Huber-type weights. An algorithm for obtaining the robust estimators is developed. Consistent estimates of standard errors of the robust estimators are provided. The robust approaches are compared against normal-distribution-based maximum likelihood (NML) with respect to power and accuracy of parameter estimates through a simulation study. Results show that the robust approaches outperform NML under various distributional conditions. Application of the robust methods is illustrated through a real data example. An R program is developed and documented to facilitate the application of the robust methods.

  19. Entanglement Criteria of Two Two-Level Atoms Interacting with Two Coupled Modes

    Science.gov (United States)

    Baghshahi, Hamid Reza; Tavassoly, Mohammad Kazem; Faghihi, Mohammad Javad

    2015-08-01

    In this paper, we study the interaction between two two-level atoms and two coupled modes of a quantized radiation field in the form of parametric frequency converter injecting within an optical cavity enclosed by a medium with Kerr nonlinearity. It is demonstrated that, by applying the Bogoliubov-Valatin canonical transformation, the introduced model is reduced to a well-known form of the generalized Jaynes-Cummings model. Then, under particular initial conditions for the atoms (in a coherent superposition of its ground and upper states) and the fields (in a standard coherent state) which may be prepared, the time evolution of state vector of the entire system is analytically evaluated. In order to understand the degree of entanglement between subsystems (atom-field and atom-atom), the dynamics of entanglement through different measures, namely, von Neumann reduced entropy, concurrence and negativity is evaluated. In each case, the effects of Kerr nonlinearity and detuning parameter on the above measures are numerically analyzed, in detail. It is illustrated that the amount of entanglement can be tuned by choosing the evolved parameters, appropriately.

  20. Multilevel Converter by Cascading Two-Level Three-Phase Voltage Source Converter

    Directory of Open Access Journals (Sweden)

    Abdullrahman A. Al-Shamma’a

    2018-04-01

    Full Text Available This paper proposes a topology using isolated, cascaded multilevel voltage source converters (VSCs and employing two-winding magnetic elements for high-power applications. The proposed topology synthesizes 6 two-level, three-phase VSCs, so the power capability of the presented converter is six times the capability of each VSC module. The characteristics of the proposed topology are demonstrated through analyzing its current relationships, voltage relationships and power capability in detail. The power rating is equally shared among the VSC modules without the need for a sharing algorithm; thus, the converter operates as a single three-phase VSC. The comparative analysis with classical neutral-point clamped, flying capacitor and cascaded H-bridge exhibits the superior features of fewer insulated gate bipolar transistors (IGBTs, capacitor requirement and fewer diodes. To validate the theoretical performance of the proposed converter, it is simulated in a MATLAB/Simulink environment and the results are experimentally demonstrated using a laboratory prototype.

  1. Acoustic interactions between inversion symmetric and asymmetric two-level systems

    International Nuclear Information System (INIS)

    Churkin, A; Schechter, M; Barash, D

    2014-01-01

    Amorphous solids, as well as many disordered lattices, display remarkable universality in their low temperature acoustic properties. This universality is attributed to the attenuation of phonons by tunneling two-level systems (TLSs), facilitated by the interaction of the TLSs with the phonon field. TLS-phonon interaction also mediates effective TLS–TLS interactions, which dictates the existence of a glassy phase and its low energy properties. Here we consider KBr:CN, the archetypal disordered lattice showing universality. We calculate numerically, using conjugate gradients method, the effective TLS–TLS interactions for inversion symmetric (CN flips) and asymmetric (CN rotations) TLSs, in the absence and presence of disorder, in two and three dimensions. The observed dependence of the magnitude and spatial power law of the interaction on TLS symmetry, and its change with disorder, characterizes TLS–TLS interactions in disordered lattices in both extreme and moderate dilutions. Our results are in good agreement with the two-TLS model, recently introduced to explain long-standing questions regarding the quantitative universality of phonon attenuation and the energy scale of ≈1–3 K below which universality is observed. (paper)

  2. Generalized Heine–Stieltjes and Van Vleck polynomials associated with two-level, integrable BCS models

    International Nuclear Information System (INIS)

    Marquette, Ian; Links, Jon

    2012-01-01

    We study the Bethe ansatz/ordinary differential equation (BA/ODE) correspondence for Bethe ansatz equations that belong to a certain class of coupled, nonlinear, algebraic equations. Through this approach we numerically obtain the generalized Heine–Stieltjes and Van Vleck polynomials in the degenerate, two-level limit for four cases of integrable Bardeen–Cooper–Schrieffer (BCS) pairing models. These are the s-wave pairing model, the p + ip-wave pairing model, the p + ip pairing model coupled to a bosonic molecular pair degree of freedom, and a newly introduced extended d + id-wave pairing model with additional interactions. The zeros of the generalized Heine–Stieltjes polynomials provide solutions of the corresponding Bethe ansatz equations. We compare the roots of the ground states with curves obtained from the solution of a singular integral equation approximation, which allows for a characterization of ground-state phases in these systems. Our techniques also permit the computation of the roots of the excited states. These results illustrate how the BA/ODE correspondence can be used to provide new numerical methods to study a variety of integrable systems. (paper)

  3. SPONGY (SPam ONtoloGY: Email Classification Using Two-Level Dynamic Ontology

    Directory of Open Access Journals (Sweden)

    Seongwook Youn

    2014-01-01

    Full Text Available Email is one of common communication methods between people on the Internet. However, the increase of email misuse/abuse has resulted in an increasing volume of spam emails over recent years. An experimental system has been designed and implemented with the hypothesis that this method would outperform existing techniques, and the experimental results showed that indeed the proposed ontology-based approach improves spam filtering accuracy significantly. In this paper, two levels of ontology spam filters were implemented: a first level global ontology filter and a second level user-customized ontology filter. The use of the global ontology filter showed about 91% of spam filtered, which is comparable with other methods. The user-customized ontology filter was created based on the specific user’s background as well as the filtering mechanism used in the global ontology filter creation. The main contributions of the paper are (1 to introduce an ontology-based multilevel filtering technique that uses both a global ontology and an individual filter for each user to increase spam filtering accuracy and (2 to create a spam filter in the form of ontology, which is user-customized, scalable, and modularized, so that it can be embedded to many other systems for better performance.

  4. Quasiparticle-induced decoherence of microscopic two-level-systems in superconducting qubits

    Energy Technology Data Exchange (ETDEWEB)

    Bilmes, Alexander; Lisenfeld, Juergen; Zanker, Sebastian; Weiss, Georg; Ustinov, Alexey V. [PHI, KIT, Karlsruhe (Germany); Marthaler, Michael; Schoen, Gerd [TFP, KIT, Karlsruhe (Germany)

    2016-07-01

    Parasitic Two-Level-Systems (TLS) are one of the main sources of decoherence in superconducting nano-scale devices such as SQUIDs, resonators and quantum bits (qubits), although the TLS' microscopic nature remains unclear. We use a superconducting phase qubit to detect TLS contained within the tunnel barrier of the qubit's Al/AlOx/Al Josephson junction. If the TLS transition frequency lies within the 6-10 GHz range, we can coherently drive it by resonant microwave pulses and access its quantum state by utilizing the strong coupling to the qubit. Our previous measurements of TLS coherence in dependence of the temperature indicate that quasiparticles (QPs), which diffuse from the superconducting Al electrodes into the oxide layer, may give rise to TLS energy loss and dephasing. Here, we probe the TLS-QP interaction using a reliable method of in-situ QP injection via an on-chip dc-SQUID that is pulse-biased beyond its switching current. The QP density is calibrated by measuring associated characteristic changes to the qubit's energy relaxation rate. We will present experimental data which show the QP-induced TLS decoherence in good agreement to theoretical predictions.

  5. Two-Level Evaluation on Sensor Interoperability of Features in Fingerprint Image Segmentation

    Directory of Open Access Journals (Sweden)

    Ya-Shuo Li

    2012-03-01

    Full Text Available Features used in fingerprint segmentation significantly affect the segmentation performance. Various features exhibit different discriminating abilities on fingerprint images derived from different sensors. One feature which has better discriminating ability on images derived from a certain sensor may not adapt to segment images derived from other sensors. This degrades the segmentation performance. This paper empirically analyzes the sensor interoperability problem of segmentation feature, which refers to the feature’s ability to adapt to the raw fingerprints captured by different sensors. To address this issue, this paper presents a two-level feature evaluation method, including the first level feature evaluation based on segmentation error rate and the second level feature evaluation based on decision tree. The proposed method is performed on a number of fingerprint databases which are obtained from various sensors. Experimental results show that the proposed method can effectively evaluate the sensor interoperability of features, and the features with good evaluation results acquire better segmentation accuracies of images originating from different sensors.

  6. Amplification without inversion, fast light and optical bistability in a duplicated two-level system

    International Nuclear Information System (INIS)

    Ebrahimi Zohravi, Lida; Vafafard, Azar; Mahmoudi, Mohammad

    2014-01-01

    The optical properties of a weak probe field in a duplicated two-level system are investigated in multi-photon resonance (MPR) condition and beyond it. It is shown that by changing the relative phase of applied fields, the absorption switches to the amplification without inversion in MPR condition. By applying the Floquet decomposition to the equations of motion beyond MPR condition, it is shown that the phase-dependent behavior is valid only in MPR condition. Moreover, it is demonstrated that the group velocity of light pulse can be controlled by the intensity of the applied fields and the gain-assisted superluminal light propagation (fast light) is obtained in this system. In addition, the optical bistability (OB) behavior of the system is studied beyond MPR condition. We apply an indirect incoherent pumping field to the system and it is found that the group velocity and OB behavior of the system can be controlled by the incoherent pumping rate. - Highlights: • We studied the optical properties of DTL system under MPR condition and beyond it. • By changing the relative phase, the absorption switches to the amplification without inversion in MPR condition. • The gain-assisted superluminal light propagation (fast light) is obtained in this system. • The optical bistability (OB) behavior of the system is studied beyond MPR condition. • The incoherent pumping rate has a major role in controlling the group velocity and OB behavior of the system

  7. Automatic QRS complex detection using two-level convolutional neural network.

    Science.gov (United States)

    Xiang, Yande; Lin, Zhitao; Meng, Jianyi

    2018-01-29

    The QRS complex is the most noticeable feature in the electrocardiogram (ECG) signal, therefore, its detection is critical for ECG signal analysis. The existing detection methods largely depend on hand-crafted manual features and parameters, which may introduce significant computational complexity, especially in the transform domains. In addition, fixed features and parameters are not suitable for detecting various kinds of QRS complexes under different circumstances. In this study, based on 1-D convolutional neural network (CNN), an accurate method for QRS complex detection is proposed. The CNN consists of object-level and part-level CNNs for extracting different grained ECG morphological features automatically. All the extracted morphological features are used by multi-layer perceptron (MLP) for QRS complex detection. Additionally, a simple ECG signal preprocessing technique which only contains difference operation in temporal domain is adopted. Based on the MIT-BIH arrhythmia (MIT-BIH-AR) database, the proposed detection method achieves overall sensitivity Sen = 99.77%, positive predictivity rate PPR = 99.91%, and detection error rate DER = 0.32%. In addition, the performance variation is performed according to different signal-to-noise ratio (SNR) values. An automatic QRS detection method using two-level 1-D CNN and simple signal preprocessing technique is proposed for QRS complex detection. Compared with the state-of-the-art QRS complex detection approaches, experimental results show that the proposed method acquires comparable accuracy.

  8. A Two-Level Task Scheduler on Multiple DSP System for OpenCL

    Directory of Open Access Journals (Sweden)

    Li Tian

    2014-04-01

    Full Text Available This paper addresses the problem that multiple DSP system does not support OpenCL programming. With the compiler, runtime, and the kernel scheduler proposed, an OpenCL application becomes portable not only between multiple CPU and GPU, but also between embedded multiple DSP systems. Firstly, the LLVM compiler was imported for source-to-source translation in which the translated source was supported by CCS. Secondly, two-level schedulers were proposed to support efficient OpenCL kernel execution. The DSP/BIOS is used to schedule system level tasks such as interrupts and drivers; however, the synchronization mechanism resulted in heavy overhead during task switching. So we designed an efficient second level scheduler especially for OpenCL kernel work-item scheduling. The context switch process utilizes the 8 functional units and cross path links which was superior to DSP/BIOS in the aspect of task switching. Finally, dynamic loading and software managed CACHE were redesigned for OpenCL running on multiple DSP system. We evaluated the performance using some common OpenCL kernels from NVIDIA, AMD, NAS, and Parboil benchmarks. Experimental results show that the DSP OpenCL can efficiently exploit the computing resource of multiple cores.

  9. Two-level image authentication by two-step phase-shifting interferometry and compressive sensing

    Science.gov (United States)

    Zhang, Xue; Meng, Xiangfeng; Yin, Yongkai; Yang, Xiulun; Wang, Yurong; Li, Xianye; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi

    2018-01-01

    A two-level image authentication method is proposed; the method is based on two-step phase-shifting interferometry, double random phase encoding, and compressive sensing (CS) theory, by which the certification image can be encoded into two interferograms. Through discrete wavelet transform (DWT), sparseness processing, Arnold transform, and data compression, two compressed signals can be generated and delivered to two different participants of the authentication system. Only the participant who possesses the first compressed signal attempts to pass the low-level authentication. The application of Orthogonal Match Pursuit CS algorithm reconstruction, inverse Arnold transform, inverse DWT, two-step phase-shifting wavefront reconstruction, and inverse Fresnel transform can result in the output of a remarkable peak in the central location of the nonlinear correlation coefficient distributions of the recovered image and the standard certification image. Then, the other participant, who possesses the second compressed signal, is authorized to carry out the high-level authentication. Therefore, both compressed signals are collected to reconstruct the original meaningful certification image with a high correlation coefficient. Theoretical analysis and numerical simulations verify the feasibility of the proposed method.

  10. SPONGY (SPam ONtoloGY): email classification using two-level dynamic ontology.

    Science.gov (United States)

    Youn, Seongwook

    2014-01-01

    Email is one of common communication methods between people on the Internet. However, the increase of email misuse/abuse has resulted in an increasing volume of spam emails over recent years. An experimental system has been designed and implemented with the hypothesis that this method would outperform existing techniques, and the experimental results showed that indeed the proposed ontology-based approach improves spam filtering accuracy significantly. In this paper, two levels of ontology spam filters were implemented: a first level global ontology filter and a second level user-customized ontology filter. The use of the global ontology filter showed about 91% of spam filtered, which is comparable with other methods. The user-customized ontology filter was created based on the specific user's background as well as the filtering mechanism used in the global ontology filter creation. The main contributions of the paper are (1) to introduce an ontology-based multilevel filtering technique that uses both a global ontology and an individual filter for each user to increase spam filtering accuracy and (2) to create a spam filter in the form of ontology, which is user-customized, scalable, and modularized, so that it can be embedded to many other systems for better performance.

  11. Crises-induced intermittencies in a coherently driven system of two-level atoms

    International Nuclear Information System (INIS)

    Pando L, C.L.; Perez, G.; Cerdeira, H.A.

    1993-04-01

    We study the coherent dynamics of a thin layer of two-level atoms driven by an external coherent field and a phase conjugated mirror (PCM). Since the variables of the system are defined on the Bloch sphere, the third dimension is provided by the temporal modulation of the Rabi frequencies, which are induced by a PCM which reflects an electric field with a carrier frequency different from the incident one. We show that as the PCM gain coefficient is changed period doubling leading to chaos occurs. We find crises of attractor merging and attractor widening types related to homoclinic and heteroclinic tangencies respectively. For the attractor merging crises we find the critical exponent for the characteristic time of intermittency versus the control parameter which is given by the gain coefficient of the PCM. We show that during the crises of attractor widening type, another crisis due to attractor destruction occurs as the control parameter is changed. The latter is due to the collision of the old attractor with its basin boundary when a new attractor is created. This new attractor is stable only in a very small interval in the neighborhood of this second crisis. (author). 31 refs, 15 figs

  12. Dynamics of a quantum two-level system under the action of phase-diffusion field

    Energy Technology Data Exchange (ETDEWEB)

    Sobakinskaya, E.A. [Institute for Physics of Microstructures of RAS, Nizhny Novgorod, 603950 (Russian Federation); Pankratov, A.L., E-mail: alp@ipm.sci-nnov.ru [Institute for Physics of Microstructures of RAS, Nizhny Novgorod, 603950 (Russian Federation); Vaks, V.L. [Institute for Physics of Microstructures of RAS, Nizhny Novgorod, 603950 (Russian Federation)

    2012-01-09

    We study a behavior of quantum two-level system, interacting with noisy phase-diffusion field. The dynamics is shown to split into two regimes, determined by the coherence time of the phase-diffusion field. For both regimes we present a model of quantum system behavior and discuss possible applications of the obtained effect for spectroscopy. In particular, the obtained analytical formula for the macroscopic polarization demonstrates that the phase-diffusion field does not affect the absorption line shape, which opens up an intriguing possibility of noisy spectroscopy, based on broadband sources with Lorentzian line shape. -- Highlights: ► We study dynamics of quantum system interacting with noisy phase-diffusion field. ► At short times the phase-diffusion field induces polarization in the quantum system. ► At long times the noise leads to polarization decay and heating of a quantum system. ► Simple model of interaction is derived. ► Application of the described effects for spectroscopy is discussed.

  13. Bayesian feedback versus Markovian feedback in a two-level atom

    International Nuclear Information System (INIS)

    Wiseman, H.M.; Mancini, Stefano; Wang Jin

    2002-01-01

    We compare two different approaches to the control of the dynamics of a continuously monitored open quantum system. The first is Markovian feedback, as introduced in quantum optics by Wiseman and Milburn [Phys. Rev. Lett. 70, 548 (1993)]. The second is feedback based on an estimate of the system state, developed recently by Doherty and Jacobs [Phys. Rev. A 60, 2700 (1999)]. Here we choose to call it, for brevity, Bayesian feedback. For systems with nonlinear dynamics, we expect these two methods of feedback control to give markedly different results. The simplest possible nonlinear system is a driven and damped two-level atom, so we choose this as our model system. The monitoring is taken to be homodyne detection of the atomic fluorescence, and the control is by modulating the driving. The aim of the feedback in both cases is to stabilize the internal state of the atom as close as possible to an arbitrarily chosen pure state, in the presence of inefficient detection and other forms of decoherence. Our results (obtained without recourse to stochastic simulations) prove that Bayesian feedback is never inferior, and is usually superior, to Markovian feedback. However, it would be far more difficult to implement than Markovian feedback and it loses its superiority when obvious simplifying approximations are made. It is thus not clear which form of feedback would be better in the face of inevitable experimental imperfections

  14. Testing a Quantum Heat Pump with a Two-Level Spin

    Directory of Open Access Journals (Sweden)

    Luis A. Correa

    2016-04-01

    Full Text Available Once in its non-equilibrium steady state, a nanoscale system coupled to several heat baths may be thought of as a “quantum heat pump”. Depending on the direction of its stationary heat flows, it may function as, e.g., a refrigerator or a heat transformer. These continuous heat devices can be arbitrarily complex multipartite systems, and yet, their working principle is always the same: they are made up of several elementary three-level stages operating in parallel. As a result, it is possible to devise external “black-box” testing strategies to learn about their functionality and performance regardless of any internal details. In particular, one such heat pump can be tested by coupling a two-level spin to one of its “contact transitions”. The steady state of this external probe contains information about the presence of heat leaks and internal dissipation in the device and, also, about the direction of its steady-state heat currents. Provided that the irreversibility of the heat pump is low, one can further estimate its coefficient of performance. These techniques may find applications in the emerging field of quantum thermal engineering, as they facilitate the diagnosis and design optimization of complex thermodynamic cycles.

  15. SPONGY (SPam ONtoloGY): Email Classification Using Two-Level Dynamic Ontology

    Science.gov (United States)

    2014-01-01

    Email is one of common communication methods between people on the Internet. However, the increase of email misuse/abuse has resulted in an increasing volume of spam emails over recent years. An experimental system has been designed and implemented with the hypothesis that this method would outperform existing techniques, and the experimental results showed that indeed the proposed ontology-based approach improves spam filtering accuracy significantly. In this paper, two levels of ontology spam filters were implemented: a first level global ontology filter and a second level user-customized ontology filter. The use of the global ontology filter showed about 91% of spam filtered, which is comparable with other methods. The user-customized ontology filter was created based on the specific user's background as well as the filtering mechanism used in the global ontology filter creation. The main contributions of the paper are (1) to introduce an ontology-based multilevel filtering technique that uses both a global ontology and an individual filter for each user to increase spam filtering accuracy and (2) to create a spam filter in the form of ontology, which is user-customized, scalable, and modularized, so that it can be embedded to many other systems for better performance. PMID:25254240

  16. Two level undercut-profile substrate-based filamentary coated conductors produced using metal organic chemical vapor deposition

    DEFF Research Database (Denmark)

    Insinga, Andrea R.; Sundaram, Aarthi; Hazelton, Drew W.

    2018-01-01

    The two level undercut-profile substrate (2LUPS) has been introduced as a concept for subdividing rare-earth-Ba$_{2}$Cu$_{3}$O$_{7}$ (REBCO) coated conductors (CC) into narrow filaments which reduces the AC losses and improves field stability for DC magnets. The 2LUPS consists of two levels...

  17. Ordering policies of a deteriorating item in an EOQ model with backorder under two-level partial trade credit

    Science.gov (United States)

    Molamohamadi, Zohreh; Arshizadeh, Rahman; Ismail, Napsiah

    2015-05-01

    In the classical inventory model, it was assumed that the retailer must settle the accounts of the purchased items as soon as they are received. In practice, however, the supplier usually offers a full or partial delay period to the retailer to pay for the amount of the purchasing costs. In the partial trade credit contract, which is mostly applied to avoid non-payment risks, the retailer must pay for a portion of the purchased goods at the time of ordering and may delay settling the rest until the end of the predefined agreed upon period, so-called credit period. This paper assumes a two-level partial trade credit where both supplier and retailer offer a partial trade credit to their downstream members. The objective here is to determine the retailer's ordering policy of a deteriorating item by formulating his economic order quantity (EOQ) inventory system with backorder as a cost minimization problem. The sensitivity of the variables on different parameters has been also analyzed by applying numerical examples.

  18. Two-level mixed modeling of longitudinal pedigree data for genetic association analysis

    DEFF Research Database (Denmark)

    Tan, Q.

    2013-01-01

    of follow-up. Approaches have been proposed to integrate kinship correlation into the mixed effect models to explicitly model the genetic relationship which have been proven as an efficient way for dealing with sample clustering in pedigree data. Although useful for adjusting relatedness in the mixed...... assess the genetic associations with the mean level and the rate of change in a phenotype both with kinship correlation integrated in the mixed effect models. We apply our method to longitudinal pedigree data to estimate the genetic effects on systolic blood pressure measured over time in large pedigrees......Genetic association analysis on complex phenotypes under a longitudinal design involving pedigrees encounters the problem of correlation within pedigrees which could affect statistical assessment of the genetic effects on both the mean level of the phenotype and its rate of change over the time...

  19. Responding to Young People's Health Risks in Primary Care: A Cluster Randomised Trial of Training Clinicians in Screening and Motivational Interviewing.

    Directory of Open Access Journals (Sweden)

    Lena Sanci

    Full Text Available To evaluate the effectiveness of a complex intervention implementing best practice guidelines recommending clinicians screen and counsel young people across multiple psychosocial risk factors, on clinicians' detection of health risks and patients' risk taking behaviour, compared to a didactic seminar on young people's health.Pragmatic cluster randomised trial where volunteer general practices were stratified by postcode advantage or disadvantage score and billing type (private, free national health, community health centre, then randomised into either intervention or comparison arms using a computer generated random sequence. Three months post-intervention, patients were recruited from all practices post-consultation for a Computer Assisted Telephone Interview and followed up three and 12 months later. Researchers recruiting, consenting and interviewing patients and patients themselves were masked to allocation status; clinicians were not.General practices in metropolitan and rural Victoria, Australia.General practices with at least one interested clinician (general practitioner or nurse and their 14-24 year old patients.This complex intervention was designed using evidence based practice in learning and change in clinician behaviour and general practice systems, and included best practice approaches to motivating change in adolescent risk taking behaviours. The intervention involved training clinicians (nine hours in health risk screening, use of a screening tool and motivational interviewing; training all practice staff (receptionists and clinicians in engaging youth; provision of feedback to clinicians of patients' risk data; and two practice visits to support new screening and referral resources. Comparison clinicians received one didactic educational seminar (three hours on engaging youth and health risk screening.Primary outcomes were patient report of (1 clinician detection of at least one of six health risk behaviours (tobacco, alcohol

  20. Responding to Young People's Health Risks in Primary Care: A Cluster Randomised Trial of Training Clinicians in Screening and Motivational Interviewing.

    Science.gov (United States)

    Sanci, Lena; Chondros, Patty; Sawyer, Susan; Pirkis, Jane; Ozer, Elizabeth; Hegarty, Kelsey; Yang, Fan; Grabsch, Brenda; Shiell, Alan; Cahill, Helen; Ambresin, Anne-Emmanuelle; Patterson, Elizabeth; Patton, George

    2015-01-01

    To evaluate the effectiveness of a complex intervention implementing best practice guidelines recommending clinicians screen and counsel young people across multiple psychosocial risk factors, on clinicians' detection of health risks and patients' risk taking behaviour, compared to a didactic seminar on young people's health. Pragmatic cluster randomised trial where volunteer general practices were stratified by postcode advantage or disadvantage score and billing type (private, free national health, community health centre), then randomised into either intervention or comparison arms using a computer generated random sequence. Three months post-intervention, patients were recruited from all practices post-consultation for a Computer Assisted Telephone Interview and followed up three and 12 months later. Researchers recruiting, consenting and interviewing patients and patients themselves were masked to allocation status; clinicians were not. General practices in metropolitan and rural Victoria, Australia. General practices with at least one interested clinician (general practitioner or nurse) and their 14-24 year old patients. This complex intervention was designed using evidence based practice in learning and change in clinician behaviour and general practice systems, and included best practice approaches to motivating change in adolescent risk taking behaviours. The intervention involved training clinicians (nine hours) in health risk screening, use of a screening tool and motivational interviewing; training all practice staff (receptionists and clinicians) in engaging youth; provision of feedback to clinicians of patients' risk data; and two practice visits to support new screening and referral resources. Comparison clinicians received one didactic educational seminar (three hours) on engaging youth and health risk screening. Primary outcomes were patient report of (1) clinician detection of at least one of six health risk behaviours (tobacco, alcohol and

  1. Risk group characteristics and viral transmission clusters in South-East Asian patients infected with HIV-1 circulating recombinant form (CRF)01_AE and subtype B

    Science.gov (United States)

    Oyomopito, Rebecca A; Chen, Yen-Ju; Sungkanuparph, Somnuek; Kantor, Rami; Merati, Tuti; Yam, Wing-Cheong; Sirisanthana, Thira; Li, Patrick CK; Kantipong, Pacharee; Phanuphak, Praphan; Lee, Chris KC; Kamarulzaman, Adeeba; Ditangco, Rossana; Huang, Szu-Wei; Sohn, Annette H; Law, Matthew; Chen, Yi Ming A

    2016-01-01

    HIV-1 epidemics in Asian countries are driven by varying exposures. The epidemiology of the regional pandemic has been changing with the spread of HIV-1 to lower-risk populations through sexual transmission. Common HIV-1 genotypes include subtype B and circulating recombinant form (CRF)01_AE. Our objective was to use HIV-1 genotypic data to better quantify local epidemics. TASER-M is a multi-centre prospective cohort of HIV-infected patients. Associations between HIV-exposure, patient gender, country of sample origin and HIV-1 genotype were evaluated by multivariate logistic regression. Phylogenetic methods were used on genotypic data to investigate transmission relationships. A total of 1086 patients from Thailand, Hong Kong, Malaysia and the Philippines were included in analyses. Proportions of males within countries varied (Thailand: 55.6%, Hong Kong: 86.1%, Malaysia: 81.4%, Philippines: 93.8%; p Malaysia: 47.8%, Philippines: 25.0%; p <0.001). After adjustment, we found increased subtype B infection among men-who-have-sex with-men, relative to heterosexual-reported exposures (OR = 2.4, p <0.001). We further describe four transmission clusters of 8–15 treatment naive, predominantly symptomatic patients (two each for subtype B and CRF01_AE). Risk-group sub-populations differed with respect to the infecting HIV-1 genotype. Homosexual exposure patients had a higher odds of being infected with subtype B. Where HIV-1 genotypes circulate within countries or patient risk-groups, local monitoring of genotype-specific transmissions may play a role in focussing public health prevention strategies. Phylogenetic evaluations provide complementary information for surveillance and monitoring of viruses with high mutation rates such as HIV-1 and Ebola. PMID:26362956

  2. Clustering Dycom

    KAUST Repository

    Minku, Leandro L.

    2017-10-06

    Background: Software Effort Estimation (SEE) can be formulated as an online learning problem, where new projects are completed over time and may become available for training. In this scenario, a Cross-Company (CC) SEE approach called Dycom can drastically reduce the number of Within-Company (WC) projects needed for training, saving the high cost of collecting such training projects. However, Dycom relies on splitting CC projects into different subsets in order to create its CC models. Such splitting can have a significant impact on Dycom\\'s predictive performance. Aims: This paper investigates whether clustering methods can be used to help finding good CC splits for Dycom. Method: Dycom is extended to use clustering methods for creating the CC subsets. Three different clustering methods are investigated, namely Hierarchical Clustering, K-Means, and Expectation-Maximisation. Clustering Dycom is compared against the original Dycom with CC subsets of different sizes, based on four SEE databases. A baseline WC model is also included in the analysis. Results: Clustering Dycom with K-Means can potentially help to split the CC projects, managing to achieve similar or better predictive performance than Dycom. However, K-Means still requires the number of CC subsets to be pre-defined, and a poor choice can negatively affect predictive performance. EM enables Dycom to automatically set the number of CC subsets while still maintaining or improving predictive performance with respect to the baseline WC model. Clustering Dycom with Hierarchical Clustering did not offer significant advantage in terms of predictive performance. Conclusion: Clustering methods can be an effective way to automatically generate Dycom\\'s CC subsets.

  3. Spatiotemporal clustering, climate periodicity, and social-ecological risk factors for dengue during an outbreak in Machala, Ecuador, in 2010.

    Science.gov (United States)

    Stewart-Ibarra, Anna M; Muñoz, Ángel G; Ryan, Sadie J; Ayala, Efraín Beltrán; Borbor-Cordova, Mercy J; Finkelstein, Julia L; Mejía, Raúl; Ordoñez, Tania; Recalde-Coronel, G Cristina; Rivero, Keytia

    2014-11-25

    Dengue fever, a mosquito-borne viral disease, is a rapidly emerging public health problem in Ecuador and throughout the tropics. However, we have a limited understanding of the disease transmission dynamics in these regions. Previous studies in southern coastal Ecuador have demonstrated the potential to develop a dengue early warning system (EWS) that incorporates climate and non-climate information. The objective of this study was to characterize the spatiotemporal dynamics and climatic and social-ecological risk factors associated with the largest dengue epidemic to date in Machala, Ecuador, to inform the development of a dengue EWS. The following data from Machala were included in analyses: neighborhood-level georeferenced dengue cases, national census data, and entomological surveillance data from 2010; and time series of weekly dengue cases (aggregated to the city-level) and meteorological data from 2003 to 2012. We applied LISA and Moran's I to analyze the spatial distribution of the 2010 dengue cases, and developed multivariate logistic regression models through a multi-model selection process to identify census variables and entomological covariates associated with the presence of dengue at the neighborhood level. Using data aggregated at the city-level, we conducted a time-series (wavelet) analysis of weekly climate and dengue incidence (2003-2012) to identify significant time periods (e.g., annual, biannual) when climate co-varied with dengue, and to describe the climate conditions associated with the 2010 outbreak. We found significant hotspots of dengue transmission near the center of Machala. The best-fit model to predict the presence of dengue included older age and female gender of the head of the household, greater access to piped water in the home, poor housing condition, and less distance to the central hospital. Wavelet analyses revealed that dengue transmission co-varied with rainfall and minimum temperature at annual and biannual cycles, and we

  4. Clustering analysis

    International Nuclear Information System (INIS)

    Romli

    1997-01-01

    Cluster analysis is the name of group of multivariate techniques whose principal purpose is to distinguish similar entities from the characteristics they process.To study this analysis, there are several algorithms that can be used. Therefore, this topic focuses to discuss the algorithms, such as, similarity measures, and hierarchical clustering which includes single linkage, complete linkage and average linkage method. also, non-hierarchical clustering method, which is popular name K -mean method ' will be discussed. Finally, this paper will be described the advantages and disadvantages of every methods

  5. 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

  6. 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...

  7. Chemical exposure and leukemia clusters

    International Nuclear Information System (INIS)

    Cartwright, R.A.

    1992-01-01

    This paper draws attention to the heterogeneous distribution of leukemia in childhood and in adults. The topic of cluster reports and generalized clustering is addressed. These issues are applied to what is known of the risk factor for both adult and childhood leukemia. Finally, the significance of parental occupational exposure and childhood leukemia is covered. (author). 23 refs

  8. The prevention access and risk taking in young people (PARTY) project protocol: a cluster randomised controlled trial of health risk screening and motivational interviewing for young people presenting to general practice.

    Science.gov (United States)

    Sanci, Lena; Grabsch, Brenda; Chondros, Patty; Shiell, Alan; Pirkis, Jane; Sawyer, Susan; Hegarty, Kelsey; Patterson, Elizabeth; Cahill, Helen; Ozer, Elizabeth; Seymour, Janelle; Patton, George

    2012-06-06

    There are growing worldwide concerns about the ability of primary health care systems to manage the major burden of illness in young people. Over two thirds of premature adult deaths result from risks that manifest in adolescence, including injury, neuropsychiatric problems and consequences of risky behaviours. One policy response is to better reorientate primary health services towards prevention and early intervention. Currently, however, there is insufficient evidence to support this recommendation for young people. This paper describes the design and implementation of a trial testing an intervention to promote psychosocial risk screening of all young people attending general practice and to respond to identified risks using motivational interviewing. clinicians' detection of risk-taking and emotional distress, young people's intention to change and reduction of risk taking. pathways to care, trust in the clinician and likelihood of returning for future visits. The design of the economic and process evaluation are not detailed in this protocol. PARTY is a cluster randomised trial recruiting 42 general practices in Victoria, Australia. Baseline measures include: youth friendly practice characteristics; practice staff's self-perceived competency in young people's care and clinicians' detection and response to risk taking behaviours and emotional distress in 14-24 year olds, attending the practice. Practices are then stratified by a social disadvantage index and billing methods and randomised. Intervention practices receive: nine hours of training and tools; feedback of their baseline data and two practice visits over six weeks. Comparison practices receive a three hour seminar in youth friendly practice only. Six weeks post-intervention, 30 consecutive young people are interviewed post-consultation from each practice and followed-up for self-reported risk taking behaviour and emotional distress three and 12 months post consultation. The PARTY trial is the

  9. The prevention access and risk taking in young people (PARTY project protocol: A cluster randomised controlled trial of health risk screening and motivational interviewing for young people presenting to general practice

    Directory of Open Access Journals (Sweden)

    Sanci Lena

    2012-06-01

    Full Text Available Abstract Background There are growing worldwide concerns about the ability of primary health care systems to manage the major burden of illness in young people. Over two thirds of premature adult deaths result from risks that manifest in adolescence, including injury, neuropsychiatric problems and consequences of risky behaviours. One policy response is to better reorientate primary health services towards prevention and early intervention. Currently, however, there is insufficient evidence to support this recommendation for young people. This paper describes the design and implementation of a trial testing an intervention to promote psychosocial risk screening of all young people attending general practice and to respond to identified risks using motivational interviewing. Main outcomes: clinicians’ detection of risk-taking and emotional distress, young people’s intention to change and reduction of risk taking. Secondary outcomes: pathways to care, trust in the clinician and likelihood of returning for future visits. The design of the economic and process evaluation are not detailed in this protocol. Methods PARTY is a cluster randomised trial recruiting 42 general practices in Victoria, Australia. Baseline measures include: youth friendly practice characteristics; practice staff’s self-perceived competency in young people’s care and clinicians’ detection and response to risk taking behaviours and emotional distress in 14–24 year olds, attending the practice. Practices are then stratified by a social disadvantage index and billing methods and randomised. Intervention practices receive: nine hours of training and tools; feedback of their baseline data and two practice visits over six weeks. Comparison practices receive a three hour seminar in youth friendly practice only. Six weeks post-intervention, 30 consecutive young people are interviewed post-consultation from each practice and followed-up for self-reported risk taking

  10. Lambda-Based Data Processing Architecture for Two-Level Load Forecasting in Residential Buildings

    Directory of Open Access Journals (Sweden)

    Gde Dharma Nugraha

    2018-03-01

    Full Text Available Building energy management systems (BEMS have been intensively used to manage the electricity consumption of residential buildings more efficiently. However, the dynamic behavior of the occupants introduces uncertainty problems that affect the performance of the BEMS. To address this uncertainty problem, the BEMS may implement load forecasting as one of the BEMS modules. Load forecasting utilizes historical load data to compute model predictions for a specific time in the future. Recently, smart meters have been introduced to collect electricity consumption data. Smart meters not only capture aggregation data, but also individual data that is more frequently close to real-time. The processing of both smart meter data types for load forecasting can enhance the performance of the BEMS when confronted with uncertainty problems. The collection of smart meter data can be processed using a batch approach for short-term load forecasting, while the real-time smart meter data can be processed for very short-term load forecasting, which adjusts the short-term load forecasting to adapt to the dynamic behavior of the occupants. This approach requires different data processing techniques for aggregation and individual of smart meter data. In this paper, we propose Lambda-based data processing architecture to process the different types of smart meter data and implement the two-level load forecasting approach, which combines short-term and very short-term load forecasting techniques on top of our proposed data processing architecture. The proposed approach is expected to enhance the BEMS to address the uncertainty problem in order to process data in less time. Our experiment showed that the proposed approaches improved the accuracy by 7% compared to a typical BEMS with only one load forecasting technique, and had the lowest computation time when processing the smart meter data.

  11. Absorption spectrum of a two-level atom in a bad cavity with injected squeezed vacuum

    Science.gov (United States)

    Zhou, Peng; Swain, S.

    1996-02-01

    We study the absorption spectrum of a coherently driven two-level atom interacting with a resonant cavity mode which is coupled to a broadband squeezed vacuum through its input-output mirror in the bad cavity limit. We study the modification of the two-photon correlation strength of the injected squeezed vacuum inside the cavity, and show that the equations describing probe absorption in the cavity environment are formally identical to these in free space, but with modified parameters describing the squeezed vacuum. The two photon correlations induced by the squeezed vacuum are always weaker than in free space. We pay particular attention to the spectral behaviour at line centre in the region of intermediate trength driving intensities, where anomalous spectral features such as hole-burning and dispersive profiles are displayed. These unusual spectral features are very sensitive to the squeezing phase and the Rabi frequency of the driving field. We also derive the threshold value of the Rabi frequency which gives rise to the transparency of the probe beam at the driving frequency. When the Rabi frequency is less than the threshold value, the probe beam is absorbed, whilst the probe beam is amplified (without population inversion under certain conditions) when the Rabi frequency is larger than this threshold. The anomalous spectral features all take place in the vicinity of the critical point dividing the different dynamical regimes, probe absorption and amplification, of the atomic radiation. The physical origin of the strong amplification without population inversion, and the feasibility of observing it, are discussed.

  12. A two level mutation-selection model of cultural evolution and diversity.

    Science.gov (United States)

    Salazar-Ciudad, Isaac

    2010-11-21

    Cultural evolution is a complex process that can happen at several levels. At the level of individuals in a population, each human bears a set of cultural traits that he or she can transmit to its offspring (vertical transmission) or to other members of his or her society (horizontal transmission). The relative frequency of a cultural trait in a population or society can thus increase or decrease with the relative reproductive success of its bearers (individual's level) or the relative success of transmission (called the idea's level). This article presents a mathematical model on the interplay between these two levels. The first aim of this article is to explore when cultural evolution is driven by the idea's level, when it is driven by the individual's level and when it is driven by both. These three possibilities are explored in relation to (a) the amount of interchange of cultural traits between individuals, (b) the selective pressure acting on individuals, (c) the rate of production of new cultural traits, (d) the individual's capacity to remember cultural traits and to the population size. The aim is to explore the conditions in which cultural evolution does not lead to a better adaptation of individuals to the environment. This is to contrast the spread of fitness-enhancing ideas, which make individual bearers better adapted to the environment, to the spread of "selfish" ideas, which spread well simply because they are easy to remember but do not help their individual bearers (and may even hurt them). At the same time this article explores in which conditions the adaptation of individuals is maximal. The second aim is to explore how these factors affect cultural diversity, or the amount of different cultural traits in a population. This study suggests that a larger interchange of cultural traits between populations could lead to cultural evolution not improving the adaptation of individuals to their environment and to a decrease of cultural diversity

  13. Occupational Clusters.

    Science.gov (United States)

    Pottawattamie County School System, Council Bluffs, IA.

    The 15 occupational clusters (transportation, fine arts and humanities, communications and media, personal service occupations, construction, hospitality and recreation, health occupations, marine science occupations, consumer and homemaking-related occupations, agribusiness and natural resources, environment, public service, business and office…

  14. 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...

  15. Risk for self-reported anorexia or bulimia nervosa based on drive for thinness and negative affect clusters/dimensions during adolescence: A three-year prospective study of the TChAD cohort.

    Science.gov (United States)

    Peñas-Lledó, Eva; Bulik, Cynthia M; Lichtenstein, Paul; Larsson, Henrik; Baker, Jessica H

    2015-09-01

    This study explored the cross-sectional and predictive effect of drive for thinness and/or negative affect scores on the development of self-reported anorexia nervosa (AN) and bulimia nervosa (BN). K-means were used to cluster the Eating Disorder Inventory-Drive for Thinness (DT) and Child Behavior Checklist Anxious/Depressed (A/D) scores from 615 unrelated female twins at age 16-17. Logistic regressions were used to assess the effect of these clusters on self-reported eating disorder diagnosis at ages 16-17 (n = 565) and 19-20 (n = 451). DT and A/D scores were grouped into four clusters: Mild (scores lower than 90th percentile on both scales), DT (higher scores only on DT), A/D (higher scores only on A/D), and DT-A/D (higher scores on both the DT and A/D scales). DT and DT-A/D clusters at age 16-17 were associated cross-sectionally with AN and both cross-sectionally and longitudinally with BN. The DT-A/D cluster had the highest prevalence of AN at follow-up compared with all other clusters. Similarly, an interaction was observed between DT and A/D that predicted risk for AN. Having elevated DT and A/D scores may increase risk for eating disorder symptomatology above and beyond a high score on either alone. Findings suggest that cluster modeling based on DT and A/D may be useful to inform novel and useful intervention strategies for AN and BN in adolescents. © 2015 Wiley Periodicals, Inc.

  16. Cluster generator

    Science.gov (United States)

    Donchev, Todor I [Urbana, IL; Petrov, Ivan G [Champaign, IL

    2011-05-31

    Described herein is an apparatus and a method for producing atom clusters based on a gas discharge within a hollow cathode. The hollow cathode includes one or more walls. The one or more walls define a sputtering chamber within the hollow cathode and include a material to be sputtered. A hollow anode is positioned at an end of the sputtering chamber, and atom clusters are formed when a gas discharge is generated between the hollow anode and the hollow cathode.

  17. Cluster Bulleticity

    OpenAIRE

    Massey, Richard; Kitching, Thomas; Nagai, Daisuke

    2010-01-01

    The unique properties of dark matter are revealed during collisions between clusters of galaxies, such as the bullet cluster (1E 0657−56) and baby bullet (MACS J0025−12). These systems provide evidence for an additional, invisible mass in the separation between the distributions of their total mass, measured via gravitational lensing, and their ordinary ‘baryonic’ matter, measured via its X-ray emission. Unfortunately, the information available from these systems is limited by their rarity. C...

  18. Cluster headache

    OpenAIRE

    Leroux, Elizabeth; Ducros, Anne

    2008-01-01

    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 ...

  19. Cost-effectiveness of a screening strategy for Q fever among pregnant women in risk areas: a clustered randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Lo-Ten-Foe Jerome R

    2010-11-01

    Full Text Available Abstract Background In The Netherlands the largest human Q fever outbreak ever reported in the literature is currently ongoing with more than 2300 notified cases in 2009. Pregnant women are particularly at risk as Q fever during pregnancy may cause maternal and obstetric complications. Since the majority of infected pregnant women are asymptomatic, a screening strategy might be of great value to reduce Q fever related complications. We designed a trial to assess the (cost-effectiveness of a screening program for Q fever in pregnant women living in risks areas in The Netherlands. Methods/design We will conduct a clustered randomized controlled trial in which primary care midwife centres in Q fever risk areas are randomized to recruit pregnant women for either the control group or the intervention group. In both groups a blood sample is taken around 20 weeks postmenstrual age. In the intervention group, this sample is immediately analyzed by indirect immunofluorescence assay for detection of IgG and IgM antibodies using a sensitive cut-off level of 1:32. In case of an active Q fever infection, antibiotic treatment is recommended and serological follow up is performed. In the control group, serum is frozen for analysis after delivery. The primary endpoint is a maternal (chronic Q fever or reactivation or obstetric complication (low birth weight, preterm delivery or fetal death in Q fever positive women. Secondary aims pertain to the course of infection in pregnant women, diagnostic accuracy of laboratory tests used for screening, histo-pathological abnormalities of the placenta of Q fever positive women, side effects of therapy, and costs. The analysis will be according to the intention-to-screen principle, and cost-effectiveness analysis will be performed by comparing the direct and indirect costs between the intervention and control group. Discussion With this study we aim to provide insight into the balance of risks of undetected and detected Q

  20. Cardiovascular risk outcome and program evaluation of a cluster randomised controlled trial of a community-based, lay peer led program for people with diabetes

    Directory of Open Access Journals (Sweden)

    M. A. Riddell

    2016-08-01

    Full Text Available Abstract Background The 2013 Global Burden of Disease Study demonstrated the increasing burden of diabetes and the challenge it poses to the health systems of all countries. The chronic and complex nature of diabetes requires active self-management by patients in addition to clinical management in order to achieve optimal glycaemic control and appropriate use of available clinical services. This study is an evaluation of a “real world” peer support program aimed at improving the control and management of type 2 diabetes (T2DM in Australia. Methods The trial used a randomised cluster design with a peer support intervention and routine care control arms and 12-month follow up. Participants in both arms received a standardised session of self-management education at baseline. The intervention program comprised monthly community-based group meetings over 12 months led by trained peer supporters and active encouragement to use primary health care and other community resources and supports related to diabetes. Clinical, behavioural and other measures were collected at baseline, 6 and 12 months. The primary outcome was the predicted 5 year cardiovascular disease risk using the United Kingdom Prospective Diabetes Study (UKPDS Risk Equation at 12 months. Secondary outcomes included clinical measures, quality of life, measures of support, psychosocial functioning and lifestyle measures. Results Eleven of 12 planned groups were successfully implemented in the intervention arm. Both the usual care and the intervention arms demonstrated a small reduction in 5 year UKPDS risk and the mean values for biochemical and anthropometric outcomes were close to target at 12 months. There were some small positive changes in self-management behaviours. Conclusions The positive changes in self-management behaviours among intervention participants were not sufficient to reduce cardiovascular risk, possibly because approximately half of the study participants

  1. Integrating Depression Care Management into Medicare Home Health Reduces Risk of 30 and 60 Day Hospitalization: The Depression CAREPATH Cluster-Randomized Trial

    Science.gov (United States)

    Bruce, Martha L.; Lohman, Matthew C.; Greenberg, Rebecca L.; Bao, Yuhua; Raue, Patrick J.

    2016-01-01

    OBJECTIVES To determine whether a depression care management intervention among Medicare home health recipients decreases risks of hospitalization. DESIGN Cluster-randomized trial. Nurse teams were randomized to Intervention (12 teams) or Enhanced Usual Care (EUC; 9 teams). SETTING Six home health agencies from distinct geographic regions. Patients were interviewed at home and by telephone. PARTICIPANTS Patients age>65 who screened positive for depression on nurse assessments (N=755), and a subset who consented to interviews (N=306). INTERVENTION The Depression CAREPATH (CARE for PATients at Home) guides nurses in managing depression during routine home visits. Clinical functions include weekly symptom assessment, medication management, care coordination, patient education, and goal setting. Researchers conducted biweekly telephone conferences with team supervisors. MEASUREMENTS The study examined acute-care hospitalization and days to hospitalization. H1 used data from the home health record to examine hospitalization over 30-day and 60-day periods while a home health patient. H2 used data from both home care record and research assessments to examine 30-day hospitalization from any setting. RESULTS The adjusted hazard ratio (HR) of being admitted to hospital directly from home health within 30 days of start of home health care was 0.65 (p=.013) for CAREPATH compared to EUC patients, and 0.72 (p=.027) within 60 days. In patients referred to home health directly from hospital, the relative hazard of being rehospitalized was approximately 55% lower (HR = 0.45, p=.001) among CAREPATH patients. CONCLUSION Integrating CAREPATH depression care management into routine nursing practice reduces hospitalization and rehospitalization risk among older adults receiving Medicare home health nursing services. PMID:27739067

  2. Integrating Depression Care Management into Medicare Home Health Reduces Risk of 30- and 60-Day Hospitalization: The Depression Care for Patients at Home Cluster-Randomized Trial.

    Science.gov (United States)

    Bruce, Martha L; Lohman, Matthew C; Greenberg, Rebecca L; Bao, Yuhua; Raue, Patrick J

    2016-11-01

    To determine whether a depression care management intervention in Medicare home health recipients decreases risk of hospitalization. Cluster-randomized trial. Nurse teams were randomized to intervention (12 teams) or enhanced usual care (EUC; 9 teams). Six home health agencies from distinct geographic regions. Home health recipients were interviewed at home and over the telephone. Individuals aged 65 and older who screened positive for depression on nurse assessments (N = 755) and a subset who consented to interviews (n = 306). The Depression CARE for PATients at Home (CAREPATH) guides nurses in managing depression during routine home visits. Clinical functions include weekly symptom assessment, medication management, care coordination, patient education, and goal setting. Researchers conducted telephone conferences with team supervisors every 2 weeks. Hospitalization while receiving home health services was assessed using data from the home health record. Hospitalization within 30 days of starting home health, regardless of how long recipients received home health services, was assessed using data from the home care record and research assessments. The relative hazard of being admitted to the hospital directly from home health was 35% lower within 30 days of starting home health care (hazard ratio (HR) = 0.65, P = .01) and 28% lower within 60 days (HR = 0.72, P = .03) for CAREPATH participants than for participants receiving EUC. In participants referred to home health directly from the hospital, the relative hazard of being rehospitalized was approximately 55% lower (HR = 0.45, P = .001) for CAREPATH participants. Integrating CAREPATH depression care management into routine nursing practice reduces hospitalization and rehospitalization risk in older adults receiving Medicare home health nursing services. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

  3. Accelerated uncertainty propagation in two-level probabilistic studies under monotony

    International Nuclear Information System (INIS)

    Limbourg, Philipp; Rocquigny, Etienne de; Andrianov, Guennadi

    2010-01-01

    Double-level probabilistic uncertainty models that separate aleatory and epistemic components enjoy significant interest in risk assessment. But the expensive computational costs associated with calculations of rare failure probabilities are still a large obstacle in practice. Computing accurately a risk lower than 10 -3 with 95% epistemic confidence usually requires 10 7 -10 8 runs in a brute-force double Monte Carlo. For single-level probabilistic studies, FORM (First Order Reliability Analysis) is a classical recipe allowing fast approximation of failure probabilities while MRM (Monotonous Reliability Method) recently proved an attractive robust alternative under monotony. This paper extends these methods to double-level probabilistic models through two novel algorithms designed to compute a set of failure probabilities or an aleatory risk level with an epistemic confidence quantile. The first, L2-FORM (level-2 FORM), allows a rapid approximation of the failure probabilities through a combination of FORM with new ideas to use similarity between computations. L2-MRM (level-2 MRM), a quadrature approach, provides 100%-guaranteed error bounds on the results. Experiments on three flood prediction problems showed that both algorithms approximate a set of 500 failure probabilities of 10 -3 -10 -2 or derived 95% epistemic quantiles with a total of only 500-1000 function evaluations, outperforming importance sampling, iterative FORM and regression splines metamodels.

  4. QAPgrid: a two level QAP-based approach for large-scale data analysis and visualization.

    Directory of Open Access Journals (Sweden)

    Mario Inostroza-Ponta

    Full Text Available BACKGROUND: The visualization of large volumes of data is a computationally challenging task that often promises rewarding new insights. There is great potential in the application of new algorithms and models from combinatorial optimisation. Datasets often contain "hidden regularities" and a combined identification and visualization method should reveal these structures and present them in a way that helps analysis. While several methodologies exist, including those that use non-linear optimization algorithms, severe limitations exist even when working with only a few hundred objects. METHODOLOGY/PRINCIPAL FINDINGS: We present a new data visualization approach (QAPgrid that reveals patterns of similarities and differences in large datasets of objects for which a similarity measure can be computed. Objects are assigned to positions on an underlying square grid in a two-dimensional space. We use the Quadratic Assignment Problem (QAP as a mathematical model to provide an objective function for assignment of objects to positions on the grid. We employ a Memetic Algorithm (a powerful metaheuristic to tackle the large instances of this NP-hard combinatorial optimization problem, and we show its performance on the visualization of real data sets. CONCLUSIONS/SIGNIFICANCE: Overall, the results show that QAPgrid algorithm is able to produce a layout that represents the relationships between objects in the data set. Furthermore, it also represents the relationships between clusters that are feed into the algorithm. We apply the QAPgrid on the 84 Indo-European languages instance, producing a near-optimal layout. Next, we produce a layout of 470 world universities with an observed high degree of correlation with the score used by the Academic Ranking of World Universities compiled in the The Shanghai Jiao Tong University Academic Ranking of World Universities without the need of an ad hoc weighting of attributes. Finally, our Gene Ontology-based study on

  5. Ethical implications of excessive cluster sizes in cluster randomised trials.

    Science.gov (United States)

    Hemming, Karla; Taljaard, Monica; Forbes, Gordon; Eldridge, Sandra M; Weijer, Charles

    2018-02-20

    The cluster randomised trial (CRT) is commonly used in healthcare research. It is the gold-standard study design for evaluating healthcare policy interventions. A key characteristic of this design is that as more participants are included, in a fixed number of clusters, the increase in achievable power will level off. CRTs with cluster sizes that exceed the point of levelling-off will have excessive numbers of participants, even if they do not achieve nominal levels of power. Excessively large cluster sizes may have ethical implications due to exposing trial participants unnecessarily to the burdens of both participating in the trial and the potential risks of harm associated with the intervention. We explore these issues through the use of two case studies. Where data are routinely collected, available at minimum cost and the intervention poses low risk, the ethical implications of excessively large cluster sizes are likely to be low (case study 1). However, to maximise the social benefit of the study, identification of excessive cluster sizes can allow for prespecified and fully powered secondary analyses. In the second case study, while there is no burden through trial participation (because the outcome data are routinely collected and non-identifiable), the intervention might be considered to pose some indirect risk to patients and risks to the healthcare workers. In this case study it is therefore important that the inclusion of excessively large cluster sizes is justifiable on other grounds (perhaps to show sustainability). In any randomised controlled trial, including evaluations of health policy interventions, it is important to minimise the burdens and risks to participants. Funders, researchers and research ethics committees should be aware of the ethical issues of excessively large cluster sizes in cluster trials. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is

  6. The off-resonant aspects of decoherence and a critique of the two-level approximation

    International Nuclear Information System (INIS)

    Savran, Kerim; Hakioglu, T; Mese, E; Sevincli, Haldun

    2006-01-01

    Conditions in favour of a realistic multilevelled description of a decohering quantum system are examined. In this regard the first crucial observation is that the thermal effects, contrary to the conventional belief, play a minor role at low temperatures in the decoherence properties. The system-environment coupling and the environmental energy spectrum dominantly affect the decoherence. In particular, zero temperature quantum fluctuations or non-equilibrium sources can be present and influential on the decoherence rates in a wide energy range allowed by the spectrum of the environment. A crucial observation against the validity of the two-level approximation is that the decoherence rates are found to be dominated not by the long time resonant but the short time off-resonant processes. This observation is demonstrated in two stages. Firstly, our zero temperature numerical results reveal that the calculated short time decoherence rates are Gaussian-like (the time dependence of the density matrix is led by the second time derivative at t = 0). Exact analytical results are also permitted in the short time limit, which, consistent with our numerical results, reveal that this specific Gaussian-like behaviour is a property of the non-Markovian correlations in the environment. These Gaussian-like rates have no dependence on any spectral parameter (position and the width of the spectrum) except, in totality, the spectral area itself. The dependence on the spectral area is a power law. Furthermore, the Gaussian-like character at short times is independent of the number of levels (N), but the numerical value of the decoherence rates is a monotonic function of N. In this context, we demonstrate that leakage, as a characteristic multilevel effect, is dominated by the non-resonant processes. The long time behaviour of decoherence is also examined. Since our spectral model allows Markovian environmental correlations at long times, the decoherence rates in this regime become

  7. Effectiveness and cost-effectiveness of a brief school-based group programme for parents of children at risk of ADHD: a cluster randomised controlled trial.

    Science.gov (United States)

    Sayal, K; Taylor, J A; Valentine, A; Guo, B; Sampson, C J; Sellman, E; James, M; Hollis, C; Daley, D

    2016-07-01

    National Institute for Health and Care Excellence guidelines recommend a stepped care approach for the identification and management of children with, or at risk of, attention-deficit/hyperactivity disorder (ADHD). We investigated the effectiveness, cost-effectiveness and acceptability of a group parenting intervention programme (+/- a teacher session) for children at risk of ADHD. In a three-arm cluster randomised controlled trial, 12 primary schools were randomly assigned to control, parent-only and combined (parent + teacher) intervention arms. Eligible children had high levels of parent-rated hyperactivity/inattention (n = 199). At 6 month follow-up, the primary outcome measure was the parent-completed Conners' Rating Scale - Revised (ADHD index). Secondary outcomes included the Conners' sub-scales (hyperactivity, cognitive problems/inattention and oppositional behaviour), the teacher-completed Conners' Rating Scale - Revised, child health-related quality of life, parental burden and parental mental health. The cost-effectiveness analyses reflected a health and personal social services perspective. ISRCTN87634685. Follow-up data were obtained from 76 parents and 169 teachers. There was no effect of the parent-only (mean difference = -1.1, 95% CI -5.1,2.9; p = 0.57) or combined interventions (mean difference = -2.1, 95% CI -6.4,2.1; p = 0.31) on the ADHD index. The combined intervention was associated with reduced parent-reported hyperactivity symptoms (mean difference = -5.3; 95% CI -10.5,-0.01; p = 0.05) and the parent-only intervention with improved parental mental health (mean difference = -1.9; 95% CI -3.2,-0.5; p = 0.009). The incremental costs of the parent-only and the combined interventions were £73 and £123, respectively. Above a willingness-to-pay of £31 per one-point improvement in the ADHD index, the parent-only programme had the highest probability of cost-effectiveness. Participants found the

  8. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013

    NARCIS (Netherlands)

    Forouzanfar, Mohammad H; Alexander, Lily; Anderson, H Ross; Bachman, Victoria F; Biryukov, Stan; Brauer, Michael; Burnett, Richard; Casey, Daniel; Coates, Matthew M; Cohen, Aaron; Delwiche, Kristen; Estep, Kara; Frostad, Joseph J; Kc, Astha; Kyu, Hmwe H; Moradi-Lakeh, Maziar; Ng, Marie; Slepak, Erica Leigh; Thomas, Bernadette A; Wagner, Joseph; Aasvang, Gunn Marit; Abbafati, Cristiana; Ozgoren, Ayse Abbasoglu; Abd-Allah, Foad; Abera, Semaw F; Aboyans, Victor; Abraham, Biju; Abraham, Jerry Puthenpurakal; Abubakar, Ibrahim; Abu-Rmeileh, Niveen M E; Aburto, Tania C; Achoki, Tom; Adelekan, Ademola; Adofo, Koranteng; Adou, Arsène K; Adsuar, José C; Afshin, Ashkan; Agardh, Emilie E; Al Khabouri, Mazin J; Al Lami, Faris H; Alam, Sayed Saidul; Alasfoor, Deena; Albittar, Mohammed I; Alegretti, Miguel A; Aleman, Alicia V; Alemu, Zewdie A; Alfonso-Cristancho, Rafael; Alhabib, Samia; Ali, Raghib; Ali, Mohammed K; Alla, François; Allebeck, Peter; Allen, Peter J; Alsharif, Ubai; Alvarez, Elena; Alvis-Guzman, Nelson; Amankwaa, Adansi A; Amare, Azmeraw T; Ameh, Emmanuel A; Ameli, Omid; Amini, Heresh; Ammar, Walid; Anderson, Benjamin O; Antonio, Carl Abelardo T; Anwari, Palwasha; Cunningham, Solveig Argeseanu; Arnlöv, Johan; Arsenijevic, Valentina S Arsic; Artaman, Al; Asghar, Rana J; Assadi, Reza; Atkins, Lydia S; Atkinson, Charles; Avila, Marco A; Awuah, Baffour; Badawi, Alaa; Bahit, Maria C; Bakfalouni, Talal; Balakrishnan, Kalpana; Balalla, Shivanthi; Balu, Ravi Kumar; Banerjee, Amitava; Barber, Ryan M; Barker-Collo, Suzanne L; Barquera, Simon; Barregard, Lars; Barrero, Lope H; Barrientos-Gutierrez, Tonatiuh; Basto-Abreu, Ana C; Basu, Arindam; Basu, Sanjay; Basulaiman, Mohammed O; Ruvalcaba, Carolina Batis; Beardsley, Justin; Bedi, Neeraj; Bekele, Tolesa; Bell, Michelle L; Benjet, Corina; Bennett, Derrick A; Benzian, Habib; Bernabé, Eduardo; Beyene, Tariku J; Bhala, Neeraj; Bhalla, Ashish; Bhutta, Zulfiqar A; Bikbov, Boris; Abdulhak, Aref A Bin; Blore, Jed D; Blyth, Fiona M; Bohensky, Megan A; Başara, Berrak Bora; Borges, Guilherme; Bornstein, Natan M; Bose, Dipan; Boufous, Soufiane; Bourne, Rupert R; Brainin, Michael; Brazinova, Alexandra; Breitborde, Nicholas J; Brenner, Hermann; Briggs, Adam D M; Broday, David M; Brooks, Peter M; Bruce, Nigel G; Brugha, Traolach S; Brunekreef, Bert|info:eu-repo/dai/nl/067548180; Buchbinder, Rachelle; Bui, Linh N; Bukhman, Gene; Bulloch, Andrew G; Burch, Michael; Burney, Peter G J; Campos-Nonato, Ismael R; Campuzano, Julio C; Cantoral, Alejandra J; Caravanos, Jack; Cárdenas, Rosario; Cardis, Elisabeth; Carpenter, David O; Caso, Valeria; Castañeda-Orjuela, Carlos A; Castro, Ruben E; Catalá-López, Ferrán; Cavalleri, Fiorella; Çavlin, Alanur; Chadha, Vineet K; Chang, Jung-Chen; Charlson, Fiona J; Chen, Honglei; Chen, Wanqing; Chen, Zhengming; Chiang, Peggy P; Chimed-Ochir, Odgerel; Chowdhury, Rajiv; Christophi, Costas A; Chuang, Ting-Wu; Chugh, Sumeet S; Cirillo, Massimo; Claßen, Thomas Kd; Colistro, Valentina; Colomar, Mercedes; Colquhoun, Samantha M; Contreras, Alejandra G; Cooper, Cyrus; Cooperrider, Kimberly; Cooper, Leslie T; Coresh, Josef; Courville, Karen J; Criqui, Michael H; Cuevas-Nasu, Lucia; Damsere-Derry, James; Danawi, Hadi; Dandona, Lalit; Dandona, Rakhi; Dargan, Paul I; Davis, Adrian; Davitoiu, Dragos V; Dayama, Anand; de Castro, E Filipa; De la Cruz-Góngora, Vanessa; De Leo, Diego; de Lima, Graça; Degenhardt, Louisa; Del Pozo-Cruz, Borja; Dellavalle, Robert P; Deribe, Kebede; Derrett, Sarah; Jarlais, Don C Des; Dessalegn, Muluken; deVeber, Gabrielle A; Devries, Karen M; Dharmaratne, Samath D; Dherani, Mukesh K; Dicker, Daniel; Ding, Eric L; Dokova, Klara; Dorsey, E Ray; Driscoll, Tim R; Duan, Leilei; Durrani, Adnan M; Ebel, Beth E; Ellenbogen, Richard G; Elshrek, Yousef M; Endres, Matthias; Ermakov, Sergey P; Erskine, Holly E; Eshrati, Babak; Esteghamati, Alireza; Fahimi, Saman; Faraon, Emerito Jose A; Farzadfar, Farshad; Fay, Derek F J; Feigin, Valery L; Feigl, Andrea B; Fereshtehnejad, Seyed-Mohammad; Ferrari, Alize J; Ferri, Cleusa P; Flaxman, Abraham D; Fleming, Thomas D; Foigt, Nataliya; Foreman, Kyle J; Paleo, Urbano Fra; Franklin, Richard C; Gabbe, Belinda; Gaffikin, Lynne; Gakidou, Emmanuela; Gamkrelidze, Amiran; Gankpé, Fortuné G; Gansevoort, Ron T; García-Guerra, Francisco A; Gasana, Evariste; Geleijnse, Johanna M; Gessner, Bradford D; Gething, Pete; Gibney, Katherine B; Gillum, Richard F; Ginawi, Ibrahim A M; Giroud, Maurice; Giussani, Giorgia; Goenka, Shifalika; Goginashvili, Ketevan; Dantes, Hector Gomez; Gona, Philimon; de Cosio, Teresita Gonzalez; González-Castell, Dinorah; Gotay, Carolyn C; Goto, Atsushi; Gouda, Hebe N; Guerrant, Richard L; Gugnani, Harish C; Guillemin, Francis; Gunnell, David; Gupta, Rahul; Gupta, Rajeev; Gutiérrez, Reyna A; Hafezi-Nejad, Nima; Hagan, Holly; Hagstromer, Maria; Halasa, Yara A; Hamadeh, Randah R; Hammami, Mouhanad; Hankey, Graeme J; Hao, Yuantao; Harb, Hilda L; Haregu, Tilahun Nigatu; Haro, Josep Maria; Havmoeller, Rasmus; Hay, Simon I; Hedayati, Mohammad T; Heredia-Pi, Ileana B; Hernandez, Lucia; Heuton, Kyle R; Heydarpour, Pouria; Hijar, Martha; Hoek, Hans W; Hoffman, Howard J; Hornberger, John C|info:eu-repo/dai/nl/304838993; Hosgood, H Dean; Hoy, Damian G; Hsairi, Mohamed; Hu, Guoqing; Hu, Howard; Huang, Cheng; Huang, John J; Hubbell, Bryan J; Huiart, Laetitia; Husseini, Abdullatif; Iannarone, Marissa L; Iburg, Kim M; Idrisov, Bulat T; Ikeda, Nayu; Innos, Kaire; Inoue, Manami; Islami, Farhad; Ismayilova, Samaya; Jacobsen, Kathryn H; Jansen, Henrica A; Jarvis, Deborah L; Jassal, Simerjot K; Jauregui, Alejandra; Jayaraman, Sudha; Jeemon, Panniyammakal; Jensen, Paul N; Jha, Vivekanand; Jiang, Fan; Jiang, Guohong; Jiang, Ying; Jonas, Jost B; Juel, Knud; Kan, Haidong; Roseline, Sidibe S Kany; Karam, Nadim E; Karch, André; Karema, Corine K; Karthikeyan, Ganesan; Kaul, Anil; Kawakami, Norito; Kazi, Dhruv S; Kemp, Andrew H; Kengne, Andre P; Keren, Andre; Khader, Yousef S; Khalifa, Shams Eldin Ali Hassan; Khan, Ejaz A; Khang, Young-Ho; Khatibzadeh, Shahab; Khonelidze, Irma; Kieling, Christian; Kim, Daniel; Kim, Sungroul; Kim, Yunjin; Kimokoti, Ruth W; Kinfu, Yohannes; Kinge, Jonas M; Kissela, Brett M; Kivipelto, Miia; Knibbs, Luke D; Knudsen, Ann Kristin; Kokubo, Yoshihiro; Kose, M Rifat; Kosen, Soewarta; Kraemer, Alexander; Kravchenko, Michael; Krishnaswami, Sanjay; Kromhout, Hans|info:eu-repo/dai/nl/074385224; Ku, Tiffany; Defo, Barthelemy Kuate; Bicer, Burcu Kucuk; Kuipers, Ernst J; Kulkarni, Chanda; Kulkarni, Veena S; Kumar, G Anil; Kwan, Gene F; Lai, Taavi; Balaji, Arjun Lakshmana; Lalloo, Ratilal; Lallukka, Tea; Lam, Hilton; Lan, Qing; Lansingh, Van C; Larson, Heidi J; Larsson, Anders; Laryea, Dennis O; Lavados, Pablo M; Lawrynowicz, Alicia E; Leasher, Janet L; Lee, Jong-Tae; Leigh, James; Leung, Ricky; Levi, Miriam; Li, Yichong; Li, Yongmei; Liang, Juan; Liang, Xiaofeng; Lim, Stephen S; Lindsay, M Patrice; Lipshultz, Steven E; Liu, Shiwei; Liu, Yang; Lloyd, Belinda K; Logroscino, Giancarlo; London, Stephanie J; Lopez, Nancy; Lortet-Tieulent, Joannie; Lotufo, Paulo A; Lozano, Rafael; Lunevicius, Raimundas; Ma, Jixiang; Ma, Stefan; Machado, Vasco M P; MacIntyre, Michael F; Magis-Rodriguez, Carlos; Mahdi, Abbas A; Majdan, Marek; Malekzadeh, Reza; Mangalam, Srikanth; Mapoma, Christopher C; Marape, Marape; Marcenes, Wagner; Margolis, David J; Margono, Christopher; Marks, Guy B; Martin, Randall V; Marzan, Melvin B; Mashal, Mohammad T; Masiye, Felix; Mason-Jones, Amanda J; Matsushita, Kunihiro; Matzopoulos, Richard; Mayosi, Bongani M; Mazorodze, Tasara T; McKay, Abigail C; McKee, Martin; McLain, Abigail; Meaney, Peter A; Medina, Catalina; Mehndiratta, Man Mohan; Mejia-Rodriguez, Fabiola; Mekonnen, Wubegzier; Melaku, Yohannes A; Meltzer, Michele; Memish, Ziad A; Mendoza, Walter; Mensah, George A; Meretoja, Atte; Mhimbira, Francis Apolinary; Micha, Renata; Miller, Ted R; Mills, Edward J; Misganaw, Awoke; Mishra, Santosh; Ibrahim, Norlinah Mohamed; Mohammad, Karzan A; Mokdad, Ali H; Mola, Glen L; Monasta, Lorenzo; Hernandez, Julio C Montañez; Montico, Marcella; Moore, Ami R; Morawska, Lidia; Mori, Rintaro; Moschandreas, Joanna; Moturi, Wilkister N; Mozaffarian, Dariush; Mueller, Ulrich O; Mukaigawara, Mitsuru; Mullany, Erin C; Murthy, Kinnari S; Naghavi, Mohsen; Nahas, Ziad; Naheed, Aliya; Naidoo, Kovin S; Naldi, Luigi; Nand, Devina; Nangia, Vinay; Narayan, Km Venkat; Nash, Denis; Neal, Bruce; Nejjari, Chakib; Neupane, Sudan P; Newton, Charles R; Ngalesoni, Frida N; de Dieu Ngirabega, Jean; Nguyen, Grant; Nguyen, Nhung T; Nieuwenhuijsen, Mark J; Nisar, Muhammad I; Nogueira, José R; Nolla, Joan M; Nolte, Sandra; Norheim, Ole F; Norman, Rosana E; Norrving, Bo; Nyakarahuka, Luke; Oh, In-Hwan; Ohkubo, Takayoshi; Olusanya, Bolajoko O; Omer, Saad B; Opio, John Nelson; Orozco, Ricardo; Pagcatipunan, Rodolfo S; Pain, Amanda W; Pandian, Jeyaraj D; Panelo, Carlo Irwin A; Papachristou, Christina; Park, Eun-Kee; Parry, Charles D; Caicedo, Angel J Paternina; Patten, Scott B; Paul, Vinod K; Pavlin, Boris I; Pearce, Neil; Pedraza, Lilia S; Pedroza, Andrea; Stokic, Ljiljana Pejin; Pekericli, Ayfer; Pereira, David M; Perez-Padilla, Rogelio; Perez-Ruiz, Fernando; Perico, Norberto; Perry, Samuel A L; Pervaiz, Aslam; Pesudovs, Konrad; Peterson, Carrie B; Petzold, Max; Phillips, Michael R; Phua, Hwee Pin; Plass, Dietrich; Poenaru, Dan; Polanczyk, Guilherme V; Polinder, Suzanne; Pond, Constance D; Pope, C Arden; Pope, Daniel; Popova, Svetlana; Pourmalek, Farshad; Powles, John; Prabhakaran, Dorairaj; Prasad, Noela M; Qato, Dima M; Quezada, Amado D; Quistberg, D Alex A; Racapé, Lionel; Rafay, Anwar; Rahimi, Kazem; Rahimi-Movaghar, Vafa; Rahman, Sajjad Ur; Raju, Murugesan; Rakovac, Ivo; Rana, Saleem M; Rao, Mayuree; Razavi, Homie; Reddy, K Srinath; Refaat, Amany H; Rehm, Jürgen; Remuzzi, Giuseppe; Ribeiro, Antonio L; Riccio, Patricia M; Richardson, Lee; Riederer, Anne; Robinson, Margaret; Roca, Anna; Rodriguez, Alina; Rojas-Rueda, David; Romieu, Isabelle; Ronfani, Luca; Room, Robin; Roy, Nobhojit; Ruhago, George M; Rushton, Lesley; Sabin, Nsanzimana; Sacco, Ralph L; Saha, Sukanta; Sahathevan, Ramesh; Sahraian, Mohammad Ali; Salomon, Joshua A; Salvo, Deborah; Sampson, Uchechukwu K; Sanabria, Juan R; Sanchez, Luz Maria; Sánchez-Pimienta, Tania G; Sanchez-Riera, Lidia; Sandar, Logan; Santos, Itamar S; Sapkota, Amir; Satpathy, Maheswar; Saunders, James E; Sawhney, Monika; Saylan, Mete I; Scarborough, Peter; Schmidt, Jürgen C; Schneider, Ione J C; Schöttker, Ben; Schwebel, David C; Scott, James G; Seedat, Soraya; Sepanlou, Sadaf G; Serdar, Berrin; Servan-Mori, Edson E; Shaddick, Gavin; Shahraz, Saeid; Levy, Teresa Shamah; Shangguan, Siyi; She, Jun; Sheikhbahaei, Sara; Shibuya, Kenji; Shin, Hwashin H; Shinohara, Yukito; Shiri, Rahman; Shishani, Kawkab; Shiue, Ivy; Sigfusdottir, Inga D; Silberberg, Donald H; Simard, Edgar P; Sindi, Shireen; Singh, Abhishek; Singh, Gitanjali M; Singh, Jasvinder A; Skirbekk, Vegard; Sliwa, Karen; Soljak, Michael; Soneji, Samir; Søreide, Kjetil; Soshnikov, Sergey; Sposato, Luciano A; Sreeramareddy, Chandrashekhar T; Stapelberg, Nicolas J C; Stathopoulou, Vasiliki; Steckling, Nadine; Stein, Dan J; Stein, Murray B; Stephens, Natalie; Stöckl, Heidi; Straif, Kurt; Stroumpoulis, Konstantinos; Sturua, Lela; Sunguya, Bruno F; Swaminathan, Soumya; Swaroop, Mamta; Sykes, Bryan L; Tabb, Karen M; Takahashi, Ken; Talongwa, Roberto T; Tandon, Nikhil; Tanne, David; Tanner, Marcel; Tavakkoli, Mohammad; Te Ao, Braden J; Teixeira, Carolina M; Téllez Rojo, Martha M; Terkawi, Abdullah S; Texcalac-Sangrador, José Luis; Thackway, Sarah V; Thomson, Blake; Thorne-Lyman, Andrew L; Thrift, Amanda G; Thurston, George D; Tillmann, Taavi; Tobollik, Myriam; Tonelli, Marcello; Topouzis, Fotis; Towbin, Jeffrey A; Toyoshima, Hideaki; Traebert, Jefferson; Tran, Bach X; Trasande, Leonardo; Trillini, Matias; Trujillo, Ulises; Dimbuene, Zacharie Tsala; Tsilimbaris, Miltiadis; Tuzcu, Emin Murat; Uchendu, Uche S; Ukwaja, Kingsley N; Uzun, Selen B; van de Vijver, Steven; Van Dingenen, Rita; van Gool, Coen H; van Os, Jim; Varakin, Yuri Y; Vasankari, Tommi J; Vasconcelos, Ana Maria N; Vavilala, Monica S; Veerman, Lennert J; Velasquez-Melendez, Gustavo; Venketasubramanian, N; Vijayakumar, Lakshmi; Villalpando, Salvador; Violante, Francesco S; Vlassov, Vasiliy Victorovich; Vollset, Stein Emil; Wagner, Gregory R; Waller, Stephen G; Wallin, Mitchell T; Wan, Xia; Wang, Haidong; Wang, JianLi; Wang, Linhong; Wang, Wenzhi; Wang, Yanping; Warouw, Tati S; Watts, Charlotte H; Weichenthal, Scott; Weiderpass, Elisabete; Weintraub, Robert G; Werdecker, Andrea; Wessells, K Ryan; Westerman, Ronny; Whiteford, Harvey A; Wilkinson, James D; Williams, Hywel C; Williams, Thomas N; Woldeyohannes, Solomon M; Wolfe, Charles D A; Wong, John Q; Woolf, Anthony D; Wright, Jonathan L; Wurtz, Brittany; Xu, Gelin; Yan, Lijing L; Yang, Gonghuan; Yano, Yuichiro; Ye, Pengpeng; Yenesew, Muluken; Yentür, Gökalp K; Yip, Paul; Yonemoto, Naohiro; Yoon, Seok-Jun; Younis, Mustafa Z; Younoussi, Zourkaleini; Yu, Chuanhua; Zaki, Maysaa E; Zhao, Yong; Zheng, Yingfeng; Zhou, Maigeng; Zhu, Jun; Zhu, Shankuan; Zou, Xiaonong; Zunt, Joseph R; Lopez, Alan D; Vos, Theo; Murray, Christopher J

    2015-01-01

    BACKGROUND: The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for

  9. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013 : A systematic analysis for the Global Burden of Disease Study 2013

    NARCIS (Netherlands)

    Forouzanfar, Mohammad H.; Alexander, Lily; Anderson, H. Ross; Bachman, Victoria F.; Biryukov, Stan; Brauer, Michael; Burnett, Richard; Casey, Daniel; Coates, Matthew M.; Cohen, Aaron; Delwiche, Kristen; Estep, Kara; Frostad, Joseph J.; Astha, K. C.; Kyu, Hmwe H.; Moradi-Lakeh, Maziar; Ng, Marie; Slepak, Erica Leigh; Thomas, Bernadette A.; Wagner, Joseph; Aasvang, Gunn Marit; Abbafati, Cristiana; Ozgoren, Ayse Abbasoglu; Abd-Allah, Foad; Abera, Semaw F.; Aboyans, Victor; Abraham, Biju; Abraham, Jerry Puthenpurakal; Abubakar, Ibrahim; Abu-Rmeileh, Niveen M. E.; Aburto, Tania C.; Achoki, Tom; Adelekan, Ademola; Adofo, Koranteng; Adou, Arsene K.; Adsuar, Jose C.; Afshin, Ashkan; Agardh, Emilie E.; Al Khabouri, Mazin J.; Al Lami, Faris H.; Alam, Sayed Saidul; Alasfoor, Deena; Albittar, Mohammed I.; Alegretti, Miguel A.; Aleman, Alicia V.; Alemu, Zewdie A.; Amare, Azmeraw T.; Gansevoort, Ron T.; Hoek, Hans W.; Liu, Yang

    2015-01-01

    Background The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for

  10. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010

    NARCIS (Netherlands)

    Lim, S.S.; Vos, T.; Flaxman, A.D.; Danaei, G.; Shibuya, K.; Adair-Rohani, H.; Amann, M.; Anderson, H.R.; Andrews, K.G.; Aryee, M.; Atkinson, C.; Bacchus, L.J.; Bahalim, A.N.; Balakrishnan, K.; Balmes, J.; Barker-Collo, S.; Baxter, A.; Bell, M.L.; Blore, J.D.; Blyth, F.; Bonner, C.; Borges, G.; Bourne, R.; Boussinesq, M.; Brauer, M.|info:eu-repo/dai/nl/31149157X; Brooks, P.; Bruce, N.G.; Brunekreef, B.|info:eu-repo/dai/nl/067548180; Bryan-Hancock, C.; Bucello, C.; Buchbinder, R.; Bull, F.; Burnett, R.T.; Byers, T.E.; Calabria, B.; Carapetis, J.; Carnahan, E.; Chafe, Z.; Charlson, F.; Chen, H.; Chen, J.S.; Cheng, A.T.; Child, J.C.; Cohen, A.; Colson, K.E.; Cowie, B.C.; Darby, S.; Darling, S.; Davis, A.; Degenhardt, L.; Dentener, F.; Des Jarlais, D.C.; Devries, K.; Dherani, M.; Ding, E.L.; Dorsey, E.R.; Driscoll, T.; Edmond, K.; Ali, S.E.; Engell, R.E.; Erwin, P.J.; Fahimi, S.; Falder, G.; Farzadfar, F.; Ferrari, A.; Finucane, M.M.; Flaxman, S.; Fowkes, F.G.R.; Freedman, G.; Freeman, M.K.; Gakidou, E.; Ghosh, S.; Giovannucci, E.; Gmel, G.; Graham, K.; Grainger, R.; Grant, B.; Gunnell, D.; Gutierrez, H.R.; Hall, W.; Hoek, H.W.; Hogan, A.; Hosgood, H.D.; Hoy, D.; Hu, H.; Hubbell, B.J.; Hutchings, S.J.; Ibeanusi, S.E.; Jacklyn, G.L.; Jasrasaria, R.; Jonas, J.B.; Kan, H.; Kanis, J.A.; Kassebaum, N.; Kawakami, N.; Khang, Y-H.; Khatibzadeh, S.; Khoo, J-P.; de Kok, C.; Laden, F.; Lalloo, R.; Lan, Q.; Lathlean, T.; Leasher, J.L.; Leigh, J.; Li, Y.; Lin, J.K.; Lipshultz, S.E.; London, S.; Lozano, R.; Lu, Y.; Mak, J.; Malekzadeh, R.; Mallinger, L.; Marcenes, W.; March, L.; Marks, R.; Martin, R.; McGale, P.; McGrath, J.; Mehta, S.; Mensah, G.A.; Merriman, T.R.; Micha, R.; Michaud, C.; Mishra, V.; Hanafiah, K.M.; Mokdad, A.A.; Morawska, L.; Mozaffarian, D.; Murphy, T.; Naghavi, M.; Neal, B.; Nelson, P.K.; Nolla, J.M.; Norman, R.; Olives, C.; Omer, S. B; Orchard, J.; Osborne, R.; Ostro, B.; Page, A.; Pandey, K.D.; Parry, C.D.H.; Passmore, E.; Patra, J.; Pearce, N.; Pelizzari, P.M.; Petzold, M.; Phillips, M.R.; Pope, D.; Pope, C.A.; Powles, J.; Rao, M.; Razavi, H.; Rehfuess, E.A.; Rehm, J.T.; Ritz, B.; Rivara, F.P.; Roberts, T.; Robinson, C.; Rodriguez-Portales, J.A.; Romieu, I.; Room, R.; Rosenfeld, L.C.; Roy, A.; Rushton, L.; Salomon, J.A.; Sampson, U.; Sanchez-Riera, L.; Sanman, E.; Sapkota, A.; Seedat, S.; Shi, P.; Shield, K.; Shivakoti, R.; Singh, G.M.; Sleet, D.A.; Smith, E.; Smith, K.R.; Stapelberg, N.J.C.; Steenland, K.; Stöckl, H.; Stovner, L.J.; Straif, K.; Straney, L.; Thurston, G.D.; Tran, J.H.; van Dingenen, R.; van Donkelaar, A.; Veerman, J.L.; Vijayakumar, L.; Weintraub, R.; Weissman, M.M.; White, R.A.; Whiteford, H.; Wiersma, S.T.; Wilkinson, J.D.; Williams, H.C.; Williams, W.; Wilson, N.; Woolf, A.D.; Yip, P.; Zielinski, J.M.; Lopez, A.D.; Murray, C.J.L.; Ezzati, M.

    2012-01-01

    BACKGROUND Quantification of the disease burden caused by different risks informs prevention by providing an account of health loss different to that provided by a disease-by-disease analysis. No complete revision of global disease burden caused by risk factors has been done since a comparative risk

  11. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013

    NARCIS (Netherlands)

    Forouzanfar, Mohammad H.; Alexander, Lily; Anderson, H. Ross; Bachman, Victoria F.; Biryukov, Stan; Brauer, Michael; Burnett, Richard; Casey, Daniel; Coates, Matthew M.; Cohen, Aaron; Delwiche, Kristen; Estep, Kara; Frostad, Joseph J.; Astha, K. C.; Kyu, Hmwe H.; Moradi-Lakeh, Maziar; Ng, Marie; Slepak, Erica Leigh; Thomas, Bernadette A.; Wagner, Joseph; Aasvang, Gunn Marit; Abbafati, Cristiana; Abbasoglu Ozgoren, Ayse; Abd-Allah, Foad; Abera, Semaw F.; Aboyans, Victor; Abraham, Biju; Abraham, Jerry Puthenpurakal; Abubakar, Ibrahim; Abu-Rmeileh, Niveen M. E.; Aburto, Tania C.; Achoki, Tom; Adelekan, Ademola; Adofo, Koranteng; Adou, Arsène K.; Adsuar, José C.; Afshin, Ashkan; Agardh, Emilie E.; Al Khabouri, Mazin J.; Al Lami, Faris H.; Alam, Sayed Saidul; Alasfoor, Deena; Albittar, Mohammed I.; Alegretti, Miguel A.; Aleman, Alicia V.; Alemu, Zewdie A.; Alfonso-Cristancho, Rafael; Alhabib, Samia; Ali, Raghib; Ali, Mohammed K.; Alla, François; Allebeck, Peter; Allen, Peter J.; Alsharif, Ubai; Alvarez, Elena; Alvis-Guzman, Nelson; Amankwaa, Adansi A.; Amare, Azmeraw T.; Ameh, Emmanuel A.; Ameli, Omid; Amini, Heresh; Ammar, Walid; Anderson, Benjamin O.; Antonio, Carl Abelardo T.; Anwari, Palwasha; Argeseanu Cunningham, Solveig; Arnlöv, Johan; Arsenijevic, Valentina S. Arsic; Artaman, Al; Asghar, Rana J.; Assadi, Reza; Atkins, Lydia S.; Atkinson, Charles; Avila, Marco A.; Awuah, Baffour; Badawi, Alaa; Bahit, Maria C.; Bakfalouni, Talal; Balakrishnan, Kalpana; Balalla, Shivanthi; Balu, Ravi Kumar; Banerjee, Amitava; Barber, Ryan M.; Barker-Collo, Suzanne L.; Barquera, Simon; Barregard, Lars; Barrero, Lope H.; Barrientos-Gutierrez, Tonatiuh; Basto-Abreu, Ana C.; Basu, Arindam; Basu, Sanjay; Basulaiman, Mohammed O.; Batis Ruvalcaba, Carolina; Beardsley, Justin; Bedi, Neeraj; Bekele, Tolesa; Bell, Michelle L.; Benjet, Corina; Bennett, Derrick A.; Benzian, Habib; Bernabé, Eduardo; Beyene, Tariku J.; Bhala, Neeraj; Bhalla, Ashish; Bhutta, Zulfiqar A.; Bikbov, Boris; Bin Abdulhak, Aref A.; Blore, Jed D.; Blyth, Fiona M.; Bohensky, Megan A.; Bora Başara, Berrak; Borges, Guilherme; Bornstein, Natan M.; Bose, Dipan; Boufous, Soufiane; Bourne, Rupert R.; Brainin, Michael; Brazinova, Alexandra; Breitborde, Nicholas J.; Brenner, Hermann; Briggs, Adam D. M.; Broday, David M.; Brooks, Peter M.; Bruce, Nigel G.; Brugha, Traolach S.; Brunekreef, Bert; Buchbinder, Rachelle; Bui, Linh N.; Bukhman, Gene; Bulloch, Andrew G.; Burch, Michael; Burney, Peter G. J.; Campos-Nonato, Ismael R.; Campuzano, Julio C.; Cantoral, Alejandra J.; Caravanos, Jack; Cárdenas, Rosario; Cardis, Elisabeth; Carpenter, David O.; Caso, Valeria; Castañeda-Orjuela, Carlos A.; Castro, Ruben E.; Catalá-López, Ferrán; Cavalleri, Fiorella; Çavlin, Alanur; Chadha, Vineet K.; Chang, Jung-Chen; Charlson, Fiona J.; Chen, Honglei; Chen, Wanqing; Chen, Zhengming; Chiang, Peggy P.; Chimed-Ochir, Odgerel; Chowdhury, Rajiv; Christophi, Costas A.; Chuang, Ting-Wu; Chugh, Sumeet S.; Cirillo, Massimo; Claßen, Thomas K. D.; Colistro, Valentina; Colomar, Mercedes; Colquhoun, Samantha M.; Contreras, Alejandra G.; Cooper, Cyrus; Cooperrider, Kimberly; Cooper, Leslie T.; Coresh, Josef; Courville, Karen J.; Criqui, Michael H.; Cuevas-Nasu, Lucia; Damsere-Derry, James; Danawi, Hadi; Dandona, Lalit; Dandona, Rakhi; Dargan, Paul I.; Davis, Adrian; Davitoiu, Dragos V.; Dayama, Anand; de Castro, E. Filipa; de la Cruz-Góngora, Vanessa; de Leo, Diego; de Lima, Graça; Degenhardt, Louisa; del Pozo-Cruz, Borja; Dellavalle, Robert P.; Deribe, Kebede; Derrett, Sarah; des Jarlais, Don C.; Dessalegn, Muluken; deVeber, Gabrielle A.; Devries, Karen M.; Dharmaratne, Samath D.; Dherani, Mukesh K.; Dicker, Daniel; Ding, Eric L.; Dokova, Klara; Dorsey, E. Ray; Driscoll, Tim R.; Duan, Leilei; Durrani, Adnan M.; Ebel, Beth E.; Ellenbogen, Richard G.; Elshrek, Yousef M.; Endres, Matthias; Ermakov, Sergey P.; Erskine, Holly E.; Eshrati, Babak; Esteghamati, Alireza; Fahimi, Saman; Faraon, Emerito Jose A.; Farzadfar, Farshad; Fay, Derek F. J.; Feigin, Valery L.; Feigl, Andrea B.; Fereshtehnejad, Seyed-Mohammad; Ferrari, Alize J.; Ferri, Cleusa P.; Flaxman, Abraham D.; Fleming, Thomas D.; Foigt, Nataliya; Foreman, Kyle J.; Paleo, Urbano Fra; Franklin, Richard C.; Gabbe, Belinda; Gaffikin, Lynne; Gakidou, Emmanuela; Gamkrelidze, Amiran; Gankpé, Fortuné G.; Gansevoort, Ron T.; García-Guerra, Francisco A.; Gasana, Evariste; Geleijnse, Johanna M.; Gessner, Bradford D.; Gething, Pete; Gibney, Katherine B.; Gillum, Richard F.; Ginawi, Ibrahim A. M.; Giroud, Maurice; Giussani, Giorgia; Goenka, Shifalika; Goginashvili, Ketevan; Gomez Dantes, Hector; Gona, Philimon; Gonzalez de Cosio, Teresita; González-Castell, Dinorah; Gotay, Carolyn C.; Goto, Atsushi; Gouda, Hebe N.; Guerrant, Richard L.; Gugnani, Harish C.; Guillemin, Francis; Gunnell, David; Gupta, Rahul; Gupta, Rajeev; Gutiérrez, Reyna A.; Hafezi-Nejad, Nima; Hagan, Holly; Hagstromer, Maria; Halasa, Yara A.; Hamadeh, Randah R.; Hammami, Mouhanad; Hankey, Graeme J.; Hao, Yuantao; Harb, Hilda L.; Haregu, Tilahun Nigatu; Haro, Josep Maria; Havmoeller, Rasmus; Hay, Simon I.; Hedayati, Mohammad T.; Heredia-Pi, Ileana B.; Hernandez, Lucia; Heuton, Kyle R.; Heydarpour, Pouria; Hijar, Martha; Hoek, Hans W.; Hoffman, Howard J.; Hornberger, John C.; Hosgood, H. Dean; Hoy, Damian G.; Hsairi, Mohamed; Hu, Guoqing; Hu, Howard; Huang, Cheng; Huang, John J.; Hubbell, Bryan J.; Huiart, Laetitia; Husseini, Abdullatif; Iannarone, Marissa L.; Iburg, Kim M.; Idrisov, Bulat T.; Ikeda, Nayu; Innos, Kaire; Inoue, Manami; Islami, Farhad; Ismayilova, Samaya; Jacobsen, Kathryn H.; Jansen, Henrica A.; Jarvis, Deborah L.; Jassal, Simerjot K.; Jauregui, Alejandra; Jayaraman, Sudha; Jeemon, Panniyammakal; Jensen, Paul N.; Jha, Vivekanand; Jiang, Fan; Jiang, Guohong; Jiang, Ying; Jonas, Jost B.; Juel, Knud; Kan, Haidong; Kany Roseline, Sidibe S.; Karam, Nadim E.; Karch, André; Karema, Corine K.; Karthikeyan, Ganesan; Kaul, Anil; Kawakami, Norito; Kazi, Dhruv S.; Kemp, Andrew H.; Kengne, Andre P.; Keren, Andre; Khader, Yousef S.; Khalifa, Shams Eldin Ali Hassan; Khan, Ejaz A.; Khang, Young-Ho; Khatibzadeh, Shahab; Khonelidze, Irma; Kieling, Christian; Kim, Daniel; Kim, Sungroul; Kim, Yunjin; Kimokoti, Ruth W.; Kinfu, Yohannes; Kinge, Jonas M.; Kissela, Brett M.; Kivipelto, Miia; Knibbs, Luke D.; Knudsen, Ann Kristin; Kokubo, Yoshihiro; Kose, M. Rifat; Kosen, Soewarta; Kraemer, Alexander; Kravchenko, Michael; Krishnaswami, Sanjay; Kromhout, Hans; Ku, Tiffany; Kuate Defo, Barthelemy; Kucuk Bicer, Burcu; Kuipers, Ernst J.; Kulkarni, Chanda; Kulkarni, Veena S.; Kumar, G. Anil; Kwan, Gene F.; Lai, Taavi; Lakshmana Balaji, Arjun; Lalloo, Ratilal; Lallukka, Tea; Lam, Hilton; Lan, Qing; Lansingh, Van C.; Larson, Heidi J.; Larsson, Anders; Laryea, Dennis O.; Lavados, Pablo M.; Lawrynowicz, Alicia E.; Leasher, Janet L.; Lee, Jong-Tae; Leigh, James; Leung, Ricky; Levi, Miriam; Li, Yichong; Li, Yongmei; Liang, Juan; Liang, Xiaofeng; Lim, Stephen S.; Lindsay, M. Patrice; Lipshultz, Steven E.; Liu, Shiwei; Liu, Yang; Lloyd, Belinda K.; Logroscino, Giancarlo; London, Stephanie J.; Lopez, Nancy; Lortet-Tieulent, Joannie; Lotufo, Paulo A.; Lozano, Rafael; Lunevicius, Raimundas; Ma, Jixiang; Ma, Stefan; Machado, Vasco M. P.; MacIntyre, Michael F.; Magis-Rodriguez, Carlos; Mahdi, Abbas A.; Majdan, Marek; Malekzadeh, Reza; Mangalam, Srikanth; Mapoma, Christopher C.; Marape, Marape; Marcenes, Wagner; Margolis, David J.; Margono, Christopher; Marks, Guy B.; Martin, Randall V.; Marzan, Melvin B.; Mashal, Mohammad T.; Masiye, Felix; Mason-Jones, Amanda J.; Matsushita, Kunihiro; Matzopoulos, Richard; Mayosi, Bongani M.; Mazorodze, Tasara T.; McKay, Abigail C.; McKee, Martin; McLain, Abigail; Meaney, Peter A.; Medina, Catalina; Mehndiratta, Man Mohan; Mejia-Rodriguez, Fabiola; Mekonnen, Wubegzier; Melaku, Yohannes A.; Meltzer, Michele; Memish, Ziad A.; Mendoza, Walter; Mensah, George A.; Meretoja, Atte; Mhimbira, Francis Apolinary; Micha, Renata; Miller, Ted R.; Mills, Edward J.; Misganaw, Awoke; Mishra, Santosh; Mohamed Ibrahim, Norlinah; Mohammad, Karzan A.; Mokdad, Ali H.; Mola, Glen L.; Monasta, Lorenzo; Montañez Hernandez, Julio C.; Montico, Marcella; Moore, Ami R.; Morawska, Lidia; Mori, Rintaro; Moschandreas, Joanna; Moturi, Wilkister N.; Mozaffarian, Dariush; Mueller, Ulrich O.; Mukaigawara, Mitsuru; Mullany, Erin C.; Murthy, Kinnari S.; Naghavi, Mohsen; Nahas, Ziad; Naheed, Aliya; Naidoo, Kovin S.; Naldi, Luigi; Nand, Devina; Nangia, Vinay; Narayan, K. M. Venkat; Nash, Denis; Neal, Bruce; Nejjari, Chakib; Neupane, Sudan P.; Newton, Charles R.; Ngalesoni, Frida N.; Ngirabega, Jean de Dieu; Nguyen, Grant; Nguyen, Nhung T.; Nieuwenhuijsen, Mark J.; Nisar, Muhammad I.; Nogueira, José R.; Nolla, Joan M.; Nolte, Sandra; Norheim, Ole F.; Norman, Rosana E.; Norrving, Bo; Nyakarahuka, Luke; Oh, In-Hwan; Ohkubo, Takayoshi; Olusanya, Bolajoko O.; Omer, Saad B.; Opio, John Nelson; Orozco, Ricardo; Pagcatipunan, Rodolfo S.; Pain, Amanda W.; Pandian, Jeyaraj D.; Panelo, Carlo Irwin A.; Papachristou, Christina; Park, Eun-Kee; Parry, Charles D.; Paternina Caicedo, Angel J.; Patten, Scott B.; Paul, Vinod K.; Pavlin, Boris I.; Pearce, Neil; Pedraza, Lilia S.; Pedroza, Andrea; Pejin Stokic, Ljiljana; Pekericli, Ayfer; Pereira, David M.; Perez-Padilla, Rogelio; Perez-Ruiz, Fernando; Perico, Norberto; Perry, Samuel A. L.; Pervaiz, Aslam; Pesudovs, Konrad; Peterson, Carrie B.; Petzold, Max; Phillips, Michael R.; Phua, Hwee Pin; Plass, Dietrich; Poenaru, Dan; Polanczyk, Guilherme V.; Polinder, Suzanne; Pond, Constance D.; Pope, C. Arden; Pope, Daniel; Popova, Svetlana; Pourmalek, Farshad; Powles, John; Prabhakaran, Dorairaj; Prasad, Noela M.; Qato, Dima M.; Quezada, Amado D.; Quistberg, D. Alex A.; Racapé, Lionel; Rafay, Anwar; Rahimi, Kazem; Rahimi-Movaghar, Vafa; Rahman, Sajjad Ur; Raju, Murugesan; Rakovac, Ivo; Rana, Saleem M.; Rao, Mayuree; Razavi, Homie; Reddy, K. Srinath; Refaat, Amany H.; Rehm, Jürgen; Remuzzi, Giuseppe; Ribeiro, Antonio L.; Riccio, Patricia M.; Richardson, Lee; Riederer, Anne; Robinson, Margaret; Roca, Anna; Rodriguez, Alina; Rojas-Rueda, David; Romieu, Isabelle; Ronfani, Luca; Room, Robin; Roy, Nobhojit; Ruhago, George M.; Rushton, Lesley; Sabin, Nsanzimana; Sacco, Ralph L.; Saha, Sukanta; Sahathevan, Ramesh; Sahraian, Mohammad Ali; Salomon, Joshua A.; Salvo, Deborah; Sampson, Uchechukwu K.; Sanabria, Juan R.; Sanchez, Luz Maria; Sánchez-Pimienta, Tania G.; Sanchez-Riera, Lidia; Sandar, Logan; Santos, Itamar S.; Sapkota, Amir; Satpathy, Maheswar; Saunders, James E.; Sawhney, Monika; Saylan, Mete I.; Scarborough, Peter; Schmidt, Jürgen C.; Schneider, Ione J. C.; Schöttker, Ben; Schwebel, David C.; Scott, James G.; Seedat, Soraya; Sepanlou, Sadaf G.; Serdar, Berrin; Servan-Mori, Edson E.; Shaddick, Gavin; Shahraz, Saeid; Levy, Teresa Shamah; Shangguan, Siyi; She, Jun; Sheikhbahaei, Sara; Shibuya, Kenji; Shin, Hwashin H.; Shinohara, Yukito; Shiri, Rahman; Shishani, Kawkab; Shiue, Ivy; Sigfusdottir, Inga D.; Silberberg, Donald H.; Simard, Edgar P.; Sindi, Shireen; Singh, Abhishek; Singh, Gitanjali M.; Singh, Jasvinder A.; Skirbekk, Vegard; Sliwa, Karen; Soljak, Michael; Soneji, Samir; Søreide, Kjetil; Soshnikov, Sergey; Sposato, Luciano A.; Sreeramareddy, Chandrashekhar T.; Stapelberg, Nicolas J. C.; Stathopoulou, Vasiliki; Steckling, Nadine; Stein, Dan J.; Stein, Murray B.; Stephens, Natalie; Stöckl, Heidi; Straif, Kurt; Stroumpoulis, Konstantinos; Sturua, Lela; Sunguya, Bruno F.; Swaminathan, Soumya; Swaroop, Mamta; Sykes, Bryan L.; Tabb, Karen M.; Takahashi, Ken; Talongwa, Roberto T.; Tandon, Nikhil; Tanne, David; Tanner, Marcel; Tavakkoli, Mohammad; te Ao, Braden J.; Teixeira, Carolina M.; Téllez Rojo, Martha M.; Terkawi, Abdullah S.; Texcalac-Sangrador, José Luis; Thackway, Sarah V.; Thomson, Blake; Thorne-Lyman, Andrew L.; Thrift, Amanda G.; Thurston, George D.; Tillmann, Taavi; Tobollik, Myriam; Tonelli, Marcello; Topouzis, Fotis; Towbin, Jeffrey A.; Toyoshima, Hideaki; Traebert, Jefferson; Tran, Bach X.; Trasande, Leonardo; Trillini, Matias; Trujillo, Ulises; Dimbuene, Zacharie Tsala; Tsilimbaris, Miltiadis; Tuzcu, Emin Murat; Uchendu, Uche S.; Ukwaja, Kingsley N.; Uzun, Selen B.; van de Vijver, Steven; van Dingenen, Rita; van Gool, Coen H.; van Os, Jim; Varakin, Yuri Y.; Vasankari, Tommi J.; Vasconcelos, Ana Maria N.; Vavilala, Monica S.; Veerman, Lennert J.; Velasquez-Melendez, Gustavo; Venketasubramanian, N.; Vijayakumar, Lakshmi; Villalpando, Salvador; Violante, Francesco S.; Vlassov, Vasiliy Victorovich; Vollset, Stein Emil; Wagner, Gregory R.; Waller, Stephen G.; Wallin, Mitchell T.; Wan, Xia; Wang, Haidong; Wang, JianLi; Wang, Linhong; Wang, Wenzhi; Wang, Yanping; Warouw, Tati S.; Watts, Charlotte H.; Weichenthal, Scott; Weiderpass, Elisabete; Weintraub, Robert G.; Werdecker, Andrea; Wessells, K. Ryan; Westerman, Ronny; Whiteford, Harvey A.; Wilkinson, James D.; Williams, Hywel C.; Williams, Thomas N.; Woldeyohannes, Solomon M.; Wolfe, Charles D. A.; Wong, John Q.; Woolf, Anthony D.; Wright, Jonathan L.; Wurtz, Brittany; Xu, Gelin; Yan, Lijing L.; Yang, Gonghuan; Yano, Yuichiro; Ye, Pengpeng; Yenesew, Muluken; Yentür, Gökalp K.; Yip, Paul; Yonemoto, Naohiro; Yoon, Seok-Jun; Younis, Mustafa Z.; Younoussi, Zourkaleini; Yu, Chuanhua; Zaki, Maysaa E.; Zhao, Yong; Zheng, Yingfeng; Zhou, Maigeng; Zhu, Jun; Zhu, Shankuan; Zou, Xiaonong; Zunt, Joseph R.; Lopez, Alan D.; Vos, Theo; Murray, Christopher J.

    2015-01-01

    Background The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for

  12. Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016

    NARCIS (Netherlands)

    Abajobir, Amanuel Alemu; Abate, Kalkidan Hassen; Abbafati, Cristiana; Abbas, Kaja M.; Abd-Allah, Foad; Abdulle, Abdishakur M.; Abera, Semaw Ferede; Aboyans, Victor; Abu-Raddad, Laith J.; Abu-Rmeileh, Niveen M E; Abyu, Gebre Yitayih; Adedeji, Isaac Akinkunmi; Adetokunboh, Olatunji; Afarideh, Mohsen; Afshin, Ashkan; Agrawal, Anurag; Agrawal, Sutapa; Ahmadieh, Hamid; Ahmed, Muktar Beshir; Aichour, Miloud Taki Eddine; Aichour, Amani Nidhal; Aichour, Ibtihel; Akinyemi, Rufus Olusola; Akseer, Nadia; Alahdab, Fares; Al-Aly, Ziyad; Alam, Khurshid; Alam, Noore; Alam, Tahiya; Alasfoor, Deena; Alene, Kefyalew Addis; Ali, Komal; Alizadeh-Navaei, Reza; Alkerwi, Ala'a; Alla, François; Allebeck, Peter; Al-Raddadi, Rajaa; Alsharif, Ubai; Altirkawi, Khalid A.; Alvis-Guzman, Nelson; Amare, Azmeraw T; Amini, Erfan; Ammar, Walid; Amoako, Yaw Ampem; Ansari, Hossein; Antó, Josep M.; Antonio, Carl Abelardo T; Anwari, Palwasha; Arian, Nicholas; Ärnlöv, Johan; Artaman, Al; Aryal, Krishna Kumar; Asayesh, Hamid; Asgedom, Solomon Weldegebreal; Atey, Tesfay Mehari; Avila-Burgos, Leticia; Avokpaho, Euripide Frinel G.Arthur; Awasthi, Ashish; Azzopardi, Peter; Bacha, Umar; Badawi, Alaa; Balakrishnan, Kalpana; Ballew, Shoshana H.; Barac, Aleksandra; Barber, Ryan M; Barker-Collo, Suzanne L; Bärnighausen, Till; Barquera, Simon; Barregard, Lars; Barrero, Lope H; Batis, Carolina; Battle, Katherine E.; Baumgarner, Blair R.; Baune, Bernhard T.; Beardsley, Justin; Bedi, Neeraj; Beghi, Ettore; Bell, Michelle L; Bennett, Derrick A; Bennett, James R.; Bensenor, Isabela M.; Berhane, Adugnaw; Berhe, Derbew Fikadu; Bernabé, Eduardo; Betsu, Balem Demtsu; Beuran, Mircea; Beyene, Addisu Shunu; Bhansali, Anil; Bhutta, Zulfiqar A; Bicer, Burcu Kucuk; Bikbov, Boris; Birungi, Charles; Biryukov, Stan; Blosser, Christopher D.; Boneya, Dube Jara; Bou-Orm, Ibrahim R.; Brauer, Michael; Breitborde, Nicholas J.K.; Brenner, Hermann; Brugha, Traolach S; Bulto, Lemma Negesa Bulto; Butt, Zahid A.; Cahuana-Hurtado, Lucero; Cárdenas, Rosario; Carrero, Juan Jesus; Castañeda-Orjuela, Carlos A; Catalá-López, Ferrán; Cercy, Kelly; Chang, Hsing Yi; Charlson, Fiona J; Chimed-Ochir, Odgerel; Chisumpa, Vesper Hichilombwe; Chitheer, Abdulaal A.; Christensen, Hanne; Christopher, Devasahayam Jesudas; Cirillo, Massimo; Cohen, Aaron J; Comfort, Haley; Cooper, Cyrus; Coresh, Josef; Cornaby, Leslie; Cortesi, Paolo Angelo; Criqui, Michael H; Crump, John A; Dandona, Lalit; Dandona, Rakhi; das Neves, José; Davey, Gail; Davitoiu, Dragos V; Davletov, Kairat; de Courten, Barbora; Defo, Barthelemy Kuate; Degenhardt, Louisa; Deiparine, Selina; Dellavalle, Robert P; Deribe, Kebede; Deshpande, Aniruddha; Dharmaratne, Samath D; Ding, Eric L; Djalalinia, Shirin; Do, Huyen Phuc; Dokova, Klara; Doku, David Teye; Donkelaar, Aaron van; Dorsey, E Ray; Driscoll, Tim R; Dubey, Manisha; Duncan, Bruce Bartholow; Duncan, Sarah; Ebrahimi, Hedyeh; El-Khatib, Ziad Ziad; Enayati, Ahmadali; Endries, Aman Yesuf; Ermakov, Sergey Petrovich; Erskine, Holly E; Eshrati, Babak; Eskandarieh, Sharareh; Esteghamati, Alireza; Estep, Kara; Faraon, Emerito Jose Aquino; Farinha, Carla Sofia e.Sa; Faro, André; Farzadfar, Farshad; Fay, Kairsten; Feigin, Valery L; Fereshtehnejad, Seyed-Mohammad; Fernandes, João C.; Ferrari, Alize J; Feyissa, Tesfaye Regassa; Filip, Irina; Fischer, Florian; Fitzmaurice, Christina; Flaxman, Abraham D; Foigt, Nataliya; Foreman, Kyle J; Frostad, Joseph J; Fullman, Nancy; Fürst, Thomas; Furtado, Joao M.; Gakidou, Emmanuela; Ganji, Morsaleh; Garcia-Basteiro, Alberto L.; Gebrehiwot, Tsegaye Tewelde; Geleijnse, Johanna M.; Geleto, Ayele; Gemechu, Bikila Lencha; Gesesew, Hailay Abrha; Gething, Peter W.; Ghajar, Alireza; Gibney, Katherine B; Gill, Paramjit Singh; Gillum, Richard F; Giref, Ababi Zergaw; Gishu, Melkamu Dedefo; Giussani, Giorgia; Godwin, William W.; Gona, Philimon N.; Goodridge, Amador; Gopalani, Sameer Vali; Goryakin, Yevgeniy; Goulart, Alessandra Carvalho; Graetz, Nicholas; Gugnani, Harish Chander; Guo, Jingwen; Gupta, Rajeev; Gupta, Tanush; Gupta, Vipin; Gutiérrez, Reyna A; Hachinski, Vladimir; Hafezi-Nejad, Nima; Hailu, Gessessew Bugssa; Hamadeh, Randah Ribhi; Hamidi, Samer; Hammami, Mouhanad; Handal, Alexis J.; Hankey, Graeme J.; Hanson, Sarah Wulf; Harb, Hilda L; Hareri, Habtamu Abera; Hassanvand, Mohammad Sadegh; Havmoeller, Rasmus; Hawley, Caitlin; Hay, Simon I; Hedayati, Mohammad T; Hendrie, Delia; Heredia-Pi, Ileana Beatriz; Hernandez, Julio Cesar Montañez; Hoek, Hans W; Horita, Nobuyuki; Hosgood, H. Dean; Hostiuc, Sorin; Hoy, Damian G; Hsairi, Mohamed; Hu, Guoqing; Huang, John J; Huang, Hsiang; Ibrahim, Norlinah Mohamed; Iburg, Kim Moesgaard; Ikeda, Chad; Inoue, Manami; Irvine, Caleb Mackay Salpeter; Jackson, Maria Delores; Jacobsen, Kathryn H; Jahanmehr, Nader; Jakovljevic, Mihajlo B.; Jauregui, Alejandra; Javanbakht, Mehdi; Jeemon, Panniyammakal; Johansson, Lars R.K.; Johnson, Catherine O.; Jonas, Jost B; Jürisson, Mikk; Kabir, Zubair; Kadel, Rajendra; Kahsay, Amaha; Kamal, Ritul; Karch, André; Karema, Corine Kakizi; Kasaeian, Amir; Kassebaum, Nicholas J.; Kastor, Anshul; Katikireddi, Srinivasa Vittal; Kawakami, Norito; Keiyoro, Peter Njenga; Kelbore, Sefonias Getachew; Kemmer, Laura; Kengne, Andre Pascal; Kesavachandran, Chandrasekharan Nair; Khader, Yousef Saleh; Khalil, Ibrahim A.; Khan, Ejaz Ahmad; Khang, Young-Ho; Khosravi, Ardeshir; Khubchandani, Jagdish; Kiadaliri, Aliasghar Ahmad; Kieling, Christian; Kim, Jun Y.; Kim, Yun Jin; Kim, Daniel; Kimokoti, Ruth W; Kinfu, Yohannes; Kisa, Adnan; Kissimova-Skarbek, Katarzyna A.; Kivimaki, Mika; Knibbs, Luke D; Knudsen, Ann Kristin; Kopec, Jacek A.; Kosen, Soewarta; Koul, Parvaiz A.; Koyanagi, Ai; Kravchenko, Michael; Krohn, Kristopher J.; Kromhout, Hans|info:eu-repo/dai/nl/074385224; Kumar, G Anil; Kutz, Michael; Kyu, Hmwe H; Lal, Dharmesh Kumar; Lalloo, Ratilal; Lallukka, Tea; Lan, Qing; Lansingh, Van C; Larsson, Anders; Lee, Paul H.; Lee, Alexander; Leigh, James; Leung, Janni; Levi, Miriam; Levy, Teresa Shamah; Li, Yichong; Li, Yongmei; Liang, Xiaofeng; Liben, Misgan Legesse; Lim, Stephen S; Linn, Shai; Liu, Patrick; Lodha, Rakesh; Logroscino, Giancarlo; Looker, Katherine J.; Lopez, Alan D; Lorkowski, Stefan; Lotufo, Paulo A; Lozano, Rafael; Lunevicius, Raimundas; Macarayan, Erlyn Rachelle King; Magdy Abd El Razek, Hassan; Magdy Abd El Razek, Mohammed; Majdan, Marek; Majdzadeh, Reza; Majeed, Azeem; Malekzadeh, Reza; Malhotra, Rajesh; Malta, Deborah Carvalho; Mamun, Abdullah A.; Manguerra, Helena; Mantovani, Lorenzo G.; Mapoma, Chabila C.; Martin, Randall V; Martinez-Raga, Jose; Martins-Melo, Francisco Rogerlândio; Mathur, Manu Raj; Matsushita, Kunihiro; Matzopoulos, Richard; Mazidi, Mohsen; McAlinden, Colm; McGrath, John W; Mehata, Suresh; Mehndiratta, Man Mohan; Meier, Toni; Melaku, Yohannes Adama; Memiah, Peter; Memish, Ziad A.; Mendoza, Walter; Mengesha, Melkamu Merid; Mensah, George A; Mensink, Gert B.M.; Mereta, Seid Tiku; Meretoja, Tuomo J.; Meretoja, Atte; Mezgebe, Haftay Berhane; Micha, Renata; Millear, Anoushka; Miller, Ted R; Minnig, Shawn; Mirarefin, Mojde; Mirrakhimov, Erkin M.; Misganaw, Awoke; Mishra, Shiva Raj; Mohammad, Karzan Abdulmuhsin; Mohammed, Kedir Endris; Mohammed, Shafiu; Mohan, Murali B.V.; Mokdad, Ali H; Monasta, Lorenzo; Montico, Marcella; Moradi-Lakeh, Maziar; Moraga, Paula; Morawska, Lidia; Morrison, Shane D.; Mountjoy-Venning, Cliff; Mueller, Ulrich O; Mullany, Erin C; Muller, Kate; Murray, Christopher J L; Murthy, Gudlavalleti Venkata Satyanarayana; Musa, Kamarul Imran; Naghavi, Mohsen; Naheed, Aliya; Nangia, Vinay; Natarajan, Gopalakrishnan; Negoi, Ruxandra Irina; Negoi, Ionut; Nguyen, Cuong Tat; Nguyen, Quyen Le; Nguyen, Trang Huyen; Nguyen, Grant; Nguyen, Minh Hao; Nichols, Emma; Ningrum, Dina Nur Anggraini; Nomura, Marika; Nong, Vuong Minh; Norheim, Ole F; Norrving, Bo; Noubiap, Jean Jacques N.; Obermeyer, Carla Makhlouf; Ogbo, Felix Akpojene; Oh, In-Hwan; Oladimeji, Olanrewaju; Olagunju, Andrew Toyin; Olagunju, Tinuke Oluwasefunmi; Olivares, Pedro R.; Olsen, Helen E.; Olusanya, Bolajoko Olubukunola; Olusanya, Jacob Olusegun; Opio, John Nelson; Oren, Eyal; Ortiz, Alberto; Ota, Erika; Owolabi, Mayowa O.; PA, Mahesh; Pacella, Rosana E.; Pana, Adrian; Panda, Basant Kumar; Panda-Jonas, Songhomitra; Pandian, Jeyaraj D; Papachristou, Christina; Park, Eun-Kee; Parry, Charles D; Patten, Scott B; Patton, George C.; Pereira, David M; Perico, Norberto; Pesudovs, Konrad; Petzold, Max; Phillips, Michael Robert; Pillay, Julian David; Piradov, Michael A.; Pishgar, Farhad; Plass, Dietrich; Pletcher, Martin A.; Polinder, Suzanne; Popova, Svetlana; Poulton, Richie G.; Pourmalek, Farshad; Prasad, Narayan; Purcell, Carrie; Qorbani, Mostafa; Radfar, Amir; Rafay, Anwar; Rahimi-Movaghar, Afarin; Rahimi-Movaghar, Vafa; Rahman, Mohammad Hifz Ur; Rahman, Muhammad Aziz; Rahman, Mahfuzar; Rai, Rajesh Kumar; Rajsic, Sasa; Ram, Usha; Rawaf, Salman; Rehm, Colin D.; Rehm, Jürgen; Reiner, Robert C.; Reitsma, Marissa B.; Remuzzi, Giuseppe; Renzaho, Andre M.N.; Resnikoff, Serge; Reynales-Shigematsu, Luz Myriam; Rezaei, Satar; Ribeiro, Antonio L; Rivera, Juan A.; Roba, Kedir Teji; Rojas-Rueda, David; Roman, Yesenia; Room, Robin; Roshandel, Gholamreza; Roth, Gregory A.; Rothenbacher, Dietrich; Rubagotti, Enrico; Rushton, Lesley; Sadat, Nafis; Safdarian, Mahdi; Safi, Sare; Safiri, Saeid; Sahathevan, Ramesh; Salama, Joseph; Salomon, Joshua A; Samy, Abdallah M.; Sanabria, Juan Ramon; Sanchez-Niño, Maria Dolores; Sánchez-Pimienta, Tania G; Santomauro, Damian; Santos, Itamar S; Santric Milicevic, Milena M.; Sartorius, Benn; Satpathy, Maheswar; Sawhney, Monika; Saxena, Sonia; Schmidt, Maria Inês; Schneider, Ione J C; Schutte, Aletta E.; Schwebel, David C; Schwendicke, Falk; Seedat, Soraya; Sepanlou, Sadaf G; Serdar, Berrin; Servan-Mori, Edson E; Shaddick, Gavin; Shaheen, Amira; Shahraz, Saeid; Shaikh, Masood Ali; Shamsipour, Mansour; Shamsizadeh, Morteza; Shariful Islam, Sheikh Mohammed; Sharma, Jayendra; Sharma, Rajesh; She, Jun; Shen, Jiabin; Shi, Peilin; Shibuya, Kenji; Shields, Chloe; Shiferaw, Mekonnen Sisay; Shigematsu, Mika; Shin, Min Jeong; Shiri, Rahman; Shirkoohi, Reza; Shishani, Kawkab; Shoman, Haitham; Shrime, Mark G.; Sigfusdottir, Inga Dora; Silva, Diego Augusto Santos; Silva, João Pedro; Silveira, Dayane Gabriele Alves; Singh, Jasvinder A; Singh, Virendra; Sinha, Dhirendra Narain; Skiadaresi, Eirini; Slepak, Erica Leigh; Smith, David L.; Smith, Mari; Sobaih, Badr H.A.; Sobngwi, Eugene; Soneji, Samir; Sorensen, Reed J.D.; Sposato, Luciano A; Sreeramareddy, Chandrashekhar T; Srinivasan, Vinay; Steel, Nicholas; Stein, Dan J.; Steiner, Caitlyn; Steinke, Sabine; Stokes, Mark Andrew; Strub, Bryan; Subart, Michelle; Sufiyan, Muawiyyah Babale; Suliankatchi, Rizwan Abdulkader; Sur, Patrick J.; Swaminathan, Soumya; Sykes, Bryan L; Szoeke, Cassandra E.I.; Tabarés-Seisdedos, Rafael; Tadakamadla, Santosh Kumar; Takahashi, Ken; Takala, Jukka S.; Tandon, Nikhil; Tanner, Marcel; Tarekegn, Yihunie L.; Tavakkoli, Mohammad; Tegegne, Teketo Kassaw; Tehrani-Banihashemi, Arash; Terkawi, Abdullah Sulieman; Tesssema, Belay; Thakur, J. S.; Thamsuwan, Ornwipa; Thankappan, Kavumpurathu Raman; Theis, Andrew M.; Thomas, Matthew Lloyd; Thomson, Alan J.; Thrift, Amanda G; Tillmann, Taavi; Tobe-Gai, Ruoyan; Tobollik, Myriam; Tollanes, Mette C.; Tonelli, Marcello; Topor-Madry, Roman; Torre, Anna; Tortajada, Miguel; Touvier, Mathilde; Tran, Bach Xuan; Truelsen, Thomas; Tuem, Kald Beshir; Tuzcu, Emin Murat; Tyrovolas, Stefanos; Ukwaja, Kingsley Nnanna; Uneke, Chigozie Jesse; Updike, Rachel; Uthman, Olalekan A.; van Boven, Job F.M.; Varughese, Santosh; Vasankari, Tommi J; Veerman, Lennert J; Venkateswaran, Vidhya; Venketasubramanian, Narayanaswamy; Violante, Francesco S; Vladimirov, Sergey K.; Vlassov, Vasiliy Victorovich; Vollset, Stein Emil; Vos, Theo; Wadilo, Fiseha; Wakayo, Tolassa; Wallin, Mitchell T; Wang, Yuan Pang; Weichenthal, Scott; Weiderpass, Elisabete; Weintraub, Robert G; Weiss, Daniel J.; Werdecker, Andrea; Westerman, Ronny; Whiteford, Harvey A; Wiysonge, Charles Shey; Woldeyes, Belete Getahun; Wolfe, Charles D A; Woodbrook, Rachel; Workicho, Abdulhalik; Xavier, Denis; Xu, Gelin; Yadgir, Simon; Yakob, Bereket; Yan, Lijing L; Yaseri, Mehdi; Yimam, Hassen Hamid; Yip, Paul; Yonemoto, Naohiro; Yoon, Seok-Jun; Yotebieng, Marcel; Younis, Mustafa Z; Zaidi, Zoubida; Zaki, Maysaa El Sayed; Zavala-Arciniega, Luis; Zhang, Xueying; Zimsen, Stephanie Raman M.; Zipkin, Ben; Zodpey, Sanjay

    2017-01-01

    Background The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) provides a comprehensive assessment of risk factor exposure and attributable burden of disease. By providing estimates over a long time series, this study can monitor risk exposure trends critical to health

  13. Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016

    NARCIS (Netherlands)

    Gakidou, Emmanuela; Geleijnse, J.M.

    2017-01-01

    Background
    The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) provides a comprehensive assessment of risk factor exposure and attributable burden of disease. By providing estimates over a long time series, this study can monitor risk exposure trends critical to

  14. Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2016 : a systematic analysis for the Global Burden of Disease Study 2016

    NARCIS (Netherlands)

    Gakidou, Emmanuela; Afshin, Ashkan; Abajobir, Amanuel Alemu; Abate, Kalkidan Hassen; Abbafati, Cristiana; Abbas, Kaja M.; Abd-Allah, Foad; Abdulle, Abdishakur M.; Abera, Semaw Ferede; Aboyans, Victor; Abu-Raddad, Laith J.; Abu-Rmeileh, Niveen M. E.; Abyu, Gebre Yitayih; Adedeji, Isaac Akinkunmi; Adetokunboh, Olatunji; Afarideh, Mohsen; Agrawal, Anurag; Agrawal, Sutapa; Kiadaliri, Aliasghar Ahmad; Ahmadieh, Hamid; Ahmed, Muktar Beshir; Aichour, Amani Nidhal; Aichour, Ibtihel; Aichour, Miloud Taki Eddine; Akinyemi, Rufus Olusola; Akseer, Nadia; Alahdab, Fares; Al-Aly, Ziyad; Alam, Khurshid; Alam, Noore; Alam, Tahiya; Alasfoor, Deena; Alene, Kefyalew Addis; Ali, Komal; Alizadeh-Navaei, Reza; Alkerwi, Ala'a; Alla, Francois; Allebeck, Peter; Al-Raddadi, Rajaa; Alsharif, Ubai; Altirkawi, Khalid A.; Alvis-Guzman, Nelson; Amare, Azmeraw T.; Amini, Erfan; Ammar, Walid; Amoako, Yaw Ampem; Ansari, Hossein; Berhe, Derbew Fikadu; Hoek, Hans W.; van Boven, Job F. M.

    2017-01-01

    Background The Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) provides a comprehensive assessment of risk factor exposure and attributable burden of disease. By providing estimates over a long time series, this study can monitor risk exposure trends critical to health

  15. Optimization of Two-Level Disassembly/Remanufacturing/Assembly System with an Integrated Maintenance Strategy

    Directory of Open Access Journals (Sweden)

    Zouhour Guiras

    2018-04-01

    Full Text Available With an increase of environmental pressure on economic activities, reverse flow is increasingly important. It seeks to save resources, eliminate waste, and improve productivity. This paper investigates the optimization of the disassembly, remanufacturing and assembly system, taking into account assembly-disassembly system degradation. An analytical model is developed to consider disassembly, remanufacturing of used/end-of-life product and assembly of the finished product. The finished product is composed of remanufactured and new components. A maintenance policy is sequentially integrated to reduce the system unavailability. The aim of this study is to help decision-makers, under certain conditions, choose the most cost-effective process for them to satisfy the customer as well as to adapt to the potential risk that can perturb the disassembly-assembly system. A heuristic is developed to determine the optimal ordered date of the used end-of-life product as well as the optimum release dates of new external components. The results reveal that considering some remanufacturing and purchase components costs, the proposed model is more economical in comparison with a model without remanufactured parts. Numerical results are provided to illustrate the impact of the variation of the ordering cost and quality of the used end-of-life product on the system profitability. Finally, the risk due to system repair periods is discussed, which has an impact on managerial decision-making.

  16. A Cluster-Randomized Controlled Trial to Reduce Diarrheal Disease and Dengue Entomological Risk Factors in Rural Primary Schools in Colombia.

    Directory of Open Access Journals (Sweden)

    Hans J Overgaard

    2016-11-01

    Full Text Available As many neglected tropical diseases are co-endemic and have common risk factors, integrated control can efficiently reduce disease burden and relieve resource-strained public health budgets. Diarrheal diseases and dengue fever are major global health problems sharing common risk factors in water storage containers. Where provision of clean water is inadequate, water storage is crucial. Fecal contamination of stored water is a common source of diarrheal illness, but stored water also provides breeding sites for dengue vector mosquitoes. Integrating improved water management and educational strategies for both diseases in the school environment can potentially improve the health situation for students and the larger community. The objective of this trial was to investigate whether interventions targeting diarrhea and dengue risk factors would significantly reduce absence due to diarrheal disease and dengue entomological risk factors in schools.A factorial cluster randomized controlled trial was carried out in 34 rural primary schools (1,301 pupils in La Mesa and Anapoima municipalities, Cundinamarca, Colombia. Schools were randomized to one of four study arms: diarrhea interventions (DIA, dengue interventions (DEN, combined diarrhea and dengue interventions (DIADEN, and control (CON. Interventions had no apparent effect on pupil school absence due to diarrheal disease (p = 0.45 or on adult female Aedes aegypti density (p = 0.32 (primary outcomes. However, the dengue interventions reduced the Breteau Index on average by 78% (p = 0.029, with Breteau indices of 10.8 and 6.2 in the DEN and DIADEN arms, respectively compared to 37.5 and 46.9 in the DIA and CON arms, respectively. The diarrhea interventions improved water quality as assessed by the amount of Escherichia coli colony forming units (CFU; the ratio of Williams mean E. coli CFU being 0.22, or 78% reduction (p = 0.008.Integrated control of dengue and diarrhea has never been conducted before

  17. A Cluster-Randomized Controlled Trial to Reduce Diarrheal Disease and Dengue Entomological Risk Factors in Rural Primary Schools in Colombia

    Science.gov (United States)

    Overgaard, Hans J.; Alexander, Neal; Matiz, Maria Ines; Jaramillo, Juan Felipe; Olano, Victor Alberto; Vargas, Sandra; Sarmiento, Diana; Lenhart, Audrey; Stenström, Thor Axel

    2016-01-01

    Background As many neglected tropical diseases are co-endemic and have common risk factors, integrated control can efficiently reduce disease burden and relieve resource-strained public health budgets. Diarrheal diseases and dengue fever are major global health problems sharing common risk factors in water storage containers. Where provision of clean water is inadequate, water storage is crucial. Fecal contamination of stored water is a common source of diarrheal illness, but stored water also provides breeding sites for dengue vector mosquitoes. Integrating improved water management and educational strategies for both diseases in the school environment can potentially improve the health situation for students and the larger community. The objective of this trial was to investigate whether interventions targeting diarrhea and dengue risk factors would significantly reduce absence due to diarrheal disease and dengue entomological risk factors in schools. Methodology/Principal Findings A factorial cluster randomized controlled trial was carried out in 34 rural primary schools (1,301 pupils) in La Mesa and Anapoima municipalities, Cundinamarca, Colombia. Schools were randomized to one of four study arms: diarrhea interventions (DIA), dengue interventions (DEN), combined diarrhea and dengue interventions (DIADEN), and control (CON). Interventions had no apparent effect on pupil school absence due to diarrheal disease (p = 0.45) or on adult female Aedes aegypti density (p = 0.32) (primary outcomes). However, the dengue interventions reduced the Breteau Index on average by 78% (p = 0.029), with Breteau indices of 10.8 and 6.2 in the DEN and DIADEN arms, respectively compared to 37.5 and 46.9 in the DIA and CON arms, respectively. The diarrhea interventions improved water quality as assessed by the amount of Escherichia coli colony forming units (CFU); the ratio of Williams mean E. coli CFU being 0.22, or 78% reduction (p = 0.008). Conclusions/Significance Integrated

  18. Clustering Dycom

    KAUST Repository

    Minku, Leandro L.; Hou, Siqing

    2017-01-01

    baseline WC model is also included in the analysis. Results: Clustering Dycom with K-Means can potentially help to split the CC projects, managing to achieve similar or better predictive performance than Dycom. However, K-Means still requires the number

  19. Pathways: patient-centred decision counselling for women at risk of cancer-related infertility: a protocol for a comparative effectiveness cluster randomised trial.

    Science.gov (United States)

    Woodard, Terri Lynn; Hoffman, Aubri S; Crocker, Laura C; Holman, Deborah A; Hoffman, Derek B; Ma, Jusheng; Bassett, Roland L; Leal, Viola B; Volk, Robert J

    2018-02-21

    National guidelines recommend that all reproductive-age women with cancer be informed of their fertility risks and offered referral to fertility specialists to discuss fertility preservation options. However, reports indicate that only 5% of patients have consultations, and rates of long-term infertility-related distress remain high. Previous studies report several barriers to fertility preservation; however, initial success has been reported using provider education, patient decision aids and navigation support. This protocol will test effects of a multicomponent intervention compared with usual care on women's fertility preservation knowledge and decision-making outcomes. This cluster-randomised trial will compare the multicomponent intervention (provider education, patient decision aid and navigation support) with usual care (consultation and referral, if requested). One hundred newly diagnosed English-speaking women of reproductive age who are at risk of cancer-related infertility will be recruited from four regional oncology clinics.The Pathways patient decision aid website provides (1) up-to-date evidence and descriptions of fertility preservation and other family-building options, tailored to cancer type; (2) structured guidance to support personalising the information and informed decision-making; and (3) a printable summary to help women prepare for discussions with their oncologist and/or fertility specialist. Four sites will be randomly assigned to intervention or control groups. Participants will be recruited after their oncology consultation and asked to complete online questionnaires at baseline, 1 week and 2 months to assess their demographics, fertility preservation knowledge, and decision-making process and quality. The primary outcome (decisional conflict) will be tested using Fisher's exact test. Secondary outcomes will be assessed using generalised linear mixed models, and sensitivity analyses will be conducted, as appropriate. The University of

  20. Can cannabis use be prevented by targeting personality risk in schools? Twenty?four?month outcome of the adventure trial on cannabis use: a cluster?randomized controlled trial

    OpenAIRE

    Mahu, Ioan T.; Doucet, Christine; O'Leary?Barrett, Maeve; Conrod, Patricia J.

    2015-01-01

    Aims To examine the effectiveness of a personality?targeted intervention program (Adventure trial) delivered by trained teachers to high?risk (HR) high?school students on reducing marijuana use and frequency of use. Design A cluster?randomized controlled trial. Setting Secondary schools in London, UK. Participants Twenty?one secondary schools were randomized to intervention (n?=?12) or control (n?=?9) conditions, encompassing a total of 1038 HR students in the ninth grade [mean (standard devi...

  1. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015 : A systematic analysis for the Global Burden of Disease Study 2015

    NARCIS (Netherlands)

    Forouzanfar, Mohammad H.; Afshin, Ashkan; Alexander, Lily T.; Anderson, H. Ross; Bhutta, Zulficiar A.; Biryukov, Stan; Brauer, Michael; Burnett, Richard; Cercy, Kelly; Charlson, Fiona J.; Cohen, Aaron J.; Dandona, Lalit; Estep, Kara; Ferrari, Alize J.; Frostad, Joseph J.; Fullman, Nancy; Gething, Peter W.; Godwin, William W.; Griswold, Max; Kinfu, Yohannes; Kyu, Hmwe H.; Larson, Heidi J.; Liang, Xiaofeng; Lim, Stephen S.; Liu, Patrick Y.; Lopez, Alan D.; Lozano, Rafael; Marczak, Laurie; Mensah, George A.; Mokdad, Ali H.; Moradi-Lakeh, Maziar; Naghavi, Mohsen; Neal, Bruce; Reitsma, Marissa B.; Roth, Gregory A.; Salomon, Joshua A.; Sur, Patrick J.; Vos, Theo; Wagner, Joseph A.; Wang, Haidong; Zhao, Yi; Zhou, Maigeng; Aasvang, Gunn Marit; Abajobir, Amanuel Alemu; Abate, Kalkidan Hassen; Abbafati, Cristiana; Amare, Azmeraw T.; Hoek, Hans W.; Singh, Abhishek; Tura, Abera Kenay

    2016-01-01

    Background The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform

  2. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015

    NARCIS (Netherlands)

    Forouzanfar, Mohammad Hossein; Afshin, Ashkan; Alexander, Lily T.; Ross Anderson, H.; Bhutta, Zulfiqar; Biryukov, Stan; Brauer, M.; Burnett, Richard; Cercy, Kelly; Charlson, Fiona J.; Geleijnse, J.M.

    2016-01-01

    Background
    The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform

  3. Direct Power Control for Three-Phase Two-Level Voltage-Source Rectifiers Based on Extended-State Observation

    DEFF Research Database (Denmark)

    Song, Zhanfeng; Tian, Yanjun; Yan, Zhuo

    2016-01-01

    This paper proposed a direct power control strategy for three-phase two-level voltage-source rectifiers based on extended-state observation. Active and reactive powers are directly regulated in the stationary reference frame. Similar to the family of predictive controllers whose inherent characte......This paper proposed a direct power control strategy for three-phase two-level voltage-source rectifiers based on extended-state observation. Active and reactive powers are directly regulated in the stationary reference frame. Similar to the family of predictive controllers whose inherent...

  4. The Population Inversion and the Entropy of a Moving Two-Level Atom in Interaction with a Quantized Field

    Science.gov (United States)

    Abo-Kahla, D. A. M.; Abdel-Aty, M.; Farouk, A.

    2018-05-01

    An atom with only two energy eigenvalues is described by a two-dimensional state space spanned by the two energy eigenstates is called a two-level atom. We consider the interaction between a two-level atom system with a constant velocity. An analytic solution of the systems which interacts with a quantized field is provided. Furthermore, the significant effect of the temperature on the atomic inversion, the purity and the information entropy are discussed in case of the initial state either an exited state or a maximally mixed state. Additionally, the effect of the half wavelengths number of the field-mode is investigated.

  5. 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...... or management. Both the Accelerate Wales and the Accelerate Cluster programmes target this issue by trying to establish networks between companies that can be used to supply knowledge from research institutions to manufacturing companies. The paper concludes that public sector interventions can make...... businesses. The universities were not considered by the participating companies to be important parts of the local business environment and inputs from universities did not appear to be an important source to access knowledge about new product development or new techniques in production, distribution...

  6. 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,...

  7. Cluster analysis

    OpenAIRE

    Mucha, Hans-Joachim; Sofyan, Hizir

    2000-01-01

    As an explorative technique, duster analysis provides a description or a reduction in the dimension of the data. It classifies a set of observations into two or more mutually exclusive unknown groups based on combinations of many variables. Its aim is to construct groups in such a way that the profiles of objects in the same groups are relatively homogenous whereas the profiles of objects in different groups are relatively heterogeneous. Clustering is distinct from classification techniques, ...

  8. Quality of care, risk management, and technology in obstetrics to reduce hospital-based maternal mortality in Senegal and Mali (QUARITE): a cluster-randomised trial.

    Science.gov (United States)

    Dumont, Alexandre; Fournier, Pierre; Abrahamowicz, Michal; Traoré, Mamadou; Haddad, Slim; Fraser, William D

    2013-07-13

    Maternal mortality is higher in west Africa than in most industrialised countries, so the development and validation of effective interventions is essential. We did a trial to assess the effect of a multifaceted intervention to promote maternity death reviews and onsite training in emergency obstetric care in referral hospitals with high maternal mortality rates in Senegal and Mali. We did a pragmatic cluster-randomised controlled trial, with hospitals as the units of randomisation and patients as the unit of analysis. 46 public first-level and second-level referral hospitals with more than 800 deliveries a year were enrolled, stratified by country and hospital type, and randomly assigned to either the intervention group (n=23) or the control group with no external intervention (n=23). All women who delivered in each of the participating facilities during the baseline and post-intervention periods were included. The intervention, implemented over a period of 2 years at the hospital level, consisted of an initial interactive workshop and quarterly educational clinically-oriented and evidence-based outreach visits focused on maternal death reviews and best practices implementation. The primary outcome was reduction of risk of hospital-based mortality. Analysis was by intention-to-treat and relied on the generalised estimating equations extension of the logistic regression model to account for clustering of women within hospitals. This study is registered with ClinicalTrials.gov, number ISRCTN46950658. 191,167 patients who delivered in the participating hospitals were analysed (95,931 in the intervention groups and 95,236 in the control groups). Overall, mortality reduction in intervention hospitals was significantly higher than in control hospitals (odds ratio [OR] 0·85, 95% CI 0·73-0·98, p=0·0299), but this effect was limited to capital and district hospitals, which mainly acted as first-level referral hospitals in this trial. There was no effect in second

  9. Clustering of Sun Exposure Measurements

    OpenAIRE

    Have, Anna Szynkowiak; Larsen, Jan; Hansen, Lars Kai; Philipsen, Peter Alshede; Thieden, Elisabeth; Wulf, Hans Christian

    2002-01-01

    In a medically motivated Sun-exposure study, questionnaires concerning Sun-habits were collected from a number of subjects together with UV radiation measurements. This paper focuses on identifying clusters in the heterogeneous set of data for the purpose of understanding possible relations between Sun-habits exposure and eventually assessing the risk of skin cancer. A general probabilistic framework originally developed for text and Web mining is demonstrated to be useful for clustering of b...

  10. Open quantum systems and the two-level atom interacting with a single mode of the electromagnetic field

    International Nuclear Information System (INIS)

    Sandulescu, A.; Stefanescu, E.

    1987-07-01

    On the basis of Lindblad theory of open quantum systems we obtain new optical equations for the system of two-level atom interacting with a single mode of the electromagnetic field. The conventional Block equations in a generalized form with field phases are obtained in the hypothesis that all the terms are slowly varying in the rotating frame.(authors)

  11. Analytical Design of Passive LCL Filter for Three-phase Two-level Power Factor Correction Rectifiers

    DEFF Research Database (Denmark)

    Kouchaki, Alireza; Nymand, Morten

    2017-01-01

    This paper proposes a comprehensive analytical LCL filter design method for three-phase two-level power factor correction rectifiers (PFCs). The high frequency converter current ripple generates the high frequency current harmonics that need to be attenuated with respect to the grid standards...

  12. Quantum driving protocols for a two-level system: From generalized Landau-Zener sweeps to transitionless control

    DEFF Research Database (Denmark)

    Malossi, Nicola; Bason, Mark George; Viteau, Matthieu

    2013-01-01

    We present experimental results on the preparation of a desired quantum state in a two-level system with the maximum possible fidelity using driving protocols ranging from generalizations of the linear Landau-Zener protocol to transitionless driving protocols that ensure perfect following of the ...

  13. QUARITE (quality of care, risk management and technology in obstetrics: a cluster-randomized trial of a multifaceted intervention to improve emergency obstetric care in Senegal and Mali

    Directory of Open Access Journals (Sweden)

    Gaye Alioune

    2009-09-01

    Full Text Available Abstract Background Maternal and perinatal mortality are major problems for which progress in sub-Saharan Africa has been inadequate, even though childbirth services are available, even in the poorest countries. Reducing them is the aim of two of the main Millennium Development Goals. Many initiatives have been undertaken to remedy this situation, such as the Advances in Labour and Risk Management (ALARM International Program, whose purpose is to improve the quality of obstetric services in low-income countries. However, few interventions have been evaluated, in this context, using rigorous methods for analyzing effectiveness in terms of health outcomes. The objective of this trial is to evaluate the effectiveness of the ALARM International Program (AIP in reducing maternal mortality in referral hospitals in Senegal and Mali. Secondary goals include evaluation of the relationships between effectiveness and resource availability, service organization, medical practices, and satisfaction among health personnel. Methods/Design This is an international, multi-centre, controlled cluster-randomized trial of a complex intervention. The intervention is based on the concept of evidence-based practice and on a combination of two approaches aimed at improving the performance of health personnel: 1 Educational outreach visits; and 2 the implementation of facility-based maternal death reviews. The unit of intervention is the public health facility equipped with a functional operating room. On the basis of consent provided by hospital authorities, 46 centres out of 49 eligible were selected in Mali and Senegal. Using randomization stratified by country and by level of care, 23 centres will be allocated to the intervention group and 23 to the control group. The intervention will last two years. It will be preceded by a pre-intervention one-year period for baseline data collection. A continuous clinical data collection system has been set up in all

  14. QUARITE (quality of care, risk management and technology in obstetrics): a cluster-randomized trial of a multifaceted intervention to improve emergency obstetric care in Senegal and Mali.

    Science.gov (United States)

    Dumont, Alexandre; Fournier, Pierre; Fraser, William; Haddad, Slim; Traore, Mamadou; Diop, Idrissa; Gueye, Mouhamadou; Gaye, Alioune; Couturier, François; Pasquier, Jean-Charles; Beaudoin, François; Lalonde, André; Hatem, Marie; Abrahamowicz, Michal

    2009-09-18

    Maternal and perinatal mortality are major problems for which progress in sub-Saharan Africa has been inadequate, even though childbirth services are available, even in the poorest countries. Reducing them is the aim of two of the main Millennium Development Goals. Many initiatives have been undertaken to remedy this situation, such as the Advances in Labour and Risk Management (ALARM) International Program, whose purpose is to improve the quality of obstetric services in low-income countries. However, few interventions have been evaluated, in this context, using rigorous methods for analyzing effectiveness in terms of health outcomes. The objective of this trial is to evaluate the effectiveness of the ALARM International Program (AIP) in reducing maternal mortality in referral hospitals in Senegal and Mali. Secondary goals include evaluation of the relationships between effectiveness and resource availability, service organization, medical practices, and satisfaction among health personnel. This is an international, multi-centre, controlled cluster-randomized trial of a complex intervention. The intervention is based on the concept of evidence-based practice and on a combination of two approaches aimed at improving the performance of health personnel: 1) Educational outreach visits; and 2) the implementation of facility-based maternal death reviews. The unit of intervention is the public health facility equipped with a functional operating room. On the basis of consent provided by hospital authorities, 46 centres out of 49 eligible were selected in Mali and Senegal. Using randomization stratified by country and by level of care, 23 centres will be allocated to the intervention group and 23 to the control group. The intervention will last two years. It will be preceded by a pre-intervention one-year period for baseline data collection. A continuous clinical data collection system has been set up in all participating centres. This, along with the inventory of

  15. Does the addition of deep breathing exercises to physiotherapy-directed early mobilisation alter patient outcomes following high-risk open upper abdominal surgery? Cluster randomised controlled trial.

    Science.gov (United States)

    Silva, Y R; Li, S K; Rickard, M J F X

    2013-09-01

    To investigate whether the inclusion of deep breathing exercises in physiotherapy-directed early mobilisation confers any additional benefit in reducing postoperative pulmonary complications (PPCs) when patients are treated once daily after elective open upper abdominal surgery. This study also compared postoperative outcomes following early and delayed mobilisation. Cluster randomised controlled trial. Single-centre study in a teaching hospital. Eighty-six high-risk patients undergoing elective open upper abdominal surgery. Three groups: early mobilisation (Group A), early mobilisation plus breathing exercises (Group B), and delayed mobilisation (mobilised from third postoperative day) plus breathing exercises (Group C). PPCs and postoperative outcomes [number of days until discharge from physiotherapy, physiotherapy input and length of stay (LOS)]. There was no significant difference in PPCs between Groups A and B. The LOS for Group A {mean 10.7 [standard deviation (SD) 5.0] days} was significantly shorter than the LOS for Groups B [mean 16.7 (SD 9.7) days] and C [mean 15.2 (SD 9.8) days; P=0.036]. The greatest difference was between Groups A and B (mean difference -5.93, 95% confidence interval -10.22 to -1.65; P=0.008). Group C had fewer smokers (26%) and patients with chronic obstructive pulmonary disease (0%) compared with Group B (53% and 14%, respectively). This may have led to fewer PPCs in Group C, but the difference was not significant. Despite Group C having fewer PPCs and less physiotherapy input, the number of days until discharge from physiotherapy and LOS were similar to Group B. The addition of deep breathing exercises to physiotherapy-directed early mobilisation did not further reduce PPCs compared with mobility alone. PPCs can be reduced with once-daily physiotherapy if the patients are mobilised to a moderate level of exertion. Delayed mobilisation tended to increase physiotherapy input and the number of days until discharge from physiotherapy

  16. Reducing musculoskeletal injury and concussion risk in schoolboy rugby players with a pre-activity movement control exercise programme: a cluster randomised controlled trial.

    Science.gov (United States)

    Hislop, Michael D; Stokes, Keith A; Williams, Sean; McKay, Carly D; England, Mike E; Kemp, Simon P T; Trewartha, Grant

    2017-08-01

    Injury risk in youth rugby has received much attention, highlighting the importance of establishing evidence-based injury reduction strategies. To determine the efficacy of a movement control exercise programme in reducing injuries in youth rugby players and to investigate the effect of programme dose on injury measures. In a cluster-randomised controlled trial, 40 independent schools (118 teams, 3188 players aged 14-18 years) were allocated to receive either the intervention or a reference programme, both of which were to be delivered by school coaches. The intervention comprised balance training, whole-body resistance training, plyometric training, and controlled rehearsal of landing and cutting manoeuvres. Time-loss (>24 hours) injuries arising from school rugby matches were recorded by coaches and medical staff. 441 time-loss match injuries (intervention, 233; control, 208) were reported across 15 938 match exposure-hours (intervention, 9083; control, 6855). Intention-to-treat results indicated unclear effects of trial arm on overall match injury incidence (rate ratio (RR)=0.85, 90% confidence limits 0.61 to 1.17), although clear reductions were evident in the intervention arm for concussion incidence (RR=0.71, 0.48 to 1.05). When trial arm comparisons were limited to teams who had completed three or more weekly programme sessions on average, clear reductions in overall match injury incidence (RR=0.28, 0.14 to 0.51) and concussion incidence (RR=0.41, 0.17 to 0.99) were noted in the intervention group. A preventive movement control exercise programme can reduce match injury outcomes, including concussion, in schoolboy rugby players when compared with a standardised control exercise programme, although to realise the greatest effects players should complete the programme at least three times per week. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted

  17. PSCAD modeling of a two-level space vector pulse width modulation algorithm for power electronics education

    Directory of Open Access Journals (Sweden)

    Ahmet Mete Vural

    2016-09-01

    Full Text Available This paper presents the design details of a two-level space vector pulse width modulation algorithm in PSCAD that is able to generate pulses for three-phase two-level DC/AC converters with two different switching patterns. The presented FORTRAN code is generic and can be easily modified to meet many other kinds of space vector modulation strategies. The code is also editable for hardware programming. The new component is tested and verified by comparing its output as six gating signals with those of a similar component in MATLAB library. Moreover the component is used to generate digital signals for closed-loop control of STATCOM for reactive power compensation in PSCAD. This add-on can be an effective tool to give students better understanding of the space vector modulation algorithm for different control tasks in power electronics area, and can motivate them for learning.

  18. Non-Hermitian wave packet approximation for coupled two-level systems in weak and intense fields

    Energy Technology Data Exchange (ETDEWEB)

    Puthumpally-Joseph, Raiju; Charron, Eric [Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay (France); Sukharev, Maxim [Science and Mathematics Faculty, College of Letters and Sciences, Arizona State University, Mesa, Arizona 85212 (United States)

    2016-04-21

    We introduce a non-Hermitian Schrödinger-type approximation of optical Bloch equations for two-level systems. This approximation provides a complete and accurate description of the coherence and decoherence dynamics in both weak and strong laser fields at the cost of losing accuracy in the description of populations. In this approach, it is sufficient to propagate the wave function of the quantum system instead of the density matrix, providing that relaxation and dephasing are taken into account via automatically adjusted time-dependent gain and decay rates. The developed formalism is applied to the problem of scattering and absorption of electromagnetic radiation by a thin layer comprised of interacting two-level emitters.

  19. Minimax approach problem with incomplete information for the two-level hierarchical discrete-time dynamical system

    Energy Technology Data Exchange (ETDEWEB)

    Shorikov, A. F. [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002, Russia and Institute of Mathematics and Mechanics, Ural Division of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation)

    2014-11-18

    We consider a discrete-time dynamical system consisting of three controllable objects. The motions of all objects are given by the corresponding vector linear or convex discrete-time recurrent vector relations, and control system for its has two levels: basic (first or I level) that is dominating and subordinate level (second or II level) and both have different criterions of functioning and united a priori by determined informational and control connections defined in advance. For the dynamical system in question, we propose a mathematical formalization in the form of solving a multistep problem of two-level hierarchical minimax program control over the terminal approach process with incomplete information and give a general scheme for its solution.

  20. Adiabatic interpretation of a two-level atom diode, a laser device for unidirectional transmission of ground-state atoms

    International Nuclear Information System (INIS)

    Ruschhaupt, A.; Muga, J. G.

    2006-01-01

    We present a generalized two-level scheme for an 'atom diode', namely, a laser device that lets a two-level ground-state atom pass in one direction, say from left to right, but not in the opposite direction. The laser field is composed of two lateral state-selective mirror regions and a central pumping region. We demonstrate the robustness of the scheme and propose a physical realization. It is shown that the inclusion of a counterintuitive laser field blocking the excited atoms on the left side of the device is essential for a perfect diode effect. The reason for this, the diodic behavior, and the robustness may be understood with an adiabatic approximation. The conditions to break down the approximation, which imply also the diode failure, are analyzed

  1. Two-level MOC calculation scheme in APOLLO2 for cross-section library generation for LWR hexagonal assemblies

    International Nuclear Information System (INIS)

    Petrov, Nikolay; Todorova, Galina; Kolev, Nikola; Damian, Frederic

    2011-01-01

    The accurate and efficient MOC calculation scheme in APOLLO2, developed by CEA for generating multi-parameterized cross-section libraries for PWR assemblies, has been adapted to hexagonal assemblies. The neutronic part of this scheme is based on a two-level calculation methodology. At the first level, a multi-cell method is used in 281 energy groups for cross-section definition and self-shielding. At the second level, precise MOC calculations are performed in a collapsed energy mesh (30-40 groups). In this paper, the application and validation of the two-level scheme for hexagonal assemblies is described. Solutions for a VVER assembly are compared with TRIPOLI4® calculations and direct 281g MOC solutions. The results show that the accuracy is close to that of the 281g MOC calculation while the CPU time is substantially reduced. Compared to the multi-cell method, the accuracy is markedly improved. (author)

  2. Effectiveness of a selective intervention program targeting personality risk factors for alcohol misuse among young adolescents: results of a cluster randomized controlled trial

    NARCIS (Netherlands)

    Lammers, J.; Goossens, F.; Conrod, P.; Engels, R.C.M.E.; Wiers, R.W.H.J.; Kleinjan, M.

    2015-01-01

    Aim The effectiveness of Preventure was tested on drinking behaviour of young adolescents in secondary education in the Netherlands. Design A cluster randomized controlled trial was carried out, with participants assigned randomly to a two-session coping skills intervention or a control

  3. Nuclear clustering - a cluster core model study

    International Nuclear Information System (INIS)

    Paul Selvi, G.; Nandhini, N.; Balasubramaniam, M.

    2015-01-01

    Nuclear clustering, similar to other clustering phenomenon in nature is a much warranted study, since it would help us in understanding the nature of binding of the nucleons inside the nucleus, closed shell behaviour when the system is highly deformed, dynamics and structure at extremes. Several models account for the clustering phenomenon of nuclei. We present in this work, a cluster core model study of nuclear clustering in light mass nuclei

  4. Fabrication of Ni stamp with high aspect ratio, two-leveled, cylindrical microstructures using dry etching and electroplating

    DEFF Research Database (Denmark)

    Petersen, Ritika Singh; Keller, Stephan Sylvest; Hansen, Ole

    2015-01-01

    obtained by defining a reservoir and a separating trench with different depths of 85 and 125 μm, respectively, in a single embossing step. The fabrication of the required two leveled stamp is done using a modified DEEMO (dry etching, electroplating and molding) process. Dry etching using the Bosch process...... and electroplating are optimized to obtain a stamp with smooth stamp surfaces and a positive sidewall profile. Using this stamp, hot embossing is performed successfully with excellent yield and high replication fidelity....

  5. An EOQ Model with Stock-Dependent Demand under Two Levels of Trade Credit and Time Value of Money

    OpenAIRE

    H.A.O. Jia-Qin; M.O. Jiangtao

    2013-01-01

    Since the value of money changes with time, it is necessary to take account of the influence of time factor in making the replenishment policy. In this study, to investigate the influence of the time value of money to the inventory strategy, an inventory system for deteriorating items with stock-dependent demand is investigated under two levels of trade credit. The method to efficiently determine the optimal cycle time is presented. Numerical examples are provided to demonstrate the model and...

  6. Coherent control of the group velocity in a dielectric slab doped with duplicated two-level atoms

    Science.gov (United States)

    Ziauddin; Chuang, You-Lin; Lee, Ray-Kuang; Qamar, Sajid

    2016-01-01

    Coherent control of reflected and transmitted pulses is investigated theoretically through a slab doped with atoms in a duplicated two-level configuration. When a strong control field and a relatively weak probe field are employed, coherent control of the group velocity is achieved via changing the phase shift ϕ between control and probe fields. Furthermore, the peak values in the delay time of the reflected and transmitted pulses are also studied by varying the phase shift ϕ.

  7. Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

    Institute of Scientific and Technical Information of China (English)

    Zhang Jian; Shao Bin; Zou Jian

    2009-01-01

    In this paper,we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling.We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially.The effects of the field squeezing factor,the two-level atomic transition frequency,the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed.Without intrinsic decoherence,the increase of field squeezing factor can break the entropy squeezing.The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing.The influence of the second field frequency is complicated.With the intrinsic decoherence taken into consideration,the results show that the stronger the intrinsic decoherence is,the more quickly the entropy squeezing will disappear.The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing.

  8. Asynchronous Two-Level Checkpointing Scheme for Large-Scale Adjoints in the Spectral-Element Solver Nek5000

    Energy Technology Data Exchange (ETDEWEB)

    Schanen, Michel; Marin, Oana; Zhang, Hong; Anitescu, Mihai

    2016-01-01

    Adjoints are an important computational tool for large-scale sensitivity evaluation, uncertainty quantification, and derivative-based optimization. An essential component of their performance is the storage/recomputation balance in which efficient checkpointing methods play a key role. We introduce a novel asynchronous two-level adjoint checkpointing scheme for multistep numerical time discretizations targeted at large-scale numerical simulations. The checkpointing scheme combines bandwidth-limited disk checkpointing and binomial memory checkpointing. Based on assumptions about the target petascale systems, which we later demonstrate to be realistic on the IBM Blue Gene/Q system Mira, we create a model of the expected performance of our checkpointing approach and validate it using the highly scalable Navier-Stokes spectralelement solver Nek5000 on small to moderate subsystems of the Mira supercomputer. In turn, this allows us to predict optimal algorithmic choices when using all of Mira. We also demonstrate that two-level checkpointing is significantly superior to single-level checkpointing when adjoining a large number of time integration steps. To our knowledge, this is the first time two-level checkpointing had been designed, implemented, tuned, and demonstrated on fluid dynamics codes at large scale of 50k+ cores.

  9. Performance and meat quality traits of beef heifers fed with two levels of concentrate and ruminally undegradable protein.

    Science.gov (United States)

    Duarte, Marcio de Souza; Paulino, Pedro Veiga Rodrigues; Valadares Filho, Sebastião de Campos; Paulino, Mario Fonseca; Detmann, Edenio; Zervoudakis, Joanis Tilemahos; Monnerat, João Paulo Ismerio dos Santos; Viana, Gabriel da Silva; Silva, Luiz Henrique P; Serão, Nicola Vergara Lopes

    2011-04-01

    The effects of two levels of concentrate and ruminally undegradable protein (RUP) on performance, intake, digestibility, carcass characteristics, meat quality traits, and commercial cuts yield were assessed. Twenty crossbred heifers (240 kg average body weight) were used. At the beginning of the trial, four animals were slaughtered as reference group and the 16 remaining animals were randomly assigned to four treatments, in a 2 × 2 factorial design: two levels of concentrate (40% and 80%, dry matter (DM) basis) and two levels of RUP (48.79% and 27.19% of CP). At the end of the trial, all the animals were slaughtered. There was no interaction (P > 0.05) between concentrate and RUP levels. Dry matter intake and nutrients digestibility was not affected (P > 0.05) by RUP level. Heifers fed the highest RUP level had greater (P  0.05) DMI and ADG. Heifers fed diets with 80% concentrate had greater intake of TDN and EE, and lower intake of NDF (P RUP levels did not affect (P > 0.05) the carcass characteristics and carcass gain composition. Heifers fed 80% concentrate diets had larger (P  0.05) the composition of carcass gain. There was no effect (P > 0.05) of RUP and concentrate levels on meat quality traits and commercial cut yields.

  10. Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

    International Nuclear Information System (INIS)

    Jian, Zhang; Bin, Shao; Jian, Zou

    2009-01-01

    In this paper, we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling. We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially. The effects of the field squeezing factor, the two-level atomic transition frequency, the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed. Without intrinsic decoherence, the increase of field squeezing factor can break the entropy squeezing. The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing. The influence of the second field frequency is complicated. With the intrinsic decoherence taken into consideration, the results show that the stronger the intrinsic decoherence is, the more quickly the entropy squeezing will disappear. The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing. (classical areas of phenomenology)

  11. An Indication of Reliability of the Two-Level Approach of the AWIN Welfare Assessment Protocol for Horses

    Directory of Open Access Journals (Sweden)

    Irena Czycholl

    2018-01-01

    Full Text Available To enhance feasibility, the Animal Welfare Indicators (AWIN assessment protocol for horses consists of two levels: the first is a visual inspection of a sample of horses performed from a distance, the second a close-up inspection of all horses. The aim was to analyse whether information would be lost if only the first level were performed. In this study, 112 first and 112 second level assessments carried out on a subsequent day by one observer were compared by calculating the Spearman’s Rank Correlation Coefficient (RS, Intraclass Correlation Coefficients (ICC, Smallest Detectable Changes (SDC and Limits of Agreements (LoA. Most indicators demonstrated sufficient reliability between the two levels. Exceptions were the Horse Grimace Scale, the Avoidance Distance Test and the Voluntary Human Approach Test (e.g., Voluntary Human Approach Test: RS: 0.38, ICC: 0.38, SDC: 0.21, LoA: −0.25–0.17, which could, however, be also interpreted as a lack of test-retest reliability. Further disagreement was found for the indicator consistency of manure (RS: 0.31, ICC: 0.38, SDC: 0.36, LoA: −0.38–0.36. For these indicators, an adaptation of the first level would be beneficial. Overall, in this study, the division into two levels was reliable and might therewith have the potential to enhance feasibility in other welfare assessment schemes.

  12. Identification of Urban Leprosy Clusters

    Directory of Open Access Journals (Sweden)

    José Antonio Armani Paschoal

    2013-01-01

    Full Text Available Overpopulation of urban areas results from constant migrations that cause disordered urban growth, constituting clusters defined as sets of people or activities concentrated in relatively small physical spaces that often involve precarious conditions. Aim. Using residential grouping, the aim was to identify possible clusters of individuals in São José do Rio Preto, Sao Paulo, Brazil, who have or have had leprosy. Methods. A population-based, descriptive, ecological study using the MapInfo and CrimeStat techniques, geoprocessing, and space-time analysis evaluated the location of 425 people treated for leprosy between 1998 and 2010. Clusters were defined as concentrations of at least 8 people with leprosy; a distance of up to 300 meters between residences was adopted. Additionally, the year of starting treatment and the clinical forms of the disease were analyzed. Results. Ninety-eight (23.1% of 425 geocoded cases were located within one of ten clusters identified in this study, and 129 cases (30.3% were in the region of a second-order cluster, an area considered of high risk for the disease. Conclusion. This study identified ten clusters of leprosy cases in the city and identified an area of high risk for the appearance of new cases of the disease.

  13. Identification of Urban Leprosy Clusters

    Science.gov (United States)

    Paschoal, José Antonio Armani; Paschoal, Vania Del'Arco; Nardi, Susilene Maria Tonelli; Rosa, Patrícia Sammarco; Ismael, Manuela Gallo y Sanches; Sichieri, Eduvaldo Paulo

    2013-01-01

    Overpopulation of urban areas results from constant migrations that cause disordered urban growth, constituting clusters defined as sets of people or activities concentrated in relatively small physical spaces that often involve precarious conditions. Aim. Using residential grouping, the aim was to identify possible clusters of individuals in São José do Rio Preto, Sao Paulo, Brazil, who have or have had leprosy. Methods. A population-based, descriptive, ecological study using the MapInfo and CrimeStat techniques, geoprocessing, and space-time analysis evaluated the location of 425 people treated for leprosy between 1998 and 2010. Clusters were defined as concentrations of at least 8 people with leprosy; a distance of up to 300 meters between residences was adopted. Additionally, the year of starting treatment and the clinical forms of the disease were analyzed. Results. Ninety-eight (23.1%) of 425 geocoded cases were located within one of ten clusters identified in this study, and 129 cases (30.3%) were in the region of a second-order cluster, an area considered of high risk for the disease. Conclusion. This study identified ten clusters of leprosy cases in the city and identified an area of high risk for the appearance of new cases of the disease. PMID:24288467

  14. Comparison of Cervical Kinematics, Pain, and Functional Disability Between Single- and Two-level Anterior Cervical Discectomy and Fusion.

    Science.gov (United States)

    Chien, Andy; Lai, Dar-Ming; Wang, Shwu-Fen; Hsu, Wei-Li; Cheng, Chih-Hsiu; Wang, Jaw-Lin

    2016-08-01

    A prospective, time series design. The purpose of this study is two-fold: firstly, to investigate the impact of altered cervical alignment and range of motion (ROM) on patients' self-reported outcomes after anterior cervical discectomy and fusion (ACDF), and secondly, to comparatively differentiate the influence of single- and two-level ACDF on the cervical ROM and adjacent segmental kinematics up to 12-month postoperatively. ACDF is one of the most commonly employed surgical interventions to treat degenerative disc disease. However, there are limited in vivo data on the impact of ACDF on the cervical kinematics and its association with patient-reported clinical outcomes. Sixty-two patients (36 males; 55.63 ± 11.6 yrs) undergoing either a single- or consecutive two-level ACDF were recruited. The clinical outcomes were assessed with the Pain Visual Analogue Scale (VAS) and the Neck Disability Index (NDI). Radiological results included cervical lordosis, global C2-C7 ROM, ROM of the Functional Spinal Unit (FSU), and its adjacent segments. The outcome measures were collected preoperatively and then at 3, 6, and 12-month postoperatively. A significant reduction of both VAS and NDI was found for both groups from the preoperative to 3-month period (P < 0.01). Pearson correlation revealed no significant correlation between global ROM with neither VAS (P = 0.667) nor NDI (P = 0.531). A significant reduction of global ROM was identified for the two-level ACDF group at 12 months (P = 0.017) but not for the single-level group. A significant interaction effect was identified for the upper adjacent segment ROM (P = 0.024) but not at the lower adjacent segment. Current study utilized dynamic radiographs to comparatively evaluate the biomechanical impact of single- and two-level ACDF. The results highlighted that the two-level group demonstrated a greater reduction of global ROM coupled with an increased upper adjacent segmental compensatory motions that

  15. Effects of PREPARE, a Multi-component, School-Based HIV and Intimate Partner Violence (IPV) Prevention Programme on Adolescent Sexual Risk Behaviour and IPV: Cluster Randomised Controlled Trial.

    Science.gov (United States)

    Mathews, Catherine; Eggers, Sander M; Townsend, Loraine; Aarø, Leif E; de Vries, Petrus J; Mason-Jones, Amanda J; De Koker, Petra; McClinton Appollis, Tracy; Mtshizana, Yolisa; Koech, Joy; Wubs, Annegreet; De Vries, Hein

    2016-09-01

    Young South Africans, especially women, are at high risk of HIV. We evaluated the effects of PREPARE, a multi-component, school-based HIV prevention intervention to delay sexual debut, increase condom use and decrease intimate partner violence (IPV) among young adolescents. We conducted a cluster RCT among Grade eights in 42 high schools. The intervention comprised education sessions, a school health service and a school sexual violence prevention programme. Participants completed questionnaires at baseline, 6 and 12 months. Regression was undertaken to provide ORs or coefficients adjusted for clustering. Of 6244 sampled adolescents, 55.3 % participated. At 12 months there were no differences between intervention and control arms in sexual risk behaviours. Participants in the intervention arm were less likely to report IPV victimisation (35.1 vs. 40.9 %; OR 0.77, 95 % CI 0.61-0.99; t(40) = 2.14) suggesting the intervention shaped intimate partnerships into safer ones, potentially lowering the risk for HIV.

  16. A multifaceted strategy using mobile technology to assist rural primary healthcare doctors and frontline health workers in cardiovascular disease risk management: protocol for the SMARTHealth India cluster randomised controlled trial.

    Science.gov (United States)

    Praveen, Devarsetty; Patel, Anushka; McMahon, Stephen; Prabhakaran, Dorairaj; Clifford, Gari D; Maulik, Pallab K; Joshi, Rohina; Jan, Stephen; Heritier, Stephane; Peiris, David

    2013-11-25

    Blood Pressure related disease affected 118 million people in India in the year 2000; this figure will double by 2025. Around one in four adults in rural India have hypertension, and of those, only a minority are accessing appropriate care. Health systems in India face substantial challenges to meet these gaps in care, and innovative solutions are needed. We hypothesise that a multifaceted intervention involving capacity strengthening of primary healthcare doctors and non-physician healthcare workers through use of a mobile device-based clinical decision support system will result in improved blood pressure control for individuals at high risk of a cardiovascular disease event when compared with usual healthcare. This intervention will be implemented as a stepped wedge, cluster randomised controlled trial in 18 primary health centres and 54 villages in rural Andhra Pradesh involving adults aged ≥40 years at high cardiovascular disease event risk (approximately 15,000 people). Cardiovascular disease event risk will be calculated based on World Health Organisation/International Society of Hypertension's region-specific risk charts. Cluster randomisation will occur at the level of the primary health centres. Outcome analyses will be conducted blinded to intervention allocation. The primary study outcome is the difference in the proportion of people meeting guideline-recommended blood pressure targets in the intervention period vs. the control period. Secondary outcomes include mean reduction in blood pressure levels; change in other cardiovascular disease risk factors, including body mass index, current smoking, reported healthy eating habits, and reported physical activity levels; self-reported use of blood pressure and other cardiovascular medicines; quality of life (using the EQ-5D); and cardiovascular disease events (using hospitalisation data). Trial outcomes will be accompanied by detailed process and economic evaluations. The findings are likely to inform

  17. 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

  18. Two-level anterior lumbar interbody fusion with percutaneous pedicle screw fixation. A minimum 3-year follow-up study

    International Nuclear Information System (INIS)

    Lee, Dong-Yeob; Lee, Sang-Ho; Maeng, Dae-Hyeon

    2010-01-01

    The clinical and radiological outcomes of two-level anterior lumbar interbody fusion (ALIF) with percutaneous pedicle screw fixation (PSF) were evaluated in 24 consecutive patients who underwent two level ALIF with percutaneous PSF for segmental instability and were followed up for more than 3 years. Clinical outcomes were assessed using a visual analogue scale (VAS) score and the Oswestry Disability Index (ODI). Sagittal alignment, bone union, and adjacent segment degeneration (ASD) were assessed using radiography and magnetic resonance imaging. The mean age of the patients at the time of operation was 56.3 years (range 39-70 years). Minor complications occurred in 2 patients in the perioperative period. At a mean follow-up duration of 39.4 months (range 36-42 months), VAS scores for back pain and leg pain, and ODI score decreased significantly (from 6.5, 6.8, and 46.9% to 3.0, 1.9, and 16.3%, respectively). Clinical success was achieved in 22 of the 24 patients. The mean segmental lordosis, whole lumbar lordosis, and sacral tilt significantly increased after surgery (from 25.1deg, 39.2deg, and 32.6deg to 32.9deg, 44.5deg, and 36.6deg, respectively). Solid fusion was achieved in 21 patients. ASD was found in 8 of the 24 patients. No patient underwent revision surgery due to nonunion or ASD. Two-level ALIF with percutaneous PSF yielded satisfactory clinical and radiological outcomes and could be a useful alternative to posterior fusion surgery. (author)

  19. Two-level anterior lumbar interbody fusion with percutaneous pedicle screw fixation. A minimum 3-year follow-up study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong-Yeob; Lee, Sang-Ho; Maeng, Dae-Hyeon [Wooridul Spine Hospital, Seoul (Korea, Republic of)

    2010-08-15

    The clinical and radiological outcomes of two-level anterior lumbar interbody fusion (ALIF) with percutaneous pedicle screw fixation (PSF) were evaluated in 24 consecutive patients who underwent two level ALIF with percutaneous PSF for segmental instability and were followed up for more than 3 years. Clinical outcomes were assessed using a visual analogue scale (VAS) score and the Oswestry Disability Index (ODI). Sagittal alignment, bone union, and adjacent segment degeneration (ASD) were assessed using radiography and magnetic resonance imaging. The mean age of the patients at the time of operation was 56.3 years (range 39-70 years). Minor complications occurred in 2 patients in the perioperative period. At a mean follow-up duration of 39.4 months (range 36-42 months), VAS scores for back pain and leg pain, and ODI score decreased significantly (from 6.5, 6.8, and 46.9% to 3.0, 1.9, and 16.3%, respectively). Clinical success was achieved in 22 of the 24 patients. The mean segmental lordosis, whole lumbar lordosis, and sacral tilt significantly increased after surgery (from 25.1deg, 39.2deg, and 32.6deg to 32.9deg, 44.5deg, and 36.6deg, respectively). Solid fusion was achieved in 21 patients. ASD was found in 8 of the 24 patients. No patient underwent revision surgery due to nonunion or ASD. Two-level ALIF with percutaneous PSF yielded satisfactory clinical and radiological outcomes and could be a useful alternative to posterior fusion surgery. (author)

  20. Entropy squeezing for a two-level atom in the Jaynes-Cummings model with an intensity-depend coupling

    Institute of Scientific and Technical Information of China (English)

    李春先; 方卯发

    2003-01-01

    We study the squeezing for a two-level atom in the Jaynes-Cummings model with intensity-dependent coupling using quantum information entropy, and examine the influences of the initial state of the system on the squeezed component number and direction of the information entropy squeezing. Our results show that, the squeezed component number depends on the atomic initial distribution angle, while the squeezed direction is determined by both the phases of the atom and the field for the information entropy squeezing. Quantum information entropy is shown to be a remarkable precision measure for atomic squeezing.

  1. Entropy as a measure of the noise extent in a two-level quantum feedback controlled system

    Institute of Scientific and Technical Information of China (English)

    Wang Tao-Bo; Fang Mao-Fa; Hu Yao-Hua

    2007-01-01

    By introducing the von Neumann entropy as a measure of the extent of noise, this paper discusses the entropy evolution in a two-level quantum feedback controlled system. The results show that the feedback control can induce the reduction of the degree of noise, and different control schemes exhibit different noise controlling ability, the extent of the reduction also related with the position of the target state on the Bloch sphere. It is shown that the evolution of entropy can provide a real time noise observation and a systematic guideline to make reasonable choice of control strategy.

  2. Comparison of PI and PR current controllers applied on two-level VSC-HVDC transmission system

    DEFF Research Database (Denmark)

    Manoloiu, A.; Pereria, H.A.; Teodorescu, Remus

    2015-01-01

    This paper analyzes differences between αβ and dq reference frames regarding the control of two-level VSC-HVDC current loop and dc-link voltage outer loop. In the first part, voltage feedforward effect is considered with PI and PR controllers. In the second part, the feedforward effect is removed...... and the PR gains are tuned to keep the dynamic performance. Also, the power feedforward is removed and the outer loop PI controller is tuned in order to maintain the system dynamic performance. The paper is completed with simulation results, which highlight the advantages of using PR controller....

  3. On the deviation from the sech2 superradiant emission law in a two-level atomic system

    International Nuclear Information System (INIS)

    Goncalves, A.E.

    1990-01-01

    The atomic superradiant emission is treated in the single particle mean field approximation. A single particle Hamiltonian, which represents a dressed two-level atom in a radiation field, can be obtained and it is verified that it describes the transient regime of the emission process. While the line shape emission for a bare atom follows the sech 2 law, for the dressed atom the line shape deviates appreciably from this law and it is verified that the deviation depends crucially on the ratio of the dynamic frequency shift to the transition frequency. This kind of deviation is observed in experimental results. (Author) [pt

  4. 2L-PCA: a two-level principal component analyzer for quantitative drug design and its applications.

    Science.gov (United States)

    Du, Qi-Shi; Wang, Shu-Qing; Xie, Neng-Zhong; Wang, Qing-Yan; Huang, Ri-Bo; Chou, Kuo-Chen

    2017-09-19

    A two-level principal component predictor (2L-PCA) was proposed based on the principal component analysis (PCA) approach. It can be used to quantitatively analyze various compounds and peptides about their functions or potentials to become useful drugs. One level is for dealing with the physicochemical properties of drug molecules, while the other level is for dealing with their structural fragments. The predictor has the self-learning and feedback features to automatically improve its accuracy. It is anticipated that 2L-PCA will become a very useful tool for timely providing various useful clues during the process of drug development.

  5. Cluster analysis for portfolio optimization

    OpenAIRE

    Vincenzo Tola; Fabrizio Lillo; Mauro Gallegati; Rosario N. Mantegna

    2005-01-01

    We consider the problem of the statistical uncertainty of the correlation matrix in the optimization of a financial portfolio. We show that the use of clustering algorithms can improve the reliability of the portfolio in terms of the ratio between predicted and realized risk. Bootstrap analysis indicates that this improvement is obtained in a wide range of the parameters N (number of assets) and T (investment horizon). The predicted and realized risk level and the relative portfolio compositi...

  6. Brightest Cluster Galaxies in REXCESS Clusters

    Science.gov (United States)

    Haarsma, Deborah B.; Leisman, L.; Bruch, S.; Donahue, M.

    2009-01-01

    Most galaxy clusters contain a Brightest Cluster Galaxy (BCG) which is larger than the other cluster ellipticals and has a more extended profile. In the hierarchical model, the BCG forms through many galaxy mergers in the crowded center of the cluster, and thus its properties give insight into the assembly of the cluster as a whole. In this project, we are working with the Representative XMM-Newton Cluster Structure Survey (REXCESS) team (Boehringer et al 2007) to study BCGs in 33 X-ray luminous galaxy clusters, 0.055 < z < 0.183. We are imaging the BCGs in R band at the Southern Observatory for Astrophysical Research (SOAR) in Chile. In this poster, we discuss our methods and give preliminary measurements of the BCG magnitudes, morphology, and stellar mass. We compare these BCG properties with the properties of their host clusters, particularly of the X-ray emitting gas.

  7. 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...

  8. Risk

    Science.gov (United States)

    Cole, Stephen R.; Hudgens, Michael G.; Brookhart, M. Alan; Westreich, Daniel

    2015-01-01

    The epidemiologist primarily studies transitions between states of health and disease. The purpose of the present article is to define a foundational parameter for such studies, namely risk. We begin simply and build to the setting in which there is more than 1 event type (i.e., competing risks or competing events), as well as more than 1 treatment or exposure level of interest. In the presence of competing events, the risks are a set of counterfactual cumulative incidence functions for each treatment. These risks can be depicted visually and summarized numerically. We use an example from the study of human immunodeficiency virus to illustrate concepts. PMID:25660080

  9. A Two-Level Sensorless MPPT Strategy Using SRF-PLL on a PMSG Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Amina Echchaachouai

    2017-01-01

    Full Text Available In this paper, a two-level sensorless Maximum Power Point Tracking (MPPT strategy is presented for a variable speed Wind Energy Conversion System (WECS. The proposed system is composed of a wind turbine, a direct-drive Permanent Magnet Synchronous Generator (PMSG and a three phase controlled rectifier connected to a DC load. The realised generator output power maximization analysis justifies the use of the Field Oriented Control (FOC giving the six Pulse Width Modulation (PWM signals to the active rectifier. The generator rotor speed and position required by the FOC and the sensorless MPPT are estimated using a Synchronous Reference Frame Phase Locked Loop (SRF-PLL. The MPPT strategy used consists of two levels, the first level is a power regulation loop and the second level is an extremum seeking bloc generating the coefficient gathering the turbine characteristics. Experimental results validated on a hardware test setup using a DSP digital board (dSPACE 1104 are presented. Figures illustrating the estimated speed and angle confirm that the SRF-PLL is able to give an estimated speed and angle which closely follow the real ones. Also, the power at the DC load and the power at the generator output indicate that the MPPT gives optimum extracted power. Finally, other results show the effectiveness of the adopted approach in real time applications.

  10. Transverse magnetic field effect on the giant Goos–Hänchen shifts based on a degenerate two-level system

    Science.gov (United States)

    Nasehi, R.

    2018-06-01

    We study the effect of the Goos–Hänchen (GH) shifts through a cavity with degenerate two-level systems in the line of . For this purpose, we focus on the transverse magnetic field (TMF) in a Floquet frame to obtain the giant GH shifts. Physically, the collisional effects of TMF lead to increasing the population trapping in the ground state. However, we demonstrate that the population trapping generates the large negative or positive GH shifts and simultaneously switches from superluminal to subluminal (or vice versa). Also, we investigate the other optical properties such as the longitudinal magnetic field (LMF), which plays an important role in the control of the GH shifts and leads to the generation of new subsystems. In the next step, we evaluate the GH shifts beyond the multi-photon resonance condition by the control of TMF. Moreover, we compute the appearance of negative and positive GH shifts by setting the width of the incident Gaussian beams in the presence of a multi-photon resonance condition. Our results show that superluminal or subluminal light propagation can be simultaneously controlled by adjusting the rates of the TMF and LMF. The significant effects of these factors on the degenerate two-level systems provide different applications such as slow light, optical switches and quantum information storage.

  11. Political legitimacy and European monetary union: contracts, constitutionalism and the normative logic of two-level games

    Science.gov (United States)

    Bellamy, Richard; Weale, Albert

    2015-01-01

    ABSTRACT The crisis of the euro area has severely tested the political authority of the European Union (EU). The crisis raises questions of normative legitimacy both because the EU is a normative order and because the construction of economic and monetary union (EMU) rested upon a theory that stressed the normative value of the depoliticization of money. However, this theory neglected the normative logic of the two-level game implicit in EMU. It also neglected the need for an impartial and publically acceptable constitutional order to acknowledge reasonable disagreements. By contrast, we contend that any reconstruction of the EU's economic constitution has to pay attention to reconciling a European monetary order with the legitimacy of member state governance. The EU requires a two-level contract to meet this standard. Member states must treat each other as equals and be representative of and accountable to their citizens on an equitable basis. These criteria entail that the EU's political legitimacy requires a form of demoicracy that we call ‘republican intergovernmentalism’. Only rules that could be acceptable as the product of a political constitution among the peoples of Europe can ultimately meet the required standards of political legitimacy. Such a political constitution could be brought about through empowering national parliaments in EU decision-making. PMID:26924935

  12. Experimental study of magnetocaloric effect in the two-level quantum system KTm(MoO4)2

    Science.gov (United States)

    Tarasenko, R.; Tkáč, V.; Orendáčová, A.; Orendáč, M.; Valenta, J.; Sechovský, V.; Feher, A.

    2018-05-01

    KTm(MoO4)2 belongs to the family of binary alkaline rare-earth molybdates. This compound can be considered to be an almost ideal quantum two-level system at low temperatures. Magnetocaloric properties of KTm(MoO4)2 single crystals were investigated using specific heat and magnetization measurement in the magnetic field applied along the easy axis. Large conventional magnetocaloric effect (-ΔSM ≈ 10.3 J/(kg K)) was observed in the magnetic field of 5 T in a relatively wide temperature interval. The isothermal magnetic entropy change of about 8 J/(kgK) has been achieved already for the magnetic field of 2 T. Temperature dependence of the isothermal entropy change under different magnetic fields is in good agreement with theoretical predictions for a quantum two-level system with Δ ≈ 2.82 cm-1. Investigation of magnetocaloric properties of KTm(MoO4)2 suggests that the studied system can be considered as a good material for magnetic cooling at low temperatures.

  13. Optimal control of quantum gates and suppression of decoherence in a system of interacting two-level particles

    International Nuclear Information System (INIS)

    Grace, Matthew; Brif, Constantin; Rabitz, Herschel; Walmsley, Ian A; Kosut, Robert L; Lidar, Daniel A

    2007-01-01

    Methods of optimal control are applied to a model system of interacting two-level particles (e.g., spin-half atomic nuclei or electrons or two-level atoms) to produce high-fidelity quantum gates while simultaneously negating the detrimental effect of decoherence. One set of particles functions as the quantum information processor, whose evolution is controlled by a time-dependent external field. The other particles are not directly controlled and serve as an effective environment, coupling to which is the source of decoherence. The control objective is to generate target one- and two-qubit unitary gates in the presence of strong environmentally-induced decoherence and under physically motivated restrictions on the control field. The quantum-gate fidelity, expressed in terms of a novel state-independent distance measure, is maximized with respect to the control field using combined genetic and gradient algorithms. The resulting high-fidelity gates demonstrate the feasibility of precisely guiding the quantum evolution via optimal control, even when the system complexity is exacerbated by environmental coupling. It is found that the gate duration has an important effect on the control mechanism and resulting fidelity. An analysis of the sensitivity of the gate performance to random variations in the system parameters reveals a significant degree of robustness attained by the optimal control solutions

  14. An Economic Order Quantity Model with Completely Backordering and Nondecreasing Demand under Two-Level Trade Credit

    Directory of Open Access Journals (Sweden)

    Zohreh Molamohamadi

    2014-01-01

    Full Text Available In the traditional inventory system, it was implicitly assumed that the buyer pays to the seller as soon as he receives the items. In today’s competitive industry, however, the seller usually offers the buyer a delay period to settle the account of the goods. Not only the seller but also the buyer may apply trade credit as a strategic tool to stimulate his customers’ demands. This paper investigates the effects of the latter policy, two-level trade credit, on a retailer’s optimal ordering decisions within the economic order quantity framework and allowable shortages. Unlike most of the previous studies, the demand function of the customers is considered to increase with time. The objective of the retailer’s inventory model is to maximize the profit. The replenishment decisions optimally are obtained using genetic algorithm. Two special cases of the proposed model are discussed and the impacts of parameters on the decision variables are finally investigated. Numerical examples demonstrate the profitability of the developed two-level supply chain with backorder.

  15. Political legitimacy and European monetary union: contracts, constitutionalism and the normative logic of two-level games.

    Science.gov (United States)

    Bellamy, Richard; Weale, Albert

    2015-02-07

    The crisis of the euro area has severely tested the political authority of the European Union (EU). The crisis raises questions of normative legitimacy both because the EU is a normative order and because the construction of economic and monetary union (EMU) rested upon a theory that stressed the normative value of the depoliticization of money. However, this theory neglected the normative logic of the two-level game implicit in EMU. It also neglected the need for an impartial and publically acceptable constitutional order to acknowledge reasonable disagreements. By contrast, we contend that any reconstruction of the EU's economic constitution has to pay attention to reconciling a European monetary order with the legitimacy of member state governance. The EU requires a two-level contract to meet this standard. Member states must treat each other as equals and be representative of and accountable to their citizens on an equitable basis. These criteria entail that the EU's political legitimacy requires a form of demoi cracy that we call 'republican intergovernmentalism'. Only rules that could be acceptable as the product of a political constitution among the peoples of Europe can ultimately meet the required standards of political legitimacy. Such a political constitution could be brought about through empowering national parliaments in EU decision-making.

  16. Achieving involvement: process outcomes from a cluster randomized trial of shared decision making skill development and use of risk communication aids in general practice.

    NARCIS (Netherlands)

    Elwyn, G.; Edwards, A.; Hood, K.; Robling, M.; Atwell, C.; Russell, I.; Wensing, M.J.P.; Grol, R.P.T.M.

    2004-01-01

    BACKGROUND: A consulting method known as 'shared decision making' (SDM) has been described and operationalized in terms of several 'competences'. One of these competences concerns the discussion of the risks and benefits of treatment or care options-'risk communication'. Few data exist on

  17. Improving patient adherence to lifestyle advice (IMPALA: a cluster-randomised controlled trial on the implementation of a nurse-led intervention for cardiovascular risk management in primary care (protocol

    Directory of Open Access Journals (Sweden)

    Grol Richard

    2008-01-01

    Full Text Available Abstract Background Many patients at high risk of cardiovascular diseases are managed and monitored in general practice. Recommendations for cardiovascular risk management, including lifestyle change, are clearly described in the Dutch national guideline. Although lifestyle interventions, such as advice on diet, physical exercise, smoking and alcohol, have moderate, but potentially relevant effects in these patients, adherence to lifestyle advice in general practice is not optimal. The IMPALA study intends to improve adherence to lifestyle advice by involving patients in decision making on cardiovascular prevention by nurse-led clinics. The aim of this paper is to describe the design and methods of a study to evaluate an intervention aimed at involving patients in cardiovascular risk management. Methods A cluster-randomised controlled trial in 20 general practices, 10 practices in the intervention arm and 10 in the control arm, starting on October 2005. A total of 720 patients without existing cardiovascular diseases but eligible for cardiovascular risk assessment will be recruited. In both arms, the general practitioners and nurses will be trained to apply the national guideline for cardiovascular risk management. Nurses in the intervention arm will receive an extended training in risk assessment, risk communication, the use of a decision aid and adapted motivational interviewing. This communication technique will be used to support the shared decision-making process about risk reduction. The intervention comprises 2 consultations and 1 follow-up telephone call. The nurses in the control arm will give usual care after the risk estimation, according to the national guideline. Primary outcome measures are self-reported adherence to lifestyle advice and drug treatment. Secondary outcome measures are the patients' perception of risk and their motivation to change their behaviour. The measurements will take place at baseline and after 12 and 52

  18. Diversity among galaxy clusters

    International Nuclear Information System (INIS)

    Struble, M.F.; Rood, H.J.

    1988-01-01

    The classification of galaxy clusters is discussed. Consideration is given to the classification scheme of Abell (1950's), Zwicky (1950's), Morgan, Matthews, and Schmidt (1964), and Morgan-Bautz (1970). Galaxies can be classified based on morphology, chemical composition, spatial distribution, and motion. The correlation between a galaxy's environment and morphology is examined. The classification scheme of Rood-Sastry (1971), which is based on clusters's morphology and galaxy population, is described. The six types of clusters they define include: (1) a cD-cluster dominated by a single large galaxy, (2) a cluster dominated by a binary, (3) a core-halo cluster, (4) a cluster dominated by several bright galaxies, (5) a cluster appearing flattened, and (6) an irregularly shaped cluster. Attention is also given to the evolution of cluster structures, which is related to initial density and cluster motion

  19. Risk

    Science.gov (United States)

    Barshi, Immanuel

    2016-01-01

    Speaking up, i.e. expressing ones concerns, is a critical piece of effective communication. Yet, we see many situations in which crew members have concerns and still remain silent. Why would that be the case? And how can we assess the risks of speaking up vs. the risks of keeping silent? And once we do make up our minds to speak up, how should we go about it? Our workshop aims to answer these questions, and to provide us all with practical tools for effective risk assessment and effective speaking-up strategies..

  20. Supply chain model with price- and trade credit-sensitive demand under two-level permissible delay in payments

    Science.gov (United States)

    Giri, B. C.; Maiti, T.

    2013-05-01

    This article develops a single-manufacturer and single-retailer supply chain model under two-level permissible delay in payments when the manufacturer follows a lot-for-lot policy in response to the retailer's demand. The manufacturer offers a trade credit period to the retailer with the contract that the retailer must share a fraction of the profit earned during the trade credit period. On the other hand, the retailer provides his customer a partial trade credit which is less than that of the manufacturer. The demand at the retailer is assumed to be dependent on the selling price and the trade credit period offered to the customers. The average net profit of the supply chain is derived and an algorithm for finding the optimal solution is developed. Numerical examples are given to demonstrate the coordination policy of the supply chain and examine the sensitivity of key model-parameters.

  1. Inverse problem for a two-level medium with an inhomgeneously broadened transition in the field of a periodic wave

    International Nuclear Information System (INIS)

    Zabolotskii, A.A.

    1995-01-01

    The inverse problem is considered for a spectral problem, which is formally equivalent to a system of Bloch equations for an inhomogeneously broadened transition interacting with the electric field. Two cases are considered to demonstrate that, for any given frequency interval, one can determine the pulse of the shape which corresponds to the interaction with only this frequency interval. In the general case, the pulse shape is described by a nonlinear periodic wave. The first example is the resonance interaction of light with a gas of two-level atoms. The second example is interaction of a linearly polarized light with the molecular J-J transition, where J much-gt 1. In the latter case, the role of inhomogeneous broadening belongs to the frequency shift induced by the applied magnetic field. 10 refs

  2. Quantum correlations between each two-level system in a pair of atoms and general coherent fields

    Directory of Open Access Journals (Sweden)

    S. Abdel-Khalek

    Full Text Available The quantitative description of the quantum correlations between each two-level system in a two-atom system and the coherent fields initially defined in a coherent state in the framework of power-law potentials (PLPCSs is considered. Specifically, we consider two atoms locally interacting with PLPCSs and take into account the different terms of interactions, the entanglement and quantum discord are studied including the time-dependent coupling and photon transition effects. Using the monogamic relation between the entanglement of formation and quantum discord in tripartite systems, we show that the control and preservation of the different kinds of quantum correlations greatly benefit from the combination of the choice of the physical quantities. Finally, we explore the link between the dynamical behavior of quantum correlations and nonclassicality of the fields with and without atomic motion effect. Keywords: Quantum correlations, Monogamic relation, Coherent states, Power-law potentials, Wehrl entropy

  3. Cascaded two-photon nonlinearity in a one-dimensional waveguide with multiple two-level emitters

    Science.gov (United States)

    Roy, Dibyendu

    2013-01-01

    We propose and theoretically investigate a model to realize cascaded optical nonlinearity with few atoms and photons in one-dimension (1D). The optical nonlinearity in our system is mediated by resonant interactions of photons with two-level emitters, such as atoms or quantum dots in a 1D photonic waveguide. Multi-photon transmission in the waveguide is nonreciprocal when the emitters have different transition energies. Our theory provides a clear physical understanding of the origin of nonreciprocity in the presence of cascaded nonlinearity. We show how various two-photon nonlinear effects including spatial attraction and repulsion between photons, background fluorescence can be tuned by changing the number of emitters and the coupling between emitters (controlled by the separation). PMID:23948782

  4. Temporal Bell-type inequalities for two-level Rydberg atoms coupled to a high-Q resonator

    International Nuclear Information System (INIS)

    Huelga, S.F.; Marshall, T.W.; Santos, E.

    1996-01-01

    Following the strategy of showing specific quantum effects by means of the violation of a classical inequality, a pair of Bell-type inequalities is derived on the basis of certain additional assumptions, whose plausibility is discussed in detail. Such inequalities are violated by the quantum mechanical predictions for the interaction of a two-level Rydberg atom with a single mode sustained by a high-Q resonator. The experimental conditions required in order to show the existence of forbidden values, according to a hidden variables formalism, in a real experiment are analyzed for various initial field statistics. In particular, the revival dynamics expected for the interaction with a coherent field leads to classically forbidden values, which would indicate a purely quantum effect. copyright 1996 The American Physical Society

  5. Dynamics of a trapped two-level and three-level atom interacting with classical electromagnetic field

    International Nuclear Information System (INIS)

    Ray, Aditi

    2004-01-01

    The dynamics of a two-level atom driven by a single laser beam and three-level atom (Lambda configuration) irradiated by two laser beams are studied taking into account of the quantized center-of-mass motion of the atom. It is shown that the trapped atom system under appropriate resonance condition exhibits the large time-scale revivals when the index of the vibrational sideband responsible for the atomic electronic transition is greater than unity. The revival times are shown to be dependent on the initial number of vibrational excitations and the magnitude of the Lamb-Dicke parameter. The sub-Poissonian statistics in vibrational quantum number is observed at certain time intervals. The minimum time of interaction for which the squeezed states of motional quadrature are generated is found to be decreasing with the increase in the Lamb-Dicke parameter

  6. LCL filter design for three-phase two-level power factor correction using line impedance stabilization network

    DEFF Research Database (Denmark)

    Kouchaki, Alireza; Nymand, Morten

    2016-01-01

    This paper presents LCL filter design method for three-phase two-level power factor correction (PFC) using line impedance stabilization network (LISN). A straightforward LCL filter design along with variation in grid impedance is not simply achievable and inevitably lead to an iterative solution...... for filter. By introducing of fast power switches for PFC applications such as silicon-carbide, major current harmonics around the switching frequency drops in the region that LISN can actively provide well-defined impedance for measuring the harmonics (i.e. 9 kHz- 30MHz). Therefore, LISN can be replaced...... is derived using the current ripple behavior of converter-side inductor. The grid-side inductor is achieved as a function of LISN impedance to fulfill the grid regulation. To verify the analyses, an LCL filter is designed for a 5 kW SiC-based PFC. The simulation and experimental results support the validity...

  7. Loschmidt echo of a two-level qubit coupled to nonuniform anisotropic XY chains in a transverse field

    International Nuclear Information System (INIS)

    Zhong Ming; Tong Peiqing

    2011-01-01

    The Loschmidt echo (LE) of a central two-level qubit coupled to nonuniform anisotropic XY chains in a transverse field is studied. A general formula for LE is derived, which we use to discuss the influence of the criticality of the environment on LE. It is found that for the periodic XY chain the behaviors of LE in the vicinity of the critical points are similar to those of the uniform case. It is different for the disordered transverse Ising chains. For the aperiodic chains, if the surrounding systems are bounded chains, the behaviors of LE are similar to those of the uniform case, while if the surrounding systems are unbounded chains, they are similar to those of the disordered case.

  8. The EPQ model under conditions of two levels of trade credit and limited storage capacity in supply chain management

    Science.gov (United States)

    Chung, Kun-Jen

    2013-09-01

    An inventory problem involves a lot of factors influencing inventory decisions. To understand it, the traditional economic production quantity (EPQ) model plays rather important role for inventory analysis. Although the traditional EPQ models are still widely used in industry, practitioners frequently question validities of assumptions of these models such that their use encounters challenges and difficulties. So, this article tries to present a new inventory model by considering two levels of trade credit, finite replenishment rate and limited storage capacity together to relax the basic assumptions of the traditional EPQ model to improve the environment of the use of it. Keeping in mind cost-minimisation strategy, four easy-to-use theorems are developed to characterise the optimal solution. Finally, the sensitivity analyses are executed to investigate the effects of the various parameters on ordering policies and the annual total relevant costs of the inventory system.

  9. Dynamics of a Landau-Zener transitions in a two-level system driven by a dissipative environment

    Science.gov (United States)

    Ateuafack, M. E.; Diffo, J. T.; Fai, L. C.

    2016-02-01

    The paper investigates the effects of a two-level quantum system coupled to transversal and longitudinal dissipative environment. The time-dependent phase accumulation, LZ transition probability and entropy in the presence of fast-ohmic, sub-ohmic and super-ohmic quantum noise are derived. Analytical results are obtained in terms of temperature, dissipation strength, LZ parameter and bath cutoff frequency. The bath is observed to modify the standard occupation difference by a decaying random phase factor and also produces dephasing during the transfer of population. The dephasing characteristics or the initial non-zero decoherence rate are observed to increase in time with the bath temperature and depend on the system-bath coupling strength and cutoff frequency. These parameters are found to strongly affect the memory and thus tailor the coherence process of the system.

  10. Dynamics of a Landau–Zener transitions in a two-level system driven by a dissipative environment

    Energy Technology Data Exchange (ETDEWEB)

    Ateuafack, M.E., E-mail: esouamath@yahoo.fr [Mesoscopic and Multilayer Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang (Cameroon); Diffo, J.T., E-mail: diffojaures@yahoo.com [Mesoscopic and Multilayer Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang (Cameroon); Department of Physics, Higher Teachers' Training College, The University of Maroua, PO Box 55 Maroua (Cameroon); Fai, L.C., E-mail: corneliusfai@yahoo.fr [Mesoscopic and Multilayer Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang (Cameroon)

    2016-02-15

    The paper investigates the effects of a two-level quantum system coupled to transversal and longitudinal dissipative environment. The time-dependent phase accumulation, LZ transition probability and entropy in the presence of fast-ohmic, sub-ohmic and super-ohmic quantum noise are derived. Analytical results are obtained in terms of temperature, dissipation strength, LZ parameter and bath cutoff frequency. The bath is observed to modify the standard occupation difference by a decaying random phase factor and also produces dephasing during the transfer of population. The dephasing characteristics or the initial non-zero decoherence rate are observed to increase in time with the bath temperature and depend on the system-bath coupling strength and cutoff frequency. These parameters are found to strongly affect the memory and thus tailor the coherence process of the system.

  11. An acceleration of the characteristics by a space-angle two-level method using surface discontinuity factors

    Energy Technology Data Exchange (ETDEWEB)

    Grassi, G. [Commissariat a l' Energie Atomique, CEA de Saclay, DM2S/SERMA/LENR, 91191, Gif-sur-Yvette (France)

    2006-07-01

    We present a non-linear space-angle two-level acceleration scheme for the method of the characteristics (MOC). To the fine level on which the MOC transport calculation is performed, we associate a more coarsely discretized phase space in which a low-order problem is solved as an acceleration step. Cross sections on the coarse level are obtained by a flux-volume homogenisation technique, which entails the non-linearity of the acceleration. Discontinuity factors per surface are introduced as additional degrees of freedom on the coarse level in order to ensure the equivalence of the heterogeneous and the homogenised problem. After each fine transport iteration, a low-order transport problem is iteratively solved on the homogenised grid. The solution of this problem is then used to correct the angular moments of the flux resulting from the previous free transport sweep. Numerical tests for a given benchmark have been performed. Results are discussed. (authors)

  12. An acceleration of the characteristics by a space-angle two-level method using surface discontinuity factors

    International Nuclear Information System (INIS)

    Grassi, G.

    2006-01-01

    We present a non-linear space-angle two-level acceleration scheme for the method of the characteristics (MOC). To the fine level on which the MOC transport calculation is performed, we associate a more coarsely discretized phase space in which a low-order problem is solved as an acceleration step. Cross sections on the coarse level are obtained by a flux-volume homogenisation technique, which entails the non-linearity of the acceleration. Discontinuity factors per surface are introduced as additional degrees of freedom on the coarse level in order to ensure the equivalence of the heterogeneous and the homogenised problem. After each fine transport iteration, a low-order transport problem is iteratively solved on the homogenised grid. The solution of this problem is then used to correct the angular moments of the flux resulting from the previous free transport sweep. Numerical tests for a given benchmark have been performed. Results are discussed. (authors)

  13. A Two-level-games Analysis of AFTA Agreements: What Caused ASEAN States to Move towards Economic Integration?

    Directory of Open Access Journals (Sweden)

    Yi-hung Chiou

    2010-04-01

    Full Text Available The goal of this article is to investigate the conditions under which ASEAN states are more likely to pursue regional economic integration, namely, a series of ASEAN Free Trade Area (AFTA agreements/ protocols. Adopting Putnam’s two-level-games model, this article examines the influences of domestic politics, political elites’ preferences, economic performance, and external impacts. Through the construction of a set of hypotheses, this article investigates five AFTA agreements/ protocols and the conditions of ASEAN states during the 1992–2003 period. The findings indicate that political leaders’ preferences have played a pivotal role in the development of the AFTA. Economic performance and domestic support in individual states has also affected the AFTA. The close link between AFTA agreements and external impacts reveals that the AFTA’s inherent nature is defensive.

  14. Effects of using the simplified airway risk index vs usual airway assessment on unanticipated difficult tracheal intubation - a cluster randomized trial with 64,273 participants

    DEFF Research Database (Denmark)

    Nørskov, A K; Wetterslev, J; Rosenstock, C V

    2016-01-01

    departments vs 1.00% (302) in Non-SARI departments. Adjusted OR was 1.26 (0.68-2.34). CONCLUSIONS: Using the SARI compared with usual airway assessment we detected no statistical significant changes in unanticipated difficult- or easy intubations. CLINICAL TRIAL REGISTRATION: NCT01718561.......BACKGROUND: Unanticipated difficult intubation remains a challenge in anaesthesia. The Simplified Airway Risk Index (SARI) is a multivariable risk model consisting of seven independent risk factors for difficult intubation. Our aim was to compare preoperative airway assessment based on the SARI...

  15. Clustering of Sun Exposure Measurements

    DEFF Research Database (Denmark)

    Have, Anna Szynkowiak; Larsen, Jan; Hansen, Lars Kai

    2002-01-01

    In a medically motivated Sun-exposure study, questionnaires concerning Sun-habits were collected from a number of subjects together with UV radiation measurements. This paper focuses on identifying clusters in the heterogeneous set of data for the purpose of understanding possible relations between...... Sun-habits exposure and eventually assessing the risk of skin cancer. A general probabilistic framework originally developed for text and Web mining is demonstrated to be useful for clustering of behavioral data. The framework combines principal component subspace projection with probabilistic...

  16. Design of a Two-level Adaptive Multi-Agent System for Malaria Vectors driven by an ontology

    Directory of Open Access Journals (Sweden)

    Etang Josiane

    2007-07-01

    Full Text Available Abstract Background The understanding of heterogeneities in disease transmission dynamics as far as malaria vectors are concerned is a big challenge. Many studies while tackling this problem don't find exact models to explain the malaria vectors propagation. Methods To solve the problem we define an Adaptive Multi-Agent System (AMAS which has the property to be elastic and is a two-level system as well. This AMAS is a dynamic system where the two levels are linked by an Ontology which allows it to function as a reduced system and as an extended system. In a primary level, the AMAS comprises organization agents and in a secondary level, it is constituted of analysis agents. Its entry point, a User Interface Agent, can reproduce itself because it is given a minimum of background knowledge and it learns appropriate "behavior" from the user in the presence of ambiguous queries and from other agents of the AMAS in other situations. Results Some of the outputs of our system present a series of tables, diagrams showing some factors like Entomological parameters of malaria transmission, Percentages of malaria transmission per malaria vectors, Entomological inoculation rate. Many others parameters can be produced by the system depending on the inputted data. Conclusion Our approach is an intelligent one which differs from statistical approaches that are sometimes used in the field. This intelligent approach aligns itself with the distributed artificial intelligence. In terms of fight against malaria disease our system offers opportunities of reducing efforts of human resources who are not obliged to cover the entire territory while conducting surveys. Secondly the AMAS can determine the presence or the absence of malaria vectors even when specific data have not been collected in the geographical area. In the difference of a statistical technique, in our case the projection of the results in the field can sometimes appeared to be more general.

  17. A preventive maintenance model with a two-level inspection policy based on a three-stage failure process

    International Nuclear Information System (INIS)

    Wang, Wenbin; Zhao, Fei; Peng, Rui

    2014-01-01

    Inspection is always an important preventive maintenance (PM) activity and can have different depths and cover all or part of plant systems. This paper introduces a two-level inspection policy model for a single component plant system based on a three-stage failure process. Such a failure process divides the system′s life into three stages: good, minor defective and severe defective stages. The first level of inspection, the minor inspection, can only identify the minor defective stage with a certain probability, but can always reveal the severe defective stage. The major inspection can however identify both defective stages perfectly. Once the system is found to be in the minor defective stage, a shortened inspection interval is adopted. If however the system is found to be in the severe defective stage, we may delay the maintenance action if the time to the next planned PM window is less than a threshold level, but otherwise, replace immediately. This corresponds to the well adopted maintenance policy in practice such as periodic inspections with planned PMs. A numerical example is presented to demonstrate the proposed model by comparing with other models. - Highlights: • The system′s deterioration goes through a three-stage process, namely, normal, minor defective and severe defective. • Two levels of inspections are proposed, e.g., minor and major inspections. • Once the minor defective stage is found, instead of taking a maintenance action, a shortened inspection interval is recommended. • When the severe defective stage is found, we delay the maintenance according to the threshold to the next PM. • The decision variables are the inspection intervals and the threshold to PM

  18. Clinical evaluation of an allogeneic bone matrix containing viable osteogenic cells in patients undergoing one- and two-level posterolateral lumbar arthrodesis with decompressive laminectomy.

    Science.gov (United States)

    Musante, David B; Firtha, Michael E; Atkinson, Brent L; Hahn, Rebekah; Ryaby, James T; Linovitz, Raymond J

    2016-05-27

    Trinity Evolution® cellular bone allograft (TE) possesses the osteogenic, osteoinductive, and osteoconductive elements essential for bone healing. The purpose of this study is to evaluate the radiographic and clinical outcomes when TE is used as a graft extender in combination with locally derived bone in one- and two-level instrumented lumbar posterolateral arthrodeses. In this retrospective evaluation, a consecutive series of subject charts that had posterolateral arthrodesis with TE and a 12-month radiographic follow-up were evaluated. All subjects were diagnosed with degenerative disc disease, radiculopathy, stenosis, and decreased disc height. At 2 weeks and at 3 and 12 months, plain radiographs were performed and the subject's back and leg pain (VAS) was recorded. An evaluation of fusion status was performed at 12 months. The population consisted of 43 subjects and 47 arthrodeses. At 12 months, a fusion rate of 90.7 % of subjects and 89.4 % of surgical levels was observed. High-risk subjects (e.g., diabetes, tobacco use, etc.) had fusion rates comparable to normal patients. Compared with the preoperative leg or back pain level, the postoperative pain levels were significantly (p < 0.0001) improved at every time point. There were no adverse events attributable to TE. Fusion rates using TE were higher than or comparable to fusion rates with autologous iliac crest bone graft that have been reported in the recent literature for posterolateral fusion procedures, and TE fusion rates were not adversely affected by several high-risk patient factors. The positive results provide confidence that TE can safely replace autologous iliac crest bone graft when used as a bone graft extender in combination with locally derived bone in the setting of posterolateral lumbar arthrodesis in patients with or without risk factors for compromised bone healing. Because of the retrospective nature of this study, the trial was not registered.

  19. 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 longit...... but being quick to withdraw in times of crisis....

  20. 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.

  1. 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...... clusters. Their results are typically highly redundant, i.e. many clusters are detected multiple times in several projections. In this work, we propose a novel model for relevant subspace clustering (RESCU). We present a global optimization which detects the most interesting non-redundant subspace clusters...... achieves top clustering quality while competing approaches show greatly varying performance....

  2. Cluster ion beam facilities

    International Nuclear Information System (INIS)

    Popok, V.N.; Prasalovich, S.V.; Odzhaev, V.B.; Campbell, E.E.B.

    2001-01-01

    A brief state-of-the-art review in the field of cluster-surface interactions is presented. Ionised cluster beams could become a powerful and versatile tool for the modification and processing of surfaces as an alternative to ion implantation and ion assisted deposition. The main effects of cluster-surface collisions and possible applications of cluster ion beams are discussed. The outlooks of the Cluster Implantation and Deposition Apparatus (CIDA) being developed in Guteborg University are shown

  3. Comparison of the effects of growth hormone on acylated ghrelin and following acute intermittent exercise in two levels of obesity

    Directory of Open Access Journals (Sweden)

    Majid Gholipour

    2013-08-01

    Full Text Available Background: The prevalence of obesity has risen enormously over the past few decad-es. Both food intake (Appetite and energy expenditure can influence body weight. Acylated ghrelin enhances appetite, and its plasma level is suppressed by growth horm-one. The present study, examines the effects of an intermittent exercise with progress-ive intensities on acylated ghrelin, appetite, and growth hormone in inactive male students with two levels of obesity.Methods: Eleven inactive males were allocated into two groups on the basis of their body mass index (BMI. Six subjects in group one, BMI= 31.18±0.92 kg/m2, and five subjects in group two, BMI= 36.94±2.25 kg/m2, ran on the treadmill with progressive intensities of 50, 60, 70 and 80% of VO2max for 10, 10, 5, and 2 min respectively. Blood samples were collected before the exercise (as the resting values, after each workload (during the exercise, and at 30, 60, and 120 min (during recovery.Results: Plasma acylated ghrelin concentrations and hunger ratings in two groups were decreased and remained significantly lower than resting values (P=0.008 and P=0.002 respectively at the end of the trial and there was no significant differences between groups. Growth hormone levels in two groups were increased and remained significant-ly higher than resting values (groups one P=0.012, group two P=0.005 at the end of the trial and there was no significant differences between groups. In addition, there were no significant differences between area under the curves (AUC values over total periods for acylated ghrelin, hunger ratings, and growth hormone in two groups.Conclusion: These findings indicate that individuals with two levels of obesity have the same response to the different intensities of treadmill running and two hours thereafter during recovery period, which can be considered for designing a more effective weighting loss training program.

  4. PREFACE: Nuclear Cluster Conference; Cluster'07

    Science.gov (United States)

    Freer, Martin

    2008-05-01

    The Cluster Conference is a long-running conference series dating back to the 1960's, the first being initiated by Wildermuth in Bochum, Germany, in 1969. The most recent meeting was held in Nara, Japan, in 2003, and in 2007 the 9th Cluster Conference was held in Stratford-upon-Avon, UK. As the name suggests the town of Stratford lies upon the River Avon, and shortly before the conference, due to unprecedented rainfall in the area (approximately 10 cm within half a day), lay in the River Avon! Stratford is the birthplace of the `Bard of Avon' William Shakespeare, and this formed an intriguing conference backdrop. The meeting was attended by some 90 delegates and the programme contained 65 70 oral presentations, and was opened by a historical perspective presented by Professor Brink (Oxford) and closed by Professor Horiuchi (RCNP) with an overview of the conference and future perspectives. In between, the conference covered aspects of clustering in exotic nuclei (both neutron and proton-rich), molecular structures in which valence neutrons are exchanged between cluster cores, condensates in nuclei, neutron-clusters, superheavy nuclei, clusters in nuclear astrophysical processes and exotic cluster decays such as 2p and ternary cluster decay. The field of nuclear clustering has become strongly influenced by the physics of radioactive beam facilities (reflected in the programme), and by the excitement that clustering may have an important impact on the structure of nuclei at the neutron drip-line. It was clear that since Nara the field had progressed substantially and that new themes had emerged and others had crystallized. Two particular topics resonated strongly condensates and nuclear molecules. These topics are thus likely to be central in the next cluster conference which will be held in 2011 in the Hungarian city of Debrechen. Martin Freer Participants and Cluster'07

  5. HIV prevalence and related risk behaviours in female seasonal farm workers in Souss Massa Draa, Morocco: results from a cross-sectional survey using cluster-based sampling.

    Science.gov (United States)

    Bozicevic, Ivana; Guezzar, Fatiha; Stulhofer, Aleksandar; Bennani, Aziza; Handanagic, Senad; Barbaric, Jelena; El Rhilani, Houssine; Alami, Kamal; Khattabi, Hamida; Riedner, Gabriele; Maaroufi, Abderrahmane

    2017-06-08

    To determine prevalence of HIV and HIV-related behaviours in female seasonal farm workers (FSFWs) in two provinces of Souss Massa Draa (SMD) region in Morocco. SMD has a higher burden of HIV compared with other parts of Morocco and is characterised by a substantial aggregation of FSFW. We carried out a cross-sectional HIV biobehavioural survey using cluster-based sampling of farms in the provinces Chtouka Aït Baha and Taroudant Ouled Teïma in 2014. HIV testing was done using the Determine HIV-1/2 rapid test and reactive specimens were tested using ELISA and western blot. Collected data were post hoc weighted for region-based stratification and adjusted for clustering effects using complex survey functions of SPSS (V.21). Among those eligible to participate, the response rate was 92.8%. HIV prevalence was 0.9% (95% CI 0.4% to 2.4%) among 520 recruited participants. A high proportion of respondents (67.7%) had no education. Ever having sex was reported by 79.8% and among these, 12.7% ever exchanged sex for money or goods. Sixty-one per cent reported condom use at most recent commercial vaginal sex in the past 12 months. STI symptom recognition was found to be low because 62.4% and 46.8% of FSFW could not report any STI symptoms in men and women, respectively. Twenty-seven per cent of respondents had an HIV test in the past 12 months. In multivariable analysis, those with primary or higher education (adjusted OR (aOR)=2.38, 95% CI 1.33 to 4.27) and those who participated in an HIV educational session at their workplace (aOR=11.00, 95% CI 3.99 to 30.31) had higher odds of ever been tested for HIV. Although we found a relatively low HIV prevalence among FSFW in SMD, HIV interventions should be intensified, in particular, in a subgroup of women who are involved in sex work. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  6. The Sydney playground project--levelling the playing field: a cluster trial of a primary school-based intervention aiming to promote manageable risk-taking in children with disability.

    Science.gov (United States)

    Bundy, Anita C; Wyver, Shirley; Beetham, Kassia S; Ragen, Jo; Naughton, Geraldine; Tranter, Paul; Norman, Richard; Villeneuve, Michelle; Spencer, Grace; Honey, Anne; Simpson, Judith; Baur, Louise; Sterman, Julia

    2015-11-14

    Providing children and adults with opportunities to engage in manageable risk taking may be a stepping stone toward closing the gap in life conditions currently experienced by young people with disabilities. We aim to demonstrate the effectiveness of a simple, innovative program for 1) changing the way parents and teachers view manageable risk-taking for children with disabilities and 2) increasing the level of responsibility that children take for their own actions, as seen on the school playground. We will employ a cluster repeated measures trial with six Sydney-area primary-school-based programs for children with disabilities. The intervention comprises two arms. 1) Risk-reframing--teachers and parents will participate together in small group intervention sessions focusing on the benefits of manageable risk-taking; 2) Introduction of play materials--materials without a defined purpose and facilitative of social cooperation will be introduced to the school playground for children to use at all break times. A control period will be undertaken first for two school terms, followed by two terms of the intervention period. Outcome measures will include playground observations, The Coping Inventory, qualitative field notes, and The Tolerance of Risk in Play Scale. New national programs, such as Australia's National Disability Insurance Scheme, will place increasing demands on young people with disabilities to assume responsibility for difficult decisions regarding procuring services. Innovative approaches, commencing early in life, are required to prepare young people and their carers for this level of responsibility. This research offers innovative intervention strategies for promoting autonomy in children with disabilities and their carers. Australian and New Zealand Clinical Trials Registration Number ACTRN12614000549628 (registered 22/5/2014).

  7. Evaluating the clinical and cost effectiveness of a behaviour change intervention for lowering cardiovascular disease risk for people with severe mental illnesses in primary care (PRIMROSE study): study protocol for a cluster randomised controlled trial.

    Science.gov (United States)

    Osborn, David; Burton, Alexandra; Walters, Kate; Nazareth, Irwin; Heinkel, Samira; Atkins, Lou; Blackburn, Ruth; Holt, Richard; Hunter, Racheal; King, Michael; Marston, Louise; Michie, Susan; Morris, Richard; Morris, Steve; Omar, Rumana; Peveler, Robert; Pinfold, Vanessa; Zomer, Ella; Barnes, Thomas; Craig, Tom; Gilbert, Hazel; Grey, Ben; Johnston, Claire; Leibowitz, Judy; Petersen, Irene; Stevenson, Fiona; Hardy, Sheila; Robinson, Vanessa

    2016-02-12

    People with severe mental illnesses die up to 20 years earlier than the general population, with cardiovascular disease being the leading cause of death. National guidelines recommend that the physical care of people with severe mental illnesses should be the responsibility of primary care; however, little is known about effective interventions to lower cardiovascular disease risk in this population and setting. Following extensive peer review, funding was secured from the United Kingdom National Institute for Health Research (NIHR) to deliver the proposed study. The aim of the trial is to test the effectiveness of a behavioural intervention to lower cardiovascular disease risk in people with severe mental illnesses in United Kingdom General Practices. The study is a cluster randomised controlled trial in 70 GP practices for people with severe mental illnesses, aged 30 to 75 years old, with elevated cardiovascular disease risk factors. The trial will compare the effectiveness of a behavioural intervention designed to lower cardiovascular disease risk and delivered by a practice nurse or healthcare assistant, with standard care offered in General Practice. A total of 350 people will be recruited and followed up at 6 and 12 months. The primary outcome is total cholesterol level at the 12-month follow-up and secondary outcomes include blood pressure, body mass index, waist circumference, smoking status, quality of life, adherence to treatments and services and behavioural measures for diet, physical activity and alcohol use. An economic evaluation will be carried out to determine the cost effectiveness of the intervention compared with standard care. The results of this pragmatic trial will provide evidence on the clinical and cost effectiveness of the intervention on lowering total cholesterol and addressing multiple cardiovascular disease risk factors in people with severe mental illnesses in GP Practices. Current Controlled Trials ISRCTN13762819. Date of

  8. Implementation of the Participatory Approach for Supervisors to Increase Self-Efficacy in Addressing Risk of Sick Leave of Employees : Results of a Cluster-Randomized Controlled Trial

    NARCIS (Netherlands)

    Ketelaar, S. M.; Schaafsma, F. G.; Geldof, M. F.; Kraaijeveld, R. A.; Boot, C. R. L.; Shaw, W. S.; Bultmann, U.; Anema, J. R.

    Purpose To study the effectiveness of a multifaceted strategy to implement the participatory approach (PA) for supervisors to increase their self-efficacy in addressing risk of sick leave of employees. Methods Supervisors from three organizations were invited to participate. Randomization was

  9. Controlled ultrafast transfer and stability degree of generalized coherent states of a kicked two-level ion

    Science.gov (United States)

    Chen, Hao; Kong, Chao; Hai, Wenhua

    2018-06-01

    We investigate quantum dynamics of a two-level ion trapped in the Lamb-Dicke regime of a δ -kicked optical lattice, based on the exact generalized coherent states rotated by a π / 2 pulse of Ramsey type experiment. The spatiotemporal evolutions of the spin-motion entangled states in different parameter regions are illustrated, and the parameter regions of different degrees of quantum stability described by the quantum fidelity are found. Time evolutions of the probability for the ion being in different pseudospin states reveal that the ultrafast entanglement generation and population transfers of the system can be analytically controlled by managing the laser pulses. The probability in an initially disentangled state shows periodic collapses (entanglement) and revivals (de-entanglement). Reduction of the stability degree results in enlarging the period of de-entanglement, while the instability and potential chaos will cause the sustained entanglement. The results could be justified experimentally in the existing setups and may be useful in engineering quantum dynamics for quantum information processing.

  10. A two-level discount model for coordinating a decentralized supply chain considering stochastic price-sensitive demand

    Science.gov (United States)

    Heydari, Jafar; Norouzinasab, Yousef

    2015-12-01

    In this paper, a discount model is proposed to coordinate pricing and ordering decisions in a two-echelon supply chain (SC). Demand is stochastic and price sensitive while lead times are fixed. Decentralized decision making where downstream decides on selling price and order size is investigated. Then, joint pricing and ordering decisions are extracted where both members act as a single entity aim to maximize whole SC profit. Finally, a coordination mechanism based on quantity discount is proposed to coordinate both pricing and ordering decisions simultaneously. The proposed two-level discount policy can be characterized from two aspects: (1) marketing viewpoint: a retail price discount to increase the demand, and (2) operations management viewpoint: a wholesale price discount to induce the retailer to adjust its order quantity and selling price jointly. Results of numerical experiments demonstrate that the proposed policy is suitable to coordinate SC and improve the profitability of SC as well as all SC members in comparison with decentralized decision making.

  11. Statistical Analysis of the Figure of Merit of a Two-Level Thermoelectric System: A Random Matrix Approach

    KAUST Repository

    Abbout, Adel

    2016-08-05

    Using the tools of random matrix theory we develop a statistical analysis of the transport properties of thermoelectric low-dimensional systems made of two electron reservoirs set at different temperatures and chemical potentials, and connected through a low-density-of-states two-level quantum dot that acts as a conducting chaotic cavity. Our exact treatment of the chaotic behavior in such devices lies on the scattering matrix formalism and yields analytical expressions for the joint probability distribution functions of the Seebeck coefficient and the transmission profile, as well as the marginal distributions, at arbitrary Fermi energy. The scattering matrices belong to circular ensembles which we sample to numerically compute the transmission function, the Seebeck coefficient, and their relationship. The exact transport coefficients probability distributions are found to be highly non-Gaussian for small numbers of conduction modes, and the analytical and numerical results are in excellent agreement. The system performance is also studied, and we find that the optimum performance is obtained for half-transparent quantum dots; further, this optimum may be enhanced for systems with few conduction modes.

  12. Optomechanically induced transparency in multi-cavity optomechanical system with and without one two-level atom.

    Science.gov (United States)

    Sohail, Amjad; Zhang, Yang; Zhang, Jun; Yu, Chang-Shui

    2016-06-28

    We analytically study the optomechanically induced transparency (OMIT) in the N-cavity system with the Nth cavity driven by pump, probing laser fields and the 1st cavity coupled to mechanical oscillator. We also consider that one atom could be trapped in the ith cavity. Instead of only illustrating the OMIT in such a system, we are interested in how the number of OMIT windows is influenced by the cavities and the atom and what roles the atom could play in different cavities. In the resolved sideband regime, we find that, the number of cavities precisely determines the maximal number of OMIT windows. It is interesting that, when the two-level atom is trapped in the even-labeled cavity, the central absorptive peak (odd N) or dip (even N) is split and forms an extra OMIT window, but if the atom is trapped in the odd-labeled cavity, the central absorptive peak (odd N) or dip (even N) is only broadened and thus changes the width of the OMIT windows rather than induces an extra window.

  13. Cavity quantum electrodynamics using a near-resonance two-level system: Emergence of the Glauber state

    Energy Technology Data Exchange (ETDEWEB)

    Sarabi, B.; Ramanayaka, A. N. [Laboratory for Physical Sciences, College Park, Maryland 20740 (United States); Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Burin, A. L. [Department of Chemistry, Tulane University, New Orleans, Louisiana 70118 (United States); Wellstood, F. C. [Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Joint Quantum Institute, University of Maryland, College Park, Maryland 20742 (United States); Osborn, K. D. [Laboratory for Physical Sciences, College Park, Maryland 20740 (United States); Joint Quantum Institute, University of Maryland, College Park, Maryland 20742 (United States)

    2015-04-27

    Random tunneling two-level systems (TLSs) in dielectrics have been of interest recently because they adversely affect the performance of superconducting qubits. The coupling of TLSs to qubits has allowed individual TLS characterization, which has previously been limited to TLSs within (thin) Josephson tunneling barriers made from aluminum oxide. Here, we report on the measurement of an individual TLS within the capacitor of a lumped-element LC microwave resonator, which forms a cavity quantum electrodynamics (CQED) system and allows for individual TLS characterization in a different structure and material than demonstrated with qubits. Due to the reduced volume of the dielectric (80 μm{sup 3}), even with a moderate dielectric thickness (250 nm), we achieve the strong coupling regime as evidenced by the vacuum Rabi splitting observed in the cavity spectrum. A TLS with a coherence time of 3.2 μs was observed in a film of silicon nitride as analyzed with a Jaynes-Cummings spectral model, which is larger than seen from superconducting qubits. As the drive power is increased, we observe an unusual but explicable set of continuous and discrete crossovers from the vacuum Rabi split transitions to the Glauber (coherent) state.

  14. Statistical Analysis of the Figure of Merit of a Two-Level Thermoelectric System: A Random Matrix Approach

    KAUST Repository

    Abbout, Adel; Ouerdane, Henni; Goupil, Christophe

    2016-01-01

    Using the tools of random matrix theory we develop a statistical analysis of the transport properties of thermoelectric low-dimensional systems made of two electron reservoirs set at different temperatures and chemical potentials, and connected through a low-density-of-states two-level quantum dot that acts as a conducting chaotic cavity. Our exact treatment of the chaotic behavior in such devices lies on the scattering matrix formalism and yields analytical expressions for the joint probability distribution functions of the Seebeck coefficient and the transmission profile, as well as the marginal distributions, at arbitrary Fermi energy. The scattering matrices belong to circular ensembles which we sample to numerically compute the transmission function, the Seebeck coefficient, and their relationship. The exact transport coefficients