WorldWideScience

Sample records for random search strategies

  1. Spying on Search Strategies

    Science.gov (United States)

    Tenopir, Carol

    2004-01-01

    Only the most dedicated super-searchers are motivated to learn and control command systems, like DialogClassic, that rely on the user to input complex search strategies. Infrequent searchers and most end users choose interfaces that do some of the work for them and make the search process appear easy. However, the easier a good interface seems to…

  2. Electronic search strategies to identify reports of cluster randomized trials in MEDLINE: low precision will improve with adherence to reporting standards

    Directory of Open Access Journals (Sweden)

    Grimshaw Jeremy M

    2010-02-01

    Full Text Available Abstract Background Cluster randomized trials (CRTs present unique methodological and ethical challenges. Researchers conducting systematic reviews of CRTs (e.g., addressing methodological or ethical issues require efficient electronic search strategies (filters or hedges to identify trials in electronic databases such as MEDLINE. According to the CONSORT statement extension to CRTs, the clustered design should be clearly identified in titles or abstracts; however, variability in terminology may make electronic identification challenging. Our objectives were to (a evaluate sensitivity ("recall" and precision of a well-known electronic search strategy ("randomized controlled trial" as publication type with respect to identifying CRTs, (b evaluate the feasibility of new search strategies targeted specifically at CRTs, and (c determine whether CRTs are appropriately identified in titles or abstracts of reports and whether there has been improvement over time. Methods We manually examined a wide range of health journals to identify a gold standard set of CRTs. Search strategies were evaluated against the gold standard set, as well as an independent set of CRTs included in previous systematic reviews. Results The existing strategy (randomized controlled trial.pt is sensitive (93.8% for identifying CRTs, but has relatively low precision (9%, number needed to read 11; the number needed to read can be halved to 5 (precision 18.4% by combining with cluster design-related terms using the Boolean operator AND; combining with the Boolean operator OR maximizes sensitivity (99.4% but would require 28.6 citations read to identify one CRT. Only about 50% of CRTs are clearly identified as cluster randomized in titles or abstracts; approximately 25% can be identified based on the reported units of randomization but are not amenable to electronic searching; the remaining 25% cannot be identified except through manual inspection of the full-text article. The

  3. Electronic search strategies to identify reports of cluster randomized trials in MEDLINE: low precision will improve with adherence to reporting standards.

    Science.gov (United States)

    Taljaard, Monica; McGowan, Jessie; Grimshaw, Jeremy M; Brehaut, Jamie C; McRae, Andrew; Eccles, Martin P; Donner, Allan

    2010-02-16

    Cluster randomized trials (CRTs) present unique methodological and ethical challenges. Researchers conducting systematic reviews of CRTs (e.g., addressing methodological or ethical issues) require efficient electronic search strategies (filters or hedges) to identify trials in electronic databases such as MEDLINE. According to the CONSORT statement extension to CRTs, the clustered design should be clearly identified in titles or abstracts; however, variability in terminology may make electronic identification challenging. Our objectives were to (a) evaluate sensitivity ("recall") and precision of a well-known electronic search strategy ("randomized controlled trial" as publication type) with respect to identifying CRTs, (b) evaluate the feasibility of new search strategies targeted specifically at CRTs, and (c) determine whether CRTs are appropriately identified in titles or abstracts of reports and whether there has been improvement over time. We manually examined a wide range of health journals to identify a gold standard set of CRTs. Search strategies were evaluated against the gold standard set, as well as an independent set of CRTs included in previous systematic reviews. The existing strategy (randomized controlled trial.pt) is sensitive (93.8%) for identifying CRTs, but has relatively low precision (9%, number needed to read 11); the number needed to read can be halved to 5 (precision 18.4%) by combining with cluster design-related terms using the Boolean operator AND; combining with the Boolean operator OR maximizes sensitivity (99.4%) but would require 28.6 citations read to identify one CRT. Only about 50% of CRTs are clearly identified as cluster randomized in titles or abstracts; approximately 25% can be identified based on the reported units of randomization but are not amenable to electronic searching; the remaining 25% cannot be identified except through manual inspection of the full-text article. The proportion of trials clearly identified has

  4. Search Strategies for Scheduling Problems

    OpenAIRE

    Kypta, Tomáš

    2012-01-01

    In the present work I compare the search strategies for solving scheduling problems from the view of constraint programming. The thesis is focused on scheduling problems containing alternative activities. An analysis of previously published various ways of modelling the problems is provided, next description and experimental comparison of search strategies targetting these models is provided. The influence of strategies on the speed of the solver is studied primarily. As a sideeffect the work...

  5. University Students' Online Information Searching Strategies in Different Search Contexts

    Science.gov (United States)

    Tsai, Meng-Jung; Liang, Jyh-Chong; Hou, Huei-Tse; Tsai, Chin-Chung

    2012-01-01

    This study investigates the role of search context played in university students' online information searching strategies. A total of 304 university students in Taiwan were surveyed with questionnaires in which two search contexts were defined as searching for learning, and searching for daily life information. Students' online search strategies…

  6. A parallel algorithm for random searches

    Science.gov (United States)

    Wosniack, M. E.; Raposo, E. P.; Viswanathan, G. M.; da Luz, M. G. E.

    2015-11-01

    We discuss a parallelization procedure for a two-dimensional random search of a single individual, a typical sequential process. To assure the same features of the sequential random search in the parallel version, we analyze the former spatial patterns of the encountered targets for different search strategies and densities of homogeneously distributed targets. We identify a lognormal tendency for the distribution of distances between consecutively detected targets. Then, by assigning the distinct mean and standard deviation of this distribution for each corresponding configuration in the parallel simulations (constituted by parallel random walkers), we are able to recover important statistical properties, e.g., the target detection efficiency, of the original problem. The proposed parallel approach presents a speedup of nearly one order of magnitude compared with the sequential implementation. This algorithm can be easily adapted to different instances, as searches in three dimensions. Its possible range of applicability covers problems in areas as diverse as automated computer searchers in high-capacity databases and animal foraging.

  7. Search strategies of Wikipedia readers.

    Science.gov (United States)

    Rodi, Giovanna Chiara; Loreto, Vittorio; Tria, Francesca

    2017-01-01

    The quest for information is one of the most common activity of human beings. Despite the the impressive progress of search engines, not to miss the needed piece of information could be still very tough, as well as to acquire specific competences and knowledge by shaping and following the proper learning paths. Indeed, the need to find sensible paths in information networks is one of the biggest challenges of our societies and, to effectively address it, it is important to investigate the strategies adopted by human users to cope with the cognitive bottleneck of finding their way in a growing sea of information. Here we focus on the case of Wikipedia and investigate a recently released dataset about users' click on the English Wikipedia, namely the English Wikipedia Clickstream. We perform a semantically charged analysis to uncover the general patterns followed by information seekers in the multi-dimensional space of Wikipedia topics/categories. We discover the existence of well defined strategies in which users tend to start from very general, i.e., semantically broad, pages and progressively narrow down the scope of their navigation, while keeping a growing semantic coherence. This is unlike strategies associated to tasks with predefined search goals, namely the case of the Wikispeedia game. In this case users first move from the 'particular' to the 'universal' before focusing down again to the required target. The clear picture offered here represents a very important stepping stone towards a better design of information networks and recommendation strategies, as well as the construction of radically new learning paths.

  8. The Effect of Teaching Search Strategies on Perceptual Performance.

    Science.gov (United States)

    van der Gijp, Anouk; Vincken, Koen L; Boscardin, Christy; Webb, Emily M; Ten Cate, Olle Th J; Naeger, David M

    2017-06-01

    Radiology expertise is dependent on the use of efficient search strategies. The aim of this study is to investigate the effect of teaching search strategies on trainee's accuracy in detecting lung nodules at computed tomography. Two search strategies, "scanning" and "drilling," were tested with a randomized crossover design. Nineteen junior radiology residents were randomized into two groups. Both groups first completed a baseline lung nodule detection test allowing a free search strategy, followed by a test after scanning instruction and drilling instruction or vice versa. True positive (TP) and false positive (FP) scores and scroll behavior were registered. A mixed-design analysis of variance was applied to compare the three search conditions. Search strategy instruction had a significant effect on scroll behavior, F(1.3) = 54.2, P search (M = 15.3, SD = 4.6), t(18) = 4.44, P search. FP scores for drilling (M = 7.3, SD = 5.6) were significantly lower than for free search (M = 12.5, SD = 7.8), t(18) = 4.86, P < 0.001. Teaching a drilling strategy is preferable to teaching a scanning strategy for finding lung nodules. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  9. STAIRS Search Strategy: Ideas and Opinions.

    Science.gov (United States)

    Quinn, Karen Takle

    1980-01-01

    Concentrates on the practical, everyday aspects of online search strategy, specifically offering ideas and comments on search strategies for STAIRS users. Included are tables listing the logical operators available on the system and the search level (document, paragraph, sentence, word) of each. (Author/JD)

  10. PREFACE: The random search problem: trends and perspectives The random search problem: trends and perspectives

    Science.gov (United States)

    da Luz, Marcos G. E.; Grosberg, Alexander; Raposo, Ernesto P.; Viswanathan, Gandhi M.

    2009-10-01

    very important to solve computationally complex problems (e.g., protein folding), which involve optimizations in very high dimensional energy landscapes. On the other hand, random searches can also be studied from the perspective of diffusion and transport properties which is an important topic in condensed matter and statistical physics. For instance, the features of light scattered in a media, where the scatterers have a power-law distribution of sizes in many aspects, may resemble the patterns generated by a searcher performing Lévy walks. There are many questions related to random searches: how the searcher moves or should move, what are the patterns generated during the locomotion, how do the encounter rates depend on parameters of the search, etc. But perhaps, the most well known issue is how to optimize the search for specific target scenarios. The optimization can be in either continuous or discrete environments, when the information available is limited. The answer to this question determines specific strategies of movement that would maximize some properly defined search efficiency measure. The relevance of the question stems from the fact that the strategy-dynamics represents one of the most important factors that modulate the rate of encounters (e.g., the encounter rate between predator and prey). In the general context, strategy choices can be essential in determining the outcome and thus the success of a given search. For instance, realistic searches—and locomotion in general—require the expenditure of energy. Thus, inefficient search could deplete energy reserves (e.g., fat) and lead to rates of encounters below a minimum acceptable threshold (resulting in extinction of a species, for example). The framework of the random search `game' distinguishes between the two interacting players in a context of pursuit and chance. They are either a `searcher' (e.g., predator, protein, radar, `crawler') or a `target' (e.g., prey, DNA sequence, a missing

  11. Routine development of objectively derived search strategies

    Directory of Open Access Journals (Sweden)

    Hausner Elke

    2012-02-01

    Full Text Available Abstract Background Over the past few years, information retrieval has become more and more professionalized, and information specialists are considered full members of a research team conducting systematic reviews. Research groups preparing systematic reviews and clinical practice guidelines have been the driving force in the development of search strategies, but open questions remain regarding the transparency of the development process and the available resources. An empirically guided approach to the development of a search strategy provides a way to increase transparency and efficiency. Methods Our aim in this paper is to describe the empirically guided development process for search strategies as applied by the German Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen, or "IQWiG". This strategy consists of the following steps: generation of a test set, as well as the development, validation and standardized documentation of the search strategy. Results We illustrate our approach by means of an example, that is, a search for literature on brachytherapy in patients with prostate cancer. For this purpose, a test set was generated, including a total of 38 references from 3 systematic reviews. The development set for the generation of the strategy included 25 references. After application of textual analytic procedures, a strategy was developed that included all references in the development set. To test the search strategy on an independent set of references, the remaining 13 references in the test set (the validation set were used. The validation set was also completely identified. Discussion Our conclusion is that an objectively derived approach similar to that used in search filter development is a feasible way to develop and validate reliable search strategies. Besides creating high-quality strategies, the widespread application of this approach will result in a

  12. Collaborative Search Strategies for Green Innovation

    DEFF Research Database (Denmark)

    Ørding Olsen, Anders; Sofka, Wolfgang; Grimpe, Christoph

    Recent innovation and strategy research emphasizes the importance of firm’s search for external knowledge to improve innovation performance. We focus on such search strategies within the domain of sustainable innovation in which problems are inherently complex and the relevant knowledge is widely...... dispersed. Hence, firms need to collaborate. We shed new light on collaborative search strategies led by firms in general and for solving environmental problems in particular. Both topics are largely absent in the extant open innovation literature. Using data from the European Seventh Framework Program...... for Research and Technological Development (FP7), our results indicate that the problem-solving potential of a search strategy increases with the diversity of existing knowledge of the partners in a consortium and with the experience of the partners involved. Moreover, we identify a substantial negative effect...

  13. Strategy for early SUSY searches at ATLAS

    CERN Document Server

    Yamamoto, S

    2007-01-01

    The CERN Large Hadron Collider (LHC) is scheduled to commence operation in 2008 and inclusive searches for supersymmetry (SUSY) will be one of our primary tasks in the first days of LHC operation. It is certain that the final state of â€ワmultijets + missing transverse energy” will provide a superior performance in SUSY searches. As yet, well-considered strategies for the understanding of instrumental effects of detectors and the realistic estimations of the Standard Model (SM) backgrounds would not be clear: they are urgent issues for the coming data. We describe the strategy for early SUSY searches at the ATLAS experiment using the fist data corresponding to the integrated luminosity up to 1fb−1, which comprises many progresses in the data-driven technique for the SM background estimations.

  14. Strategy for early SUSY searches at ATLAS

    CERN Document Server

    Yamamoto, Shimpei

    2008-01-01

    The CERN Large Hadron Collider (LHC) is scheduled to commence operation in 2008 and inclusive searches for supersymmetry (SUSY) will be one of our primary tasks in the first days of LHC operation. It is certain that the final state of multijets plus missing transverse energy will provide a superior performance in SUSY searches. As yet, well-considered strategies for the understanding of instrumental effects of detectors and the realistic estimations of the Standard Model (SM) backgrounds would not be clear: they are urgent issues for the coming data. We describe the strategy for early SUSY searches at the ATLAS experiment using the fist data corresponding to the integrated luminosity up to 1fb^-1, which comprises many progresses in the data-driven technique for the SM background estimations.

  15. Strategy for early SUSY searches at ATLAS

    CERN Document Server

    Yamamoto, S

    2007-01-01

    The CERN Large Hadron Collider (LHC) is scheduled to commence operation in 2008 and inclusive searches for supersymmetry (SUSY) will be one of our primary tasks in the first days of LHC operation. It is certain that the final state of multijets plus missing transverse energy will provide a superior performance in SUSY searches. As yet, well-considered strategies for the understanding of instrumental effects of detectors and the realistic estimations of the Standard Model (SM) backgrounds would not be clear: they are urgent issues for the coming data. We describe the strategy for early SUSY searches at the ATLAS experiment using the fist data corresponding to the integrated luminosity up to 1fb^-1, which includes many progresses in the data-driven technique for the SM background estimations.

  16. Formalized Search Strategies for Human Risk Contributions

    DEFF Research Database (Denmark)

    Rasmussen, Jens; Pedersen, O. M.

    For risk management, the results of a probabilistic risk analysis (PRA) as well as the underlying assumptions can be used as references in a closed-loop risk control; and the analyses of operational experiences as a means of feedback. In this context, the need for explicit definition...... risk contributions are described on the basis of general plant design features relevant for risk and accident analysis. With this background, search strategies for human risk contributions are treated: Under the designation "work analysis", procedures for the analysis of familiar, well trained, planned...... tasks are proposed. Strategies for identifying human risk contributions outside this category are outlined....

  17. Food Searching Strategy of Amoeboid Cells by Starvation Induced Run Length Extension

    NARCIS (Netherlands)

    Van Haastert, Peter J. M.; Bosgraaf, Leonard

    2009-01-01

    Food searching strategies of animals are key to their success in heterogeneous environments. The optimal search strategy may include specialized random walks such as Levy walks with heavy power-law tail distributions, or persistent walks with preferred movement in a similar direction. We have

  18. Efficiency of pragmatic search strategies to update clinical guidelines recommendations.

    Science.gov (United States)

    Martínez García, L; Sanabria, A J; Araya, I; Lawson, J; Solà, I; Vernooij, R W M; López, D; García Álvarez, E; Trujillo-Martín, M M; Etxeandia-Ikobaltzeta, I; Kotzeva, A; Rigau, D; Louro-González, A; Barajas-Nava, L; Díaz del Campo, P; Estrada, M D; Gracia, J; Salcedo-Fernandez, F; Haynes, R B; Alonso-Coello, P

    2015-07-31

    A major challenge in updating clinical guidelines is to efficiently identify new, relevant evidence. We evaluated the efficiency and feasibility of two new approaches: the development of restrictive search strategies using PubMed Clinical Queries for MEDLINE and the use of the PLUS (McMaster Premium Literature Service) database. We evaluated a random sample of recommendations from a national guideline development program and identified the references that would potentially trigger an update (key references) using an exhaustive approach. We designed restrictive search strategies using the minimum number of Medical Subject Headings (MeSH) terms and text words required from the original exhaustive search strategies and applying broad and narrow filters. We developed PLUS search strategies, matching Medical Subject Headings (MeSH) and Systematized Nomenclature of Medicine (SNOMED) terms with guideline topics. We compared the number of key references retrieved by these approaches with those retrieved by the exhaustive approach. The restrictive approach retrieved 68.1 % fewer references than the exhaustive approach (12,486 versus 39,136), and identified 89.9 % (62/69) of key references and 88 % (22/25) of recommendation updates. The use of PLUS retrieved 88.5 % fewer references than the exhaustive approach (4,486 versus 39,136) and identified substantially fewer key references (18/69, 26.1 %) and fewer recommendation updates (10/25, 40 %). The proposed restrictive approach is a highly efficient and feasible method to identify new evidence that triggers a recommendation update. Searching only in the PLUS database proved to be a suboptimal approach and suggests the need for topic-specific tailoring.

  19. Organizational Search Strategy: An Examination of Interdependencies, Locus and Temporality of Search

    NARCIS (Netherlands)

    Ebrahim, Mahdi

    2017-01-01

    Notwithstanding the ample research on organizational search and its performance implications, the factors that shape the organizations’ search strategy is fairly under-explored. This study investigates how problems’ characteristics influence the managerial decision of searching jointly or

  20. Mate choice and optimal search behavior: fitness returns under the fixed sample and sequential search strategies.

    Science.gov (United States)

    Wiegmann, Daniel D; Seubert, Steven M; Wade, Gordon A

    2010-02-21

    The behavior of a female in search of a mate determines the likelihood that she encounters a high-quality male in the search process. The fixed sample (best-of-n) search strategy and the sequential search (fixed threshold) strategy are two prominent models of search behavior. The sequential search strategy dominates the former strategy--yields an equal or higher expected net fitness return to searchers--when search costs are nontrivial and the distribution of quality among prospective mates is uniform or truncated normal. In this paper our objective is to determine whether there are any search costs or distributions of male quality for which the sequential search strategy is inferior to the fixed sample search strategy. The two search strategies are derived under general conditions in which females evaluate encountered males by inspection of an indicator character that has some functional relationship to male quality. The solutions are identical to the original models when the inspected male attribute is itself male quality. The sequential search strategy is shown to dominate the fixed sample search strategy for all search costs and distributions of male quality. Low search costs have been implicated to explain empirical observations that are consistent with the use of a fixed sample search strategy, but under conditions in which the original models were derived there is no search cost or distribution of male quality that favors the fixed sample search strategy. Plausible alternative explanations for the apparent use of this search strategy are discussed. (c) 2009 Elsevier Ltd. All rights reserved.

  1. Optimal intermittent search strategies: smelling the prey

    Energy Technology Data Exchange (ETDEWEB)

    Revelli, J A; Wio, H S [Instituto de Fisica de Cantabria, Universidad de Cantabria and CSIC, E-39005 Santander (Spain); Rojo, F; Budde, C E [Fa.M.A.F., Universidad Nacional de Cordoba, Ciudad Universitaria, X5000HUA Cordoba (Argentina)

    2010-05-14

    We study the kinetics of the search of a single fixed target by a searcher/walker that performs an intermittent random walk, characterized by different states of motion. In addition, we assume that the walker has the ability to detect the scent left by the prey/target in its surroundings. Our results, in agreement with intuition, indicate that the prey's survival probability could be strongly reduced (increased) if the predator is attracted (or repelled) by the trace left by the prey. We have also found that, for a positive trace (the predator is guided towards the prey), increasing the inhomogeneity's size reduces the prey's survival probability, while the optimal value of {alpha} (the parameter that regulates intermittency) ceases to exist. The agreement between theory and numerical simulations is excellent.

  2. Genetic algorithms as global random search methods

    Science.gov (United States)

    Peck, Charles C.; Dhawan, Atam P.

    1995-01-01

    Genetic algorithm behavior is described in terms of the construction and evolution of the sampling distributions over the space of candidate solutions. This novel perspective is motivated by analysis indicating that the schema theory is inadequate for completely and properly explaining genetic algorithm behavior. Based on the proposed theory, it is argued that the similarities of candidate solutions should be exploited directly, rather than encoding candidate solutions and then exploiting their similarities. Proportional selection is characterized as a global search operator, and recombination is characterized as the search process that exploits similarities. Sequential algorithms and many deletion methods are also analyzed. It is shown that by properly constraining the search breadth of recombination operators, convergence of genetic algorithms to a global optimum can be ensured.

  3. Greedy Local Search and Vertex Cover in Sparse Random Graphs

    DEFF Research Database (Denmark)

    Witt, Carsten

    2009-01-01

    finds an optimal cover in polynomial time with a probability arbitrarily close to 1. This behavior relies on the absence of a giant component. As an additional insight into the randomized search, it is shown that the heuristic fails badly also on graphs consisting of a single tree component of maximum......Recently, various randomized search heuristics have been studied for the solution of the minimum vertex cover problem, in particular for sparse random instances according to the G(n, c/n) model, where c > 0 is a constant. Methods from statistical physics suggest that the problem is easy if c .... This work starts with a rigorous explanation for this claim based on the refined analysis of the Karp-Sipser algorithm by Aronson et al. Subsequently, theoretical supplements are given to experimental studies of search heuristics on random graphs. For c search heuristic...

  4. Uncovering Web search strategies in South African higher education

    Directory of Open Access Journals (Sweden)

    Surika Civilcharran

    2016-11-01

    Full Text Available Background: In spite of the enormous amount of information available on the Web and the fact that search engines are continuously evolving to enhance the search experience, students are nevertheless faced with the difficulty of effectively retrieving information. It is, therefore, imperative for the interaction between students and search tools to be understood and search strategies to be identified, in order to promote successful information retrieval. Objectives: This study identifies the Web search strategies used by postgraduate students and forms part of a wider study into information retrieval strategies used by postgraduate students at the University of KwaZulu-Natal (UKZN, Pietermaritzburg campus, South Africa. Method: Largely underpinned by Thatcher’s cognitive search strategies, the mixed-methods approach was utilised for this study, in which questionnaires were employed in Phase 1 and structured interviews in Phase 2. This article reports and reflects on the findings of Phase 2, which focus on identifying the Web search strategies employed by postgraduate students. The Phase 1 results were reported in Civilcharran, Hughes and Maharaj (2015. Results: Findings reveal the Web search strategies used for academic information retrieval. In spite of easy access to the invisible Web and the advent of meta-search engines, the use of Web search engines still remains the preferred search tool. The UKZN online library databases and especially the UKZN online library, Online Public Access Catalogue system, are being underutilised. Conclusion: Being ranked in the top three percent of the world’s universities, UKZN is investing in search tools that are not being used to their full potential. This evidence suggests an urgent need for students to be trained in Web searching and to have a greater exposure to a variety of search tools. This article is intended to further contribute to the design of undergraduate training programmes in order to deal

  5. Uncovering Web search strategies in South African higher education

    Directory of Open Access Journals (Sweden)

    Surika Civilcharran

    2016-04-01

    Full Text Available Background: In spite of the enormous amount of information available on the Web and the fact that search engines are continuously evolving to enhance the search experience, students are nevertheless faced with the difficulty of effectively retrieving information. It is, therefore, imperative for the interaction between students and search tools to be understood and search strategies to be identified, in order to promote successful information retrieval.Objectives: This study identifies the Web search strategies used by postgraduate students and forms part of a wider study into information retrieval strategies used by postgraduate students at the University of KwaZulu-Natal (UKZN, Pietermaritzburg campus, South Africa. Method: Largely underpinned by Thatcher’s cognitive search strategies, the mixed-methods approach was utilised for this study, in which questionnaires were employed in Phase 1 and structured interviews in Phase 2. This article reports and reflects on the findings of Phase 2, which focus on identifying the Web search strategies employed by postgraduate students. The Phase 1 results were reported in Civilcharran, Hughes and Maharaj (2015.Results: Findings reveal the Web search strategies used for academic information retrieval. In spite of easy access to the invisible Web and the advent of meta-search engines, the use of Web search engines still remains the preferred search tool. The UKZN online library databases and especially the UKZN online library, Online Public Access Catalogue system, are being underutilised.Conclusion: Being ranked in the top three percent of the world’s universities, UKZN is investing in search tools that are not being used to their full potential. This evidence suggests an urgent need for students to be trained in Web searching and to have a greater exposure to a variety of search tools. This article is intended to further contribute to the design of undergraduate training programmes in order to deal

  6. An adaptive random search for short term generation scheduling with network constraints.

    Directory of Open Access Journals (Sweden)

    J A Marmolejo

    Full Text Available This paper presents an adaptive random search approach to address a short term generation scheduling with network constraints, which determines the startup and shutdown schedules of thermal units over a given planning horizon. In this model, we consider the transmission network through capacity limits and line losses. The mathematical model is stated in the form of a Mixed Integer Non Linear Problem with binary variables. The proposed heuristic is a population-based method that generates a set of new potential solutions via a random search strategy. The random search is based on the Markov Chain Monte Carlo method. The main key of the proposed method is that the noise level of the random search is adaptively controlled in order to exploring and exploiting the entire search space. In order to improve the solutions, we consider coupling a local search into random search process. Several test systems are presented to evaluate the performance of the proposed heuristic. We use a commercial optimizer to compare the quality of the solutions provided by the proposed method. The solution of the proposed algorithm showed a significant reduction in computational effort with respect to the full-scale outer approximation commercial solver. Numerical results show the potential and robustness of our approach.

  7. Search strategies in systematic reviews in periodontology and implant dentistry.

    Science.gov (United States)

    Faggion, Clovis M; Atieh, Momen A; Park, Stephanie

    2013-09-01

    To perform an overview of literature search strategies in systematic reviews (SRs) published in periodontology and implant dentistry. Two electronic databases (PubMed and Cochrane Database of SRs) were searched, independently and in duplicate, for SRs with meta-analyses on interventions, with the last search performed on 11 November 2012. Manual searches of the reference lists of included SRs and 10 specialty dental journals were conducted. Methodological issues of the search strategies of included SRs were assessed with Cochrane collaboration guidelines and AMSTAR recommendations. The search strategies employed in Cochrane and paper-based SRs were compared. A total of 146 SRs with meta-analyses were included, including 19 Cochrane and 127 paper-based SRs. Some issues, such as "the use of keywords," were reported in most of the SRs (86%). Other issues, such as "search of grey literature" and "language restriction," were not fully reported (34% and 50% respectively). The quality of search strategy reporting in Cochrane SRs was better than that of paper-based SRs for seven of the eight criteria assessed. There is room for improving the quality of reporting of search strategies in SRs in periodontology and implant dentistry, particularly in SRs published in paper-based journals. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Influence of scene structure and content on visual search strategies.

    Science.gov (United States)

    Amor, Tatiana A; Luković, Mirko; Herrmann, Hans J; Andrade, José S

    2017-07-01

    When searching for a target within an image, our brain can adopt different strategies, but which one does it choose? This question can be answered by tracking the motion of the eye while it executes the task. Following many individuals performing various search tasks, we distinguish between two competing strategies. Motivated by these findings, we introduce a model that captures the interplay of the search strategies and allows us to create artificial eye-tracking trajectories, which could be compared with the experimental ones. Identifying the model parameters allows us to quantify the strategy employed in terms of ensemble averages, characterizing each experimental cohort. In this way, we can discern with high sensitivity the relation between the visual landscape and the average strategy, disclosing how small variations in the image induce changes in the strategy. © 2017 The Author(s).

  9. Target contact and exploration strategies in haptic search

    NARCIS (Netherlands)

    van Polanen, V.; Bergmann Tiest, W.M.; Kappers, A.M.L.

    2014-01-01

    In a haptic search task, one has to detect the presence of a target among distractors using the sense of touch. A salient target can be detected faster than a non-salient target. However, little is known about the exploration strategies that are used, especially in 3D search tasks where items are

  10. Randomized discrepancy bounded local search for transmission expansion planning

    Energy Technology Data Exchange (ETDEWEB)

    Bent, Russell W [Los Alamos National Laboratory; Daniel, William B [Los Alamos National Laboratory

    2010-11-23

    In recent years the transmission network expansion planning problem (TNEP) has become increasingly complex. As the TNEP is a non-linear and non-convex optimization problem, researchers have traditionally focused on approximate models of power flows to solve the TNEP. Existing approaches are often tightly coupled to the approximation choice. Until recently these approximations have produced results that are straight-forward to adapt to the more complex (real) problem. However, the power grid is evolving towards a state where the adaptations are no longer easy (e.g. large amounts of limited control, renewable generation) and necessitates new approaches. Recent work on deterministic Discrepancy Bounded Local Search (DBLS) has shown it to be quite effective in addressing this question. DBLS encapsulates the complexity of power flow modeling in a black box that may be queried for information about the quality of proposed expansions. In this paper, we propose a randomization strategy that builds on DBLS and dramatically increases the computational efficiency of the algorithm.

  11. Designing Search UX Strategies for eCommerce Success

    CERN Document Server

    Nudelman, Greg

    2011-01-01

    Best practices, practical advice, and design ideas for successful ecommerce search A glaring gap has existed in the market for a resource that offers a comprehensive, actionable design patterns and design strategies for ecommerce search-but no longer. With this invaluable book, user experience designer and user researcher Greg Nudelman shares his years of experience working on popular ecommerce sites as he tackles even the most difficult ecommerce search design problems. Nudelman helps you create highly effective and intuitive ecommerce search design solutions and he takes a unique forward-thi

  12. Concentrated Hitting Times of Randomized Search Heuristics with Variable Drift

    DEFF Research Database (Denmark)

    Lehre, Per Kristian; Witt, Carsten

    2014-01-01

    Drift analysis is one of the state-of-the-art techniques for the runtime analysis of randomized search heuristics (RSHs) such as evolutionary algorithms (EAs), simulated annealing etc. The vast majority of existing drift theorems yield bounds on the expected value of the hitting time for a target...

  13. The Correlates of Taiwan Teachers' Epistemological Beliefs concerning Internet Environments, Online Search Strategies, and Search Outcomes

    Science.gov (United States)

    Tsai, Pei-Shan; Tsai, Chin-Chung; Hwang, Gwo-Jen

    2011-01-01

    This study aimed to explore the correlates among teachers' epistemological beliefs concerning Internet environments, their web search strategies and search outcomes. The sample of this study included 105 teachers from 63 grades 1 to 9 schools in Taiwan. The results show that the teachers with more advanced epistemological beliefs concerning…

  14. Online games: a novel approach to explore how partial information influences human random searches

    Science.gov (United States)

    Martínez-García, Ricardo; Calabrese, Justin M.; López, Cristóbal

    2017-01-01

    Many natural processes rely on optimizing the success ratio of a search process. We use an experimental setup consisting of a simple online game in which players have to find a target hidden on a board, to investigate how the rounds are influenced by the detection of cues. We focus on the search duration and the statistics of the trajectories traced on the board. The experimental data are explained by a family of random-walk-based models and probabilistic analytical approximations. If no initial information is given to the players, the search is optimized for cues that cover an intermediate spatial scale. In addition, initial information about the extension of the cues results, in general, in faster searches. Finally, strategies used by informed players turn into non-stationary processes in which the length of e ach displacement evolves to show a well-defined characteristic scale that is not found in non-informed searches.

  15. Theory of Randomized Search Heuristics in Combinatorial Optimization

    DEFF Research Database (Denmark)

    such as time, money, or knowledge to obtain good specific algorithms. It is widely acknowledged that a solid mathematical foundation for such heuristics is needed. Most designers of RSHs, however, rather focused on mimicking processes in nature (such as evolution) rather than making the heuristics amenable......The rigorous mathematical analysis of randomized search heuristics(RSHs) with respect to their expected runtime is a growing research area where many results have been obtained in recent years. This class of heuristics includes well-known approaches such as Randomized Local Search (RLS...... to a mathematical analysis. This is different to the classical design of (randomized) algorithms which are developed with their theoretical analysis of runtime (and proof of correctness) in mind. Despite these obstacles, research from the last about 15 years has shown how to apply the methods for the probabilistic...

  16. Optimizing Event Selection with the Random Grid Search

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, Pushpalatha C. [Fermilab; Prosper, Harrison B. [Florida State U.; Sekmen, Sezen [Kyungpook Natl. U.; Stewart, Chip [Broad Inst., Cambridge

    2017-06-29

    The random grid search (RGS) is a simple, but efficient, stochastic algorithm to find optimal cuts that was developed in the context of the search for the top quark at Fermilab in the mid-1990s. The algorithm, and associated code, have been enhanced recently with the introduction of two new cut types, one of which has been successfully used in searches for supersymmetry at the Large Hadron Collider. The RGS optimization algorithm is described along with the recent developments, which are illustrated with two examples from particle physics. One explores the optimization of the selection of vector boson fusion events in the four-lepton decay mode of the Higgs boson and the other optimizes SUSY searches using boosted objects and the razor variables.

  17. Search strategies to identify reports on “off-label” drug use in EMBASE

    Directory of Open Access Journals (Sweden)

    Mesgarpour Bita

    2012-12-01

    Full Text Available Abstract Background Medications are frequently prescribed outside their regulatory approval (off-label by physicians particularly where appropriate therapies are not available. However, the risk/benefit ratio of drugs in off-label use needs to be critically appraised because it may differ from approved on-label usage. Therefore, an extensive exploration of current evidence on clinical data is well-advised. The objective of this study was to develop a search strategy that facilitates detection of the off-label drug use documents in EMBASE via OvidSP. Methods We constructed two sets of gold standards from relevant records to off-label drug use by a sensitive search of MEDLINE and EMBASE. Search queries, including search words and strings, were conceived based on definition of off-label use of medications as well as text analysis of 500 randomly selected relevant documents. The selected terms were searched in EMBASE (from 1988 to 2011 and their retrieval performance was compared with the gold standards. We developed a sensitivity-maximizing, and a sensitivity- and precision-maximizing search strategy. Results From 4067 records relevant to off-label drug use in our full gold standard set, 3846 records were retrievable from EMBASE. “off label*.af.” was the most sensitive single term (overall sensitivity 77.5%, sensitivity within EMBASE 81.9%, precision 88.1%. The highest sensitive search strategy was achieved by combining 36 search queries with overall sensitivity of 94.0% and precision of 69.5%. An optimal sensitive and precise search strategy was yielded precision 87.4% at the expense of decreasing overall sensitivity to 89.4%. Conclusion We developed highly sensitive search strategies to enhance the retrieval of studies on off-label drug use in OvidSP EMBASE.

  18. STRATEGIES IN SEARCH FOR INTERNATIONAL PARTNERSHIPS

    Directory of Open Access Journals (Sweden)

    Denise de Freitas

    Full Text Available Introduction: Internationalization is the process which integrates universal, intercultural or global dimension in a program, in this case, postgraduate. It can be understood as the process of increasing participation in international operations. Method: To offer design and motivational logistics on how to run a process of international scientific relationship. Results: It is necessary to develop several different aspects to be reached internationalization: to know the fundamentals of internationalization; to have international vision; to promote strategy for internationalization; to know the characteristics of an institutional center of internationalization; and to understand the institutional advantages of internationalization. Conclusion: Internationalization is essential to aerate the Brazilian postgraduate and not mischaracterize or weakens the process. On the contrary, it contributes to increase its vitality and capacity for innovation. Today is not possible to imagine science without internationalization.

  19. Random search optimization based on genetic algorithm and discriminant function

    Science.gov (United States)

    Kiciman, M. O.; Akgul, M.; Erarslanoglu, G.

    1990-01-01

    The general problem of optimization with arbitrary merit and constraint functions, which could be convex, concave, monotonic, or non-monotonic, is treated using stochastic methods. To improve the efficiency of the random search methods, a genetic algorithm for the search phase and a discriminant function for the constraint-control phase were utilized. The validity of the technique is demonstrated by comparing the results to published test problem results. Numerical experimentation indicated that for cases where a quick near optimum solution is desired, a general, user-friendly optimization code can be developed without serious penalties in both total computer time and accuracy.

  20. Search strategies in practice: Influence of information and task constraints.

    Science.gov (United States)

    Pacheco, Matheus M; Newell, Karl M

    2017-11-07

    The practice of a motor task has been conceptualized as a process of search through a perceptual-motor workspace. The present study investigated the influence of information and task constraints on the search strategy as reflected in the sequential relations of the outcome in a discrete movement virtual projectile task. The results showed that the relation between the changes of trial-to-trial movement outcome to performance level was dependent on the landscape of the task dynamics and the influence of inherent variability. Furthermore, the search was in a constrained parameter region of the perceptual-motor workspace that depended on the task constraints. These findings show that there is not a single function of trial-to-trial change over practice but rather that local search strategies (proportional, discontinuous, constant) adapt to the level of performance and the confluence of constraints to action. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Quasi-steady-state analysis of two-dimensional random intermittent search processes

    KAUST Repository

    Bressloff, Paul C.

    2011-06-01

    We use perturbation methods to analyze a two-dimensional random intermittent search process, in which a searcher alternates between a diffusive search phase and a ballistic movement phase whose velocity direction is random. A hidden target is introduced within a rectangular domain with reflecting boundaries. If the searcher moves within range of the target and is in the search phase, it has a chance of detecting the target. A quasi-steady-state analysis is applied to the corresponding Chapman-Kolmogorov equation. This generates a reduced Fokker-Planck description of the search process involving a nonzero drift term and an anisotropic diffusion tensor. In the case of a uniform direction distribution, for which there is zero drift, and isotropic diffusion, we use the method of matched asymptotics to compute the mean first passage time (MFPT) to the target, under the assumption that the detection range of the target is much smaller than the size of the domain. We show that an optimal search strategy exists, consistent with previous studies of intermittent search in a radially symmetric domain that were based on a decoupling or moment closure approximation. We also show how the decoupling approximation can break down in the case of biased search processes. Finally, we analyze the MFPT in the case of anisotropic diffusion and find that anisotropy can be useful when the searcher starts from a fixed location. © 2011 American Physical Society.

  2. Performance of a class of multi-robot deploy and search strategies based on centroidal voronoi configurations

    Science.gov (United States)

    Guruprasad, K. R.; Ghose, Debasish

    2013-04-01

    This article considers a class of deploy and search strategies for multi-robot systems and evaluates their performance. The application framework used is deployment of a system of autonomous mobile robots equipped with required sensors in a search space to gather information. The lack of information about the search space is modelled as an uncertainty density distribution. The agents are deployed to maximise single-step search effectiveness. The centroidal Voronoi configuration, which achieves a locally optimal deployment, forms the basis for sequential deploy and search (SDS) and combined deploy and search (CDS) strategies. Completeness results are provided for both search strategies. The deployment strategy is analysed in the presence of constraints on robot speed and limit on sensor range for the convergence of trajectories with corresponding control laws responsible for the motion of robots. SDS and CDS strategies are compared with standard greedy and random search strategies on the basis of time taken to achieve reduction in the uncertainty density below a desired level. The simulation experiments reveal several important issues related to the dependence of the relative performances of the search strategies on parameters such as the number of robots, speed of robots and their sensor range limits.

  3. A Competitive and Experiential Assignment in Search Engine Optimization Strategy

    Science.gov (United States)

    Clarke, Theresa B.; Clarke, Irvine, III

    2014-01-01

    Despite an increase in ad spending and demand for employees with expertise in search engine optimization (SEO), methods for teaching this important marketing strategy have received little coverage in the literature. Using Bloom's cognitive goals hierarchy as a framework, this experiential assignment provides a process for educators who may be new…

  4. Alternative search strategies to explore ATLAS diboson excess

    Indian Academy of Sciences (India)

    Charanjit K Khosa

    Alternative search strategies to explore ATLAS diboson excess. CHARANJIT K KHOSA. Centre for High Energy Physics, Indian Institute of Science, Bengaluru 560 012, India. E-mail: khosacharanjit@chep.iisc.ernet.in. Published online 5 October 2017. Abstract. We consider the s-channel resonance to fit the 2 TeV ATLAS ...

  5. A search strategy for occupational health intervention studies

    NARCIS (Netherlands)

    Verbeek, J.; Salmi, J.; Pasternack, I.; Jauhiainen, M.; Laamanen, I.; Schaafsma, F.; Hulshof, C.; van Dijk, F.

    2005-01-01

    As a result of low numbers and diversity in study type, occupational health intervention studies are not easy to locate in electronic literature databases. To develop a search strategy that facilitates finding occupational health intervention studies in Medline, both for researchers and

  6. Early detection network design and search strategy issues

    Science.gov (United States)

    We conducted a series of field and related modeling studies (2005-2012) to evaluate search strategies for Great Lakes coastal ecosystems that are at risk of invasion by non-native aquatic species. In developing a network, we should design to achieve an acceptable limit of detect...

  7. Strategies to optimize MEDLINE and EMBASE search strategies for anesthesiology systematic reviews. An experimental study.

    Science.gov (United States)

    Volpato, Enilze de Souza Nogueira; Betini, Marluci; Puga, Maria Eduarda; Agarwal, Arnav; Cataneo, Antônio José Maria; Oliveira, Luciane Dias de; Bazan, Rodrigo; Braz, Leandro Gobbo; Pereira, José Eduardo Guimarães; Dib, Regina El

    2018-01-15

    A high-quality electronic search is essential for ensuring accuracy and comprehensiveness among the records retrieved when conducting systematic reviews. Therefore, we aimed to identify the most efficient method for searching in both MEDLINE (through PubMed) and EMBASE, covering search terms with variant spellings, direct and indirect orders, and associations with MeSH and EMTREE terms (or lack thereof). Experimental study. UNESP, Brazil. We selected and analyzed 37 search strategies that had specifically been developed for the field of anesthesiology. These search strategies were adapted in order to cover all potentially relevant search terms, with regard to variant spellings and direct and indirect orders, in the most efficient manner. When the strategies included variant spellings and direct and indirect orders, these adapted versions of the search strategies selected retrieved the same number of search results in MEDLINE (mean of 61.3%) and a higher number in EMBASE (mean of 63.9%) in the sample analyzed. The numbers of results retrieved through the searches analyzed here were not identical with and without associated use of MeSH and EMTREE terms. However, association of these terms from both controlled vocabularies retrieved a larger number of records than did the use of either one of them. In view of these results, we recommend that the search terms used should include both preferred and non-preferred terms (i.e. variant spellings and direct/indirect order of the same term) and associated MeSH and EMTREE terms, in order to develop highly-sensitive search strategies for systematic reviews.

  8. Strategies to optimize MEDLINE and EMBASE search strategies for anesthesiology systematic reviews. An experimental study

    Directory of Open Access Journals (Sweden)

    Enilze de Souza Nogueira Volpato

    2018-01-01

    Full Text Available ABSTRACT BACKGROUND: A high-quality electronic search is essential for ensuring accuracy and comprehensiveness among the records retrieved when conducting systematic reviews. Therefore, we aimed to identify the most efficient method for searching in both MEDLINE (through PubMed and EMBASE, covering search terms with variant spellings, direct and indirect orders, and associations with MeSH and EMTREE terms (or lack thereof. DESIGN AND SETTING: Experimental study. UNESP, Brazil. METHODS: We selected and analyzed 37 search strategies that had specifically been developed for the field of anesthesiology. These search strategies were adapted in order to cover all potentially relevant search terms, with regard to variant spellings and direct and indirect orders, in the most efficient manner. RESULTS: When the strategies included variant spellings and direct and indirect orders, these adapted versions of the search strategies selected retrieved the same number of search results in MEDLINE (mean of 61.3% and a higher number in EMBASE (mean of 63.9% in the sample analyzed. The numbers of results retrieved through the searches analyzed here were not identical with and without associated use of MeSH and EMTREE terms. However, association of these terms from both controlled vocabularies retrieved a larger number of records than did the use of either one of them. CONCLUSIONS: In view of these results, we recommend that the search terms used should include both preferred and non-preferred terms (i.e. variant spellings and direct/indirect order of the same term and associated MeSH and EMTREE terms, in order to develop highly-sensitive search strategies for systematic reviews.

  9. An experimental search strategy retrieves more precise results than PubMed and Google for questions about medical interventions

    Directory of Open Access Journals (Sweden)

    Robert G. Badgett

    2015-04-01

    Full Text Available Objective. We compared the precision of a search strategy designed specifically to retrieve randomized controlled trials (RCTs and systematic reviews of RCTs with search strategies designed for broader purposes.Methods. We designed an experimental search strategy that automatically revised searches up to five times by using increasingly restrictive queries as long at least 50 citations were retrieved. We compared the ability of the experimental and alternative strategies to retrieve studies relevant to 312 test questions. The primary outcome, search precision, was defined for each strategy as the proportion of relevant, high quality citations among the first 50 citations retrieved.Results. The experimental strategy had the highest median precision (5.5%; interquartile range [IQR]: 0%–12% followed by the narrow strategy of the PubMed Clinical Queries (4.0%; IQR: 0%–10%. The experimental strategy found the most high quality citations (median 2; IQR: 0–6 and was the strategy most likely to find at least one high quality citation (73% of searches; 95% confidence interval 68%–78%. All comparisons were statistically significant.Conclusions. The experimental strategy performed the best in all outcomes although all strategies had low precision.

  10. Improved quantum-behaved particle swarm optimization with local search strategy

    Directory of Open Access Journals (Sweden)

    Maolong Xi

    2017-03-01

    Full Text Available Quantum-behaved particle swarm optimization, which was motivated by analysis of particle swarm optimization and quantum system, has shown compared performance in finding the optimal solutions for many optimization problems to other evolutionary algorithms. To address the problem of premature, a local search strategy is proposed to improve the performance of quantum-behaved particle swarm optimization. In proposed local search strategy, a super particle is presented which is a collection body of randomly selected particles’ dimension information in the swarm. The selected probability of particles in swarm is different and determined by their fitness values. To minimization problems, the fitness value of one particle is smaller; the selected probability is more and will contribute more information in constructing the super particle. In addition, in order to investigate the influence on algorithm performance with different local search space, four methods of computing the local search radius are applied in local search strategy and propose four variants of local search quantum-behaved particle swarm optimization. Empirical studies on a suite of well-known benchmark functions are undertaken in order to make an overall performance comparison among the proposed methods and other quantum-behaved particle swarm optimization. The simulation results show that the proposed quantum-behaved particle swarm optimization variants have better advantages over the original quantum-behaved particle swarm optimization.

  11. Localization Transition Induced by Learning in Random Searches

    Science.gov (United States)

    Falcón-Cortés, Andrea; Boyer, Denis; Giuggioli, Luca; Majumdar, Satya N.

    2017-10-01

    We solve an adaptive search model where a random walker or Lévy flight stochastically resets to previously visited sites on a d -dimensional lattice containing one trapping site. Because of reinforcement, a phase transition occurs when the resetting rate crosses a threshold above which nondiffusive stationary states emerge, localized around the inhomogeneity. The threshold depends on the trapping strength and on the walker's return probability in the memoryless case. The transition belongs to the same class as the self-consistent theory of Anderson localization. These results show that similarly to many living organisms and unlike the well-studied Markovian walks, non-Markov movement processes can allow agents to learn about their environment and promise to bring adaptive solutions in search tasks.

  12. Optimization by GRASP greedy randomized adaptive search procedures

    CERN Document Server

    Resende, Mauricio G C

    2016-01-01

    This is the first book to cover GRASP (Greedy Randomized Adaptive Search Procedures), a metaheuristic that has enjoyed wide success in practice with a broad range of applications to real-world combinatorial optimization problems. The state-of-the-art coverage and carefully crafted pedagogical style lends this book highly accessible as an introductory text not only to GRASP, but also to combinatorial optimization, greedy algorithms, local search, and path-relinking, as well as to heuristics and metaheuristics, in general. The focus is on algorithmic and computational aspects of applied optimization with GRASP with emphasis given to the end-user, providing sufficient information on the broad spectrum of advances in applied optimization with GRASP. For the more advanced reader, chapters on hybridization with path-relinking and parallel and continuous GRASP present these topics in a clear and concise fashion. Additionally, the book offers a very complete annotated bibliography of GRASP and combinatorial optimizat...

  13. Search strategies on the Internet: general and specific.

    Science.gov (United States)

    Bottrill, Krys

    2004-06-01

    Some of the most up-to-date information on scientific activity is to be found on the Internet; for example, on the websites of academic and other research institutions and in databases of currently funded research studies provided on the websites of funding bodies. Such information can be valuable in suggesting new approaches and techniques that could be applicable in a Three Rs context. However, the Internet is a chaotic medium, not subject to the meticulous classification and organisation of classical information resources. At the same time, Internet search engines do not match the sophistication of search systems used by database hosts. Also, although some offer relatively advanced features, user awareness of these tends to be low. Furthermore, much of the information on the Internet is not accessible to conventional search engines, giving rise to the concept of the "Invisible Web". General strategies and techniques for Internet searching are presented, together with a comparative survey of selected search engines. The question of how the Invisible Web can be accessed is discussed, as well as how to keep up-to-date with Internet content and improve searching skills.

  14. Visual Search Strategy During Regatta Starts in a Sailing Simulation.

    Science.gov (United States)

    Manzanares, Aaron; Menayo, Ruperto; Segado, Francisco

    2017-10-01

    In a sport conditioned by natural elements such as sailing, visual perception is a key factor for the performance. Research has shown that the visual behavior of athletes at different skill levels varies, which may cause differences in the performance achieved. The aim of this research was to examine the visual behavior of sailors from different ranking positions at the start of a race in a simulated situation. Twenty junior sailors (N = 10 top and N = 10 bottom ranking) participated in this study. The visual behavior was recorded at the start of a sailing simulation. The top-ranking sailors performed more visual fixations on the locations that have more highly relevant information, such as "telltales" and "rivals," than do bottom-ranking sailors (p visual search strategy shows that top-ranking sailors employed a more active visual search strategy. More experienced athletes can make better use of the information obtained from the important locations.

  15. Search strategies for charged Higgs bosons in ATLAS

    CERN Document Server

    Ferrari, A; The ATLAS collaboration

    2010-01-01

    Charged Higgs bosons are predicted by various theories beyond the Standard Model, where the Higgs sector consists of more than only one doublet of scalar fields. Search strategies for charged Higgs bosons in the ATLAS experiment at the Large Hadron Collider (LHC) are presented. In particular, if m(H+)search strategies for heavy charged Higgs bosons, for a 14 TeV LHC operation, results of Monte-Carlo studies recently performed for a 7 TeV centre-of-mass energy, i.e. for the early data-taking period, is presented.

  16. Search strategies for charged Higgs bosons in ATLAS

    CERN Document Server

    Ferrari, A; The ATLAS collaboration

    2010-01-01

    Charged Higgs bosons are predicted by various theories beyond the Standard Model, where the Higgs sector consists of more than only one doublet of scalar fields. Search strategies for charged Higgs bosons in the ATLAS experiment at the Large Hadron Collider (LHC) are presented. In particular, if m_{H+} search strategies for heavy charged Higgs bosons, for a 14 TeV LHC operation, results of Monte-Carlo studies recently performed for a 7 TeV centre-of-mass energy, i.e. for the early data-taking period, are presented.

  17. In Search of Search Engine Marketing Strategy Amongst SME's in Ireland

    Science.gov (United States)

    Barry, Chris; Charleton, Debbie

    Researchers have identified the Web as a searchers first port of call for locating information. Search Engine Marketing (SEM) strategies have been noted as a key consideration when developing, maintaining and managing Websites. A study presented here of SEM practices of Irish small to medium enterprises (SMEs) reveals they plan to spend more resources on SEM in the future. Most firms utilize an informal SEM strategy, where Website optimization is perceived most effective in attracting traffic. Respondents cite the use of ‘keywords in title and description tags’ as the most used SEM technique, followed by the use of ‘keywords throughout the whole Website’; while ‘Pay for Placement’ was most widely used Paid Search technique. In concurrence with the literature, measuring SEM performance remains a significant challenge with many firms unsure if they measure it effectively. An encouraging finding is that Irish SMEs adopt a positive ethical posture when undertaking SEM.

  18. Optimal swimming strategies in mate searching pelagic copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2008-01-01

    Male copepods must swim to find females, but swimming increases the risk of meeting predators and is expensive in terms of energy expenditure. Here I address the trade-offs between gains and risks and the question of how much and how fast to swim using simple models that optimise the number...... of lifetime mate encounters. Radically different swimming strategies are predicted for different feeding behaviours, and these predictions are tested experimentally using representative species. In general, male swimming speeds and the difference in swimming speeds between the genders are predicted...... and observed to increase with increasing conflict between mate searching and feeding. It is high in ambush feeders, where searching (swimming) and feeding are mutually exclusive and low in species, where the matured males do not feed at all. Ambush feeding males alternate between stationary ambush feeding...

  19. ATLAS Search Strategy for Single-Top Production

    CERN Document Server

    Husemann, U; The ATLAS collaboration

    2010-01-01

    The search strategy of the ATLAS experiment for single top quark production during the first two years of data-taking at the LHC is presented. The study fucuses on the dominant t-channel production process, assuming an integrated luminoisyt of 200/pb at a center-of-mass energy of 10 TeV. An artificial neural network is employed to control background from ttbar production and W boson production in association with jets. Single-top sensitivities obtained with a sequential cut analysis and a robust likelihood ratio discriminant are compared.

  20. The Impact of Parametrization on Randomized Search Heuristics

    DEFF Research Database (Denmark)

    Gießen, Christian

    optimization algorithms. We consider the following topics. Escaping local optima using local search. We analyze memetic algorithms, i.e. evolutionary algorithms equipped with a local search after mutation. To this end we consider the (1+1) EA equipped with Standard Local Search (SLS) and Variable-Depth Search...

  1. An Improved Harmony Search Based on Teaching-Learning Strategy for Unconstrained Optimization Problems

    Directory of Open Access Journals (Sweden)

    Shouheng Tuo

    2013-01-01

    Full Text Available Harmony search (HS algorithm is an emerging population-based metaheuristic algorithm, which is inspired by the music improvisation process. The HS method has been developed rapidly and applied widely during the past decade. In this paper, an improved global harmony search algorithm, named harmony search based on teaching-learning (HSTL, is presented for high dimension complex optimization problems. In HSTL algorithm, four strategies (harmony memory consideration, teaching-learning strategy, local pitch adjusting, and random mutation are employed to maintain the proper balance between convergence and population diversity, and dynamic strategy is adopted to change the parameters. The proposed HSTL algorithm is investigated and compared with three other state-of-the-art HS optimization algorithms. Furthermore, to demonstrate the robustness and convergence, the success rate and convergence analysis is also studied. The experimental results of 31 complex benchmark functions demonstrate that the HSTL method has strong convergence and robustness and has better balance capacity of space exploration and local exploitation on high dimension complex optimization problems.

  2. Demystifying the Search Button: A Comprehensive PubMed Search Strategy for Performing an Exhaustive Literature Review.

    Science.gov (United States)

    McKeever, Liam; Nguyen, Van; Peterson, Sarah J; Gomez-Perez, Sandra; Braunschweig, Carol

    2015-08-01

    A thorough review of the literature is the basis of all research and evidence-based practice. A gold-standard efficient and exhaustive search strategy is needed to ensure all relevant citations have been captured and that the search performed is reproducible. The PubMed database comprises both the MEDLINE and non-MEDLINE databases. MEDLINE-based search strategies are robust but capture only 89% of the total available citations in PubMed. The remaining 11% include the most recent and possibly relevant citations but are only searchable through less efficient techniques. An effective search strategy must employ both the MEDLINE and the non-MEDLINE portion of PubMed to ensure all studies have been identified. The robust MEDLINE search strategies are used for the MEDLINE portion of the search. Usage of the less robust strategies is then efficiently confined to search only the remaining 11% of PubMed citations that have not been indexed for MEDLINE. The current article offers step-by-step instructions for building such a search exploring methods for the discovery of medical subject heading (MeSH) terms to search MEDLINE, text-based methods for exploring the non-MEDLINE database, information on the limitations of convenience algorithms such as the "related citations feature," the strengths and pitfalls associated with commonly used filters, the proper usage of Boolean operators to organize a master search strategy, and instructions for automating that search through "MyNCBI" to receive search query updates by email as new citations become available. © 2015 The Author(s).

  3. Efficient sampling of complex network with modified random walk strategies

    Science.gov (United States)

    Xie, Yunya; Chang, Shuhua; Zhang, Zhipeng; Zhang, Mi; Yang, Lei

    2018-02-01

    We present two novel random walk strategies, choosing seed node (CSN) random walk and no-retracing (NR) random walk. Different from the classical random walk sampling, the CSN and NR strategies focus on the influences of the seed node choice and path overlap, respectively. Three random walk samplings are applied in the Erdös-Rényi (ER), Barabási-Albert (BA), Watts-Strogatz (WS), and the weighted USAir networks, respectively. Then, the major properties of sampled subnets, such as sampling efficiency, degree distributions, average degree and average clustering coefficient, are studied. The similar conclusions can be reached with these three random walk strategies. Firstly, the networks with small scales and simple structures are conducive to the sampling. Secondly, the average degree and the average clustering coefficient of the sampled subnet tend to the corresponding values of original networks with limited steps. And thirdly, all the degree distributions of the subnets are slightly biased to the high degree side. However, the NR strategy performs better for the average clustering coefficient of the subnet. In the real weighted USAir networks, some obvious characters like the larger clustering coefficient and the fluctuation of degree distribution are reproduced well by these random walk strategies.

  4. Adolescents' Internet Search Strategies: Drawing upon Familiar Cognitive Paradigms when Accessing Electronic Information Sources

    Science.gov (United States)

    Guinee, Kathleen; Eagleton, Maya B.; Hall, Tracey E.

    2003-01-01

    The goal of this study was to evaluate and describe the Internet search strategies of adolescent learners. Participants were 161 middle and high school students. Collected data included students' descriptions of the search process, observations of student searching behaviors, and audit trail lists of search strings used by students. The students…

  5. Two Complementary Strategies for New Physics Searches at Lepton Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Hooberman, Benjamin Henry [Univ. of California, Berkeley, CA (United States)

    2009-07-06

    In this thesis I present two complementary strategies for probing beyond-the-Standard Model physics using data collected in e+e- collisions at lepton colliders. One strategy involves searching for effects at low energy mediated by new particles at the TeV mass scale, at which new physics is expected to manifest. Several new physics scenarios, including Supersymmetry and models with leptoquarks or compositeness, may lead to observable rates for charged lepton-flavor violating processes, which are forbidden in the Standard Model. I present a search for lepton-flavor violating decays of the Υ(3S) using data collected with the BABAR detector. This study establishes the 90% confidence level upper limits BF(Υ(3S) → eτ) < 5.0 x 10-6 and BF(Υ(3S) → μτ) < 4.1 x 10-6 which are used to place constraints on new physics contributing to lepton-flavor violation at the TeV mass scale. An alternative strategy is to increase the collision energy above the threshold for new particles and produce them directly. I discuss research and development efforts aimed at producing a vertex tracker which achieves the physics performance required of a high energy lepton collider. A small-scale vertex tracker prototype is constructed using Silicon sensors of 50 μm thickness and tested using charged particle beams. This tracker achieves the targeted impact parameter resolution of σLP = (5⊕10 GeV/pT) as well as a longitudinal vertex resolution of (260 ± 10) μm, which is consistent with the requirements of a TeV-scale lepton collider. This detector research and development effort must be motivated and directed by simulation studies of physics processes. Investigation of a dark matter-motivated Supersymmetry scenario is presented, in which the dark matter is composed of Supersymmetric neutralinos. In this scenario, studies of the e+e- → H0A0 production process allow for

  6. Expected Fitness Gains of Randomized Search Heuristics for the Traveling Salesperson Problem.

    Science.gov (United States)

    Nallaperuma, Samadhi; Neumann, Frank; Sudholt, Dirk

    2017-01-01

    Randomized search heuristics are frequently applied to NP-hard combinatorial optimization problems. The runtime analysis of randomized search heuristics has contributed tremendously to our theoretical understanding. Recently, randomized search heuristics have been examined regarding their achievable progress within a fixed-time budget. We follow this approach and present a fixed-budget analysis for an NP-hard combinatorial optimization problem. We consider the well-known Traveling Salesperson Problem (TSP) and analyze the fitness increase that randomized search heuristics are able to achieve within a given fixed-time budget. In particular, we analyze Manhattan and Euclidean TSP instances and Randomized Local Search (RLS), (1+1) EA and (1+[Formula: see text]) EA algorithms for the TSP in a smoothed complexity setting, and derive the lower bounds of the expected fitness gain for a specified number of generations.

  7. Analysis of an iterated local search algorithm for vertex cover in sparse random graphs

    DEFF Research Database (Denmark)

    Witt, Carsten

    2012-01-01

    finds an optimal cover in polynomial time with a probability arbitrarily close to 1. This behavior relies on the absence of a giant component. As an additional insight into the randomized search, it is shown that the heuristic fails badly also on graphs consisting of a single tree component of maximum......Recently, various randomized search heuristics have been studied for the solution of the minimum vertex cover problem, in particular for sparse random instances according to the G(n,c/n) model, where c>0 is a constant. Methods from statistical physics suggest that the problem is easy if c......search heuristics on random graphs. For csearch heuristic...

  8. Search Engine Marketing (SEM: Financial & Competitive Advantages of an Effective Hotel SEM Strategy

    Directory of Open Access Journals (Sweden)

    Leora Halpern Lanz

    2015-05-01

    Full Text Available Search Engine Marketing and Optimization (SEO, SEM are keystones of a hotels marketing strategy, in fact research shows that 90% of travelers start their vacation planning with a Google search. Learn five strategies that can enhance a hotels SEO and SEM strategies to boost bookings.

  9. Search Engine Marketing (SEM): Financial & Competitive Advantages of an Effective Hotel SEM Strategy

    OpenAIRE

    Leora Halpern Lanz

    2015-01-01

    Search Engine Marketing and Optimization (SEO, SEM) are keystones of a hotels marketing strategy, in fact research shows that 90% of travelers start their vacation planning with a Google search. Learn five strategies that can enhance a hotels SEO and SEM strategies to boost bookings.

  10. CALL FOR PAPERS: Special issue on the random search problem: trends and perspectives

    Science.gov (United States)

    da Luz, Marcos G. E.; Grosberg, Alexander Y.; Raposo, Ernesto P.; Viswanathan, Gandhi M.

    2008-11-01

    This is a call for contributions to a special issue of Journal of Physics A: Mathematical and Theoretical dedicated to the subject of the random search problem. The motivation behind this special issue is to summarize in a single comprehensive publication, the main aspects (past and present), latest developments, different viewpoints and the directions being followed in this multidisciplinary field. We hope that such a special issue could become a particularly valuable reference for the broad scientific community working with the general random search problem. The Editorial Board has invited Marcos G E da Luz, Alexander Y Grosberg, Ernesto P Raposo and Gandhi M Viswanathan to serve as Guest Editors for the special issue. The general question of how to optimize the search for specific target objects in either continuous or discrete environments when the information available is limited is of significant importance in a broad range of fields. Representative examples include ecology (animal foraging, dispersion of populations), geology (oil recovery from mature reservoirs), information theory (automated researchers of registers in high-capacity database), molecular biology (proteins searching for their sites, e.g., on DNA ), etc. One reason underlying the richness of the random search problem relates to the `ignorance' of the locations of the randomly located `targets'. A statistical approach to the search problem can deal adequately with incomplete information and so stochastic strategies become advantageous. The general problem of how to search efficiently for randomly located target sites can thus be quantitatively described using the concepts and methods of statistical physics and stochastic processes. Scope Thus far, to the best of our knowledge, no recent textbook or review article in a physics journal has appeared on this topic. This makes a special issue with review and research articles attractive to those interested in acquiring a general introduction to the

  11. Effective speeding up strategies for tabu search heuristics

    NARCIS (Netherlands)

    Lai, David S.W.; Dullaert, Wout

    2015-01-01

    Tabu search metaheuristics have been developed for decades, making them one of the most widely applied metaheuristic frameworks. Although a standard tabu search framework can offer interesting performance, the effectiveness of a tabu search metaheuristic can be strongly improved by specific

  12. Expert Search Strategies: The Information Retrieval Practices of Healthcare Information Professionals.

    Science.gov (United States)

    Russell-Rose, Tony; Chamberlain, Jon

    2017-10-02

    Healthcare information professionals play a key role in closing the knowledge gap between medical research and clinical practice. Their work involves meticulous searching of literature databases using complex search strategies that can consist of hundreds of keywords, operators, and ontology terms. This process is prone to error and can lead to inefficiency and bias if performed incorrectly. The aim of this study was to investigate the search behavior of healthcare information professionals, uncovering their needs, goals, and requirements for information retrieval systems. A survey was distributed to healthcare information professionals via professional association email discussion lists. It investigated the search tasks they undertake, their techniques for search strategy formulation, their approaches to evaluating search results, and their preferred functionality for searching library-style databases. The popular literature search system PubMed was then evaluated to determine the extent to which their needs were met. The 107 respondents indicated that their information retrieval process relied on the use of complex, repeatable, and transparent search strategies. On average it took 60 minutes to formulate a search strategy, with a search task taking 4 hours and consisting of 15 strategy lines. Respondents reviewed a median of 175 results per search task, far more than they would ideally like (100). The most desired features of a search system were merging search queries and combining search results. Healthcare information professionals routinely address some of the most challenging information retrieval problems of any profession. However, their needs are not fully supported by current literature search systems and there is demand for improved functionality, in particular regarding the development and management of search strategies.

  13. Solving the wind farm layout optimization problem using random search algorithm

    DEFF Research Database (Denmark)

    Feng, Ju; Shen, Wen Zhong

    2015-01-01

    Wind farm (WF) layout optimization is to find the optimal positions of wind turbines (WTs) inside a WF, so as to maximize and/or minimize a single objective or multiple objectives, while satisfying certain constraints. In this work, a random search (RS) algorithm based on continuous formulation...... by expert guesses or other optimization methods, and as an optimization tool to find the optimal layout of WF with a certain number of WTs. A new strategy to evaluate layouts is also used, which can largely save the computation cost. This method is first applied to a widely studied ideal test problem....... In this application, it is also found that in order to get consistent and reliable optimization results, up to 360 or more sectors for wind direction have to be used. Finally, considering the inevitable inter-annual variations in the wind conditions, the robustness of the optimized layouts against wind condition...

  14. The efficiency of different search strategies in estimating parsimony jackknife, bootstrap, and Bremer support

    Directory of Open Access Journals (Sweden)

    Müller Kai F

    2005-10-01

    Full Text Available Abstract Background For parsimony analyses, the most common way to estimate confidence is by resampling plans (nonparametric bootstrap, jackknife, and Bremer support (Decay indices. The recent literature reveals that parameter settings that are quite commonly employed are not those that are recommended by theoretical considerations and by previous empirical studies. The optimal search strategy to be applied during resampling was previously addressed solely via standard search strategies available in PAUP*. The question of a compromise between search extensiveness and improved support accuracy for Bremer support received even less attention. A set of experiments was conducted on different datasets to find an empirical cut-off point at which increased search extensiveness does not significantly change Bremer support and jackknife or bootstrap proportions any more. Results For the number of replicates needed for accurate estimates of support in resampling plans, a diagram is provided that helps to address the question whether apparently different support values really differ significantly. It is shown that the use of random addition cycles and parsimony ratchet iterations during bootstrapping does not translate into higher support, nor does any extension of the search extensiveness beyond the rather moderate effort of TBR (tree bisection and reconnection branch swapping plus saving one tree per replicate. Instead, in case of very large matrices, saving more than one shortest tree per iteration and using a strict consensus tree of these yields decreased support compared to saving only one tree. This can be interpreted as a small risk of overestimating support but should be more than compensated by other factors that counteract an enhanced type I error. With regard to Bremer support, a rule of thumb can be derived stating that not much is gained relative to the surplus computational effort when searches are extended beyond 20 ratchet iterations per

  15. Testing search strategies for systematic reviews in the Medline literature database through PubMed.

    Science.gov (United States)

    Volpato, Enilze S N; Betini, Marluci; El Dib, Regina

    2014-04-01

    A high-quality electronic search is essential in ensuring accuracy and completeness in retrieved records for the conducting of a systematic review. We analysed the available sample of search strategies to identify the best method for searching in Medline through PubMed, considering the use or not of parenthesis, double quotation marks, truncation and use of a simple search or search history. In our cross-sectional study of search strategies, we selected and analysed the available searches performed during evidence-based medicine classes and in systematic reviews conducted in the Botucatu Medical School, UNESP, Brazil. We analysed 120 search strategies. With regard to the use of phrase searches with parenthesis, there was no difference between the results with and without parenthesis and simple searches or search history tools in 100% of the sample analysed (P = 1.0). The number of results retrieved by the searches analysed was smaller using double quotations marks and using truncation compared with the standard strategy (P = 0.04 and P = 0.08, respectively). There is no need to use phrase-searching parenthesis to retrieve studies; however, we recommend the use of double quotation marks when an investigator attempts to retrieve articles in which a term appears to be exactly the same as what was proposed in the search form. Furthermore, we do not recommend the use of truncation in search strategies in the Medline via PubMed. Although the results of simple searches or search history tools were the same, we recommend using the latter.

  16. The development of PubMed search strategies for patient preferences for treatment outcomes

    Directory of Open Access Journals (Sweden)

    Ralph van Hoorn

    2016-07-01

    Full Text Available Abstract Background The importance of respecting patients’ preferences when making treatment decisions is increasingly recognized. Efficiently retrieving papers from the scientific literature reporting on the presence and nature of such preferences can help to achieve this goal. The objective of this study was to create a search filter for PubMed to help retrieve evidence on patient preferences for treatment outcomes. Methods A total of 27 journals were hand-searched for articles on patient preferences for treatment outcomes published in 2011. Selected articles served as a reference set. To develop optimal search strategies to retrieve this set, all articles in the reference set were randomly split into a development and a validation set. MeSH-terms and keywords retrieved using PubReMiner were tested individually and as combinations in PubMed and evaluated for retrieval performance (e.g. sensitivity (Se and specificity (Sp. Results Of 8238 articles, 22 were considered to report empirical evidence on patient preferences for specific treatment outcomes. The best search filters reached Se of 100 % [95 % CI 100-100] with Sp of 95 % [94–95 %] and Sp of 97 % [97–98 %] with 75 % Se [74–76 %]. In the validation set these queries reached values of Se of 90 % [89–91 %] with Sp 94 % [93–95 %] and Se of 80 % [79–81 %] with Sp of 97 % [96–96 %], respectively. Conclusions Narrow and broad search queries were developed which can help in retrieving literature on patient preferences for treatment outcomes. Identifying such evidence may in turn enhance the incorporation of patient preferences in clinical decision making and health technology assessment.

  17. The development of PubMed search strategies for patient preferences for treatment outcomes.

    Science.gov (United States)

    van Hoorn, Ralph; Kievit, Wietske; Booth, Andrew; Mozygemba, Kati; Lysdahl, Kristin Bakke; Refolo, Pietro; Sacchini, Dario; Gerhardus, Ansgar; van der Wilt, Gert Jan; Tummers, Marcia

    2016-07-29

    The importance of respecting patients' preferences when making treatment decisions is increasingly recognized. Efficiently retrieving papers from the scientific literature reporting on the presence and nature of such preferences can help to achieve this goal. The objective of this study was to create a search filter for PubMed to help retrieve evidence on patient preferences for treatment outcomes. A total of 27 journals were hand-searched for articles on patient preferences for treatment outcomes published in 2011. Selected articles served as a reference set. To develop optimal search strategies to retrieve this set, all articles in the reference set were randomly split into a development and a validation set. MeSH-terms and keywords retrieved using PubReMiner were tested individually and as combinations in PubMed and evaluated for retrieval performance (e.g. sensitivity (Se) and specificity (Sp)). Of 8238 articles, 22 were considered to report empirical evidence on patient preferences for specific treatment outcomes. The best search filters reached Se of 100 % [95 % CI 100-100] with Sp of 95 % [94-95 %] and Sp of 97 % [97-98 %] with 75 % Se [74-76 %]. In the validation set these queries reached values of Se of 90 % [89-91 %] with Sp 94 % [93-95 %] and Se of 80 % [79-81 %] with Sp of 97 % [96-96 %], respectively. Narrow and broad search queries were developed which can help in retrieving literature on patient preferences for treatment outcomes. Identifying such evidence may in turn enhance the incorporation of patient preferences in clinical decision making and health technology assessment.

  18. Levy-taxis: a novel search strategy for finding odor plumes in turbulent flow-dominated environments

    Energy Technology Data Exchange (ETDEWEB)

    Pasternak, Zohar; Grasso, Frank W [BioMimetic and Cognitive Robotics Laboratory, Department of Psychology, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn 11210, NY (United States); Bartumeus, Frederic [Department of Ecology and Evolutionary Biology and Princeton Environmental Institute, 106 Guyot Hall, Princeton University, Princeton 08544, NJ (United States)], E-mail: zpast@yahoo.com

    2009-10-30

    Locating chemical plumes in aquatic or terrestrial environments is important for many economic, conservation, security and health related human activities. The localization process is composed mainly of two phases: finding the chemical plume and then tracking it to its source. Plume tracking has been the subject of considerable study whereas plume finding has received little attention. We address here the latter issue, where the searching agent must find the plume in a region often many times larger than the plume and devoid of the relevant chemical cues. The probability of detecting the plume not only depends on the movements of the searching agent but also on the fluid mechanical regime, shaping plume intermittency in space and time; this is a basic, general problem when exploring for ephemeral resources (e.g. moving and/or concealing targets). Here we present a bio-inspired search strategy named Levy-taxis that, under certain conditions, located odor plumes significantly faster and with a better success rate than other search strategies such as Levy walks (LW), correlated random walks (CRW) and systematic zig-zag. These results are based on computer simulations which contain, for the first time ever, digitalized real-world water flow and chemical plume instead of their theoretical model approximations. Combining elements of LW and CRW, Levy-taxis is particularly efficient for searching in flow-dominated environments: it adaptively controls the stochastic search pattern using environmental information (i.e. flow) that is available throughout the course of the search and shows correlation with the source providing the cues. This strategy finds natural application in real-world search missions, both by humans and autonomous robots, since it accommodates the stochastic nature of chemical mixing in turbulent flows. In addition, it may prove useful in the field of behavioral ecology, explaining and predicting the movement patterns of various animals searching for food

  19. Lévy-taxis: a novel search strategy for finding odor plumes in turbulent flow-dominated environments

    Science.gov (United States)

    Pasternak, Zohar; Bartumeus, Frederic; Grasso, Frank W.

    2009-10-01

    Locating chemical plumes in aquatic or terrestrial environments is important for many economic, conservation, security and health related human activities. The localization process is composed mainly of two phases: finding the chemical plume and then tracking it to its source. Plume tracking has been the subject of considerable study whereas plume finding has received little attention. We address here the latter issue, where the searching agent must find the plume in a region often many times larger than the plume and devoid of the relevant chemical cues. The probability of detecting the plume not only depends on the movements of the searching agent but also on the fluid mechanical regime, shaping plume intermittency in space and time; this is a basic, general problem when exploring for ephemeral resources (e.g. moving and/or concealing targets). Here we present a bio-inspired search strategy named Lévy-taxis that, under certain conditions, located odor plumes significantly faster and with a better success rate than other search strategies such as Lévy walks (LW), correlated random walks (CRW) and systematic zig-zag. These results are based on computer simulations which contain, for the first time ever, digitalized real-world water flow and chemical plume instead of their theoretical model approximations. Combining elements of LW and CRW, Lévy-taxis is particularly efficient for searching in flow-dominated environments: it adaptively controls the stochastic search pattern using environmental information (i.e. flow) that is available throughout the course of the search and shows correlation with the source providing the cues. This strategy finds natural application in real-world search missions, both by humans and autonomous robots, since it accomodates the stochastic nature of chemical mixing in turbulent flows. In addition, it may prove useful in the field of behavioral ecology, explaining and predicting the movement patterns of various animals searching for

  20. Search and Discovery Strategies for Biotechnology: the Paradigm Shift

    Science.gov (United States)

    Bull, Alan T.; Ward, Alan C.; Goodfellow, Michael

    2000-01-01

    Profound changes are occurring in the strategies that biotechnology-based industries are deploying in the search for exploitable biology and to discover new products and develop new or improved processes. The advances that have been made in the past decade in areas such as combinatorial chemistry, combinatorial biosynthesis, metabolic pathway engineering, gene shuffling, and directed evolution of proteins have caused some companies to consider withdrawing from natural product screening. In this review we examine the paradigm shift from traditional biology to bioinformatics that is revolutionizing exploitable biology. We conclude that the reinvigorated means of detecting novel organisms, novel chemical structures, and novel biocatalytic activities will ensure that natural products will continue to be a primary resource for biotechnology. The paradigm shift has been driven by a convergence of complementary technologies, exemplified by DNA sequencing and amplification, genome sequencing and annotation, proteome analysis, and phenotypic inventorying, resulting in the establishment of huge databases that can be mined in order to generate useful knowledge such as the identity and characterization of organisms and the identity of biotechnology targets. Concurrently there have been major advances in understanding the extent of microbial diversity, how uncultured organisms might be grown, and how expression of the metabolic potential of microorganisms can be maximized. The integration of information from complementary databases presents a significant challenge. Such integration should facilitate answers to complex questions involving sequence, biochemical, physiological, taxonomic, and ecological information of the sort posed in exploitable biology. The paradigm shift which we discuss is not absolute in the sense that it will replace established microbiology; rather, it reinforces our view that innovative microbiology is essential for releasing the potential of microbial

  1. Strategies for chemical reaction searching in SciFinder

    Science.gov (United States)

    Ridley

    2000-09-01

    The bibliographic, chemical structure, and chemical reaction databases produced by Chemical Abstracts Service allow a number of possibilities for chemical reaction searching. While these same databases may be searched through the STN network, many end-users find the intuitive software interface SciFinder simpler, but there still are issues to address. Searching may be performed through keywords, chemical structures, or chemical reactions, and the answers may vary with respect to precision and comprehension. Often combinations of search options may be needed to best solve the problem. Retrosynthetic analyses are easily performed in the chemical reaction database and can give unique insights into synthetic alternatives.

  2. On the relationship between human search strategies, conspicuity and search performance

    NARCIS (Netherlands)

    Hogervorst, M.A.; Toet, A.; Bijl, P.

    2005-01-01

    We determined the relationship between search performance with a limited field of view (FOV) and several scanning- and scene parameters in human observer experiments. The observers (38 trained army scouts) searched through a large search sector for a target (a camouflaged person) on a heath. From

  3. Websites for children: Search strategies and interface design - Three studies on children's search performance and evaluation

    NARCIS (Netherlands)

    Jochmann-Mannak, Hanna

    2014-01-01

    Every day, more children use digital media to search for information. While most children aged 8-12 make use of Google to search for information, research shows that children experience all kinds of problems using search interfaces such as Google. One of the reasons is that these informational

  4. Multitarget search on complex networks: A logarithmic growth of global mean random cover time

    Science.gov (United States)

    Weng, Tongfeng; Zhang, Jie; Small, Michael; Yang, Ji; Bijarbooneh, Farshid Hassani; Hui, Pan

    2017-09-01

    We investigate multitarget search on complex networks and derive an exact expression for the mean random cover time that quantifies the expected time a walker needs to visit multiple targets. Based on this, we recover and extend some interesting results of multitarget search on networks. Specifically, we observe the logarithmic increase of the global mean random cover time with the target number for a broad range of random search processes, including generic random walks, biased random walks, and maximal entropy random walks. We show that the logarithmic growth pattern is a universal feature of multi-target search on networks by using the annealed network approach and the Sherman-Morrison formula. Moreover, we find that for biased random walks, the global mean random cover time can be minimized, and that the corresponding optimal parameter also minimizes the global mean first passage time, pointing towards its robustness. Our findings further confirm that the logarithmic growth pattern is a universal law governing multitarget search in confined media.

  5. A Discrete Group Search Optimizer for Hybrid Flowshop Scheduling Problem with Random Breakdown

    National Research Council Canada - National Science Library

    Cui, Zhe; Gu, Xingsheng

    2014-01-01

    ...) together with a discrete group search optimizer algorithm (DGSO). In particular, two different working cases, preempt-resume case, and preempt-repeat case are considered under random breakdown...

  6. Strategies in localization proofs for one-dimensional random ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Strategies in localization proofs for one-dimensional random. Schrödinger operators. G ¨UNTER STOLZ. Department of Mathematics, University of Alabama at Birmingham, Birmingham, AL. 35294-1170, USA. E-mail: stolz@math.uab.edu. Abstract. Recent results on localization, both exponential and dynamical, for various.

  7. Job Search Strategies Utilized by Certified Aspiring and Incumbent Female and Male Public School Administrators.

    Science.gov (United States)

    Pavan, Barbara Nelson

    A survey of 622 aspiring and incumbent school administrators was conducted in order to document job search strategies used by men and women seeking principalships and superintendent or assistant superintendent positions. Since these positions are predominantly held by men, it has been suggested that men's and women's job search strategies differ…

  8. Usefulness of systematic review search strategies in finding child health systematic reviews in MEDLINE

    NARCIS (Netherlands)

    Boluyt, Nicole; Tjosvold, Lisa; Lefebvre, Carol; Klassen, Terry P.; Offringa, Martin

    2008-01-01

    OBJECTIVE: To determine the sensitivity and precision of existing search strategies for retrieving child health systematic reviews in MEDLINE using PubMed. DESIGN: Filter (diagnostic) accuracy study. We identified existing search strategies for systematic reviews, combined them with a filter that

  9. Pure random search for ambient sensor distribution optimisation in a smart home environment.

    Science.gov (United States)

    Poland, Michael P; Nugent, Chris D; Wang, Hui; Chen, Liming

    2011-01-01

    Smart homes are living spaces facilitated with technology to allow individuals to remain in their own homes for longer, rather than be institutionalised. Sensors are the fundamental physical layer with any smart home, as the data they generate is used to inform decision support systems, facilitating appropriate actuator actions. Positioning of sensors is therefore a fundamental characteristic of a smart home. Contemporary smart home sensor distribution is aligned to either a) a total coverage approach; b) a human assessment approach. These methods for sensor arrangement are not data driven strategies, are unempirical and frequently irrational. This Study hypothesised that sensor deployment directed by an optimisation method that utilises inhabitants' spatial frequency data as the search space, would produce more optimal sensor distributions vs. the current method of sensor deployment by engineers. Seven human engineers were tasked to create sensor distributions based on perceived utility for 9 deployment scenarios. A Pure Random Search (PRS) algorithm was then tasked to create matched sensor distributions. The PRS method produced superior distributions in 98.4% of test cases (n=64) against human engineer instructed deployments when the engineers had no access to the spatial frequency data, and in 92.0% of test cases (n=64) when engineers had full access to these data. These results thus confirmed the hypothesis.

  10. Identifying nurse staffing research in Medline: development and testing of empirically derived search strategies with the PubMed interface.

    Science.gov (United States)

    Simon, Michael; Hausner, Elke; Klaus, Susan F; Dunton, Nancy E

    2010-08-23

    The identification of health services research in databases such as PubMed/Medline is a cumbersome task. This task becomes even more difficult if the field of interest involves the use of diverse methods and data sources, as is the case with nurse staffing research. This type of research investigates the association between nurse staffing parameters and nursing and patient outcomes. A comprehensively developed search strategy may help identify nurse staffing research in PubMed/Medline. A set of relevant references in PubMed/Medline was identified by means of three systematic reviews. This development set was used to detect candidate free-text and MeSH terms. The frequency of these terms was compared to a random sample from PubMed/Medline in order to identify terms specific to nurse staffing research, which were then used to develop a sensitive, precise and balanced search strategy. To determine their precision, the newly developed search strategies were tested against a) the pool of relevant references extracted from the systematic reviews, b) a reference set identified from an electronic journal screening, and c) a sample from PubMed/Medline. Finally, all newly developed strategies were compared to PubMed's Health Services Research Queries (PubMed's HSR Queries). The sensitivities of the newly developed search strategies were almost 100% in all of the three test sets applied; precision ranged from 6.1% to 32.0%. PubMed's HSR queries were less sensitive (83.3% to 88.2%) than the new search strategies. Only minor differences in precision were found (5.0% to 32.0%). As with other literature on health services research, nurse staffing studies are difficult to identify in PubMed/Medline. Depending on the purpose of the search, researchers can choose between high sensitivity and retrieval of a large number of references or high precision, i.e. and an increased risk of missing relevant references, respectively. More standardized terminology (e.g. by consistent use of the

  11. The relationship between emotion regulation strategies and job search behavior among fourth-year university students.

    Science.gov (United States)

    Wang, Ling; Xu, Huihui; Zhang, Xue; Fang, Ping

    2017-08-01

    The job search process is a stressful experience. This study investigated the effect of emotion regulation strategies on job search behavior in combination with anxiety and job search self-efficacy among Chinese university fourth-year students (N = 816, mean age = 21.98, 31.5% male, 34.9% majored in science, 18.0% from "211 Project" universities). Results showed that cognitive reappraisal was positively related to job search behavior, while expressive suppression was negatively related to job search behavior. Additionally, anxiety was negatively related to job search behavior, while job search self-efficacy was positively associated with job search behavior. Moreover, both anxiety and job search self-efficacy mediated the relationship between emotion regulation strategies and job search behavior. In general, emotion regulation strategies played an important role in job search behavior. Implications include the notion that emotion regulation interventions may be helpful to increase job search behavior among university students. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  12. A Search for Alternatives to Random Assignment to Treatment Groups.

    Science.gov (United States)

    Halasa, Ofelia

    In a public school setting administrators are frequently under local pressure to make a new project service available to all eligible children. However, comparable control groups for project evaluation are often absent, and although random assignment to treatment groups remains the most systematic method of providing controls, this is not often…

  13. SHERLOCK: A quasi-model-independent new physics search strategy.

    Science.gov (United States)

    Knuteson, Bruce

    2000-04-01

    We develop a quasi-model-independent prescription for searching for physics responsible for the electroweak symmetry breaking in the Standard Model, and show a preliminary version of what we find when this prescription is applied to the DZero data.

  14. The topography of the environment alters the optimal search strategy for active particles

    Science.gov (United States)

    Volpe, Giorgio; Volpe, Giovanni

    2017-10-01

    In environments with scarce resources, adopting the right search strategy can make the difference between succeeding and failing, even between life and death. At different scales, this applies to molecular encounters in the cell cytoplasm, to animals looking for food or mates in natural landscapes, to rescuers during search and rescue operations in disaster zones, and to genetic computer algorithms exploring parameter spaces. When looking for sparse targets in a homogeneous environment, a combination of ballistic and diffusive steps is considered optimal; in particular, more ballistic Lévy flights with exponent α≤1 are generally believed to optimize the search process. However, most search spaces present complex topographies. What is the best search strategy in these more realistic scenarios? Here, we show that the topography of the environment significantly alters the optimal search strategy toward less ballistic and more Brownian strategies. We consider an active particle performing a blind cruise search for nonregenerating sparse targets in a 2D space with steps drawn from a Lévy distribution with the exponent varying from α=1 to α=2 (Brownian). We show that, when boundaries, barriers, and obstacles are present, the optimal search strategy depends on the topography of the environment, with α assuming intermediate values in the whole range under consideration. We interpret these findings using simple scaling arguments and discuss their robustness to varying searcher's size. Our results are relevant for search problems at different length scales from animal and human foraging to microswimmers' taxis to biochemical rates of reaction.

  15. Modal generation of the design parameters of an elastic spacecraft by the random search method

    Science.gov (United States)

    Titov, B. A.

    A method for the modal generation of the dynamic properties of an elastic spacecraft is proposed which is based on algorithms of random search in the space of design parameters. A practical implementation of this approach is illustrated by an example. It is shown that the modal parameter generation procedure based on the random search solves the problem of parameter selection. However, as in any other method, the accuracy of the computation of matrix elements is largely determined by the initial set of permissible values and the number of random samples in determining the subgradient of the objective function.

  16. Academic Users' Information Searching on Research Topics: Characteristics of Research Tasks and Search Strategies

    Science.gov (United States)

    Du, Jia Tina; Evans, Nina

    2011-01-01

    This project investigated how academic users search for information on their real-life research tasks. This article presents the findings of the first of two studies. The study data were collected in the Queensland University of Technology (QUT) in Brisbane, Australia. Eleven PhD students' searching behaviors on personal research topics were…

  17. Coevolution of quantum and classical strategies on evolving random networks.

    Directory of Open Access Journals (Sweden)

    Qiang Li

    Full Text Available We study the coevolution of quantum and classical strategies on weighted and directed random networks in the realm of the prisoner's dilemma game. During the evolution, agents can break and rewire their links with the aim of maximizing payoffs, and they can also adjust the weights to indicate preferences, either positive or negative, towards their neighbors. The network structure itself is thus also subject to evolution. Importantly, the directionality of links does not affect the accumulation of payoffs nor the strategy transfers, but serves only to designate the owner of each particular link and with it the right to adjust the link as needed. We show that quantum strategies outperform classical strategies, and that the critical temptation to defect at which cooperative behavior can be maintained rises, if the network structure is updated frequently. Punishing neighbors by reducing the weights of their links also plays an important role in maintaining cooperation under adverse conditions. We find that the self-organization of the initially random network structure, driven by the evolutionary competition between quantum and classical strategies, leads to the spontaneous emergence of small average path length and a large clustering coefficient.

  18. Heterogeneity in search strategies among Cochrane acupuncture reviews: is there room for improvement?

    Science.gov (United States)

    Lui, Steve; Smith, Erica J; Terplan, Mishka

    2010-09-01

    Given the international focus and rigorous literature searches employed in Cochrane systematic reviews, this study was undertaken to evaluate strategies employed in Cochrane reviews and protocols assessing acupuncture as a primary or secondary intervention. The Cochrane Collaboration of systematic reviews was searched in February 2009 for all reviews and protocols including information on acupuncture. Information was abstracted from all retrieved articles on review status, type and number of English and Chinese language databases searched, participation of at least one Chinese speaking author and language restriction. Frequencies were calculated and bivariate analyses were performed stratifying on interventions of interest to assess differences in search strategy techniques, language restrictions and results. The search retrieved 68 titles, including 48 completed reviews, 17 protocols and three previously withdrawn titles. Acupuncture was the primary intervention of interest in 44/65 (67.7%) of the retrieved reviews and protocols. While all articles searched at least one English language database, only 26/65 (40.0%) articles searched Chinese language databases. Significantly more articles where acupuncture was the primary intervention of interest searched Chinese language databases (53% vs 9%, pacupuncture were found in 28/48 (58.3%) of all completed reviews; this type of finding was more common in reviews which did not search any Chinese language databases. It is important for reviews assessing the effectiveness of acupuncture to search Chinese language databases. The Cochrane Collaboration should develop specific criteria for Chinese language search strategies to ensure the continued publication of high-quality reviews.

  19. Online consumer search strategies for smoking-cessation information.

    Science.gov (United States)

    Cobb, Nathan K

    2010-03-01

    For many Americans, the Internet has become a primary mechanism for locating information on healthcare and treatment options, including tobacco addiction. Detailed information on this behavior could inform design decisions for next-generation cessation interventions, but very little is known about how consumers search or what resources they locate. A subset of a publicly available, anonymized record of the search behavior of 650,000 individuals over 3 months in 2006 was analyzed. Smoking cessation-related queries were extracted and coded via manual identification of terms and by back-identifying terms by matching them to the websites ultimately visited. Destination sites were coded as to whether or not they originated from a professional source based on the literature and known healthcare organizations. A total of 628 individuals (0.10%) made 1106 cessation-related searches during the observation period. Of these, 76% resulted in the individual reaching a website; professional sites were reached by only 34% of searchers. Complementary or alternative therapies were popular, with 10% of individuals searching for "laser" therapy. A concerning disconnect exists between consumer demand (as demonstrated by search behavior) and the sites produced by researchers and health professionals. This "demand gap" may contribute to low overall participation rates and hamper the potential impact of such systems. Further research is needed to link online consumer preferences to intervention design decisions. 2010 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  20. Development of a Search Strategy for an Evidence Based Retrieval Service

    Science.gov (United States)

    Ho, Gah Juan; Liew, Su May; Ng, Chirk Jenn; Hisham Shunmugam, Ranita; Glasziou, Paul

    2016-01-01

    Background Physicians are often encouraged to locate answers for their clinical queries via an evidence-based literature search approach. The methods used are often not clearly specified. Inappropriate search strategies, time constraint and contradictory information complicate evidence retrieval. Aims Our study aimed to develop a search strategy to answer clinical queries among physicians in a primary care setting Methods Six clinical questions of different medical conditions seen in primary care were formulated. A series of experimental searches to answer each question was conducted on 3 commonly advocated medical databases. We compared search results from a PICO (patients, intervention, comparison, outcome) framework for questions using different combinations of PICO elements. We also compared outcomes from doing searches using text words, Medical Subject Headings (MeSH), or a combination of both. All searches were documented using screenshots and saved search strategies. Results Answers to all 6 questions using the PICO framework were found. A higher number of systematic reviews were obtained using a 2 PICO element search compared to a 4 element search. A more optimal choice of search is a combination of both text words and MeSH terms. Despite searching using the Systematic Review filter, many non-systematic reviews or narrative reviews were found in PubMed. There was poor overlap between outcomes of searches using different databases. The duration of search and screening for the 6 questions ranged from 1 to 4 hours. Conclusion This strategy has been shown to be feasible and can provide evidence to doctors’ clinical questions. It has the potential to be incorporated into an interventional study to determine the impact of an online evidence retrieval system. PMID:27935993

  1. Search strategies for retrieving complementary and alternative medicine clinical trials in oncology.

    Science.gov (United States)

    Bardia, Aditya; Wahner-Roedler, Dietlind L; Erwin, Patricia L; Sood, Amit

    2006-09-01

    Several Medline search strategies exist to retrieve complementary and alternative medicine (CAM) literature related to oncology. The objective of this study was to compare different search methods to ascertain the most optimal strategy. All clinical trials with CAM interventions in patients with cancer, published from 1965 to 2004, were abstracted using 4 different approaches. In the CAM filter search, the PubMed complementary medicine filter was used. The Ovid search was performed using a complex search strategy with the Ovid search engine. CAM keyword and not phytogenic searches involved the CAM filter search with the addition of the search terms "AND (complementary OR alternative)" and "NOT (antineoplastic agents, phytogenic), respectively. Articles were evaluated by 3 reviewers to ascertain whether they were clinical trials, the study intervention was related to CAM, and the condition prevented/treated was cancer related (inclusion criteria). The CAM filter search retrieved 10 718 citations, Ovid retrieved 1190, CAM keyword retrieved 2895, and not phytogenic retrieved 1806. Compared to the CAM filter search, all other methods had significantly lower sensitivity (Ovid 48.3% +/- 3.2%, CAM keyword 5.8% +/- 1.5%, and not phytogenic 77.9% +/- 2.7%, P searches was significantly higher (P filter (8.8% +/- 0.5%) and CAM keyword searches (1.9% +/- 0.5%). The search strategy using PubMed's complementary medicine filter, although comprehensive, lacks specificity; other methods, although more specific, lack sensitivity. Future indexing of all CAM clinical trials with a common medical subject heading term complementary medicine would enhance efficient retrieval of relevant citations.

  2. Development of a Search Strategy for an Evidence Based Retrieval Service.

    Science.gov (United States)

    Ho, Gah Juan; Liew, Su May; Ng, Chirk Jenn; Hisham Shunmugam, Ranita; Glasziou, Paul

    2016-01-01

    Physicians are often encouraged to locate answers for their clinical queries via an evidence-based literature search approach. The methods used are often not clearly specified. Inappropriate search strategies, time constraint and contradictory information complicate evidence retrieval. Our study aimed to develop a search strategy to answer clinical queries among physicians in a primary care setting. Six clinical questions of different medical conditions seen in primary care were formulated. A series of experimental searches to answer each question was conducted on 3 commonly advocated medical databases. We compared search results from a PICO (patients, intervention, comparison, outcome) framework for questions using different combinations of PICO elements. We also compared outcomes from doing searches using text words, Medical Subject Headings (MeSH), or a combination of both. All searches were documented using screenshots and saved search strategies. Answers to all 6 questions using the PICO framework were found. A higher number of systematic reviews were obtained using a 2 PICO element search compared to a 4 element search. A more optimal choice of search is a combination of both text words and MeSH terms. Despite searching using the Systematic Review filter, many non-systematic reviews or narrative reviews were found in PubMed. There was poor overlap between outcomes of searches using different databases. The duration of search and screening for the 6 questions ranged from 1 to 4 hours. This strategy has been shown to be feasible and can provide evidence to doctors' clinical questions. It has the potential to be incorporated into an interventional study to determine the impact of an online evidence retrieval system.

  3. Are random trading strategies more successful than technical ones?

    Directory of Open Access Journals (Sweden)

    Alessio Emanuele Biondo

    Full Text Available In this paper we explore the specific role of randomness in financial markets, inspired by the beneficial role of noise in many physical systems and in previous applications to complex socio-economic systems. After a short introduction, we study the performance of some of the most used trading strategies in predicting the dynamics of financial markets for different international stock exchange indexes, with the goal of comparing them to the performance of a completely random strategy. In this respect, historical data for FTSE-UK, FTSE-MIB, DAX, and S & P500 indexes are taken into account for a period of about 15-20 years (since their creation until today.

  4. Metagenomic search strategies for interactions among plants and multiple microbes

    Directory of Open Access Journals (Sweden)

    Ulrich Karl Melcher

    2014-06-01

    Full Text Available Plants harbor multiple microbes. Metagenomics can facilitate understanding of the significance, for the plant, of the microbes and of the interactions among them. However, current approaches to metagenomic analysis of plants are computationally time-consuming. Efforts to speed the discovery process include improvement of computational speed, condensing the sequencing reads into smaller datasets before BLAST searches, simplifying the target database of BLAST searches, and flipping the roles of metagenomic and reference datasets. The latter is exemplified by the E-probe diagnostic nucleic acid analysis (EDNA approach originally devised for improving analysis during plant quarantine.

  5. Optimal Search Strategy for the Definition of a DNAPL Source

    Science.gov (United States)

    2009-08-01

    construction of a variogram model. With this measure of uncertainty , 200 realizations of hydraulic conductivity for these layers were generated...was used as the mean of this layer’s random variable. Uncertainty for hydraulic conductivity in this layer was determined 58 with variogram ...concentration random field and its associated uncertainty . The model assumes a finite number of potential source locations. Each potential source location is

  6. Search strategies-identified reports on "off-label" drug use in MEDLINE.

    Science.gov (United States)

    Mesgarpour, Bita; Müller, Markus; Herkner, Harald

    2012-08-01

    We developed search strategies that facilitate the identification of studies on "off-label" drug use in the bibliographic database OvidSP MEDLINE. We compiled a gold standard reference set of reports classified as relevant or not relevant to off-label drug use. We conceived search queries, including search words and word strings. We searched MEDLINE via OvidSP from 1948 to 2011. In comparison with the gold standard, we determined sensitivity and precision of search queries and their combinations. We attempted to achieve the highest possible sensitive search strategy and an optimal balance of sensitivity and precision. Our gold standard set contained 4,067 relevant documents overall of 6,785 records, among those 2,177 could be retrieved from MEDLINE. The most sensitive single term was "off label∗.af." (overall sensitivity 40.9%, sensitivity within MEDLINE 76.4%, and precision 84.4%). A combination of 31 search queries had the maximum overall sensitivity of 53.3% (sensitivity within MEDLINE 99.5%) at a precision of 60.3%. A search strategy with the maximum precision (84.0%) yielded a sensitivity of 49.0% (sensitivity within MEDLINE 91.5%). We empirically developed two versions of optimized sensitive search strategies, which can achieve reasonable performance for retrieving off-label drug use documents in OvidSP MEDLINE. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. The Strategies WDK: a graphical search interface and web development kit for functional genomics databases.

    Science.gov (United States)

    Fischer, Steve; Aurrecoechea, Cristina; Brunk, Brian P; Gao, Xin; Harb, Omar S; Kraemer, Eileen T; Pennington, Cary; Treatman, Charles; Kissinger, Jessica C; Roos, David S; Stoeckert, Christian J

    2011-01-01

    Web sites associated with the Eukaryotic Pathogen Bioinformatics Resource Center (EuPathDB.org) have recently introduced a graphical user interface, the Strategies WDK, intended to make advanced searching and set and interval operations easy and accessible to all users. With a design guided by usability studies, the system helps motivate researchers to perform dynamic computational experiments and explore relationships across data sets. For example, PlasmoDB users seeking novel therapeutic targets may wish to locate putative enzymes that distinguish pathogens from their hosts, and that are expressed during appropriate developmental stages. When a researcher runs one of the approximately 100 searches available on the site, the search is presented as a first step in a strategy. The strategy is extended by running additional searches, which are combined with set operators (union, intersect or minus), or genomic interval operators (overlap, contains). A graphical display uses Venn diagrams to make the strategy's flow obvious. The interface facilitates interactive adjustment of the component searches with changes propagating forward through the strategy. Users may save their strategies, creating protocols that can be shared with colleagues. The strategy system has now been deployed on all EuPathDB databases, and successfully deployed by other projects. The Strategies WDK uses a configurable MVC architecture that is compatible with most genomics and biological warehouse databases, and is available for download at code.google.com/p/strategies-wdk. Database URL: www.eupathdb.org.

  8. After Iraq: The Search for a Sustainable National Security Strategy

    National Research Council Canada - National Science Library

    Gray, Colin S

    2009-01-01

    ...?" Thus to answer the first question, one has to identify both the policy that strategy must serve as well as the components of that Unfortunately for the convenience and self-confidence of defense...

  9. Reference Question Analysis and Search Strategy Development by Man and Machine

    Science.gov (United States)

    Jahoda, Gerald

    1974-01-01

    Question analysis and search strategy development were broken down into nine steps for answering reference questions. These steps were examined for possible mechanization of the answering process. Such automation was not proved feasible. (LS)

  10. Strategies for the search of life in the universe

    OpenAIRE

    Schneider, Jean

    1996-01-01

    The discovery of an increasing number of Jupiter-like planets in orbit around other stars (or extra-solar planets) is a promising first step toward the search for Life in the Universe. We review all aspects of the question: - definition of Life - definition and characterization of the `habitable zone' around a star - overview of detection methods of planets, with special attention to habitable planets - present fingings - future projects.

  11. Alumni Job Search Strategies, Class of 2011. GMAC[R] Data-to-Go Series

    Science.gov (United States)

    Graduate Management Admission Council, 2012

    2012-01-01

    Examining the job search strategies and employment outcomes for Class of 2011 graduate business school alumni sheds light on current job market trends and the effort required to secure a first job after earning a graduate business degree. This fact sheet highlights the job search methods used by Class of 2011 business school graduates as reported…

  12. An exploratory study of user goals and strategies in podcast search

    NARCIS (Netherlands)

    Besser, J.; Hofmann, K.; Larson, M.; Mandl, T.; Fuhr, N.; Henrich, A.

    2008-01-01

    We report on an exploratory, qualitative user study designed to identify users’ goals underlying podcast search, the strategies used to gain access to podcasts, and how currently available tools influence podcast search. We employed a multi-method approach. First, we conducted an online survey to

  13. On the expected duration of a search for a fixed pattern in random data

    DEFF Research Database (Denmark)

    Nielsen, Peter Tolstrup

    1973-01-01

    An expression is obtained for the expected duration of a search to find a givenL-ary sequence in a semi-infinite stream of randomL-ary data. The search time is found to be an increasing function of the lengths of the "bifices" of the pattern, where the term bifix denotes a sequence which is both ...... a prefix and a suffix....

  14. Optimal intermittence in search strategies under speed-selective target detection.

    Science.gov (United States)

    Campos, Daniel; Méndez, Vicenç; Bartumeus, Frederic

    2012-01-13

    Random search theory has been previously explored for both continuous and intermittent scanning modes with full target detection capacity. Here we present a new class of random search problems in which a single searcher performs flights of random velocities, the detection probability when it passes over a target location being conditioned to the searcher speed. As a result, target detection involves an N-passage process for which the mean search time is here analytically obtained through a renewal approximation. We apply the idea of speed-selective detection to random animal foraging since a fast movement is known to significantly degrade perception abilities in many animals. We show that speed-selective detection naturally introduces an optimal level of behavioral intermittence in order to solve the compromise between fast relocations and target detection capability.

  15. Websites for children: search strategies and interface design. Three studies on children's search performance and evaluation

    NARCIS (Netherlands)

    Jochmann-Mannak, Hanna

    2014-01-01

    Children experience all kinds of problems using search interfaces for adults such as Google. The research reported in this dissertation is about the design of informational interfaces for children between 8 and 12 years old. The goal of the research was to learn more about interfaces that ‘work’ for

  16. How Interface Design and Search Strategy Influence Children’s Search Performance and Evaluation

    NARCIS (Netherlands)

    Jochmann-Mannak, Hanna; Lentz, Leo; Huibers, Theo W.C.; Sanders, Ted

    This chapter presents an experiment with 158 children, aged 10 to 12, in which search performance and attitudes towards an informational Website are investigated. The same Website was designed in 3 different types of interface design varying in playfulness of navigation structure and in playfulness

  17. Alternative search strategies to explore ATLAS diboson excess

    Science.gov (United States)

    Khosa, Charanjit K.

    2017-10-01

    We consider the s-channel resonance to fit the 2 TeV ATLAS diboson excess. We address the production mechanism of the resonance, its decay and coupling measurement. In order to explain only the hadronic channel excess, we consider the scenario where resonance decays to two new beyond Standard Model (BSM) particles (in the mass range of W / Z boson) and also explore the possibility of three-particle BSM final state mimicking diboson excess. Techniques suggested in this work are generic and could be used for heavy BSM resonance searches.

  18. PRESS Peer Review of Electronic Search Strategies: 2015 Guideline Statement.

    Science.gov (United States)

    McGowan, Jessie; Sampson, Margaret; Salzwedel, Douglas M; Cogo, Elise; Foerster, Vicki; Lefebvre, Carol

    2016-07-01

    To develop an evidence-based guideline for Peer Review of Electronic Search Strategies (PRESS) for systematic reviews (SRs), health technology assessments, and other evidence syntheses. An SR, Web-based survey of experts, and consensus development forum were undertaken to identify checklists that evaluated or validated electronic literature search strategies and to determine which of their elements related to search quality or errors. Systematic review: No new search elements were identified for addition to the existing (2008-2010) PRESS 2015 Evidence-Based Checklist, and there was no evidence refuting any of its elements. Results suggested that structured PRESS could identify search errors and improve the selection of search terms. Web-based survey of experts: Most respondents felt that peer review should be undertaken after the MEDLINE search had been prepared but before it had been translated to other databases. Consensus development forum: Of the seven original PRESS elements, six were retained: translation of the research question; Boolean and proximity operators; subject headings; text word search; spelling, syntax and line numbers; and limits and filters. The seventh (skilled translation of the search strategy to additional databases) was removed, as there was consensus that this should be left to the discretion of searchers. An updated PRESS 2015 Guideline Statement was developed, which includes the following four documents: PRESS 2015 Evidence-Based Checklist, PRESS 2015 Recommendations for Librarian Practice, PRESS 2015 Implementation Strategies, and PRESS 2015 Guideline Assessment Form. The PRESS 2015 Guideline Statement should help to guide and improve the peer review of electronic literature search strategies. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Users’ Perceived Difficulties and Corresponding Reformulation Strategies in Google Voice Search

    Directory of Open Access Journals (Sweden)

    Wei Jeng

    2016-06-01

    Full Text Available In this article, we report users’ perceptions of query input errors and query reformulation strategies in voice search using data collected through a laboratory user study. Our results reveal that: 1 users’ perceived obstacles during a voice search can be related to speech recognition errors and topic complexity; 2 users naturally develop different strategies to deal with various types of words (e.g., acronyms, single-worded queries, non-English words with high error rates in speech recognition; and 3 users can have various emotional reactions when encounter voice input errors and they develop preferred usage occasions for voice search.

  20. Win the game of Googleopoly unlocking the secret strategy of search engines

    CERN Document Server

    Bradley, Sean V

    2015-01-01

    Rank higher in search results with this guide to SEO and content building supremacy Google is not only the number one search engine in the world, it is also the number one website in the world. Only 5 percent of site visitors search past the first page of Google, so if you're not in those top ten results, you are essentially invisible. Winning the Game of Googleopoly is the ultimate roadmap to Page One Domination. The POD strategy is what gets you on that super-critical first page of Google results by increasing your page views. You'll learn how to shape your online presence for Search Engine

  1. Strategy for Searching for a Dark Matter Sterile Neutrino

    CERN Document Server

    Boyarsky, A; Ruchayskiy, O; Shaposhnikov, M E; Tkachev, I I

    2006-01-01

    We propose a strategy of how to look for dark matter (DM) particles possessing a radiative decay channel and derive constraints on their parameters from observations of X-rays from our own Galaxy and its dwarf satellites. When applied to the sterile neutrinos in keV mass range, it allows a significant improvement of restrictions to its parameters, as compared with previous works.

  2. Analysis of strategies for serial-search spread-spectrum code acquisition - Direct approach

    Science.gov (United States)

    Jovanovic, Vladan M.

    1988-11-01

    A direct approach to obtaining statistics of the code acquisition time for serial search spread-spectrum receivers is presented. It combines algebraic characterization of the search with transform-domain methods. Besides being a valid alternative to the more usual flow graph approach, it is a very general unified technique, yielding many other known results as special cases. This method also gives a very deep insight into the nature of the acquisition process, enabling simple derivations of the probability density functions and moments for numerous cases of practical interest. One of the major advantages of the direct approach is that the effect of the search strategy on moments of the acquisition time can be isolated from the effect of the detection/verification logic. This fact permits the author to analyze all known search strategies, confirming several conclusions regarding their comparative performance, and to propose two novel strategies (alternate search) that outperform the conventional ones when the code rewinding time is small in comparison to the dwell times. Optimum search strategy based on the maximum a posteriori criterion (MAP) is analyzed, ensuring an absolute and uniform basis of comparison. The two proposed strategies perform well by this measure.

  3. Optimal strategies of radial velocity observations in planet search surveys

    Science.gov (United States)

    Baluev, Roman V.

    2008-09-01

    Applications of the theory of optimal design of experiments to radial velocity (RV) planet search surveys are considered. Different optimality criteria are discussed, basing on the Fisher, Shannon and Kullback-Leibler informations. Algorithms of optimal scheduling of RV observations for two important practical problems are considered. The first problem is finding the time for future observations to yield the maximum improvement of the precision of exoplanetary orbital parameters and masses. The second problem is finding the most favourable time for distinguishing alternative orbital fits (the scheduling of discriminating observations). These methods of optimal planning are demonstrated to be potentially efficient for multiplanet extrasolar systems, in particular for resonant ones. In these cases, the optimal dates of observations are often concentrated in quite narrow time segments.

  4. Critical Assessment of Search Strategies in Systematic Reviews in Endodontics.

    Science.gov (United States)

    Yaylali, Ibrahim Ethem; Alaçam, Tayfun

    2016-06-01

    The aim of this study was to perform an overview of literature search strategies in systematic reviews (SRs) published in 2 endodontic journals, Journal of Endodontics and International Endodontic Journal. A search was done by using the MEDLINE (PubMed interface) database to retrieve the articles published between January 1, 2000 and December 31, 2015. The last search was on January 10, 2016. All the SRs published in the 2 journals were retrieved and screened. Eligible SRs were assessed by using 11 questions about search strategies in the SRs that were adapted from 2 guidelines (ie, AMSTAR checklist and the Cochrane Handbook). A total of 83 SRs were retrieved by electronic search. Of these, 55 were from the Journal of Endodontics, and 28 were from the International Endodontic Journal. After screening, 2 SRs were excluded, and 81 SRs were included in the study. Some issues, such as search of grey literature and contact with study authors, were not fully reported (30% and 25%, respectively). On the other hand, some issues, such as the use of index terms and key words and search in at least 2 databases, were reported in most of the SRs (97% and 95%, respectively). The overall quality of the search strategy in both journals was 61%. No significant difference was found between the 2 journals in terms of evaluation criteria (P > .05). There exist areas for improving the quality of reporting of search strategies in SRs; for example, grey literature should be searched for unpublished studies, no language limitation should be applied to databases, and authors should make an attempt to contact the authors of included studies to obtain further relevant information. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Search Strategy to Identify Dental Survival Analysis Articles Indexed in MEDLINE.

    Science.gov (United States)

    Layton, Danielle M; Clarke, Michael

    2016-01-01

    Articles reporting survival outcomes (time-to-event outcomes) in patients over time are challenging to identify in the literature. Research shows the words authors use to describe their dental survival analyses vary, and that allocation of medical subject headings by MEDLINE indexers is inconsistent. Together, this undermines accurate article identification. The present study aims to develop and validate a search strategy to identify dental survival analyses indexed in MEDLINE (Ovid). A gold standard cohort of articles was identified to derive the search terms, and an independent gold standard cohort of articles was identified to test and validate the proposed search strategies. The first cohort included all 6,955 articles published in the 50 dental journals with the highest impact factors in 2008, of which 95 articles were dental survival articles. The second cohort included all 6,514 articles published in the 50 dental journals with the highest impact factors for 2012, of which 148 were dental survival articles. Each cohort was identified by a systematic hand search. Performance parameters of sensitivity, precision, and number needed to read (NNR) for the search strategies were calculated. Sensitive, precise, and optimized search strategies were developed and validated. The performances of the search strategy maximizing sensitivity were 92% sensitivity, 14% precision, and 7.11 NNR; the performances of the strategy maximizing precision were 93% precision, 10% sensitivity, and 1.07 NNR; and the performances of the strategy optimizing the balance between sensitivity and precision were 83% sensitivity, 24% precision, and 4.13 NNR. The methods used to identify search terms were objective, not subjective. The search strategies were validated in an independent group of articles that included different journals and different publication years. Across the three search strategies, dental survival articles can be identified with sensitivity up to 92%, precision up to 93

  6. Development and use of a content search strategy for retrieving studies on patients' views and preferences.

    Science.gov (United States)

    Selva, Anna; Solà, Ivan; Zhang, Yuan; Pardo-Hernandez, Hector; Haynes, R Brian; Martínez García, Laura; Navarro, Tamara; Schünemann, Holger; Alonso-Coello, Pablo

    2017-08-30

    Identifying scientific literature addressing patients' views and preferences is complex due to the wide range of studies that can be informative and the poor indexing of this evidence. Given the lack of guidance we developed a search strategy to retrieve this type of evidence. We assembled an initial list of terms from several sources, including the revision of the terms and indexing of topic-related studies and, methods research literature, and other relevant projects and systematic reviews. We used the relative recall approach, evaluating the capacity of the designed search strategy for retrieving studies included in relevant systematic reviews for the topic. We implemented in practice the final version of the search strategy for conducting systematic reviews and guidelines, and calculated search's precision and the number of references needed to read (NNR). We assembled an initial version of the search strategy, which had a relative recall of 87.4% (yield of 132/out of 151 studies). We then added some additional terms from the studies not initially identified, and re-tested this improved version against the studies included in a new set of systematic reviews, reaching a relative recall of 85.8% (151/out of 176 studies, 95% CI 79.9 to 90.2). This final version of the strategy includes two sets of terms related with two domains: "Patient Preferences and Decision Making" and "Health State Utilities Values". When we used the search strategy for the development of systematic reviews and clinical guidelines we obtained low precision values (ranging from 2% to 5%), and the NNR from 20 to 50. This search strategy fills an important research gap in this field. It will help systematic reviewers, clinical guideline developers, and policy-makers to retrieve published research on patients' views and preferences. In turn, this will facilitate the inclusion of this critical aspect when formulating heath care decisions, including recommendations.

  7. Fitness levels with tail bounds for the analysis of randomized search heuristics

    DEFF Research Database (Denmark)

    Witt, Carsten

    2014-01-01

    The fitness-level method, also called the method of f-based partitions, is an intuitive and widely used technique for the running time analysis of randomized search heuristics. It was originally defined to prove upper and lower bounds on the expected running time. Recently, upper tail bounds were...

  8. Optimizing Linear Functions with Randomized Search Heuristics - The Robustness of Mutation

    DEFF Research Database (Denmark)

    Witt, Carsten

    2012-01-01

    The analysis of randomized search heuristics on classes of functions is fundamental for the understanding of the underlying stochastic process and the development of suitable proof techniques. Recently, remarkable progress has been made in bounding the expected optimization time of the simple (1...

  9. Tight Bounds on the Optimization Time of a Randomized Search Heuristic on Linear Functions

    DEFF Research Database (Denmark)

    Witt, Carsten

    2013-01-01

    The analysis of randomized search heuristics on classes of functions is fundamental to the understanding of the underlying stochastic process and the development of suitable proof techniques. Recently, remarkable progress has been made in bounding the expected optimization time of a simple...

  10. Neural network based adaptive control of nonlinear plants using random search optimization algorithms

    Science.gov (United States)

    Boussalis, Dhemetrios; Wang, Shyh J.

    1992-01-01

    This paper presents a method for utilizing artificial neural networks for direct adaptive control of dynamic systems with poorly known dynamics. The neural network weights (controller gains) are adapted in real time using state measurements and a random search optimization algorithm. The results are demonstrated via simulation using two highly nonlinear systems.

  11. Synthesis strategies in the search for hierarchical zeolites.

    Science.gov (United States)

    Serrano, D P; Escola, J M; Pizarro, P

    2013-05-07

    Great interest has arisen in the past years in the development of hierarchical zeolites, having at least two levels of porosities. Hierarchical zeolites show an enhanced accessibility, leading to improved catalytic activity in reactions suffering from steric and/or diffusional limitations. Moreover, the secondary porosity offers an ideal space for the deposition of additional active phases and for functionalization with organic moieties. However, the secondary surface represents a discontinuity of the crystalline framework, with a low connectivity and a high concentration of silanols. Consequently, hierarchical zeolites exhibit a less "zeolitic behaviour" than conventional ones in terms of acidity, hydrophobic/hydrophilic character, confinement effects, shape-selectivity and hydrothermal stability. Nevertheless, this secondary surface is far from being amorphous, which provides hierarchical zeolites with a set of novel features. A wide variety of innovative strategies have been developed for generating a secondary porosity in zeolites. In the present review, the different synthetic routes leading to hierarchical zeolites have been classified into five categories: removal of framework atoms, surfactant-assisted procedures, hard-templating, zeolitization of preformed solids and organosilane-based methods. Significant advances have been achieved recently in several of these alternatives. These include desilication, due to its versatility, dual templating with polyquaternary ammonium surfactants and framework reorganization by treatment with surfactant-containing basic solutions. In the last two cases, the materials so prepared show both mesoscopic ordering and zeolitic lattice planes. Likewise, interesting results have been obtained with the incorporation of different types of organosilanes into the zeolite crystallization gels, taking advantage of their high affinity for silicate and aluminosilicate species. Crystallization of organofunctionalized species favours the

  12. Local search methods based on variable focusing for random K -satisfiability

    Science.gov (United States)

    Lemoy, Rémi; Alava, Mikko; Aurell, Erik

    2015-01-01

    We introduce variable focused local search algorithms for satisfiabiliity problems. Usual approaches focus uniformly on unsatisfied clauses. The methods described here work by focusing on random variables in unsatisfied clauses. Variants are considered where variables are selected uniformly and randomly or by introducing a bias towards picking variables participating in several unsatistified clauses. These are studied in the case of the random 3-SAT problem, together with an alternative energy definition, the number of variables in unsatisfied constraints. The variable-based focused Metropolis search (V-FMS) is found to be quite close in performance to the standard clause-based FMS at optimal noise. At infinite noise, instead, the threshold for the linearity of solution times with instance size is improved by picking preferably variables in several UNSAT clauses. Consequences for algorithmic design are discussed.

  13. Optimal Search Strategy of Robotic Assembly Based on Neural Vibration Learning

    Directory of Open Access Journals (Sweden)

    Lejla Banjanovic-Mehmedovic

    2011-01-01

    Full Text Available This paper presents implementation of optimal search strategy (OSS in verification of assembly process based on neural vibration learning. The application problem is the complex robot assembly of miniature parts in the example of mating the gears of one multistage planetary speed reducer. Assembly of tube over the planetary gears was noticed as the most difficult problem of overall assembly. The favourable influence of vibration and rotation movement on compensation of tolerance was also observed. With the proposed neural-network-based learning algorithm, it is possible to find extended scope of vibration state parameter. Using optimal search strategy based on minimal distance path between vibration parameter stage sets (amplitude and frequencies of robots gripe vibration and recovery parameter algorithm, we can improve the robot assembly behaviour, that is, allow the fastest possible way of mating. We have verified by using simulation programs that search strategy is suitable for the situation of unexpected events due to uncertainties.

  14. Searches for Randomized Controlled Trials of Drugs in MEDLINE and EMBASE Using Only Generic Drug Names Compared with Searches Applied in Current Practice in Systematic Reviews

    Science.gov (United States)

    Waffenschmidt, Siw; Guddat, Charlotte

    2015-01-01

    Background: It is unclear which terms should be included in bibliographic searches for randomized controlled trials (RCTs) of drugs, and identifying relevant drug terms can be extremely laborious. The aim of our analysis was to determine whether a bibliographic search using only the generic drug name produces sufficient results for the generation…

  15. Lyman continuum leaking galaxies. Search strategies and local candidates

    Science.gov (United States)

    Bergvall, N.; Leitet, E.; Zackrisson, E.; Marquart, T.

    2013-06-01

    Context. Star-forming dwarf galaxies may have played an important role in the reionization of the Universe, provided that some fraction of their ionizing radiation were able to escape into the intergalactic medium. Local galaxies exhibiting such Lyman-continuum (LyC) leakage could potentially shed light on the escape mechanisms involved, but only two low-redshift cases of LyC leakage have been identified so far. Here, we argue that this meager harvest may be caused by unsuitable selection criteria. Candidates for LyC leakage are normally selected by indicators of starburst activity, one of which is a high equivalent width in Hα. Such a criterion will guarantee a high production of LyC photons but will also bias the selection in favour of a high column density in the neutral gas, effectively ruling out LyC escape. Aims: In this work we want to investigate whether the lack of local LyC emitters can be caused in part by biased selection criteria, and we present a novel method of selecting targets with high escape fractions. By applying these criteria, we assemble a sample of observation targets to study their basic properties. Methods: We introduce a new selection strategy here where the potential LyC leakers are selected by their blue colours and weak emission lines. The selection is based on data from the Sloan Digital Sky Survey (SDSS). We also take a closer look at the properties of 8 LyC leaking candidates at z ~ 0.03 which we have observed with ESO/NTT in broadband B and Hα. Results: We find that 7 of the 8 target galaxies are involved in interaction with neighbours or show signs of mergers. In 7 cases the young stellar population is clearly displaced relative to the main body of these galaxies, often directly bordering the halo region. In about half of our targets the absorption spectra show young post-starburst signatures. Comparing the scale lengths in Hα with those of the stellar continua shows that the scale lengths in Hα typically are 30% smaller

  16. Searching for Survivors through Random Human-Body Movement Outdoors by Continuous-Wave Radar Array.

    Science.gov (United States)

    Li, Chuantao; Chen, Fuming; Qi, Fugui; Liu, Miao; Li, Zhao; Liang, Fulai; Jing, Xijing; Lu, Guohua; Wang, Jianqi

    2016-01-01

    It is a major challenge to search for survivors after chemical or nuclear leakage or explosions. At present, biological radar can be used to achieve this goal by detecting the survivor's respiration signal. However, owing to the random posture of an injured person at a rescue site, the radar wave may directly irradiate the person's head or feet, in which it is difficult to detect the respiration signal. This paper describes a multichannel-based antenna array technology, which forms an omnidirectional detection system via 24-GHz Doppler biological radar, to address the random positioning relative to the antenna of an object to be detected. Furthermore, since the survivors often have random body movement such as struggling and twitching, the slight movements of the body caused by breathing are obscured by these movements. Therefore, a method is proposed to identify random human-body movement by utilizing multichannel information to calculate the background variance of the environment in combination with a constant-false-alarm-rate detector. The conducted outdoor experiments indicate that the system can realize the omnidirectional detection of random human-body movement and distinguish body movement from environmental interference such as movement of leaves and grass. The methods proposed in this paper will be a promising way to search for survivors outdoors.

  17. On the Runtime of Randomized Local Search and Simple Evolutionary Algorithms for Dynamic Makespan Scheduling

    DEFF Research Database (Denmark)

    Neumann, Frank; Witt, Carsten

    2015-01-01

    Evolutionary algorithms have been frequently used for dynamic optimization problems. With this paper, we contribute to the theoretical understanding of this research area. We present the first computational complexity analysis of evolutionary algorithms for a dynamic variant of a classical...... combinatorial optimization problem, namely makespan scheduling. We study the model of a strong adversary which is allowed to change one job at regular intervals. Furthermore, we investigate the setting of random changes. Our results show that randomized local search and a simple evolutionary algorithm are very...... effective in dynamically tracking changes made to the problem instance....

  18. In search of random uncorrelated particle motion (RUM) in a simple random flow field

    CERN Document Server

    Reeks, Michael W; Soldati, Alfredo

    2012-01-01

    DNS studies of dispersed particle motion in isotropic homogeneous turbulence [1] have revealed the existence of a component of random uncorrelated motion (RUM)dependent on the particle inertia {\\tau}p(normalised particle response time or Stoke number). This paper reports the presence of RUM in a simple linear random smoothly varying flow field of counter rotating vortices where the two-particle velocity correlation was measured as a function of spatial separation. Values of the correlation less than one for zero separation indicated the presence of RUM. In terms of Stokes number, the motion of the particles in one direction corresponds to either a heavily damped ({\\tau}p 0.25)harmonic oscillator. In the lightly damped case the particles overshoot the stagnation lines of the flow and are projected from one vortex to another (the so-called sling-shot effect). It is shown that RUM occurs only when {\\tau}p > 0.25, increasing monotonically with increasing Stokes number. Calculations of the particle pair separatio...

  19. Application of an Optimal Search Strategy for the DNAPL Source Identification to a Field Site in Nanjing, China

    Science.gov (United States)

    Longting, M.; Ye, S.; Wu, J.

    2014-12-01

    Identification and removing the DNAPL source in aquifer system is vital in rendering remediation successful and lowering the remediation time and cost. Our work is to apply an optimal search strategy introduced by Zoi and Pinder[1], with some modifications, to a field site in Nanjing City, China to define the strength, and location of DNAPL sources using the least samples. The overall strategy uses Monte Carlo stochastic groundwater flow and transport modeling, incorporates existing sampling data into the search strategy, and determines optimal sampling locations that are selected according to the reduction in overall uncertainty of the field and the proximity to the source locations. After a sample is taken, the plume is updated using a Kalman filter. The updated plume is then compared to the concentration fields that emanate from each individual potential source using fuzzy set technique. The comparison followed provides weights that reflect the degree of truth regarding the location of the source. The above steps are repeated until the optimal source characteristics are determined. Considering our site case, some specific modifications and work have been done as follows. K random fields are generated after fitting the measurement K data to the variogram model. The locations of potential sources that are given initial weights are targeted based on the field survey, with multiple potential source locations around the workshops and wastewater basin. Considering the short history (1999-2010) of manufacturing optical brightener PF at the site, and the existing sampling data, a preliminary source strength is then estimated, which will be optimized by simplex method or GA later. The whole algorithm then will guide us for optimal sampling and update as the investigation proceeds, until the weights finally stabilized. Reference [1] Dokou Zoi, and George F. Pinder. "Optimal search strategy for the definition of a DNAPL source." Journal of Hydrology 376.3 (2009): 542

  20. Biclustering of gene expression data using reactive greedy randomized adaptive search procedure.

    Science.gov (United States)

    Dharan, Smitha; Nair, Achuthsankar S

    2009-01-30

    Biclustering algorithms belong to a distinct class of clustering algorithms that perform simultaneous clustering of both rows and columns of the gene expression matrix and can be a very useful analysis tool when some genes have multiple functions and experimental conditions are diverse. Cheng and Church have introduced a measure called mean squared residue score to evaluate the quality of a bicluster and has become one of the most popular measures to search for biclusters. In this paper, we review basic concepts of the metaheuristics Greedy Randomized Adaptive Search Procedure (GRASP)-construction and local search phases and propose a new method which is a variant of GRASP called Reactive Greedy Randomized Adaptive Search Procedure (Reactive GRASP) to detect significant biclusters from large microarray datasets. The method has two major steps. First, high quality bicluster seeds are generated by means of k-means clustering. In the second step, these seeds are grown using the Reactive GRASP, in which the basic parameter that defines the restrictiveness of the candidate list is self-adjusted, depending on the quality of the solutions found previously. We performed statistical and biological validations of the biclusters obtained and evaluated the method against the results of basic GRASP and as well as with the classic work of Cheng and Church. The experimental results indicate that the Reactive GRASP approach outperforms the basic GRASP algorithm and Cheng and Church approach. The Reactive GRASP approach for the detection of significant biclusters is robust and does not require calibration efforts.

  1. Multiple random walks on complex networks: A harmonic law predicts search time

    Science.gov (United States)

    Weng, Tongfeng; Zhang, Jie; Small, Michael; Hui, Pan

    2017-05-01

    We investigate multiple random walks traversing independently and concurrently on complex networks and introduce the concept of mean first parallel passage time (MFPPT) to quantify their search efficiency. The mean first parallel passage time represents the expected time required to find a given target by one or some of the multiple walkers. We develop a general theory that allows us to calculate the MFPPT analytically. Interestingly, we find that the global MFPPT follows a harmonic law with respect to the global mean first passage times of the associated walkers. Remarkably, when the properties of multiple walkers are identical, the global MFPPT decays in a power law manner with an exponent of unity, irrespective of network structure. These findings are confirmed by numerical and theoretical results on various synthetic and real networks. The harmonic law reveals a universal principle governing multiple random walks on networks that uncovers the contribution and role of the combined walkers in a target search. Our paradigm is also applicable to a broad range of random search processes.

  2. PARAMETRIC IDENTIFICATION OF STOCHASTIC SYSTEM BY NON-GRADIENT RANDOM SEARCHING

    Directory of Open Access Journals (Sweden)

    A. A. Lobaty

    2017-01-01

    Full Text Available At this moment we know a great variety of identification objects, tasks and methods and its significance is constantly increasing in various fields of science and technology.  The identification problem is dependent on a priori information about identification object, besides that  the existing approaches and methods of identification are determined by the form of mathematical models (deterministic, stochastic, frequency, temporal, spectral etc.. The paper considers a problem for determination of system parameters  (identification object which is assigned by the stochastic mathematical model including random functions of time. It has been shown  that while making optimization of the stochastic systems subject to random actions deterministic methods can be applied only for a limited approximate optimization of the system by taking into account average random effects and fixed structure of the system. The paper proposes an algorithm for identification of  parameters in a mathematical model of  the stochastic system by non-gradient random searching. A specific  feature  of the algorithm is its applicability  practically to mathematic models of any type because the applied algorithm does not depend on linearization and differentiability of functions included in the mathematical model of the system. The proposed algorithm  ensures searching of  an extremum for the specified quality criteria in terms of external uncertainties and limitations while using random searching of parameters for a mathematical model of the system. The paper presents results of the investigations on operational capability of the considered identification method  while using mathematical simulation of hypothetical control system with a priori unknown parameter values of the mathematical model. The presented results of the mathematical simulation obviously demonstrate the operational capability of the proposed identification method.

  3. The Anthropology of Online Search Strategy Formation: A Study of Four Countries.

    Science.gov (United States)

    Still, Julie

    1996-01-01

    Discusses the results of a survey sent to online searchers in four countries, the United Kingdom, the United States, Australia, and Canada, to investigate the influence of national culture on information retrieval skills. The survey form provided a sample question and asked searchers to prepare a preliminary search strategy in Sociological…

  4. Recognition of Facially Expressed Emotions and Visual Search Strategies in Adults with Asperger Syndrome

    Science.gov (United States)

    Falkmer, Marita; Bjallmark, Anna; Larsson, Matilda; Falkmer, Torbjorn

    2011-01-01

    Can the disadvantages persons with Asperger syndrome frequently experience with reading facially expressed emotions be attributed to a different visual perception, affecting their scanning patterns? Visual search strategies, particularly regarding the importance of information from the eye area, and the ability to recognise facially expressed…

  5. Opinions of Teachers on Using Internet Searching Strategies: An Elementary School Case in Turkey

    Science.gov (United States)

    Kabakci, Isil; Firat, Mehmet; Izmirli, Serkan; Kuzu, Elif Bugra

    2010-01-01

    The purpose of the current study is to determine opinions of teachers on using internet searching strategies in an elementary school. The study conducted through qualitative method was designed on survey research model. Participants were consisted of 21 teachers at an elementary school in Eskisehir in Turkey. Questionnaires consisting of…

  6. The “I’m Feeling Lucky Syndrome”: Teacher-Candidates’ Knowledge of Web Searching Strategies

    Directory of Open Access Journals (Sweden)

    Corinne Laverty

    2008-06-01

    Full Text Available The need for web literacy has become increasingly important with the exponential growth of learning materials on the web that are freely accessible to educators. Teachers need the skills to locate these tools and also the ability to teach their students web search strategies and evaluation of websites so they can effectively explore the web by themselves. This study examined the web searching strategies of 253 teachers-in-training using both a survey (247 participants and live screen capture with think aloud audio recording (6 participants. The results present a picture of the strategic, syntactic, and evaluative search abilities of these students that librarians and faculty can use to plan how instruction can target information skill deficits in university student populations.

  7. Institutional Embeddedness of Search Strategies and the Implications for Innovation Performance

    DEFF Research Database (Denmark)

    Grimpe, Christoph; Sofka, Wolfgang

    2013-01-01

    to experience the negative performance effects of oversearch. Based on a comprehensive sample of almost 8,000 firms from ten European countries, we find that institutions matter considerably for firms’ search activity. Higher market orientation of institutions increases the effectiveness of firms’ search...... ignored the institutional context that provides or denies access to external knowledge at the country level. Combining institutional and knowledge search theory, we suggest that the market orientation of the institutional environment and the magnitude of institutional change influence when firms begin...... for external knowledge while higher magnitudes of institutional change decrease it. Our results provide important insights for management on how to adapt search strategies to the institutional context....

  8. Localization Accuracy of Track-before-Detect Search Strategies for Distributed Sensor Networks

    Directory of Open Access Journals (Sweden)

    Michael J. Walsh

    2007-12-01

    Full Text Available The localization accuracy of a track-before-detect search for a target moving across a distributed sensor field is examined in this paper. The localization accuracy of the search is defined in terms of the area of intersection of the spatial-temporal sensor coverage regions, as seen from the perspective of the target. The expected value and variance of this area are derived for sensors distributed randomly according to an arbitrary distribution function. These expressions provide an important design objective for use in the planning of distributed sensor fields. Several examples are provided that experimentally validate the analytical results.

  9. Information search and decision making: effects of age and complexity on strategy use.

    Science.gov (United States)

    Queen, Tara L; Hess, Thomas M; Ennis, Gilda E; Dowd, Keith; Grühn, Daniel

    2012-12-01

    The impact of task complexity on information search strategy and decision quality was examined in a sample of 135 young, middle-aged, and older adults. We were particularly interested in the competing roles of fluid cognitive ability and domain knowledge and experience, with the former being a negative influence and the latter being a positive influence on older adults' performance. Participants utilized 2 decision matrices, which varied in complexity, regarding a consumer purchase. Using process tracing software and an algorithm developed to assess decision strategy, we recorded search behavior, strategy selection, and final decision. Contrary to expectations, older adults were not more likely than the younger age groups to engage in information-minimizing search behaviors in response to increases in task complexity. Similarly, adults of all ages used comparable decision strategies and adapted their strategies to the demands of the task. We also examined decision outcomes in relation to participants' preferences. Overall, it seems that older adults utilize simpler sets of information primarily reflecting the most valued attributes in making their choice. The results of this study suggest that older adults are adaptive in their approach to decision making and that this ability may benefit from accrued knowledge and experience. 2013 APA, all rights reserved

  10. Identifying quality improvement intervention publications - A comparison of electronic search strategies

    Directory of Open Access Journals (Sweden)

    Rubenstein Lisa V

    2011-08-01

    Full Text Available Abstract Background The evidence base for quality improvement (QI interventions is expanding rapidly. The diversity of the initiatives and the inconsistency in labeling these as QI interventions makes it challenging for researchers, policymakers, and QI practitioners to access the literature systematically and to identify relevant publications. Methods We evaluated search strategies developed for MEDLINE (Ovid and PubMed based on free text words, Medical subject headings (MeSH, QI intervention components, continuous quality improvement (CQI methods, and combinations of the strategies. Three sets of pertinent QI intervention publications were used for validation. Two independent expert reviewers screened publications for relevance. We compared the yield, recall rate, and precision of the search strategies for the identification of QI publications and for a subset of empirical studies on effects of QI interventions. Results The search yields ranged from 2,221 to 216,167 publications. Mean recall rates for reference publications ranged from 5% to 53% for strategies with yields of 50,000 publications or fewer. The 'best case' strategy, a simple text word search with high face validity ('quality' AND 'improv*' AND 'intervention*' identified 44%, 24%, and 62% of influential intervention articles selected by Agency for Healthcare Research and Quality (AHRQ experts, a set of exemplar articles provided by members of the Standards for Quality Improvement Reporting Excellence (SQUIRE group, and a sample from the Cochrane Effective Practice and Organization of Care Group (EPOC register of studies, respectively. We applied the search strategy to a PubMed search for articles published in 10 pertinent journals in a three-year period which retrieved 183 publications. Among these, 67% were deemed relevant to QI by at least one of two independent raters. Forty percent were classified as empirical studies reporting on a QI intervention. Conclusions The presented

  11. Precision and recall of search strategies for identifying studies on return-to-work in Medline.

    Science.gov (United States)

    Gehanno, Jean-François; Rollin, Laetitia; Le Jean, Tony; Louvel, Alexandre; Darmoni, Stefan; Shaw, William

    2009-09-01

    The purpose of this study was to report on the qualities of various search strategies and keywords to find return to work (RTW) studies in the Medline bibliographic database. We searched Medline for articles on RTW published in 2003, using multiple search strings, and hand searched 16 major periodicals of rehabilitation or occupational medicine. Among the retrieved articles, those considered to be relevant, were pooled in a Gold Standard Database. From this database, we identified candidate text words or MeSH terms for search strategies using a word frequency analysis of the abstracts and a MEDLINE categorization algorithm. According to the frequency of identified terms, searches were run for each term independently and in combination. We computed Recall, Precision, and number needed to read (NNR = 1/Precision) of each keyword or combination of keywords. Among the 8,073 articles examined, 314 (3.9%) were considered relevant and included in the Gold Standard Database. The search strings ("Rehabilitation, Vocational" [MeSH]), ("Return to work"[All]) and ("Back to work"[All]) had Recall/Precision ratio of 30.46/19.11, 59.55/87.38 and 3.18/90.91%, respectively. Their combination with the Boolean operator OR yielded to a Recall/Precision ratio of 73.89/58.44% and a NNR of 1.7. For the end user requiring comprehensive literature search, the best string was ("Return to work" OR "Back to work" OR "Rehabilitation, vocational"[MeSH] OR "rehabilitation"[Subheading]), with a Recall of 88.22% and a NNR of 18. No single MeSH term is available to help the physician to identify relevant studies on RTW in Medline. Locating these types of studies requires the use of various MeSH and non-MeSH terms in combination to obtain a satisfactory Recall. Nevertheless, enhancing the Recall of search strategies may lead to lower Precision, and higher NNR, although with a non linear trend. This factor must be taken into consideration by the end user in order to improve the cost

  12. Improving search over Electronic Health Records using UMLS-based query expansion through random walks.

    Science.gov (United States)

    Martinez, David; Otegi, Arantxa; Soroa, Aitor; Agirre, Eneko

    2014-10-01

    Most of the information in Electronic Health Records (EHRs) is represented in free textual form. Practitioners searching EHRs need to phrase their queries carefully, as the record might use synonyms or other related words. In this paper we show that an automatic query expansion method based on the Unified Medicine Language System (UMLS) Metathesaurus improves the results of a robust baseline when searching EHRs. The method uses a graph representation of the lexical units, concepts and relations in the UMLS Metathesaurus. It is based on random walks over the graph, which start on the query terms. Random walks are a well-studied discipline in both Web and Knowledge Base datasets. Our experiments over the TREC Medical Record track show improvements in both the 2011 and 2012 datasets over a strong baseline. Our analysis shows that the success of our method is due to the automatic expansion of the query with extra terms, even when they are not directly related in the UMLS Metathesaurus. The terms added in the expansion go beyond simple synonyms, and also add other kinds of topically related terms. Expansion of queries using related terms in the UMLS Metathesaurus beyond synonymy is an effective way to overcome the gap between query and document vocabularies when searching for patient cohorts. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Sleuth: A quasi-model-independent search strategy for new physics

    Energy Technology Data Exchange (ETDEWEB)

    Bruce O. Knuteson

    2001-10-03

    How can we search for new physics when we only vaguely know what it should look like? How can we perform an unbiased yet data-driven search? If we see apparently anomalous events in our data, how can we quantify their ''interestingness'' a posteriori? We present an analysis strategy (SLEUTH) that simultaneously addresses each of these questions, and we demonstrate its application to over thirty exclusive final states in data collected by D0 in Run I of the Fermilab Tevatron.

  14. Effect of Learning Search, Solve, Create and Share with Metacognitive Strategies to Solving Ability and Critical Thinking Physics

    Directory of Open Access Journals (Sweden)

    Nia Suciati

    2014-06-01

    Full Text Available Pengaruh Pembelajaran Search, Solve, Create dan Share dengan Strategi Metakognitif terhadap Kemampuan Menyelesaikan Masalah dan Berpikir Kritis Fisika Abstract: This study aims to examine the differences in students 'abilities to think critically and solve problems of physics and the effectiveness of the learning model SSCS with metacognitive strategies to improve students' skills in problem solving and critical thinking physics compared with SSCS learning model and conventional learning. The design of the study is postest Only Control Group Design with a random sample selection. Data were collected through tests problem solving skills, critical thinking skills tests, and observation of learning. The results showed that there are differences in students 'abilities to think critically and solve problems of physics and SSCS learning model with a more effective metacognitive strategies to improve students' skills in critical thinking to solve the problem of physics than the SSCS learning model and conventional learning. Key Words: SSCS learning, metacognitive strategies, solve problems, think critically Abstrak: Penelitian ini bertujuan menguji perbedaan kemampuan siswa menyelesaikan masalah dan berpikir kritis fisika serta efektifitas model pembelajaran SSCS dengan strategi metakognitif untuk meningkatkan kemampuan siswa dalam menyelesaikan masalah dan berpikir kritis fisika dibandingkan dengan model pembelajaran SSCS dan pembelajaran konvensional. Rancangan penelitian yang digunakan adalah Postest Only Control Group Design dengan pemilihan sampel acak. Data dikumpulkan melalui tes kemampuan menyelesaikan masalah, tes kemampuan berpikir kritis, dan observasi pembelajaran. Hasil penelitian menunjukkan bahwa terdapat perbedaan kemampuan siswa menyelesaikan masalah dan berpikir kritis fisika serta model pembelajaran SSCS dengan strategi metakognitif lebih efektif untuk meningkatkan kemampuan siswa dalam menyelesaikan masalah berpikir kritis fisika

  15. Search strategy in a complex and dynamic environment (the Indian Ocean case)

    Science.gov (United States)

    Loire, Sophie; Arbabi, Hassan; Clary, Patrick; Ivic, Stefan; Crnjaric-Zic, Nelida; Macesic, Senka; Crnkovic, Bojan; Mezic, Igor; UCSB Team; Rijeka Team

    2014-11-01

    The disappearance of Malaysia Airlines Flight 370 (MH370) in the early morning hours of 8 March 2014 has exposed the disconcerting lack of efficient methods for identifying where to look and how to look for missing objects in a complex and dynamic environment. The search area for plane debris is a remote part of the Indian Ocean. Searches, of the lawnmower type, have been unsuccessful so far. Lagrangian kinematics of mesoscale features are visible in hypergraph maps of the Indian Ocean surface currents. Without a precise knowledge of the crash site, these maps give an estimate of the time evolution of any initial distribution of plane debris and permits the design of a search strategy. The Dynamic Spectral Multiscale Coverage search algorithm is modified to search a spatial distribution of targets that is evolving with time following the dynamic of ocean surface currents. Trajectories are generated for multiple search agents such that their spatial coverage converges to the target distribution. Central to this DSMC algorithm is a metric for the ergodicity.

  16. The Importance of the Eye Area in Face Identification Abilities and Visual Search Strategies in Persons with Asperger Syndrome

    Science.gov (United States)

    Falkmer, Marita; Larsson, Matilda; Bjallmark, Anna; Falkmer, Torbjorn

    2010-01-01

    Partly claimed to explain social difficulties observed in people with Asperger syndrome, face identification and visual search strategies become important. Previous research findings are, however, disparate. In order to explore face identification abilities and visual search strategies, with special focus on the importance of the eye area, 24…

  17. Optimization of Wind Farm Layout: A Refinement Method by Random Search

    DEFF Research Database (Denmark)

    Feng, Ju; Shen, Wen Zhong

    2013-01-01

    Wind farm layout optimization is to find the optimal positions of wind turbines inside a wind farm, so as to maximize and/or minimize a single objective or multiple objectives, while satisfying certain constraints. Most of the works in the literature divide the wind farm into cells in which...... turbines can be placed, hence, simplifying the problem from with continuous variables to with discrete variables. In this paper, a refinement method, based on continuous formulation, by using random search is proposed to improve the optimization results based on discrete formulations. Two sets...

  18. Evolution of optimal L\\'evy-flight strategies in human mental searches

    CERN Document Server

    Radicchi, Filippo

    2012-01-01

    Recent analysis of empirical data [F. Radicchi, A. Baronchelli & L.A.N. Amaral. PloS ONE {\\bf 7}, e029910 (2012)] showed that humans adopt L\\'evy flight strategies when exploring the bid space in on-line auctions. A game theoretical model proved that the observed L\\'evy exponents are nearly optimal, being close to the exponent value that guarantees the maximal economical return to players. Here, we rationalize these findings by adopting an evolutionary perspective. We show that a simple evolutionary process is able to account for the empirical measurements with the only assumption that the reproductive fitness of a player is proportional to her search ability. Contrarily to previous modeling, our approach describes the emergence of the observed exponent without resorting to any strong assumptions on the initial searching strategies. Our results generalize earlier research, and open novel questions in cognitive, behavioral and evolutionary sciences.

  19. Evolution of optimal Lévy-flight strategies in human mental searches

    Science.gov (United States)

    Radicchi, Filippo; Baronchelli, Andrea

    2012-06-01

    Recent analysis of empirical data [Radicchi, Baronchelli, and Amaral, PloS ONE1932-620310.1371/journal.pone.0029910 7, e029910 (2012)] showed that humans adopt Lévy-flight strategies when exploring the bid space in online auctions. A game theoretical model proved that the observed Lévy exponents are nearly optimal, being close to the exponent value that guarantees the maximal economical return to players. Here, we rationalize these findings by adopting an evolutionary perspective. We show that a simple evolutionary process is able to account for the empirical measurements with the only assumption that the reproductive fitness of the players is proportional to their search ability. Contrary to previous modeling, our approach describes the emergence of the observed exponent without resorting to any strong assumptions on the initial searching strategies. Our results generalize earlier research, and open novel questions in cognitive, behavioral, and evolutionary sciences.

  20. A Discrete Group Search Optimizer for Hybrid Flowshop Scheduling Problem with Random Breakdown

    Directory of Open Access Journals (Sweden)

    Zhe Cui

    2014-01-01

    Full Text Available The scheduling problems have been discussed in the literature extensively under the assumption that the machines are permanently available without any breakdown. However, in the real manufacturing environments, the machines could be unavailable inevitably for many reasons. In this paper, the authors introduce the hybrid flowshop scheduling problem with random breakdown (RBHFS together with a discrete group search optimizer algorithm (DGSO. In particular, two different working cases, preempt-resume case, and preempt-repeat case are considered under random breakdown. The proposed DGSO algorithm adopts the vector representation and several discrete operators, such as insert, swap, differential evolution, destruction, and construction in the producers, scroungers, and rangers phases. In addition, an orthogonal test is applied to configure the adjustable parameters in the DGSO algorithm. The computational results in both cases indicate that the proposed algorithm significantly improves the performances compared with other high performing algorithms in the literature.

  1. Russia-EU: in search of an energy strategy; Russie-UE: quelles strategies energetiques?

    Energy Technology Data Exchange (ETDEWEB)

    Beyou, C. [Documentation Francaise, 75 - Paris (France); Verluise, P. [Geopolitique de l' Union europeenne, 75 - Paris (France)

    2007-02-15

    EU member states have become increasingly dependent on Russian oil. Moreover, their industries are seeing the agreements signed during the Yeltsin years being called into question... and the price they have to pay for the opportunities they once dreamed of is increasing as well. On the other hand Russia is now deriving significant financial and strategic advantage from its oil. Claiming protection of its own interests, it wants to impose its control over extraction and its monopoly of transport while also profiting from the opening up of European markets to establish itself there. The resulting strategies seem a priori incompatible. (authors)

  2. Light-mediated host searching strategies in a fish ectoparasite, Argulus foliaceus L. (crustacea: branchiura).

    Science.gov (United States)

    Mikheev, V N; Mikheev, A V; Pasternak, A F; Valtonen, E T

    2000-04-01

    Argulus foliaceus, an obligate fish ectoparasite, can search for its hosts in both light and dark conditions and uses vision in the light. We have examined what searching mode is used at night, when the infection rate was at its highest, and which stimuli produced by the fish are most important. A change of illumination produced a clear difference in the searching behaviour of adult Argulus females. The mean swimming speed and the area explored were 3-4 times higher in the dark, when the parasite employed a cruising search strategy. This changed to an ambush (hover-and-wait) strategy in the light. The swimming activity is accompanied by changes in metabolic costs; the activity of the electron transport system being approximately 25 % lower in the light. The most pronounced light-induced differences in host-searching behaviour took place in moderately hungry parasites (starved for 24-96 h). Less motivated (just having left a fish) or exhausted animals did not exhibit any clear differences in swimming speed. Among the external signals tested, fish smell, from both perch (Perca fluviatilis) and roach (Rutilus rutilus), induced an elevated swimming speed of the parasite. Periodic water movements caused similar but weaker effects. The effects of these stimuli were observed under both light and dark conditions. We conclude that host-searching behaviour of A. foliaceus is under internal (state of hunger) and external (illumination and host-induced signals) control and involves all its sensory equipment (vision, olfaction and mechano-reception). Perch (but not roach) reduced their swimming speed in the dark, which make them more susceptible to cruising Argulus. Thus the behavioural interplay between hosts and parasites can also influence the infection rate of A. foliaceus found on perch and roach in Finnish lakes.

  3. Movement Strategies During Haptic Search: Implications for the Learning of Blind Populations

    OpenAIRE

    Morash, Valerie Starr

    2014-01-01

    This research investigates the finger-movement strategies used by blindfolded sighted participants when completing a search task on a tactile map. These participants can be considered similar to individuals with recent vision loss, for example due to age-related causes that are responsible for the majority visual impairments in the developed world. The results could also be extended to children with acquired visual impairments, who are likely to encounter a large number of tactile maps and gr...

  4. Hippocampal Neurogenesis Levels Predict WATERMAZE Search Strategies in the Aging Brain

    Science.gov (United States)

    Choquette, Will; Gothard, Russ; Simpson, Jessica M.; Christie, Brian R.

    2013-01-01

    The hippocampus plays a crucial role in the formation of spatial memories, and it is thought that adult hippocampal neurogenesis may participate in this form of learning. To better elucidate the relationship between neurogenesis and spatial learning, we examined both across the entire life span of mice. We found that cell proliferation, neuronal differentiation, and neurogenesis significantly decrease with age, and that there is an abrupt reduction in these processes early on, between 1.5-3 months of age. After this, the neurogenic capacity continues to decline steadily. The initial abrupt decline in adult neurogenesis was paralleled by a significant reduction in Morris Water Maze performance, however overall learning and memory remained constant thereafter. Further analysis of the search strategies employed revealed that reductions in neurogenesis in the aging brain were strongly correlated with the adoption of spatially imprecise search strategies. Overall, performance measures of learning and memory in the Morris Water Maze were maintained at relatively constant levels in aging animals due to an increase in the use of spatially imprecise search strategies. PMID:24086453

  5. A structured approach to documenting a search strategy for publication: a 12 step guideline for authors.

    Science.gov (United States)

    Kable, Ashley K; Pich, Jacqueline; Maslin-Prothero, Sian E

    2012-11-01

    This paper describes a structured approach for documenting a search strategy, prior to the scholarly critique and review of the retrieved literature. There has been a shift in publication expectations when it comes to the presentation of a literature review, from the more traditional narrative review to a more systematic approach, following a specific framework. This paper presents a 12 step framework for documenting the search strategy prior to undertaking a critique and synthesis of the retrieved literature. The authors provide a worked example about potential sources of cross contamination including hospital bath basins and soap and water bathing. An overview of the 12 step framework is presented. This includes step-by-step instructions on how to conduct and write a search strategy for a literature review. A number of resources available for creating reviews and critiquing reviews are referenced, but these are not exclusive. Reviews can be an important and valuable contribution when undertaken well, providing the reader with evidence of a clear structure. This paper provides a 12 step framework that will be of benefit to students, educationalists, and researchers required to embark on a review. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. A fast search strategy for gravitational waves from low-mass X-ray binaries

    CERN Document Server

    Messenger, C

    2007-01-01

    We present a new type of search strategy designed specifically to find continuously emitting gravitational wave sources in known binary systems based on the incoherent sum of frequency modulated binary signal sidebands. The search pipeline can be divided into three stages: the first is a wide bandwidth, F-statistic search demodulated for sky position. This is followed by a fast second stage in which areas in frequency space are identified as signal candidates through the frequency domain convolution of the F-statistic with an approximate signal template. For this second stage only precise information on the orbit period and approximate information on the orbital semi-major axis are required apriori. For the final stage we propose a fully coherent Markov chain monte carlo based follow up search on the frequency subspace defined by the candidates identified by the second stage. This search is particularly suited to the low-mass X-ray binaries, for which orbital period and sky position are typically well known a...

  7. PubMed search strategies for the identification of etiologic associations between hypothalamic-pituitary disorders and other medical conditions.

    Science.gov (United States)

    Guaraldi, Federica; Grottoli, Silvia; Arvat, Emanuela; Mattioli, Stefano; Ghigo, Ezio; Gori, Davide

    2013-12-01

    Biomedical literature has enormously grown in the last decades and become broadly available through online databases. Ad-hoc search methods, created on the basis of research field and goals, are required to enhance the quality of searching. Aim of this study was to formulate efficient, evidence-based PubMed search strategies to retrieve articles assessing etiologic associations between a condition of interest and hypothalamic-pituitary disorders (HPD). Based on expert knowledge, 17 MeSH (Medical Subjects Headings) and 79 free terms related to HPD were identified to search PubMed. Using random samples of abstracts retrieved by each term, we estimated the proportion of articles containing pertinent information and formulated two strings (one more specific, one more sensitive) for the detection of articles focusing on the etiology of HPD, that were then applied to retrieve articles identifying possible etiologic associations between HPD and three diseases (malaria, LHON and celiac disease) considered not associated to HPD, and define the number of abstracts needed to read (NNR) to find one potentially pertinent article. We propose two strings: one sensitive string derived from the combination of articles providing the largest literature coverage in the field and one specific including combined terms retrieving ≥40% of potentially pertinent articles. NNR were 2.1 and 1.6 for malaria, 3.36 and 2.29 for celiac disease, 2.8 and 2.2 for LHON, respectively. For the first time, two reliable, readily applicable strings are proposed for the retrieval of medical literature assessing putative etiologic associations between HPD and other medical conditions of interest.

  8. Strategies in localization proofs for one-dimensional random ...

    Indian Academy of Sciences (India)

    Recent results on localization, both exponential and dynamical, for various models of one-dimensional, continuum, random Schrödinger operators are reviewed. This includes Anderson models with indefinite single site potentials, the Bernoulli–Anderson model, the Poisson model, and the random displacement model.

  9. Optimal search strategies for detecting cost and economic studies in EMBASE

    Science.gov (United States)

    McKinlay, R James; Wilczynski, Nancy L; Haynes, R Brian

    2006-01-01

    Background Economic evaluations in the medical literature compare competing diagnosis or treatment methods for their use of resources and their expected outcomes. The best evidence currently available from research regarding both cost and economic comparisons will continue to expand as this type of information becomes more important in today's clinical practice. Researchers and clinicians need quick, reliable ways to access this information. A key source of this type of information is large bibliographic databases such as EMBASE. The objective of this study was to develop search strategies that optimize the retrieval of health costs and economics studies from EMBASE. Methods We conducted an analytic survey, comparing hand searches of journals with retrievals from EMBASE for candidate search terms and combinations. 6 research assistants read all issues of 55 journals indexed by EMBASE for the publishing year 2000. We rated all articles using purpose and quality indicators and categorized them into clinically relevant original studies, review articles, general papers, or case reports. The original and review articles were then categorized for purpose (i.e., cost and economics and other clinical topics) and depending on the purpose as 'pass' or 'fail' for methodologic rigor. Candidate search strategies were developed for economic and cost studies, then run in the 55 EMBASE journals, the retrievals being compared with the hand search data. The sensitivity, specificity, precision, and accuracy of the search strategies were calculated. Results Combinations of search terms for detecting both cost and economic studies attained levels of 100% sensitivity with specificity levels of 92.9% and 92.3% respectively. When maximizing for both sensitivity and specificity, the combination of terms for detecting cost studies (sensitivity) increased 2.2% over the single term but at a slight decrease in specificity of 0.9%. The maximized combination of terms for economic studies saw no

  10. Hybrid geometric-random template-placement algorithm for gravitational wave searches from compact binary coalescences

    Science.gov (United States)

    Roy, Soumen; Sengupta, Anand S.; Thakor, Nilay

    2017-05-01

    Astrophysical compact binary systems consisting of neutron stars and black holes are an important class of gravitational wave (GW) sources for advanced LIGO detectors. Accurate theoretical waveform models from the inspiral, merger, and ringdown phases of such systems are used to filter detector data under the template-based matched-filtering paradigm. An efficient grid over the parameter space at a fixed minimal match has a direct impact on the overall time taken by these searches. We present a new hybrid geometric-random template placement algorithm for signals described by parameters of two masses and one spin magnitude. Such template banks could potentially be used in GW searches from binary neutron stars and neutron star-black hole systems. The template placement is robust and is able to automatically accommodate curvature and boundary effects with no fine-tuning. We also compare these banks against vanilla stochastic template banks and show that while both are equally efficient in the fitting-factor sense, the bank sizes are ˜25 % larger in the stochastic method. Further, we show that the generation of the proposed hybrid banks can be sped up by nearly an order of magnitude over the stochastic bank. Generic issues related to optimal implementation are discussed in detail. These improvements are expected to directly reduce the computational cost of gravitational wave searches.

  11. In situ measures of foraging success and prey encounter reveal marine habitat-dependent search strategies.

    Science.gov (United States)

    Thums, Michele; Bradshaw, Corey J A; Hindelli, Mark A

    2011-06-01

    Predators are thought to reduce travel speed and increase turning rate in areas where resources are relatively more abundant, a behavior termed "area-restricted search." However, evidence for this is rare, and few empirical data exist for large predators. Animals exhibiting foraging site fidelity could also be spatially aware of suitable feeding areas based on prior experience; changes in movement patterns might therefore arise from the anticipation of higher prey density. We tested the hypothesis that regions of area-restricted search were associated with a higher number of daily speed spikes (a proxy for potential prey encounter rate) and foraging success in southern elephant seals (Mirounga leonina), a species exhibiting both area-restricted searches and high interannual foraging site fidelity. We used onshore morphological measurements and diving data from archival tags deployed during winter foraging trips. Foraging success was inferred from in situ changes in relative lipid content derived from measured changes in buoyancy, and first-passage time analysis was used to identify area-restricted search behavior. Seals exhibited relatively direct southerly movement on average, with intensive search behavior predominantly located at the distal end of tracks. The probability of being in search mode was positively related to changes in relative lipid content; thus, intensively searched areas were associated with the highest foraging success. However, there was high foraging success during the outward transit even though seals moved through quickly without slowing down and increasing turning rate to exploit these areas. In addition, the probability of being in search mode was negatively related to the number of daily speed spikes. These results suggest that movement patterns represent a response to prior expectation of the location of predictable and profitable resources. Shelf habitat was 4-9 times more profitable than the other habitats, emphasizing the importance

  12. Online strategies to facilitate health-related knowledge transfer: a systematic search and review.

    Science.gov (United States)

    Mairs, Katie; McNeil, Heather; McLeod, Jordache; Prorok, Jeanette C; Stolee, Paul

    2013-12-01

    Health interventions and practices often lag behind the available research, and the need for timely translation of new health knowledge into practice is becoming increasingly important. The objective of this study was to conduct a systematic search and review of the literature on online knowledge translation techniques that foster the interaction between various stakeholders and assist in the sharing of ideas and knowledge within the health field. The search strategy included all published literature in the English language since January 2003 and used the medline, Cumulative Index to Nursing and Allied Health Literature (cinahl), embase and Inspec databases. The results of the review indicate that online strategies are diverse, yet all are applicable in facilitating online health-related knowledge translation. The method of knowledge sharing ranged from use of wikis, discussion forums, blogs, and social media to data/knowledge management tools, virtual communities of practice and conferencing technology - all of which can encourage online health communication and knowledge translation. Online technologies are a key facilitator of health-related knowledge translation. This review of online strategies to facilitate health-related knowledge translation can inform the development and improvement of future strategies to expedite the translation of research to practice. © 2013 Health Libraries Group of CILIP and John Wiley & Sons Ltd.

  13. Determination of slope safety factor with analytical solution and searching critical slip surface with genetic-traversal random method.

    Science.gov (United States)

    Niu, Wen-jie

    2014-01-01

    In the current practice, to determine the safety factor of a slope with two-dimensional circular potential failure surface, one of the searching methods for the critical slip surface is Genetic Algorithm (GA), while the method to calculate the slope safety factor is Fellenius' slices method. However GA needs to be validated with more numeric tests, while Fellenius' slices method is just an approximate method like finite element method. This paper proposed a new method to determine the minimum slope safety factor which is the determination of slope safety factor with analytical solution and searching critical slip surface with Genetic-Traversal Random Method. The analytical solution is more accurate than Fellenius' slices method. The Genetic-Traversal Random Method uses random pick to utilize mutation. A computer automatic search program is developed for the Genetic-Traversal Random Method. After comparison with other methods like slope/w software, results indicate that the Genetic-Traversal Random Search Method can give very low safety factor which is about half of the other methods. However the obtained minimum safety factor with Genetic-Traversal Random Search Method is very close to the lower bound solutions of slope safety factor given by the Ansys software.

  14. Where the Sidewalk Ends: Jets and Missing Energy Search Strategies for the 7 TeV LHC

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Daniele S.M.; Izaguirre, Eder; Wacker, Jay G.; /SLAC /Stanford U., ITP

    2011-08-15

    This work explores the potential reach of the 7 TeV LHC to new colored states in the context of simplified models and addresses the issue of which search regions are necessary to cover an extensive set of event topologies and kinematic regimes. This article demonstrates that if searches are designed to focus on specific regions of phase space, then new physics may be missed if it lies in unexpected corners. Simple multiregion search strategies can be designed to cover all of kinematic possibilities. A set of benchmark models are created that cover the qualitatively different signatures and a benchmark multiregion search strategy is presented that covers these models.

  15. The Impact of Competencies, Information Search, and Competitive Strategy on the Export Performance

    Directory of Open Access Journals (Sweden)

    Lena Elitan

    2011-04-01

    Full Text Available This confirmatory study is aimed at analyzing the impact of relationships, information search, and competencies on competitive strategy and SMEs performance in Indonesia. The study used 100 SMEs samples that obtained through mailed questionnaires. The results show: Firstly, the perception of information, information sources, and export competence has no significant effect on competitive strategy. However the findings for SMEs in Indonesia, indicated that export related information has negative effects on competitive strategy. Secondly, export competencies has an enormous influence on the company’s capacity and ability to use information appropriately,when the company must deal with challenges or when the company is eager to take advantage of the opportunities to increase growth and profitability. Thirdly, competitive strategy does not directly affect export performance but it is moderated by the environment uncertainty. It indicates that the influence of competitive strategy would be greater in an uncertain business environment. The uncertain business environment will encourage companies to explore competitive strategy to improve their performance.

  16. Random Search with Memory in Patchy Media: Exploration-Exploitation Tradeoff

    CERN Document Server

    Chupeau, M; Redner, S

    2016-01-01

    How to best exploit patchy resources? This long-standing question belongs to the extensively studied class of explore/exploit problems that arise in a wide range of situations, from animal foraging, to robotic exploration, and to human decision processes. Despite its broad relevance, the issue of optimal exploitation has previously only been tackled through two paradigmatic limiting models---patch-use and random search---that do not account for the interplay between searcher motion within patches and resource depletion. Here, we bridge this gap by introducing a minimal patch exploitation model that incorporates this coupling: the searcher depletes the resources along its random-walk trajectory within a patch and travels to a new patch after it takes $\\mathcal{S}$ consecutive steps without finding resources. We compute the distribution of the amount of resources $F_t$ consumed by time $t$ for this non-Markovian random walker and show that exploring multiple patches is beneficial. In one dimension, we analytica...

  17. New Search Strategies Optimize MEDLINE Retrieval of Sound Studies on Treatment or Prevention of Health Disorders. A review of: Haynes, R. Brian, K. Ann McKibbon, Nancy L. Wilczynski, Stephen D. Walter, and Stephen R. Were. “Optimal search strategies for retrieving scientifically strong studies of treatment from Medline: analytical survey.” BMJ 330.7501 (21 May 2005: 1179.

    Directory of Open Access Journals (Sweden)

    Marcy L. Brown

    2006-06-01

    Full Text Available Objective – To develop and test search strategies for retrieving clinically sound studies from the MEDLINE database on the prevention or treatment of health disorders. Design – Analytical survey. Subjects – The data sources were articles about treatment studies selected from 161 journal titles indexed for MEDLINE in the year 2000. Setting – MEDLINE database searches performed at the Health Information Research Unit, McMaster University, in Ontario, Canada. Methods – Researchers hand searched each issue of 161 journal titles indexed in MEDLINE in the year 2000 to find treatment studies. Journal content included internal medicine, family practice, nursing, and mental health titles. Selected studies met the following criteria: randomisation of subjects, outcome assessment for at least 80% of who entered the study, and an analysis consistent with study design. Of 49,028 potential articles, 6,568 were identified as being treatment or prevention related, and 1,587 met the evaluation criteria. The study authors then created search strategies designed to retrieve articles in MEDLINE that met the same criteria, while excluding articles that did not. They compiled a list of 4,862 unique terms related to study criteria, and tested them using the Ovid Technologies search platform. Overall, 18,404 multiple‐term search strategies were tested. Single terms with specificity greater than 75% and sensitivity greater than 25% were combined into strategies with two or more terms. These multiple term strategies were tested if they yielded sensitivity or accuracy greater than 75% and specificity of at least 50%. Main Results – Of the 4,862 unique terms, 3,807 retrieved citations from MEDLINE that researchers used to assess sensitivity, specificity, precision, and accuracy. The single term that yielded the best accuracy while keeping sensitivity greater than 50% was ‘randomized controlled trial.pt.’. The single term that yielded the best precision

  18. Development of an Eastern Mediterranean Region search strategy for biomedical citations indexed in PubMed.

    Science.gov (United States)

    Tadmouri, Ghazi O; Mandil, Ahmed; Rashidian, Arash

    2017-11-19

    PubMed, a 'barrier-free' bibliographic database covering biomedical and health disciplines, has been successfully used to identify a multitude of indicators that assist in analyzing global trends for biomedical research productivity. The current study represents an original attempt to develop and optimize an Eastern Mediterranean Region (EMR) search strategy in PubMed to pave the way for subsequent descriptive analyses. The refined EMR search strategy contains elaborate syntaxes which facilitate controlling the search process and maintaining a proper balance between sensitivity and precision of the obtained results. Country-specific citation data were manually scanned for false positive publications. Our results indicate that publication productivity increased nearly five-fold in the EMR from 2004 to 2013. Five countries (Islamic Republic of Iran, Egypt, Saudi Arabia, Tunisia and Pakistan; in order of total publications) contributed to 80% of all EMR publications during this period. Each of the remaining 17 EMR countries contributed less than 4%. We believe that the methodology presented in this study can be used in conjunction with other metrics to extract invaluable indicators to describe EMR health research systems.

  19. Multi-attribute mate choice decisions and uncertainty in the decision process: a generalized sequential search strategy.

    Science.gov (United States)

    Wiegmann, Daniel D; Weinersmith, Kelly L; Seubert, Steven M

    2010-04-01

    The behavior of females in search of a mate determines the likelihood that high quality males are encountered and adaptive search strategies rely on the effective use of available information on the quality of prospective mates. The sequential search strategy was formulated, like most models of search behavior, on the assumption that females obtain perfect information on the quality of encountered males. In this paper, we modify the strategy to allow for uncertainty of male quality and we determine how the magnitude of this uncertainty and the ability of females to inspect multiple male attributes to reduce uncertainty influence mate choice decisions. In general, searchers are sensitive to search costs and higher costs lower acceptance criteria under all versions of the model. The choosiness of searchers increases with the variability of the quality of prospective mates under conditions of the original model, but under conditions of uncertainty the choosiness of searchers may increase or decrease with the variability of inspected male attributes. The behavioral response depends on the functional relationship between observed male attributes and the fitness return to searchers and on costs associated with the search process. Higher uncertainty often induces searchers to pay more for information and under conditions of uncertainty the fitness return to searchers is never higher than under conditions of the original model. Further studies of the performance of alternative search strategies under conditions of uncertainty may consequently be necessary to identify search strategies likely to be used under natural conditions.

  20. SOME SYSTEMATIC SAMPLING STRATEGIES USING MULTIPLE RANDOM STARTS

    Directory of Open Access Journals (Sweden)

    Sampath Sundaram

    2010-09-01

    Full Text Available In this paper an attempt is made to extend linear systematic sampling using multiple random starts due to Gautschi(1957for various types of systematic sampling schemes available in literature, namely(i  Balanced Systematic Sampling (BSS of  Sethi (1965 and (ii Modified Systematic Sampling (MSS of Singh, Jindal, and Garg  (1968. Further, the proposed methods were compared with Yates corrected estimator developed with reference to Gautschi’s Linear systematic sampling (LSS with two random starts using appropriate super population models with the  help of R package for statistical computing.

  1. Derivation and validation of automated electronic search strategies to extract Charlson comorbidities from electronic medical records.

    Science.gov (United States)

    Singh, Balwinder; Singh, Amandeep; Ahmed, Adil; Wilson, Gregory A; Pickering, Brian W; Herasevich, Vitaly; Gajic, Ognjen; Li, Guangxi

    2012-09-01

    To develop and validate automated electronic note search strategies (automated digital algorithm) to identify Charlson comorbidities. The automated digital algorithm was built by a series of programmatic queries applied to an institutional electronic medical record database. The automated digital algorithm was derived from secondary analysis of an observational cohort study of 1447 patients admitted to the intensive care unit from January 1 through December 31, 2006, and validated in an independent cohort of 240 patients. The sensitivity, specificity, and positive and negative predictive values of the automated digital algorithm and International Classification of Diseases, Ninth Revision (ICD-9) codes were compared with comprehensive medical record review (reference standard) for the Charlson comorbidities. In the derivation cohort, the automated digital algorithm achieved a median sensitivity of 100% (range, 99%-100%) and a median specificity of 99.7% (range, 99%-100%). In the validation cohort, the sensitivity of the automated digital algorithm ranged from 91% to 100%, and the specificity ranged from 98% to 100%. The sensitivity of the ICD-9 codes ranged from 8% for dementia to 100% for leukemia, whereas specificity ranged from 86% for congestive heart failure to 100% for leukemia, dementia, and AIDS. Our results suggest that search strategies that use automated electronic search strategies to extract Charlson comorbidities from the clinical notes contained within the electronic medical record are feasible and reliable. Automated digital algorithm outperformed ICD-9 codes in all the Charlson variables except leukemia, with greater sensitivity, specificity, and positive and negative predictive values. Copyright © 2012 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  2. Literature search strategies for interdisciplinary research a sourcebook for scientists and engineers

    CERN Document Server

    Ackerson, Linda G

    2006-01-01

    The amount of published literature can be overwhelming for scientists and researchers moving from a broad disciplinary research area to a more specialized one, particularly in fields that use information from more than one discipline. Without a focused inquiry, the researcher may find too little information or may be overcome by too much. Striking the correct balance of information is the focus of Literature Search Strategies for Interdisciplinary Research. This useful reference tool studies diverse interdisciplinary areas revealing the general and individual qualities that dictate the strateg

  3. Understanding and practice of evidence based search strategy among postgraduate dental students: a preliminary study.

    Science.gov (United States)

    Qureshi, Ambrina; Bokhari, Syed Akhtar Hussain; Pirvani, Madiha; Dawani, Narendar

    2015-06-01

    One of the core attributes of competent practice is the ability to locate and analyze high-quality evidence. Research on information seeking knowledge of dental graduates is scarce. The objective was to evaluate pertinent knowledge and skills on formulation of answerable questions and searching skills through the understanding and application of EBP. Participants' understanding and abilities to develop answerable questions in application of EBP were assessed through a quasi-experimental study design among freshly inducted postgraduate dental students at Dow University of Health Sciences. Pre and post workshop activity sessions were conducted and assessment was made through a tool that was an adaptation of the Fresno Test. The assessments performed were calculated for mean scores and standard deviations to draw descriptive results for the participants' understanding of the search items and clinical question formulation skills. Wilcoxon-signed rank test was performed to compare the pre and post workshop mean scores. Forty two participants (females = 20, males = 22) attended the workshop. Pre-workshop knowledge and understanding about the terminologies used in EBP was low among participants. Post-workshop performance of the participants to formulate a question, find evidence and search on PubMed was improved to a "Limited" level. The improvements were statistically significant but could not attain "Strong" and "Excellent" grades as far as the EBP skills were concerned. This study observed a potential to improve search skills of dental graduates after their training and exposure to search strategies available on databases. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. A simple heuristic for Internet-based evidence search in primary care: a randomized controlled trial.

    Science.gov (United States)

    Eberbach, Andreas; Becker, Annette; Rochon, Justine; Finkemeler, Holger; Wagner, Achim; Donner-Banzhoff, Norbert

    2016-01-01

    General practitioners (GPs) are confronted with a wide variety of clinical questions, many of which remain unanswered. In order to assist GPs in finding quick, evidence-based answers, we developed a learning program (LP) with a short interactive workshop based on a simple three-step-heuristic to improve their search and appraisal competence (SAC). We evaluated the LP effectiveness with a randomized controlled trial (RCT). Participants (intervention group [IG] n=20; control group [CG] n=31) rated acceptance and satisfaction and also answered 39 knowledge questions to assess their SAC. We controlled for previous knowledge in content areas covered by the test. Main outcome - SAC: within both groups, the pre-post test shows significant (P=0.00) improvements in correctness (IG 15% vs CG 11%) and confidence (32% vs 26%) to find evidence-based answers. However, the SAC difference was not significant in the RCT. Most workshop participants rated "learning atmosphere" (90%), "skills acquired" (90%), and "relevancy to my practice" (86%) as good or very good. The LP-recommendations were implemented by 67% of the IG, whereas 15% of the CG already conformed to LP recommendations spontaneously (odds ratio 9.6, P=0.00). After literature search, the IG showed a (not significantly) higher satisfaction regarding "time spent" (IG 80% vs CG 65%), "quality of information" (65% vs 54%), and "amount of information" (53% vs 47%). Long-standing established GPs have a good SAC. Despite high acceptance, strong learning effects, positive search experience, and significant increase of SAC in the pre-post test, the RCT of our LP showed no significant difference in SAC between IG and CG. However, we suggest that our simple decision heuristic merits further investigation.

  5. Investigation of High School Students' Online Science Information Searching Performance: The Role of Implicit and Explicit Strategies

    Science.gov (United States)

    Tsai, Meng-Jung; Hsu, Chung-Yuan; Tsai, Chin-Chung

    2012-01-01

    Due to a growing trend of exploring scientific knowledge on the Web, a number of studies have been conducted to highlight examination of students' online searching strategies. The investigation of online searching generally employs methods including a survey, interview, screen-capturing, or transactional logs. The present study firstly intended to…

  6. Optimal strategy analysis based on robust predictive control for inventory system with random demand

    Science.gov (United States)

    Saputra, Aditya; Widowati, Sutrisno

    2017-12-01

    In this paper, the optimal strategy for a single product single supplier inventory system with random demand is analyzed by using robust predictive control with additive random parameter. We formulate the dynamical system of this system as a linear state space with additive random parameter. To determine and analyze the optimal strategy for the given inventory system, we use robust predictive control approach which gives the optimal strategy i.e. the optimal product volume that should be purchased from the supplier for each time period so that the expected cost is minimal. A numerical simulation is performed with some generated random inventory data. We simulate in MATLAB software where the inventory level must be controlled as close as possible to a set point decided by us. From the results, robust predictive control model provides the optimal strategy i.e. the optimal product volume that should be purchased and the inventory level was followed the given set point.

  7. The Beneficial Role of Random Strategies in Social and Financial Systems

    Science.gov (United States)

    Biondo, Alessio Emanuele; Pluchino, Alessandro; Rapisarda, Andrea

    2013-05-01

    In this paper we focus on the beneficial role of random strategies in social sciences by means of simple mathematical and computational models. We briefly review recent results obtained by two of us in previous contributions for the case of the Peter principle and the efficiency of a Parliament. Then, we develop a new application of random strategies to the case of financial trading and discuss in detail our findings about forecasts of markets dynamics.

  8. Random intermittent search and the tug-of-war model of motor-driven transport

    KAUST Repository

    Newby, Jay

    2010-04-16

    We formulate the \\'tug-of-war\\' model of microtubule cargo transport by multiple molecular motors as an intermittent random search for a hidden target. A motor complex consisting of multiple molecular motors with opposing directional preference is modeled using a discrete Markov process. The motors randomly pull each other off of the microtubule so that the state of the motor complex is determined by the number of bound motors. The tug-of-war model prescribes the state transition rates and corresponding cargo velocities in terms of experimentally measured physical parameters. We add space to the resulting Chapman-Kolmogorov (CK) equation so that we can consider delivery of the cargo to a hidden target at an unknown location along the microtubule track. The target represents some subcellular compartment such as a synapse in a neuron\\'s dendrites, and target delivery is modeled as a simple absorption process. Using a quasi-steady-state (QSS) reduction technique we calculate analytical approximations of the mean first passage time (MFPT) to find the target. We show that there exists an optimal adenosine triphosphate (ATP) concentration that minimizes the MFPT for two different cases: (i) the motor complex is composed of equal numbers of kinesin motors bound to two different microtubules (symmetric tug-of-war model) and (ii) the motor complex is composed of different numbers of kinesin and dynein motors bound to a single microtubule (asymmetric tug-of-war model). © 2010 IOP Publishing Ltd.

  9. Stochastic foundations in movement ecology anomalous diffusion, front propagation and random searches

    CERN Document Server

    Méndez, Vicenç; Bartumeus, Frederic

    2014-01-01

    This book presents the fundamental theory for non-standard diffusion problems in movement ecology. Lévy processes and anomalous diffusion have shown to be both powerful and useful tools for qualitatively and quantitatively describing a wide variety of spatial population ecological phenomena and dynamics, such as invasion fronts and search strategies. Adopting a self-contained, textbook-style approach, the authors provide the elements of statistical physics and stochastic processes on which the modeling of movement ecology is based and systematically introduce the physical characterization of ecological processes at the microscopic, mesoscopic and macroscopic levels. The explicit definition of these levels and their interrelations is particularly suitable to coping with the broad spectrum of space and time scales involved in bio-ecological problems.   Including numerous exercises (with solutions), this text is aimed at graduate students and newcomers in this field at the interface of theoretical ecology, mat...

  10. SOME SYSTEMATIC SAMPLING STRATEGIES USING MULTIPLE RANDOM STARTS

    OpenAIRE

    Sampath Sundaram; Ammani Sivaraman

    2010-01-01

    In this paper an attempt is made to extend linear systematic sampling using multiple random starts due to Gautschi(1957)for various types of systematic sampling schemes available in literature, namely(i)  Balanced Systematic Sampling (BSS) of  Sethi (1965) and (ii) Modified Systematic Sampling (MSS) of Singh, Jindal, and Garg  (1968). Further, the proposed methods were compared with Yates corrected estimator developed with reference to Gautschi’s Linear systematic samplin...

  11. Developing search strategies for clinical practice guidelines in SUMSearch and Google Scholar and assessing their retrieval performance

    Directory of Open Access Journals (Sweden)

    Kirchner Hanna

    2007-06-01

    Full Text Available Abstract Background Information overload, increasing time constraints, and inappropriate search strategies complicate the detection of clinical practice guidelines (CPGs. The aim of this study was to provide clinicians with recommendations for search strategies to efficiently identify relevant CPGs in SUMSearch and Google Scholar. Methods We compared the retrieval efficiency (retrieval performance of search strategies to identify CPGs in SUMSearch and Google Scholar. For this purpose, a two-term GLAD (GuideLine And Disease strategy was developed, combining a defined CPG term with a specific disease term (MeSH term. We used three different CPG terms and nine MeSH terms for nine selected diseases to identify the most efficient GLAD strategy for each search engine. The retrievals for the nine diseases were pooled. To compare GLAD strategies, we used a manual review of all retrievals as a reference standard. The CPGs detected had to fulfil predefined criteria, e.g., the inclusion of therapeutic recommendations. Retrieval performance was evaluated by calculating so-called diagnostic parameters (sensitivity, specificity, and "Number Needed to Read" [NNR] for search strategies. Results The search yielded a total of 2830 retrievals; 987 (34.9% in Google Scholar and 1843 (65.1% in SUMSearch. Altogether, we found 119 unique and relevant guidelines for nine diseases (reference standard. Overall, the GLAD strategies showed a better retrieval performance in SUMSearch than in Google Scholar. The performance pattern between search engines was similar: search strategies including the term "guideline" yielded the highest sensitivity (SUMSearch: 81.5%; Google Scholar: 31.9%, and search strategies including the term "practice guideline" yielded the highest specificity (SUMSearch: 89.5%; Google Scholar: 95.7%, and the lowest NNR (SUMSearch: 7.0; Google Scholar: 9.3. Conclusion SUMSearch is a useful tool to swiftly gain an overview of available CPGs. Its retrieval

  12. Radiotherapy Planning Using an Improved Search Strategy in Particle Swarm Optimization.

    Science.gov (United States)

    Modiri, Arezoo; Gu, Xuejun; Hagan, Aaron M; Sawant, Amit

    2017-05-01

    Evolutionary stochastic global optimization algorithms are widely used in large-scale, nonconvex problems. However, enhancing the search efficiency and repeatability of these techniques often requires well-customized approaches. This study investigates one such approach. We use particle swarm optimization (PSO) algorithm to solve a 4D radiation therapy (RT) inverse planning problem, where the key idea is to use respiratory motion as an additional degree of freedom in lung cancer RT. The primary goal is to administer a lethal dose to the tumor target while sparing surrounding healthy tissue. Our optimization iteratively adjusts radiation fluence-weights for all beam apertures across all respiratory phases. We implement three PSO-based approaches: conventionally used unconstrained, hard-constrained, and our proposed virtual search. As proof of concept, five lung cancer patient cases are optimized over ten runs using each PSO approach. For comparison, a dynamically penalized likelihood (DPL) algorithm-a popular RT optimization technique is also implemented and used. The proposed technique significantly improves the robustness to random initialization while requiring fewer iteration cycles to converge across all cases. DPL manages to find the global optimum in 2 out of 5 RT cases over significantly more iterations. The proposed virtual search approach boosts the swarm search efficiency, and consequently, improves the optimization convergence rate and robustness for PSO. RT planning is a large-scale, nonconvex optimization problem, where finding optimal solutions in a clinically practical time is critical. Our proposed approach can potentially improve the optimization efficiency in similar time-sensitive problems.

  13. Enhanced Differential Evolution Based on Adaptive Mutation and Wrapper Local Search Strategies for Global Optimization Problems

    Directory of Open Access Journals (Sweden)

    Chun-Liang Lu

    2014-12-01

    Full Text Available Differential evolution (DE is a simple, powerful optimization algorithm, which has been widely used in many areas. However, the choices of the best mutation and search strategies are difficult for the specific issues. To alleviate these drawbacks and enhance the performance of DE, in this paper, the hybrid framework based on the adaptive mutation and Wrapper Local Search (WLS schemes, is proposed to improve searching ability to efficiently guide the evolution of the population toward the global optimum. Furthermore, the effective particle encoding representation named Particle Segment Operation-Machine Assignment (PSOMA that we previously published is applied to always produce feasible candidate solutions for solving the Flexible Job-shop Scheduling Problem (FJSP. Experiments were conducted on comprehensive set of complex benchmarks including the unimodal, multimodal and hybrid composition function, to validate performance of the proposed method and to compare with other state-of-the art DE variants such as jDE, JADE, MDE_pBX etc. Meanwhile, the hybrid DE model incorporating PSOMA is used to solve different representative instances based on practical data for multi-objective FJSP verifications. Simulation results indicate that the proposed method performs better for the majority of the single-objective scalable benchmark functions in terms of the solution accuracy and convergence rate. In addition, the wide range of Pareto-optimal solutions and more Gantt chart decision-makings can be provided for the multi-objective FJSP combinatorial optimizations.

  14. Metagenomic Taxonomy-Guided Database-Searching Strategy for Improving Metaproteomic Analysis.

    Science.gov (United States)

    Xiao, Jinqiu; Tanca, Alessandro; Jia, Ben; Yang, Runqing; Wang, Bo; Zhang, Yu; Li, Jing

    2018-02-26

    Metaproteomics provides a direct measure of the functional information by investigating all proteins expressed by a microbiota. However, due to the complexity and heterogeneity of microbial communities, it is very hard to construct a sequence database suitable for a metaproteomic study. Using a public database, researchers might not be able to identify proteins from poorly characterized microbial species, while a sequencing-based metagenomic database may not provide adequate coverage for all potentially expressed protein sequences. To address this challenge, we propose a metagenomic taxonomy-guided database-search strategy (MT), in which a merged database is employed, consisting of both taxonomy-guided reference protein sequences from public databases and proteins from metagenome assembly. By applying our MT strategy to a mock microbial mixture, about two times as many peptides were detected as with the metagenomic database only. According to the evaluation of the reliability of taxonomic attribution, the rate of misassignments was comparable to that obtained using an a priori matched database. We also evaluated the MT strategy with a human gut microbial sample, and we found 1.7 times as many peptides as using a standard metagenomic database. In conclusion, our MT strategy allows the construction of databases able to provide high sensitivity and precision in peptide identification in metaproteomic studies, enabling the detection of proteins from poorly characterized species within the microbiota.

  15. Family Health Strategy: assessment and reasons for searching of health service by users

    Directory of Open Access Journals (Sweden)

    Loeste de Arruda-Barbosa

    2011-12-01

    Full Text Available Objective: To assess the evaluation of the users regarding the family health services and identify the main reasons that led them to seek such services. Methods: A descriptive study with qualitative approach, carried out in 5 Family Health Units with 25 users of theFamily Health Strategy (FHS of the city of Crato-CE, Brazil. The study took place from March to April 2009. Semi-structured interview was applied and recorded. We used thetechnique of thematic content analysis. Results: We found that the users of the FHS have great dissatisfaction, especially on the organization and access to health services, evaluating the family health as inefficient, although bringing care closer to the population, primarily through home visits. It was clear also that there is a search to the service mainly supported by curative vision and the acquisition of medicines. Conclusions: The subjects evaluate the organization and access to healthcare services as unsatisfactory, but value the actions, when there is a bond with the health team. However, there is still demand for health services, based on the search for medicines and medical consultation. Thus, it is necessary to improve services of the Family Health Strategy in Crato, with a view to ensure quality, accessibilityand greater resolution of health services.

  16. Visual search strategies of soccer players executing a power vs. placement penalty kick.

    Directory of Open Access Journals (Sweden)

    Matthew A Timmis

    Full Text Available When taking a soccer penalty kick, there are two distinct kicking techniques that can be adopted; a 'power' penalty or a 'placement' penalty. The current study investigated how the type of penalty kick being taken affected the kicker's visual search strategy and where the ball hit the goal (end ball location.Wearing a portable eye tracker, 12 university footballers executed 2 power and placement penalty kicks, indoors, both with and without the presence of a goalkeeper. Video cameras were used to determine initial ball velocity and end ball location.When taking the power penalty, the football was kicked significantly harder and more centrally in the goal compared to the placement penalty. During the power penalty, players fixated on the football for longer and more often at the goalkeeper (and by implication the middle of the goal, whereas in the placement penalty, fixated longer at the goal, specifically the edges. Findings remained consistent irrespective of goalkeeper presence.Findings indicate differences in visual search strategy and end ball location as a function of type of penalty kick. When taking the placement penalty, players fixated and kicked the football to the edges of the goal in an attempt to direct the ball to an area that the goalkeeper would have difficulty reaching and saving. Fixating significantly longer on the football when taking the power compared to placement penalty indicates a greater importance of obtaining visual information from the football. This can be attributed to ensuring accurate foot-to-ball contact and subsequent generation of ball velocity. Aligning gaze and kicking the football centrally in the goal when executing the power compared to placement penalty may have been a strategy to reduce the risk of kicking wide of the goal altogether.

  17. On random search: Collection kinetics of Paramecia into a trap embedded in a closed domain

    Science.gov (United States)

    Deforet, Maxime; Duplat, Jérôme; Vandenberghe, Nicolas; Villermaux, Emmanuel

    2010-06-01

    We study the kinetics of a large number of organisms initially spread uniformly in a circular two-dimensional medium, at the center of which a smaller circular trap has been introduced. We take advantage of the acidophily of Paramecium caudatum, which, coming from a neutral medium, penetrates a region of moderate acidity but moves back in the opposite situation when it meets a sharp negative acidity gradient to quantify its rate of irreversible aggregation into a spot of acidified medium in water. Two regimes are distinguished: A ballistic regime characteristic of "fresh" paramecia where the organisms swim in a straight path with a well defined velocity and a Brownian regime characteristic of older paramecia where the mean free path of the organisms is smaller than the system size. Both regimes are characterized by distinct aggregation laws. They both result from a pure random trapping process that appears to have no adaptive strategy.

  18. A simple heuristic for Internet-based evidence search in primary care: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Eberbach A

    2016-08-01

    Full Text Available Andreas Eberbach,1 Annette Becker,1 Justine Rochon,2 Holger Finkemeler,1Achim Wagner,3 Norbert Donner-Banzhoff1 1Department of Family and Community Medicine, Philipp University of Marburg, Marburg, Germany; 2Institute of Medical Biometry and Informatics, University of Heidelberg, Heidelberg, Germany; 3Department of Sport Medicine, Justus-Liebig-University of Giessen, Giessen, Germany Background: General practitioners (GPs are confronted with a wide variety of clinical questions, many of which remain unanswered. Methods: In order to assist GPs in finding quick, evidence-based answers, we developed a learning program (LP with a short interactive workshop based on a simple ­three-step-heuristic to improve their search and appraisal competence (SAC. We evaluated the LP ­effectiveness with a randomized controlled trial (RCT. Participants (intervention group [IG] n=20; ­control group [CG] n=31 rated acceptance and satisfaction and also answered 39 ­knowledge ­questions to assess their SAC. We controlled for previous knowledge in content areas covered by the test. Results: Main outcome – SAC: within both groups, the pre–post test shows significant (P=0.00 improvements in correctness (IG 15% vs CG 11% and confidence (32% vs 26% to find evidence-based answers. However, the SAC difference was not significant in the RCT. Other measures: Most workshop participants rated “learning atmosphere” (90%, “skills acquired” (90%, and “relevancy to my practice” (86% as good or very good. The ­LP-recommendations were implemented by 67% of the IG, whereas 15% of the CG already conformed to LP recommendations spontaneously (odds ratio 9.6, P=0.00. After literature search, the IG showed a (not significantly higher satisfaction regarding “time spent” (IG 80% vs CG 65%, “quality of information” (65% vs 54%, and “amount of information” (53% vs 47%.Conclusion: Long-standing established GPs have a good SAC. Despite high acceptance, strong

  19. Decision making in family medicine: randomized trial of the effects of the InfoClinique and Trip database search engines.

    Science.gov (United States)

    Labrecque, Michel; Ratté, Stéphane; Frémont, Pierre; Cauchon, Michel; Ouellet, Jérôme; Hogg, William; McGowan, Jessie; Gagnon, Marie-Pierre; Njoya, Merlin; Légaré, France

    2013-10-01

    To compare the ability of users of 2 medical search engines, InfoClinique and the Trip database, to provide correct answers to clinical questions and to explore the perceived effects of the tools on the clinical decision-making process. Randomized trial. Three family medicine units of the family medicine program of the Faculty of Medicine at Laval University in Quebec city, Que. Fifteen second-year family medicine residents. Residents generated 30 structured questions about therapy or preventive treatment (2 questions per resident) based on clinical encounters. Using an Internet platform designed for the trial, each resident answered 20 of these questions (their own 2, plus 18 of the questions formulated by other residents, selected randomly) before and after searching for information with 1 of the 2 search engines. For each question, 5 residents were randomly assigned to begin their search with InfoClinique and 5 with the Trip database. The ability of residents to provide correct answers to clinical questions using the search engines, as determined by third-party evaluation. After answering each question, participants completed a questionnaire to assess their perception of the engine's effect on the decision-making process in clinical practice. Of 300 possible pairs of answers (1 answer before and 1 after the initial search), 254 (85%) were produced by 14 residents. Of these, 132 (52%) and 122 (48%) pairs of answers concerned questions that had been assigned an initial search with InfoClinique and the Trip database, respectively. Both engines produced an important and similar absolute increase in the proportion of correct answers after searching (26% to 62% for InfoClinique, for an increase of 36%; 24% to 63% for the Trip database, for an increase of 39%; P = .68). For all 30 clinical questions, at least 1 resident produced the correct answer after searching with either search engine. The mean (SD) time of the initial search for each question was 23.5 (7

  20. Comparing patient characteristics, type of intervention, control, and outcome (PICO) queries with unguided searching: a randomized controlled crossover trial

    NARCIS (Netherlands)

    Hoogendam, A.; Vries Robbé, P.F. de; Overbeke, A.J.P.M.

    2012-01-01

    BACKGROUND: Translating a question into a query using patient characteristics, type of intervention, control, and outcome (PICO) should help answer therapeutic questions in PubMed searches. The authors performed a randomized crossover trial to determine whether the PICO format was useful for quick

  1. Visual Search Strategies of Tag Clouds - Results from an Eyetracking Study

    Science.gov (United States)

    Schrammel, Johann; Deutsch, Stephanie; Tscheligi, Manfred

    Tag clouds have become a frequently used interaction technique in the web in the past couple of years. Research has shown the influence of variables such as tag size and location on the perception of tag clouds. However, several questions remain unclear. First, little is know on how tag clouds are perceived visually and which search strategies users apply when looking for tags in a tag cloud. Second, there are variables, especially tag location, were prior work comes to conflicting results. Third, several approaches to present tag clouds with the tags semantically clustered have been proposed recently. However, it remains unclear which effects these new approaches have on the perception of tag clouds. In this paper we report the results of an extensive study on the perception of tag clouds using eye tracking technology that allows answering these questions.

  2. Intelligent energy allocation strategy for PHEV charging station using gravitational search algorithm

    Science.gov (United States)

    Rahman, Imran; Vasant, Pandian M.; Singh, Balbir Singh Mahinder; Abdullah-Al-Wadud, M.

    2014-10-01

    Recent researches towards the use of green technologies to reduce pollution and increase penetration of renewable energy sources in the transportation sector are gaining popularity. The development of the smart grid environment focusing on PHEVs may also heal some of the prevailing grid problems by enabling the implementation of Vehicle-to-Grid (V2G) concept. Intelligent energy management is an important issue which has already drawn much attention to researchers. Most of these works require formulation of mathematical models which extensively use computational intelligence-based optimization techniques to solve many technical problems. Higher penetration of PHEVs require adequate charging infrastructure as well as smart charging strategies. We used Gravitational Search Algorithm (GSA) to intelligently allocate energy to the PHEVs considering constraints such as energy price, remaining battery capacity, and remaining charging time.

  3. Risk stratification for COPD diagnosis through an active search strategy in primary care

    Directory of Open Access Journals (Sweden)

    Marcos PJ

    2016-03-01

    Full Text Available Pedro J Marcos,1 Rosa Malo de Molina,2 Ricard Casamor3 1Servicio de Neumología, Instituto de investigación Biomédica de A Coruña (INIBIC, Complejo Hospitalario Universitario de A Coruña (CHUAC, Sergas Universidade da Coruña (UDC, A Coruña, 2Servicio de Neumología, Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, 3Medical Department, Novartis Farmacéutica SA, Barcelona, Spain Background: The aim of this study was to identify the percentage of undiagnosed patients with COPD through the implementation of an active search strategy in a selected subject population. Methods: An observational, cross-sectional, multicenter study was conducted in a primary care setting in Spain. General practitioners gave their diagnostic impression of COPD (yes/no on the basis of clinical criteria of subjects with respiratory symptoms and tobacco exposure. Subsequently, post-bronchodilator spirometry and quality-of-life tests were performed. Multivariate logistic regression techniques using receiver operating characteristic (ROC curves were used to identify the combination of variables that best discriminates COPD. Results: A total of 2,758 patients were screened at 368 primary care centers, of which 1,725 patients were included in the study. Seven hundred and ninety-three patients (46% were diagnosed with COPD. Clinical judgment resulted in suspected COPD in 1,393 (81% of the subjects. The best variables to discriminate COPD were a history of lower respiratory tract infections, cough, and dyspnea. This combination identified COPD with a ROCAUC of 0.61 denoting a poor discriminative ability. Conclusion: Employing an active search strategy leads to a new COPD diagnosis in almost half of the subjects. Screening of COPD with post-bronchodilator spirometry should be considered mandatory for any high-risk subject visiting the general practitioner clinic for any reason. Keywords: COPD, post-bronchodilator spirometry, primary care, screening

  4. A hybrid search algorithm for swarm robots searching in an unknown environment.

    Science.gov (United States)

    Li, Shoutao; Li, Lina; Lee, Gordon; Zhang, Hao

    2014-01-01

    This paper proposes a novel method to improve the efficiency of a swarm of robots searching in an unknown environment. The approach focuses on the process of feeding and individual coordination characteristics inspired by the foraging behavior in nature. A predatory strategy was used for searching; hence, this hybrid approach integrated a random search technique with a dynamic particle swarm optimization (DPSO) search algorithm. If a search robot could not find any target information, it used a random search algorithm for a global search. If the robot found any target information in a region, the DPSO search algorithm was used for a local search. This particle swarm optimization search algorithm is dynamic as all the parameters in the algorithm are refreshed synchronously through a communication mechanism until the robots find the target position, after which, the robots fall back to a random searching mode. Thus, in this searching strategy, the robots alternated between two searching algorithms until the whole area was covered. During the searching process, the robots used a local communication mechanism to share map information and DPSO parameters to reduce the communication burden and overcome hardware limitations. If the search area is very large, search efficiency may be greatly reduced if only one robot searches an entire region given the limited resources available and time constraints. In this research we divided the entire search area into several subregions, selected a target utility function to determine which subregion should be initially searched and thereby reduced the residence time of the target to improve search efficiency.

  5. Can horizontally oriented breast tomosynthesis image volumes or the use of a systematic search strategy improve interpretation? An eye tracking and free response human observer study

    Science.gov (United States)

    Lång, Kristina; Zackrisson, Sophia; Holmqvist, Kenneth; Nyström, Marcus; Andersson, Ingvar; Förnvik, Daniel; Tingberg, Anders; Timberg, Pontus

    2011-03-01

    Our aim was to evaluate if there is a benefit in diagnostic accuracy and efficiency of viewing breast tomosynthesis (BT) image volumes presented horizontally oriented, but also to evaluate the use of a systematic search strategy where the breast is divided, and analyzed consecutively, into two sections. These image presentations were compared to regular vertical image presentation. All methods were investigated using viewing procedures consisting of free scroll volume browsing, and a combination of initial cine loops at three different frame rates (9, 14, 25 fps) terminated upon request followed by free scroll volume browsing if needed. Fifty-five normal BT image volumes in MLO view were collected. In these, simulated lesions (20 masses and 20 clusters of microcalcifications) were randomly inserted, creating four unique image sets for each procedure. Four readers interpreted the cases in a random order. Their task was to locate the lesions, mark and assign a five level confidence scale. The diagnostic accuracy was analyzed using Jackknife Free Receiver Operating Characteristics (JAFROC). Time efficiency and visual search behavior were also investigated using eye tracking. Results indicate there was no statistically significant difference in JAFROC FOM between the different image presentations, although visual search was more time efficient when viewing horizontally oriented image volumes in medium cine loops.

  6. Comparing patient characteristics, type of intervention, control, and outcome (PICO) queries with unguided searching: a randomized controlled crossover trial.

    Science.gov (United States)

    Hoogendam, Arjen; de Vries Robbé, Pieter F; Overbeke, A John P M

    2012-04-01

    Translating a question into a query using patient characteristics, type of intervention, control, and outcome (PICO) should help answer therapeutic questions in PubMed searches. The authors performed a randomized crossover trial to determine whether the PICO format was useful for quick searches of PubMed. Twenty-two residents and specialists working at the Radboud University Nijmegen Medical Centre were trained in formulating PICO queries and then presented with a randomized set of questions derived from Cochrane reviews. They were asked to use the best query possible in a five-minute search, using standard and PICO queries. Recall and precision were calculated for both standard and PICO queries. Twenty-two physicians created 434 queries using both techniques. Average precision was 4.02% for standard queries and 3.44% for PICO queries (difference nonsignificant, t(21) = -0.56, P = 0.58). Average recall was 12.27% for standard queries and 13.62% for PICO queries (difference nonsignificant, t(21) = -0.76, P = 0.46). PICO queries do not result in better recall or precision in time-limited searches. Standard queries containing enough detail are sufficient for quick searches.

  7. Searching for answers to clinical questions using google versus evidence-based summary resources: a randomized controlled crossover study.

    Science.gov (United States)

    Kim, Sarang; Noveck, Helaine; Galt, James; Hogshire, Lauren; Willett, Laura; O'Rourke, Kerry

    2014-06-01

    To compare the speed and accuracy of answering clinical questions using Google versus summary resources. In 2011 and 2012, 48 internal medicine interns from two classes at Rutgers University Robert Wood Johnson Medical School, who had been trained to use three evidence-based summary resources, performed four-minute computer searches to answer 10 clinical questions. Half were randomized to initiate searches for answers to questions 1 to 5 using Google; the other half initiated searches using a summary resource. They then crossed over and used the other resource for questions 6 to 10. They documented the time spent searching and the resource where the answer was found. Time to correct response and percentage of correct responses were compared between groups using t test and general estimating equations. Of 480 questions administered, interns found answers for 393 (82%). Interns initiating searches in Google used a wider variety of resources than those starting with summary resources. No significant difference was found in mean time to correct response (138.5 seconds for Google versus 136.1 seconds for summary resource; P = .72). Mean correct response rate was 58.4% for Google versus 61.5% for summary resource (mean difference -3.1%; 95% CI -10.3% to 4.2%; P = .40). The authors found no significant differences in speed or accuracy between searches initiated using Google versus summary resources. Although summary resources are considered to provide the highest quality of evidence, improvements to allow for better speed and accuracy are needed.

  8. Effect of Learning Search, Solve, Create and Share with Metacognitive Strategies to Solving Ability and Critical Thinking Physics

    OpenAIRE

    Suciati, Nia

    2013-01-01

    Pengaruh Pembelajaran Search, Solve, Create dan Share dengan Strategi Metakognitif terhadap Kemampuan Menyelesaikan Masalah dan Berpikir Kritis Fisika Abstract: This study aims to examine the differences in students 'abilities to think critically and solve problems of physics and the effectiveness of the learning model SSCS with metacognitive strategies to improve students' skills in problem solving and critical thinking physics compared with SSCS learning model and conventional learning...

  9. NSGA-II Algorithm with a Local Search Strategy for Multiobjective Optimal Design of Dry-Type Air-Core Reactor

    Directory of Open Access Journals (Sweden)

    Chengfen Zhang

    2015-01-01

    Full Text Available Dry-type air-core reactor is now widely applied in electrical power distribution systems, for which the optimization design is a crucial issue. In the optimization design problem of dry-type air-core reactor, the objectives of minimizing the production cost and minimizing the operation cost are both important. In this paper, a multiobjective optimal model is established considering simultaneously the two objectives of minimizing the production cost and minimizing the operation cost. To solve the multi-objective optimization problem, a memetic evolutionary algorithm is proposed, which combines elitist nondominated sorting genetic algorithm version II (NSGA-II with a local search strategy based on the covariance matrix adaptation evolution strategy (CMA-ES. NSGA-II can provide decision maker with flexible choices among the different trade-off solutions, while the local-search strategy, which is applied to nondominated individuals randomly selected from the current population in a given generation and quantity, can accelerate the convergence speed. Furthermore, another modification is that an external archive is set in the proposed algorithm for increasing the evolutionary efficiency. The proposed algorithm is tested on a dry-type air-core reactor made of rectangular cross-section litz-wire. Simulation results show that the proposed algorithm has high efficiency and it converges to a better Pareto front.

  10. Comparing a stratified treatment strategy with the standard treatment in randomized clinical trials

    DEFF Research Database (Denmark)

    Sun, Hong; Bretz, Frank; Gerke, Oke

    2016-01-01

    The increasing emergence of predictive markers for different treatments in the same patient population allows us to define stratified treatment strategies. We consider randomized clinical trials that compare a standard treatment with a new stratified treatment strategy that divides the study...... population into subgroups receiving different treatments. Because the new strategy may not be beneficial in all subgroups, we consider in this paper an intermediate approach that establishes a treatment effect in a subset of patients built by joining several subgroups. The approach is based on the simple...

  11. Multisite Randomized Controlled Trial Examining Intelligent Tutoring of Structure Strategy for Fifth-Grade Readers

    Science.gov (United States)

    Wijekumar, Kausalai; Meyer, Bonnie J. F.; Lei, Pui-Wa; Lin, Yu-Chu; Johnson, Lori A.; Spielvogel, James A.; Shurmatz, Kathryn M.; Ray, Melissa; Cook, Michael

    2014-01-01

    This article reports on a large scale randomized controlled trial to study the efficacy of a web-based intelligent tutoring system for the structure strategy designed to improve content area reading comprehension. The research was conducted with 128 fifth-grade classrooms within 12 school districts in rural and suburban settings. Classrooms within…

  12. Supplemental Reading Strategy Instruction for Adolescents: A Randomized Trial and Follow-up Study

    Science.gov (United States)

    Cantrell, Susan Chambers; Almasi, Janice F.; Rintamaa, Margaret; Carter, Janis C.

    2016-01-01

    In this study, the authors examine the impact of a yearlong supplemental reading course involving daily instruction in the learning strategies curriculum on lower achieving adolescent students' reading achievement and motivation. Using a multiple-cohort randomized treatment-control group design over 4 years, they compared achievement and…

  13. Similarity Digest Search: A Survey and Comparative Analysis of Strategies to Perform Known File Filtering Using Approximate Matching

    Directory of Open Access Journals (Sweden)

    Vitor Hugo Galhardo Moia

    2017-01-01

    Full Text Available Digital forensics is a branch of Computer Science aiming at investigating and analyzing electronic devices in the search for crime evidence. There are several ways to perform this search. Known File Filter (KFF is one of them, where a list of interest objects is used to reduce/separate data for analysis. Holding a database of hashes of such objects, the examiner performs lookups for matches against the target device. However, due to limitations over hash functions (inability to detect similar objects, new methods have been designed, called approximate matching. This sort of function has interesting characteristics for KFF investigations but suffers mainly from high costs when dealing with huge data sets, as the search is usually done by brute force. To mitigate this problem, strategies have been developed to better perform lookups. In this paper, we present the state of the art of similarity digest search strategies, along with a detailed comparison involving several aspects, as time complexity, memory requirement, and search precision. Our results show that none of the approaches address at least these main aspects. Finally, we discuss future directions and present requirements for a new strategy aiming to fulfill current limitations.

  14. The optimal strategy of percutaneous coronary intervention for ST-elevation myocardial infarction patients with multivessel disease: an updated meta-analysis of 9 randomized controlled trials.

    Science.gov (United States)

    Fan, Zhong G; Gao, Xiao F; Li, Xiao B; Mao, Wen X; Chen, Li W; Tian, Nai L

    2017-04-01

    The optimal strategy of percutaneous coronary intervention (PCI) for patients with ST-elevation myocardial infarction (STEMI) and multivessel disease (MVD) still remains controversial. This study sought to explore the optimal PCI strategy for those patients. Medline, EMBASE and the Cochrane Controlled Trials Registry were searched for relevant studies. We analyzed the comparison of major adverse cardiac events (MACEs) as the primary end point between the preventive PCI strategy and the culprit only PCI strategy (CV-PCI). The further analysis of two subgroups described as the complete multivessel PCI strategy during primary procedure (CMV-PCI) and the staged PCI strategy (S-PCI) was also performed. Nine randomized trials were identified. The risk of MACEs was reduced significantly regarding to preventive PCI strategy (OR=0.41, 95% CI: 0.31-0.53, Pstrategy. There were lower risks of long-term mortality, reinfarction and repeat revascularization in the preventive PCI group compared to the CV-PCI group (OR=0.41, 95% CI: 0.27-0.62, Pstrategy reduced the incidence of long-term mortality versus CMV-PCI strategy. The preventive PCI is associated with the lower risk of MACEs in STEMI patients with MVD compared to the CV-PCI strategy, and the S-PCI strategy seems to be an optimal choice for these patients rather than the CMV-PCI.

  15. Preservation of biological information in thermal spring deposits - Developing a strategy for the search for fossil life on Mars

    Science.gov (United States)

    Walter, M. R.; Des Marais, David J.

    1993-01-01

    Paleobiological experience on earth is used here to develop a search strategy for fossil life on Mars. In particular, the exploration of thermal spring deposits is proposed as a way to maximize the chance of finding fossil life on Mars. As a basis for this suggestion, the characteristics of thermal springs are discussed in some detail.

  16. A Content Analysis of Strategies and Tactics Observed among MLIS Students in an Online Searching Course

    Science.gov (United States)

    Ondrusek, Anita L.; Ren, Xiaoai; Yang, Changwoo

    2017-01-01

    Online searching is a skill that all professional programs educating librarians consider an essential part of their curricula. However, investigations of online searching behavior have centered almost exclusively on end users, and there have been no recent formal studies that explore the online searching behaviors of MLIS students. In this study,…

  17. Unveiling Gargantua: A new search strategy for the most massive central cluster black holes

    Science.gov (United States)

    Brockamp, M.; Baumgardt, H.; Britzen, S.; Zensus, A.

    2016-01-01

    Aims: We aim to unveil the most massive central cluster black holes in the Universe. Methods: We present a new search strategy, which is based on a black hole mass gain sensitive calorimeter and which links the innermost stellar density profile of a galaxy to the adiabatic growth of its central supermassive black hole (SMBH). As a first step we convert observationally inferred feedback powers into SMBH growth rates using reasonable energy conversion efficiency parameters, ɛ. In the main part of this paper we use these black hole growth rates, sorted in logarithmically increasing steps encompassing our whole parameter space, to conduct N-body computations of brightest cluster galaxies (BCGs) with the newly developed Muesli software. For the initial setup of galaxies, we use core-Sérsic models to account for SMBH scouring. Results: We find that adiabatically driven core regrowth is significant at the highest accretion rates. As a result, the most massive black holes should be located in BCGs with less pronounced cores when compared to the predictions of empirical scaling relations, which are usually calibrated in less extreme environments. For efficiency parameters ɛ< 0.1, BCGs in the most massive, relaxed, and X-ray luminous galaxy clusters might even develop steeply rising density cusps. Finally, we discuss several promising candidates for follow-up investigations, among them the nuclear black hole in the Phoenix cluster. Based on our results, its central black hole might have a mass of the order of 1011 M⊙.

  18. Training of Masters in Philology in Ukraine and Abroad: Search for Educational Strategies

    Directory of Open Access Journals (Sweden)

    Semenog Olena

    2015-03-01

    Full Text Available The paper outlines the modernization experience of philology Master programs in Ukraine, the USA, Poland and Russia. It has been proved that the Masters’ training is on the search educational strategies phase, which allows to form a single educational space on the principles of internationalization, institutionalization, integration, cultural convergence, common goals and values. An important field of Masters’ training is a competency-based approach. It is based on the idea of flexibility, variability of programs, and profiling, philological integration with other humanities, criteria, standards and principles of improving the quality of education. Attention is focused on the formation of constructive-technological, operational, educational, reflective, educational, qualimetric and creative skills of future teachers. Among the perspective forms of education lecture is distinguished as it is focused on the co-creation and co-thinking of lecturer and students, monographic lectures. Among innovative teaching methods and assessment of Master training are selected case-method, cluster, reference compendium, portfolio, performance tests. The variability of final work is defined as an effective way of learning individualization. It has been proved that the result of Master’s training should be the specialist with a high level of social maturity, active citizenship, education, culture and responsibility for his professional and scientific activity.

  19. Response Time, Visual Search Strategy, and Anticipatory Skills in Volleyball Players

    Directory of Open Access Journals (Sweden)

    Alessandro Piras

    2014-01-01

    Full Text Available This paper aimed at comparing expert and novice volleyball players in a visuomotor task using realistic stimuli. Videos of a volleyball setter performing offensive action were presented to participants, while their eye movements were recorded by a head-mounted video based eye tracker. Participants were asked to foresee the direction (forward or backward of the setter’s toss by pressing one of two keys. Key-press response time, response accuracy, and gaze behaviour were measured from the first frame showing the setter’s hand-ball contact to the button pressed by the participants. Experts were faster and more accurate in predicting the direction of the setting than novices, showing accurate predictions when they used a search strategy involving fewer fixations of longer duration, as well as spending less time in fixating all display areas from which they extract critical information for the judgment. These results are consistent with the view that superior performance in experts is due to their ability to efficiently encode domain-specific information that is relevant to the task.

  20. Response Time, Visual Search Strategy, and Anticipatory Skills in Volleyball Players

    Science.gov (United States)

    Lobietti, Roberto

    2014-01-01

    This paper aimed at comparing expert and novice volleyball players in a visuomotor task using realistic stimuli. Videos of a volleyball setter performing offensive action were presented to participants, while their eye movements were recorded by a head-mounted video based eye tracker. Participants were asked to foresee the direction (forward or backward) of the setter's toss by pressing one of two keys. Key-press response time, response accuracy, and gaze behaviour were measured from the first frame showing the setter's hand-ball contact to the button pressed by the participants. Experts were faster and more accurate in predicting the direction of the setting than novices, showing accurate predictions when they used a search strategy involving fewer fixations of longer duration, as well as spending less time in fixating all display areas from which they extract critical information for the judgment. These results are consistent with the view that superior performance in experts is due to their ability to efficiently encode domain-specific information that is relevant to the task. PMID:24876946

  1. Search strategy selection in the Morris water maze indicates allocentric map formation during learning that underpins spatial memory formation.

    Science.gov (United States)

    Rogers, Jake; Churilov, Leonid; Hannan, Anthony J; Renoir, Thibault

    2017-03-01

    Using a Matlab classification algorithm, we demonstrate that a highly salient distal cue array is required for significantly increased likelihoods of spatial search strategy selection during Morris water maze spatial learning. We hypothesized that increased spatial search strategy selection during spatial learning would be the key measure demonstrating the formation of an allocentric map to the escape location. Spatial memory, as indicated by quadrant preference for the area of the pool formally containing the hidden platform, was assessed as the main measure that this allocentric map had formed during spatial learning. Our C57BL/6J wild-type (WT) mice exhibit quadrant preference in the highly salient cue paradigm but not the low, corresponding with a 120% increase in the odds of a spatial search strategy selection during learning. In contrast, quadrant preference remains absent in serotonin 1A receptor (5-HT 1A R) knockout (KO) mice, who exhibit impaired search strategy selection during spatial learning. Additionally, we also aimed to assess the impact of the quality of the distal cue array on the spatial learning curves of both latency to platform and path length using mixed-effect regression models and found no significant associations or interactions. In contrast, we demonstrated that the spatial learning curve for search strategy selection was absent during training in the low saliency paradigm. Therefore, we propose that allocentric search strategy selection during spatial learning is the learning parameter in mice that robustly indicates the formation of a cognitive map for the escape goal location. These results also suggest that both latency to platform and path length spatial learning curves do not discriminate between allocentric and egocentric spatial learning and do not reliably predict spatial memory formation. We also show that spatial memory, as indicated by the absolute time in the quadrant formerly containing the hidden platform alone (without

  2. Operation management of daily economic dispatch using novel hybrid particle swarm optimization and gravitational search algorithm with hybrid mutation strategy

    Science.gov (United States)

    Wang, Yan; Huang, Song; Ji, Zhicheng

    2017-07-01

    This paper presents a hybrid particle swarm optimization and gravitational search algorithm based on hybrid mutation strategy (HGSAPSO-M) to optimize economic dispatch (ED) including distributed generations (DGs) considering market-based energy pricing. A daily ED model was formulated and a hybrid mutation strategy was adopted in HGSAPSO-M. The hybrid mutation strategy includes two mutation operators, chaotic mutation, Gaussian mutation. The proposed algorithm was tested on IEEE-33 bus and results show that the approach is effective for this problem.

  3. Sequential causal inference: application to randomized trials of adaptive treatment strategies.

    Science.gov (United States)

    Dawson, Ree; Lavori, Philip W

    2008-05-10

    Clinical trials that randomize subjects to decision algorithms, which adapt treatments over time according to individual response, have gained considerable interest as investigators seek designs that directly inform clinical decision making. We consider designs in which subjects are randomized sequentially at decision points, among adaptive treatment options under evaluation. We present a sequential method to estimate the comparative effects of the randomized adaptive treatments, which are formalized as adaptive treatment strategies. Our causal estimators are derived using Bayesian predictive inference. We use analytical and empirical calculations to compare the predictive estimators to (i) the 'standard' approach that allocates the sequentially obtained data to separate strategy-specific groups as would arise from randomizing subjects at baseline; (ii) the semi-parametric approach of marginal mean models that, under appropriate experimental conditions, provides the same sequential estimator of causal differences as the proposed approach. Simulation studies demonstrate that sequential causal inference offers substantial efficiency gains over the standard approach to comparing treatments, because the predictive estimators can take advantage of the monotone structure of shared data among adaptive strategies. We further demonstrate that the semi-parametric asymptotic variances, which are marginal 'one-step' estimators, may exhibit significant bias, in contrast to the predictive variances. We show that the conditions under which the sequential method is attractive relative to the other two approaches are those most likely to occur in real studies.

  4. Strategies for prevention of postoperative delirium: a systematic review and meta-analysis of randomized trials

    Science.gov (United States)

    2013-01-01

    Introduction The ideal measures to prevent postoperative delirium remain unestablished. We conducted this systematic review and meta-analysis to clarify the significance of potential interventions. Methods The PRISMA statement guidelines were followed. Two researchers searched MEDLINE, EMBASE, CINAHL and the Cochrane Library for articles published in English before August 2012. Additional sources included reference lists from reviews and related articles from 'Google Scholar'. Randomized clinical trials (RCTs) on interventions seeking to prevent postoperative delirium in adult patients were included. Data extraction and methodological quality assessment were performed using predefined data fields and scoring system. Meta-analysis was accomplished for studies that used similar strategies. The primary outcome measure was the incidence of postoperative delirium. We further tested whether interventions effective in preventing postoperative delirium shortened the length of hospital stay. Results We identified 38 RCTs with interventions ranging from perioperative managements to pharmacological, psychological or multicomponent interventions. Meta-analysis showed dexmedetomidine sedation was associated with less delirium compared to sedation produced by other drugs (two RCTs with 415 patients, pooled risk ratio (RR) = 0.39; 95% confidence interval (CI) = 0.16 to 0.95). Both typical (three RCTs with 965 patients, RR = 0.71; 95% CI = 0.54 to 0.93) and atypical antipsychotics (three RCTs with 627 patients, RR = 0.36; 95% CI = 0.26 to 0.50) decreased delirium occurrence when compared to placebos. Multicomponent interventions (two RCTs with 325 patients, RR = 0.71; 95% CI = 0.58 to 0.86) were effective in preventing delirium. No difference in the incidences of delirium was found between: neuraxial and general anesthesia (four RCTs with 511 patients, RR = 0.99; 95% CI = 0.65 to 1.50); epidural and intravenous analgesia (three RCTs with 167 patients, RR = 0.93; 95% CI = 0.61 to 1

  5. Strategies for prevention of postoperative delirium: a systematic review and meta-analysis of randomized trials.

    Science.gov (United States)

    Zhang, Hao; Lu, Yan; Liu, Meng; Zou, Zui; Wang, Long; Xu, Feng-Ying; Shi, Xue-Yin

    2013-03-18

    The ideal measures to prevent postoperative delirium remain unestablished. We conducted this systematic review and meta-analysis to clarify the significance of potential interventions. The PRISMA statement guidelines were followed. Two researchers searched MEDLINE, EMBASE, CINAHL and the Cochrane Library for articles published in English before August 2012. Additional sources included reference lists from reviews and related articles from 'Google Scholar'. Randomized clinical trials (RCTs) on interventions seeking to prevent postoperative delirium in adult patients were included. Data extraction and methodological quality assessment were performed using predefined data fields and scoring system. Meta-analysis was accomplished for studies that used similar strategies. The primary outcome measure was the incidence of postoperative delirium. We further tested whether interventions effective in preventing postoperative delirium shortened the length of hospital stay. We identified 38 RCTs with interventions ranging from perioperative managements to pharmacological, psychological or multicomponent interventions. Meta-analysis showed dexmedetomidine sedation was associated with less delirium compared to sedation produced by other drugs (two RCTs with 415 patients, pooled risk ratio (RR)=0.39; 95% confidence interval (CI)=0.16 to 0.95). Both typical (three RCTs with 965 patients, RR=0.71; 95% CI=0.54 to 0.93) and atypical antipsychotics (three RCTs with 627 patients, RR=0.36; 95% CI=0.26 to 0.50) decreased delirium occurrence when compared to placebos. Multicomponent interventions (two RCTs with 325 patients, RR=0.71; 95% CI=0.58 to 0.86) were effective in preventing delirium. No difference in the incidences of delirium was found between: neuraxial and general anesthesia (four RCTs with 511 patients, RR=0.99; 95% CI=0.65 to 1.50); epidural and intravenous analgesia (three RCTs with 167 patients, RR=0.93; 95% CI=0.61 to 1.43) or acetylcholinesterase inhibitors and placebo

  6. Protein-Level Integration Strategy of Multiengine MS Spectra Search Results for Higher Confidence and Sequence Coverage.

    Science.gov (United States)

    Zhao, Panpan; Zhong, Jiayong; Liu, Wanting; Zhao, Jing; Zhang, Gong

    2017-12-01

    Multiple search engines based on various models have been developed to search MS/MS spectra against a reference database, providing different results for the same data set. How to integrate these results efficiently with minimal compromise on false discoveries is an open question due to the lack of an independent, reliable, and highly sensitive standard. We took the advantage of the translating mRNA sequencing (RNC-seq) result as a standard to evaluate the integration strategies of the protein identifications from various search engines. We used seven mainstream search engines (Andromeda, Mascot, OMSSA, X!Tandem, pFind, InsPecT, and ProVerB) to search the same label-free MS data sets of human cell lines Hep3B, MHCCLM3, and MHCC97H from the Chinese C-HPP Consortium for Chromosomes 1, 8, and 20. As expected, the union of seven engines resulted in a boosted false identification, whereas the intersection of seven engines remarkably decreased the identification power. We found that identifications of at least two out of seven engines resulted in maximizing the protein identification power while minimizing the ratio of suspicious/translation-supported identifications (STR), as monitored by our STR index, based on RNC-Seq. Furthermore, this strategy also significantly improves the peptides coverage of the protein amino acid sequence. In summary, we demonstrated a simple strategy to significantly improve the performance for shotgun mass spectrometry by protein-level integrating multiple search engines, maximizing the utilization of the current MS spectra without additional experimental work.

  7. Comparing cost effects of two quality strategies to improve test ordering in primary care: a randomized trial.

    NARCIS (Netherlands)

    Verstappen, W.H.; Merode, F. van; Grimshaw, J.; Dubois, W.; Grol, R.P.T.M.; Weijden, T. van der

    2004-01-01

    OBJECTIVE: To determine the costs and cost reductions of an innovative strategy aimed at improving test ordering routines of primary care physicians, compared with a traditional strategy. DESIGN: Multicenter randomized controlled trial with randomization at the local primary care physicians group

  8. The search for alien life in our solar system: strategies and priorities.

    Science.gov (United States)

    Shapiro, Robert; Schulze-Makuch, Dirk

    2009-05-01

    With the assumption that future attempts to explore our Solar System for life will be limited by economic constraints, we have formulated a series of principles to guide future searches: (1) the discovery of life that has originated independently of our own would have greater significance than evidence for panspermia; (2) an unambiguous identification of living beings (or the fully preserved, intact remains of such beings) is more desirable than the discovery of markers or fossils that would inform us of the presence of life but not its composition; (3) we should initially seek carbon-based life that employs a set of monomers and polymers substantially different than our own, which would effectively balance the need for ease of detection with that of establishing a separate origin; (4) a "follow-the-carbon" strategy appears optimal for locating such alternative carbon-based life. In following this agenda, we judge that an intensive investigation of a small number of bodies in our Solar System is more likely to succeed than a broad-based survey of a great number of worlds. Our priority for investigation is (1) Titan, (2) Mars, (3) Europa. Titan displays a rich organic chemistry and offers several alternative possibilities for the discovery of extant life or the early stages that lead to life. Mars has already been subjected to considerable study through landers and orbiters. Although only small amounts of methane testify to the inventory of reduced carbon on the planet, a number of other indicators suggest that the presence of microbial life is a possibility. Care will be needed, of course, to distinguish indigenous life from that which may have spread by panspermia. Europa appears to contain a subsurface ocean with the possibility of hydrothermal vents as an energy source. Its inventory of organic carbon is not yet known.

  9. Fermi paradox and alternative strategies for SETI programs - The anthropic principle and the search for close solar analogs

    Science.gov (United States)

    Fracassini, Massimo; Pasinetti Fracassini, Laura E.; Pasinetti, Antonio L.

    1988-07-01

    The Anthropic Principle, a new trend of modern cosmology, claims that the origin of life and the development of intelligent beings on the Earth is the result of highly selective biological processes, strictly tuned in the fundamental physical characteristics of the Universe. This principle could account for the failure of some programs of search for extraterrestrial intelligences (SETI) and suggests the search for strict solar analogs as a primary target for SETI strategies. In this connection, the authors have selected 22 solar analogs and discussed their choice.

  10. Language-specific strategy for programming hearing aids - A double-blind randomized controlled crossover study.

    Science.gov (United States)

    Matsumoto, Nozomu; Suzuki, Nobuyoshi; Iwasaki, Satoshi; Ishikawa, Kazuha; Tsukiji, Hiroki; Higashino, Yoshie; Tabuki, Tomoko; Nakagawa, Takashi

    2017-11-17

    Voice-aligned compression (VAC) is a method used in Oticon's hearing aids to provide more comfortable hearing without sacrificing speech discrimination. The complex, non-linear compression curve for the VAC strategy is designed based on the frequency profile of certain spoken Western languages. We hypothesized that hearing aids could be further customized for Japanese-speaking users by modifying the compression curve using the frequency profile of spoken Japanese. A double-blind randomized controlled crossover study was performed to determine whether or not Oticon's modified amplification strategy (VAC-J) provides subjectively preferable hearing aids for Japanese-speaking hearing aid users compared to the same company's original amplification strategy (VAC). The participants were randomized to two groups. The VAC-first group received a pair of hearing aids programmed using the VAC strategy and wore them for three weeks, and then received a pair of hearing aids programmed using VAC-J strategy and wore them for three weeks. The VAC-J-first group underwent the same study, but they received hearing aids in the reverse sequence. A Speech, Spatial and Qualities (SSQ) questionnaire was administered before beginning to use the hearing aids, at the end of using the first pair of hearing aids, and at the end of using the second pair of hearing aids. Twenty-five participants that met the inclusion/exclusion criteria from January 1 to October 31, 2016, were randomized to two groups. Twenty-two participants completed the study. There were no statistically significant differences in the increment of SSQ scores between the participants when using the VAC- or the VAC-J-programmed hearing aids. However, participants preferred the VAC-J strategy to the VAC strategy at the end of the study, and this difference was statistically significant. Japanese-speaking hearing aid users preferred using hearing aids that were fitted with the VAC-J strategy. Our results show that the VAC strategy

  11. Comparing three knowledge communication strategies - Diffusion, Dissemination and Translation - through randomized controlled studies.

    Science.gov (United States)

    Lane, Joseph P; Stone, Vathsala I

    2015-01-01

    This paper describes a series of three randomized controlled case studies comparing the effectiveness of three strategies for communicating new research-based knowledge (Diffusion, Dissemination, Translation), to different Assistive Technology (AT) stakeholder groups. Pre and post intervention measures for level of knowledge use (unaware, aware, interested, using) via the LOKUS instrument, assessed the relative effectiveness of the three strategies. The latter two approaches were both more effective than diffusion but also equally effective. The results question the value added by tailoring research findings to specific audiences, and instead supports the critical yet neglected role for relevance in determining knowledge use by stakeholders.

  12. Randomized dynamical decoupling strategies and improved one-way key rates for quantum cryptography

    Energy Technology Data Exchange (ETDEWEB)

    Kern, Oliver

    2009-05-25

    The present thesis deals with various methods of quantum error correction. It is divided into two parts. In the first part, dynamical decoupling methods are considered which have the task of suppressing the influence of residual imperfections in a quantum memory. Such imperfections might be given by couplings between the finite dimensional quantum systems (qudits) constituting the quantum memory, for instance. The suppression is achieved by altering the dynamics of an imperfect quantum memory with the help of a sequence of local unitary operations applied to the qudits. Whereas up to now the operations of such decoupling sequences have been constructed in a deterministic fashion, strategies are developed in this thesis which construct the operations by random selection from a suitable set. Formulas are derived which estimate the average performance of such strategies. As it turns out, randomized decoupling strategies offer advantages and disadvantages over deterministic ones. It is possible to benefit from the advantages of both kind of strategies by designing combined strategies. Furthermore, it is investigated if and how the discussed decoupling strategies can be employed to protect a quantum computation running on the quantum memory. It is shown that a purely randomized decoupling strategy may be used by applying the decoupling operations and adjusted gates of the quantum algorithm in an alternating fashion. Again this method can be enhanced by the means of deterministic methods in order to obtain a combined decoupling method for quantum computations analogously to the combining strategies for quantum memories. The second part of the thesis deals with quantum error-correcting codes and protocols for quantum key distribution. The focus is on the BB84 and the 6-state protocol making use of only one-way communication during the error correction and privacy amplification steps. It is shown that by adding additional errors to the preliminary key (a process called

  13. Search Result Clustering via Randomized Partitioning of Query-Induced Subgraphs

    Directory of Open Access Journals (Sweden)

    A. Bradic

    2009-06-01

    Full Text Available In this paper, we present an approach to search result clustering, using partitioning of underlying link graph. We define the notion of "query-induced subgraph" and formulate the problem of search result clustering as a problem of efficient partitioning of a given subgraph into topic-related clusters. Also, we propose a novel algorithm for approximative partitioning of such a graph, which results in a cluster quality comparable to the one obtained by deterministic algorithms, while operating in a more efficient computation time, suitable for practical implementations. Finally, we present a practical clustering search engine developed as a part of this research and use it to get results about real-world performance of proposed concepts.

  14. Search Strategy Development in a Flipped Library Classroom: A Student-Focused Assessment

    Science.gov (United States)

    Goates, Michael C.; Nelson, Gregory M.; Frost, Megan

    2017-01-01

    Librarians at Brigham Young University compared search statement development between traditional lecture and flipped instruction sessions. Students in lecture sessions scored significantly higher on developing search statements than those in flipped sessions. However, student evaluations show a strong preference for pedagogies that incorporate…

  15. Job-Searching Expectations, Expectancy Violations, and Communication Strategies of Recent College Graduates

    Science.gov (United States)

    Smith, Stephanie A.

    2017-01-01

    Expectancy violations theory, a communicative framework, is applied in this study to understand how recent college graduates form, evaluate, and respond to violated job-searching expectations. In-depth interviews of college seniors (N = 20) who were currently job searching helped answer the three research questions posed. Using a thematic…

  16. More than Just Finding Color: Strategy in Global Visual Search Is Shaped by Learned Target Probabilities

    Science.gov (United States)

    Williams, Carrick C.; Pollatsek, Alexander; Cave, Kyle R.; Stroud, Michael J.

    2009-01-01

    In 2 experiments, eye movements were examined during searches in which elements were grouped into four 9-item clusters. The target (a red or blue "T") was known in advance, and each cluster contained different numbers of target-color elements. Rather than color composition of a cluster invariantly guiding the order of search though…

  17. Search strategies to identify diagnostic accuracy studies in MEDLINE and EMBASE

    NARCIS (Netherlands)

    Beynon, Rebecca; Leeflang, Mariska M. G.; McDonald, Steve; Eisinga, Anne; Mitchell, Ruth L.; Whiting, Penny; Glanville, Julie M.

    2013-01-01

    A systematic and extensive search for as many eligible studies as possible is essential in any systematic review. When searching for diagnostic test accuracy (DTA) studies in bibliographic databases, it is recommended that terms for disease (target condition) are combined with terms for the

  18. New Search Strategies Successfully Optimize Retrieval of Clinically Sound Treatment Studies in EMBASE. A review of: Wong, Sharon S‐L, Nancy L. Wilczynski, and R. Brian Haynes. “Developing Optimal Search Strategies for Detecting Clinically Sound Treatment Studies in EMBASE.” Journal of the Medical Library Association 94.1 (Jan. 2006: 41‐47. 14 May 2007 http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1324770.

    Directory of Open Access Journals (Sweden)

    John Loy

    2007-06-01

    Full Text Available Objective – To develop and test the sensitivity and specificity, precision andaccuracy of search strategies to retrieve clinically sound treatment studies in the EMBASE database.Design – Analytical study.Setting – Methodologically sound studies of treatment from 55 journals indexed in EMBASE for the year 2000.Subjects – EMBASE and hand searches performed at the Health Information Research Unit of McMaster University, Ontario, Canada.Methods – The authors compare the results of EMBASE searches using their search strategies with the “gold standard” of articles retrieved by hand search. Research assistants initially hand searched each issue of 55 selected journals published in 2000 to identify articles detailing studies on healthcare treatment of humans. Subject coverage of the journals was wide ranging and included obstetrics and gynaecology, psychiatry, oncology, neurology, surgery and general practice. Studies were then assessed to ensure they met the qualifying criteria: random allocation of participants to groups, outcome assessment of at least 80% of participants who began the study, and analysis consistent with study design. Initially, 3850 articles on treatment were identified, of which 1256 (32.6% were methodologically sound. To construct a comprehensive set of search terms, input was sought from librarians and researchers in the US and Canada. This initially produced a list of 5385 terms, of which 4843 were unique and 3524 produced hits. Individual search terms with sensitivity greater then 25% and specificity greater then 75% were incorporated into search strategies for use within the OVID interface for the EMBASE database to retrieve articles meeting the same criteria. These strategies were developed using all 27,769 articles published in the 55 journals in 2000. This all inclusive approach was used to test the search strategies’ ability to identify high quality treatment articles from a larger pool of material

  19. Robust Network Architecture Against Random Threats in WMD Environments: Theoretical Limits and Recovery Strategies

    Science.gov (United States)

    2017-08-01

    help us understand how a social environment evolves so that we are able to make predictions about its impact. Moreover, we might even learn how to...Mika, B. Schlkopf, and R. Williamson, “ Regularized principal manifolds,” Journal of Machine Learning Research,, vol. 1, pp. 179–209, June 2001. [74] H...Architecture Against Random Threats in WMD Environments : Theoretical Limits and Recovery Strategies Distribution Statement A. Approved for public

  20. Using a multi-objective genetic algorithm for developing aerial sensor team search strategies

    Science.gov (United States)

    Ridder, Jeffrey P.; Herweg, Jared A.; Sciortino, John C., Jr.

    2008-04-01

    Finding certain associated signals in the modern electromagnetic environment can prove a difficult task due to signal characteristics and associated platform tactics as well as the systems used to find these signals. One approach to finding such signal sets is to employ multiple small unmanned aerial systems (UASs) equipped with RF sensors in a team to search an area. The search environment may be partially known, but with a significant level of uncertainty as to the locations and emissions behavior of the individual signals and their associated platforms. The team is likely to benefit from a combination of using uncertain a priori information for planning and online search algorithms for dynamic tasking of the team. Two search algorithms are examined for effectiveness: Archimedean spirals, in which the UASs comprising the team do not respond to the environment, and artificial potential fields, in which they use environmental perception and interactions to dynamically guide the search. A multi-objective genetic algorithm (MOGA) is used to explore the desirable characteristics of search algorithms for this problem using two performance objectives. The results indicate that the MOGA can successfully use uncertain a priori information to set the parameters of the search algorithms. Also, we find that artificial potential fields may result in good performance, but that each of the fields has a different contribution that may be appropriate only in certain states.

  1. Evaluation of five search strategies in retrieving qualitative patient-reported electronic data on the impact of pressure ulcers on quality of life.

    Science.gov (United States)

    Gorecki, Claudia A; Brown, Julia M; Briggs, Michelle; Nixon, Jane

    2010-03-01

    This paper is a report of a study conducted to compare the effectiveness of qualitative methodology search strategies with subject-specific (health-related quality of life) search strategies in the retrieval of qualitative patient-reported data of the impact of pressure ulcers on health-related quality of life. Methods to locate qualitative patient-reported health-related quality of life research data electronically have undergone little replication and validation. A major problem in searching for this type of data is that it is reported in accounts of both primary qualitative research as well as mixed methods research. We combined five search strategies with terms for pressure ulcer and searched seven electronic databases from inception to October 2007. The sensitivity, specificity, precision and accuracy for each search strategy were assessed. A subject-specific (health-related quality of life) search strategy, developed by us, had a high yield (100% sensitivity), but low specificity (quality of life data, whereas, research methodology-based strategies did not identify qualitative data reported in mixed method studies, making subject-based strategies more effective in retrieving qualitative patient-reported health-related quality of life research. An important consideration in the health-related quality of life field is that qualitative data are reported in both qualitative and mixed methodology research and searching for this type data involves trade-offs between yield, sensitivity and specificity. Accurate indexing of subject-specific outcomes and methodology used in electronic databases and publications is also needed.

  2. An Improved Differential Evolution Method Based on the Dynamic Search Strategy to Solve Dynamic Economic Dispatch Problem with Valve-Point Effects

    Directory of Open Access Journals (Sweden)

    Guangyu Chen

    2014-01-01

    Full Text Available An improved differential evolution (DE method based on the dynamic search strategy (IDEBDSS is proposed to solve dynamic economic dispatch problem with valve-point effects in this paper. The proposed method combines the DE algorithm with the dynamic search strategy, which improves the performance of the algorithm. DE is the main optimizer in the method proposed. While chaotic sequences are applied to obtain the dynamic parameter settings in DE, dynamic search strategy which consists of two steps, global search strategy and local search strategy, is used to improve algorithm efficiency. To accelerate convergence, a new infeasible solution handing method is adopted in the local search strategy; meanwhile, an orthogonal crossover (OX operator is added to the global search strategy to enhance the optimization search ability. Finally, the feasibility and effectiveness of the proposed methods are demonstrated by three test systems, and the simulation results reveal that the IDEBDSS method can obtain better solutions with higher efficiency than the standard DE and other methods reported in the recent literature.

  3. A highly sensitive search strategy for clinical trials in Literatura Latino Americana e do Caribe em Ciências da Saúde (LILACS) was developed.

    Science.gov (United States)

    Manríquez, Juan J

    2008-04-01

    Systematic reviews should include as many articles as possible. However, many systematic reviews use only databases with high English language content as sources of trials. Literatura Latino Americana e do Caribe em Ciências da Saúde (LILACS) is an underused source of trials, and there is not a validated strategy for searching clinical trials to be used in this database. The objective of this study was to develop a sensitive search strategy for clinical trials in LILACS. An analytical survey was performed. Several single and multiple-term search strategies were tested for their ability to retrieve clinical trials in LILACS. Sensitivity, specificity, and accuracy of each single and multiple-term strategy were calculated using the results of a hand-search of 44 Chilean journals as gold standard. After combining the most sensitive, specific, and accurate single and multiple-term search strategy, a strategy with a sensitivity of 97.75% (95% confidence interval [CI]=95.98-99.53) and a specificity of 61.85 (95% CI=61.19-62.51) was obtained. LILACS is a source of trials that could improve systematic reviews. A new highly sensitive search strategy for clinical trials in LILACS has been developed. It is hoped this search strategy will improve and increase the utilization of LILACS in future systematic reviews.

  4. GRASP (Greedy Randomized Adaptive Search Procedures) applied to optimization of petroleum products distribution in pipeline networks; GRASP (Greedy Randomized Adaptative Search Procedures) aplicado ao 'scheduling' de redes de distribuicao de petroleo e derivados

    Energy Technology Data Exchange (ETDEWEB)

    Conte, Viviane Cristhyne Bini; Arruda, Lucia Valeria Ramos de; Yamamoto, Lia [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)

    2008-07-01

    Planning and scheduling of the pipeline network operations aim the most efficient use of the resources resulting in a better performance of the network. A petroleum distribution pipeline network is composed by refineries, sources and/or storage parks, connected by a set of pipelines, which operate the transportation of petroleum and derivatives among adjacent areas. In real scenes, this problem is considered a combinatorial problem, which has difficult solution, which makes necessary methodologies of the resolution that present low computational time. This work aims to get solutions that attempt the demands and minimize the number of batch fragmentations on the sent operations of products for the pipelines in a simplified model of a real network, through by application of the local search metaheuristic GRASP. GRASP does not depend of solutions of previous iterations and works in a random way so it allows the search for the solution in an ampler and diversified search space. GRASP utilization does not demand complex calculation, even the construction stage that requires more computational effort, which provides relative rapidity in the attainment of good solutions. GRASP application on the scheduling of the operations of this network presented feasible solutions in a low computational time. (author)

  5. Randomized comparison of conservative versus aggressive strategy for provisional side branch intervention in coronary bifurcation lesions: results from the SMART-STRATEGY (Smart Angioplasty Research Team-Optimal Strategy for Side Branch Intervention in Coronary Bifurcation Lesions) randomized trial.

    Science.gov (United States)

    Song, Young Bin; Hahn, Joo-Yong; Song, Pil-Sang; Yang, Jeong Hoon; Choi, Jin-Ho; Choi, Seung-Hyuk; Lee, Sang Hoon; Gwon, Hyeon-Cheol

    2012-11-01

    The authors sought to compare conservative and aggressive strategies for provisional side branch (SB) intervention in coronary bifurcation lesions. The optimal provisional approach for coronary bifurcation lesions has not been established. In this prospective randomized trial, 258 patients with a coronary bifurcation lesion treated with drug-eluting stents were randomized to a conservative (n = 128) or aggressive (n = 130) SB intervention strategy. The criteria for SB intervention after main vessel stenting differed between the conservative and aggressive groups; Thrombolysis In Myocardial Infarction flow grade 75% for non-left main bifurcations and diameter stenosis >75% versus diameter stenosis >50% for left main bifurcations. The primary endpoint was target vessel failure (cardiac death, myocardial infarction, or target vessel revascularization) at 12 months. Left main bifurcation lesions were noted in 114 patients (44%) and true bifurcation lesions in 171 patients (66%). SB ballooning after main vessel stenting and SB stenting after SB ballooning were performed less frequently in the conservative group than in the aggressive group (25.8% vs. 68.5%, p strategy was associated with a lower incidence of procedure-related myocardial necrosis compared with the aggressive strategy (5.5% vs. 17.7%, p = 0.002). At 12 months, the incidence of target vessel failure was similar in both groups (9.4% in the conservative group vs. 9.2% in the aggressive group, p = 0.97). Compared with the aggressive strategy, the conservative strategy for provisional SB intervention was associated with similar long-term clinical outcomes and a lower incidence of procedure-related myocardial necrosis. (Optimal Strategy for Side Branch Stenting in Coronary Bifurcation Lesions [SMART-STRATEGY]; NCT00794014). Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  6. In Search of Meaning: Are School Rampage Shootings Random and Senseless Violence?

    Science.gov (United States)

    Madfis, Eric

    2017-01-02

    This article discusses Joel Best's ( 1999 ) notion of random violence and applies his concepts of pointlessness, patternlessness, and deterioration to the reality about multiple-victim school shootings gleaned from empirical research about the phenomenon. Best describes how violence is rarely random, as scholarship reveals myriad observable patterns, lots of discernable motives and causes, and often far too much fear-mongering over how bad society is getting and how violent we are becoming. In contrast, it is vital that the media, scholars, and the public better understand crime patterns, criminal motivations, and the causes of fluctuating crime rates. As an effort toward such progress, this article reviews the academic literature on school rampage shootings and explores the extent to which these attacks are and are not random acts of violence.

  7. A Collaborative Search Strategy to Solve Combinatorial Optimization and Scheduling Problems

    OpenAIRE

    Nader AZIZI; Zolfaghari, Saeed; Liang, Ming

    2010-01-01

    Various scheduling problems that occur in manufacturing industries have been investigated in the literature. They are inherently complex and often referred to as combinatorial NonPolynomial (NP) hard problems. These problems are very difficult to solve using existing heuristics or conventional techniques. This chapter presents a generic framework of a collaborative search algorithm to solve scheduling problems. The proposed framework contains two independent search modules that exchange infor...

  8. Job Search Strategies and Outcomes for Academic Economists: A Middle-Market View

    OpenAIRE

    Kevin Duncan; Dirk Yandell; Kokila Doshi

    2000-01-01

    The job market for academic economists is examined with data from a sample of applicants for a position at a middle-tier university. Search methods and outcomes are reported, and regression results for an accepted salary equation are presented. A recursive system of equations is also estimated to examine the effects of gender, degree quality and networking on the outcomes of the various stages in the job search process.

  9. Protocol: a systematic review of studies developing and/or evaluating search strategies to identify prognosis studies.

    Science.gov (United States)

    Corp, Nadia; Jordan, Joanne L; Hayden, Jill A; Irvin, Emma; Parker, Robin; Smith, Andrea; van der Windt, Danielle A

    2017-04-20

    Prognosis research is on the rise, its importance recognised because chronic health conditions and diseases are increasingly common and costly. Prognosis systematic reviews are needed to collate and synthesise these research findings, especially to help inform effective clinical decision-making and healthcare policy. A detailed, comprehensive search strategy is central to any systematic review. However, within prognosis research, this is challenging due to poor reporting and inconsistent use of available indexing terms in electronic databases. Whilst many published search filters exist for finding clinical trials, this is not the case for prognosis studies. This systematic review aims to identify and compare existing methodological filters developed and evaluated to identify prognosis studies of any of the three main types: overall prognosis, prognostic factors, and prognostic [risk prediction] models. Primary studies reporting the development and/or evaluation of methodological search filters to retrieve any type of prognosis study will be included in this systematic review. Multiple electronic bibliographic databases will be searched, grey literature will be sought from relevant organisations and websites, experts will be contacted, and citation tracking of key papers and reference list checking of all included papers will be undertaken. Titles will be screened by one person, and abstracts and full articles will be reviewed for inclusion independently by two reviewers. Data extraction and quality assessment will also be undertaken independently by two reviewers with disagreements resolved by discussion or by a third reviewer if necessary. Filters' characteristics and performance metrics reported in the included studies will be extracted and tabulated. To enable comparisons, filters will be grouped according to database, platform, type of prognosis study, and type of filter for which it was intended. This systematic review will identify all existing validated

  10. Penerapan Teknik Seo (Search Engine Optimization pada Website dalam Strategi Pemasaran melalui Internet

    Directory of Open Access Journals (Sweden)

    Rony Baskoro Lukito

    2014-12-01

    Full Text Available The purpose of this research is how to optimize a web design that can increase the number of visitors. The number of Internet users in the world continues to grow in line with advances in information technology. Products and services marketing media do not just use the printed and electronic media. Moreover, the cost of using the Internet as a medium of marketing is relatively inexpensive when compared to the use of television as a marketing medium. The penetration of the internet as a marketing medium lasted for 24 hours in different parts of the world. But to make an internet site into a site that is visited by many internet users, the site is not only good from the outside view only. Web sites that serve as a medium for marketing must be built with the correct rules, so that the Web site be optimal marketing media. One of the good rules in building the internet site as a marketing medium is how the content of such web sites indexed well in search engines like google. Search engine optimization in the index will be focused on the search engine Google for 83% of internet users across the world using Google as a search engine. Search engine optimization commonly known as SEO (Search Engine Optimization is an important rule that the internet site is easier to find a user with the desired keywords.

  11. The Search for Suitable Strategy: Threat-Based and Capabilities-Based Strategies in a Complex World

    Science.gov (United States)

    2016-05-26

    bound our discussion and define “strategy,” which is somewhat of a loaded word. The word is based in military thought and has its origins in the Greek ...reference to German unification interpreted as a threat by France.49 Second was a Prussian railway through Switzerland financed by Bismarck as a

  12. School-based strategies for oral health education of adolescents- a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Haleem Abdul

    2012-12-01

    Full Text Available Abstract Background Oral health education (OHE in schools has largely been imparted by dental professionals. Considering the substantial cost of this expert-led approach, the strategies relying on teachers, peer-leaders and learners themselves have also been utilized. However the evidence for comparative effectiveness of these strategies is lacking in the dental literature. The present study was conducted to compare the effectiveness of dentist-led, teacher-led, peer-led and self-learning strategies of oral health education. Methods A two-year cluster randomized controlled trial following a parallel design was conducted. It involved five groups of adolescents aged 10-11 years at the start of the study. The trial involved process as well as four outcome evaluations. The present paper discusses the findings of the study pertaining to the baseline and final outcome evaluation, both comprising of a self-administered questionnaire, a structured interview and clinical oral examination. The data were analyzed using Generalized Estimating Equations. Results All the three educator-led strategies of OHE had statistically higher mean oral health knowledge (OHK, oral health behavior (OHB, oral hygiene status (OHS and combined knowledge, behavior and oral hygiene status (KBS scores than the self-learning and control groups (p Conclusions The dentist-led, teacher-led and peer-led strategies of oral health education are equally effective in improving the oral health knowledge and oral hygiene status of adolescents. The peer-led strategy, however, is almost as effective as the dentist-led strategy and comparatively more effective than the teacher-led and self-learning strategies in improving their oral health behavior. Trail registration SRCTN39391017

  13. Honeybees (Apis mellifera exhibit flexible visual search strategies for vertical targets presented at various heights [v2; ref status: indexed, http://f1000r.es/51p

    Directory of Open Access Journals (Sweden)

    Linde Morawetz

    2015-02-01

    Full Text Available When honeybees are presented with a colour discrimination task, they tend to choose swiftly and accurately when objects are presented in the ventral part of their frontal visual field. In contrast, poor performance is observed when objects appear in the dorsal part. Here we investigate if this asymmetry is caused by fixed search patterns or if bees can increase their detection ability of objects in search scenarios when targets appear frequently or exclusively in the dorsal area of the visual field. We trained individual honeybees to choose an orange rewarded target among blue distractors. Target and distractors were presented in the ventral visual field, the dorsal field or both. Bees presented with targets in the ventral visual field consistently had the highest search efficiency, with rapid decisions, high accuracy and direct flight paths. In contrast, search performance for dorsally located targets was inaccurate and slow at the beginning of the experimental phase, but bees increased their search performance significantly after a few foraging bouts: they found the target faster, made fewer errors and flew in a straight line towards the target. However, bees needed thrice as long to improve the search for a dorsally located target when the target’s position changed randomly between the ventral and the dorsal visual field. We propose that honeybees form expectations of the location of the target’s appearance and adapt their search strategy accordingly. A variety of possible mechanisms underlying this behavioural adaptation, for example spatial attention, are discussed.

  14. Search strategies to identify diagnostic accuracy studies in MEDLINE and EMBASE.

    Science.gov (United States)

    Beynon, Rebecca; Leeflang, Mariska M G; McDonald, Steve; Eisinga, Anne; Mitchell, Ruth L; Whiting, Penny; Glanville, Julie M

    2013-09-11

    A systematic and extensive search for as many eligible studies as possible is essential in any systematic review. When searching for diagnostic test accuracy (DTA) studies in bibliographic databases, it is recommended that terms for disease (target condition) are combined with terms for the diagnostic test (index test). Researchers have developed methodological filters to try to increase the precision of these searches. These consist of text words and database indexing terms and would be added to the target condition and index test searches.Efficiently identifying reports of DTA studies presents challenges because the methods are often not well reported in their titles and abstracts, suitable indexing terms may not be available and relevant indexing terms do not seem to be consistently assigned. A consequence of using search filters to identify records for diagnostic reviews is that relevant studies might be missed, while the number of irrelevant studies that need to be assessed may not be reduced. The current guidance for Cochrane DTA reviews recommends against the addition of a methodological search filter to target condition and index test search, as the only search approach. To systematically review empirical studies that report the development or evaluation, or both, of methodological search filters designed to retrieve DTA studies in MEDLINE and EMBASE. We searched MEDLINE (1950 to week 1 November 2012); EMBASE (1980 to 2012 Week 48); the Cochrane Methodology Register (Issue 3, 2012); ISI Web of Science (11 January 2013); PsycINFO (13 March 2013); Library and Information Science Abstracts (LISA) (31 May 2010); and Library, Information Science & Technology Abstracts (LISTA) (13 March 2013). We undertook citation searches on Web of Science, checked the reference lists of relevant studies, and searched the Search Filters Resource website of the InterTASC Information Specialists' Sub-Group (ISSG). Studies reporting the development or evaluation, or both, of a

  15. Comparison of the Two Followup Observation Strategies for Gravitational Microlensing Planet Searches

    OpenAIRE

    Han, Cheongho; Kim, Yong-Gi

    2000-01-01

    There are two different strategies of followup observations for the detection of planets by using microlensing. One is detecting the light curve anomalies affected by the planetary caustic from continuous monitoring of all events detected by microlensing survey programs (type I strategy) and the other is detecting anomalies near the peak amplification affected by the central caustic from intensive monitoring of high amplification events (type II strategy). It was shown by Griest & Safizadeh t...

  16. School-based strategies for oral health education of adolescents- a cluster randomized controlled trial

    Science.gov (United States)

    2012-01-01

    Background Oral health education (OHE) in schools has largely been imparted by dental professionals. Considering the substantial cost of this expert-led approach, the strategies relying on teachers, peer-leaders and learners themselves have also been utilized. However the evidence for comparative effectiveness of these strategies is lacking in the dental literature. The present study was conducted to compare the effectiveness of dentist-led, teacher-led, peer-led and self-learning strategies of oral health education. Methods A two-year cluster randomized controlled trial following a parallel design was conducted. It involved five groups of adolescents aged 10-11 years at the start of the study. The trial involved process as well as four outcome evaluations. The present paper discusses the findings of the study pertaining to the baseline and final outcome evaluation, both comprising of a self-administered questionnaire, a structured interview and clinical oral examination. The data were analyzed using Generalized Estimating Equations. Results All the three educator-led strategies of OHE had statistically higher mean oral health knowledge (OHK), oral health behavior (OHB), oral hygiene status (OHS) and combined knowledge, behavior and oral hygiene status (KBS) scores than the self-learning and control groups (poral health education are equally effective in improving the oral health knowledge and oral hygiene status of adolescents. The peer-led strategy, however, is almost as effective as the dentist-led strategy and comparatively more effective than the teacher-led and self-learning strategies in improving their oral health behavior. Trail registration SRCTN39391017 PMID:23249443

  17. Strategies to improve recruitment and retention of older stroke survivors to a randomized clinical exercise trial.

    Science.gov (United States)

    Taylor-Piliae, Ruth E; Boros, Daniella; Coull, Bruce M

    2014-03-01

    Relatively few exercise randomized clinical trials (RCTs) among stroke survivors have reported the effectiveness of recruitment and retention strategies, despite its central importance to study integrity. Our objective is to examine recruitment and retention strategies used among a group of older community-dwelling stroke survivors for an exercise RCT. Recruitment strategies were multidimensional using both paid (ie, newspaper, radio and, television) and unpaid advertisements (ie, staff visits, flyers, and brochures placed at outpatient rehabilitation centers, physician offices, and community facilities working with older adults; free media coverage of the study, presentations at stroke support groups, relatives/friends, and study Web site) to obtain referrals. Retention strategies centered on excellent communication, the study participants' needs, and having dedicated study staff. Attrition rates and adherence to the intervention were used to examine the effectiveness of these retention strategies. A total of 393 referrals were received, 233 persons were screened, and 145 stroke survivors enrolled in the study. During 3 years of study recruitment, we achieved 97% of our enrollment target. We enrolled 62% of those screened. Study enrollment from paid advertising was 21.4% (n = 31), whereas unpaid advertisements resulted in 78.6% (n = 114) of our participants. Attrition was 10% (n = 14 dropouts), and adherence to the intervention was 85%. Recruitment and retention of participants in an exercise RCT are time and labor intensive. Multiple recruitment and retention strategies are required to ensure an adequate sample of community-dwelling stroke survivors. Many of these strategies are also relevant for exercise RCTs among adults with other chronic illnesses. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  18. What Kind of Networking Strategy Advice Should Career Counsellors Offer University Graduates Searching for a Job?

    Science.gov (United States)

    Villar, Esperanca; Juan, Jaume; Corominas, Enric; Capell, Dolors

    2000-01-01

    Investigates the relationship between social networking and job placement of university graduates. Results reveal two different approaches to the process of job entry-use of formal or informal contacts. Significant differences were found between use of formal and informal sources of help relating to graduates' job-search intention and confidence…

  19. Information Retrieval Strategies of Millennial Undergraduate Students in Web and Library Database Searches

    Science.gov (United States)

    Porter, Brandi

    2009-01-01

    Millennial students make up a large portion of undergraduate students attending colleges and universities, and they have a variety of online resources available to them to complete academically related information searches, primarily Web based and library-based online information retrieval systems. The content, ease of use, and required search…

  20. Implications of structural genomics target selection strategies: Pfam5000, whole genome, and random approaches

    Energy Technology Data Exchange (ETDEWEB)

    Chandonia, John-Marc; Brenner, Steven E.

    2004-07-14

    The structural genomics project is an international effort to determine the three-dimensional shapes of all important biological macromolecules, with a primary focus on proteins. Target proteins should be selected according to a strategy which is medically and biologically relevant, of good value, and tractable. As an option to consider, we present the Pfam5000 strategy, which involves selecting the 5000 most important families from the Pfam database as sources for targets. We compare the Pfam5000 strategy to several other proposed strategies that would require similar numbers of targets. These include including complete solution of several small to moderately sized bacterial proteomes, partial coverage of the human proteome, and random selection of approximately 5000 targets from sequenced genomes. We measure the impact that successful implementation of these strategies would have upon structural interpretation of the proteins in Swiss-Prot, TrEMBL, and 131 complete proteomes (including 10 of eukaryotes) from the Proteome Analysis database at EBI. Solving the structures of proteins from the 5000 largest Pfam families would allow accurate fold assignment for approximately 68 percent of all prokaryotic proteins (covering 59 percent of residues) and 61 percent of eukaryotic proteins (40 percent of residues). More fine-grained coverage which would allow accurate modeling of these proteins would require an order of magnitude more targets. The Pfam5000 strategy may be modified in several ways, for example to focus on larger families, bacterial sequences, or eukaryotic sequences; as long as secondary consideration is given to large families within Pfam, coverage results vary only slightly. In contrast, focusing structural genomics on a single tractable genome would have only a limited impact in structural knowledge of other proteomes: a significant fraction (about 30-40 percent of the proteins, and 40-60 percent of the residues) of each proteome is classified in small

  1. Human strategies for multitasking, search, and control improved via real-time memory aid for gaze location

    Directory of Open Access Journals (Sweden)

    P. eTaylor

    2015-09-01

    Full Text Available OBJECTIVE: We aimed to elucidate how our domain-general cuing algorithm improved multitasking performance and changed behavioral strategies in human operators. BACKGROUND: Though many gaze-control systems have been designed, previous real-time gaze-aware assistance systems were not both successful and domain general. It is largely unknown what constitutes optimal search efficiency using the eyes, or ideal control using the mouse. It is unclear what the best coordinating strategies are between these two modalities. Our previously developed closed-loop multitasking aid drastically improved multitasking performance, though the behavioral mechanisms through which it acted were unknown. METHODS: We performed in-depth analyses and generated novel eye tracking and mouse movement measures, to explore the complex effects of our helpful system on gaze and motor behavior. RESULTS: Our overlay cuing algorithm improved control efficiency and reduced well-known biases in search patterns. This system also reduced micromanaging behavior, with humans rationally relying more on imperfect automation in experimental assistance cue conditions. We showed that mouse and gaze were more independently specialized in the helpful cuing condition than in control conditions. Specifically, with our aid, the gaze performed more global movement, and the mouse performed more local clustered movement. Further, the gaze shifted towards search over processing with the helpful cuing system. We also illustrated a relationship between the mouse and the gaze, such that in these studies, the hand was quicker than the eye. CONCLUSIONS: Overall, results suggested that our cuing system improved performance and reduced short term working memory load on humans by delegating it to the computer in real time. Further, it reduced the number of required repeated decisions by an estimate of about one per second. It also enabled the gaze to specialize for improved visual search behavior, and the

  2. Normal and tumoral melanocytes exhibit q-Gaussian random search patterns.

    Directory of Open Access Journals (Sweden)

    Priscila C A da Silva

    Full Text Available In multicellular organisms, cell motility is central in all morphogenetic processes, tissue maintenance, wound healing and immune surveillance. Hence, failures in its regulation potentiates numerous diseases. Here, cell migration assays on plastic 2D surfaces were performed using normal (Melan A and tumoral (B16F10 murine melanocytes in random motility conditions. The trajectories of the centroids of the cell perimeters were tracked through time-lapse microscopy. The statistics of these trajectories was analyzed by building velocity and turn angle distributions, as well as velocity autocorrelations and the scaling of mean-squared displacements. We find that these cells exhibit a crossover from a normal to a super-diffusive motion without angular persistence at long time scales. Moreover, these melanocytes move with non-Gaussian velocity distributions. This major finding indicates that amongst those animal cells supposedly migrating through Lévy walks, some of them can instead perform q-Gaussian walks. Furthermore, our results reveal that B16F10 cells infected by mycoplasmas exhibit essentially the same diffusivity than their healthy counterparts. Finally, a q-Gaussian random walk model was proposed to account for these melanocytic migratory traits. Simulations based on this model correctly describe the crossover to super-diffusivity in the cell migration tracks.

  3. Normal and tumoral melanocytes exhibit q-Gaussian random search patterns.

    Science.gov (United States)

    da Silva, Priscila C A; Rosembach, Tiago V; Santos, Anésia A; Rocha, Márcio S; Martins, Marcelo L

    2014-01-01

    In multicellular organisms, cell motility is central in all morphogenetic processes, tissue maintenance, wound healing and immune surveillance. Hence, failures in its regulation potentiates numerous diseases. Here, cell migration assays on plastic 2D surfaces were performed using normal (Melan A) and tumoral (B16F10) murine melanocytes in random motility conditions. The trajectories of the centroids of the cell perimeters were tracked through time-lapse microscopy. The statistics of these trajectories was analyzed by building velocity and turn angle distributions, as well as velocity autocorrelations and the scaling of mean-squared displacements. We find that these cells exhibit a crossover from a normal to a super-diffusive motion without angular persistence at long time scales. Moreover, these melanocytes move with non-Gaussian velocity distributions. This major finding indicates that amongst those animal cells supposedly migrating through Lévy walks, some of them can instead perform q-Gaussian walks. Furthermore, our results reveal that B16F10 cells infected by mycoplasmas exhibit essentially the same diffusivity than their healthy counterparts. Finally, a q-Gaussian random walk model was proposed to account for these melanocytic migratory traits. Simulations based on this model correctly describe the crossover to super-diffusivity in the cell migration tracks.

  4. Implementation of client versus care-provider strategies to improve external cephalic version rates: a cluster randomized controlled trial

    NARCIS (Netherlands)

    Vlemmix, F.; Rosman, A.N.; Rijnders, M.E.; Beuckens, A.; Opmeer, B.C.; Mol, B.W.J.; Kok, M.; Fleuren, M.A.H.

    2015-01-01

    Onjective: To determine the effectiveness of a client or care-provider strategy to improve the implementation of external cephalic version. Design: Cluster randomized controlled trial.Setting: Twenty-five clusters; hospitals and their referring midwifery practices randomly selected in the

  5. Randomized Trial of MST and ARC in a Two-Level Evidence-Based Treatment Implementation Strategy

    Science.gov (United States)

    Glisson, Charles; Schoenwald, Sonja K.; Hemmelgarn, Anthony; Green, Philip; Dukes, Denzel; Armstrong, Kevin S.; Chapman, Jason E.

    2010-01-01

    Objective: A randomized trial assessed the effectiveness of a 2-level strategy for implementing evidence-based mental health treatments for delinquent youth. Method: A 2 x 2 design encompassing 14 rural Appalachian counties included 2 factors: (a) the random assignment of delinquent youth within each county to a multisystemic therapy (MST) program…

  6. PHILOSOPHY OF WAR AND PEACE: IN SEARCH OF NEW EUROPEAN SECURITY STRATEGY

    Directory of Open Access Journals (Sweden)

    O. O. Bazaluk

    2017-12-01

    Full Text Available Introduction. The contemporary European social and cultural landscape feels the pressure of security challenges. It is true, that Europe has a strategy of overcoming the possible challenges, but it has sense to review ones strategy abilities to be effective at the face of new manifestations of aggression. Methodology. The authors use heuristic philosophical methodology which can make mentioned strategy more holistic having clear vision of the essence of war and peace phenomena. The research is going to perform precious conceptualization of the strategy contours initiated at the previous publications of O. Bazaluk. Originality. Authors defined the series “fatal” mistakes of the European Security Strategy and formulated the list of objectives of the revised security strategy. Conclusions. Five key objectives of perspective European Security Strategy were formulated. The first objective should include the complex measures for the identification, registration and organization of the system of preventive work with mentalities, in which the pathologies in the structure and function of the neural ensembles of subconsciousness and consciousness are clearly expressed that refract the active principle (as natural force in aggressive manifestations. The second one should include the complex measures ensuring control over the direction of the physicochemical, predisposing, provoking and supporting factors of the external environment that have a direct impact on the manifestations of a mental space in ontogeny. The third objective should include the complex measures of prediction and solution of international (interstate conflicts. The fourth objective of the security strategy should be aimed at eliminating the cause of war. The fifth objective should provide the complex measures involving the peaceful extension of comfortable conditions for the full realization of its internal creative potentials by a mental space.

  7. Page 1 Heuristic strategies for multiobjective search 281 6.4a MOR ...

    Indian Academy of Sciences (India)

    lowing result has been established (Korf 1985) for strategies such as IDA": • If for some constant b (such that b% = N for some integer K), b' new nodes are expanded in the ith iteration, then the worst case complexity of the strategy reduces from O(N*) to O(N). Based on this result, the algorithm IDA*_CR was developed by ...

  8. Heuristic methods using variable neighborhood random local search for the clustered traveling salesman problem

    Directory of Open Access Journals (Sweden)

    Mário Mestria

    2014-11-01

    Full Text Available In this paper, we propose new heuristic methods for solver the Clustered Traveling Salesman Problem (CTSP. The CTSP is a generalization of the Traveling Salesman Problem (TSP in which the set of vertices is partitioned into disjoint clusters and objective is to find a minimum cost Hamiltonian cycle such that the vertices of each cluster are visited contiguously. We develop two Variable Neighborhood Random Descent with Iterated Local for solver the CTSP. The heuristic methods proposed were tested in types of instances with data at different level of granularity for the number of vertices and clusters. The computational results showed that the heuristic methods outperform recent existing methods in the literature and they are competitive with an exact algorithm using the Parallel CPLEX software.

  9. Strategies to enhance venous thromboprophylaxis in hospitalized medical patients (SENTRY: a pilot cluster randomized trial

    Directory of Open Access Journals (Sweden)

    Pai Menaka

    2013-01-01

    Full Text Available Abstract Background Venous thromboembolism (VTE is a common preventable cause of mortality in hospitalized medical patients. Despite rigorous randomized trials generating strong recommendations for anticoagulant use to prevent VTE, nearly 40% of medical patients receive inappropriate thromboprophylaxis. Knowledge-translation strategies are needed to bridge this gap. Methods We conducted a 16-week pilot cluster randomized controlled trial (RCT to determine the proportion of medical patients that were appropriately managed for thromboprophylaxis (according to the American College of Chest Physician guidelines within 24 hours of admission, through the use of a multicomponent knowledge-translation intervention. Our primary goal was to determine the feasibility of conducting this study on a larger scale. The intervention comprised clinician education, a paper-based VTE risk assessment algorithm, printed physicians’ orders, and audit and feedback sessions. Medical wards at six hospitals (representing clusters in Ontario, Canada were included; three were randomized to the multicomponent intervention and three to usual care (i.e., no active strategies for thromboprophylaxis in place. Blinding was not used. Results A total of 2,611 patients (1,154 in the intervention and 1,457 in the control group were eligible and included in the analysis. This multicomponent intervention did not lead to a significant difference in appropriate VTE prophylaxis rates between intervention and control hospitals (appropriate management rate odds ratio = 0.80; 95% confidence interval: 0.50, 1.28; p = 0.36; intra-class correlation coefficient: 0.022, and thus was not considered feasible. Major barriers to effective knowledge translation were poor attendance by clinical staff at education and feedback sessions, difficulty locating preprinted orders, and lack of involvement by clinical and administrative leaders. We identified several factors that may increase uptake of a VTE

  10. Implementing school nursing strategies to reduce LGBTQ adolescent suicide: a randomized cluster trial study protocol.

    Science.gov (United States)

    Willging, Cathleen E; Green, Amy E; Ramos, Mary M

    2016-10-22

    Reducing youth suicide in the United States (U.S.) is a national public health priority, and lesbian, gay, bisexual, transgender, and queer or questioning (LGBTQ) youth are at elevated risk. The Centers for Disease Control and Prevention (CDC) endorses six evidence-based (EB) strategies that center on meeting the needs of LGBTQ youth in schools; however, fewer than 6 % of U.S. schools implement all of them. The proposed intervention model, "RLAS" (Implementing School Nursing Strategies to Reduce LGBTQ Adolescent Suicide), builds on the Exploration, Preparation, Implementation, and Sustainment (EPIS) conceptual framework and the Dynamic Adaptation Process (DAP) to implement EB strategies in U.S. high schools. The DAP accounts for the multilevel context of school settings and uses Implementation Resource Teams (IRTs) to facilitate appropriate expertise, advise on acceptable adaptations, and provide data feedback to make schools implementation ready and prepared to sustain changes. Mixed methods will be used to examine individual, school, and community factors influencing both implementation process and youth outcomes. A cluster randomized controlled trial will assess whether LGBTQ students and their peers in RLAS intervention schools (n = 20) report reductions in suicidality, depression, substance use, bullying, and truancy related to safety concerns compared to those in usual care schools (n = 20). Implementation progress and fidelity for each EB strategy in RLAS intervention schools will be examined using a modified version of the Stages of Implementation Completion checklist. During the implementation and sustainment phases, annual focus groups will be conducted with the 20 IRTs to document their experiences identifying and advancing adaptation supports to facilitate use of EB strategies and their perceptions of the DAP. The DAP represents a data-informed, collaborative, multiple stakeholder approach to progress from exploration to sustainment and obtain

  11. Implementing school nursing strategies to reduce LGBTQ adolescent suicide: a randomized cluster trial study protocol

    Directory of Open Access Journals (Sweden)

    Cathleen E. Willging

    2016-10-01

    Full Text Available Abstract Background Reducing youth suicide in the United States (U.S. is a national public health priority, and lesbian, gay, bisexual, transgender, and queer or questioning (LGBTQ youth are at elevated risk. The Centers for Disease Control and Prevention (CDC endorses six evidence-based (EB strategies that center on meeting the needs of LGBTQ youth in schools; however, fewer than 6 % of U.S. schools implement all of them. The proposed intervention model, “RLAS” (Implementing School Nursing Strategies to Reduce LGBTQ Adolescent Suicide, builds on the Exploration, Preparation, Implementation, and Sustainment (EPIS conceptual framework and the Dynamic Adaptation Process (DAP to implement EB strategies in U.S. high schools. The DAP accounts for the multilevel context of school settings and uses Implementation Resource Teams (IRTs to facilitate appropriate expertise, advise on acceptable adaptations, and provide data feedback to make schools implementation ready and prepared to sustain changes. Methods/Design Mixed methods will be used to examine individual, school, and community factors influencing both implementation process and youth outcomes. A cluster randomized controlled trial will assess whether LGBTQ students and their peers in RLAS intervention schools (n = 20 report reductions in suicidality, depression, substance use, bullying, and truancy related to safety concerns compared to those in usual care schools (n = 20. Implementation progress and fidelity for each EB strategy in RLAS intervention schools will be examined using a modified version of the Stages of Implementation Completion checklist. During the implementation and sustainment phases, annual focus groups will be conducted with the 20 IRTs to document their experiences identifying and advancing adaptation supports to facilitate use of EB strategies and their perceptions of the DAP. Discussion The DAP represents a data-informed, collaborative, multiple stakeholder

  12. A Cluster-Randomized Trial of Two Strategies to Improve Antibiotic Use for Patients with a Complicated Urinary Tract Infection

    NARCIS (Netherlands)

    Spoorenberg, Veroniek; Hulscher, Marlies E. J. L.; Geskus, Ronald B.; de Reijke, Theo M.; Opmeer, Brent C.; Prins, Jan M.; Geerlings, Suzanne E.

    2015-01-01

    Up to 50% of hospital antibiotic use is inappropriate and therefore improvement strategies are urgently needed. We compared the effectiveness of two strategies to improve the quality of antibiotic use in patients with a complicated urinary tract infection (UTI). In a multicentre, cluster-randomized

  13. The Effect of Different Types of Monitoring Strategies on Weight Loss: A Randomized Controlled Trial.

    Science.gov (United States)

    Jospe, Michelle R; Roy, Melyssa; Brown, Rachel C; Williams, Sheila M; Osborne, Hamish R; Meredith-Jones, Kim A; McArthur, Jenny R; Fleming, Elizabeth A; Taylor, Rachael W

    2017-09-01

    To determine the effectiveness of various monitoring strategies on weight loss, body composition, blood markers, exercise, and psychosocial indices in adults with overweight and obesity following a 12-month weight loss program. Two hundred fifty adults with BMI ≥ 27 were randomized to brief, monthly, individual consults, daily self-monitoring of weight, self-monitoring of diet using MyFitnessPal, self-monitoring of hunger, or control over 12 months. All groups received diet and exercise advice, and 171 participants (68.4%) remained at 12 months. No significant differences in weight, body composition, blood markers, exercise, or eating behavior were apparent between those in the four monitoring groups and the control condition at 12 months (all P ≥ 0.053). Weight differences between groups ranged from -1.1 kg (-3.8 to 1.6) to 2.2 kg (-1.0 to 5.3). However, brief support and hunger training groups reported significantly lower scores for depression (difference [95% CI]: -3.16 [-5.70 to -0.62] and -3.05 [-5.61 to -0.50], respectively) and anxiety (-1.84, [-3.67 to -0.02]) scores than control participants. Although adding a monitoring strategy to diet and exercise advice did not further increase weight loss, no adverse effects on eating behavior were observed, and some monitoring strategies may even benefit mental health. © 2017 The Obesity Society.

  14. Commissioning of the CMS muon detector and development of generic search strategies for new physics

    Energy Technology Data Exchange (ETDEWEB)

    Biallass, Philipp Alexander

    2009-03-27

    The detection and reconstruction of cosmic muon rays is important for the commissioning phase and alignment of the Compact Muon Solenoid experiment (CMS), in particular during the early phases of operation with physics collisions. In this context the Magnet Test/Cosmic Challenge (MTCC) with its comprehensive cosmic data taking periods including the presence of the magnetic field has been like a dress rehearsal of detector hardware and software for the upcoming start-up of the CMS detector. In addition to data taking also the comparison with simulated events is a crucial part of physics analyses. The first part of this thesis introduces a new cosmic muon generator, CMSCGEN, and it presents its validation by comparing its predictions with data from MTCC. As an example, results from a reconstruction study using the barrel muon system are shown, comparing data and Monte Carlo prediction at the level of single chambers up to reconstructed tracks including momentum measurements. Since leptons (electrons, muons) constitute very clean signatures for signals of new physics these commissioning and alignment procedures are also vital to most physics analyses. In the second part of this thesis a model independent search approach for new physics within CMS is presented, utilizing events with leptons and relying only on the knowledge of the Standard Model simulation. Such an analysis can contribute to the understanding of the detector and the tuning of the event generators. Due to the absence of a theoretical bias this approach is sensitive to a variety of models, including those not yet thought of. Within this feasibility study events are classified according to their particle content (muons, electrons, photons, jets, missing energy) into so called event classes. A broad scan of various distributions is performed, identifying significant deviations from the SM Monte Carlo simulation. The importance of systematic uncertainties is outlined, which are taken into account rigorously

  15. Development of a magnetometer-based search strategy for stopped monopoles at the Large Hadron Collider

    CERN Document Server

    De Roeck, A.; Hirt, A M; Joergensen, M-D; Katre, A; Mermod, P; Milstead, D; Sloan, T

    2012-01-01

    If produced in high energy particle collisions at the LHC, magnetic monopoles could stop in material surrounding the interaction points. Obsolete parts of the beam pipe near the CMS interaction region, which were exposed to the products of pp and heavy ion collisions, were analysed using a SQUID-based magnetometer. The purpose of this work is to quantify the performance of the magnetometer in the context of a monopole search using a small set of samples of accelerator material ahead of the 2013 shutdown.

  16. A comparison of visual search strategies of elite and non-elite tennis players through cluster analysis.

    Science.gov (United States)

    Murray, Nicholas P; Hunfalvay, Melissa

    2017-02-01

    Considerable research has documented that successful performance in interceptive tasks (such as return of serve in tennis) is based on the performers' capability to capture appropriate anticipatory information prior to the flight path of the approaching object. Athletes of higher skill tend to fixate on different locations in the playing environment prior to initiation of a skill than their lesser skilled counterparts. The purpose of this study was to examine visual search behaviour strategies of elite (world ranked) tennis players and non-ranked competitive tennis players (n = 43) utilising cluster analysis. The results of hierarchical (Ward's method) and nonhierarchical (k means) cluster analyses revealed three different clusters. The clustering method distinguished visual behaviour of high, middle-and low-ranked players. Specifically, high-ranked players demonstrated longer mean fixation duration and lower variation of visual search than middle-and low-ranked players. In conclusion, the results demonstrated that cluster analysis is a useful tool for detecting and analysing the areas of interest for use in experimental analysis of expertise and to distinguish visual search variables among participants'.

  17. Building with Nature: in search of resilient storm surge protection strategies

    NARCIS (Netherlands)

    van Slobbe, E.; de Vriend, Huib J.; Aarninkhof, S.G.J.; Lulofs, Kristiaan R.D.; de Vries, M.; Dircke, P.

    2013-01-01

    Low-lying, densely populated coastal areas worldwide are under threat, requiring coastal managers to develop new strategies to cope with land subsidence, sea-level rise and the increasing risk of storm-surge-induced floods. Traditional engineering approaches optimizing for safety are often

  18. Job Search Strategies of Recent University Graduates in Poland: Plans and Effectiveness

    Science.gov (United States)

    Piróg, Danuta

    2016-01-01

    The objective of this article was to highlight plans versus actual actions of university graduates in Poland aimed at finding employment. The paper also empirically verifies the impact of chosen job-seeking strategies on the success or failure of their transition to employment. The study was Polish-wide and included graduates of geography. It…

  19. The Search for Progress Elementary Student Achievement and the Bay Area School Reform Collaborative's Focal Strategy

    Science.gov (United States)

    Porter, Kristin E.; Snipes, Jason C.; Eisberg, Jean

    2006-01-01

    A number of forces have increased the momentum for school districts to develop district-wide reform strategies as a means of initiating and sustaining school improvement. First, districts have sometimes found it easier to manage and support a single districtwide initiative rather than many different school reform models. Second, they have come to…

  20. Millennial Students’ Online Search Strategies are Associated With Their Mental Models of Search. A Review of: Holman, L. (2011. Millennial students’ mental models of search: Implications for academic librarians and database developers. Journal of Academic Librarianship, 37(1, 19-27. doi:10.1016/j.acalib.2010.10.003

    Directory of Open Access Journals (Sweden)

    Leslie Bussert

    2011-09-01

    Full Text Available Objective – To examine first-year college students’ information seeking behaviours and determine whether their mental models of the search process influence their ability to effectively search for and find scholarly materials.Design – Mixed methods including contextual inquiry, concept mapping, observation, and interviews.Setting – University of Baltimore, a public institution in Maryland, United States of America, offering undergraduate, graduate, and professional degrees.Subjects – A total of 21 first-year undergraduate students, ages 16 to 19 years, undertaking research assignments for which they chose to use online resources.Methods – First-year students were recruited in the fall of 2008 and met with the researcher in a university usability lab for about one hour over a three week period. The researcher observed and videotaped the students as they conducted research in their chosen search engines or article databases. The searches were captured using software, and students were encouraged to think aloud about their research process, search strategies, and anticipated search results. Observation sessions concluded with a 10-question interview incorporating a review of the keywords the student used, the student’s reflection on the success of his or her searches, and possible alternate keywords. The interview also offered prompts to help the researcher learn about students’ conceptualizations of search tools’ utilization of keywords to generate results. The researcher then asked the students to provide a visual diagram of the relationship between their search terms and the items retrieved in the search tool.Data were analyzed by identifying the 21 different search tools used by the students and categorizing all 210 searches and student diagrams for further analysis. A scheme similar to Guinee, Eagleton, and Hall’s (2003 characterized the student searches into four categories: simple single-term searches, topic plus focus

  1. A Novel Randomized Search Technique for Multiple Mobile Robot Paths Planning In Repetitive Dynamic Environment

    Directory of Open Access Journals (Sweden)

    Vahid Behravesh

    2012-08-01

    Full Text Available Presented article is studying the issue of path navigating for numerous robots. Our presented approach is based on both priority and the robust method for path finding in repetitive dynamic. Presented model can be generally implementable and useable: We do not assume any restriction regarding the quantity of levels of freedom for robots, and robots of diverse kinds can be applied at the same time. We proposed a random method and hill-climbing technique in the area based on precedence plans, which is used to determine a solution to a given trajectory planning problem and to make less the extent of total track. Our method plans trajectories for particular robots in the setting-time scope. Therefore, in order to specifying the interval of constant objects similar to other robots and the extent of the tracks which is traversed. For measuring the hazard for robots to conflict with each other it applied a method based on probability of the movements of robots. This algorithm applied to real robots with successful results. The proposed method performed and judged on both real robots and in simulation. We performed sequence of100tests with 8 robots for comparing with coordination method and current performances are effective. However, maximizing the performance is still possible. These performances estimations performed on Windows operating system and 3GHz Intel Pentium IV with and compiles with GCC 3.4. We used our PCGA robot for all experiments.  For a large environment of 19×15m2where we accomplished 40tests, our model is competent to plan high-quality paths in a severely short time (less than a second. Moreover, this article utilized lookup tables to keep expenses the formerly navigated robots made, increasing the number of robots don’t expand computation time.

  2. How breast cancer patients want to search for and retrieve information from stories of other patients on the internet: an online randomized controlled experiment.

    Science.gov (United States)

    Overberg, Regina; Otten, Wilma; de Man, Andries; Toussaint, Pieter; Westenbrink, Judith; Zwetsloot-Schonk, Bertie

    2010-03-09

    Other patients' stories on the Internet can give patients information, support, reassurance, and practical advice. We examined which search facility for online stories resulted in patients' satisfaction and search success. This study was a randomized controlled experiment with a 2x2 factorial design conducted online. We facilitated access to 170 stories of breast cancer patients in four ways based on two factors: (1) no versus yes search by story topic, and (2) no versus yes search by writer profile. Dutch speaking women with breast cancer were recruited. Women who gave informed consent were randomly assigned to one of four groups. After searching for stories, women were offered a questionnaire relating to satisfaction with the search facility, the stories retrieved, and impact of the stories on coping with breast cancer. Of 353 enrolled women, 182 (51.6%) completed the questionnaire: control group (n = 37), story topics group (n = 49), writer profile group (n = 51), and combination group (n = 45). Questionnaire completers were evenly distributed over the four groups (chi(2) (3) = 3.7, P = .30). Women who had access to the story topics search facility (yes vs no): were more positive about (mean scores 4.0 vs 3.6, P = .001) and more satisfied with the search facility (mean scores 7.3 vs 6.3, P search options (mean scores 2.3 vs 2.1, P = .04); were better enabled to find desired information (mean scores 3.3 vs 2.8, P = .001); were more likely to recommend the search facility to others or intend to use it themselves (mean scores 4.1 vs 3.5, P search (yes vs no): being more positive about (mean scores 3.9 vs 3.6, P = .005) and more satisfied with the search facility (mean scores 7.1 vs 6.5, P =. 01), and being more positive about how retrieved stories were displayed (mean scores 3.8 vs 2.9, P search facility, an interaction effect was found (P = .03): at least one of the two search facilities was needed for satisfaction. Having access to the story topics search

  3. Misuse of randomization

    DEFF Research Database (Denmark)

    Liu, Jianping; Kjaergard, Lise Lotte; Gluud, Christian

    2002-01-01

    The quality of randomization of Chinese randomized trials on herbal medicines for hepatitis B was assessed. Search strategy and inclusion criteria were based on the published protocol. One hundred and seventy-six randomized clinical trials (RCTs) involving 20,452 patients with chronic hepatitis B....../150) of the studies were imbalanced at the 0.05 level of probability for the two treatments and 13.3% (20/150) imbalanced at the 0.01 level in the randomization. It is suggested that there may exist misunderstanding of the concept and the misuse of randomization based on the review....

  4. Turkey in Search of Relevant Foreign Policy Strategy (2002-2016

    Directory of Open Access Journals (Sweden)

    Urmanov Dayan R.

    2016-06-01

    Full Text Available The main idea of this article is to describe the process of Turkish foreign policy evolvement during the rule of Justice and Development party (JDP. From weak economy and unstable political situation in 2001, JDP quickly formulated a new strategy of foreign policy and stabilized economy. In the article the Turkish foreign policy in the 21st century is divided into several stages which respond to different international threats and circumstances. The first stage was a peacekeeping stage when Turkey tried to stabilize the situation near its borders and implement peace initiatives for the purpose to find new markets and allies. As a result, Turkey formulated a new strategy of foreign policy, called “Zero Problems Policy” which aimed to create a ring of friendly countries on the borders. On the second stage, Turkish foreign policy was more active – Turkey tried to balance among regional power centers and confront with one of the most powerful actors – Israel. Confrontation with Tel Aviv was a preface to the third stage, and today under the influence of “Arab Spring” and desire to change its role in international relations, Turkey refused “Zero Problems Policy” strategy and turned to a new aggressive and revanchist idea – neo- Ottomanism. Ankara tries to build a new regional set of rules where Turkey will play a leading role.

  5. STRATEGIES IN SEARCHING HOMOGENEITY IN A FACULTY OF A POSTGRADUATE PROGRAM

    Directory of Open Access Journals (Sweden)

    José G Cecatti

    Full Text Available The professor plays a fundamental role in a graduate program, considering he/she is who plans and performs a great part of the tasks, and he/she is also responsible for spreading knowledge among students. The professor should use didactical resources for his/her continuous qualification, being responsible for situations favoring the development of students who should learn according to the best and easier way. The homogeneity in the postgraduate program consists of having subgroups of research corresponding to the Areas of Concentration, where each subgroup works with some distinct topics of research. It is desirable that the staff of postgraduate program has a significant and high quality scientific production, homogeneously distributed among them. The professors must systematically search for resources for research in agencies supporting research, not only for sponsoring the studies, but also for adding value to the researchers involved in the whole activities. The postgraduate programs need to support the professional qualification of their staff who should improve their knowledge on epidemiology for clinical studies, ethics in research and teaching skills. Two characteristics of the postgraduate system in Brazil are the nucleation and solidarity, based on the capacity and/or interest of those more structured programs to help those beginners, cooperating with their activities. The Capes (the national governmental agency responsible for coordinating and evaluating all postgraduate programs in Brazil valorizes the social insertion in the context of postgraduate programs´ activities. It includes the recognition of activities with technological, cultural, educational and social impact as criteria for evaluation of the programs. Does exist an ideal model of postgraduate program? We think that there is no a mathematical formulae nor an ideal model for a postgraduate program. Each institution should make adaptations and search for improvements of

  6. Equilibrium Model of Discrete Dynamic Supply Chain Network with Random Demand and Advertisement Strategy

    Directory of Open Access Journals (Sweden)

    Guitao Zhang

    2014-01-01

    Full Text Available The advertisement can increase the consumers demand; therefore it is one of the most important marketing strategies in the operations management of enterprises. This paper aims to analyze the impact of advertising investment on a discrete dynamic supply chain network which consists of suppliers, manufactures, retailers, and demand markets associated at different tiers under random demand. The impact of advertising investment will last several planning periods besides the current period due to delay effect. Based on noncooperative game theory, variational inequality, and Lagrange dual theory, the optimal economic behaviors of the suppliers, the manufactures, the retailers, and the consumers in the demand markets are modeled. In turn, the supply chain network equilibrium model is proposed and computed by modified project contraction algorithm with fixed step. The effectiveness of the model is illustrated by numerical examples, and managerial insights are obtained through the analysis of advertising investment in multiple periods and advertising delay effect among different periods.

  7. Cerebral collateral therapeutics in acute ischemic stroke: A randomized preclinical trial of four modulation strategies.

    Science.gov (United States)

    Beretta, Simone; Versace, Alessandro; Carone, Davide; Riva, Matteo; Dell'Era, Valentina; Cuccione, Elisa; Cai, Ruiyao; Monza, Laura; Pirovano, Silvia; Padovano, Giada; Stiro, Fabio; Presotto, Luca; Paternò, Giovanni; Rossi, Emanuela; Giussani, Carlo; Sganzerla, Erik P; Ferrarese, Carlo

    2017-10-01

    Cerebral collaterals are dynamically recruited after arterial occlusion and highly affect tissue outcome in acute ischemic stroke. We investigated the efficacy and safety of four pathophysiologically distinct strategies for acute modulation of collateral flow (collateral therapeutics) in the rat stroke model of transient middle cerebral artery (MCA) occlusion. A composed randomization design was used to assign rats (n = 118) to receive phenylephrine (induced hypertension), polygeline (intravascular volume load), acetazolamide (cerebral arteriolar vasodilation), head down tilt (HDT) 15° (cerebral blood flow diversion), or no treatment, starting 30 min after MCA occlusion. Compared to untreated animals, treatment with collateral therapeutics was associated with lower infarct volumes (62% relative mean difference; 51.57 mm3 absolute mean difference; p therapy.

  8. Evaluation of vaccination strategies for SIR epidemics on random networks incorporating household structure

    CERN Document Server

    Ball, Frank

    2016-01-01

    This paper is concerned with the analysis of vaccination strategies in a stochastic SIR (susceptible $\\to$ infected $\\to$ removed) model for the spread of an epidemic amongst a population of individuals with a random network of social contacts that is also partitioned into households. Under various vaccine action models, we consider both household-based vaccination schemes, in which the way in which individuals are chosen for vaccination depends on the size of the households in which they reside, and acquaintance vaccination, which targets individuals of high degree in the social network. For both types of vaccination scheme, assuming a large population with few initial infectives, we derive a threshold parameter which determines whether or not a large outbreak can occur and also the probability and fraction of the population infected by such an outbreak. The performance of these schemes is studied numerically, focusing on the influence of the household size distribution and the degree distribution of the soc...

  9. Relevant feature set estimation with a knock-out strategy and random forests

    DEFF Research Database (Denmark)

    Ganz, Melanie; Greve, Douglas N; Fischl, Bruce

    2015-01-01

    Group analysis of neuroimaging data is a vital tool for identifying anatomical and functional variations related to diseases as well as normal biological processes. The analyses are often performed on a large number of highly correlated measurements using a relatively smaller number of samples...... unintuitive and difficult to determine. In this article, we propose a novel MVPA method for group analysis of high-dimensional data that overcomes the drawbacks of the current techniques. Our approach explicitly aims to identify all relevant variations using a "knock-out" strategy and the Random Forest...... algorithm. In evaluations with synthetic datasets the proposed method achieved substantially higher sensitivity and accuracy than the state-of-the-art MVPA methods, and outperformed the univariate approach when the effect size is low. In experiments with real datasets the proposed method identified regions...

  10. Using MeSH (medical subject headings) to enhance PubMed search strategies for evidence-based practice in physical therapy.

    Science.gov (United States)

    Richter, Randy R; Austin, Tricia M

    2012-01-01

    Evidence-based practice (EBP) is an important paradigm in health care. Physical therapists report lack of knowledge and time constraints as barriers to EBP. The purpose of this technical report is to illustrate how Medical Subject Headings (MeSH), a controlled vocabulary thesaurus of indexing terms, is used to efficiently search MEDLINE, the largest component of PubMed. Using clinical questions, this report illustrates how search terms common to physical therapist practice do or do not map to appropriate MeSH terms. A PubMed search strategy that takes advantage of text words and MeSH terms is provided. A search of 139 terms and 13 acronyms was conducted to determine whether they appropriately mapped to a MeSH term. The search results were categorized into 1 of 5 outcomes. Nearly half (66/139) of the search terms mapped to an appropriate MeSH term (outcome 1). When a search term did not appropriately map to a MeSH term, it was entered into the MeSH database to search for an appropriate MeSH term. Twenty-one appropriate MeSH terms were found (outcomes 2 and 4), and there were 52 search terms for which an appropriate MeSH term was not found (outcomes 3 and 5). Nearly half of the acronyms did not map to an appropriate MeSH term, and an appropriate MeSH term was not found in the database. The results are based on a limited number of search terms and acronyms. Understanding how search terms map to MeSH terms and using the PubMed search strategy can enable physical therapists to take full advantage of available MeSH terms and should result in more-efficient and better-informed searches.

  11. Current strategies in the search for low penetrance genes in cancer.

    Science.gov (United States)

    Milne, R L; Benítez, J

    2008-04-01

    The genetic etiology of most cancers remains largely unclear and it has been hypothesised that common genetic variants with modest effects on disease susceptibility cause the bulk of this unexplained risk. Case-control association studies are considered the most effective strategy to identify these low-penetrance genes. While traditionally, such studies have focused on putative functional single nucleotide polymorphisms (SNPs) in candidate genes, a more comprehensive approach can now be taken, as a result of a number of recent developments: the mapping of the human genome, including the identification of almost ten million SNPs; and the development of high-throughput genotyping technologies that enable hundreds of thousands of SNPs to be genotyped in a single reaction, in multiple subjects and at an affordable cost. All common genomic variation can be captured by genotyping SNPs in gene-, pathway- or genome-wide-based strategies and these are now being applied to many diseases, including cancer. We present an outline of each of these approaches, including recent published examples, and discuss a number of challenges that remain to be addressed.

  12. A cluster randomized trial of decision support strategies for reducing antibiotic use in acute bronchitis.

    Science.gov (United States)

    Gonzales, Ralph; Anderer, Tammy; McCulloch, Charles E; Maselli, Judith H; Bloom, Frederick J; Graf, Thomas R; Stahl, Melissa; Yefko, Michelle; Molecavage, Julie; Metlay, Joshua P

    2013-02-25

    National quality indicators show little change in the overuse of antibiotics for uncomplicated acute bronchitis. We compared the effect of 2 decision support strategies on antibiotic treatment of uncomplicated acute bronchitis. We conducted a 3-arm cluster randomized trial among 33 primary care practices belonging to an integrated health care system in central Pennsylvania. The printed decision support intervention sites (11 practices) received decision support for acute cough illness through a print-based strategy, the computer-assisted decision support intervention sites (11 practices) received decision support through an electronic medical record-based strategy, and the control sites (11 practices) served as a control arm. Both intervention sites also received clinician education and feedback on prescribing practices, as well as patient education brochures at check-in. Antibiotic prescription rates for uncomplicated acute bronchitis in the winter period (October 1, 2009, through March 31, 2010) following introduction of the intervention were compared with the previous 3 winter periods in an intent-to-treat analysis. Compared with the baseline period, the percentage of adolescents and adults prescribed antibiotics during the intervention period decreased at the printed decision support intervention sites (from 80.0% to 68.3%) and at the computer-assisted decision support intervention sites (from 74.0% to 60.7%) but increased slightly at the control sites (from 72.5% to 74.3%). After controlling for patient and clinician characteristics, as well as clustering of observations by clinician and practice site, the differences for the intervention sites were statistically significant from the control sites (P = .003 for control sites vs printed decision support intervention sites and P = .01 for control sites vs computer-assisted decision support intervention sites) but not between themselves (P = .67 for printed decision support intervention sites vs computer

  13. Multiplicity of Mathematical Modeling Strategies to Search for Molecular and Cellular Insights into Bacteria Lung Infection.

    Science.gov (United States)

    Cantone, Martina; Santos, Guido; Wentker, Pia; Lai, Xin; Vera, Julio

    2017-01-01

    Even today two bacterial lung infections, namely pneumonia and tuberculosis, are among the 10 most frequent causes of death worldwide. These infections still lack effective treatments in many developing countries and in immunocompromised populations like infants, elderly people and transplanted patients. The interaction between bacteria and the host is a complex system of interlinked intercellular and the intracellular processes, enriched in regulatory structures like positive and negative feedback loops. Severe pathological condition can emerge when the immune system of the host fails to neutralize the infection. This failure can result in systemic spreading of pathogens or overwhelming immune response followed by a systemic inflammatory response. Mathematical modeling is a promising tool to dissect the complexity underlying pathogenesis of bacterial lung infection at the molecular, cellular and tissue levels, and also at the interfaces among levels. In this article, we introduce mathematical and computational modeling frameworks that can be used for investigating molecular and cellular mechanisms underlying bacterial lung infection. Then, we compile and discuss published results on the modeling of regulatory pathways and cell populations relevant for lung infection and inflammation. Finally, we discuss how to make use of this multiplicity of modeling approaches to open new avenues in the search of the molecular and cellular mechanisms underlying bacterial infection in the lung.

  14. A randomized controlled trial evaluating the impact of knowledge translation and exchange strategies

    Directory of Open Access Journals (Sweden)

    O'Mara Linda

    2009-09-01

    Full Text Available Abstract Context Significant resources and time are invested in the production of research knowledge. The primary objective of this randomized controlled trial was to evaluate the effectiveness of three knowledge translation and exchange strategies in the incorporation of research evidence into public health policies and programs. Methods This trial was conducted with a national sample of public health departments in Canada from 2004 to 2006. The three interventions, implemented over one year in 2005, included access to an online registry of research evidence; tailored messaging; and a knowledge broker. The primary outcome assessed the extent to which research evidence was used in a recent program decision, and the secondary outcome measured the change in the sum of evidence-informed healthy body weight promotion policies or programs being delivered at health departments. Mixed-effects models were used to test the hypotheses. Findings One hundred and eight of 141 (77% health departments participated in this study. No significant effect of the intervention was observed for primary outcome (p e.g., value placed on research evidence in decision making. Conclusion The results of this study suggest that under certain conditions tailored, targeted messages are more effective than knowledge brokering and access to an online registry of research evidence. Greater emphasis on the identification of organizational factors is needed in order to implement strategies that best meet the needs of individual organizations. Trial Registration The trial registration number and title are as follows: ISRCTN35240937 -- Is a knowledge broker more effective than other strategies in promoting evidence-based physical activity and healthy body weight programming?

  15. Anaesthesiological strategies in elective craniotomy: randomized, equivalence, open trial – The NeuroMorfeo trial

    Directory of Open Access Journals (Sweden)

    Guzzetti Stefano

    2009-04-01

    Full Text Available Abstract Background Many studies have attempted to determine the "best" anaesthetic technique for neurosurgical procedures in patients without intracranial hypertension. So far, no study comparing intravenous (IA with volatile-based neuroanaesthesia (VA has been able to demonstrate major outcome differences nor a superiority of one of the two strategies in patients undergoing elective supratentorial neurosurgery. Therefore, current practice varies and includes the use of either volatile or intravenous anaesthetics in addition to narcotics. Actually the choice of the anaestesiological strategy depends only on the anaesthetists' preferences or institutional policies. This trial, named NeuroMorfeo, aims to assess the equivalence between volatile and intravenous anaesthetics for neurosurgical procedures. Methods/Design NeuroMorfeo is a multicenter, randomized, open label, controlled trial, based on an equivalence design. Patients aged between 18 and 75 years, scheduled for elective craniotomy for supratentorial lesion without signs of intracranial hypertension, in good physical state (ASA I-III and Glasgow Coma Scale (GCS equal to 15, are randomly assigned to one of three anaesthesiological strategies (two VA arms, sevoflurane + fentanyl or sevoflurane + remifentanil, and one IA, propofol + remifentanil. The equivalence between intravenous and volatile-based neuroanaesthesia will be evaluated by comparing the intervals required to reach, after anaesthesia discontinuation, a modified Aldrete score ≥ 9 (primary end-point. Two statistical comparisons have been planned: 1 sevoflurane + fentanyl vs. propofol + remifentanil; 2 sevoflurane + remifentanil vs. propofol + remifentanil. Secondary end-points include: an assessment of neurovegetative stress based on (a measurement of urinary catecholamines and plasma and urinary cortisol and (b estimate of sympathetic/parasympathetic balance by power spectrum analyses of electrocardiographic tracings recorded

  16. Cognitive biases and heuristics in medical decision making: a critical review using a systematic search strategy.

    Science.gov (United States)

    Blumenthal-Barby, J S; Krieger, Heather

    2015-05-01

    The role of cognitive biases and heuristics in medical decision making is of growing interest. The purpose of this study was to determine whether studies on cognitive biases and heuristics in medical decision making are based on actual or hypothetical decisions and are conducted with populations that are representative of those who typically make the medical decision; to categorize the types of cognitive biases and heuristics found and whether they are found in patients or in medical personnel; and to critically review the studies based on standard methodological quality criteria. Data sources were original, peer-reviewed, empirical studies on cognitive biases and heuristics in medical decision making found in Ovid Medline, PsycINFO, and the CINAHL databases published in 1980-2013. Predefined exclusion criteria were used to identify 213 studies. During data extraction, information was collected on type of bias or heuristic studied, respondent population, decision type, study type (actual or hypothetical), study method, and study conclusion. Of the 213 studies analyzed, 164 (77%) were based on hypothetical vignettes, and 175 (82%) were conducted with representative populations. Nineteen types of cognitive biases and heuristics were found. Only 34% of studies (n = 73) investigated medical personnel, and 68% (n = 145) confirmed the presence of a bias or heuristic. Each methodological quality criterion was satisfied by more than 50% of the studies, except for sample size and validated instruments/questions. Limitations are that existing terms were used to inform search terms, and study inclusion criteria focused strictly on decision making. Most of the studies on biases and heuristics in medical decision making are based on hypothetical vignettes, raising concerns about applicability of these findings to actual decision making. Biases and heuristics have been underinvestigated in medical personnel compared with patients. © The Author(s) 2014.

  17. Learning, memory and search strategies of inbred mouse strains with different visual abilities in the Barnes maze.

    Science.gov (United States)

    O'Leary, Timothy P; Savoie, Vicki; Brown, Richard E

    2011-01-20

    Visuo-spatial learning and memory were assessed in male and female mice of 13 inbred strains on a small diameter mouse version of the Barnes maze surrounded by a wall and intra-maze visual cues. Mice completed acquisition and reversal training to assess learning, followed by a probe test to assess memory for the spatial location of the escape hole. The C57BL/6J and CAST/EiJ strains showed better learning performance than the other strains. A/J and 129/SvImJ strains showed poor learning performance, which may be due to their low rates of exploration. No differences in memory were found between strains in the probe test. Males showed better learning performance than females in the DBA/2J and C3H/HeJ strains, but there were no sex differences in the other strains. However, mice may not have used visuo-spatial cues to locate the escape hole in this maze, as (1) all strains primarily used the non-spatial serial/thigmotaxic search strategy, (2) no strains showed a reversal effect when the escape hole location was moved, and (3) learning and memory performance were not correlated with measures of visual ability. Multivariate and univariate analyses of variance indicated that mice with good visual ability performed better than mice with poor visual ability, but the effect sizes were small. The small diameter of the maze and the presence of a wall around the edge of the maze may promote thigmotaxis in mice, increasing the use of a non-visual search strategy, thereby reducing the influence of vision on performance and decreasing the sensitivity of this maze design to detect strain differences in visuo-spatial learning and memory. These results indicate that the design of the Barnes maze has a significant effect on learning and memory processes. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Gastrointestinal neuroendocrine tumors: Searching the optimal treatment strategy--A literature review.

    Science.gov (United States)

    Berardi, Rossana; Rinaldi, Silvia; Torniai, Mariangela; Morgese, Francesca; Partelli, Stefano; Caramanti, Miriam; Onofri, Azzurra; Polenta, Vanessa; Pagliaretta, Silvia; Falconi, Massimo; Cascinu, Stefano

    2016-02-01

    Neuroendocrine tumors of the gastro-entero-pancreatic system (GEP-NETs) are a heterogeneous group of neoplasms, with different malignant potential and behavior. Many treatment options are available. Surgery should be considered for localized tumors and in some selected cases of metastatic disease. Somatostatin analogs, useful for symptoms control in functioning tumors, are also effective to inhibit tumor progression in specific settings. The multi-TKI sunitinib and of the mTOR-inhibitor everolimus are efficacy for metastatic pancreatic NET (P-NET) treatment. Chemotherapy is generally used in symptomatic and progressive NETs. Peptide receptor radionuclide therapy (PRRT) should be recommended after failure of medical therapy. For tumors confined to the liver ablative techniques should be considered. Nevertheless a shared therapeutic sequence for GEP-NET treatment still does not exist. In this review, we analyzed available data trying to identify the better treatment strategy and to suggest potential therapeutic algorithms distinguishing P-NETs from gastrointestinal NETs (GI-NETs). Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. From Marx to Marcos - Search of the Subject and the Strategy of Revolution

    Directory of Open Access Journals (Sweden)

    Ilya L. Morozov

    2017-12-01

    Full Text Available The article discusses the evolution of theories of social revolution from the mid-nineteenth to the late twentieth centuries. The author analyzes the basic concepts of theorists and practitioners of the armed revolutionary struggle – from the founder of the classical Communist theory of Karl Marx to the Mexican guerrilla leader Subcomandante Marcos. The author focuses on the analysis of changes in the understanding of the subject (“driving forces” of the left political revolution, as well as the strategy of armed revolutionary struggle. The author comes to the conclusion about the historical evolution of the subject of the revolutionary struggle from major sustainable macro-groups (“classes”, targeted at the armed struggle, to self-born (by the network principle unstructured protest groups, situational leaders, mild forms of the revolutionary struggle, which minimize the armed violence, though do not eliminate it completely. The author substantiates the conclusion about the absence in the modern protest movement of social forces, able to become the subject of revolution socialist orientation. This increases the danger of dominance of the social protest of extremist nationalist and religious political spectra. The author offers two models of response to this threat: the growing influence of the reigning centre-right conservative parties of Russia; return to center-left positions of the social democratic movement of the countries of the European Union.

  20. Towards Improved Airborne Fire Detection Systems Using Beetle Inspired Infrared Detection and Fire Searching Strategies

    Directory of Open Access Journals (Sweden)

    Herbert Bousack

    2015-06-01

    Full Text Available Every year forest fires cause severe financial losses in many countries of the world. Additionally, lives of humans as well as of countless animals are often lost. Due to global warming, the problem of wildfires is getting out of control; hence, the burning of thousands of hectares is obviously increasing. Most important, therefore, is the early detection of an emerging fire before its intensity becomes too high. More than ever, a need for early warning systems capable of detecting small fires from distances as large as possible exists. A look to nature shows that pyrophilous “fire beetles” of the genus Melanophila can be regarded as natural airborne fire detection systems because their larvae can only develop in the wood of fire-killed trees. There is evidence that Melanophila beetles can detect large fires from distances of more than 100 km by visual and infrared cues. In a biomimetic approach, a concept has been developed to use the surveying strategy of the “fire beetles” for the reliable detection of a smoke plume of a fire from large distances by means of a basal infrared emission zone. Future infrared sensors necessary for this ability are also inspired by the natural infrared receptors of Melanophila beetles.

  1. STRATEGIES IN SEARCHING HOMOGENEITY IN A FACULTY OF A POSTGRADUATE PROGRAM.

    Science.gov (United States)

    Cecatti, José G; Fernandes, Karayna G; Souza, Renato T; Silveira, Carla; Surita, Fernanda G

    2015-01-01

    The professor plays a fundamental role in a graduate program, considering he/she is who plans and performs a great part of the tasks, and he/she is also responsible for spreading knowledge among students. The professor should use didactical resources for his/her continuous qualification, being responsible for situations favoring the development of students who should learn according to the best and easier way. The homogeneity in the postgraduate program consists of having subgroups of research corresponding to the Areas of Concentration, where each subgroup works with some distinct topics of research. It is desirable that the staff of postgraduate program has a significant and high quality scientific production, homogeneously distributed among them. The professors must systematically search for resources for research in agencies supporting research, not only for sponsoring the studies, but also for adding value to the researchers involved in the whole activities. The postgraduate programs need to support the professional qualification of their staff who should improve their knowledge on epidemiology for clinical studies, ethics in research and teaching skills. Two characteristics of the postgraduate system in Brazil are the nucleation and solidarity, based on the capacity and/or interest of those more structured programs to help those beginners, cooperating with their activities. The Capes (the national governmental agency responsible for coordinating and evaluating all postgraduate programs in Brazil) valorizes the social insertion in the context of postgraduate programs´ activities. It includes the recognition of activities with technological, cultural, educational and social impact as criteria for evaluation of the programs. Does exist an ideal model of postgraduate program? We think that there is no a mathematical formulae nor an ideal model for a postgraduate program. Each institution should make adaptations and search for improvements of their faculty and

  2. Condition-Based Conveyor Belt Replacement Strategy in Lignite Mines with Random Belt Deterioration

    Science.gov (United States)

    Blazej, Ryszard; Jurdziak, Leszek

    2017-12-01

    In Polish lignite surface mines, condition-based belt replacement strategies are applied in order to assure profitable refurbishment of worn out belts performed by external firms specializing in belt maintenance. In two of three lignite mines, staff asses belt condition subjectively during visual inspections. Only one mine applies specialized diagnostic device (HRDS) allowing objective magnetic evaluation of belt core condition in order to choose the most profitable moment for the dismantling of worn out belt segments from conveyors and sending them to the maintenance firm which provides their refurbishment. This article describes the advantages of a new diagnostic device called DiagBelt. It was developed at the Faculty of Geoengineering, Mining and Geology, Wroclaw University of Science and Technology. Economic gains from its application are calculated for the lignite mine and for the belt maintenance firm, taking into account random life (durability) of new and reconditioned belts (after the 1st and the 2nd refurbishment). Recursive calculations for following years allow the estimation of the length and costs of replaced, reconditioned and purchased belts on an annual basis, while the use of the Monte Carlo method allows the estimation of their variability caused by random deterioration of belts. Savings are obtained due to better selection of moments (times) for the replacement of belt segments and die to the possibility to qualify worn out belts for refurbishment without the need to remove their covers. In effect, increased belt durability and lowered share of waste belts (which were not qualified for reconditioning) create savings which can quickly cover expenditures on new diagnostic tools and regular belt inspections in the mine.

  3. In Search for Anti-Aging Strategy: Can We Rejuvenate Our Aging Stem Cells?

    Directory of Open Access Journals (Sweden)

    Anna Meiliana

    2015-08-01

    Full Text Available BACKGROUND: Recent evidence suggested that we grow old partly because of our stem cells grow old as a result of mechanisms that suppress the development of cancer over a lifetime. We believe that a further, more precise mechanistic understanding of this process will be required before this knowledge can be translated into human anti-aging therapies. CONTENT: A diminished capacity to maintain tissue homeostasis is a central physiological characteristic of aging. As stem cells regulate tissue homeostasis, depletion of stem cell reserves and/or diminished stem cell function have been postulated to contribute to aging. It has further been suggested that accumulated DNA damage could be a principal mechanism underlying age-dependent stem cell decline. It is interesting that many of the rejuvenating interventions act on the stem cell compartments, perhaps reflecting shared genetic and biochemical pathways controlling stem cell function and longevity. Strategy to slow down the aging processes is based on caloric restriction refers to a dietary regimen low in calories but without undernutrition. Sirtuin (SIRT1 and 3, increases longevity by mimicking the beneficial effects of caloric restriction. SIRT3 regulates stress-responsive mitochondrial homeostasis, and more importantly, SIRT3 upregulation rejuvenates aged stem cells in tissues. Resveratrol (3,5,4’-trihydroxystilbene, a natural polyphenol found in grapes and wine, was the most powerful natural activator of SIRT1. In fact, resveratrol treatment has been demonstrated to rescue adult stem cell decline, slow down bodyweight loss, improve trabecular bone structure and mineral density, and significantly extend lifespan. SUMMARY: Tissue-specific stem cells persist throughout the entire lifespan to repair and maintain tissues, but their self-renewal and differentiation potential become dysregulated with aging. Given that adult stem cells are thought to be central to tissue maintenance and organismal

  4. Gaze and visual search strategies of children with Asperger syndrome/high functioning autism viewing a magic trick.

    Science.gov (United States)

    Joosten, Annette; Girdler, Sonya; Albrecht, Matthew A; Horlin, Chiara; Falkmer, Marita; Leung, Denise; Ordqvist, Anna; Fleischer, Håkan; Falkmer, Torbjörn

    2016-01-01

    To examine visual search patterns and strategies used by children with and without Asperger syndrome/high functioning autism (AS/HFA) while watching a magic trick. Limited responsivity to gaze cues is hypothesised to contribute to social deficits in children with AS/HFA. Twenty-one children with AS/HFA and 31 matched peers viewed a video of a gaze-cued magic trick twice. Between the viewings, they were informed about how the trick was performed. Participants' eye movements were recorded using a head-mounted eye-tracker. Children with AS/HFA looked less frequently and had shorter fixation on the magician's direct and averted gazes during both viewings and more frequently at not gaze-cued objects and on areas outside the magician's face. After being informed of how the trick was conducted, both groups made fewer fixations on gaze-cued objects and direct gaze. Information may enhance effective visual strategies in children with and without AS/HFA.

  5. Modelling sensory limitation: the role of tree selection, memory and information transfer in bats' roost searching strategies.

    Directory of Open Access Journals (Sweden)

    Ireneusz Ruczyński

    Full Text Available Sensory limitation plays an important role in the evolution of animal behaviour. Animals have to find objects of interest (e.g. food, shelters, predators. When sensory abilities are strongly limited, animals adjust their behaviour to maximize chances for success. Bats are nocturnal, live in complex environments, are capable of flight and must confront numerous perceptual challenges (e.g. limited sensory range, interfering clutter echoes. This makes them an excellent model for studying the role of compensating behaviours to decrease costs of finding resources. Cavity roosting bats are especially interesting because the availability of tree cavities is often limited, and their quality is vital for bats during the breeding season. From a bat's sensory point of view, cavities are difficult to detect and finding them requires time and energy. However, tree cavities are also long lasting, allowing information transfer among conspecifics. Here, we use a simple simulation model to explore the benefits of tree selection, memory and eavesdropping (compensation behaviours to searches for tree cavities by bats with short and long perception range. Our model suggests that memory and correct discrimination of tree suitability are the basic strategies decreasing the cost of roost finding, whereas perceptual range plays a minor role in this process. Additionally, eavesdropping constitutes a buffer that reduces the costs of finding new resources (such as roosts, especially when they occur in low density. We conclude that natural selection may promote different strategies of roost finding in relation to habitat conditions and cognitive skills of animals.

  6. Optimal Power Flow Using Gbest-Guided Cuckoo Search Algorithm with Feedback Control Strategy and Constraint Domination Rule

    Directory of Open Access Journals (Sweden)

    Gonggui Chen

    2017-01-01

    Full Text Available The optimal power flow (OPF is well-known as a significant optimization tool for the security and economic operation of power system, and OPF problem is a complex nonlinear, nondifferentiable programming problem. Thus this paper proposes a Gbest-guided cuckoo search algorithm with the feedback control strategy and constraint domination rule which is named as FCGCS algorithm for solving OPF problem and getting optimal solution. This FCGCS algorithm is guided by the global best solution for strengthening exploitation ability. Feedback control strategy is devised to dynamically regulate the control parameters according to actual and specific feedback value in the simulation process. And the constraint domination rule can efficiently handle inequality constraints on state variables, which is superior to traditional penalty function method. The performance of FCGCS algorithm is tested and validated on the IEEE 30-bus and IEEE 57-bus example systems, and simulation results are compared with different methods obtained from other literatures recently. The comparison results indicate that FCGCS algorithm can provide high-quality feasible solutions for different OPF problems.

  7. Renal Insufficiency Following Contrast Media Administration Trial (REMEDIAL): a randomized comparison of 3 preventive strategies.

    Science.gov (United States)

    Briguori, Carlo; Airoldi, Flavio; D'Andrea, Davide; Bonizzoni, Erminio; Morici, Nuccia; Focaccio, Amelia; Michev, Iassen; Montorfano, Matteo; Carlino, Mauro; Cosgrave, John; Ricciardelli, Bruno; Colombo, Antonio

    2007-03-13

    Volume supplementation by saline infusion combined with N-acetylcysteine (NAC) represents an effective strategy to prevent contrast agent-induced nephrotoxicity (CIN). Preliminary data support the concept that sodium bicarbonate and ascorbic acid also may be effective in preventing CIN. Three hundred twenty-six consecutive patients with chronic kidney disease, referred to our institutions for coronary and/or peripheral procedures, were randomly assigned to prophylactic administration of 0.9% saline infusion plus NAC (n=111), sodium bicarbonate infusion plus NAC (n=108), and 0.9% saline plus ascorbic acid plus NAC (n=107). All enrolled patients had serum creatinine > or = 2.0 mg/dL and/or estimated glomerular filtration rate or = 25% in the creatinine concentration 48 hours after the procedure (CIN). The amount of contrast media administered (179+/-102, 169+/-92, and 169+/-94 mL, respectively; P=0.69) and risk scores (9.1+/-3.4, 9.5+/-3.6, and 9.3+/-3.6; P=0.21) were similar in the 3 groups. CIN occurred in 11 of 111 patients (9.9%) in the saline plus NAC group, in 2 of 108 (1.9%) in the bicarbonate plus NAC group (P=0.019 by Fisher exact test versus saline plus NAC group), and in 11 of 107 (10.3%) in the saline plus ascorbic acid plus NAC group (P=1.00 versus saline plus NAC group). The strategy of volume supplementation by sodium bicarbonate plus NAC seems to be superior to the combination of normal saline with NAC alone or with the addition of ascorbic acid in preventing CIN in patients at medium to high risk.

  8. Randomized Controlled Trial Evaluating a Standardized Strategy for Uveitis Etiologic Diagnosis (ULISSE).

    Science.gov (United States)

    de Parisot, Audrey; Kodjikian, Laurent; Errera, Marie-Hélène; Sedira, Neila; Heron, Emmanuel; Pérard, Laurent; Cornut, Pierre-Loïc; Schneider, Christelle; Rivière, Sophie; Ollé, Priscille; Pugnet, Grégory; Cathébras, Pascal; Manoli, Pierre; Bodaghi, Bahram; Saadoun, David; Baillif, Stéphanie; Tieulie, Nathalie; Andre, Marc; Chiambaretta, Frédéric; Bonin, Nicolas; Bielefeld, Philip; Bron, Alain; Mouriaux, Frédéric; Bienvenu, Boris; Vicente, Stéphanie; Bin, Sylvie; Broussolle, Christiane; Decullier, Evelyne; Sève, Pascal

    2017-06-01

    To prospectively assess the efficiency of a standardized diagnostic approach, compared to an open strategy, for the etiologic diagnosis of uveitis. Noninferiority, prospective, multicenter, clustered randomized controlled trial. Consecutive patients with uveitis, who visited 1 of the participating departments of ophthalmology, were included. In the standardized group, all patients had a minimal evaluation regardless of the type of uveitis (complete blood count, erythrocyte sedimentation rate, C-reactive protein, tuberculin skin test, syphilis serology, and chest radiograph) followed by more complex investigations according to ophthalmologic findings. In the open group, the ophthalmologist could order any type of investigation. Main outcome was the percentage of etiologic diagnoses at 6 months. Nine hundred and three patients with uveitis were included from January 2010 to May 2013 and the per-protocol population comprised 676 patients (open 373; standardized 303). Mean age at diagnosis was 46 years. Anatomic distribution of uveitis was as follows: anterior (60.8% and 72.3%, P = .0017), intermediate (11.7% and 12.3%, P = .8028), posterior (17.8% and 8.2%, P = .0004), and panuveitis (15.3% and 15.2%, P = .9596). An etiologic diagnosis was established in 54.4% of cases in the open group and 49.5% in the standardized group (P = .2029). The difference between both strategies (standardized minus open) was -4.9% (95% CI [-12.5%; 2.6%]). There were more investigations in the open group than in the standardized group (5371 vs 3759, P uveitis, although its noninferiority cannot be proved. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Metaphor use and health literacy: a pilot study of strategies to explain randomization in cancer clinical trials.

    Science.gov (United States)

    Krieger, Janice L; Parrott, Roxanne L; Nussbaum, Jon F

    2011-01-01

    Patients often have difficulty understanding what randomization is and why it is needed in Phase III clinical trials. Physicians commonly report using metaphorical language to convey the role of chance in being assignment to treatment; however, the effectiveness of this strategy as an educational tool has not been explored. Guided by W. McGuire's (1972) information-processing model, the purpose of this pilot study was to explore effects of metaphors to explain randomization on message acceptance and behavioral intention to participate in a Phase III clinical trial among a sample of low-income, rural women (N = 64). Participants were randomly assigned to watch a video that explained randomization using 1 of 3 message strategies: a low-literacy definition, standard metaphor (i.e., flip of a coin), or a culturally derived metaphor (i.e., sex of a baby). The influence of attention on behavioral intentions to participate in clinical trials was partially moderated by message strategy. Under conditions of low attention, participants in the culturally derived metaphor condition experienced significantly higher intentions to participate in clinical trials compared with participants in the standard metaphor condition. However, as attention increased, differences in intentions among the conditions diminished. Having a positive affective response to the randomization message was a strong, positive predictor of behavioral intentions to participate in clinical trials. The authors discuss the theoretical and practical implications of these findings.

  10. Efficacy of the Lexicon Pirate Strategy Therapy for Improving Lexical Learning in School-Age Children: A Randomized Controlled Trial

    Science.gov (United States)

    Motsch, Hans-Joachim; Marks, Dana-Kristin

    2015-01-01

    Lexicon Pirate was originally developed as a strategy intervention programme to treat lexical disorders of pre-school children. To evaluate the therapy's effectiveness for school-age students, a randomized controlled trial (RCT, N = 157) was conducted. Based on a pre--post-test design, the programme's impacts were compared with a control group…

  11. A randomized controlled trial of two primary school intervention strategies to prevent early onset tobacco smoking.

    Science.gov (United States)

    Storr, Carla L; Ialongo, Nicholas S; Kellam, Sheppard G; Anthony, James C

    2002-03-01

    In this article, we examine the impact of two universal, grade 1 preventive interventions on the onset of tobacco smoking as assessed in early adolescence. The classroom-centered (CC) intervention was designed to reduce the risk for tobacco smoking by enhancing teachers' behavior management skills in first grade and, thereby, reducing child attention problems and aggressive and shy behavior-known risk behaviors for later substance use. The family-school partnership (FSP) intervention targeted these early risk behaviors via improvements in parent-teacher communication and parents' child behavior management strategies. A cohort of 678 urban, predominately African-American, public school students were randomly assigned to one of three Grade 1 classrooms at entrance to primary school (age 6). One classroom featured the CC intervention, a second the FSP intervention, and the third served as a control classroom. Six years later, 81% of the students completed audio computer-assisted self-interviews. Relative to controls, a modest attenuation in the risk of smoking initiation was found for students who had been assigned to either the CC or FSP intervention classrooms (26% versus 33%) (adjusted relative risk for CC/control contrast=0.57, 95% confidence interval (CI), 0.34-0.96; adjusted relative risk for FSP/control contrast=0.69, 95% CI, 0.50-0.97). Results lend support to targeting the early antecedent risk behaviors for tobacco smoking.

  12. Retrieval of overviews of systematic reviews in MEDLINE was improved by the development of an objectively derived and validated search strategy.

    Science.gov (United States)

    Lunny, Carole; McKenzie, Joanne E; McDonald, Steve

    2016-06-01

    Locating overviews of systematic reviews is difficult because of an absence of appropriate indexing terms and inconsistent terminology used to describe overviews. Our objective was to develop a validated search strategy to retrieve overviews in MEDLINE. We derived a test set of overviews from the references of two method articles on overviews. Two population sets were used to identify discriminating terms, that is, terms that appear frequently in the test set but infrequently in two population sets of references found in MEDLINE. We used text mining to conduct a frequency analysis of terms appearing in the titles and abstracts. Candidate terms were combined and tested in MEDLINE in various permutations, and the performance of strategies measured using sensitivity and precision. Two search strategies were developed: a sensitivity-maximizing strategy, achieving 93% sensitivity (95% confidence interval [CI]: 87, 96) and 7% precision (95% CI: 6, 8), and a sensitivity-and-precision-maximizing strategy, achieving 66% sensitivity (95% CI: 58, 74) and 21% precision (95% CI: 17, 25). The developed search strategies enable users to more efficiently identify overviews of reviews compared to current strategies. Consistent language in describing overviews would aid in their identification, as would a specific MEDLINE Publication Type. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Efficacy of a Maternal Depression Prevention Strategy in Head Start: A Randomized Clinical Trial.

    Science.gov (United States)

    Silverstein, Michael; Diaz-Linhart, Yaminette; Cabral, Howard; Beardslee, William; Hegel, Mark; Haile, Winta; Sander, Jenna; Patts, Gregory; Feinberg, Emily

    2017-08-01

    Low-income and minority mothers experience a disproportionate incidence of depression and lack access to treatment services. Development of prevention strategies in accessible community-based venues is a potentially important public health strategy. To determine the efficacy of a depression prevention strategy embedded in Head Start. This randomized clinical trial was performed from February 15, 2011, through May 9, 2016, at 6 Head Start agencies serving families at or below the federal poverty level. Participants included mothers with depressed mood, anhedonia, or depression history but who were not in a current major depressive episode. Participants were followed up for 12 months with masked outcome assessments. Final follow-up was completed on May 9, 2016. Participants were randomized to a problem-solving education (PSE) intervention (n = 111) or usual Head Start services (n = 119). Primary outcomes were problem-solving skills and depressive symptoms. To capture the chronicity and intensity of symptoms, the Quick Inventory of Depressive Symptoms was administered bimonthly, and rates of clinically significant symptom elevations were compared across groups. Secondarily, the presence of a major depressive episode was assessed using the Structured Clinical Interview for DSM-IV Axis I Disorders. Among the 230 participants, 152 (66.1%) were Hispanic, with a mean (SD) age of 31.4 (7.3) years. An intention-to-treat analysis among 223 participants contributing follow-up data found no differences in problem-solving skills across groups. The mean (SD) number of depressive symptom elevations among the PSE participants was 0.84 (1.39) compared with 1.12 (1.47) among the usual service participants (adjusted incident rate ratio [aIRR], 0.60; 95% CI, 0.41-0.90). In analyses stratified according to baseline depressive symptoms, PSE exerted a preventive effect among those with lower-level baseline symptoms, with a mean (SD) of 0.39 (0.84) elevations among PSE participants

  14. Best strategies to implement clinical pathways in an emergency department setting: study protocol for a cluster randomized controlled trial.

    Science.gov (United States)

    Jabbour, Mona; Curran, Janet; Scott, Shannon D; Guttman, Astrid; Rotter, Thomas; Ducharme, Francine M; Lougheed, M Diane; McNaughton-Filion, M Louise; Newton, Amanda; Shafir, Mark; Paprica, Alison; Klassen, Terry; Taljaard, Monica; Grimshaw, Jeremy; Johnson, David W

    2013-05-22

    The clinical pathway is a tool that operationalizes best evidence recommendations and clinical practice guidelines in an accessible format for 'point of care' management by multidisciplinary health teams in hospital settings. While high-quality, expert-developed clinical pathways have many potential benefits, their impact has been limited by variable implementation strategies and suboptimal research designs. Best strategies for implementing pathways into hospital settings remain unknown. This study will seek to develop and comprehensively evaluate best strategies for effective local implementation of externally developed expert clinical pathways. We will develop a theory-based and knowledge user-informed intervention strategy to implement two pediatric clinical pathways: asthma and gastroenteritis. Using a balanced incomplete block design, we will randomize 16 community emergency departments to receive the intervention for one clinical pathway and serve as control for the alternate clinical pathway, thus conducting two cluster randomized controlled trials to evaluate this implementation intervention. A minimization procedure will be used to randomize sites. Intervention sites will receive a tailored strategy to support full clinical pathway implementation. We will evaluate implementation strategy effectiveness through measurement of relevant process and clinical outcomes. The primary process outcome will be the presence of an appropriately completed clinical pathway on the chart for relevant patients. Primary clinical outcomes for each clinical pathway include the following: Asthma--the proportion of asthmatic patients treated appropriately with corticosteroids in the emergency department and at discharge; and Gastroenteritis--the proportion of relevant patients appropriately treated with oral rehydration therapy. Data sources include chart audits, administrative databases, environmental scans, and qualitative interviews. We will also conduct an overall process

  15. A cluster randomized controlled trial of the Promoting Alternative Thinking Strategies (PATHS) curriculum.

    Science.gov (United States)

    Humphrey, Neil; Barlow, Alexandra; Wigelsworth, Michael; Lendrum, Ann; Pert, Kirsty; Joyce, Craig; Stephens, Emma; Wo, Lawrence; Squires, Garry; Woods, Kevin; Calam, Rachel; Turner, Alex

    2016-10-01

    This randomized controlled trial (RCT) evaluated the efficacy of the Promoting Alternative Thinking Strategies curriculum (PATHS; Kusche & Greenberg, 1994) as a means to improve children's social-emotional competence (assessed via the Social Skills Improvement System (SSIS); Gresham & Elliot, 2008) and mental health outcomes (assessed via the Strengths and Difficulties Questionnaire (SDQ); Goodman, 1997). Forty-five schools in Greater Manchester, England, were randomly assigned to treatment and control groups. Allocation was balanced by proportions of children eligible for free school meals and speaking English as an additional language via minimization. Children (N=4516) aged 7-9years at baseline in the participating schools were the target cohort. During the two-year trial period, teachers of this cohort in schools allocated to the intervention group delivered the PATHS curriculum, while their counterparts in the control group continued their usual provision. Teachers in PATHS schools received initial training and on-going support and assistance from trained coaches. Hierarchical linear modeling of outcome data was undertaken to identify both primary (e.g., for all children) and secondary (e.g., for children classified as "at-risk") intervention effects. A primary effect of the PATHS curriculum was found, demonstrating increases in teacher ratings of changes in children's social-emotional competence. Additionally, secondary effects of PATHS were identified, showing reductions in teacher ratings of emotional symptoms and increases in pro-social behavior and child ratings of engagement among children identified as at-risk at baseline. However, our analyses also identified primary effects favoring the usual provision group, showing reductions in teacher ratings of peer problems and emotional symptoms, and secondary effects demonstrating reductions in teacher ratings of conduct problems and child ratings of co-operation among at-risk children. Effect sizes were small

  16. Biomarker-based strategy for early discontinuation of empirical antifungal treatment in critically ill patients: a randomized controlled trial.

    Science.gov (United States)

    Rouzé, Anahita; Loridant, Séverine; Poissy, Julien; Dervaux, Benoit; Sendid, Boualem; Cornu, Marjorie; Nseir, Saad

    2017-11-01

    The aim of this study was to determine the impact of a biomarker-based strategy on early discontinuation of empirical antifungal treatment. Prospective randomized controlled single-center unblinded study, performed in a mixed ICU. A total of 110 patients were randomly assigned to a strategy in which empirical antifungal treatment duration was determined by (1,3)-β-D-glucan, mannan, and anti-mannan serum assays, performed on day 0 and day 4; or to a routine care strategy, based on international guidelines, which recommend 14 days of treatment. In the biomarker group, early stop recommendation was determined using an algorithm based on the results of biomarkers. The primary outcome was the percentage of survivors discontinuing empirical antifungal treatment early, defined as a discontinuation strictly before day 7. A total of 109 patients were analyzed (one patient withdraw consent). Empirical antifungal treatment was discontinued early in 29 out of 54 patients in the biomarker strategy group, compared with one patient out of 55 in the routine strategy group [54% vs 2%, p empirical antifungal treatment among critically ill patients with suspected invasive Candida infection. These results confirm previous findings suggesting that early discontinuation of empirical antifungal treatment had no negative impact on outcome. However, further studies are needed to confirm the safety of this strategy. This trial was registered at ClinicalTrials.gov, NCT02154178.

  17. Testing the implementation and sustainment facilitation (ISF strategy as an effective adjunct to the Addiction Technology Transfer Center (ATTC strategy: study protocol for a cluster randomized trial

    Directory of Open Access Journals (Sweden)

    Bryan R. Garner

    2017-11-01

    Full Text Available Abstract Background Improving the extent to which evidence-based practices (EBPs—treatments that have been empirically shown to be efficacious or effective—are integrated within routine practice is a well-documented challenge across numerous areas of health. In 2014, the National Institute on Drug Abuse funded a type 2 effectiveness–implementation hybrid trial titled the substance abuse treatment to HIV Care (SAT2HIV Project. Aim 1 of the SAT2HIV Project tests the effectiveness of a motivational interviewing-based brief intervention (MIBI for substance use as an adjunct to usual care within AIDS service organizations (ASOs as part of its MIBI Experiment. Aim 2 of the SAT2HIV Project tests the effectiveness of implementation and sustainment facilitation (ISF as an adjunct to the Addiction Technology Transfer Center (ATTC model for training staff in motivational interviewing as part of its ISF Experiment. The current paper describes the study protocol for the ISF Experiment. Methods Using a cluster randomized design, case management and leadership staff from 39 ASOs across the United States were randomized to receive either the ATTC strategy (control condition or the ATTC + ISF strategy (experimental condition. The ATTC strategy is staff-focused and includes 10 discrete strategies (e.g., provide centralized technical assistance, conduct educational meetings, provide ongoing consultation. The ISF strategy is organization-focused and includes seven discrete strategies (e.g., use an implementation advisor, organize implementation team meetings, conduct cyclical small tests of change. Building upon the exploration–preparation–implementation–sustainment (EPIS framework, the effectiveness of the ISF strategy is examined via three staff-level measures: (1 time-to-proficiency (i.e., preparation phase outcome, (2 implementation effectiveness (i.e., implementation phase outcome, and (3 level of sustainment (i.e., sustainment phase outcome

  18. Testing the implementation and sustainment facilitation (ISF) strategy as an effective adjunct to the Addiction Technology Transfer Center (ATTC) strategy: study protocol for a cluster randomized trial.

    Science.gov (United States)

    Garner, Bryan R; Zehner, Mark; Roosa, Mathew R; Martino, Steve; Gotham, Heather J; Ball, Elizabeth L; Stilen, Patricia; Speck, Kathryn; Vandersloot, Denna; Rieckmann, Traci R; Chaple, Michael; Martin, Erika G; Kaiser, David; Ford, James H

    2017-11-17

    Improving the extent to which evidence-based practices (EBPs)-treatments that have been empirically shown to be efficacious or effective-are integrated within routine practice is a well-documented challenge across numerous areas of health. In 2014, the National Institute on Drug Abuse funded a type 2 effectiveness-implementation hybrid trial titled the substance abuse treatment to HIV Care (SAT2HIV) Project. Aim 1 of the SAT2HIV Project tests the effectiveness of a motivational interviewing-based brief intervention (MIBI) for substance use as an adjunct to usual care within AIDS service organizations (ASOs) as part of its MIBI Experiment. Aim 2 of the SAT2HIV Project tests the effectiveness of implementation and sustainment facilitation (ISF) as an adjunct to the Addiction Technology Transfer Center (ATTC) model for training staff in motivational interviewing as part of its ISF Experiment. The current paper describes the study protocol for the ISF Experiment. Using a cluster randomized design, case management and leadership staff from 39 ASOs across the United States were randomized to receive either the ATTC strategy (control condition) or the ATTC + ISF strategy (experimental condition). The ATTC strategy is staff-focused and includes 10 discrete strategies (e.g., provide centralized technical assistance, conduct educational meetings, provide ongoing consultation). The ISF strategy is organization-focused and includes seven discrete strategies (e.g., use an implementation advisor, organize implementation team meetings, conduct cyclical small tests of change). Building upon the exploration-preparation-implementation-sustainment (EPIS) framework, the effectiveness of the ISF strategy is examined via three staff-level measures: (1) time-to-proficiency (i.e., preparation phase outcome), (2) implementation effectiveness (i.e., implementation phase outcome), and (3) level of sustainment (i.e., sustainment phase outcome). Although not without limitations, the ISF

  19. Personalized versus standardized dosing strategies for the treatment of childhood amblyopia: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Moseley, Merrick J; Wallace, Michael P; Stephens, David A; Fielder, Alistair R; Smith, Laura C; Stewart, Catherine E

    2015-04-25

    Amblyopia is the commonest visual disorder of childhood in Western societies, affecting, predominantly, spatial visual function. Treatment typically requires a period of refractive correction ('optical treatment') followed by occlusion: covering the nonamblyopic eye with a fabric patch for varying daily durations. Recent studies have provided insight into the optimal amount of patching ('dose'), leading to the adoption of standardized dosing strategies, which, though an advance on previous ad-hoc regimens, take little account of individual patient characteristics. This trial compares the effectiveness of a standardized dosing strategy (that is, a fixed daily occlusion dose based on disease severity) with a personalized dosing strategy (derived from known treatment dose-response functions), in which an initially prescribed occlusion dose is modulated, in a systematic manner, dependent on treatment compliance. A total of 120 children aged between 3 and 8 years of age diagnosed with amblyopia in association with either anisometropia or strabismus, or both, will be randomized to receive either a standardized or a personalized occlusion dose regimen. To avoid confounding by the known benefits of refractive correction, participants will not be randomized until they have completed an optical treatment phase. The primary study objective is to determine whether, at trial endpoint, participants receiving a personalized dosing strategy require fewer hours of occlusion than those in receipt of a standardized dosing strategy. Secondary objectives are to quantify the relationship between observed changes in visual acuity (logMAR, logarithm of the Minimum Angle of Resolution) with age, amblyopia type, and severity of amblyopic visual acuity deficit. This is the first randomized controlled trial of occlusion therapy for amblyopia to compare a treatment arm representative of current best practice with an arm representative of an entirely novel treatment regimen based on statistical

  20. Test-Enhanced E-Learning Strategies in Postgraduate Medical Education: A Randomized Cohort Study.

    Science.gov (United States)

    DelSignore, Lisa A; Wolbrink, Traci A; Zurakowski, David; Burns, Jeffrey P

    2016-11-21

    The optimal design of pedagogical strategies for e-learning in graduate and postgraduate medical education remains to be determined. Video-based e-learning use is increasing, with initial research suggesting that taking short breaks while watching videos (independent of answering test questions) may improve learning by focusing attention on the content presented. Interspersed test questions may also improve knowledge acquisition and retention. To examine the effect of interspersed test questions and periodic breaks on immediate knowledge acquisition and retention at 6 months by pediatric residents engaged in video-based e-learning. First- and second-year pediatric residents were randomized to 1 of the following 3 groups: viewing the complete video uninterrupted (full video), viewing the video interrupted with unrelated logic puzzles (logic puzzles), or viewing the video interrupted with brief comprehension test questions (short answer questions). Residents answered pre- and post-tests before and after video viewing, followed by a retention test at 6 months. Primary outcome included comparison of the change in test scores between groups. A total of 49 residents completed the initial testing session. All 3 learning groups had comparable mean increases in immediate knowledge gain, but with no significant differences between groups (F2,46=0.35, P=.71). Thirty-five residents completed retention testing with comparable degrees of knowledge retention in the full video and short answer test questions groups (P<.001), but no significant change in the logic puzzles group (F1,32=2.44, P=.13). Improved knowledge gain was not demonstrated among residents answering interspersed questions or completing logic puzzles during interrupted online video viewing when compared with residents viewing uninterrupted video content. However, residents who either participated in uninterrupted video viewing or answered interspersed questions during interrupted video viewing demonstrated

  1. Control group selection in critical care randomized controlled trials evaluating interventional strategies: An ethical assessment.

    Science.gov (United States)

    Silverman, Henry J; Miller, Franklin G

    2004-03-01

    Ethical concern has been raised with critical care randomized controlled trials in which the standard of care reflects a broad range of clinical practices. Commentators have argued that trials without an unrestricted control group, in which standard practices are implemented at the discretion of the attending physician, lack the ability to redefine the standard of care and might expose subjects to excessive harms due to an inability to stop early. To develop a framework for analyzing control group selection for critical care trials. Ethical analysis. A key ethical variable in trial design is the extent with which the control group adequately reflects standard care practices. Such a control group might incorporate either the "unrestricted" practices of physicians or a protocol that specifies and restricts the parameters of standard practices. Control group selection should be determined with respect to the following ethical objectives of trial design: 1) clinical value, 2) scientific validity, 3) efficiency and feasibility, and 4) protection of human subjects. Because these objectives may conflict, control group selection will involve trade-offs and compromises. Trials using a protocolized rather than an unrestricted standard care control group will likely have enhanced validity. However, if the protocolized control group lacks representativeness to standard care practices, then trials that use such groups will offer less clinical value and could provide less assurance of protecting subjects compared with trials that use unrestricted control groups. For trials evaluating contrasting strategies that do not adequately represent standard practices, use of a third group that is more representative of standard practices will enhance clinical value and increase the ability to stop early if needed to protect subjects. These advantages might come at the expense of efficiency and feasibility. Weighing and balancing the competing ethical objectives of trial design should be

  2. Optimal search behavior and classic foraging theory

    Energy Technology Data Exchange (ETDEWEB)

    Bartumeus, F [Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ (United States); Catalan, J [Centre d' Estudis Avancats de Blanes CEAB-CSIC, C/Acces a la Cala Sant Francesc 14, 17300 Blanes, Catalonia (Spain)

    2009-10-30

    Random walk methods and diffusion theory pervaded ecological sciences as methods to analyze and describe animal movement. Consequently, statistical physics was mostly seen as a toolbox rather than as a conceptual framework that could contribute to theory on evolutionary biology and ecology. However, the existence of mechanistic relationships and feedbacks between behavioral processes and statistical patterns of movement suggests that, beyond movement quantification, statistical physics may prove to be an adequate framework to understand animal behavior across scales from an ecological and evolutionary perspective. Recently developed random search theory has served to critically re-evaluate classic ecological questions on animal foraging. For instance, during the last few years, there has been a growing debate on whether search behavior can include traits that improve success by optimizing random (stochastic) searches. Here, we stress the need to bring together the general encounter problem within foraging theory, as a mean for making progress in the biological understanding of random searching. By sketching the assumptions of optimal foraging theory (OFT) and by summarizing recent results on random search strategies, we pinpoint ways to extend classic OFT, and integrate the study of search strategies and its main results into the more general theory of optimal foraging.

  3. A Study on Information Search and Commitment Strategies on Web Environment and Internet Usage Self-Efficacy Beliefs of University Students'

    Science.gov (United States)

    Geçer, Aynur Kolburan

    2014-01-01

    This study addresses university students' information search and commitment strategies on web environment and internet usage self-efficacy beliefs in terms of such variables as gender, department, grade level and frequency of internet use; and whether there is a significant relation between these beliefs. Descriptive method was used in the study.…

  4. Students' Scientific Epistemic Beliefs, Online Evaluative Standards, and Online Searching Strategies for Science Information: The Moderating Role of Cognitive Load Experience

    Science.gov (United States)

    Hsieh, Ya-Hui; Tsai, Chin-Chung

    2014-01-01

    The purpose of this study is to examine the moderating role of cognitive load experience between students' scientific epistemic beliefs and information commitments, which refer to online evaluative standards and online searching strategies. A total of 344 science-related major students participated in this study. Three questionnaires were…

  5. Face Recognition and Visual Search Strategies in Autism Spectrum Disorders: Amending and Extending a Recent Review by Weigelt et al.

    Directory of Open Access Journals (Sweden)

    Julia Tang

    Full Text Available The purpose of this review was to build upon a recent review by Weigelt et al. which examined visual search strategies and face identification between individuals with autism spectrum disorders (ASD and typically developing peers. Seven databases, CINAHL Plus, EMBASE, ERIC, Medline, Proquest, PsychInfo and PubMed were used to locate published scientific studies matching our inclusion criteria. A total of 28 articles not included in Weigelt et al. met criteria for inclusion into this systematic review. Of these 28 studies, 16 were available and met criteria at the time of the previous review, but were mistakenly excluded; and twelve were recently published. Weigelt et al. found quantitative, but not qualitative, differences in face identification in individuals with ASD. In contrast, the current systematic review found both qualitative and quantitative differences in face identification between individuals with and without ASD. There is a large inconsistency in findings across the eye tracking and neurobiological studies reviewed. Recommendations for future research in face recognition in ASD were discussed.

  6. Identification of antithrombotic drugs related to total joint replacement using anonymised free-text notes: a search strategy in the Clinical Practice Research Datalink.

    Science.gov (United States)

    Nielen, Johannes Th; van den Bemt, Bart J F; Boonen, Annelies; Dagnelie, Pieter C; Emans, Pieter J; Veldhorst, Nicole; Lalmohamed, Arief; van Staa, Tjeerd-Pieter; de Vries, Frank

    2015-11-30

    We aimed to design and test a method to extract information on antithrombotic therapy from anonymised free-text notes in the Clinical Practice Research Datalink (CPRD). General practice database representative of the UK. All patients undergoing total hip replacement (THR, n=25,898) or total knee replacement (TKR, n=22,231) between January 2008 and October 2012 were included. Antithrombotic drug use related to THR or TKR was identified using anonymised free text and prescription data. Internal validity of our newly designed method was determined by calculating positive predictive values (PPVs) of hits for predefined keywords in a random sample of anonymised free-text notes. In order to determine potential detection bias, total joint replacement (TJR) patient characteristics were compared as per their status of exposure to antithrombotics. PPVs ranging between 97% and 99% for new oral anticoagulants (NOAC) or low-molecular weight heparins (LMWH) exposure related to TJR were obtained with our method. Our search strategy increased detection rates by 57%, yielding a total proportion of 18.5% of all THR and 18.6% of all TKR surgeries. Identified users of NOACs and LMWHs were largely similar with regards to age, sex, lifestyle, disease and drug history compared to patients without identified drug use. We have developed a useful method to identify additional exposure to NOACs or LMWHs with TJR surgery. 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/

  7. Randomized controlled trial comparing four strategies for delivering e-curriculum to health care professionals [ISRCTN88148532

    Directory of Open Access Journals (Sweden)

    Mitra Ananda

    2006-01-01

    Full Text Available Abstract Background Internet education is increasingly provided to health professionals, but little is known about the most effective strategies for delivering the content. The purpose of this study is to compare four strategies for delivering an Internet-based (e- curriculum on clinicians' knowledge (K, confidence (CONF, and communication (COMM about herbs and other dietary supplements (HDS. Methods This national randomized 2 × 2 factorial trial included physicians, pharmacists, nurses, nutritionists and trainees in these fields. Participants were randomly assigned to one of four curriculum delivery strategies for 40 brief modules about HDS: a delivering four (4 modules weekly over ten (10 weeks by email (drip-push; b modules accessible on web site with 4 reminders weekly for 10 weeks (drip-pull; c 40 modules delivered within 4 days by email (bolus-push; and d 40 modules available on the Internet with one email informing participants of availability (bolus-pull. Results Of the 1,267 enrollees, 25% were male; the average age was 40 years. The completion rate was 62%, without significant differences between delivery groups. There were statistically significant improvements in K, CONF and COMM scores after the course (P Conclusion All delivery strategies tested similarly improved K, CONF, COMM scores about HDS. Educators can use the strategy that is most convenient without diminishing effectiveness. Additional curricula may be necessary to make substantial changes in clinicians' communication practices.

  8. Lévy walks for autonomous search

    Science.gov (United States)

    Flenner, Arjuna; Flenner, Jennifer; Bobinchak, James; Mercier, David; Le, Anhtuan; Estabridis, Katia; Hewer, Gary

    2012-06-01

    A canonical problem for autonomy is search and discovery. Often, searching needs to be unpredictable in order to be effective. In this paper, we investigate and compare the effectiveness of the traditional and predictable lawnmower search strategy to that of a random search. Specifically the family of searches with paths determined by heavy tailed distributions called Lévy stable searches is investigated. These searches are characterized by long flight paths, followed by a new random direction, with the flight path lengths determined by the distribution parameter α. Two basic search scenarios are considered in this study: stationary targets, and moving targets, both on planar surfaces. Monte-Carlo simulations demonstrate the advantages of Lévy over the lawnmower strategy especially for moving targets. Ultimately to corroborate the suitability of the Lévy strategy for UAVs, we implement and demonstrate the feasibility of the algorithm in the Multiple Unified Simulation Environment (MUSE), which includes vehicle's constraints and dynamics. The MUSE / Air Force Synthetic Environment for Reconnaissance and Surveillance (AFSERS) simulation system is the primary virtual ISR and UAV simulation within DOD for command and staff level training for the Joint Services.

  9. Pictorial mnemonic-strategy interventions for children with special needs: Illustration of a multiply randomized single-case crossover design.

    Science.gov (United States)

    Hwang, Yooyeun; Levin, Joel R; Johnson, Evan W

    2016-01-25

    An innovative single-case crossover design containing multiple forms of randomization was implemented with eight participants in seven weekly sessions, during which instruction was given in the use of two different pictorial mnemonic (memory-enhancing) strategies: one designed to improve the children's learning of the dates of various inventions and the other designed to improve the children's acquisition of unfamiliar vocabulary items. A composite randomization statistical test revealed that when compared with the children's own preferred learning methods, the mnemonic-strategy approach produced the predicted facilitation effects. At the same time, it was evident that mnemonic instruction enhanced children's performance to a greater extent on the vocabulary task than on the inventions task. In-depth examination of both individual student performance profiles and the tasks/procedures were conducted, yielding recommendations and challenges for follow-up single-case intervention research on the topic.

  10. Optimizing Household Chlorination Marketing Strategies: A Randomized Controlled Trial on the Effect of Price and Promotion on Adoption in Haiti.

    Science.gov (United States)

    Ritter, Michael; Camille, Eveline; Velcine, Christophe; Guillaume, Rose-Kerline; Lantagne, Daniele

    2017-07-01

    Household water treatment can reduce diarrheal morbidity and mortality in developing countries, but adoption remains low and supply is often unreliable. To test effects of marketing strategies on consumers and suppliers, we randomized 1,798 households in rural Haiti and collected data on purchases of a household chlorination product for 4 months. Households received randomly selected prices ($0.11-$0.56 per chlorine bottle), and half received monthly visits from sales agents. Each $0.22 drop in price increased purchases by 0.10 bottles per household per month (P effective use of resources than household visits, though all marketing strategies tested offer cost-effective ways to achieve incremental health impact. Decisions about pricing and promotion for health products in developing countries affect health impact, cost recovery, and cost-effectiveness, and tradeoffs between these goals should be made explicit in program design.

  11. Study protocol: Couples Partnering for Lipid Enhancing Strategies (CouPLES – a randomized, controlled trial

    Directory of Open Access Journals (Sweden)

    Weinberger Morris

    2009-02-01

    Full Text Available Abstract Background Almost 50% of Americans have elevated low-density lipoprotein cholesterol (LDL-C. The behaviors required to lower LDL-C levels may be difficult to adhere to if they are inconsistent with spouses' health practices, and, alternatively, may be enhanced by enlisting support from the spouse. This trial extends previous trials by requiring spouse enrollment, teaching spouses how to provide emotional and instrumental support, allowing patients to decide which component of the intervention they would like to receive, and having patients determine their own goals and action plans. Methods Veteran outpatients with above-goal LDL-C (N = 250 and their spouses are randomized, as a couple, to receive printed education materials only or the materials plus an 11-month, nurse-delivered, telephone-based intervention. The intervention contains four modules: medication adherence, diet, exercise, and patient-physician communication. Patients decide which modules they complete and in which order; modules may be repeated or omitted. Telephone calls are to patients and spouses separately and occur monthly. During each patient telephone call, patients' progress is reviewed, and patients create goals and action plans for the upcoming month. During spouse telephone calls, which occur within one week of patient calls, spouses are informed of patients' goals and action plans and devise strategies to increase emotional and instrumental support. The primary outcome is patients' LDL-C, measured at baseline, 6 months, and 11 months. Linear mixed models will be used to test the primary hypothesis that an 11-month, telephone-based patient-spouse intervention will result in a greater reduction in LDL-C as compared to printed education materials. Various process measures, including social support, self-efficacy, medication adherence, dietary behavior, and exercise, are also assessed to explain any change, or lack thereof, in LDL-C. Discussion Given the social

  12. A Randomized Trial Examining Three Strategies for Supporting Health Insurance Decisions among the Uninsured.

    Science.gov (United States)

    Politi, Mary C; Kaphingst, Kimberly A; Liu, Jingxia Esther; Perkins, Hannah; Furtado, Karishma; Kreuter, Matthew W; Shacham, Enbal; McBride, Timothy

    2016-10-01

    The Affordable Care Act allows uninsured individuals to select health insurance from numerous private plans, a challenging decision-making process. This study examined the effectiveness of strategies to support health insurance decisions among the uninsured. Participants (N = 343) from urban, suburban, and rural areas were randomized to 1 of 3 conditions: 1) a plain language table; 2) a visual condition where participants chose what information to view and in what order; and 3) a narrative condition. We administered measures assessing knowledge (true/false responses about key features of health insurance), confidence in choices (uncertainty subscale of the Decisional Conflict Scale), satisfaction (items from the Health Information National Trends Survey), preferences for insurance features (measured on a Likert scale from not at all important to very important), and plan choice. Although we did not find significant differences in knowledge, confidence in choice, or satisfaction across condition, participants across conditions made value-consistent choices, selecting plans that aligned with their preferences for key insurance features. In addition, those with adequate health literacy skills as measured by the Rapid Estimate of Adult Literacy in Medicine-Short Form (REALM-SF) had higher knowledge overall ([Formula: see text] = 6.1 v. 4.8, P < 0.001) and preferred the plain language table to the visual (P = 0.04) and visual to narrative (P = 0.0002) conditions, while those with inadequate health literacy skills showed no preference for study condition. A similar pattern was seen for those with higher subjective numeracy skills and higher versus lower education with regard to health insurance knowledge. Individuals with higher income felt less confident in their choices ([Formula: see text] = 28.7 v. 10.0, where higher numbers indicate less confidence/more uncertainty; P = 0.004). Those developing materials about the health insurance marketplace to support health

  13. A mild ovarian stimulation strategy in women with poor ovarian reserve undergoing IVF: a multicenter randomized non-inferiority trial.

    Science.gov (United States)

    Youssef, M A; van Wely, M; Al-Inany, H; Madani, T; Jahangiri, N; Khodabakhshi, S; Alhalabi, M; Akhondi, M; Ansaripour, S; Tokhmechy, R; Zarandi, L; Rizk, A; El-Mohamedy, M; Shaeer, E; Khattab, M; Mochtar, M H; van der Veen, F

    2017-01-01

    In subfertile women with poor ovarian reserve undergoing IVF does a mild ovarian stimulation strategy lead to comparable ongoing pregnancy rates in comparison to a conventional ovarian stimulation strategy? A mild ovarian stimulation strategy in women with poor ovarian reserve undergoing IVF leads to similar ongoing pregnancy rates as a conventional ovarian stimulation strategy. Women diagnosed with poor ovarian reserve are treated with a conventional ovarian stimulation strategy consisting of high-dose gonadotropins and pituitary downregulation with a long mid-luteal start GnRH-agonist protocol. Previous studies comparing a conventional strategy with a mild ovarian stimulation strategy consisting of low-dose gonadotropins and pituitary downregulation with a GnRH-antagonist have been under powered and their effectiveness is inconclusive. This open label multicenter randomized trial was designed to compare one cycle of a mild ovarian stimulation strategy consisting of low-dose gonadotropins (150 IU FSH) and pituitary downregulation with a GnRH-antagonist to one cycle of a conventional ovarian stimulation strategy consisting of high-dose gonadotropins (450 IU HMG) and pituitary downregulation with a long mid-luteal GnRH-agonist in women of advanced maternal age and/or women with poor ovarian reserve undergoing IVF between May 2011 and April 2014. Couples seeking infertility treatment were eligible if they fulfilled the following inclusion criteria: female age ≥35 years, a raised basal FSH level >10 IU/ml irrespective of age, a low antral follicular count of ≤5 follicles or poor ovarian response or cycle cancellation during a previous IVF cycle irrespective of age. The primary outcome was ongoing pregnancy rate per woman randomized. Analyses were on an intention-to-treat basis. We randomly assigned 195 women to the mild ovarian stimulation strategy and 199 women to the conventional ovarian stimulation strategy. Ongoing pregnancy rate was 12.8% (25/195) for mild

  14. Different strategies for mechanical VENTilation during CardioPulmonary Bypass (CPBVENT 2014): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Bignami, Elena; Guarnieri, Marcello; Saglietti, Francesco; Maglioni, Enivarco Massimo; Scolletta, Sabino; Romagnoli, Stefano; De Paulis, Stefano; Paternoster, Gianluca; Trumello, Cinzia; Meroni, Roberta; Scognamiglio, Antonio; Budillon, Alessandro Maria; Pota, Vincenzo; Zangrillo, Alberto; Alfieri, Ottavio

    2017-06-07

    There is no consensus on which lung-protective strategies should be used in cardiac surgery patients. Sparse and small randomized clinical and animal trials suggest that maintaining mechanical ventilation during cardiopulmonary bypass is protective on the lungs. Unfortunately, such evidence is weak as it comes from surrogate and minor clinical endpoints mainly limited to elective coronary surgery. According to the available data in the academic literature, an unquestionable standardized strategy of lung protection during cardiopulmonary bypass cannot be recommended. The purpose of the CPBVENT study is to investigate the effectiveness of different strategies of mechanical ventilation during cardiopulmonary bypass on postoperative pulmonary function and complications. The CPBVENT study is a single-blind, multicenter, randomized controlled trial. We are going to enroll 870 patients undergoing elective cardiac surgery with planned use of cardiopulmonary bypass. Patients will be randomized into three groups: (1) no mechanical ventilation during cardiopulmonary bypass, (2) continuous positive airway pressure of 5 cmH2O during cardiopulmonary bypass, (3) respiratory rate of 5 acts/min with a tidal volume of 2-3 ml/Kg of ideal body weight and positive end-expiratory pressure of 3-5 cmH2O during cardiopulmonary bypass. The primary endpoint will be the incidence of a PaO2/FiO2 ratio bypass will have an impact on postoperative pulmonary complications and outcomes of patients undergoing cardiac surgery. ClinicalTrials.gov, ID: NCT02090205 . Registered on 8 March 2014.

  15. Improvement of sampling strategies for randomly distributed hotspots in soil applying a computerized simulation considering the concept of uncertainty.

    Science.gov (United States)

    Hildebrandt, Thomas; Pick, Denis; Einax, Jürgen W

    2012-02-01

    The pollution of soil and environment as a result of human activity is a major problem. Nowadays, the determination of local contaminations is of interest for environmental remediation. These hotspots can have various toxic effects on plants, animals, humans, and the whole ecological system. However, economical and juridical consequences are also possible, e.g., high costs for remediation measures. In this study three sampling strategies (simple random sampling, stratified sampling, and systematic sampling) were applied on randomly distributed hotspot contaminations to prove their efficiency in term of finding hotspots. The results were used for the validation of a computerized simulation. This application can simulate the contamination on a field, the sampling pattern, and a virtual sampling. A constant hit rate showed that none of the sampling patterns could reach better results than others. Furthermore, the uncertainty associated with the results is described by confidence intervals. It is to be considered that the uncertainty during sampling is enormous and will decrease slightly, even the number of samples applied was increased to an unreasonable amount. It is hardly possible to identify the exact number of randomly distributed hotspot contaminations by statistical sampling. But a range of possible results could be calculated. Depending on various parameters such as shape and size of the area, number of hotspots, and sample quantity, optimal sampling strategies could be derived. Furthermore, an estimation of bias arising from sampling methodology is possible. The developed computerized simulation is an innovative tool for optimizing sampling strategies in terrestrial compartments for hotspot distributions.

  16. Strategies to Reduce Injuries and Develop Confidence in Elders (STRIDE): A Cluster-Randomized Pragmatic Trial of a Multifactorial Fall Injury Prevention Strategy: Design and Methods.

    Science.gov (United States)

    Bhasin, Shalender; Gill, Thomas M; Reuben, David B; Latham, Nancy K; Gurwitz, Jerry H; Dykes, Patricia; McMahon, Siobhan; Storer, Thomas W; Duncan, Pamela W; Ganz, David A; Basaria, Shehzad; Miller, Michael E; Travison, Thomas G; Greene, Erich J; Dziura, James; Esserman, Denise; Allore, Heather; Carnie, Martha B; Fagan, Maureen; Hanson, Catherine; Baker, Dorothy; Greenspan, Susan L; Alexander, Neil; Ko, Fred; Siu, Albert L; Volpi, Elena; Wu, Albert W; Rich, Jeremy; Waring, Stephen C; Wallace, Robert; Casteel, Carri; Magaziner, Jay; Charpentier, Peter; Lu, Charles; Araujo, Katy; Rajeevan, Haseena; Margolis, Scott; Eder, Richard; McGloin, Joanne M; Skokos, Eleni; Wiggins, Jocelyn; Garber, Lawrence; Clauser, Steven B; Correa-De-Araujo, Rosaly; Peduzzi, Peter

    2017-10-14

    Fall injuries are a major cause of morbidity and mortality among older adults. We describe the design of a pragmatic trial to compare the effectiveness of an evidence-based, patient-centered multifactorial fall injury prevention strategy to an enhanced usual care. Strategies to Reduce Injuries and Develop Confidence in Elders (STRIDE) is a 40-month cluster-randomized, parallel-group, superiority, pragmatic trial being conducted at 86 primary care practices in 10 healthcare systems across USA. The 86 practices were randomized to intervention or control group using covariate-based constrained randomization, stratified by healthcare system. Participants are community-living persons, ≥70 years, at increased risk for serious fall injuries. The intervention is a co-management model in which a nurse Falls Care Manager performs multifactorial risk assessments, develops individualized care plans, which include surveillance, follow-up evaluation, and intervention strategies. Control group receives enhanced usual care, with clinicians and patients receiving evidence-based information on falls prevention. Primary outcome is serious fall injuries, operationalized as those leading to medical attention (non-vertebral fractures, joint dislocation, head injury, lacerations, and other major sequelae). Secondary outcomes include all fall injuries, all falls, and well-being (concern for falling; anxiety and depressive symptoms; physical function and disability). Target sample size was 5,322 participants to provide 90% power to detect 20% reduction in primary outcome rate relative to control. Trial enrolled 5451 subjects in 20 months. Intervention and follow-up are ongoing. The findings of the STRIDE study will have important clinical and policy implications for the prevention of fall injuries in older adults.

  17. A Cluster-Randomized Trial of Two Strategies to Improve Antibiotic Use for Patients with a Complicated Urinary Tract Infection.

    Science.gov (United States)

    Spoorenberg, Veroniek; Hulscher, Marlies E J L; Geskus, Ronald B; de Reijke, Theo M; Opmeer, Brent C; Prins, Jan M; Geerlings, Suzanne E

    2015-01-01

    Up to 50% of hospital antibiotic use is inappropriate and therefore improvement strategies are urgently needed. We compared the effectiveness of two strategies to improve the quality of antibiotic use in patients with a complicated urinary tract infection (UTI). In a multicentre, cluster-randomized trial 19 Dutch hospitals (departments Internal Medicine and Urology) were allocated to either a multi-faceted strategy including feedback, educational sessions, reminders and additional/optional improvement actions, or a competitive feedback strategy, i.e. providing professionals with non-anonymous comparative feedback on the department's appropriateness of antibiotic use. Retrospective baseline- and post-intervention measurements were performed in 2009 and 2012 in 50 patients per department, resulting in 1,964 and 2,027 patients respectively. Principal outcome measures were nine validated guideline-based quality indicators (QIs) that define appropriate antibiotic use in patients with a complicated UTI, and a QI sumscore that summarizes for each patient the appropriateness of antibiotic use. Performance scores on several individual QIs showed improvement from baseline to post-intervention measurements, but no significant differences were found between both strategies. The mean patient's QI sum score improved significantly in both strategy groups (multi-faceted: 61.7% to 65.0%, P = 0.04 and competitive feedback: 62.8% to 66.7%, P = 0.01). Compliance with the strategies was suboptimal, but better compliance was associated with more improvement. The effectiveness of both strategies was comparable and better compliance with the strategies was associated with more improvement. To increase effectiveness, improvement activities should be rigorously applied, preferably by a locally initiated multidisciplinary team. Nederlands Trial Register 1742.

  18. A Cluster-Randomized Trial of Two Strategies to Improve Antibiotic Use for Patients with a Complicated Urinary Tract Infection.

    Directory of Open Access Journals (Sweden)

    Veroniek Spoorenberg

    Full Text Available Up to 50% of hospital antibiotic use is inappropriate and therefore improvement strategies are urgently needed. We compared the effectiveness of two strategies to improve the quality of antibiotic use in patients with a complicated urinary tract infection (UTI.In a multicentre, cluster-randomized trial 19 Dutch hospitals (departments Internal Medicine and Urology were allocated to either a multi-faceted strategy including feedback, educational sessions, reminders and additional/optional improvement actions, or a competitive feedback strategy, i.e. providing professionals with non-anonymous comparative feedback on the department's appropriateness of antibiotic use. Retrospective baseline- and post-intervention measurements were performed in 2009 and 2012 in 50 patients per department, resulting in 1,964 and 2,027 patients respectively. Principal outcome measures were nine validated guideline-based quality indicators (QIs that define appropriate antibiotic use in patients with a complicated UTI, and a QI sumscore that summarizes for each patient the appropriateness of antibiotic use.Performance scores on several individual QIs showed improvement from baseline to post-intervention measurements, but no significant differences were found between both strategies. The mean patient's QI sum score improved significantly in both strategy groups (multi-faceted: 61.7% to 65.0%, P = 0.04 and competitive feedback: 62.8% to 66.7%, P = 0.01. Compliance with the strategies was suboptimal, but better compliance was associated with more improvement.The effectiveness of both strategies was comparable and better compliance with the strategies was associated with more improvement. To increase effectiveness, improvement activities should be rigorously applied, preferably by a locally initiated multidisciplinary team.Nederlands Trial Register 1742.

  19. A Fuzzy-Logic Power Management Strategy Based on Markov Random Prediction for Hybrid Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Yanzi Wang

    2016-01-01

    Full Text Available Over the last few years; issues regarding the use of hybrid energy storage systems (HESSs in hybrid electric vehicles have been highlighted by the industry and in academic fields. This paper proposes a fuzzy-logic power management strategy based on Markov random prediction for an active parallel battery-UC HESS. The proposed power management strategy; the inputs for which are the vehicle speed; the current electric power demand and the predicted electric power demand; is used to distribute the electrical power between the battery bank and the UC bank. In this way; the battery bank power is limited to a certain range; and the peak and average charge/discharge power of the battery bank and overall loss incurred by the whole HESS are also reduced. Simulations and scaled-down experimental platforms are constructed to verify the proposed power management strategy. The simulations and experimental results demonstrate the advantages; feasibility and effectiveness of the fuzzy-logic power management strategy based on Markov random prediction.

  20. Principles and strategies for monitoring data collection integrity in a multi-site randomized clinical trial of a behavioral intervention.

    Science.gov (United States)

    Phillips-Salimi, Celeste R; Donovan Stickler, Molly A; Stegenga, Kristin; Lee, Melissa; Haase, Joan E

    2011-08-01

    Although treatment fidelity strategies for enhancing the integrity of behavioral interventions have been well described, little has been written about monitoring data collection integrity. This article describes the principles and strategies developed to monitor data collection integrity of the "Stories and Music for Adolescent/Young Adult Resilience During Transplant" study (R01NR008583, U10CA098543, and U10CA095861)-a multi-site Children's Oncology Group randomized clinical trial of a music therapy intervention for adolescents and young adults undergoing stem cell transplant. The principles and strategies outlined in this article provide one model for development and evaluation of a data collection integrity monitoring plan for behavioral interventions that may be adapted by investigators and may be useful to funding agencies and grant application reviewers in evaluating proposals. Copyright © 2011 Wiley Periodicals, Inc.

  1. Search predicts and changes patience in intertemporal choice.

    Science.gov (United States)

    Reeck, Crystal; Wall, Daniel; Johnson, Eric J

    2017-11-07

    Intertemporal choice impacts many important outcomes, such as decisions about health, education, wealth, and the environment. However, the psychological processes underlying decisions involving outcomes at different points in time remain unclear, limiting opportunities to intervene and improve people's patience. This research examines information-search strategies used during intertemporal choice and their impact on decisions. In experiment 1, we demonstrate that search strategies vary substantially across individuals. We subsequently identify two distinct search strategies across individuals. Comparative searchers, who compare features across options, discount future options less and are more susceptible to acceleration versus delay framing than integrative searchers, who integrate the features of an option. Experiment 2 manipulates search using an unobtrusive method to establish a causal relationship between strategy and choice, randomly assigning participants to conditions promoting either comparative or integrative search. Again, comparative search promotes greater patience than integrative search. Additionally, when participants adopt a comparative search strategy, they also exhibit greater effects of acceleration versus delay framing. Although most participants reported that the manipulation did not change their behavior, promoting comparative search decreased discounting of future rewards substantially and speeded patient choices. These findings highlight the central role that heterogeneity in psychological processes plays in shaping intertemporal choice. Importantly, these results indicate that theories that ignore variability in search strategies may be inadvertently aggregating over different subpopulations that use very different processes. The findings also inform interventions in choice architecture to increase patience and improve consumer welfare. Copyright © 2017 the Author(s). Published by PNAS.

  2. Permissive Hypotension vs. Conventional Resuscitation Strategies in Adult Trauma Patients with Hemorrhagic Shock: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

    Science.gov (United States)

    Tran, Alexandre; Yates, Jeffrey; Lau, Aaron; Lampron, Jacinthe; Matar, Maher

    2018-01-24

    Aggressive fluid resuscitation in trauma promotes deleterious effects such as clot disruption, dilutional coagulopathy and hypothermia. Animal studies suggest that permissive hypotension maintains appropriate organ perfusion, reduces bleeding and improves mortality. This review assesses the efficacy and safety of permissive hypotension in adult trauma patients with hemorrhagic shock. We searched the MEDLINE and EMBASE databases from inception to May 2017 for randomized controlled trials comparing permissive hypotension vs. conventional resuscitation following traumatic injury. We included pre-operative and intraoperative resuscitation strategies. The primary outcome was 30-day or in-hospital mortality. Secondary outcomes included blood product utilization, estimated blood loss and in-hospital complications. Pooling was performed with a random-effects model. We screened 722 abstracts, from which five randomized trials evaluating 1158 patients were included. Blood pressure targets in the intervention arms varied from systolic BP 50 - 70 mmHg or MAP ≥ 50 mmHg as compared to systolic BP 65 - 100 mmHg or MAP ≥ 65 in the control arms. Two studies evaluated only patients with penetrating injury while the remaining three additionally included blunt injuries. Four trials suggested a survival benefit for 30-day or in-hospital mortality with hypotensive resuscitation, although three studies were insufficiently powered to find statistical significance. Studies were of poor to moderate quality due to poor protocol reporting and lack of blinding. The pooled odds ratio was 0.70 (95% CI 0.53 to 0.92), suggesting a survival benefit for permissive hypotension. Those patients received fewer blood products and had lesser estimated blood loss. Permissive hypotension may offer a survival benefit over conventional resuscitation for patients with hemorrhagic injury. It may additionally reduce blood loss and blood product utilization. However, the majority of studies were underpowered

  3. A new combined strategy to implement a community occupational therapy intervention: designing a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Adang Eddy

    2011-03-01

    Full Text Available Abstract Background Even effective interventions for people with dementia and their caregivers require specific implementation efforts. A pilot study showed that the highly effective community occupational therapy in dementia (COTiD program was not implemented optimally due to various barriers. To decrease these barriers and make implementation of the program more effective a combined implementation (CI strategy was developed. In our study we will compare the effectiveness of this CI strategy with the usual educational (ED strategy. Methods In this cluster randomized, single-blinded, controlled trial, each cluster consists of at least two occupational therapists, a manager, and a physician working at Dutch healthcare organizations that deliver community occupational therapy. Forty-five clusters, stratified by healthcare setting (nursing home, hospital, mental health service, have been allocated randomly to either the intervention group (CI strategy or the control group (ED strategy. The study population consists of the professionals included in each cluster and community-dwelling people with dementia and their caregivers. The primary outcome measures are the use of community OT, the adherence of OTs to the COTiD program, and the cost effectiveness of implementing the COTiD program in outpatient care. Secondary outcome measures are patient and caregiver outcomes and knowledge of managers, physicians and OTs about the COTiD program. Discussion Implementation research is fairly new in the field of occupational therapy, making this a unique study. This study does not only evaluate the effects of the CI-strategy on professionals, but also the effects of professionals' degree of implementation on client and caregiver outcomes. Clinical trials registration NCT01117285

  4. Comparing Two Story-Writing Mnemonic Strategies: A Randomized Control Trial Study

    Science.gov (United States)

    Dunn, Michael

    2013-01-01

    Educators often use mnemonic strategies as a prime method to help children who struggle with writing. This study analyzed 12 fourth-grade students' stories during their participation in one of three groups. The first group learned the Ask, Reflect, Text (ART) mnemonic strategy with art media in the pre-writing/planning phase. The second group used…

  5. A randomized trial of an intervention to improve use and adherence to effective coronary heart disease prevention strategies

    Directory of Open Access Journals (Sweden)

    Sheridan Stacey L

    2011-12-01

    Full Text Available Abstract Background Efficacious strategies for the primary prevention of coronary heart disease (CHD are underused, and, when used, have low adherence. Existing efforts to improve use and adherence to these efficacious strategies have been so intensive that they are impractical for clinical practice. Methods We conducted a randomized trial of a CHD prevention intervention (including a computerized decision aid and automated tailored adherence messages at one university general internal medicine practice. After obtaining informed consent and collecting baseline data, we randomized patients (men and women age 40-79 with no prior history of cardiovascular disease to either the intervention or usual care. We then saw them for two additional study visits over 3 months. For intervention participants, we administered the decision aid at the primary study visit (1 week after baseline visit and then mailed 3 tailored adherence reminders at 2, 4, and 6 weeks. We assessed our outcomes (including the predicted likelihood of angina, myocardial infarction, and CHD death over 10 years (CHD risk and self-reported adherence between groups at 3 month follow-up. Data collection occurred from June 2007 through December 2009. All study procedures were IRB approved. Results We randomized 160 eligible patients (81 intervention; 79 control and followed 96% to study conclusion. Mean predicted CHD risk at baseline was 11.3%. The intervention increased self-reported adherence to chosen risk reducing strategies by 25 percentage points (95% CI 8% to 42%, with the biggest effect for aspirin. It also changed predicted CHD risk by -1.1% (95% CI -0.16% to -2%, with a larger effect in a pre-specified subgroup of high risk patients. Conclusion A computerized intervention that involves patients in CHD decision making and supports adherence to effective prevention strategies can improve adherence and reduce predicted CHD risk. Clinical trials registration number Clinical

  6. Strategies to Make Ramadan Fasting Safer in Type 2 Diabetics: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials and Observational Studies.

    Science.gov (United States)

    Lee, Shaun Wen Huey; Lee, Jun Yang; Tan, Christina San San; Wong, Chee Piau

    2016-01-01

    Ramadan is the holy month for Muslims whereby they fast from predawn to after sunset and is observed by all healthy Muslim adults as well as a large population of type 2 diabetic Muslims.To determine the comparative effectiveness of various strategies that have been used for type 2 diabetic Muslim who fast during Ramadan.A systematic review and network meta-analysis of randomized controlled studies (RCT) as well as observational studies for patients with type 2 diabetes who fasted during Ramadan was conducted. Eight databases were searched from January 1980 through October 2015 for relevant studies. Two reviewers independently screened and assessed study for eligibility, assessed the risk of bias, and extracted relevant data. A network meta-analysis for each outcome was fitted separately, combining direct and indirect evidence for each comparison.Twenty-nine studies, 16 RCTs and 13 observational studies each met the inclusion criteria. The most common strategy used was drug changes during the Ramadan period, which found that the use of DPP-4 (Dipeptidyl peptidase inhibitor -4) inhibitors were associated with a reduction in incidence of experiencing hypoglycemia during Ramadan in both RCTs (pooled relative risk: 0.56; 95% confidence interval: 0.44-0.72) as well as in observational studies (pooled relative risk: 0.27; 0.09-0.75). Ramadan-focused education was shown to be beneficial in reducing hypoglycemia in observational studies but not RCTs (0.25 versus 1.00). Network meta-analyses suggest that incretin mimetics can reduce the risk of hypoglycemia by nearly 1.5 times.The newer antidiabetic agents appear to lower the risk of hypoglycemia and improved glycemic control when compared with sulfonylureas. Ramadan-focused education shows to be a promising strategy but more rigorous examination from RCTs are required.

  7. The variability of male quality and female mate choice decisions: second-order stochastic dominance and the behavior of searchers under a sequential search strategy.

    Science.gov (United States)

    Seubert, Steven M; Wade, Gordon A; Wiegmann, Daniel D

    2011-12-01

    The strategy employed by a female to sample prospective mates determines the likelihood that a high-quality male is encountered in the search process. In general, the choosiness of females is expected to depend on the variability of quality amongst the males that are sampled. The sequential search strategy is a prominent model of search behavior that involves the use of a threshold criterion to evaluate encountered individuals. In this paper, we show that the stochastic dominance of one distribution of male quality over another at the second order is necessary and sufficient for the optimal threshold criterion to differ under two distributions of male quality when the cost to sample males is held constant and the mean quality of males under each of the distributions is identical. A difference of the variance of male quality between two distributions does not imply that one distribution stochastically dominates the other at the second order and, hence, should not, in general, be used to assess the relative variability of quality amongst prospective mates. The adjustment of the threshold criterion in response to experimental manipulations of the distribution of male quality has been inferred from induced differences of the duration of search or the number of males sampled in the search process. Here we show that such inferences are unjustified. In particular, the difference of the threshold criterion imposed by second-order stochastic dominance does not determine the distribution under which females are expected to sample a larger number of males in the search process. © Springer-Verlag 2011

  8. A new strategy for complete identification of sea buckthorn cultivars by using random amplified polymorphic DNA markers.

    Science.gov (United States)

    Yang, G; Ding, J; Wu, L R; Duan, Y D; Li, A Y; Shan, J Y; Wu, Y X

    2015-03-13

    DNA fingerprinting is both a popular and important technique with several advantages in plant cultivar identification. However, this technique has not been used widely and efficiently in practical plant identification because the analysis and recording of data generated from fingerprinting and genotyping are tedious and difficult. We developed a novel approach known as a cultivar identification diagram (CID) strategy that uses DNA markers to separate plant individuals in a more efficient, practical, and referable manner. A CID was manually constructed and a polymorphic marker was generated from each polymerase chain reaction for sample separation. In this study, 67 important sea buckthorn cultivars cultivated in China were successfully separated with random amplified polymorphic DNA markers using the CID analysis strategy, with only seven 11-nucleotide primers employed. The utilization of the CID of these 67 sea buckthorn cultivars was verified by identifying 2 randomly chosen groups of cultivars among the 67 cultivars. The main advantages of this identification strategy include fewer primers used and separation of all cultivars using the corresponding primers. This sea buckthorn CID was able to separate any sea buckthorn cultivars among the 67 studied, which is useful for sea buckthorn cultivar identification, cultivar-right-protection, and for the sea buckthorn nursery industry in China.

  9. Assessment of strategies for switching patients from olanzapine to risperidone: A randomized, open-label, rater-blinded study

    Directory of Open Access Journals (Sweden)

    Berry Sally A

    2008-06-01

    Full Text Available Abstract Background In clinical practice, physicians often need to change the antipsychotic medications they give to patients because of an inadequate response or the presence of unacceptable or unsafe side effects. However, there is a lack of consensus in the field as to the optimal switching strategy for antipsychotics, especially with regards to the speed at which the dose of the previous antipsychotic should be reduced. This paper assesses the short-term results of strategies for the discontinuation of olanzapine when initiating risperidone. Methods In a 6-week, randomized, open-label, rater-blinded study, patients with schizophrenia or schizoaffective disorder, on a stable drug dose for more than 30 days at entry, who were intolerant of or exhibiting a suboptimal symptom response to more than 30 days of olanzapine treatment, were randomly assigned to the following switch strategies (common risperidone initiation scheme; varying olanzapine discontinuation: (i abrupt strategy, where olanzapine was discontinued at risperidone initiation; (ii gradual 1 strategy, where olanzapine was given at 50% entry dose for 1 week after risperidone initiation and then discontinued; or (iii gradual 2 strategy, where olanzapine was given at 100% entry dose for 1 week, then at 50% in the second week, and then discontinued. Results The study enrolled 123 patients on stable doses of olanzapine. Their mean age was 40.3 years and mean (± standard deviation (SD baseline Positive and Negative Syndrome Scale (PANSS total score of 75.6 ± 11.5. All-cause treatment discontinuation was lowest (12% in the group with the slowest olanzapine dose reduction (gradual 2 and occurred at half the discontinuation rate in the other two groups (25% in abrupt and 28% in gradual 1. The relative risk of early discontinuation was 0.77 (confidence interval 0.61–0.99 for the slowest dose reduction compared with the other two strategies. After the medication was changed, improvements at

  10. A cognitive strategy instruction to improve math calculation for children with ADHD and LD: a randomized controlled study.

    Science.gov (United States)

    Iseman, Jackie S; Naglieri, Jack A

    2011-01-01

    The authors examined the effectiveness of cognitive strategy instruction based on PASS (Planning, Attention, Simultaneous, Successive) given by special education teachers to students with ADHD randomly assigned by classroom. Students in the experimental group were exposed to a brief cognitive strategy instruction for 10 days, which was designed to encourage development and application of effective planning for mathematical computation, whereas the comparison group received-standard math instruction. Standardized tests of cognitive processes and math achievement were given at pretest. All students completed math worksheets throughout the experimental phase. Standardized achievement tests (Woodcock-Johnson Tests of Achievement, Third Edition, Math Fluency and Wechsler Individualized Achievement Test, Second Edition, Numerical Operations) were administered pre- and postintervention, and Math Fluency was also administered at 1 year follow-up. Large pre-post effect sizes were found for students in the experimental group but not the comparison group on math worksheets (0.85 and 0.26), Math Fluency (1.17 and 0.09), and Numerical Operations (0.40 and -0.14, respectively). At 1 year follow-up, the experimental group continued to outperform the comparison group. These findings suggest that students with ADHD evidenced greater improvement in math worksheets, far transfer to standardized tests of math (which measured the skill of generalizing learned strategies to other similar tasks), and continued advantage 1 year later when provided the PASS-based cognitive strategy instruction.

  11. Postoperative blood transfusion strategy in frail, anemic elderly patients with hip fracture: the TRIFE randomized controlled trial.

    Science.gov (United States)

    Gregersen, Merete; Borris, Lars C; Damsgaard, Else Marie

    2015-06-01

    Hip fracture (HF) in frail elderly patients is associated with poor physical recovery and death. There is often postoperative blood loss and the hemoglobin (Hb) threshold for red blood cell (RBC) transfusions in these patients is unknown. We investigated whether RBC transfusion strategies were associated with the degree of physical recovery or with reduced mortality after HF surgery. We enrolled 284 consecutive post-surgical HF patients (aged ≥ 65 years) with Hb levels nursing homes or sheltered housing. Allocation was stratified by residence. The patients were randomly assigned to either restrictive (Hb nursing home residents in the restrictive transfusion group (36%) than for those in the liberal group (20%) (HR = 2.0, 95% CI: 1.1-3.6; p = 0.01). According to our Hb thresholds, recovery from physical disabilities in frail elderly hip fracture patients was similar after a restrictive RBC transfusion strategy and after a liberal strategy. Implementation of a liberal RBC transfusion strategy in nursing home residents has the potential to increase survival.

  12. Pioneering Strategies for Relieving Dental Anxiety in Hearing Impaired Children: a Randomized Controlled Clinical Study

    OpenAIRE

    Shalini Chandrasekhar; Ghanashyam Prasad Madu; Naga Radhakrishna Ambati; Pavani Reddy Suravarapu; Kalyani Uppu; Deepthi Bolla

    2017-01-01

    Statement of the Problem: Hearing impaired children have a problem in understanding and comprehending with dental treatments. Visual language is the sensible answer of how to improve communication with them. Purpose: To evaluate the applicability of dental sign language in Hearing impaired children in relieving anxiety during stressful dental treatment by improving their means of communication. Materials and Method: This randomized clinical trial was carried out in the Department of Ped...

  13. A supersymmetry search strategy with single-lepton events at 13 TeV by the CMS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lobanov, Artur; Seitz, Claudia; Melzer-Pellmann, Isabell; Singh, Akshansh [DESY, Hamburg (Germany)

    2016-07-01

    We present an inclusive search for supersymmetry in the single-lepton channel with 13 TeV. To optimise the sensitivity to various new-physics topologies, we search in several exclusive categories which differ in the number of jets and b-tagged jets. We determine the background from data, exploiting the fact that the main background is located at small values of the azimuthal angle between the W-boson candidate and the charged lepton. To be less dependent on the new-physics scale, we also introduce separate search categories based on the scalar sum of the jet transverse momenta and on the scalar sum of the transverse missing momentum and the transverse momentum of the lepton. Depending on the signal model, the signals regions have varying sensitivity. Here we concentrate on gluino-gluino production, where the pair-produced gluinos decay to a top-antitop pair and the lightest neutralino.

  14. Human Proteomic Variation Revealed by Combining RNA-Seq Proteogenomics and Global Post-Translational Modification (G-PTM) Search Strategy.

    Science.gov (United States)

    Cesnik, Anthony J; Shortreed, Michael R; Sheynkman, Gloria M; Frey, Brian L; Smith, Lloyd M

    2016-03-04

    Mass-spectrometry-based proteomic analysis underestimates proteomic variation due to the absence of variant peptides and posttranslational modifications (PTMs) from standard protein databases. Each individual carries thousands of missense mutations that lead to single amino acid variants, but these are missed because they are absent from generic proteomic search databases. Myriad types of protein PTMs play essential roles in biological processes but remain undetected because of increased false discovery rates in variable modification searches. We address these two fundamental shortcomings of bottom-up proteomics with two recently developed software tools. The first consists of workflows in Galaxy that mine RNA sequencing data to generate sample-specific databases containing variant peptides and products of alternative splicing events. The second tool applies a new strategy that alters the variable modification approach to consider only curated PTMs at specific positions, thereby avoiding the combinatorial explosion that traditionally leads to high false discovery rates. Using RNA-sequencing-derived databases with this Global Post-Translational Modification (G-PTM) search strategy revealed hundreds of single amino acid variant peptides, tens of novel splice junction peptides, and several hundred posttranslationally modified peptides in each of ten human cell lines.

  15. Recruitment of lactating women into a randomized dietary intervention: successful strategies and factors promoting enrollment and retention.

    Science.gov (United States)

    Stendell-Hollis, Nicole R; Laudermilk, Monica J; West, Julie L; Thompson, Patricia A; Thomson, Cynthia A

    2011-07-01

    Recruitment and retention of lactating women require unique strategies to prevent high attrition. The purpose of this report is to identify successful recruitment strategies and evaluate demographic and lifestyle characteristics associated with study completion. A randomized, controlled trial was initiated to test the hypothesis that lactating women adhering to a Mediterranean diet will show a significant reduction in anthropometric measurements as compared to lactating women randomized to the USDA's MyPyramid diet for Pregnancy and Breastfeeding (control diet). Measurements were collected at baseline, 2 months, and 4 months. Recruitment methods and baseline characteristics of completers and non-completers are described. The largest percentage of women, 24.8%, were recruited from a local parenting magazine, 20.9% from Craig's List, 20.2% from local hospitals, and 34.1% from various other sources. At baseline, women (n = 129) were mostly Non-Hispanic (75.2%), average age 29.7 years, BMI averaged 27.2 kg/m(2), waist:hip ratio 0.84 cm (SD: 0.07), and body fat averaged 30.8%. Approximately 72% were exclusively breastfeeding, a mean 17.5 weeks postpartum, and 69.0% had a college degree. Non-completers were more likely to have supplemented with formula at baseline as compared to completers (Pwomen may consider "exclusive breastfeeding" as a study inclusion criterion to prevent high attrition rates or include additional breastfeeding support to study participants. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Implementing school nursing strategies to reduce LGBTQ adolescent suicide: a randomized cluster trial study protocol

    OpenAIRE

    Willging, Cathleen E; Green, Amy E; Ramos, Mary M.

    2016-01-01

    Background Reducing youth suicide in the United States (U.S.) is a national public health priority, and lesbian, gay, bisexual, transgender, and queer or questioning (LGBTQ) youth are at elevated risk. The Centers for Disease Control and Prevention (CDC) endorses six evidence-based (EB) strategies that center on meeting the needs of LGBTQ youth in schools; however, fewer than 6?% of U.S. schools implement all of them. The proposed intervention model, ?RLAS? (Implementing School Nursing Strate...

  17. Searching circular DNA strands

    Energy Technology Data Exchange (ETDEWEB)

    Eliazar, Iddo [Department of Technology Management, Holon Institute of Technology, Holon 58102 (Israel); Koren, Tal [School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Klafter, Joseph [School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel)

    2007-02-14

    We introduce and explore a model of an ensemble of enzymes searching, in parallel, a circular DNA strand for a target site. The enzymes performing the search combine local scanning-conducted by a 1D motion along the strand-and random relocations on the strand-conducted via a confined motion in the medium containing the strand. Both the local scan mechanism and the relocation mechanism are considered general. The search durations are analysed, and their limiting probability distributions-for long DNA strands-are obtained in closed form. The results obtained (i) encompass the cases of single, parallel and massively parallel searches, taking place in the presence of either finite-mean or heavy-tailed relocation times, (ii) are applicable to a wide spectrum of local scan mechanisms including linear, Brownian, selfsimilar, and sub-diffusive motions (iii) provide a quantitative theoretical justification for the necessity of the relocation mechanism, and (iv) facilitate the derivation of optimal relocation strategies.

  18. Did online publishers "get it right"? Using a naturalistic search strategy to review cognitive health promotion content on internet webpages.

    Science.gov (United States)

    Hunter, P V; Delbaere, M; O'Connell, M E; Cammer, A; Seaton, J X; Friedrich, T; Fick, F

    2017-06-15

    One of the most common uses of the Internet is to search for health-related information. Although scientific evidence pertaining to cognitive health promotion has expanded rapidly in recent years, it is unclear how much of this information has been made available to Internet users. Thus, the purpose of our study was to assess the reliability and quality of information about cognitive health promotion encountered by typical Internet users. To generate a list of relevant search terms employed by Internet users, we entered seed search terms in Google Trends and recorded any terms consistently used in the prior 2 years. To further approximate the behaviour of typical Internet users, we entered each term in Google and sampled the first two relevant results. This search, completed in October 2014, resulted in a sample of 86 webpages, 48 of which had content related to cognitive health promotion. An interdisciplinary team rated the information reliability and quality of these webpages using a standardized measure. We found that information reliability and quality were moderate, on average. Just one retrieved page mentioned best practice, national recommendations, or consensus guidelines by name. Commercial content (i.e., product promotion, advertising content, or non-commercial) was associated with differences in reliability and quality, with product promoter webpages having the lowest mean reliability and quality ratings. As efforts to communicate the association between lifestyle and cognitive health continue to expand, we offer these results as a baseline assessment of the reliability and quality of cognitive health promotion on the Internet.

  19. Hybrid and Cooperative Strategies Using Harmony Search and Artificial Immune Systems for Solving the Nurse Rostering Problem

    Directory of Open Access Journals (Sweden)

    Suk Ho Jin

    2017-06-01

    Full Text Available The nurse rostering problem is an important search problem that features many constraints. In a nurse rostering problem, these constraints are defined by processes such as maintaining work regulations, assigning nurse shifts, and considering nurse preferences. A number of approaches to address these constraints, such as penalty function methods, have been investigated in the literature. We propose two types of hybrid metaheuristic approaches for solving the nurse rostering problem, which are based on combining harmony search techniques and artificial immune systems to balance local and global searches and prevent slow convergence speeds and prematurity. The proposed algorithms are evaluated against a benchmarking dataset of nurse rostering problems; the results show that they identify better or best known solutions compared to those identified in other studies for most instances. The results also show that the combination of harmony search and artificial immune systems is better suited than using single metaheuristic or other hybridization methods for finding upper-bound solutions for nurse rostering problems and discrete optimization problems.

  20. Assessment strategies: how patients cope with the diverse quality levels of websites when searching for health information

    NARCIS (Netherlands)

    S.A. Adams (Samantha)

    2003-01-01

    textabstractThe quality of online medical information available for patients has long been a concern of health care professionals. [1-4] Although initiatives exist for patients to use when searching for information, there is the concern that these initiatives are either

  1. Pioneering Strategies for Relieving Dental Anxiety in Hearing Impaired Children: a Randomized Controlled Clinical Study.

    Science.gov (United States)

    Chandrasekhar, Shalini; Madu, Ghanashyam Prasad; Ambati, Naga Radhakrishna; Suravarapu, Pavani Reddy; Uppu, Kalyani; Bolla, Deepthi

    2017-06-01

    Hearing impaired children have a problem in understanding and comprehending with dental treatments. Visual language is the sensible answer of how to improve communication with them. To evaluate the applicability of dental sign language in Hearing impaired children in relieving anxiety during stressful dental treatment by improving their means of communication. This randomized clinical trial was carried out in the Department of Pedodontics and Preventive Dentistry which included 40 Hearing Impaired children meeting inclusion criteria. The selected children were randomly divided into the study and control group comprising of 20 each. In the control group, initial oral examination and dental treatment (oral prophylaxis and class I restoration) were performed without the use of dental sign language. In the study group, the dental sign language specific to dental treatment was educated and during their subsequent visit to the dental clinic after dental sign language reinforcement, oral prophylaxis and class I restoration were done. Subjective and objective measurements of anxiety were recorded for both groups using facial image scale (FIS), pulse oximeter and electronic blood pressure apparatus to compare for correlation. The obtained data were subjected to statistical analysis using unpaired t-test. There was a statistically significant reduction in the anxiety levels (panxiety in children who are hard of hearing. Dental sign language was able to improve behavior positively during dental treatment and may also aid in developing a positive dental attitude among children who are hard of hearing.

  2. Effect of a novel movement strategy in decreasing ACL risk factors in female adolescent soccer players: a randomized controlled trial.

    Science.gov (United States)

    Celebrini, Richard G; Eng, Janice J; Miller, William C; Ekegren, Christina L; Johnston, James D; Depew, Thomas A; Macintyre, Donna L

    2014-03-01

    To determine the effect of a novel movement strategy incorporated within a soccer warm-up on biomechanical risk factors for anterior cruciate ligament injury during 3 sport-specific movement tasks. Single-blind, randomized controlled clinical trial. Laboratory setting. Twenty top-tier female teenage soccer players. Subjects were randomized to the Core Position and Control movement strategy (Core-PAC) warm-up or standard warm-up, which took place before their regular soccer practice over a 6-week period. The Core-PAC focuses on getting the centre of mass closer to the plant foot or base of support. Peak knee flexion angle and abduction moments during a side-hop (SH), side-cut, and unanticipated side-cut task after the 6 weeks with (intervention group only) and without a reminder to use the Core-PAC strategy. The Core-PAC group increased peak flexion angles during the SH task [mean difference = 6.2 degrees; 95% confidence interval (CI), 1.9-10.5 degrees; effect size = 1.01; P = 0.034] after the 6-week warm-up program without a reminder. In addition, the Core-PAC group demonstrated increased knee flexion angles for the side-cut (mean difference = 8.5 degrees; 95% CI, 4.8-12.2 degrees; ES = 2.02; P = 0.001) and SH (mean difference = 10.0 degrees; 95% CI, 5.7-14.3 degrees; ES = 1.66; P = 0.001) task after a reminder. No changes in abduction moments were found. The results of this study suggest that the Core-PAC may be one method of modifying high-risk soccer-specific movements and can be implemented within a practical, team-based soccer warm-up. The results should be interpreted with caution because of the small sample size.

  3. A Mizuno-Todd-Ye predictor-corrector infeasible-interior-point method for symmetric optimization with the arc-search strategy

    Directory of Open Access Journals (Sweden)

    Ximei Yang

    2017-11-01

    Full Text Available Abstract In this paper, we propose a Mizuno-Todd-Ye predictor-corrector infeasible-interior-point method for symmetric optimization using the arc-search strategy. The proposed algorithm searches for optimizers along the ellipses that approximate the central path and ensures that the duality gap and the infeasibility have the same rate of decline. By analyzing, we obtain the iteration complexity O ( r log ε − 1 $\\mathcal{O}(r\\log \\varepsilon^{-1}$ for the Nesterov-Todd direction, where r is the rank of the associated Euclidean Jordan algebra and ε is the required precision. To our knowledge, the obtained complexity bounds coincide with the currently best known theoretical complexity bounds for infeasible symmetric optimization.

  4. How to prepare a systematic review of economic evaluations for clinical practice guidelines: database selection and search strategy development (part 2/3).

    Science.gov (United States)

    Thielen, F W; Van Mastrigt, Gapg; Burgers, L T; Bramer, W M; Majoie, Hjm; Evers, Smaa; Kleijnen, J

    2016-12-01

    This article is part of the series "How to prepare a systematic review of economic evaluations (EES) for informing evidence-based healthcare decisions", in which a five-step approach is proposed. Areas covered: This paper focuses on the selection of relevant databases and developing a search strategy for detecting EEs, as well as on how to perform the search and how to extract relevant data from retrieved records. Expert commentary: Thus far, little has been published on how to conduct systematic review EEs. Moreover, reliable sources of information, such as the Health Economic Evaluation Database, have ceased to publish updates. Researchers are thus left without authoritative guidance on how to conduct SR-EEs. Together with van Mastrigt et al. we seek to fill this gap.

  5. Manipulating Google’s Knowledge Graph Box to Counter Biased Information Processing During an Online Search on Vaccination: Application of a Technological Debiasing Strategy

    Science.gov (United States)

    Allam, Ahmed; Schulz, Peter J

    2016-01-01

    Background One of people’s major motives for going online is the search for health-related information. Most consumers start their search with a general search engine but are unaware of the fact that its sorting and ranking criteria do not mirror information quality. This misconception can lead to distorted search outcomes, especially when the information processing is characterized by heuristic principles and resulting cognitive biases instead of a systematic elaboration. As vaccination opponents are vocal on the Web, the chance of encountering their non‒evidence-based views on immunization is high. Therefore, biased information processing in this context can cause subsequent impaired judgment and decision making. A technological debiasing strategy could counter this by changing people’s search environment. Objective This study aims at testing a technological debiasing strategy to reduce the negative effects of biased information processing when using a general search engine on people’s vaccination-related knowledge and attitudes. This strategy is to manipulate the content of Google’s knowledge graph box, which is integrated in the search interface and provides basic information about the search topic. Methods A full 3x2 factorial, posttest-only design was employed with availability of basic factual information (comprehensible vs hardly comprehensible vs not present) as the first factor and a warning message as the second factor of experimental manipulation. Outcome variables were the evaluation of the knowledge graph box, vaccination-related knowledge, as well as beliefs and attitudes toward vaccination, as represented by three latent variables emerged from an exploratory factor analysis. Results Two-way analysis of variance revealed a significant main effect of availability of basic information in the knowledge graph box on participants’ vaccination knowledge scores (F2,273=4.86, P=.01), skepticism/fear of vaccination side effects (F2,273=3.5, P=.03

  6. Manipulating Google's Knowledge Graph Box to Counter Biased Information Processing During an Online Search on Vaccination: Application of a Technological Debiasing Strategy.

    Science.gov (United States)

    Ludolph, Ramona; Allam, Ahmed; Schulz, Peter J

    2016-06-02

    One of people's major motives for going online is the search for health-related information. Most consumers start their search with a general search engine but are unaware of the fact that its sorting and ranking criteria do not mirror information quality. This misconception can lead to distorted search outcomes, especially when the information processing is characterized by heuristic principles and resulting cognitive biases instead of a systematic elaboration. As vaccination opponents are vocal on the Web, the chance of encountering their non‒evidence-based views on immunization is high. Therefore, biased information processing in this context can cause subsequent impaired judgment and decision making. A technological debiasing strategy could counter this by changing people's search environment. This study aims at testing a technological debiasing strategy to reduce the negative effects of biased information processing when using a general search engine on people's vaccination-related knowledge and attitudes. This strategy is to manipulate the content of Google's knowledge graph box, which is integrated in the search interface and provides basic information about the search topic. A full 3x2 factorial, posttest-only design was employed with availability of basic factual information (comprehensible vs hardly comprehensible vs not present) as the first factor and a warning message as the second factor of experimental manipulation. Outcome variables were the evaluation of the knowledge graph box, vaccination-related knowledge, as well as beliefs and attitudes toward vaccination, as represented by three latent variables emerged from an exploratory factor analysis. Two-way analysis of variance revealed a significant main effect of availability of basic information in the knowledge graph box on participants' vaccination knowledge scores (F2,273=4.86, P=.01), skepticism/fear of vaccination side effects (F2,273=3.5, P=.03), and perceived information quality (F2

  7. Implementing targeted expectant management in fertility care using prognostic modelling: a cluster randomized trial with a multifaceted strategy.

    Science.gov (United States)

    Kersten, F A M; Nelen, W L D M; van den Boogaard, N M; van Rumste, M M; Koks, C A; IntHout, J; Verhoeve, H R; Pelinck, M J; Boks, D E S; Gianotten, J; Broekmans, F J M; Goddijn, M; Braat, D D M; Mol, B W J; Hermens, R P G M

    2017-08-01

    What is the effectiveness of a multifaceted implementation strategy compared to usual care on improving the adherence to guideline recommendations on expectant management for couples with unexplained infertility? The multifaceted implementation strategy did not significantly increase adherence to guideline recommendations on expectant management compared to care as usual. Intrauterine insemination (IUI) with or without ovarian hyperstimulation has no beneficial effect compared to no treatment for 6 months after the fertility work-up for couples with unexplained infertility and a good prognosis of natural conception. Therefore, various professionals and policy makers have advocated the use of prognostic profiles and expectant management in guideline recommendations. A cluster randomized controlled trial in 25 clinics in the Netherlands was conducted between March 2013 and May 2014. Clinics were randomized between the implementation strategy (intervention, n = 13) and care as usual (control, n = 12). The effect of the implementation strategy was evaluated by comparing baseline and effect measurement data. Data collection was retrospective and obtained from medical record research and a patient questionnaire. A total of 544 couples were included at baseline and 485 at the effect measurement (247 intervention group/238 control group). Guideline adherence increased from 49 to 69% (OR 2.66; 95% CI 1.45-4.89) in the intervention group, and from 49 to 61% (OR 2.03; 95% CI 1.38-3.00) in the control group. Multilevel analysis with case-mix adjustment showed that the difference of 8% was not statistically significant (OR 1.31; 95% CI 0.67-2.59). The ongoing pregnancy rate within six months after fertility work-up did not significantly differ between intervention and control group (25% versus 27%: OR 0.72; 95% CI 0.40-1.27). There is a possible selection bias, couples included in the study had a higher socio-economic status than non-responders. How this affects guideline

  8. Teaching basic life support: a prospective randomized study on low-cost training strategies in secondary schools.

    Science.gov (United States)

    Van Raemdonck, Veerle; Monsieurs, Koenraad G; Aerenhouts, Dirk; De Martelaer, Kristine

    2014-08-01

    Cardiopulmonary resuscitation (CPR) training at school is recommended. Limited school resources prevent implementation. The learning efficacy of low-cost training strategies is unknown. To evaluate the efficacy of different CPR learning strategies using low-cost didactic tools. Children (n=593, 15-16 years) were randomized to four training conditions: (1) manikin+teacher instruction (control group), (2) manikin+video instruction, (3) foam dice+plastic bag+peer training+teacher instruction, and (4) foam dice+plastic bag+peer training+video instruction. After a 50 min training, a 3 min CPR test on a manikin was performed using SkillReporting Software (Laerdal, Norway), and repeated after 6 months. The data of children without previous CPR training were analysed. Analysis of variance and the χ-test assessed differences between groups. Complete data sets were available for 165 pupils. Initially, group 3 scored lower on the mean ventilation volume (PTraining efficacy with low-cost equipment was not different from training with a manikin. The outcome for all training strategies was suboptimal. The basics of CPR can be taught with alternative equipment if manikins are not available.

  9. Worksite Tobacco Prevention: A Randomized, Controlled Trial of Adoption, Dissemination Strategies, and Aggregated Health-Related Outcomes across Companies

    Directory of Open Access Journals (Sweden)

    Verena Friedrich

    2015-01-01

    Full Text Available Evidence based public health requires knowledge about successful dissemination of public health measures. This study analyses (a the changes in worksite tobacco prevention (TP in the Canton of Zurich, Switzerland, between 2007 and 2009; (b1 the results of a multistep versus a “brochure only” dissemination strategy; (b2 the results of a monothematic versus a comprehensive dissemination strategy that aim to get companies to adopt TP measures; and (c whether worksite TP is associated with health-related outcomes. A longitudinal design with randomized control groups was applied. Data on worksite TP and health-related outcomes were gathered by a written questionnaire (baseline n=1627; follow-up n=1452 and analysed using descriptive statistics, nonparametric procedures, and ordinal regression models. TP measures at worksites improved slightly between 2007 and 2009. The multistep dissemination was superior to the “brochure only” condition. No significant differences between the monothematic and the comprehensive dissemination strategies were observed. However, improvements in TP measures at worksites were associated with improvements in health-related outcomes. Although dissemination was approached at a mass scale, little change in the advocated adoption of TP measures was observed, suggesting the need for even more aggressive outreach or an acceptance that these channels do not seem to be sufficiently effective.

  10. A randomized controlled trial of an inference generation strategy intervention for adults with high-functioning autism spectrum disorder.

    Science.gov (United States)

    Murza, Kimberly A; Nye, Chad; Schwartz, Jamie B; Ehren, Barbara J; Hahs-Vaughn, Debbie L

    2014-08-01

    The present intervention study investigated the efficacy of the ACT & Check Strategy intervention to improve inference generation when reading, metacognitive ability, general reading comprehension, and social inference ability in adults with high-functioning autism spectrum disorder (HF-ASD). Twenty-five adults with HF-ASD were randomly assigned to either a treatment or a control group. Treatment sessions were conducted in 1-hr sessions, twice a week, for a total of 6 weeks. Treatment focused on explicit instruction of components of inference generation, categories of inferences, and increasingly independent strategy use. The treatment group demonstrated significantly superior performance on 1 of 2 measures of inference generation in reading and 1 measure of metacognitive ability compared with the control group. Significant differences between groups were not found on measures of reading comprehension or social inference ability. These findings suggest that the ACT & Check Strategy was effective in improving participants' ability to generate inferences in reading and certain metacognitive abilities, but the skills do not appear to generalize to other social communication contexts, such as social inference generation. This research provides a measure of support for explicitly teaching inference generation to address a reading inference deficit in adults with HF-ASD.

  11. A new interdisciplinary treatment strategy versus usual medical care for the treatment of subacromial impingement syndrome: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    van der Meer Klaas

    2007-02-01

    Full Text Available Abstract Background Subacromial impingement syndrome (SIS is the most frequently recorded shoulder disorder. When conservative treatment of SIS fails, a subacromial decompression is warranted. However, the best moment of referral for surgery is not well defined. Both early and late referrals have disadvantages – unnecessary operations and smaller improvements in shoulder function, respectively. This paper describes the design of a new interdisciplinary treatment strategy for SIS (TRANSIT, which comprises rules to treat SIS in primary care and a well-defined moment of referral for surgery. Methods/Design The effectiveness of an arthroscopic subacromial decompression versus usual medical care will be evaluated in a randomized controlled trial (RCT. Patients are eligible for inclusion when experiencing a recurrence of SIS within one year after a first episode of SIS which was successfully treated with a subacromial corticosteroid injection. After inclusion they will receive injection treatment again by their general practitioner. When, after this treatment, there is a second recurrence within a year post-injection, the participants will be randomized to either an arthroscopic subacromial decompression (intervention group or continuation of usual medical care (control group. The latter will be performed by a general practitioner according to the Dutch National Guidelines for Shoulder Problems. At inclusion, at randomization and three, six and 12 months post-randomization an outcome assessment will take place. The primary outcome measure is the patient-reported Shoulder Disability Questionnaire. The secondary outcome measures include both disease-specific and generic measures, and an economic evaluation. Treatment effects will be compared for all measurement points by using a GLM repeated measures analyses. Discussion The rationale and design of an RCT comparing arthroscopic subacromial decompression with usual medical care for subacromial

  12. A randomized comparison of different ventilator strategies during thoracotomy for pulmonary resection.

    Science.gov (United States)

    Maslow, Andrew D; Stafford, Todd S; Davignon, Kristopher R; Ng, Thomas

    2013-07-01

    Protective lung ventilation is reported to benefit patients with acute respiratory distress syndrome. It is not known whether protective lung ventilation is also beneficial to patients undergoing single-lung ventilation for elective pulmonary resection. In an institutional review board-approved prospective randomized trial, 34 patients undergoing elective pulmonary resection requiring single-lung ventilation were enrolled. Informed consent was obtained. Patients were randomized to 1 of 2 groups: (1) high tidal volume (Hi-TV) of 10 mL/kg, rate of 7 breaths/min, and zero positive end-expiratory pressure or (2) low tidal volume (Lo-TV) of 5 mL/kg, rate of 14 breaths/min, and 5 cmH2O positive end-expiratory pressure. Ventilator settings were continued during both double- and single-lung ventilation. Pulmonary functions, hemodynamics, and postoperative outcomes were recorded. Patient demographics, operative characteristics, intraoperative hemodynamics, and postoperative pain and sedation scores were similar between the 2 groups. During most time periods, airway pressures (peak and plateau) were significantly higher in the Hi-TV group; however, plateau pressures remained less than 30 cmH2O at all times for all patients. The Hi-TV group had significantly lower arterial carbon dioxide tension, less arterial carbon dioxide tension-end-tidal carbon dioxide gradient, lower alveolar dead space ratio, and higher dynamic pulmonary compliance. There were no differences in postoperative morbidity and hospital days between the 2 groups, but atelectasis scores on postoperative days 1 and 2 were lower in the Hi-TV group. The use of Hi-TV during single-lung ventilation for pulmonary resection resulted in no increase in morbidity and was associated with less hypercarbia, less dead space ventilation, better dynamic compliance, and less postoperative atelectasis. Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  13. Developing Generic Image Search Strategies for Large Astronomical Data Sets and Archives using Convolutional Neural Networks and Transfer Learning

    Science.gov (United States)

    Peek, Joshua E. G.; Hargis, Jonathan R.; Jones, Craig R.

    2018-01-01

    Astronomical instruments produce petabytes of images every year, vastly more than can be inspected by a member of the astronomical community in search of a specific population of structures. Fortunately, the sky is mostly black and source extraction algorithms have been developed to provide searchable catalogs of unconfused sources like stars and galaxies. These tools often fail for studies of more diffuse structures like the interstellar medium and unresolved stellar structures in nearby galaxies, leaving astronomers interested in observations of photodissociation regions, stellar clusters, diffuse interstellar clouds without the crucial ability to search. In this work we present a new path forward for finding structures in large data sets similar to an input structure using convolutional neural networks, transfer learning, and machine learning clustering techniques. We show applications to archival data in the Mikulski Archive for Space Telescopes (MAST).

  14. Clinician search behaviors may be influenced by search engine design.

    Science.gov (United States)

    Lau, Annie Y S; Coiera, Enrico; Zrimec, Tatjana; Compton, Paul

    2010-06-30

    Searching the Web for documents using information retrieval systems plays an important part in clinicians' practice of evidence-based medicine. While much research focuses on the design of methods to retrieve documents, there has been little examination of the way different search engine capabilities influence clinician search behaviors. Previous studies have shown that use of task-based search engines allows for faster searches with no loss of decision accuracy compared with resource-based engines. We hypothesized that changes in search behaviors may explain these differences. In all, 75 clinicians (44 doctors and 31 clinical nurse consultants) were randomized to use either a resource-based or a task-based version of a clinical information retrieval system to answer questions about 8 clinical scenarios in a controlled setting in a university computer laboratory. Clinicians using the resource-based system could select 1 of 6 resources, such as PubMed; clinicians using the task-based system could select 1 of 6 clinical tasks, such as diagnosis. Clinicians in both systems could reformulate search queries. System logs unobtrusively capturing clinicians' interactions with the systems were coded and analyzed for clinicians' search actions and query reformulation strategies. The most frequent search action of clinicians using the resource-based system was to explore a new resource with the same query, that is, these clinicians exhibited a "breadth-first" search behaviour. Of 1398 search actions, clinicians using the resource-based system conducted 401 (28.7%, 95% confidence interval [CI] 26.37-31.11) in this way. In contrast, the majority of clinicians using the task-based system exhibited a "depth-first" search behavior in which they reformulated query keywords while keeping to the same task profiles. Of 585 search actions conducted by clinicians using the task-based system, 379 (64.8%, 95% CI 60.83-68.55) were conducted in this way. This study provides evidence that

  15. Did online publishers ?get it right?? Using a naturalistic search strategy to review cognitive health promotion content on internet webpages

    OpenAIRE

    Hunter, P.V.; Delbaere, M.; O?Connell, M.E.; Cammer, A.; Seaton, J. X.; Friedrich, T.; Fick, F.

    2017-01-01

    Background One of the most common uses of the Internet is to search for health-related information. Although scientific evidence pertaining to cognitive health promotion has expanded rapidly in recent years, it is unclear how much of this information has been made available to Internet users. Thus, the purpose of our study was to assess the reliability and quality of information about cognitive health promotion encountered by typical Internet users. Methods To generate a list of relevant sear...

  16. Asymmetric Move Selection Strategies in Monte-Carlo Tree Search: Minimizing the Simple Regret at Max Nodes

    OpenAIRE

    Liu, Yun-Ching; Tsuruoka, Yoshimasa

    2016-01-01

    The combination of multi-armed bandit (MAB) algorithms with Monte-Carlo tree search (MCTS) has made a significant impact in various research fields. The UCT algorithm, which combines the UCB bandit algorithm with MCTS, is a good example of the success of this combination. The recent breakthrough made by AlphaGo, which incorporates convolutional neural networks with bandit algorithms in MCTS, also highlights the necessity of bandit algorithms in MCTS. However, despite the various investigation...

  17. Comparison of minimalist footwear strategies for simulating barefoot running: a randomized crossover study.

    Directory of Open Access Journals (Sweden)

    Karsten Hollander

    Full Text Available Possible benefits of barefoot running have been widely discussed in recent years. Uncertainty exists about which footwear strategy adequately simulates barefoot running kinematics. The objective of this study was to investigate the effects of athletic footwear with different minimalist strategies on running kinematics. Thirty-five distance runners (22 males, 13 females, 27.9 ± 6.2 years, 179.2 ± 8.4 cm, 73.4 ± 12.1 kg, 24.9 ± 10.9 km x week(-1 performed a treadmill protocol at three running velocities (2.22, 2.78 and 3.33 m x s(-1 using four footwear conditions: barefoot, uncushioned minimalist shoes, cushioned minimalist shoes, and standard running shoes. 3D kinematic analysis was performed to determine ankle and knee angles at initial foot-ground contact, rate of rear-foot strikes, stride frequency and step length. Ankle angle at foot strike, step length and stride frequency were significantly influenced by footwear conditions (p<0.001 at all running velocities. Posthoc pairwise comparisons showed significant differences (p<0.001 between running barefoot and all shod situations as well as between the uncushioned minimalistic shoe and both cushioned shoe conditions. The rate of rear-foot strikes was lowest during barefoot running (58.6% at 3.33 m x s(-1, followed by running with uncushioned minimalist shoes (62.9%, cushioned minimalist (88.6% and standard shoes (94.3%. Aside from showing the influence of shod conditions on running kinematics, this study helps to elucidate differences between footwear marked as minimalist shoes and their ability to mimic barefoot running adequately. These findings have implications on the use of footwear applied in future research debating the topic of barefoot or minimalist shoe running.

  18. Comparison of minimalist footwear strategies for simulating barefoot running: a randomized crossover study.

    Science.gov (United States)

    Hollander, Karsten; Argubi-Wollesen, Andreas; Reer, Rüdiger; Zech, Astrid

    2015-01-01

    Possible benefits of barefoot running have been widely discussed in recent years. Uncertainty exists about which footwear strategy adequately simulates barefoot running kinematics. The objective of this study was to investigate the effects of athletic footwear with different minimalist strategies on running kinematics. Thirty-five distance runners (22 males, 13 females, 27.9 ± 6.2 years, 179.2 ± 8.4 cm, 73.4 ± 12.1 kg, 24.9 ± 10.9 km x week(-1)) performed a treadmill protocol at three running velocities (2.22, 2.78 and 3.33 m x s(-1)) using four footwear conditions: barefoot, uncushioned minimalist shoes, cushioned minimalist shoes, and standard running shoes. 3D kinematic analysis was performed to determine ankle and knee angles at initial foot-ground contact, rate of rear-foot strikes, stride frequency and step length. Ankle angle at foot strike, step length and stride frequency were significantly influenced by footwear conditions (p<0.001) at all running velocities. Posthoc pairwise comparisons showed significant differences (p<0.001) between running barefoot and all shod situations as well as between the uncushioned minimalistic shoe and both cushioned shoe conditions. The rate of rear-foot strikes was lowest during barefoot running (58.6% at 3.33 m x s(-1)), followed by running with uncushioned minimalist shoes (62.9%), cushioned minimalist (88.6%) and standard shoes (94.3%). Aside from showing the influence of shod conditions on running kinematics, this study helps to elucidate differences between footwear marked as minimalist shoes and their ability to mimic barefoot running adequately. These findings have implications on the use of footwear applied in future research debating the topic of barefoot or minimalist shoe running.

  19. Efficacy of different strategies to treat anemia in children: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    García Olga P

    2010-09-01

    Full Text Available Abstract Background Anemia continues to be a major public health problem among children in many regions of the world, and it is still not clear which strategy to treat it is most effective. Objective To evaluate the efficacy and children's acceptance of several recognized strategies to treat anemia. Methods Non-breastfed children (n = 577, 6 to 43 mo of age, were screened for the trial; 267 were anemic (hemoglobin Results All treatments significantly increased Hb and total iron concentration; ferritin did not change significantly. Groups MMS, IS and IFS increased Hb (g/dL [1.50 (95%CI: 1.17, 1.83, 1.48 [(1.18, 1.78 and 1.57 (1.26, 1.88, respectively] and total iron ((μg/dL [0.15 (0.01, 0.29, 0.19 (0.06, 0.31 and 0.12(-0.01, 0.25, respectively] significantly more than FCF [0.92 (0.64, 1.20] but not to FW group [0.14 (0.04, 0.24]. The prevalence of anemia was reduced to a greater extent in the MMS and IFS groups (72% and 69%, respectively than in the FCF group (45% (p Conclusion The three supplements IS, ISF and MMS increased Hb more than the FCF; the supplements that contained micronutrients (IFS and MMS were more effective for reducing the prevalence of anemia. In general, fortified foods were better accepted by the study participants than supplements. ClinicalTrial.gov Identifier NCT00822380

  20. When Gravity Fails: Local Search Topology

    Science.gov (United States)

    Frank, Jeremy; Cheeseman, Peter; Stutz, John; Lau, Sonie (Technical Monitor)

    1997-01-01

    Local search algorithms for combinatorial search problems frequently encounter a sequence of states in which it is impossible to improve the value of the objective function; moves through these regions, called {\\em plateau moves), dominate the time spent in local search. We analyze and characterize {\\em plateaus) for three different classes of randomly generated Boolean Satisfiability problems. We identify several interesting features of plateaus that impact the performance of local search algorithms. We show that local minima tend to be small but occasionally may be very large. We also show that local minima can be escaped without unsatisfying a large number of clauses, but that systematically searching for an escape route may be computationally expensive if the local minimum is large. We show that plateaus with exits, called benches, tend to be much larger than minima, and that some benches have very few exit states which local search can use to escape. We show that the solutions (i.e. global minima) of randomly generated problem instances form clusters, which behave similarly to local minima. We revisit several enhancements of local search algorithms and explain their performance in light of our results. Finally we discuss strategies for creating the next generation of local search algorithms.

  1. A behavioral strategy to minimize air pollution exposure in pregnant women: a randomized controlled trial.

    Science.gov (United States)

    Araban, Marzieh; Tavafian, Sedigheh Sadat; Zarandi, Saeed Motesaddi; Hidarnia, Ali Reza; Burri, Andrea; Montazeri, Ali

    2017-04-04

    Pregnant women and their fetus belong to a sensitive group in response to air pollution hazards. The aim of this study was to evaluate the effectiveness of a theory-based educational program to change pollution exposure behavior in pregnant women. In this randomized controlled trial, pregnant women attending a prenatal clinic in Tehran, Iran were selected and randomized into the experimental and control groups. The inclusion criteria were age between 18 and 35 years, having a history of pregnancies without adverse outcomes and not suffering from chronic diseases. Data collected at baseline and 2-month follow-up. At baseline face-to-face interviews were conducted using a valid and reliable questionnaire including items on demographic characteristics, stages of change, self-efficacy, decisional balance and practice regarding air pollution preventive behaviors. The intervention composed of three parts: motivational interviewing, a booklet and daily small message service (SMS). The control group received no intervention except receiving usual care. Follow-up data were collected after the intervention. Data were analyzed performing t-test, Mann-Whitney U test, and chi-squared. In all the data for 104 pregnant women (53 in the intervention and 51 in the control group) were analyzed. The mean age of participants was 27.2 (SD = 4.11) years and it was 22.89 (SD = 8.75) weeks for gestational age. At baseline there were no significant statistical differences between intervention and control groups on the study measures while we found significant group differences in terms of stages of change, self-efficacy, perceived benefits and practice regarding air pollution preventive behaviors at follow-up assessment (P pollution preventive behaviors among pregnant women. This study provided a framework to modify some psychosocial determinants of air pollution preventive behavior other than knowledge using constructs of Transtheoretical model of behavior change, additionally

  2. Eye Movement Training and Suggested Gaze Strategies in Tunnel Vision - A Randomized and Controlled Pilot Study.

    Directory of Open Access Journals (Sweden)

    Iliya V Ivanov

    Full Text Available Degenerative retinal diseases, especially retinitis pigmentosa (RP, lead to severe peripheral visual field loss (tunnel vision, which impairs mobility. The lack of peripheral information leads to fewer horizontal eye movements and, thus, diminished scanning in RP patients in a natural environment walking task. This randomized controlled study aimed to improve mobility and the dynamic visual field by applying a compensatory Exploratory Saccadic Training (EST.Oculomotor responses during walking and avoiding obstacles in a controlled environment were studied before and after saccade or reading training in 25 RP patients. Eye movements were recorded using a mobile infrared eye tracker (Tobii glasses that measured a range of spatial and temporal variables. Patients were randomly assigned to two training conditions: Saccade (experimental and reading (control training. All subjects who first performed reading training underwent experimental training later (waiting list control group. To assess the effect of training on subjects, we measured performance in the training task and the following outcome variables related to daily life: Response Time (RT during exploratory saccade training, Percent Preferred Walking Speed (PPWS, the number of collisions with obstacles, eye position variability, fixation duration, and the total number of fixations including the ones in the subjects' blind area of the visual field.In the saccade training group, RTs on average decreased, while the PPWS significantly increased. The improvement persisted, as tested 6 weeks after the end of the training. On average, the eye movement range of RP patients before and after training was similar to that of healthy observers. In both, the experimental and reading training groups, we found many fixations outside the subjects' seeing visual field before and after training. The average fixation duration was significantly shorter after the training, but only in the experimental training

  3. Eye Movement Training and Suggested Gaze Strategies in Tunnel Vision - A Randomized and Controlled Pilot Study

    Science.gov (United States)

    Ivanov, Iliya V.; Mackeben, Manfred; Vollmer, Annika; Martus, Peter; Nguyen, Nhung X.; Trauzettel-Klosinski, Susanne

    2016-01-01

    Purpose Degenerative retinal diseases, especially retinitis pigmentosa (RP), lead to severe peripheral visual field loss (tunnel vision), which impairs mobility. The lack of peripheral information leads to fewer horizontal eye movements and, thus, diminished scanning in RP patients in a natural environment walking task. This randomized controlled study aimed to improve mobility and the dynamic visual field by applying a compensatory Exploratory Saccadic Training (EST). Methods Oculomotor responses during walking and avoiding obstacles in a controlled environment were studied before and after saccade or reading training in 25 RP patients. Eye movements were recorded using a mobile infrared eye tracker (Tobii glasses) that measured a range of spatial and temporal variables. Patients were randomly assigned to two training conditions: Saccade (experimental) and reading (control) training. All subjects who first performed reading training underwent experimental training later (waiting list control group). To assess the effect of training on subjects, we measured performance in the training task and the following outcome variables related to daily life: Response Time (RT) during exploratory saccade training, Percent Preferred Walking Speed (PPWS), the number of collisions with obstacles, eye position variability, fixation duration, and the total number of fixations including the ones in the subjects' blind area of the visual field. Results In the saccade training group, RTs on average decreased, while the PPWS significantly increased. The improvement persisted, as tested 6 weeks after the end of the training. On average, the eye movement range of RP patients before and after training was similar to that of healthy observers. In both, the experimental and reading training groups, we found many fixations outside the subjects' seeing visual field before and after training. The average fixation duration was significantly shorter after the training, but only in the

  4. Implementation of kangaroo mother care: a randomized trial of two outreach strategies.

    Science.gov (United States)

    Pattinson, Robert C; Arsalo, Irmeli; Bergh, Anne-Marie; Malan, Atties F; Patrick, Mark; Phillips, Noel

    2005-07-01

    To test whether a well-designed educational package on the implementation of kangaroo mother care (KMC) used on its own can be as effective in implementing KMC in a healthcare facility as the combination of a visiting facilitator used in conjunction with the package. Thirty-four hospitals in KwaZulu-Natal Province, South Africa. The hospitals were paired with respect to their geographical location and annual number of births at the facility. One hospital in each pair was randomly allocated to receive either the implementation package alone (group A) or the implementation package and visits from a facilitator (group B). Hospitals in group B received three facilitation visits. All hospitals were evaluated by a site visit 8 mo after launching the process and were scored by means of a progress-monitoring tool. Successful implementation was regarded as demonstrating evidence of practice (score>10) during the site visit. Group B scored significantly better than group A (ppackage was clearly superior to using a package alone. Some sites do not need facilitation for successful implementation.

  5. Effectiveness of home visit falls prevention strategy for Taiwanese community-dwelling elders: randomized trial.

    Science.gov (United States)

    Huang, Tzu-Ting; Acton, Gayle J

    2004-01-01

    The purpose of this research was to examine the effect of a multifactorial intervention to prevent falls by increasing self-efficacy to prevent falls, improving the knowledge of medication safety, and decreasing the number of environmental risks in older persons dwelling in the community. A sample of 120 cognitively intact residents of this community who were 65 years of age and older were recruited into a two-group pretest-post-test experimental design and randomly assigned to an experimental group and a comparison group (60 in each group). The intervention was delivered, and data were collected during three home visits in a 4-month period. (1) Experimental subjects improved their fall self-efficacy, environmental safety, and knowledge of medication safety significantly (p falls was reduced at post-test in both groups compared to pretest scores, and the falling was more serious in the comparison group at post-test compared to that in the experimental group. The results can help community health professionals to individualize their interventions to the specific needs of the elderly, thus helping to prevent falls among community-dwelling elders.

  6. The utility of the random controlled trial for evaluating sexual offender treatment: the gold standard or an inappropriate strategy?

    Science.gov (United States)

    Marshall, W L; Marshall, L E

    2007-06-01

    This paper examines the scientific, practical, and ethical issues surrounding the employment of the Random Controlled Trial (RCT) in the evaluation of sexual offender treatment. Consideration of these issues leads us to conclude that the RCT design is not suitable for determining the effectiveness of sexual offender treatment. We also examine the RCT study by Marques et al. (Sexual Abuse: A Journal of Research and Treatment and Evaluation 17:79-107, 2005) that is often held up as the model for the evaluation of sexual offender treatment. We found several problems with this study that, in our opinion, reduce its relevance for deciding whether treatment is effective with these clients. Finally, we examine two alternative strategies for evaluating treatment that may allow treatment providers to more readily examine, and report, the results of their programs.

  7. Efficacy of different strategies to treat anemia in children: a randomized clinical trial

    Science.gov (United States)

    2010-01-01

    Background Anemia continues to be a major public health problem among children in many regions of the world, and it is still not clear which strategy to treat it is most effective. Objective To evaluate the efficacy and children's acceptance of several recognized strategies to treat anemia. Methods Non-breastfed children (n = 577), 6 to 43 mo of age, were screened for the trial; 267 were anemic (hemoglobin acid supplement (IFS), a multiple micronutrient supplement (MMS), a micronutrient-fortified complementary food as porridge powder (FCF), or zinc+iron+ascorbic acid fortified water (FW). The iron content of each daily dose was 20, 12.5, 10, 10 and 6.7 mg respectively. Hemoglobin (Hb), ferritin, total iron, weight and height were measured at baseline and after 4 months of treatment. Morbidity, treatment acceptability and adherence were recorded during the intervention. Results All treatments significantly increased Hb and total iron concentration; ferritin did not change significantly. Groups MMS, IS and IFS increased Hb (g/dL) [1.50 (95%CI: 1.17, 1.83), 1.48 [(1.18, 1.78) and 1.57 (1.26, 1.88), respectively] and total iron ((μg/dL) [0.15 (0.01, 0.29), 0.19 (0.06, 0.31) and 0.12(-0.01, 0.25), respectively] significantly more than FCF [0.92 (0.64, 1.20)] but not to FW group [0.14 (0.04, 0.24)]. The prevalence of anemia was reduced to a greater extent in the MMS and IFS groups (72% and 69%, respectively) than in the FCF group (45%) (p children, than IFS, FCF and FW. Conclusion The three supplements IS, ISF and MMS increased Hb more than the FCF; the supplements that contained micronutrients (IFS and MMS) were more effective for reducing the prevalence of anemia. In general, fortified foods were better accepted by the study participants than supplements. ClinicalTrial.gov Identifier NCT00822380 PMID:20863398

  8. Use of online recruitment strategies in a randomized trial of cancer survivors.

    Science.gov (United States)

    Juraschek, Stephen P; Plante, Timothy B; Charleston, Jeanne; Miller, Edgar R; Yeh, Hsin-Chieh; Appel, Lawrence J; Jerome, Gerald J; Gayles, Debra; Durkin, Nowella; White, Karen; Dalcin, Arlene; Hermosilla, Manuel

    2017-12-01

    Despite widespread Internet adoption, online advertising remains an underutilized tool to recruit participants into clinical trials. Whether online advertising is a cost-effective method to enroll participants compared to other traditional forms of recruitment is not known. Recruitment for the Survivorship Promotion In Reducing IGF-1 Trial, a community-based study of cancer survivors, was conducted from June 2015 through December 2016 via in-person community fairs, advertisements in periodicals, and direct postal mailings. In addition, "Right Column" banner ads were purchased from Facebook to direct participants to the Survivorship Promotion In Reducing IGF-1 Trial website. Response rates, costs of traditional and online advertisements, and demographic data were determined and compared across different online and traditional recruitment strategies. Micro-trials optimizing features of online advertisements were also explored. Of the 406 respondents to our overall outreach efforts, 6% (24 of 406) were referred from online advertising. Facebook advertisements were shown over 3 million times (impressions) to 124,476 people, which resulted in 4401 clicks on our advertisement. Of these, 24 people ultimately contacted study staff, 6 underwent prescreening, and 4 enrolled in the study. The cost of online advertising per enrollee was $794 when targeting a general population versus $1426 when accounting for strategies that specifically targeted African Americans or men. By contrast, community fairs, direct mail, or periodicals cost $917, $799, or $436 per enrollee, respectively. Utilization of micro-trials to assess online ads identified subtleties (e.g. use of an advertisement title) that substantially impacted viewer interest in our trial. Online advertisements effectively directed a relevant population to our website, which resulted in new enrollees in the Survivorship Promotion In Reducing IGF-1 Trial at a cost comparable to traditional methods. Costs were

  9. Effectiveness of a clinical practice guideline implementation strategy for patients with anxiety disorders in primary care: cluster randomized trial

    Directory of Open Access Journals (Sweden)

    Tello-Bernabé Eugenia

    2011-12-01

    Full Text Available Abstract Background Anxiety is a common mental health problem seen in primary care. However, its management in clinical practice varies greatly. Clinical practice guidelines (CPGs have the potential to reduce variations and improve the care received by patients by promoting interventions of proven benefit. However, uptake and adherence to their recommendations can be low. Method/design This study involves a community based on cluster randomized trial in primary healthcare centres in the Madrid Region (Spain. The project aims to determine whether the use of implementation strategy (including training session, information, opinion leader, reminders, audit, and feed-back of CPG for patients with anxiety disorders in primary care is more effective than usual diffusion. The number of patients required is 296 (148 in each arm, all older than 18 years and diagnosed with generalized anxiety disorder, panic disorder, and panic attacks by the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV. They are chosen by consecutive sampling. The main outcome variable is the change in two or more points into Goldberg anxiety scale at six and twelve months. Secondary outcome variables include quality of life (EuroQol 5D, and degree of compliance with the CPG recommendations on treatment, information, and referrals to mental health services. Main effectiveness will be analyzed by comparing the patients percentage improvement on the Goldberg scale between the intervention group and the control group. Logistic regression with random effects will be used to adjust for prognostic factors. Confounding factors or factors that might alter the effect recorded will be taken into account in this analysis. Discussion There is a need to identify effective implementation strategies for CPG for the management of anxiety disorders present in primary care. Ensuring the appropriate uptake of guideline recommendations can reduce clinical variation and improve the care

  10. [Randomized clinical trial of a fall-prevention strategy for institutionalized elderly based on the Mini Falls Assessment Instrument].

    Science.gov (United States)

    Salvà, Antoni; Rojano, Xavier; Coll-Planas, Laura; Domènech, Sara; Roqué I Figuls, Marta

    2016-01-01

    The Mini Falls Assessment Instrument (MFAI) identifies risk factors for falls in an individual and links them to specific interventions. This study evaluates the effectiveness of MFAI as the basis for a falls prevention strategy in institutionalized elderly. A cluster randomized clinical trial (identifier NCT00888953) was conducted in 16 nursing homes randomized to apply MFAI (intervention) or a modified version not linked to actions (control). The primary endpoint was the occurrence of falls during follow-up (12 months). Secondary variables were total number of falls, physical function, quality of life, functional status, and adverse effects. Data from 330 participants (197 intervention, 137 control) were analyzed. Both groups had a similar number of risk factors: 7 in the intervention group (range 1-12) and 8 (1-13) in the control group. In the intervention group there were more fallers (49% vs. 38%), and higher number of falls (315 vs. 109), and fall rate per 100 person-years (192.5 vs. 179.8) than the control group. In the multivariate analysis, there were no significant differences in fall risk (odds ratio=1.45; 95% confidence interval [CI]: .67 to 3.14; P=.350), but the incidence rate is significantly higher in the intervention group (Incidence rate ratio=2.23; 95% CI: 1.43 to 3.48; P<.001). The results on the efficacy of the MFAI as a fall prevention strategy are inconclusive. Additional studies are needed in order to provide good quality evidence. Copyright © 2014 SEGG. Published by Elsevier Espana. All rights reserved.

  11. Search Improvement Process-Chaotic Optimization-Particle Swarm Optimization-Elite Retention Strategy and Improved Combined Cooling-Heating-Power Strategy Based Two-Time Scale Multi-Objective Optimization Model for Stand-Alone Microgrid Operation

    Directory of Open Access Journals (Sweden)

    Fei Wang

    2017-11-01

    Full Text Available The optimal dispatching model for a stand-alone microgrid (MG is of great importance to its operation reliability and economy. This paper aims at addressing the difficulties in improving the operational economy and maintaining the power balance under uncertain load demand and renewable generation, which could be even worse in such abnormal conditions as storms or abnormally low or high temperatures. A new two-time scale multi-objective optimization model, including day-ahead cursory scheduling and real-time scheduling for finer adjustments, is proposed to optimize the operational cost, load shedding compensation and environmental benefit of stand-alone MG through controllable load (CL and multi-distributed generations (DGs. The main novelty of the proposed model is that the synergetic response of CL and energy storage system (ESS in real-time scheduling offset the operation uncertainty quickly. And the improved dispatch strategy for combined cooling-heating-power (CCHP enhanced the system economy while the comfort is guaranteed. An improved algorithm, Search Improvement Process-Chaotic Optimization-Particle Swarm Optimization-Elite Retention Strategy (SIP-CO-PSO-ERS algorithm with strong searching capability and fast convergence speed, was presented to deal with the problem brought by the increased errors between actual renewable generation and load and prior predictions. Four typical scenarios are designed according to the combinations of day types (work day or weekend and weather categories (sunny or rainy to verify the performance of the presented dispatch strategy. The simulation results show that the proposed two-time scale model and SIP-CO-PSO-ERS algorithm exhibit better performance in adaptability, convergence speed and search ability than conventional methods for the stand-alone MG’s operation.

  12. Randomized Trial of Hypnosis as a Pain and Symptom Management Strategy in Adults with Sickle Cell Disease

    Science.gov (United States)

    Wallen, Gwenyth R; Middleton, Kimberly R; Ames, Nancy; Brooks, Alyssa T; Handel, Daniel

    2014-01-01

    Sickle cell disease (SCD) is the most common genetic disease in African-Americans, characterized by recurrent painful vaso-occlusive crises. Medical therapies for controlling or preventing crises are limited because of efficacy and/or toxicity. This is a randomized, controlled, single-crossover protocol of hypnosis for managing pain in SCD patients. Participants receive hypnosis from a trained hypnosis therapist followed by six weeks of self-hypnosis using digital media. Those in the control arm receive SCD education followed by a six-week waiting period before crossing over to the hypnosis arm of the study. Outcome measures include assessments of pain (frequency, intensity and quality), anxiety, coping strategies, sleep, depression, and health care utilization. To date, there are no published randomized, controlled trials evaluating the efficacy of hypnosis on SCD pain modulation in adults. Self-hypnosis for pain management may be helpful in modulating chronic pain, improving sleep quality, and decreasing use of narcotics in patients with SCD. TRIAL REGISTRATION ClinicalTrials.gov: NCT00393250 PMID:25520557

  13. Randomized Trial of Hypnosis as a Pain and Symptom Management Strategy in Adults with Sickle Cell Disease

    Directory of Open Access Journals (Sweden)

    Gwenyth R. Wallen

    2014-01-01

    Full Text Available Sickle cell disease (SCD is the most common genetic disease in African-Americans, characterized by recurrent painful vaso-occlusive crises. Medical therapies for controlling or preventing crises are limited because of efficacy and/or toxicity. This is a randomized, controlled, single-crossover protocol of hypnosis for managing pain in SCD patients. Participants receive hypnosis from a trained hypnosis therapist followed by six weeks of self-hypnosis using digital media. Those in the control arm receive SCD education followed by a six-week waiting period before crossing over to the hypnosis arm of the study. Outcome measures include assessments of pain (frequency, intensity and quality, anxiety, coping strategies, sleep, depression, and health care utilization. To date, there are no published randomized, controlled trials evaluating the efficacy of hypnosis on SCD pain modulation in adults. Self-hypnosis for pain management may be helpful in modulating chronic pain, improving sleep quality, and decreasing use of narcotics in patients with SCD. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00393250

  14. A spin transfer torque magnetoresistance random access memory-based high-density and ultralow-power associative memory for fully data-adaptive nearest neighbor search with current-mode similarity evaluation and time-domain minimum searching

    Science.gov (United States)

    Ma, Yitao; Miura, Sadahiko; Honjo, Hiroaki; Ikeda, Shoji; Hanyu, Takahiro; Ohno, Hideo; Endoh, Tetsuo

    2017-04-01

    A high-density nonvolatile associative memory (NV-AM) based on spin transfer torque magnetoresistive random access memory (STT-MRAM), which achieves highly concurrent and ultralow-power nearest neighbor search with full adaptivity of the template data format, has been proposed and fabricated using the 90 nm CMOS/70 nm perpendicular-magnetic-tunnel-junction hybrid process. A truly compact current-mode circuitry is developed to realize flexibly controllable and high-parallel similarity evaluation, which makes the NV-AM adaptable to any dimensionality and component-bit of template data. A compact dual-stage time-domain minimum searching circuit is also developed, which can freely extend the system for more template data by connecting multiple NM-AM cores without additional circuits for integrated processing. Both the embedded STT-MRAM module and the computing circuit modules in this NV-AM chip are synchronously power-gated to completely eliminate standby power and maximally reduce operation power by only activating the currently accessed circuit blocks. The operations of a prototype chip at 40 MHz are demonstrated by measurement. The average operation power is only 130 µW, and the circuit density is less than 11 µm2/bit. Compared with the latest conventional works in both volatile and nonvolatile approaches, more than 31.3% circuit area reductions and 99.2% power improvements are achieved, respectively. Further power performance analyses are discussed, which verify the special superiority of the proposed NV-AM in low-power and large-memory-based VLSIs.

  15. Research Strategy in the Study of Memory: Fads, Fallacies, and the Search for the "Coordinates of Truth".

    Science.gov (United States)

    Hintzman, Douglas L

    2011-05-01

    This article presents an evaluation of research strategy in the psychology of memory. To the extent that a strategy can be discerned, it appears less than optimal in several respects. It relates only weakly to subjective experience, it does not clearly differentiate between structure and strategy, and it is oriented more toward remembering which words were in a list than to the diverse functions that memory serves. This last limitation fosters assumptions about memory that are false: that encoding and retrieval are distinct modes of operation; that the effects of repetition, duration, and recency are interchangeable; and that memory is ahistorical. Theories that parsimoniously explain data from single tasks will never generalize to memory as a whole because their core assumptions are too limited. Instead, memory theory should be based on a broad variety of evidence. Using findings from several memory tasks and observations of everyday memory, I suggest some ways in which involuntary reminding plays a central role in cognition. The evolutionary purpose of memory may have been the construction and maintenance-through reminding-of a spatio-temporal model of the environment. I conclude by recommending ways in which efficiency of the field's research strategy might be improved. © The Author(s) 2011.

  16. Financial Incentives for Adherence to Hepatitis C Virus Clinical Care and Treatment: A Randomized Trial of Two Strategies

    Science.gov (United States)

    Allmon, Andrew G.; Evon, Donna; Hurt, Christopher; Reifeis, Sarah Ailleen; Thirumurthy, Harsha; Straub, Becky; Edwards, Angela; Mollan, Katie R.

    2017-01-01

    Abstract Background. Although rates of sustained virologic response (SVR) after hepatitis C virus (HCV) treatment with direct-acting antivirals (DAAs) surpass 90% in trials and some more “real world” settings, some patients, such as those with substance use disorders, will be challenged to adhere to HCV care. Methods. To assess the feasibility of 2 strategies for financially incentivizing adherence to HCV care, patients with a substance use history prescribed 12 weeks of a sofosbuvir-containing regimen were randomized to either fixed or lottery-based monetary incentives for attending clinic appointments, pill count adherence >90%, and SVR achievement. Electronic medication monitoring provided an objective measure of DAA adherence. Results. Fifty-nine participants were randomized to the lottery (n = 31) or fixed-incentive (n = 28) arms. All 31 (100%) in the lottery arm and 24 of 28 (86%) in the fixed arm completed 12 weeks of therapy. By intent-to-treat, 93% in the lottery arm and 92% in the fixed arm achieved SVR (estimated difference: 0.5%; 95% confidence interval, −17.5 to 18.8). Overall, 92% of scheduled visits were attended without significant differences between arms. The mean adherence ratio (days with ≥1 bottle opening:monitored days) was 0.91 for lottery and 0.92 for fixed arms. Conclusions. In this pilot, fixed- and lottery-based financial incentives were successfully implemented and accepted by patients with a substance use history. High levels of HCV therapy and care adherence, as well as rates of SVR, were observed. Financial incentives may be useful to support treatment adherence in patients with substance use disorders and should be tested in a larger, randomized, controlled trial. PMID:28695144

  17. Random search for shared chromosomal regions in four affected individuals: the assignment of a new hereditary ataxia locus

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    Nikali, K.; Suomalainen, A.; Koskinen, T.; Peltonen, L. [Univ. of Helsinki (Finland); Terwilliger, J. [Univ. of Oxford (United Kingdom); Weissenbach, J. [Genethon, Evry (France)

    1995-05-01

    Infantile-onset spinocerebellar ataxia (IOSCA) is an autosomal recessively inherited progressive neurological disorder of unknown etiology. This ataxia, identified so far only in the genetically isolated Finnish population, does not share gene locus with any of the previously identified hereditary ataxias, and a random mapping approach was adopted to assign the IOSCA locus. Based on the assumption of one founder mutation, a primary screening of the genome was performed using samples from just four affected individuals in two consanguineous pedigrees. The identification of a shared chromosomal region in these four patients provided the first evidence that the IOSCA gene locus is on chromosome 10q23.3-q24.1, which was confirmed by conventional linkage analysis in the complete family material. Strong linkage disequilibrium observed between IOSCA and the linked markers was utilized to define accurately the critical chromosomal region. The results showed the power of linkage disequilibrium in the locus assignment of diseases with very limited family materials. 30 refs., 3 figs., 2 tabs.

  18. Caries management strategies for primary molars: 1-yr randomized control trial results.

    Science.gov (United States)

    Santamaria, R M; Innes, N P T; Machiulskiene, V; Evans, D J P; Splieth, C H

    2014-11-01

    Minimal invasive approaches to managing caries, such as partial caries removal techniques, are showing increasing evidence of improved outcomes over the conventional complete caries removal. There is also increasing interest in techniques where no caries is removed. We present the 1-yr results of clinical efficacy for 3 caries management options for occlusoproximal cavitated lesions in primary molars: conventional restorations (CR; complete caries removal and compomer restoration), Hall technique (HT; no caries removal, sealing in with stainless steel crowns), and nonrestorative caries treatment (NRCT; no caries removal, opening up the cavity, teaching brushing and fluoride application). In sum, 169 children (3-8 yr old; mean, 5.56 ± 1.45 yr) were enrolled in this secondary care-based, 3-arm, parallel-group, randomized clinical trial. Treatments were carried out by specialist pediatric dentists or postgraduate trainees. One lesion per child received CR, HT, or NRCT. Outcome measures were clinical failure rates, grouped as minor failure (restoration loss/need for replacement, reversible pulpitis, caries progression, etc.) and major failure (irreversible pulpitis, abscess, etc.). There were 148 children (87.6%) with a minimum follow-up of 11 mo (mean, 12.23 ± 0.98 mo). Twenty teeth were recorded as having at least 1 minor failure: NRCT, n = 8 (5%); CR, n = 11 (7%); HT, n = 1 (1%) (p = .002, 95% CI = 0.001 to 0.003). Only the comparison between NRCT and CR showed no significant difference (p = .79, 95% CI = 0.78 to 0.80). Nine (6%) experienced at least 1 major failure: NRCT, n = 4 (2%); CR, n = 5 (3%); HT, n = 0 (0%) (p = .002, 95% CI = 0.001 to 0.003). Individual comparison of NRCT and CR showed no statistically significant difference in major failures (p = .75, 95% CI = 0.73 to 0.76). Success and failure rates were not significantly affected by pediatric dentists' level of experience (p = .13, 95% CI = 0.12 to 0.14). The HT was significantly more successful

  19. Searching for consensus through multi-criteria decision analysis. Assessment of screening strategies for hemoglobinopathies in southeastern France.

    Science.gov (United States)

    Le Gales, C; Moatti, J P

    1990-01-01

    Until now, no systematic strategy for the prevention of major hemoglobinopathies has been implemented in southeastern France, in spite of frequencies of beta-thalassemia trait and HbS trait as high as 2.5-8% in some ethnic populations. The purpose of the study was to help a group of experts, brought together by the Regional Center for Disease Control, to reach a consensus about screening for carriers of heterozygote hemoglobinopathies. A multicriteria decision-analysis model was used to take into account not only the costs and effectiveness of potential screening strategies, but also five other qualitative criteria: technical and practical feasibilities, ethical acceptability, information follow-up in time, and global impact on health education. Conclusions differ significantly from those of a pure cost-effectiveness analysis, but a multicriteria approach seems best suited to medical experts' preferences.

  20. Rationale and study design for an individualized perioperative open lung ventilatory strategy (iPROVE): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Ferrando, Carlos; Soro, Marina; Canet, Jaume; Unzueta, Ma Carmen; Suárez, Fernando; Librero, Julián; Peiró, Salvador; Llombart, Alicia; Delgado, Carlos; León, Irene; Rovira, Lucas; Ramasco, Fernando; Granell, Manuel; Aldecoa, César; Diaz, Oscar; Balust, Jaume; Garutti, Ignacio; de la Matta, Manuel; Pensado, Alberto; Gonzalez, Rafael; Durán, M Eugenia; Gallego, Lucia; Del Valle, Santiago García; Redondo, Francisco J; Diaz, Pedro; Pestaña, David; Rodríguez, Aurelio; Aguirre, Javier; García, Jose M; García, Javier; Espinosa, Elena; Charco, Pedro; Navarro, Jose; Rodríguez, Clara; Tusman, Gerardo; Belda, Francisco Javier

    2015-04-27

    Postoperative pulmonary and non-pulmonary complications are common problems that increase morbidity and mortality in surgical patients, even though the incidence has decreased with the increased use of protective lung ventilation strategies. Previous trials have focused on standard strategies in the intraoperative or postoperative period, but without personalizing these strategies to suit the needs of each individual patient and without considering both these periods as a global perioperative lung-protective approach. The trial presented here aims at comparing postoperative complications when using an individualized ventilatory management strategy in the intraoperative and immediate postoperative periods with those when using a standard protective ventilation strategy in patients scheduled for major abdominal surgery. This is a comparative, prospective, multicenter, randomized, and controlled, four-arm trial that will include 1012 patients with an intermediate or high risk for postoperative pulmonary complications. The patients will be divided into four groups: (1) individualized perioperative group: intra- and postoperative individualized strategy; (2) intraoperative individualized strategy + postoperative continuous positive airway pressure (CPAP); (3) intraoperative standard ventilation + postoperative CPAP; (4) intra- and postoperative standard strategy (conventional strategy). The primary outcome is a composite analysis of postoperative complications. The Individualized Perioperative Open-lung Ventilatory Strategy (iPROVE) is the first multicenter, randomized, and controlled trial to investigate whether an individualized perioperative approach prevents postoperative pulmonary complications. Registered on 5 June 2014 with identification no. NCT02158923 .

  1. Ringed Seal Search for Global Optimization via a Sensitive Search Model.

    Science.gov (United States)

    Saadi, Younes; Yanto, Iwan Tri Riyadi; Herawan, Tutut; Balakrishnan, Vimala; Chiroma, Haruna; Risnumawan, Anhar

    2016-01-01

    The efficiency of a metaheuristic algorithm for global optimization is based on its ability to search and find the global optimum. However, a good search often requires to be balanced between exploration and exploitation of the search space. In this paper, a new metaheuristic algorithm called Ringed Seal Search (RSS) is introduced. It is inspired by the natural behavior of the seal pup. This algorithm mimics the seal pup movement behavior and its ability to search and choose the best lair to escape predators. The scenario starts once the seal mother gives birth to a new pup in a birthing lair that is constructed for this purpose. The seal pup strategy consists of searching and selecting the best lair by performing a random walk to find a new lair. Affected by the sensitive nature of seals against external noise emitted by predators, the random walk of the seal pup takes two different search states, normal state and urgent state. In the normal state, the pup performs an intensive search between closely adjacent lairs; this movement is modeled via a Brownian walk. In an urgent state, the pup leaves the proximity area and performs an extensive search to find a new lair from sparse targets; this movement is modeled via a Levy walk. The switch between these two states is realized by the random noise emitted by predators. The algorithm keeps switching between normal and urgent states until the global optimum is reached. Tests and validations were performed using fifteen benchmark test functions to compare the performance of RSS with other baseline algorithms. The results show that RSS is more efficient than Genetic Algorithm, Particles Swarm Optimization and Cuckoo Search in terms of convergence rate to the global optimum. The RSS shows an improvement in terms of balance between exploration (extensive) and exploitation (intensive) of the search space. The RSS can efficiently mimic seal pups behavior to find best lair and provide a new algorithm to be used in global

  2. Ringed Seal Search for Global Optimization via a Sensitive Search Model.

    Directory of Open Access Journals (Sweden)

    Younes Saadi

    Full Text Available The efficiency of a metaheuristic algorithm for global optimization is based on its ability to search and find the global optimum. However, a good search often requires to be balanced between exploration and exploitation of the search space. In this paper, a new metaheuristic algorithm called Ringed Seal Search (RSS is introduced. It is inspired by the natural behavior of the seal pup. This algorithm mimics the seal pup movement behavior and its ability to search and choose the best lair to escape predators. The scenario starts once the seal mother gives birth to a new pup in a birthing lair that is constructed for this purpose. The seal pup strategy consists of searching and selecting the best lair by performing a random walk to find a new lair. Affected by the sensitive nature of seals against external noise emitted by predators, the random walk of the seal pup takes two different search states, normal state and urgent state. In the normal state, the pup performs an intensive search between closely adjacent lairs; this movement is modeled via a Brownian walk. In an urgent state, the pup leaves the proximity area and performs an extensive search to find a new lair from sparse targets; this movement is modeled via a Levy walk. The switch between these two states is realized by the random noise emitted by predators. The algorithm keeps switching between normal and urgent states until the global optimum is reached. Tests and validations were performed using fifteen benchmark test functions to compare the performance of RSS with other baseline algorithms. The results show that RSS is more efficient than Genetic Algorithm, Particles Swarm Optimization and Cuckoo Search in terms of convergence rate to the global optimum. The RSS shows an improvement in terms of balance between exploration (extensive and exploitation (intensive of the search space. The RSS can efficiently mimic seal pups behavior to find best lair and provide a new algorithm to be

  3. Ringed Seal Search for Global Optimization via a Sensitive Search Model

    Science.gov (United States)

    Saadi, Younes; Yanto, Iwan Tri Riyadi; Herawan, Tutut; Balakrishnan, Vimala; Chiroma, Haruna; Risnumawan, Anhar

    2016-01-01

    The efficiency of a metaheuristic algorithm for global optimization is based on its ability to search and find the global optimum. However, a good search often requires to be balanced between exploration and exploitation of the search space. In this paper, a new metaheuristic algorithm called Ringed Seal Search (RSS) is introduced. It is inspired by the natural behavior of the seal pup. This algorithm mimics the seal pup movement behavior and its ability to search and choose the best lair to escape predators. The scenario starts once the seal mother gives birth to a new pup in a birthing lair that is constructed for this purpose. The seal pup strategy consists of searching and selecting the best lair by performing a random walk to find a new lair. Affected by the sensitive nature of seals against external noise emitted by predators, the random walk of the seal pup takes two different search states, normal state and urgent state. In the normal state, the pup performs an intensive search between closely adjacent lairs; this movement is modeled via a Brownian walk. In an urgent state, the pup leaves the proximity area and performs an extensive search to find a new lair from sparse targets; this movement is modeled via a Levy walk. The switch between these two states is realized by the random noise emitted by predators. The algorithm keeps switching between normal and urgent states until the global optimum is reached. Tests and validations were performed using fifteen benchmark test functions to compare the performance of RSS with other baseline algorithms. The results show that RSS is more efficient than Genetic Algorithm, Particles Swarm Optimization and Cuckoo Search in terms of convergence rate to the global optimum. The RSS shows an improvement in terms of balance between exploration (extensive) and exploitation (intensive) of the search space. The RSS can efficiently mimic seal pups behavior to find best lair and provide a new algorithm to be used in global

  4. Strategic search from long-term memory: an examination of semantic and autobiographical recall.

    Science.gov (United States)

    Unsworth, Nash; Brewer, Gene A; Spillers, Gregory J

    2014-01-01

    Searching long-term memory is theoretically driven by both directed (search strategies) and random components. In the current study we conducted four experiments evaluating strategic search in semantic and autobiographical memory. Participants were required to generate either exemplars from the category of animals or the names of their friends for several minutes. Self-reported strategies suggested that participants typically relied on visualization strategies for both tasks and were less likely to rely on ordered strategies (e.g., alphabetic search). When participants were instructed to use particular strategies, the visualization strategy resulted in the highest levels of performance and the most efficient search, whereas ordered strategies resulted in the lowest levels of performance and fairly inefficient search. These results are consistent with the notion that retrieval from long-term memory is driven, in part, by search strategies employed by the individual, and that one particularly efficient strategy is to visualize various situational contexts that one has experienced in the past in order to constrain the search and generate the desired information.

  5. SETI The Search for Extraterrestrial Intelligence.

    Science.gov (United States)

    Jones, Barrie W.

    1991-01-01

    Discussed is the search for life on other planets similar to Earth based on the Drake equation. Described are search strategies and microwave searches. The reasons why people are searching are also discussed. (KR)

  6. Novel directed search strategy to detect continuous gravitational waves from neutron stars in low- and high-eccentricity binary systems

    Science.gov (United States)

    Leaci, Paola; Astone, Pia; D'Antonio, Sabrina; Frasca, Sergio; Palomba, Cristiano; Piccinni, Ornella; Mastrogiovanni, Simone

    2017-06-01

    We describe a novel, very fast and robust, directed search incoherent method (which means that the phase information is lost) for periodic gravitational waves from neutron stars in binary systems. As a directed search, we assume the source sky position to be known with enough accuracy, but all other parameters (including orbital ones) are supposed to be unknown. We exploit the frequency modulation due to source orbital motion to unveil the signal signature by commencing from a collection of time and frequency peaks (the so-called "peakmap"). We validate our algorithm (pipeline), adding 131 artificial continuous-wave signals from pulsars in binary systems to simulated detector Gaussian noise, characterized by a power spectral density Sh=4 ×10-24 Hz-1 /2 in the frequency interval [70, 200] Hz, which is overall commensurate with the advanced detector design sensitivities. The pipeline detected 128 signals, and the weakest signal injected (added) and detected has a gravitational-wave strain amplitude of ˜10-24, assuming one month of gapless data collected by a single advanced detector. We also provide sensitivity estimations, which show that, for a single-detector data covering one month of observation time, depending on the source orbital Doppler modulation, we can detect signals with an amplitude of ˜7 ×10-25. By using three detectors, and one year of data, we would easily gain a factor 3 in sensitivity, translating into being able to detect weaker signals. We also discuss the parameter estimate proficiency of our method, as well as computational budget: sifting one month of single-detector data and 131 Hz-wide frequency range takes roughly 2.4 CPU hours. Hence, the current procedure can be readily applied in ally-sky schemes, sieving in parallel as many sky positions as permitted by the available computational power. Finally, we introduce (ongoing and future) approaches to attain sensitivity improvements and better accuracy on parameter estimates in view of the

  7. An Improved Ensemble of Random Vector Functional Link Networks Based on Particle Swarm Optimization with Double Optimization Strategy.

    Science.gov (United States)

    Ling, Qing-Hua; Song, Yu-Qing; Han, Fei; Yang, Dan; Huang, De-Shuang

    2016-01-01

    For ensemble learning, how to select and combine the candidate classifiers are two key issues which influence the performance of the ensemble system dramatically. Random vector functional link networks (RVFL) without direct input-to-output links is one of suitable base-classifiers for ensemble systems because of its fast learning speed, simple structure and good generalization performance. In this paper, to obtain a more compact ensemble system with improved convergence performance, an improved ensemble of RVFL based on attractive and repulsive particle swarm optimization (ARPSO) with double optimization strategy is proposed. In the proposed method, ARPSO is applied to select and combine the candidate RVFL. As for using ARPSO to select the optimal base RVFL, ARPSO considers both the convergence accuracy on the validation data and the diversity of the candidate ensemble system to build the RVFL ensembles. In the process of combining RVFL, the ensemble weights corresponding to the base RVFL are initialized by the minimum norm least-square method and then further optimized by ARPSO. Finally, a few redundant RVFL is pruned, and thus the more compact ensemble of RVFL is obtained. Moreover, in this paper, theoretical analysis and justification on how to prune the base classifiers on classification problem is presented, and a simple and practically feasible strategy for pruning redundant base classifiers on both classification and regression problems is proposed. Since the double optimization is performed on the basis of the single optimization, the ensemble of RVFL built by the proposed method outperforms that built by some single optimization methods. Experiment results on function approximation and classification problems verify that the proposed method could improve its convergence accuracy as well as reduce the complexity of the ensemble system.

  8. Recruiting and retaining low-income, multi-ethnic women into randomized controlled trials: successful strategies and staffing.

    Science.gov (United States)

    Barnett, Josephine; Aguilar, Stephanie; Brittner, Mindy; Bonuck, Karen

    2012-09-01

    Developing effective recruitment and retention strategies in populations with traditionally high attrition rates is critical to the success of Randomized Controlled Trials (RCTs). Data on successful participation of women from low-income, minority populations in RCTs of behavioral interventions are limited. This is problematic given the multiplicity of Healthy People 2020 goals that target health disparities in these populations. This paper reports successful recruitment and retention methods from two separately funded NIH clinical trials of primary care-based prenatal interventions to increase breastfeeding among ethnically diverse, low-income women in urban medical centers in the Bronx, NY. It also presents the required staff effort necessary to conduct such a successful RCT, in terms of full-time equivalents (FTEs). Results include timely recruitment of 941 participants over 29 months, with 98.1% completing >¯¯1 follow-up interview. A recruitment and retention plan that maximized study staff access and availability to the participant, as well as strong study staff rapport with participants, addressed previously reported barriers in this population, optimizing follow-up rates. A qualitative assessment of the participants' study experience suggesting that high retention was due to strong rapport with participants, short interviews requiring little time commitment, and participants' perception of the study as informative, provides further evidence of our approach's effectiveness. Logistical protocol procedures and staff management strategies relating to successful recruitment/retention are provided to propose a practical, cost-effective and translational recruitment-retention plan for other researchers to adopt. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Comparative Effectiveness of Post-Discharge Strategies for Hospitalized Smokers: study protocol for the Helping HAND 2 randomized controlled trial.

    Science.gov (United States)

    Reid, Zachary Z; Regan, Susan; Kelley, Jennifer H K; Streck, Joanna M; Ylioja, Thomas; Tindle, Hilary A; Chang, Yuchiao; Levy, Douglas E; Park, Elyse R; Singer, Daniel E; Carpenter, Kelly M; Reyen, Michele; Rigotti, Nancy A

    2015-02-07

    Smoking cessation interventions for hospitalized smokers are effective in promoting smoking cessation, but only if the tobacco dependence treatment continues after the patient leaves the hospital. Sustaining tobacco dependence treatment after hospital discharge is a challenge for health care systems. Our previous single-site randomized controlled trial demonstrated the effectiveness of an intervention that facilitated the delivery of comprehensive tobacco cessation treatment, including both medication and counseling, after hospital discharge. We subsequently streamlined the intervention model to increase its potential for dissemination. This new model is being tested in a larger multi-site trial with broader eligibility criteria in order to enroll a more representative sample of hospitalized smokers. This paper describes the trial design and contrasts it with the earlier study. A 2-arm, 3-site randomized controlled trial is testing the hypothesis that a multi-component Sustained Care intervention is more effective than Standard Care in helping hospitalized cigarette smokers stop smoking after hospital discharge. The trial enrolls adult daily cigarette smokers who are admitted to 1 of 3 participating hospitals in Massachusetts or Pennsylvania. Participants receive the same smoking cessation intervention in the hospital. They are randomly assigned to receive either Standard Care or Sustained Care after hospital discharge. Participants in the Sustained Care arm receive a free 3-month supply of FDA-approved smoking cessation medication and 5 interactive voice response calls that provide tailored motivational messages, medication refills, and access to a live tobacco treatment counselor. Participants in the Standard Care arm receive a smoking cessation medication recommendation and information about community resources. Outcomes are assessed at 1, 3, and 6 months after discharge. The primary outcome is biochemically-validated tobacco abstinence for the past 7 days at 6

  10. Cost-effectiveness of a mild compared with a standard strategy for IVF: a randomized comparison using cumulative term live birth as the primary endpoint.

    Science.gov (United States)

    Polinder, S; Heijnen, E M E W; Macklon, N S; Habbema, J D F; Fauser, B J C M; Eijkemans, M J C

    2008-02-01

    BACKGROUND Conventional ovarian stimulation and the transfer of two embryos in IVF exhibits an inherent high probability of multiple pregnancies, resulting in high costs. We evaluated the cost-effectiveness of a mild compared with a conventional strategy for IVF. METHODS Four hundred and four patients were randomly assigned to undergo either mild ovarian stimulation/GnRH antagonist co-treatment combined with single embryo transfer, or standard stimulation/GnRH agonist long protocol and the transfer of two embryos. The main outcome measures are total costs of treatment within a 12 months period after randomization, and the relationship between total costs and proportion of cumulative pregnancies resulting in term live birth within 1 year of randomization. RESULTS Despite a significantly increased average number of IVF cycles (2.3 versus 1.7; P strategy. This was mainly due to higher costs of the obstetric and post-natal period for the standard strategy, related to multiple pregnancies. The costs per pregnancy leading to term live birth were euro19 156 in the mild strategy and euro24 038 in the standard. The incremental cost-effectiveness ratio of the standard strategy compared with the mild strategy was euro185 000 per extra pregnancy leading to term live birth. CONCLUSIONS Despite an increased mean number of IVF cycles within 1 year, from an economic perspective, the mild treatment strategy is more advantageous per term live birth. It is unlikely, over a wide range of society's willingness-to-pay, that the standard treatment strategy is cost-effective, compared with the mild strategy.

  11. Cost-effectiveness of antibiotic treatment strategies for community-acquired pneumonia : results from a cluster randomized cross-over trial

    NARCIS (Netherlands)

    van Werkhoven, Cornelis H; Postma, Douwe F; Mangen, Marie-Josee J; Oosterheert, Jan Jelrik; Bonten, Marc J M

    2017-01-01

    BACKGROUND: To determine the cost-effectiveness of strategies of preferred antibiotic treatment with beta-lactam/macrolide combination or fluoroquinolone monotherapy compared to beta-lactam monotherapy. METHODS: Costs and effects were estimated using data from a cluster-randomized cross-over trial

  12. Efficacy of Self-Regulated Strategy Development Instruction for Developing Writers with and without Disabilities in Rural Schools: A Randomized Controlled Trial

    Science.gov (United States)

    Mason, Linda H.; Cramer, Anne Mong; Garwood, Justin D.; Varghese, Cheryl; Hamm, Jill; Murray, Allen

    2017-01-01

    A workshop with virtual consultation practice-based professional development model for self-regulated strategy development persuasive writing instruction was evaluated in a randomized controlled trial. Nineteen general education teachers and 564 Grade 5 and 6 students in 16 low-wealth rural schools participated. Following training, teachers…

  13. Examining Contextual Influences on Classroom-Based Implementation of Positive Behavior Support Strategies: Findings from a Randomized Controlled Effectiveness Trial.

    Science.gov (United States)

    Pas, Elise T; Waasdorp, Tracy E; Bradshaw, Catherine P

    2015-11-01

    Although it is widely recognized that variation in implementation fidelity influences the impact of preventive interventions, little is known about how specific contextual factors may affect the implementation of social and behavioral interventions in classrooms. Theoretical research highlights the importance of multiple contextual influences on implementation, including factors at the classroom and school level (Domitrovich et al., Advances in School Mental Health Promotion, 1, 6-28, 2008). The current study used multi-level modeling to empirically examine the influence of teacher, classroom, and school characteristics on the implementation of classroom-based positive behavior support strategies over the course of 4 years. Data were collected in the context of a 37-school randomized controlled trial examining the effectiveness of school-wide Positive Behavioral Interventions and Supports. Multi-level results identified several school-level contextual factors (e.g., school size, behavioral disruptions) and teacher-level factors (perceptions of school organizational health and grade level taught) associated with variability in the implementation of classroom-based positive behavior supports. Implications for prevention research and practice are discussed.

  14. A cluster randomized controlled trial of strategies to increase adolescents' physical activity and motivation in physical education: results of the Motivating Active Learning in Physical Education (MALP) trial.

    Science.gov (United States)

    Lonsdale, Chris; Rosenkranz, Richard R; Sanders, Taren; Peralta, Louisa R; Bennie, Andrew; Jackson, Ben; Taylor, Ian M; Lubans, David R

    2013-11-01

    Physical education (PE) programs aim to promote physical activity (PA) and reach most school-aged youth. However, PA levels within PE lessons are often low. In this cluster-randomized controlled trial, we examined the effects of three self-determination theory-based motivational strategies on PA and sedentary behavior, as well as their hypothesized antecedents during PE lessons. Data were collected in Sydney, Australia (October-December 2011). After baseline testing, teachers (n=16) and their classes (n=288 students; M=13.6 years, 50.4% male) were randomly assigned to one of four teaching strategy conditions: (1) explaining relevance; (2) providing choice; (3) complete free choice; or (4) usual practice. Teachers then delivered the assigned strategy. Primary outcomes were accelerometer-assessed PA and student motivation during lessons. Secondary outcomes included sedentary behavior, perceptions of teachers' support and psychological needs satisfaction. The 'free choice' intervention increased PA (pPE lessons. © 2013.

  15. Mastering Search Analytics Measuring SEO, SEM and Site Search

    CERN Document Server

    Chaters, Brent

    2011-01-01

    Many companies still approach Search Engine Optimization (SEO) and paid search as separate initiatives. This in-depth guide shows you how to use these programs as part of a comprehensive strategy-not just to improve your site's search rankings, but to attract the right people and increase your conversion rate. Learn how to measure, test, analyze, and interpret all of your search data with a wide array of analytic tools. Gain the knowledge you need to determine the strategy's return on investment. Ideal for search specialists, webmasters, and search marketing managers, Mastering Search Analyt

  16. Effect of a lung protective strategy for organ donors on eligibility and availability of lungs for transplantation: a randomized controlled trial.

    Science.gov (United States)

    Mascia, Luciana; Pasero, Daniela; Slutsky, Arthur S; Arguis, M Jose; Berardino, Maurizio; Grasso, Salvatore; Munari, Marina; Boifava, Silvia; Cornara, Giuseppe; Della Corte, Francesco; Vivaldi, Nicoletta; Malacarne, Paolo; Del Gaudio, Paolo; Livigni, Sergio; Zavala, Elisabeth; Filippini, Claudia; Martin, Erica L; Donadio, Pier Paolo; Mastromauro, Ilaria; Ranieri, V Marco

    2010-12-15

    Many potential donor lungs deteriorate between the time of brain death and evaluation for transplantation suitability, possibly because of the ventilatory strategy used after brain death. To test whether a lung protective strategy increases the number of lungs available for transplantation. Multicenter randomized controlled trial of patients with beating hearts who were potential organ donors conducted at 12 European intensive care units from September 2004 to May 2009 in the Protective Ventilatory Strategy in Potential Lung Donors Study. Interventions Potential donors were randomized to the conventional ventilatory strategy (with tidal volumes of 10-12 mL/kg of predicted body weight, positive end-expiratory pressure [PEEP] of 3-5 cm H(2)O, apnea tests performed by disconnecting the ventilator, and open circuit for airway suction) or the protective ventilatory strategy (with tidal volumes of 6-8 mL/kg of predicted body weight, PEEP of 8-10 cm H(2)O, apnea tests performed by using continuous positive airway pressure, and closed circuit for airway suction). The number of organ donors meeting eligibility criteria for harvesting, number of lungs harvested, and 6-month survival of lung transplant recipients. The trial was stopped after enrolling 118 patients (59 in the conventional ventilatory strategy and 59 in the protective ventilatory strategy) because of termination of funding. The number of patients who met lung donor eligibility criteria after the 6-hour observation period was 32 (54%) in the conventional strategy vs 56 (95%) in the protective strategy (difference of 41% [95% confidence interval {CI}, 26.5% to 54.8%]; P <.001). The number of patients in whom lungs were harvested was 16 (27%) in the conventional strategy vs 32 (54%) in the protective strategy (difference of 27% [95% CI, 10.0% to 44.5%]; P = .004). Six-month survival rates did not differ between recipients who received lungs from donors ventilated with the conventional strategy compared with the

  17. Demystifying the Search Button

    Science.gov (United States)

    McKeever, Liam; Nguyen, Van; Peterson, Sarah J.; Gomez-Perez, Sandra

    2015-01-01

    A thorough review of the literature is the basis of all research and evidence-based practice. A gold-standard efficient and exhaustive search strategy is needed to ensure all relevant citations have been captured and that the search performed is reproducible. The PubMed database comprises both the MEDLINE and non-MEDLINE databases. MEDLINE-based search strategies are robust but capture only 89% of the total available citations in PubMed. The remaining 11% include the most recent and possibly relevant citations but are only searchable through less efficient techniques. An effective search strategy must employ both the MEDLINE and the non-MEDLINE portion of PubMed to ensure all studies have been identified. The robust MEDLINE search strategies are used for the MEDLINE portion of the search. Usage of the less robust strategies is then efficiently confined to search only the remaining 11% of PubMed citations that have not been indexed for MEDLINE. The current article offers step-by-step instructions for building such a search exploring methods for the discovery of medical subject heading (MeSH) terms to search MEDLINE, text-based methods for exploring the non-MEDLINE database, information on the limitations of convenience algorithms such as the “related citations feature,” the strengths and pitfalls associated with commonly used filters, the proper usage of Boolean operators to organize a master search strategy, and instructions for automating that search through “MyNCBI” to receive search query updates by email as new citations become available. PMID:26129895

  18. Comparison of mailed invitation strategies to improve fecal occult blood test participation in men: protocol for a randomized controlled trial.

    Science.gov (United States)

    Duncan, Amy; Zajac, Ian; Flight, Ingrid; Stewart, Benjamin J R; Wilson, Carlene; Turnbull, Deborah

    2013-07-31

    Men have a significantly increased risk of being diagnosed with, and dying from, colorectal cancer (CRC) than women. Men also participate in fecal occult blood test (FOBT) screening at a lower rate than women. This study will determine whether strategies that target men's attitudes toward screening, and matched to stage of readiness to screen, increase men's FOBT participation compared to a standard approach. Eligible trial participants will be a national sample of 9,200 men aged 50 to 74 years, living in urban Australia and randomly selected from the Australian electoral roll. Trial participants will be mailed an advance notification letter, followed 2 weeks later by an invitation letter and a free fecal immunochemical test (FIT) kit. The intervention is a factorial design, randomized controlled trial (RCT) with four trial arms, including a control. The content of the advance notification and invitation letters will differ by trial arm as follows: 1) standard advance notification and standard invitation (control arm); 2) targeted advance notification and standard invitation; 3) standard advance notification and targeted invitation; and 4) targeted advance notification and targeted invitation. The standard letters will replicate as closely as possible the letters included in the Australian National Bowel Cancer Screening Program (NBCSP). Modified advance notification and invitation letters will incorporate additional messages to target men in the precontemplation (advance notification) and contemplation stages (invitation). The primary outcome is return of the completed FIT within 12 weeks of invitation. Analysts will be blinded to trial assignment and participants will be blinded to the use of varying invitational materials. Subsamples from each trial arm will complete baseline and endpoint surveys to measure the psychological impact of the intervention, and qualitative interviews will be conducted to evaluate attitudes toward the intervention. The outcomes of

  19. Recruitment strategies should not be randomly selected: empirically improving recruitment success and diversity in developmental psychology research

    Science.gov (United States)

    Sugden, Nicole A.; Moulson, Margaret C.

    2015-01-01

    Psychological and developmental research have been critiqued for the lack of diversity of research samples. Because differences in culture, race, and ethnicity can influence participant behavior, limited diversity limits the generalizability of the findings. These differences may also impact how participants behave in response to recruitment attempts, which suggests that recruitment itself may be leveraged to increase sample diversity. The goal of the current study was to determine what factors, within a recruitment interaction, could be leveraged to increase success and diversity when recruiting families with children for developmental research. Study 1 found three factors influenced success: (1) recruitment was more successful when other potential participants were also interested (i.e., recruiters were busy), (2) recruiters of particular races were more successful than recruiters of other races, and (3) differences in success were related to what the recruiter said to engage the potential participant (i.e., the script). The latter two factors interacted, suggesting some recruiters were using less optimal scripts. To improve success rates, study 2 randomly assigned scripts to recruiters and encouraged them to recruit more vigorously during busy periods. Study 2 found that two factors influenced success: (1) some scripts were more successful than others and (2) we were more successful at recruiting non-White potential participants than White participants. These two interacted, with some scripts being more successful with White and other scripts being more successful with non-White families. This intervention significantly increased recruitment success rate by 8.1% and the overall number of families recruited by 15.3%. These findings reveal that empirically evaluating and tailoring recruitment efforts based on the most successful strategies is effective in boosting diversity through increased participation of children from non-White families. PMID:25972829

  20. Strategies to Maximize Data Collection Response Rates in a Randomized Control Trial Focused on Children with Medical Complexity.

    Science.gov (United States)

    Finkelstein, Stanley M; Celebrezze, Margaret; Cady, Rhonda; Lunos, Scott; Looman, Wendy S

    2016-04-01

    Obtaining complete and timely subject data is key to the success of clinical trials, particularly for studies requiring data collected from subjects at home or other remote sites. A multifaceted strategy for data collection in a randomized controlled trial (RCT) focused on care coordination for children with medical complexity is described. The influences of data collection mode, incentives, and study group membership on subject response patterns are analyzed. Data collection included monthly healthcare service utilization (HCSU) calendars and annual surveys focused on care coordination outcomes. One hundred sixty-three families were enrolled in the 30-month TeleFamilies RCT. Subjects were 2-15 years of age at enrollment. HCSU data were collected by parent/guardian self-report using mail, e-mail, telephone, or texting. Surveys were collected by mail. Incentives were provided for completed surveys after 8 months to improve collection returns. Outcome measures were the number of HCSU calendars and surveys returned, the return interval, data collection mode, and incentive impact. Return rates of 90% for HCSU calendars and 82% for annual surveys were achieved. Mean return intervals were 72 and 65 days for HCSU and surveys, respectively. Survey response increased from 55% to 95% after introduction of a gift card and added research staff. High return rates for HCSU calendars and health-related surveys are attainable but required a flexible and personnel-intensive approach to collection methods. Family preference for data collection approach should be obtained at enrollment, should be modified as needed, and requires flexible options, training, intensive staff/family interaction, and patience.

  1. Recruitment strategies should not be randomly selected: empirically improving recruitment success and diversity in developmental psychology research.

    Science.gov (United States)

    Sugden, Nicole A; Moulson, Margaret C

    2015-01-01

    Psychological and developmental research have been critiqued for the lack of diversity of research samples. Because differences in culture, race, and ethnicity can influence participant behavior, limited diversity limits the generalizability of the findings. These differences may also impact how participants behave in response to recruitment attempts, which suggests that recruitment itself may be leveraged to increase sample diversity. The goal of the current study was to determine what factors, within a recruitment interaction, could be leveraged to increase success and diversity when recruiting families with children for developmental research. Study 1 found three factors influenced success: (1) recruitment was more successful when other potential participants were also interested (i.e., recruiters were busy), (2) recruiters of particular races were more successful than recruiters of other races, and (3) differences in success were related to what the recruiter said to engage the potential participant (i.e., the script). The latter two factors interacted, suggesting some recruiters were using less optimal scripts. To improve success rates, study 2 randomly assigned scripts to recruiters and encouraged them to recruit more vigorously during busy periods. Study 2 found that two factors influenced success: (1) some scripts were more successful than others and (2) we were more successful at recruiting non-White potential participants than White participants. These two interacted, with some scripts being more successful with White and other scripts being more successful with non-White families. This intervention significantly increased recruitment success rate by 8.1% and the overall number of families recruited by 15.3%. These findings reveal that empirically evaluating and tailoring recruitment efforts based on the most successful strategies is effective in boosting diversity through increased participation of children from non-White families.

  2. Recruitment strategies shouldn’t be randomly selected: Empirically improving recruitment success and diversity in developmental psychology research

    Directory of Open Access Journals (Sweden)

    Nicole Andrea Sugden

    2015-04-01

    Full Text Available Psychological and developmental research have been critiqued for the lack of diversity of research samples. Because differences in culture, race, and ethnicity can influence participant behavior, limited diversity limits the generalizability of the findings. These differences may also impact how participants behave in response to recruitment attempts, which suggests that recruitment itself may be leveraged to increase sample diversity. The goal of the current study was to determine what factors, within a recruitment interaction, could be leveraged to increase success and diversity when recruiting families with children for developmental research. Study 1 found three factors influenced success: 1 recruitment was more successful when other potential participants were also interested (i.e., recruiters were busy, 2 recruiters of particular races were more successful than recruiters of other races, and 3 differences in success were related to what the recruiter said to engage the potential participant (i.e., the script. The latter two factors interacted, suggesting some recruiters were using less optimal scripts. To improve success rates, study 2 randomly assigned scripts to recruiters and encouraged them to recruit more vigorously during busy periods. Study 2 found that two factors influenced success: 1 some scripts were more successful than others and 2 we were more successful at recruiting non-White potential participants than White participants. These two interacted, with some scripts being more successful with White and other scripts being more successful with non-White families. This intervention significantly increased recruitment success rate by 8.1% and the overall number of families recruited by 15.3%. These findings reveal that empirically evaluating and tailoring recruitment efforts based on the most successful strategies is effective in boosting diversity through increased participation of children from non-White families.

  3. Comparison of two strategies for initiating renal replacement therapy in the intensive care unit: study protocol for a randomized controlled trial (AKIKI).

    Science.gov (United States)

    Gaudry, Stéphane; Hajage, David; Schortgen, Fréderique; Martin-Lefevre, Laurent; Tubach, Florence; Pons, Bertrand; Boulet, Eric; Boyer, Alexandre; Lerolle, Nicolas; Chevrel, Guillaume; Carpentier, Dorothée; Lautrette, Alexandre; Bretagnol, Anne; Mayaux, Julien; Thirion, Marina; Markowicz, Philippe; Thomas, Guillemette; Dellamonica, Jean; Richecoeur, Jack; Darmon, Michael; de Prost, Nicolas; Yonis, Hodane; Megarbane, Bruno; Loubières, Yann; Blayau, Clarisse; Maizel, Julien; Zuber, Benjamin; Nseir, Saad; Bigé, Naïke; Hoffmann, Isabelle; Ricard, Jean-Damien; Dreyfuss, Didier

    2015-04-17

    There is currently no validated strategy for the timing of renal replacement therapy (RRT) for acute kidney injury (AKI) in the intensive care unit (ICU) when short-term life-threatening metabolic abnormalities are absent. No adequately powered prospective randomized study has addressed this issue to date. As a result, significant practice heterogeneity exists and may expose patients to either unnecessary hazardous procedures or undue delay in RRT. This is a multicenter, prospective, randomized, open-label parallel-group clinical trial that compares the effect of two RRT initiation strategies on overall survival of critically ill patients receiving intravenous catecholamines or invasive mechanical ventilation and presenting with AKI classification stage 3 (KDIGO 2012). In the 'early' strategy, RRT is initiated immediately. In the 'delayed' strategy, clinical and metabolic conditions are closely monitored and RRT is initiated only when one or more events (severity criteria) occur, including: oliguria or anuria for more than 72 hours after randomization, serum urea concentration >40 mmol/l, serum potassium concentration >6 mmol/l, serum potassium concentration >5.5 mmol/l persisting despite medical treatment, arterial blood pH 5 l/min to maintain SpO2 > 95% or FiO2 > 50% under invasive or noninvasive mechanical ventilation. The primary outcome measure is overall survival, measured from randomization (D0) until death, regardless of the cause. The minimum follow-up duration for each patient will be 60 days. Two interim analyses are planned, blinded to group allocation. It is expected that there will be 620 subjects in all. The AKIKI study will be one of the very few large randomized controlled trials evaluating mortality according to the timing of RRT in critically ill patients with AKI classification stage 3 (KDIGO 2012). Results should help clinicians decide when to initiate RRT. ClinicalTrials.gov NCT01932190.

  4. Prices and heterogeneous search costs

    NARCIS (Netherlands)

    Moraga Gonzalez, J.L.; Sandor, Z.; Wildenbeest, M.R.

    2017-01-01

    We study price formation in a model of consumer search for differentiated products in which consumers have heterogeneous search costs. We provide conditions under which a pure-strategy symmetric Nash equilibrium exists and is unique. Search costs affect two margins—the intensive search margin (or

  5. Management strategies for fibromyalgia.

    Science.gov (United States)

    Le Marshall, Kim Francis; Littlejohn, Geoffrey Owen

    2011-01-01

    What are the effective, evidence-based strategies available for the management of fibromyalgia? There are a number of management strategies available with robust evidence to support their use in clinical practice. Fibromyalgia is a complex pain syndrome characterized by widespread, chronic muscular pain and tenderness, disordered sleep, emotional distress, cognitive disturbance, and fatigue. Its prevalence is estimated to be 3%-5% in the population and higher yet in patients with comorbid rheumatic diseases. Systematic reviews, meta-analyses, randomized controlled trials (RCTs). PubMed, Cochrane Library, manual search. Key messages for patients and clinicians are: There are many effective pharmacological management strategies available for fibromyalgia.A nonpharmacological, multicomponent approach utilizing education, aerobic exercise, psychological therapy, and other strategies is also effective for fibromyalgia.Despite the significant and, at times, disabling physical and psychological symptoms, fibromyalgia can be a manageable condition with a potentially good outcome.

  6. Searching for Adverse Effects in MEDLINE and EMBASE Requires a Combined Approach for Efficient Retrieval, A review of: Golder, Su, Heather M. McIntosh, Steve Duffy, and Julie Glanville. “Developing Efficient Search Strategies to Identify Reports of Adverse Effects in MEDLINE and EMBASE.” Health Information & Libraries Journal 23.1 (Mar. 2006: 3-12.

    Directory of Open Access Journals (Sweden)

    Marcy L. Brown

    2006-09-01

    Full Text Available Objective – To assess the sensitivity and precision of various search strategies for retrieving adverse effects studies from the MEDLINE and EMBASE databases. Design – Analytical survey. Subjects – A case study using a recently published systematic review of the effectiveness and adverse effects of seven new anti-epileptic drugs. Setting – MEDLINE and EMBASE searches performed by researchers at the Centre for Reviews and Dissemination and the UK Cochrane Centre Search Filters Design Group at the University of York, UK. Methods – Five key approaches to searching were defined. The first approach used either text words or controlled vocabulary to search for specific adverse effects. The second used subheadings or qualifiers either attached to drug names found in the controlled vocabulary (approach 2a or ‘floating’ without drug names (approach 2b. The third approach used text words as synonyms for the phrase ‘adverse effects.’ The fourth used controlled indexing terms for adverse effects. The fifth and final approach used two published search strategies incorporating study design (Badgett et al., Loke et al.. These five approaches were used to search for studies of the adverse effects of seven new anti‐epileptic drugs. 5,011 unique papers were retrieved. Of these, 236 were judged potentially relevant and 225 full text articles were obtained. The inclusion criteria from a previously published systematic review (Wilby et al. were applied to the papers, and 79 met the criteria. Five papers were added to the set after being identified from reference lists, clinical experts, and other sources. This new set of 84 studies was used as a quasi gold standard (QGS against which more than 300 combinations of the five approaches could be tested. To create the set of possible approaches, the researchers combined search strategies one through four in all possible ways, and used all available subheading combinations from 2a and 2b. The Badgett

  7. The effect of an intraoperative, lung-protective ventilation strategy in neurosurgical patients undergoing craniotomy: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Zhang, Liyong; Xiong, Wei; Peng, Yuming; Zhang, Wei; Han, Ruquan

    2018-02-02

    Ventilator-induced lung injury is a major cause of postoperative pulmonary complications (PPCs) in patients undergoing neurosurgery after general anesthesia. However, there is no study on the effect of a lung-protective ventilation strategy in patients undergoing neurosurgery. This is a single-center, randomized, parallel-group controlled trial which will be carried out at Beijing Tiantan Hospital, Capital Medical University. Three hundred and thirty-four patients undergoing intracranial tumor surgery will be randomly allocated to the control group and the protective-ventilation strategy group. In the control group, tidal volume (VT) will be set at 10-12 ml/kg of predicted body weight but PEEP and recruitment maneuvers will not be used. In the protective group, VT will be set at 6-8 ml/kg of predicted body weight, PEEP at 6-8 cmH 2 O, and a recruitment maneuver will be used intermittently. The primary outcome is pulmonary complications within 7 days postoperatively. Secondary outcomes include intraoperative brain relaxation, the postoperative complications within 30 days and the cost analysis. This study aims to determine if the protective, pulmonary-ventilation strategy decreases the incidence of PPCs in patients undergoing neurosurgical anesthesia. If our results are positive, the study will indicate whether the protective, pulmonary-ventilation strategy is efficiently and safely used in neurosurgical patients undergoing the craniotomy. ClinicalTrials.gov, ID: NCT02386683 . Registered on 18 October 2014.

  8. National evaluation of strategies to reduce safety violations for working from heights in construction companies: results from a randomized controlled trial.

    Science.gov (United States)

    van der Molen, Henk F; den Herder, Aalt; Warning, Jan; Frings-Dresen, Monique H W

    2016-01-09

    The objective of this study is to evaluate the effectiveness of a face-to-face strategy and a direct mail strategy on safety violations while working from heights among construction companies compared to a control condition. Construction companies with workers at risk for fall injuries were eligible for this three-armed randomized controlled trial. In total, 27 cities were randomly assigned to intervention groups-where eligible companies were given either a face-to-face guidance strategy or a direct mailing strategy with access to internet facilities-or to a control group. The primary outcomes were the number and type of safety violations recorded by labor inspectors after three months. A process evaluation for both strategies was performed to determine reach, program implementation, satisfaction, knowledge and perceived safety behavior. A cost analysis was performed to establish the financial costs for each intervention strategy. Analyses were done by intention to treat. In total, 41% (n = 88) of the companies eligible for the face-to-face intervention participated and 73% (n = 69) for direct mail. Intervention materials were delivered to 69 % (face-to-face group) and 100 % (direct mail group); completion of intervention activities within companies was low. Satisfaction, increase in knowledge, and safety behavior did not differ between the intervention groups. Costs for personal advice were 28% higher than for direct mail. Ultimately, nine intervention companies were captured in the 288 worksite measurements performed by the labor inspectorate. No statistical differences in mean number of safety violations (1.8-2.4) or penalties (72%-100%) were found between the intervention and control groups based on all worksite inspections. No conclusions about the effect of face-to-face and direct mail strategies on safety violations could be drawn due to the limited number of intervention companies captured in the primary outcome measurements. The costs for a face

  9. Effective Strategies to Recruit Young Adults Into the TXT2BFiT mHealth Randomized Controlled Trial for Weight Gain Prevention

    Science.gov (United States)

    Balestracci, Kate; Wong, Annette TY; Hebden, Lana; McGeechan, Kevin; Denney-Wilson, Elizabeth; Harris, Mark F; Phongsavan, Philayrath; Bauman, Adrian; Allman-Farinelli, Margaret

    2015-01-01

    Background Younger adults are difficult to engage in preventive health, yet in Australia they are gaining more weight and increasing in waist circumference faster than middle-to-older adults. A further challenge to engaging 18- to 35-year-olds in interventions is the limited reporting of outcomes of recruitment strategies. Objective This paper describes the outcomes of strategies used to recruit young adults to a randomized controlled trial (RCT), healthy lifestyle mHealth program, TXT2BFiT, for prevention of weight gain. The progression from enquiry through eligibility check to randomization into the trial and the costs of recruitment strategies are reported. Factors associated with nonparticipation are explored. Methods Participants were recruited either via letters of invitation from general practitioners (GPs) or via electronic or print advertisements, including Facebook and Google—social media and advertising—university electronic newsletters, printed posters, mailbox drops, and newspapers. Participants recruited from GP invitation letters had an appointment booked with their GP for eligibility screening. Those recruited from other methods were sent an information pack to seek approval to participate from their own GP. The total number and source of enquiries were categorized according to eligibility and subsequent completion of steps to enrolment. Cost data and details of recruitment strategies were recorded. Results From 1181 enquiries in total from all strategies, 250 (21.17%) participants were randomized. A total of 5311 invitation letters were sent from 12 GP practices—16 participating GPs. A total of 131 patients enquired with 68 participants randomized (68/74 of those eligible, 92%). The other recruitment methods yielded the remaining 182 randomized participants. Enrolment from print media was 26% of enquiries, from electronic media was 20%, and from other methods was 3%. Across all strategies the average cost of recruitment was Australian Dollar

  10. Effective Strategies to Recruit Young Adults Into the TXT2BFiT mHealth Randomized Controlled Trial for Weight Gain Prevention.

    Science.gov (United States)

    Partridge, Stephanie R; Balestracci, Kate; Wong, Annette Ty; Hebden, Lana; McGeechan, Kevin; Denney-Wilson, Elizabeth; Harris, Mark F; Phongsavan, Philayrath; Bauman, Adrian; Allman-Farinelli, Margaret

    2015-06-05

    Younger adults are difficult to engage in preventive health, yet in Australia they are gaining more weight and increasing in waist circumference faster than middle-to-older adults. A further challenge to engaging 18- to 35-year-olds in interventions is the limited reporting of outcomes of recruitment strategies. This paper describes the outcomes of strategies used to recruit young adults to a randomized controlled trial (RCT), healthy lifestyle mHealth program, TXT2BFiT, for prevention of weight gain. The progression from enquiry through eligibility check to randomization into the trial and the costs of recruitment strategies are reported. Factors associated with nonparticipation are explored. Participants were recruited either via letters of invitation from general practitioners (GPs) or via electronic or print advertisements, including Facebook and Google-social media and advertising-university electronic newsletters, printed posters, mailbox drops, and newspapers. Participants recruited from GP invitation letters had an appointment booked with their GP for eligibility screening. Those recruited from other methods were sent an information pack to seek approval to participate from their own GP. The total number and source of enquiries were categorized according to eligibility and subsequent completion of steps to enrolment. Cost data and details of recruitment strategies were recorded. From 1181 enquiries in total from all strategies, 250 (21.17%) participants were randomized. A total of 5311 invitation letters were sent from 12 GP practices-16 participating GPs. A total of 131 patients enquired with 68 participants randomized (68/74 of those eligible, 92%). The other recruitment methods yielded the remaining 182 randomized participants. Enrolment from print media was 26% of enquiries, from electronic media was 20%, and from other methods was 3%. Across all strategies the average cost of recruitment was Australian Dollar (AUD) $139 per person. The least expensive

  11. Comparison of on-demand vs planned relaparotomy strategy in patients with severe peritonitis: a randomized trial

    NARCIS (Netherlands)

    van Ruler, Oddeke; Mahler, Cecilia W.; Boer, Kimberly R.; Reuland, E. Ascelijn; Gooszen, Hein G.; Opmeer, Brent C.; de Graaf, Peter W.; Lamme, Bas; Gerhards, Michael F.; Steller, E. Philip; van Till, J. W. Olivier; de Borgie, Corianne J. A. M.; Gouma, Dirk J.; Reitsma, Johannes B.; Boermeester, Marja A.

    2007-01-01

    CONTEXT: In patients with severe secondary peritonitis, there are 2 surgical treatment strategies following an initial emergency laparotomy: planned relaparotomy and relaparotomy only when the patient's condition demands it ("on-demand"). The on-demand strategy may reduce mortality, morbidity,

  12. A Cluster-Randomized Trial of Two Strategies to Improve Antibiotic Use for Patients with a Complicated Urinary Tract Infection

    NARCIS (Netherlands)

    Spoorenberg, V.; Hulscher, M.E.J.L.; Geskus, R.B.; Reijke, T.M. de; Opmeer, B.C.; Prins, J.M.; Geerlings, S.E.

    2015-01-01

    BACKGROUND: Up to 50% of hospital antibiotic use is inappropriate and therefore improvement strategies are urgently needed. We compared the effectiveness of two strategies to improve the quality of antibiotic use in patients with a complicated urinary tract infection (UTI). METHODS: In a

  13. Search efficiency of biased migration towards stationary or moving targets in heterogeneously structured environments

    Science.gov (United States)

    Azimzade, Youness; Mashaghi, Alireza

    2017-12-01

    Efficient search acts as a strong selective force in biological systems ranging from cellular populations to predator-prey systems. The search processes commonly involve finding a stationary or mobile target within a heterogeneously structured environment where obstacles limit migration. An open generic question is whether random or directionally biased motions or a combination of both provide an optimal search efficiency and how that depends on the motility and density of targets and obstacles. To address this question, we develop a simple model that involves a random walker searching for its targets in a heterogeneous medium of bond percolation square lattice and used mean first passage time (〈T 〉 ) as an indication of average search time. Our analysis reveals a dual effect of directional bias on the minimum value of 〈T 〉 . For a homogeneous medium, directionality always decreases 〈T 〉 and a pure directional migration (a ballistic motion) serves as the optimized strategy, while for a heterogeneous environment, we find that the optimized strategy involves a combination of directed and random migrations. The relative contribution of these modes is determined by the density of obstacles and motility of targets. Existence of randomness and motility of targets add to the efficiency of search. Our study reveals generic and simple rules that govern search efficiency. Our findings might find application in a number of areas including immunology, cell biology, ecology, and robotics.

  14. Patients' and providers' perspectives of a polypill strategy to improve cardiovascular prevention in Australian primary health care: a qualitative study set within a pragmatic randomized, controlled trial.

    Science.gov (United States)

    Liu, Hueiming; Massi, Luciana; Laba, Tracey-Lea; Peiris, David; Usherwood, Tim; Patel, Anushka; Cass, Alan; Eades, Anne-Marie; Redfern, Julie; Hayman, Noel; Howard, Kirsten; Brien, Jo-anne; Jan, Stephen

    2015-05-01

    This study explores health provider and patient attitudes toward the use of a cardiovascular polypill as a health service strategy to improve cardiovascular prevention. In-depth, semistructured interviews (n=94) were conducted with health providers and patients from Australian general practice, Aboriginal community-controlled and government-run Indigenous Health Services participating in a pragmatic randomized controlled trial evaluating a polypill-based strategy for high-risk primary and secondary cardiovascular disease prevention. Interview topics included polypill strategy acceptability, factors affecting adherence, and trial implementation. Transcribed interview data were analyzed thematically and interpretively. Polypill patients commented frequently on cost-savings, ease, and convenience of a daily-dosing pill. Most providers considered a polypill strategy to facilitate improved patient medication use. Indigenous Health Services providers and indigenous patients thought the strategy acceptable and beneficial for indigenous patients given the high disease burden. Providers noted the inflexibility of the fixed dose regimen, with dosages sometimes inappropriate for patients with complex management considerations. Future polypill formulations with varied strengths and classes of medications may overcome this barrier. Many providers suggested the polypill strategy, in its current formulations, might be more suited to high-risk primary prevention patients. The polypill strategy was generally acceptable to patients and providers in cardiovascular prevention. Limitations to provider acceptability of this particular polypill were revealed, as was a perception it might be more suitable for high-risk primary prevention patients, though future combinations could facilitate its use in secondary prevention. Participants suggested a polypill-based strategy as particularly appropriate for lowering the high cardiovascular burden in indigenous populations. URL: http

  15. Best practice guidance for the use of strategies to improve retention in randomized trials developed from two consensus workshops.

    Science.gov (United States)

    Brueton, Valerie; Stenning, Sally P; Stevenson, Fiona; Tierney, Jayne; Rait, Greta

    2017-08-01

    To develop best practice guidance for the use of retention strategies in randomized clinical trials (RCTs). Consensus development workshops conducted at two UK Clinical Trials Units. Sixty-six statisticians, clinicians, RCT coordinators, research scientists, research assistants, and data managers associated with RCTs participated. The consensus development workshops were based on the consensus development conference method used to develop best practice for treatment of medical conditions. Workshops commenced with a presentation of the evidence for incentives, communication, questionnaire format, behavioral, case management, and methodological retention strategies identified by a Cochrane review and associated qualitative study. Three simultaneous group discussions followed focused on (1) how convinced the workshop participants were by the evidence for retention strategies, (2) barriers to the use of effective retention strategies, (3) types of RCT follow-up that retention strategies could be used for, and (4) strategies for future research. Summaries of each group discussion were fed back to the workshop. Coded content for both workshops was compared for agreement and disagreement. Agreed consensus on best practice guidance for retention was identified. Workshop participants agreed best practice guidance for the use of small financial incentives to improve response to postal questionnaires in RCTs. Use of second-class post was thought to be adequate for postal communication with RCT participants. The most relevant validated questionnaire was considered best practice for collecting RCT data. Barriers identified for the use of effective retention strategies were: the small improvements seen in questionnaire response for the addition of monetary incentives, and perceptions among trialists that some communication strategies are outdated. Furthermore, there was resistance to change existing retention practices thought to be effective. Face-to-face and electronic follow

  16. Statistical signatures of a targeted search by bacteria

    Science.gov (United States)

    Jashnsaz, Hossein; Anderson, Gregory G.; Pressé, Steve

    2017-12-01

    Chemoattractant gradients are rarely well-controlled in nature and recent attention has turned to bacterial chemotaxis toward typical bacterial food sources such as food patches or even bacterial prey. In environments with localized food sources reminiscent of a bacterium’s natural habitat, striking phenomena—such as the volcano effect or banding—have been predicted or expected to emerge from chemotactic models. However, in practice, from limited bacterial trajectory data it is difficult to distinguish targeted searches from an untargeted search strategy for food sources. Here we use a theoretical model to identify statistical signatures of a targeted search toward point food sources, such as prey. Our model is constructed on the basis that bacteria use temporal comparisons to bias their random walk, exhibit finite memory and are subject to random (Brownian) motion as well as signaling noise. The advantage with using a stochastic model-based approach is that a stochastic model may be parametrized from individual stochastic bacterial trajectories but may then be used to generate a very large number of simulated trajectories to explore average behaviors obtained from stochastic search strategies. For example, our model predicts that a bacterium’s diffusion coefficient increases as it approaches the point source and that, in the presence of multiple sources, bacteria may take substantially longer to locate their first source giving the impression of an untargeted search strategy.

  17. RANDOMIZED STUDY OF IMPLANTABLE DEFIBRILLATOR AS FIRST-CHOICE THERAPY VERSUS CONVENTIONAL STRATEGY IN POSTINFARCT SUDDEN-DEATH SURVIVORS

    NARCIS (Netherlands)

    WEVER, EFD; HAUER, RNW; VANCAPELLE, FJL; TIJSSEN, JGP; CRIJNS, HJGM; ALGRA, A; WIESFELD, ACP; BAKKER, PFA; DEMEDINA, EOR

    1995-01-01

    Background In retrospective studies of sudden cardiac death survivors, the implantable cardioverter-defibrillator (ICD) compares favorably with medical and surgical therapy. Thus, use of the conventional strategy of starting treatment with antiarrhythmic drugs (AD), at least in certain patient

  18. A description of a knowledge broker role implemented as part of a randomized controlled trial evaluating three knowledge translation strategies

    National Research Council Canada - National Science Library

    Dobbins, Maureen; Robeson, Paula; Ciliska, Donna; Hanna, Steve; Cameron, Roy; O'Mara, Linda; DeCorby, Kara; Mercer, Shawna

    2009-01-01

    A knowledge broker (KB) is a popular knowledge translation and exchange (KTE) strategy emerging in Canada to promote interaction between researchers and end users, as well as to develop capacity for evidence-informed decision making...

  19. Best strategies to implement clinical pathways in an emergency department setting: study protocol for a cluster randomized controlled trial

    National Research Council Canada - National Science Library

    Jabbour, Mona; Curran, Janet; Scott, Shannon D; Guttman, Astrid; Rotter, Thomas; Ducharme, Francine M; Lougheed, M Diane; McNaughton-Filion, M Louise; Newton, Amanda; Shafir, Mark; Paprica, Alison; Klassen, Terry; Taljaard, Monica; Grimshaw, Jeremy; Johnson, David W

    2013-01-01

    ... teams in hospital settings. While high-quality, expert-developed clinical pathways have many potential benefits, their impact has been limited by variable implementation strategies and suboptimal research designs...

  20. Engaging foster parents in treatment: a randomized trial of supplementing trauma-focused cognitive behavioral therapy with evidence-based engagement strategies.

    Science.gov (United States)

    Dorsey, Shannon; Pullmann, Michael D; Berliner, Lucy; Koschmann, Elizabeth; McKay, Mary; Deblinger, Esther

    2014-09-01

    The goal of this study was to examine the impact of supplementing Trauma-focused Cognitive Behavioral Therapy (TF-CBT; Cohen et al., 2006) with evidence-based engagement strategies on foster parent and foster youth engagement in treatment, given challenges engaging foster parents in treatment. A randomized controlled trial of TF-CBT standard delivery compared to TF-CBT plus evidence-based engagement strategies was conducted with 47 children and adolescents in foster care and one of their foster parents. Attendance, engagement, and clinical outcomes were assessed 1 month into treatment, end of treatment, and 3 months post-treatment. Youth and foster parents who received TF-CBT plus evidence-based engagement strategies were more likely to be retained in treatment through four sessions and were less likely to drop out of treatment prematurely. The engagement strategies did not appear to have an effect on the number of canceled or no-show sessions or on treatment satisfaction. Clinical outcomes did not differ by study condition, but exploratory analyses suggest that youth had significant improvements with treatment. Strategies that specifically target engagement may hold promise for increasing access to evidence-based treatments and for increasing likelihood of treatment completion. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. A cluster-randomized controlled trial of strategies to increase adolescents' physical activity and motivation during physical education lessons: the Motivating Active Learning in Physical Education (MALP) trial.

    Science.gov (United States)

    Rosenkranz, Richard R; Lubans, David R; Peralta, Louisa R; Bennie, Andrew; Sanders, Taren; Lonsdale, Chris

    2012-10-01

    The physical activity (PA) levels of many children and adolescents in Australia are currently insufficient to promote health benefits. Physical education (PE) programs aim to promote PA and reach nearly all school-aged children, but PA levels within PE lessons are often low. PE teachers may influence children's motivation to be physically active in PE lessons, but little is known about teacher strategies that effectively motivate children to participate in PA, and few intervention studies have examined motivational strategies in PE. The purpose of this study was to compare the effect of three motivational strategies, each based on Self-Determination Theory (SDT), on PA levels, and their hypothesized antecedents, during year 8 PE lessons. This study employed a cluster-randomized controlled trial design. Following a familiarization session, PA levels and hypothesized PA antecedents were measured during a baseline lesson and a post-intervention or control lesson. Teachers (n = 16) and their classes from five secondary schools in Sydney, Australia were randomly assigned into four blocks and instructed to provide one of four 20-min lesson teaching strategy conditions: (1) explaining the relevance of activities; (2) providing choice from PA options selected by the teacher; (3) providing equipment and free choice of activities; or (4) usual practice. The primary outcomes were lesson time spent in moderate-to-vigorous PA, and motivation towards the lesson. Secondary outcomes were perceptions of teacher behavior, psychological needs satisfaction, and lesson time spent in sedentary behavior. PA and sedentary behavior were measured during baseline and post-intervention lessons with waist-mounted Actigraph GT3X accelerometers. Teacher behavior, psychological needs satisfaction, and motivation were assessed via questionnaires at the end of each lesson. Linear mixed-model analyses will be run on all outcomes, with students nested within teachers as a random effect. Study

  2. A cluster-randomized controlled trial of strategies to increase adolescents’ physical activity and motivation during physical education lessons: the Motivating Active Learning in Physical Education (MALP trial

    Directory of Open Access Journals (Sweden)

    Rosenkranz Richard R

    2012-10-01

    Full Text Available Abstract Background The physical activity (PA levels of many children and adolescents in Australia are currently insufficient to promote health benefits. Physical education (PE programs aim to promote PA and reach nearly all school-aged children, but PA levels within PE lessons are often low. PE teachers may influence children’s motivation to be physically active in PE lessons, but little is known about teacher strategies that effectively motivate children to participate in PA, and few intervention studies have examined motivational strategies in PE. The purpose of this study was to compare the effect of three motivational strategies, each based on Self-Determination Theory (SDT, on PA levels, and their hypothesized antecedents, during year 8 PE lessons. Methods/design This study employed a cluster-randomized controlled trial design. Following a familiarization session, PA levels and hypothesized PA antecedents were measured during a baseline lesson and a post-intervention or control lesson. Teachers (n = 16 and their classes from five secondary schools in Sydney, Australia were randomly assigned into four blocks and instructed to provide one of four 20-min lesson teaching strategy conditions: (1 explaining the relevance of activities; (2 providing choice from PA options selected by the teacher; (3 providing equipment and free choice of activities; or (4 usual practice. The primary outcomes were lesson time spent in moderate-to-vigorous PA, and motivation towards the lesson. Secondary outcomes were perceptions of teacher behavior, psychological needs satisfaction, and lesson time spent in sedentary behavior. PA and sedentary behavior were measured during baseline and post-intervention lessons with waist-mounted Actigraph GT3X accelerometers. Teacher behavior, psychological needs satisfaction, and motivation were assessed via questionnaires at the end of each lesson. Linear mixed-model analyses will be run on all outcomes, with students nested

  3. Placement and promotion strategies to increase sales of healthier products in supermarkets in low-income, ethnically diverse neighborhoods: a randomized controlled trial.

    Science.gov (United States)

    Foster, Gary D; Karpyn, Allison; Wojtanowski, Alexis C; Davis, Erica; Weiss, Stephanie; Brensinger, Colleen; Tierney, Ann; Guo, Wensheng; Brown, Jeffery; Spross, Carly; Leuchten, Donna; Burns, Patrick J; Glanz, Karen

    2014-06-01

    The greater presence of supermarkets in low-income, high-minority neighborhoods has the potential to positively affect diet quality among those at greatest risk of obesity. In-store marketing strategies that draw attention to healthier products may be effective, sustainable, and scalable for improving diet quality and health. Few controlled studies of in-store marketing strategies to promote sales of healthier items in low-income, high-minority neighborhoods have been conducted. The objective of this study was to evaluate the effects of in-store marketing strategies to promote the purchase of specific healthier items in 5 product categories: milk, ready-to-eat cereal, frozen meals, in-aisle beverages, and checkout cooler beverages. The design was a cluster-randomized controlled trial conducted from 2011 to 2012. Eight urban supermarkets in low-income, high-minority neighborhoods were the unit of randomization, intervention, and analysis. Stores were matched on the percentage of sales from government food-assistance programs and store size and randomly assigned to an intervention or control group. The 4 intervention stores received a 6-mo, in-store marketing intervention that promoted the sales of healthier products through placement, signage, and product availability strategies. The 4 control stores received no intervention and were assessment-only controls. The main outcome measure was weekly sales of the targeted products, which was assessed on the basis of the stores' sales data. Intervention stores showed significantly greater sales of skim and 1% milk, water (in aisle and at checkout), and 2 of 3 types of frozen meals compared with control store sales during the same time period. No differences were found between the stores in sales of cereal, whole or 2% milk, beverages, or diet beverages. These data indicate that straightforward placement strategies can significantly enhance the sales of healthier items in several food and beverage categories. Such

  4. A Proposed Multisite Double-Blind Randomized Clinical Trial of Neurofeedback for ADHD: Need, Rationale, and Strategy

    Science.gov (United States)

    Kerson, Cynthia

    2013-01-01

    Objective: Additional treatments with persisting benefit are needed for ADHD. Because ADHD often shows excessive theta electroencephalogram (EEG) power, low beta, and excessive theta-beta ratio (TBR), a promising treatment is neurofeedback (NF) downtraining TBR. Although several nonblind randomized clinical trials (RCTs) show a medium-large…

  5. Effect of perioperative insulin infusion on surgical morbidity and mortality: systematic review and meta-analysis of randomized trials.7

    DEFF Research Database (Denmark)

    Gandhi, G.Y.; Murad, M.H.; Flynn, D.N.

    2008-01-01

    OBJECTIVE: To conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of perioperative insulin infusion on outcomes important to patients. PATIENTS AND METHODS: We used 6 search strategies including an electronic database search of MEDLINE, EMBA...

  6. Randomized Trials for Endovascular Treatment of Infrainguinal Arterial Disease: Systematic Review and Meta-analysis (Part 2: Below the Knee)

    NARCIS (Netherlands)

    Jens, S.; Conijn, A. P.; Koelemay, M. J. W.; Bipat, S.; Reekers, J. A.

    2014-01-01

    Objective: To evaluate 1 to 48 month follow-up outcomes of different endovascular treatment strategies in below-the-knee (BTK) arterial segments in critical limb ischemia (CLI) patients. Methods: Medline and Embase were searched (last searched on 5 November 2013) for studies of randomized controlled

  7. A randomized matched-pairs study of feasibility, acceptability, and effectiveness of systems consultation: a novel implementation strategy for adopting clinical guidelines for Opioid prescribing in primary care.

    Science.gov (United States)

    Quanbeck, Andrew; Brown, Randall T; Zgierska, Aleksandra E; Jacobson, Nora; Robinson, James M; Johnson, Roberta A; Deyo, Brienna M; Madden, Lynn; Tuan, Wen-Jan; Alagoz, Esra

    2018-01-25

    This paper reports on the feasibility, acceptability, and effectiveness of an innovative implementation strategy named "systems consultation" aimed at improving adherence to clinical guidelines for opioid prescribing in primary care. While clinical guidelines for opioid prescribing have been developed, they have not been widely implemented, even as opioid abuse reaches epidemic levels. We tested a blended implementation strategy consisting of several discrete implementation strategies, including audit and feedback, academic detailing, and external facilitation. The study compares four intervention clinics to four control clinics in a randomized matched-pairs design. Each systems consultant aided clinics on implementing the guidelines during a 6-month intervention consisting of monthly site visits and teleconferences/videoconferences. The mixed-methods evaluation employs the RE-AIM (Reach, Effectiveness, Adoption, Implementation, Maintenance) framework. Quantitative outcomes are compared using time series analysis. Qualitative methods included focus groups, structured interviews, and ethnographic field techniques. Seven clinics were randomly approached to recruit four intervention clinics. Each clinic designated a project team consisting of six to eight staff members, each with at least one prescriber. Attendance at intervention meetings was 83%. More than 80% of staff respondents agreed or strongly agreed with the statements: "I am more familiar with guidelines for safe opioid prescribing" and "My clinic's workflow for opioid prescribing is easier." At 6 months, statistically significant improvements were noted in intervention clinics in the percentage of patients with mental health screens, treatment agreements, urine drug tests, and opioid-benzodiazepine co-prescribing. At 12 months, morphine-equivalent daily dose was significantly reduced in intervention clinics compared to controls. The cost to deliver the strategy was $7345 per clinic. Adaptations were

  8. Search Patterns

    CERN Document Server

    Morville, Peter

    2010-01-01

    What people are saying about Search Patterns "Search Patterns is a delight to read -- very thoughtful and thought provoking. It's the most comprehensive survey of designing effective search experiences I've seen." --Irene Au, Director of User Experience, Google "I love this book! Thanks to Peter and Jeffery, I now know that search (yes, boring old yucky who cares search) is one of the coolest ways around of looking at the world." --Dan Roam, author, The Back of the Napkin (Portfolio Hardcover) "Search Patterns is a playful guide to the practical concerns of search interface design. It cont

  9. Drinker prototype alteration and cue reminders as strategies in a tailored web-based intervention reducing adults' alcohol consumption: randomized controlled trial.

    Science.gov (United States)

    van Lettow, Britt; de Vries, Hein; Burdorf, Alex; Boon, Brigitte; van Empelen, Pepijn

    2015-02-04

    Excessive alcohol use is a prevalent and worldwide problem. Excessive drinking causes a significant burden of disease and is associated with both morbidity and excess mortality. Prototype alteration and provision of a cue reminder could be useful strategies to enhance the effectiveness of online tailored interventions for excessive drinking. Through a Web-based randomized controlled trial, 2 strategies (ie, prototype alteration and cue reminders) within an existing online personalized feedback intervention (Drinktest) aimed to reduce adults' excessive drinking. It was expected that both strategies would add to Drinktest and would result in reductions in alcohol consumption by intrinsic motivation and the seizure of opportunities to act. Participants were recruited online and through printed materials. Excessive drinking adults (N=2634) were randomly assigned to 4 conditions: original Drinktest, Drinktest plus prototype alteration, Drinktest plus cue reminder, and Drinktest plus prototype alteration and cue reminder. Evaluation took place at 1-month posttest and 6-month follow-up. Differences in drinking behavior, intentions, and behavioral willingness (ie, primary outcomes) were assessed by means of longitudinal multilevel analyses using a last observation carried forward method. Measures were based on self-reports. All conditions showed reductions in drinking behavior and willingness to drink, and increased intentions to reduce drinking. Prototype alteration (B=-0.15, Pprototypes. Thus, prototype alteration and cue reminder usage may be feasible and simple intervention strategies to promote reductions in alcohol consumption among adults, with an effect up to 6 months. Nederlands Trial Register (NTR): 4169; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4169 (Archived by WebCite at http://www.webcitation.org/6VD2jnxmB).

  10. Drinker Prototype Alteration and Cue Reminders as Strategies in a Tailored Web-Based Intervention Reducing Adults’ Alcohol Consumption: Randomized Controlled Trial

    Science.gov (United States)

    2015-01-01

    Background Excessive alcohol use is a prevalent and worldwide problem. Excessive drinking causes a significant burden of disease and is associated with both morbidity and excess mortality. Prototype alteration and provision of a cue reminder could be useful strategies to enhance the effectiveness of online tailored interventions for excessive drinking. Objective Through a Web-based randomized controlled trial, 2 strategies (ie, prototype alteration and cue reminders) within an existing online personalized feedback intervention (Drinktest) aimed to reduce adults’ excessive drinking. It was expected that both strategies would add to Drinktest and would result in reductions in alcohol consumption by intrinsic motivation and the seizure of opportunities to act. Methods Participants were recruited online and through printed materials. Excessive drinking adults (N=2634) were randomly assigned to 4 conditions: original Drinktest, Drinktest plus prototype alteration, Drinktest plus cue reminder, and Drinktest plus prototype alteration and cue reminder. Evaluation took place at 1-month posttest and 6-month follow-up. Differences in drinking behavior, intentions, and behavioral willingness (ie, primary outcomes) were assessed by means of longitudinal multilevel analyses using a last observation carried forward method. Measures were based on self-reports. Results All conditions showed reductions in drinking behavior and willingness to drink, and increased intentions to reduce drinking. Prototype alteration (B=–0.15, Pprototypes. Thus, prototype alteration and cue reminder usage may be feasible and simple intervention strategies to promote reductions in alcohol consumption among adults, with an effect up to 6 months. Trial Registration Nederlands Trial Register (NTR): 4169; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4169 (Archived by WebCite at http://www.webcitation.org/6VD2jnxmB). PMID:25653199

  11. Feasibility and acceptability of two incentive-based implementation strategies for mental health therapists implementing cognitive-behavioral therapy: a pilot study to inform a randomized controlled trial.

    Science.gov (United States)

    Beidas, Rinad S; Becker-Haimes, Emily M; Adams, Danielle R; Skriner, Laura; Stewart, Rebecca E; Wolk, Courtney Benjamin; Buttenheim, Alison M; Williams, Nathaniel J; Inacker, Patricia; Richey, Elizabeth; Marcus, Steven C

    2017-12-15

    Informed by our prior work indicating that therapists do not feel recognized or rewarded for implementation of evidence-based practices, we tested the feasibility and acceptability of two incentive-based implementation strategies that seek to improve therapist adherence to cognitive-behavioral therapy for youth, an evidence-based practice. This study was conducted over 6 weeks in two community mental health agencies with therapists (n = 11) and leaders (n = 4). Therapists were randomized to receive either a financial or social incentive if they achieved a predetermined criterion on adherence to cognitive-behavioral therapy. In the first intervention period (block 1; 2 weeks), therapists received the reward they were initially randomized to if they achieved criterion. In the second intervention period (block 2; 2 weeks), therapists received both rewards if they achieved criterion. Therapists recorded 41 sessions across 15 unique clients over the project period. Primary outcomes included feasibility and acceptability. Feasibility was assessed quantitatively. Fifteen semi-structured interviews were conducted with therapists and leaders to assess acceptability. Difference in therapist adherence by condition was examined as an exploratory outcome. Adherence ratings were ascertained using an established and validated observational coding system of cognitive-behavioral therapy. Both implementation strategies were feasible and acceptable-however, modifications to study design for the larger trial will be necessary based on participant feedback. With respect to our exploratory analysis, we found a trend suggesting the financial reward may have had a more robust effect on therapist adherence than the social reward. Incentive-based implementation strategies can be feasibly administered in community mental health agencies with good acceptability, although iterative pilot work is essential. Larger, fully powered trials are needed to compare the effectiveness of

  12. The EBC TWO Study (European Bifurcation Coronary TWO): A Randomized Comparison of Provisional T-Stenting Versus a Systematic 2 Stent Culotte Strategy in Large Caliber True Bifurcations.

    Science.gov (United States)

    Hildick-Smith, David; Behan, Miles W; Lassen, Jens F; Chieffo, Alaide; Lefèvre, Thierry; Stankovic, Goran; Burzotta, Francesco; Pan, Manuel; Ferenc, Miroslaw; Bennett, Lorraine; Hovasse, Thomas; Spence, Mark J; Oldroyd, Keith; Brunel, Philippe; Carrie, Didier; Baumbach, Andreas; Maeng, Michael; Skipper, Nicola; Louvard, Yves

    2016-09-01

    For the treatment of coronary bifurcation lesions, a provisional strategy is superior to systematic 2-stent techniques for the most bifurcation lesions. However, complex anatomies with large side branches (SBs) with significant ostial disease length are considered by expert consensus to warrant a 2-stent technique upfront. This consensus view has not been scientifically assessed. Symptomatic patients with large caliber true bifurcation lesions (SB diameter ≥2.5 mm) and significant ostial disease length (≥5 mm) were randomized to either a provisional T-stent strategy or a dual stent culotte technique. Two hundred patients aged 64±10 years, 82% male, were randomized in 20 European centers. The clinical presentations were stable coronary disease (69%) and acute coronary syndromes (31%). SB stent diameter (2.67±0.27 mm) and length (20.30±5.89 mm) confirmed the extent of SB disease. Procedural success (provisional 97%, culotte 94%) and kissing balloon inflation (provisional 95%, culotte 98%) were high. Sixteen percent of patients in the provisional group underwent T-stenting. The primary end point (a composite of death, myocardial infarction, and target vessel revascularization at 12 months) occurred in 7.7% of the provisional T-stent group versus 10.3% of the culotte group (hazard ratio, 1.02; 95% confidence interval, 0.78-1.34; P=0.53). Procedure time, x-ray dose, and cost all favored the simpler procedure. When treating complex coronary bifurcation lesions with large stenosed SBs, there is no difference between a provisional T-stent strategy and a systematic 2-stent culotte strategy in a composite end point of death, myocardial infarction, and target vessel revascularization at 12 months. URL: http://www.clinicaltrials.gov. Unique identifier: NCT 01560455. © 2016 American Heart Association, Inc.

  13. 'Doctor Google' ending the diagnostic odyssey in lysosomal storage disorders: parents using internet search engines as an efficient diagnostic strategy in rare diseases.

    Science.gov (United States)

    Bouwman, Machtelt G; Teunissen, Quirine G A; Wijburg, Frits A; Linthorst, Gabor E

    2010-08-01

    The expansion of the internet has resulted in widespread availability of medical information for both patients and physicians. People increasingly spend time on the internet searching for an explanation, diagnosis or treatment for their symptoms. Regarding rare diseases, the use of the internet may be an important tool in the diagnostic process. The authors present two cases in which concerned parents made a correct diagnosis of a lysosomal storage disorder in their child by searching the internet after a long doctor's delay. These cases illustrate the utility of publicly available internet search engines in diagnosing rare disorders and in addition illustrate the lengthy diagnostic odyssey which is common in these disorders.

  14. Mnemonic strategy training improves memory for object location associations in both healthy elderly and patients with amnestic mild cognitive impairment: a randomized, single-blind study.

    Science.gov (United States)

    Hampstead, Benjamin M; Sathian, Krish; Phillips, Pamela A; Amaraneni, Akshay; Delaune, William R; Stringer, Anthony Y

    2012-05-01

    To evaluate the efficacy of mnemonic strategy training versus a matched-exposure control condition and to examine the relationship between training-related gains, neuropsychological abilities, and medial temporal lobe volumetrics in patients with amnestic mild cognitive impairment (aMCI) and age-matched healthy controls. Twenty-three of 45 screened healthy controls and 29 of 42 screened patients with aMCI were randomized to mnemonic strategy or matched-exposure groups. Groups were run in parallel, with participants blind to the other intervention. All participants completed five sessions within 2 weeks. Memory testing for object-location associations (OLAs) was performed during sessions one and five and at a 1-month follow-up. During Sessions 2-4, participants received either mnemonic strategy training or a matched number of exposures with corrective feedback for a total of 45 OLAs. Structural magnetic resonance imaging was performed in most participants, and medial temporal lobe volumetrics were acquired. Twenty-one healthy controls and 28 patients with aMCI were included in data analysis. Mnemonic strategy training was significantly more beneficial than matched exposure immediately after training, p = .006, partial η2 = .16, and at 1 month, p Mnemonic strategy-related improvement was correlated positively with baseline memory and executive functioning and negatively with inferior lateral ventricle volume in patients with aMCI; no significant relationships were evident in matched-exposure patients. Mnemonic strategies effectively improve memory for specific content for at least 1 month in patients with aMCI.

  15. Investigating bang for your training buck: a randomized controlled trial comparing three methods of training clinicians in two core strategies of dialectical behavior therapy.

    Science.gov (United States)

    Dimeff, Linda A; Harned, Melanie S; Woodcock, Eric A; Skutch, Julie M; Koerner, Kelly; Linehan, Marsha M

    2015-05-01

    The present study examined the efficacy of online training (OLT), instructor-led training (ILT), and a treatment manual (TM) in training mental health clinicians in two core strategies of Dialectical Behavior Therapy (DBT): chain analysis and validation. A randomized controlled trial compared OLT, ILT, and TM among clinicians naïve to DBT (N=172) who were assessed at baseline, post-training, and 30, 60, and 90 days following training. Primary outcomes included satisfaction, self-efficacy, motivation, knowledge, clinical proficiency, and clinical use. Overall, ILT outperformed OLT and TM in satisfaction, self-efficacy, and motivation, whereas OLT was the most effective method for increasing knowledge. The conditions did not differ in observer-rated clinical proficiency or self-reported clinical use, which both increased to moderate levels after training. In addition, ILT was particularly effective at improving motivation to use chain analysis, whereas OLT was particularly effective at increasing knowledge of validation strategies. These findings suggest that these types of brief, didactic trainings may be effective methods of increasing knowledge of new treatment strategies, but may not be sufficient to enable clinicians to achieve a high level of clinical use or proficiency. Additional research examining the possible advantages of matching training methods to types of treatment strategies may help to determine a tailored, more effective approach to training clinicians in empirically supported treatments. Copyright © 2015. Published by Elsevier Ltd.

  16. Random sampling or geostatistical modelling? Choosing between design-based and model-based sampling strategies for soil (with discussion)

    NARCIS (Netherlands)

    Brus, D.J.; Gruijter, de J.J.

    1997-01-01

    Classical sampling theory has been repeatedly identified with classical statistics which assumes that data are identically and independently distributed. This explains the switch of many soil scientists from design-based sampling strategies, based on classical sampling theory, to the model-based

  17. Nest and food search behaviour in desert ants, Cataglyphis: a critical comparison.

    Science.gov (United States)

    Pfeffer, Sarah E; Bolek, Siegfried; Wolf, Harald; Wittlinger, Matthias

    2015-07-01

    North African desert ants, Cataglyphis, use path integration to calculate a home vector during their foraging trips, constantly informing them about their position relative to the nest. This home vector is also used to find the way back to a productive feeding site the ant has encountered and thus memorized. When the animal fails to arrive at its goal after having run off the home or food vector, a systematic search is initiated. The basic search strategies are identical for nest and food searches, consisting of a search spiral superimposed by a random walk. While nest searches have been investigated in much detail, food site searches have received comparatively little attention. Here, we quantify and compare nest and food site searches recorded under similar conditions, particularly constant nest-feeder distance, and we observe notable differences in nest and food search performances. The parameters of nest searches are relatively constant and improve little with experience, although those small improvements had not been recognized previously. Food searches, by contrast, are more flexible and cover smaller or larger areas, mainly depending on the reliability of food encounter over several visits. Intriguingly, food site searches may be significantly more focussed than nest searches, although the nest should be the most important goal in an ant's life. These results demonstrate both adaptability and high accuracy of the ants' search programme.

  18. Combining rational and random strategies in β-glucosidase Zm-p60.1 protein library construction.

    Directory of Open Access Journals (Sweden)

    Dušan Turek

    Full Text Available Saturation mutagenesis is a cornerstone technique in protein engineering because of its utility (in conjunction with appropriate analytical techniques for assessing effects of varying residues at selected positions on proteins' structures and functions. Site-directed mutagenesis with degenerate primers is the simplest and most rapid saturation mutagenesis technique. Thus, it is highly appropriate for assessing whether or not variation at certain sites is permissible, but not necessarily the most time- and cost-effective technique for detailed assessment of variations' effects. Thus, in the presented study we applied the technique to randomize position W373 in β-glucosidase Zm-p60.1, which is highly conserved among β-glucosidases. Unexpectedly, β-glucosidase activity screening of the generated variants showed that most variants were active, although they generally had significantly lower activity than the wild type enzyme. Further characterization of the library led us to conclude that a carefully selected combination of randomized codon-based saturation mutagenesis and site-directed mutagenesis may be most efficient, particularly when constructing and investigating randomized libraries with high fractions of positive hits.

  19. Management strategies for fibromyalgia

    Directory of Open Access Journals (Sweden)

    Le Marshall KF

    2011-07-01

    Full Text Available Kim Francis Le Marshall, Geoffrey Owen LittlejohnDepartments of Rheumatology and Medicine, Monash Medical Centre and Monash University, Victoria, AustraliaDate of preparation: 14 June 2011Clinical question: What are the effective, evidence-based strategies available for the management of fibromyalgia?Conclusion: There are a number of management strategies available with robust evidence to support their use in clinical practice.Definition: Fibromyalgia is a complex pain syndrome characterized by widespread, chronic muscular pain and tenderness, disordered sleep, emotional distress, cognitive disturbance, and fatigue. Its prevalence is estimated to be 3%–5% in the population and higher yet in patients with comorbid rheumatic diseases.Level of evidence: Systematic reviews, meta-analyses, randomized controlled trials (RCTs.Search sources: PubMed, Cochrane Library, manual searchConsumer summary: Key messages for patients and clinicians are:1. There are many effective pharmacological management strategies available for fibromyalgia.2. A nonpharmacological, multicomponent approach utilizing education, aerobic exercise, psychological therapy, and other strategies is also effective for fibromyalgia.3. Despite the significant and, at times, disabling physical and psychological symptoms, fibromyalgia can be a manageable condition with a potentially good outcome.Keywords: fibromyalgia, pain, treatment, management, evidence 

  20. Darwin on the Web: The Evolution of Search Tools.

    Science.gov (United States)

    Vidmar, Dale J.

    1999-01-01

    Discusses various search strategies and tools that can be used for searching on the Internet, including search engines and search directories; Boolean searching; metasearching; relevancy ranking; automatic phrase detection; backlinks; natural-language searching; clustering and cataloging information; image searching; customization and portals;…

  1. Effect of Individualized vs Standard Blood Pressure Management Strategies on Postoperative Organ Dysfunction Among High-Risk Patients Undergoing Major Surgery: A Randomized Clinical Trial.

    Science.gov (United States)

    Futier, Emmanuel; Lefrant, Jean-Yves; Guinot, Pierre-Gregoire; Godet, Thomas; Lorne, Emmanuel; Cuvillon, Philippe; Bertran, Sebastien; Leone, Marc; Pastene, Bruno; Piriou, Vincent; Molliex, Serge; Albanese, Jacques; Julia, Jean-Michel; Tavernier, Benoit; Imhoff, Etienne; Bazin, Jean-Etienne; Constantin, Jean-Michel; Pereira, Bruno; Jaber, Samir

    2017-10-10

    Perioperative hypotension is associated with an increase in postoperative morbidity and mortality, but the appropriate management strategy remains uncertain. To evaluate whether an individualized blood pressure management strategy tailored to individual patient physiology could reduce postoperative organ dysfunction. The Intraoperative Norepinephrine to Control Arterial Pressure (INPRESS) study was a multicenter, randomized, parallel-group clinical trial conducted in 9 French university and nonuniversity hospitals. Adult patients (n = 298) at increased risk of postoperative complications with a preoperative acute kidney injury risk index of class III or higher (indicating moderate to high risk of postoperative kidney injury) undergoing major surgery lasting 2 hours or longer under general anesthesia were enrolled from December 4, 2012, through August 28, 2016 (last follow-up, September 28, 2016). Individualized management strategy aimed at achieving a systolic blood pressure (SBP) within 10% of the reference value (ie, patient's resting SBP) or standard management strategy of treating SBP less than 80 mm Hg or lower than 40% from the reference value during and for 4 hours following surgery. The primary outcome was a composite of systemic inflammatory response syndrome and dysfunction of at least 1 organ system of the renal, respiratory, cardiovascular, coagulation, and neurologic systems by day 7 after surgery. Secondary outcomes included the individual components of the primary outcome, durations of ICU and hospital stay, adverse events, and all-cause mortality at 30 days after surgery. Among 298 patients who were randomized, 292 patients completed the trial (mean [SD] age, 70 [7] years; 44 [15.1%] women) and were included in the modified intention-to-treat analysis. The primary outcome event occurred in 56 of 147 patients (38.1%) assigned to the individualized treatment strategy vs 75 of 145 patients (51.7%) assigned to the standard treatment strategy

  2. A comparison of 3 ventilation strategies in children younger than 1 year using a Proseal laryngeal mask airway: a randomized controlled trial.

    Science.gov (United States)

    Templeton, T Wesley; Hoke, Lauren K; Templeton, Leah B; Ririe, Douglas G; Rose, Danielle M; Bryan, Yvon F

    2016-12-01

    To determine quantitative differences in several routinely measured ventilation parameters using a standardized anesthetic technique and 3 different ventilation modalities in patients younger than 1 year with a ProSeal laryngeal mask airway (PLMA). Randomized prospective study. Tertiary care pediatric hospital. Thirty-nine American Society Anesthesiologists classifications 1 to 2, pediatric patients younger than 1 year. Three different ventilation strategies (spontaneous ventilation [SV], pressure support ventilation [PSV], and pressure-controlled ventilation [PCV]) were randomly applied to patients who underwent a standardized mask induction with sevoflurane/oxygen and propofol 2 mg/kg and fentanyl 2 μg/kg administered intravenously followed by PLMA insertion. Patients were maintained on sevoflurane and N 2 O. We measured the differences in end-tidal CO 2 (etco 2 ), tidal volume (TV), and respiratory rate (RR) over time between SV, PSV, and PCV. These data were recorded at 5-minute intervals. etco 2 (mm Hg) was not significantly higher in the SV vs PSV (P=2.11) and SV vs PCV (P=.24). TV (mL/kg) was significantly lower in SV vs PSV (Pchildren younger than 1 year. Although we did not observe a statistically significant increase in etco 2 , differences in TV and RR, and the small but significant incidence of apnea may make PSV or PCV more optimal ventilation strategies in children younger than 1 year when using a PLMA. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Experimental blunt chest trauma--cardiorespiratory effects of different mechanical ventilation strategies with high positive end-expiratory pressure: a randomized controlled study.

    Science.gov (United States)

    Schreiter, Dierk; Carvalho, Nadja C; Katscher, Sebastian; Mende, Ludger; Reske, Alexander P; Spieth, Peter M; Carvalho, Alysson R; Beda, Alessandro; Lachmann, Burkhard; Amato, Marcelo B P; Wrigge, Hermann; Reske, Andreas W

    2016-01-12

    Uncertainty persists regarding the optimal ventilatory strategy in trauma patients developing acute respiratory distress syndrome (ARDS). This work aims to assess the effects of two mechanical ventilation strategies with high positive end-expiratory pressure (PEEP) in experimental ARDS following blunt chest trauma. Twenty-six juvenile pigs were anesthetized, tracheotomized and mechanically ventilated. A contusion was applied to the right chest using a bolt-shot device. Ninety minutes after contusion, animals were randomized to two different ventilation modes, applied for 24 h: Twelve pigs received conventional pressure-controlled ventilation with moderately low tidal volumes (VT, 8 ml/kg) and empirically chosen high external PEEP (16 cmH2O) and are referred to as the HP-CMV-group. The other group (n = 14) underwent high-frequency inverse-ratio pressure-controlled ventilation (HFPPV) involving respiratory rate of 65 breaths · min(-1), inspiratory-to-expiratory-ratio 2:1, development of intrinsic PEEP and recruitment maneuvers, compatible with the rationale of the Open Lung Concept. Hemodynamics, gas exchange and respiratory mechanics were monitored during 24 h. Computed tomography and histology were analyzed in subgroups. Comparing changes which occurred from randomization (90 min after chest trauma) over the 24-h treatment period, groups differed statistically significantly (all P values for group effect ventilation improved respiratory function and fulfilled relevant ventilation endpoints for trauma patients, i.e. restoration of oxygenation and lung aeration while avoiding hypercapnia and respiratory acidosis.

  4. Hemodialysis without systemic anticoagulation: a prospective randomized trial to evaluate 3 strategies in patients at risk of bleeding.

    Directory of Open Access Journals (Sweden)

    Bruno Guéry

    Full Text Available In this clinical trial, we aimed to compare three means of performing chronic hemodialysis in patients with contra-indication to systemic heparinization.This open-label monocentric randomized « n-of-one » trial, conducted in a single tertiary care center, recruited chronic hemodialysis patients with a contra-indication to systemic heparinization for at least 3 consecutive sessions. All patients underwent hemodialysis with an AN69ST dialyzer, and were administered three alternative dialysis procedures in a random sequence: intermittent saline flushes, constant saline infusion, or pre-dialysis heparin coating of the membrane. The primary outcome was the need to interrupt the dialysis session because of clotting events due to either (i a complete coagulation of the circuit; (ii a partial coagulation of the circuit; (iii a>50% rise over baseline in the venous pressure.At the end of the inclusion period (May, 2007 to December, 2008, the number of patients to include (n=75 was not reached: only 46 patients were included and underwent randomization. The study was terminated, and statistical analysis took into account 224 hemodialysis sessions performed in 44 patients with analyzable data. Heparin adsorption was associated with a significant reduction of the need to interrupt the dialysis session because of clotting events: odds ratio 0.3 (CI 95% 0.2 to 0.6; p3 h dialysis sessions and for having complete blood restitution. There were no significant effects of the dialysis procedure on weight loss, online ionic dialysance, and adverse events.Heparin-coated AN69ST dialysis membrane is a safe and effective method to avoid or delay per-dialytic clotting events in patients with contra-indication to systemic anticoagulation. However, results are not generalizable safely to patients with active bleeding, since weak heparinemia, not assessed in this study, may occur.ClinicalTrials.gov NCT00473109.

  5. Random Assignment of Schools to Groups in the Drug Resistance Strategies Rural Project: Some New Methodological Twists

    Science.gov (United States)

    Pettigrew, Jonathan; Miller-Day, Michelle; Krieger, Janice L.; Zhou, Jiangxiu; Hecht, Michael L.

    2014-01-01

    Random assignment to groups is the foundation for scientifically rigorous clinical trials. But assignment is challenging in group randomized trials when only a few units (schools) are assigned to each condition. In the DRSR project, we assigned 39 rural Pennsylvania and Ohio schools to three conditions (rural, classic, control). But even with 13 schools per condition, achieving pretest equivalence on important variables is not guaranteed. We collected data on six important school-level variables: rurality, number of grades in the school, enrollment per grade, percent white, percent receiving free/assisted lunch, and test scores. Key to our procedure was the inclusion of school-level drug use data, available for a subset of the schools. Also, key was that we handled the partial data with modern missing data techniques. We chose to create one composite stratifying variable based on the seven school-level variables available. Principal components analysis with the seven variables yielded two factors, which were averaged to form the composite inflate-suppress (CIS) score which was the basis of stratification. The CIS score was broken into three strata within each state; schools were assigned at random to the three program conditions from within each stratum, within each state. Results showed that program group membership was unrelated to the CIS score, the two factors making up the CIS score, and the seven items making up the factors. Program group membership was not significantly related to pretest measures of drug use (alcohol, cigarettes, marijuana, chewing tobacco; smallest p>.15), thus verifying that pretest equivalence was achieved. PMID:23722619

  6. Autonomous change of behavior for environmental context: An intermittent search model with misunderstanding search pattern

    Science.gov (United States)

    Murakami, Hisashi; Gunji, Yukio-Pegio

    2017-07-01

    Although foraging patterns have long been predicted to optimally adapt to environmental conditions, empirical evidence has been found in recent years. This evidence suggests that the search strategy of animals is open to change so that animals can flexibly respond to their environment. In this study, we began with a simple computational model that possesses the principal features of an intermittent strategy, i.e., careful local searches separated by longer steps, as a mechanism for relocation, where an agent in the model follows a rule to switch between two phases, but it could misunderstand this rule, i.e., the agent follows an ambiguous switching rule. Thanks to this ambiguity, the agent's foraging strategy can continuously change. First, we demonstrate that our model can exhibit an optimal change of strategy from Brownian-type to Lévy-type depending on the prey density, and we investigate the distribution of time intervals for switching between the phases. Moreover, we show that the model can display higher search efficiency than a correlated random walk.

  7. A pragmatic randomized trial of a polypill-based strategy to improve use of indicated preventive treatments in people at high cardiovascular disease risk.

    Science.gov (United States)

    Patel, Anushka; Cass, Alan; Peiris, David; Usherwood, Tim; Brown, Alex; Jan, Stephen; Neal, Bruce; Hillis, Graham S; Rafter, Natasha; Tonkin, Andrew; Webster, Ruth; Billot, Laurent; Bompoint, Severine; Burch, Carol; Burke, Hugh; Hayman, Noel; Molanus, Barbara; Reid, Christopher M; Shiel, Louise; Togni, Samantha; Rodgers, Anthony

    2015-07-01

    Most individuals at high cardiovascular disease (CVD) risk worldwide do not receive any or optimal preventive drugs. We aimed to determine whether fixed dose combinations of generic drugs ('polypills') would promote use of such medications. We conducted a randomized, open-label trial involving 623 participants from Australian general practices. Participants had established CVD or an estimated five-year CVD risk of ≥15%, with indications for antiplatelet, statin and ≥2 blood pressure lowering drugs ('combination treatment'). Participants randomized to the 'polypill-based strategy' received a polypill containing aspirin 75 mg, simvastatin 40 mg, lisinopril 10 mg and either atenolol 50 mg or hydrochlorothiazide 12.5 mg. Participants randomized to 'usual care' continued with separate medications and doses as prescribed by their doctor. Primary outcomes were self-reported combination treatment use, systolic blood pressure and total cholesterol. After a median of 18 months, the polypill-based strategy was associated with greater use of combination treatment (70% vs. 47%; relative risk 1.49, (95% confidence interval (CI) 1.30 to 1.72) p study end, 17% and 67% of participants in polypill and usual care groups, respectively, were taking atorvastatin or rosuvastatin. Provision of a polypill improved self-reported use of indicated preventive treatments. The lack of differences in blood pressure and cholesterol may reflect limited study power, although for cholesterol, improved statin use in the polypill group counter-balanced use of more potent statins with usual care. © The European Society of Cardiology 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  8. Effective trapping of random walkers in complex networks.

    Science.gov (United States)

    Hwang, S; Lee, D-S; Kahng, B

    2012-04-01

    Exploring the World Wide Web has become one of the key issues in information science, specifically in view of its application to the PageRank-like algorithms used in search engines. The random walk approach has been employed to study such a problem. The probability of return to the origin (RTO) of random walks is inversely related to how information can be accessed during random surfing. We find analytically that the RTO probability for a given starting node shows a crossover from a slow to a fast decay behavior with time and the crossover time increases with the degree of the starting node. We remark that the RTO probability becomes almost constant in the early-time regime as the degree exponent approaches two. This result indicates that a random surfer can be effectively trapped at the hub and supports the necessity of the random jump strategy empirically used in the Google's search engine.

  9. The effect of feedback regarding coping strategies and illness behavior on hand surgery patient satisfaction and communication: a randomized controlled trial.

    Science.gov (United States)

    Mellema, Jos J; O'Connor, Casey M; Overbeek, Celeste L; Hageman, Michiel G; Ring, David

    2015-09-01

    Patients and surgeons can feel uncomfortable discussing coping strategies, psychological distress, and stressful circumstances. It has been suggested that patient-reported outcome measures (PROMs) facilitate the discussion of factors associated with increased symptoms and disability. This study assessed the effect of providing feedback to patients regarding their coping strategy and illness behavior on patient satisfaction and patient-physician communication in orthopedic surgery. In a prospective study, 136 orthopedic patients were randomly assigned to either receive feedback about the Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference computer-adaptive test (CAT) prior to the visit with the hand surgeon or not. The primary outcome was patient satisfaction with the consultation and secondary outcomes involved patient-physician communication. Bivariate and multivariable analyses were performed to determine the influence of the feedback on patient satisfaction and communication. There was no significant difference in patient satisfaction between patients who received feedback and patients who did not (P = 0.70). Feedback was associated with more frequent discussion of coping strategies (P = 0.045) in bivariate analysis but was not independently associated: in multivariable analysis, only PROMIS Pain Interference CAT and age were identified as independent predictors (odds ratio (OR) 1.1; 95 % confidence interval (CI) 1.0-1.1, P = 0.013, and OR 0.97, 95 % CI 0.94-0.99, P = 0.032, respectively). No factors were associated with discussion of stressors. Discussion of circumstances was independently associated with increased PROMIS Pain Interference CAT, marital status, and work status. We found that feedback regarding coping strategies and illness behavior using the PROMIS Pain Interference CAT did not affect patient satisfaction. Although feedback was associated with increased discussion of illness behavior in bivariate

  10. Effectiveness of a multi-strategy intervention in increasing the implementation of vegetable and fruit breaks by Australian primary schools: a non-randomized controlled trial

    Science.gov (United States)

    2012-01-01

    Background Limited evidence exists describing the effectiveness of strategies in facilitating the implementation of vegetable and fruit programs by schools on a population wide basis. The aim of this study was to examine the effectiveness of a multi-strategy intervention in increasing the population-wide implementation of vegetable and fruit breaks by primary schools and to determine if intervention effectiveness varied by school characteristics. Methods A quasi-experimental study was conducted in primary schools in the state of New South Wales, Australia. All primary schools in one region of the state (n = 422) received a multi-strategy intervention. A random sample of schools (n = 406) in the remainder of the state served as comparison schools. The multi-strategy intervention to increase vegetable and fruit breaks involved the development and provision of: program consensus and leadership; staff training; program materials; incentives; follow-up support; and implementation feedback. Comparison schools had access to routine information-based Government support. Data to assess the prevalence of vegetable and fruit breaks were collected by telephone from Principals of the intervention and comparison schools at baseline (2006–2007) and 11 to 15 months following the commencement of the intervention (2009–2010). GEE analysis was used to examine the change in the prevalence of vegetable and fruit breaks in intervention schools compared to comparison schools. Results At follow-up, prevalence of vegetable and fruit breaks increased significantly in both intervention (50.3 % to 82.0 %, p schools. The increase in prevalence in intervention schools was significantly larger than among comparison schools (OR 2.36; 95 % CI 1.60-3.49, p effect size was similar between schools regardless of the rurality or socioeconomic status of school location, school size or government or non-government school type. Conclusion The findings suggest that a multi-strategy intervention can

  11. Effectiveness of an (18)F-FDG-PET based strategy to optimize the diagnostic trajectory of suspected recurrent laryngeal carcinoma after radiotherapy: The RELAPS multicenter randomized trial.

    Science.gov (United States)

    de Bree, Remco; van der Putten, Lisa; van Tinteren, Harm; Wedman, Jan; Oyen, Wim J G; Janssen, Luuk M; van den Brekel, Michiel W M; Comans, Emile F I; Pruim, Jan; Takes, Robert P; Hobbelink, Monique G G; Valdés Olmos, Renato; van der Laan, Bernard F A M; Boers, Maarten; Hoekstra, Otto S; Leemans, C René

    2016-02-01

    The purpose of this study is to evaluate the efficacy of (18)F-FDG-PET as first-line diagnostic investigation, prior to performing a direct laryngoscopy with biopsy under general anesthesia, in patients suspected of recurrent laryngeal carcinoma after radiotherapy. 150 patients suspected of recurrent T2-4 laryngeal carcinoma at least two months after prior (chemo)radiotherapy with curative intent for resectable disease were randomized to direct laryngoscopy (CWU: conventional workup strategy) or to (18)F-FDG-PET only followed by direct laryngoscopy if PET was assessed 'positive' or 'equivocal' (PWU: PET based workup strategy), to compare the effectiveness of these strategies. Primary endpoint was the number of indications for direct laryngoscopies classified as unnecessary bas