Presenting quality data to vulnerable groups: charts, summaries or behavioral economic nudges?

PubMed

Elbel, Brian; Gillespie, Colleen; Raven, Maria C

2014-07-01

Despite the increased focus on health care consumers' active choice, not enough is known about how to best facilitate the choice process. We sought to assess methods of improving this process for vulnerable consumers in the United States by testing alternatives that emphasize insights from behavioral economics, or 'nudges'. We performed a hypothetical choice experiment where subjects were randomized to one of five experimental conditions and asked to choose a health center (location where they would receive all their care). The conditions presented the same information about health centers in different ways, including graphically as a chart, via written summary and using behavioral economics, 'nudging' consumers toward particular choices. We hypothesized that these 'nudges' might help simplify the choice process. Our primary outcomes focused on the health center chosen and whether consumers were willing to accept 'nudges'. We found that consumer choice was influenced by the method of presentation and the majority of consumers accepted the health center they were 'nudged' towards. Consumers were accepting of choices grounded in insights from behavioral economics and further consideration should be given to their role in patient choice. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Decoy-state quantum key distribution with biased basis choice

PubMed Central

Wei, Zhengchao; Wang, Weilong; Zhang, Zhen; Gao, Ming; Ma, Zhi; Ma, Xiongfeng

2013-01-01

We propose a quantum key distribution scheme that combines a biased basis choice with the decoy-state method. In this scheme, Alice sends all signal states in the Z basis and decoy states in the X and Z basis with certain probabilities, and Bob measures received pulses with optimal basis choice. This scheme simplifies the system and reduces the random number consumption. From the simulation result taking into account of statistical fluctuations, we find that in a typical experimental setup, the proposed scheme can increase the key rate by at least 45% comparing to the standard decoy-state scheme. In the postprocessing, we also apply a rigorous method to upper bound the phase error rate of the single-photon components of signal states. PMID:23948999

Decoy-state quantum key distribution with biased basis choice.

PubMed

Wei, Zhengchao; Wang, Weilong; Zhang, Zhen; Gao, Ming; Ma, Zhi; Ma, Xiongfeng

2013-01-01

We propose a quantum key distribution scheme that combines a biased basis choice with the decoy-state method. In this scheme, Alice sends all signal states in the Z basis and decoy states in the X and Z basis with certain probabilities, and Bob measures received pulses with optimal basis choice. This scheme simplifies the system and reduces the random number consumption. From the simulation result taking into account of statistical fluctuations, we find that in a typical experimental setup, the proposed scheme can increase the key rate by at least 45% comparing to the standard decoy-state scheme. In the postprocessing, we also apply a rigorous method to upper bound the phase error rate of the single-photon components of signal states.

Randomized controlled trial of a computer-based module to improve contraceptive method choice.

PubMed

Garbers, Samantha; Meserve, Allison; Kottke, Melissa; Hatcher, Robert; Ventura, Alicia; Chiasson, Mary Ann

2012-10-01

Unintended pregnancy is common in the United States, and interventions are needed to improve contraceptive use among women at higher risk of unintended pregnancy, including Latinas and women with low educational attainment. A three-arm randomized controlled trial was conducted at two family planning sites serving low-income, predominantly Latina populations. The trial tested the efficacy of a computer-based contraceptive assessment module in increasing the proportion of patients choosing an effective method of contraception (<10 pregnancies/100 women per year, typical use). Participants were randomized to complete the module and receive tailored health materials, to complete the module and receive generic health materials, or to a control condition. In intent-to-treat analyses adjusted for recruitment site (n=2231), family planning patients who used the module were significantly more likely to choose an effective contraceptive method: 75% among those who received tailored materials [odds ratio (OR)=1.56; 95% confidence interval (CI): 1.23-1.98] and 78% among those who received generic materials (OR=1.74; 95% CI: 1.35-2.25), compared to 65% among control arm participants. The findings support prior research suggesting that patient-centered interventions can positively influence contraceptive method choice. Copyright © 2012 Elsevier Inc. All rights reserved.

The effect of choice on the physiology of emotion: an affective startle modulation study.

PubMed

Genevsky, Alexander; Gard, David E

2012-04-01

The affective startle modulation task has been an important measure in understanding physiological aspects of emotion and motivational responses. Research utilizing this method has relied primarily on a 'passive' viewing paradigm, which stands in contrast to everyday life where much of emotion and motivation involves some active choice or agency. The present study investigated the role of choice on the physiology of emotion. Eighty-four participants were randomized into 'choice' (n=44) or 'no-choice' (n=40) groups distinguished by the ability to choose between stimuli. EMG eye blink responses were recorded in both anticipation and stimulus viewing. Results indicated a significant attenuation of the startle magnitude in choice condition trials (relative to no-choice) across all picture categories and probe times. We interpret these findings as an indication that the act of choice may decrease one's defensive response, or conversely, lacking choice may heighten the defensive response. Implications for future research are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

Asymmetrically dominated choice problems, the isolation hypothesis and random incentive mechanisms.

PubMed

Cox, James C; Sadiraj, Vjollca; Schmidt, Ulrich

2014-01-01

This paper presents an experimental study of the random incentive mechanisms which are a standard procedure in economic and psychological experiments. Random incentive mechanisms have several advantages but are incentive-compatible only if responses to the single tasks are independent. This is true if either the independence axiom of expected utility theory or the isolation hypothesis of prospect theory holds. We present a simple test of this in the context of choice under risk. In the baseline (one task) treatment we observe risk behavior in a given choice problem. We show that by integrating a second, asymmetrically dominated choice problem in a random incentive mechanism risk behavior can be manipulated systematically. This implies that the isolation hypothesis is violated and the random incentive mechanism does not elicit true preferences in our example.

How we became the Schmams: conceptualizations of fairness in the decision-making process for Latina/o children.

PubMed

Langhout, Regina Day; Kohfeldt, Danielle M; Ellison, Erin Rose

2011-12-01

The current study examines 16 Latina/o fifth grade children's desires for a decision-making structure within a youth participatory action research (yPAR) program. When given the choices of consensus, majority rule, authoritarian rule, delegation, and random choice models, children chose random choice. Procedural, distributive and emotional justice were heavily weighted in their reasoning around fairness and decision making. Many thought random choice offered the best alternative because it flattened power hierarchies so that each child would, at some point, have the power to make a decision. Additionally, children argued that the neutrality of random choice allowed them to sidestep interpersonal tensions. Implications include how social identities inform definitions of fairness and how yPAR programs should work with youth around how they will make decisions.

Probabilistic choice models in health-state valuation research: background, theories, assumptions and applications.

PubMed

Arons, Alexander M M; Krabbe, Paul F M

2013-02-01

Interest is rising in measuring subjective health outcomes, such as treatment outcomes that are not directly quantifiable (functional disability, symptoms, complaints, side effects and health-related quality of life). Health economists in particular have applied probabilistic choice models in the area of health evaluation. They increasingly use discrete choice models based on random utility theory to derive values for healthcare goods or services. Recent attempts have been made to use discrete choice models as an alternative method to derive values for health states. In this article, various probabilistic choice models are described according to their underlying theory. A historical overview traces their development and applications in diverse fields. The discussion highlights some theoretical and technical aspects of the choice models and their similarity and dissimilarity. The objective of the article is to elucidate the position of each model and their applications for health-state valuation.

Methodology Series Module 5: Sampling Strategies.

PubMed

Setia, Maninder Singh

2016-01-01

Once the research question and the research design have been finalised, it is important to select the appropriate sample for the study. The method by which the researcher selects the sample is the ' Sampling Method'. There are essentially two types of sampling methods: 1) probability sampling - based on chance events (such as random numbers, flipping a coin etc.); and 2) non-probability sampling - based on researcher's choice, population that accessible & available. Some of the non-probability sampling methods are: purposive sampling, convenience sampling, or quota sampling. Random sampling method (such as simple random sample or stratified random sample) is a form of probability sampling. It is important to understand the different sampling methods used in clinical studies and mention this method clearly in the manuscript. The researcher should not misrepresent the sampling method in the manuscript (such as using the term ' random sample' when the researcher has used convenience sample). The sampling method will depend on the research question. For instance, the researcher may want to understand an issue in greater detail for one particular population rather than worry about the ' generalizability' of these results. In such a scenario, the researcher may want to use ' purposive sampling' for the study.

Methodology Series Module 5: Sampling Strategies

PubMed Central

Setia, Maninder Singh

2016-01-01

Once the research question and the research design have been finalised, it is important to select the appropriate sample for the study. The method by which the researcher selects the sample is the ‘ Sampling Method’. There are essentially two types of sampling methods: 1) probability sampling – based on chance events (such as random numbers, flipping a coin etc.); and 2) non-probability sampling – based on researcher's choice, population that accessible & available. Some of the non-probability sampling methods are: purposive sampling, convenience sampling, or quota sampling. Random sampling method (such as simple random sample or stratified random sample) is a form of probability sampling. It is important to understand the different sampling methods used in clinical studies and mention this method clearly in the manuscript. The researcher should not misrepresent the sampling method in the manuscript (such as using the term ‘ random sample’ when the researcher has used convenience sample). The sampling method will depend on the research question. For instance, the researcher may want to understand an issue in greater detail for one particular population rather than worry about the ‘ generalizability’ of these results. In such a scenario, the researcher may want to use ‘ purposive sampling’ for the study. PMID:27688438

Random Testing and Model Checking: Building a Common Framework for Nondeterministic Exploration

NASA Technical Reports Server (NTRS)

Groce, Alex; Joshi, Rajeev

2008-01-01

Two popular forms of dynamic analysis, random testing and explicit-state software model checking, are perhaps best viewed as search strategies for exploring the state spaces introduced by nondeterminism in program inputs. We present an approach that enables this nondeterminism to be expressed in the SPIN model checker's PROMELA language, and then lets users generate either model checkers or random testers from a single harness for a tested C program. Our approach makes it easy to compare model checking and random testing for models with precisely the same input ranges and probabilities and allows us to mix random testing with model checking's exhaustive exploration of non-determinism. The PROMELA language, as intended in its design, serves as a convenient notation for expressing nondeterminism and mixing random choices with nondeterministic choices. We present and discuss a comparison of random testing and model checking. The results derive from using our framework to test a C program with an effectively infinite state space, a module in JPL's next Mars rover mission. More generally, we show how the ability of the SPIN model checker to call C code can be used to extend SPIN's features, and hope to inspire others to use the same methods to implement dynamic analyses that can make use of efficient state storage, matching, and backtracking.

Ability Group Configuration for the High School Physics Classroom

NASA Astrophysics Data System (ADS)

Zitnik, Scott

This research project looks to investigate the effectiveness of different ability grouping arrangements for the high school physics classroom. Students were first organized based on their academic aptitude in physics into three general groups of high, medium, and low achieving students. They were then divided into both groups of four and dyads that were constructed in one of four arrangements, namely: random, homogeneous, heterogeneous, or student choice. Data was collected based on their academic performance as well as survey responses regarding the group and dyad performance. Students worked in a rotation of these groups and dyads for a unit to measure student preference and introduce collaborative work formally to the classes. At this point it was evident that students preferred the student choice arrangement based on survey responses, yet the student choice survey responses also resulted in the lowest level of reliability when compared to all other grouping methods. For the next unit students were kept in either the random, homogeneous, or heterogeneous grouping arrangement for the entirety of the unit. At the conclusion of the second unit student achievement as well as survey responses were analyzed. As a result of this research there appears to be a slight student preference as well as academic benefit to homogeneous group and dyad arrangements for each of the three ability groups of students in the high school physics classroom when compared to random and heterogeneous grouping methods of academic group arrangement.

The effect of choice on the physiology of emotion: An affective startle modulation study

PubMed Central

Genevsky, Alexander; Gard, David E.

2014-01-01

The affective startle modulation task has been an important measure in understanding physiological aspects of emotion and motivational responses. Research utilizing this method has relied primarily on a ‘passive’ viewing paradigm, which stands in contrast to everyday life where much of emotion and motivation involves some active choice or agency. The present study investigated the role of choice on the physiology of emotion. Eighty-four participants were randomized into ‘choice’ (n=44) or ‘no-choice’ (n=40) groups distinguished by the ability to choose between stimuli. EMG eye blink responses were recorded in both anticipation and stimulus viewing. Results indicated a significant attenuation of the startle magnitude in choice condition trials (relative to no-choice) across all picture categories and probe times. We interpret these findings as an indication that the act of choice may decrease one’s defensive response, or conversely, lacking choice may heighten the defensive response. Implications for future research are discussed. PMID:22285891

Algorithm 971: An Implementation of a Randomized Algorithm for Principal Component Analysis

PubMed Central

LI, HUAMIN; LINDERMAN, GEORGE C.; SZLAM, ARTHUR; STANTON, KELLY P.; KLUGER, YUVAL; TYGERT, MARK

2017-01-01

Recent years have witnessed intense development of randomized methods for low-rank approximation. These methods target principal component analysis and the calculation of truncated singular value decompositions. The present article presents an essentially black-box, foolproof implementation for Mathworks’ MATLAB, a popular software platform for numerical computation. As illustrated via several tests, the randomized algorithms for low-rank approximation outperform or at least match the classical deterministic techniques (such as Lanczos iterations run to convergence) in basically all respects: accuracy, computational efficiency (both speed and memory usage), ease-of-use, parallelizability, and reliability. However, the classical procedures remain the methods of choice for estimating spectral norms and are far superior for calculating the least singular values and corresponding singular vectors (or singular subspaces). PMID:28983138

Reducing Unintended Pregnancies Through Web-Based Reproductive Life Planning and Contraceptive Action Planning among Privately Insured Women: Study Protocol for the MyNewOptions Randomized, Controlled Trial.

PubMed

Chuang, Cynthia H; Velott, Diana L; Weisman, Carol S; Sciamanna, Christopher N; Legro, Richard S; Chinchilli, Vernon M; Moos, Merry-K; Francis, Erica B; Confer, Lindsay N; Lehman, Erik B; Armitage, Christopher J

2015-01-01

The Affordable Care Act mandates that most women of reproductive age with private health insurance have full contraceptive coverage with no out-of-pocket costs, creating an actionable time for women to evaluate their contraceptive choices without cost considerations. The MyNewOptions study is a three-arm, randomized, controlled trial testing web-based interventions aimed at assisting privately insured women with making contraceptive choices that are consistent with their reproductive goals. Privately insured women between the ages of 18 and 40 not intending pregnancy were randomly assigned to one of three groups: 1) a reproductive life planning (RLP) intervention, 2) a reproductive life planning enriched with contraceptive action planning (RLP+) intervention, or 3) an information only control group. Both the RLP and RLP+ guide women to identify their individualized reproductive goals and contraceptive method requirements. The RLP+ additionally includes a contraceptive action planning component, which uses if-then scenarios that allow the user to problem solve situations that make it difficult to be adherent to their contraceptive method. All three groups have access to a reproductive options library containing information about their contraceptive coverage and the attributes of alternative contraceptive methods. Women completed a baseline survey with follow-up surveys every 6 months for 2 years concurrent with intervention boosters. Study outcomes include contraceptive use and adherence. ClinicalTrials.gov identifier: NCT02100124. Results from the MyNewOptions study will demonstrate whether web-based reproductive life planning, with or without contraceptive action planning, helps insured women make patient-centered contraceptive choices compared with an information-only control condition. Copyright © 2015 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.

Piloting an online grocery store simulation to assess children's food choices.

PubMed

Heard, Amy M; Harris, Jennifer L; Liu, Sai; Schwartz, Marlene B; Li, Xun

2016-01-01

Public health interventions must address poor diet among U.S. children, but research is needed to better understand factors influencing children's food choices. Using an online grocery store simulation, this research piloted a novel method to assess children's snack selection in a controlled but naturalistic laboratory setting, evaluate predictors of choice, and experimentally test whether promotions on food packages altered choices. Children (7-12 years, N = 61) were randomly assigned to one of three conditions: promotions on healthy products; promotions on unhealthy products; and no promotions (control). They selected from a variety of healthy and unhealthy foods and beverages and rated all products on healthfulness and taste. Promotions on food packaging did not affect snack selection in this study, but findings supported our other hypothesis that perceived taste would be the strongest predictor of food choice. Children accurately rated product healthfulness, but these ratings did not predict healthy snack choices or taste ratings for healthy or unhealthy snacks. These results suggest that interventions to improve children's food choices should focus on increasing availability of healthy options and identifying opportunities to enhance children's liking of healthy options. However, nutrition education alone is unlikely to improve children's diets. Further testing is required, but the simulated online grocery store method shows potential for measuring children's food choices. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of the Use of Two Visual Methods in Teaching College Chemistry to Non-Science Majors.

ERIC Educational Resources Information Center

Koechel, Loretta

This was a quantified study on the learning of certain theoretical topics in general chemistry as influenced by two methods of visual technique (single concept films, overhead projections). Four classes of chemistry students (non-science majors) registered in sections on a random basis, participated. Objective, multiple choice tests on each of the…

A Bayesian hierarchical model for discrete choice data in health care.

PubMed

Antonio, Anna Liza M; Weiss, Robert E; Saigal, Christopher S; Dahan, Ely; Crespi, Catherine M

2017-01-01

In discrete choice experiments, patients are presented with sets of health states described by various attributes and asked to make choices from among them. Discrete choice experiments allow health care researchers to study the preferences of individual patients by eliciting trade-offs between different aspects of health-related quality of life. However, many discrete choice experiments yield data with incomplete ranking information and sparsity due to the limited number of choice sets presented to each patient, making it challenging to estimate patient preferences. Moreover, methods to identify outliers in discrete choice data are lacking. We develop a Bayesian hierarchical random effects rank-ordered multinomial logit model for discrete choice data. Missing ranks are accounted for by marginalizing over all possible permutations of unranked alternatives to estimate individual patient preferences, which are modeled as a function of patient covariates. We provide a Bayesian version of relative attribute importance, and adapt the use of the conditional predictive ordinate to identify outlying choice sets and outlying individuals with unusual preferences compared to the population. The model is applied to data from a study using a discrete choice experiment to estimate individual patient preferences for health states related to prostate cancer treatment.

Can Broad Inferences Be Drawn from Lottery Analyses of School Choice Programs? An Exploration of Appropriate Sensitivity Analyses

ERIC Educational Resources Information Center

Zimmer, Ron; Engberg, John

2016-01-01

School choice programs continue to be controversial, spurring a number of researchers into evaluating them. When possible, researchers evaluate the effect of attending a school of choice using randomized designs to eliminate possible selection bias. Randomized designs are often thought of as the gold standard for research, but many circumstances…

Effect of Increasing the Choice of Active Options on Children’s Physical Activity

PubMed Central

Feda, Denise M.; Lambiase, Maya J.; McCarthy, Thomas F.; Barkley, Jacob E.; Roemmich, James. N.

2012-01-01

Objectives To determine whether increasing the choice of physical activity options increases the duration and intensity of children’s physically active play. Design This cross-sectional laboratory study included gender (male, female) and choice group [single toy (no choice), three toys (low choice), five toys (high choice)] as between participant factors. Methods Boys and girls (n = 36, 8–12 y) were stratified, randomly assigned to a choice group that always provided access to each participant’s most liked active toy(s), and allowed 60 min of free time. The same sedentary alternatives were freely available to all participants. Physical activity outcomes were measured by accelerometry, heart rate, and direct observation. Results The number of active toys the children played with increased (p < 0.001) across each choice group. Minutes spent in MPA were greater in the low choice (p < 0.05) and high choice (p < 0.02) groups than the no choice group. Active play time was greater (p < 0.01) in the low choice (79%) and high choice (95%) groups compared to the no choice group. Girls in the low and high choice groups had greater (p < 0.05) percent heart rate reserve when compared to girls in the no choice group. There was no difference in the boys’ percent heart rate reserve between the no choice, low choice and high choice groups. Conclusions Increasing the choice of active toys increases both the duration and intensity of physically active play, especially in girls. PMID:22342111

A method for multi-codon scanning mutagenesis of proteins based on asymmetric transposons.

PubMed

Liu, Jia; Cropp, T Ashton

2012-02-01

Random mutagenesis followed by selection or screening is a commonly used strategy to improve protein function. Despite many available methods for random mutagenesis, nearly all generate mutations at the nucleotide level. An ideal mutagenesis method would allow for the generation of 'codon mutations' to change protein sequence with defined or mixed amino acids of choice. Herein we report a method that allows for mutations of one, two or three consecutive codons. Key to this method is the development of a Mu transposon variant with asymmetric terminal sequences. As a demonstration of the method, we performed multi-codon scanning on the gene encoding superfolder GFP (sfGFP). Characterization of 50 randomly chosen clones from each library showed that more than 40% of the mutants in these three libraries contained seamless, in-frame mutations with low site preference. By screening only 500 colonies from each library, we successfully identified several spectra-shift mutations, including a S205D variant that was found to bear a single excitation peak in the UV region.

Choice Set Size and Decision-Making: The Case of Medicare Part D Prescription Drug Plans

PubMed Central

Bundorf, M. Kate; Szrek, Helena

2013-01-01

Background The impact of choice on consumer decision-making is controversial in U.S. health policy. Objective Our objective was to determine how choice set size influences decision-making among Medicare beneficiaries choosing prescription drug plans. Methods We randomly assigned members of an internet-enabled panel age 65 and over to sets of prescription drug plans of varying sizes (2, 5, 10, and 16) and asked them to choose a plan. Respondents answered questions about the plan they chose, the choice set, and the decision process. We used ordered probit models to estimate the effect of choice set size on the study outcomes. Results Both the benefits of choice, measured by whether the chosen plan is close to the ideal plan, and the costs, measured by whether the respondent found decision-making difficult, increased with choice set size. Choice set size was not associated with the probability of enrolling in any plan. Conclusions Medicare beneficiaries face a tension between not wanting to choose from too many options and feeling happier with an outcome when they have more alternatives. Interventions that reduce cognitive costs when choice sets are large may make this program more attractive to beneficiaries. PMID:20228281

Functional-diversity indices can be driven by methodological choices and species richness.

PubMed

Poos, Mark S; Walker, Steven C; Jackson, Donald A

2009-02-01

Functional diversity is an important concept in community ecology because it captures information on functional traits absent in measures of species diversity. One popular method of measuring functional diversity is the dendrogram-based method, FD. To calculate FD, a variety of methodological choices are required, and it has been debated about whether biological conclusions are sensitive to such choices. We studied the probability that conclusions regarding FD were sensitive, and that patterns in sensitivity were related to alpha and beta components of species richness. We developed a randomization procedure that iteratively calculated FD by assigning species into two assemblages and calculating the probability that the community with higher FD varied across methods. We found evidence of sensitivity in all five communities we examined, ranging from a probability of sensitivity of 0 (no sensitivity) to 0.976 (almost completely sensitive). Variations in these probabilities were driven by differences in alpha diversity between assemblages and not by beta diversity. Importantly, FD was most sensitive when it was most useful (i.e., when differences in alpha diversity were low). We demonstrate that trends in functional-diversity analyses can be largely driven by methodological choices or species richness, rather than functional trait information alone.

A Randomized Prospective Trial Comparing Paravertebral Block and General Anesthesia for Operative Treatment of Breast Cancer

DTIC Science & Technology

2001-10-01

block the anesthetic of choice for operative treatment of breast cancer. To test this hypothesis we proposed a prospective randomized clinical trial ...coordinators. Months 4-6. Status: Complete The study’s existing part-time Clinical Trial Coordinator, Mr. John Arbo, was enlisted full-time in June...of full-time Clinical Trial Coordinator for Mount Sinai. ■ Poster presentation by Mount Sinai staff of study goals and methods at a Department of

Choice of birth control methods among European women and the role of partners and providers.

PubMed

de Irala, Jokin; Osorio, Alfonso; Carlos, Silvia; Lopez-del Burgo, Cristina

2011-12-01

The choice of a birth control method is influenced by sociocultural and personal factors. We explored the perceived influences in women's choice of a birth control method in five European countries (Germany, France, the UK, Romania and Sweden), where contraception is widely used. This is a cross-sectional study of 1137 randomly selected women aged 18-49 years. An anonymous, 31-item questionnaire related to birth control methods was used. Logistic regression was used to identify variables associated with partner participation in choice of a contraceptive. Oral contraceptives were mainly used in Germany (54.3%), France (50.5%) and Sweden (34.6%) and condoms in the UK (29.6%) and Romania (22.9%). Sweden showed the highest use of intrauterine devices (IUD, 19%). Romania had the lowest use of contraception. Oral contraceptives and IUDs use were frequently suggested by providers instead of by women. Choosing the method with the partner was associated with age [odds ratio (OR)=0.97, 95% confidence interval (CI) 0.94-0.99], being a university graduate (OR=1.59, 95% CI 1.01-2.29), married (OR=1.52, 95% CI 1.01-2.29) and with using a method that requires partner's cooperation (OR=8.18, 95% CI 5.46-12.27). Hormonal contraceptives and IUDs are commonly recommended by providers rather than requested by women. Partner preferences are taken into account when his cooperation in the use of the method is needed. As fertility care is a male and female issue, there is still more room for actively involving both women and men in their choice of a birth control method. Copyright © 2011 Elsevier Inc. All rights reserved.

An empirical comparison of methods for analyzing correlated data from a discrete choice survey to elicit patient preference for colorectal cancer screening

PubMed Central

2012-01-01

Background A discrete choice experiment (DCE) is a preference survey which asks participants to make a choice among product portfolios comparing the key product characteristics by performing several choice tasks. Analyzing DCE data needs to account for within-participant correlation because choices from the same participant are likely to be similar. In this study, we empirically compared some commonly-used statistical methods for analyzing DCE data while accounting for within-participant correlation based on a survey of patient preference for colorectal cancer (CRC) screening tests conducted in Hamilton, Ontario, Canada in 2002. Methods A two-stage DCE design was used to investigate the impact of six attributes on participants' preferences for CRC screening test and willingness to undertake the test. We compared six models for clustered binary outcomes (logistic and probit regressions using cluster-robust standard error (SE), random-effects and generalized estimating equation approaches) and three models for clustered nominal outcomes (multinomial logistic and probit regressions with cluster-robust SE and random-effects multinomial logistic model). We also fitted a bivariate probit model with cluster-robust SE treating the choices from two stages as two correlated binary outcomes. The rank of relative importance between attributes and the estimates of β coefficient within attributes were used to assess the model robustness. Results In total 468 participants with each completing 10 choices were analyzed. Similar results were reported for the rank of relative importance and β coefficients across models for stage-one data on evaluating participants' preferences for the test. The six attributes ranked from high to low as follows: cost, specificity, process, sensitivity, preparation and pain. However, the results differed across models for stage-two data on evaluating participants' willingness to undertake the tests. Little within-patient correlation (ICC ≈ 0) was found in stage-one data, but substantial within-patient correlation existed (ICC = 0.659) in stage-two data. Conclusions When small clustering effect presented in DCE data, results remained robust across statistical models. However, results varied when larger clustering effect presented. Therefore, it is important to assess the robustness of the estimates via sensitivity analysis using different models for analyzing clustered data from DCE studies. PMID:22348526

The statistical pitfalls of the partially randomized preference design in non-blinded trials of psychological interventions.

PubMed

Gemmell, Isla; Dunn, Graham

2011-03-01

In a partially randomized preference trial (PRPT) patients with no treatment preference are allocated to groups at random, but those who express a preference receive the treatment of their choice. It has been suggested that the design can improve the external and internal validity of trials. We used computer simulation to illustrate the impact that an unmeasured confounder could have on the results and conclusions drawn from a PRPT. We generated 4000 observations ("patients") that reflected the distribution of the Beck Depression Index (DBI) in trials of depression. Half were randomly assigned to a randomized controlled trial (RCT) design and half were assigned to a PRPT design. In the RCT, "patients" were evenly split between treatment and control groups; whereas in the preference arm, to reflect patient choice, 87.5% of patients were allocated to the experimental treatment and 12.5% to the control. Unadjusted analyses of the PRPT data consistently overestimated the treatment effect and its standard error. This lead to Type I errors when the true treatment effect was small and Type II errors when the confounder effect was large. The PRPT design is not recommended as a method of establishing an unbiased estimate of treatment effect due to the potential influence of unmeasured confounders. Copyright © 2011 John Wiley & Sons, Ltd.

Contraceptive method choice among women in slum and non-slum communities in Nairobi, Kenya.

PubMed

Ochako, Rhoune; Izugbara, Chimaraoke; Okal, Jerry; Askew, Ian; Temmerman, Marleen

2016-07-12

Understanding women's contraceptive method choices is key to enhancing family planning services provision and programming. Currently however, very little research has addressed inter and intra-regional disparities in women's contraceptive method choice. Using data from slum and non-slum contexts in Nairobi, Kenya, the current study investigates the prevalence of and factors associated with contraceptive method choice among women. Data were from a cross-sectional quantitative study conducted among a random sample of 1,873 women (aged 15-49 years) in two non-slum and two slum settlement areas in Nairobi, Kenya. The study locations were purposively sampled by virtue of being part of the Nairobi Urban Health and Demographic Surveillance System. Bivariate and multivariate logistic regression were used to explore the association between the outcome variable, contraceptive method choice, and explanatory variables. The prevalence of contraceptive method choice was relatively similar across slum and non-slum settlements. 34.3 % of women in slum communities and 28.1 % of women in non-slum communities reported using short-term methods. Slightly more women living in the non-slum settlements reported use of long-term methods, 9.2 %, compared to 3.6 % in slum communities. Older women were less likely to use short-term methods than their younger counterparts but more likely to use long-term methods. Currently married women were more likely than never married women to use short-term and long-term methods. Compared to those with no children, women with three or more children were more likely to report using long term methods. Women working outside the home or those in formal employment also used modern methods of contraception more than those in self-employment or unemployed. Use of short-term and long-term methods is generally low among women living in slum and non-slum contexts in Nairobi. Investments in increasing women's access to various contraceptive options are urgently needed to help increase contraceptive prevalence rate. Thus, interventions that focus on more disadvantaged segments of the population will accelerate contraceptive uptake and improve maternal and child health in Kenya.

Effect of Allowing Choice of Diet on Weight Loss: A Randomized Trial.

PubMed

Yancy, William S; Mayer, Stephanie B; Coffman, Cynthia J; Smith, Valerie A; Kolotkin, Ronette L; Geiselman, Paula J; McVay, Megan A; Oddone, Eugene Z; Voils, Corrine I

2015-06-16

Choosing a diet rather than being prescribed one could improve weight loss. To examine whether offering choice of diet improves weight loss. Double-randomized preference trial of choice between 2 diets (choice) versus random assignment to a diet (comparator) over 48 weeks. (ClinicalTrials.gov: NCT01152359). Outpatient clinic at a Veterans Affairs medical center. Outpatients with a body mass index of at least 30 kg/m2. Choice participants received information about their food preferences and 2 diet options (low-carbohydrate diet [LCD] or low-fat diet [LFD]) before choosing and were allowed to switch diets at 12 weeks. Comparator participants were randomly assigned to 1 diet for 48 weeks. Both groups received group and telephone counseling for 48 weeks. The primary outcome was weight at 48 weeks. Of 105 choice participants, 61 (58%) chose the LCD and 44 (42%) chose the LFD; 5 (3 on the LCD and 2 on the LFD) switched diets at 12 weeks, and 87 (83%) completed measurements at 48 weeks. Of 102 comparator participants, 53 (52%) were randomly assigned to the LCD and 49 (48%) were assigned to the LFD; 88 (86%) completed measurements. At 48 weeks, estimated mean weight loss was 5.7 kg (95% CI, 4.3 to 7.0 kg) in the choice group and 6.7 kg (CI, 5.4 to 8.0 kg) in the comparator group (mean difference, -1.1 kg [CI, -2.9 to 0.8 kg]; P = 0.26). Secondary outcomes of dietary adherence, physical activity, and weight-related quality of life were similar between groups at 48 weeks. Only 2 diet options were provided. Results from this sample of older veterans might not be generalizable to other populations. Contrary to expectations, the opportunity to choose a diet did not improve weight loss.

QTest: Quantitative Testing of Theories of Binary Choice.

PubMed

Regenwetter, Michel; Davis-Stober, Clintin P; Lim, Shiau Hong; Guo, Ying; Popova, Anna; Zwilling, Chris; Cha, Yun-Shil; Messner, William

2014-01-01

The goal of this paper is to make modeling and quantitative testing accessible to behavioral decision researchers interested in substantive questions. We provide a novel, rigorous, yet very general, quantitative diagnostic framework for testing theories of binary choice. This permits the nontechnical scholar to proceed far beyond traditionally rather superficial methods of analysis, and it permits the quantitatively savvy scholar to triage theoretical proposals before investing effort into complex and specialized quantitative analyses. Our theoretical framework links static algebraic decision theory with observed variability in behavioral binary choice data. The paper is supplemented with a custom-designed public-domain statistical analysis package, the QTest software. We illustrate our approach with a quantitative analysis using published laboratory data, including tests of novel versions of "Random Cumulative Prospect Theory." A major asset of the approach is the potential to distinguish decision makers who have a fixed preference and commit errors in observed choices from decision makers who waver in their preferences.

Consumers' Use of HCAHPS Ratings and Word-of-Mouth in Hospital Choice

PubMed Central

Huppertz, John W; Carlson, Jay P

2010-01-01

Objective To investigate the impact of the HCAHPS report of patient experiences and word-of-mouth narratives on consumers' hospital choice. Data Sources Online consumer research panel of U.S. adults ages 18 and older. Study Design/Data Collection/Extraction Methods In an experiment, 309 consumers were randomly assigned to see positive or negative information about a hospital in two modalities: HCAHPS graphs and a relative's narrative e-mail. Then they indicated their intentions to choose the hospital for elective surgery. Principal Findings A simple, one-paragraph e-mail and 10 HCAHPS graphs had similar impacts on consumers' hospital choice. When information was inconsistent between the HCAHPS data and e-mail narrative, one modality attenuated the other's effect on hospital choice. Conclusions The findings illustrate the power of anecdotal narratives, suggesting that policy makers should consider how HCAHPS data can be affected by word-of-mouth communication. PMID:20698896

Implementation of a quantum random number generator based on the optimal clustering of photocounts

NASA Astrophysics Data System (ADS)

Balygin, K. A.; Zaitsev, V. I.; Klimov, A. N.; Kulik, S. P.; Molotkov, S. N.

2017-10-01

To implement quantum random number generators, it is fundamentally important to have a mathematically provable and experimentally testable process of measurements of a system from which an initial random sequence is generated. This makes sure that randomness indeed has a quantum nature. A quantum random number generator has been implemented with the use of the detection of quasi-single-photon radiation by a silicon photomultiplier (SiPM) matrix, which makes it possible to reliably reach the Poisson statistics of photocounts. The choice and use of the optimal clustering of photocounts for the initial sequence of photodetection events and a method of extraction of a random sequence of 0's and 1's, which is polynomial in the length of the sequence, have made it possible to reach a yield rate of 64 Mbit/s of the output certainly random sequence.

Comparison of traditional and interactive teaching methods in a UK emergency department.

PubMed

Armstrong, Peter; Elliott, Tim; Ronald, Julie; Paterson, Brodie

2009-12-01

Didactic teaching remains a core component of undergraduate education, but developing computer assisted learning (CAL) packages may provide useful alternatives. We compared the effectiveness of interactive multimedia-based tutorials with traditional, lecture-based models for teaching arterial blood gas interpretation to fourth year medical students. Participants were randomized to complete a tutorial in either lecture or multimedia format containing identical content. Upon completion, students answered five multiple choice questions assessing post-tutorial knowledge, and provided feedback on their allocated learning method. Marks revealed no significant difference between either group. All lecture candidates rated their teaching as good, compared with 89% of the CAL group. All CAL users found multiple choice questions assessment useful, compared with 83% of lecture participants. Both groups highlighted the importance of interaction. CAL complements other teaching methods, but should be seen as an adjunct to, rather than a replacement for, traditional methods, thus offering students a blended learning environment.

No evidence for MHC class II-based non-random mating at the gametic haplotype in Atlantic salmon.

PubMed

Promerová, M; Alavioon, G; Tusso, S; Burri, R; Immler, S

2017-06-01

Genes of the major histocompatibility complex (MHC) are a likely target of mate choice because of their role in inbreeding avoidance and potential benefits for offspring immunocompetence. Evidence for female choice for complementary MHC alleles among competing males exists both for the pre- and the postmating stages. However, it remains unclear whether the latter may involve non-random fusion of gametes depending on gametic haplotypes resulting in transmission ratio distortion or non-random sequence divergence among fused gametes. We tested whether non-random gametic fusion of MHC-II haplotypes occurs in Atlantic salmon Salmo salar. We performed in vitro fertilizations that excluded interindividual sperm competition using a split family design with large clutch sample sizes to test for a possible role of the gametic haplotype in mate choice. We sequenced two MHC-II loci in 50 embryos per clutch to assess allelic frequencies and sequence divergence. We found no evidence for transmission ratio distortion at two linked MHC-II loci, nor for non-random gamete fusion with respect to MHC-II alleles. Our findings suggest that the gametic MHC-II haplotypes play no role in gamete association in Atlantic salmon and that earlier findings of MHC-based mate choice most likely reflect choice among diploid genotypes. We discuss possible explanations for these findings and how they differ from findings in mammals.

Rescaling quality of life values from discrete choice experiments for use as QALYs: a cautionary tale

PubMed Central

Flynn, Terry N; Louviere, Jordan J; Marley, Anthony AJ; Coast, Joanna; Peters, Tim J

2008-01-01

Background Researchers are increasingly investigating the potential for ordinal tasks such as ranking and discrete choice experiments to estimate QALY health state values. However, the assumptions of random utility theory, which underpin the statistical models used to provide these estimates, have received insufficient attention. In particular, the assumptions made about the decisions between living states and the death state are not satisfied, at least for some people. Estimated values are likely to be incorrectly anchored with respect to death (zero) in such circumstances. Methods Data from the Investigating Choice Experiments for the preferences of older people CAPability instrument (ICECAP) valuation exercise were analysed. The values (previously anchored to the worst possible state) were rescaled using an ordinal model proposed previously to estimate QALY-like values. Bootstrapping was conducted to vary artificially the proportion of people who conformed to the conventional random utility model underpinning the analyses. Results Only 26% of respondents conformed unequivocally to the assumptions of conventional random utility theory. At least 14% of respondents unequivocally violated the assumptions. Varying the relative proportions of conforming respondents in sensitivity analyses led to large changes in the estimated QALY values, particularly for lower-valued states. As a result these values could be either positive (considered to be better than death) or negative (considered to be worse than death). Conclusion Use of a statistical model such as conditional (multinomial) regression to anchor quality of life values from ordinal data to death is inappropriate in the presence of respondents who do not conform to the assumptions of conventional random utility theory. This is clearest when estimating values for that group of respondents observed in valuation samples who refuse to consider any living state to be worse than death: in such circumstances the model cannot be estimated. Only a valuation task requiring respondents to make choices in which both length and quality of life vary can produce estimates that properly reflect the preferences of all respondents. PMID:18945358

Housing First, Consumer Choice, and Harm Reduction for Homeless Individuals With a Dual Diagnosis

PubMed Central

Tsemberis, Sam; Gulcur, Leyla; Nakae, Maria

2004-01-01

Objectives. We examined the longitudinal effects of a Housing First program for homeless, mentally ill individuals’ on those individuals’ consumer choice, housing stability, substance use, treatment utilization, and psychiatric symptoms. Methods. Two hundred twenty-five participants were randomly assigned to receive housing contingent on treatment and sobriety (control) or to receive immediate housing without treatment prerequisites (experimental). Interviews were conducted every 6 months for 24 months. Results. The experimental group obtained housing earlier, remained stably housed, and reported higher perceived choice. Utilization of substance abuse treatment was significantly higher for the control group, but no differences were found in substance use or psychiatric symptoms. Conclusions. Participants in the Housing First program were able to obtain and maintain independent housing without compromising psychiatric or substance abuse symptoms. PMID:15054020

Powerful Voter Selection for Making Multistep Delegate Ballot Fair

NASA Astrophysics Data System (ADS)

Yamakawa, Hiroshi

For decision by majority, each voter often exercises his right by delegating to trustable other voters. Multi-step delegates rule allows indirect delegating through more than one voter, and this helps each voter finding his delegate voters. In this paper, we propose powerful voter selection method depending on the multi-step delegate rule. This method sequentially selects voters who is most delegated indirectly. Multi-agent simulation demonstrate that we can achieve highly fair poll results from small number of vote by using proposed method. Here, fairness is prediction accuracy to sum of all voters preferences for choices. In simulation, each voter selects choices arranged on one dimensional preference axis for voting. Acquaintance relationships among voters were generated as a random network, and each voter delegates some of his acquaintances who has similar preferences. We obtained simulation results from various acquaintance networks, and then averaged these results. Firstly, if each voter has enough acquaintances in average, proposed method can help predicting sum of all voters' preferences of choices from small number of vote. Secondly, if the number of each voter's acquaintances increases corresponding to an increase in the number of voters, prediction accuracy (fairness) from small number of vote can be kept in appropriate level.

Optimized bioregenerative space diet selection with crew choice

NASA Technical Reports Server (NTRS)

Vicens, Carrie; Wang, Carolyn; Olabi, Ammar; Jackson, Peter; Hunter, Jean

2003-01-01

Previous studies on optimization of crew diets have not accounted for choice. A diet selection model with crew choice was developed. Scenario analyses were conducted to assess the feasibility and cost of certain crew preferences, such as preferences for numerous-desserts, high-salt, and high-acceptability foods. For comparison purposes, a no-choice and a random-choice scenario were considered. The model was found to be feasible in terms of food variety and overall costs. The numerous-desserts, high-acceptability, and random-choice scenarios all resulted in feasible solutions costing between 13.2 and 17.3 kg ESM/person-day. Only the high-sodium scenario yielded an infeasible solution. This occurred when the foods highest in salt content were selected for the crew-choice portion of the diet. This infeasibility can be avoided by limiting the total sodium content in the crew-choice portion of the diet. Cost savings were found by reducing food variety in scenarios where the preference bias strongly affected nutritional content.

Reproductive Health CHOICES for Young Adults with Sickle Cell Disease or Trait: Randomized Controlled Trial Immediate Posttest Effects

PubMed Central

Wilkie, Diana J; Gallo, Agatha M.; Yao, Yingwei; Molokie, Robert E.; Stahl, Christine; Hershberger, Patricia E.; Zhao, Zhongsheng; Suarez, Marie L.; Labotka, Robert J.; Johnson, Bonnye; Angulo, Rigo; Angulo, Veronica; Carrasco, Jesus; Shuey, David; Pelligra, Stephanie; Wang, Edward; Rogers, Dennie T.; Thompson, Alexis A.

2013-01-01

Background People with sickle cell disease (SCD) or sickle cell trait (SCT) may not have information about genetic inheritance needed for making informed reproductive health decisions. CHOICES is a web-based, multimedia educational intervention that provides information about reproductive options and consequences to help those with SCD or SCT identify and implement an informed parenting plan. Efficacy of CHOICES compared with usual care must be evaluated. Objective The purpose was to compare immediate posttest effects of CHOICES versus an attention control usual care intervention (e-Book) on SCD/SCT-related reproductive health knowledge, intention, and behavior. Methods In a randomized controlled study, we recruited subjects with SCD/SCT from clinics, community settings, and online networks with data collected at sites convenient to the 234 subjects with SCD (n = 136) or SCT (n = 98) (age ranged from18-35 years, 65% were female, and 94% were African American). Subjects completed a measure of sickle cell reproductive knowledge, intention, and behavior before and immediately after the intervention. Results Compared to the e-Book group, the CHOICES group had significantly higher average knowledge scores and probability of reporting a parenting plan to avoid SCD or SCD and SCT when pretest scores were controlled. Effects on intention and planned behavior were not significant. The CHOICES group showed significant change in their intention and planned behavior; the e-Book group did not show significant change in their intention, but their planned behavior differed significantly. Discussion Initial efficacy findings are encouraging but warrant planned booster sessions and outcome follow-ups to determine sustained intervention efficacy on reproductive health knowledge, intention, and actual behavior of persons with SCD/SCT. PMID:23995469

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.

PubMed

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 (p<.05). 'Providing choice' and 'free choice' interventions decreased sedentary behavior (p<.05). The interventions did not influence motivation, but students' autonomy increased during both choice-based interventions (p<.05). Promoting choice can produce short-term increases in PA and decreases in sedentary behavior, as well as increased perceived autonomy during PE lessons. © 2013.

Where Have All the Indians Gone? American Indian Representation in Secondary History Textbooks

ERIC Educational Resources Information Center

Shadowwalker, Depree M.

2012-01-01

This dissertation used a mixed method to develop an analytical model from a random selection of one of eight secondary history textbooks for instances of Indians to determine if the textual content: (1) constructs negative or inaccurate knowledge through word choice or narratives; (2) reinforces stereotype portraits; (3) omits similar minority…

A Free-Recall Demonstration versus a Lecture-Only Control: Learning Benefits

ERIC Educational Resources Information Center

Balch, William R.

2012-01-01

On their first class day, introductory psychology students took a 14-question multiple-choice pretest on several principles of memory including primacy, recency, storage, retrieval, counterbalancing, and the free-recall method. I randomly preassigned students to come at one of two different times to the second class, 2 days later, when they either…

Contraceptive method choice and use by married women of reproductive age in two Districts of East Harerge.

PubMed

Dubiwak, Rahel; Seme, Assefa

2014-01-01

Contraceptive method mix and choice is not uniform across all countries. Literatures have shown that a significant variation exists in contraceptive method mix among regions and countries. In Africa most mothers rely on short-term contraceptives such as pills and injectables or traditional methods while in Asia and Latin America permanent methods mainly male and female sterilizations are commonly used. Though long-term methods of contraception are recommended for its effectiveness and efficiencies in countries like Ethiopia where high fertility rate is a concern, its choice and utilization remains low. The main objective of the study was to assess factors influencing contraceptive method choice and use among married women of reproductive age in rural Districts of East Harerge Zone of Oromia Region. A community-based cross-sectional study using both quantitative and qualitative methods was conducted among 473 married women of reproductive age in two rural districts of East Harerge Zone. A systematic random sampling method was used to select the study participants from the list of all married women who have been using contraceptives in the project sites. Data was collected using structured and pretested questionnaires. Data entry and analysis was done using EPI Info version 6.04d and SPSS for Windows version 15, respectively. Frequencies and proportions were used for description while odds ratio with 95% CI was used to determine the strength and significance of association between independent and outcome variables. Multiple logistic regression analysis was used to control confounding variables. A total of 473 currently married women who were using modern contraceptives were interviewed for the survey. About 6 in ten (58.8%) were in the age range of 25-34 years with the mean (+/- SD) age of 29.5 (+/- 5.7) years. About three-fourth (74%) were short-term contraceptive method users while only 26% were long-term contraceptive method users. Duration of family planning use, reasons for contraceptive use and provider's choice of the method were positively associated with long-term contraceptive use by married women of reproductive age in the study area. Qualitative finding showed that religious and cultural perceptions about contraceptives and values the society, particularly men, gives to large family size has negatively influenced contraceptive use. Long-term contraceptive method use is influenced by duration and reason for use of the methods and provider 's choice in the study area. Misconceptions about fertility regulations and the value the society gives to large family size do also affect contraceptive use. Beside availing contraceptives of choice, reproductive health/family planning awareness creation targeting religious leaders as well as interventions aimed at respecting women's right of accessing family planning method of their choice has to be strengthened in the study area.

Method and apparatus for routing data in an inter-nodal communications lattice of a massively parallel computer system by semi-randomly varying routing policies for different packets

DOEpatents

Archer, Charles Jens; Musselman, Roy Glenn; Peters, Amanda; Pinnow, Kurt Walter; Swartz, Brent Allen; Wallenfelt, Brian Paul

2010-11-23

A massively parallel computer system contains an inter-nodal communications network of node-to-node links. Nodes vary a choice of routing policy for routing data in the network in a semi-random manner, so that similarly situated packets are not always routed along the same path. Semi-random variation of the routing policy tends to avoid certain local hot spots of network activity, which might otherwise arise using more consistent routing determinations. Preferably, the originating node chooses a routing policy for a packet, and all intermediate nodes in the path route the packet according to that policy. Policies may be rotated on a round-robin basis, selected by generating a random number, or otherwise varied.

Improving health outcomes for youth living with the human immunodeficiency virus: a multisite randomized trial of a motivational intervention targeting multiple risk behaviors.

PubMed

Naar-King, Sylvie; Parsons, Jeffrey T; Murphy, Debra A; Chen, Xinguang; Harris, D Robert; Belzer, Marvin E

2009-12-01

To determine if Healthy Choices, a motivational interviewing intervention targeting multiple risk behaviors, improved human immunodeficiency virus (HIV) viral load. A randomized, 2-group repeated measures design with analysis of data from baseline and 6- and 9-month follow-up collected from 2005 to 2007. Five US adolescent medicine HIV clinics. A convenience sample with at least 1 of 3 risk behaviors (nonadherence to HIV medications, substance abuse, and unprotected sex) was enrolled. The sample was aged 16 to 24 years and primarily African American. Of the 205 enrolled, 19 did not complete baseline data collections, for a final sample size of 186. Young people living with HIV were randomized to the intervention plus specialty care (n = 94) or specialty care alone (n = 92). The 3- and 6-month follow-up rates, respectively, were 86% and 82% for the intervention group and 81% and 73% for controls. Intervention Healthy Choices was a 4-session individual clinic-based motivational interviewing intervention delivered during a 10-week period. Motivational interviewing is a method of communication designed to elicit and reinforce intrinsic motivation for change. Outcome Measure Plasma viral load. Youth randomized to Healthy Choices showed a significant decline in viral load at 6 months postintervention compared with youth in the control condition (beta = -0.36, t = -2.15, P = .03), with those prescribed antiretroviral medications showing the lowest viral loads. Differences were no longer significant at 9 months. A motivational interviewing intervention targeting multiple risk behaviors resulted in short-term improvements in viral load for youth living with HIV. Trial Registration clinicaltrials.gov Identifier: NCT00103532.

Active Choice and Financial Incentives to Increase Rates of Screening Colonoscopy-A Randomized Controlled Trial.

PubMed

Mehta, Shivan J; Feingold, Jordyn; Vandertuyn, Matthew; Niewood, Tess; Cox, Catherine; Doubeni, Chyke A; Volpp, Kevin G; Asch, David A

2017-11-01

Behavioral economic approaches could increase uptake for colorectal cancer screening. We performed a randomized controlled trial of 2245 employees to determine whether an email containing a phone number for scheduling (control), an email with the active choice to opt in or opt out (active choice), or the active choice email plus a $100 incentive (financial incentive) increased colonoscopy completion within 3 months. Higher proportions of participants in the financial incentive group underwent screening (3.7%) than in the control (1.6%) or active choice groups (1.5%) (P = .01 and P < .01). We found no difference in uptake of screening between the active choice and control groups (P = .88). The $100 conditional incentive modestly but significantly increased colonoscopy use. ClinicalTrials.gov no: NCT02660671. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Random Behaviour or Rational Choice? Family Planning, Teenage Pregnancy and Sexually Transmitted Infections

ERIC Educational Resources Information Center

Paton, David

2006-01-01

Rational choice models of teenage sexual behaviour lead to radically different predictions than do models that assume such behaviour is random. Existing empirical evidence has not been able to distinguish conclusively between these competing models. I use regional data from England between 1998 and 2001 to examine the impact of recent increases in…

A New Method of Random Environmental Walking for Assessing Behavioral Preferences for Different Lighting Applications

PubMed Central

Patching, Geoffrey R.; Rahm, Johan; Jansson, Märit; Johansson, Maria

2017-01-01

Accurate assessment of people’s preferences for different outdoor lighting applications is increasingly considered important in the development of new urban environments. Here a new method of random environmental walking is proposed to complement current methods of assessing urban lighting applications, such as self-report questionnaires. The procedure involves participants repeatedly walking between different lighting applications by random selection of a lighting application and preferred choice or by random selection of a lighting application alone. In this manner, participants are exposed to all lighting applications of interest more than once and participants’ preferences for the different lighting applications are reflected in the number of times they walk to each lighting application. On the basis of an initial simulation study, to explore the feasibility of this approach, a comprehensive field test was undertaken. The field test included random environmental walking and collection of participants’ subjective ratings of perceived pleasantness (PP), perceived quality, perceived strength, and perceived flicker of four lighting applications. The results indicate that random environmental walking can reveal participants’ preferences for different lighting applications that, in the present study, conformed to participants’ ratings of PP and perceived quality of the lighting applications. As a complement to subjectively stated environmental preferences, random environmental walking has the potential to expose behavioral preferences for different lighting applications. PMID:28337163

The Treatment of Adolescent Suicide Attempters Study (TASA): Predictors of Suicidal Events in an Open Treatment Trial

ERIC Educational Resources Information Center

Brent, David A.; Greenhill, Laurence L.; Compton, Scott; Emslie, Graham; Wells, Karen; Walkup, John T.; Vitiello, Benedetto; Bukstein, Oscar; Stanley, Barbara; Posner, Kelly; Kennard, Betsy D.; Cwik, Mary F.; Wagner, Ann; Coffey, Barbara; March, John S.; Riddle, Mark; Goldstein, Tina; Curry, John; Barnett, Shannon; Capasso, Lisa; Zelazny, Jamie; Hughes, Jennifer; Shen, Sa; Gugga, S. Sonia; Turner, J. Blake

2009-01-01

Objective: To identify the predictors of suicidal events and attempts in adolescent suicide attempters with depression treated in an open treatment trial. Method: Adolescents who had made a recent suicide attempt and had unipolar depression (n =124) were either randomized (n = 22) or given a choice (n = 102) among three conditions. Two…

QTest: Quantitative Testing of Theories of Binary Choice

PubMed Central

Regenwetter, Michel; Davis-Stober, Clintin P.; Lim, Shiau Hong; Guo, Ying; Popova, Anna; Zwilling, Chris; Cha, Yun-Shil; Messner, William

2014-01-01

The goal of this paper is to make modeling and quantitative testing accessible to behavioral decision researchers interested in substantive questions. We provide a novel, rigorous, yet very general, quantitative diagnostic framework for testing theories of binary choice. This permits the nontechnical scholar to proceed far beyond traditionally rather superficial methods of analysis, and it permits the quantitatively savvy scholar to triage theoretical proposals before investing effort into complex and specialized quantitative analyses. Our theoretical framework links static algebraic decision theory with observed variability in behavioral binary choice data. The paper is supplemented with a custom-designed public-domain statistical analysis package, the QTest software. We illustrate our approach with a quantitative analysis using published laboratory data, including tests of novel versions of “Random Cumulative Prospect Theory.” A major asset of the approach is the potential to distinguish decision makers who have a fixed preference and commit errors in observed choices from decision makers who waver in their preferences. PMID:24999495

What influences the choice of assessment methods in health technology assessments? Statistical analysis of international health technology assessments from 1989 to 2002.

PubMed

Draborg, Eva; Andersen, Christian Kronborg

2006-01-01

Health technology assessment (HTA) has been used as input in decision making worldwide for more than 25 years. However, no uniform definition of HTA or agreement on assessment methods exists, leaving open the question of what influences the choice of assessment methods in HTAs. The objective of this study is to analyze statistically a possible relationship between methods of assessment used in practical HTAs, type of assessed technology, type of assessors, and year of publication. A sample of 433 HTAs published by eleven leading institutions or agencies in nine countries was reviewed and analyzed by multiple logistic regression. The study shows that outsourcing of HTA reports to external partners is associated with a higher likelihood of using assessment methods, such as meta-analysis, surveys, economic evaluations, and randomized controlled trials; and with a lower likelihood of using assessment methods, such as literature reviews and "other methods". The year of publication was statistically related to the inclusion of economic evaluations and shows a decreasing likelihood during the year span. The type of assessed technology was related to economic evaluations with a decreasing likelihood, to surveys, and to "other methods" with a decreasing likelihood when pharmaceuticals were the assessed type of technology. During the period from 1989 to 2002, no major developments in assessment methods used in practical HTAs were shown statistically in a sample of 433 HTAs worldwide. Outsourcing to external assessors has a statistically significant influence on choice of assessment methods.

Rigorously testing multialternative decision field theory against random utility models.

PubMed

Berkowitsch, Nicolas A J; Scheibehenne, Benjamin; Rieskamp, Jörg

2014-06-01

Cognitive models of decision making aim to explain the process underlying observed choices. Here, we test a sequential sampling model of decision making, multialternative decision field theory (MDFT; Roe, Busemeyer, & Townsend, 2001), on empirical grounds and compare it against 2 established random utility models of choice: the probit and the logit model. Using a within-subject experimental design, participants in 2 studies repeatedly choose among sets of options (consumer products) described on several attributes. The results of Study 1 showed that all models predicted participants' choices equally well. In Study 2, in which the choice sets were explicitly designed to distinguish the models, MDFT had an advantage in predicting the observed choices. Study 2 further revealed the occurrence of multiple context effects within single participants, indicating an interdependent evaluation of choice options and correlations between different context effects. In sum, the results indicate that sequential sampling models can provide relevant insights into the cognitive process underlying preferential choices and thus can lead to better choice predictions. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Choice Experiments to Quantify Preferences for Health and Healthcare: State of the Practice.

PubMed

Mühlbacher, Axel; Johnson, F Reed

2016-06-01

Stated-preference methods increasingly are used to quantify preferences in health economics, health technology assessment, benefit-risk analysis and health services research. The objective of stated-preference studies is to acquire information about trade-off preferences among treatment outcomes, prioritization of clinical decision criteria, likely uptake or adherence to healthcare products and acceptability of healthcare services or policies. A widely accepted approach to eliciting preferences is discrete-choice experiments. Patient, physician, insurant or general-public respondents choose among constructed, experimentally controlled alternatives described by decision-relevant features or attributes. Attributes can represent complete health states, sets of treatment outcomes or characteristics of a healthcare system. The observed pattern of choice reveals how different respondents or groups of respondents implicitly weigh, value and assess different characteristics of treatments, products or services. An important advantage of choice experiments is their foundation in microeconomic utility theory. This conceptual framework provides tests of internal validity, guidance for statistical analysis of latent preference structures, and testable behavioural hypotheses. Choice experiments require expertise in survey-research methods, random-utility theory, experimental design and advanced statistical analysis. This paper should be understood as an introduction to setting up a basic experiment rather than an exhaustive critique of the latest findings and procedures. Where appropriate, we have identified topics of active research where a broad consensus has not yet been established.

Influence of Choice of Null Network on Small-World Parameters of Structural Correlation Networks

PubMed Central

Hosseini, S. M. Hadi; Kesler, Shelli R.

2013-01-01

In recent years, coordinated variations in brain morphology (e.g., volume, thickness) have been employed as a measure of structural association between brain regions to infer large-scale structural correlation networks. Recent evidence suggests that brain networks constructed in this manner are inherently more clustered than random networks of the same size and degree. Thus, null networks constructed by randomizing topology are not a good choice for benchmarking small-world parameters of these networks. In the present report, we investigated the influence of choice of null networks on small-world parameters of gray matter correlation networks in healthy individuals and survivors of acute lymphoblastic leukemia. Three types of null networks were studied: 1) networks constructed by topology randomization (TOP), 2) networks matched to the distributional properties of the observed covariance matrix (HQS), and 3) networks generated from correlation of randomized input data (COR). The results revealed that the choice of null network not only influences the estimated small-world parameters, it also influences the results of between-group differences in small-world parameters. In addition, at higher network densities, the choice of null network influences the direction of group differences in network measures. Our data suggest that the choice of null network is quite crucial for interpretation of group differences in small-world parameters of structural correlation networks. We argue that none of the available null models is perfect for estimation of small-world parameters for correlation networks and the relative strengths and weaknesses of the selected model should be carefully considered with respect to obtained network measures. PMID:23840672

The Dependent Poisson Race Model and Modeling Dependence in Conjoint Choice Experiments

ERIC Educational Resources Information Center

Ruan, Shiling; MacEachern, Steven N.; Otter, Thomas; Dean, Angela M.

2008-01-01

Conjoint choice experiments are used widely in marketing to study consumer preferences amongst alternative products. We develop a class of choice models, belonging to the class of Poisson race models, that describe a "random utility" which lends itself to a process-based description of choice. The models incorporate a dependence structure which…

Patient choice in opt-in, active choice, and opt-out HIV screening: randomized clinical trial

PubMed Central

Dow, William H; Kaplan, Beth C

2016-01-01

Study question What is the effect of default test offers—opt-in, opt-out, and active choice—on the likelihood of acceptance of an HIV test among patients receiving care in an emergency department? Methods This was a randomized clinical trial conducted in the emergency department of an urban teaching hospital and regional trauma center. Patients aged 13-64 years were randomized to opt-in, opt-out, and active choice HIV test offers. The primary outcome was HIV test acceptance percentage. The Denver Risk Score was used to categorize patients as being at low, intermediate, or high risk of HIV infection. Study answer and limitations 38.0% (611/1607) of patients in the opt-in testing group accepted an HIV test, compared with 51.3% (815/1628) in the active choice arm (difference 13.3%, 95% confidence interval 9.8% to 16.7%) and 65.9% (1031/1565) in the opt-out arm (difference 27.9%, 24.4% to 31.3%). Compared with active choice testing, opt-out testing led to a 14.6 (11.1 to 18.1) percentage point increase in test acceptance. Patients identified as being at intermediate and high risk were more likely to accept testing than were those at low risk in all arms (difference 6.4% (3.4% to 9.3%) for intermediate and 8.3% (3.3% to 13.4%) for high risk). The opt-out effect was significantly smaller among those reporting high risk behaviors, but the active choice effect did not significantly vary by level of reported risk behavior. Patients consented to inclusion in the study after being offered an HIV test, and inclusion varied slightly by treatment assignment. The study took place at a single county hospital in a city that is somewhat unique with respect to HIV testing; although the test acceptance percentages themselves might vary, a different pattern for opt-in versus active choice versus opt-out test schemes would not be expected. What this paper adds Active choice is a distinct test regimen, with test acceptance patterns that may best approximate patients’ true preferences. Opt-out regimens can substantially increase HIV testing, and opt-in schemes may reduce testing, compared with active choice testing. Funding, competing interests, data sharing This study was supported by grant NIA 1RC4AG039078 from the National Institute on Aging. The full dataset is available from the corresponding author. Consent for data sharing was not obtained, but the data are anonymized and risk of identification is low. Trial registration Clinical trials NCT01377857. PMID:26786744

Non-random mate choice in humans: insights from a genome scan.

PubMed

Laurent, R; Toupance, B; Chaix, R

2012-02-01

Little is known about the genetic factors influencing mate choice in humans. Still, there is evidence for non-random mate choice with respect to physical traits. In addition, some studies suggest that the Major Histocompatibility Complex may affect pair formation. Nowadays, the availability of high density genomic data sets gives the opportunity to scan the genome for signatures of non-random mate choice without prior assumptions on which genes may be involved, while taking into account socio-demographic factors. Here, we performed a genome scan to detect extreme patterns of similarity or dissimilarity among spouses throughout the genome in three populations of African, European American, and Mexican origins from the HapMap 3 database. Our analyses identified genes and biological functions that may affect pair formation in humans, including genes involved in skin appearance, morphogenesis, immunity and behaviour. We found little overlap between the three populations, suggesting that the biological functions potentially influencing mate choice are population specific, in other words are culturally driven. Moreover, whenever the same functional category of genes showed a significant signal in two populations, different genes were actually involved, which suggests the possibility of evolutionary convergences. © 2011 Blackwell Publishing Ltd.

Effects of calorie labeling and value size pricing on fast food meal choices: Results from an experimental trial

PubMed Central

Harnack, Lisa J; French, Simone A; Oakes, J Michael; Story, Mary T; Jeffery, Robert W; Rydell, Sarah A

2008-01-01

Background Although point-of-purchase calorie labeling at restaurants has been proposed as a strategy for improving consumer food choices, a limited number of studies have evaluated this approach. Likewise, little research has been conducted to evaluate the influence of value size pricing on restaurant meal choices. Methods To examine the effect of point-of-purchase calorie information and value size pricing on fast food meal choices a randomized 2 × 2 factorial experiment was conducted in which participants ordered a fast food meal from one of four menus that varied with respect to whether calorie information was provided and whether value size pricing was used. Study participants included 594 adolescents and adults who regularly ate at fast food restaurants. Study staff recorded the foods ordered and consumed by each participant. Participants also completed surveys to assess attitudes, beliefs and practices related to fast food and nutrition. Results No significant differences in the energy composition of meals ordered or eaten were found between menu conditions. The average energy content of meals ordered by those randomized to a menu that included calorie information and did not include value size pricing was 842 kcals compared with 827 kcals for those who ordered their meal from a menu that did not include calorie information but had value size pricing (control menu). Results were similar in most analyses conducted stratified by factors such as age, race and education level. Conclusion Additional research is needed to better evaluate the effects of calorie labeling and value size pricing on fast food meal choices. Studies in which participants are repeatedly exposed to these factors are needed since long term exposure may be required for behavior change. PMID:19061510

Human choice among five alternatives when reinforcers decay.

PubMed

Rothstein, Jacob B; Jensen, Greg; Neuringer, Allen

2008-06-01

Human participants played a computer game in which choices among five alternatives were concurrently reinforced according to dependent random-ratio schedules. "Dependent" indicates that choices to any of the wedges activated the random-number generators governing reinforcers on all five alternatives. Two conditions were compared. In the hold condition, once scheduled, a reinforcer - worth a constant five points - remained available until it was collected. In the decay condition, point values decreased with intervening responses, i.e., rapid collection was differentially reinforced. Slopes of matching functions were higher in the decay than hold condition. However inter-subject variability was high in both conditions.

Women With Gestational Diabetes Mellitus Randomized to a Higher-Complex Carbohydrate/Low-Fat Diet Manifest Lower Adipose Tissue Insulin Resistance, Inflammation, Glucose, and Free Fatty Acids: A Pilot Study.

PubMed

Hernandez, Teri L; Van Pelt, Rachael E; Anderson, Molly A; Reece, Melanie S; Reynolds, Regina M; de la Houssaye, Becky A; Heerwagen, Margaret; Donahoo, William T; Daniels, Linda J; Chartier-Logan, Catherine; Janssen, Rachel C; Friedman, Jacob E; Barbour, Linda A

2016-01-01

Diet therapy in gestational diabetes mellitus (GDM) has focused on carbohydrate restriction but is poorly substantiated. In this pilot randomized clinical trial, we challenged the conventional low-carbohydrate/higher-fat (LC/CONV) diet, hypothesizing that a higher-complex carbohydrate/lower-fat (CHOICE) diet would improve maternal insulin resistance (IR), adipose tissue (AT) lipolysis, and infant adiposity. At 31 weeks, 12 diet-controlled overweight/obese women with GDM were randomized to an isocaloric LC/CONV (40% carbohydrate/45% fat/15% protein; n = 6) or CHOICE (60%/25%/15%; n = 6) diet. All meals were provided. AT was biopsied at 37 weeks. After ∼7 weeks, fasting glucose (P = 0.03) and free fatty acids (P = 0.06) decreased on CHOICE, whereas fasting glucose increased on LC/CONV (P = 0.03). Insulin suppression of AT lipolysis was improved on CHOICE versus LC/CONV (56 vs. 31%, P = 0.005), consistent with improved IR. AT expression of multiple proinflammatory genes was lower on CHOICE (P < 0.01). Infant adiposity trended lower with CHOICE (10.1 ± 1.4 vs. 12.6 ± 2%, respectively). A CHOICE diet may improve maternal IR and infant adiposity, challenging recommendations for a LC/CONV diet. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Taiwanese consumer survey data for investigating the role of information on equivalence of organic standards in directing food choice.

PubMed

Yeh, Ching-Hua; Hartmann, Monika; Hirsch, Stefan

2018-06-01

The presentation of credence attributes such as the product's origin or the production method has a significant influence on consumers' food purchase decisions. The dataset includes survey responses from a discrete choice experiment with 1309 food shoppers in Taiwan using the example of sweet pepper. The survey was carried out in 2014 in the three largest Taiwanese cities. It evaluates the impact of providing information on the equality of organic standards on consumers' preferences at the example of sweet pepper. Equality of organic standards implies that regardless of products' country-of-origin (COO) organic certifications are based on the same production regulation and managerial processes. Respondents were randomly allocated to the information treatment and the control group. The dataset contains the product choices of participants in both groups, as well as their sociodemographic information.

Evidence, values, guidelines and rational decision-making.

PubMed

Barrett, Bruce

2012-02-01

Medical decision-making involves choices, which can lead to benefits or to harms. Most benefits and harms may or may not occur, and can be minor or major when they do. Medical research, especially randomized controlled trials, provides estimates of chance of occurrence and magnitude of event. Because there is no universally accepted method for weighing harms against benefits, and because the ethical principle of autonomy mandates informed choice by patient, medical decision-making is inherently an individualized process. It follows that the practice of aiming for universal implementation of standardized guidelines is irrational and unethical. Irrational because the possibility of benefits is implicitly valued more than the possibility of comparable harms, and unethical because guidelines remove decision making from the patient and give it instead to a physician, committee or health care system. This essay considers the cases of cancer screening and diabetes management, where guidelines often advocate universal implementation, without regard to informed choice and individual decision-making.

Unexpected benefits of deciding by mind wandering

PubMed Central

Giblin, Colleen E.; Morewedge, Carey K.; Norton, Michael I.

2013-01-01

The mind wanders, even when people are attempting to make complex decisions. We suggest that mind wandering—allowing one's thoughts to wander until the “correct” choice comes to mind—can positively impact people's feelings about their decisions. We compare post-choice satisfaction from choices made by mind wandering to reason-based choices and randomly assigned outcomes. Participants chose a poster by mind wandering or deliberating, or were randomly assigned a poster. Whereas forecasters predicted that participants who chose by mind wandering would evaluate their outcome as inferior to participants who deliberated (Experiment 1), participants who used mind wandering as a decision strategy evaluated their choice just as positively as did participants who used deliberation (Experiment 2). In some cases, it appears that people can spare themselves the effort of deliberation and instead “decide by wind wandering,” yet experience no decrease in satisfaction. PMID:24046760

The Dynamics of Study-Work Choice and Its Effect on Intended and Actual University Attainment

ERIC Educational Resources Information Center

Gong, Xiaodong

2017-01-01

We study the dynamics of study-work choices of Australian high school students and how these choices affect intended and actual enrolment in universities when they finish their school education. A dynamic random effect multi-equation model is constructed and estimated. We find that study-work choices are state dependent, driven by student…

Challenging local realism with human choices.

PubMed

2018-05-01

A Bell test is a randomized trial that compares experimental observations against the philosophical worldview of local realism 1 , in which the properties of the physical world are independent of our observation of them and no signal travels faster than light. A Bell test requires spatially distributed entanglement, fast and high-efficiency detection and unpredictable measurement settings 2,3 . Although technology can satisfy the first two of these requirements 4-7 , the use of physical devices to choose settings in a Bell test involves making assumptions about the physics that one aims to test. Bell himself noted this weakness in using physical setting choices and argued that human 'free will' could be used rigorously to ensure unpredictability in Bell tests 8 . Here we report a set of local-realism tests using human choices, which avoids assumptions about predictability in physics. We recruited about 100,000 human participants to play an online video game that incentivizes fast, sustained input of unpredictable selections and illustrates Bell-test methodology 9 . The participants generated 97,347,490 binary choices, which were directed via a scalable web platform to 12 laboratories on five continents, where 13 experiments tested local realism using photons 5,6 , single atoms 7 , atomic ensembles 10 and superconducting devices 11 . Over a 12-hour period on 30 November 2016, participants worldwide provided a sustained data flow of over 1,000 bits per second to the experiments, which used different human-generated data to choose each measurement setting. The observed correlations strongly contradict local realism and other realistic positions in bipartite and tripartite 12 scenarios. Project outcomes include closing the 'freedom-of-choice loophole' (the possibility that the setting choices are influenced by 'hidden variables' to correlate with the particle properties 13 ), the utilization of video-game methods 14 for rapid collection of human-generated randomness, and the use of networking techniques for global participation in experimental science.

Offering self-administered oral HIV testing to truck drivers in Kenya to increase testing: a randomized controlled trial.

PubMed

Kelvin, Elizabeth A; George, Gavin; Mwai, Eva; Nyaga, Eston; Mantell, Joanne E; Romo, Matthew L; Odhiambo, Jacob O; Starbuck, Lila; Govender, Kaymarlin

2018-01-01

We conducted a randomized controlled trial among 305 truck drivers from two North Star Alliance roadside wellness clinics in Kenya to see if offering HIV testing choices would increase HIV testing uptake. Participants were randomized to be offered (1) a provider-administered rapid blood (finger-prick) HIV test (i.e., standard of care [SOC]) or (2) a Choice between SOC or a self-administered oral rapid HIV test with provider supervision in the clinic. Participants in the Choice arm who refused HIV testing in the clinic were offered a test kit for home use with phone-based posttest counseling. We compared HIV test uptake using the Mantel Haenszel odds ratio (OR) adjusting for clinic. Those in the Choice arm had higher odds of HIV test uptake than those in the SOC arm (OR = 1.5), but the difference was not statistically significant (p = 0.189). When adding the option to take an HIV test kit for home use, the Choice arm had significantly greater odds of testing uptake (OR = 2.8, p = 0.002). Of those in the Choice arm who tested, 26.9% selected the SOC test, 64.6% chose supervised self-testing in the clinic, and 8.5% took a test kit for home use. Participants varied in the HIV test they selected when given choices. Importantly, when participants who refused HIV testing in the clinic were offered a test kit for home use, an additional 8.5% tested. Offering truck drivers a variety of HIV testing choices may increase HIV testing uptake in this key population.

Decision aid on radioactive iodine treatment for early stage papillary thyroid cancer: update to study protocol with follow-up extension.

PubMed

Sawka, Anna M; Straus, Sharon; Rodin, Gary; Thorpe, Kevin E; Ezzat, Shereen; Gafni, Amiram; Goldstein, David P

2015-07-14

Patient decision aids (P-DAs) are used to inform patients about healthcare choices, but there is limited knowledge about their longer term effects, beyond the time period of decision-making. We developed a computerized P-DA that explains the choice of radioactive iodine (RAI) adjuvant treatment or no RAI, for patients with low risk papillary thyroid cancer after total thyroidectomy. The original protocol for a randomized controlled trial, comparing the use of the P-DA (with usual care) to usual care alone, has been published in Trials http://www.trialsjournal.com/content/11/1/81. We found that P-DA (with usual care) significantly improved patients' medical knowledge at the time of decision-making (primary outcome) compared to usual care alone (control). In this update, we present the protocol for an extended follow-up study (15 to 23 months post-randomization), including qualitative and quantitative methods. The patient outcomes evaluated using quantitative questionnaires include: the degree to which patients feel well-informed about their RAI treatment choice, decision satisfaction, decision regret, cancer-related worry, mood, and trust in the treating physician. The qualitative component explores the experiences of RAI treatment decision-making, treatment satisfaction, and trial participation in a representative subgroup of patients. Extended follow-up study results will be described for the entire study population, and data will be compared between the P-DA and control groups. This mixed methods extended follow-up study will provide data on long term outcomes, relating to the use of a computerized P-DA in decision-making about adjuvant RAI treatment in early stage papillary thyroid cancer. Our results are intended to inform future research in this area, particularly relating to long term effects of the use of P-DAs in making healthcare choices. Clinicaltrials.gov identifier NCT01083550, registered 24 February 2010 and last updated 5 January 2015.

Perspective: Randomized Controlled Trials Are Not a Panacea for Diet-Related Research12

PubMed Central

Hébert, James R; Frongillo, Edward A; Adams, Swann A; Turner-McGrievy, Gabrielle M; Hurley, Thomas G; Miller, Donald R; Ockene, Ira S

2016-01-01

Research into the role of diet in health faces a number of methodologic challenges in the choice of study design, measurement methods, and analytic options. Heavier reliance on randomized controlled trial (RCT) designs is suggested as a way to solve these challenges. We present and discuss 7 inherent and practical considerations with special relevance to RCTs designed to study diet: 1) the need for narrow focus; 2) the choice of subjects and exposures; 3) blinding of the intervention; 4) perceived asymmetry of treatment in relation to need; 5) temporal relations between dietary exposures and putative outcomes; 6) strict adherence to the intervention protocol, despite potential clinical counter-indications; and 7) the need to maintain methodologic rigor, including measuring diet carefully and frequently. Alternatives, including observational studies and adaptive intervention designs, are presented and discussed. Given high noise-to-signal ratios interjected by using inaccurate assessment methods in studies with weak or inappropriate study designs (including RCTs), it is conceivable and indeed likely that effects of diet are underestimated. No matter which designs are used, studies will require continued improvement in the assessment of dietary intake. As technology continues to improve, there is potential for enhanced accuracy and reduced user burden of dietary assessments that are applicable to a wide variety of study designs, including RCTs. PMID:27184269

Effects of choice architecture and chef-enhanced meals on the selection and consumption of healthier school foods: a randomized clinical trial.

PubMed

Cohen, Juliana F W; Richardson, Scott A; Cluggish, Sarah A; Parker, Ellen; Catalano, Paul J; Rimm, Eric B

2015-05-01

Little is known about the long-term effect of a chef-enhanced menu on healthier food selection and consumption in school lunchrooms. In addition, it remains unclear if extended exposure to other strategies to promote healthier foods (eg, choice architecture) also improves food selection or consumption. To evaluate the short- and long-term effects of chef-enhanced meals and extended exposure to choice architecture on healthier school food selection and consumption. A school-based randomized clinical trial was conducted during the 2011-2012 school year among 14 elementary and middle schools in 2 urban, low-income school districts (intent-to-treat analysis). Included in the study were 2638 students in grades 3 through 8 attending participating schools (38.4% of eligible participants). Schools were first randomized to receive a professional chef to improve school meal palatability (chef schools) or to a delayed intervention (control group). To assess the effect of choice architecture (smart café), all schools after 3 months were then randomized to the smart café intervention or to the control group. School food selection was recorded, and consumption was measured using plate waste methods. After 3 months, vegetable selection increased in chef vs control schools (odds ratio [OR], 1.75; 95% CI, 1.36-2.24), but there was no effect on the selection of other components or on meal consumption. After long-term or extended exposure to the chef or smart café intervention, fruit selection increased in the chef (OR, 3.08; 95% CI, 2.23-4.25), smart café (OR, 1.45; 95% CI, 1.13-1.87), and chef plus smart café (OR, 3.10; 95% CI, 2.26-4.25) schools compared with the control schools, and consumption increased in the chef schools (OR, 0.17; 95% CI, 0.03-0.30 cups/d). Vegetable selection increased in the chef (OR, 2.54; 95% CI, 1.83-3.54), smart café (OR, 1.91; 95% CI, 1.46-2.50), and chef plus smart café schools (OR, 7.38, 95% CI, 5.26-10.35) compared with the control schools, and consumption also increased in the chef (OR, 0.16; 95% CI, 0.09-0.22 cups/d) and chef plus smart café (OR, 0.13; 95% CI, 0.05-0.19 cups/d) schools; however, the smart café intervention alone had no effect on consumption. Schools should consider both collaborating with chefs and using choice architecture to increase fruit and vegetable selection. Efforts to improve the taste of school foods through chef-enhanced meals should remain a priority because this was the only method that also increased consumption. This was observed only after students were repeatedly exposed to the new foods for 7 months. Therefore, schools should not abandon healthier options if they are initially met with resistance. clinicaltrials.gov Identifier: NCT02309840.

A cluster randomized trial of strategies to increase uptake amongst young women invited for their first cervical screen: The STRATEGIC trial.

PubMed

Kitchener, H; Gittins, M; Cruickshank, M; Moseley, C; Fletcher, S; Albrow, R; Gray, A; Brabin, L; Torgerson, D; Crosbie, E J; Sargent, A; Roberts, C

2018-06-01

Objectives To measure the feasibility and effectiveness of interventions to increase cervical screening uptake amongst young women. Methods A two-phase cluster randomized trial conducted in general practices in the NHS Cervical Screening Programme. In Phase 1, women in practices randomized to intervention due for their first invitation to cervical screening received a pre-invitation leaflet and, separately, access to online booking. In Phase 2, non-attenders at six months were randomized to one of: vaginal self-sample kits sent unrequested or offered; timed appointments; nurse navigator; or the choice between nurse navigator or self-sample kits. Primary outcome was uplift in intervention vs. control practices, at 3 and 12 months post invitation. Results Phase 1 randomized 20,879 women. Neither pre-invitation leaflet nor online booking increased screening uptake by three months (18.8% pre-invitation leaflet vs. 19.2% control and 17.8% online booking vs. 17.2% control). Uptake was higher amongst human papillomavirus vaccinees at three months (OR 2.07, 95% CI 1.69-2.53, p < 0.001). Phase 2 randomized 10,126 non-attenders, with 32-34 clusters for each intervention and 100 clusters as controls. Sending self-sample kits increased uptake at 12 months (OR 1.51, 95% CI 1.20-1.91, p = 0.001), as did timed appointments (OR 1.41, 95% CI 1.14-1.74, p = 0.001). The offer of a nurse navigator, a self-sample kits on request, and choice between timed appointments and nurse navigator were ineffective. Conclusions Amongst non-attenders, self-sample kits sent and timed appointments achieved an uplift in screening over the short term; longer term impact is less certain. Prior human papillomavirus vaccination was associated with increased screening uptake.

Mate choice could be random in female rats (Rattus norvegicus).

PubMed

Le Moëne, Olivia; Snoeren, Eelke M

2018-02-01

Female mate choice is often investigated in terms of reproductive success in order to understand how male characteristics contribute to sexual attractiveness. Previous studies have found that females rats prefer mating with their first encounter rather than males visited subsequently, suggesting that the rewarding value of this first encounter is enough to reinforce mating with the first partner. Using a multiple chambers paradigm, we allowed female rats to copulate freely with three males placed each in a different chamber. Then, we switched the males' position, and let the female interact with them freely again within the same session. We tested whether female mate choice was relying rather on a preferred male rat or on a preferred mating location. The results showed that females spent most time with the male in the chamber of 1st entry in the beginning, but as soon as male rats switched chambers, the female rat continued to copulate with the new male in the same chamber of 1st entry, instead of mating with her previously preferred male rat. This suggests that the male preference is an artefact of location preference. Therefore, female mate choice seems to be rather random than the consequence of an individual choice based on male characteristics. This finding, although contradictory with the intuitive feeling that mate choice is a crucial feature in sexual and reproductive behavior, is supported by several recent observations. In the coming years, behavioral neuroscience should bring light to the brain processes at work in random mate choice. Copyright © 2017 Elsevier Inc. All rights reserved.

Teen Dating Violence Prevention: Cluster-Randomized Trial of Teen Choices, an Online, Stage-Based Program for Healthy, Nonviolent Relationships.

PubMed

Levesque, Deborah A; Johnson, Janet L; Welch, Carol A; Prochaska, Janice M; Paiva, Andrea L

2016-07-01

Teen dating violence is a serious public health problem. A cluster-randomized trial was conducted to assess the efficacy of Teen Choices , a 3-session online program that delivers assessments and individualized guidance matched to dating history, dating violence experiences, and stage of readiness for using healthy relationship skills. For high risk victims of dating violence, the program addresses readiness to keep oneself safe in relationships. Twenty high schools were randomly assigned to the Teen Choices condition ( n =2,000) or a Comparison condition ( n =1,901). Emotional and physical dating violence victimization and perpetration were assessed at 6 and 12 months in the subset of participants (total n =2,605) who reported a past-year history of dating violence at baseline, and/or who dated during the study. The Teen Choices program was associated with significantly reduced odds of all four types of dating violence (adjusted ORs ranging from .45 to .63 at 12 months follow-up). For three of the four violence outcomes, participants with a past-year history of that type of violence benefited significantly more from the intervention than students without a past-year history. The Teen Choices program provides an effective and practicable strategy for intervention for teen dating violence prevention.

A randomized study comparing skin closure in cesarean sections: staples vs subcuticular sutures.

PubMed

Rousseau, Julie-Anne; Girard, Karine; Turcot-Lemay, Lucile; Thomas, Nancy

2009-03-01

We sought to compare postoperative pain according to the skin closure method (subcuticular sutures vs staples) after an elective term cesarean section. A randomized controlled trial of 101 women was performed. Women were randomly assigned to subcuticular sutures or staples. Operative technique and postoperative analgesia were standardized. Stratification was used for primary vs repeat cesareans. Analog pain and satisfaction scales ranging from 0-10 were completed at postoperative days 1 and 3, and at 6 weeks postoperatively. A digital photograph of the incision was taken at 6 weeks postoperatively and evaluated by 3 independent blinded observers. Pain at 6 weeks postoperatively was significantly less in the staple group (0.17 vs 0.51; P = .04). Operative time was shorter in that group (24.6 vs 32.9 minutes; P < .0001). No difference was noted for incision appearance and women's satisfaction. Staples are the method of choice for skin closure for elective term cesareans in our population.

Age-Related Differences of Individuals’ Arithmetic Strategy Utilization with Different Level of Math Anxiety

PubMed Central

Si, Jiwei; Li, Hongxia; Sun, Yan; Xu, Yanli; Sun, Yu

2016-01-01

The present study used the choice/no-choice method to investigate the effect of math anxiety on the strategy used in computational estimation and mental arithmetic tasks and to examine age-related differences in this regard. Fifty-seven fourth graders, 56 sixth graders, and 60 adults were randomly selected to participate in the experiment. Results showed the following: (1) High-anxious individuals were more likely to use a rounding-down strategy in the computational estimation task under the best-choice condition. Additionally, sixth-grade students and adults performed faster than fourth-grade students on the strategy execution parameter. Math anxiety affected response times (RTs) and the accuracy with which strategies were executed. (2) The execution of the partial-decomposition strategy was superior to that of the full-decomposition strategy on the mental arithmetic task. Low-math-anxious persons provided more accurate answers than did high-math-anxious participants under the no-choice condition. This difference was significant for sixth graders. With regard to the strategy selection parameter, the RTs for strategy selection varied with age. PMID:27803685

Age-Related Differences of Individuals' Arithmetic Strategy Utilization with Different Level of Math Anxiety.

PubMed

Si, Jiwei; Li, Hongxia; Sun, Yan; Xu, Yanli; Sun, Yu

2016-01-01

The present study used the choice/no-choice method to investigate the effect of math anxiety on the strategy used in computational estimation and mental arithmetic tasks and to examine age-related differences in this regard. Fifty-seven fourth graders, 56 sixth graders, and 60 adults were randomly selected to participate in the experiment. Results showed the following: (1) High-anxious individuals were more likely to use a rounding-down strategy in the computational estimation task under the best-choice condition. Additionally, sixth-grade students and adults performed faster than fourth-grade students on the strategy execution parameter. Math anxiety affected response times (RTs) and the accuracy with which strategies were executed. (2) The execution of the partial-decomposition strategy was superior to that of the full-decomposition strategy on the mental arithmetic task. Low-math-anxious persons provided more accurate answers than did high-math-anxious participants under the no-choice condition. This difference was significant for sixth graders. With regard to the strategy selection parameter, the RTs for strategy selection varied with age.

There is no silver bullet--a guide to low-level data transforms and normalisation methods for microarray data.

PubMed

Kreil, David P; Russell, Roslin R

2005-03-01

To overcome random experimental variation, even for simple screens, data from multiple microarrays have to be combined. There are, however, systematic differences between arrays, and any bias remaining after experimental measures to ensure consistency needs to be controlled for. It is often difficult to make the right choice of data transformation and normalisation methods to achieve this end. In this tutorial paper we review the problem and a selection of solutions, explaining the basic principles behind normalisation procedures and providing guidance for their application.

On Adaptation, Maximization, and Reinforcement Learning among Cognitive Strategies

ERIC Educational Resources Information Center

Erev, Ido; Barron, Greg

2005-01-01

Analysis of binary choice behavior in iterated tasks with immediate feedback reveals robust deviations from maximization that can be described as indications of 3 effects: (a) a payoff variability effect, in which high payoff variability seems to move choice behavior toward random choice; (b) underweighting of rare events, in which alternatives…

Kinetics of Aggregation with Choice

DOE PAGES

Ben-Naim, Eli; Krapivsky, Paul

2016-12-01

Here we generalize the ordinary aggregation process to allow for choice. In ordinary aggregation, two random clusters merge and form a larger aggregate. In our implementation of choice, a target cluster and two candidate clusters are randomly selected and the target cluster merges with the larger of the two candidate clusters.We study the long-time asymptotic behavior and find that as in ordinary aggregation, the size density adheres to the standard scaling form. However, aggregation with choice exhibits a number of different features. First, the density of the smallest clusters exhibits anomalous scaling. Second, both the small-size and the large-size tailsmore » of the density are overpopulated, at the expense of the density of moderate-size clusters. Finally, we also study the complementary case where the smaller candidate cluster participates in the aggregation process and find an abundance of moderate clusters at the expense of small and large clusters. Additionally, we investigate aggregation processes with choice among multiple candidate clusters and a symmetric implementation where the choice is between two pairs of clusters.« less

Some practical problems in implementing randomization.

PubMed

Downs, Matt; Tucker, Kathryn; Christ-Schmidt, Heidi; Wittes, Janet

2010-06-01

While often theoretically simple, implementing randomization to treatment in a masked, but confirmable, fashion can prove difficult in practice. At least three categories of problems occur in randomization: (1) bad judgment in the choice of method, (2) design and programming errors in implementing the method, and (3) human error during the conduct of the trial. This article focuses on these latter two types of errors, dealing operationally with what can go wrong after trial designers have selected the allocation method. We offer several case studies and corresponding recommendations for lessening the frequency of problems in allocating treatment or for mitigating the consequences of errors. Recommendations include: (1) reviewing the randomization schedule before starting a trial, (2) being especially cautious of systems that use on-demand random number generators, (3) drafting unambiguous randomization specifications, (4) performing thorough testing before entering a randomization system into production, (5) maintaining a dataset that captures the values investigators used to randomize participants, thereby allowing the process of treatment allocation to be reproduced and verified, (6) resisting the urge to correct errors that occur in individual treatment assignments, (7) preventing inadvertent unmasking to treatment assignments in kit allocations, and (8) checking a sample of study drug kits to allow detection of errors in drug packaging and labeling. Although we performed a literature search of documented randomization errors, the examples that we provide and the resultant recommendations are based largely on our own experience in industry-sponsored clinical trials. We do not know how representative our experience is or how common errors of the type we have seen occur. Our experience underscores the importance of verifying the integrity of the treatment allocation process before and during a trial. Clinical Trials 2010; 7: 235-245. http://ctj.sagepub.com.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ben-Naim, Eli; Krapivsky, Paul

Here we generalize the ordinary aggregation process to allow for choice. In ordinary aggregation, two random clusters merge and form a larger aggregate. In our implementation of choice, a target cluster and two candidate clusters are randomly selected and the target cluster merges with the larger of the two candidate clusters.We study the long-time asymptotic behavior and find that as in ordinary aggregation, the size density adheres to the standard scaling form. However, aggregation with choice exhibits a number of different features. First, the density of the smallest clusters exhibits anomalous scaling. Second, both the small-size and the large-size tailsmore » of the density are overpopulated, at the expense of the density of moderate-size clusters. Finally, we also study the complementary case where the smaller candidate cluster participates in the aggregation process and find an abundance of moderate clusters at the expense of small and large clusters. Additionally, we investigate aggregation processes with choice among multiple candidate clusters and a symmetric implementation where the choice is between two pairs of clusters.« less

On the Choice of Adequate Randomization Ranges for Limiting the Use of Unwanted Cues in Same-Different, Dual-Pair, and Oddity Tasks

PubMed Central

Dai, Huanping; Micheyl, Christophe

2010-01-01

A major concern when designing a psychophysical experiment is that participants may use another stimulus feature (“cue”) than that intended by the experimenter. One way to avoid this involves applying random variations to the corresponding feature across stimulus presentations, to make the “unwanted” cue unreliable. An important question facing experimenters who use this randomization (“roving”) technique is: How large should the randomization range be to ensure that participants cannot achieve a certain proportion correct (PC) by using the unwanted cue, while at the same time avoiding unnecessary interference of the randomization with task performance? Previous publications have provided formulas for the selection of adequate randomization ranges in yes-no and multiple-alternative, forced-choice tasks. In this article, we provide figures and tables, which can be used to select randomization ranges that are better suited to experiments involving a same-different, dual-pair, or oddity task. PMID:20139466

Clinical Health Outcomes Initiative in Comparative Effectiveness for Bipolar Disorder (Bipolar CHOICE): A Pragmatic Trial of Complex Treatment for a Complex Disorder

PubMed Central

Nierenberg, Andrew A.; Sylvia, Louisa G.; Leon, Andrew C.; Reilly-Harrington, Noreen; Shesler, Leah W.; McElroy, Susan L.; Friedman, Edward S.; Thase, Michael E.; Shelton, Richard C.; Bowden, Charles; Tohen, Mauricio; Singh, Vivek; Deckersbach, Thilo; Ketter, Terence; Kocsis, James; McInnis, Melvin G.; Schoenfeld, David; Bobo, William V.; Calabrese, Joseph R.

2015-01-01

Background Classic and second generation antipsychotic mood stabilizers are recommended for treatment of bipolar disorder, yet there are no randomized comparative effectiveness studies that have examined the “real-world” advantages and disadvantages of these medications Purpose We describe the strategic decisions in the design of the Clinical and Health Outcomes Initiative in Comparative Effectiveness for Bipolar Disorder (Bipolar CHOICE). This paper outlines the key issues and solutions the investigators faced in designing a clinical trial that would maximize generalizability and inform real-world clinical treatment of bipolar disorder. Methods Bipolar CHOICE was a 6-month, multi-site, prospective, randomized clinical trial of outpatients with bipolar disorder. This study compares the effectiveness of quetiapine versus lithium, each with adjunctive personalized treatments. The co-primary outcomes selected are the overall benefits and harms of the study medications (as measured by the Clinical Global Impression-Efficacy Index) and the Necessary Clinical Adjustments (a measure of the number of medication changes). Secondary outcomes are continuous measures of mood, the Framingham General Cardiovascular Risk Score and the Longitudinal Interval Follow up Evaluation Range of Impaired Functioning Tool. Results The final study design consisted of a single-blind, randomized comparative effectiveness trial of quetiapine versus lithium, plus adjunctive personalized treatment (APT), across ten sites. Other important study considerations included limited exclusion criteria to maximize generalizability, flexible dosing of APT medications to mimic real-world treatment, and an intent-to-treat analysis plan. 482 participants were randomized to the study and 364 completed. Limitations The potential limitations of the study include the heterogeneity of APT, selection of study medications, lack of a placebo-control group, and participants’ ability to pay for study medications. Conclusion We expect that this study will inform our understanding of the benefits and harms of lithium, a classic mood stabilizer, compared to quetiapine, a second generation antipsychotic with broad-spectrum activity in bipolar disorder and will provide an example of a well-designed and well-conducted randomized comparative effectiveness clinical trial. PMID:24346608

Fine-tuned evaluation of olfactory function in patients operated for nasal polyposis.

PubMed

Sonnet, Marie-Hortense; Nguyen, Duc Trung; Nguyen-Thi, Phi-Linh; Arous, Fabien; Jankowski, Roger; Rumeau, Cécile

2017-07-01

Given the forced-choice procedure of the identification test, patients with profound anosmia are more likely to have higher identification scores by chance than patients with hyposmia or normosmia. This may be a confusing factor when assessing the sense of smell, which alters the appreciation of real olfaction improvement. The aim of this study was to fine-tune the results of the identification Sniffin' Sticks test before and 6 weeks after surgery using the real identification score. A total of 133 patients underwent the Identification (I) and Threshold (T) tests the day before and 6 weeks after nasalization surgery. The scores of the identification test, called I G (global identification), were ranked from 0 to 16. Patients had to specify if their forced-choice answers were given either surely or randomly, called I H (hazard identification). The real score of identification I R was obtained as follow: I R  = I G  - I H . Patients with an immeasurable threshold according to the T test were more prone to give randomly correct answers. On the basis of I G scores, 43.6% of patients remained hypo-anosmic after surgery compared to 72.9% before surgery. Using I R scores, only 3.8% of patients remained anosmic (I R  = 0) at 6 weeks after surgery. Hence, patients with real anosmia (I R  = 0) were less prone to improve their olfaction than patients with I R  > 0. The analysis of random factor when using identification test allows differentiating a real anosmia from a hyposmia. An I G  ≤ 4 could be considered as a profound/real anosmia or a severe hyposmia. This procedure cannot, however, replace the forced-choice method in odor identification testing.

The Good, the Bad, and the Irrelevant: Neural Mechanisms of Learning Real and Hypothetical Rewards and Effort

PubMed Central

Kolling, Nils; Nelissen, Natalie; Wittmann, Marco K.; Harmer, Catherine J.; Rushworth, Matthew F. S.

2015-01-01

Natural environments are complex, and a single choice can lead to multiple outcomes. Agents should learn which outcomes are due to their choices and therefore relevant for future decisions and which are stochastic in ways common to all choices and therefore irrelevant for future decisions between options. We designed an experiment in which human participants learned the varying reward and effort magnitudes of two options and repeatedly chose between them. The reward associated with a choice was randomly real or hypothetical (i.e., participants only sometimes received the reward magnitude associated with the chosen option). The real/hypothetical nature of the reward on any one trial was, however, irrelevant for learning the longer-term values of the choices, and participants ought to have only focused on the informational content of the outcome and disregarded whether it was a real or hypothetical reward. However, we found that participants showed an irrational choice bias, preferring choices that had previously led, by chance, to a real reward in the last trial. Amygdala and ventromedial prefrontal activity was related to the way in which participants' choices were biased by real reward receipt. By contrast, activity in dorsal anterior cingulate cortex, frontal operculum/anterior insula, and especially lateral anterior prefrontal cortex was related to the degree to which participants resisted this bias and chose effectively in a manner guided by aspects of outcomes that had real and more sustained relationships with particular choices, suppressing irrelevant reward information for more optimal learning and decision making. SIGNIFICANCE STATEMENT In complex natural environments, a single choice can lead to multiple outcomes. Human agents should only learn from outcomes that are due to their choices, not from outcomes without such a relationship. We designed an experiment to measure learning about reward and effort magnitudes in an environment in which other features of the outcome were random and had no relationship with choice. We found that, although people could learn about reward magnitudes, they nevertheless were irrationally biased toward repeating certain choices as a function of the presence or absence of random reward features. Activity in different brain regions in the prefrontal cortex either reflected the bias or reflected resistance to the bias. PMID:26269633

A mixed-methods analysis of patient reviews of hospital care in England: implications for public reporting of health care quality data in the United States.

PubMed

Lagu, Tara; Goff, Sarah L; Hannon, Nicholas S; Shatz, Amy; Lindenauer, Peter K

2013-01-01

In the United States patients have limited opportunities to read and write narrative reviews about hospitals. In contrast, the National Health Service (NHS) in England encourages patients to provide feedback to hospitals on their quality-reporting website, NHS Choices. The scope and content of the narrative feedback was studied. All NHS hospitals with more than 10 reviews posted on NHS Choices were included in a cross-sectional mixed-methods (qualitative and quantitative) analysis of patients' reviews of 20 randomly selected hospitals. The final sample consisted of 264 hospitals and 2,640 patient responses to structured questions. All 200 reviews from the 20 hospitals randomly selected were subjected to further quantitative and qualitative analysis. Comments about clinicians and staff were common (179 [90%]) and overwhelmingly positive, with 149 (83%) favorable to workers. In 124 (62%) of the 200 reviews, patients commented on technical aspects of hospital care, including quality of care, injuries, errors, and incorrect medical record or discharge documentation. Perceived medical errors were described in 51 (26%) hospital reviews. Comments about the hospital facility appeared in half (52%) of reviews, describing hospital cleanliness, food, parking, and amenities. Hospitals replied to 56% of the patient reviews. NHS Choices represents the first government-run initiative that enables any patient to provide narrative feedback about hospital care. Reviews appear to have similar domains to those covered in existing satisfaction surveys but also include detailed feedback that would be unlikely to be revealed by such surveys. Online narrative reviews can therefore provide useful and complementary information to consumers (patients) and hospitals, particularly when combined with systematically collected patient experience data.

Population density equations for stochastic processes with memory kernels

NASA Astrophysics Data System (ADS)

Lai, Yi Ming; de Kamps, Marc

2017-06-01

We present a method for solving population density equations (PDEs)-a mean-field technique describing homogeneous populations of uncoupled neurons—where the populations can be subject to non-Markov noise for arbitrary distributions of jump sizes. The method combines recent developments in two different disciplines that traditionally have had limited interaction: computational neuroscience and the theory of random networks. The method uses a geometric binning scheme, based on the method of characteristics, to capture the deterministic neurodynamics of the population, separating the deterministic and stochastic process cleanly. We can independently vary the choice of the deterministic model and the model for the stochastic process, leading to a highly modular numerical solution strategy. We demonstrate this by replacing the master equation implicit in many formulations of the PDE formalism by a generalization called the generalized Montroll-Weiss equation—a recent result from random network theory—describing a random walker subject to transitions realized by a non-Markovian process. We demonstrate the method for leaky- and quadratic-integrate and fire neurons subject to spike trains with Poisson and gamma-distributed interspike intervals. We are able to model jump responses for both models accurately to both excitatory and inhibitory input under the assumption that all inputs are generated by one renewal process.

Multiple-Choice and Short-Answer Exam Performance in a College Classroom

ERIC Educational Resources Information Center

Funk, Steven C.; Dickson, K. Laurie

2011-01-01

The authors experimentally investigated the effects of multiple-choice and short-answer format exam items on exam performance in a college classroom. They randomly assigned 50 students to take a 10-item short-answer pretest or posttest on two 50-item multiple-choice exams in an introduction to personality course. Students performed significantly…

Should multiple imputation be the method of choice for handling missing data in randomized trials?

PubMed Central

Sullivan, Thomas R; White, Ian R; Salter, Amy B; Ryan, Philip; Lee, Katherine J

2016-01-01

The use of multiple imputation has increased markedly in recent years, and journal reviewers may expect to see multiple imputation used to handle missing data. However in randomized trials, where treatment group is always observed and independent of baseline covariates, other approaches may be preferable. Using data simulation we evaluated multiple imputation, performed both overall and separately by randomized group, across a range of commonly encountered scenarios. We considered both missing outcome and missing baseline data, with missing outcome data induced under missing at random mechanisms. Provided the analysis model was correctly specified, multiple imputation produced unbiased treatment effect estimates, but alternative unbiased approaches were often more efficient. When the analysis model overlooked an interaction effect involving randomized group, multiple imputation produced biased estimates of the average treatment effect when applied to missing outcome data, unless imputation was performed separately by randomized group. Based on these results, we conclude that multiple imputation should not be seen as the only acceptable way to handle missing data in randomized trials. In settings where multiple imputation is adopted, we recommend that imputation is carried out separately by randomized group. PMID:28034175

Should multiple imputation be the method of choice for handling missing data in randomized trials?

PubMed

Sullivan, Thomas R; White, Ian R; Salter, Amy B; Ryan, Philip; Lee, Katherine J

2016-01-01

The use of multiple imputation has increased markedly in recent years, and journal reviewers may expect to see multiple imputation used to handle missing data. However in randomized trials, where treatment group is always observed and independent of baseline covariates, other approaches may be preferable. Using data simulation we evaluated multiple imputation, performed both overall and separately by randomized group, across a range of commonly encountered scenarios. We considered both missing outcome and missing baseline data, with missing outcome data induced under missing at random mechanisms. Provided the analysis model was correctly specified, multiple imputation produced unbiased treatment effect estimates, but alternative unbiased approaches were often more efficient. When the analysis model overlooked an interaction effect involving randomized group, multiple imputation produced biased estimates of the average treatment effect when applied to missing outcome data, unless imputation was performed separately by randomized group. Based on these results, we conclude that multiple imputation should not be seen as the only acceptable way to handle missing data in randomized trials. In settings where multiple imputation is adopted, we recommend that imputation is carried out separately by randomized group.

Search predicts and changes patience in intertemporal choice

PubMed Central

Johnson, Eric J.

2017-01-01

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. PMID:29078303

Search predicts and changes patience in intertemporal choice.

PubMed

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.

Evaluating the Impact of Menu Labeling on Food Choices and Intake

PubMed Central

Larsen, Peter D.; Agnew, Henry; Baik, Jenny; Brownell, Kelly D.

2010-01-01

Objectives. We assessed the impact of restaurant menu calorie labels on food choices and intake. Methods. Participants in a study dinner (n = 303) were randomly assigned to either (1) a menu without calorie labels (no calorie labels), (2) a menu with calorie labels (calorie labels), or (3) a menu with calorie labels and a label stating the recommended daily caloric intake for an average adult (calorie labels plus information). Food choices and intake during and after the study dinner were measured. Results. Participants in both calorie label conditions ordered fewer calories than those in the no calorie labels condition. When calorie label conditions were combined, that group consumed 14% fewer calories than the no calorie labels group. Individuals in the calorie labels condition consumed more calories after the study dinner than those in both other conditions. When calories consumed during and after the study dinner were combined, participants in the calorie labels plus information group consumed an average of 250 fewer calories than those in the other groups. Conclusions. Calorie labels on restaurant menus impacted food choices and intake; adding a recommended daily caloric requirement label increased this effect, suggesting menu label legislation should require such a label. Future research should evaluate menu labeling's impact on children's food choices and consumption. PMID:20019307

The effect of mobile phone short messaging system on healthy food choices among Iranian postmenopausal women.

PubMed

Vakili, Mahdis; Abedi, Parvin; Afshari, Poorandokht; Kaboli, Nayereh Esmael

2015-01-01

Central adiposity and metabolic syndrome are quite common among postmenopausal women. Dietary diversity and healthy food choices have essential role in health and also in prevention of obesity. The main objective of this study was to evaluate the impact of mobile phone short messaging system on healthy food choices among Iranian postmenopausal women. This was a randomized controlled trial in which 100 postmenopausal women aged 40-60 years were recruited and assigned to two groups (50 each in the intervention and control groups). Food frequency consumption was measured using a questionnaire. A total of 16 text messages including information about modification of food selection (healthy choices, benefits, methods, etc.,) were sent to participants in the intervention group during 4 months follow-up (1/week). The Chi-square and independent t-test used for data analysis. Ninety-two women completed the study. The consumption of Vitamin A rich fruits and vegetables significantly increased in the intervention group compared to the control group (P < 0.001). More women in the intervention group consumed fish after intervention (P = 0.02). The consumption of green leafy vegetables showed a nonsignificant increase in the intervention group. Using mobile phone short messaging system can improve the healthy food choices regarding Vitamin A rich fruits and vegetables and fish among postmenopausal women.

Safer choices: reducing teen pregnancy, HIV, and STDs.

PubMed Central

Coyle, K.; Basen-Engquist, K.; Kirby, D.; Parcel, G.; Banspach, S.; Collins, J.; Baumler, E.; Carvajal, S.; Harrist, R.

2001-01-01

OBJECTIVES: This study evaluated the long-term effectiveness of Safer Choices, a theory-based, multi-component educational program designed to reduce sexual risk behaviors and increase protective behaviors in preventing HIV, other STDs, and pregnancy among high school students. METHODS: The study used a randomized controlled trial involving 20 high schools in California and Texas. A cohort of 3869 ninth-grade students was tracked for 31 months from fall semester 1993 (baseline) to spring semester 1996 (31-month follow-up). Data were collected using self-report surveys administered by trained data collectors. Response rate at 31-month follow-up was 79%. RESULTS: Safer Choices had its greatest effect on measures involving condom use. The program reduced the frequency of intercourse without a condom during the three months prior to the survey, reduced the number of sexual partners with whom students had intercourse without a condom, and increased use of condoms and other protection against pregnancy at last intercourse. Safer Choices also improved 7 of 13 psychosocial variables, many related to condom use, but did not have a significant effect upon rates of sexual initiation. CONCLUSIONS: The Safer Choices program was effective in reducing important risk behaviors for HIV, other STDs, and pregnancy and in enhancing most psychosocial determinants of such behavior. PMID:11889277

Box-Cox Mixed Logit Model for Travel Behavior Analysis

NASA Astrophysics Data System (ADS)

Orro, Alfonso; Novales, Margarita; Benitez, Francisco G.

2010-09-01

To represent the behavior of travelers when they are deciding how they are going to get to their destination, discrete choice models, based on the random utility theory, have become one of the most widely used tools. The field in which these models were developed was halfway between econometrics and transport engineering, although the latter now constitutes one of their principal areas of application. In the transport field, they have mainly been applied to mode choice, but also to the selection of destination, route, and other important decisions such as the vehicle ownership. In usual practice, the most frequently employed discrete choice models implement a fixed coefficient utility function that is linear in the parameters. The principal aim of this paper is to present the viability of specifying utility functions with random coefficients that are nonlinear in the parameters, in applications of discrete choice models to transport. Nonlinear specifications in the parameters were present in discrete choice theory at its outset, although they have seldom been used in practice until recently. The specification of random coefficients, however, began with the probit and the hedonic models in the 1970s, and, after a period of apparent little practical interest, has burgeoned into a field of intense activity in recent years with the new generation of mixed logit models. In this communication, we present a Box-Cox mixed logit model, original of the authors. It includes the estimation of the Box-Cox exponents in addition to the parameters of the random coefficients distribution. Probability of choose an alternative is an integral that will be calculated by simulation. The estimation of the model is carried out by maximizing the simulated log-likelihood of a sample of observed individual choices between alternatives. The differences between the predictions yielded by models that are inconsistent with real behavior have been studied with simulation experiments.

No evidence of an MHC-based female mating preference in great reed warblers.

PubMed

Westerdahl, Helena

2004-08-01

Female mate-choice based on genetic compatibility is an area of growing interest. The major histocompatibility complex (MHC) genes are likely candidates for such mate-choice since these highly polymorphic genes may both increase offspring viability and also provide direct cues for mate-choice. In great reed warblers, females actively choose a breeding partner out of a handful of males that they visit and evaluate; thus, female preference for compatible or heterozygous MHC genes could have evolved. Here, I investigate whether great reed warbler females preferentially mate with males with dissimilar MHC class I alleles or with males that are heterozygous at MHC class I. Despite favourable conditions, a thorough screening method and a large sample size, there was no evidence of an MHC-based female mating preference based on either genetic compatibility or heterozygosity in this population. Power analyses of the data sets revealed that relatively small differences (15% and 8%, respectively) between true and random pairs should have been detected. Copyright 2004 Blackwell Publishing Ltd

Randomizing bipartite networks: the case of the World Trade Web.

PubMed

Saracco, Fabio; Di Clemente, Riccardo; Gabrielli, Andrea; Squartini, Tiziano

2015-06-01

Within the last fifteen years, network theory has been successfully applied both to natural sciences and to socioeconomic disciplines. In particular, bipartite networks have been recognized to provide a particularly insightful representation of many systems, ranging from mutualistic networks in ecology to trade networks in economy, whence the need of a pattern detection-oriented analysis in order to identify statistically-significant structural properties. Such an analysis rests upon the definition of suitable null models, i.e. upon the choice of the portion of network structure to be preserved while randomizing everything else. However, quite surprisingly, little work has been done so far to define null models for real bipartite networks. The aim of the present work is to fill this gap, extending a recently-proposed method to randomize monopartite networks to bipartite networks. While the proposed formalism is perfectly general, we apply our method to the binary, undirected, bipartite representation of the World Trade Web, comparing the observed values of a number of structural quantities of interest with the expected ones, calculated via our randomization procedure. Interestingly, the behavior of the World Trade Web in this new representation is strongly different from the monopartite analogue, showing highly non-trivial patterns of self-organization.

Techniques for investigation of an apparent outbreak of infections with Candida glabrata.

PubMed Central

Arif, S; Barkham, T; Power, E G; Howell, S A

1996-01-01

A cluster of Candida glabrata isolates recovered from seven patients in an intensive care unit over a 10-week period were compared with a collection of isolates from six epidemiologically distinct outpatients and a reference strain by several DNA typing methods. Restriction enzyme analysis with HinII distinguished 13 strains from the 14 sources and was the method of choice. Pulsed-field gel electrophoresis and random amplification of polymorphic DNA both detected nine types from the 14 sources; however, the results of these two methods did not always correlate. These methods demonstrated that five of the seven patients had distinguishable strains and that cross-infection was unlikely. PMID:8862586

Effects of Choice on Intervention Outcomes for College Students Sanctioned for Campus Alcohol Policy Violations

PubMed Central

Carey, Kate B.; DeMartini, Kelly S.; Prince, Mark A.; Luteran, Carrie; Carey, Michael P.

2012-01-01

This study tested the hypothesis that client choice influences intervention outcomes. We recruited 288 student drinkers (60% male, 67% freshmen) required to participate in an intervention due to a violation of campus alcohol policy. Participants were randomized either to self-chosen or researcher-assigned interventions. In the choice condition they selected either a brief motivational intervention (BMI) or a computer-delivered educational program. In the assigned condition they received one of the two interventions, assigned randomly. Follow-up assessments at 1- and 2-months revealed that choice was associated with higher intervention satisfaction. However, the assigned and choice conditions did not differentially change on consumption or consequences across intervention type. Overall, change scores favored the BMI over the computer-delivered intervention on consumption and consequences. Exploratory analyses revealed that, given the choice of intervention, heavier drinking students self-selected into the face-to-face BMI. Furthermore, among the students who received a BMI, the students who chose it (despite their heavier drinking) reduced drinks per drinking day more than the assigned students. In sum, offering a choice of intervention to students mandated for campus alcohol violations increased the chance that at-risk students will select a more intensive and effective intervention. PMID:23046274

Contraceptive use during the reproductive lifecycle as reported by 46-year-old women in Sweden.

PubMed

Sköld, Annelie; Larsson, Margareta

2012-03-01

The aim of this study was to investigate the contraceptive methods 46-year-old women in Sweden had chosen during different phases of their reproductive lifecycle and, the factors affecting their choice. The design was a retrospective cross-sectional study and targeted 46-year-old women. Five hundred Swedish women were randomly selected from a national population-based register and sent a questionnaire with 18 multiple response questions: the response rate was 47%. The women used different contraceptive methods during different phases of their reproductive lifecycle. Women mainly used oral contraceptive pills and condoms before pregnancy, copper-IUD between pregnancies and, hormonal- and copper IUD after pregnancy. Condoms were used during all phases of women's fertile period. Women with early sexual debut were more likely to have used condom as their first contraceptive method than women with late sexual debut, and women who had children were more likely to use IUD as current contraception than women without children. High efficacy, accessibility and advice from a counselor were the most cited reasons for choosing a particular method. The most common reasons for discontinuing contraceptive use were a wish to be pregnant and concerns about side effects. The partner had little or no influence on choice of method, but advice from a gynecologist or midwife was influential. 46-year-old women in Sweden had chosen different contraceptive methods during different phases of their reproductive lifecycle. Partners appear to have limited influence over this choice. Individualized counseling by health care providers seems important. Copyright © 2011 Elsevier B.V. All rights reserved.

Effects of Mayfield's Four Questions (M4Q) on Nursing Students' Self-Efficacy and Multiple-Choice Test Scores

ERIC Educational Resources Information Center

Mayfield, Linda Riggs

2010-01-01

This study examined the effects of being taught the Mayfield's Four Questions multiple-choice test-taking strategy on the perceived self-efficacy and multiple-choice test scores of nursing students in a two-year associate degree program. Experimental and control groups were chosen by stratified random sampling. Subjects completed the 10-statement…

The impact of decision aids to enhance shared decision making for diabetes (the DAD study): protocol of a cluster randomized trial.

PubMed

LeBlanc, Annie; Ruud, Kari L; Branda, Megan E; Tiedje, Kristina; Boehmer, Kasey R; Pencille, Laurie J; Van Houten, Holly; Matthews, Marc; Shah, Nilay D; May, Carl R; Yawn, Barbara P; Montori, Victor M

2012-05-28

Shared decision making contributes to high quality healthcare by promoting a patient-centered approach. Patient involvement in selecting the components of a diabetes medication program that best match the patient's values and preferences may also enhance medication adherence and improve outcomes. Decision aids are tools designed to involve patients in shared decision making, but their adoption in practice has been limited. In this study, we propose to obtain a preliminary estimate of the impact of patient decision aids vs. usual care on measures of patient involvement in decision making, diabetes care processes, medication adherence, glycemic and cardiovascular risk factor control, and resource utilization. In addition, we propose to identify, describe, and explain factors that promote or inhibit the routine embedding of decision aids in practice. We will be conducting a mixed-methods study comprised of a cluster-randomized, practical, multicentered trial enrolling clinicians and their patients (n = 240) with type 2 diabetes from rural and suburban primary care practices (n = 8), with an embedded qualitative study to examine factors that influence the incorporation of decision aids into routine practice. The intervention will consist of the use of a decision aid (Statin Choice and Aspirin Choice, or Diabetes Medication Choice) during the clinical encounter. The qualitative study will include analysis of video recordings of clinical encounters and in-depth, semi-structured interviews with participating patients, clinicians, and clinic support staff, in both trial arms. Upon completion of this trial, we will have new knowledge about the effectiveness of diabetes decision aids in these practices. We will also better understand the factors that promote or inhibit the successful implementation and normalization of medication choice decision aids in the care of chronic patients in primary care practices. NCT00388050.

Rationale and study protocol for the Nursing Home Compare Plus (NHCPlus) randomized controlled trial: A personalized decision aid for patients transitioning from the hospital to a skilled-nursing facility

PubMed Central

Sorkin, Dara H.; Amin, Alpesh; Weimer, David L.; Sharit, Joseph; Ladd, Heather

2016-01-01

Background Annually more than 3 million people are admitted to one of the 15,965 skilled nursing facilities (SNFs) in the United States with 90% of admissions occurring from a hospital. Although the Centers for Medicare and Medicaid Services (CMS) publishes several web-based report cards, including one for nursing homes (Nursing Home Compare, NHC), they are not widely used. This is due, in part, to the complexity of the information available and the fact that the choice of nursing homes is typically made while in the hospital without access to the web-based NHC. We developed Nursing Home Compare Plus (NHCPlus) to address these limitations and to improve the decision-making process. Methods/Design This paper describes the design and rationale of a two-arm randomized controlled trial designed to test the effectiveness of NHCPlus compared to usual care only, in a sample of patients being discharged from the hospital to an SNF (N=229). Assessments were conducted within 24-hours prior to patient discharge and 30-days post discharge. Primary outcomes to be examined included use of NHC, increased choice of nursing homes with better reported outcomes, and increased distance between patient/family residence and nursing home. Secondary outcomes included satisfaction with the decision to go to a nursing home, confidence in the choice of nursing home, and reduced hospital length of stay. Discussion NHCPlus is an innovative mobile application designed to allow patients to personalize their choice of nursing homes to meet their medical needs and preferences. The application to other quality report cards is discussed. PMID:26772624

Valuing Non-market Benefits of Rehabilitation of Hydrologic Cycle Improvements in the Anyangcheon Watershed: Using Mixed Logit Models

NASA Astrophysics Data System (ADS)

Yoo, J.; Kong, K.

2010-12-01

This research the findings from a discrete-choice experiment designed to estimate the economic benefits associated with the Anyangcheon watershed improvements in Rep. of Korea. The Anyangcheon watershed has suffered from streamflow depletion and poor stream quality, which often negatively affect instream and near-stream ecologic integrity, as well as water supply. Such distortions in the hydrologic cycle mainly result from rapid increase of impermeable area due to urbanization, decreases of baseflow runoff due to groundwater pumping, and reduced precipitation inputs driven by climate forcing. As well, combined sewer overflows and increase of non-point source pollution from urban regions decrease water quality. The appeal of choice experiments (CE) in economic analysis is that it is based on random utility theory (McFadden, 1974; Ben-Akiva and Lerman, 1985). In contrast to contingent valuation method (CVM), which asks people to choose between a base case and a specific alternative, CE asks people to choice between cases that are described by attributes. The attributes of this study were selected from hydrologic vulnerability components that represent flood damage possibility, instreamflow depletion, water quality deterioration, form of the watershed and tax. Their levels were divided into three grades include status quo. Two grades represented the ideal conditions. These scenarios were constructed from a 35 orthogonal main effect design. This design resulted in twenty-seven choice sets. The design had nine different choice scenarios presented to each respondent. The most popular choice models in use are the conditional logit (CNL). This model provides closed-form choice probability calculation. The shortcoming of CNL comes from irrelevant alternatives (IIA). In this paper, the mixed logit (ML) is applied to allow the coefficient’s variation for random taste heterogeneity in the population. The mixed logit model(with normal distributions for the attributes) fit the data best, indication that allowing for both heterogeneous preferences across households and correlation between repeated choices may represent actual choice behaviors best of all the estimated models. The annual benefits to improve of the Anyancheon watershed for 1% improvement of each attribute was 406.7 billion Won(0.34 billion USD). This study is expected to contribute to the decision-making process for policy-makers by providing useful methodological framework and quantitative information related to watershed improvement projects.Table 1. Estimated Results of Conditional Logit and Mixed Logit Model 1) t-values are shown in brackets

A novel global Harmony Search method based on Ant Colony Optimisation algorithm

NASA Astrophysics Data System (ADS)

Fouad, Allouani; Boukhetala, Djamel; Boudjema, Fares; Zenger, Kai; Gao, Xiao-Zhi

2016-03-01

The Global-best Harmony Search (GHS) is a stochastic optimisation algorithm recently developed, which hybridises the Harmony Search (HS) method with the concept of swarm intelligence in the particle swarm optimisation (PSO) to enhance its performance. In this article, a new optimisation algorithm called GHSACO is developed by incorporating the GHS with the Ant Colony Optimisation algorithm (ACO). Our method introduces a novel improvisation process, which is different from that of the GHS in the following aspects. (i) A modified harmony memory (HM) representation and conception. (ii) The use of a global random switching mechanism to monitor the choice between the ACO and GHS. (iii) An additional memory consideration selection rule using the ACO random proportional transition rule with a pheromone trail update mechanism. The proposed GHSACO algorithm has been applied to various benchmark functions and constrained optimisation problems. Simulation results demonstrate that it can find significantly better solutions when compared with the original HS and some of its variants.

Relationship between lifestyle choices and hyperuricemia in Chinese men and women.

PubMed

Liu, Li; Lou, Shanshan; Xu, Ke; Meng, Zhaowei; Zhang, Qing; Song, Kun

2013-02-01

We aimed to explore correlations between lifestyle choices and hyperuricemia in a large Chinese population, emphasizing the differences from opposite sex. Ten thousand four hundred fifty subjects were randomly recruited from Tianjin municipality in China. Hyperuricemia was defined as serum uric acid >420 μmol/L for men and >360 μmol/L for women. Demographic data, highest education degree, work type, commuting means, smoking and drinking status, exercise frequency, and quantitative assessments of dietary factors were collected. Anthropometric measurements and fasting blood tests were performed. Statistical analyses were conducted. Total hyperuricemic prevalence was 12.89 %, with male significantly higher than female. Body mass index, waist circumference, serum indices, and age displayed high correlation coefficients, and most lifestyle factors also showed significant correlations as well. Binary logistic regression models showed odds ratio of developing hyperuricemia were much greater in males than in females by eating habits. However, physical activity-related lifestyle choices tended to cast much greater influences on the likelihood of hyperuricemia in females. Lifestyle choices and hyperuricemia are closely related. For males, eating habits have greater influences on the likelihood of developing hyperuricemia. For females, lifestyle factors like work type, commuting method, and exercise have such effects.

Counterfactual thinking affects the excitability of the motor cortex.

PubMed

Vicario, Carmelo M; Rafal, Robert D; Avenanti, Alessio

2015-04-01

Evidence suggests that monetary reward and affective experiences induce activity in the cortical motor system. Nevertheless, it is unclear whether counterfactual thinking related to wrong choices that lead to monetary loss and regret affects motor excitability. Using transcranial magnetic stimulation (TMS) of the motor cortex, we measured corticospinal excitability of 2 groups of healthy humans asked to actively guess the winning key among two possible alternatives (choice group); or passively assist to monetary outcomes randomly selected by the computer program (follow group). Results document a selective increment of the corticospinal excitability when a monetary loss outcome followed the key selection (i.e., in the choice group). On the other hand, no change in corticospinal excitability was found when participants passively assisted to a monetary loss randomly selected by the computer program (i.e., follow group). These findings suggest that counterfactual thinking and the negative emotional experiences arising from choices causing monetary loss--i.e., "I would have won instead of lost money if I'd made a different choice"--are mapped in the motor system. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Study of the Efficiency of Spatial Indexing Methods Applied to Large Astronomical Databases

NASA Astrophysics Data System (ADS)

Donaldson, Tom; Berriman, G. Bruce; Good, John; Shiao, Bernie

2018-01-01

Spatial indexing of astronomical databases generally uses quadrature methods, which partition the sky into cells used to create an index (usually a B-tree) written as database column. We report the results of a study to compare the performance of two common indexing methods, HTM and HEALPix, on Solaris and Windows database servers installed with a PostgreSQL database, and a Windows Server installed with MS SQL Server. The indexing was applied to the 2MASS All-Sky Catalog and to the Hubble Source catalog. On each server, the study compared indexing performance by submitting 1 million queries at each index level with random sky positions and random cone search radius, which was computed on a logarithmic scale between 1 arcsec and 1 degree, and measuring the time to complete the query and write the output. These simulated queries, intended to model realistic use patterns, were run in a uniform way on many combinations of indexing method and indexing level. The query times in all simulations are strongly I/O-bound and are linear with number of records returned for large numbers of sources. There are, however, considerable differences between simulations, which reveal that hardware I/O throughput is a more important factor in managing the performance of a DBMS than the choice of indexing scheme. The choice of index itself is relatively unimportant: for comparable index levels, the performance is consistent within the scatter of the timings. At small index levels (large cells; e.g. level 4; cell size 3.7 deg), there is large scatter in the timings because of wide variations in the number of sources found in the cells. At larger index levels, performance improves and scatter decreases, but the improvement at level 8 (14 min) and higher is masked to some extent in the timing scatter caused by the range of query sizes. At very high levels (20; 0.0004 arsec), the granularity of the cells becomes so high that a large number of extraneous empty cells begin to degrade performance. Thus, for the use patterns studied here the database performance is not critically dependent on the exact choices of index or level.

Design considerations and rationale of a multi-center trial to sustain weight loss: the Weight Loss Maintenance Trial.

PubMed

Brantley, Phillip; Appel, Lawrence; Hollis, Jack; Stevens, Victor; Ard, Jamy; Champagne, Catherine; Elmer, Patricia; Harsha, David; Myers, Valerie; Proschan, Michael; William, Vollmer; Svetkey, Laura

2008-01-01

The Weight Loss Maintenance Trial (WLM) is a multi-center, randomized, controlled trial that compares the effects of two 30-month maintenance interventions, i.e., Personal Contact (PC) and Interactive Technology (IT) to a self-directed usual care control group (SD), in overweight or obese individuals who are at high risk for cardiovascular disease. This paper provides an overview of the design and methods, and design considerations and lessons learned from this trial. All participants received a 6-month behavioral weight loss program consisting of weekly group sessions. Participants who lost 4 kg were randomized to one of three conditions (PC, IT, or SD). The PC condition provided monthly contacts with an interventionist primarily via telephone and quarterly face-to-face visits. The IT condition provided frequent, individualized contact through a tailored, website system. Both the PC and IT maintenance programs encouraged the DASH dietary pattern and employed theory-based behavioral techniques to promote maintenance. Design considerations included choice of study population, frequency and type of intervention visits, and choice of primary outcome. Overweight or obese persons with CVD risk factors were studied. The pros and cons of studying this population while excluding others are presented. We studied intervention contact strategies that made fewer demands on participant time and travel, while providing frequent opportunities for interaction. The primary outcome variable for the trial was change in weight from randomization to end of follow-up (30 months). Limits to generalizability are discussed. Individuals in need of weight loss strategies may have been excluded due to barriers associated with internet use. Other participants may have been excluded secondary to a comorbid condition. This paper highlights the design and methods of WLM and informs readers of discussions of critical issues and lessons learned from the trial.

Gene-targeted Random Mutagenesis to Select Heterochromatin-destabilizing Proteasome Mutants in Fission Yeast.

PubMed

Seo, Hogyu David; Lee, Daeyoup

2018-05-15

Random mutagenesis of a target gene is commonly used to identify mutations that yield the desired phenotype. Of the methods that may be used to achieve random mutagenesis, error-prone PCR is a convenient and efficient strategy for generating a diverse pool of mutants (i.e., a mutant library). Error-prone PCR is the method of choice when a researcher seeks to mutate a pre-defined region, such as the coding region of a gene while leaving other genomic regions unaffected. After the mutant library is amplified by error-prone PCR, it must be cloned into a suitable plasmid. The size of the library generated by error-prone PCR is constrained by the efficiency of the cloning step. However, in the fission yeast, Schizosaccharomyces pombe, the cloning step can be replaced by the use of a highly efficient one-step fusion PCR to generate constructs for transformation. Mutants of desired phenotypes may then be selected using appropriate reporters. Here, we describe this strategy in detail, taking as an example, a reporter inserted at centromeric heterochromatin.

Application of at-site peak-streamflow frequency analyses for very low annual exceedance probabilities

USGS Publications Warehouse

Asquith, William H.; Kiang, Julie E.; Cohn, Timothy A.

2017-07-17

The U.S. Geological Survey (USGS), in cooperation with the U.S. Nuclear Regulatory Commission, has investigated statistical methods for probabilistic flood hazard assessment to provide guidance on very low annual exceedance probability (AEP) estimation of peak-streamflow frequency and the quantification of corresponding uncertainties using streamgage-specific data. The term “very low AEP” implies exceptionally rare events defined as those having AEPs less than about 0.001 (or 1 × 10–3 in scientific notation or for brevity 10–3). Such low AEPs are of great interest to those involved with peak-streamflow frequency analyses for critical infrastructure, such as nuclear power plants. Flood frequency analyses at streamgages are most commonly based on annual instantaneous peak streamflow data and a probability distribution fit to these data. The fitted distribution provides a means to extrapolate to very low AEPs. Within the United States, the Pearson type III probability distribution, when fit to the base-10 logarithms of streamflow, is widely used, but other distribution choices exist. The USGS-PeakFQ software, implementing the Pearson type III within the Federal agency guidelines of Bulletin 17B (method of moments) and updates to the expected moments algorithm (EMA), was specially adapted for an “Extended Output” user option to provide estimates at selected AEPs from 10–3 to 10–6. Parameter estimation methods, in addition to product moments and EMA, include L-moments, maximum likelihood, and maximum product of spacings (maximum spacing estimation). This study comprehensively investigates multiple distributions and parameter estimation methods for two USGS streamgages (01400500 Raritan River at Manville, New Jersey, and 01638500 Potomac River at Point of Rocks, Maryland). The results of this study specifically involve the four methods for parameter estimation and up to nine probability distributions, including the generalized extreme value, generalized log-normal, generalized Pareto, and Weibull. Uncertainties in streamflow estimates for corresponding AEP are depicted and quantified as two primary forms: quantile (aleatoric [random sampling] uncertainty) and distribution-choice (epistemic [model] uncertainty). Sampling uncertainties of a given distribution are relatively straightforward to compute from analytical or Monte Carlo-based approaches. Distribution-choice uncertainty stems from choices of potentially applicable probability distributions for which divergence among the choices increases as AEP decreases. Conventional goodness-of-fit statistics, such as Cramér-von Mises, and L-moment ratio diagrams are demonstrated in order to hone distribution choice. The results generally show that distribution choice uncertainty is larger than sampling uncertainty for very low AEP values.

Consumer satisfaction with primary care provider choice and associated trust

PubMed Central

Chu-Weininger, Ming Ying L; Balkrishnan, Rajesh

2006-01-01

Background Development of managed care, characterized by limited provider choice, is believed to undermine trust. Provider choice has been identified as strongly associated with physician trust. Stakeholders in a competitive healthcare market have competing agendas related to choice. The purpose of this study is to analyze variables associated with consumer's satisfaction that they have enough choice when selecting their primary care provider (PCP), and to analyze the importance of these variables on provider trust. Methods A 1999 randomized national cross-sectional telephone survey conducted of United States residential households, who had a telephone, had seen a medical professional at least twice in the past two years, and aged ≥ 20 years was selected for secondary data analyses. Among 1,117 households interviewed, 564 were selected as the final sample. Subjects responded to a core set of questions related to provider trust, and a subset of questions related to trust in the insurer. A previously developed conceptual framework was adopted. Linear and logistic regressions were performed based on this framework. Results Results affirmed 'satisfaction with amount of PCP choice' was significantly (p < .001) associated with provider trust. 'PCP's care being extremely effective' was strongly associated with 'satisfaction with amount of PCP choice' and 'provider trust'. Having sought a second opinion(s) was associated with lower trust. 'Spoke to the PCP outside the medical office,' 'satisfaction with the insurer' and 'insurer charges less if PCP within network' were all variables associated with 'satisfaction with amount of PCP choice' (all p < .05). Conclusion This study confirmed the association of 'satisfaction with amount of PCP choice' with provider trust. Results affirmed 'enough PCP choice' was a strong predictor of provider trust. 'Second opinion on PCP' may indicate distrust in the provider. Data such as 'trust in providers in general' and 'the role of provider performance information' in choice, though import in PCP choice, were not available for analysis and should be explored in future studies. Results have implications for rethinking the relationships among consumer choice, consumer behaviors in making trade-offs in PCP choice, and the role of healthcare experiences in 'satisfaction with amount of PCP choice' or 'provider trust.' PMID:17059611

Elephant random walks and their connection to Pólya-type urns

NASA Astrophysics Data System (ADS)

Baur, Erich; Bertoin, Jean

2016-11-01

In this paper, we explain the connection between the elephant random walk (ERW) and an urn model à la Pólya and derive functional limit theorems for the former. The ERW model was introduced in [Phys. Rev. E 70, 045101 (2004), 10.1103/PhysRevE.70.045101] to study memory effects in a highly non-Markovian setting. More specifically, the ERW is a one-dimensional discrete-time random walk with a complete memory of its past. The influence of the memory is measured in terms of a memory parameter p between zero and one. In the past years, a considerable effort has been undertaken to understand the large-scale behavior of the ERW, depending on the choice of p . Here, we use known results on urns to explicitly solve the ERW in all memory regimes. The method works as well for ERWs in higher dimensions and is widely applicable to related models.

Choice of optical system is critical for the security of double random phase encryption systems

NASA Astrophysics Data System (ADS)

Muniraj, Inbarasan; Guo, Changliang; Malallah, Ra'ed; Cassidy, Derek; Zhao, Liang; Ryle, James P.; Healy, John J.; Sheridan, John T.

2017-06-01

The linear canonical transform (LCT) is used in modeling a coherent light-field propagation through first-order optical systems. Recently, a generic optical system, known as the quadratic phase encoding system (QPES), for encrypting a two-dimensional image has been reported. In such systems, two random phase keys and the individual LCT parameters (α,β,γ) serve as secret keys of the cryptosystem. It is important that such encryption systems also satisfy some dynamic security properties. We, therefore, examine such systems using two cryptographic evaluation methods, the avalanche effect and bit independence criterion, which indicate the degree of security of the cryptographic algorithms using QPES. We compared our simulation results with the conventional Fourier and the Fresnel transform-based double random phase encryption (DRPE) systems. The results show that the LCT-based DRPE has an excellent avalanche and bit independence characteristics compared to the conventional Fourier and Fresnel-based encryption systems.

Consumers' practical understanding of healthy food choices: a fake food experiment.

PubMed

Mötteli, Sonja; Keller, Carmen; Siegrist, Michael; Barbey, Jana; Bucher, Tamara

2016-08-01

Little is known about laypeople's practical understanding of a healthy diet, although this is important to successfully promote healthy eating. The present study is the first to experimentally examine how consumers define healthy and balanced food choices for an entire day compared with normal choices and compared with dietary guidelines. We used an extensive fake food buffet (FFB) with 179 foods commonly consumed in the Swiss diet. The FFB is a validated method to investigate food choice behaviour in a well-controlled laboratory setting. People from the general population in Switzerland (n 187; 51·9 % females), aged between 18 and 65 years, were randomly assigned to one of two conditions. In the control group, the participants were instructed to serve themselves foods they would eat on a normal day, whereas in the 'healthy' group they were instructed to choose foods representing a healthy diet. Participants chose significantly more healthy foods, with 4·5 g more dietary fibre, 2 % more protein and 2 % less SFA in the 'healthy' group compared with the control group. However, in both experimental conditions, participants served themselves foods containing twice as much sugar and salt than recommended by dietary guidelines. The results suggest that laypeople lack knowledge about the recommended portion sizes and the amounts of critical nutrients in processed food, which has important implications for communicating dietary guidelines. Furthermore, the energy of the food served was substantially correlated with the energy needs of the participants, demonstrating the potential of the fake food buffet method.

Resourcefulness Training for Women Dementia Caregivers: Acceptability and Feasibility of Two Methods.

PubMed

Zauszniewski, Jaclene A; Lekhak, Nirmala; Napoleon, Betty; Morris, Diana L

2016-01-01

Almost 10 million women in the United States are caregivers for elders with dementia and many experience extreme stress that compromises their health. Acceptable and feasible interventions to teach them resourcefulness skills for managing stress may improve their health and facilitate continued caregiving. This study examined two commonly used methods for practicing skills taught during resourcefulness training (RT) to women caregivers of elders with dementia (n=63): journaling and digital voice recording. It also explored whether providing caregivers a choice between the two methods made it more acceptable or feasible. Qualitative and quantitative data were collected before, during, and after RT. Caregivers who recorded used more words (M=5446) but recorded fewer days (M=17) than those who journaled (M=2792 words and M=27 days). Similar concerns in relation to time management and practice method were expressed by women caregivers irrespective of practice method (journal versus recorder) or random versus choice condition. While journaling was more frequent than recording, more words were expressed during recordings. Perceived stress and depressive symptoms were unrelated to the number of practice days or word counts, suggesting RT acceptability and feasibility even for highly stressed or depressed caregivers. Because intervention feasibility is important for RT effectiveness testing, alternatives to the journaling and recording methods for practicing RT skills should be considered.

Random walkers with extreme value memory: modelling the peak-end rule

NASA Astrophysics Data System (ADS)

Harris, Rosemary J.

2015-05-01

Motivated by the psychological literature on the ‘peak-end rule’ for remembered experience, we perform an analysis within a random walk framework of a discrete choice model where agents’ future choices depend on the peak memory of their past experiences. In particular, we use this approach to investigate whether increased noise/disruption always leads to more switching between decisions. Here extreme value theory illuminates different classes of dynamics indicating that the long-time behaviour is dependent on the scale used for reflection; this could have implications, for example, in questionnaire design.

Simulation study to determine the impact of different design features on design efficiency in discrete choice experiments

PubMed Central

Vanniyasingam, Thuva; Cunningham, Charles E; Foster, Gary; Thabane, Lehana

2016-01-01

Objectives Discrete choice experiments (DCEs) are routinely used to elicit patient preferences to improve health outcomes and healthcare services. While many fractional factorial designs can be created, some are more statistically optimal than others. The objective of this simulation study was to investigate how varying the number of (1) attributes, (2) levels within attributes, (3) alternatives and (4) choice tasks per survey will improve or compromise the statistical efficiency of an experimental design. Design and methods A total of 3204 DCE designs were created to assess how relative design efficiency (d-efficiency) is influenced by varying the number of choice tasks (2–20), alternatives (2–5), attributes (2–20) and attribute levels (2–5) of a design. Choice tasks were created by randomly allocating attribute and attribute level combinations into alternatives. Outcome Relative d-efficiency was used to measure the optimality of each DCE design. Results DCE design complexity influenced statistical efficiency. Across all designs, relative d-efficiency decreased as the number of attributes and attribute levels increased. It increased for designs with more alternatives. Lastly, relative d-efficiency converges as the number of choice tasks increases, where convergence may not be at 100% statistical optimality. Conclusions Achieving 100% d-efficiency is heavily dependent on the number of attributes, attribute levels, choice tasks and alternatives. Further exploration of overlaps and block sizes are needed. This study's results are widely applicable for researchers interested in creating optimal DCE designs to elicit individual preferences on health services, programmes, policies and products. PMID:27436671

Using partial site aggregation to reduce bias in random utility travel cost models

NASA Astrophysics Data System (ADS)

Lupi, Frank; Feather, Peter M.

1998-12-01

We propose a "partial aggregation" strategy for defining the recreation sites that enter choice sets in random utility models. Under the proposal, the most popular sites and sites that will be the subject of policy analysis enter choice sets as individual sites while remaining sites are aggregated into groups of similar sites. The scheme balances the desire to include all potential substitute sites in the choice sets with practical data and modeling constraints. Unlike fully aggregate models, our analysis and empirical applications suggest that the partial aggregation approach reasonably approximates the results of a disaggregate model. The partial aggregation approach offers all of the data and computational advantages of models with aggregate sites but does not suffer from the same degree of bias as fully aggregate models.

Advertising influences on young children's food choices and parental influence.

PubMed

Ferguson, Christopher J; Muñoz, Monica E; Medrano, Maria R

2012-03-01

To evaluate whether advertising for food influences choices made by children, the strength of these influences, and whether they might be easily undone by parental influences. Children between 3 and 8 years of age (n=75) were randomized to watch a series of programs with embedded commercials. Some children watched a commercial for a relatively healthy food item, the other children watched a commercial for a less healthy item, both from the same fast-food company. Children were also randomized either to receive parental encouragement to choose the healthy item or to choose whichever item they preferred. Results indicated that children were more likely to choose the advertised item, despite parental input. Parental input only slightly moderated this influence. Although advertising impact on children's food choices is moderate in size, it appears resilient to parental efforts to intervene. Food advertisements directed at children may have a small but meaningful effect on their healthy food choices. Copyright © 2012 Mosby, Inc. All rights reserved.

A hybrid heuristic for the multiple choice multidimensional knapsack problem

NASA Astrophysics Data System (ADS)

Mansi, Raïd; Alves, Cláudio; Valério de Carvalho, J. M.; Hanafi, Saïd

2013-08-01

In this article, a new solution approach for the multiple choice multidimensional knapsack problem is described. The problem is a variant of the multidimensional knapsack problem where items are divided into classes, and exactly one item per class has to be chosen. Both problems are NP-hard. However, the multiple choice multidimensional knapsack problem appears to be more difficult to solve in part because of its choice constraints. Many real applications lead to very large scale multiple choice multidimensional knapsack problems that can hardly be addressed using exact algorithms. A new hybrid heuristic is proposed that embeds several new procedures for this problem. The approach is based on the resolution of linear programming relaxations of the problem and reduced problems that are obtained by fixing some variables of the problem. The solutions of these problems are used to update the global lower and upper bounds for the optimal solution value. A new strategy for defining the reduced problems is explored, together with a new family of cuts and a reformulation procedure that is used at each iteration to improve the performance of the heuristic. An extensive set of computational experiments is reported for benchmark instances from the literature and for a large set of hard instances generated randomly. The results show that the approach outperforms other state-of-the-art methods described so far, providing the best known solution for a significant number of benchmark instances.

Pigeons' Choices between Fixed-Interval and Random-Interval Schedules: Utility of Variability?

ERIC Educational Resources Information Center

Andrzejewski, Matthew E.; Cardinal, Claudia D.; Field, Douglas P.; Flannery, Barbara A.; Johnson, Michael; Bailey, Kathleen; Hineline, Philip N.

2005-01-01

Pigeons' choosing between fixed-interval and random-interval schedules of reinforcement was investigated in three experiments using a discrete-trial procedure. In all three experiments, the random-interval schedule was generated by sampling a probability distribution at an interval (and in multiples of the interval) equal to that of the…

Can Nonexperimental Estimates Replicate Estimates Based on Random Assignment in Evaluations of School Choice? A Within-Study Comparison

ERIC Educational Resources Information Center

Bifulco, Robert

2012-01-01

The ability of nonexperimental estimators to match impact estimates derived from random assignment is examined using data from the evaluation of two interdistrict magnet schools. As in previous within-study comparisons, nonexperimental estimates differ from estimates based on random assignment when nonexperimental estimators are implemented…

The Association among Emotions and Food Choices in First-Year College Students Using mobile-Ecological Momentary Assessments.

PubMed

Ashurst, Jessica; van Woerden, Irene; Dunton, Genevieve; Todd, Michael; Ohri-Vachaspati, Punam; Swan, Pamela; Bruening, Meg

2018-05-02

Studies have examined the associations between emotions and overeating but have only rarely considered associations between emotions and specific food choices. The purpose of this secondary data analysis was to use mobile ecological momentary assessments (mEMAs) to examine associations between emotions and food choices among first-year college students living in residence halls. Using an intensive repeated-measures design, mEMAs were used to assess concurrent emotions and food choices in a racially/ethnically diverse sample of first-year college students (n = 663). Emotions were categorized as negative (sad, stressed, tired), positive (happy, energized, relaxed), and apathetic (bored, meh). Assessments were completed multiple times per day on four quasi-randomly selected days (three random weekdays and one random weekend day) during a 7-day period using random prompt times. Generalized estimating equations (GEE) were used to examine between- and within-person associations of emotional status with a variety of healthy and unhealthy food choices (sweets, salty snacks/fried foods, fruits/vegetables, pizza/fast food, sandwiches/wraps, meats/proteins, pasta/rice, cereals), adjusting for gender, day of week, and time of day, accounting for within-person dependencies among repeated measurements of eating behavior. At the between-person level, participants who reported positive emotions more frequently compared to others consumed meats/proteins more often (OR = 1.8; 99% CI = 1.2, 2.8). At the within-person level, on occasions when any negative emotion was reported (versus no negative emotion reported) participants were more likely to consume meats/proteins (OR = 1.5, 99% CI = 1.0, 2.1); on occasions when any positive emotion was reported as compared to occasions with no positive emotions, participants were more likely to consume sweets (OR = 1.7, 99% CI = 1.1, 2.6), but less likely to consume pizza/fast food (OR = 0.6, 99% CI = 0.4, 1.0). Negative and positive emotions were significantly associated with food choices. mEMA methodology provides a unique opportunity to examine these associations within and between people, providing insights for individual and population-level interventions. These findings can be used to guide future longitudinal studies and to develop and test interventions that encourage healthy food choices among first-year college students and ultimately reduce the risk of weight gain.

Management of malignant pleural effusion.

PubMed

Chen, Hongbin; Brahmer, Julie

2008-07-01

Malignant pleural effusion (MPE) often presents in patients with cancer at an advanced stage and thus carries a poor prognosis. This review updates the current knowledge on the management of MPE, focusing on recent literature about the efficacy and safety of the most common methods, including pleurodesis by either thoracoscopy with talc insufflation or thoracostomy with talc slurry, use of an indwelling pleural catheter, and intrapleural chemotherapy. Talc remains the agent of choice in pleurodesis, although the use of alternative agents continues to be explored. The choice of procedure to achieve pleurodesis depends on careful patient selection based on predictive factors and individual characteristics. Talc pleuro-desis is relatively well tolerated and safe, as is an indwelling pleural catheter, in an appropriate patient population. Because MPE is a common problem in cancer patients, future research with more randomized, prospective designs and innovative interventions is needed.

Energy-Based Wavelet De-Noising of Hydrologic Time Series

PubMed Central

Sang, Yan-Fang; Liu, Changming; Wang, Zhonggen; Wen, Jun; Shang, Lunyu

2014-01-01

De-noising is a substantial issue in hydrologic time series analysis, but it is a difficult task due to the defect of methods. In this paper an energy-based wavelet de-noising method was proposed. It is to remove noise by comparing energy distribution of series with the background energy distribution, which is established from Monte-Carlo test. Differing from wavelet threshold de-noising (WTD) method with the basis of wavelet coefficient thresholding, the proposed method is based on energy distribution of series. It can distinguish noise from deterministic components in series, and uncertainty of de-noising result can be quantitatively estimated using proper confidence interval, but WTD method cannot do this. Analysis of both synthetic and observed series verified the comparable power of the proposed method and WTD, but de-noising process by the former is more easily operable. The results also indicate the influences of three key factors (wavelet choice, decomposition level choice and noise content) on wavelet de-noising. Wavelet should be carefully chosen when using the proposed method. The suitable decomposition level for wavelet de-noising should correspond to series' deterministic sub-signal which has the smallest temporal scale. If too much noise is included in a series, accurate de-noising result cannot be obtained by the proposed method or WTD, but the series would show pure random but not autocorrelation characters, so de-noising is no longer needed. PMID:25360533

Deterministic Walks with Choice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beeler, Katy E.; Berenhaut, Kenneth S.; Cooper, Joshua N.

2014-01-10

This paper studies deterministic movement over toroidal grids, integrating local information, bounded memory and choice at individual nodes. The research is motivated by recent work on deterministic random walks, and applications in multi-agent systems. Several results regarding passing tokens through toroidal grids are discussed, as well as some open questions.

The effects of Georgia's Choice curricular reform model on third grade science scores on the Georgia Criterion Referenced Competency Test

NASA Astrophysics Data System (ADS)

Phemister, Art W.

The purpose of this study was to evaluate the effectiveness of the Georgia's Choice reading curriculum on third grade science scores on the Georgia Criterion Referenced Competency Test from 2002 to 2008. In assessing the effectiveness of the Georgia's Choice curriculum model this causal comparative study examined the 105 elementary schools that implemented Georgia's Choice and 105 randomly selected elementary schools that did not elect to use Georgia's Choice. The Georgia's Choice reading program used intensified instruction in an effort to increase reading levels for all students. The study used a non-equivalent control group with a pretest and posttest design to determine the effectiveness of the Georgia's Choice curriculum model. Findings indicated that third grade students in Non-Georgia's Choice schools outscored third grade students in Georgia's Choice schools across the span of the study.

Early myeloid lineage choice is not initiated by random PU.1 to GATA1 protein ratios.

PubMed

Hoppe, Philipp S; Schwarzfischer, Michael; Loeffler, Dirk; Kokkaliaris, Konstantinos D; Hilsenbeck, Oliver; Moritz, Nadine; Endele, Max; Filipczyk, Adam; Gambardella, Adriana; Ahmed, Nouraiz; Etzrodt, Martin; Coutu, Daniel L; Rieger, Michael A; Marr, Carsten; Strasser, Michael K; Schauberger, Bernhard; Burtscher, Ingo; Ermakova, Olga; Bürger, Antje; Lickert, Heiko; Nerlov, Claus; Theis, Fabian J; Schroeder, Timm

2016-07-14

The mechanisms underlying haematopoietic lineage decisions remain disputed. Lineage-affiliated transcription factors with the capacity for lineage reprogramming, positive auto-regulation and mutual inhibition have been described as being expressed in uncommitted cell populations. This led to the assumption that lineage choice is cell-intrinsically initiated and determined by stochastic switches of randomly fluctuating cross-antagonistic transcription factors. However, this hypothesis was developed on the basis of RNA expression data from snapshot and/or population-averaged analyses. Alternative models of lineage choice therefore cannot be excluded. Here we use novel reporter mouse lines and live imaging for continuous single-cell long-term quantification of the transcription factors GATA1 and PU.1 (also known as SPI1). We analyse individual haematopoietic stem cells throughout differentiation into megakaryocytic-erythroid and granulocytic-monocytic lineages. The observed expression dynamics are incompatible with the assumption that stochastic switching between PU.1 and GATA1 precedes and initiates megakaryocytic-erythroid versus granulocytic-monocytic lineage decision-making. Rather, our findings suggest that these transcription factors are only executing and reinforcing lineage choice once made. These results challenge the current prevailing model of early myeloid lineage choice.

You Can't Always Get What You Want: The Influence of Choice on Nocebo and Placebo Responding.

PubMed

Bartley, Hannah; Faasse, Kate; Horne, Rob; Petrie, Keith J

2016-06-01

Choice may be an important influence on the effectiveness and side effects of medical treatments. We investigated the impact of having a choice of medication compared to no choice on both nocebo and placebo responding. Sixty-one participants were randomly assigned to either choose between or be assigned to one of the two equivalent beta-blocker medications (actually placebos) for pre-examination anxiety. There was a greater nocebo response in the no choice group and an increased placebo response in the choice group. Participants in the no choice group attributed significantly more side effects to the tablet than the choice group (p = 0.045), particularly at the 24-h follow-up (p = 0.002). The choice group showed a stronger placebo response in heart rate than the non-choice group. Not being given a choice of medication increased the nocebo effect and reduced the placebo response to the treatment.

Valuing SF-6D Health States Using a Discrete Choice Experiment.

PubMed

Norman, Richard; Viney, Rosalie; Brazier, John; Burgess, Leonie; Cronin, Paula; King, Madeleine; Ratcliffe, Julie; Street, Deborah

2014-08-01

SF-6D utility weights are conventionally produced using a standard gamble (SG). SG-derived weights consistently demonstrate a floor effect not observed with other elicitation techniques. Recent advances in discrete choice methods have allowed estimation of utility weights. The objective was to produce Australian utility weights for the SF-6D and to explore the application of discrete choice experiment (DCE) methods in this context. We hypothesized that weights derived using this method would reflect the largely monotonic construction of the SF-6D. We designed an online DCE and administered it to an Australia-representative online panel (n = 1017). A range of specifications investigating nonlinear preferences with respect to additional life expectancy were estimated using a random-effects probit model. The preferred model was then used to estimate a preference index such that full health and death were valued at 1 and 0, respectively, to provide an algorithm for Australian cost-utility analyses. Physical functioning, pain, mental health, and vitality were the largest drivers of utility weights. Combining levels to remove illogical orderings did not lead to a poorer model fit. Relative to international SG-derived weights, the range of utility weights was larger with 5% of health states valued below zero. s. DCEs can be used to investigate preferences for health profiles and to estimate utility weights for multi-attribute utility instruments. Australian cost-utility analyses can now use domestic SF-6D weights. The comparability of DCE results to those using other elicitation methods for estimating utility weights for quality-adjusted life-year calculations should be further investigated. © The Author(s) 2013.

Work Conditions and the Food Choice Coping Strategies of Employed Parents

ERIC Educational Resources Information Center

Devine, Carol M.; Farrell, Tracy J.; Blake, Christine E.; Jastran, Margaret; Wethington, Elaine; Bisogni, Carole A.

2009-01-01

Objective: How work conditions relate to parents' food choice coping strategies. Design: Pilot telephone survey. Setting: City in the northeastern United States (US). Participants: Black, white, and Hispanic employed mothers (25) and fathers (25) randomly recruited from low-/moderate-income zip codes; 78% of those reached and eligible…

Assortment of encounters and evolution of cooperativeness.

PubMed

Eshel, I; Cavalli-Sforza, L L

1982-02-01

The method of evolutionary stable strategies (ESS), in its current form, is confronted with a difficulty when it tries to explain how some social behaviors initiate their evolution. We show that this difficulty may be removed by changing the assumption made tacitly in game theory (and in ESS) of randomness of meetings or encounters. In reality, such randomness seems to be rare in nature. Family, population and social structure, customs, and habits impose various types of deviation from randomness. Introducing nonrandomness of meeting in a way formally similar to assortative mating, we show that the bar to initial increase of inherited cooperative or altruistic behaviors can be removed, provided there is sufficient assortment of meetings. Family structure may cause contacts predominantly between certain types of relatives, and one can reconstruct some results of classical kin selection in terms of evolutionary stable strategy with assortative meetings. Neighbor effects and group selection might be similarly treated. Assortment need not be a passive consequence of population and social structure, but it can also be actively pursued. Behaviors favoring the choice of cooperative companions will have the effect of favoring the evolution of cooperativeness. It can be shown that discrimination in the choice of companions, especially if combined with assortment, can favor the development of cooperativeness, making initial increase of cooperative behavior possible even at levels of assortment passively imposed which would not be adequate, per se, to guarantee the increase of cooperativeness. It is possible that, in some cases, cooperativeness and behavior favoring some type of assortment are coselected.

A Randomized Educational Intervention Trial to Determine the Effect of Online Education on the Quality of Resident-Delivered Care

PubMed Central

Dolan, Brigid M.; Yialamas, Maria A.; McMahon, Graham T.

2015-01-01

Background There is limited research on whether online formative self-assessment and learning can change the behavior of medical professionals. Objective We sought to determine if an adaptive longitudinal online curriculum in bone health would improve resident physicians' knowledge, and change their behavior regarding prevention of fragility fractures in women. Methods We used a randomized control trial design in which 50 internal medicine resident physicians at a large academic practice were randomized to either receive a standard curriculum in bone health care alone, or to receive it augmented with an adaptive, longitudinal, online formative self-assessment curriculum delivered via multiple-choice questions. Outcomes were assessed 10 months after the start of the intervention. Knowledge outcomes were measured by a multiple-choice question examination. Clinical outcomes were measured by chart review, including bone density screening rate, calculation of the fracture risk assessment tool (FRAX) score, and rate of appropriate bisphosphonate prescription. Results Compared to the control group, residents participating in the intervention had higher scores on the knowledge test at the end of the study. Bone density screening rates and appropriate use of bisphosphonates were significantly higher in the intervention group compared with the control group. FRAX score reporting did not differ between the groups. Conclusions Residents participating in a novel adaptive online curriculum outperformed peers in knowledge of fragility fracture prevention and care practices to prevent fracture. Online adaptive education can change behavior to improve patient care. PMID:26457142

Design and protocol of a randomized multiple behavior change trial: Make Better Choices 2 (MBC2).

PubMed

Pellegrini, Christine A; Steglitz, Jeremy; Johnston, Winter; Warnick, Jennifer; Adams, Tiara; McFadden, H G; Siddique, Juned; Hedeker, Donald; Spring, Bonnie

2015-03-01

Suboptimal diet and inactive lifestyle are among the most prevalent preventable causes of premature death. Interventions that target multiple behaviors are potentially efficient; however the optimal way to initiate and maintain multiple health behavior changes is unknown. The Make Better Choices 2 (MBC2) trial aims to examine whether sustained healthful diet and activity change are best achieved by targeting diet and activity behaviors simultaneously or sequentially. Study design approximately 250 inactive adults with poor quality diet will be randomized to 3 conditions examining the best way to prescribe healthy diet and activity change. The 3 intervention conditions prescribe: 1) an increase in fruit and vegetable consumption (F/V+), decrease in sedentary leisure screen time (Sed-), and increase in physical activity (PA+) simultaneously (Simultaneous); 2) F/V+ and Sed- first, and then sequentially add PA+ (Sequential); or 3) Stress Management Control that addresses stress, relaxation, and sleep. All participants will receive a smartphone application to self-monitor behaviors and regular coaching calls to help facilitate behavior change during the 9 month intervention. Healthy lifestyle change in fruit/vegetable and saturated fat intakes, sedentary leisure screen time, and physical activity will be assessed at 3, 6, and 9 months. MBC2 is a randomized m-Health intervention examining methods to maximize initiation and maintenance of multiple healthful behavior changes. Results from this trial will provide insight about an optimal technology supported approach to promote improvement in diet and physical activity. Copyright © 2015 Elsevier Inc. All rights reserved.

Interpreting indirect treatment comparisons and network meta-analysis for health-care decision making: report of the ISPOR Task Force on Indirect Treatment Comparisons Good Research Practices: part 1.

PubMed

Jansen, Jeroen P; Fleurence, Rachael; Devine, Beth; Itzler, Robbin; Barrett, Annabel; Hawkins, Neil; Lee, Karen; Boersma, Cornelis; Annemans, Lieven; Cappelleri, Joseph C

2011-06-01

Evidence-based health-care decision making requires comparisons of all relevant competing interventions. In the absence of randomized, controlled trials involving a direct comparison of all treatments of interest, indirect treatment comparisons and network meta-analysis provide useful evidence for judiciously selecting the best choice(s) of treatment. Mixed treatment comparisons, a special case of network meta-analysis, combine direct and indirect evidence for particular pairwise comparisons, thereby synthesizing a greater share of the available evidence than a traditional meta-analysis. This report from the ISPOR Indirect Treatment Comparisons Good Research Practices Task Force provides guidance on the interpretation of indirect treatment comparisons and network meta-analysis to assist policymakers and health-care professionals in using its findings for decision making. We start with an overview of how networks of randomized, controlled trials allow multiple treatment comparisons of competing interventions. Next, an introduction to the synthesis of the available evidence with a focus on terminology, assumptions, validity, and statistical methods is provided, followed by advice on critically reviewing and interpreting an indirect treatment comparison or network meta-analysis to inform decision making. We finish with a discussion of what to do if there are no direct or indirect treatment comparisons of randomized, controlled trials possible and a health-care decision still needs to be made. Copyright © 2011 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Automatic liver segmentation on Computed Tomography using random walkers for treatment planning

PubMed Central

Moghbel, Mehrdad; Mashohor, Syamsiah; Mahmud, Rozi; Saripan, M. Iqbal Bin

2016-01-01

Segmentation of the liver from Computed Tomography (CT) volumes plays an important role during the choice of treatment strategies for liver diseases. Despite lots of attention, liver segmentation remains a challenging task due to the lack of visible edges on most boundaries of the liver coupled with high variability of both intensity patterns and anatomical appearances with all these difficulties becoming more prominent in pathological livers. To achieve a more accurate segmentation, a random walker based framework is proposed that can segment contrast-enhanced livers CT images with great accuracy and speed. Based on the location of the right lung lobe, the liver dome is automatically detected thus eliminating the need for manual initialization. The computational requirements are further minimized utilizing rib-caged area segmentation, the liver is then extracted by utilizing random walker method. The proposed method was able to achieve one of the highest accuracies reported in the literature against a mixed healthy and pathological liver dataset compared to other segmentation methods with an overlap error of 4.47 % and dice similarity coefficient of 0.94 while it showed exceptional accuracy on segmenting the pathological livers with an overlap error of 5.95 % and dice similarity coefficient of 0.91. PMID:28096782

Latent class instrumental variables: A clinical and biostatistical perspective

PubMed Central

Baker, Stuart G.; Kramer, Barnett S.; Lindeman, Karen S.

2015-01-01

In some two-arm randomized trials, some participants receive the treatment assigned to the other arm as a result of technical problems, refusal of a treatment invitation, or a choice of treatment in an encouragement design. In some before-and-after studies, the availability of a new treatment changes from one time period to this next. Under assumptions that are often reasonable, the latent class instrumental variable (IV) method estimates the effect of treatment received in the aforementioned scenarios involving all-or-none compliance and all-or-none availability. Key aspects are four initial latent classes (sometimes called principal strata) based on treatment received if in each randomization group or time period, the exclusion restriction assumption (in which randomization group or time period is an instrumental variable), the monotonicity assumption (which drops an implausible latent class from the analysis), and the estimated effect of receiving treatment in one latent class (sometimes called efficacy, the local average treatment effect, or the complier average causal effect). Since its independent formulations in the biostatistics and econometrics literatures, the latent class IV method (which has no well-established name) has gained increasing popularity. We review the latent class IV method from a clinical and biostatistical perspective, focusing on underlying assumptions, methodological extensions, and applications in our fields of obstetrics and cancer research. PMID:26239275

The episodic random utility model unifies time trade-off and discrete choice approaches in health state valuation

PubMed Central

Craig, Benjamin M; Busschbach, Jan JV

2009-01-01

Background To present an episodic random utility model that unifies time trade-off and discrete choice approaches in health state valuation. Methods First, we introduce two alternative random utility models (RUMs) for health preferences: the episodic RUM and the more common instant RUM. For the interpretation of time trade-off (TTO) responses, we show that the episodic model implies a coefficient estimator, and the instant model implies a mean slope estimator. Secondly, we demonstrate these estimators and the differences between the estimates for 42 health states using TTO responses from the seminal Measurement and Valuation in Health (MVH) study conducted in the United Kingdom. Mean slopes are estimates with and without Dolan's transformation of worse-than-death (WTD) responses. Finally, we demonstrate an exploded probit estimator, an extension of the coefficient estimator for discrete choice data that accommodates both TTO and rank responses. Results By construction, mean slopes are less than or equal to coefficients, because slopes are fractions and, therefore, magnify downward errors in WTD responses. The Dolan transformation of WTD responses causes mean slopes to increase in similarity to coefficient estimates, yet they are not equivalent (i.e., absolute mean difference = 0.179). Unlike mean slopes, coefficient estimates demonstrate strong concordance with rank-based predictions (Lin's rho = 0.91). Combining TTO and rank responses under the exploded probit model improves the identification of health state values, decreasing the average width of confidence intervals from 0.057 to 0.041 compared to TTO only results. Conclusion The episodic RUM expands upon the theoretical framework underlying health state valuation and contributes to health econometrics by motivating the selection of coefficient and exploded probit estimators for the analysis of TTO and rank responses. In future MVH surveys, sample size requirements may be reduced through the incorporation of multiple responses under a single estimator. PMID:19144115

The optimal number of menu options per panel

NASA Technical Reports Server (NTRS)

Paap, Kenneth R.; Roske-Hofstrand, Renate J.

1986-01-01

An evaluation is made of the effects of the 'funneling' phenomenon, in an analysis of hierarchical menu structures' optimal search times which builds on the work of Lee and MacGregor (1985). Funneling is a reduction in the total number of options processed through the design of a system of greater choice 'depth' and correspondingly restricted choice 'breadth'. Both random and ordered menus are treated. The available evidence is found to support the general conclusion that randomly ordered menu panels should have only a few (4-8) options, while organized menus should contain as many options as 64.

Factors influencing infant-feeding choices selected by HIV-infected mothers: perspectives from Zimbabwe.

PubMed

Marembo, Joan; Zvinavashe, Mathilda; Nyamakura, Rudo; Shaibu, Sheila; Mogobe, Keitshokile Dintle

2014-10-01

To assess factors influencing infant-feeding methods selected by HIV-infected mothers. A descriptive quantitative study was conducted among 80 mothers with babies aged 0-6 months who were randomly selected and interviewed. Descriptive statistics were used to summarize the findings. Factors considered by women in choosing the infant-feeding methods included sociocultural acceptability (58.8%), feasibility and support from significant others (35%), knowledge of the selected method (55%), affordability (61.2%), implementation of the infant-feeding method without interference (62.5%), and safety (47.5%). Exclusive breast-feeding was the most preferred method of infant feeding. Disclosure of HIV status by a woman to her partner is a major condition for successful replacement feeding method, especially within the African cultural context. However, disclosure of HIV status to the partner was feared by most women as only 16.2% of the women disclosed their HIV status to partners. The factors considered by women in choosing the infant-feeding option were ability to implement the options without interference from significant others, affordability, and sociocultural acceptability. Knowledge of the selected option, its advantages and disadvantages, safety, and feasibility were also important factors. Nurses and midwives have to educate clients and support them in their choice of infant-feeding methods. © 2013 The Authors. Japan Journal of Nursing Science © 2013 Japan Academy of Nursing Science.

Voice Quality After Treatment of Early Vocal Cord Cancer: A Randomized Trial Comparing Laser Surgery With Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, Leena-Maija, E-mail: leena-maija.aaltonen@hus.fi; Rautiainen, Noora; Sellman, Jaana

Objective: Early laryngeal cancer is usually treated with either transoral laser surgery or radiation therapy. The quality of voice achieved with these treatments has not been compared in a randomized trial. Methods and Materials: Male patients with carcinoma limited to 1 mobile vocal cord (T1aN0M0) were randomly assigned to receive either laser surgery (n=32) or external beam radiation therapy (n=28). Surgery consisted of tumor excision with a CO{sub 2} laser with the patient under general anaesthesia. External beam radiation therapy to the larynx was delivered to a cumulative dose of 66 Gy in 2-Gy daily fractions over 6.5 weeks. Voice quality wasmore » assessed at baseline and 6 and 24 months after treatment. The main outcome measures were expert-rated voice quality on a grade, roughness, breathiness, asthenia, and strain (GRBAS) scale, videolaryngostroboscopic findings, and the patients' self-rated voice quality and its impact on activities of daily living. Results: Overall voice quality between the groups was rated similar, but voice was more breathy and the glottal gap was wider in patients treated with laser surgery than in those who received radiation therapy. Patients treated with radiation therapy reported less hoarseness-related inconvenience in daily living 2 years after treatment. Three patients in each group had local cancer recurrence within 2 years from randomization. Conclusions: Radiation therapy may be the treatment of choice for patients whose requirements for voice quality are demanding. Overall voice quality was similar in both treatment groups, however, indicating a need for careful consideration of patient-related factors in the choice of a treatment option.« less

Parametric and non-parametric masking of randomness in sequence alignments can be improved and leads to better resolved trees.

PubMed

Kück, Patrick; Meusemann, Karen; Dambach, Johannes; Thormann, Birthe; von Reumont, Björn M; Wägele, Johann W; Misof, Bernhard

2010-03-31

Methods of alignment masking, which refers to the technique of excluding alignment blocks prior to tree reconstructions, have been successful in improving the signal-to-noise ratio in sequence alignments. However, the lack of formally well defined methods to identify randomness in sequence alignments has prevented a routine application of alignment masking. In this study, we compared the effects on tree reconstructions of the most commonly used profiling method (GBLOCKS) which uses a predefined set of rules in combination with alignment masking, with a new profiling approach (ALISCORE) based on Monte Carlo resampling within a sliding window, using different data sets and alignment methods. While the GBLOCKS approach excludes variable sections above a certain threshold which choice is left arbitrary, the ALISCORE algorithm is free of a priori rating of parameter space and therefore more objective. ALISCORE was successfully extended to amino acids using a proportional model and empirical substitution matrices to score randomness in multiple sequence alignments. A complex bootstrap resampling leads to an even distribution of scores of randomly similar sequences to assess randomness of the observed sequence similarity. Testing performance on real data, both masking methods, GBLOCKS and ALISCORE, helped to improve tree resolution. The sliding window approach was less sensitive to different alignments of identical data sets and performed equally well on all data sets. Concurrently, ALISCORE is capable of dealing with different substitution patterns and heterogeneous base composition. ALISCORE and the most relaxed GBLOCKS gap parameter setting performed best on all data sets. Correspondingly, Neighbor-Net analyses showed the most decrease in conflict. Alignment masking improves signal-to-noise ratio in multiple sequence alignments prior to phylogenetic reconstruction. Given the robust performance of alignment profiling, alignment masking should routinely be used to improve tree reconstructions. Parametric methods of alignment profiling can be easily extended to more complex likelihood based models of sequence evolution which opens the possibility of further improvements.

Effect of guided relaxation and imagery on falls self-efficacy: a randomized controlled trial.

PubMed

Kim, Bang Hyun; Newton, Roberta A; Sachs, Michael L; Glutting, Joseph J; Glanz, Karen

2012-06-01

To examine the effects of guided relaxation and imagery (GRI) on improvement in falls self-efficacy in older adults who report having a fear of falling. Randomized, controlled trial with allocation to GRI or guided relaxation with music of choice. General community. Ninety-one men and women aged 60 to 92. Participants were randomized to listen to a GRI audio compact disk (intervention group) or a guided relaxation audio compact disk and music of choice (control group) twice a week for 6 weeks for 10 minutes per session. Primary outcome measure was the Short Falls Efficacy Scale-International (FES-I). Secondary outcome measures were the Leisure Time Exercise Questionnaire (LTEQ) and the Timed Up and Go (TUG) mobility test. GRI participants reported greater improvements on the Short FES-I (P = .002) and LTEQ (P = .001) scores and shorter time on the TUG (P = .002) than the guided relaxation and music-of-choice group. GRI was more effective at increasing falls self-efficacy and self-reported leisure time exercise and reducing times on a simple mobility test than was guided relaxation with music of choice. GRI is an effective, simple, low-cost tool for older adults to improve falls self-efficacy and leisure time exercise behaviors. © 2012, Copyright the Authors Journal compilation © 2012, The American Geriatrics Society.

Predictability of monthly temperature and precipitation using automatic time series forecasting methods

NASA Astrophysics Data System (ADS)

Papacharalampous, Georgia; Tyralis, Hristos; Koutsoyiannis, Demetris

2018-02-01

We investigate the predictability of monthly temperature and precipitation by applying automatic univariate time series forecasting methods to a sample of 985 40-year-long monthly temperature and 1552 40-year-long monthly precipitation time series. The methods include a naïve one based on the monthly values of the last year, as well as the random walk (with drift), AutoRegressive Fractionally Integrated Moving Average (ARFIMA), exponential smoothing state-space model with Box-Cox transformation, ARMA errors, Trend and Seasonal components (BATS), simple exponential smoothing, Theta and Prophet methods. Prophet is a recently introduced model inspired by the nature of time series forecasted at Facebook and has not been applied to hydrometeorological time series before, while the use of random walk, BATS, simple exponential smoothing and Theta is rare in hydrology. The methods are tested in performing multi-step ahead forecasts for the last 48 months of the data. We further investigate how different choices of handling the seasonality and non-normality affect the performance of the models. The results indicate that: (a) all the examined methods apart from the naïve and random walk ones are accurate enough to be used in long-term applications; (b) monthly temperature and precipitation can be forecasted to a level of accuracy which can barely be improved using other methods; (c) the externally applied classical seasonal decomposition results mostly in better forecasts compared to the automatic seasonal decomposition used by the BATS and Prophet methods; and (d) Prophet is competitive, especially when it is combined with externally applied classical seasonal decomposition.

Improving influenza vaccination rates in the workplace: a randomized trial.

PubMed

Nowalk, Mary Patricia; Lin, Chyongchiou J; Toback, Seth L; Rousculp, Matthew D; Eby, Charles; Raymund, Mahlon; Zimmerman, Richard K

2010-03-01

To minimize absenteeism resulting from influenza, employers frequently offer on-site influenza vaccination to employees. Yet the level of uptake of vaccine is low among working adults. This study was designed to increase workplace influenza vaccination rates by offering both a choice of intranasal (LAIV) and injectable (TIV) influenza vaccines to eligible employees, and an incentive for being vaccinated, and by increasing awareness of the vaccine clinic. This study used a stratified randomized cluster trial. A total of 12,222 employees in 53 U.S. companies with previous influenza vaccine clinics were examined. Control sites advertised and offered vaccine clinics as previously done. Choice sites offered LAIV or TIV and maintained their previous advertising level but promoted the choice of vaccines. Choice Plus sites increased advertising and promoted and offered a choice of vaccines and a nominal incentive. These included vaccination rates among eligible employees. Hierarchic linear modeling (HLM) was used to determine factors associated with vaccination. The overall vaccination rate increased from 39% in 2007-2008 to 46% in 2008-2009 (p<0.001). The difference in vaccination rates for LAIV was 6.5% for Choice versus Control and 9.9% for Choice Plus versus Control (both p<0.001). Rates of TIV increased by 15.9 percentage points in the Choice Plus arm versus Control for workers aged > or =50 years (p=0.024). Rates of TIV did not change in workers aged 18-49 years in either intervention arm or in workers aged > or =50 years in the Choice arm. In HLM analyses, factors significantly associated with increased vaccination were older age, female gender, previous company vaccination rate, and the Choice Plus intervention. An incentive for vaccination, an intensified advertising campaign, and offering a choice of influenza vaccines improved vaccination rates in the workplace. Copyright (c) 2010 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Differential equations as a tool for community identification.

PubMed

Krawczyk, Małgorzata J

2008-06-01

We consider the task of identification of a cluster structure in random networks. The results of two methods are presented: (i) the Newman algorithm [M. E. J. Newman and M. Girvan, Phys. Rev. E 69, 026113 (2004)]; and (ii) our method based on differential equations. A series of computer experiments is performed to check if in applying these methods we are able to determine the structure of the network. The trial networks consist initially of well-defined clusters and are disturbed by introducing noise into their connectivity matrices. Further, we show that an improvement of the previous version of our method is possible by an appropriate choice of the threshold parameter beta . With this change, the results obtained by the two methods above are similar, and our method works better, for all the computer experiments we have done.

An empirical understanding of triple collocation evaluation measure

NASA Astrophysics Data System (ADS)

Scipal, Klaus; Doubkova, Marcela; Hegyova, Alena; Dorigo, Wouter; Wagner, Wolfgang

2013-04-01

Triple collocation method is an advanced evaluation method that has been used in the soil moisture field for only about half a decade. The method requires three datasets with an independent error structure that represent an identical phenomenon. The main advantages of the method are that it a) doesn't require a reference dataset that has to be considered to represent the truth, b) limits the effect of random and systematic errors of other two datasets, and c) simultaneously assesses the error of three datasets. The objective of this presentation is to assess the triple collocation error (Tc) of the ASAR Global Mode Surface Soil Moisture (GM SSM 1) km dataset and highlight problems of the method related to its ability to cancel the effect of error of ancillary datasets. In particular, the goal is to a) investigate trends in Tc related to the change in spatial resolution from 5 to 25 km, b) to investigate trends in Tc related to the choice of a hydrological model, and c) to study the relationship between Tc and other absolute evaluation methods (namely RMSE and Error Propagation EP). The triple collocation method is implemented using ASAR GM, AMSR-E, and a model (either AWRA-L, GLDAS-NOAH, or ERA-Interim). First, the significance of the relationship between the three soil moisture datasets was tested that is a prerequisite for the triple collocation method. Second, the trends in Tc related to the choice of the third reference dataset and scale were assessed. For this purpose the triple collocation is repeated replacing AWRA-L with two different globally available model reanalysis dataset operating at different spatial resolution (ERA-Interim and GLDAS-NOAH). Finally, the retrieved results were compared to the results of the RMSE and EP evaluation measures. Our results demonstrate that the Tc method does not eliminate the random and time-variant systematic errors of the second and the third dataset used in the Tc. The possible reasons include the fact a) that the TC method could not fully function with datasets acting at very different spatial resolutions, or b) that the errors were not fully independent as initially assumed.

Personalized Risk Prediction in Clinical Oncology Research: Applications and Practical Issues Using Survival Trees and Random Forests.

PubMed

Hu, Chen; Steingrimsson, Jon Arni

2018-01-01

A crucial component of making individualized treatment decisions is to accurately predict each patient's disease risk. In clinical oncology, disease risks are often measured through time-to-event data, such as overall survival and progression/recurrence-free survival, and are often subject to censoring. Risk prediction models based on recursive partitioning methods are becoming increasingly popular largely due to their ability to handle nonlinear relationships, higher-order interactions, and/or high-dimensional covariates. The most popular recursive partitioning methods are versions of the Classification and Regression Tree (CART) algorithm, which builds a simple interpretable tree structured model. With the aim of increasing prediction accuracy, the random forest algorithm averages multiple CART trees, creating a flexible risk prediction model. Risk prediction models used in clinical oncology commonly use both traditional demographic and tumor pathological factors as well as high-dimensional genetic markers and treatment parameters from multimodality treatments. In this article, we describe the most commonly used extensions of the CART and random forest algorithms to right-censored outcomes. We focus on how they differ from the methods for noncensored outcomes, and how the different splitting rules and methods for cost-complexity pruning impact these algorithms. We demonstrate these algorithms by analyzing a randomized Phase III clinical trial of breast cancer. We also conduct Monte Carlo simulations to compare the prediction accuracy of survival forests with more commonly used regression models under various scenarios. These simulation studies aim to evaluate how sensitive the prediction accuracy is to the underlying model specifications, the choice of tuning parameters, and the degrees of missing covariates.

Patient-Physician Communication About Code Status Preferences: A Randomized Controlled Trial

PubMed Central

Rhondali, Wadih; Perez-Cruz, Pedro; Hui, David; Chisholm, Gary B.; Dalal, Shalini; Baile, Walter; Chittenden, Eva; Bruera, Eduardo

2013-01-01

Purpose Code status discussions are important in cancer care. The best modality for such discussions has not been established. Our objective was to determine the impact of a physician ending a code status discussion with a question (autonomy approach) versus a recommendation (beneficence approach) on patients' do-not-resuscitate (DNR) preference. Methods Patients in a supportive care clinic watched two videos showing a physician-patient discussion regarding code status. Both videos were identical except for the ending: one ended with the physician asking for the patient's code status preference and the other with the physician recommending DNR. Patients were randomly assigned to watch the videos in different sequences. The main outcome was the proportion of patients choosing DNR for the video patient. Results 78 patients completed the study. 74% chose DNR after the question video, 73% after the recommendation video. Median physician compassion score was very high and not different for both videos. 30/30 patients who had chosen DNR for themselves and 30/48 patients who had not chosen DNR for themselves chose DNR for the video patient (100% v/s 62%). Age (OR=1.1/year) and white ethnicity (OR=9.43) predicted DNR choice for the video patient. Conclusion Ending DNR discussions with a question or a recommendation did not impact DNR choice or perception of physician compassion. Therefore, both approaches are clinically appropriate. All patients who chose DNR for themselves and most patients who did not choose DNR for themselves chose DNR for the video patient. Age and race predicted DNR choice. PMID:23564395

Reproductive Health CHOICES for Young Adults with Sickle Cell Disease or Trait: Randomized Controlled Trial Outcomes over Two Years.

PubMed

Gallo, Agatha M; Wilkie, Diana J; Yao, Yingwei; Molokie, Robert E; Stahl, Christiane; Hershberger, Patricia E; Zhao, Zhongsheng; Suarez, Marie L; Johnson, Bonnye; Angulo, Rigoberto; Carrasco, Jesus; Angulo, Veronica; Thompson, Alexis A

2016-04-01

Interventions to assist reproductive health decision-making in populations affected by sickle cell disease (SCD) or trait (SCT) lack proven efficacy over time. Our aim was to compare effects of CHOICES, a Web-based multimedia education program on implementing informed reproductive plans, and usual care education (e-Book) on reproductive knowledge, intention, and behavior over 24 months. We randomized 234 participants with SCD (n = 138) or SCT (n = 96) (age 18-35 years, 35 % male, 94 % African American) to CHOICES and e-Book groups. Participants completed a sickle cell-specific reproductive measure before and four times after the intervention (6, 12, 18 and 24 months). Compared to the e-Book group the CHOICES group had significantly more improvement in knowledge over time (p = .004) but not intention (p = .18) or behavior (p = .69). At baseline, 114 (48.7 %) participants reported having partners who would not put the couple at risk for their children inheriting SCD. Of the 116 (49.6 %) at-risk participants, a higher poroportion of those who were in the CHOICES group chose partners that reduced their risk by the last visit than the e-Book group (p = .04). Study findings provide important insights for designing a national trial of the CHOICES intervention focusing on subjects whose partner status puts them at risk for having a child with SCD.

Probalistic Finite Elements (PFEM) structural dynamics and fracture mechanics

NASA Technical Reports Server (NTRS)

Liu, Wing-Kam; Belytschko, Ted; Mani, A.; Besterfield, G.

1989-01-01

The purpose of this work is to develop computationally efficient methodologies for assessing the effects of randomness in loads, material properties, and other aspects of a problem by a finite element analysis. The resulting group of methods is called probabilistic finite elements (PFEM). The overall objective of this work is to develop methodologies whereby the lifetime of a component can be predicted, accounting for the variability in the material and geometry of the component, the loads, and other aspects of the environment; and the range of response expected in a particular scenario can be presented to the analyst in addition to the response itself. Emphasis has been placed on methods which are not statistical in character; that is, they do not involve Monte Carlo simulations. The reason for this choice of direction is that Monte Carlo simulations of complex nonlinear response require a tremendous amount of computation. The focus of efforts so far has been on nonlinear structural dynamics. However, in the continuation of this project, emphasis will be shifted to probabilistic fracture mechanics so that the effect of randomness in crack geometry and material properties can be studied interactively with the effect of random load and environment.

Nutrition Knowledge and Food Choices of Elementary School Children.

ERIC Educational Resources Information Center

Kandiah, Jay; Jones, Charlotte

2002-01-01

Investigated the effect of a 3-week school-based nutrition education program on nutrition knowledge and healthy food choices of fifth graders randomly assigned to experimental or control group. Found that the experimental group exhibited a significant increase in nutrition knowledge from pretest to posttest and significant change in compliance in…

The Impact of Institutional Grant Aid on College Choice

ERIC Educational Resources Information Center

Hurwitz, Michael

2012-01-01

In this study, I exploit exogenous differences in institutional policies regarding the treatment of home equity in grant aid allocation to estimate a causal impact of institutional grant aid on college choice. Because institutional grant aid is typically not awarded randomly, the college-estimated home equity value serves as an instrumental…

Evaluation of a web-based program promoting healthy eating and physical activity for adolescents: Teen Choice: Food and Fitness

USDA-ARS?s Scientific Manuscript database

This randomized clinical trial tested the impact of a website promoting nutrition and physical activity for adolescents (Teen Choice: Food and Fitness). Participants, 408 12- to 17-year-old adolescents in the Houston area, completed online surveys measuring diet, physical activity, sedentary behavio...

Effects of Career Choice Intervention on Components of Career Preparation

ERIC Educational Resources Information Center

Koivisto, Petri; Vinokur, Amiram D.; Vuori, Jukka

2011-01-01

This randomized experimental study (N = 1,034) examines both the direct and the indirect effects of the Towards Working Life intervention on 2 components of adolescents' career preparation: preparedness for career choice and attitude toward career planning. The intervention comprised a 1-week workshop program, the proximal goals of which were to…

The effects of condom choice on self-reported condom use among men in Ghana, Kenya and South Africa: a randomized trial.

PubMed

Weaver, Mark A; Joanis, Carol; Toroitich-Ruto, Cathy; Parker, Warren; Gyamenah, Nana A; Rinaldi, Anne; Omungo, Zablon; Steiner, Markus J

2011-09-01

Male condoms are readily available and affordable in many settings, but risky sexual acts still go unprotected. This unblinded randomized trial, conducted in Ghana, Kenya and South Africa, was designed to assess the impact of providing a choice of condoms on self-reported use and uptake over 6 months. We enrolled 1,274 men. The mean subject-specific proportion of protected acts with all partners increased from baseline to 6 months by 0.07 in the control group compared to 0.03 in the choice group (p=.025). The observed results were largely consistent across all three countries. In the choice group, men clearly preferred one condom type over the others, and this preference was consistent across all three countries. Providing one type of male condom in public sector programs appears justified. Programs should not focus on the number of brands available, but should encourage effective promotion and consistent and correct use of available brands. Copyright © 2011 Elsevier Inc. All rights reserved.

Abnormal Papanicolaou smears, genital tract infections, and contraception.

PubMed

Hawkins, J W; Matteson, P S; Mersha, G

1999-01-01

Cervical cancer ranks second among all cancers in women world-wide, and the rate of invasive cervical cancer among women under 50 is rising in the United States. Risk factors for abnormal Papanicolaou (Pap) smears and invasive cervical cancer include genital tract infections. This study was designed to compare the rates of genital tract infections and the contraceptive choices of a random sample of 800 women, using an ex post facto design. The Pap positive women had a significantly higher rate of genital tract infections than did the Pap negative women but did not differ significantly in use of contraceptive methods. Findings support those of other researchers suggesting genital tract infections as risk factors for abnormal Pap smears and are consistent with the literature in suggesting a role for oral contraceptive pills (OCPs) in acquisition of the human papillomavirus (HPV). Caregivers can help empower women to reduce their risks through informed choices about protection and sexual behaviors.

In the search for the low-complexity sequences in prokaryotic and eukaryotic genomes: how to derive a coherent picture from global and local entropy measures

NASA Astrophysics Data System (ADS)

Acquisti, Claudia; Allegrini, Paolo; Bogani, Patrizia; Buiatti, Marcello; Catanese, Elena; Fronzoni, Leone; Grigolini, Paolo; Mersi, Giuseppe; Palatella, Luigi

2004-04-01

We investigate on a possible way to connect the presence of Low-Complexity Sequences (LCS) in DNA genomes and the nonstationary properties of base correlations. Under the hypothesis that these variations signal a change in the DNA function, we use a new technique, called Non-Stationarity Entropic Index (NSEI) method, and we prove that this technique is an efficient way to detect functional changes with respect to a random baseline. The remarkable aspect is that NSEI does not imply any training data or fitting parameter, the only arbitrarity being the choice of a marker in the sequence. We make this choice on the basis of biological information about LCS distributions in genomes. We show that there exists a correlation between changing the amount in LCS and the ratio of long- to short-range correlation.

A comparative evaluation of teaching methods in an introductory neuroscience course for physical therapy students

NASA Astrophysics Data System (ADS)

Willett, Gilbert M.

Background and purpose. Use of computer based instruction (CBI) in physical therapy (P.T.) education is growing. P.T. educators have reported few studies regarding the effectiveness of CBI compared to lecture based instruction, and none have specifically addressed the area of neuroscience. The purpose of this study was to determine whether CBI would be a better alternative than lecture for teaching introductory neuroscience information to first year P.T. students. Subjects. This study was conducted over two years, with 28 participants in 2003 and 34 in 2004. Methods. A randomized, cross-over design was employed for this investigation. The course in which the study took place was divided into two sections with an exam after each. Both sections included 5 one hour lectures (or 5 equivalent CBI modules) and a two hour laboratory experience. Exams consisted of 30 multiple choice questions. Students in one group participated in CBI during the first half of the course and lecture during the second half. The order of participation was reversed for students in the other group. A review exam (60 multiple choice questions) was also taken by participants six months post-participation in the course. Exam scores, study time, course development costs, and student opinions regarding teaching methods were collected after each section of the course and analyzed using quantitative and qualitative methods. Results. There were no statistically significant differences in "within course" or review exam scores between participant groups based on instructional method, however, CBI taught students spent less time studying. Student opinions did not distinguish a major preference for either instruction method. Many students preferred that CBI be used as a complimentary rather than mutually exclusive instructional method. Lecture based instruction was clearly more cost effective than CBI. Conclusion. In this study, lecture based instruction was clearly the better choice of teaching method in terms of cost, but CBI was more time efficient in terms of student learning.

Neural Mechanism for Stochastic Behavior During a Competitive Game

PubMed Central

Soltani, Alireza; Lee, Daeyeol; Wang, Xiao-Jing

2006-01-01

Previous studies have shown that non-human primates can generate highly stochastic choice behavior, especially when this is required during a competitive interaction with another agent. To understand the neural mechanism of such dynamic choice behavior, we propose a biologically plausible model of decision making endowed with synaptic plasticity that follows a reward-dependent stochastic Hebbian learning rule. This model constitutes a biophysical implementation of reinforcement learning, and it reproduces salient features of behavioral data from an experiment with monkeys playing a matching pennies game. Due to interaction with an opponent and learning dynamics, the model generates quasi-random behavior robustly in spite of intrinsic biases. Furthermore, non-random choice behavior can also emerge when the model plays against a non-interactive opponent, as observed in the monkey experiment. Finally, when combined with a meta-learning algorithm, our model accounts for the slow drift in the animal’s strategy based on a process of reward maximization. PMID:17015181

Functionality limit of classical simulated annealing

NASA Astrophysics Data System (ADS)

Hasegawa, M.

2015-09-01

By analyzing the system dynamics in the landscape paradigm, optimization function of classical simulated annealing is reviewed on the random traveling salesman problems. The properly functioning region of the algorithm is experimentally determined in the size-time plane and the influence of its boundary on the scalability test is examined in the standard framework of this method. From both results, an empirical choice of temperature length is plausibly explained as a minimum requirement that the algorithm maintains its scalability within its functionality limit. The study exemplifies the applicability of computational physics analysis to the optimization algorithm research.

Undesirable Choice Biases with Small Differences in the Spatial Structure of Chance Stimulus Sequences.

PubMed

Herrera, David; Treviño, Mario

2015-01-01

In two-alternative discrimination tasks, experimenters usually randomize the location of the rewarded stimulus so that systematic behavior with respect to irrelevant stimuli can only produce chance performance on the learning curves. One way to achieve this is to use random numbers derived from a discrete binomial distribution to create a 'full random training schedule' (FRS). When using FRS, however, sporadic but long laterally-biased training sequences occur by chance and such 'input biases' are thought to promote the generation of laterally-biased choices (i.e., 'output biases'). As an alternative, a 'Gellerman-like training schedule' (GLS) can be used. It removes most input biases by prohibiting the reward from appearing on the same location for more than three consecutive trials. The sequence of past rewards obtained from choosing a particular discriminative stimulus influences the probability of choosing that same stimulus on subsequent trials. Assuming that the long-term average ratio of choices matches the long-term average ratio of reinforcers, we hypothesized that a reduced amount of input biases in GLS compared to FRS should lead to a reduced production of output biases. We compared the choice patterns produced by a 'Rational Decision Maker' (RDM) in response to computer-generated FRS and GLS training sequences. To create a virtual RDM, we implemented an algorithm that generated choices based on past rewards. Our simulations revealed that, although the GLS presented fewer input biases than the FRS, the virtual RDM produced more output biases with GLS than with FRS under a variety of test conditions. Our results reveal that the statistical and temporal properties of training sequences interacted with the RDM to influence the production of output biases. Thus, discrete changes in the training paradigms did not translate linearly into modifications in the pattern of choices generated by a RDM. Virtual RDMs could be further employed to guide the selection of proper training schedules for perceptual decision-making studies.

Social Norms and Financial Incentives to Promote Employees’ Healthy Food Choices: A Randomized Controlled Trial

PubMed Central

Thorndike, Anne N.; Riis, Jason; Levy, Douglas E.

2016-01-01

Population-level strategies to improve healthy food choices are needed for obesity prevention. We conducted a randomized controlled trial of 2,672 employees at Massachusetts General Hospital who were regular customers of the hospital cafeteria with all items labeled green (healthy), yellow (less healthy), or red (unhealthy) to determine if social norm (peer-comparison) feedback with or without financial incentives increased employees’ healthy food choices. Participants were randomized in 2012 to three arms: 1) monthly letter with social norm feedback about healthy food purchases, comparing employee to “all” and to “healthiest” customers (feedback-only); 2) monthly letter with social norm feedback plus small financial incentive for increasing green purchases (feedback-incentive); or 3) no contact (control). The main outcome was change in proportion of green-labeled purchases at end of 3-month intervention. Post-hoc analyses examined linear trends. At baseline, the proportion of green-labeled purchases (50%) did not differ between arms. At end of the 3-month intervention, the percentage increase in green-labeled purchases was larger in the feedback-incentive arm compared to control (2.2% vs. 0.1%, P=0.03), but the two intervention arms were not different. The rate of increase in green-labeled purchases was higher in both feedback-only (P=0.04) and feedback-incentive arms (P=0.004) compared to control. At end of a 3-month wash-out, there were no differences between control and intervention arms. Social norms plus small financial incentives increased employees’ healthy food choices over the short-term. Future research will be needed to assess the impact of this relatively low-cost intervention on employees’ food choices and weight over the long-term. Trial Registration: Clinical Trials.gov NCT01604499 PMID:26827617

Social norms and financial incentives to promote employees' healthy food choices: A randomized controlled trial.

PubMed

Thorndike, Anne N; Riis, Jason; Levy, Douglas E

2016-05-01

Population-level strategies to improve healthy food choices are needed for obesity prevention. We conducted a randomized controlled trial of 2672 employees at the Massachusetts General Hospital who were regular customers of the hospital cafeteria with all items labeled green (healthy), yellow (less healthy), or red (unhealthy) to determine if social norm (peer-comparison) feedback with or without financial incentives increased employees' healthy food choices. Participants were randomized in 2012 to three arms: 1) monthly letter with social norm feedback about healthy food purchases, comparing employee to "all" and to "healthiest" customers (feedback-only); 2) monthly letter with social norm feedback plus small financial incentive for increasing green purchases (feedback-incentive); or 3) no contact (control). The main outcome was change in proportion of green-labeled purchases at the end of 3-month intervention. Post-hoc analyses examined linear trends. At baseline, the proportion of green-labeled purchases (50%) did not differ between arms. At the end of the 3-month intervention, the percentage increase in green-labeled purchases was larger in the feedback-incentive arm compared to control (2.2% vs. 0.1%, P=0.03), but the two intervention arms were not different. The rate of increase in green-labeled purchases was higher in both feedback-only (P=0.04) and feedback-incentive arms (P=0.004) compared to control. At the end of a 3-month wash-out, there were no differences between control and intervention arms. Social norms plus small financial incentives increased employees' healthy food choices over the short-term. Future research will be needed to assess the impact of this relatively low-cost intervention on employees' food choices and weight over the long-term. Clinical Trials.gov: NCT01604499. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of Non-Normal Outlier-Prone Error Distribution on Kalman Filter Track

DTIC Science & Technology

1991-09-01

other possibilities exist. For example the GST (Generic Statistical Tracker) uses four motion models [Ref. 41. The GST keeps track of both the target...1.011 + + + 3.113 1.291 4 Although this procedure is not easily statistically interpretable, it was used for the sake of comparison with the other... TRANSITOR TARGET’ WRITE(6,*)’ 3 SECOND ORDER GAUSS MARKOV TARGET’ WRITE(6,*)’ 4 RANDOM TOUR TARGET’ READ(6,*) CHOICE IF((CHOICE.LT.1).OR.(CHOICE.GT.4

Rejection of randomly coinciding 2ν2β events in ZnMoO4 scintillating bolometers

NASA Astrophysics Data System (ADS)

Chernyak, D. M.; Danevich, F. A.; Giuliani, A.; Mancuso, M.; Nones, C.; Olivieri, E.; Tenconi, M.; Tretyak, V. I.

2014-01-01

Random coincidence of 2ν2β decay events could be one of the main sources of background for 0ν2β decay in cryogenic bolometers due to their poor time resolution. Pulse-shape discrimination by using front edge analysis, the mean-time and χ2 methods was applied to discriminate randomly coinciding 2ν2β events in ZnMoO4 cryogenic scintillating bolometers. The background can be effectively rejected on the level of 99% by the mean-time analysis of heat signals with the rise time about 14 ms and the signal-to-noise ratio 900, and on the level of 98% for the light signals with 3 ms rise time and signal-to-noise ratio of 30 (under a requirement to detect 95% of single events). Importance of the signal-to-noise ratio, correct finding of the signal start and choice of an appropriate sampling frequency are discussed.

Random technique to encode complex valued holograms with on axis reconstruction onto phase-only displays.

PubMed

Luis Martínez Fuentes, Jose; Moreno, Ignacio

2018-03-05

A new technique for encoding the amplitude and phase of diffracted fields in digital holography is proposed. It is based on a random spatial multiplexing of two phase-only diffractive patterns. The first one is the phase information of the intended pattern, while the second one is a diverging optical element whose purpose is the control of the amplitude. A random number determines the choice between these two diffractive patterns at each pixel, and the amplitude information of the desired field governs its discrimination threshold. This proposed technique is computationally fast and does not require iterative methods, and the complex field reconstruction appears on axis. We experimentally demonstrate this new encoding technique with holograms implemented onto a flicker-free phase-only spatial light modulator (SLM), which allows the axial generation of such holograms. The experimental verification includes the phase measurement of generated patterns with a phase-shifting polarization interferometer implemented in the same experimental setup.

The design and implementation of a randomized controlled trial of a risk reduction and human immunodeficiency virus prevention videogame intervention in minority adolescents: PlayForward: Elm City Stories

PubMed Central

Fiellin, Lynn E; Kyriakides, Tassos C; Hieftje, Kimberly D; Pendergrass, Tyra M; Duncan, Lindsay R; Dziura, James D; Sawyer, Benjamin G; Fiellin, David A

2016-01-01

Background To address the need for risk behavior reduction and HIV prevention interventions that capture adolescents “where they live,” we created a tablet-based videogame to teach skills and knowledge and influence psychosocial antecedents for decreasing risk and preventing HIV infection in minority youth in schools, after-school programs, and summer camps. Methods We developed PlayForward: Elm City Stories over a 2-year period, working with researchers, commercial game designers, and staff and teens from community programs. The videogame PlayForward provides an interactive world where players, using an avatar, “travel” through time, facing challenges such as peer pressure to drink alcohol or engage in risky sexual behaviors. Players experience how their choices affect their future and then are able to go back in time and change their choices, creating different outcomes. A randomized controlled trial was designed to evaluate the efficacy of PlayForward. Participants were randomly assigned to play PlayForward or a set of attention/time control games on a tablet at their community-based program. Assessment data were collected during face-to-face study visits and entered into a web-based platform and unique real-time “in-game” PlayForward data were collected as players engaged in the game. The innovative methods of this randomized controlled trial are described. We highlight the logistical issues of conducting a large-scale trial using mobile technology such as the iPad®, and collecting, transferring, and storing large amounts of in-game data. We outline the methods used to analyze the in-game data alone and in conjunction with standardized assessment data to establish correlations between behaviors during gameplay and those reported in real life. We also describe the use of the in-game data as a measure of fidelity to the intervention. Results In total, 333 boys and girls, aged 11–14 years, were randomized over a 14-month period: 166 were assigned to play PlayForward and 167 to play the control games. To date (as of 1 March 2016), 18 have withdrawn from the study; the following have completed the protocol-defined assessments: 6 weeks: 271 (83%); 3 months: 269 (84%); 6 months: 254 (79%); 12 months: 259 (82%); and 24 months: is ongoing with 152 having completed out of the 199 participants (76%) who were eligible to date (assessment windows were still open). Conclusion Videogames can be developed to address complex behaviors and can be subject to empiric testing using community-based randomized controlled trials. Although mobile technologies pose challenges in their use as interventions and in the collection and storage of data they produce, they provide unique opportunities as new sources of potentially valid data and novel methods to measure the fidelity of digitally delivered behavioral interventions. PMID:27013483

Extrapolating Survival from Randomized Trials Using External Data: A Review of Methods

PubMed Central

Jackson, Christopher; Stevens, John; Ren, Shijie; Latimer, Nick; Bojke, Laura; Manca, Andrea; Sharples, Linda

2016-01-01

This article describes methods used to estimate parameters governing long-term survival, or times to other events, for health economic models. Specifically, the focus is on methods that combine shorter-term individual-level survival data from randomized trials with longer-term external data, thus using the longer-term data to aid extrapolation of the short-term data. This requires assumptions about how trends in survival for each treatment arm will continue after the follow-up period of the trial. Furthermore, using external data requires assumptions about how survival differs between the populations represented by the trial and external data. Study reports from a national health technology assessment program in the United Kingdom were searched, and the findings were combined with “pearl-growing” searches of the academic literature. We categorized the methods that have been used according to the assumptions they made about how the hazards of death vary between the external and internal data and through time, and we discuss the appropriateness of the assumptions in different circumstances. Modeling choices, parameter estimation, and characterization of uncertainty are discussed, and some suggestions for future research priorities in this area are given. PMID:27005519

Strategies for communicating contraceptive effectiveness.

PubMed

Lopez, Laureen M; Steiner, Markus; Grimes, David A; Hilgenberg, Deborah; Schulz, Kenneth F

2013-04-30

Knowledge of contraceptive effectiveness is crucial to making an informed choice. The consumer has to comprehend the pros and cons of the contraceptive methods being considered. Choice may be influenced by understanding the likelihood of pregnancy with each method and factors that influence effectiveness. To review all randomized controlled trials comparing strategies for communicating to consumers the effectiveness of contraceptives in preventing pregnancy. Through February 2013, we searched the computerized databases of MEDLINE, POPLINE, CENTRAL, PsycINFO and CINAHL, ClinicalTrials.gov, and ICTRP. Previous searches also included EMBASE. We also examined references lists of relevant articles. For the initial review, we wrote to known investigators for information about other published or unpublished trials. We included randomized controlled trials that compared methods for communicating contraceptive effectiveness to consumers. The comparison could be usual practice or an alternative to the experimental intervention.Outcome measures were knowledge of contraceptive effectiveness, attitude about contraception or toward any particular contraceptive, and choice or use of contraceptive method. For the initial review, two authors independently extracted the data. One author entered the data into RevMan, and a second author verified accuracy. For the update, an author and a research associate extracted, entered, and checked the data.For dichotomous variables, we calculated the Mantel-Haenszel odds ratio with 95% confidence intervals (CI). For continuous variables, we computed the mean difference (MD) with 95% CI. Seven trials met the inclusion criteria and had a total of 4526 women. Five were multi-site studies. Four trials were conducted in the USA, while Nigeria and Zambia were represented by one study each, and one trial was done in both Jamaica and India.Two trials provided multiple sessions for participants. In one study that examined contraceptive choice, women in the expanded program were more likely to choose sterilization (OR 4.26; 95% CI 2.46 to 7.37) or use a modern contraceptive method (OR 2.35; 95% CI 1.82 to 3.03), i.e., sterilization, pills, injectable, intrauterine device or barrier method. For the other study, the groups received educational interventions with differing format and intensity. Both groups reportedly had increases in contraceptive use, but they did not differ significantly by six months in consistent use of an effective contraceptive, i.e., sterilization, IUD, injectable, implant, and consistent use of oral contraceptives, diaphragm, or male condoms.Five trials provided one session and focused on testing educational material or media. In one study, knowledge gain favored a slide-and-sound presentation versus a physician's oral presentation (MD -19.00; 95% CI -27.52 to -10.48). In another trial, a table with contraceptive effectiveness categories led to more correct answers than a table based on pregnancy numbers [ORs were 2.42 (95% CI 1.43 to 4.12) and 2.19 (95% CI 1.21 to 3.97)] or a table with effectiveness categories and pregnancy numbers [ORs were 2.58 (95% CI 1.5 to 4.42) and 2.03 (95% CI 1.13 to 3.64)]. Still another trial provided structured counseling with a flipchart on contraceptive methods. The intervention and usual-care groups did not differ significantly in choice of contraceptive method (by effectiveness category) or in continuation of the chosen method at three months. Lastly, a study with couples used videos to communicate contraceptive information (control, motivational, contraceptive methods, and both motivational and methods videos). The analyses showed no significant difference between the groups in the types of contraceptives chosen. These trials varied greatly in the types of participants and interventions to communicate contraceptive effectiveness. Therefore, we cannot say overall what would help consumers choose an appropriate contraceptive method. For presenting pregnancy risk data, one trial showed that effectiveness categories were better than pregnancy numbers. In another trial, audiovisual aids worked better than the usual oral presentation. Strategies should be tested in clinical settings and measured for their effect on contraceptive choice. More detailed reporting of intervention content would help in interpreting results. Reports could also include whether the instruments used to assess knowledge or attitudes were tested for validity or reliability. Follow-up should be incorporated to assess retention of knowledge over time. The overall quality of evidence was considered to be low for this review, given that five of the seven studies provided low or very low quality evidence.

Anthropometric methods for obesity screening in schoolchildren: the Ouro Preto Study.

PubMed

Cándido, A P C; Alosta, J P S; Oliveira, C T; Freitas, R N; Freitas, S N; Machado-Coelho, G L L

2012-01-01

Childhood obesity is increasing dramatically in last decades. To evaluate the usefulness of body mass index (BMI), skinfold thickness (ST), waist circumference (WC), and foot-to-foot bioelectrical impedance (BIA-FF) for screening for obesity in mixed-race population, using the tetrapolar bioelectrical impedance (BIA-T) technique as reference method. A cross-sectional-based population study was performed in the city of Ouro Preto, Brazil, in 2006. Schoolchildren aged 6-15 years (n = 788) was randomly selected according to age and sex stratified by the proportion of students in each schools of the city. Nonparametric receiver operating characteristic (ROC) analysis was used to define the sensitivity and specificity for each method studied using the tetrapolar method as reference. The BMI and the BIA-FF were the most suitable for adiposity screening in pre-pubertal and pubertal stages because they present a better balance between sensitivity and specificity, and smaller misclassification. For post-pubertal boys, the BF-ST-D was the best body fat assessment method. The results suggest that BIA-FF and BMI are choice methods for obesity screening in mixed population and that the method choice for body fat screening must be done according to sexual maturity of boys and girls. The present study demonstrates the need to perform studies in wider mixed-race population to determine anthropometric parameters and to examine the predictive ability of methods and cut-offs here elucidated in the development of obesity.

MHC class II-assortative mate choice in European badgers (Meles meles).

PubMed

Sin, Yung Wa; Annavi, Geetha; Newman, Chris; Buesching, Christina; Burke, Terry; Macdonald, David W; Dugdale, Hannah L

2015-06-01

The major histocompatibility complex (MHC) plays a crucial role in the immune system, and in some species, it is a target by which individuals choose mates to optimize the fitness of their offspring, potentially mediated by olfactory cues. Under the genetic compatibility hypothesis, individuals are predicted to choose mates with compatible MHC alleles, to increase the fitness of their offspring. Studies of MHC-based mate choice in wild mammals are under-represented currently, and few investigate more than one class of MHC genes. We investigated mate choice based on the compatibility of MHC class I and II genes in a wild population of European badgers (Meles meles). We also investigated mate choice based on microsatellite-derived pairwise relatedness, to attempt to distinguish MHC-specific effects from genomewide effects. We found MHC-assortative mating, based on MHC class II, but not class I genes. Parent pairs had smaller MHC class II DRB amino acid distances and smaller functional distances than expected from random pairings. When we separated the analyses into within-group and neighbouring-group parent pairs, only neighbouring-group pairs showed MHC-assortative mating, due to similarity at MHC class II loci. Our randomizations showed no evidence of genomewide-based inbreeding, based on 35 microsatellite loci; MHC class II similarity was therefore the apparent target of mate choice. We propose that MHC-assortative mate choice may be a local adaptation to endemic pathogens, and this assortative mate choice may have contributed to the low MHC genetic diversity in this population. © 2015 The Authors. Molecular Ecology published by John Wiley & Sons Ltd.

Effect of price and information on the food choices of women university students in Saudi Arabia: An experimental study.

PubMed

Halimic, Aida; Gage, Heather; Raats, Monique; Williams, Peter

2018-04-01

To explore the impact of price manipulation and healthy eating information on intended food choices. Health information was provided to a random half of subjects (vs. information on Saudi agriculture). Each subject chose from the same lunch menu, containing two healthy and two unhealthy entrees, deserts and beverages, on five occasions. Reference case prices were 5, 3 and 2 Saudi Arabian Reals (SARs). Prices of healthy and unhealthy items were manipulated up (taxed) and down (subsidized) by 1 SAR in four menu variations (random order); subjects were given a budget enabling full choice within any menu. The number of healthy food choices were compared with different price combinations, and between information groups. Linear regression modelling explored the effect of relative prices of healthy/unhealthy options and information on number of healthy choices controlling for dietary behaviours and hunger levels. University campus, Saudi Arabia, 2013. 99 women students. In the reference case, 49.5% of choices were for healthy items. When the price of healthy items was reduced, 58.5% of selections were healthy; 57.2% when the price of unhealthy items rose. In regression modelling, reducing the price of healthy items and increasing the price of unhealthy items increased the number of healthy choices by 5% and 6% respectively. Students reporting a less healthy usual diet selected significantly fewer healthy items. Providing healthy eating information was not a significant influence. Price manipulation offers potential for altering behaviours to combat rising youth obesity in Saudi Arabia. Copyright © 2018 Elsevier Ltd. All rights reserved.

Perception of young adults with sickle cell disease or sickle cell trait about participation in the CHOICES randomized controlled trial.

PubMed

Hershberger, Patricia E; Gallo, Agatha M; Molokie, Robert; Thompson, Alexis A; Suarez, Marie L; Yao, Yingwei; Wilkie, Diana J

2016-06-01

To gain an in-depth understanding of the perceptions of young adults with sickle cell disease and sickle cell trait about parenthood and participating in the CHOICES randomized controlled trial that used computer-based, educational programmes. In the USA, there is insufficient education to assure that all young adults with sickle cell disease or sickle cell trait understand genetic inheritance risks and reproductive options to make informed reproductive decisions. To address this educational need, we developed a computer-based, multimedia program (CHOICES) and reformatted usual care into a computer-based (e-Book) program. We then conducted a two-year randomized controlled trial that included a qualitative component that would deepen understanding of young adults' perceptions of parenthood and use of computer-based, educational programmes. A qualitative descriptive approach completed after a randomized controlled trial. Sixty-eight men and women of childbearing age participated in semi-structured interviews at the completion of the randomized controlled trial from 2012-2013. Thematic content analysis guided the qualitative description. Three main themes were identified: (1) increasing knowledge and new ways of thinking and behaving; (2) rethinking parenting plans; and (3) appraising the program design and delivery. Most participants reported increased knowledge and rethinking of their parenting plans and were supportive of computer-based learning. Some participants expressed difficulty in determining individual transmission risks. Participants perceived the computer programs as beneficial to their learning. Future development of an Internet-based educational programme is warranted, with emphasis on providing tailored education or memory boosters about individual transmission risks. © 2015 John Wiley & Sons Ltd.

Comparison of cast materials for the treatment of congenital idiopathic clubfoot using the Ponseti method: a prospective randomized controlled trial

PubMed Central

Hui, Catherine; Joughin, Elaine; Nettel-Aguirre, Alberto; Goldstein, Simon; Harder, James; Kiefer, Gerhard; Parsons, David; Brauer, Carmen; Howard, Jason

2014-01-01

Background The Ponseti method of congenital idiopathic clubfoot correction has traditionally specified plaster of Paris (POP) as the cast material of choice; however, there are negative aspects to using POP. We sought to determine the influence of cast material (POP v. semirigid fibreglass [SRF]) on clubfoot correction using the Ponseti method. Methods Patients were randomized to POP or SRF before undergoing the Ponseti method. The primary outcome measure was the number of casts required for clubfoot correction. Secondary outcome measures included the number of casts by severity, ease of cast removal, need for Achilles tenotomy, brace compliance, deformity relapse, need for repeat casting and need for ancillary surgical procedures. Results We enrolled 30 patients: 12 randomized to POP and 18 to SRF. There was no difference in the number of casts required for clubfoot correction between the groups (p = 0.13). According to parents, removal of POP was more difficult (p < 0.001), more time consuming (p < 0.001) and required more than 1 method (p < 0.001). At a final follow-up of 30.8 months, the mean times to deformity relapse requiring repeat casting, surgery or both were 18.7 and 16.4 months for the SRF and POP groups, respectively. Conclusion There was no significant difference in the number of casts required for correction of clubfoot between the 2 materials, but SRF resulted in a more favourable parental experience, which cannot be ignored as it may have a positive impact on psychological well-being despite the increased cost associated. PMID:25078929

Treatment of Subacromial Impingement Syndrome: Platelet-Rich Plasma or Exercise Therapy? A Randomized Controlled Trial

PubMed Central

Nejati, Parisa; Ghahremaninia, Armita; Naderi, Farrokh; Gharibzadeh, Safoora; Mazaherinezhad, Ali

2017-01-01

Background: Subacromial impingement syndrome (SAIS) is the most common disorder of the shoulder. The evidence for the effectiveness of treatment options is inconclusive and limited. Therefore, there is a need for more evidence in this regard, particularly for long-term outcomes. Hypothesis: Platelet-rich plasma (PRP) would be an effective method in treating subacromial impingement. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: This was a single-blinded randomized clinical trial with 1-, 3-, and 6-month follow-up. Sixty-two patients were randomly placed into 2 groups, receiving either PRP or exercise therapy. The outcome parameters were pain, shoulder range of motion (ROM), muscle force, functionality, and magnetic resonance imaging findings. Results: Both treatment options significantly reduced pain and increased shoulder ROM compared with baseline measurements. Both treatments also significantly improved functionality. However, the treatment choices were not significantly effective in improving muscle force. Trend analysis revealed that in the first and third months, exercise therapy was superior to PRP in pain, shoulder flexion and abduction, and functionality. However, in the sixth month, only shoulder abduction and total Western Ontario Rotator Cuff score were significantly different between the 2 groups. Conclusion: Both PRP injection and exercise therapy were effective in reducing pain and disability in patients with SAIS, with exercise therapy proving more effective. PMID:28567426

Linking Implementation Process to Intervention Outcomes in a Middle School Obesity Prevention Curriculum, "Choice, Control and Change"

ERIC Educational Resources Information Center

Gray, Heewon Lee; Contento, Isobel R.; Koch, Pamela A.

2015-01-01

This study investigates the link between process evaluation components and the outcomes of a school-based nutrition curriculum intervention, "Choice, Control and Change". Ten New York City public middle schools were recruited and randomly assigned into intervention or control condition. The curriculum was to improve sixth to seventh…

Designing a Weight Gain Prevention Trial for Young Adults: The CHOICES Study

ERIC Educational Resources Information Center

Lytle, Leslie A.; Moe, Stacey G.; Nanney, M. Susie; Laska, Melissa N.; Linde, Jennifer A.; Petrich, Christine A.; Sevcik, Sarah M.

2014-01-01

Background: Young adults are at risk for weight gain. Little is known about how to design weight control programs to meet the needs of young adults and few theory-based interventions have been evaluated in a randomized control trial. The Choosing Healthy Options in College Environments and Settings (CHOICES) study was funded to create a…

The Effects of Coloring on Anxiety, Mood, and Perseverance

ERIC Educational Resources Information Center

Eaton, Judy; Tieber, Christine

2017-01-01

This study tested whether the structure of a coloring task has an effect on anxiety, mood, and perseverance. Eighty-five undergraduate students were randomly assigned to 1 of 2 coloring conditions: free choice, where they could color an image using any colors they wanted, and forced choice, where they were instructed to copy the colors of a…

The Use of Choice-Based Distraction to Decrease the Distress of Children at the Dentist

ERIC Educational Resources Information Center

Filcheck, Holly A.; Allen, Keith D.; Ogren, Hilary; Darby, James Brandt; Holstein, Brian; Hupp, Steve

2005-01-01

This research was conducted to examine whether choice-based distraction provides an effective means of reducing the distress of children undergoing routine dental treatment. Sixty children between the ages of 5-12 who required restorative dental treatment were assigned randomly to either a Control group or a Distraction group in which the…

Free-Response and Multiple-Choice Items: Measures of the Same Ability?

ERIC Educational Resources Information Center

Bennett, Randy Elliot; And Others

This study examined the relationship of multiple-choice and free-response items contained on the College Board's Advanced Placement Computer Science (APCS) examination. Subjects were two samples of 1,000 randomly drawn from the population of 7,372 high school students taking the 1988 examination of the APCS "AB" form. Most were high…

Lay public's understanding of equipoise and randomisation in randomised controlled trials.

PubMed

Robinson, E J; Kerr, C E P; Stevens, A J; Lilford, R J; Braunholtz, D A; Edwards, S J; Beck, S R; Rowley, M G

2005-03-01

To research the lay public's understanding of equipoise and randomisation in randomised controlled trials (RCTs) and to look at why information on this may not be not taken in or remembered, as well as the effects of providing information designed to overcome barriers. Investigations were informed by an update of systematic review on patients' understanding of consent information in clinical trials, and by relevant theory and evidence from experimental psychology. Nine investigations were conducted with nine participants. Access (return to education), leisure and vocational courses at Further Education Colleges in the Midlands, UK. Healthy adults with a wide range of educational backgrounds and ages. Participants read hypothetical scenarios and wrote brief answers to subsequent questions. Sub-samples of participants were interviewed individually to elaborate on their written answers. Participants' background assumptions concerning equipoise and randomisation were examined and ways of helping participants recognise the scientific benefits of randomisation were explored. Judgments on allocation methods; treatment preferences; the acceptability of random allocation; whether or not individual doctors could be completely unsure about the best treatment; whether or not doctors should reveal treatment preferences under conditions of collective equipoise; and how sure experts would be about the best treatment following random allocation vs doctor/patient choice. Assessments of understanding hypothetical trial information. Recent literature continues to report trial participants' failure to understand or remember information about randomisation and equipoise, despite the provision of clear and readable trial information leaflets. In current best practice, written trial information describes what will happen without offering accessible explanations. As a consequence, patients may create their own incorrect interpretations and consent or refusal may be inadequately informed. In six investigations, most participants identified which methods of allocation were random, but judged the random allocation methods to be unacceptable in a trial context; the mere description of a treatment as new was insufficient to engender a preference for it over a standard treatment; around half of the participants denied that a doctor could be completely unsure about the best treatment. A majority of participants judged it unacceptable for a doctor to suggest letting chance decide when uncertain of the best treatment, and, in the absence of a justification for random allocation, participants did not recognise scientific benefits of random allocation over normal treatment allocation methods. The pattern of results across three intervention studies suggests that merely supplementing written trial information with an explanation is unlikely to be helpful. However, when people manage to focus on the trial's aim of increasing knowledge (as opposed to making treatment decisions about individuals), and process an explanation actively, they may be helped to understand the scientific reasons for random allocation. This research was not carried out in real healthcare settings. However, participants who could correctly identify random allocation methods, yet judged random allocation unacceptable, doubted the possibility of individual equipoise and saw no scientific benefits of random allocation over doctor/patient choice, are unlikely to draw upon contrasting views if invited to enter a real clinical trial. This suggests that many potential trial participants may have difficulty understanding and remembering trial information that conforms to current best practice in its descriptions of randomisation and equipoise. Given the extent of the disparity between the assumptions underlying trial design and the assumptions held by the lay public, the solution is unlikely to be simple. Nevertheless, the results suggest that including an accessible explanation of the scientific benefits of randomisation may be beneficial provided potential participants are also enabled to reflect on the trial's aim of advancing knowledge, and to think actively about the information presented. Further areas for consideration include: the identification of effective combinations of written and oral information; helping participants to reflect on the aim of advancing knowledge; and an evidence-based approach to leaflet construction.

The effect of learning climate on snack consumption and ego depletion among undergraduate students.

PubMed

Magaraggia, Christian; Dimmock, James A; Jackson, Ben

2013-10-01

We explored the effect of controlled and autonomous learning choices on the consumption of a high-energy snack food, and also examined whether snack consumption during a controlled choice learning activity could 'up-regulate' subsequent performance on a self-regulation task. Participants were randomly assigned to a controlled choice learning condition in which food was provided, a controlled choice learning condition in which food was not provided, or an autonomous choice learning condition in which food was provided. Results indicated that the autonomous choice group consumed significantly less snack food than the controlled-choice-and-food group. Participants in the autonomous choice condition also performed better on the subsequent self-regulation task than the controlled-choice-and-food group, even after controlling for the amount of food consumed. Furthermore, within the controlled-choice-and-food condition, there was no association between food consumption and subsequent self-regulation task performance. Discussion focuses on the potential impact of a controlled learning climate on snack food consumption and on the degradation of self-regulation capacities. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Brownian dynamics of confined rigid bodies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delong, Steven; Balboa Usabiaga, Florencio; Donev, Aleksandar, E-mail: donev@courant.nyu.edu

2015-10-14

We introduce numerical methods for simulating the diffusive motion of rigid bodies of arbitrary shape immersed in a viscous fluid. We parameterize the orientation of the bodies using normalized quaternions, which are numerically robust, space efficient, and easy to accumulate. We construct a system of overdamped Langevin equations in the quaternion representation that accounts for hydrodynamic effects, preserves the unit-norm constraint on the quaternion, and is time reversible with respect to the Gibbs-Boltzmann distribution at equilibrium. We introduce two schemes for temporal integration of the overdamped Langevin equations of motion, one based on the Fixman midpoint method and the othermore » based on a random finite difference approach, both of which ensure that the correct stochastic drift term is captured in a computationally efficient way. We study several examples of rigid colloidal particles diffusing near a no-slip boundary and demonstrate the importance of the choice of tracking point on the measured translational mean square displacement (MSD). We examine the average short-time as well as the long-time quasi-two-dimensional diffusion coefficient of a rigid particle sedimented near a bottom wall due to gravity. For several particle shapes, we find a choice of tracking point that makes the MSD essentially linear with time, allowing us to estimate the long-time diffusion coefficient efficiently using a Monte Carlo method. However, in general, such a special choice of tracking point does not exist, and numerical techniques for simulating long trajectories, such as the ones we introduce here, are necessary to study diffusion on long time scales.« less

Mendelian randomization with fine-mapped genetic data: Choosing from large numbers of correlated instrumental variables.

PubMed

Burgess, Stephen; Zuber, Verena; Valdes-Marquez, Elsa; Sun, Benjamin B; Hopewell, Jemma C

2017-12-01

Mendelian randomization uses genetic variants to make causal inferences about the effect of a risk factor on an outcome. With fine-mapped genetic data, there may be hundreds of genetic variants in a single gene region any of which could be used to assess this causal relationship. However, using too many genetic variants in the analysis can lead to spurious estimates and inflated Type 1 error rates. But if only a few genetic variants are used, then the majority of the data is ignored and estimates are highly sensitive to the particular choice of variants. We propose an approach based on summarized data only (genetic association and correlation estimates) that uses principal components analysis to form instruments. This approach has desirable theoretical properties: it takes the totality of data into account and does not suffer from numerical instabilities. It also has good properties in simulation studies: it is not particularly sensitive to varying the genetic variants included in the analysis or the genetic correlation matrix, and it does not have greatly inflated Type 1 error rates. Overall, the method gives estimates that are less precise than those from variable selection approaches (such as using a conditional analysis or pruning approach to select variants), but are more robust to seemingly arbitrary choices in the variable selection step. Methods are illustrated by an example using genetic associations with testosterone for 320 genetic variants to assess the effect of sex hormone related pathways on coronary artery disease risk, in which variable selection approaches give inconsistent inferences. © 2017 The Authors Genetic Epidemiology Published by Wiley Periodicals, Inc.

Effects of Choice Architecture and Chef-Enhanced Meals on the Selection and Consumption of Healthier School Foods

PubMed Central

Cohen, Juliana F.W.; Richardson, Scott A.; Cluggish, Sarah A.; Parker, Ellen; Catalano, Paul J.; Rimm, Eric B.

2015-01-01

IMPORTANCE Little is known about the long-term effect of a chef-enhanced menu on healthier food selection and consumption in school lunchrooms. In addition, it remains unclear if extended exposure to other strategies to promote healthier foods (eg, choice architecture) also improves food selection or consumption. OBJECTIVE To evaluate the short- and long-term effects of chef-enhanced meals and extended exposure to choice architecture on healthier school food selection and consumption. DESIGN, SETTING, AND PARTICIPANTS A school-based randomized clinical trial was conducted during the 2011–2012 school year among 14 elementary and middle schools in 2 urban, low-income school districts (intent-to-treat analysis). Included in the study were 2638 students in grades 3 through 8 attending participating schools (38.4%of eligible participants). INTERVENTIONS Schools were first randomized to receive a professional chef to improve school meal palatability (chef schools) or to a delayed intervention (control group). To assess the effect of choice architecture (smart café), all schools after 3 months were then randomized to the smart café intervention or to the control group. MAIN OUTCOMES AND MEASURES School food selection was recorded, and consumption was measured using plate waste methods. RESULTS After 3 months, vegetable selection increased in chef vs control schools (odds ratio [OR], 1.75; 95% CI, 1.36–2.24), but there was no effect on the selection of other components or on meal consumption. After long-term or extended exposure to the chef or smart café intervention, fruit selection increased in the chef (OR, 3.08; 95% CI, 2.23–4.25), smart café (OR, 1.45; 95% CI, 1.13–1.87), and chef plus smart café (OR, 3.10; 95% CI, 2.26–4.25) schools compared with the control schools, and consumption increased in the chef schools (OR, 0.17; 95% CI, 0.03–0.30 cups/d). Vegetable selection increased in the chef (OR, 2.54; 95% CI, 1.83–3.54), smart café (OR, 1.91; 95% CI, 1.46–2.50), and chef plus smart café schools (OR, 7.38, 95% CI, 5.26–10.35) compared with the control schools, and consumption also increased in the chef (OR, 0.16; 95% CI, 0.09–0.22 cups/d) and chef plus smart café (OR, 0.13; 95% CI, 0.05–0.19 cups/d) schools; however, the smart café intervention alone had no effect on consumption. CONCLUSIONS AND RELEVANCE Schools should consider both collaborating with chefs and using choice architecture to increase fruit and vegetable selection. Efforts to improve the taste of school foods through chef-enhanced meals should remain a priority because this was the only method that also increased consumption. This was observed only after students were repeatedly exposed to the new foods for 7 months. Therefore, schools should not abandon healthier options if they are initially met with resistance. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT02309840 PMID:25798990

Latent class instrumental variables: a clinical and biostatistical perspective.

PubMed

Baker, Stuart G; Kramer, Barnett S; Lindeman, Karen S

2016-01-15

In some two-arm randomized trials, some participants receive the treatment assigned to the other arm as a result of technical problems, refusal of a treatment invitation, or a choice of treatment in an encouragement design. In some before-and-after studies, the availability of a new treatment changes from one time period to this next. Under assumptions that are often reasonable, the latent class instrumental variable (IV) method estimates the effect of treatment received in the aforementioned scenarios involving all-or-none compliance and all-or-none availability. Key aspects are four initial latent classes (sometimes called principal strata) based on treatment received if in each randomization group or time period, the exclusion restriction assumption (in which randomization group or time period is an instrumental variable), the monotonicity assumption (which drops an implausible latent class from the analysis), and the estimated effect of receiving treatment in one latent class (sometimes called efficacy, the local average treatment effect, or the complier average causal effect). Since its independent formulations in the biostatistics and econometrics literatures, the latent class IV method (which has no well-established name) has gained increasing popularity. We review the latent class IV method from a clinical and biostatistical perspective, focusing on underlying assumptions, methodological extensions, and applications in our fields of obstetrics and cancer research. Copyright © 2015 John Wiley & Sons, Ltd.

Behavioral Contexts, Food-Choice Coping Strategies, and Dietary Quality of a Multiethnic Sample of Employed Parents

PubMed Central

Blake, Christine E.; Wethington, Elaine; Farrell, Tracy J.; Bisogni, Carole A.; Devine, Carol M.

2012-01-01

Employed parents’ work and family conditions provide behavioral contexts for their food choices. Relationships between employed parents’ food-choice coping strategies, behavioral contexts, and dietary quality were evaluated. Data on work and family conditions, sociodemographic characteristics, eating behavior, and dietary intake from two 24-hour dietary recalls were collected in a random sample cross-sectional pilot telephone survey in the fall of 2006. Black, white, and Latino employed mothers (n=25) and fathers (n=25) were recruited from a low/moderate income urban area in upstate New York. Hierarchical cluster analysis (Ward’s method) identified three clusters of parents differing in use of food-choice coping strategies (ie, Individualized Eating, Missing Meals, and Home Cooking). Cluster sociodemographic, work, and family characteristics were compared using χ2 and Fisher’s exact tests. Cluster differences in dietary quality (Healthy Eating Index 2005) were analyzed using analysis of variance. Clusters differed significantly (P≤0.05) on food-choice coping strategies, dietary quality, and behavioral contexts (ie, work schedule, marital status, partner’s employment, and number of children). Individualized Eating and Missing Meals clusters were characterized by nonstandard work hours, having a working partner, single parenthood and with family meals away from home, grabbing quick food instead of a meal, using convenience entrées at home, and missing meals or individualized eating. The Home Cooking cluster included considerably more married fathers with nonemployed spouses and more home-cooked family meals. Food-choice coping strategies affecting dietary quality reflect parents’ work and family conditions. Nutritional guidance and family policy needs to consider these important behavioral contexts for family nutrition and health. PMID:21338739

Behavioral contexts, food-choice coping strategies, and dietary quality of a multiethnic sample of employed parents.

PubMed

Blake, Christine E; Wethington, Elaine; Farrell, Tracy J; Bisogni, Carole A; Devine, Carol M

2011-03-01

Employed parents' work and family conditions provide behavioral contexts for their food choices. Relationships between employed parents' food-choice coping strategies, behavioral contexts, and dietary quality were evaluated. Data on work and family conditions, sociodemographic characteristics, eating behavior, and dietary intake from two 24-hour dietary recalls were collected in a random sample cross-sectional pilot telephone survey in the fall of 2006. Black, white, and Latino employed mothers (n=25) and fathers (n=25) were recruited from a low/moderate income urban area in upstate New York. Hierarchical cluster analysis (Ward's method) identified three clusters of parents differing in use of food-choice coping strategies (ie, Individualized Eating, Missing Meals, and Home Cooking). Cluster sociodemographic, work, and family characteristics were compared using χ(2) and Fisher's exact tests. Cluster differences in dietary quality (Healthy Eating Index 2005) were analyzed using analysis of variance. Clusters differed significantly (P≤0.05) on food-choice coping strategies, dietary quality, and behavioral contexts (ie, work schedule, marital status, partner's employment, and number of children). Individualized Eating and Missing Meals clusters were characterized by nonstandard work hours, having a working partner, single parenthood and with family meals away from home, grabbing quick food instead of a meal, using convenience entrées at home, and missing meals or individualized eating. The Home Cooking cluster included considerably more married fathers with nonemployed spouses and more home-cooked family meals. Food-choice coping strategies affecting dietary quality reflect parents' work and family conditions. Nutritional guidance and family policy needs to consider these important behavioral contexts for family nutrition and health. Copyright © 2011 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

The Choice of Surgical Specialization by Medical Students and Their Syncopal History

PubMed Central

Rudnicki, Jerzy; Zyśko, Dorota; Kozłowski, Dariusz; Kuliczkowski, Wiktor; Koźluk, Edward; Lelonek, Małgorzata; Piątkowska, Agnieszka; Gajek, Jacek; Negrusz-Kawecka, Marta; Agrawal, Anil Kumar

2013-01-01

Background The aim of the study was to assess whether medical students’ fainting outside the university or while witnessing surgical procedures and/or autopsies influenced their choice of a specialization. Materials and Methods The study group consisted of 605 medical students (from fourth to sixth year of study) from five medical universities in Poland (325 women, 212 men and 8 responders of an unspecified gender). The median age of subjects studied was 23 years, and the interquartile range was 23–24 years. The students at each university were chosen randomly by the author who worked there and had contact with them. An anonymous questionnaire was developed to gather information regarding demographics, the specialization which each student wanted to choose, the syncope occurrence in the medical history, the syncope and presyncope occurrence during surgery and autopsy as well as the syncopal events’ characteristics. Results The group of 15% of women and 30% of men declared to have pursued the surgical specialization (P<0.001), 29% of women and 56% of men declared the intention to pursue an invasive specialization (P<0.001). As many as 36.0% of women studied and 13.1% of men studied reported syncopal spells outside university (P<0.001). Only 41 students (6.8%) reported that syncope or presyncope in any studied circumstances had an impact on their specialization choice. The multivariate analysis showed that the choice of surgical specialization is related to the male gender and the absence of syncopal spells outside the university. Conclusions Syncopal and presyncopal spells may affect the professional choices of the medical students. The male gender and a lack of syncope occurrence outside operating room are related to the choice of surgical specialization. PMID:23383122

Time-frequency signal analysis and synthesis - The choice of a method and its application

NASA Astrophysics Data System (ADS)

Boashash, Boualem

In this paper, the problem of choosing a method for time-frequency signal analysis is discussed. It is shown that a natural approach leads to the introduction of the concepts of the analytic signal and instantaneous frequency. The Wigner-Ville Distribution (WVD) is a method of analysis based upon these concepts and it is shown that an accurate Time-Frequency representation of a signal can be obtained by using the WVD for the analysis of a class of signals referred to as 'asymptotic'. For this class of signals, the instantaneous frequency describes an important physical parameter characteristic of the process under investigation. The WVD procedure for signal analysis and synthesis is outlined and its properties are reviewed for deterministic and random signals.

Time-Frequency Signal Analysis And Synthesis The Choice Of A Method And Its Application

NASA Astrophysics Data System (ADS)

Boashash, Boualem

1988-02-01

In this paper, the problem of choosing a method for time-frequency signal analysis is discussed. It is shown that a natural approach leads to the introduction of the concepts of the analytic signal and in-stantaneous frequency. The Wigner-Ville Distribution (WVD) is a method of analysis based upon these concepts and it is shown that an accurate Time-Frequency representation of a signal can be obtained by using the WVD for the analysis of a class of signals referred to as "asymptotic". For this class of signals, the instantaneous frequency describes an important physical parameter characteristic of the process under investigation. The WVD procedure for signal analysis and synthesis is outlined and its properties are reviewed for deterministic and random signals.

Priming healthy eating. You can't prime all the people all of the time☆

PubMed Central

Forwood, Suzanna E.; Ahern, Amy L.; Hollands, Gareth J.; Ng, Yin-Lam; Marteau, Theresa M.

2015-01-01

Objective In the context of a food purchasing environment filled with advertising and promotions, and an increased desire from policy makers to guide individuals toward choosing healthier foods, this study tests whether priming methods that use healthy food adverts to increase preference for healthier food generalize to a representative population. MethodsIn two studies (Study 1 n = 143; Study 2 n = 764), participants were randomly allocated to a prime condition, where they viewed fruit and vegetable advertisements, or a control condition, with no advertisements. A subsequent forced choice task assessed preference between fruits and other sweet snacks. Additional measures included current hunger and thirst, dietary restraint, age, gender, education and self-reported weight and height. ResultsIn Study 1, hunger reduced preferences for fruits (OR (95% CI) = 0.38 (0.26–0.56), p < 0.0001), an effect countered by the prime (OR (95% CI) = 2.29 (1.33–3.96), p = 0.003). In Study 2, the effect of the prime did not generalize to a representative population. More educated participants, as used in Study 1, chose more fruit when hungry and primed (OR (95% CI) = 1.42 (1.13–1.79), p = 0.003), while less educated participants' fruit choice was unaffected by hunger or the prime. ConclusionThis study provides preliminary evidence that the effects of adverts on healthy eating choices depend on key individual traits (education level) and states (hunger), do not generalize to a broader population and have the potential to increase health inequalities arising from food choice. PMID:25636234

Does Introducing Imprecision around Probabilities for Benefit and Harm Influence the Way People Value Treatments?

PubMed

Bansback, Nick; Harrison, Mark; Marra, Carlo

2016-05-01

Imprecision in estimates of benefits and harms around treatment choices is rarely described to patients. Variation in sampling error between treatment alternatives (e.g., treatments have similar average risks, but one treatment has a larger confidence interval) can result in patients failing to choose the option that is best for them. The aim of this study is to use a discrete choice experiment to describe how 2 methods for conveying imprecision in risk influence people's treatment decisions. We randomized a representative sample of the Canadian general population to 1 of 3 surveys that sought choices between hypothetical treatments for rheumatoid arthritis based on different levels of 7 attributes: route and frequency of administration, chance of benefit, serious and minor side effects and life expectancy, and imprecision in benefit and side-effect estimates. The surveys differed in the way imprecision was described: 1) no imprecision, 2) quantitative description based on a range with a visual graphic, and 3) qualitative description simply describing the confidence in the evidence. The analyzed data were from 2663 respondents. Results suggested that more people understood imprecision when it was described qualitatively (88%) versus quantitatively (68%). Respondents who appeared to understand imprecision descriptions placed high value on increased precision regarding the actual benefits and harms of treatment, equivalent to the value placed on the information about the probability of serious side effects. Both qualitative and quantitative methods led to small but significant increases in decision uncertainty for choosing any treatment. Limitations included some issues in defining understanding of imprecision and the use of an internet survey of panel members. These findings provide insight into how conveying imprecision information influences patient treatment choices. © The Author(s) 2015.

Simple model for multiple-choice collective decision making

NASA Astrophysics Data System (ADS)

Lee, Ching Hua; Lucas, Andrew

2014-11-01

We describe a simple model of heterogeneous, interacting agents making decisions between n ≥2 discrete choices. For a special class of interactions, our model is the mean field description of random field Potts-like models and is effectively solved by finding the extrema of the average energy E per agent. In these cases, by studying the propagation of decision changes via avalanches, we argue that macroscopic dynamics is well captured by a gradient flow along E . We focus on the permutation symmetric case, where all n choices are (on average) the same, and spontaneous symmetry breaking (SSB) arises purely from cooperative social interactions. As examples, we show that bimodal heterogeneity naturally provides a mechanism for the spontaneous formation of hierarchies between decisions and that SSB is a preferred instability to discontinuous phase transitions between two symmetric points. Beyond the mean field limit, exponentially many stable equilibria emerge when we place this model on a graph of finite mean degree. We conclude with speculation on decision making with persistent collective oscillations. Throughout the paper, we emphasize analogies between methods of solution to our model and common intuition from diverse areas of physics, including statistical physics and electromagnetism.

Rational group decision making: A random field Ising model at T = 0

NASA Astrophysics Data System (ADS)

Galam, Serge

1997-02-01

A modified version of a finite random field Ising ferromagnetic model in an external magnetic field at zero temperature is presented to describe group decision making. Fields may have a non-zero average. A postulate of minimum inter-individual conflicts is assumed. Interactions then produce a group polarization along one very choice which is however randomly selected. A small external social pressure is shown to have a drastic effect on the polarization. Individual bias related to personal backgrounds, cultural values and past experiences are introduced via quenched local competing fields. They are shown to be instrumental in generating a larger spectrum of collective new choices beyond initial ones. In particular, compromise is found to results from the existence of individual competing bias. Conflict is shown to weaken group polarization. The model yields new psychosociological insights about consensus and compromise in groups.

Advances in nonmarket valuation econometrics: Spatial heterogeneity in hedonic pricing models and preference heterogeneity in stated preference models

NASA Astrophysics Data System (ADS)

Yoo, Jin Woo

In my 1st essay, the study explores Pennsylvania residents. willingness to pay for development of renewable energy technologies such as solar power, wind power, biomass electricity, and other renewable energy using a choice experiment method. Principle component analysis identified 3 independent attitude components that affect the variation of preference, a desire for renewable energy and environmental quality and concern over cost. The results show that urban residents have a higher desire for environmental quality and concern less about cost than rural residents and consequently have a higher willingness to pay to increase renewable energy production. The results of sub-sample analysis show that a representative respondent in rural (urban) Pennsylvania is willing to pay 3.8(5.9) and 4.1(5.7)/month for increasing the share of Pennsylvania electricity generated from wind power and other renewable energy by 1 percent point, respectively. Mean WTP for solar and biomass electricity was not significantly different from zero. In my second essay, heterogeneity of individual WTP for various renewable energy technologies is investigated using several different variants of the multinomial logit model: a simple MNL with interaction terms, a latent class choice model, a random parameter mixed logit choice model, and a random parameter-latent class choice model. The results of all models consistently show that respondents. preference for individual renewable technology is heterogeneous, but the degree of heterogeneity differs for different renewable technologies. In general, the random parameter logit model with interactions and a hybrid random parameter logit-latent class model fit better than other models and better capture respondents. heterogeneity of preference for renewable energy. The impact of the land under agricultural conservation easement (ACE) contract on the values of nearby residential properties is investigated using housing sales data in two Pennsylvania Counties. The spatial-lag (SLM), the spatial error (SEM) and the spatial error component (SEC) models were compared. A geographically weighted regression (GWR) model is estimated to study the spatial heterogeneity of the marginal implicit prices of ACE impact within each county. New hybrid spatial hedonic models, the GWR-SEC and a modified GWR-SEM, are estimated such that both spatial autocorrelation and heterogeneity are accounted. The results show that the coefficient of land under easement contract varies spatially within one county, but not within the other county studied. Also, ACE's are found to have both positive and negative impacts on the values of nearby residential properties. Among global spatial models, the SEM fit better than the SLM and the SEC. Statistical goodness of fit measures showed that the GWR-SEC model fit better than the GWR or the GWR-SEC model. Finally, the GWR-SEC showed spatial autocorrelation is stronger in one county than in the other county.

Stable Atlas-based Mapped Prior (STAMP) machine-learning segmentation for multicenter large-scale MRI data.

PubMed

Kim, Eun Young; Magnotta, Vincent A; Liu, Dawei; Johnson, Hans J

2014-09-01

Machine learning (ML)-based segmentation methods are a common technique in the medical image processing field. In spite of numerous research groups that have investigated ML-based segmentation frameworks, there remains unanswered aspects of performance variability for the choice of two key components: ML algorithm and intensity normalization. This investigation reveals that the choice of those elements plays a major part in determining segmentation accuracy and generalizability. The approach we have used in this study aims to evaluate relative benefits of the two elements within a subcortical MRI segmentation framework. Experiments were conducted to contrast eight machine-learning algorithm configurations and 11 normalization strategies for our brain MR segmentation framework. For the intensity normalization, a Stable Atlas-based Mapped Prior (STAMP) was utilized to take better account of contrast along boundaries of structures. Comparing eight machine learning algorithms on down-sampled segmentation MR data, it was obvious that a significant improvement was obtained using ensemble-based ML algorithms (i.e., random forest) or ANN algorithms. Further investigation between these two algorithms also revealed that the random forest results provided exceptionally good agreement with manual delineations by experts. Additional experiments showed that the effect of STAMP-based intensity normalization also improved the robustness of segmentation for multicenter data sets. The constructed framework obtained good multicenter reliability and was successfully applied on a large multicenter MR data set (n>3000). Less than 10% of automated segmentations were recommended for minimal expert intervention. These results demonstrate the feasibility of using the ML-based segmentation tools for processing large amount of multicenter MR images. We demonstrated dramatically different result profiles in segmentation accuracy according to the choice of ML algorithm and intensity normalization chosen. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of method and format on subjects' responses to a control of variables reasoning problem

NASA Astrophysics Data System (ADS)

Staver, John R.

Excessive time and training demands have rendered Piaget's clinical method of reasoning assessment impractical for researchers and science teachers who work with large numbers of students. The published literature[Note ][See: Lawson, A. E. Journal of Research in Science Teaching, 1978, 15(1), 11-24; Shayer, M., Adey, P., & Wylam, H. Journal of Research in Science Teaching, 1981, 18(2), 157-168; Staver, J. R., & Gabel, D. L. Journal of Research in Science Teaching, 1979, 16(6), 534-544; Tobin, K. G., & Capie, W. Educational and Psychological Measurement, 1981, 41(2), 413-424.] indicates that reliable, valid alternatives to clinical assessment are feasible. However, the overestimate/underestimate of reasoning for different methods and formats remains unresolved through research. The objective of this study was to determine the effects of various methods and formats on subjects' responses to a Piagetian reasoning problem requiring control of variables. The task chosen for this investigation was the Mealworm problem.[Note ][See: Karplus, R., Lawson, A., Wollman, W., Appel, M., Bernoff, R., Howe, A., Rusch, J., & Sullivan, F. Science teaching and the development of reasoning. Berkeley, CA: University of California, 1977.] The task was presented by three methods: (1) individual clinical interview; (2) group presentation of task followed by paper-and-pencil problem with illustration; and (3) group administration of paper-and-pencil instrument with illustration. Each method included four formats: (1) completion answer with essay justification; (2) completion answer with multiplechoice justification; (3) multiple-choice answer with essay justification; and (4) multiple-choice answer with multiple-choice justification. Two hundred and fifty-three (253) students who were enrolled in a freshman level biological science class participated in the study. The research design was a 3 × 4 factorial design with method and format of assessment as the main effects. The participants were in 12 randomly selected laboratory or discussion sections, and each section was randomly assigned to a cell in the research design. Regression analysis with the individual as the unit of analysis showed that format but not method of assessment accounted for a significant amount of variance in student performance. The overall interaction was nonsignificant. Regression analysis with sections as the unit of analysis revealed nonsignificant findings for both method and format. The interrater agreement in the scoring of the Mealworm task was 82.1%. The principal conclusion is that format but not method of task administration influenced the performance of subjects, and the influence is similar for various combinations of method and format. Discussion is focused on the relative importance of the nonsignificant and significant findings for using alternative methods of Piagetian assessment. The results are also discussed with respect to earlier work, and suggestions for future research as well as implications for teachers are set forth.

TNO/Centaurs grouping tested with asteroid data sets

NASA Astrophysics Data System (ADS)

Fulchignoni, M.; Birlan, M.; Barucci, M. A.

2001-11-01

Recently, we have discussed the possible subdivision in few groups of a sample of 22 TNO and Centaurs for which the BVRIJ photometry were available (Barucci et al., 2001, A&A, 371,1150). We obtained this results using the multivariate statistics adopted to define the current asteroid taxonomy, namely the Principal Components Analysis and the G-mode method (Tholen & Barucci, 1989, in ASTEROIDS II). How these methods work with a very small statistical sample as the TNO/Centaurs one? Theoretically, the number of degrees of freedom of the sample is correct. In fact it is 88 in our case and have to be larger then 50 to cope with the requirements of the G-mode. Does the random sampling of the small number of members of a large population contain enough information to reveal some structure in the population? We extracted several samples of 22 asteroids out of a data-base of 86 objects of known taxonomic type for which BVRIJ photometry is available from ECAS (Zellner et al. 1985, ICARUS 61, 355), SMASS II (S.W. Bus, 1999, PhD Thesis, MIT), and the Bell et al. Atlas of the asteroid infrared spectra. The objects constituting the first sample were selected in order to give a good representation of the major asteroid taxonomic classes (at least three samples each class): C,S,D,A, and G. Both methods were able to distinguish all these groups confirming the validity of the adopted methods. The S class is hard to individuate as a consequence of the choice of I and J variables, which imply a lack of information on the absorption band at 1 micron. The other samples were obtained by random choice of the objects. Not all the major groups were well represented (less than three samples per groups), but the general trend of the asteroid taxonomy has been always obtained. We conclude that the quoted grouping of TNO/Centaurs is representative of some physico-chemical structure of the outer solar system small body population.

Nonconscious Influence of Masked Stimuli on Response Selection Is Limited to Concrete Stimulus-Response Associations

ERIC Educational Resources Information Center

Klapp, Stuart T.; Haas, Brian W.

2005-01-01

A pattern-masked arrow negatively biased the "free choice" between 2 manual responses or between 2 vocal responses. This apparently nonconscious influence occurred only when the free-choice trials were intermixed randomly with other trials that terminated in fully visible arrows, which directed a response of the same modality (manual vs. vocal) as…

Reliability of individual valuations of public and private goods: Choice consistency, response time, and preference refinement

Treesearch

Thomas C. Brown; David Kingsley; George L. Peterson; Nicholas E. Flores; Andrea Clarke; Andrej Birjulin

2008-01-01

We examined the reliability of a large set of paired comparison value judgments involving public goods, private goods, and sums of money. As respondents progressed through a random sequence of paired choices they were each given, their response time decreased and they became more consistent, apparently fine-tuning their responses, suggesting that respondents tend to...

Determinants of Tracking Intentions, and Actual Education Choices among Junior High School Students in Rural China

ERIC Educational Resources Information Center

Song, Yingquan; Loyalka, Prashant; Wei, Jianguo

2013-01-01

This article analyzes rural middle school students' tracking intentions (academic high school, vocational high school, or going to work), actual education choices, and the factors affecting them, using a random sampled baseline survey and follow-up survey of 2,216 second-year students residing outside of county seats in forty-one impoverished…

Controlling for Response Order Effects in Ranking Items Using Latent Choice Factor Modeling

ERIC Educational Resources Information Center

Vriens, Ingrid; Moors, Guy; Gelissen, John; Vermunt, Jeroen K.

2017-01-01

Measuring values in sociological research sometimes involves the use of ranking data. A disadvantage of a ranking assignment is that the order in which the items are presented might influence the choice preferences of respondents regardless of the content being measured. The standard procedure to rule out such effects is to randomize the order of…

Getting Lucky: How Guessing Threatens the Validity of Performance Classifications

ERIC Educational Resources Information Center

Foley, Brett P.

2016-01-01

There is always a chance that examinees will answer multiple choice (MC) items correctly by guessing. Design choices in some modern exams have created situations where guessing at random through the full exam--rather than only for a subset of items where the examinee does not know the answer--can be an effective strategy to pass the exam. This…

Hybrid recommendation methods in complex networks.

PubMed

Fiasconaro, A; Tumminello, M; Nicosia, V; Latora, V; Mantegna, R N

2015-07-01

We propose two recommendation methods, based on the appropriate normalization of already existing similarity measures, and on the convex combination of the recommendation scores derived from similarity between users and between objects. We validate the proposed measures on three data sets, and we compare the performance of our methods to other recommendation systems recently proposed in the literature. We show that the proposed similarity measures allow us to attain an improvement of performances of up to 20% with respect to existing nonparametric methods, and that the accuracy of a recommendation can vary widely from one specific bipartite network to another, which suggests that a careful choice of the most suitable method is highly relevant for an effective recommendation on a given system. Finally, we study how an increasing presence of random links in the network affects the recommendation scores, finding that one of the two recommendation algorithms introduced here can systematically outperform the others in noisy data sets.

What influences participation in genetic carrier testing? Results from a discrete choice experiment.

PubMed

Hall, Jane; Fiebig, Denzil G; King, Madeleine T; Hossain, Ishrat; Louviere, Jordan J

2006-05-01

This study explores factors that influence participation in genetic testing programs and the acceptance of multiple tests. Tay Sachs and cystic fibrosis are both genetically determined recessive disorders with differing severity, treatment availability, and prevalence in different population groups. We used a discrete choice experiment with a general community and an Ashkenazi Jewish sample; data were analysed using multinomial logit with random coefficients. Although Jewish respondents were more likely to be tested, both groups seem to be making very similar tradeoffs across attributes when they make genetic testing choices.

Patient choice in opt-in, active choice, and opt-out HIV screening: randomized clinical trial.

PubMed

Montoy, Juan Carlos C; Dow, William H; Kaplan, Beth C

2016-01-19

What is the effect of default test offers--opt-in, opt-out, and active choice--on the likelihood of acceptance of an HIV test among patients receiving care in an emergency department? This was a randomized clinical trial conducted in the emergency department of an urban teaching hospital and regional trauma center. Patients aged 13-64 years were randomized to opt-in, opt-out, and active choice HIV test offers. The primary outcome was HIV test acceptance percentage. The Denver Risk Score was used to categorize patients as being at low, intermediate, or high risk of HIV infection. 38.0% (611/1607) of patients in the opt-in testing group accepted an HIV test, compared with 51.3% (815/1628) in the active choice arm (difference 13.3%, 95% confidence interval 9.8% to 16.7%) and 65.9% (1031/1565) in the opt-out arm (difference 27.9%, 24.4% to 31.3%). Compared with active choice testing, opt-out testing led to a 14.6 (11.1 to 18.1) percentage point increase in test acceptance. Patients identified as being at intermediate and high risk were more likely to accept testing than were those at low risk in all arms (difference 6.4% (3.4% to 9.3%) for intermediate and 8.3% (3.3% to 13.4%) for high risk). The opt-out effect was significantly smaller among those reporting high risk behaviors, but the active choice effect did not significantly vary by level of reported risk behavior. Patients consented to inclusion in the study after being offered an HIV test, and inclusion varied slightly by treatment assignment. The study took place at a single county hospital in a city that is somewhat unique with respect to HIV testing; although the test acceptance percentages themselves might vary, a different pattern for opt-in versus active choice versus opt-out test schemes would not be expected. Active choice is a distinct test regimen, with test acceptance patterns that may best approximate patients' true preferences. Opt-out regimens can substantially increase HIV testing, and opt-in schemes may reduce testing, compared with active choice testing. This study was supported by grant NIA 1RC4AG039078 from the National Institute on Aging. The full dataset is available from the corresponding author. Consent for data sharing was not obtained, but the data are anonymized and risk of identification is low.Trial registration Clinical trials NCT01377857. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Inbreeding avoidance, patch isolation and matrix permeability influence dispersal and settlement choices by male agile antechinus in a fragmented landscape.

PubMed

Banks, Sam C; Lindenmayer, David B

2014-03-01

Animal dispersal is highly non-random and has important implications for the dynamics of populations in fragmented habitat. We identified interpatch dispersal events from genetic tagging, parentage analyses and assignment tests and modelled the factors associated with apparent emigration and post-dispersal settlement choices by individual male agile antechinus (Antechinus agilis, a marsupial carnivore of south-east Australian forests). Emigration decisions were best modelled with on data patch isolation and inbreeding risk. The choice of dispersal destination by males was influenced by inbreeding risk, female abundance, patch size, patch quality and matrix permeability (variation in land cover). Males were less likely to settle in patches without highly unrelated females. Our findings highlight the importance of individual-level dispersal data for understanding how multiple processes drive non-randomness in dispersal in modified landscapes. Fragmented landscapes present novel environmental, demographic and genetic contexts in which dispersal decisions are made, so the major factors affecting dispersal decisions in fragmented habitat may differ considerably from unfragmented landscapes. We show that the spatial scale of genetic neighbourhoods can be large in fragmented habitat, such that dispersing males can potentially settle in the presence of genetically similar females after moving considerable distances, thereby necessitating both a choice to emigrate and a choice of where to settle to avoid inbreeding. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

Diagramming the Never Ending Story: Student-generated diagrammatic stories integrate and retain science concepts improving science literacy

NASA Astrophysics Data System (ADS)

Pillsbury, Ralph T.

This research examined an instructional strategy called Diagramming the Never Ending Story: A method called diagramming was taught to sixth grade students via an outdoor science inquiry ecology unit. Students generated diagrams of the new ecology concepts they encountered, creating explanatory 'captions' for their newly drawn diagrams while connecting them in a memorable story. The diagramming process culminates in 20-30 meter-long murals called the Never Ending Story: Months of science instruction are constructed as pictorial scrolls, making sense of all new science concepts they encounter. This method was taught at a North Carolina "Public" Charter School, Children's Community School, to measure its efficacy in helping students comprehend scientific concepts and retain them thereby increasing science literacy. There were four demographically similar classes of 20 students each. Two 'treatment' classes, randomly chosen from the four classes, generated their own Never Ending Stories after being taught the diagramming method. A Solomon Four-Group Design was employed: Two Classes (one control, one treatment) were administered pre- and post; two classes received post tests only. The tests were comprised of multiple choice, fill-in and extended response (open-ended) sections. Multiple choice and fill-in test data were not statistically significant whereas extended response test data confirm that treatment classes made statistically significant gains.

Unified framework to evaluate panmixia and migration direction among multiple sampling locations.

PubMed

Beerli, Peter; Palczewski, Michal

2010-05-01

For many biological investigations, groups of individuals are genetically sampled from several geographic locations. These sampling locations often do not reflect the genetic population structure. We describe a framework using marginal likelihoods to compare and order structured population models, such as testing whether the sampling locations belong to the same randomly mating population or comparing unidirectional and multidirectional gene flow models. In the context of inferences employing Markov chain Monte Carlo methods, the accuracy of the marginal likelihoods depends heavily on the approximation method used to calculate the marginal likelihood. Two methods, modified thermodynamic integration and a stabilized harmonic mean estimator, are compared. With finite Markov chain Monte Carlo run lengths, the harmonic mean estimator may not be consistent. Thermodynamic integration, in contrast, delivers considerably better estimates of the marginal likelihood. The choice of prior distributions does not influence the order and choice of the better models when the marginal likelihood is estimated using thermodynamic integration, whereas with the harmonic mean estimator the influence of the prior is pronounced and the order of the models changes. The approximation of marginal likelihood using thermodynamic integration in MIGRATE allows the evaluation of complex population genetic models, not only of whether sampling locations belong to a single panmictic population, but also of competing complex structured population models.

The role of free choice in memory for past decisions.

PubMed

Benney, Kristen Stoll; Henkel, Linda A

2006-11-01

After choosing between different options, people tend to remember the features of the options in ways that favour the chosen alternative. The present experiment examined how limitations on freedom to choose between options affected this memory bias. Participants were given a series of two-option choices and were either allowed free choice between options or were assigned to an option. Participants assigned to an option were led to believe that either the selection was random or was made in their best interest based on their personality profile. Results indicated that the choice and best interest conditions demonstrated memory attributions that favoured their received options, whereas the assignment condition did not. These findings support the view that memory biases towards received options are not unique to free choice situations, but may stem from expectations and implicit theories about how and why the choice was made.

The Impact of Disulfiram Treatment on the Reinforcing Effects of Cocaine: A Randomized Clinical Trial

PubMed Central

Haile, Colin N.; De La Garza, Richard; Mahoney, James J.; Nielsen, David A.; Kosten, Thomas R.; Newton, Thomas F.

2012-01-01

Background Clinical trials indicate that disulfiram (250 mg/d) reduces cocaine use, though one study found that treatment with lower doses of disulfiram (62.5 and 125 mg/d) increased cocaine use. We conducted the present study to better understand how disulfiram alters the reinforcing effects of cocaine in cocaine users. Methods Seventeen non-treatment seeking, cocaine-dependent volunteers participated in this double-blind, placebo-controlled, laboratory-based study. A cross-over design was utilized in which participants received placebo in one phase and disulfiram (250 mg/d) in the other. Following three days of study medication participants completed two choice sessions. In one they made 10 choices between receiving an intravenous infusion of saline or money that increased in value (US$ 0.05–16) and in the other cocaine (20 mg) or money. Results Participants chose cocaine more than saline under both disulfiram and placebo conditions (p<0.05). Unexpectedly, disulfiram increased both the number of cocaine and saline infusion choices (p<0.05). We next examined the relationship between disulfiram dose and cocaine choices. Disulfiram dose (mg/kg bodyweight) was negatively correlated with number of choices for cocaine (p<0.05). Disulfiram also enhanced cocaine-induced increases in cardiovascular measures (p's<0.05–0.01). Conclusions Disulfiram's impact on the reinforcing effects of cocaine depends on dose relative to body weight. Our results suggest that the use of weight-based medication doses would produce more reliable effects, consistent with weight-based dosing used in pediatrics and in preclinical research. Trial Registration Clinicaltrials.gov NCT00729300 PMID:23144826

Effects of environmental and pharmacological manipulations on a novel delayed nonmatching-to-sample 'working memory' procedure in unrestrained rhesus monkeys.

PubMed

Hutsell, Blake A; Banks, Matthew L

2015-08-15

Working memory is a domain of 'executive function.' Delayed nonmatching-to-sample (DNMTS) procedures are commonly used to examine working memory in both human laboratory and preclinical studies. The aim was to develop an automated DNMTS procedure maintained by food pellets in rhesus monkeys using a touch-sensitive screen attached to the housing chamber. Specifically, the DNMTS procedure was a 2-stimulus, 2-choice recognition memory task employing unidimensional discriminative stimuli and randomized delay interval presentations. DNMTS maintained a delay-dependent decrease in discriminability that was independent of the retention interval distribution. Eliminating reinforcer availability during a single delay session or providing food pellets before the session did not systematically alter accuracy, but did reduce total choices. Increasing the intertrial interval enhanced accuracy at short delays. Acute Δ(9)-THC pretreatment produced delay interval-dependent changes in the forgetting function at doses that did not alter total choices. Acute methylphenidate pretreatment only decreased total choices. All monkeys were trained to perform NMTS at the 1s training delay within 60 days of initiating operant touch training. Furthermore, forgetting functions were reliably delay interval-dependent and stable over the experimental period (∼6 months). Consistent with previous studies, increasing the intertrial interval improved DNMTS performance, whereas Δ(9)-THC disrupted DNMTS performance independent of changes in total choices. Overall, the touchscreen-based DNMTS procedure described provides an efficient method for training and testing experimental manipulations on working memory in unrestrained rhesus monkeys. Copyright © 2015 Elsevier B.V. All rights reserved.

Impact of a Randomized Controlled Trial in Arsenic Risk Communication on Household Water-Source Choices in Bangladesh

PubMed Central

Tarozzi, Alessandro; Pfaff, Alexander; Balasubramanya, Soumya; Ahmed, Kazi Matin; van Geen, Alexander

2013-01-01

We conducted a randomized controlled trial in rural Bangladesh to examine how household drinking-water choices were affected by two different messages about risk from naturally occurring groundwater arsenic. Households in both randomized treatment arms were informed about the arsenic level in their well and whether that level was above or below the Bangladesh standard for arsenic. Households in one group of villages were encouraged to seek water from wells below the national standard. Households in the second group of villages received additional information explaining that lower-arsenic well water is always safer and these households were encouraged to seek water from wells with lower levels of arsenic, irrespective of the national standard. A simple model of household drinking-water choice indicates that the effect of the emphasis message is theoretically ambiguous. Empirically, we find that the richer message had a negative, but insignificant, effect on well-switching rates, but the estimates are sufficiently precise that we can rule out large positive effects. The main policy implication of this finding is that a one-time oral message conveying richer information on arsenic risks, while inexpensive and easily scalable, is unlikely to be successful in reducing exposure relative to the status-quo policy. PMID:23997355

Undermining position effects in choices from arrays, with implications for police lineups.

PubMed

Palmer, Matthew A; Sauer, James D; Holt, Glenys A

2017-03-01

Choices from arrays are often characterized by position effects, such as edge-aversion. We investigated position effects when participants attempted to pick a suspect from an array similar to a police photo lineup. A reanalysis of data from 2 large-scale field studies showed that choices made under realistic conditions-closely matching eyewitness identification decisions in police investigations-displayed edge-aversion and bias to choose from the top row (Study 1). In a series of experiments (Studies 2a-2c and 3), participants guessing the location of a suspect exhibited edge-aversion regardless of whether the lineup was constructed to maximize the chances of the suspect being picked, to ensure the suspect did not stand out, or randomly. Participants favored top locations only when the lineup was constructed to maximize the chances of the suspect being picked. In Studies 4 and 5, position effects disappeared when (a) response options were presented in an array with no obvious center, edges, or corners, and (b) instructions stated that the suspect was placed randomly. These findings show that position effects are influenced by a combination of task instructions and array shape. Randomizing the location of the suspect and modifying the shape of the lineup array may reduce misidentification. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

No evidence for inbreeding avoidance in a natural population of song sparrows (Melospiza melodia).

PubMed

Keller, L F; Arcese, P

1998-09-01

We studied mate choice and inbreeding avoidance a natural population of song sparrows (Melospiza melodia) on Mandarte Island, Canada. Inbreeding occurred regularly: 59% all matings were between known relatives. We tested for inbreeding avoidance by comparing the observed levels of inbreeding to those expected if mate choice had been random with respect to relatedness. Independent of our assumptions about the availability of mates in the random mating model, we found that the expected and observed distributions of inbreeding coefficients were similar, as was the expected and observed frequency of close (f >/= 0.125) inbreeding. Furthermore, there was no difference in relatedness observed pairs and those that would have resulted had birds mated instead with their nearest neighbors. The only evidence to suggest any inbreeding avoidance was a reduced rate of parent-offspring matings as compared to one random mating model but not the other. Hence, despite substantial inbreeding depression in this population, we found little evidence for inbreeding avoidance through mate choice. We present a simple model to suggest that variation in inbreeding avoidance behaviors in birds may arise from differences in survival rates: in species with low survival rates, the costs of forfeiting matings to avoid inbreeding may exceed the costs of inbreeding.

How universal are human mate choices? Size does not matter when Hadza foragers are choosing a mate

PubMed Central

Sear, Rebecca; Marlowe, Frank W.

2009-01-01

It has been argued that size matters on the human mate market: both stated preferences and mate choices have been found to be non-random with respect to height and weight. But how universal are these patterns? Most of the literature on human mating patterns is based on post-industrial societies. Much less is known about mating behaviour in more traditional societies. Here we investigate mate choice by analysing whether there is any evidence for non-random mating with respect to size and strength in a forager community, the Hadza of Tanzania. We test whether couples assort for height, weight, body mass index (BMI), per cent fat and grip strength. We test whether there is a male-taller norm. Finally, we test for an association between anthropometric variables and number of marriages. Our results show no evidence for assortative mating for height, weight, BMI or per cent fat; no evidence for a male-taller norm and no evidence that number of marriages is associated with our size variables. Hadza couples may assort positively for grip strength, but grip strength does not affect the number of marriages. Overall we conclude that, in contrast to post-industrial societies, mating appears to be random with respect to size in the Hadza. PMID:19570778

A dose optimization method for electron radiotherapy using randomized aperture beams

NASA Astrophysics Data System (ADS)

Engel, Konrad; Gauer, Tobias

2009-09-01

The present paper describes the entire optimization process of creating a radiotherapy treatment plan for advanced electron irradiation. Special emphasis is devoted to the selection of beam incidence angles and beam energies as well as to the choice of appropriate subfields generated by a refined version of intensity segmentation and a novel random aperture approach. The algorithms have been implemented in a stand-alone programme using dose calculations from a commercial treatment planning system. For this study, the treatment planning system Pinnacle from Philips has been used and connected to the optimization programme using an ASCII interface. Dose calculations in Pinnacle were performed by Monte Carlo simulations for a remote-controlled electron multileaf collimator (MLC) from Euromechanics. As a result, treatment plans for breast cancer patients could be significantly improved when using randomly generated aperture beams. The combination of beams generated through segmentation and randomization achieved the best results in terms of target coverage and sparing of critical organs. The treatment plans could be further improved by use of a field reduction algorithm. Without a relevant loss in dose distribution, the total number of MLC fields and monitor units could be reduced by up to 20%. In conclusion, using randomized aperture beams is a promising new approach in radiotherapy and exhibits potential for further improvements in dose optimization through a combination of randomized electron and photon aperture beams.

Factors associated with choice of a low-fat or low-carbohydrate diet during a behavioral weight loss intervention.

PubMed

McVay, Megan A; Voils, Corrine I; Coffman, Cynthia J; Geiselman, Paula J; Kolotkin, Ronette L; Mayer, Stephanie B; Smith, Valerie A; Gaillard, Leslie; Turner, Marsha J; Yancy, William S

2014-12-01

Individuals undertaking a weight loss effort have a choice among proven dietary approaches. Factors contributing to choice of either a low-fat/low-calorie diet or a low-carbohydrate diet, two of the most studied and popular dietary approaches, are unknown. The current study used data from participants randomized to the 'choice' arm of a trial examining whether being able to choose a diet regimen yields higher weight loss than being randomly assigned to a diet. At study entry, participants attended a group session during which they were provided tailored feedback indicating which diet was most consistent with their food preferences using the Geiselman Food Preference Questionnaire (FPQ), information about both diets, and example meals for each diet. One week later, they indicated which diet they chose to follow during the 48-week study, with the option of switching diets after 12 weeks. Of 105 choice arm participants, 44 (42%) chose the low-fat/low-calorie diet and 61 (58%) chose the low-carbohydrate diet. In bivariate analyses, diet choice was not associated with age, race, sex, education, BMI, or diabetes (all p > 0.05). Low-carbohydrate diet choice was associated with baseline higher percent fat intake (p = 0.007), lower percent carbohydrate intake (p = 0.02), and food preferences consistent with a low-carbohydrate diet according to FPQ (p < 0.0001). In a multivariable logistic regression model, only FPQ diet preference was associated with diet choice (p = 0.001). Reported reasons for diet choice were generally similar for those choosing either diet; however, concerns about negative health effects of the unselected diet was rated as more influential among participants selecting the low-fat diet. Only three low-carbohydrate and two low-fat diet participants switched diets at 12 weeks. Results suggest that when provided a choice between two popular weight loss dietary approaches, an individual's selection is likely influenced by baseline dietary intake pattern, and especially by his or her dietary preferences. Research is needed to determine if congruency between food preferences and dietary approach is associated with weight loss. Published by Elsevier Ltd.

Make Better Choices (MBC): Study design of a randomized controlled trial testing optimal technology-supported change in multiple diet and physical activity risk behaviors

PubMed Central

2010-01-01

Background Suboptimal diet and physical inactivity are prevalent, co-occurring chronic disease risk factors, yet little is known about how to maximize multiple risk behavior change. Make Better Choices, a randomized controlled trial, tests competing hypotheses about the optimal way to promote healthy change in four bundled risk behaviors: high saturated fat intake, low fruit and vegetable intake, low physical activity, and high sedentary leisure screen time. The study aim is to determine which combination of two behavior change goals - one dietary, one activity - yields greatest overall healthy lifestyle change. Methods/Design Adults (n = 200) with poor quality diet and sedentary lifestyle will be recruited and screened for study eligibility. Participants will be trained to record their diet and activities onto a personal data assistant, and use it to complete two weeks of baseline. Those who continue to show all four risk behaviors after baseline recording will be randomized to one of four behavior change prescriptions: 1) increase fruits and vegetables and increase physical activity, 2) decrease saturated fat and increase physical activity, 3) increase fruits and vegetable and decrease saturated fat, or 4) decrease saturated fat and decrease sedentary activity. They will use decision support feedback on the personal digital assistant and receive counseling from a coach to alter their diet and activity during a 3-week prescription period when payment is contingent upon meeting behavior change goals. They will continue recording on an intermittent schedule during a 4.5-month maintenance period when payment is not contingent upon goal attainment. The primary outcome is overall healthy lifestyle change, aggregated across all four risk behaviors. Discussion The Make Better Choices trial tests a disseminable lifestyle intervention supported by handheld technology. Findings will fill a gap in knowledge about optimal goal prescription to facilitate simultaneous diet and activity change. Results will shed light on which goal prescription maximizes healthful lifestyle change. Trial Registration Clinical Trials Gov. Identifier NCT00113672 PMID:20920275

Sequential and simultaneous choices: testing the diet selection and sequential choice models.

PubMed

Freidin, Esteban; Aw, Justine; Kacelnik, Alex

2009-03-01

We investigate simultaneous and sequential choices in starlings, using Charnov's Diet Choice Model (DCM) and Shapiro, Siller and Kacelnik's Sequential Choice Model (SCM) to integrate function and mechanism. During a training phase, starlings encountered one food-related option per trial (A, B or R) in random sequence and with equal probability. A and B delivered food rewards after programmed delays (shorter for A), while R ('rejection') moved directly to the next trial without reward. In this phase we measured latencies to respond. In a later, choice, phase, birds encountered the pairs A-B, A-R and B-R, the first implementing a simultaneous choice and the second and third sequential choices. The DCM predicts when R should be chosen to maximize intake rate, and SCM uses latencies of the training phase to predict choices between any pair of options in the choice phase. The predictions of both models coincided, and both successfully predicted the birds' preferences. The DCM does not deal with partial preferences, while the SCM does, and experimental results were strongly correlated to this model's predictions. We believe that the SCM may expose a very general mechanism of animal choice, and that its wider domain of success reflects the greater ecological significance of sequential over simultaneous choices.

Capturing the Cumulative Effects of School Reform: An 11-Year Study of the Impacts of America's Choice on Student Achievement

ERIC Educational Resources Information Center

May, Henry; Supovitz, Jonathan A.

2006-01-01

This article presents the results of an 11-year longitudinal study of the impact of America's Choice comprehensive school reform (CSR) design on student learning gains in Rochester, New York. A quasi-experimental interrupted time-series approach using Bayesian hierarchical growth curve analysis with crossed random effects is used to compare the…

A Comparison of Maternal Outcomes from an Alcohol, Tobacco, and Other Drug Prevention Program for Mothers Choosing an Intervention versus Being Randomized

ERIC Educational Resources Information Center

Byrnes, Hilary F.; Miller, Brenda A.; Laborde, Nicole

2013-01-01

Self-determination theory and substantial research findings suggest that more desirable outcomes may occur when participants are able to choose their prevention or treatment interventions, as having a choice may lead to greater motivation and feelings of self-efficacy. The present study examined the influence of having a choice of family-based…

A note on nonlinearity bias and dichotomous choice CVM: implications for aggregate benefits estimation

Treesearch

R.A. Souter; J. Michael Bowker

1996-01-01

It is a generally known statistical fact that the mean of a nonlinear function of a set of random variables is not equivalent to the function evaluated at the means of the variables. However, in dichotomous choice contingent valuation studies, a common practice is to calculate an overall mean (or median) by integrating over offer space (numerically or analytically) an...

Orbitofrontal cortical activity during repeated free choice.

PubMed

Campos, Michael; Koppitch, Kari; Andersen, Richard A; Shimojo, Shinsuke

2012-06-01

Neurons in the orbitofrontal cortex (OFC) have been shown to encode subjective values, suggesting a role in preference-based decision-making, although the precise relation to choice behavior is unclear. In a repeated two-choice task, subjective values of each choice can account for aggregate choice behavior, which is the overall likelihood of choosing one option over the other. Individual choices, however, are impossible to predict with knowledge of relative subjective values alone. In this study we investigated the role of internal factors in choice behavior with a simple but novel free-choice task and simultaneous recording from individual neurons in nonhuman primate OFC. We found that, first, the observed sequences of choice behavior included periods of exceptionally long runs of each of two available options and periods of frequent switching. Neither a satiety-based mechanism nor a random selection process could explain the observed choice behavior. Second, OFC neurons encode important features of the choice behavior. These features include activity selective for exceptionally long runs of a given choice (stay selectivity) as well as activity selective for switches between choices (switch selectivity). These results suggest that OFC neural activity, in addition to encoding subjective values on a long timescale that is sensitive to satiety, also encodes a signal that fluctuates on a shorter timescale and thereby reflects some of the statistically improbable aspects of free-choice behavior.

Orbitofrontal cortical activity during repeated free choice

PubMed Central

Koppitch, Kari; Andersen, Richard A.; Shimojo, Shinsuke

2012-01-01

Neurons in the orbitofrontal cortex (OFC) have been shown to encode subjective values, suggesting a role in preference-based decision-making, although the precise relation to choice behavior is unclear. In a repeated two-choice task, subjective values of each choice can account for aggregate choice behavior, which is the overall likelihood of choosing one option over the other. Individual choices, however, are impossible to predict with knowledge of relative subjective values alone. In this study we investigated the role of internal factors in choice behavior with a simple but novel free-choice task and simultaneous recording from individual neurons in nonhuman primate OFC. We found that, first, the observed sequences of choice behavior included periods of exceptionally long runs of each of two available options and periods of frequent switching. Neither a satiety-based mechanism nor a random selection process could explain the observed choice behavior. Second, OFC neurons encode important features of the choice behavior. These features include activity selective for exceptionally long runs of a given choice (stay selectivity) as well as activity selective for switches between choices (switch selectivity). These results suggest that OFC neural activity, in addition to encoding subjective values on a long timescale that is sensitive to satiety, also encodes a signal that fluctuates on a shorter timescale and thereby reflects some of the statistically improbable aspects of free-choice behavior. PMID:22423007

Randomized controlled trials and meta-analysis in medical education: what role do they play?

PubMed

Cook, David A

2012-01-01

Education researchers seek to understand what works, for whom, in what circumstances. Unfortunately, educational environments are complex and research itself is highly context dependent. Faced with these challenges, some have argued that qualitative methods should supplant quantitative methods such as randomized controlled trials (RCTs) and meta-analysis. I disagree. Good qualitative and mixed-methods research are complementary to, rather than exclusive of, quantitative methods. The complexity and challenges we face should not beguile us into ignoring methods that provide strong evidence. What, then, is the proper role for RCTs and meta-analysis in medical education? First, the choice of study design depends on the research question. RCTs and meta-analysis are appropriate for many, but not all, study goals. They have compelling strengths but also numerous limitations. Second, strong methods will not compensate for a pointless question. RCTs do not advance the science when they make confounded comparisons, or make comparison with no intervention. Third, clinical medicine now faces many of the same challenges we encounter in education. We can learn much from other fields about how to handle complexity in RCTs. Finally, no single study will definitively answer any research question. We need carefully planned, theory-building, programmatic research, reflecting a variety of paradigms and approaches, as we accumulate evidence to change the art and science of education.

Culturally Responsive Adolescent Pregnancy and Sexually Transmitted Infection Prevention Program for Middle School Students in Hawai‘i

PubMed Central

Barker, Linda Toms; Chan, Vincent; Eucogco, Jasmine

2016-01-01

Objectives. To evaluate the effectiveness of Pono Choices, a culturally responsive adolescent pregnancy and sexually transmitted infection (STI) prevention program targeting middle school youths in Hawai‘i. Methods. We conducted a cluster randomized controlled trial with the school as the unit of random assignment over 3 semesters between 2012 and 2013. The sample consisted of 36 middle schools and 2203 students. We administered student surveys to collect baseline outcomes, student demographic data, and outcomes at 12 months after baseline. Results. We found statistically significant effects for the knowledge assessment, which focused on basic understanding of adolescent pregnancy and STI prevention. The average percentage of correct responses was 73.6 for the treatment group and 60.4 for the control group (P < .001). We did not find statistically significant effects on behavioral outcomes (initiation of sexual activity or engagement in high-risk sexual behavior) or on other nonbehavioral outcomes (attitudes, skills, intentions). Conclusions. Pono Choices had a statistically significant impact on knowledge of adolescent pregnancy and STI prevention among middle school students at 12 months after baseline, though it did not lead to detectable changes in behavioral outcomes within the 1-year observation period. These results call for an exploration of longer-term outcomes to assess effects on knowledge retention and behavioral changes. PMID:27689477

Choosy Wolves? Heterozygote Advantage But No Evidence of MHC-Based Disassortative Mating.

PubMed

Galaverni, Marco; Caniglia, Romolo; Milanesi, Pietro; Lapalombella, Silvana; Fabbri, Elena; Randi, Ettore

2016-03-01

A variety of nonrandom mate choice strategies, including disassortative mating, are used by vertebrate species to avoid inbreeding, maintain heterozygosity and increase fitness. Disassortative mating may be mediated by the major histocompatibility complex (MHC), an important gene cluster controlling immune responses to pathogens. We investigated the patterns of mate choice in 26 wild-living breeding pairs of gray wolf (Canis lupus) that were identified through noninvasive genetic methods and genotyped at 3 MHC class II and 12 autosomal microsatellite (STR) loci. We tested for deviations from random mating and evaluated the covariance of genetic variables at functional and STR markers with fitness proxies deduced from pedigree reconstructions. Results did not show evidences of MHC-based disassortative mating. Rather we found a higher peptide similarity between mates at MHC loci as compared with random expectations. Fitness values were positively correlated with heterozygosity of the breeders at both MHC and STR loci, whereas they decreased with relatedness at STRs. These findings may indicate fitness advantages for breeders that, while avoiding highly related mates, are more similar at the MHC and have high levels of heterozygosity overall. Such a pattern of MHC-assortative mating may reflect local coadaptation of the breeders, while a reduction in genetic diversity may be balanced by heterozygote advantages. © The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Potential effectiveness of traditional Chinese medicine for cardiac syndrome X (CSX): a systematic review and meta-analysis

PubMed Central

2013-01-01

Background Treatment of cardiac syndrome X with unknown pathological mechanism remains a big challenge for clinicians. Complementary and alternative medicine may bring a new choice for its management. The aim of this study is to evaluate the clinical effects of traditional Chinese medicine on cardiac syndrome X patients. Methods We systematically searched databases such as Cochrane CENTRAL, PubMed, EMBASE, CBM, Chinese National Knowledge Infrastructure (CNKI), WanFang and VIP, and handsearched relevant journals to identify randomized controlled trials. Following the steps of systematic review recommended by the Cochrane group, we assessed the quality of included studies, extracted valid data and undertook meta-analysis. Results Twenty one moderate-to low-quality randomized controlled trials involving 1143 patients were included. The results showed that traditional Chinese medicine could improve angina [OR=1.34, 95% CI: 1.2 to 1.50], electrocardiogram (ECG), endothelin-1 (ET-1) levels, prolong exercise duration in treadmill tests, and reduce angina frequency per week compared with routine treatment. No other side effect was reported except two cases of stomach pain. Conclusion Compared with conventional treatment, traditional Chinese medicine shows the potential of optimizing symptomatic outcomes and improving ECG and exercise duration. The efficacy of TCM may find explanation in its pharmacological activity of adjusting the endothelial function. TCM, as a kind of alternative and complementary medicine, may provide another choice for CSX patients. PMID:23497135

Eye Movements in Strategic Choice

PubMed Central

Gächter, Simon; Noguchi, Takao; Mullett, Timothy L.

2015-01-01

Abstract In risky and other multiattribute choices, the process of choosing is well described by random walk or drift diffusion models in which evidence is accumulated over time to threshold. In strategic choices, level‐k and cognitive hierarchy models have been offered as accounts of the choice process, in which people simulate the choice processes of their opponents or partners. We recorded the eye movements in 2 × 2 symmetric games including dominance‐solvable games like prisoner's dilemma and asymmetric coordination games like stag hunt and hawk–dove. The evidence was most consistent with the accumulation of payoff differences over time: we found longer duration choices with more fixations when payoffs differences were more finely balanced, an emerging bias to gaze more at the payoffs for the action ultimately chosen, and that a simple count of transitions between payoffs—whether or not the comparison is strategically informative—was strongly associated with the final choice. The accumulator models do account for these strategic choice process measures, but the level‐k and cognitive hierarchy models do not. © 2015 The Authors. Journal of Behavioral Decision Making published by John Wiley & Sons Ltd. PMID:27513881

Testing how voluntary participation requirements in an environmental study affect the planned random sample design outcomes: implications for the predictions of values and their uncertainty.

NASA Astrophysics Data System (ADS)

Ander, Louise; Lark, Murray; Smedley, Pauline; Watts, Michael; Hamilton, Elliott; Fletcher, Tony; Crabbe, Helen; Close, Rebecca; Studden, Mike; Leonardi, Giovanni

2015-04-01

Random sampling design is optimal in order to be able to assess outcomes, such as the mean of a given variable across an area. However, this optimal sampling design may be compromised to an unknown extent by unavoidable real-world factors: the extent to which the study design can still be considered random, and the influence this may have on the choice of appropriate statistical data analysis is examined in this work. We take a study which relied on voluntary participation for the sampling of private water tap chemical composition in England, UK. This study was designed and implemented as a categorical, randomised study. The local geological classes were grouped into 10 types, which were considered to be most important in likely effects on groundwater chemistry (the source of all the tap waters sampled). Locations of the users of private water supplies were made available to the study group from the Local Authority in the area. These were then assigned, based on location, to geological groups 1 to 10 and randomised within each group. However, the permission to collect samples then required active, voluntary participation by householders and thus, unlike many environmental studies, could not always follow the initial sample design. Impediments to participation ranged from 'willing but not available' during the designated sampling period, to a lack of response to requests to sample (assumed to be wholly unwilling or unable to participate). Additionally, a small number of unplanned samples were collected via new participants making themselves known to the sampling teams, during the sampling period. Here we examine the impact this has on the 'random' nature of the resulting data distribution, by comparison with the non-participating known supplies. We consider the implications this has on choice of statistical analysis methods to predict values and uncertainty at un-sampled locations.

Design issues in a randomized controlled trial of a pre-emptive versus empiric antifungal strategy for invasive aspergillosis in patients with high-risk hematologic malignancies.

PubMed

Morrissey, C Orla; Chen, Sharon C-A; Sorrell, Tania C; Bradstock, Kenneth F; Szer, Jeffrey; Halliday, Catriona L; Gilroy, Nicole M; Schwarer, Anthony P; Slavin, Monica A

2011-02-01

Invasive aspergillosis (IA) is a major cause of mortality in patients with hematological malignancies, due largely to the inability of traditional culture and biopsy methods to make an early or accurate diagnosis. Diagnostic accuracy studies suggest that Aspergillus galactomannan (GM) enzyme immunoassay (ELISA) and Aspergillus PCR-based methods may overcome these limitations, but their impact on patient outcomes should be evaluated in a diagnostic randomized controlled trial (D-RCT). This article describes the methodology of a D-RCT which compares a new pre-emptive strategy (GM-ELISA- and Aspergillus PCR-driven antifungal therapy) with the standard fever-driven empiric antifungal treatment strategy. Issues including primary end-point and patient selection, duration of screening, choice of tests for the pre-emptive strategy, antifungal prophylaxis and bias control, which were considered in the design of the trial, are discussed. We suggest that the template presented herein is considered by researchers when evaluating the utility of new diagnostic tests (ClinicalTrials.gov number, NCT00163722).

The design and implementation of a randomized controlled trial of a risk reduction and human immunodeficiency virus prevention videogame intervention in minority adolescents: PlayForward: Elm City Stories.

PubMed

Fiellin, Lynn E; Kyriakides, Tassos C; Hieftje, Kimberly D; Pendergrass, Tyra M; Duncan, Lindsay R; Dziura, James D; Sawyer, Benjamin G; Fiellin, David A

2016-08-01

To address the need for risk behavior reduction and human immunodeficiency virus prevention interventions that capture adolescents "where they live," we created a tablet-based videogame to teach skills and knowledge and influence psychosocial antecedents for decreasing risk and preventing human immunodeficiency virus infection in minority youth in schools, after-school programs, and summer camps. We developed PlayForward: Elm City Stories over a 2-year period, working with researchers, commercial game designers, and staff and teens from community programs. The videogame PlayForward provides an interactive world where players, using an avatar, "travel" through time, facing challenges such as peer pressure to drink alcohol or engage in risky sexual behaviors. Players experience how their choices affect their future and then are able to go back in time and change their choices, creating different outcomes. A randomized controlled trial was designed to evaluate the efficacy of PlayForward. Participants were randomly assigned to play PlayForward or a set of attention/time control games on a tablet at their community-based program. Assessment data were collected during face-to-face study visits and entered into a web-based platform and unique real-time "in-game" PlayForward data were collected as players engaged in the game. The innovative methods of this randomized controlled trial are described. We highlight the logistical issues of conducting a large-scale trial using mobile technology such as the iPad(®), and collecting, transferring, and storing large amounts of in-game data. We outline the methods used to analyze the in-game data alone and in conjunction with standardized assessment data to establish correlations between behaviors during gameplay and those reported in real life. We also describe the use of the in-game data as a measure of fidelity to the intervention. In total, 333 boys and girls, aged 11-14 years, were randomized over a 14-month period: 166 were assigned to play PlayForward and 167 to play the control games. To date (as of 1 March 2016), 18 have withdrawn from the study; the following have completed the protocol-defined assessments: 6 weeks: 271 (83%), 3 months: 269 (84%), 6 months: 254 (79%), 12 months: 259 (82%), and 24 months: is ongoing with 152 having completed out of the 199 participants (76%) who were eligible to date (assessment windows were still open). Videogames can be developed to address complex behaviors and can be subject to empiric testing using community-based randomized controlled trials. Although mobile technologies pose challenges in their use as interventions and in the collection and storage of data they produce, they provide unique opportunities as new sources of potentially valid data and novel methods to measure the fidelity of digitally delivered behavioral interventions. © The Author(s) 2016.

Young children do not succeed in choice tasks that imply evaluating chances.

PubMed

Girotto, Vittorio; Fontanari, Laura; Gonzalez, Michel; Vallortigara, Giorgio; Blaye, Agnès

2016-07-01

Preverbal infants manifest probabilistic intuitions in their reactions to the outcomes of simple physical processes and in their choices. Their ability conflicts with the evidence that, before the age of about 5years, children's verbal judgments do not reveal probability understanding. To assess these conflicting results, three studies tested 3-5-year-olds on choice tasks on which infants perform successfully. The results showed that children of all age groups made optimal choices in tasks that did not require forming probabilistic expectations. In probabilistic tasks, however, only 5-year-olds made optimal choices. Younger children performed at random and/or were guided by superficial heuristics. These results suggest caution in interpreting infants' ability to evaluate chance, and indicate that the development of this ability may not follow a linear trajectory. Copyright © 2016 Elsevier B.V. All rights reserved.

The Testing Methods and Gender Differences in Multiple-Choice Assessment

NASA Astrophysics Data System (ADS)

Ng, Annie W. Y.; Chan, Alan H. S.

2009-10-01

This paper provides a comprehensive review of the multiple-choice assessment in the past two decades for facilitating people to conduct effective testing in various subject areas. It was revealed that a variety of multiple-choice test methods viz. conventional multiple-choice, liberal multiple-choice, elimination testing, confidence marking, probability testing, and order-of-preference scheme are available for use in assessing subjects' knowledge and decision ability. However, the best multiple-choice test method for use has not yet been identified. The review also indicated that the existence of gender differences in multiple-choice task performance might be due to the test area, instruction/scoring condition, and item difficulty.

Kinesiotaping as an alternative treatment method for carpal tunnel syndrome.

PubMed

Geler Külcü, Duygu; Bursali, Canan; Aktaş, İlknur; Bozkurt Alp, Selin; Ünlü Özkan, Feyza; Akpinar, Pınar

2016-06-23

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy. Conservative treatment choices are not always satisfactory. The aim of this study was to investigate the effect of kinesiotaping (KT) on pain level, grip strength, and functional status compared with that of placebo KT and orthotic device (OD) in patients with CTS. In this randomized, placebo-controlled study, participants were allocated into one of three groups: an experimental KT group (Group 1), a placebo KT group (Group 2), and an OD group (Group 3). Visual analogue scale (VAS) and Douleur Neuropathique 4 (DN4) scores, dynamometric grip strength measures, and the Boston CTS questionnaire (BQ) were the outcome measures. All groups significantly improved in terms of VAS scores (P < 0.05), DN4 scores (P < 0.05), and BQ scores (P < 0.05). Grip strength improved in Group 3 (P = 0.001). There was a significant difference among the groups with respect to BQ scores (P < 0.05). KT application for the treatment of CTS should be an alternative treatment choice.

The use of the mandibular infiltration anesthetic technique in adults.

PubMed

Meechan, John G

2011-09-01

The author describes the use of the infiltration anesthetic technique to anesthetize mandibular teeth in adults and explores its mechanism of action. The author reviewed articles describing randomized controlled trials of the mandibular infiltration anesthetic technique in healthy participants. The author found that using the mandibular infiltration anesthetic technique can produce anesthesia in adult mandibular teeth. The success was dose dependent and the choice of anesthetic solution was significant; 4 percent articaine with 1:100,000 epinephrine was more effective than 2 percent lidocaine with 1:100,000 epinephrine. Combining buccal and lingual infiltrations increased success in the mandibular incisor region. The success of the mechanism of infiltration of anesthetic at the mandibular first molar appeared to depend on the mental foramen. The mandibular infiltration anesthetic technique is an effective method of anesthetizing mandibular incisors. Four percent articaine with epinephrine appears to be the preferred solution. The choice of anesthetic solution is important when using the infiltration anesthetic technique in the adult mandible.

Providing choice and/or variety during a meal: Impact on vegetable liking and intake.

PubMed

Parizel, Odile; Labouré, Hélène; Marsset-Baglieri, Agnès; Fromentin, Gilles; Sulmont-Rossé, Claire

2017-01-01

Out-of-home catering services frequently offer consumers the opportunity to choose their foods from among different proposals and/or provide consumers with a variety of food. The aim of the present study was to assess the impact of choice and/or variety on food liking and food intake. Fifty-nine normal-weight adults were recruited under the condition that they equally liked three vegetable recipes (green beans with butter, zucchinis with olive oil, spinach with cream). Volunteers participated in four sessions at lunch time. In the no-choice/no-variety condition, volunteers were served one dish randomly selected from among the three. In the no-choice/variety condition, volunteers were served all three dishes. In the choice/no-variety condition, participants chose one dish from among the three dishes. In the choice/variety condition, volunteers chose as many dishes as they desired from among the three dishes. Results showed that providing choice increased vegetable liking and vegetable intake, while offering a variety of vegetables only increased their liking. No synergy effect between choice and variety was observed on vegetable liking and vegetable intake (i.e. the effect in the choice/variety condition was not significantly higher than the effects in no-choice/variety and the choice/no-variety conditions). Published by Elsevier Ltd.

Sensitivity of Above-Ground Biomass Estimates to Height-Diameter Modelling in Mixed-Species West African Woodlands

PubMed Central

Aynekulu, Ermias; Pitkänen, Sari; Packalen, Petteri

2016-01-01

It has been suggested that above-ground biomass (AGB) inventories should include tree height (H), in addition to diameter (D). As H is a difficult variable to measure, H-D models are commonly used to predict H. We tested a number of approaches for H-D modelling, including additive terms which increased the complexity of the model, and observed how differences in tree-level predictions of H propagated to plot-level AGB estimations. We were especially interested in detecting whether the choice of method can lead to bias. The compared approaches listed in the order of increasing complexity were: (B0) AGB estimations from D-only; (B1) involving also H obtained from a fixed-effects H-D model; (B2) involving also species; (B3) including also between-plot variability as random effects; and (B4) involving multilevel nested random effects for grouping plots in clusters. In light of the results, the modelling approach affected the AGB estimation significantly in some cases, although differences were negligible for some of the alternatives. The most important differences were found between including H or not in the AGB estimation. We observed that AGB predictions without H information were very sensitive to the environmental stress parameter (E), which can induce a critical bias. Regarding the H-D modelling, the most relevant effect was found when species was included as an additive term. We presented a two-step methodology, which succeeded in identifying the species for which the general H-D relation was relevant to modify. Based on the results, our final choice was the single-level mixed-effects model (B3), which accounts for the species but also for the plot random effects reflecting site-specific factors such as soil properties and degree of disturbance. PMID:27367857

Pseudo-random generator based on Chinese Remainder Theorem

NASA Astrophysics Data System (ADS)

Bajard, Jean Claude; Hördegen, Heinrich

2009-08-01

Pseudo-Random Generators (PRG) are fundamental in cryptography. Their use occurs at different level in cipher protocols. They need to verify some properties for being qualified as robust. The NIST proposes some criteria and a tests suite which gives informations on the behavior of the PRG. In this work, we present a PRG constructed from the conversion between further residue systems of representation of the elements of GF(2)[X]. In this approach, we use some pairs of co-prime polynomials of degree k and a state vector of 2k bits. The algebraic properties are broken by using different independent pairs during the process. Since this method is reversible, we also can use it as a symmetric crypto-system. We evaluate the cost of a such system, taking into account that some operations are commonly implemented on crypto-processors. We give the results of the different NIST Tests and we explain this choice compare to others found in the literature. We describe the behavior of this PRG and explain how the different rounds are chained for ensuring a fine secure randomness.

Conduct Problems and Peer Rejection in Childhood: A Randomized Trial of the Making Choices and Strong Families Programs

ERIC Educational Resources Information Center

Fraser, Mark W.; Day, Steven H.; Galinsky, Maeda J.; Hodges, Vanessa G.; Smokowski, Paul R.

2004-01-01

This article discusses the effectiveness of a multicomponent intervention designed to disrupt developmental processes associated with conduct problems and peer rejection in childhood. Compared with 41 children randomized to a wait list control condition, 45 children in an intervention condition received a social skills training program. At the…

The Potential Use of the Discouraging Random Guessing (DRG) Approach in Multiple-Choice Exams in Medical Education.

ERIC Educational Resources Information Center

Friedman, Miriam; And Others

1987-01-01

Test performances of sophomore medical students on a pretest and final exam (under guessing and no-guessing instructions) were compared. Discouraging random guessing produced test information with improved test reliability and less distortion of item difficulty. More able examinees were less compliant than less able examinees. (Author/RH)

Scaling Academic Planning in Community College: A Randomized Controlled Trial. REL 2017-204

ERIC Educational Resources Information Center

Visher, Mary G.; Mayer, Alexander K.; Johns, Michael; Rudd, Timothy; Levine, Andrew; Rauner, Mary

2016-01-01

Community college students often lack an academic plan to guide their choices of coursework to achieve their educational goals, in part because counseling departments typically lack the capacity to advise students at scale. This randomized controlled trial tests the impact of guaranteed access to one of two alternative counseling sessions (group…

Logical-Rule Models of Classification Response Times: A Synthesis of Mental-Architecture, Random-Walk, and Decision-Bound Approaches

ERIC Educational Resources Information Center

Fific, Mario; Little, Daniel R.; Nosofsky, Robert M.

2010-01-01

We formalize and provide tests of a set of logical-rule models for predicting perceptual classification response times (RTs) and choice probabilities. The models are developed by synthesizing mental-architecture, random-walk, and decision-bound approaches. According to the models, people make independent decisions about the locations of stimuli…

Risk Communication, Values Clarification, and Vaccination Decisions.

PubMed

Witteman, Holly O; Chipenda Dansokho, Selma; Exe, Nicole; Dupuis, Audrey; Provencher, Thierry; Zikmund-Fisher, Brian J

2015-10-01

Many health-related decisions require choosing between two options, each with risks and benefits. When presented with such tradeoffs, people often make choices that fail to align with scientific evidence or with their own values. This study tested whether risk communication and values clarification methods could help parents and guardians make evidence-based, values-congruent decisions about children's influenza vaccinations. In 2013-2014 we conducted an online 2×2 factorial experiment in which a diverse sample of U.S. parents and guardians (n = 407) were randomly assigned to view either standard information about influenza vaccines or risk communication using absolute and incremental risk formats. Participants were then either presented or not presented with an interactive values clarification interface with constrained sliders and dynamic visual feedback. Participants randomized to the risk communication condition combined with the values clarification interface were more likely to indicate intentions to vaccinate (β = 2.10, t(399) = 2.63, p < 0.01). The effect was particularly notable among participants who had previously demonstrated less interest in having their children vaccinated against influenza (β = -2.14, t(399) = -2.06, p < 0.05). When assessing vaccination status reported by participants who agreed to participate in a follow-up study six months later (n = 116), vaccination intentions significantly predicted vaccination status (OR = 1.66, 95%CI (1.13, 2.44), p < 0.05) and rates of informed choice (OR = 1.51, 95%CI (1.07, 2.13), p < 0.012), although there were no direct effects of experimental factors on vaccination rates. Qualitative analysis suggested that logistical barriers impeded immunization rates. Risk communication and values clarification methods may contribute to increased vaccination intentions, which may, in turn, predict vaccination status if logistical barriers are also addressed. © 2015 Society for Risk Analysis.

Dominance of Sterilization and Alternative Choices of Contraception in India: An Appraisal of the Socioeconomic Impact

PubMed Central

de Oliveira, Isabel Tiago; Dias, José G.; Padmadas, Sabu S.

2014-01-01

Background The recent decline in fertility in India has been unprecedented especially in southern India, where fertility is almost exclusively controlled by means of permanent contraceptive methods, mainly female sterilization, which constitutes about two-thirds of overall contraceptive use. Many Indian women undergo sterilization at relatively young ages as a consequence of early marriage and childbearing in short birth intervals. This research aims to investigate the socioeconomic factors determining the choices for alternative contraceptive choices against the dominant preference for sterilization among married women in India. Methods Data for this study are drawn from the 2005–06 National Family Health Surveys focusing on a sample of married women who reported having used a method of contraception in the five years preceding the survey. A multilevel multinomial logit regression is used to estimate the impact of socioeconomic factors on contraceptive choices, differentiating temporary modern or traditional methods versus sterilization. Findings Religious affiliation, women's education and occupation had overarching influence on method choices amongst recent users. Muslim women were at higher odds of choosing a traditional or modern temporary method than sterilization. Higher level of women's education increased the odds of modern temporary method choices but the education effect on traditional method choices was only marginally significant. Recent users belonging to wealthier households had higher odds of choosing modern methods over sterilization. Exposure to family planning messages through radio had a positive effect on modern and traditional method choices. Community variations in method choices were highly significant. Conclusion The persistent dominance of sterilization in the Indian family planning programme is largely determined by socioeconomic conditions. Reproductive health programmes should address the socioeconomic barriers and consider multiple cost-effective strategies such as mass media to promote awareness of modern temporary methods. PMID:24489759

Teaching Semantic Prosody of English Verbs through the DDL Approach and Its Effect on Learners' Vocabulary Choice Appropriateness in a Persian EFL Context

ERIC Educational Resources Information Center

Mansoory, Niloofar; Jafarpour, Mohsen

2014-01-01

This study examined teaching SP of English verbs through the data-driven learning (DDL) approach and its effect on learners' vocabulary choice appropriateness in the Persian English foreign language (EFL) context. In the present study, two male intact classes were selected. One of these two classes was randomly selected as a treatment group and…

The WOMEN study: what is the optimal method for ischemia evaluation in women? A multi-center, prospective, randomized study to establish the optimal method for detection of coronary artery disease (CAD) risk in women at an intermediate-high pretest likelihood of CAD: study design.

PubMed

Mieres, Jennifer H; Shaw, Leslee J; Hendel, Robert C; Heller, Gary V

2009-01-01

Coronary artery disease remains the leading cause of morbidity and mortality in women. The optimal non-invasive test for evaluation of ischemic heart disease in women is unknown. Although current guidelines support the choice of the exercise tolerance test (ETT) as a first line test for women with a normal baseline ECG and adequate exercise capabilities, supportive data for this recommendation are controversial. The what is the optimal method for ischemia evaluation in women? (WOMEN) study was designed to determine the optimal non-invasive strategy for CAD risk detection of intermediate and high risk women presenting with chest pain or equivalent symptoms suggestive of ischemic heart disease. The study will prospectively compare the 2-year event rates in women capable of performing exercise treadmill testing or Tc-99 m tetrofosmin SPECT myocardial perfusion imaging (MPI). The study will enroll women presenting for the evaluation of chest pain or anginal equivalent symptoms who are capable of performing >5 METs of exercise while at intermediate-high pretest risk for ischemic heart disease who will be randomized to either ETT testing alone or with Tc-99 m tetrofosmin SPECT MPI. The null hypothesis for this project is that the exercise ECG has the same negative predictive value for risk detection as gated myocardial perfusion SPECT in women. The primary aim is to compare 2-year cardiac event rates in women randomized to SPECT MPI to those randomized to ETT. The WOMEN study seeks to provide objective information for guidelines for the evaluation of symptomatic women with an intermediate-high likelihood for CAD.

Evaluation of implementation of a healthy food and drink supply strategy throughout the whole school environment in Queensland state schools, Australia.

PubMed

Dick, M; Lee, A; Bright, M; Turner, K; Edwards, R; Dawson, J; Miller, J

2012-10-01

This paper reports on the evaluation of the Smart Choices healthy food and drink supply strategy for Queensland schools (Smart Choices) implementation across the whole school environment in state government primary and secondary schools in Queensland, Australia. Three concurrent surveys using different methods for each group of stakeholders that targeted all 1275 school Principals, all 1258 Parent and Citizens' Associations (P&Cs) and a random sample of 526 tuckshop convenors throughout Queensland. Nine hundred and seventy-three Principals, 598 P&Cs and 513 tuckshop convenors participated with response rates of 78%, 48% and 98%, respectively. Nearly all Principals (97%), P&Cs (99%) and tuckshop convenors (97%) reported that their school tuckshop had implemented Smart Choices. The majority of Principals and P&Cs reported implementation, respectively, in: school breakfast programs (98 and 92%); vending machine stock (94 and 83%); vending machine advertising (85 and 84%); school events (87 and 88%); school sporting events (81 and 80%); sponsorship and advertising (93 and 84%); fundraising events (80 and 84%); and sporting clubs (73 and 75%). Implementation in curriculum activities, classroom rewards and class parties was reported, respectively, by 97%, 86% and 75% of Principals. Respondents also reported very high levels of understanding of Smart Choices and engagement of the school community. The results demonstrated that food supply interventions to promote nutrition across all domains of the school environment can be implemented successfully.

Factors associated with choice of a low-fat or low-carbohydrate diet during a behavioral weight loss intervention☆, ☆☆

PubMed Central

McVay, Megan A.; Voils, Corrine I.; Coffman, Cynthia J.; Geiselman, Paula J.; Kolotkin, Ronette L.; Mayer, Stephanie B.; Smith, Valerie A.; Gaillard, Leslie; Turner, Marsha J.; Yancy, William S.

2016-01-01

Individuals undertaking a weight loss effort have a choice among proven dietary approaches. Factors contributing to choice of either a low-fat/low-calorie diet or a low-carbohydrate diet, two of the most studied and popular dietary approaches, are unknown. The current study used data from participants randomized to the ‘choice’ arm of a trial examining whether being able to choose a diet regimen yields higher weight loss than being randomly assigned to a diet. At study entry, participants attended a group session during which they were provided tailored feedback indicating which diet was most consistent with their food preferences using the Geiselman Food Preference Questionnaire (FPQ), information about both diets, and example meals for each diet. One week later, they indicated which diet they chose to follow during the 48-week study, with the option of switching diets after 12 weeks. Of 105 choice arm participants, 44 (42%) chose the low-fat/low-calorie diet and 61 (58%) chose the low-carbohydrate diet. In bivariate analyses, diet choice was not associated with age, race, sex, education, BMI, or diabetes (all p > 0.05). Low-carbohydrate diet choice was associated with baseline higher percent fat intake (p = 0.007), lower percent carbohydrate intake (p = 0.02), and food preferences consistent with a low-carbohydrate diet according to FPQ (p < 0.0001). In a multivariable logistic regression model, only FPQ diet preference was associated with diet choice (p = 0.001). Reported reasons for diet choice were generally similar for those choosing either diet; however, concerns about negative health effects of the unselected diet was rated as more influential among participants selecting the low-fat diet. Only three low-carbohydrate and two low-fat diet participants switched diets at 12 weeks. Results suggest that when provided a choice between two popular weight loss dietary approaches, an individual's selection is likely influenced by baseline dietary intake pattern, and especially by his or her dietary preferences. Research is needed to determine if congruency between food preferences and dietary approach is associated with weight loss. PMID:25149197

Are patients’ preferences regarding the place of treatment heard and addressed at the point of referral: an exploratory study based on observations of GP-patient consultations

PubMed Central

2013-01-01

Background Today, in several north-western European countries, patients are encouraged to choose, actively, a healthcare provider. However, patients often visit the provider that is recommended by their general practitioner (GP). The introduction of patient choice requires GPs to support patients to be involved, actively, in the choice of a healthcare provider. We aim to investigate whether policy on patient choice is reflected in practice, i.e. what the role of the patient is in their choices of healthcare providers at the point of referral and to what extent GPs’ and patients’ healthcare paths influence the role that patients play in the referral decision. Methods In 2007–2008, we videotaped Dutch GP-patient consultations. For this study, we selected, at random, 72 videotaped consultations between 72 patients and 39 GPs in which the patient was referred to a healthcare provider. These were analysed using an observation protocol developed by the researchers. Results The majority of the patients had little or no input into the choice of a healthcare provider at the point of referral by their GP. Their GPs did not support them in actively choosing a provider and the patients often agreed with the provider that the GP proposed. Patients who were referred for diagnostic purposes seem to have had even less input into their choice of a provider than patients who were referred for treatment. Conclusions We found that the GP chooses a healthcare provider on behalf of the patient in most consultations, even though policy on patient choice expects from patients that they choose, actively, a provider. On the one hand, this could indicate that the policy needs adjustments. On the other hand, adjustments may be needed to practice. For instance, GPs could help patients to make an active choice of provider. However, certain patients prefer to let their GP decide as their agent. Even then, GPs need to know patients’ preferences, because in a principal-agent relationship, it is necessary that the agent is fully informed about the principal’s preferences. PMID:24325155

Dominance of sterilization and alternative choices of contraception in India: an appraisal of the socioeconomic impact.

PubMed

de Oliveira, Isabel Tiago; Dias, José G; Padmadas, Sabu S

2014-01-01

The recent decline in fertility in India has been unprecedented especially in southern India, where fertility is almost exclusively controlled by means of permanent contraceptive methods, mainly female sterilization, which constitutes about two-thirds of overall contraceptive use. Many Indian women undergo sterilization at relatively young ages as a consequence of early marriage and childbearing in short birth intervals. This research aims to investigate the socioeconomic factors determining the choices for alternative contraceptive choices against the dominant preference for sterilization among married women in India. Data for this study are drawn from the 2005-06 National Family Health Surveys focusing on a sample of married women who reported having used a method of contraception in the five years preceding the survey. A multilevel multinomial logit regression is used to estimate the impact of socioeconomic factors on contraceptive choices, differentiating temporary modern or traditional methods versus sterilization. Religious affiliation, women's education and occupation had overarching influence on method choices amongst recent users. Muslim women were at higher odds of choosing a traditional or modern temporary method than sterilization. Higher level of women's education increased the odds of modern temporary method choices but the education effect on traditional method choices was only marginally significant. Recent users belonging to wealthier households had higher odds of choosing modern methods over sterilization. Exposure to family planning messages through radio had a positive effect on modern and traditional method choices. Community variations in method choices were highly significant. The persistent dominance of sterilization in the Indian family planning programme is largely determined by socioeconomic conditions. Reproductive health programmes should address the socioeconomic barriers and consider multiple cost-effective strategies such as mass media to promote awareness of modern temporary methods.

Music-evoked incidental happiness modulates probability weighting during risky lottery choices

PubMed Central

Schulreich, Stefan; Heussen, Yana G.; Gerhardt, Holger; Mohr, Peter N. C.; Binkofski, Ferdinand C.; Koelsch, Stefan; Heekeren, Hauke R.

2014-01-01

We often make decisions with uncertain consequences. The outcomes of the choices we make are usually not perfectly predictable but probabilistic, and the probabilities can be known or unknown. Probability judgments, i.e., the assessment of unknown probabilities, can be influenced by evoked emotional states. This suggests that also the weighting of known probabilities in decision making under risk might be influenced by incidental emotions, i.e., emotions unrelated to the judgments and decisions at issue. Probability weighting describes the transformation of probabilities into subjective decision weights for outcomes and is one of the central components of cumulative prospect theory (CPT) that determine risk attitudes. We hypothesized that music-evoked emotions would modulate risk attitudes in the gain domain and in particular probability weighting. Our experiment featured a within-subject design consisting of four conditions in separate sessions. In each condition, the 41 participants listened to a different kind of music—happy, sad, or no music, or sequences of random tones—and performed a repeated pairwise lottery choice task. We found that participants chose the riskier lotteries significantly more often in the “happy” than in the “sad” and “random tones” conditions. Via structural regressions based on CPT, we found that the observed changes in participants' choices can be attributed to changes in the elevation parameter of the probability weighting function: in the “happy” condition, participants showed significantly higher decision weights associated with the larger payoffs than in the “sad” and “random tones” conditions. Moreover, elevation correlated positively with self-reported music-evoked happiness. Thus, our experimental results provide evidence in favor of a causal effect of incidental happiness on risk attitudes that can be explained by changes in probability weighting. PMID:24432007

Nudging and social marketing techniques encourage employees to make healthier food choices: a randomized controlled trial in 30 worksite cafeterias in The Netherlands.

PubMed

Velema, Elizabeth; Vyth, Ellis L; Hoekstra, Trynke; Steenhuis, Ingrid H M

2018-02-01

Currently, many studies focus on how the environment can be changed to encourage healthier eating behavior, referred to as choice architecture or "nudging." However, to date, these strategies are not often investigated in real-life settings, such as worksite cafeterias, or are only done so on a short-term basis. The objective of this study is to examine the effects of a healthy worksite cafeteria ["worksite cafeteria 2.0" (WC 2.0)] intervention on Dutch employees' purchase behavior over a 12-wk period. We conducted a randomized controlled trial in 30 worksite cafeterias. Worksite cafeterias were randomized to either the intervention or control group. The intervention aimed to encourage employees to make healthier food choices during their daily worksite cafeteria visits. The intervention consisted of 14 simultaneously executed strategies based on nudging and social marketing theories, involving product, price, placement, and promotion. Adjusted multilevel models showed significant positive effects of the intervention on purchases for 3 of the 7 studied product groups: healthier sandwiches, healthier cheese as a sandwich filling, and the inclusion of fruit. The increased sales of these healthier meal options were constant throughout the 12-wk intervention period. This study shows that the way worksite cafeterias offer products affects purchase behavior. Situated nudging and social marketing-based strategies are effective in promoting healthier choices and aim to remain effective over time. Some product groups only indicated an upward trend in purchases. Such an intervention could ultimately help prevent and reduce obesity in the Dutch working population. This trial was registered at the Dutch Trial Register (http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=5372) as NTR5372.

Considering Patient Diet Preference to Optimize Weight Loss: Design Considerations of a Randomized Trial Investigating the Impact of Choice

PubMed Central

Yancy, William S.; Coffman, Cynthia J.; Geiselman, Paula J.; Kolotkin, Ronette L.; Almirall, Daniel; Oddone, Eugene Z.; Mayer, Stephanie B.; Gaillard, Leslie A.; Turner, Marsha; Smith, Valerie A.; Voils, Corrine I.

2015-01-01

A variety of diet approaches achieve moderate weight loss in many individuals. Yet, most diet interventions fail to achieve meaningful weight loss in more than a few individuals, likely due to inadequate adherence to the diet. It is widely conjectured that targeting the diet to an individual's food preferences will enhance adherence, thereby improving weight loss. This article describes the design considerations of a study protocol aimed at testing this hypothesis. The study is a 2-arm randomized trial recruiting 216 medical outpatients with BMI ≥30 kg/m2 followed for 48 weeks. Participants in the experimental arm (Choice) select from two of the most widely studied diets for weight loss, a low-carbohydrate, calorie-unrestricted diet (LCD) or a low-fat, reduced-calorie diet (LFD). The participant's choice is informed by results from a validated food preference questionnaire and a discussion of diet options with trained personnel. Choice participants are given the option to switch to the other diet after three months, if desired. Participants in the Control arm are randomly assigned to follow one of the two diets for the duration of follow-up. The primary outcome is weight assessed every 2-4 weeks for 48 weeks. Secondary outcomes include adherence to diet by food frequency questionnaire and obesity-specific health-related quality of life. If assisting patients to choose their diet enhances adherence and increases weight loss, the results will support the provision of diet options to patients who desire weight loss, and bring us one step closer to remediating the obesity epidemic faced by our healthcare systems. PMID:23506974

Music-evoked incidental happiness modulates probability weighting during risky lottery choices.

PubMed

Schulreich, Stefan; Heussen, Yana G; Gerhardt, Holger; Mohr, Peter N C; Binkofski, Ferdinand C; Koelsch, Stefan; Heekeren, Hauke R

2014-01-07

We often make decisions with uncertain consequences. The outcomes of the choices we make are usually not perfectly predictable but probabilistic, and the probabilities can be known or unknown. Probability judgments, i.e., the assessment of unknown probabilities, can be influenced by evoked emotional states. This suggests that also the weighting of known probabilities in decision making under risk might be influenced by incidental emotions, i.e., emotions unrelated to the judgments and decisions at issue. Probability weighting describes the transformation of probabilities into subjective decision weights for outcomes and is one of the central components of cumulative prospect theory (CPT) that determine risk attitudes. We hypothesized that music-evoked emotions would modulate risk attitudes in the gain domain and in particular probability weighting. Our experiment featured a within-subject design consisting of four conditions in separate sessions. In each condition, the 41 participants listened to a different kind of music-happy, sad, or no music, or sequences of random tones-and performed a repeated pairwise lottery choice task. We found that participants chose the riskier lotteries significantly more often in the "happy" than in the "sad" and "random tones" conditions. Via structural regressions based on CPT, we found that the observed changes in participants' choices can be attributed to changes in the elevation parameter of the probability weighting function: in the "happy" condition, participants showed significantly higher decision weights associated with the larger payoffs than in the "sad" and "random tones" conditions. Moreover, elevation correlated positively with self-reported music-evoked happiness. Thus, our experimental results provide evidence in favor of a causal effect of incidental happiness on risk attitudes that can be explained by changes in probability weighting.

Reproductive health choices for young adults with sickle cell disease or trait: randomized controlled trial immediate posttest effects.

PubMed

Wilkie, Diana J; Gallo, Agatha M; Yao, Yingwei; Molokie, Robert E; Stahl, Christine; Hershberger, Patricia E; Zhao, Zhongsheng; Suarez, Marie L; Labotka, Robert J; Johnson, Bonnye; Angulo, Rigo; Angulo, Veronica; Carrasco, Jesus; Shuey, David; Pelligra, Stephanie; Wang, Edward; Rogers, Dennie T; Thompson, Alexis A

2013-01-01

People with sickle cell disease (SCD) or sickle cell trait (SCT) may not have information about genetic inheritance needed for making informed reproductive health decisions. CHOICES is a Web-based, multimedia educational intervention that provides information about reproductive options and consequences to help those with SCD or SCT identify and implement an informed parenting plan. Efficacy of CHOICES compared with usual care must be evaluated. The purpose was to compare immediate posttest effects of CHOICES versus an attention-control usual care intervention (e-Book) on SCD-/SCT-related reproductive health knowledge, intention, and behavior. In a randomized controlled study, we recruited subjects with SCD/SCT from clinics, community settings, and online networks with data collected at sites convenient to the 234 subjects with SCD (n = 136) or SCT (n = 98). Their ages ranged from 18 to 35 years; 65% were women, and 94% were African American. Subjects completed a measure of sickle cell reproductive knowledge, intention, and behavior before and immediately after the intervention. Compared with the e-Book group, the CHOICES group had significantly higher average knowledge scores and probability of reporting a parenting plan to avoid SCD or SCD and SCT when pretest scores were controlled. Effects on intention and planned behavior were not significant. The CHOICES group showed significant change in their intention and planned behavior, whereas the e-Book group did not show significant change in their intention, but their planned behavior differed significantly. Initial efficacy findings are encouraging but warrant planned booster sessions and outcome follow-ups to determine sustained intervention efficacy on reproductive health knowledge, intention, and actual behavior of persons with SCD/SCT.

Choice of fluid therapy in patients of craniopharyngioma in the perioperative period: A hospital-based preliminary study

PubMed Central

Mukherjee, K. K.; Dutta, Pinaki; Singh, Apinderpreet; Gupta, Prakamya; Srinivasan, Anand; Bhagat, Hemant; Mathuriya, S. N.; Shah, Viral N.; Bhansali, Anil

2014-01-01

Background: Electrolyte imbalance and acute diabetes insipidus (DI) are the most common complications in patients undergoing craniopharyngioma surgery. Improper management of water and electrolyte imbalance is common cause of morbidity and mortality. Data is sparse and controversial regarding the choice of fluid therapy in this population during perioperative period. Methods: In this retrospective-prospective study involving 73 patients (58 retrospective), the type of fluid therapy was correlated with occurrence of hypernatremia, hyponatremia, DI, morbidity, and mortality. In the retrospective study, 48 patients received normal saline and 10 received mixed fluids as per the prevailing practice. In the prospective group, five patients each received normal saline, half normal saline, and 5% dextrose randomly. Results: The sodium values were significantly higher in first 48 h in the group that received normal saline compared with other groups (P < 0.001). The use of normal saline was associated with higher incidence of hypernatremia, DI, and mortality (P = 0.05), while the group that received 5% dextrose was associated with hyponatremia, hypoglycemia, and seizures. There was no perioperative hypotension with use of any of the fluids. Conclusion: Our results indicate half normal saline was fluid of choice with diminished incidence of water and electrolyte abnormalities without increase in mortality during postoperative period. PMID:25101200

The effects of food advertising and cognitive load on food choices

PubMed Central

2014-01-01

Background Advertising has been implicated in the declining quality of the American diet, but much of the research has been conducted with children rather than adults. This study tested the effects of televised food advertising on adult food choice. Methods Participants (N = 351) were randomized into one of 4 experimental conditions: exposure to food advertising vs. exposure to non-food advertising, and within each of these groups, exposure to a task that was either cognitively demanding or not cognitively demanding. The number of unhealthy snacks chosen was subsequently measured, along with total calories of the snacks chosen. Results Those exposed to food advertising chose 28% more unhealthy snacks than those exposed to non-food-advertising (95% CI: 7% - 53%), with a total caloric value that was 65 kcal higher (95% CI: 10-121). The effect of advertising was not significant among those assigned to the low-cognitive-load group, but was large and significant among those assigned to the high-cognitive-load group: 43% more unhealthy snacks (95% CI: 11% - 85%) and 94 more total calories (95% CI: 19-169). Conclusions Televised food advertising has strong effects on individual food choice, and these effects are magnified when individuals are cognitively occupied by other tasks. PMID:24721289

Incentives for Blood Donation: A Discrete Choice Experiment to Analyze Extrinsic Motivation.

PubMed

Sadler, Andrew; Shi, Ling; Bethge, Susanne; Mühlbacher, Axel

2018-04-01

Background: Demographic trends affect size and age structure of populations. One of the consequences will be an increasing need for blood products to treat age-related diseases. Donation services rely on voluntariness and charitable motivation. It might be questioned whether there will be sufficient blood supply with voluntary donation. The present study focused on elicitation of preferences for incentives and aimed to contribute to the discussion on how to increase donation rates. Methods: A self-administered discrete choice experiment (DCE) was applied. Respondents were repeatedly asked to choose between hypothetical blood donation centers. In case of reluctance to receiving incentives a none-option was included. Random parameter logit (RPL) and latent class models (LCM) were used for analysis. Results: The study sample included 416 college students from the US and Germany. Choice decisions were significantly influenced by the characteristics of the donation center in the DCE. Incentives most preferred were monetary compensation, paid leave, and blood screening test. LCM identified subgroups with preference heterogeneity. Small subgroups indicated moderate to strong aversion to incentives. Conclusion: The majority of the sample positively responded to incentives and indicated a willingness to accept incentives. In face of future challenges, the judicious use and appropriate utilization of incentives might be an option to motivate potential donors and should be open to discussion.

Mitigating randomness of consumer preferences under certain conditional choices

NASA Astrophysics Data System (ADS)

Bothos, John M. A.; Thanos, Konstantinos-Georgios; Papadopoulou, Eirini; Daveas, Stelios; Thomopoulos, Stelios C. A.

2017-05-01

Agent-based crowd behaviour consists a significant field of research that has drawn a lot of attention in recent years. Agent-based crowd simulation techniques have been used excessively to forecast the behaviour of larger or smaller crowds in terms of certain given conditions influenced by specific cognition models and behavioural rules and norms, imposed from the beginning. Our research employs conditional event algebra, statistical methodology and agent-based crowd simulation techniques in developing a behavioural econometric model about the selection of certain economic behaviour by a consumer that faces a spectre of potential choices when moving and acting in a multiplex mall. More specifically we try to analyse the influence of demographic, economic, social and cultural factors on the economic behaviour of a certain individual and then we try to link its behaviour with the general behaviour of the crowds of consumers in multiplex malls using agent-based crowd simulation techniques. We then run our model using Generalized Least Squares and Maximum Likelihood methods to come up with the most probable forecast estimations, regarding the agent's behaviour. Our model is indicative about the formation of consumers' spectre of choices in multiplex malls under the condition of predefined preferences and can be used as a guide for further research in this area.

Health concern, food choice motives, and attitudes toward healthy eating: the mediating role of food choice motives.

PubMed

Sun, Yu-Hua Christine

2008-07-01

This study addresses how various health concerns might influence not only consumers' food choice motives but also consumers' subsequent attitudes toward healthy eating. This study expects that those consumers with greater health concerns would have different food choice motives and better attitudes toward healthy eating. A self-completion questionnaire was used to gather information. Participants, a random sample of 500 undergraduate students from a national university in Taipei, Taiwan, provided a total of 456 usable questionnaires, representing a valid response rate of 91%. The average age of the respondents at the time of the survey was 21 years and 63% of respondents were females. The relationship between health concern and healthy eating attitudes was confirmed. The relationship between health concern of developing diseases and attitudes toward healthy eating was fully mediated by food choice motives. However, the relationship between calorie consumption health concern and healthy eating attitudes was only partially mediated by food choice motives. Implications of these findings are discussed.

Resistance of Collard Green Genotypes to Bemisia tabaci Biotype B: Characterization of Antixenosis.

PubMed

Domingos, G M; Baldin, E L L; Canassa, V F; Silva, I F; Lourenção, A L

2018-08-01

Bemisia tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) is an important pest of vegetable crops, including collard greens Brassica oleracea var. acephala (Brassicaceae). The use of resistant genotypes is an interesting option to reduce insect populations and can be used as an important tool for integrated pest management (IPM). This study evaluated 32 genotypes of collard greens against the attack of silver leaf whitefly, with the aim to characterize antixenosis. Initially, a multiple-choice trial was conducted using all genotypes, in which the adult attractiveness was assessed on two leaves per genotype at 24 and 48 h after infestation. After 48 h, one leaf of each genotype was randomly selected for the determination of the number of eggs per square centimeter. From the results of the multiple-choice trial, 13 genotypes were selected for a no-choice oviposition test, following the same method of the previous test. Colorimetric analyses were also performed to establish possible correlations between leaf color and insect colonization. Genotypes HS-20, OE, and VA were less attractive, demonstrating antixenosis. Genotypes LG, VE, J, MG, MOP, HS-20, VA, and MT had less oviposition in the multiple-choice test, which indicated expression of antixenosis. In the no-choice test, genotypes VE, P1C, CCB, RI-919, H, and J had less oviposition, which also characterized antixenosis. Therefore, genotypes VE and J showed the highest resistance stability because both had less oviposition in both test modalities. Thus, the resistance to B. tabaci biotype B indicates the genotypes HS-20, OE, VA, VE, and J are promising for use in breeding programs to develop resistance to whitefly.

Parents' meal choices for their children at fast food and family restaurants with different menu labeling presentations

PubMed Central

2018-01-01

BACKGROUND/OBJECTIVES This study examined the effect of nutrition labeling formats on parents' food choices for their children at different restaurant types. SUBJECTS/METHODS An online survey was conducted with 1,980 parents of children aged 3–12 years. Participants were randomly assigned to fast food or family restaurant scenarios, and one of four menu stimuli conditions: no labeling, low-calorie symbol (symbol), numeric value (numeric), and both low-calorie symbol and numeric value (symbol + numeric). Participants selected menu items for their children. Menu choices and total calories were compared by nutrition labeling formats in each type of the restaurant. RESULTS Low-calorie item selections were scored and a two-way analysis of variance (ANOVA) was conducted for an interaction effect between restaurant and labeling type. In the fast food restaurant group, parents presented with low-calorie symbols selected the lowest calorie items more often than those not presented with the format. Parents in the symbol + numeric condition selected significantly fewer calories (653 kcal) than those in the no labeling (677 kcal) or numeric conditions (674 kcal) (P = 0.006). In the family restaurant group, no significant difference were observed among different labeling conditions. A significant interaction between restaurant and labeling type on low-calorie selection score (F = 6.03, P < 0.01) suggests that the effect of nutrition labeling format interplays with restaurant type to jointly affect parents' food choices for their children. CONCLUSIONS The provision of easily interpretable nutritional information format at fast food restaurants may encourage healthier food choices of parents for their children; however, the effects were negligible at family restaurants. PMID:29854330

Acceptability of a transdermal gel-based male hormonal contraceptive in a randomized controlled trial.

PubMed

Roth, Mara Y; Shih, Grace; Ilani, Niloufar; Wang, Christina; Page, Stephanie T; Bremner, William J; Swerdloff, Ronald S; Sitruk-Ware, Regine; Blithe, Diana L; Amory, John K

2014-10-01

Fifty percent of pregnancies in the United States are unintended despite numerous contraceptive methods available to women. The only male contraceptive methods, vasectomy and condoms, are used by 10% and 16% of couples, respectively. Prior studies have shown efficacy of male hormonal contraceptives in development, but few have evaluated patient acceptability and potential use if commercially available. The objective of this study is to determine if a transdermal gel-based male hormonal contraceptive regimen, containing testosterone and Nestorone® gels, would be acceptable to study participants as a primary contraceptive method. As part of a three-arm, 6-month, double-blind, randomized controlled trial of testosterone and nestorone gels at two academic medical centers, subjects completed a questionnaire to assess the acceptability of the regimen. Of the 99 men randomized, 79 provided data for analysis. Overall, 56% (44/79) of men were satisfied or extremely satisfied with this gel-based method of contraception, and 51% (40/79) reported that they would recommend this method to others. One third of subjects (26/79) reported that they would use this as their primary method of contraception if it were commercially available today. However, men with concerns about sexually transmitted disease were significantly less satisfied than men without such concerns (p=0.03). A majority of the men who volunteered to participate in this trial of an experimental male hormonal contraceptive were satisfied with this transdermal male hormonal contraceptive. If commercially available, a combination of topical nesterone and testosterone gels could provide a reversible, effective method of contraception that is appealing to men. A substantial portion of men report they would use this transdermal male contraceptive regimen if commercially available. This method would provide a novel, reversible method of contraception for men, whose current choices are limited to condoms and vasectomy. Copyright © 2014 Elsevier Inc. All rights reserved.

Acceptability of a transdermal gel-based male hormonal contraceptive in a randomized controlled trial☆, ☆☆, ★

PubMed Central

Roth, Mara Y.; Shih, Grace; Ilani, Niloufar; Wang, Christina; Page, Stephanie T.; Bremner, William J.; Swerdloff, Ronald S.; Sitruk-Ware, Regine; Blithe, Diana L.; Amory, John K.

2014-01-01

Objective Fifty percent of pregnancies in the United States are unintended despite numerous contraceptive methods available to women. The only male contraceptive methods, vasectomy and condoms, are used by 10% and 16% of couples, respectively. Prior studies have shown efficacy of male hormonal contraceptives in development, but few have evaluated patient acceptability and potential use if commercially available. The objective of this study is to determine if a transdermal gel-based male hormonal contraceptive regimen, containing testosterone and Nestorone® gels, would be acceptable to study participants as a primary contraceptive method. Study Design As part of a three-arm, 6-month, double-blind, randomized controlled trial of testosterone and nestorone gels at two academic medical centers, subjects completed a questionnaire to assess the acceptability of the regimen. Of the 99 men randomized, 79 provided data for analysis. Results Overall, 56% (44/79) of men were satisfied or extremely satisfied with this gel-based method of contraception, and 51% (40/79) reported that they would recommend this method to others. One third of subjects (26/79) reported that they would use this as their primary method of contraception if it were commercially available today. However, men with concerns about sexually transmitted disease were significantly less satisfied than men without such concerns (p=0.03). Conclusions A majority of the men who volunteered to participate in this trial of an experimental male hormonal contraceptive were satisfied with this transdermal male hormonal contraceptive. If commercially available, a combination of topical nesterone and testosterone gels could provide a reversible, effective method of contraception that is appealing to men. Implications A substantial portion of men report they would use this transdermal male contraceptive regimen if commercially available. This method would provide a novel, reversible method of contraception for men, whose current choices are limited to condoms and vasectomy. PMID:24981149

Comparison of paragraph comprehension test scores with reading versus listening-reading and multiple-choice versus nominal recall administration techniques: justification for the bypass approach.

PubMed

Weinberg, W A; McLean, A; Snider, R L; Rintelmann, J W; Brumback, R A

1989-12-01

Eight groups of learning disabled children (N = 100), categorized by the clinical Lexical Paradigm as good readers or poor readers, were individually administered the Gilmore Oral Reading Test, Form D, by one of four input/retrieval methods: (1) the standardized method of administration in which the child reads each paragraph aloud and then answers five questions relating to the paragraph [read/recall method]; (2) the child reads each paragraph aloud and then for each question selects the correct answer from among three choices read by the examiner [read/choice method]; (3) the examiner reads each paragraph aloud and reads each of the five questions to the child to answer [listen/recall method]; and (4) the examiner reads each paragraph aloud and then for each question reads three multiple-choice answers from which the child selects the correct answer [listen/choice method]. The major difference in scores was between the groups tested by the recall versus the orally read multiple-choice methods. This study indicated that poor readers who listened to the material and were tested by orally read multiple-choice format could perform as well as good readers. The performance of good readers was not affected by listening or by the method of testing. The multiple-choice testing improved the performance of poor readers independent of the input method. This supports the arguments made previously that a "bypass approach" to education of poor readers in which testing is accomplished using an orally read multiple-choice format can enhance the child's school performance on reading-related tasks. Using a listening while reading input method may further enhance performance.

Randomized Controlled Trial of Full and Brief Cognitive-Behaviour Therapy and Wait-List for Paediatric Obsessive-Compulsive Disorder

ERIC Educational Resources Information Center

Bolton, Derek; Williams, Tim; Perrin, Sean; Atkinson, Linda; Gallop, Catherine; Waite, Polly; Salkovskis, Paul

2011-01-01

Background: Reviews and practice guidelines for paediatric obsessive-compulsive disorder (OCD) recommend cognitive-behaviour therapy (CBT) as the psychological treatment of choice, but note that it has not been sufficiently evaluated for children and adolescents and that more randomized controlled trials are needed. The aim of this trial was to…

A Randomized Trial Comparison of the Effects of Verbal and Pictorial Naturalistic Communication Strategies on Spoken Language for Young Children with Autism

ERIC Educational Resources Information Center

Schreibman, Laura; Stahmer, Aubyn C.

2014-01-01

Presently there is no consensus on the specific behavioral treatment of choice for targeting language in young nonverbal children with autism. This randomized clinical trial compared the effectiveness of a verbally-based intervention, Pivotal Response Training (PRT) to a pictorially-based behavioral intervention, the Picture Exchange Communication…

Feasibility of Conducting a Randomized Trial to Promote Healthy Eating, Active Play and Sustainability Awareness in Early Childhood Curricula

ERIC Educational Resources Information Center

Morris, Heather; Skouteris, Helen; Edwards, Susan; Rutherford, Leonie Margaret; Cutter-Mackenzie, Amy; O'Connor, Amanda; Mantilla, Ana; Huang, Terry TK; Lording, Kate Marion; Williams-Smith, Janet

2016-01-01

We sought to evaluate the feasibility of conducting a randomized trial to evaluate the efficacy of a preschool/kindergarten curriculum intervention designed to increase 4-year-old children's knowledge of healthy eating, active play and the sustainability consequences of their food and toy choices. Ninety intervention and 65 control parent/child…

Random preferences towards bioenergy environmental externalities: a case study of woody biomass based electricity in the Southern United States

Treesearch

Andres Susaeta; Pankaj Lal; Janaki Alavalapati; Evan Mercer

2011-01-01

This paper contrasts alternate methodological approaches of investigating public preferences, the random parameter logit (RPL) where tastes and preferences of respondents are assumed to be heterogeneous and the conditional logit (CL) approach where tastes and preferences remain fixed for individuals. We conducted a choice experiment to assess preferences for woody...

Metal-backed versus all-polyethylene tibial components in primary total knee arthroplasty

PubMed Central

2011-01-01

Background and purpose The choice of either all-polyethylene (AP) tibial components or metal-backed (MB) tibial components in total knee arthroplasty (TKA) remains controversial. We therefore performed a meta-analysis and systematic review of randomized controlled trials that have evaluated MB and AP tibial components in primary TKA. Methods The search strategy included a computerized literature search (Medline, EMBASE, Scopus, and the Cochrane Central Register of Controlled Trials) and a manual search of major orthopedic journals. A meta-analysis and systematic review of randomized or quasi-randomized trials that compared the performance of tibial components in primary TKA was performed using a fixed or random effects model. We assessed the methodological quality of studies using Detsky quality scale. Results 9 randomized controlled trials (RCTs) published between 2000 and 2009 met the inclusion quality standards for the systematic review. The mean standardized Detsky score was 14 (SD 3). We found that the frequency of radiolucent lines in the MB group was significantly higher than that in the AP group. There were no statistically significant differences between the MB and AP tibial components regarding component positioning, knee score, knee range of motion, quality of life, and postoperative complications. Interpretation Based on evidence obtained from this study, the AP tibial component was comparable with or better than the MB tibial component in TKA. However, high-quality RCTs are required to validate the results. PMID:21895503

The Numerical Competency of Two Bird Species (Corvus splendens and Acridotheres tristis).

PubMed

Rahman, Nor Amira Abdul; Fadzly, Nik; Dzakwan, Najibah Mohd; Zulkifli, Nur Hazwani

2014-08-01

We conducted a series of experiments to test the numerical competency of two species of birds, Corvus splendens (House Crow) and Acridotheres tristis (Common Myna). Both species were allowed to choose from seven different groups of mealworms with varying proportions. We considered the birds to have made a correct choice when it selected the food group with the highest number of mealworms. Our overall results indicated that the Common Myna is able to count numbers (161 successful choices out of 247 trials) better than House Crows (133 successful choices out of 241 trials). We suspect that House Crows do not rely on a numerical sense when selecting food. Although House Crows mostly chose the cup with more mealworms (from seven food item proportions), only one proportion was chosen at rate above random chance. The Common Myna, however, were slow performers at the beginning but became increasingly more capable of numerical sense during the remainder of the experiment (four out of seven food proportion groups were chosen at a rate above random chance).

The Numerical Competency of Two Bird Species (Corvus splendens and Acridotheres tristis)

PubMed Central

Rahman, Nor Amira Abdul; Fadzly, Nik; Dzakwan, Najibah Mohd; Zulkifli, Nur Hazwani

2014-01-01

We conducted a series of experiments to test the numerical competency of two species of birds, Corvus splendens (House Crow) and Acridotheres tristis (Common Myna). Both species were allowed to choose from seven different groups of mealworms with varying proportions. We considered the birds to have made a correct choice when it selected the food group with the highest number of mealworms. Our overall results indicated that the Common Myna is able to count numbers (161 successful choices out of 247 trials) better than House Crows (133 successful choices out of 241 trials). We suspect that House Crows do not rely on a numerical sense when selecting food. Although House Crows mostly chose the cup with more mealworms (from seven food item proportions), only one proportion was chosen at rate above random chance. The Common Myna, however, were slow performers at the beginning but became increasingly more capable of numerical sense during the remainder of the experiment (four out of seven food proportion groups were chosen at a rate above random chance). PMID:25210590

What's good and bad about contraceptive products?: a best-worst attribute experiment comparing the values of women consumers and GPs.

PubMed

Knox, Stephanie A; Viney, Rosalie C; Street, Deborah J; Haas, Marion R; Fiebig, Denzil G; Weisberg, Edith; Bateson, Deborah

2012-12-01

In the past decade, the range of contraceptives available has increased dramatically. There are limited data on the factors that determine women's choices on contraceptive alternatives or what factors providers consider most important when recommending contraceptive products to women. Our objectives were to compare women's (consumers') preferences and GPs' (providers') views in relation to existing and new contraceptive methods, and particularly to examine what factors increase the acceptability of different contraceptive products. A best-worst attribute stated-choice experiment was completed online. Participants (Australian women of reproductive age and Australian GPs) completed questions on 16 contraceptive profiles. 200 women of reproductive age were recruited through a commercial panel. GPs from all states of Australia were randomly sampled and approached by phone; 162 GPs agreed to participate. Participants chose the best and worst attribute levels of hypothetical but realistic prescribed contraceptive products. Best and worst choices were modelled using multinomial logit and product features were ranked from best to worst according to the size of model coefficients. The most attractive feature of the contraceptive products for both GPs and women consumers were an administration frequency of longer than 1 year and light or no bleeding. Women indicated that the hormonal vaginal ring was the least attractive mode of administration. Women and GPs agree that longer-acting methods with less bleeding are important features in preferred methods of contraception; however, women are also attracted to products involving less invasive modes of administration. While the vaginal ring may fill the niche in Australia for a relatively non-invasive, moderately long-acting and effective contraceptive, the results of this study indicate that GPs will need to promote the benefits of the vaginal ring to overcome negative perceptions about this method among women who may benefit from using it.

The effect of bearing surface on risk of periprosthetic joint infection in total hip arthroplasty: a systematic review and meta-analysis.

PubMed

Hexter, A T; Hislop, S M; Blunn, G W; Liddle, A D

2018-02-01

Periprosthetic joint infection (PJI) is a serious complication of total hip arthroplasty (THA). Different bearing surface materials have different surface properties and it has been suggested that the choice of bearing surface may influence the risk of PJI after THA. The objective of this meta-analysis was to compare the rate of PJI between metal-on-polyethylene (MoP), ceramic-on-polyethylene (CoP), and ceramic-on-ceramic (CoC) bearings. Electronic databases (Medline, Embase, Cochrane library, Web of Science, and Cumulative Index of Nursing and Allied Health Literature) were searched for comparative randomized and observational studies that reported the incidence of PJI for different bearing surfaces. Two investigators independently reviewed studies for eligibility, evaluated risk of bias, and performed data extraction. Meta-analysis was performed using the Mantel-Haenzel method and random-effects model in accordance with methods of the Cochrane group. Our search strategy revealed 2272 studies, of which 17 met the inclusion criteria and were analyzed. These comprised 11 randomized controlled trials and six observational studies. The overall quality of included studies was high but the observational studies were at high risk of bias due to inadequate adjustment for confounding factors. The overall cumulative incidence of PJI across all studies was 0.78% (1514/193 378). For each bearing combination, the overall incidence was as follows: MoP 0.85% (1353/158 430); CoP 0.38% (67/17 489); and CoC 0.53% (94/17 459). The meta-analysis showed no significant difference between the three bearing combinations in terms of risk of PJI. On the basis of the clinical studies available, there is no evidence that bearing choice influences the risk of PJI. Future research, including basic science studies and large, adequately controlled registry studies, may be helpful in determining whether implant materials play a role in determining the risk of PJI following arthroplasty surgery. Cite this article: Bone Joint J 2018;100-B:134-42. ©2018 The British Editorial Society of Bone & Joint Surgery.

Treatment of Subacromial Impingement Syndrome: Platelet-Rich Plasma or Exercise Therapy? A Randomized Controlled Trial.

PubMed

Nejati, Parisa; Ghahremaninia, Armita; Naderi, Farrokh; Gharibzadeh, Safoora; Mazaherinezhad, Ali

2017-05-01

Subacromial impingement syndrome (SAIS) is the most common disorder of the shoulder. The evidence for the effectiveness of treatment options is inconclusive and limited. Therefore, there is a need for more evidence in this regard, particularly for long-term outcomes. Platelet-rich plasma (PRP) would be an effective method in treating subacromial impingement. Randomized controlled trial; Level of evidence, 1. This was a single-blinded randomized clinical trial with 1-, 3-, and 6-month follow-up. Sixty-two patients were randomly placed into 2 groups, receiving either PRP or exercise therapy. The outcome parameters were pain, shoulder range of motion (ROM), muscle force, functionality, and magnetic resonance imaging findings. Both treatment options significantly reduced pain and increased shoulder ROM compared with baseline measurements. Both treatments also significantly improved functionality. However, the treatment choices were not significantly effective in improving muscle force. Trend analysis revealed that in the first and third months, exercise therapy was superior to PRP in pain, shoulder flexion and abduction, and functionality. However, in the sixth month, only shoulder abduction and total Western Ontario Rotator Cuff score were significantly different between the 2 groups. Both PRP injection and exercise therapy were effective in reducing pain and disability in patients with SAIS, with exercise therapy proving more effective.

Methods for converging correlation energies within the dielectric matrix formalism

NASA Astrophysics Data System (ADS)

Dixit, Anant; Claudot, Julien; Gould, Tim; Lebègue, Sébastien; Rocca, Dario

2018-03-01

Within the dielectric matrix formalism, the random-phase approximation (RPA) and analogous methods that include exchange effects are promising approaches to overcome some of the limitations of traditional density functional theory approximations. The RPA-type methods however have a significantly higher computational cost, and, similarly to correlated quantum-chemical methods, are characterized by a slow basis set convergence. In this work we analyzed two different schemes to converge the correlation energy, one based on a more traditional complete basis set extrapolation and one that converges energy differences by accounting for the size-consistency property. These two approaches have been systematically tested on the A24 test set, for six points on the potential-energy surface of the methane-formaldehyde complex, and for reaction energies involving the breaking and formation of covalent bonds. While both methods converge to similar results at similar rates, the computation of size-consistent energy differences has the advantage of not relying on the choice of a specific extrapolation model.

Error simulation of paired-comparison-based scaling methods

NASA Astrophysics Data System (ADS)

Cui, Chengwu

2000-12-01

Subjective image quality measurement usually resorts to psycho physical scaling. However, it is difficult to evaluate the inherent precision of these scaling methods. Without knowing the potential errors of the measurement, subsequent use of the data can be misleading. In this paper, the errors on scaled values derived form paired comparison based scaling methods are simulated with randomly introduced proportion of choice errors that follow the binomial distribution. Simulation results are given for various combinations of the number of stimuli and the sampling size. The errors are presented in the form of average standard deviation of the scaled values and can be fitted reasonably well with an empirical equation that can be sued for scaling error estimation and measurement design. The simulation proves paired comparison based scaling methods can have large errors on the derived scaled values when the sampling size and the number of stimuli are small. Examples are also given to show the potential errors on actually scaled values of color image prints as measured by the method of paired comparison.

Information fusion methods based on physical laws.

PubMed

Rao, Nageswara S V; Reister, David B; Barhen, Jacob

2005-01-01

We consider systems whose parameters satisfy certain easily computable physical laws. Each parameter is directly measured by a number of sensors, or estimated using measurements, or both. The measurement process may introduce both systematic and random errors which may then propagate into the estimates. Furthermore, the actual parameter values are not known since every parameter is measured or estimated, which makes the existing sample-based fusion methods inapplicable. We propose a fusion method for combining the measurements and estimators based on the least violation of physical laws that relate the parameters. Under fairly general smoothness and nonsmoothness conditions on the physical laws, we show the asymptotic convergence of our method and also derive distribution-free performance bounds based on finite samples. For suitable choices of the fuser classes, we show that for each parameter the fused estimate is probabilistically at least as good as its best measurement as well as best estimate. We illustrate the effectiveness of this method for a practical problem of fusing well-log data in methane hydrate exploration.

Image quality enhancement in low-light-level ghost imaging using modified compressive sensing method

NASA Astrophysics Data System (ADS)

Shi, Xiaohui; Huang, Xianwei; Nan, Suqin; Li, Hengxing; Bai, Yanfeng; Fu, Xiquan

2018-04-01

Detector noise has a significantly negative impact on ghost imaging at low light levels, especially for existing recovery algorithm. Based on the characteristics of the additive detector noise, a method named modified compressive sensing ghost imaging is proposed to reduce the background imposed by the randomly distributed detector noise at signal path. Experimental results show that, with an appropriate choice of threshold value, modified compressive sensing ghost imaging algorithm can dramatically enhance the contrast-to-noise ratio of the object reconstruction significantly compared with traditional ghost imaging and compressive sensing ghost imaging methods. The relationship between the contrast-to-noise ratio of the reconstruction image and the intensity ratio (namely, the average signal intensity to average noise intensity ratio) for the three reconstruction algorithms are also discussed. This noise suppression imaging technique will have great applications in remote-sensing and security areas.

Considerations of multiple imputation approaches for handling missing data in clinical trials.

PubMed

Quan, Hui; Qi, Li; Luo, Xiaodong; Darchy, Loic

2018-07-01

Missing data exist in all clinical trials and missing data issue is a very serious issue in terms of the interpretability of the trial results. There is no universally applicable solution for all missing data problems. Methods used for handling missing data issue depend on the circumstances particularly the assumptions on missing data mechanisms. In recent years, if the missing at random mechanism cannot be assumed, conservative approaches such as the control-based and returning to baseline multiple imputation approaches are applied for dealing with the missing data issues. In this paper, we focus on the variability in data analysis of these approaches. As demonstrated by examples, the choice of the variability can impact the conclusion of the analysis. Besides the methods for continuous endpoints, we also discuss methods for binary and time to event endpoints as well as consideration for non-inferiority assessment. Copyright © 2018. Published by Elsevier Inc.

Association of funding and conclusions in randomized drug trials: a reflection of treatment effect or adverse events?

PubMed

Als-Nielsen, Bodil; Chen, Wendong; Gluud, Christian; Kjaergard, Lise L

2003-08-20

Previous studies indicate that industry-sponsored trials tend to draw proindustry conclusions. To explore whether the association between funding and conclusions in randomized drug trials reflects treatment effects or adverse events. Observational study of 370 randomized drug trials included in meta-analyses from Cochrane reviews selected from the Cochrane Library, May 2001. From a random sample of 167 Cochrane reviews, 25 contained eligible meta-analyses (assessed a binary outcome; pooled at least 5 full-paper trials of which at least 1 reported adequate and 1 reported inadequate allocation concealment). The primary binary outcome from each meta-analysis was considered the primary outcome for all trials included in each meta-analysis. The association between funding and conclusions was analyzed by logistic regression with adjustment for treatment effect, adverse events, and additional confounding factors (methodological quality, control intervention, sample size, publication year, and place of publication). Conclusions in trials, classified into whether the experimental drug was recommended as the treatment of choice or not. The experimental drug was recommended as treatment of choice in 16% of trials funded by nonprofit organizations, 30% of trials not reporting funding, 35% of trials funded by both nonprofit and for-profit organizations, and 51% of trials funded by for-profit organizations (P<.001; chi2 test). Logistic regression analyses indicated that funding, treatment effect, and double blinding were the only significant predictors of conclusions. Adjusted analyses showed that trials funded by for-profit organizations were significantly more likely to recommend the experimental drug as treatment of choice (odds ratio, 5.3; 95% confidence interval, 2.0-14.4) compared with trials funded by nonprofit organizations. This association did not appear to reflect treatment effect or adverse events. Conclusions in trials funded by for-profit organizations may be more positive due to biased interpretation of trial results. Readers should carefully evaluate whether conclusions in randomized trials are supported by data.

The evolution of mate choice: a dialogue between theory and experiment.

PubMed

Roff, Derek A

2015-12-01

Research on the evolution of mate choice has followed three avenues of investigation: (1) theoretical models of the evolution of preference and the preferred trait; (2) proposed models of mate choice; and (3) experiments and observations on mate choice, both in the laboratory and with free-ranging animals. However, there has been relatively little dialogue among these three areas. Most attempts to account for observations of mate choice using theoretical mate-choice models have focused only upon a subset of particular models and have generally failed to consider the difference between probabilistic and deterministic models. In this review, I outline the underlying reasoning of the commonly cited mate-choice models and review the conclusions of the empirical investigations. I present a brief outline of how one might go about testing these models. It remains uncertain if, in general, mate-choice models can be realistically analyzed. Although it is clear that females frequently discriminate among males, data also suggest that females may typically have a very limited number of males from which to choose. The extent to which female choice under natural conditions is relatively random because of limited opportunities remains an open question for the majority of species. © 2015 New York Academy of Sciences.

Modeling Mode Choice Behavior Incorporating Household and Individual Sociodemographics and Travel Attributes Based on Rough Sets Theory

PubMed Central

Chen, Xuewu; Wei, Ming; Wu, Jingxian; Hou, Xianyao

2014-01-01

Most traditional mode choice models are based on the principle of random utility maximization derived from econometric theory. Alternatively, mode choice modeling can be regarded as a pattern recognition problem reflected from the explanatory variables of determining the choices between alternatives. The paper applies the knowledge discovery technique of rough sets theory to model travel mode choices incorporating household and individual sociodemographics and travel information, and to identify the significance of each attribute. The study uses the detailed travel diary survey data of Changxing county which contains information on both household and individual travel behaviors for model estimation and evaluation. The knowledge is presented in the form of easily understood IF-THEN statements or rules which reveal how each attribute influences mode choice behavior. These rules are then used to predict travel mode choices from information held about previously unseen individuals and the classification performance is assessed. The rough sets model shows high robustness and good predictive ability. The most significant condition attributes identified to determine travel mode choices are gender, distance, household annual income, and occupation. Comparative evaluation with the MNL model also proves that the rough sets model gives superior prediction accuracy and coverage on travel mode choice modeling. PMID:25431585

The effect of homework choices on achievement and intrinsic motivation

NASA Astrophysics Data System (ADS)

Christensen, Emily Fast

The purpose of this research was to test an intervention of choices in homework on the achievement and intrinsic motivation of seventh-grade science students at a middle school. The intervention was based on concepts from the cognitive evaluation theory of Edward L. Deci and Richard M. Ryan (1985). The subjects were sixteen heterogeneous classes of seventh-grade students, who were divided among four teachers. Two randomly chosen classes from each teacher received choices in their homework and the remaining two classes of each teacher received similar homework assignments without choices. Two hypotheses were developed for this study: (1) Seventh-grade science students given choices in their homework would show an increase in intrinsic motivation as measured on a motivation orientation measure, compared to students not given choices in their homework, and (2) Seventh-grade science students given choices in their homework would show an increase in achievement on an achievement measure, compared to students not given choices in their homework. Having choices in homework did not increase intrinsic motivation or achievement. However, students who did their homework did significantly better on the posttest, and students who were more intrinsically motivated did significantly better on the posttest. Just doing the homework was important for achievement, and intrinsic motivation was linked to achievement.

Lost in the crowd? Using eye-tracking to investigate the effect of complexity on attribute non-attendance in discrete choice experiments.

PubMed

Spinks, Jean; Mortimer, Duncan

2016-02-03

The provision of additional information is often assumed to improve consumption decisions, allowing consumers to more accurately weigh the costs and benefits of alternatives. However, increasing the complexity of decision problems may prompt changes in information processing. This is particularly relevant for experimental methods such as discrete choice experiments (DCEs) where the researcher can manipulate the complexity of the decision problem. The primary aims of this study are (i) to test whether consumers actually process additional information in an already complex decision problem, and (ii) consider the implications of any such 'complexity-driven' changes in information processing for design and analysis of DCEs. A discrete choice experiment (DCE) is used to simulate a complex decision problem; here, the choice between complementary and conventional medicine for different health conditions. Eye-tracking technology is used to capture the number of times and the duration that a participant looks at any part of a computer screen during completion of DCE choice sets. From this we can analyse what has become known in the DCE literature as 'attribute non-attendance' (ANA). Using data from 32 participants, we model the likelihood of ANA as a function of choice set complexity and respondent characteristics using fixed and random effects models to account for repeated choice set completion. We also model whether participants are consistent with regard to which characteristics (attributes) they consider across choice sets. We find that complexity is the strongest predictor of ANA when other possible influences, such as time pressure, ordering effects, survey specific effects and socio-demographic variables (including proxies for prior experience with the decision problem) are considered. We also find that most participants do not apply a consistent information processing strategy across choice sets. Eye-tracking technology shows promise as a way of obtaining additional information from consumer research, improving DCE design, and informing the design of policy measures. With regards to DCE design, results from the present study suggest that eye-tracking data can identify the point at which adding complexity (and realism) to DCE choice scenarios becomes self-defeating due to unacceptable increases in ANA. Eye-tracking data therefore has clear application in the construction of guidelines for DCE design and during piloting of DCE choice scenarios. With regards to design of policy measures such as labelling requirements for CAM and conventional medicines, the provision of additional information has the potential to make difficult decisions even harder and may not have the desired effect on decision-making.

Wavelet analysis in ecology and epidemiology: impact of statistical tests

PubMed Central

Cazelles, Bernard; Cazelles, Kévin; Chavez, Mario

2014-01-01

Wavelet analysis is now frequently used to extract information from ecological and epidemiological time series. Statistical hypothesis tests are conducted on associated wavelet quantities to assess the likelihood that they are due to a random process. Such random processes represent null models and are generally based on synthetic data that share some statistical characteristics with the original time series. This allows the comparison of null statistics with those obtained from original time series. When creating synthetic datasets, different techniques of resampling result in different characteristics shared by the synthetic time series. Therefore, it becomes crucial to consider the impact of the resampling method on the results. We have addressed this point by comparing seven different statistical testing methods applied with different real and simulated data. Our results show that statistical assessment of periodic patterns is strongly affected by the choice of the resampling method, so two different resampling techniques could lead to two different conclusions about the same time series. Moreover, our results clearly show the inadequacy of resampling series generated by white noise and red noise that are nevertheless the methods currently used in the wide majority of wavelets applications. Our results highlight that the characteristics of a time series, namely its Fourier spectrum and autocorrelation, are important to consider when choosing the resampling technique. Results suggest that data-driven resampling methods should be used such as the hidden Markov model algorithm and the ‘beta-surrogate’ method. PMID:24284892

Wavelet analysis in ecology and epidemiology: impact of statistical tests.

PubMed

Cazelles, Bernard; Cazelles, Kévin; Chavez, Mario

2014-02-06

Wavelet analysis is now frequently used to extract information from ecological and epidemiological time series. Statistical hypothesis tests are conducted on associated wavelet quantities to assess the likelihood that they are due to a random process. Such random processes represent null models and are generally based on synthetic data that share some statistical characteristics with the original time series. This allows the comparison of null statistics with those obtained from original time series. When creating synthetic datasets, different techniques of resampling result in different characteristics shared by the synthetic time series. Therefore, it becomes crucial to consider the impact of the resampling method on the results. We have addressed this point by comparing seven different statistical testing methods applied with different real and simulated data. Our results show that statistical assessment of periodic patterns is strongly affected by the choice of the resampling method, so two different resampling techniques could lead to two different conclusions about the same time series. Moreover, our results clearly show the inadequacy of resampling series generated by white noise and red noise that are nevertheless the methods currently used in the wide majority of wavelets applications. Our results highlight that the characteristics of a time series, namely its Fourier spectrum and autocorrelation, are important to consider when choosing the resampling technique. Results suggest that data-driven resampling methods should be used such as the hidden Markov model algorithm and the 'beta-surrogate' method.

Discrete choice experiments of pharmacy services: a systematic review.

PubMed

Vass, Caroline; Gray, Ewan; Payne, Katherine

2016-06-01

Background Two previous systematic reviews have summarised the application of discrete choice experiments to value preferences for pharmacy services. These reviews identified a total of twelve studies and described how discrete choice experiments have been used to value pharmacy services but did not describe or discuss the application of methods used in the design or analysis. Aims (1) To update the most recent systematic review and critically appraise current discrete choice experiments of pharmacy services in line with published reporting criteria and; (2) To provide an overview of key methodological developments in the design and analysis of discrete choice experiments. Methods The review used a comprehensive strategy to identify eligible studies (published between 1990 and 2015) by searching electronic databases for key terms related to discrete choice and best-worst scaling (BWS) experiments. All healthcare choice experiments were then hand-searched for key terms relating to pharmacy. Data were extracted using a published checklist. Results A total of 17 discrete choice experiments eliciting preferences for pharmacy services were identified for inclusion in the review. No BWS studies were identified. The studies elicited preferences from a variety of populations (pharmacists, patients, students) for a range of pharmacy services. Most studies were from a United Kingdom setting, although examples from Europe, Australia and North America were also identified. Discrete choice experiments for pharmacy services tended to include more attributes than non-pharmacy choice experiments. Few studies reported the use of qualitative research methods in the design and interpretation of the experiments (n = 9) or use of new methods of analysis to identify and quantify preference and scale heterogeneity (n = 4). No studies reported the use of Bayesian methods in their experimental design. Conclusion Incorporating more sophisticated methods in the design of pharmacy-related discrete choice experiments could help researchers produce more efficient experiments which are better suited to valuing complex pharmacy services. Pharmacy-related discrete choice experiments could also benefit from more sophisticated analytical techniques such as investigations into scale and preference heterogeneity. Employing these sophisticated methods for both design and analysis could extend the usefulness of discrete choice experiments to inform health and pharmacy policy.

Heterogeneous Suppression of Sequential Effects in Random Sequence Generation, but Not in Operant Learning.

PubMed

Shteingart, Hanan; Loewenstein, Yonatan

2016-01-01

There is a long history of experiments in which participants are instructed to generate a long sequence of binary random numbers. The scope of this line of research has shifted over the years from identifying the basic psychological principles and/or the heuristics that lead to deviations from randomness, to one of predicting future choices. In this paper, we used generalized linear regression and the framework of Reinforcement Learning in order to address both points. In particular, we used logistic regression analysis in order to characterize the temporal sequence of participants' choices. Surprisingly, a population analysis indicated that the contribution of the most recent trial has only a weak effect on behavior, compared to more preceding trials, a result that seems irreconcilable with standard sequential effects that decay monotonously with the delay. However, when considering each participant separately, we found that the magnitudes of the sequential effect are a monotonous decreasing function of the delay, yet these individual sequential effects are largely averaged out in a population analysis because of heterogeneity. The substantial behavioral heterogeneity in this task is further demonstrated quantitatively by considering the predictive power of the model. We show that a heterogeneous model of sequential dependencies captures the structure available in random sequence generation. Finally, we show that the results of the logistic regression analysis can be interpreted in the framework of reinforcement learning, allowing us to compare the sequential effects in the random sequence generation task to those in an operant learning task. We show that in contrast to the random sequence generation task, sequential effects in operant learning are far more homogenous across the population. These results suggest that in the random sequence generation task, different participants adopt different cognitive strategies to suppress sequential dependencies when generating the "random" sequences.

Influence of choice on vegetable intake in children: an in-home study.

PubMed

de Wild, Victoire W T; de Graaf, Cees; Boshuizen, Hendriek C; Jager, Gerry

2015-08-01

Children's vegetable consumption is still far below that recommended, and stimulating their intake is a challenge for caregivers. The objective of this study was to investigate whether choice-offering is an effective strategy to increase children's vegetable intake in an in-home situation. Seventy children (mean age 3.7; SD 1) randomly assigned to a choice or a no-choice condition, were exposed 12 times to six familiar target vegetables at home during dinner. In the choice group, two selected vegetables were offered each time, whereas the no-choice group only received one vegetable. Vegetable intake was measured by weighing children's plates before and after dinner. A mixed linear model with age, gender, and baseline vegetable liking as covariates was used to compare intake between the choice and the no-choice group. Mixed linear model analysis yielded estimated means for vegetable intake of 48.5 g +/- 30 in the no-choice group and 57.7 g +/- 31 for the choice group (P = 0.09). In addition, baseline vegetable liking (P <0.001) and age (P = 0.06) predicted vegetable intake to be higher when the child liked vegetables better and with older age. These findings suggest that choice-offering has some, but hardly robust, effect on increasing vegetable intake in children. Other factors such as age and liking of vegetables also mediate the effect of offering a choice. Copyright © 2015 Elsevier Ltd. All rights reserved.

SU-E-E-02: An Excel-Based Study Tool for ABR-Style Exams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cline, K; Stanley, D; Defoor, D

2015-06-15

Purpose: As the landscape of learning and testing shifts toward a computer-based environment, a replacement for paper-based methods of studying is desirable. Using Microsoft Excel, a study tool was developed that allows the user to populate multiple-choice questions and then generate an interactive quiz session to answer them. Methods: The code for the tool was written using Microsoft Excel Visual Basic for Applications with the intent that this tool could be implemented by any institution with Excel. The base tool is a template with a setup macro, which builds out the structure based on user’s input. Once the framework ismore » built, the user can input sets of multiple-choice questions, answer choices, and even add figures. The tool can be run in random-question or sequential-question mode for single or multiple courses of study. The interactive session allows the user to select answer choices and immediate feedback is provided. Once the user is finished studying, the tool records the day’s progress by reporting progress statistics useful for trending. Results: Six doctoral students at UTHSCSA have used this tool for the past two months to study for their qualifying exam, which is similar in format and content to the American Board of Radiology (ABR) Therapeutic Part II exam. The students collaborated to create a repository of questions, met weekly to go over these questions, and then used the tool to prepare for their exam. Conclusion: The study tool has provided an effective and efficient way for students to collaborate and be held accountable for exam preparation. The ease of use and familiarity of Excel are important factors for the tool’s use. There are software packages to create similar question banks, but this study tool has no additional cost for those that already have Excel. The study tool will be made openly available.« less

Optimization of Ferroelectric Ceramics by Design at the Microstructure Level

NASA Astrophysics Data System (ADS)

Jayachandran, K. P.; Guedes, J. M.; Rodrigues, H. C.

2010-05-01

Ferroelectric materials show remarkable physical behaviors that make them essential for many devices and have been extensively studied for their applications of nonvolatile random access memory (NvRAM) and high-speed random access memories. Although ferroelectric ceramics (polycrystals) present ease in manufacture and in compositional modifications and represent the widest application area of materials, computational and theoretical studies are sparse owing to many reasons including the large number of constituent atoms. Macroscopic properties of ferroelectric polycrystals are dominated by the inhomogeneities at the crystallographic domain/grain level. Orientation of grains/domains is critical to the electromechanical response of the single crystalline and polycrystalline materials. Polycrystalline materials have the potential of exhibiting better performance at a macroscopic scale by design of the domain/grain configuration at the domain-size scale. This suggests that piezoelectric properties can be optimized by a proper choice of the parameters which control the distribution of grain orientations. Nevertheless, this choice is complicated and it is impossible to analyze all possible combinations of the distribution parameters or the angles themselves. Hence we have implemented the stochastic optimization technique of simulated annealing combined with the homogenization for the optimization problem. The mathematical homogenization theory of a piezoelectric medium is implemented in the finite element method (FEM) by solving the coupled equilibrium electrical and mechanical fields. This implementation enables the study of the dependence of the macroscopic electromechanical properties of a typical crystalline and polycrystalline ferroelectric ceramic on the grain orientation.

Use of Biomarkers to Guide Decisions on Adjuvant Systemic Therapy for Women With Early-Stage Invasive Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline

PubMed Central

Harris, Lyndsay N.; McShane, Lisa M.; Andre, Fabrice; Collyar, Deborah E.; Gonzalez-Angulo, Ana M.; Hammond, Elizabeth H.; Kuderer, Nicole M.; Liu, Minetta C.; Mennel, Robert G.; Van Poznak, Catherine; Bast, Robert C.; Hayes, Daniel F.

2016-01-01

Purpose To provide recommendations on appropriate use of breast tumor biomarker assay results to guide decisions on adjuvant systemic therapy for women with early-stage invasive breast cancer. Methods A literature search and prospectively defined study selection sought systematic reviews, meta-analyses, randomized controlled trials, prospective-retrospective studies, and prospective comparative observational studies published from 2006 through 2014. Outcomes of interest included overall survival and disease-free or recurrence-free survival. Expert panel members used informal consensus to develop evidence-based guideline recommendations. Results The literature search identified 50 relevant studies. One randomized clinical trial and 18 prospective-retrospective studies were found to have evaluated the clinical utility, as defined by the guideline, of specific biomarkers for guiding decisions on the need for adjuvant systemic therapy. No studies that met guideline criteria for clinical utility were found to guide choice of specific treatments or regimens. Recommendations In addition to estrogen and progesterone receptors and human epidermal growth factor receptor 2, the panel found sufficient evidence of clinical utility for the biomarker assays Oncotype DX, EndoPredict, PAM50, Breast Cancer Index, and urokinase plasminogen activator and plasminogen activator inhibitor type 1 in specific subgroups of breast cancer. No biomarker except for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 was found to guide choices of specific treatment regimens. Treatment decisions should also consider disease stage, comorbidities, and patient preferences. PMID:26858339

Random forests and stochastic gradient boosting for predicting tree canopy cover: Comparing tuning processes and model performance

Treesearch

E. Freeman; G. Moisen; J. Coulston; B. Wilson

2014-01-01

Random forests (RF) and stochastic gradient boosting (SGB), both involving an ensemble of classification and regression trees, are compared for modeling tree canopy cover for the 2011 National Land Cover Database (NLCD). The objectives of this study were twofold. First, sensitivity of RF and SGB to choices in tuning parameters was explored. Second, performance of the...

Random Measurement Error Does Not Bias the Treatment Effect Estimate in the Regression-Discontinuity Design. II. When an Interaction Effect Is Present.

ERIC Educational Resources Information Center

Trochim, William M. K.; And Others

1991-01-01

The regression-discontinuity design involving a treatment interaction effect (TIE), pretest-posttest functional form specification, and choice of point-of-estimation of the TIE are examined. Formulas for controlling the magnitude of TIE in simulations can be used for simulating the randomized experimental case where estimation is not at the…

Reinterpretaion of the friendship paradox

NASA Astrophysics Data System (ADS)

Fu, Jingcheng; Wu, Jianliang

The friendship paradox (FP) is a sociological phenomenon stating that most people have fewer friends than their friends do. It is to say that in a social network, the number of friends that most individuals have is smaller than the average number of friends of friends. This has been verified by Feld. We call this interpreting method mean value version. But is it the best choice to portray the paradox? In this paper, we propose a probability method to reinterpret this paradox, and we illustrate that the explanation using our method is more persuasive. An individual satisfies the FP if his (her) randomly chosen friend has more friends than him (her) with probability not less than 1/2. Comparing the ratios of nodes satisfying the FP in networks, rp, we can see that the probability version is stronger than the mean value version in real networks both online and offline. We also show some results about the effects of several parameters on rp in random network models. Most importantly, rp is a quadratic polynomial of the power law exponent γ in Price model, and rp is higher when the average clustering coefficient is between 0.4 and 0.5 in Petter-Beom (PB) model. The introduction of the probability method to FP can shed light on understanding the network structure in complex networks especially in social networks.

Robust, Adaptive Functional Regression in Functional Mixed Model Framework.

PubMed

Zhu, Hongxiao; Brown, Philip J; Morris, Jeffrey S

2011-09-01

Functional data are increasingly encountered in scientific studies, and their high dimensionality and complexity lead to many analytical challenges. Various methods for functional data analysis have been developed, including functional response regression methods that involve regression of a functional response on univariate/multivariate predictors with nonparametrically represented functional coefficients. In existing methods, however, the functional regression can be sensitive to outlying curves and outlying regions of curves, so is not robust. In this paper, we introduce a new Bayesian method, robust functional mixed models (R-FMM), for performing robust functional regression within the general functional mixed model framework, which includes multiple continuous or categorical predictors and random effect functions accommodating potential between-function correlation induced by the experimental design. The underlying model involves a hierarchical scale mixture model for the fixed effects, random effect and residual error functions. These modeling assumptions across curves result in robust nonparametric estimators of the fixed and random effect functions which down-weight outlying curves and regions of curves, and produce statistics that can be used to flag global and local outliers. These assumptions also lead to distributions across wavelet coefficients that have outstanding sparsity and adaptive shrinkage properties, with great flexibility for the data to determine the sparsity and the heaviness of the tails. Together with the down-weighting of outliers, these within-curve properties lead to fixed and random effect function estimates that appear in our simulations to be remarkably adaptive in their ability to remove spurious features yet retain true features of the functions. We have developed general code to implement this fully Bayesian method that is automatic, requiring the user to only provide the functional data and design matrices. It is efficient enough to handle large data sets, and yields posterior samples of all model parameters that can be used to perform desired Bayesian estimation and inference. Although we present details for a specific implementation of the R-FMM using specific distributional choices in the hierarchical model, 1D functions, and wavelet transforms, the method can be applied more generally using other heavy-tailed distributions, higher dimensional functions (e.g. images), and using other invertible transformations as alternatives to wavelets.

Robust, Adaptive Functional Regression in Functional Mixed Model Framework

PubMed Central

Zhu, Hongxiao; Brown, Philip J.; Morris, Jeffrey S.

2012-01-01

Functional data are increasingly encountered in scientific studies, and their high dimensionality and complexity lead to many analytical challenges. Various methods for functional data analysis have been developed, including functional response regression methods that involve regression of a functional response on univariate/multivariate predictors with nonparametrically represented functional coefficients. In existing methods, however, the functional regression can be sensitive to outlying curves and outlying regions of curves, so is not robust. In this paper, we introduce a new Bayesian method, robust functional mixed models (R-FMM), for performing robust functional regression within the general functional mixed model framework, which includes multiple continuous or categorical predictors and random effect functions accommodating potential between-function correlation induced by the experimental design. The underlying model involves a hierarchical scale mixture model for the fixed effects, random effect and residual error functions. These modeling assumptions across curves result in robust nonparametric estimators of the fixed and random effect functions which down-weight outlying curves and regions of curves, and produce statistics that can be used to flag global and local outliers. These assumptions also lead to distributions across wavelet coefficients that have outstanding sparsity and adaptive shrinkage properties, with great flexibility for the data to determine the sparsity and the heaviness of the tails. Together with the down-weighting of outliers, these within-curve properties lead to fixed and random effect function estimates that appear in our simulations to be remarkably adaptive in their ability to remove spurious features yet retain true features of the functions. We have developed general code to implement this fully Bayesian method that is automatic, requiring the user to only provide the functional data and design matrices. It is efficient enough to handle large data sets, and yields posterior samples of all model parameters that can be used to perform desired Bayesian estimation and inference. Although we present details for a specific implementation of the R-FMM using specific distributional choices in the hierarchical model, 1D functions, and wavelet transforms, the method can be applied more generally using other heavy-tailed distributions, higher dimensional functions (e.g. images), and using other invertible transformations as alternatives to wavelets. PMID:22308015

Patient Preferences for Features of Health Care Delivery Systems: A Discrete Choice Experiment.

PubMed

Mühlbacher, Axel C; Bethge, Susanne; Reed, Shelby D; Schulman, Kevin A

2016-04-01

To estimate the relative importance of organizational-, procedural-, and interpersonal-level features of health care delivery systems from the patient perspective. We designed four discrete choice experiments (DCEs) to measure patient preferences for 21 health system attributes. Participants were recruited through the online patient portal of a large health system. We analyzed the DCE data using random effects logit models. DCEs were performed in which respondents were provided with descriptions of alternative scenarios and asked to indicate which scenario they prefer. Respondents were randomly assigned to one of the three possible health scenarios (current health, new lung cancer diagnosis, or diabetes) and asked to complete 15 choice tasks. Each choice task included an annual out-of-pocket cost attribute. A total of 3,900 respondents completed the survey. The out-of-pocket cost attribute was considered the most important across the four different DCEs. Following the cost attribute, trust and respect, multidisciplinary care, and shared decision making were judged as most important. The relative importance of out-of-pocket cost was consistently lower in the hypothetical context of a new lung cancer diagnosis compared with diabetes or the patient's current health. This study demonstrates the complexity of patient decision making processes regarding features of health care delivery systems. Our findings suggest the importance of these features may change as a function of an individual's medical conditions. © Health Research and Educational Trust.

Factors that influence beverage choices at meal times. An application of the food choice kaleidoscope framework.

PubMed

Mueller Loose, S; Jaeger, S R

2012-12-01

Beverages are consumed at almost every meal occasion, but knowledge about the factors that influence beverage choice is less than for food choice. The aim of this research was to characterize and quantify factors that influence beverage choices at meal times. Insights into what beverages are chosen by whom, when and where can be helpful for manufacturers, dieticians/health care providers, and health policy makers. A descriptive framework - the food choice kaleidoscope (Jaeger et al., 2011) - was applied to self-reported 24h food recall data from a sample of New Zealand consumers. Participants (n=164) described 8356 meal occasions in terms of foods and beverages consumed, and the contextual characteristics of the occasion. Beverage choice was explored with random-parameter logit regressions to reveal influences linked to food items eaten, context factors and person factors. Thereby this study contributed to the food choice kaleidoscope research approach by expressing the degree of context dependency in the form of odds ratios and according significance levels. The exploration of co-occurrence of beverages with food items suggests that beverage-meal item combinations can be meal specific. Furthermore, this study integrates psychographic variables into the 'person' mirror of the food choice kaleidoscope. A measure of habit in beverage choice was obtained from the inter-participant correlation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Impact of nutrition environmental interventions on point-of-purchase behavior in adults: a review.

PubMed

Seymour, Jennifer D; Yaroch, Amy Lazarus; Serdula, Mary; Blanck, Heidi Michels; Khan, Laura Kettel

2004-09-01

Nutrition interventions targeted to individuals are unlikely to significantly shift US dietary patterns as a whole. Environmental and policy interventions are more promising for shifting these patterns. We review interventions that influenced the environment through food availability, access, pricing, or information at the point-of-purchase in worksites, universities, grocery stores, and restaurants. Thirty-eight nutrition environmental intervention studies in adult populations, published between 1970 and June 2003, were reviewed and evaluated on quality of intervention design, methods, and description (e.g., sample size, randomization). No policy interventions that met inclusion criteria were found. Many interventions were not thoroughly evaluated or lacked important evaluation information. Direct comparison of studies across settings was not possible, but available data suggest that worksite and university interventions have the most potential for success. Interventions in grocery stores appear to be the least effective. The dual concerns of health and taste of foods promoted were rarely considered. Sustainability of environmental change was never addressed. Interventions in "limited access" sites (i.e., where few other choices were available) had the greatest effect on food choices. Research is needed using consistent methods, better assessment tools, and longer durations; targeting diverse populations; and examining sustainability. Future interventions should influence access and availability, policies, and macroenvironments.

Health-Related Quality-of-Life Analysis From KEYNOTE-045: A Phase III Study of Pembrolizumab Versus Chemotherapy for Previously Treated Advanced Urothelial Cancer.

PubMed

Vaughn, David J; Bellmunt, Joaquim; Fradet, Yves; Lee, Jae Lyun; Fong, Lawrence; Vogelzang, Nicholas J; Climent, Miguel A; Petrylak, Daniel P; Choueiri, Toni K; Necchi, Andrea; Gerritsen, Winald; Gurney, Howard; Quinn, David I; Culine, Stephane; Sternberg, Cora N; Mai, Yabing; Li, Haojie; Perini, Rodolfo F; Bajorin, Dean F; de Wit, Ronald

2018-03-28

Purpose In the phase III KEYNOTE-045 study ( ClinicalTrials.gov identifier: NCT02256436), pembrolizumab significantly prolonged overall survival compared with investigator's choice of chemotherapy in patients with previously treated advanced urothelial cancer. Here, we report the results of health-related quality-of-life (HRQoL) analyses from the KEYNOTE-045 trial. Patients and Methods Patients were randomly assigned 1:1 to pembrolizumab 200 mg or investigator's choice of docetaxel 75 mg/m 2 , paclitaxel 175 mg/m 2 , or vinflunine 320 mg/m 2 administered intravenously every 3 weeks. Key prespecified HRQoL analyses were time to deterioration (TTD) and mean change from baseline to week 15 in European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 global health status/quality-of-life score. Results Of 542 patients who were randomly assigned, 519 were included in HRQoL analyses (pembrolizumab, n = 266; chemotherapy, n = 253). HRQoL compliance was > 95% at baseline and approximately 88% at week 15 for both groups. Pembrolizumab prolonged TTD in global health status/quality-of-life score compared with chemotherapy (median, 3.5 months v 2.3 months; hazard ratio, 0.72; nominal one-sided P = .004). Mean (95% CI) change from baseline to week 15 in global health status/quality-of-life score was 0.69 (-2.40 to 3.77) with pembrolizumab and -8.36 (-11.84 to -4.89) with chemotherapy (mean difference, 9.05 points; 95% CI, 4.61 to 13.50; nominal two-sided P < .001). Conclusion Pembrolizumab prolonged TTD in HRQoL compared with chemotherapy. Patients who were treated with pembrolizumab had stable or improved global health status/quality of life, whereas those who were treated with investigator's choice of chemotherapy experienced declines in global health status/quality of life. Combined with efficacy and safety outcomes, these data support pembrolizumab as standard of care for patients with platinum-refractory advanced urothelial cancer.

A PET reconstruction formulation that enforces non-negativity in projection space for bias reduction in Y-90 imaging

NASA Astrophysics Data System (ADS)

Lim, Hongki; Dewaraja, Yuni K.; Fessler, Jeffrey A.

2018-02-01

Most existing PET image reconstruction methods impose a nonnegativity constraint in the image domain that is natural physically, but can lead to biased reconstructions. This bias is particularly problematic for Y-90 PET because of the low probability positron production and high random coincidence fraction. This paper investigates a new PET reconstruction formulation that enforces nonnegativity of the projections instead of the voxel values. This formulation allows some negative voxel values, thereby potentially reducing bias. Unlike the previously reported NEG-ML approach that modifies the Poisson log-likelihood to allow negative values, the new formulation retains the classical Poisson statistical model. To relax the non-negativity constraint embedded in the standard methods for PET reconstruction, we used an alternating direction method of multipliers (ADMM). Because choice of ADMM parameters can greatly influence convergence rate, we applied an automatic parameter selection method to improve the convergence speed. We investigated the methods using lung to liver slices of XCAT phantom. We simulated low true coincidence count-rates with high random fractions corresponding to the typical values from patient imaging in Y-90 microsphere radioembolization. We compared our new methods with standard reconstruction algorithms and NEG-ML and a regularized version thereof. Both our new method and NEG-ML allow more accurate quantification in all volumes of interest while yielding lower noise than the standard method. The performance of NEG-ML can degrade when its user-defined parameter is tuned poorly, while the proposed algorithm is robust to any count level without requiring parameter tuning.

An enquiry into the method of paired comparison: reliability, scaling, and Thurstone's Law of Comparative Judgment

Treesearch

Thomas C. Brown; George L. Peterson

2009-01-01

The method of paired comparisons is used to measure individuals' preference orderings of items presented to them as discrete binary choices. This paper reviews the theory and application of the paired comparison method, describes a new computer program available for eliciting the choices, and presents an analysis of methods for scaling paired choice data to...

Effect of default menus on food selection and consumption in a college dining hall simulation study.

PubMed

Radnitz, Cynthia; Loeb, Katharine L; Keller, Kathleen L; Boutelle, Kerri; Schwartz, Marlene B; Todd, Lauren; Marcus, Sue

2018-05-01

To test an obesity prevention strategy derived from behavioural economics (optimal defaults plus delay), focused on changing the college dining hall service method. After a uniform pre-load, participants attended an experimental lunch in groups randomized to one of three conditions: a nutrient-dense, lower-fat/energy lunch as an optimal default (OD); a less-nutrient-dense, higher-fat/energy lunch as a suboptimal default (SD); or a free array (FA) lunch. In the OD condition, students were presented a menu depicting healthier vegetarian and omnivore foods as default, with opt-out alternatives (SD menu) available on request with a 15 min wait. In the SD condition, the same menu format was used with the positioning of food items switched. In the FA condition, all choices were presented in uniform fonts and were available immediately. Private rooms designed to provide a small version of a college dining hall, on two campuses of a Northeastern US university. First-year college students (n 129). There was a significant main effect for condition on percentage of optimal choices selected, with 94 % of food choices in the OD condition optimal, 47 % in the FA condition optimal and none in the SD condition optimal. Similarly, energy intake for those in the SD condition significantly exceeded that in the FA condition, which exceeded that in the OD condition. Presenting menu items as optimal defaults with a delay had a significant impact on choice and consumption, suggesting that further research into its long-term applicability is warranted.

Not seeking yet trying long-acting reversible contraception: a 24-month randomized trial on continuation, unintended pregnancy and satisfaction.

PubMed

Hubacher, David; Spector, Hannah; Monteith, Charles; Chen, Pai-Lien

2018-06-01

To measure the 24-month impact on continuation, unintended pregnancy and satisfaction of trying long-acting reversible contraception (LARC) in a population seeking short-acting reversible contraception (SARC). We enrolled 916 women aged 18-29 who were seeking pills or injectables in a partially randomized patient preference trial. Women with strong preferences for pills or injectables started on those products, while others opted for randomization to LARC or SARC and received their methods gratis. We estimated continuation and unintended pregnancy rates through 24months. Intent-to-treat principles were applied after method initiation for comparing incidence of unintended pregnancy. We also examined how satisfaction levels varied by cohort and how baseline negative LARC attitudes were associated with satisfaction over time. Forty-three percent chose randomization, and 57% chose the preference option. Complete loss to follow-up was<2%. The 24-month LARC continuation probability was 64.3% [95% confidence interval (CI): 56.6-70.9], statistically higher than SARC groups [25.5% (randomized) and 40.0% (preference)]. The 24-month cumulative unintended pregnancy probabilities were 9.9% (95% CI: 7.2-12.6) (preference-SARC), 6.9% (95% CI: 3.3-10.6) (randomized-SARC) and 3.6% (95% CI: 1.8-6.4) (randomized-LARC). Statistical tests for comparing randomized groups on unintended pregnancy were mixed: binomial at 24-month time point (p=.02) and log-rank survival probabilities (p=.14 for first pregnancies and p=.07 when including second pregnancies). LARC satisfaction was high (80% happy/neutral, 73% would use LARC again, 81% would recommend to a friend). Baseline negative attitudes toward LARC (27%) were not clearly associated with satisfaction or early discontinuation. The decision to try LARC resulted in high continuation rates and substantial protection from unintended pregnancy over 24months. Despite participants' initial desires to begin short-acting regimens, they had high satisfaction with LARC. Voluntary decisions to try LARC will benefit large proportions of typical SARC users. Even women who do not necessarily view LARC as a first choice may have a highly satisfying experience and avoid unintended pregnancy if they try it. Copyright © 2018 Elsevier Inc. All rights reserved.

A random rule model of surface growth

NASA Astrophysics Data System (ADS)

Mello, Bernardo A.

2015-02-01

Stochastic models of surface growth are usually based on randomly choosing a substrate site to perform iterative steps, as in the etching model, Mello et al. (2001) [5]. In this paper I modify the etching model to perform sequential, instead of random, substrate scan. The randomicity is introduced not in the site selection but in the choice of the rule to be followed in each site. The change positively affects the study of dynamic and asymptotic properties, by reducing the finite size effect and the short-time anomaly and by increasing the saturation time. It also has computational benefits: better use of the cache memory and the possibility of parallel implementation.

Concise evaluation of decision aids.

PubMed

Stalmeier, Peep F M; Roosmalen, Marielle S

2009-01-01

Decision aids purport to help patients make treatment related choices. Several instruments exist to evaluate decision aids. Our aim is to compare the responsiveness of several instruments. Two different decision aids were randomized in patients at high risk for breast and ovarian cancer. Treatment choices were between prophylactic surgery and screening. Effect sizes were calculated to compare the responsiveness of the measures. One decision aid was randomized in 390 women, the other in 91 ensuing mutation carriers. Three factors were identified related to Information, Well-being and Decision Making. Within each factor, single item measures were as responsive as multi-item measures. Four single items, 'the amount of information received for decision making,' 'strength of preference,' 'I weighed the pros and cons,' and 'General Health,' were adequately responsive to the decision aids. These items might be considered for inclusion in questionnaires to evaluate decision aids.

A Randomized Comparison of Aripiprazole and Risperidone for the Acute Treatment of First-Episode Schizophrenia and Related Disorders: 3-Month Outcomes

PubMed Central

Robinson, Delbert G.; Gallego, Juan A.; John, Majnu; Petrides, Georgios; Hassoun, Youssef; Zhang, Jian-Ping; Lopez, Leonardo; Braga, Raphael J.; Sevy, Serge M.; Addington, Jean; Kellner, Charles H.; Tohen, Mauricio; Naraine, Melissa; Bennett, Natasha; Greenberg, Jessica; Lencz, Todd; Correll, Christoph U.; Kane, John M.; Malhotra, Anil K.

2015-01-01

Research findings are particularly important for medication choice for first-episode patients as individual prior medication response to guide treatment decisions is unavailable. We describe the first large-scale double-masked randomized comparison with first-episode patients of aripiprazole and risperidone, 2 commonly used first-episode treatment agents. One hundred ninety-eight participants aged 15–40 years with schizophrenia, schizophreniform disorder, schizoaffective disorder or psychotic disorder Not Otherwise Specified, and who had been treated in their lifetime with antipsychotics for 2 weeks or less were randomly assigned to double-masked aripiprazole (5–30mg/d) or risperidone (1–6mg/d) and followed for 12 weeks. Positive symptom response rates did not differ (62.8% vs 56.8%) nor did time to response. Aripiprazole-treated participants had better negative symptom outcomes but experienced more akathisia. Body mass index change did not differ between treatments but advantages were found for aripiprazole treatment for total and low-density lipoprotein cholesterol, fasting glucose, and prolactin levels. Post hoc analyses suggested advantages for aripiprazole on depressed mood. Overall, if the potential for akathisia is a concern, low-dose risperidone as used in this trial maybe a preferred choice over aripiprazole. Otherwise, aripiprazole would be the preferred choice over risperidone in most situations based upon metabolic outcome advantages and some symptom advantages within the context of similar positive symptom response between medications. PMID:26338693

Planning for Schools of Choice: Achieving Equity and Excellence. Book II--Planning Guide.

ERIC Educational Resources Information Center

Clinchy, Evans; Kolb, Frances Arick, Ed.

Designed to aid school personnel considering school choice as a possible desegregation method, this booklet explains the principles of controlled choice, presents an overall plan and flow chart, and reviews the types of organizations that might be developed. Controlled choice is a desegregation method that is voluntary, empowers parents and school…

A self-determination theory approach to adults' healthy body weight motivation: A longitudinal study focussing on food choices and recreational physical activity.

PubMed

Hartmann, Christina; Dohle, Simone; Siegrist, Michael

2015-01-01

This study focuses on body weight motivation based on self-determination theory. The impact of body weight motivation on longitudinal changes in food choices, recreational physical activity and body mass index was explored. A sample of adults (N = 2917, 47% men), randomly selected from the telephone book, completed a questionnaire in two consecutive years (2012, 2013), self-reporting food choices, recreational physical activity and body weight motivation. Types of body weight motivation at T1 (autonomous regulation, introjected regulation, and external regulation) were tested with regard to their predictive potential for changes in food choices, recreational physical activity and body mass index (BMI). Autonomous motivation predicted improvements in food choices and long-term adherence to vigorous recreational physical activity in both genders. Introjected motivation predicted long-term adherence to vigorous recreational physical activity only in women. External motivation predicted negative changes in food choices; however, the type of body weight motivation had no impact on BMI in overweight adults in the long term. Autonomous goal-setting regarding body weight seems to be substantial for healthy food choices and adherence to recreational physical activity.

Associating a product with a luxury brand label modulates neural reward processing and favors choices in materialistic individuals.

PubMed

Audrin, Catherine; Ceravolo, Leonardo; Chanal, Julien; Brosch, Tobias; Sander, David

2017-11-23

The present study investigated the extent to which luxury vs. non-luxury brand labels (i.e., extrinsic cues) randomly assigned to items and preferences for these items impact choice, and how this impact may be moderated by materialistic tendencies (i.e., individual characteristics). The main objective was to investigate the neural correlates of abovementioned effects using functional magnetic resonance imaging. Behavioural results showed that the more materialistic people are, the more they choose and like items labelled with luxury brands. Neuroimaging results revealed the implication of a neural network including the dorsolateral and ventromedial prefrontal cortex and the orbitofrontal cortex that was modulated by the brand label and also by the participants' preference. Most importantly, items with randomly assigned luxurious brand labels were preferentially chosen by participants and triggered enhanced signal in the caudate nucleus. This effect increased linearly with materialistic tendencies. Our results highlight the impact of brand-item association, although random in our study, and materialism on preference, relying on subparts of the brain valuation system for the integration of extrinsic cues, preferences and individual characteristics.

Adjusting for multiple prognostic factors in the analysis of randomised trials

PubMed Central

2013-01-01

Background When multiple prognostic factors are adjusted for in the analysis of a randomised trial, it is unclear (1) whether it is necessary to account for each of the strata, formed by all combinations of the prognostic factors (stratified analysis), when randomisation has been balanced within each stratum (stratified randomisation), or whether adjusting for the main effects alone will suffice, and (2) the best method of adjustment in terms of type I error rate and power, irrespective of the randomisation method. Methods We used simulation to (1) determine if a stratified analysis is necessary after stratified randomisation, and (2) to compare different methods of adjustment in terms of power and type I error rate. We considered the following methods of analysis: adjusting for covariates in a regression model, adjusting for each stratum using either fixed or random effects, and Mantel-Haenszel or a stratified Cox model depending on outcome. Results Stratified analysis is required after stratified randomisation to maintain correct type I error rates when (a) there are strong interactions between prognostic factors, and (b) there are approximately equal number of patients in each stratum. However, simulations based on real trial data found that type I error rates were unaffected by the method of analysis (stratified vs unstratified), indicating these conditions were not met in real datasets. Comparison of different analysis methods found that with small sample sizes and a binary or time-to-event outcome, most analysis methods lead to either inflated type I error rates or a reduction in power; the lone exception was a stratified analysis using random effects for strata, which gave nominal type I error rates and adequate power. Conclusions It is unlikely that a stratified analysis is necessary after stratified randomisation except in extreme scenarios. Therefore, the method of analysis (accounting for the strata, or adjusting only for the covariates) will not generally need to depend on the method of randomisation used. Most methods of analysis work well with large sample sizes, however treating strata as random effects should be the analysis method of choice with binary or time-to-event outcomes and a small sample size. PMID:23898993

Prolonged breast-feeding and mortality up to two years post-partum among HIV-positive women in Zambia

PubMed Central

Kuhn, Louise; Kasonde, Prisca; Sinkala, Moses; Kankasa, Chipepo; Semrau, Katherine; Vwalika, Cheswa; Tsai, Wei-Yann; Aldrovandi, Grace M.; Thea, Donald M.

2005-01-01

Background A previously reported association between prolonged lactation and maternal mortality has generated concern that breast-feeding may be detrimental for HIV-positive women. Methods As part of a trial conducted in Lusaka, Zambia, 653 HIV-positive women were randomly assigned either to a counseling program that encouraged abrupt cessation of breast-feeding at 4 months (group A) or to a program that encouraged prolonged breast-feeding for the duration of the woman’s own informed choice (group B). We examined whether mortality up to 2 years post-partum increased with breast-feeding for a longer duration. Results There was no difference in mortality 12 months after delivery between 326 HIV-positive women randomly assigned to short breast-feeding [group A: 4.93%; 95% confidence interval (CI), 2.42–7.46] versus 327 women assigned to long breast-feeding (group B: 4.89%; 95% CI, 2.38–7.40). Analysis based on actual practice, rather than random assignment, also demonstrated no increased mortality due to breast-feeding. Conclusions Although HIV-related mortality was high in this cohort of untreated HIV-positive women, prolonged lactation was not associated with increased mortality. PMID:16184038

Poverty and Economic Decision-Making: Evidence from Changes in Financial Resources at Payday

PubMed Central

Carvalho, Leandro S.; Meier, Stephan; Wang, Stephanie W.

2016-01-01

We study the effect of financial resources on decision-making. Low-income U.S. households are randomly assigned to receive an online survey before or after payday. The survey collects measures of cognitive function and administers risk and intertemporal choice tasks. The study design generates variation in cash, checking and savings balances, and expenditures. Before-payday participants behave as if they are more present-biased when making intertemporal choices about monetary rewards but not when making intertemporal choices about non-monetary real-effort tasks. Nor do we find before-after differences in risk-taking, the quality of decision-making, the performance in cognitive function tasks, or in heuristic judgments. PMID:28003681

Using augmented reality to inform consumer choice and lower carbon footprints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isley, Steven C.; Ketcham, Robert; Arent, Douglas J.

Consumers who wish to consider product attributes like carbon footprints in their purchasing decisions are often blocked from meaningful action by a lack of information. We conducted a single randomized controlled trial at a grocery store to evaluate the effects of providing such product attribute and carbon footprint information via augmented reality (AR) displays on bottled water and breakfast cereal, two frequently purchased goods. Using an AR smartphone app that incorporates comparative and detailed product information into personalized data and recommendations, a 23% statistically significant reduction in carbon footprint was found for bottled water, and non-significant reductions for breakfast cereal.more » Furthermore, AR informed choice lead to healthier cereal choices.« less

Using augmented reality to inform consumer choice and lower carbon footprints

DOE PAGES

Isley, Steven C.; Ketcham, Robert; Arent, Douglas J.

2017-05-23

Consumers who wish to consider product attributes like carbon footprints in their purchasing decisions are often blocked from meaningful action by a lack of information. We conducted a single randomized controlled trial at a grocery store to evaluate the effects of providing such product attribute and carbon footprint information via augmented reality (AR) displays on bottled water and breakfast cereal, two frequently purchased goods. Using an AR smartphone app that incorporates comparative and detailed product information into personalized data and recommendations, a 23% statistically significant reduction in carbon footprint was found for bottled water, and non-significant reductions for breakfast cereal.more » Furthermore, AR informed choice lead to healthier cereal choices.« less

Strategies in a symmetric quantum Kolkata restaurant problem

NASA Astrophysics Data System (ADS)

Sharif, Puya; Heydari, Hoshang

2012-12-01

The Quantum Kolkata restaurant problem is a multiple-choice version of the quantum minority game, where a set of n non-communicating players have to chose between one of m choices. A payoff is granted to the players that make a unique choice. It has previously been shown that shared entanglement and quantum operations can aid the players to coordinate their actions and acquire higher payoffs than is possible with classical randomization. In this paper the initial quantum state is expanded to a family of GHZ-type states and strategies are discussed in terms of possible final outcomes. It is shown that the players individually seek outcomes that maximize the collective good.

Tree leaves extraction in natural images: comparative study of preprocessing tools and segmentation methods.

PubMed

Grand-Brochier, Manuel; Vacavant, Antoine; Cerutti, Guillaume; Kurtz, Camille; Weber, Jonathan; Tougne, Laure

2015-05-01

In this paper, we propose a comparative study of various segmentation methods applied to the extraction of tree leaves from natural images. This study follows the design of a mobile application, developed by Cerutti et al. (published in ReVeS Participation--Tree Species Classification Using Random Forests and Botanical Features. CLEF 2012), to highlight the impact of the choices made for segmentation aspects. All the tests are based on a database of 232 images of tree leaves depicted on natural background from smartphones acquisitions. We also propose to study the improvements, in terms of performance, using preprocessing tools, such as the interaction between the user and the application through an input stroke, as well as the use of color distance maps. The results presented in this paper shows that the method developed by Cerutti et al. (denoted Guided Active Contour), obtains the best score for almost all observation criteria. Finally, we detail our online benchmark composed of 14 unsupervised methods and 6 supervised ones.

[The optimization of restoration approaches of advanced hand activity using the sensorial glove and the mCIMT method].

PubMed

Mozheiko, E Yu; Prokopenko, S V; Alekseevich, G V

To reason the choice of methods of restoration of advanced hand activity depending on severity of motor disturbance in the top extremity. Eighty-eight patients were randomized into 3 groups: 1) the mCIMT group, 2) the 'touch glove' group, 3) the control group. For assessment of physical activity of the top extremity Fugl-Meyer Assessment Upper Extremity, Nine-Hole Peg Test, Motor Assessment Scale were used. Assessment of non-use phenomenon was carried out with the Motor Activity Log scale. At a stage of severe motor dysfunction, there was a restoration of proximal departments of a hand in all groups, neither method was superior to the other. In case of moderate severity of motor deficiency of the upper extremity the most effective was the method based on the principle of biological feedback - 'a touch glove'. In the group with mild severity of motor dysfunction, the best recovery was achieved in the mCIMT group.

Chocolate scents and product sales: a randomized controlled trial in a Canadian bookstore and café.

PubMed

McGrath, Mary C; Aronow, Peter M; Shotwell, Vivien

2016-01-01

We report the results of a 31-day trial on the effects of chocolate scent on purchasing behavior in a bookstore. Our study replicates and extends a 10-day randomized controlled trial in order to examine the generalizability of the original finding. We first introduce the study of store atmospherics and highlight the importance and dearth of replication in this area. In the next section, we describe the original study and discuss the theory of ambient scent effects on product sales, and the role of scent-product congruity. We then describe our design and methods, followed by presentation and discussion of our results. We find no evidence that chocolate scent affects sales. These findings indicate the importance of replication in varied settings. Contextual factors and the choices available to customers may moderate the effects of ambient scent on purchasing behavior. Our study highlights the value of examining the generalizability of experimental findings, both for theory and practice.

The Influence of Consumer Goals and Marketing Activities on Product Bundling

NASA Astrophysics Data System (ADS)

Haijun, Wang

Upon entering a store, consumers are faced with the questions of whether to buy, what to buy, and how much to buy. Consumers include products from different categories in their decision process. Product categories can be related in different ways. Product bundling is a process that involves the choice of at least two non-substitutable items. In this research, the consumers' explicit product bundling activity at the point of sale is focused. We focuses on the retailers' perspective and therefore leaves out consumers' brand choice decisions, concentrating on purchase incidence and quantity. At the base of the current model of the exist researches, we integrate behavioural choice analysis and predictive choice modelling through the underlying behavioural models, called random utility maximization (RUM) models. The methodological contribution of this research lies therein to combine a nested logit choice model with a latent variable factor model. We point out several limitations for both theory and practice at the end.

Studies of Plasma Instabilities using Unstructured Discontinuous Galerkin Method with the Two-Fluid Plasma Model

NASA Astrophysics Data System (ADS)

Song, Yang; Srinivasan, Bhuvana

2017-10-01

The discontinuous Galerkin (DG) method has the advantage of resolving shocks and sharp gradients that occur in neutral fluids and plasmas. An unstructured DG code has been developed in this work to study plasma instabilities using the two-fluid plasma model. Unstructured meshes are known to produce small and randomized grid errors compared to traditional structured meshes. Computational tests for Rayleigh-Taylor instabilities in radially-converging flows are performed using the MHD model. Choice of grid geometry is not obvious for simulations of instabilities in these circular configurations. Comparisons of the effects for different grids are made. A 2D magnetic nozzle simulation using the two-fluid plasma model is also performed. A vacuum boundary condition technique is applied to accurately solve the Riemann problem on the edge of the plume.

Disentangling WTP per QALY data: different analytical approaches, different answers.

PubMed

Gyrd-Hansen, Dorte; Kjaer, Trine

2012-03-01

A large random sample of the Danish general population was asked to value health improvements by way of both the time trade-off elicitation technique and willingness-to-pay (WTP) using contingent valuation methods. The data demonstrate a high degree of heterogeneity across respondents in their relative valuations on the two scales. This has implications for data analysis. We show that the estimates of WTP per QALY are highly sensitive to the analytical strategy. For both open-ended and dichotomous choice data we demonstrate that choice of aggregated approach (ratios of means) or disaggregated approach (means of ratios) affects estimates markedly as does the interpretation of the constant term (which allows for disproportionality across the two scales) in the regression analyses. We propose that future research should focus on why some respondents are unwilling to trade on the time trade-off scale, on how to interpret the constant value in the regression analyses, and on how best to capture the heterogeneity in preference structures when applying mixed multinomial logit. Copyright © 2011 John Wiley & Sons, Ltd.

Exploring "psychic transparency" during pregnancy: a mixed-methods approach.

PubMed

Oriol, Cécile; Tordjman, Sylvie; Dayan, Jacques; Poulain, Patrice; Rosenblum, Ouriel; Falissard, Bruno; Dindoyal, Asha; Naudet, Florian

2016-08-12

Psychic transparency is described as a psychic crisis occurring during pregnancy. The objective was to test if it was clinically detectable. Seven primiparous and seven nulliparous subjects were recorded during 5 min of spontaneous speech about their dreams. 25 raters from five groups (psychoanalysts, psychiatrists, general practitioners, pregnant women and medical students) listened to the audiotapes. They were asked to rate the probability of the women being pregnant or not. Their ability to discriminate the primiparous women was tested. The probability of being identified correctly or not was calculated for each woman. A qualitative analysis of the speech samples was performed. No group of rater was able to correctly classify pregnant and non-pregnant women. However, the raters' choices were not completely random. The wish to be pregnant or to have a baby could be linked to a primiparous classification whereas job priorities could be linked to a nulliparous classification. It was not possible to detect Psychic transparency in this study. The wish for a child might be easier to identify. In addition, the raters' choices seemed to be connected to social representations of motherhood.

Configuration memory in patchwork dynamics for low-dimensional spin glasses

NASA Astrophysics Data System (ADS)

Yang, Jie; Middleton, A. Alan

2017-12-01

A patchwork method is used to study the dynamics of loss and recovery of an initial configuration in spin glass models in dimensions d =1 and d =2 . The patchwork heuristic is used to accelerate the dynamics to investigate how models might reproduce the remarkable memory effects seen in experiment. Starting from a ground-state configuration computed for one choice of nearest-neighbor spin couplings, the sample is aged up to a given scale under new random couplings, leading to the partial erasure of the original ground state. The couplings are then restored to the original choice and patchwork coarsening is again applied, in order to assess the recovery of the original state. Eventual recovery of the original ground state upon coarsening is seen in two-dimensional Ising spin glasses and one-dimensional clock models, while one-dimensional Ising spin systems neither lose nor gain overlap with the ground state during the recovery stage. The recovery for the two-dimensional Ising spin glasses suggests scaling relations that lead to a recovery length scale that grows as a power of the aging length scale.

Discrete Choice Modeling (DCM): An Exciting Marketing Research Survey Method for Educational Researchers.

ERIC Educational Resources Information Center

Berdie, Doug R.

Discrete Choice Marketing (DCM), a research technique that has become more popular in recent marketing research, is described. DCM is a method that forces people to look at the combination of relevant variables within each choice domain and, with each option fully defined in terms of the values for those variables, make a choice of options. DCM…

Image discrimination models predict detection in fixed but not random noise

NASA Technical Reports Server (NTRS)

Ahumada, A. J. Jr; Beard, B. L.; Watson, A. B. (Principal Investigator)

1997-01-01

By means of a two-interval forced-choice procedure, contrast detection thresholds for an aircraft positioned on a simulated airport runway scene were measured with fixed and random white-noise masks. The term fixed noise refers to a constant, or unchanging, noise pattern for each stimulus presentation. The random noise was either the same or different in the two intervals. Contrary to simple image discrimination model predictions, the same random noise condition produced greater masking than the fixed noise. This suggests that observers seem unable to hold a new noisy image for comparison. Also, performance appeared limited by internal process variability rather than by external noise variability, since similar masking was obtained for both random noise types.

Reinforcement learning and decision making in monkeys during a competitive game.

PubMed

Lee, Daeyeol; Conroy, Michelle L; McGreevy, Benjamin P; Barraclough, Dominic J

2004-12-01

Animals living in a dynamic environment must adjust their decision-making strategies through experience. To gain insights into the neural basis of such adaptive decision-making processes, we trained monkeys to play a competitive game against a computer in an oculomotor free-choice task. The animal selected one of two visual targets in each trial and was rewarded only when it selected the same target as the computer opponent. To determine how the animal's decision-making strategy can be affected by the opponent's strategy, the computer opponent was programmed with three different algorithms that exploited different aspects of the animal's choice and reward history. When the computer selected its targets randomly with equal probabilities, animals selected one of the targets more often, violating the prediction of probability matching, and their choices were systematically influenced by the choice history of the two players. When the computer exploited only the animal's choice history but not its reward history, animal's choice became more independent of its own choice history but was still related to the choice history of the opponent. This bias was substantially reduced, but not completely eliminated, when the computer used the choice history of both players in making its predictions. These biases were consistent with the predictions of reinforcement learning, suggesting that the animals sought optimal decision-making strategies using reinforcement learning algorithms.

Insurees' preferences in hospital choice-A population-based study.

PubMed

Schuldt, Johannes; Doktor, Anna; Lichters, Marcel; Vogt, Bodo; Robra, Bernt-Peter

2017-10-01

In Germany, the patient himself makes the choice for or against a health service provider. Hospital comparison websites offer him possibilities to inform himself before choosing. However, it remains unclear, how health care consumers use those websites, and there is little information about how preferences in hospital choice differ interpersonally. We conducted a Discrete-Choice-Experiment (DCE) on hospital choice with 1500 randomly selected participants (age 40-70) in three different German cities selecting four attributes for hospital vignettes. The analysis of the study draws on multilevel mixed effects logit regression analyses with the dependent variables: "chance to select a hospital" and "choice confidence". Subsequently, we performed a Latent-Class-Analysis to uncover consumer segments with distinct preferences. 590 of the questionnaires were evaluable. All four attributes of the hospital vignettes have a significant impact on hospital choice. The attribute "complication rate" exerts the highest impact on consumers' decisions and reported choice confidence. Latent-Class-Analysis results in one dominant consumer segment that considered the complication rate the most important decision criterion. Using DCE, we were able to show that the complication rate is an important trusted criterion in hospital choice to a large group of consumers. Our study supports current governmental efforts in Germany to concentrate the provision of specialized health care services. We suggest further national and cross-national research on the topic. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Effectiveness and Cost-Effectiveness of Occupation-Based Occupational Therapy Using the Aid for Decision Making in Occupation Choice (ADOC) for Older Residents: Pilot Cluster Randomized Controlled Trial

PubMed Central

Nagayama, Hirofumi; Tomori, Kounosuke; Ohno, Kanta; Takahashi, Kayoko; Ogahara, Kakuya; Sawada, Tatsunori; Uezu, Sei; Nagatani, Ryutaro; Yamauchi, Keita

2016-01-01

Background Care-home residents are mostly inactive, have little interaction with staff, and are dependent on staff to engage in daily occupations. We recently developed an iPad application called the Aid for Decision-making in Occupation Choice (ADOC) to promote shared decision-making in activities and occupation-based goal setting by choosing from illustrations describing daily activities. This study aimed to evaluate if interventions based on occupation-based goal setting using the ADOC could focus on meaningful activities to improve quality of life and independent activities of daily living, with greater cost-effectiveness than an impairment-based approach as well as to evaluate the feasibility of conducting a large cluster, randomized controlled trial. Method In this single (assessor)-blind pilot cluster randomized controlled trial, the intervention group (ADOC group) received occupational therapy based on occupation-based goal setting using the ADOC, and the interventions were focused on meaningful occupations. The control group underwent an impairment-based approach focused on restoring capacities, without goal setting tools. In both groups, the 20-minute individualized intervention sessions were conducted twice a week for 4 months. Main Outcome Measures Short Form-36 (SF-36) score, SF-6D utility score, quality adjusted life years (QALY), Barthel Index, and total care cost. Results We randomized and analyzed 12 facilities (44 participants, 18.5% drop-out rate), with 6 facilities each allocated to the ADOC (n = 23) and control (n = 21) groups. After the 4-month intervention, the ADOC group had a significantly greater change in the BI score, with improved scores (P = 0.027, 95% CI 0.41 to 6.87, intracluster correlation coefficient = 0.14). No other outcome was significantly different. The incremental cost-effectiveness ratio, calculated using the change in BI score, was $63.1. Conclusion The results suggest that occupational therapy using the ADOC for older residents might be effective and cost-effective. We also found that conducting an RCT in the occupational therapy setting is feasible. Trial Registration UMIN Clinical Trials Registry UMIN000012994 PMID:26930191

An improved label propagation algorithm based on node importance and random walk for community detection

NASA Astrophysics Data System (ADS)

Ma, Tianren; Xia, Zhengyou

2017-05-01

Currently, with the rapid development of information technology, the electronic media for social communication is becoming more and more popular. Discovery of communities is a very effective way to understand the properties of complex networks. However, traditional community detection algorithms consider the structural characteristics of a social organization only, with more information about nodes and edges wasted. In the meanwhile, these algorithms do not consider each node on its merits. Label propagation algorithm (LPA) is a near linear time algorithm which aims to find the community in the network. It attracts many scholars owing to its high efficiency. In recent years, there are more improved algorithms that were put forward based on LPA. In this paper, an improved LPA based on random walk and node importance (NILPA) is proposed. Firstly, a list of node importance is obtained through calculation. The nodes in the network are sorted in descending order of importance. On the basis of random walk, a matrix is constructed to measure the similarity of nodes and it avoids the random choice in the LPA. Secondly, a new metric IAS (importance and similarity) is calculated by node importance and similarity matrix, which we can use to avoid the random selection in the original LPA and improve the algorithm stability. Finally, a test in real-world and synthetic networks is given. The result shows that this algorithm has better performance than existing methods in finding community structure.

Predictors of 12-Step Attendance and Participation for Individuals with Stimulant Use Disorders

PubMed Central

Hatch-Maillette, Mary; Wells, Elizabeth A.; Doyle, Suzanne R.; Brigham, Gregory S.; Daley, Dennis; DiCenzo, Jessica; Donovan, Dennis; Garrett, Sharon; Horigian, Viviana E.; Jenkins, Lindsay; Killeen, Therese; Owens, Mandy; Perl, Harold I.

2017-01-01

Objective Few studies have examined the effectiveness of 12-step peer recovery support programs with drug use disorders, especially stimulant use, and it is difficult to know how outcomes related to 12-step attendance and participation generalize to individuals with non-alcohol substance use disorders (SUDs). Method A clinical trial of 12-step facilitation (N=471) focusing on individuals with cocaine or methamphetamine use disorders allowed examination of four questions: Q1) To what extent do treatment-seeking stimulant users use 12-step programs and, which ones? Q2) Do factors previously found to predict 12-step participation among those with alcohol use disorders also predict participation among stimulant users? Q3) What specific baseline “12-step readiness” factors predict subsequent 12-step participation and attendance? And Q4) Does stimulant drug of choice differentially predict 12-step participation and attendance? Results The four outcomes variables, Attendance, Speaking, Duties at 12-step meetings, and other peer recovery support Activities, were not related to baseline demographic or substance problem history or severity. Drug of choice was associated with differential days of Alcoholics Anonymous (AA) and Narcotics Anonymous (NA) attendance among those who reported attending, and cocaine users reported more days of attending AA or NA at 1-, 3- and 6-month follow-ups than did methamphetamine users. Pre-randomization measures of Perceived Benefit of 12-step groups predicted 12-step Attendance at 3- and 6-month follow-ups. Pre-randomization 12-step Attendance significantly predicted number of other Self-Help Activities at end-of-treatment, 3- and 6-month follow-ups. Pre-randomization Perceived Benefit and problem severity both predicted number of Self-Help Activities at end-of-treatment and 3-month follow-up. Pre-randomization Perceived Barriers to 12-step groups were negatively associated with Self-Help Activities at end-of-treatment and 3-month follow-up. Whether or not one participated in any Duties was predicted at all time points by pre-randomization involvement in Self-Help Activities. Conclusions The primary finding of this study is one of continuity: prior attendance and active involvement with 12-step programs were the main signs pointing to future involvement. Limitations and Recommendations are discussed. PMID:27431050

Evaluating Health Workers' Potential Resistance to New Interventions: A Role for Discrete Choice Experiments

PubMed Central

Lagarde, Mylene; Smith Paintain, Lucy; Antwi, Gifti; Jones, Caroline; Greenwood, Brian; Chandramohan, Daniel; Tagbor, Harry; Webster, Jayne

2011-01-01

Background The currently recommended approach for preventing malaria in pregnancy (MiP), intermittent preventive treatment with sulphadoxine-pyrimethamine (SP-IPT), has been questioned due to the spread of resistance to SP. Whilst trials are underway to test the efficacy of future alternative approaches, it is important to start exploring the feasibility of their implementation. Methods and Findings This study uses a discrete choice experiment (DCE) method to assess the potential resistance of health workers to changing strategies for control of MiP. In Ashanti region in Ghana, 133 antenatal clinic health workers were presented with 16 choice sets of two alternative policy options, each consisting of a bundle of six attributes representing certain clinical guidelines for controlling MiP (type of approach and drug used), possible associated maternal and neo-natal outcomes, workload and financial incentives. The data were analysed using a random effects logit model. Overall, staff showed a preference for a curative approach with pregnant women tested for malaria parasites and treated only if positive, compared to a preventive approach (OR 1.6; p = 0.001). Increasing the incidence of low birth weight or severe anaemia by 1% would reduce the odds of preferring an approach by 18% and 10% respectively. Midwives were more resistant to potential changes to current guidelines than lower-level cadres. Conclusions In Ashanti Region, resistance to change by antenatal clinic workers from a policy of SP-IPT to IST would generally be low, and it would disappear amongst midwives if health outcomes for the mother and baby were improved by the new strategy. DCEs are a promising approach to identifying factors that will increase the likelihood of effective implementation of new interventions immediately after their efficacy has been proven. PMID:21886800

Maternal age–based prenatal screening for chromosomal disorders

PubMed Central

Carroll, June C.; Rideout, Andrea; Wilson, Brenda J.; Allanson, Judith; Blaine, Sean; Esplen, Mary Jane; Farrell, Sandra; Graham, Gail E.; MacKenzie, Jennifer; Meschino, Wendy S.; Prakash, Preeti; Shuman, Cheryl; Taylor, Sherry; Tobin, Stasey

2013-01-01

Objective To explore views of women and health care providers (HCPs) about the changing recommendations regarding maternal age–based prenatal screening. Design Mixed-methods design. Setting Ontario. Participants A sample of women who had given birth within the previous 2 years and who had attended a family medicine centre, midwifery practice, or baby and mother wellness program (n = 42); and a random sample of family physicians (n = 1600), and all Ontario obstetricians (n = 694) and midwives (n = 334) who provided prenatal care. Methods We used focus groups (FGs) to explore women's views. Content analysis was used to uncover themes and delineate meaning. To explore HCPs' views, we conducted a cross-sectional self-completion survey. Main findings All FG participants (42 women in 6 FGs) expressed the importance of individual choice of prenatal screening modality, regardless of age. They described their perception that society considers women older than 35 to be at high obstetric risk and raised concerns that change in the maternal age–related screening policy would require education. The HCP survey response rate was 40%. Results showed 24% of HCPs agreed that women of any age should be eligible for invasive diagnostic testing regardless of prenatal screening results; 15% agreed that the age for diagnostic testing should be increased to 40 years, 14% agreed that diagnostic testing should be reserved for women with positive prenatal screening results, and 45% agreed that prenatal screening should remain unchanged. Conclusion Maternity care organizations have recommended that maternal age–based prenatal screening is no longer appropriate. Informed choice is of paramount importance to women and should be part of any change. Health care providers need to be engaged in and educated about any change to screening guidelines to offer women informed choices. PMID:23341678

Effects of calorie labeling and value size pricing on fast food meal choices: results from an experimental trial.

PubMed

Harnack, Lisa J; French, Simone A; Oakes, J Michael; Story, Mary T; Jeffery, Robert W; Rydell, Sarah A

2008-12-05

Although point-of-purchase calorie labeling at restaurants has been proposed as a strategy for improving consumer food choices, a limited number of studies have evaluated this approach. Likewise, little research has been conducted to evaluate the influence of value size pricing on restaurant meal choices. To examine the effect of point-of-purchase calorie information and value size pricing on fast food meal choices a randomized 2 x 2 factorial experiment was conducted in which participants ordered a fast food meal from one of four menus that varied with respect to whether calorie information was provided and whether value size pricing was used. Study participants included 594 adolescents and adults who regularly ate at fast food restaurants. Study staff recorded the foods ordered and consumed by each participant. Participants also completed surveys to assess attitudes, beliefs and practices related to fast food and nutrition. No significant differences in the energy composition of meals ordered or eaten were found between menu conditions. The average energy content of meals ordered by those randomized to a menu that included calorie information and did not include value size pricing was 842 kcals compared with 827 kcals for those who ordered their meal from a menu that did not include calorie information but had value size pricing (control menu). Results were similar in most analyses conducted stratified by factors such as age, race and education level. Additional research is needed to better evaluate the effects of calorie labeling and value size pricing on fast food meal choices. Studies in which participants are repeatedly exposed to these factors are needed since long term exposure may be required for behavior change.

Tubal anastomosis after previous sterilization: a systematic review.

PubMed

van Seeters, Jacoba A H; Chua, Su Jen; Mol, Ben W J; Koks, Carolien A M

2017-05-01

Female sterilization is one of the most common contraceptive methods. A small number of women, however, opt for reversal of sterilization procedures after they experience regret. Procedures can be performed by laparotomy or laparoscopy, with or without robotic assistance. Another commonly utilized alternative is IVF. The choice between surgery and IVF is often influenced by reimbursement politics for that particular geographic location. We evaluated the fertility outcomes of different surgical methods available for the reversal of female sterilization, compared these to IVF and assessed the prognostic factors for success. Two search strategies were employed. Firstly, we searched for randomized and non-randomized clinical studies presenting fertility outcomes of sterilization reversal up to July 2016. Data on the following outcomes were collected: pregnancy rate, ectopic pregnancy rate, cost of the procedure and operative time. Eligible study designs included prospective or retrospective studies, randomized controlled trials, cohort studies, case-control studies and case series. No age restriction was applied. Exclusion criteria were patients suffering from tubal infertility from any other reason (e.g. infection, endometriosis and adhesions from previous surgery) and studies including <10 participants. The following factors likely to influence the success of sterilization reversal procedures were then evaluated: female age, BMI and duration and method of sterilization. Secondly, we searched for randomized and non-randomized clinical studies that compared reversal of sterilization to IVF and evaluated them for pregnancy outcomes and cost effectiveness. We included 37 studies that investigated a total of 10 689 women. No randomized controlled trials were found. Most studies were retrospective cohort studies of a moderate quality. The pooled pregnancy rate after sterilization reversal was 42-69%, with heterogeneity seen from the different methods utilized. The reported ectopic pregnancy rate was 4-8%. The only prognostic factor affecting the chance of conception was female age. The surgical approach (i.e. laparotomy [microscopic], laparoscopy or robotic) had no impact on the outcome, with the exception of the macroscopic laparotomic technique, which had inferior results and is not currently utilized. For older women, IVF could be a more cost-effective alternative for the reversal of sterilization. However, direct comparative data are lacking and a cut-off age cannot be stated. In sterilized women who suffer regret, surgical tubal re-anastomosis is an effective treatment, especially in younger women. However, there is a need for randomized controlled trials comparing the success rates and costs of surgical reversal with IVF. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Enrollment in prescription drug insurance: the interaction of numeracy and choice set size.

PubMed

Szrek, Helena; Bundorf, M Kate

2014-04-01

To determine how choice set size affects decision quality among individuals of different levels of numeracy choosing prescription drug plans. Members of an Internet-enabled panel age 65 and over were randomly assigned to sets of prescription drug plans varying in size from 2 to 16 plans from which they made a hypothetical choice. They answered questions about enrollment likelihood and the costs and benefits of their choice. The measure of decision quality was enrollment likelihood among those for whom enrollment was beneficial. Enrollment likelihood by numeracy and choice set size was calculated. A model of moderated mediation was analyzed to understand the role of numeracy as a moderator of the relationship between the number of plans and the quality of the enrollment decision and the roles of the costs and benefits in mediating that relationship. More numerate adults made better decisions than less numerate adults when choosing among a small number of alternatives but not when choice sets were larger. Choice set size had little effect on decision making of less numerate adults. Differences in decision making costs between more and less numerate adults helped explain the effect of choice set size on decision quality. Interventions to improve decision making in the context of Medicare Part D may differentially affect lower and higher numeracy adults. The conflicting results on choice overload in the psychology literature may be explained in part by differences amongst individuals in how they respond to choice set size.

Mate choice for neutral and MHC genetic characteristics in Alpine marmots: different targets in different contexts?

PubMed

Ferrandiz-Rovira, Mariona; Allainé, Dominique; Callait-Cardinal, Marie-Pierre; Cohas, Aurélie

2016-07-01

Sexual selection through female mate choice for genetic characteristics has been suggested to be an important evolutionary force maintaining genetic variation in animal populations. However, the genetic targets of female mate choice are not clearly identified and whether female mate choice is based on neutral genetic characteristics or on particular functional loci remains an open question. Here, we investigated the genetic targets of female mate choice in Alpine marmots (Marmota marmota), a socially monogamous mammal where extra-pair paternity (EPP) occurs. We used 16 microsatellites to describe neutral genetic characteristics and two MHC loci belonging to MHC class I and II as functional genetic characteristics. Our results reveal that (1) neutral and MHC genetic characteristics convey different information in this species, (2) social pairs show a higher MHC class II dissimilarity than expected under random mate choice, and (3) the occurrence of EPP increases when social pairs present a high neutral genetic similarity or dissimilarity but also when they present low MHC class II dissimilarity. Thus, female mate choice is based on both neutral and MHC genetic characteristics, and the genetic characteristics targeted seem to be context dependent (i.e., the genes involved in social mate choice and genetic mate choice differ). We emphasize the need for empirical studies of mate choice in the wild using both neutral and MHC genetic characteristics because whether neutral and functional genetic characteristics convey similar information is not universal.

A higher-complex carbohydrate diet in gestational diabetes mellitus achieves glucose targets and lowers postprandial lipids: a randomized crossover study.

PubMed

Hernandez, Teri L; Van Pelt, Rachael E; Anderson, Molly A; Daniels, Linda J; West, Nancy A; Donahoo, William T; Friedman, Jacob E; Barbour, Linda A

2014-01-01

The conventional diet approach to gestational diabetes mellitus (GDM) advocates carbohydrate restriction, resulting in higher fat (HF), also a substrate for fetal fat accretion and associated with maternal insulin resistance. Consequently, there is no consensus about the ideal GDM diet. We hypothesized that, compared with a conventional, lower-carbohydrate/HF diet (40% carbohydrate/45% fat/15% protein), consumption of a higher-complex carbohydrate (HCC)/lower-fat (LF) Choosing Healthy Options in Carbohydrate Energy (CHOICE) diet (60/25/15%) would result in 24-h glucose area under the curve (AUC) profiles within therapeutic targets and lower postprandial lipids. Using a randomized, crossover design, we provided 16 GDM women (BMI 34 ± 1 kg/m2) with two 3-day isocaloric diets at 31 ± 0.5 weeks (washout between diets) and performed continuous glucose monitoring. On day 4 of each diet, we determined postprandial (5 h) glucose, insulin, triglycerides (TGs), and free fatty acids (FFAs) following a controlled breakfast meal. There were no between-diet differences for fasting or mean nocturnal glucose, but 24-h AUC was slightly higher (∼6%) on the HCC/LF CHOICE diet (P = 0.02). The continuous glucose monitoring system (CGMS) revealed modestly higher 1- and 2-h postprandial glucose on CHOICE (1 h, 115 ± 2 vs. 107 ± 3 mg/dL, P ≤ 0.01; 2 h, 106 ± 3 vs. 97 ± 3 mg/dL, P = 0.001) but well below current targets. After breakfast, 5-h glucose and insulin AUCs were slightly higher (P < 0.05), TG AUC was no different, but the FFA AUC was significantly lower (∼19%; P ≤ 0.01) on the CHOICE diet. This highly controlled study randomizing isocaloric diets and using a CGMS is the first to show that liberalizing complex carbohydrates and reducing fat still achieved glycemia below current treatment targets and lower postprandial FFAs. This diet strategy may have important implications for preventing macrosomia.

Effects of nutrition label format and product assortment on the healthfulness of food choice.

PubMed

Aschemann-Witzel, Jessica; Grunert, Klaus G; van Trijp, Hans C M; Bialkova, Svetlana; Raats, Monique M; Hodgkins, Charo; Wasowicz-Kirylo, Grazyna; Koenigstorfer, Joerg

2013-12-01

This study aims to find out whether front-of-pack nutrition label formats influence the healthfulness of consumers' food choices and important predictors of healthful choices, depending on the size of the choice set that is made available to consumers. The predictors explored were health motivation and perceived capability of making healthful choices. One thousand German and Polish consumers participated in the study that manipulated the format of nutrition labels. All labels referred to the content of calories and four negative nutrients and were presented on savoury and sweet snacks. The different formats included the percentage of guideline daily amount, colour coding schemes, and text describing low, medium and high content of each nutrient. Participants first chose from a set of 10 products and then from a set of 20 products, which was, on average, more healthful than the first choice set. The results showed that food choices were more healthful in the extended 20-product (vs. 10-product) choice set and that this effect is stronger than a random choice would produce. The formats colour coding and texts, particularly colour coding in Germany, increased the healthfulness of product choices when consumers were asked to choose a healthful product, but not when they were asked to choose according to their preferences. The formats did not influence consumers' motivation to choose healthful foods. Colour coding, however, increased consumers' perceived capability of making healthful choices. While the results revealed no consistent differences in the effects between the formats, they indicate that manipulating choice sets by including healthier options is an effective strategy to increase the healthfulness of food choices. Copyright © 2013 Elsevier Ltd. All rights reserved.

Providing Choice in Exercise Influences Food Intake at the Subsequent Meal.

PubMed

Beer, Natalya J; Dimmock, James A; Jackson, Ben; Guelfi, Kym J

2017-10-01

The benefits of regular exercise for health are well established; however, certain behaviors after exercise, such as unhealthy or excessive food consumption, can counteract some of these benefits. To investigate the effect of autonomy support (through the provision of choice) in exercise-relative to a no-choice condition with matched energy expenditure-on appetite and subsequent energy intake. Fifty-eight men and women (body mass index, 22.9 ± 2.3 kg·m; peak oxygen consumption, 52.7 ± 6.4 mL·kg·min) completed one familiarization session and one experimental trial, in which they were randomized to either a choice or no-choice exercise condition using a between-subjects yoked design. Ad libitum energy intake from a laboratory test meal was assessed after exercise, together with perceptions of mood, perceived choice, enjoyment, and value. Despite similar ratings of perceived appetite across conditions (P > 0.05), energy intake was significantly higher after exercise performed under the no-choice condition (2456 ± 1410 kJ) compared with the choice condition (1668 ± 1215 kJ; P = 0.026; d = 0.60). In particular, the proportion of energy intake from unhealthy foods was significantly greater after exercise in the no-choice condition (1412 ± 1304 kJ) compared with the choice condition (790 ± 861 kJ; P = 0.037, d = 0.56). Participants in the choice condition also reported higher perceptions of choice (P < 0.001), enjoyment (P = 0.008), and value (P = 0.009) relating to the exercise session, whereas there were no between-condition differences in mood (P > 0.05). A lack of choice in exercise is associated with greater energy intake from "unhealthy" foods in recovery. This finding highlights the importance of facilitating an autonomy supportive environment during exercise prescription and instruction.

A systematic approach to novel virus discovery in emerging infectious disease outbreaks.

PubMed

Sridhar, Siddharth; To, Kelvin K W; Chan, Jasper F W; Lau, Susanna K P; Woo, Patrick C Y; Yuen, Kwok-Yung

2015-05-01

The discovery of novel viruses is of great importance to human health-both in the setting of emerging infectious disease outbreaks and in disease syndromes of unknown etiology. Despite the recent proliferation of many efficient virus discovery methods, careful selection of a combination of methods is important to demonstrate a novel virus, its clinical associations, and its relevance in a timely manner. The identification of a patient or an outbreak with distinctive clinical features and negative routine microbiological workup is often the starting point for virus hunting. This review appraises the roles of culture, electron microscopy, and nucleic acid detection-based methods in optimizing virus discovery. Cell culture is generally slow but may yield viable virus. Although the choice of cell line often involves trial and error, it may be guided by the clinical syndrome. Electron microscopy is insensitive but fast, and may provide morphological clues to choice of cell line or consensus primers for nucleic acid detection. Consensus primer PCR can be used to detect viruses that are closely related to known virus families. Random primer amplification and high-throughput sequencing can catch any virus genome but cannot yield an infectious virion for testing Koch postulates. A systematic approach that incorporates carefully chosen combinations of virus detection techniques is required for successful virus discovery. Copyright © 2015 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Habitat discrimination by gravid Anopheles gambiae sensu lato – a push-pull system

PubMed Central

2014-01-01

Background The non-random distribution of anopheline larvae in natural habitats suggests that gravid females discriminate between habitats of different quality. Whilst physical and chemical cues used by Culex and Aedes vector mosquitoes for selecting an oviposition site have been extensively studied, those for Anopheles remain poorly explored. Here the habitat selection by Anopheles gambiae sensu lato (s.l.), the principal African malaria vector, was investigated when presented with a choice of two infusions made from rabbit food pellets, or soil. Methods Natural colonization and larval survival was evaluated in artificial ponds filled randomly with either infusion. Dual-choice, egg-count bioassays evaluated the responses of caged gravid females to (1) two- to six-day old infusions versus lake water; (2) autoclaved versus non-autoclaved soil infusions; and assessed (3) the olfactory memory of gravid females conditioned in pellet infusion as larvae. Results Wild Anopheles exclusively colonized ponds with soil infusion and avoided those with pellet infusion. When the individual infusions were tested in comparison with lake water, caged An. gambiae sensu stricto (s.s.) showed a dose response: females increasingly avoided the pellet infusion with increasing infusion age (six-day versus lake water: odds ratio (OR) 0.22; 95% confidence interval (CI) 0.1-0.5) and showed increasing preference to lay eggs as soil infusion age increased (six-day versus lake water: OR 2.1; 95% CI 1.4-3.3). Larvae survived in soil infusions equally well as in lake water but died in pellet infusions. Anopheles gambiae s.s. preferred to lay eggs in the non-autoclaved soil (OR 2.6; 95% CI 1.8-3.7) compared with autoclaved soil. There was no change in the avoidance of pellet infusion by individuals reared in the infusion compared with those reared in lake water. Conclusion Wild and caged An. gambiae s.l. females discriminate between potential aquatic habitats for oviposition. These choices benefit the survival of the offspring. Although the study was not designed to distinguish between stimuli that acted over a distance or on contact, it could be demonstrated that the choice of habitat is mediated by chemical cues based on both preference and avoidance. These cues, if identified, might be developed for ‘push-pull’ strategies to improve malaria vector monitoring and control. PMID:24693951

Does health affect portfolio choice?

PubMed

Love, David A; Smith, Paul A

2010-12-01

A number of recent studies find that poor health is empirically associated with a safer portfolio allocation. It is difficult to say, however, whether this relationship is truly causal. Both health status and portfolio choice are influenced by unobserved characteristics such as risk attitudes, impatience, information, and motivation, and these unobserved factors, if not adequately controlled for, can induce significant bias in the estimates of asset demand equations. Using the 1992-2006 waves of the Health and Retirement Study, we investigate how much of the connection between health and portfolio choice is causal and how much is due to the effects of unobserved heterogeneity. Accounting for unobserved heterogeneity with fixed effects and correlated random effects models, we find that health does not appear to significantly affect portfolio choice among single households. For married households, we find a small effect (about 2-3 percentage points) from being in the lowest of five self-reported health categories. Copyright © 2009 John Wiley & Sons, Ltd.

Consumers' use of HCAHPS ratings and word-of-mouth in hospital choice.

PubMed

Huppertz, John W; Carlson, Jay P

2010-12-01

To investigate the impact of the HCAHPS report of patient experiences and word-of-mouth narratives on consumers' hospital choice. Online consumer research panel of U.S. adults ages 18 and older. In an experiment, 309 consumers were randomly assigned to see positive or negative information about a hospital in two modalities: HCAHPS graphs and a relative's narrative e-mail. Then they indicated their intentions to choose the hospital for elective surgery. A simple, one-paragraph e-mail and 10 HCAHPS graphs had similar impacts on consumers' hospital choice. When information was inconsistent between the HCAHPS data and e-mail narrative, one modality attenuated the other's effect on hospital choice. The findings illustrate the power of anecdotal narratives, suggesting that policy makers should consider how HCAHPS data can be affected by word-of-mouth communication. © Health Research and Educational Trust.

Impact of nutrition messages on children's food choice: pilot study.

PubMed

Bannon, Katie; Schwartz, Marlene B

2006-03-01

This pilot study tested the influence of nutrition message framing on snack choice among kindergarteners. Three classrooms were randomly assigned to watch one of the following 60s videos: (a) a gain-framed nutrition message (i.e. the positive benefits of eating apples) (n=14); (b) a loss-framed message (i.e. the negative consequences of not eating apples) (n=18); or (c) a control scene (children playing a game) (n=18). Following this, the children were offered a choice between animal crackers and an apple for their snack. Among the children who saw one of the nutrition message videos, 56% chose apples rather than animal crackers; in the control condition only 33% chose apples. This difference was statistically significant (chi2=7.56, p<0.01). These results suggest that videos containing nutritional messages may have a positive influence on children's short-term food choices.

A randomized trial of decision-making in asymptomatic carotid stenosis.

PubMed

Silver, B; Zaman, I F; Ashraf, K; Majed, Y; Norwood, E M; Schuh, L A; Smith, B J; Smith, R E; Schultz, L R

2012-01-31

We sought to evaluate whether different presentation formats, presenter characteristics, and patient characteristics affect decision-making in asymptomatic carotid stenosis. Subjects included individuals presenting to a neurology clinic. Participants included those over age 18 without known carotid stenosis. Subjects were randomized to a 30-second video with 1 of 5 presentation formats (absolute risk, absolute event-free survival, annualized absolute risk, relative risk, and a qualitative description) delivered by 1 of 4 presenter physicians (black woman, white woman, black man, white man). Subjects then completed a one-page form regarding background demographics and their decision regarding treatment choice. A total of 409 subjects watched the video and completed the survey. Overall, 48.4% of subjects chose surgery. Presentation format strongly predicted choice of surgery (qualitative [64%], relative risk [63%], absolute risk [43%], absolute event-free survival [37%], and annualized absolute risk [35%], p < 0.001). There was a trend for younger age (mean age 52 vs 55, p = 0.054), male gender (53% vs 45%, p = 0.08), and advanced education (42% for high school education or less vs 52% for more than high school education, p = 0.052) to predict surgery choice. Gender and race of presenter, and race of subject, had no influence on the choice of treatment. Presentation format (information framing) strongly determines patient decision-making in asymptomatic carotid stenosis. Subject age, gender, and education level may also influence the decision. Clinicians should consider the influence of these variables when counseling patients.

How People Use Social Information to Find out What to Want in the Paradigmatic Case of Inter-temporal Preferences

PubMed Central

Dolan, Raymond J.

2016-01-01

The weight with which a specific outcome feature contributes to preference quantifies a person’s ‘taste’ for that feature. However, far from being fixed personality characteristics, tastes are plastic. They tend to align, for example, with those of others even if such conformity is not rewarded. We hypothesised that people can be uncertain about their tastes. Personal tastes are therefore uncertain beliefs. People can thus learn about them by considering evidence, such as the preferences of relevant others, and then performing Bayesian updating. If a person’s choice variability reflects uncertainty, as in random-preference models, then a signature of Bayesian updating is that the degree of taste change should correlate with that person’s choice variability. Temporal discounting coefficients are an important example of taste–for patience. These coefficients quantify impulsivity, have good psychometric properties and can change upon observing others’ choices. We examined discounting preferences in a novel, large community study of 14–24 year olds. We assessed discounting behaviour, including decision variability, before and after participants observed another person’s choices. We found good evidence for taste uncertainty and for Bayesian taste updating. First, participants displayed decision variability which was better accounted for by a random-taste than by a response-noise model. Second, apparent taste shifts were well described by a Bayesian model taking into account taste uncertainty and the relevance of social information. Our findings have important neuroscientific, clinical and developmental significance. PMID:27447491

Remote-online case-based learning: A comparison of remote-online and face-to-face, case-based learning - a randomized controlled trial.

PubMed

Nicklen, Peter; Keating, Jenny L; Paynter, Sophie; Storr, Michael; Maloney, Stephen

2016-01-01

Case-based learning (CBL) is an educational approach where students work in small, collaborative groups to solve problems. Computer assisted learning (CAL) is the implementation of computer technology in education. The purpose of this study was to compare the effects of a remote-online CBL (RO-CBL) with traditional face-to-face CBL on learning the outcomes of undergraduate physiotherapy students. Participants were randomized to either the control (face-to-face CBL) or to the CAL intervention (RO-CBL). The entire 3rd year physiotherapy cohort (n = 41) at Monash University, Victoria, Australia, were invited to participate in the randomized controlled trial. Outcomes included a postintervention multiple-choice test evaluating the knowledge gained from the CBL, a self-assessment of learning based on examinable learning objectives and student satisfaction with the CBL. In addition, a focus group was conducted investigating perceptions and responses to the online format. Thirty-eight students (control n = 19, intervention n = 19) participated in two CBL sessions and completed the outcome assessments. CBL median scores for the postintervention multiple-choice test were comparable (Wilcoxon rank sum P = 0.61) (median/10 [range] intervention group: 9 [8-10] control group: 10 [7-10]). Of the 15 examinable learning objectives, eight were significantly in favor of the control group, suggesting a greater perceived depth of learning. Eighty-four percent of students (16/19) disagreed with the statement "I enjoyed the method of CBL delivery." Key themes identified from the focus group included risks associated with the implementation of, challenges of communicating in, and flexibility offered, by web-based programs. RO-CBL appears to provide students with a comparable learning experience to traditional CBL. Procedural and infrastructure factors need to be addressed in future studies to counter student dissatisfaction and decreased perceived depth of learning.

An aggregate method to calibrate the reference point of cumulative prospect theory-based route choice model for urban transit network

NASA Astrophysics Data System (ADS)

Zhang, Yufeng; Long, Man; Luo, Sida; Bao, Yu; Shen, Hanxia

2015-12-01

Transit route choice model is the key technology of public transit systems planning and management. Traditional route choice models are mostly based on expected utility theory which has an evident shortcoming that it cannot accurately portray travelers' subjective route choice behavior for their risk preferences are not taken into consideration. Cumulative prospect theory (CPT), a brand new theory, can be used to describe travelers' decision-making process under the condition of uncertainty of transit supply and risk preferences of multi-type travelers. The method to calibrate the reference point, a key parameter to CPT-based transit route choice model, determines the precision of the model to a great extent. In this paper, a new method is put forward to obtain the value of reference point which combines theoretical calculation and field investigation results. Comparing the proposed method with traditional method, it shows that the new method can promote the quality of CPT-based model by improving the accuracy in simulating travelers' route choice behaviors based on transit trip investigation from Nanjing City, China. The proposed method is of great significance to logical transit planning and management, and to some extent makes up the defect that obtaining the reference point is solely based on qualitative analysis.

Optimization of radiotherapy. Some notes on the principles and practice of optimization in cancer treatment and implications for clinical research.

PubMed

Andrews, J R

1981-01-01

Two methods dominate cancer treatment--one, the traditional best practice, individualized treatment method and two, the a priori determined decision method of the interinstitutional, cooperative, clinical trial. In the first, choices are infinite and can be made at the time of treatment; in the second, choices are finite and are made in advance of treatment on a random basis. Neither method systematically selects, identifies, or formalizes the optimum level of effect in the treatment chosen. Of the two, it can be argued that the first, other things being equal, is more likely to select the optimum treatment. The determination of level of effect for the optimization of cancer treatment requires the generation of dose-response relationships for both benefit and risk and the introduction of benefit and risk considerations and judgements. The clinical trial, as presently constituted, doses not yield this kind of information, it being, generally, of the binary yes or no, better or worse type. The best practice, individualized treatment method can yield, when adequately documented, both a range of dose-response relationships and a variety of benefit and risk considerations. The presentation will be limited to a consideration of a single modality of cancer treatment, radiation therapy, but an analogy with other modalities of cancer treatment will be inferred. Criteria for optimization will be developed and graphic means for its identification and formalization will be demonstrated with examples taken from the radiotherapy literature. The general problem of optimization theory and practice will be discussed; the necessity for its exploration in relation to the increasing complexity of cancer treatment will be developed; and recommendations for clinical research will be made including a proposal for the support of clinics as an alternative to the support of programs.

A Randomized Controlled Trial of a CPR Decision Support Video for Patients Admitted to the General Medicine Service.

PubMed

Merino, Aimee M; Greiner, Ryan; Hartwig, Kristopher

2017-09-01

Patient preferences regarding cardiopulmonary resuscitation (CPR) are important, especially during hospitalization when a patient's health is changing. Yet many patients are not adequately informed or involved in the decision-making process. We examined the effect of an informational video about CPR on hospitalized patients' code status choices. This was a prospective, randomized trial conducted at the Minneapolis Veterans Affairs Health Care System in Minnesota. We enrolled 119 patients, hospitalized on the general medicine service, and at least 65 years old. The majority were men (97%) with a mean age of 75. A video described code status choices: full code (CPR and intubation if required), do not resuscitate (DNR), and do not resuscitate/do not intubate (DNR/DNI). Participants were randomized to watch the video (n = 59) or usual care (n = 60). The primary outcome was participants' code status preferences. Secondary outcomes included a questionnaire designed to evaluate participants' trust in their healthcare team and knowledge and perceptions about CPR. Participants who viewed the video were less likely to choose full code (37%) compared to participants in the usual care group (71%) and more likely to choose DNR/DNI (56% in the video group vs. 17% in the control group) ( < 0.00001). We did not see a difference in trust in their healthcare team or knowledge and perceptions about CPR as assessed by our questionnaire. Hospitalized patients who watched a video about CPR and code status choices were less likely to choose full code and more likely to choose DNR/DNI. © 2017 Society of Hospital Medicine

No Effect of Commercial Cognitive Training on Brain Activity, Choice Behavior, or Cognitive Performance.

PubMed

Kable, Joseph W; Caulfield, M Kathleen; Falcone, Mary; McConnell, Mairead; Bernardo, Leah; Parthasarathi, Trishala; Cooper, Nicole; Ashare, Rebecca; Audrain-McGovern, Janet; Hornik, Robert; Diefenbach, Paul; Lee, Frank J; Lerman, Caryn

2017-08-02

Increased preference for immediate over delayed rewards and for risky over certain rewards has been associated with unhealthy behavioral choices. Motivated by evidence that enhanced cognitive control can shift choice behavior away from immediate and risky rewards, we tested whether training executive cognitive function could influence choice behavior and brain responses. In this randomized controlled trial, 128 young adults (71 male, 57 female) participated in 10 weeks of training with either a commercial web-based cognitive training program or web-based video games that do not specifically target executive function or adapt the level of difficulty throughout training. Pretraining and post-training, participants completed cognitive assessments and functional magnetic resonance imaging during performance of the following validated decision-making tasks: delay discounting (choices between smaller rewards now vs larger rewards in the future) and risk sensitivity (choices between larger riskier rewards vs smaller certain rewards). Contrary to our hypothesis, we found no evidence that cognitive training influences neural activity during decision-making; nor did we find effects of cognitive training on measures of delay discounting or risk sensitivity. Participants in the commercial training condition improved with practice on the specific tasks they performed during training, but participants in both conditions showed similar improvement on standardized cognitive measures over time. Moreover, the degree of improvement was comparable to that observed in individuals who were reassessed without any training whatsoever. Commercial adaptive cognitive training appears to have no benefits in healthy young adults above those of standard video games for measures of brain activity, choice behavior, or cognitive performance. SIGNIFICANCE STATEMENT Engagement of neural regions and circuits important in executive cognitive function can bias behavioral choices away from immediate rewards. Activity in these regions may be enhanced through adaptive cognitive training. Commercial brain training programs claim to improve a broad range of mental processes; however, evidence for transfer beyond trained tasks is mixed. We undertook the first randomized controlled trial of the effects of commercial adaptive cognitive training (Lumosity) on neural activity and decision-making in young adults ( N = 128) compared with an active control (playing on-line video games). We found no evidence for relative benefits of cognitive training with respect to changes in decision-making behavior or brain response, or for cognitive task performance beyond those specifically trained. Copyright © 2017 the authors 0270-6474/17/377390-13$15.00/0.

No Effect of Commercial Cognitive Training on Brain Activity, Choice Behavior, or Cognitive Performance

PubMed Central

Caulfield, M. Kathleen; McConnell, Mairead; Bernardo, Leah; Parthasarathi, Trishala; Cooper, Nicole; Ashare, Rebecca; Audrain-McGovern, Janet; Lee, Frank J.; Lerman, Caryn

2017-01-01

Increased preference for immediate over delayed rewards and for risky over certain rewards has been associated with unhealthy behavioral choices. Motivated by evidence that enhanced cognitive control can shift choice behavior away from immediate and risky rewards, we tested whether training executive cognitive function could influence choice behavior and brain responses. In this randomized controlled trial, 128 young adults (71 male, 57 female) participated in 10 weeks of training with either a commercial web-based cognitive training program or web-based video games that do not specifically target executive function or adapt the level of difficulty throughout training. Pretraining and post-training, participants completed cognitive assessments and functional magnetic resonance imaging during performance of the following validated decision-making tasks: delay discounting (choices between smaller rewards now vs larger rewards in the future) and risk sensitivity (choices between larger riskier rewards vs smaller certain rewards). Contrary to our hypothesis, we found no evidence that cognitive training influences neural activity during decision-making; nor did we find effects of cognitive training on measures of delay discounting or risk sensitivity. Participants in the commercial training condition improved with practice on the specific tasks they performed during training, but participants in both conditions showed similar improvement on standardized cognitive measures over time. Moreover, the degree of improvement was comparable to that observed in individuals who were reassessed without any training whatsoever. Commercial adaptive cognitive training appears to have no benefits in healthy young adults above those of standard video games for measures of brain activity, choice behavior, or cognitive performance. SIGNIFICANCE STATEMENT Engagement of neural regions and circuits important in executive cognitive function can bias behavioral choices away from immediate rewards. Activity in these regions may be enhanced through adaptive cognitive training. Commercial brain training programs claim to improve a broad range of mental processes; however, evidence for transfer beyond trained tasks is mixed. We undertook the first randomized controlled trial of the effects of commercial adaptive cognitive training (Lumosity) on neural activity and decision-making in young adults (N = 128) compared with an active control (playing on-line video games). We found no evidence for relative benefits of cognitive training with respect to changes in decision-making behavior or brain response, or for cognitive task performance beyond those specifically trained. PMID:28694338

The nonlinear, complex sequential organization of behavior in schizophrenic patients: neurocognitive strategies and clinical correlations.

PubMed

Paulus, M P; Perry, W; Braff, D L

1999-09-01

Thought disorder is a hallmark of schizophrenia and can be inferred from disorganized behavior. Measures of the sequential organization of behavior are important because they reflect the cognitive processes of the selection and sequencing of behavioral elements, which generate observable and analyzable behavioral patterns. In this context, sequences of choices generated by schizophrenic patients in a two-choice guessing task fluctuate significantly, which reflects an "oscillating dysregulation" between highly predictable and highly unpredictable subsequences within a single test session. In this study, we aimed to clarify the significance of dysregulation by seeing whether demographic, clinical, neuropsychological, and psychological measures predict the degree of dysregulation observed on this two-choice task. Thirty schizophrenic patients repeatedly performed a LEFT or RIGHT key press that was followed by a stimulus, which occurred randomly on the left or right side of the computer screen. Thus, the stimulus location had nothing to do with the key press behavior. The range of key press sequence predictabilities as measured by the dynamical entropy was used to quantify the dysregulation of response sequences and reflects the range of fixity and randomness of the responses. A factor analysis was performed and step-wise multiple regression analyses were used to relate the factor scores to demographic, clinical, symptomatic, Wisconsin Card Sorting Test (WCST), and Rorschach variables. The LEFT/RIGHT key press sequences were determined by three factors: 1) the degree of win-stay/lose-shift strategy; 2) the degree of contextual influence on the current choice; and 3) the degree of dysregulation on the choice task. Demographic and clinical variables did not predict any of the three response patterns on the choice task. In contrast, the WCST and Rorschach test predicted performance on various factors of choice task response patterns. Schizophrenic patients employ several rules, i.e., "win-stay/lose-shift" and "decide according to the previous choice," that fluctuate significantly when generating sequences on this task, confirming that a basic behavioral dysregulation occurs in a single schizophrenic subject across a single test session. The organization or the "temporal architecture" of the behavioral sequences is not related to symptoms per se, but is related to deficits in executive functioning, problem solving, and perceptual organizational abilities.

Effect of progestin vs. combined oral contraceptive pills on lactation: A double-blind randomized controlled trial

PubMed Central

Espey, Eve; Ogburn, Tony; Leeman, Larry; Singh, Rameet; Schrader, Ronald

2013-01-01

Objective To estimate the effect of progestin-only vs. combined hormonal contraceptive pills on rates of breastfeeding continuation in postpartum women. Secondary outcomes include infant growth parameters, contraceptive method continuation and patient satisfaction with breastfeeding and contraceptive method. Methods In this randomized controlled trial, postpartum breastfeeding women who desired oral contraceptives were assigned to progestin-only vs. combined hormonal contraceptive pills. At two and eight weeks postpartum, participants completed in-person questionnaires that assessed breastfeeding continuation and contraceptive use. Infant growth parameters including weight, length and head circumference were assessed at eight weeks postpartum. Telephone questionnaires assessing breastfeeding, contraceptive continuation and satisfaction were completed at 3-7 weeks and 4 and 6 months. Breastfeeding continuation was compared between groups using Cox proportional hazards regression. Differences in baseline demographic characteristics and in variables between the two intervention groups were compared using chi-square tests, Fisher’s Exact test, or two-sample t-tests as appropriate. Results Breastfeeding continuation rates, contraceptive continuation, and infant growth parameters did not differ between users of progestin-only and combined hormonal contraceptive pills. Infant formula supplementation and maternal perception of inadequate milk supply were associated with decreased rates of breastfeeding in both groups. Conclusions Choice of combined or progestin-only birth control pills administered two weeks postpartum did not adversely affect breastfeeding continuation. PMID:22143258

Forecasting Solar Flares Using Magnetogram-based Predictors and Machine Learning

NASA Astrophysics Data System (ADS)

Florios, Kostas; Kontogiannis, Ioannis; Park, Sung-Hong; Guerra, Jordan A.; Benvenuto, Federico; Bloomfield, D. Shaun; Georgoulis, Manolis K.

2018-02-01

We propose a forecasting approach for solar flares based on data from Solar Cycle 24, taken by the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) mission. In particular, we use the Space-weather HMI Active Region Patches (SHARP) product that facilitates cut-out magnetograms of solar active regions (AR) in the Sun in near-realtime (NRT), taken over a five-year interval (2012 - 2016). Our approach utilizes a set of thirteen predictors, which are not included in the SHARP metadata, extracted from line-of-sight and vector photospheric magnetograms. We exploit several machine learning (ML) and conventional statistics techniques to predict flares of peak magnitude {>} M1 and {>} C1 within a 24 h forecast window. The ML methods used are multi-layer perceptrons (MLP), support vector machines (SVM), and random forests (RF). We conclude that random forests could be the prediction technique of choice for our sample, with the second-best method being multi-layer perceptrons, subject to an entropy objective function. A Monte Carlo simulation showed that the best-performing method gives accuracy ACC=0.93(0.00), true skill statistic TSS=0.74(0.02), and Heidke skill score HSS=0.49(0.01) for {>} M1 flare prediction with probability threshold 15% and ACC=0.84(0.00), TSS=0.60(0.01), and HSS=0.59(0.01) for {>} C1 flare prediction with probability threshold 35%.

Regression dilution bias: tools for correction methods and sample size calculation.

PubMed

Berglund, Lars

2012-08-01

Random errors in measurement of a risk factor will introduce downward bias of an estimated association to a disease or a disease marker. This phenomenon is called regression dilution bias. A bias correction may be made with data from a validity study or a reliability study. In this article we give a non-technical description of designs of reliability studies with emphasis on selection of individuals for a repeated measurement, assumptions of measurement error models, and correction methods for the slope in a simple linear regression model where the dependent variable is a continuous variable. Also, we describe situations where correction for regression dilution bias is not appropriate. The methods are illustrated with the association between insulin sensitivity measured with the euglycaemic insulin clamp technique and fasting insulin, where measurement of the latter variable carries noticeable random error. We provide software tools for estimation of a corrected slope in a simple linear regression model assuming data for a continuous dependent variable and a continuous risk factor from a main study and an additional measurement of the risk factor in a reliability study. Also, we supply programs for estimation of the number of individuals needed in the reliability study and for choice of its design. Our conclusion is that correction for regression dilution bias is seldom applied in epidemiological studies. This may cause important effects of risk factors with large measurement errors to be neglected.

Maternal Opioid Treatment: Human Experimental Research (MOTHER) – Approach, Issues, and Lessons Learned

PubMed Central

Jones, Hendrée E.; Fischer, Gabriele; Heil, Sarah H.; Kaltenbach, Karol; Martin, Peter R.; Coyle, Mara G.; Selby, Peter; Stine, Susan M.; O’Grady, Kevin E.; Arria, Amelia M.

2015-01-01

Aims The Maternal Opioid Treatment: Human Experimental Research (MOTHER) project, an eight-site randomized, double-blind, double-dummy, flexible-dosing, parallel-group clinical trial is described. This study is the most current – and single most comprehensive – research effort to investigate the safety and efficacy of maternal and prenatal exposure to methadone and buprenorphine. Methods The MOTHER study design is outlined, and its basic features are presented. Conclusions At least seven important lessons have been learned from the MOTHER study: (1) an interdisciplinary focus improves the design and methods of a randomized clinical trial; (2) multiple sites in a clinical trial present continuing challenges to the investigative team due to variations in recruitment goals, patient populations, and hospital practices that in turn differentially impact recruitment rates, treatment compliance, and attrition; (3) study design and protocols must be flexible in order to meet the unforeseen demands of both research and clinical management; (4) staff turnover needs to be addressed with a proactive focus on both hiring and training; (5) the implementation of a protocol for the treatment of a particular disorder may identify important ancillary clinical issues worthy of investigation; (6) timely tracking of data in a multi-site trial is both demanding and unforgiving; and, (7) complex multi-site trials pose unanticipated challenges that complicate the choice of statistical methods, thereby placing added demands on investigators to effectively communicate their results. PMID:23106924

The impact of self-interviews on response patterns for sensitive topics: a randomized trial of electronic delivery methods for a sexual behaviour questionnaire in rural South Africa.

PubMed

Harling, Guy; Gumede, Dumile; Mutevedzi, Tinofa; McGrath, Nuala; Seeley, Janet; Pillay, Deenan; Bärnighausen, Till W; Herbst, Abraham J

2017-08-17

Self-interviews, where the respondent rather than the interviewer enters answers to questions, have been proposed as a way to reduce social desirability bias associated with interviewer-led interviews. Computer-assisted self-interviews (CASI) are commonly proposed since the computer programme can guide respondents; however they require both language and computer literacy. We evaluated the feasibility and acceptability of using electronic methods to administer quantitative sexual behaviour questionnaires in the Somkhele demographic surveillance area (DSA) in rural KwaZulu-Natal, South Africa. We conducted a four-arm randomized trial of paper-and-pen-interview, computer-assisted personal-interview (CAPI), CASI and audio-CASI with an age-sex-urbanicity stratified sample of 504 adults resident in the DSA in 2015. We compared respondents' answers to their responses to the same questions in previous surveillance rounds. We also conducted 48 cognitive interviews, dual-coding responses using the Framework approach. Three hundred forty (67%) individuals were interviewed and covariates and participation rates were balanced across arms. CASI and audio-CASI were significantly slower than interviewer-led interviews. Item non-response rates were higher in self-interview arms. In single-paper meta-analysis, self-interviewed individuals reported more socially undesirable sexual behaviours. Cognitive interviews found high acceptance of both self-interviews and the use of electronic methods, with some concerns that self-interview methods required more participant effort and literacy. Electronic data collection methods, including self-interview methods, proved feasible and acceptable for completing quantitative sexual behaviour questionnaires in a poor, rural South African setting. However, each method had both benefits and costs, and the choice of method should be based on context-specific criteria.

Clinical and Health Outcomes Initiative in Comparative Effectiveness for Bipolar Disorder (Bipolar CHOICE): a pragmatic trial of complex treatment for a complex disorder.

PubMed

Nierenberg, Andrew A; Sylvia, Louisa G; Leon, Andrew C; Reilly-Harrington, Noreen A; Shesler, Leah W; McElroy, Susan L; Friedman, Edward S; Thase, Michael E; Shelton, Richard C; Bowden, Charles L; Tohen, Mauricio; Singh, Vivek; Deckersbach, Thilo; Ketter, Terence A; Kocsis, James H; McInnis, Melvin G; Schoenfeld, David; Bobo, William V; Calabrese, Joseph R

2014-02-01

Classic and second-generation antipsychotic mood stabilizers are recommended for treatment of bipolar disorder, yet there are no randomized comparative effectiveness studies that have examined the 'real-world' advantages and disadvantages of these medications. We describe the strategic decisions in the design of the Clinical and Health Outcomes Initiative in Comparative Effectiveness for Bipolar Disorder (Bipolar CHOICE). This article outlines the key issues and solutions the investigators faced in designing a clinical trial that would maximize generalizability and inform real-world clinical treatment of bipolar disorder. Bipolar CHOICE was a 6-month, multi-site, prospective, randomized clinical trial of outpatients with bipolar disorder. This study compares the effectiveness of quetiapine versus lithium, each with adjunctive personalized treatments (APTs). The co-primary outcomes selected are the overall benefits and harms of the study medications (as measured by the Clinical Global Impression-Efficacy Index) and the Necessary Clinical Adjustments (a measure of the number of medication changes). Secondary outcomes are continuous measures of mood, the Framingham General Cardiovascular Risk Score, and the Longitudinal Interval Follow up Evaluation Range of Impaired Functioning Tool (LIFE-RIFT). The final study design consisted of a single-blind, randomized comparative effectiveness trial of quetiapine versus lithium, plus APT, across 10 sites. Other important study considerations included limited exclusion criteria to maximize generalizability, flexible dosing of APT medications to mimic real-world treatment, and an intent-to-treat analysis plan. In all, 482 participants were randomized to the study, and 364 completed the study. The potential limitations of the study include the heterogeneity of APT, selection of study medications, lack of a placebo-control group, and participants' ability to pay for study medications. We expect that this study will inform our understanding of the benefits and harms of lithium, a classic mood stabilizer, compared to quetiapine, a second-generation antipsychotic with broad-spectrum activity in bipolar disorder, and will provide an example of a well-designed and well-conducted randomized comparative effectiveness clinical trial.

Taking the sweetness out of the 'Share a Coke' marketing campaign: the influence of personalized labelling on elementary school children's bottled drink choices.

PubMed

McDarby, F; O'Hora, D; O'Shea, D; Byrne, M

2018-01-01

Drink personalization (featuring names on bottle labels) has been used by soft drink companies to make their drinks attractive to children, potentially increasing consumption. To date, no publically available research has evaluated the influence of personalization on children's drink choices. To determine (i) whether personalizing bottled drinks influences children's drink choices; (ii) whether it is comparably effective in promoting healthy and unhealthy drinks and (iii) whether drink choices are affected by self-esteem, body mass index and parental factors. Children aged 8-13 years (N = 404) were randomly assigned to one of three drink labeling conditions: Prime Healthy, Prime Unhealthy and Control. All participants selected one beverage from 12 options, comprising six healthy and unhealthy drinks. Personalizing healthy drinks increased choice of healthy drinks (OR, 2.21; 95% CI, 1.24-4.00), and personalizing unhealthy drinks reduced choice of healthy drinks (OR, 0.35; 95% CI, 0.15-.0.75). Higher self-esteem predicted choosing own-named drinks (OR = 1.08, 95% CI, 1.00-1.18; p = .049). Children's drink choices are influenced by personalizing drink bottles. Tighter regulation of this marketing strategy for soft drinks may reduce children choice of these drinks. Personalization may also be used to encourage children to choose healthy drinks. © 2016 World Obesity Federation.

Factors Associated with Informed Decisions and Participation in Bowel Cancer Screening among Adults with Lower Education and Literacy.

PubMed

Smith, Sian K; Simpson, Judy M; Trevena, Lyndal J; McCaffery, Kirsten J

2014-08-01

Making informed decisions about cancer screening involves understanding the benefits and harms in conjunction with personal values. There is little research examining factors associated with informed decision making or participation in screening in the context of a decision aid trial. To identify factors associated with informed choice and participation in fecal occult blood testing (FOBT) among lower education populations. Randomized controlled trial of an FOBT decision aid conducted between July and November 2008. Socioeconomically disadvantaged areas in New South Wales, Australia. Included 572 adults aged 55 to 64 years with lower education. Sociodemographic variables, perceived health literacy, and involvement preferences in decision making were examined to identify predictors of informed choice (knowledge, attitudes, and behavior). Multivariate analysis identified independent predictors of making an informed choice as having higher education (relative risk [RR], 1.49; 95% confidence interval [CI], 1.13-1.95; P = 0.001), receiving the decision aid (RR, 2.88; 95% CI, 1.87-4.44; P < 0.001), and being male (RR, 1.48; 95% CI, 1.11-1.97; P = 0.009). Participants with no confidence in completing forms and poorer self-reported health were less likely to make an informed choice (RR, 0.74; 95% CI, 0.53-1.03; P = 0.05 and RR, 0.57; 95% CI, 0.36-0.89; P = 0.007, respectively). Independent predictors of completing the FOBT were positive screening attitudes, receiving the standard information, preference for making the decision alone, and knowing that screening may lead to false-positive/negative results. We did not objectively measure health literacy. Participants with the lowest levels of education had greater difficulties making an informed choice about participation in bowel screening. Alternative methods are needed to support informed decision making among lower education populations. © The Author(s) 2014.

Drug-to-antibody determination for an antibody-drug-conjugate utilizing cathepsin B digestion coupled with reversed-phase high-pressure liquid chromatography analysis.

PubMed

Adamo, Michael; Sun, Guoyong; Qiu, Difei; Valente, Joseph; Lan, Wenkui; Song, Hangtian; Bolgar, Mark; Katiyar, Amit; Krishnamurthy, Girija

2017-01-20

Antibody drug conjugates or ADCs are currently being evaluated for their effectiveness as targeted chemotherapeutic agents across the pharmaceutical industry. Due to the complexity arising from the choice of antibody, drug and linker; analytical methods for release and stability testing are required to provide a detailed understanding of both the antibody and the drug during manufacturing and storage. The ADC analyzed in this work consists of a tubulysin drug analogue that is randomly conjugated to lysine residues in a human IgG1 antibody. The drug is attached to the lysine residue through a peptidic, hydrolytically stable, cathepsin B cleavable linker. The random lysine conjugation produces a heterogeneous mixture of conjugated species with a variable drug-to-antibody ratio (DAR), therefore, the average amount of drug attached to the antibody is a critical parameter that needs to be monitored. In this work we have developed a universal method for determining DAR in ADCs that employ a cathepsin B cleavable linker. The ADC is first cleaved at the hinge region and then mildly reduced prior to treatment with the cathepsin B enzyme to release the drug from the antibody fragments. This pre-treatment allows the cathepsin B enzyme unrestricted access to the cleavage sites and ensures optimal conditions for the cathepsin B to cleave all the drug from the ADC molecule. The cleaved drug is then separated from the protein components by reversed phase high performance liquid chromatography (RP-HPLC) and quantitated using UV absorbance. This method affords superior cleavage efficiency to other methods that only employ a cathepsin digestion step as confirmed by mass spectrometry analysis. This method was shown to be accurate and precise for the quantitation of the DAR for two different random lysine conjugated ADC molecules. Copyright © 2016 Elsevier B.V. All rights reserved.

Communicating uncertainties about prescription drugs to the public: a national randomized trial.

PubMed

Schwartz, Lisa M; Woloshin, Steven

2011-09-12

Many new drugs are aggressively promoted. The public may not realize that even with US Food and Drug Administration (FDA) approval, important uncertainties about the benefits and harms of these drugs remain. We assessed the US public's understanding of the meaning of FDA drug approval and tested how brief explanations communicating drug uncertainties affect consumer choices. We conducted an Internet-based randomized controlled trial using a national sample of US adults from a research panel of approximately 30,000 households. A total of 2944 participants were randomized to receive 1 of 3 explanations about a pair of cholesterol drugs (1 approved based only on a surrogate outcome [lower cholesterol] and 1 based on a patient outcome [reduced myocardial infarctions]). Participants were randomized a second time to receive 1 of 3 explanations about a pair of heartburn drugs (1 newly approved and 1 approved 8 years earlier). Controls received no explanation; the nondirective group received explanations (for the cholesterol drugs, surrogates do not always translate into patient outcomes; for the heartburn drugs, it takes time to establish the safety of new drugs); the directive group received explanations plus advice to "Ask for a drug shown to reduce heart attacks or ask for one with a longer track record." The primary outcomes were choice: the cholesterol drug reducing myocardial infarctions, and the older heartburn drug. Thirty-nine percent mistakenly believed that the FDA approves only "extremely effective" drugs; 25% mistakenly believed that the FDA approves only drugs without serious side effects. Explanations affected choices: 71% of those in the directive group, 71% in the nondirective group, and 59% of controls chose the cholesterol drug that reduced myocardial infarctions (absolute difference, 12% [95% confidence interval, 7%-18%] for each explanation vs control). For the heartburn drugs, 53% of the directive group, 53% of the nondirective group, and 34% of controls chose the older drug (absolute difference, 19% [95% confidence interval, 13%-24%] for each explanation vs control). A substantial proportion of the public mistakenly believes that the FDA approves only extremely effective drugs and drugs lacking serious side effects. Brief explanations highlighting uncertainties about the benefit of drugs approved based on surrogate outcomes and the safety of new prescription drugs improved choices. Nondirective explanations worked as well as directive ones. clinicaltrials.gov Identifiers: NCT00950157, NCT00950131.

Evaluation of Consumer Understanding of Different Front-of-Package Nutrition Labels, 2010–2011

PubMed Central

Bragg, Marie A.; Seamans, Marissa J.; Mechulan, Regine L.; Novak, Nicole; Brownell, Kelly D.

2012-01-01

Introduction Governments throughout the world are using or considering various front-of-package (FOP) food labeling systems to provide nutrition information to consumers. Our web-based study tested consumer understanding of different FOP labeling systems. Methods Adult participants (N = 480) were randomized to 1 of 5 groups to evaluate FOP labels: 1) no label; 2) multiple traffic light (MTL); 3) MTL plus daily caloric requirement icon (MTL+caloric intake); 4) traffic light with specific nutrients to limit based on food category (TL+SNL); or 5) the Choices logo. Total percentage correct quiz scores were created reflecting participants’ ability to select the healthier of 2 foods and estimate amounts of saturated fat, sugar, and sodium in foods. Participants also rated products on taste, healthfulness, and how likely they were to purchase the product. Quiz scores and product perceptions were compared with 1-way analysis of variance followed by post-hoc Tukey tests. Results The MTL+caloric intake group (mean [standard deviation], 73.3% [6.9%]) and Choices group (72.5% [13.2%]) significantly outperformed the no label group (67.8% [10.3%]) and the TL+SNL group (65.8% [7.3%]) in selecting the more healthful product on the healthier product quiz. The MTL and MTL+caloric intake groups achieved average scores of more than 90% on the saturated fat, sugar, and sodium quizzes, which were significantly better than the no label and Choices group average scores, which were between 34% and 47%. Conclusion An MTL+caloric intake label and the Choices symbol hold promise as FOP labeling systems and require further testing in different environments and population subgroups. PMID:22995103

Priming healthy eating. You can't prime all the people all of the time.

PubMed

Forwood, Suzanna E; Ahern, Amy L; Hollands, Gareth J; Ng, Yin-Lam; Marteau, Theresa M

2015-06-01

In the context of a food purchasing environment filled with advertising and promotions, and an increased desire from policy makers to guide individuals toward choosing healthier foods, this study tests whether priming methods that use healthy food adverts to increase preference for healthier food generalize to a representative population. In two studies (Study 1 n = 143; Study 2 n = 764), participants were randomly allocated to a prime condition, where they viewed fruit and vegetable advertisements, or a control condition, with no advertisements. A subsequent forced choice task assessed preference between fruits and other sweet snacks. Additional measures included current hunger and thirst, dietary restraint, age, gender, education and self-reported weight and height. In Study 1, hunger reduced preferences for fruits (OR (95% CI) = 0.38 (0.26-0.56), p <0.0001), an effect countered by the prime (OR (95% CI) = 2.29 (1.33-3.96), p = 0.003). In Study 2, the effect of the prime did not generalize to a representative population. More educated participants, as used in Study 1, chose more fruit when hungry and primed (OR (95% CI) = 1.42 (1.13-1.79), p = 0.003), while less educated participants' fruit choice was unaffected by hunger or the prime. This study provides preliminary evidence that the effects of adverts on healthy eating choices depend on key individual traits (education level) and states (hunger), do not generalize to a broader population and have the potential to increase health inequalities arising from food choice. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Critical analysis of the factors associated with enteral feeding in preventing VAP: a systematic review.

PubMed

Chen, Yu-Chih

2009-04-01

Ventilator-associated pneumonia (VAP) is a common cause of morbidity in critically ill patients. Appropriate enteral feeding is the most important factor associated with the prevention of VAP. However, the standardization of enteral feeding methods needs clarification. The purpose of this systematic review was to synthesize the factors associated with enteral feeding in order to prevent VAP and to describe the characteristics of these factors. A comprehensive search was undertaken involving all major databases from their inception to September 2008 using medical subject heading terms associated with enteral feeding in relation to VAP. The overall reference list of identified studies was audited, and eligible studies included randomized controlled trials, controlled before-and-after (pre-post) studies and meta-analyses. To generate the characteristics of the factors associated with VAP, the reported components of these trials were pinpointed and categorized. A total of 14 papers were found that had investigated the factors linking enteral feeding and VAP. For these, 11 were randomized controlled trials, 1 was a meta-analysis and 2 were case-controlled analyses. Twelve of these 14 studies were conducted at a single institute and 2 were conducted at multiple institutes. The sample sizes varied from 10 to 2,528 subjects. Three major issues were identified based on the purpose of study interventions, and these were the effects of feeding method (continuous vs. intermittent), feeding site on aspiration (gastric vs. small bowel), and the timing of enteral feeding (early vs. late). The evidence suggests that a correct choice of enteral feeding method can effectively reduce complications due to aspiration. Furthermore, intermittent enteral feeding and with a small residual volume feed can reduce gastroesophageal reflux, and increased total intake volume and early feeding can reduce ICU mortality. Nonetheless, the effects of these choices on preventing VAP still need further evaluation. A set of clinical guidelines based on these evidence-based findings with respect to enteral feeding is required, particularly one that covers all aspects of the enteral feeding process.

Review of research designs and statistical methods employed in dental postgraduate dissertations.

PubMed

Shirahatti, Ravi V; Hegde-Shetiya, Sahana

2015-01-01

There is a need to evaluate the quality of postgraduate dissertations of dentistry submitted to university in the light of the international standards of reporting. We conducted the review with an objective to document the use of sampling methods, measurement standardization, blinding, methods to eliminate bias, appropriate use of statistical tests, appropriate use of data presentation in postgraduate dental research and suggest and recommend modifications. The public access database of the dissertations from Rajiv Gandhi University of Health Sciences was reviewed. Three hundred and thirty-three eligible dissertations underwent preliminary evaluation followed by detailed evaluation of 10% of randomly selected dissertations. The dissertations were assessed based on international reporting guidelines such as strengthening the reporting of observational studies in epidemiology (STROBE), consolidated standards of reporting trials (CONSORT), and other scholarly resources. The data were compiled using MS Excel and SPSS 10.0. Numbers and percentages were used for describing the data. The "in vitro" studies were the most common type of research (39%), followed by observational (32%) and experimental studies (29%). The disciplines conservative dentistry (92%) and prosthodontics (75%) reported high numbers of in vitro research. Disciplines oral surgery (80%) and periodontics (67%) had conducted experimental studies as a major share of their research. Lacunae in the studies included observational studies not following random sampling (70%), experimental studies not following random allocation (75%), not mentioning about blinding, confounding variables and calibrations in measurements, misrepresenting the data by inappropriate data presentation, errors in reporting probability values and not reporting confidence intervals. Few studies showed grossly inappropriate choice of statistical tests and many studies needed additional tests. Overall observations indicated the need to comply with standard guidelines of reporting research.

Development of a structured observational method for the systematic assessment of school food-choice architecture.

PubMed

Ozturk, Orgul D; McInnes, Melayne M; Blake, Christine E; Frongillo, Edward A; Jones, Sonya J

2016-01-01

The objective of this study is to develop a structured observational method for the systematic assessment of the food-choice architecture that can be used to identify key points for behavioral economic intervention intended to improve the health quality of children's diets. We use an ethnographic approach with observations at twelve elementary schools to construct our survey instrument. Elements of the structured observational method include decision environment, salience, accessibility/convenience, defaults/verbal prompts, number of choices, serving ware/method/packaging, and social/physical eating environment. Our survey reveals important "nudgeable" components of the elementary school food-choice architecture, including precommitment and default options on the lunch line.

Dealing with correlated choices: how a spin-glass model can help political parties select their policies.

PubMed

Moore, M A; Katzgraber, Helmut G

2014-10-01

Starting from preferences on N proposed policies obtained via questionnaires from a sample of the electorate, an Ising spin-glass model in a field can be constructed from which a political party could find the subset of the proposed policies which would maximize its appeal, form a coherent choice in the eyes of the electorate, and have maximum overlap with the party's existing policies. We illustrate the application of the procedure by simulations of a spin glass in a random field on scale-free networks.

Autonomous choices among deterministic evolution-laws as source of uncertainty

NASA Astrophysics Data System (ADS)

Trujillo, Leonardo; Meyroneinc, Arnaud; Campos, Kilver; Rendón, Otto; Sigalotti, Leonardo Di G.

2018-03-01

We provide evidence of an extreme form of sensitivity to initial conditions in a family of one-dimensional self-ruling dynamical systems. We prove that some hyperchaotic sequences are closed-form expressions of the orbits of these pseudo-random dynamical systems. Each chaotic system in this family exhibits a sensitivity to initial conditions that encompasses the sequence of choices of the evolution rule in some collection of maps. This opens a possibility to extend current theories of complex behaviors on the basis of intrinsic uncertainty in deterministic chaos.

Stochastic Dynamics through Hierarchically Embedded Markov Chains

NASA Astrophysics Data System (ADS)

Vasconcelos, Vítor V.; Santos, Fernando P.; Santos, Francisco C.; Pacheco, Jorge M.

2017-02-01

Studying dynamical phenomena in finite populations often involves Markov processes of significant mathematical and/or computational complexity, which rapidly becomes prohibitive with increasing population size or an increasing number of individual configuration states. Here, we develop a framework that allows us to define a hierarchy of approximations to the stationary distribution of general systems that can be described as discrete Markov processes with time invariant transition probabilities and (possibly) a large number of states. This results in an efficient method for studying social and biological communities in the presence of stochastic effects—such as mutations in evolutionary dynamics and a random exploration of choices in social systems—including situations where the dynamics encompasses the existence of stable polymorphic configurations, thus overcoming the limitations of existing methods. The present formalism is shown to be general in scope, widely applicable, and of relevance to a variety of interdisciplinary problems.

Optimum allocation for a dual-frame telephone survey.

PubMed

Wolter, Kirk M; Tao, Xian; Montgomery, Robert; Smith, Philip J

2015-12-01

Careful design of a dual-frame random digit dial (RDD) telephone survey requires selecting from among many options that have varying impacts on cost, precision, and coverage in order to obtain the best possible implementation of the study goals. One such consideration is whether to screen cell-phone households in order to interview cell-phone only (CPO) households and exclude dual-user household, or to take all interviews obtained via the cell-phone sample. We present a framework in which to consider the tradeoffs between these two options and a method to select the optimal design. We derive and discuss the optimum allocation of sample size between the two sampling frames and explore the choice of optimum p , the mixing parameter for the dual-user domain. We illustrate our methods using the National Immunization Survey , sponsored by the Centers for Disease Control and Prevention.

Stochastic Dynamics through Hierarchically Embedded Markov Chains.

PubMed

Vasconcelos, Vítor V; Santos, Fernando P; Santos, Francisco C; Pacheco, Jorge M

2017-02-03

Studying dynamical phenomena in finite populations often involves Markov processes of significant mathematical and/or computational complexity, which rapidly becomes prohibitive with increasing population size or an increasing number of individual configuration states. Here, we develop a framework that allows us to define a hierarchy of approximations to the stationary distribution of general systems that can be described as discrete Markov processes with time invariant transition probabilities and (possibly) a large number of states. This results in an efficient method for studying social and biological communities in the presence of stochastic effects-such as mutations in evolutionary dynamics and a random exploration of choices in social systems-including situations where the dynamics encompasses the existence of stable polymorphic configurations, thus overcoming the limitations of existing methods. The present formalism is shown to be general in scope, widely applicable, and of relevance to a variety of interdisciplinary problems.

40 CFR 766.16 - Developing the analytical test method.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Resolution Gas Chromatography (HRGC) with High Resolution Mass Spectrometry (HRMS) is the method of choice... meet the requirements of the chemical matrix. (d) Analysis. The method of choice is High Resolution Gas...

40 CFR 766.16 - Developing the analytical test method.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Resolution Gas Chromatography (HRGC) with High Resolution Mass Spectrometry (HRMS) is the method of choice... meet the requirements of the chemical matrix. (d) Analysis. The method of choice is High Resolution Gas...

Decision aid on breast cancer screening reduces attendance rate: results of a large-scale, randomized, controlled study by the DECIDEO group

PubMed Central

Bourmaud, Aurelie; Soler-Michel, Patricia; Oriol, Mathieu; Regnier, Véronique; Tinquaut, Fabien; Nourissat, Alice; Bremond, Alain; Moumjid, Nora; Chauvin, Franck

2016-01-01

Controversies regarding the benefits of breast cancer screening programs have led to the promotion of new strategies taking into account individual preferences, such as decision aid. The aim of this study was to assess the impact of a decision aid leaflet on the participation of women invited to participate in a national breast cancer screening program. This Randomized, multicentre, controlled trial. Women aged 50 to 74 years, were randomly assigned to receive either a decision aid or the usual invitation letter. Primary outcome was the participation rate 12 months after the invitation. 16 000 women were randomized and 15 844 included in the modified intention-to-treat analysis. The participation rate in the intervention group was 40.25% (3174/7885 women) compared with 42.13% (3353/7959) in the control group (p = 0.02). Previous attendance for screening (RR = 6.24; [95%IC: 5.75-6.77]; p < 0.0001) and medium household income (RR = 1.05; [95%IC: 1.01-1.09]; p = 0.0074) were independently associated with attendance for screening. This large-scale study demonstrates that the decision aid reduced the participation rate. The decision aid activate the decision making process of women toward non-attendance to screening. These results show the importance of promoting informed patient choices, especially when those choices cannot be anticipated. PMID:26883201

Effective spreading from multiple leaders identified by percolation in the susceptible-infected-recovered (SIR) model

NASA Astrophysics Data System (ADS)

Ji, Shenggong; Lü, Linyuan; Yeung, Chi Ho; Hu, Yanqing

2017-07-01

Social networks constitute a new platform for information propagation, but its success is crucially dependent on the choice of spreaders who initiate the spreading of information. In this paper, we remove edges in a network at random and the network segments into isolated clusters. The most important nodes in each cluster then form a set of influential spreaders, such that news propagating from them would lead to extensive coverage and minimal redundancy. The method utilizes the similarities between the segmented networks before percolation and the coverage of information propagation in each social cluster to obtain a set of distributed and coordinated spreaders. Our tests of implementing the susceptible-infected-recovered model on Facebook and Enron email networks show that this method outperforms conventional centrality-based methods in terms of spreadability and coverage redundancy. The suggested way of identifying influential spreaders thus sheds light on a new paradigm of information propagation in social networks.

Study on probability distributions for evolution in modified extremal optimization

NASA Astrophysics Data System (ADS)

Zeng, Guo-Qiang; Lu, Yong-Zai; Mao, Wei-Jie; Chu, Jian

2010-05-01

It is widely believed that the power-law is a proper probability distribution being effectively applied for evolution in τ-EO (extremal optimization), a general-purpose stochastic local-search approach inspired by self-organized criticality, and its applications in some NP-hard problems, e.g., graph partitioning, graph coloring, spin glass, etc. In this study, we discover that the exponential distributions or hybrid ones (e.g., power-laws with exponential cutoff) being popularly used in the research of network sciences may replace the original power-laws in a modified τ-EO method called self-organized algorithm (SOA), and provide better performances than other statistical physics oriented methods, such as simulated annealing, τ-EO and SOA etc., from the experimental results on random Euclidean traveling salesman problems (TSP) and non-uniform instances. From the perspective of optimization, our results appear to demonstrate that the power-law is not the only proper probability distribution for evolution in EO-similar methods at least for TSP, the exponential and hybrid distributions may be other choices.

Using aversive images to enhance healthy food choices and implicit attitudes: An experimental test of evaluative conditioning.

PubMed

Hollands, Gareth J; Prestwich, Andrew; Marteau, Theresa M

2011-03-01

To examine the effect of communicating images of energy-dense snack foods paired with aversive images of the potential health consequences of unhealthy eating, on implicit and explicit attitudes and food choice behavior. Participants were randomly allocated to either an evaluative conditioning (EC) procedure that paired images of snack foods with images of potential adverse health consequences or a control condition that featured images of snack foods alone. Implicit attitudes were assessed pre- and post-intervention. Explicit attitudes and food choice behavior were assessed post-intervention. The conditioning intervention made implicit attitudes toward energy-dense snacks more negative, with this effect greatest in those with relatively more favorable implicit attitudes toward these snacks at baseline. Participants in the conditioning intervention were more likely to choose fruit rather than snacks in a behavioral choice task, a relationship mediated by changes in implicit attitudes. Presenting aversive images of potential health consequences with those of specific foodstuffs can change implicit attitudes, which impacts on subsequent food choice behavior. (c) 2011 APA, all rights reserved

Building capacity for rigorous controlled trials in autism: the importance of measuring treatment adherence.

PubMed

McConachie, H; Fletcher-Watson, S

2015-03-01

Research groups across Europe have been networking to share information and ideas about research on preschool children with autism. The paper describes preliminary work to develop capacity for future multi-site randomized controlled trials of early intervention, with a specific focus on the need to measure treatment adherence where parents deliver therapy. The paper includes a review of randomized and controlled studies of parent-mediated early intervention from two sources, a recent Cochrane Collaboration review and a mapping of European early intervention studies in autism published since 2002. The data extracted focused on methods for describing parent adherence, that is, how and to what extent parents carry out the strategies taught them by therapists. Less than half of the 32 studies reviewed included any measure of parent adherence. Only seven included a direct assessment method. The challenges of developing pan-European early intervention evaluation studies are discussed, including choice of intervention model and of important outcomes, the need for translation of measurement tools and achievement of joint training to reliability of assessors. Measurement of parent-child interaction style and of adherence to strategies taught need further study. © 2014 The Authors. Child: Care, Health and Development published by John Wiley & Sons Ltd.

Differential quantitative proteomics of Porphyromonas gingivalis by linear ion trap mass spectrometry: non-label methods comparison, q-values and LOWESS curve fitting

PubMed Central

Xia, Qiangwei; Wang, Tiansong; Park, Yoonsuk; Lamont, Richard J.; Hackett, Murray

2009-01-01

Differential analysis of whole cell proteomes by mass spectrometry has largely been applied using various forms of stable isotope labeling. While metabolic stable isotope labeling has been the method of choice, it is often not possible to apply such an approach. Four different label free ways of calculating expression ratios in a classic “two-state” experiment are compared: signal intensity at the peptide level, signal intensity at the protein level, spectral counting at the peptide level, and spectral counting at the protein level. The quantitative data were mined from a dataset of 1245 qualitatively identified proteins, about 56% of the protein encoding open reading frames from Porphyromonas gingivalis, a Gram-negative intracellular pathogen being studied under extracellular and intracellular conditions. Two different control populations were compared against P. gingivalis internalized within a model human target cell line. The q-value statistic, a measure of false discovery rate previously applied to transcription microarrays, was applied to proteomics data. For spectral counting, the most logically consistent estimate of random error came from applying the locally weighted scatter plot smoothing procedure (LOWESS) to the most extreme ratios generated from a control technical replicate, thus setting upper and lower bounds for the region of experimentally observed random error. PMID:19337574

What weather variables are important in predicting heat-related mortality? A new application of statistical learning methods

PubMed Central

Zhang, Kai; Li, Yun; Schwartz, Joel D.; O'Neill, Marie S.

2014-01-01

Hot weather increases risk of mortality. Previous studies used different sets of weather variables to characterize heat stress, resulting in variation in heat-mortality- associations depending on the metric used. We employed a statistical learning method – random forests – to examine which of various weather variables had the greatest impact on heat-related mortality. We compiled a summertime daily weather and mortality counts dataset from four U.S. cities (Chicago, IL; Detroit, MI; Philadelphia, PA; and Phoenix, AZ) from 1998 to 2006. A variety of weather variables were ranked in predicting deviation from typical daily all-cause and cause-specific death counts. Ranks of weather variables varied with city and health outcome. Apparent temperature appeared to be the most important predictor of heat-related mortality for all-cause mortality. Absolute humidity was, on average, most frequently selected one of the top variables for all-cause mortality and seven cause-specific mortality categories. Our analysis affirms that apparent temperature is a reasonable variable for activating heat alerts and warnings, which are commonly based on predictions of total mortality in next few days. Additionally, absolute humidity should be included in future heat-health studies. Finally, random forests can be used to guide choice of weather variables in heat epidemiology studies. PMID:24834832

Impact of food labelling systems on food choices and eating behaviours: a systematic review and meta-analysis of randomized studies.

PubMed

Cecchini, M; Warin, L

2016-03-01

Food labels are considered a crucial component of strategies tackling unhealthy diets and obesity. This study aims at assessing the effectiveness of food labelling in increasing the selection of healthier products and in reducing calorie intake. In addition, this study compares the relative effectiveness of traffic light schemes, Guideline Daily Amount and other food labelling schemes. A comprehensive set of databases were searched to identify randomized studies. Studies reporting homogeneous outcomes were pooled together and analysed through meta-analyses. Publication bias was evaluated with a funnel plot. Food labelling would increase the amount of people selecting a healthier food product by about 17.95% (confidence interval: +11.24% to +24.66%). Food labelling would also decrease calorie intake/choice by about 3.59% (confidence interval: -8.90% to +1.72%), but results are not statistically significant. Traffic light schemes are marginally more effective in increasing the selection of healthier options. Other food labels and Guideline Daily Amount follow. The available evidence did not allow studying the effects of single labelling schemes on calorie intake/choice. Findings of this study suggest that nutrition labelling may be an effective approach to empowering consumers in choosing healthier products. Interpretive labels, as traffic light labels, may be more effective. © 2015 World Obesity.

Implementing Clinical Research Using Factorial Designs: A Primer.

PubMed

Baker, Timothy B; Smith, Stevens S; Bolt, Daniel M; Loh, Wei-Yin; Mermelstein, Robin; Fiore, Michael C; Piper, Megan E; Collins, Linda M

2017-07-01

Factorial experiments have rarely been used in the development or evaluation of clinical interventions. However, factorial designs offer advantages over randomized controlled trial designs, the latter being much more frequently used in such research. Factorial designs are highly efficient (permitting evaluation of multiple intervention components with good statistical power) and present the opportunity to detect interactions amongst intervention components. Such advantages have led methodologists to advocate for the greater use of factorial designs in research on clinical interventions (Collins, Dziak, & Li, 2009). However, researchers considering the use of such designs in clinical research face a series of choices that have consequential implications for the interpretability and value of the experimental results. These choices include: whether to use a factorial design, selection of the number and type of factors to include, how to address the compatibility of the different factors included, whether and how to avoid confounds between the type and number of interventions a participant receives, and how to interpret interactions. The use of factorial designs in clinical intervention research poses choices that differ from those typically considered in randomized clinical trial designs. However, the great information yield of the former encourages clinical researchers' increased and careful execution of such designs. Copyright © 2017. Published by Elsevier Ltd.

Quantum thermostatted disordered systems and sensitivity under compression

NASA Astrophysics Data System (ADS)

Vanzan, Tommaso; Rondoni, Lamberto

2018-03-01

A one-dimensional quantum system with off diagonal disorder, consisting of a sample of conducting regions randomly interspersed within potential barriers is considered. Results mainly concerning the large N limit are presented. In particular, the effect of compression on the transmission coefficient is investigated. A numerical method to simulate such a system, for a physically relevant number of barriers, is proposed. It is shown that the disordered model converges to the periodic case as N increases, with a rate of convergence which depends on the disorder degree. Compression always leads to a decrease of the transmission coefficient which may be exploited to design nano-technological sensors. Effective choices for the physical parameters to improve the sensitivity are provided. Eventually large fluctuations and rate functions are analysed.

Towards designing robust coupled networks

NASA Astrophysics Data System (ADS)

Schneider, Christian M.; Yazdani, Nuri; Araújo, Nuno A. M.; Havlin, Shlomo; Herrmann, Hans J.

2013-06-01

Natural and technological interdependent systems have been shown to be highly vulnerable due to cascading failures and an abrupt collapse of global connectivity under initial failure. Mitigating the risk by partial disconnection endangers their functionality. Here we propose a systematic strategy of selecting a minimum number of autonomous nodes that guarantee a smooth transition in robustness. Our method which is based on betweenness is tested on various examples including the famous 2003 electrical blackout of Italy. We show that, with this strategy, the necessary number of autonomous nodes can be reduced by a factor of five compared to a random choice. We also find that the transition to abrupt collapse follows tricritical scaling characterized by a set of exponents which is independent on the protection strategy.

Evaluating Bayesian spatial methods for modelling species distributions with clumped and restricted occurrence data.

PubMed

Redding, David W; Lucas, Tim C D; Blackburn, Tim M; Jones, Kate E

2017-01-01

Statistical approaches for inferring the spatial distribution of taxa (Species Distribution Models, SDMs) commonly rely on available occurrence data, which is often clumped and geographically restricted. Although available SDM methods address some of these factors, they could be more directly and accurately modelled using a spatially-explicit approach. Software to fit models with spatial autocorrelation parameters in SDMs are now widely available, but whether such approaches for inferring SDMs aid predictions compared to other methodologies is unknown. Here, within a simulated environment using 1000 generated species' ranges, we compared the performance of two commonly used non-spatial SDM methods (Maximum Entropy Modelling, MAXENT and boosted regression trees, BRT), to a spatial Bayesian SDM method (fitted using R-INLA), when the underlying data exhibit varying combinations of clumping and geographic restriction. Finally, we tested how any recommended methodological settings designed to account for spatially non-random patterns in the data impact inference. Spatial Bayesian SDM method was the most consistently accurate method, being in the top 2 most accurate methods in 7 out of 8 data sampling scenarios. Within high-coverage sample datasets, all methods performed fairly similarly. When sampling points were randomly spread, BRT had a 1-3% greater accuracy over the other methods and when samples were clumped, the spatial Bayesian SDM method had a 4%-8% better AUC score. Alternatively, when sampling points were restricted to a small section of the true range all methods were on average 10-12% less accurate, with greater variation among the methods. Model inference under the recommended settings to account for autocorrelation was not impacted by clumping or restriction of data, except for the complexity of the spatial regression term in the spatial Bayesian model. Methods, such as those made available by R-INLA, can be successfully used to account for spatial autocorrelation in an SDM context and, by taking account of random effects, produce outputs that can better elucidate the role of covariates in predicting species occurrence. Given that it is often unclear what the drivers are behind data clumping in an empirical occurrence dataset, or indeed how geographically restricted these data are, spatially-explicit Bayesian SDMs may be the better choice when modelling the spatial distribution of target species.

Physical activity, mindfulness meditation, or heart rate variability biofeedback for stress reduction: a randomized controlled trial.

PubMed

van der Zwan, Judith Esi; de Vente, Wieke; Huizink, Anja C; Bögels, Susan M; de Bruin, Esther I

2015-12-01

In contemporary western societies stress is highly prevalent, therefore the need for stress-reducing methods is great. This randomized controlled trial compared the efficacy of self-help physical activity (PA), mindfulness meditation (MM), and heart rate variability biofeedback (HRV-BF) in reducing stress and its related symptoms. We randomly allocated 126 participants to PA, MM, or HRV-BF upon enrollment, of whom 76 agreed to participate. The interventions consisted of psycho-education and an introduction to the specific intervention techniques and 5 weeks of daily exercises at home. The PA exercises consisted of a vigorous-intensity activity of free choice. The MM exercises consisted of guided mindfulness meditation. The HRV-BF exercises consisted of slow breathing with a heart rate variability biofeedback device. Participants received daily reminders for their exercises and were contacted weekly to monitor their progress. They completed questionnaires prior to, directly after, and 6 weeks after the intervention. Results indicated an overall beneficial effect consisting of reduced stress, anxiety and depressive symptoms, and improved psychological well-being and sleep quality. No significant between-intervention effect was found, suggesting that PA, MM, and HRV-BF are equally effective in reducing stress and its related symptoms. These self-help interventions provide easily accessible help for people with stress complaints.

Rejection of randomly coinciding events in ZnMoO scintillating bolometers

NASA Astrophysics Data System (ADS)

Chernyak, D. M.; Danevich, F. A.; Giuliani, A.; Mancuso, M.; Nones, C.; Olivieri, E.; Tenconi, M.; Tretyak, V. I.

2014-06-01

Random coincidence of events (particularly from two neutrino double beta decay) could be one of the main sources of background in the search for neutrinoless double beta decay with cryogenic bolometers due to their poor time resolution. Pulse-shape discrimination by using front edge analysis, mean-time and methods were applied to discriminate randomly coinciding events in ZnMoO cryogenic scintillating bolometers. These events can be effectively rejected at the level of 99 % by the analysis of the heat signals with rise-time of about 14 ms and signal-to-noise ratio of 900, and at the level of 92 % by the analysis of the light signals with rise-time of about 3 ms and signal-to-noise ratio of 30, under the requirement to detect 95 % of single events. These rejection efficiencies are compatible with extremely low background levels in the region of interest of neutrinoless double beta decay of Mo for enriched ZnMoO detectors, of the order of counts/(y keV kg). Pulse-shape parameters have been chosen on the basis of the performance of a real massive ZnMoO scintillating bolometer. Importance of the signal-to-noise ratio, correct finding of the signal start and choice of an appropriate sampling frequency are discussed.

Decision-Making in Agent-Based Models of Migration: State of the Art and Challenges.

PubMed

Klabunde, Anna; Willekens, Frans

We review agent-based models (ABM) of human migration with respect to their decision-making rules. The most prominent behavioural theories used as decision rules are the random utility theory, as implemented in the discrete choice model, and the theory of planned behaviour. We identify the critical choices that must be made in developing an ABM, namely the modelling of decision processes and social networks. We also discuss two challenges that hamper the widespread use of ABM in the study of migration and, more broadly, demography and the social sciences: (a) the choice and the operationalisation of a behavioural theory (decision-making and social interaction) and (b) the selection of empirical evidence to validate the model. We offer advice on how these challenges might be overcome.

Mean-deviation analysis in the theory of choice.

PubMed

Grechuk, Bogdan; Molyboha, Anton; Zabarankin, Michael

2012-08-01

Mean-deviation analysis, along with the existing theories of coherent risk measures and dual utility, is examined in the context of the theory of choice under uncertainty, which studies rational preference relations for random outcomes based on different sets of axioms such as transitivity, monotonicity, continuity, etc. An axiomatic foundation of the theory of coherent risk measures is obtained as a relaxation of the axioms of the dual utility theory, and a further relaxation of the axioms are shown to lead to the mean-deviation analysis. Paradoxes arising from the sets of axioms corresponding to these theories and their possible resolutions are discussed, and application of the mean-deviation analysis to optimal risk sharing and portfolio selection in the context of rational choice is considered. © 2012 Society for Risk Analysis.

Eliciting population preferences for mass colorectal cancer screening organization.

PubMed

Nayaradou, Maximilien; Berchi, Célia; Dejardin, Olivier; Launoy, Guy

2010-01-01

The implementation of mass colorectal cancer (CRC) screening is a public health priority. Population participation is fundamental for the success of CRC screening as for any cancer screening program. The preferences of the population may influence their likelihood of participation. The authors sought to elicit population preferences for CRC screening test characteristics to improve the design of CRC screening campaigns. A discrete choice experiment was used. Questionnaires were compiled with a set of pairs of hypothetical CRC screening scenarios. The survey was conducted by mail from June 2006 to October 2006 on a representative sample of 2000 inhabitants, aged 50 to 74 years from the northwest of France, who were randomly selected from electoral lists. Questionnaires were sent to 2000 individuals, each of whom made 3 or 4 discrete choices between hypothetical tests that differed in 7 attributes: how screening is offered, process, sensitivity, rate of unnecessary colonoscopy, expected mortality reduction, method of screening test result transmission, and cost. Complete responses were received from 656 individuals (32.8%). The attributes that influenced population preferences included expected mortality reduction, sensitivity, cost, and process. Participants from high social classes were particularly influenced by sensitivity. The results demonstrate that the discrete choice experiment provides information on patient preferences for CRC screening: improving screening program effectiveness, for instance, by improving test sensitivity (the most valued attribute) would increase satisfaction among the general population with regard to CRC screening programs. Additional studies are required to study how patient preferences actually affect adherence to regular screening programs.

Lower-fat menu items in restaurants satisfy customers.

PubMed

Fitzpatrick, M P; Chapman, G E; Barr, S I

1997-05-01

To evaluate a restaurant-based nutrition program by measuring customer satisfaction with lower-fat menu items and assessing patrons' reactions to the program. Questionnaires to assess satisfaction with menu items were administered to patrons in eight of the nine restaurants that volunteered to participate in the nutrition program. One patron from each participating restaurant was randomly selected for a semistructured interview about nutrition programming in restaurants. Persons dining in eight participating restaurants over a 1-week period (n = 686). Independent samples t tests were used to compare respondents' satisfaction with lower-fat and regular menu items. Two-way analysis of variance tests were completed using overall satisfaction as the dependent variable and menu-item classification (ie, lower fat or regular) and one of eight other menu item and respondent characteristics as independent variables. Qualitative methods were used to analyze interview transcripts. Of 1,127 menu items rated for satisfaction, 205 were lower fat, 878 were regular, and 44 were of unknown classification. Customers were significantly more satisfied with lower-fat than with regular menu items (P < .001). Overall satisfaction did not vary by any of the other independent variables. Interview results indicate the importance of restaurant during as an indulgent experience. High satisfaction with lower-fat menu items suggests that customers will support restaurant providing such choices. Dietitians can use these findings to encourage restaurateurs to include lower-fat choices on their menus, and to assure clients that their expectations of being indulged are not incompatible with these choices.

The Influence of Sugar-Sweetened Beverage Warnings: A Randomized Trial of Adolescents' Choices and Beliefs.

PubMed

VanEpps, Eric M; Roberto, Christina A

2016-11-01

California, New York, and the cities of San Francisco and Baltimore have introduced bills requiring health-related warning labels for sugar-sweetened beverages. This study measures the extent to which these warning labels influence adolescents' beliefs and hypothetical choices. Participants completed an online survey in which they chose a beverage in a hypothetical vending machine task, rated perceptions of different beverages, and indicated interest in coupons for beverages. Data were collected and analyzed in 2015. A total of 2,202 demographically diverse adolescents aged 12-18 years completed the online survey. Participants were randomly assigned to one of six conditions: (1) no warning label; (2) calorie label; (3-6) one of four text versions of a warning label (e.g. Drinking beverages with added sugar(s) contributes to obesity, diabetes, and tooth decay). Hypothetical choices, perceptions of beverages, interest in coupons, and endorsement of warning label policies were assessed. Controlling for frequency of beverage purchases, significantly fewer adolescents chose a sugar-sweetened beverage in three of the four warning label conditions (65%, 63%, and 61%) than in the no label (77%) condition. Adolescents in the four warning label conditions chose fewer sugar-sweetened beverage coupons and believed that sugar-sweetened beverages were less likely to help them lead a healthy life and had more added sugar compared with the no label condition. Health-related warning labels on sugar-sweetened beverages improved adolescents' recognition of the sugar content of such beverages and reduced hypothetical choices to buy sugar-sweetened beverages. Published by Elsevier Inc.

On simulating large earthquakes by Green's-function addition of smaller earthquakes

NASA Astrophysics Data System (ADS)

Joyner, William B.; Boore, David M.

Simulation of ground motion from large earthquakes has been attempted by a number of authors using small earthquakes (subevents) as Green's functions and summing them, generally in a random way. We present a simple model for the random summation of subevents to illustrate how seismic scaling relations can be used to constrain methods of summation. In the model η identical subevents are added together with their start times randomly distributed over the source duration T and their waveforms scaled by a factor κ. The subevents can be considered to be distributed on a fault with later start times at progressively greater distances from the focus, simulating the irregular propagation of a coherent rupture front. For simplicity the distance between source and observer is assumed large compared to the source dimensions of the simulated event. By proper choice of η and κ the spectrum of the simulated event deduced from these assumptions can be made to conform at both low- and high-frequency limits to any arbitrary seismic scaling law. For the ω -squared model with similarity (that is, with constant Moƒ3o scaling, where ƒo is the corner frequency), the required values are η = (Mo/Moe)4/3 and κ = (Mo/Moe)-1/3, where Mo is moment of the simulated event and Moe is the moment of the subevent. The spectra resulting from other choices of η and κ, will not conform at both high and low frequency. If η is determined by the ratio of the rupture area of the simulated event to that of the subevent and κ = 1, the simulated spectrum will conform at high frequency to the ω-squared model with similarity, but not at low frequency. Because the high-frequency part of the spectrum is generally the important part for engineering applications, however, this choice of values for η and κ may be satisfactory in many cases. If η is determined by the ratio of the moment of the simulated event to that of the subevent and κ = 1, the simulated spectrum will conform at low frequency to the ω-squared model with similarity, but not at high frequency. Interestingly, the high-frequency scaling implied by this latter choice of η and κ corresponds to an ω-squared model with constant Moƒ4o—a scaling law proposed by Nuttli, although questioned recently by Haar and others. Simple scaling with κ equal to unity and η equal to the moment ratio would work if the high-frequency spectral decay were ω-1.5 instead of ω-2. Just the required decay is exhibited by the stochastic source model recently proposed by Joynet, if the dislocation-time function is deconvolved out of the spectrum. Simulated motions derived from such source models could be used as subevents rather than recorded motions as is usually done. This strategy is a promising approach to simulation of ground motion from an extended rupture.

A comparison of two experimental design approaches in applying conjoint analysis in patient-centered outcomes research: a randomized trial.

PubMed

Kinter, Elizabeth T; Prior, Thomas J; Carswell, Christopher I; Bridges, John F P

2012-01-01

While the application of conjoint analysis and discrete-choice experiments in health are now widely accepted, a healthy debate exists around competing approaches to experimental design. There remains, however, a paucity of experimental evidence comparing competing design approaches and their impact on the application of these methods in patient-centered outcomes research. Our objectives were to directly compare the choice-model parameters and predictions of an orthogonal and a D-efficient experimental design using a randomized trial (i.e., an experiment on experiments) within an application of conjoint analysis studying patient-centered outcomes among outpatients diagnosed with schizophrenia in Germany. Outpatients diagnosed with schizophrenia were surveyed and randomized to receive choice tasks developed using either an orthogonal or a D-efficient experimental design. The choice tasks elicited judgments from the respondents as to which of two patient profiles (varying across seven outcomes and process attributes) was preferable from their own perspective. The results from the two survey designs were analyzed using the multinomial logit model, and the resulting parameter estimates and their robust standard errors were compared across the two arms of the study (i.e., the orthogonal and D-efficient designs). The predictive performances of the two resulting models were also compared by computing their percentage of survey responses classified correctly, and the potential for variation in scale between the two designs of the experiments was tested statistically and explored graphically. The results of the two models were statistically identical. No difference was found using an overall chi-squared test of equality for the seven parameters (p = 0.69) or via uncorrected pairwise comparisons of the parameter estimates (p-values ranged from 0.30 to 0.98). The D-efficient design resulted in directionally smaller standard errors for six of the seven parameters, of which only two were statistically significant, and no differences were found in the observed D-efficiencies of their standard errors (p = 0.62). The D-efficient design resulted in poorer predictive performance, but this was not significant (p = 0.73); there was some evidence that the parameters of the D-efficient design were biased marginally towards the null. While no statistical difference in scale was detected between the two designs (p = 0.74), the D-efficient design had a higher relative scale (1.06). This could be observed when the parameters were explored graphically, as the D-efficient parameters were lower. Our results indicate that orthogonal and D-efficient experimental designs have produced results that are statistically equivalent. This said, we have identified several qualitative findings that speak to the potential differences in these results that may have been statistically identified in a larger sample. While more comparative studies focused on the statistical efficiency of competing design strategies are needed, a more pressing research problem is to document the impact the experimental design has on respondent efficiency.

Using Module Analysis for Multiple Choice Responses: A New Method Applied to Force Concept Inventory Data

ERIC Educational Resources Information Center

Brewe, Eric; Bruun, Jesper; Bearden, Ian G.

2016-01-01

We describe "Module Analysis for Multiple Choice Responses" (MAMCR), a new methodology for carrying out network analysis on responses to multiple choice assessments. This method is used to identify modules of non-normative responses which can then be interpreted as an alternative to factor analysis. MAMCR allows us to identify conceptual…

Advancing Tobacco Product Warning Labels Research Methods and Theory: A Summary of a Grantee Meeting Held by the US National Cancer Institute.

PubMed

Thrasher, James F; Brewer, Noel T; Niederdeppe, Jeff; Peters, Ellen; Strasser, Andrew A; Grana, Rachel; Kaufman, Annette R

2018-02-10

The World Health Organization's Framework Convention on Tobacco Control recommends prominent pictorial health warnings on tobacco products. To advance research methods, theory and understanding of how tobacco product warning labels (TPWLs) work, the US National Cancer Institute convened a grantee meeting. Our article describes the key insights that emerged from the meeting, situated within the context of the scientific literature. First, presentations confirmed that large, pictorial TPWLs motivate people to try to quit and encourage smoking cessation. Second, pictorial TPWLs increase attention, knowledge, negative affect, and thinking about the warning. Third, TPWL studies have primarily used brief-exposure laboratory studies and observational studies of sustained exposure through national policy implementation, with a few randomized trials involving several weeks of exposure-with generally consistent results found across study designs. Fourth, novel assessment methods include brain imaging, eye tracking and "best-worst" discrete choice experiments. To make TPWL even more effective, research is needed to confirm the mechanisms of their influence, their impact across vulnerable populations, and their effect on social media posts about tobacco products. Research is also needed on the effect of trial design choices, the predictive validity of new measurement approaches, and warning labels for non-cigarette tobacco products. To improve scientific understanding of TPWL effects, this grantee meeting summary describes emerging research methods, theory and study results. Directions for future research include examination of the mechanisms of how warning labels work across diverse tobacco products and across different populations and contexts. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco 2018. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Feasibility of inverse problem solution for determination of city emission function from night sky radiance measurements

NASA Astrophysics Data System (ADS)

Petržala, Jaromír

2018-07-01

The knowledge of the emission function of a city is crucial for simulation of sky glow in its vicinity. The indirect methods to achieve this function from radiances measured over a part of the sky have been recently developed. In principle, such methods represent an ill-posed inverse problem. This paper deals with the theoretical feasibility study of various approaches to solving of given inverse problem. Particularly, it means testing of fitness of various stabilizing functionals within the Tikhonov's regularization. Further, the L-curve and generalized cross validation methods were investigated as indicators of an optimal regularization parameter. At first, we created the theoretical model for calculation of a sky spectral radiance in the form of a functional of an emission spectral radiance. Consequently, all the mentioned approaches were examined in numerical experiments with synthetical data generated for the fictitious city and loaded by random errors. The results demonstrate that the second order Tikhonov's regularization method together with regularization parameter choice by the L-curve maximum curvature criterion provide solutions which are in good agreement with the supposed model emission functions.

Steel Fibre Reinforced Concrete Simulation with the SPH Method

NASA Astrophysics Data System (ADS)

Hušek, Martin; Kala, Jiří; Král, Petr; Hokeš, Filip

2017-10-01

Steel fibre reinforced concrete (SFRC) is very popular in many branches of civil engineering. Thanks to its increased ductility, it is able to resist various types of loading. When designing a structure, the mechanical behaviour of SFRC can be described by currently available material models (with equivalent material for example) and therefore no problems arise with numerical simulations. But in many scenarios, e.g. high speed loading, it would be a mistake to use such an equivalent material. Physical modelling of the steel fibres used in concrete is usually problematic, though. It is necessary to consider the fact that mesh-based methods are very unsuitable for high-speed simulations with regard to the issues that occur due to the effect of excessive mesh deformation. So-called meshfree methods are much more suitable for this purpose. The Smoothed Particle Hydrodynamics (SPH) method is currently the best choice, thanks to its advantages. However, a numerical defect known as tensile instability may appear when the SPH method is used. It causes the development of numerical (false) cracks, making simulations of ductile types of failure significantly more difficult to perform. The contribution therefore deals with the description of a procedure for avoiding this defect and successfully simulating the behaviour of SFRC with the SPH method. The essence of the problem lies in the choice of coordinates and the description of the integration domain derived from them - spatial (Eulerian kernel) or material coordinates (Lagrangian kernel). The contribution describes the behaviour of both formulations. Conclusions are drawn from the fundamental tasks, and the contribution additionally demonstrates the functionality of SFRC simulations. The random generation of steel fibres and their inclusion in simulations are also discussed. The functionality of the method is supported by the results of pressure test simulations which compare various levels of fibre reinforcement of SFRC specimens.

A PREFERENCE-OPPORTUNITY-CHOICE FRAMEWORK WITH APPLICATIONS TO INTERGROUP FRIENDSHIP*

PubMed Central

Zeng, Zhen; Xie, Yu

2009-01-01

A longstanding objective of friendship research is to identify the effects of personal preference and structural opportunity on intergroup friendship choice. Although past studies have used various methods to separate preference from opportunity, researchers have not yet systematically compared the properties and implications of these methods. We put forward a general framework for discrete choice, where choice probability is specified as proportional to the product of preference and opportunity. To implement this framework, we propose a modification to the conditional logit model for estimating preference parameters free from the influence of opportunity structure. We then compare our approach to several alternative methods for separating preference and opportunity used in the friendship choice literature. As an empirical example, we test hypotheses of homophily and status asymmetry in friendship choice using data from the National Longitudinal Study of Adolescent Health. The example also demonstrates the approach of conducting a sensitivity analysis to examine how parameter estimates vary by specification of the opportunity structure. PMID:19569394

Invitation choice structure has no impact on attendance in a female business training program in Kenya.

PubMed

Diwan, Faizan; Makana, Grace; McKenzie, David; Paruzzolo, Silvia

2014-01-01

Business training programs are a common form of support to small businesses, but organizations providing this training often struggle to get business owners to attend. We evaluate the role of invitation choice structure in determining agreement to participate and actual attendance. A field experiment randomly assigned female small business owners in Kenya (N = 1172) to one of three invitation types: a standard opt-in invitation; an active choice invitation where business owners had to explicitly say yes or no to the invitation; and an enhanced active choice invitation which highlighted the costs of saying no. We find no statistically significant effect of these alternative choice structures on willingness to participate in training, attending at least one day, and completing the course. The 95 percent confidence interval for the active treatment effect on attendance is [-1.9%, +9.5%], while for the enhanced active choice treatment it is [-4.1%, +7.7%]. The effect sizes consistent with our data are smaller than impacts measured in health and retirement savings studies in the United States. We examine several potential explanations for the lack of effect in a developing country setting. We find evidence consistent with two potential reasons being limited decision-making power amongst some women, and lower levels of cognition making the enhanced active choice wording less effective.

Consumer Behavior in the Choice of Mode of Transport: A Case Study in the Toledo-Madrid Corridor

PubMed Central

Muro-Rodríguez, Ana I.; Perez-Jiménez, Israel R.; Gutiérrez-Broncano, Santiago

2017-01-01

Within the context of the consumption of goods or services the decisions made by individuals involve the choice between a set of discrete alternatives, such as the choice of mode of transport. The methodology for analyzing the consumer behavior are the models of discrete choice based on the Theory of Random Utility. These models are based on the definition of preferences through a utility function that is maximized. These models also denominated of disaggregated demand derived from the decision of a set of individuals, who are formalized by the application of probabilistic models. The objective of this study is to determine the behavior of the consumer in the choice of a service, namely of transport services and in a short-distance corridor, such as Toledo-Madrid. The Toledo-Madrid corridor is characterized by being short distance, with high speed train available within the choice options to get the airport, along with the bus and the car. And where offers of HST and aircraft services can be proposed as complementary modes. By applying disaggregated transport models with revealed preference survey data and declared preferences, one can determine the most important variables involved in the choice and determine the arrangements for payment of individuals. These payment provisions may condition the use of certain transport policies to promote the use of efficient transportation. PMID:28676776

Pairing images of unhealthy and healthy foods with images of negative and positive health consequences: Impact on attitudes and food choice.

PubMed

Hollands, Gareth J; Marteau, Theresa M

2016-08-01

To examine the impact of presenting images of foods paired with images of positive and negative health consequences of their consumption on food choice and attitudes. Participants (N = 711) were randomly allocated in a 2 × 3 factorial design (Food Type × Affective Valence) to 1 of 6 conditioning procedures that paired images of either energy-dense snack foods or fruit, with (a) images of negative health outcomes, (b) images of positive health outcomes, or (c) a no image control. The primary outcome was food choice assessed postintervention with a behavioral choice task. Secondary outcomes were implicit attitudes (assessed pre- and postintervention) and explicit attitudes (assessed postintervention). Presenting images of negative health outcomes led to more healthy food choices relative to control and positive image conditions, irrespective of whether they were paired with images of energy-dense snack foods or fruit. This relationship was partially mediated by changes in implicit and explicit attitudes. Images of positive health outcomes did not alter food choices. This study replicates and extends previous research showing that presenting images of negative health consequences increases healthy food choices. Because effects were elicited by manipulating affective valence irrespective of paired food type, these results appear more consistent with an explanation based on priming than on evaluative conditioning. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Consumer Behavior in the Choice of Mode of Transport: A Case Study in the Toledo-Madrid Corridor.

PubMed

Muro-Rodríguez, Ana I; Perez-Jiménez, Israel R; Gutiérrez-Broncano, Santiago

2017-01-01

Within the context of the consumption of goods or services the decisions made by individuals involve the choice between a set of discrete alternatives, such as the choice of mode of transport. The methodology for analyzing the consumer behavior are the models of discrete choice based on the Theory of Random Utility. These models are based on the definition of preferences through a utility function that is maximized. These models also denominated of disaggregated demand derived from the decision of a set of individuals, who are formalized by the application of probabilistic models. The objective of this study is to determine the behavior of the consumer in the choice of a service, namely of transport services and in a short-distance corridor, such as Toledo-Madrid. The Toledo-Madrid corridor is characterized by being short distance, with high speed train available within the choice options to get the airport, along with the bus and the car. And where offers of HST and aircraft services can be proposed as complementary modes. By applying disaggregated transport models with revealed preference survey data and declared preferences, one can determine the most important variables involved in the choice and determine the arrangements for payment of individuals. These payment provisions may condition the use of certain transport policies to promote the use of efficient transportation.

Invitation Choice Structure Has No Impact on Attendance in a Female Business Training Program in Kenya

PubMed Central

Diwan, Faizan; Makana, Grace; McKenzie, David; Paruzzolo, Silvia

2014-01-01

Business training programs are a common form of support to small businesses, but organizations providing this training often struggle to get business owners to attend. We evaluate the role of invitation choice structure in determining agreement to participate and actual attendance. A field experiment randomly assigned female small business owners in Kenya (N = 1172) to one of three invitation types: a standard opt-in invitation; an active choice invitation where business owners had to explicitly say yes or no to the invitation; and an enhanced active choice invitation which highlighted the costs of saying no. We find no statistically significant effect of these alternative choice structures on willingness to participate in training, attending at least one day, and completing the course. The 95 percent confidence interval for the active treatment effect on attendance is [−1.9%, +9.5%], while for the enhanced active choice treatment it is [−4.1%, +7.7%]. The effect sizes consistent with our data are smaller than impacts measured in health and retirement savings studies in the United States. We examine several potential explanations for the lack of effect in a developing country setting. We find evidence consistent with two potential reasons being limited decision-making power amongst some women, and lower levels of cognition making the enhanced active choice wording less effective. PMID:25299647

Mindful eating reduces impulsive food choice in adolescents and adults.

PubMed

Hendrickson, Kelsie L; Rasmussen, Erin B

2017-03-01

The present study tested the extent to which age and obesity predicted impulsive choices for food and monetary outcomes and tested how a brief mindful-eating training would alter delay discounting for food and money choices compared with control groups. First, 172 adolescents (M age = 13.13 years) and 176 (M age = 23.33 years) adults completed the Food Choice Questionnaire (FCQ) and Monetary Choice Questionnaire (MCQ) as measures of food and money delay discounting, respectively. Then, participants returned to the lab and were randomly assigned to complete a brief mindful-eating training, watch a DVD on nutrition, or serve as a control. Participants completed the FCQ and MCQ again as a postmanipulation measure. Participants with high percent body fat (PBF) were more impulsive for food than those with low PBF. Adults with high PBF were also more impulsive for money compared with adults with low PBF; no PBF-related differences were found for adolescents. Participants in the mindful-eating group exhibited more self-controlled choices for food, but not for money. The control conditions did not exhibit changes. The study suggests that individuals with high PBF make more impulsive food choices relative to those with low PBF, which could increase the risk of obesity over time. It also is the first to demonstrate shifts in choice patterns for food and money using a brief mindful-eating training with adolescents. Mindful eating is a beneficial strategy to reduce impulsive food choice, at least temporarily, that may impede weight gain. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

MHC-disassortative mate choice and inbreeding avoidance in a solitary primate.

PubMed

Huchard, Elise; Baniel, Alice; Schliehe-Diecks, Susanne; Kappeler, Peter M

2013-08-01

Sexual selection theory suggests that choice for partners carrying dissimilar genes at the major histocompatibility complex (MHC) may play a role in maintaining genetic variation in animal populations by limiting inbreeding or improving the immunity of future offspring. However, it is often difficult to establish whether the observed MHC dissimilarity among mates drives mate choice or represents a by-product of inbreeding avoidance based on MHC-independent cues. Here, we used 454-sequencing and a 10-year study of wild grey mouse lemurs (Microcebus murinus), small, solitary primates from western Madagascar, to compare the relative importance on the mate choice of two MHC class II genes, DRB and DQB, that are equally variable but display contrasting patterns of selection at the molecular level, with DRB under stronger diversifying selection. We further assessed the effect of the genetic relatedness and of the spatial distance among candidate mates on the detection of MHC-dependent mate choice. Our results reveal inbreeding avoidance, along with disassortative mate choice at DRB, but not at DQB. DRB-disassortative mate choice remains detectable after excluding all related dyads (characterized by a relatedness coefficient r > 0), but varies slightly with the spatial distance among candidate mates. These findings suggest that the observed deviations from random mate choice at MHC are driven by functionally important MHC genes (like DRB) rather than passively resulting from inbreeding avoidance and further emphasize the need for taking into account the spatial and genetic structure of the population in correlative tests of MHC-dependent mate choice. © 2013 John Wiley & Sons Ltd.

Comparison between three option, four option and five option multiple choice question tests for quality parameters: A randomized study.

PubMed

Vegada, Bhavisha; Shukla, Apexa; Khilnani, Ajeetkumar; Charan, Jaykaran; Desai, Chetna

2016-01-01

Most of the academic teachers use four or five options per item of multiple choice question (MCQ) test as formative and summative assessment. Optimal number of options in MCQ item is a matter of considerable debate among academic teachers of various educational fields. There is a scarcity of the published literature regarding the optimum number of option in each item of MCQ in the field of medical education. To compare three options, four options, and five options MCQs test for the quality parameters - reliability, validity, item analysis, distracter analysis, and time analysis. Participants were 3 rd semester M.B.B.S. students. Students were divided randomly into three groups. Each group was given one set of MCQ test out of three options, four options, and five option randomly. Following the marking of the multiple choice tests, the participants' option selections were analyzed and comparisons were conducted of the mean marks, mean time, validity, reliability and facility value, discrimination index, point biserial value, distracter analysis of three different option formats. Students score more ( P = 0.000) and took less time ( P = 0.009) for the completion of three options as compared to four options and five options groups. Facility value was more ( P = 0.004) in three options group as compared to four and five options groups. There was no significant difference between three groups for the validity, reliability, and item discrimination. Nonfunctioning distracters were more in the four and five options group as compared to three option group. Assessment based on three option MCQs is can be preferred over four option and five option MCQs.

Implicit discount rates of vascular surgeons in the management of abdominal aortic aneurysms.

PubMed

Enemark, U; Lyttkens, C H; Troëng, T; Weibull, H; Ranstam, J

1998-01-01

A growing empirical literature has investigated attitudes towards discounting of health benefits with regard to social choices of life-saving and health-improving measures and individuals' time preferences for the management of their own health. In this study, the authors elicited the time preferences of vascular surgeons in the context of management of small abdominal aortic aneurysms, for which the choice between early elective surgery and watchful waiting is not straightforward. They interviewed 25 of a random sample of 30 Swedish vascular surgeons. Considerable variation in the time preferences was found in the choices between watchful waiting and surgical intervention among the otherwise very homogeneous group of surgeons. The discount rates derived ranged from 5.3% to 19.4%. The median discount rate (10.4%) is similar to those usually reported for social choices concerning life-saving measures. The surgeons who were employed in university hospitals had higher discount rates than did their colleagues in county and district hospitals.

Perceptions of randomized security schedules.

PubMed

Scurich, Nicholas; John, Richard S

2014-04-01

Security of infrastructure is a major concern. Traditional security schedules are unable to provide omnipresent coverage; consequently, adversaries can exploit predictable vulnerabilities to their advantage. Randomized security schedules, which randomly deploy security measures, overcome these limitations, but public perceptions of such schedules have not been examined. In this experiment, participants were asked to make a choice between attending a venue that employed a traditional (i.e., search everyone) or a random (i.e., a probability of being searched) security schedule. The absolute probability of detecting contraband was manipulated (i.e., 1/10, 1/4, 1/2) but equivalent between the two schedule types. In general, participants were indifferent to either security schedule, regardless of the probability of detection. The randomized schedule was deemed more convenient, but the traditional schedule was considered fairer and safer. There were no differences between traditional and random schedule in terms of perceived effectiveness or deterrence. Policy implications for the implementation and utilization of randomized schedules are discussed. © 2013 Society for Risk Analysis.

Acupuncture as prophylaxis for menstrual-related migraine: study protocol for a multicenter randomized controlled trial

PubMed Central

2013-01-01

Background Menstrual-related migraine is a common form of migraine affecting >50% of female migraineurs. Acupuncture may be a choice for menstrual-related migraine, when pharmacological prophylaxis is not suitable. However, the efficacy of acupuncture has not been confirmed. We design and perform a randomized controlled clinical trial to evaluate the efficacy of acupuncture compared with naproxen in menstrual-related migraine patients. Methods/Design This is a multicenter, single blind, randomized controlled clinical trial. A total of 184 participants will be randomly assigned to two different groups. Participants will receive verum acupuncture and placebo medicine in the treatment group, while participants in the control group will be treated with sham acupuncture and medicine (Naproxen Sustained Release Tablets). All treatments will be given for 3 months (menstrual cycles). The primary outcome measures are the change of migraine days inside the menstrual cycle and the proportion of responders (defined as the proportion of patients with at least a 50% reduction in the number of menstrual migraine days). The secondary outcome measures are the change of migraine days outside the menstrual cycle, duration of migraine attack, the Visual Analogue Scale (VAS), and intake of acute medication. The assessment will be made at baseline (before treatment), 3 months (menstrual cycles), and 4 months (menstrual cycles) after the first acupuncture session. Discussion The results of this trial will be helpful to supply the efficacy of acupuncture for menstrual-related migraine prophylaxis. Trial registration ISRCTN: ISRCTN57133712 PMID:24195839

Simplest chronoscope. III. Further comparisons between reaction times obtained by meterstick versus machine.

PubMed

Montare, Alberto

2013-06-01

The three classical Donders' reaction time (RT) tasks (simple, choice, and discriminative RTs) were employed to compare reaction time scores from college students obtained by use of Montare's simplest chronoscope (meterstick) methodology to scores obtained by use of a digital-readout multi-choice reaction timer (machine). Five hypotheses were tested. Simple RT, choice RT, and discriminative RT were faster when obtained by meterstick than by machine. The meterstick method showed higher reliability than the machine method and was less variable. The meterstick method of the simplest chronoscope may help to alleviate the longstanding problems of low reliability and high variability of reaction time performances; while at the same time producing faster performance on Donders' simple, choice and discriminative RT tasks than the machine method.

Preventing Alcohol-Exposed Pregnancies: A Randomized Controlled Trial of a Self-Administered Version of Project CHOICES with College Students and Nonstudents.

PubMed

Sobell, Linda Carter; Sobell, Mark B; Johnson, Kenneth; Heinecke, Nicholas; Agrawal, Sangeeta; Bolton, Burt

2017-06-01

Alcohol-exposed pregnancies (AEPs) are a preventable cause of birth defects and developmental disabilities for which many women are at risk. The initial 5-session Project CHOICES intervention was found to prevent AEPs. In the ensuing decade, there have been several additional CHOICES-like studies. This study, Project Healthy CHOICES, had 2 objectives: (i) to compare outcomes for students versus nonstudents; and (ii) to test a self-administered mail-based version of the Project CHOICES intervention. A randomized controlled trial (RCT) compared 2 interventions for women of childbearing age (18 to 44) who were at risk of an AEP: (i) motivational feedback based on Project CHOICES and (ii) information only. Advertisements recruited 354 women (145 college students; 209 nonstudents) at risk of an AEP. Intervention and study materials were available in English and Spanish. Of the 354 women, 44% were minorities (25% identified as Hispanics). At the 6-month follow-up, the interventions did not differ and there was no Intervention by Student Study interaction. However, over the entire 6-month follow-up, significantly more students (68%) than nonstudents (46%) were not at risk of an AEP (2.1 odds ratio; confidence interval = 1.47 to 2.95). For all groups, risk reduction occurred primarily through effective contraception. There was no significant difference between the 2 interventions. However, over the entire 6-month follow-up interval, college students were significantly more likely than nonstudents to not be at risk of an AEP and to use effective contraception. While the student groups had significantly higher reduced risk of AEP outcomes, there was also substantial risk reduction for women in the information only condition. These results suggest that the most effective AEP prevention efforts would be to inform women at risk that they could become pregnant. Because about half of all pregnancies are unplanned, identifying women at risk and preventing the risk of AEPs should be a public health priority. Copyright © 2017 by the Research Society on Alcoholism.

Comparison of estimators of standard deviation for hydrologic time series

USGS Publications Warehouse

Tasker, Gary D.; Gilroy, Edward J.

1982-01-01

Unbiasing factors as a function of serial correlation, ρ, and sample size, n for the sample standard deviation of a lag one autoregressive model were generated by random number simulation. Monte Carlo experiments were used to compare the performance of several alternative methods for estimating the standard deviation σ of a lag one autoregressive model in terms of bias, root mean square error, probability of underestimation, and expected opportunity design loss. Three methods provided estimates of σ which were much less biased but had greater mean square errors than the usual estimate of σ: s = (1/(n - 1) ∑ (xi −x¯)2)½. The three methods may be briefly characterized as (1) a method using a maximum likelihood estimate of the unbiasing factor, (2) a method using an empirical Bayes estimate of the unbiasing factor, and (3) a robust nonparametric estimate of σ suggested by Quenouille. Because s tends to underestimate σ, its use as an estimate of a model parameter results in a tendency to underdesign. If underdesign losses are considered more serious than overdesign losses, then the choice of one of the less biased methods may be wise.

Logistic random effects regression models: a comparison of statistical packages for binary and ordinal outcomes

PubMed Central

2011-01-01

Background Logistic random effects models are a popular tool to analyze multilevel also called hierarchical data with a binary or ordinal outcome. Here, we aim to compare different statistical software implementations of these models. Methods We used individual patient data from 8509 patients in 231 centers with moderate and severe Traumatic Brain Injury (TBI) enrolled in eight Randomized Controlled Trials (RCTs) and three observational studies. We fitted logistic random effects regression models with the 5-point Glasgow Outcome Scale (GOS) as outcome, both dichotomized as well as ordinal, with center and/or trial as random effects, and as covariates age, motor score, pupil reactivity or trial. We then compared the implementations of frequentist and Bayesian methods to estimate the fixed and random effects. Frequentist approaches included R (lme4), Stata (GLLAMM), SAS (GLIMMIX and NLMIXED), MLwiN ([R]IGLS) and MIXOR, Bayesian approaches included WinBUGS, MLwiN (MCMC), R package MCMCglmm and SAS experimental procedure MCMC. Three data sets (the full data set and two sub-datasets) were analysed using basically two logistic random effects models with either one random effect for the center or two random effects for center and trial. For the ordinal outcome in the full data set also a proportional odds model with a random center effect was fitted. Results The packages gave similar parameter estimates for both the fixed and random effects and for the binary (and ordinal) models for the main study and when based on a relatively large number of level-1 (patient level) data compared to the number of level-2 (hospital level) data. However, when based on relatively sparse data set, i.e. when the numbers of level-1 and level-2 data units were about the same, the frequentist and Bayesian approaches showed somewhat different results. The software implementations differ considerably in flexibility, computation time, and usability. There are also differences in the availability of additional tools for model evaluation, such as diagnostic plots. The experimental SAS (version 9.2) procedure MCMC appeared to be inefficient. Conclusions On relatively large data sets, the different software implementations of logistic random effects regression models produced similar results. Thus, for a large data set there seems to be no explicit preference (of course if there is no preference from a philosophical point of view) for either a frequentist or Bayesian approach (if based on vague priors). The choice for a particular implementation may largely depend on the desired flexibility, and the usability of the package. For small data sets the random effects variances are difficult to estimate. In the frequentist approaches the MLE of this variance was often estimated zero with a standard error that is either zero or could not be determined, while for Bayesian methods the estimates could depend on the chosen "non-informative" prior of the variance parameter. The starting value for the variance parameter may be also critical for the convergence of the Markov chain. PMID:21605357

Determining Consumer Preference for Furniture Product Characteristics

ERIC Educational Resources Information Center

Turner, Carolyn S.; Edwards, Kay P.

1974-01-01

The paper describes instruments for determining preferences of consumers for selected product characteristics associated with furniture choices--specifically style, color, color scheme, texture, and materials--and the procedures for administration of those instruments. Results are based on a random sampling of public housing residents. (Author/MW)

Reach and effectiveness of DVD and in-person diabetes self-management education.

PubMed

Glasgow, Russell E; Edwards, Linda L; Whitesides, Holly; Carroll, Nikki; Sanders, Tristan J; McCray, Barbara L

2009-12-01

To evaluate the reach and effectiveness of a diabetes self-management DVD compared to classroom-based instruction. A hybrid preference/randomized design was used with participants assigned to Choice v. Randomized and DVD v. Class conditions. One hundred and eighty-nine adults with type 2 diabetes participated. Key outcomes included self-management behaviours, process measures including DVD implementation and hypothesized mediators and clinical risk factors. In the Choice condition, four times as many participants chose the mailed DVD as selected Class-based instruction (38.8 v. 9.4%, p<0.001). At the 6-month follow-up, the DVD produced results generally not significantly different than classroom-based instruction, but a combined Class plus DVD condition did not improve outcomes beyond those produced by the classes alone. The DVD appears to have merit as an efficient and appealing alternative to brief classroom-based diabetes education, and the hybrid design is recommended to provide estimates of programme reach.

Hemodialysis as a treatment of severe accidental hypothermia.

PubMed

Caluwé, Rogier; Vanholder, Raymond; Dhondt, Annemieke

2010-03-01

We describe a case of severe accidental hypothermia (core body temperature 23.2 degrees C) successfully treated with hemodialysis in a diabetic patient with preexisting renal insufficiency. Consensus exists about cardiopulmonary bypass as the treatment of choice in cases of severe accidental hypothermia with cardiac arrest. Prospective randomized controlled trials comparing the different rewarming modalities for hemodynamically stable patients with hypothermia, however, are lacking. In our opinion, the choice of a rewarming technique should be patient tailored, knowing that hemodialysis is an efficient, minimally invasive, and readily available technique with the advantage of providing electrolyte support.

Requirements for a loophole-free photonic Bell test using imperfect setting generators

NASA Astrophysics Data System (ADS)

Kofler, Johannes; Giustina, Marissa; Larsson, Jan-Åke; Mitchell, Morgan W.

2016-03-01

Experimental violations of Bell inequalities are in general vulnerable to so-called loopholes. In this work, we analyze the characteristics of a loophole-free Bell test with photons, closing simultaneously the locality, freedom-of-choice, fair-sampling (i.e., detection), coincidence-time, and memory loopholes. We pay special attention to the effect of excess predictability in the setting choices due to nonideal random-number generators. We discuss necessary adaptations of the Clauser-Horne and Eberhard inequality when using such imperfect devices and—using Hoeffding's inequality and Doob's optional stopping theorem—the statistical analysis in such Bell tests.

Shared decision making for stroke prevention in atrial fibrillation: study protocol for a randomized controlled trial.

PubMed

Kunneman, Marleen; Branda, Megan E; Noseworthy, Peter A; Linzer, Mark; Burnett, Bruce; Dick, Sara; Spencer-Bonilla, Gabriela; Fernandez, Cara A; Gorr, Haeshik; Wambua, Mike; Keune, Shelly; Zeballos-Palacios, Claudia; Hargraves, Ian; Shah, Nilay D; Montori, Victor M

2017-09-29

Nonvalvular atrial fibrillation (AF) is a common ongoing health problem that places patients at risk of stroke. Whether and how a patient addresses this risk depends on each patient's goals, context, and values. Consequently, leading cardiovascular societies recommend using shared decision making (SDM) to individualize antithrombotic treatment in patients with AF. The aim of this study is to assess the extent to which the ANTICOAGULATION CHOICE conversation tool promotes high-quality SDM and influences anticoagulation uptake and adherence in patients with AF at risk of strokes. This study protocol describes a multicenter, encounter-level, randomized trial to assess the effect of using the ANTICOAGULATION CHOICE conversation tool in the clinical encounter, compared to usual care. The participating centers include an academic hospital system, a suburban community group practice, and an urban safety net hospital, all in Minnesota, USA. Patients with ongoing nonvalvular AF at risk of strokes (CHA 2 DS 2 -VASc score ≥ 1 in men, or ≥ 2 in women) will be eligible for participation. We aim to include 999 patients and their clinicians. The primary outcome is the quality of SDM as perceived by participants, and as assessed by a post-encounter survey that ascertains (a) knowledge transfer, (b) concordance of the decision made, (c) quality of communication, and (d) satisfaction with the decision-making process. Recordings of encounters will be reviewed to assess the extent of patient involvement and how participants use the tool (fidelity). Anticoagulant use, choice of agent, and adherence will be drawn from patients' medical and pharmacy records. Strokes and bleeding events will be drawn from patient records. This study will provide a valid and precise measure of the effect of the ANTICOAGULATION CHOICE conversation tool on SDM quality and processes, and on the treatment choices and adherence to therapy among AF patients at risk of stroke. ClinicalTrials.gov, NCT02905032 . Registered on 9 September 2016.

A patient decision aid regarding antithrombotic therapy for stroke prevention in atrial fibrillation: a randomized controlled trial.

PubMed

Man-Son-Hing, M; Laupacis, A; O'Connor, A M; Biggs, J; Drake, E; Yetisir, E; Hart, R G

1999-08-25

Decision aids are tools designed to help patients participate in the clinical decision-making process. To determine whether use of an audiobooklet (AB) decision aid explaining the results of a clinical trial affected the decision-making process of study participants. Randomized controlled trial conducted from May 1997 to April 1998. Fourteen centers that participated in the Stroke Prevention in Atrial Fibrillation (SPAF) III trial. A total of 287 patients from the SPAF III aspirin cohort study, in which patients with atrial fibrillation and a relatively low risk of stroke received 325 mg/d of aspirin and were followed up for a mean of 2 years. At the end of SPAF III, participants were randomized to be informed of the study results with usual care plus use of an AB (AB group) vs usual care alone (control group). The AB included pertinent information to help patients decide whether to continue taking aspirin or switch to warfarin. Patients' ability to make choices regarding antithrombotic therapy, and 6-month adherence to these decisions. Their knowledge, expectations, decisional conflict (the amount of uncertainty about the course of action to take), and satisfaction with the decision-making process were also measured. More patients in the AB group made a choice about antithrombotic therapy than in the control group (99% vs 94%; P = .02). Patients in the AB group were more knowledgeable and had more realistic expectations about the risk of stroke and hemorrhage (in the AB group, 53%-80% correctly estimated different risks; in the control group, 16%-28% gave correct estimates). Decisional conflict and satisfaction were similar for the 2 groups. After 6 months, a similar percentage of patients were still taking their initial choice of antithrombotic therapy (95% vs 93%; P = .44). For patients with atrial fibrillation who had participated in a major clinical trial, the use of an AB decision aid improved their understanding of the benefits and risks associated with different treatment options and helped them make definitive choices about which therapy to take. Further studies are necessary to evaluate the acceptability and impact of decision aids in other clinical settings.

Repetitive Daily Point of Choice Prompts and Occupational Sit-Stand Transfers, Concentration and Neuromuscular Performance in Office Workers: An RCT

PubMed Central

Donath, Lars; Faude, Oliver; Schefer, Yannick; Roth, Ralf; Zahner, Lukas

2015-01-01

Objective: Prolonged office sitting time adversely affects neuromuscular and cardiovascular health parameters. As a consequence, the present study investigated the effects of prompting the use of height-adjustable working desk (HAWD) on occupational sitting and standing time, neuromuscular outcomes and concentration in office workers. Methods: A single-blinded randomized controlled trial (RCT) with parallel group design was conducted. Thirty-eight office workers were supplied with HAWDs and randomly assigned (Strata: physical activity (PA), BMI, gender, workload) to a prompt (INT) or non-prompt (CON) group. INT received three daily screen-based prompts within 12 weeks. CON was only instructed once concerning the benefits of using HAWDs prior to the start of the study. Sitting and standing times were objectively assessed as primary outcomes for one entire working week using the ActiGraph wGT3X-BT at baseline (pre), after 6 (mid) and 12 weeks (post). Concentration (d2-test), postural sway during upright stance (under single, dual and triple task) and lower limb strength endurance (heel-rise) were collected as secondary outcomes. Results: With large but not statistically significant within group effects from pre to post, INT increased weekly standing time at work by 9% (p = 0.22, d = 0.8) representing an increase from 7.2 h (4.8) to 9.7 (6.6) h (p = 0.07). Concentration and neuromuscular performance did not change from pre to post testing (0.23 < p < 0.95; 0.001 < ηp² < 0.05). Conclusion: Low-frequent and low cost screen-based point of choice prompts (3 per day within 12 weeks) already result in notable increases of occupational standing time of approx. daily 30 min. These stimuli, however, did not relevantly affect neuromuscular outcomes.   PMID:25903058

Can Geographical Factors Determine the Choices of Farmers in the Ethiopian Highlands to Trade in Livestock Markets?

PubMed Central

Ortiz-Pelaez, Angel; Ashenafi, Getaneh; Roger, Francois; Waret-Szkuta, Agnes

2012-01-01

Proximity and affiliation to the local market appear to be two of the most relevant factors to explain farmer's choices to select a particular trading point. Physical barriers may limit the options , especially in developing countries. A network of villages linked by traders/farmer-traders sharing livestock markets was built with field data collected in 75 villages from 8 kebelles in the Wassona Werna wereda of the Ethiopian Highlands. Two exponential random graph models were fitted with various geographical and demographic attributes of the nodes (dyadic independent model) and three internal network structures (dyadic dependent model). Several diagnostic methods were applied to assess the goodness of fit of the models. The odds of an edge where the distance to the main market Debre Behran and the difference in altitude between two connected villages are both large increases significantly so that villages far away from the main market and at different altitude are more likely to be linked in the network than randomly. The odds of forming an edge between two villages in Abamote or Gudoberet kebelles are approximately 75% lower than an edge between villages in any other kebelles (p<0.05). The conditional log-odds of two villages forming a tie that is not included in a triangle, a 2-star or a 3-star is extremely low, increasing the odds significantly (p<0.05) each time a node is in a 2-star structure and decreasing it when a node is in a 3-star (p<0.05) or in a triangle formation (p<0.05)), conditional on the rest of the network. Two major constraining factors, namely distance and altitude, are not deterrent for the potential contact of susceptible small ruminant populations in the Highlands of Ethiopia. PMID:22355324

Using Discrete Choice Experiments to Inform the Benefit-Risk Assessment of Medicines: Are We Ready Yet?

PubMed

Vass, Caroline M; Payne, Katherine

2017-09-01

There is emerging interest in the use of discrete choice experiments as a means of quantifying the perceived balance between benefits and risks (quantitative benefit-risk assessment) of new healthcare interventions, such as medicines, under assessment by regulatory agencies. For stated preference data on benefit-risk assessment to be used in regulatory decision making, the methods to generate these data must be valid, reliable and capable of producing meaningful estimates understood by decision makers. Some reporting guidelines exist for discrete choice experiments, and for related methods such as conjoint analysis. However, existing guidelines focus on reporting standards, are general in focus and do not consider the requirements for using discrete choice experiments specifically for quantifying benefit-risk assessments in the context of regulatory decision making. This opinion piece outlines the current state of play in using discrete choice experiments for benefit-risk assessment and proposes key areas needing to be addressed to demonstrate that discrete choice experiments are an appropriate and valid stated preference elicitation method in this context. Methodological research is required to establish: how robust the results of discrete choice experiments are to formats and methods of risk communication; how information in the discrete choice experiment can be presented effectually to respondents; whose preferences should be elicited; the correct underlying utility function and analytical model; the impact of heterogeneity in preferences; and the generalisability of the results. We believe these methodological issues should be addressed, alongside developing a 'reference case', before agencies can safely and confidently use discrete choice experiments for quantitative benefit-risk assessment in the context of regulatory decision making for new medicines and healthcare products.

Evoked Emotions Predict Food Choice

PubMed Central

Dalenberg, Jelle R.; Gutjar, Swetlana; ter Horst, Gert J.; de Graaf, Kees; Renken, Remco J.; Jager, Gerry

2014-01-01

In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA) and apply Multinomial Logit Models (MLM) to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively). After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products) for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores. PMID:25521352

Evoked emotions predict food choice.

PubMed

Dalenberg, Jelle R; Gutjar, Swetlana; Ter Horst, Gert J; de Graaf, Kees; Renken, Remco J; Jager, Gerry

2014-01-01

In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA) and apply Multinomial Logit Models (MLM) to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively). After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products) for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores.

Social patterns revealed through random matrix theory

NASA Astrophysics Data System (ADS)

Sarkar, Camellia; Jalan, Sarika

2014-11-01

Despite the tremendous advancements in the field of network theory, very few studies have taken weights in the interactions into consideration that emerge naturally in all real-world systems. Using random matrix analysis of a weighted social network, we demonstrate the profound impact of weights in interactions on emerging structural properties. The analysis reveals that randomness existing in particular time frame affects the decisions of individuals rendering them more freedom of choice in situations of financial security. While the structural organization of networks remains the same throughout all datasets, random matrix theory provides insight into the interaction pattern of individuals of the society in situations of crisis. It has also been contemplated that individual accountability in terms of weighted interactions remains as a key to success unless segregation of tasks comes into play.

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

PubMed Central

2012-01-01

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 within teachers as a random effect. Discussion Study findings will inform the development of effective SDT-based teaching strategy interventions to enhance students’ psychological needs satisfaction, motivation, and PA levels. More effective teaching strategies may be identified that are capable of improving adolescents’ PA levels, and thereby provide beneficial population health outcomes. Trial registration This trial is registered with Current Controlled Trials and is traceable as ISRCTN07038258. PMID:23025261

Using generalized estimating equations and extensions in randomized trials with missing longitudinal patient reported outcome data.

PubMed

Bell, Melanie L; Horton, Nicholas J; Dhillon, Haryana M; Bray, Victoria J; Vardy, Janette

2018-05-26

Patient reported outcomes (PROs) are important in oncology research; however, missing data can pose a threat to the validity of results. Psycho-oncology researchers should be aware of the statistical options for handling missing data robustly. One rarely used set of methods, which includes extensions for handling missing data, is generalized estimating equations (GEEs). Our objective was to demonstrate use of GEEs to analyze PROs with missing data in randomized trials with assessments at fixed time points. We introduce GEEs and show, with a worked example, how to use GEEs that account for missing data: inverse probability weighted GEEs and multiple imputation with GEE. We use data from an RCT evaluating a web-based brain training for cancer survivors reporting cognitive symptoms after chemotherapy treatment. The primary outcome for this demonstration is the binary outcome of cognitive impairment. Several methods are used, and results are compared. We demonstrate that estimates can vary depending on the choice of analytical approach, with odds ratios for no cognitive impairment ranging from 2.04 to 5.74. While most of these estimates were statistically significant (P < 0.05), a few were not. Researchers using PROs should use statistical methods that handle missing data in a way as to result in unbiased estimates. GEE extensions are analytic options for handling dropouts in longitudinal RCTs, particularly if the outcome is not continuous. Copyright © 2018 John Wiley & Sons, Ltd.

Stability and dynamical properties of material flow systems on random networks

NASA Astrophysics Data System (ADS)

Anand, K.; Galla, T.

2009-04-01

The theory of complex networks and of disordered systems is used to study the stability and dynamical properties of a simple model of material flow networks defined on random graphs. In particular we address instabilities that are characteristic of flow networks in economic, ecological and biological systems. Based on results from random matrix theory, we work out the phase diagram of such systems defined on extensively connected random graphs, and study in detail how the choice of control policies and the network structure affects stability. We also present results for more complex topologies of the underlying graph, focussing on finitely connected Erdös-Réyni graphs, Small-World Networks and Barabási-Albert scale-free networks. Results indicate that variability of input-output matrix elements, and random structures of the underlying graph tend to make the system less stable, while fast price dynamics or strong responsiveness to stock accumulation promote stability.

Application of rrm as behavior mode choice on modelling transportation

NASA Astrophysics Data System (ADS)

Surbakti, M. S.; Sadullah, A. F.

2018-03-01

Transportation mode selection, the first step in transportation planning process, is probably one of the most important planning elements. The development of models that can explain the preference of passengers regarding their chosen mode of public transport option will contribute to the improvement and development of existing public transport. Logit models have been widely used to determine the mode choice models in which the alternative are different transport modes. Random Regret Minimization (RRM) theory is a theory developed from the behavior to choose (choice behavior) in a state of uncertainty. During its development, the theory was used in various disciplines, such as marketing, micro economy, psychology, management, and transportation. This article aims to show the use of RRM in various modes of selection, from the results of various studies that have been conducted both in north sumatera and western Java.

Using augmented reality to inform consumer choice and lower carbon footprints

NASA Astrophysics Data System (ADS)

Isley, Steven C.; Ketcham, Robert; Arent, Douglas J.

2017-05-01

Consumers who wish to consider product attributes like carbon footprints in their purchasing decisions are often blocked from meaningful action by a lack of information. We conducted a randomized controlled trial at a grocery store to evaluate the effects of providing such product attribute and carbon footprint information via augmented reality (AR) displays on bottled water and breakfast cereal, two frequently purchased goods. Using an AR smartphone app that combines comparative and detailed product information into personalized data and recommendations, a 23% reduction in carbon footprint was found for bottled water, and non-significant reductions for breakfast cereal. However, AR informed choice lead to healthier cereal purchases with an average of 32% less sugar, 15% less fat, and 9.8% less sodium. This research suggests that AR techniques can help facilitate complex decision-making and lead to better choices.

Female Adolescents' Educational Choices about Reproductive Health Modules

ERIC Educational Resources Information Center

Gold, Melanie A.; Chiappetta, Laurel; Young, Amanda J.; Zuckoff, Allan; DiClemente, Carlo C.

2008-01-01

Purpose: To assess girls' reproductive educational choices, satisfaction with choice, and relationship between demographics, module choice, and satisfaction. Methods: We recruited 286 girls, aged 13 to 21 years, from a hospital-based adolescent clinic, from advertisements, and by word of mouth. At enrollment, participants completed a 60-minute…

Work conditions and the food choice coping strategies of employed parents.

PubMed

Devine, Carol M; Farrell, Tracy J; Blake, Christine E; Jastran, Margaret; Wethington, Elaine; Bisogni, Carole A

2009-01-01

How work conditions relate to parents' food choice coping strategies. Pilot telephone survey. City in the northeastern United States (US). Black, white, and Hispanic employed mothers (25) and fathers (25) randomly recruited from low-/moderate-income zip codes; 78% of those reached and eligible participated. Sociodemographic characteristics; work conditions (hours, shift, job schedule, security, satisfaction, food access); food choice coping strategies (22 behavioral items for managing food in response to work and family demands (ie, food prepared at/away from home, missing meals, individualizing meals, speeding up, planning). Two-tailed chi-square and Fisher exact tests (P < or = .05, unless noted). Half or more of respondents often/sometimes used 12 of 22 food choice coping strategies. Long hours and nonstandard hours and schedules were positively associated among fathers with take-out meals, missed family meals, prepared entrees, and eating while working; and among mothers with restaurant meals, missed breakfast, and prepared entrees. Job security, satisfaction, and food access were also associated with gender-specific strategies. Structural work conditions among parents such as job hours, schedule, satisfaction, and food access are associated with food choice coping strategies with importance for dietary quality. Findings have implications for worksite interventions but need examination in a larger sample.

Eye-tracking of visual attention in web-based assessment using the Force Concept Inventory

NASA Astrophysics Data System (ADS)

Han, Jing; Chen, Li; Fu, Zhao; Fritchman, Joseph; Bao, Lei

2017-07-01

This study used eye-tracking technology to investigate students’ visual attention while taking the Force Concept Inventory (FCI) in a web-based interface. Eighty nine university students were randomly selected into a pre-test group and a post-test group. Students took the 30-question FCI on a computer equipped with an eye-tracker. There were seven weeks of instruction between the pre- and post-test data collection. Students’ performance on the FCI improved significantly from pre-test to post-test. Meanwhile, the eye-tracking results reveal that the time students spent on taking the FCI test was not affected by student performance and did not change from pre-test to post-test. Analysis of students’ attention to answer choices shows that on the pre-test students primarily focused on the naïve choices and ignored the expert choices. On the post-test, although students had shifted their primary attention to the expert choices, they still kept a high level of attention to the naïve choices, indicating significant conceptual mixing and competition during problem solving. Outcomes of this study provide new insights on students’ conceptual development in learning physics.

Methodology for studying recreation choice behavior with emphasis on grounded inquiry

Treesearch

Kent B. Downing; Roger N. Clark

1985-01-01

This paper reports methodology for investigating recreation choice behavior using grounded, naturalistic research methods. How these techniques can be coordinated with other social research methods is described. Naturalistic methods are preferred over other approaches to uncover recreationists' decision making processes at work.

Controlled Free Choice Method: A Proposal for a New Undergraduate Major Selection Policy at King Fahd University of Petroleum and Minerals

ERIC Educational Resources Information Center

Al-Dosarya, Adel S.; Rahman, Syed Masiur

2006-01-01

The prevalent undergraduate major selection at King Fahd University of Petroleum & Minerals (KFUPM) mostly depends on the student's choice regardless of academic abilities and qualifications. Owing to the adoption of this Free Choice Method (FCM), the number of students will continue to grow and external pressures at the national level may…

Note Taking and Recall

ERIC Educational Resources Information Center

Fisher, Judith L.; Harris, Mary B.

1974-01-01

To study the effect of note taking and opportunity for review on subsequent recall, 88 college students were randomly assigned to five treatment groups utilizing different note taking and review combinations. No treatment effects were found, although quality of notes was positively correlated with free recall an multiple-choice measures.…

Exploring Uncertainty with Projectile Launchers

ERIC Educational Resources Information Center

Orzel, Chad; Reich, Gary; Marr, Jonathan

2012-01-01

The proper choice of a measurement technique that minimizes systematic and random uncertainty is an essential part of experimental physics. These issues are difficult to teach in the introductory laboratory, though. Because most experiments involve only a single measurement technique, students are often unable to make a clear distinction between…

Astronomical random numbers for quantum foundations experiments

NASA Astrophysics Data System (ADS)

Leung, Calvin; Brown, Amy; Nguyen, Hien; Friedman, Andrew S.; Kaiser, David I.; Gallicchio, Jason

2018-04-01

Photons from distant astronomical sources can be used as a classical source of randomness to improve fundamental tests of quantum nonlocality, wave-particle duality, and local realism through Bell's inequality and delayed-choice quantum eraser tests inspired by Wheeler's cosmic-scale Mach-Zehnder interferometer gedanken experiment. Such sources of random numbers may also be useful for information-theoretic applications such as key distribution for quantum cryptography. Building on the design of an astronomical random number generator developed for the recent cosmic Bell experiment [Handsteiner et al. Phys. Rev. Lett. 118, 060401 (2017), 10.1103/PhysRevLett.118.060401], in this paper we report on the design and characterization of a device that, with 20-nanosecond latency, outputs a bit based on whether the wavelength of an incoming photon is greater than or less than ≈700 nm. Using the one-meter telescope at the Jet Propulsion Laboratory Table Mountain Observatory, we generated random bits from astronomical photons in both color channels from 50 stars of varying color and magnitude, and from 12 quasars with redshifts up to z =3.9 . With stars, we achieved bit rates of ˜1 ×106Hz/m 2 , limited by saturation of our single-photon detectors, and with quasars of magnitudes between 12.9 and 16, we achieved rates between ˜102 and 2 ×103Hz /m2 . For bright quasars, the resulting bitstreams exhibit sufficiently low amounts of statistical predictability as quantified by the mutual information. In addition, a sufficiently high fraction of bits generated are of true astronomical origin in order to address both the locality and freedom-of-choice loopholes when used to set the measurement settings in a test of the Bell-CHSH inequality.

A Study of Driver's Route Choice Behavior Based on Evolutionary Game Theory

PubMed Central

Jiang, Xiaowei; Ji, Yanjie; Deng, Wei

2014-01-01

This paper proposes a route choice analytic method that embeds cumulative prospect theory in evolutionary game theory to analyze how the drivers adjust their route choice behaviors under the influence of the traffic information. A simulated network with two alternative routes and one variable message sign is built to illustrate the analytic method. We assume that the drivers in the transportation system are bounded rational, and the traffic information they receive is incomplete. An evolutionary game model is constructed to describe the evolutionary process of the drivers' route choice decision-making behaviors. Here we conclude that the traffic information plays an important role in the route choice behavior. The driver's route decision-making process develops towards different evolutionary stable states in accordance with different transportation situations. The analysis results also demonstrate that employing cumulative prospect theory and evolutionary game theory to study the driver's route choice behavior is effective. This analytic method provides an academic support and suggestion for the traffic guidance system, and may optimize the travel efficiency to a certain extent. PMID:25610455

A study of driver's route choice behavior based on evolutionary game theory.

PubMed

Jiang, Xiaowei; Ji, Yanjie; Du, Muqing; Deng, Wei

2014-01-01

This paper proposes a route choice analytic method that embeds cumulative prospect theory in evolutionary game theory to analyze how the drivers adjust their route choice behaviors under the influence of the traffic information. A simulated network with two alternative routes and one variable message sign is built to illustrate the analytic method. We assume that the drivers in the transportation system are bounded rational, and the traffic information they receive is incomplete. An evolutionary game model is constructed to describe the evolutionary process of the drivers' route choice decision-making behaviors. Here we conclude that the traffic information plays an important role in the route choice behavior. The driver's route decision-making process develops towards different evolutionary stable states in accordance with different transportation situations. The analysis results also demonstrate that employing cumulative prospect theory and evolutionary game theory to study the driver's route choice behavior is effective. This analytic method provides an academic support and suggestion for the traffic guidance system, and may optimize the travel efficiency to a certain extent.

Effect of a decision aid with patient narratives in reducing decisional conflict in choice for surgery among early-stage breast cancer patients: A three-arm randomized controlled trial.

PubMed

Osaka, Wakako; Nakayama, Kazuhiro

2017-03-01

We aimed to evaluate the effect of a decision aid (DA) with patient narratives on decisional conflict in surgery choice for Japanese women with early-stage breast cancer. Two hundred ten women with early-stage breast cancer were randomly assigned to an intervention or control group. Groups 1 and 2 received standard information and a DA, with or without patient narratives, and Group 3 received standard information (control) before surgery choice. At baseline, post-intervention (Time 2), and 1 month after surgery (Time 3), we evaluated decisional conflict as the primary outcome using a decisional conflict scale (DCS). Sidak corrections for multiple comparisons in analysis of covariate were used to compare Time 2 and Time 3 DCS mean scores between each pair of groups. At Time 3, decisional conflict was significantly reduced for Group 1 vs control (P=0.021, Cohen's d =0.26) and Group 2 vs control (P=0.008, Cohen's d=0.40). The DAs with and without patient narratives are equivalently effective at reducing postoperative decisional conflict in Japanese women with early-stage breast cancer. The DAs with and without patient narratives can be used in clinical practice for women with early-stage breast cancer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Mixed-Methods Research Methodologies

ERIC Educational Resources Information Center

Terrell, Steven R.

2012-01-01

Mixed-Method studies have emerged from the paradigm wars between qualitative and quantitative research approaches to become a widely used mode of inquiry. Depending on choices made across four dimensions, mixed-methods can provide an investigator with many design choices which involve a range of sequential and concurrent strategies. Defining…

Choice architecture to promote fruit and vegetable purchases by families participating in the Special Supplemental Program for Women, Infants, and Children (WIC): randomized corner store pilot study.

PubMed

Thorndike, Anne N; Bright, Oliver-John M; Dimond, Melissa A; Fishman, Ronald; Levy, Douglas E

2017-05-01

To conduct a pilot study to determine if improving the visibility and quality of fresh produce (choice architecture) in corner stores would increase fruit/vegetable purchases by families participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). Six stores were randomly assigned to choice architecture intervention or control. Store-level WIC sales data were provided by the state. Primary outcomes were WIC fruit/vegetable voucher and non-fruit/vegetable voucher sales, comparing trends from baseline (December 2012-October 2013) with the five-month intervention period (December 2013-April 2014). Secondary outcomes were differences in customer self-reported fruit/vegetable purchases between baseline and end of the intervention. Chelsea, MA, USA, a low-income urban community. Adult customers (n 575) completing store exit interviews. During baseline, WIC fruit/vegetable and non-fruit/vegetable sales decreased in both intervention and control stores by $US 16/month. During the intervention period, WIC fruit/vegetable sales increased in intervention stores by $US 40/month but decreased in control stores by $US 23/month (difference in trends: $US 63/month; 95 % CI 4, 121 $US/month; P=0·036); WIC non-fruit/vegetable sales were not different (P=0·45). Comparing baseline and intervention-period exit interview responses by customers participating in WIC (n 134), intervention store customers reported increased fruit/vegetable purchases compared with control store customers (18 v. -2 %), but this did not achieve statistical significance (P=0·11). Placement of fruits/vegetables near the front of corner stores increased purchase of produce by customers using WIC. New policies that incentivize stores to stock and prominently display good-quality produce could promote healthier food choices of low-income families.

MHC-correlated mate choice in humans: a review.

PubMed

Havlicek, Jan; Roberts, S Craig

2009-05-01

Extremely high variability in genes of the major histocompatibility complex (MHC) in vertebrates is assumed to be a consequence of frequency-dependent parasite-driven selection and mate preferences based on promotion of offspring heterozygosity at MHC, or potentially, genome-wide inbreeding avoidance. Where effects have been found, mate choice studies on rodents and other species usually find preference for MHC-dissimilarity in potential partners. Here we critically review studies on MHC-associated mate choice in humans. These are based on three broadly different aspects: (1) odor preferences, (2) facial preferences and (3) actual mate choice surveys. As in animal studies, most odor-based studies demonstrate disassortative preferences, although there is variation in the strength and nature of the effects. In contrast, facial attractiveness research indicates a preference for MHC-similar individuals. Results concerning MHC in actual couples show a bias towards similarity in one study, dissimilarity in two studies and random distribution in several other studies. These vary greatly in sample size and heterogeneity of the sample population, both of which may significantly bias the results. This pattern of mixed results across studies may reflect context-dependent and/or life history sensitive preference expression, in addition to higher level effects arising out of population differences in genetic heterogeneity or cultural and ethnic restrictions on random mating patterns. Factors of special relevance in terms of individual preferences are reproductive status and long- vs. short-term mating context. We discuss the idea that olfactory and visual channels may work in a complementary way (i.e. odor preference for MHC-dissimilarity and visual preference for MHC-similarity) to achieve an optimal level of genetic variability, methodological issues and interesting avenues for further research.

Rationale and study protocol for the Nursing Home Compare Plus (NHCPlus) randomized controlled trial: A personalized decision aid for patients transitioning from the hospital to a skilled-nursing facility.

PubMed

Sorkin, Dara H; Amin, Alpesh; Weimer, David L; Sharit, Joseph; Ladd, Heather; Mukamel, Dana B

2016-03-01

Annually more than 3 million people are admitted to one of the 15,965 skilled nursing facilities (SNFs) in the United States, with 90% of admissions occurring from a hospital. Although the Centers for Medicare and Medicaid Services (CMS) publishes several internet-based report cards, including one for nursing homes (Nursing Home Compare, NHC), they are not widely used. This is due, in part, to the complexity of the information available and the fact that the choice of nursing homes is typically made while in the hospital without access to the web-based NHC. We developed Nursing Home Compare Plus (NHCPlus) to address these limitations and to improve the decision-making process. This paper describes the design and rationale of a two-arm randomized controlled trial designed to test the effectiveness of NHCPlus compared to usual care only, in a sample of patients being discharged from the hospital to an SNF (N=229). Assessments were conducted within 24h prior to patient discharge and 30-days post discharge. Primary outcomes to be examined included the use of NHC, increased choice of nursing homes with better reported outcomes, and increased distance between patient/family residence and nursing home. Secondary outcomes included satisfaction with the decision to go to a nursing home, confidence in the choice of nursing home, and reduced hospital length of stay. NHCPlus is an innovative mobile application designed to allow patients to personalize their choice of nursing homes to meet their medical needs and preferences. The application to other quality report cards is discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

The Patient-Oriented Eczema Measure in young children: responsiveness and minimal clinically important difference.

PubMed

Gaunt, D M; Metcalfe, C; Ridd, M

2016-11-01

The Patient-Oriented Eczema Measure (POEM) has been recommended as the core patient-reported outcome measure for trials of eczema treatments. Using data from the Choice of Moisturiser for Eczema Treatment randomized feasibility study, we assess the responsiveness to change and determine the minimal clinically important difference (MCID) of the POEM in young children with eczema. Responsiveness to change by repeated administrations of the POEM was investigated in relation to change recalled using the Parent Global Assessment (PGA) measure. Five methods of determining the MCID of the POEM were employed; three anchor-based methods using PGA as the anchor: the within-patient score change, between-patient score change and sensitivity and specificity method, and two distribution-based methods: effect size estimate and the one half standard deviation of the baseline distribution of POEM scores. Successive POEM scores were found to be responsive to change in eczema severity. The MCID of the POEM change score, in relation to a slight improvement in eczema severity as recalled by parents on the PGA, estimated by the within-patient score change (4.27), the between-patient score change (2.89) and the sensitivity and specificity method (3.00) was similar to the one half standard deviation of the POEM baseline scores (2.94) and the effect size estimate (2.50). The Patient-Oriented Eczema Measure as applied to young children is responsive to change, and the MCID is around 3. This study will encourage the use of POEM and aid in determining sample size for future randomized controlled trials of treatments for eczema in young children. © 2016 The Authors. Allergy Published by John Wiley & Sons Ltd.

Do labeled versus unlabeled treatments of alternatives' names influence stated choice outputs? Results from a mode choice study.

PubMed

Jin, Wen; Jiang, Hai; Liu, Yimin; Klampfl, Erica

2017-01-01

Discrete choice experiments have been widely applied to elicit behavioral preferences in the literature. In many of these experiments, the alternatives are named alternatives, meaning that they are naturally associated with specific names. For example, in a mode choice study, the alternatives can be associated with names such as car, taxi, bus, and subway. A fundamental issue that arises in stated choice experiments is whether to treat the alternatives' names as labels (that is, labeled treatment), or as attributes (that is, unlabeled treatment) in the design as well as the presentation phases of the choice sets. In this research, we investigate the impact of labeled versus unlabeled treatments of alternatives' names on the outcome of stated choice experiments, a question that has not been thoroughly investigated in the literature. Using results from a mode choice study, we find that the labeled or the unlabeled treatment of alternatives' names in either the design or the presentation phase of the choice experiment does not statistically affect the estimates of the coefficient parameters. We then proceed to measure the influence toward the willingness-to-pay (WTP) estimates. By using a random-effects model to relate the conditional WTP estimates to the socioeconomic characteristics of the individuals and the labeled versus unlabeled treatments of alternatives' names, we find that: a) Given the treatment of alternatives' names in the presentation phase, the treatment of alternatives' names in the design phase does not statistically affect the estimates of the WTP measures; and b) Given the treatment of alternatives' names in the design phase, the labeled treatment of alternatives' names in the presentation phase causes the corresponding WTP estimates to be slightly higher.

Do labeled versus unlabeled treatments of alternatives’ names influence stated choice outputs? Results from a mode choice study

PubMed Central

Jin, Wen; Jiang, Hai; Liu, Yimin; Klampfl, Erica

2017-01-01

Discrete choice experiments have been widely applied to elicit behavioral preferences in the literature. In many of these experiments, the alternatives are named alternatives, meaning that they are naturally associated with specific names. For example, in a mode choice study, the alternatives can be associated with names such as car, taxi, bus, and subway. A fundamental issue that arises in stated choice experiments is whether to treat the alternatives’ names as labels (that is, labeled treatment), or as attributes (that is, unlabeled treatment) in the design as well as the presentation phases of the choice sets. In this research, we investigate the impact of labeled versus unlabeled treatments of alternatives’ names on the outcome of stated choice experiments, a question that has not been thoroughly investigated in the literature. Using results from a mode choice study, we find that the labeled or the unlabeled treatment of alternatives’ names in either the design or the presentation phase of the choice experiment does not statistically affect the estimates of the coefficient parameters. We then proceed to measure the influence toward the willingness-to-pay (WTP) estimates. By using a random-effects model to relate the conditional WTP estimates to the socioeconomic characteristics of the individuals and the labeled versus unlabeled treatments of alternatives’ names, we find that: a) Given the treatment of alternatives’ names in the presentation phase, the treatment of alternatives’ names in the design phase does not statistically affect the estimates of the WTP measures; and b) Given the treatment of alternatives’ names in the design phase, the labeled treatment of alternatives’ names in the presentation phase causes the corresponding WTP estimates to be slightly higher. PMID:28806764

Changes in taste preference and steps taken after sleep curtailment.

PubMed

Smith, Shannon L; Ludy, Mary-Jon; Tucker, Robin M

2016-09-01

A substantial proportion of the population does not achieve the recommended amount of sleep. Previous work demonstrates that sleep alterations perturb energy balance by disrupting appetite hormones, increasing energy intake, and decreasing physical activity. This study explored the influence of sleep duration on taste perception as well as effects on dietary intake and physical activity. Participants (n=24 habitual short sleepers and n=27 habitual long sleepers, 82.4% female, 88.2% white, 25.2±7.7years) completed two randomized taste visits; one following short sleep duration (≤7h) and one following long sleep duration (>7h). Taste perception measures included sweet and salt detection thresholds (ascending 3-alternative, forced-choice method), as well as sweet preference (Monell 2-series, forced-choice, paired-comparison, tracking method). Steps and sleep were tracked via FitBit, an activity monitoring device. Dietary intake was assessed using 24-hour recalls and analyzed using Nutritionist Pro. Habitual long-sleepers had a higher sweet taste preference (p=0.042) and took fewer steps (p=0.036) following sleep curtailment compared to the night where they slept >7h but did not experience changes in dietary intake or detection thresholds. Habitual short-sleepers did not experience changes in taste perception, activity, or dietary intake following sleep alteration. Habitual long-sleepers may be at greater risk of gaining weight when typical sleep patterns are disrupted. Copyright © 2016 Elsevier Inc. All rights reserved.

The virtual lover: variable and easily guided 3D fish animations as an innovative tool in mate-choice experiments with sailfin mollies-I. Design and implementation

PubMed Central

Smielik, Ievgen; Hütwohl, Jan-Marco; Gierszewski, Stefanie; Witte, Klaudia; Kuhnert, Klaus-Dieter

2017-01-01

Abstract Animal behavior researchers often face problems regarding standardization and reproducibility of their experiments. This has led to the partial substitution of live animals with artificial virtual stimuli. In addition to standardization and reproducibility, virtual stimuli open new options for researchers since they are easily changeable in morphology and appearance, and their behavior can be defined. In this article, a novel toolchain to conduct behavior experiments with fish is presented by a case study in sailfin mollies Poecilia latipinna. As the toolchain holds many different and novel features, it offers new possibilities for studies in behavioral animal research and promotes the standardization of experiments. The presented method includes options to design, animate, and present virtual stimuli to live fish. The designing tool offers an easy and user-friendly way to define size, coloration, and morphology of stimuli and moreover it is able to configure virtual stimuli randomly without any user influence. Furthermore, the toolchain brings a novel method to animate stimuli in a semiautomatic way with the help of a game controller. These created swimming paths can be applied to different stimuli in real time. A presentation tool combines models and swimming paths regarding formerly defined playlists, and presents the stimuli onto 2 screens. Experiments with live sailfin mollies validated the usage of the created virtual 3D fish models in mate-choice experiments. PMID:29491963

Management of carotid stenosis in women

PubMed Central

Brown, Martin M.; Didier, Leys; Howard, Virginia J.; Moore, Wesley S.; Paciaroni, Maurizio; Ringleb, Peter; Rockman, Caron; Caso, Valeria

2013-01-01

Objective: Specific guidelines for management of cerebrovascular risk in women are currently lacking. This study aims to provide a consensus expert opinion to help make clinical decisions in women with carotid stenosis. Methods: Proposals for the use of carotid endarterectomy (CEA), carotid stenting (CAS), and medical therapy for stroke prevention in women with carotid stenosis were provided by a group of 9 international experts with consensus method. Results: Symptomatic women with severe carotid stenosis can be managed by CEA provided that the perioperative risk of the operators is low (<4%). Periprocedural stroke risks may be increased in symptomatic women if revascularization is performed by CAS; however, the choice of CAS vs CEA can be tailored in subgroups best fit for each procedure (e.g., women with restenosis or severe coronary disease, best suited for CAS; women with tortuous vessels or old age, best suited for CEA). There is currently limited evidence to consider medical therapy alone as the best choice for women with neurologically severe asymptomatic carotid stenosis, who should be best managed within randomized trials including a medical arm. Medical management and cardiovascular risk factor control must be implemented in all women with carotid stenosis in periprocedural period and lifelong regardless of whether or not intervention is planned. Conclusions: The suggestions provided in this article may constitute a decision-making basis for planning treatment of carotid stenosis in women. Most recommendations are of limited strength; however, it is unlikely that new robust data will emerge soon to induce relevant changes. PMID:23751919

The virtual lover: variable and easily guided 3D fish animations as an innovative tool in mate-choice experiments with sailfin mollies-I. Design and implementation.

PubMed

Müller, Klaus; Smielik, Ievgen; Hütwohl, Jan-Marco; Gierszewski, Stefanie; Witte, Klaudia; Kuhnert, Klaus-Dieter

2017-02-01

Animal behavior researchers often face problems regarding standardization and reproducibility of their experiments. This has led to the partial substitution of live animals with artificial virtual stimuli. In addition to standardization and reproducibility, virtual stimuli open new options for researchers since they are easily changeable in morphology and appearance, and their behavior can be defined. In this article, a novel toolchain to conduct behavior experiments with fish is presented by a case study in sailfin mollies Poecilia latipinna . As the toolchain holds many different and novel features, it offers new possibilities for studies in behavioral animal research and promotes the standardization of experiments. The presented method includes options to design, animate, and present virtual stimuli to live fish. The designing tool offers an easy and user-friendly way to define size, coloration, and morphology of stimuli and moreover it is able to configure virtual stimuli randomly without any user influence. Furthermore, the toolchain brings a novel method to animate stimuli in a semiautomatic way with the help of a game controller. These created swimming paths can be applied to different stimuli in real time. A presentation tool combines models and swimming paths regarding formerly defined playlists, and presents the stimuli onto 2 screens. Experiments with live sailfin mollies validated the usage of the created virtual 3D fish models in mate-choice experiments.

Impact of having a high-risk pregnancy on future postpartum contraceptive method choice.

PubMed

Kiykac Altinbas, Sadiman; Bayoglu Tekin, Yesim; Dilbaz, Berna; Kilic, Selim; Khalil, Susan S; Kandemir, Omer

2014-12-01

To compare the knowledge and preference of preconceptional contraception to future postpartum contraceptive method choice in high-risk pregnancies. Does a high-risk pregnancy condition affect future postpartum contraceptive method choice? Women hospitalised at the High Risk Pregnancy unit of a tertiary research and training hospital were asked to complete a self-reported questionnaire that included demographic characteristics, presence of unintended pregnancy, contraceptive method of choice before the current pregnancy, plans for contraceptive use following delivery and requests for any contraceptive counselling in the postpartum period. A total of 655 pregnant women were recruited. The mean age, gravidity and parity of the women were 27.48 ± 6.25 years, 2.81 ± 2.15 and 1.40 ± 1.77, respectively. High-risk pregnancy indications included 207 (31.6%) maternal, 396 (60.5%) foetal and 52 (7.9%) uterine factors. All postpartum contraceptive choices except for combined oral contraceptives (COCs) usage were significantly different from preconceptional contraceptive preferences (p<0.001). High-risk pregnancy indications, future child bearing, ideal number of children, income and education levels were the most important factors influencing postpartum contraceptive choices. While the leading contraceptive method in the postpartum period was long-acting reversible contraceptive methods (non-hormonal copper intrauterine device Cu-IUD, the levonorgestrel-releasing intrauterine system (LNG-IUS) (40%), the least preferred method was COCs use (5.2%) and preference of COCs use showed no difference between the preconceptional and postpartum periods (p=0.202). Overall 73.7% of the women wanted to receive contraceptive counselling before their discharge. A high-risk pregnancy condition may change the opinion and preference of contraceptive use, and also seems to affect the awareness of family planning methods. Copyright © 2014 Australian College of Midwives. All rights reserved.

Hierarchical decision processes that operate over distinct timescales underlie choice and changes in strategy

PubMed Central

Purcell, Braden A.; Kiani, Roozbeh

2016-01-01

Decision-making in a natural environment depends on a hierarchy of interacting decision processes. A high-level strategy guides ongoing choices, and the outcomes of those choices determine whether or not the strategy should change. When the right decision strategy is uncertain, as in most natural settings, feedback becomes ambiguous because negative outcomes may be due to limited information or bad strategy. Disambiguating the cause of feedback requires active inference and is key to updating the strategy. We hypothesize that the expected accuracy of a choice plays a crucial rule in this inference, and setting the strategy depends on integration of outcome and expectations across choices. We test this hypothesis with a task in which subjects report the net direction of random dot kinematograms with varying difficulty while the correct stimulus−response association undergoes invisible and unpredictable switches every few trials. We show that subjects treat negative feedback as evidence for a switch but weigh it with their expected accuracy. Subjects accumulate switch evidence (in units of log-likelihood ratio) across trials and update their response strategy when accumulated evidence reaches a bound. A computational framework based on these principles quantitatively explains all aspects of the behavior, providing a plausible neural mechanism for the implementation of hierarchical multiscale decision processes. We suggest that a similar neural computation—bounded accumulation of evidence—underlies both the choice and switches in the strategy that govern the choice, and that expected accuracy of a choice represents a key link between the levels of the decision-making hierarchy. PMID:27432960

Hierarchical decision processes that operate over distinct timescales underlie choice and changes in strategy.

PubMed

Purcell, Braden A; Kiani, Roozbeh

2016-08-02

Decision-making in a natural environment depends on a hierarchy of interacting decision processes. A high-level strategy guides ongoing choices, and the outcomes of those choices determine whether or not the strategy should change. When the right decision strategy is uncertain, as in most natural settings, feedback becomes ambiguous because negative outcomes may be due to limited information or bad strategy. Disambiguating the cause of feedback requires active inference and is key to updating the strategy. We hypothesize that the expected accuracy of a choice plays a crucial rule in this inference, and setting the strategy depends on integration of outcome and expectations across choices. We test this hypothesis with a task in which subjects report the net direction of random dot kinematograms with varying difficulty while the correct stimulus-response association undergoes invisible and unpredictable switches every few trials. We show that subjects treat negative feedback as evidence for a switch but weigh it with their expected accuracy. Subjects accumulate switch evidence (in units of log-likelihood ratio) across trials and update their response strategy when accumulated evidence reaches a bound. A computational framework based on these principles quantitatively explains all aspects of the behavior, providing a plausible neural mechanism for the implementation of hierarchical multiscale decision processes. We suggest that a similar neural computation-bounded accumulation of evidence-underlies both the choice and switches in the strategy that govern the choice, and that expected accuracy of a choice represents a key link between the levels of the decision-making hierarchy.

Modeling Dynamic Food Choice Processes to Understand Dietary Intervention Effects.

PubMed

Marcum, Christopher Steven; Goldring, Megan R; McBride, Colleen M; Persky, Susan

2018-02-17

Meal construction is largely governed by nonconscious and habit-based processes that can be represented as a collection of in dividual, micro-level food choices that eventually give rise to a final plate. Despite this, dietary behavior intervention research rarely captures these micro-level food choice processes, instead measuring outcomes at aggregated levels. This is due in part to a dearth of analytic techniques to model these dynamic time-series events. The current article addresses this limitation by applying a generalization of the relational event framework to model micro-level food choice behavior following an educational intervention. Relational event modeling was used to model the food choices that 221 mothers made for their child following receipt of an information-based intervention. Participants were randomized to receive either (a) control information; (b) childhood obesity risk information; (c) childhood obesity risk information plus a personalized family history-based risk estimate for their child. Participants then made food choices for their child in a virtual reality-based food buffet simulation. Micro-level aspects of the built environment, such as the ordering of each food in the buffet, were influential. Other dynamic processes such as choice inertia also influenced food selection. Among participants receiving the strongest intervention condition, choice inertia decreased and the overall rate of food selection increased. Modeling food selection processes can elucidate the points at which interventions exert their influence. Researchers can leverage these findings to gain insight into nonconscious and uncontrollable aspects of food selection that influence dietary outcomes, which can ultimately improve the design of dietary interventions.

Future Time Perspective Impacts Gain-Related but Not Loss-Related Intertemporal Choice.

PubMed

Li, Tian; Tan, Yuxin; Gong, Xianmin; Yin, Shufei; Qiu, Fangshu; Hu, Xue

2018-01-01

Future time perspective (FTP) modulates individuals' temporal orientation in selecting their motivations and goals, which widely influences their cognitions and behaviors. However, it remains unclear how FTP exactly affects intertemporal choice. To clarify the effect of FTP on intertemporal choice, 90 college students ( M age = 21.70, SD = 1.23) were randomly assigned to the limited FTP condition (16 males, 29 females) and the open-ended FTP condition (17 males, 28 females). In the limited FTP condition, participants were instructed to imagine their states of being 70 years old, whereas in the open-ended FTP condition, they were instructed to describe their current states. All participants then completed a series of intertemporal choice tasks, in which they chose from gain- and loss-related choices occurring at various time points. Results showed that the participants who received the future-imagining manipulation had more limited FTP compared with those who did not receive the manipulation, which confirmed the validity of the FTP manipulation. A 2 (FTP: limited vs. open-ended) × 2 (type of choice: gain vs. loss) repeated measures ANOVA on discount rate revealed a significant interaction between these two factors. The participants in the limited FTP condition had higher discount rates on gain-related choices but showed no difference on loss-related choices compared with the participants under the open-ended FTP condition. The results suggest that limited FTP could lower individuals' future orientation (i.e., willingness to delay an outcome) on gain-related, but not on loss-related, intertemporal decision-making.

Public reporting in health care: how do consumers use quality-of-care information? A systematic review.

PubMed

Faber, Marjan; Bosch, Marije; Wollersheim, Hub; Leatherman, Sheila; Grol, Richard

2009-01-01

One of the underlying goals of public reporting is to encourage the consumer to select health care providers or health plans that offer comparatively better quality-of-care. To review the weight consumers give to quality-of-care information in the process of choice, to summarize the effect of presentation formats, and to examine the impact of quality information on consumers' choice behavior. The evidence is organized in a theoretical consumer choice model. English language literature was searched in PubMed, the Cochrane Clinical Trial, and the EPOC Databases (January 1990-January 2008). Study selection was limited to randomized controlled trails, controlled before-after trials or interrupted time series. Included interventions focused on choice behavior of consumers in health care settings. Outcome measures referred to one of the steps in a consumer choice model. The quality of the study design was rated, and studies with low quality ratings were excluded. All 14 included studies examine quality information, usually CAHPS, with respect to its impact on the consumer's choice of health plans. Easy-to-read presentation formats and explanatory messages improve knowledge about and attitude towards the use of quality information; however, the weight given to quality information depends on other features, including free provider choice and costs. In real-world settings, having seen quality information is a strong determinant for choosing higher quality-rated health plans. This review contributes to an understanding of consumer choice behavior in health care settings. The small number of included studies limits the strength of our conclusions.

Future Time Perspective Impacts Gain-Related but Not Loss-Related Intertemporal Choice

PubMed Central

Li, Tian; Tan, Yuxin; Gong, Xianmin; Yin, Shufei; Qiu, Fangshu; Hu, Xue

2018-01-01

Future time perspective (FTP) modulates individuals’ temporal orientation in selecting their motivations and goals, which widely influences their cognitions and behaviors. However, it remains unclear how FTP exactly affects intertemporal choice. To clarify the effect of FTP on intertemporal choice, 90 college students (Mage = 21.70, SD = 1.23) were randomly assigned to the limited FTP condition (16 males, 29 females) and the open-ended FTP condition (17 males, 28 females). In the limited FTP condition, participants were instructed to imagine their states of being 70 years old, whereas in the open-ended FTP condition, they were instructed to describe their current states. All participants then completed a series of intertemporal choice tasks, in which they chose from gain- and loss-related choices occurring at various time points. Results showed that the participants who received the future-imagining manipulation had more limited FTP compared with those who did not receive the manipulation, which confirmed the validity of the FTP manipulation. A 2 (FTP: limited vs. open-ended) × 2 (type of choice: gain vs. loss) repeated measures ANOVA on discount rate revealed a significant interaction between these two factors. The participants in the limited FTP condition had higher discount rates on gain-related choices but showed no difference on loss-related choices compared with the participants under the open-ended FTP condition. The results suggest that limited FTP could lower individuals’ future orientation (i.e., willingness to delay an outcome) on gain-related, but not on loss-related, intertemporal decision-making. PMID:29695989

What is interesting? Exploring the appraisal structure of interest.

PubMed

Silvia, Paul J

2005-03-01

Relative to other emotions, interest is poorly understood. On the basis of theories of appraisal process and structure, it was predicted that interest consists of appraisals of novelty (factors related to unfamiliarity and complexity) and appraisals of coping potential (the ability to understand the new, complex thing). Four experiments, using in vivo rather than retrospective methods, supported this appraisal structure. The findings were general across measured and manipulated appraisals, interesting stimuli (random polygons, visual art, poetry), and measures of interest (self-reports, forced-choice, behavioral measures). Furthermore, the appraisal structure was specific to interest (it did not predict enjoyment, a related positive emotion), and appraisals predicted interest beyond relevant traits (curiosity, openness). The appraisal perspective offers a powerful way of construing the causes of interest. Copyright 2005 APA, all rights reserved.

Poisson's ratio of fiber-reinforced composites

NASA Astrophysics Data System (ADS)

Christiansson, Henrik; Helsing, Johan

1996-05-01

Poisson's ratio flow diagrams, that is, the Poisson's ratio versus the fiber fraction, are obtained numerically for hexagonal arrays of elastic circular fibers in an elastic matrix. High numerical accuracy is achieved through the use of an interface integral equation method. Questions concerning fixed point theorems and the validity of existing asymptotic relations are investigated and partially resolved. Our findings for the transverse effective Poisson's ratio, together with earlier results for random systems by other authors, make it possible to formulate a general statement for Poisson's ratio flow diagrams: For composites with circular fibers and where the phase Poisson's ratios are equal to 1/3, the system with the lowest stiffness ratio has the highest Poisson's ratio. For other choices of the elastic moduli for the phases, no simple statement can be made.

Comparison of electro and chemical cautery in the treatment of anterior epistaxis.

PubMed

Toner, J G; Walby, A P

1990-08-01

In the ENT Department of the Royal Victoria Hospital, Belfast, the impression (supported only by anecdotes) was that electro-cautery was superior to chemical cautery in the treatment of simple anterior epistaxis. Since no evaluation of the relative merits of electro and chemical cautery has been reported, a prospective randomized study was conducted to assess the effectiveness of electro-cautery and cautery with silver nitrate. The results of the study showed that there was no statistically significant difference between the two methods in either controlling the epistaxis or in the incidence of complications. It is concluded that since cautery with a silver nitrate tipped applicator is simpler, and of equal effectiveness, it would appear to be the treatment of choice for simple anterior epistaxis.

Composing compound libraries for hit discovery--rationality-driven preselection or random choice by structural diversity?

PubMed

Weidel, Elisabeth; Negri, Matthias; Empting, Martin; Hinsberger, Stefan; Hartmann, Rolf W

2014-01-01

In order to identify new scaffolds for drug discovery, surface plasmon resonance is frequently used to screen structurally diverse libraries. Usually, hit rates are low and identification processes are time consuming. Hence, approaches which improve hit rates and, thus, reduce the library size are required. In this work, we studied three often used strategies for their applicability to identify inhibitors of PqsD. In two of them, target-specific aspects like inhibition of a homologous protein or predicted binding determined by virtual screening were used for compound preselection. Finally, a fragment library, covering a large chemical space, was screened and served as comparison. Indeed, higher hit rates were observed for methods employing preselected libraries indicating that target-oriented compound selection provides a time-effective alternative.

Machine Learning methods for Quantitative Radiomic Biomarkers.

PubMed

Parmar, Chintan; Grossmann, Patrick; Bussink, Johan; Lambin, Philippe; Aerts, Hugo J W L

2015-08-17

Radiomics extracts and mines large number of medical imaging features quantifying tumor phenotypic characteristics. Highly accurate and reliable machine-learning approaches can drive the success of radiomic applications in clinical care. In this radiomic study, fourteen feature selection methods and twelve classification methods were examined in terms of their performance and stability for predicting overall survival. A total of 440 radiomic features were extracted from pre-treatment computed tomography (CT) images of 464 lung cancer patients. To ensure the unbiased evaluation of different machine-learning methods, publicly available implementations along with reported parameter configurations were used. Furthermore, we used two independent radiomic cohorts for training (n = 310 patients) and validation (n = 154 patients). We identified that Wilcoxon test based feature selection method WLCX (stability = 0.84 ± 0.05, AUC = 0.65 ± 0.02) and a classification method random forest RF (RSD = 3.52%, AUC = 0.66 ± 0.03) had highest prognostic performance with high stability against data perturbation. Our variability analysis indicated that the choice of classification method is the most dominant source of performance variation (34.21% of total variance). Identification of optimal machine-learning methods for radiomic applications is a crucial step towards stable and clinically relevant radiomic biomarkers, providing a non-invasive way of quantifying and monitoring tumor-phenotypic characteristics in clinical practice.

Conformational analysis of methylphenidate: comparison of molecular orbital and molecular mechanics methods

NASA Astrophysics Data System (ADS)

Gilbert, Kathleen M.; Skawinski, William J.; Misra, Milind; Paris, Kristina A.; Naik, Neelam H.; Buono, Ronald A.; Deutsch, Howard M.; Venanzi, Carol A.

2004-11-01

Methylphenidate (MP) binds to the cocaine binding site on the dopamine transporter and inhibits reuptake of dopamine, but does not appear to have the same abuse potential as cocaine. This study, part of a comprehensive effort to identify a drug treatment for cocaine abuse, investigates the effect of choice of calculation technique and of solvent model on the conformational potential energy surface (PES) of MP and a rigid methylphenidate (RMP) analogue which exhibits the same dopamine transporter binding affinity as MP. Conformational analysis was carried out by the AM1 and AM1/SM5.4 semiempirical molecular orbital methods, a molecular mechanics method (Tripos force field with the dielectric set equal to that of vacuum or water) and the HF/6-31G* molecular orbital method in vacuum phase. Although all three methods differ somewhat in the local details of the PES, the general trends are the same for neutral and protonated MP. In vacuum phase, protonation has a distinctive effect in decreasing the regions of space available to the local conformational minima. Solvent has little effect on the PES of the neutral molecule and tends to stabilize the protonated species. The random search (RS) conformational analysis technique using the Tripos force field was found to be capable of locating the minima found by the molecular orbital methods using systematic grid search. This suggests that the RS/Tripos force field/vacuum phase protocol is a reasonable choice for locating the local minima of MP. However, the Tripos force field gave significantly larger phenyl ring rotational barriers than the molecular orbital methods for MP and RMP. For both the neutral and protonated cases, all three methods found the phenyl ring rotational barriers for the RMP conformers/invertamers (denoted as cte, tte, and cta) to be: cte, tte> MP > cta. Solvation has negligible effect on the phenyl ring rotational barrier of RMP. The B3LYP/6-31G* density functional method was used to calculate the phenyl ring rotational barrier for neutral MP and gave results very similar to those of the HF/6-31G* method.

A randomized trial of survey participation in a national random sample of general practitioners and gynecologists in France.

PubMed

Legleye, S; Bohet, A; Razafindratsima, N; Bajos, N; Moreau, C

2014-08-01

Healthcare professionals play a critical role in women's choice of contraceptive methods. However, national surveys on sexual and reproductive health (SRH) among physicians are rare and present low participation rates. We conducted a randomized trial to test for the effectiveness of three interventions to improve survey participation of private physicians delivering reproductive health services in France. The study comprised a national random sample of 500 general practitioners and 500 gynecologists working in private offices. All received a postal invitation to participate either by completing a paper, phone or online questionnaire. Physicians were randomly assigned to six groups to test for the effect of three interventions: a non-monetary incentive in the form of a scientific book, telephone contact, and the possibility of completing the questionnaire by phone. Overall, 362 questionnaires were collected (26 online, 2 by phone) and 58 physicians were ineligible. The completion rate increased from 26.7% in physicians who received no intervention to 42.7% in those who received the book and a phone call. The phone call increased the completion rate by 11% percentage points (P=0.01), while the book had no significant effect. Results from multivariate logistic regressions also indicate that gynecologists (OR=1.6) and female physicians (OR=1.5) were more likely to participate than others. The results suggest that phone calls substantially increase participation of physicians in sexual and reproductive health surveys but have little impact on sampling distortion. Differentials in response rates by physicians' characteristics should be considered in future SRH studies among physicians. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Adjunctive Aripiprazole Versus Placebo for Antipsychotic-Induced Hyperprolactinemia: Meta-Analysis of Randomized Controlled Trials

PubMed Central

Li, Xianbin; Tang, Yilang; Wang, Chuanyue

2013-01-01

Objective To compare the safety and efficacy of adjunctive aripiprazole versus placebo for antipsychotic-induced hyperprolactinemia. Methods Population: adult patients presenting with antipsychotic-induced hyperprolactinemia diagnosed by prolactin level with or without prolactin-related symptoms. Interventions: adjunctive aripiprazole vs. adjunctive placebo. Outcome measures: adverse events and efficacy of treatment. Studies: randomized controlled trials. Results Five randomized controlled trials with a total of 639 patients (326 adjunctive aripiprazole, 313 adjunctive placebo) met the inclusion criteria. Adjunctive aripiprazole was associated with a 79.11% (125/158) prolactin level normalization rate. Meta-analysis of insomnia, headache, sedation, psychiatric disorder, extrapyramidal symptom, dry mouth, and fatigue showed no significant differences in the adjunctive aripiprazole treatment group compared with the placebo group (risk difference (Mantel-Haenszel, random or fixed) −0.05 to 0.04 (95% confidence interval −0.13 to 0.16); I2 = 0% to 68%, P = 0.20 to 0.70). However, sedation, insomnia, and headache were more frequent when the adjunctive aripiprazole dose was higher than 15 mg/day. Meta-analysis of the prolactin level normalization indicated adjunctive aripiprazole was superior to placebo (risk difference (Mantel-Haenszel, random) 0.76 (95% confidence interval 0.67 to 0.85); I2 = 43%, P<0.00001). The subgroup analysis confirmed that the subjects who received adjunctive aripiprazole 5 mg/day showed a degree of prolactin normalization similar to that of all participants. No significant differences between groups in discontinuation and improvements of psychiatric symptoms. Conclusion Adjunctive aripiprazole is both safe and effective as a reasonable choice treatment for patients with antipsychotic-induced hyperprolactinemia. The appropriate dose of adjunctive aripiprazole may be 5 mg/day. PMID:23936389

An experimental study on the effects of exposure to magazine advertising on children's food choices.

PubMed

Jones, Sandra C; Kervin, Lisa

2011-08-01

The present study sought to determine the feasibility of an experimental research design to investigate the effects of exposure to magazine advertising on children's food choices. Children were randomized to read either a magazine with food advertisements or a magazine with no food advertisements. They then chose two food items from the intervention 'store' to eat after the session. Data were also collected on attitudes to advertising and snack food preferences. Finally, participants' parents were provided with a self-completion survey on food choices and other variables (n 24). Three vacation care centres in regional New South Wales, Australia. Children aged 5-12 years (n 47). Children in the experimental condition were more likely to choose advertised foods than those in the control group. Interestingly, the majority reported taste and healthiness as the most important factors in snack food choices; however, when faced with the actual food choice, they predominantly chose unhealthy foods (eighty-two unhealthy and only twelve healthy items were chosen). This was the first study to assess the effects on children of exposure to food advertising within the context of reading a child-targeted magazine. Importantly, even with the small sample size and venue limitations, we found that exposure to magazine advertising influenced food choices. Children's magazines are an under-researched and poorly regulated medium, with considerable potential to influence children's food choices. The present study shows that the methodology is feasible, and future studies could replicate this with larger samples.

Gender Differences in Food Choice: Effects of Superior Temporal Sulcus Stimulation.

PubMed

Manippa, Valerio; Padulo, Caterina; van der Laan, Laura N; Brancucci, Alfredo

2017-01-01

The easy availability of food has caused a shift from eating for survival to hedonic eating. Women, compared to men, have shown to respond differently to food cues in the environment on a behavioral and a neural level, in particular to energy rich (compared to low energy) foods. It has been demonstrated that the right posterior superior temporal sulcus (STS) is the only region exhibiting greater activation for high vs. low calorie food choices. In order to test for a possible causal role of STS in food choice, we applied high frequency transcranial random noise stimulation (tRNS) on STS assuming a different response pattern between males and females. Our participants (18 females, 17 males) performed a forced choice task between food pairs matched for individual liking but differed in calorie, during the left STS, right STS stimulation and sham condition. Male participants showed a general preference for low calorie (LC) foods compared to females. In addition, we observed in males, but not in females, an increase of high calorie (HC) food choice during right STS tRNS compared to sham condition and left STS tRNS. Finally, we found an increase of missed choices during right STS stimulation compared to sham condition and left STS stimulation. In conclusion, thanks to tRNS evidence, we both confirm the involvement and suggest a causal role of right posterior STS in feeding behavior. Moreover, we suggest that gender differences exist in STS mechanisms underlying food choice.