WorldWideScience

Sample records for estimate unintended effects

  1. Introduction to the special issue 'unintended effects of international cooperation'.

    Science.gov (United States)

    Koch, Dirk-Jan; Schulpen, Lau

    2018-06-01

    The 'Evaluation and Program Planning' journal has contributed to the launch of an academic discussion of unintended effects of international cooperation, notably by publishing in 2016 articles by Bamberger, Tarsilla, & Hesse-Biber and by Jabeen. This special issue aims to take up the academic challenges as laid down by those authors, by providing among others a clear typology and applying it, by outlining various methodological options and testing them, and elaborating on suggestions on how to deal with the barriers that prevent unintended effects being taken into account. This special issue makes clear that it is possible to reduce the share of unforeseen effects of international cooperation. Turning the spotlight on unintended effects that can be anticipated, and aiming to make progress on uncovering those that are particularly difficult to detect and debunking those that are exaggerated is the task that lies ahead of us. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. The intended and unintended effects of advertising on children

    NARCIS (Netherlands)

    Buijzen, M.; Valkenburg, P.M.; Valdivia, A.N.; Scharrer, E.

    2013-01-01

    The effects of advertising on children have often been divided into two general types: intended effects (e.g., children's brand awareness, preferences, and purchase requests) and unintended effects (e.g., materialistic orientations, parent-child conflicts, and unhealthy eating habits). The first

  3. Unintended effects were investigated in antioxidant activity between ...

    African Journals Online (AJOL)

    Other than the targeted approach on compositional analysis, non-targeted approaches on genomics, proteomics and metabolomics are developing to search for unintended effects with respect to genetically modified (GM) food safety assessments. Antioxidant activity system was closely related with plant growth and ...

  4. Global, regional, and subregional trends in unintended pregnancy and its outcomes from 1990 to 2014: estimates from a Bayesian hierarchical model

    Directory of Open Access Journals (Sweden)

    Jonathan Bearak, PhD

    2018-04-01

    Full Text Available Summary: Background: Estimates of pregnancy incidence by intention status and outcome indicate how effectively women and couples are able to fulfil their childbearing aspirations, and can be used to monitor the impact of family-planning programmes. We estimate global, regional, and subregional pregnancy rates by intention status and outcome for 1990–2014. Methods: We developed a Bayesian hierarchical time series model whereby the unintended pregnancy rate is a function of the distribution of women across subgroups defined by marital status and contraceptive need and use, and of the risk of unintended pregnancy in each subgroup. Data included numbers of births and of women estimated by the UN Population Division, recently published abortion incidence estimates, and findings from surveys of women on the percentage of births or pregnancies that were unintended. Some 298 datapoints on the intention status of births or pregnancies were obtained for 105 countries. Findings: Worldwide, an estimated 44% (90% uncertainty interval [UI] 42–48 of pregnancies were unintended in 2010–14. The unintended pregnancy rate declined by 30% (90% UI 21–39 in developed regions, from 64 (59–81 per 1000 women aged 15–44 years in 1990–94 to 45 (42–56 in 2010–14. In developing regions, the unintended pregnancy rate fell 16% (90% UI 5–24, from 77 (74–88 per 1000 women aged 15–44 years to 65 (62–76. Whereas the decline in the unintended pregnancy rate in developed regions coincided with a declining abortion rate, the decline in developing regions coincided with a declining unintended birth rate. In 2010–14, 59% (90% UI 54–65 of unintended pregnancies ended in abortion in developed regions, as did 55% (52–60 of unintended pregnancies in developing regions. Interpretation: The unintended pregnancy rate remains substantially higher in developing regions than in developed regions. Sexual and reproductive health services are needed to help women

  5. The Unintended Effects of Private School Competition

    DEFF Research Database (Denmark)

    Andersen, Simon Calmar; Serritzlew, Søren

    2007-01-01

    We examine whether competition from private schools improves public school performance and expenditure. It is difficult methodologically to isolate the effect of competition, but we use new measures of competition in both the public and the private school sector and a data set comprising detailed...... background information on more than 35,000 public school students in the Danish voucher system. This design provides a relatively firm support for the conclusion that competition does not improve achievement of public school students but that it increases public expenditure per student. Finally, we argue...

  6. Unintended effects of electrofishing on nongame fishes

    Science.gov (United States)

    Miranda, Leandro E.; Kidwell, R. H.

    2010-01-01

    Most studies of injury associated with electrofishing have focused on game fishes, but few have given attention to cohabiting small nongame species. Under controlled laboratory conditions, we subjected small nongame cyprinids, ictalurids, and percids to a wide range of voltages and waveforms to examine potential harmful effects. Fish were treated with power levels distributed uniformly between the thresholds required to immobilize game fish and also were subjected multiple times to those thresholds to simulate the range of conditions that might exist in a heterogeneous electrical field formed during electrofishing in field situations. Across waveforms and species, the incidence of hemorrhages averaged 2% (range = 0–20%), the incidence of spinal injuries averaged 6% (range = 0–30%), and mortality averaged 16% (range = 0–90%). Continuous DC was generally less harmful than pulsed-DC waveforms; hemorrhages and spinal injuries tended to increase with high pulse frequencies, and mortalities tended to increase with low pulse frequencies. Ambiguities in the results were apparent, suggesting that some species may experience extensive harm, whereas others may not. Given the potential to harm numerically small populations and populations of imperiled species, we suggest (1) expanded efforts to overcome the power limitations that prevent effective use of continuous-DC electrofishing in many field situations and (2) pilot studies at geographic locations where numerically small populations of nongame species may be a concern.

  7. Unintended effects and their detection in genetically modified crops

    DEFF Research Database (Denmark)

    Cellini, F; Chesson, A; Colquhoun, I

    2004-01-01

    The commercialisation of GM crops in Europe is practically non-existent at the present time. The European Commission has instigated changes to the regulatory process to address the concerns of consumers and member states and to pave the way for removing the current moratorium. With regard...... to the safety of GM crops and products, the current risk assessment process pays particular attention to potential adverse effects on human and animal health and the environment. This document deals with the concept of unintended effects in GM crops and products, i.e. effects that go beyond that of the original...

  8. Aid and good governance: Examining aggregate unintended effects of aid.

    Science.gov (United States)

    Dijkstra, Geske

    2018-06-01

    Although donors generally aim to improve governance in recipient countries by various means, critics claim that the aggregate effect of large aid flows is the deterioration of governance. Aid is said to weaken domestic accountability, sustain authoritarian regimes, increase political instability, weaken government capacities, and increase corruption. Conducting a systematic search in Web of Science, this paper reviews the empirical evidence for these unintended aggregate effects of aid on the political, administrative, and judicial dimensions of good governance. It finds that the negative effects of aid on governance are much exaggerated. The aggregate effect of aid on democracy has become more positive after the Cold War, and the effect of aid on government capacity and on reducing corruption has also improved over time. Furthermore, most studies show a positive effect of aid on political stability. These findings imply that donor intentions matter: donors that are serious about their intended effects on governance are able to mitigate the possible negative unintended effects of their aid. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Safety of genetically engineered foods: approaches to assessing unintended health effects

    National Research Council Canada - National Science Library

    Committee on Identifying and Assessing Unintended Effects of Genetically Engineered Foods on Human Health, National Research Council

    2004-01-01

    Assists policymakers in evaluating the appropriate scientific methods for detecting unintended changes in food and assessing the potential for adverse health effects from genetically modified products...

  10. Unintended Side Effects of Digital Transition: Perspectives of Japanese Experts

    Directory of Open Access Journals (Sweden)

    Masahiro Sugiyama

    2017-11-01

    Full Text Available The core of the digital transition is the representation of all kinds of real-world entities and processes and an increasing number of cognitive processes by digital information and algorithms on computers. These allow for seemingly unlimited storage, operation, retrieval, and transmission capacities that make digital tools economically available for all domains of society and empower human action, particularly combined with real-world interfaces such as displays, robots, sensors, 3D printers, etc. Digital technologies are general-purpose technologies providing unprecedented potential benefits for sustainability. However, they will bring about a multitude of potential unintended side effects, and this demands a transdisciplinary discussion on unwanted societal changes as well as a shift in science from analog to digital modeling and structure. Although social discourse has begun, the topical scope and regional coverage have been limited. Here, we report on an expert roundtable on digital transition held in February 2017 in Tokyo, Japan. Drawing on a variety of disciplinary backgrounds, our discussions highlight the importance of cultural contexts and the need to bridge local and global conversations. Although Japanese experts did mention side effects, their focus was on how to ensure that AI and robots could coexist with humans. Such a perspective is not well appreciated everywhere outside Japan. Stakeholder dialogues have already begun in Japan, but greater efforts are needed to engage a broader collection of experts in addition to stakeholders to broaden the social debate.

  11. Emotional Appeals in HIV Prevention Campaigns: Unintended Stigma Effects.

    Science.gov (United States)

    Thainiyom, Prawit; Elder, Katherine

    2017-07-01

    The purpose of this study was to determine whether HIV/AIDS public service announcements (PSAs) that use emotional appeals have unintended effects of creating stigmatizing attitudes in their viewers. We analyzed data for 240 respondents located in the United States who were recruited online. Respondents were randomly assigned to one of 3 conditions, where they viewed a PSA with hope appeals, fear appeals, or non-emotional appeals. Respondents then answered a series of questions about their attitudes about HIV/AIDS; testing behavior; engagement with HIV/AIDS-related people, organizations, and issues; and HIV/AIDS knowledge. We then performed MANOVA analyses and Pearson correlations. There were no significant differences in stigmatizing attitudes and behavior across the 3 conditions. However, once the data were split by sex, men exposed to the hope condition had significantly higher stigmatizing attitudes towards people living with HIV/AIDS than men in the other 2 conditions. This result was unexpected and suggests that further research needs to be conducted with a more robust sample size to account for any moderating influences that might explain why a hopeful message that communicates togetherness would have a negative attitudinal impact on male viewers.

  12. Unintended Effects in Genetically Modified Food/Feed Safety: A Way Forward.

    Science.gov (United States)

    Fernandez, Antonio; Paoletti, Claudia

    2018-04-20

    Identifying and assessing unintended effects in genetically modified food and feed are considered paramount by the Food and Agricultural Organization (FAO), World Health Organization (WHO), and Codex Alimentarius, despite heated debate. This paper addresses outstanding needs: building consensus on the history-of-safe-use concept, harmonizing criteria to select appropriate conventional counterparts, and improving endpoint selection to identify unintended effects. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Parents' experience of unintended childbearing: A qualitative study of factors that mitigate or exacerbate effects.

    Science.gov (United States)

    Kavanaugh, Megan L; Kost, Kathryn; Frohwirth, Lori; Maddow-Zimet, Isaac; Gor, Vivian

    2017-02-01

    Births resulting from an unintended pregnancy affect individuals differentially, and some may experience more negative consequences than others. In this study, we sought to describe the mechanisms through which the severity of effects may be mitigated or exacerbated. We conducted in-depth interviews with 35 women and 30 men, all with a youngest child born resulting from an unintended pregnancy, in two urban sites in the United States. Respondents described both negative and positive effects of the child's birth in the areas of school; work and finances; partner relationships; personal health and outlook on life trajectories. Mechanisms through which unintended pregnancies mitigated or exacerbated certain effects fell at the individual (e.g. lifestyle modification), interpersonal (e.g. partner support) and structural (e.g. workplace flexibility) levels. These qualitative findings deepen understanding of the impact of unintended childbearing on the lives of women, men and families. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Genetic basis and detection of unintended effects in genetically modified crop plants

    NARCIS (Netherlands)

    Ladics, G.S.; Bartholomaeus, A.; Bregitzer, P.; Doerrer, N.G.; Gray, A.; Holzhauzer, T.; Jordan, M.; Keese, P.; Kok, E.J.; Macdonald, P.; Parrott, W.; Privalle, L.; Raybould, A.; Rhee, S.Y.; Rice, E.; Romeis, J.; Vaughn, J.; Wal, J.M.; Glenn, K.

    2015-01-01

    In January 2014, an international meeting sponsored by the International Life Sciences Institute/Health and Environmental Sciences Institute and the Canadian Food Inspection Agency titled “Genetic Basis of Unintended Effects in Modified Plants” was held in Ottawa, Canada, bringing together over 75

  15. Food safety evaluation of crops produced through genetic engineering--how to reduce unintended effects?

    Science.gov (United States)

    Jelenić, Srećko

    2005-06-01

    Scientists started applying genetic engineering techniques to improve crops two decades ago; about 70 varieties obtained via genetic engineering have been approved to date. Although genetic engineering offers the most precise and controllable genetic modification of crops in entire history of plant improvement, the site of insertion of a desirable gene cannot be predicted during the application of this technology. As a consequence, unintended effects might occur due to activation or silencing of genes, giving rise to allergic reactions or toxicity. Therefore, extensive chemical, biochemical and nutritional analyses are performed on each new genetically engineered variety. Since the unintended effects may be predictable on the basis of what is known about the insertion place of the transgenic DNA, an important aim of plant biotechnology is to define techniques for the insertion of transgene into the predetermined chromosomal position (gene targeting). Although gene targeting cannot be applied routinely in crop plants, given the recent advances, that goal may be reached in the near future.

  16. Molecular profiling techniques as tools to detect potential unintended effects in genetically engineered maize

    CSIR Research Space (South Africa)

    Barros, E

    2010-05-01

    Full Text Available Molecular Profiling Techniques as Tools to Detect Potential Unintended Effects in Genetically Engineered Maize Eugenia Barros Introduction In the early stages of production and commercialization of foods derived from genetically engineered (GE) plants... systems. In a recent paper published in Plant Biotechnology Journal,4 we compared two transgenic white maize lines with the non-transgenic counterpart to investigate two possible sources of variation: genetic engineering and environmental variation...

  17. Unintended out-of-plane actions in size effect tests of structural concrete

    International Nuclear Information System (INIS)

    Ramallo, J.C.; Danesi, R.F.; Kotsovos, M.D.; Pavlovic, M.N.

    1995-01-01

    This paper is part of a larger research program on the causes of size-effect in structural concrete. The obtained results through the application of a nonlinear finite element analysis using material models extensive tested reliability, pointed out a possible connection between unintended out-of-plane actions and the ultimate strength of reinforced concrete (RC) structures, The computational analysis brought up unacceptable discrepancies only in those cases where possible unintended out-of-plane actions could not be negligible nor neutralized. Herein, it arises the need of experimental on such situations to inquire into the role played for those actions and. if they really were detected, to try to link them to some suitable parameters that would allow to take into account their presence in numerical analysis. (author). 13 refs., 4 figs., 3 tabs

  18. Modulation of the composite face effect by unintended emotion cues.

    Science.gov (United States)

    Gray, Katie L H; Murphy, Jennifer; Marsh, Jade E; Cook, Richard

    2017-04-01

    When upper and lower regions from different emotionless faces are aligned to form a facial composite, observers 'fuse' the two halves together, perceptually. The illusory distortion induced by task-irrelevant ('distractor') halves hinders participants' judgements about task-relevant ('target') halves. This composite-face effect reveals a tendency to integrate feature information from disparate regions of intact upright faces, consistent with theories of holistic face processing. However, observers frequently perceive emotion in ostensibly neutral faces, contrary to the intentions of experimenters. This study sought to determine whether this 'perceived emotion' influences the composite-face effect. In our first experiment, we confirmed that the composite effect grows stronger as the strength of distractor emotion increased. Critically, effects of distractor emotion were induced by weak emotion intensities, and were incidental insofar as emotion cues hindered image matching, not emotion labelling per se . In Experiment 2, we found a correlation between the presence of perceived emotion in a set of ostensibly neutral distractor regions sourced from commonly used face databases, and the strength of illusory distortion they induced. In Experiment 3, participants completed a sequential matching composite task in which half of the distractor regions were rated high and low for perceived emotion, respectively. Significantly stronger composite effects were induced by the high-emotion distractor halves. These convergent results suggest that perceived emotion increases the strength of the composite-face effect induced by supposedly emotionless faces. These findings have important implications for the study of holistic face processing in typical and atypical populations.

  19. The UFAIL Approach: Unconventional Technologies and Their "Unintended" Effects

    Science.gov (United States)

    Agler, David W.

    2010-01-01

    This essay presents the use-first-and-investigate-later (UFAIL) approach to technological use through two case studies: the atomic bomb in World War II and chemical defoliants during the Vietnam War. The methodology of UFAIL is as follows: despite limited understanding of an array of potential effects (medical, environmental, etc.), technology…

  20. Modulation of the composite face effect by unintended emotion cues

    OpenAIRE

    Gray, Katie L. H.; Murphy, Jennifer; Marsh, Jade E.; Cook, Richard

    2017-01-01

    When upper and lower regions from different emotionless faces are aligned to form a facial composite, observers ‘fuse’ the two halves together, perceptually. The illusory distortion induced by task-irrelevant (‘distractor’) halves hinders participants’ judgments about task-relevant (‘target’) halves. This composite-face effect reveals a tendency to integrate feature information from disparate regions of intact upright faces, consistent with theories of holistic face processing. However, obser...

  1. Lifecycle GHG emissions of palm biodiesel: Unintended market effects negate direct benefits of the Malaysian Economic Transformation Plan (ETP)

    International Nuclear Information System (INIS)

    Abdul-Manan, Amir F.N.

    2017-01-01

    Biodiesel expansion can lead to unintended effects that offset the direct GHG benefits of biofuels. Two documented unintended effects are the indirect land use change (ILUC) and indirect energy use change (IEUC). ILUC has been included in many lifecycle GHG studies of biofuels, but IEUC has remained relatively elusive. This paper presents an updated assessment of the lifecycle GHG emissions of palm biodiesel from Malaysia and, for the first time, incorporating the two estimated indirect effects simultaneously. Future GHG emissions of palm biodiesel are projected by taking into account of Malaysia's Economic Transformation Programme (ETP) that aims to reform the oil palm industry in order to achieve a high-income nation. Uncertainties associated with lifecycle GHG models were dealt with using Monte Carlo simulation in order to identify the breadth and likelihood of GHG reductions relative to petroleum-based fuels in the context of the European directives. This study has shown that the ETP, if successfully implemented, can significantly improve the direct GHG emissions of palm biodiesel, but the benefits are offset by the rise in global emissions due to ILUC and IEUC. Biofuel policies should also include IEUC, in addition to ILUC, to avoid GHG emissions leakages. - Highlights: • Estimate current and future lifecycle GHG emissions of Malaysian palm biodiesel. • Evaluate the GHG effects of Malaysia's Economic Transformation Plan (ETP). • Direct GHG benefits of biodiesel offset by indirect market effects. • Palm biodiesel unlikely to enable global GHG emissions reductions. • Global biofuel policy must account for indirect effects.

  2. Reward and attitudes: The unintended outcomes of an effective performance appraisal

    Directory of Open Access Journals (Sweden)

    Solomon M. Semakula-Katende

    2013-10-01

    Full Text Available Orientation: Focus was on the role of reward and attitudes as major determinants in enhancing the effectiveness of performance appraisal systems. Research purpose: To develop a structural model from the qualitative and quantitative findings from which to address the identified gaps in order to improve the effectiveness of appraisals. Motivation for the study: The attention that role players tended to give to the rewarding of employees during the appraisal process made it appear as the only important determinant of an appraisal’s success. In appraisals in many public institutions, reward has been given unnecessary prominence over other drivers, such as management and development. That led most key role players (leaders, managers and employees to perceive the current employee performance management and development system (EPMDS to be purely for monetary (salary increments and cash bonuses and non-monetary (promotion purposes, which, in turn, compromised its effectiveness. Research design, approach and method: Structural equation modelling (SEM was utilised as a statistical technique for testing and estimating causal relations using a combination of statistical data and qualitative causal assumptions. This allowed both confirmatory and exploratory modelling to be undertaken, which is suited to both theory testing and theory development. A triangulation of quantitative (questionnaire and qualitative (interview study was conducted. A total of 300 questionnaires were distributed to nine government hospitals in the Free State province, namely Mofumahadi Manapo Mopeli, Dihlabeng, and Boitumelo regional hospitals, as well as Elizabeth Ross, Thebe, Phekolong, Mpumelelo, Reitz and Ficksburg district hospitals. There was a high response rate of 96 per cent, a total of 287 completed questionnaires. Respondents ranged from top executives, middle management, line management, to employees of all categories. Main findings: Reward and attitudes were found to

  3. RNA-seq analysis of unintended effects in transgenic wheat overexpressing the transcription factor GmDREB1

    Directory of Open Access Journals (Sweden)

    Qiyan Jiang

    2017-06-01

    Full Text Available The engineering of plants with enhanced tolerance to abiotic stresses typically involves complex multigene networks and may therefore have a greater potential to introduce unintended effects than the genetic modification for simple monogenic traits. For this reason, it is essential to study the unintended effects in transgenic plants engineered for stress tolerance. We selected drought- and salt-tolerant transgenic wheat overexpressing the transcription factor, GmDREB1, to investigate unintended pleiotropic effects using RNA-seq analysis. We compared the transcriptome alteration of transgenic plants with that of wild-type plants subjected to salt stress as a control. We found that GmDREB1 overexpression had a minimal impact on gene expression under normal conditions. GmDREB1 overexpression resulted in transcriptional reprogramming of the salt response, but many of the genes with differential expression are known to mitigate salt stress and contribute incrementally to the enhanced stress tolerance of transgenic wheat. GmDREB1 overexpression did not activate unintended gene networks with respect to gene expression in the roots of transgenic wheat. This work is important for establishing a method of detecting unintended effects of genetic engineering and the safety of such traits with the development of marketable transgenic crops in the near future.

  4. Synergistic Effects of Unintended Pregnancy and Young Motherhood on Shaking and Smothering of Infants among Caregivers in Nagoya City, Japan

    Directory of Open Access Journals (Sweden)

    Aya Isumi

    2017-09-01

    Full Text Available BackgroundShaking and smothering in response to infant crying are forms of child abuse that often result in death. Unintended pregnancy and young motherhood are risk factors of such child maltreatment that are often comorbid, few studies have examined their synergistic effect on shaking and smothering of infants. We examined the synergistic effects of unintended pregnancy and young motherhood on shaking and smothering among caregivers of infants in Japan.MethodsIn this retrospective cohort study, a questionnaire was administered to caregivers enrolled for a health check for 3- to 4-month-old infants between October 2013 and February 2014 in Nagoya City, Japan. The questionnaire data were linked to those from pregnancy notification forms registered at municipalities and included information on women’s age and feelings about their pregnancy (N = 4,159. Data were analyzed using logistic regression analysis in 2016.ResultsShaking and smothering of 3- to 4-month-old infants occurred at least once in the past month in 2.0 and 1.5% of cases, respectively. Of all participants, 24.8% reported unintended pregnancy while 7.3% were younger than 25 years old. Infants of young mothers (under 25 years old with unintended pregnancy were 2.77 [95% confidence interval (CI: 1.15–6.68] and 5.61 (95% CI: 2.40–13.1 times more likely to be shaken and smothered, respectively, than those of older mothers with intended pregnancy. In addition, the odds ratio of young mothers with unintended pregnancy regarding smothering was significantly higher than that of older mothers with unintended pregnancy (odds ratio: 2.12; p = 0.02.ConclusionOur findings suggest a synergistic effect of unintended pregnancy and young motherhood on smothering. Infants of young mothers with unintended pregnancy are at greater risk of abuse, especially smothering. Prevention strategies are required for young women with unintended pregnancies.

  5. Joint Assessment of Intended and Unintended Effects of Medications: An Example Using Vascular Endothelial Growth Factor Inhibitors for Neovascular Age-Related Macular Degeneration

    Directory of Open Access Journals (Sweden)

    Adrian R. Levy

    2009-01-01

    Full Text Available Objective. To estimate the net health benefits of pegaptanib and ranibizumab by considering the impact of visual acuity and unintended effects (cardiovascular and hemorrhagic events on quality-of-life among persons with neovascular age-related macular degeneration. Methods. We designed a probabilistic decision-analytic model using published data. It employed 17 visual health states and three for unintended effects. We calculated incremental net health benefits by subtracting the harms of each medication from the benefit using the quality-adjusted life year (QALY. Results. In a hypothetical cohort of 1,000 75-year olds with new-onset bilateral age-related macular degeneration followed for ten years, the mean QALYs per patient is 3.7 for usual care, 4.2 for pegaptanib, and 4.3 for ranibizumab. Net benefits decline with increasing baseline rates of unintended effects. Interpretation. Net health benefits present a quantitative, potentially useful tool to assist patients and ophthalmologists in balancing the benefits and harms of interventions for age-related macular degeneration.

  6. The Unintended Consequences of School Inspection: The Prevalence of Inspection Side-Effects in Austria, The Czech Republic, England, Ireland, The Netherlands, Sweden, and Switzerland

    Science.gov (United States)

    Jones, Karen L.; Tymms, Peter; Kemethofer, David; O'Hara, Joe; McNamara, Gerry; Huber, Stephan; Myrberg, Eva; Skedsmo, Guri; Greger, David

    2017-01-01

    It has been widely documented that accountability systems, including school inspections, bring with them unintended side effects. These unintended effects are often negative and have the potential to undo the intended positive effects. However the empirical evidence is limited. Through a European comparative study we have had the rare opportunity…

  7. Measuring unintended effects in peacebuilding: What the field of international cooperation can learn from innovative approaches shaped by complex contexts.

    Science.gov (United States)

    Lemon, Adrienne; Pinet, Mélanie

    2018-06-01

    Capturing unintended impacts has been a persistent struggle in all fields of international development, and the field of peacebuilding is no exception. However, because peacebuilding focuses on relationships in complex contexts, the field of peacebuilding has, by necessity, made efforts towards finding practical ways to reflect upon both the intended and unintended effects of this work. To explore what lessons can be learned from the peacebuilding field, this study examines the evaluations of Search for Common Ground, a peacebuilding organisation working in over 35 countries across the world. Analysis focuses on 96 evaluations completed between 2013 and 2016 in 24 countries across Africa, Asia, and the MENA regions that found unintended effects. Programmes focusing on women, youth, and radio were most effective at identifying and explaining unintended effects, likely because the project design guided broader lines of questioning from the beginning. The paper argues that OECD-DAC guidelines are not enough on their own to guide evaluators into exploration of unintended effects, and teams instead need to work together to decide where, when and how they will look for them. Different approaches were also used to capture positive and negative outcomes, suggesting that evaluators need to decide at what level they are evaluating and how to tie effects back to the project's contribution. This study explores evaluation techniques and approaches used to understand impact in complex contexts in the peacebuilding field, and draws on lessons learned for the benefit of other fields dealing with similar complexities in international development and cooperation among actors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Safety of genetically engineered foods: approaches to assessing unintended health effects

    National Research Council Canada - National Science Library

    Committee on Identifying and Assessing Unintended Effects of Genetically Engineered Foods on Human Health, National Research Council

    2004-01-01

    .... It identifies and recommends several pre- and post-market approaches to guide the assessment of unintended compositional changes that could result from genetically modified foods and research avenues...

  9. Intended and unintended effects of restrictions on the sale of cigarillos to youth: evidence from Canada.

    Science.gov (United States)

    Nguyen, Hai V; Grootendorst, Paul

    2015-07-01

    Youth consumption of cigarillos (ie, little cigars) has increased markedly in recent years. In July 2010, the Canadian government banned the sale of flavoured cigarillos and required unflavoured cigarillos to be sold in packs of at least 20 units. This paper assesses changes in young persons' use of cigarillos and regular cigars, which are potential substitutes, following the policy. To investigate of the change in cigar smoking following the policy, we constructed a segmented regression model that allowed the policy to change the height and the slope of the trend in the outcome variables. The model was estimated using data from the 2007-2011 Canadian Tobacco Use Monitoring Surveys. We obtained visual and regression-based evidence that use of cigarillos among youth declined following the policy. We also found a small, gradual increase in their use of regular cigars, possibly due to their compensatory switching from cigarillos to regular cigars. Overall, there was a net reduction in cigar use among youth after the intervention. The policy achieved its goal of reducing youth's consumption of cigarillos, but may have an unintended consequence of increasing their use of regular cigars. Policymakers should address the possibility that youth switch to regular cigars in response to restricted access to cigarillos. Possible ways of discouraging this substituting behaviour include extending the ban to cover all flavoured cigars and mandating a minimum pack size for all cigars, or raising taxes on flavoured cigars. 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.

  10. Using Behavioral Economic Theory to Increase Use of Effective Contraceptives among Opioid-maintained Women at Risk of Unintended Pregnancy

    Science.gov (United States)

    Heil, Sarah H.; Hand, Dennis J.; Sigmon, Stacey C.; Badger, Gary J.; Meyer, Marjorie C.; Higgins, Stephen T.

    2016-01-01

    Objective An unsettling aspect of the US opioid epidemic is the high rate of in utero exposure, especially since most of these pregnancies are unintended, due in part to low rates of effective contraceptive use among opioid-using women. This study tested an intervention informed by behavioral economic theory and aimed at promoting effective contraceptive use among opioid-maintained women at risk of unintended pregnancy in the Burlington, VT area between 2011–2013. Methods Thirty-one women were assigned (initial 5 consecutively, subsequent 26 randomly) to either usual care or an experimental intervention. Participants in usual care received condoms, a dose of emergency contraception, and referral to local providers. Participants in the experimental condition received usual care plus the World Health Organization’s contraception initiation protocol, including free prescription contraceptives, and financial incentives for attending 13 follow-up visits over 6 months to help manage side effects and other issues. Results Significantly more women in the experimental vs. usual care control conditions initiated prescription contraceptive use (100% vs. 29%) and reported prescription contraceptive use at 1-month (63% vs. 13%), 3-month (88% vs. 20%), and 6-month (94% vs. 13%) assessments. None of the experimental condition participants became pregnant during the 6-month protocol vs. three women (20%) in the control condition. Conclusions These results provide the first experimental evidence supporting the efficacy of an intervention for increasing prescription contraceptive use among opioid-maintained women at risk of unintended pregnancy. PMID:27346756

  11. The Role of Ethnographic Interviewing in Climate Change Evaluation Research: Investigating Intended and Unintended program effects

    Science.gov (United States)

    Lloro-Bidart, T.

    2012-12-01

    Ethnographic interviewing is an under-utilized tool in climate change evaluation research, even though it has the potential to serve as a powerful method of data collection. The utility of the ethnographic interview lies in its ability to elicit responses from program participants describing what a program is in practice, shedding light on both intended and unintended program impacts. Drawing on evaluation work involving a federally-funded climate change grant at the University of California, Riverside, I will discuss how to design an ethnographic interview protocol in an effort to share "best practices" with other climate change evaluators. Particular attention will be given to applying ethnographic approaches to various program types, even those differing from the one discussed. I will share some of the concrete findings from my work on this grant, to serve as examples of the kinds of data evaluators can collect when employing an ethnographic approach to interviewing. UC Riverside's climate change grant is multi-faceted, however the component studied ethnographically was a science fair mentoring program. About twenty K-12 students from high poverty, ethnically diverse schools who expressed an interest in participating in science fair were paired up with graduate student mentors to simultaneously research climate change and design authentic science fair projects to compete at various levels. Since one of the stated goals of the grant is to "stimulate…students to consider climate science as a career track through experiential education activities" I was particularly interested in how student experiences with the project might differ from school science which has historically "pushed out" ethnically diverse students like those in many of Riverside's schools. (In the program students are able to interact one-on-one with a mentor and in school settings there is typically one teacher for more than thirty students). I also sought to understand student perceptions of

  12. Prevalence and determinants of unintended pregnancy among women in Nairobi, Kenya.

    Science.gov (United States)

    Ikamari, Lawrence; Izugbara, Chimaraoke; Ochako, Rhoune

    2013-03-19

    The prevalence of unintended pregnancy in Kenya continues to be high. The 2003 Kenya Demographic and Health Survey (KDHS) showed that nearly 50% of unmarried women aged 15-19 and 45% of the married women reported their current pregnancies as mistimed or unwanted. The 2008-09 KDHS showed that 43% of married women in Kenya reported their current pregnancies were unintended. Unintended pregnancy is one of the most critical factors contributing to schoolgirl drop out in Kenya. Up to 13,000 Kenyan girls drop out of school every year as a result of unintended pregnancy. Unsafe pregnancy termination contributes immensely to maternal mortality which currently estimated at 488 deaths per 100 000 live births. In Kenya, the determinants of prevalence and determinants of unintended pregnancy among women in diverse social and economic situations, particularly in urban areas, are poorly understood due to lack of data. This paper addresses the prevalence and the determinants of unintended pregnancy among women in slum and non-slum settlements of Nairobi. This study used the data that was collected among a random sample of 1262 slum and non-slum women aged 15-49 years in Nairobi. The data was analyzed using simple percentages and logistic regression. The study found that 24 percent of all the women had unintended pregnancy. The prevalence of unintended pregnancy was 21 per cent among women in slum settlements compared to 27 per cent among those in non-slum settlements. Marital status, employment status, ethnicity and type of settlement were significantly associated with unintended pregnancy. Logistic analysis results indicate that age, marital status and type of settlement had statistically significantly effects on unintended pregnancy. Young women aged 15-19 were significantly more likely than older women to experience unintended pregnancy. Similarly, unmarried women showed elevated risk for unintended pregnancy than ever-married women. Women in non-slum settlements were

  13. Socioeconomic Status As a Risk Factor for Unintended Pregnancy in the Contraceptive CHOICE Project.

    Science.gov (United States)

    Iseyemi, Abigail; Zhao, Qiuhong; McNicholas, Colleen; Peipert, Jeffrey F

    2017-09-01

    To evaluate the association of low socioeconomic status as an independent risk factor for unintended pregnancy. We performed a secondary analysis of data from the Contraceptive CHOICE project. Between 2007 and 2011, 9,256 participants were recruited and followed for up to 3 years. The primary outcome of interest was unintended pregnancy; the primary exposure variable was low socioeconomic status, defined as self-report of either receiving public assistance or having difficulty paying for basic necessities. Four contraceptive groups were evaluated: 1) long-acting reversible contraceptive method (hormonal or copper intrauterine device or subdermal implant); 2) depot medroxyprogesterone acetate injection; 3) oral contraceptive pills, a transdermal patch, or a vaginal ring; or 4) other or no method. Confounders were adjusted for in the multivariable Cox proportional hazard model to estimate the effect of socioeconomic status on risk of unintended pregnancy. Participants with low socioeconomic status experienced 515 unintended pregnancies during 14,001 women-years of follow-up (3.68/100 women-years; 95% CI 3.37-4.01) compared with 200 unintended pregnancies during 10,296 women-years (1.94/100 women-years; 95% CI 1.68-2.23) among participants without low socioeconomic status. Women with low socioeconomic status were more likely to have an unintended pregnancy (unadjusted hazard ratio [HR] 1.8, 95% CI 1.5-2.2). After adjusting for age, education level, insurance status, and history of unintended pregnancy, low socioeconomic status was associated with an increased risk of unintended pregnancy (adjusted HR 1.4, 95% CI 1.1-1.7). Despite the removal of cost barriers, low socioeconomic status is associated with a higher incidence of unintended pregnancy.

  14. Unintended outcomes evaluation approach: A plausible way to evaluate unintended outcomes of social development programmes.

    Science.gov (United States)

    Jabeen, Sumera

    2018-06-01

    Social development programmes are deliberate attempts to bring about change and unintended outcomes can be considered as inherent to any such intervention. There is now a solid consensus among the international evaluation community regarding the need to consider unintended outcomes as a key aspect in any evaluative study. However, this concern often equates to nothing more than false piety. Exiting evaluation theory suffers from overlap of terminology, inadequate categorisation of unintended outcomes and lack of guidance on how to study them. To advance the knowledge of evaluation theory, methods and practice, the author has developed an evaluation approach to study unintended effects using a theory building, testing and refinement process. A comprehensive classification of unintended outcomes on the basis of knowability, value, distribution and temporality helped specify various type of unintended outcomes for programme evaluation. Corresponding to this classification, a three-step evaluation process was proposed including a) outlining programme intentions b) forecasting likely unintended effects c) mapping the anticipated and understanding unanticipated unintended outcomes. This unintended outcomes evaluation approach (UOEA) was then trialled by undertaking a multi-site and multi-method case study of a poverty alleviation programme in Pakistan and refinements were made to the approach.The case study revealed that this programme was producing a number of unintended effects, mostly negative, affecting those already disadvantaged such as the poorest, women and children. The trialling process demonstrated the effectiveness of the UOEA and suggests that this can serve as a useful guide for future evaluation practice. It also provides the discipline of evaluation with an empirically-based reference point for further theoretical developments in the study of unintended outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Unintended Consequences: Effects of Paternal Incarceration on Child School Readiness and Later Special Education Placement

    Directory of Open Access Journals (Sweden)

    Anna R Haskins

    2014-04-01

    Full Text Available Though sociologists have examined how mass incarceration affects stratification, remarkably little is known about how it shapes educational disparities. Analyzing the Fragile Families Study and its rich paternal incarceration data, I ask whether black and white children with fathers who have been incarcerated are less prepared for school both cognitively and non-cognitively as a result, and whether racial and gendered disparities in incarceration help explain the persistence of similar gaps in educational outcomes and trajectories. Using a variety of estimation strategies, I show that experiencing paternal incarceration by age five is associated with lower non-cognitive school readiness. While the main effect of incarceration does not vary by race, boys with incarcerated fathers have substantially worse non-cognitive skills at school entry, impacting the likelihood of special education placement at age nine. Mass incarceration facilitates the intergenerational transmission of male behavioral disadvantage, and because of the higher exposure of black children to incarceration, it also plays a role in explaining the persistently low achievement of black boys.

  16. Unintended Consequences: Effects of Paternal Incarceration on Child School Readiness and Later Special Education Placement.

    Science.gov (United States)

    Haskins, Anna R

    2014-04-01

    Though sociologists have examined how mass incarceration affects stratification, remarkably little is known about how it shapes educational disparities. Analyzing the Fragile Families Study and its rich paternal incarceration data, I ask whether black and white children with fathers who have been incarcerated are less prepared for school both cognitively and non-cognitively as a result, and whether racial and gendered disparities in incarceration help explain the persistence of similar gaps in educational outcomes and trajectories. Using a variety of estimation strategies, I show that experiencing paternal incarceration by age five is associated with lower non-cognitive school readiness. While the main effect of incarceration does not vary by race, boys with incarcerated fathers have substantially worse non-cognitive skills at school entry, impacting the likelihood of special education placement at age nine. Mass incarceration facilitates the intergenerational transmission of male behavioral disadvantage, and because of the higher exposure of black children to incarceration, it also plays a role in explaining the persistently low achievement of black boys.

  17. The unintended consequences of maternity leaves: How agency interventions mitigate the negative effects of longer legislated maternity leaves.

    Science.gov (United States)

    Hideg, Ivona; Krstic, Anja; Trau, Raymond N C; Zarina, Tanya

    2018-06-07

    To support women in the workplace, longer legislated maternity leaves have been encouraged in Scandinavian countries and recently in Canada. Yet, past research shows that longer legislated maternity leaves (i.e., 1 year and longer) may unintentionally harm women's career progress. To address this issue, we first sought to identify one potential mechanism underlying negative effects of longer legislated maternity leaves: others' lower perceptions of women's agency. Second, we utilize this knowledge to test interventions that boost others' perceptions of women's agency and thus mitigate negative effects of longer legislated maternity leaves. We test our hypotheses in three studies in the context of Canadian maternity leave policies. Specifically, in Study 1, we found that others' lower perceptions of women's agency mediated the negative effects of a longer legislated maternity leave, that is, 1 year (vs. shorter, i.e., 1 month maternity leave) on job commitment. In Study 2, we found that providing information about a woman's agency mitigates the unintended negative effects of a longer legislated maternity leave on job commitment and hireability. In Study 3, we showed that use of a corporate program that enables women to stay in touch with the workplace while on maternity leave (compared to conditions in which no such program was offered; a program was offered but not used by the applicant; and the program was offered, but there was no information about its usage by the applicant) enhances agency perceptions and perceptions of job commitment and hireability. Implications for theory and practice are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  18. The Unintended Hegemonic Effects of a Limited Concession: Institutional Incorporation of Chinese Schools in Post-War Hong Kong

    Science.gov (United States)

    Wong, Ting-Hong

    2012-01-01

    Using the case of Chinese schools in post-Second World War Hong Kong, this paper explores the unintended consequences of an incomplete hegemonic project. After World War II, anti-imperialist pressures and rising educational demands in the local setting propelled the colonial authorities to be more active in providing and funding Chinese schools.…

  19. The Irish Cost-Effectiveness Threshold: Does it Support Rational Rationing or Might it Lead to Unintended Harm to Ireland's Health System?

    Science.gov (United States)

    O'Mahony, James F; Coughlan, Diarmuid

    2016-01-01

    Ireland is one of the few countries worldwide to have an explicit cost-effectiveness threshold. In 2012, an agreement between government and the pharmaceutical industry that provided substantial savings on existing medications set the threshold at €45,000/quality-adjusted life-year (QALY). This replaced a previously unofficial threshold of €20,000/QALY. According to the agreement, drugs within the threshold will be granted reimbursement, whereas those exceeding it may still be approved following further negotiation. A number of drugs far exceeding the threshold have been approved recently. The agreement only applies to pharmaceuticals. There are four reasons for concern regarding Ireland's threshold. The absence of an explicit threshold for non-drug interventions leaves it unclear if there is parity in willingness to pay across all interventions. As the threshold resembles a price floor rather than a ceiling, in principle it only offers a weak barrier to cost-ineffective interventions. It has no empirical basis. Finally, it is probably too high given recent estimates of a threshold for the UK based on the cost effectiveness of services forgone of approximately £13,000/QALY. An excessive threshold risks causing the Irish health system unintended harm. The lack of an empirically informed threshold means the policy recommendations of cost-effectiveness analysis cannot be considered as fully evidence- based rational rationing. Policy makers should consider these issues and recent Irish legislation that defined cost effectiveness in terms of the opportunity cost of services forgone when choosing what threshold to apply once the current industry agreement expires at the end of 2015

  20. Approaches for predicting effects of unintended environmental exposure to an endocrine active pharmaceutical, tamoxifen

    Science.gov (United States)

    Tamoxifen is an endocrine-active pharmaceutical (EAP) that is used world-wide. Because tamoxifen is a ubiquitous pharmaceutical and interacts with estrogen receptors, a case study was conducted with this compound to (1) determine effects on reproductive endpoints in a nontarget s...

  1. Unintended pregnancy and sex education in Chile: a behavioural model.

    Science.gov (United States)

    Herold, J M; Thompson, N J; Valenzuela, M S; Morris, L

    1994-10-01

    This study analysed factors associated with unintended pregnancy among adolescent and young adult women in Santiago, Chile. Three variations of a behavioural model were developed. Logistic regression showed that the effect of sex education on unintended pregnancy works through the use of contraception. Other significant effects were found for variables reflecting socioeconomic status and a woman's acceptance of her sexuality. The results also suggested that labelling affects measurement of 'unintended' pregnancy.

  2. Unintended Side Effects of Conservation: A Case Study of Changing Land Use in Jiuzhaigou, Sichuan, China

    Directory of Open Access Journals (Sweden)

    Amanda H. Schmidt

    2017-02-01

    Full Text Available Toward the goals of returning the landscape of Jiuzhaigou National Nature Reserve to a perceived “natural” state and protecting the environment, the Reserve in 1998–2002 implemented forest preservation policies that included restrictions on forestry, agriculture, and animal herding practiced by resident Tibetans. To document the effects of these land use changes on landscape diversity and on human vulnerability to natural hazards, we mapped and characterized topographic parameters of anthropogenic treeless areas from 1973, 2004, and 2013 satellite images. Results showed that, in addition to a previously documented overall loss of cleared land, the distribution of treeless area elevation, aspect, and slope has changed. In 1973, treeless areas were distributed approximately uniformly across all elevations and a wide range of slopes, but now they are concentrated on relatively flat slopes in the valley bottoms (∼2400 m and high, subalpine elevations (∼3800 m. These changes are decreasing the topographic diversity of landscapes people use and likely also decreasing the biodiversity of the Reserve, where plant communities are highly stratified based on both elevation and aspect. In addition, many 1973 treeless areas were located on deep-seated landslides, while many 2004 and 2013 treeless areas were located on landslide deposits and alluvial fans, suggesting that relocation may not be reducing the risk of natural hazards for residents. These effects combine with the previously documented decline in overall area of montane meadows and associated losses to cultural heritage, ecosystem services, and biodiversity.

  3. An empirical review of major legislation affecting drug development: past experiences, effects, and unintended consequences.

    Science.gov (United States)

    Kesselheim, Aaron S

    2011-09-01

    With the development of transformative drugs at a low point, numerous commentators have recommended new legislation that uses supplementary market exclusivity as an incentive to promote innovation in the pharmaceutical market. This report provides an historical perspective on proposals for encouraging drug research. Four legislative programs have been primarily designed to offer market exclusivity to promote public health goals in the pharmaceutical or biomedical sciences: the Bayh-Dole Act of 1980, the Orphan Drug Act of 1983, the Hatch-Waxman Act of 1984, and the pediatric exclusivity provisions of the FDA Modernization Act of 1997. I reviewed quantitative and qualitative studies that reported on the outcomes from these programs and evaluated the quality of evidence generated. All four legislative programs generally have been regarded as successful, although such conclusions are largely based on straightforward descriptive reports rather than on more rigorous comparative data or analyses that sufficiently account for confounding. Overall, solid data demonstrate that market exclusivity incentives can attract interest from parties involved in drug development. However, using market exclusivity to promote innovation in the pharmaceutical market can be prone to misuse, leading to improper gains. In addition, important collateral effects have emerged with substantial negative public health implications. Using market exclusivity to promote pharmaceutical innovation can lead to positive outcomes, but the practice is also characterized by waste and collateral effects. Certain practices, such as mechanisms for reevaluation and closer ties of incentives programs to public health outcomes, can help address these problems. © 2011 Milbank Memorial Fund. Published by Wiley Periodicals Inc.

  4. Unintended effects of emphasizing disparities in cancer communication to African-Americans.

    Science.gov (United States)

    Nicholson, Robert A; Kreuter, Matthew W; Lapka, Christina; Wellborn, Rachel; Clark, Eddie M; Sanders-Thompson, Vetta; Jacobsen, Heather M; Casey, Chris

    2008-11-01

    Little is known about how minority groups react to public information that highlights racial disparities in cancer. This double-blind randomized study compared emotional and behavioral reactions to four versions of the same colon cancer (CRC) information presented in mock news articles to a community sample of African-American adults (n = 300). Participants read one of four articles that varied in their framing and interpretation of race-specific CRC mortality data, emphasizing impact (CRC is an important problem for African-Americans), two dimensions of disparity (Blacks are doing worse than Whites and Blacks are improving, but less than Whites), or progress (Blacks are improving over time). Participants exposed to disparity articles reported more negative emotional reactions to the information and were less likely to want to be screened for CRC than those in other groups (both P emotional reactions and participants were more likely to want to be screened. Moreover, negative emotional reaction seemed to mediate the influence of message type on individuals wanting to be screened for CRC. Overall, these results suggest that the way in which disparity research is reported in the medium can influence public attitudes and intentions, with reports about progress yielding a more positive effect on intention. This seems especially important among those with high levels of medical mistrust who are least likely to use the health care system and are thus the primary target of health promotion advertising.

  5. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions.

    Directory of Open Access Journals (Sweden)

    John Y Takekawa

    Full Text Available Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus, and chick survival of Forster's Tern (Sterna forsteri. Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction

  6. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions

    Science.gov (United States)

    Takekawa, John Y.; Ackerman, Joshua T.; Brand, Arriana; Graham, Tanya R.; Eagles-Smith, Collin A.; Herzog, Mark; Topping, Brent R.; Shellenbarger, Gregory; Kuwabara, James S.; Mruz, Eric; Piotter, Sara L.; Athearn, Nicole D.

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  7. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions.

    Science.gov (United States)

    Takekawa, John Y; Ackerman, Joshua T; Brand, L Arriana; Graham, Tanya R; Eagles-Smith, Collin A; Herzog, Mark P; Topping, Brent R; Shellenbarger, Gregory G; Kuwabara, James S; Mruz, Eric; Piotter, Sara L; Athearn, Nicole D

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  8. Unintended Side Effects of the Digital Transition: European Scientists’ Messages from a Proposition-Based Expert Round Table

    Directory of Open Access Journals (Sweden)

    Roland W. Scholz

    2018-06-01

    Full Text Available We present the main messages of a European Expert Round Table (ERT on the unintended side effects (unseens of the digital transition. Seventeen experts provided 42 propositions from ten different perspectives as input for the ERT. A full-day ERT deliberated communalities and relationships among these unseens and provided suggestions on (i what the major unseens are; (ii how rebound effects of digital transitioning may become the subject of overarching research; and (iii what unseens should become subjects of transdisciplinary theory and practice processes for developing socially robust orientations. With respect to the latter, the experts suggested that the “ownership, economic value, use and access of data” and, related to this, algorithmic decision-making call for transdisciplinary processes that may provide guidelines for key stakeholder groups on how the responsible use of digital data can be developed. A cluster-based content analysis of the propositions, the discussion and inputs of the ERT, and a theoretical analysis of major changes to levels of human systems and the human–environment relationship resulted in the following greater picture: The digital transition calls for redefining economy, labor, democracy, and humanity. Artificial Intelligence (AI-based machines may take over major domains of human labor, reorganize supply chains, induce platform economics, and reshape the participation of economic actors in the value chain. (Digital Knowledge and data supplement capital, labor, and natural resources as major economic variables. Digital data and technologies lead to a post-fuel industry (post- capitalism. Traditional democratic processes can be (intentionally or unintentionally altered by digital technologies. The unseens in this field call for special attention, research and management. Related to the conditions of ontogenetic and phylogenetic development (humanity, the ubiquitous, global, increasingly AI-shaped interlinkage of

  9. Abortion Incidence and Unintended Pregnancy in Nepal.

    Science.gov (United States)

    Puri, Mahesh; Singh, Susheela; Sundaram, Aparna; Hussain, Rubina; Tamang, Anand; Crowell, Marjorie

    2016-12-01

    Although abortion has been legal under broad criteria in Nepal since 2002, a significant proportion of women continue to obtain illegal, unsafe abortions, and no national estimates exist of the incidence of safe and unsafe abortions. Data were collected in 2014 from a nationally representative sample of 386 facilities that provide legal abortions or postabortion care and a survey of 134 health professionals knowledgeable about abortion service provision. Facility caseloads and indirect estimation techniques were used to calculate the national and regional incidence of legal and illegal abortion. National and regional levels of abortion complications and unintended pregnancy were also estimated. In 2014, women in Nepal had 323,100 abortions, of which 137,000 were legal, and 63,200 women were treated for abortion complications. The abortion rate was 42 per 1,000 women aged 15-49, and the abortion ratio was 56 per 100 live births. The abortion rate in the Central region (59 per 1,000) was substantially higher than the national average. Overall, 50% of pregnancies were unintended, and the unintended pregnancy rate was 68 per 1,000 women of reproductive age. Despite legalization of abortion and expansion of services in Nepal, unsafe abortion is still common and exacts a heavy toll on women. Programs and policies to reduce rates of unintended pregnancy and unsafe abortion, increase access to high-quality contraceptive care and expand safe abortion services are warranted.

  10. Unintended inhalation of nitric oxide by contamination of compressed air: physiologic effects and interference with intended nitric oxide inhalation in acute lung injury.

    Science.gov (United States)

    Benzing, A; Loop, T; Mols, G; Geiger, K

    1999-10-01

    Compressed air from a hospital's central gas supply may contain nitric oxide as a result of air pollution. Inhaled nitric oxide may increase arterial oxygen tension and decrease pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. Therefore, the authors wanted to determine whether unintentional nitric oxide inhalation by contamination of compressed air influences arterial oxygen tension and pulmonary vascular resistance and interferes with the therapeutic use of nitric oxide. Nitric oxide concentrations in the compressed air of a university hospital were measured continuously by chemiluminescence during two periods (4 and 2 weeks). The effects of unintended nitric oxide inhalation on arterial oxygen tension (n = 15) and on pulmonary vascular resistance (n = 9) were measured in patients with acute lung injury and acute respiratory distress syndrome by changing the source of compressed air of the ventilator from the hospital's central gas supply to a nitric oxide-free gas tank containing compressed air. In five of these patients, the effects of an additional inhalation of 5 ppm nitric oxide were evaluated. During working days, compressed air of the hospital's central gas supply contained clinically effective nitric oxide concentrations (> 80 parts per billion) during 40% of the time. Change to gas tank-supplied nitric oxide-free compressed air decreased the arterial oxygen tension by 10% and increased pulmonary vascular resistance by 13%. The addition of 5 ppm nitric oxide had a minimal effect on arterial oxygen tension and pulmonary vascular resistance when added to hospital-supplied compressed air but improved both when added to tank-supplied compressed air. Unintended inhalation of nitric oxide increases arterial oxygen tension and decreases pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. The unintended nitric oxide inhalation interferes with the

  11. Unintended pregnancy in the amazon basin of Ecuador: a multilevel analysis

    Directory of Open Access Journals (Sweden)

    San Sebastian Miguel

    2010-06-01

    Full Text Available Abstract Background It has been estimated that each year 80 million women in the world experience an unintended pregnancy. In Ecuador, recent research has revealed that 36.3% of total births are unintended; the research also details significant geographical, ethnic and socioeconomic variations. These studies focused on individual risk factors and were based on large national surveys where local samples, particularly from rural remote areas, were small. The purpose of this study was to investigate the influence of contextual and individual factors on unintended pregnancies in the Amazon Basin of Ecuador. Methods Women aged 15-44 were selected through an ongoing community-based cross-sectional survey conducted in the Orellana province between May and December 2006. Data were fitted using multilevel logistic regression, adjusting for both individual-level and community-level factors as fixed effects and allowing for heterogeneity between communities. Results The overall prevalence of unintended pregnancy was 62.7%. Two-thirds (73.7% of indigenous women reported having had at least one unintended pregnancy. Being young, single, and indigenous were significant risk factors for unintended pregnancy, alongside having low access to education and having more than two children. No relationship was found between socioeconomic status and the use of contraceptives. All the variation between communities was explained by individual-level factors. Conclusions This study showed the significance of individual factors in increasing the risk of unintended pregnancy, while the role of community factors was found to be negligible. In order for all women to be able to realize their right to reproductive autonomy, there needs to be a diverse range of solutions, with particular attention paid to cultural issues.

  12. Contraceptive use and risk of unintended pregnancy in California.

    Science.gov (United States)

    Foster, Diana G; Bley, Julia; Mikanda, John; Induni, Marta; Arons, Abigail; Baumrind, Nikki; Darney, Philip D; Stewart, Felicia

    2004-07-01

    California is home to more than one out of eight American women of reproductive age. Because California has a large, diverse and growing population, national statistics do not necessarily describe the reproductive health of California women. This article presents risk for pregnancy and sexually transmitted infections among women in California based on the California Women's Health Survey. Over 8900 women of reproductive age who participated in this survey between 1998 and 2001 provide estimates of access to care and use of family-planning methods in the state. We find that 49% of the female population aged 18-44 in California is at risk of unintended pregnancy. Nine percent (9%) of women at risk of an unintended pregnancy are not using any method of contraception, primarily for method-related reasons, such as a concern about side effects or a dislike of available contraceptive methods. Among women at risk for unintended pregnancy, we find disparities by race/ethnicity and education in use of contraceptive methods.

  13. Intended and Unintended Effects of State-Mandated High School Science and Mathematics Course Graduation Requirements on Educational Attainment.

    Science.gov (United States)

    Plunk, Andrew D; Tate, William F; Bierut, Laura J; Grucza, Richard A

    2014-06-01

    Mathematics and science course graduation requirement (CGR) increases in the 1980s and 1990s might have had both intended and unintended consequences. Using logistic regression with Census and American Community Survey (ACS) data ( n = 2,892,444), we modeled CGR exposure on (a) high school dropout, (b) beginning college, and (c) obtaining any college degree. Possible between-groups differences were also assessed. We found that higher CGRs were associated with higher odds to drop out of high school, but results for the college-level outcomes varied by group. Some were less likely to enroll, whereas others who began college were more likely to obtain a degree. Increased high school dropout was consistent across the population, but some potential benefit was also observed, primarily for those reporting Hispanic ethnicity.

  14. Decisions and their unintended consequences

    Energy Technology Data Exchange (ETDEWEB)

    Mavrodiev, P.

    2014-07-01

    All individuals who live in groups, whether they be humans or animals, rely on collective decision-making to establish and sustain viable social organisations. While the benefits of effective collective decisions are widely recognised (e.g. functioning democracies), it is the unexpected collective effects of many individual decisions that deserve attention, as they bear far-reaching consequences for our social lives. Drawing from diverse contexts, this thesis presents examples of such unintended effects and, in the spirit of complex systems, offers a way by which we can understand these effects and, sometimes, use them to our advantage. In the first part, we focus on contemporary decision-making scenarios in human societies. How does social influence affect collective decisions and can we control its effects? How can we use social herding as a mechanism to promote cooperation without explicit enforcement? Under what conditions can user actions, innocuous at first sight, cause the collapse of an online community? Using formal tools and agent-based models, we study the interaction mechanisms underlying the complexity inherent in these questions. In the second part, we shift our focus to the mitigation of unintended negative consequences. We study two colonies of Bechtein bats, whose survival is predicated on solving a coordination problem under limited information. We follow up on existing field work and apply concepts from network theory to reveal the individual contribution in maintaining the needed group cohesion. Finally, we combine agent-based modelling and network analysis to infer simple interaction rules that reproduce the observed collective coordination. We emphasise that these mechanistic rules can serve as a guide for the design of future experimental studies on collective-decision making in Bechstein bats. (author)

  15. Decisions and their unintended consequences

    International Nuclear Information System (INIS)

    Mavrodiev, P.

    2014-01-01

    All individuals who live in groups, whether they be humans or animals, rely on collective decision-making to establish and sustain viable social organisations. While the benefits of effective collective decisions are widely recognised (e.g. functioning democracies), it is the unexpected collective effects of many individual decisions that deserve attention, as they bear far-reaching consequences for our social lives. Drawing from diverse contexts, this thesis presents examples of such unintended effects and, in the spirit of complex systems, offers a way by which we can understand these effects and, sometimes, use them to our advantage. In the first part, we focus on contemporary decision-making scenarios in human societies. How does social influence affect collective decisions and can we control its effects? How can we use social herding as a mechanism to promote cooperation without explicit enforcement? Under what conditions can user actions, innocuous at first sight, cause the collapse of an online community? Using formal tools and agent-based models, we study the interaction mechanisms underlying the complexity inherent in these questions. In the second part, we shift our focus to the mitigation of unintended negative consequences. We study two colonies of Bechtein bats, whose survival is predicated on solving a coordination problem under limited information. We follow up on existing field work and apply concepts from network theory to reveal the individual contribution in maintaining the needed group cohesion. Finally, we combine agent-based modelling and network analysis to infer simple interaction rules that reproduce the observed collective coordination. We emphasise that these mechanistic rules can serve as a guide for the design of future experimental studies on collective-decision making in Bechstein bats. (author)

  16. Estimation of morbidity effects

    International Nuclear Information System (INIS)

    Ostro, B.

    1994-01-01

    Many researchers have related exposure to ambient air pollution to respiratory morbidity. To be included in this review and analysis, however, several criteria had to be met. First, a careful study design and a methodology that generated quantitative dose-response estimates were required. Therefore, there was a focus on time-series regression analyses relating daily incidence of morbidity to air pollution in a single city or metropolitan area. Studies that used weekly or monthly average concentrations or that involved particulate measurements in poorly characterized metropolitan areas (e.g., one monitor representing a large region) were not included in this review. Second, studies that minimized confounding ad omitted variables were included. For example, research that compared two cities or regions and characterized them as 'high' and 'low' pollution area were not included because of potential confounding by other factors in the respective areas. Third, concern for the effects of seasonality and weather had to be demonstrated. This could be accomplished by either stratifying and analyzing the data by season, by examining the independent effects of temperature and humidity, and/or by correcting the model for possible autocorrelation. A fourth criterion for study inclusion was that the study had to include a reasonably complete analysis of the data. Such analysis would include an careful exploration of the primary hypothesis as well as possible examination of te robustness and sensitivity of the results to alternative functional forms, specifications, and influential data points. When studies reported the results of these alternative analyses, the quantitative estimates that were judged as most representative of the overall findings were those that were summarized in this paper. Finally, for inclusion in the review of particulate matter, the study had to provide a measure of particle concentration that could be converted into PM10, particulate matter below 10

  17. Renal denervation and hypertension - The need to investigate unintended effects and neural control of the human kidney.

    Science.gov (United States)

    Grisk, Olaf

    2017-05-01

    Increased renal sympathetic nerve activity (RSNA) is present in human and experimental forms of arterial hypertension. Experimental denervation studies showed that renal nerves contribute to the development of hypertension. Clinical trials provided equivocal results on the antihypertensive efficacy of renal denervation in patients spurring discussions on technical aspects of renal denervation and further research on the role of renal nerves for the regulation of kidney function as well as the pathophysiology of hypertension. This review summarizes recent findings on adrenoceptor expression and function in the human kidney, adrenoceptor-dependent regulation of sodium chloride transport in the distal nephron, experimental data on chronic RSNA and the development of high arterial pressure and consequences of renal denervation that may limit its antihypertensive efficacy. Future research needs to reduce the gap between our knowledge on neural control of renal function in animals vs. humans to facilitate translation of experimental animal data to humans. More experimental studies on the temporal relationship between RSNA and arterial pressure in the chronic setting are needed to better define the pathogenetic role of heightened RSNA in different forms of arterial hypertension in order to improve the rational basis for renal denervation in antihypertensive therapy. Finally, research on unintended consequences of renal denervation including but not limited to reinnervation and denervation supersensitivity needs to be intensified to further assess the potential of renal denervation to slow the progression of renal disease and hypertension. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Prevention of unintended pregnancies in Nigeria; the effect of socio-demographic characteristic on the knowledge and use of emergency contraceptives among female university students

    OpenAIRE

    Olumide A. Abiodun; John Sotunsa; Olusoji Jagun; Bukola Faturoti; Franklin Ani; Imaralu John; Agboola Taiwo; Ogechukwu Taiwo

    2015-01-01

    Background: The proportion of unintended pregnancy remains high in developing regions due to unmet need for contraception and inconsistent use of modern contraceptives. Practice of emergency contraception is particularly important because of the high rates of unintended pregnancy. The aim was to assess the practice of emergency contraception among female students. Methods: A cross-sectional study was conducted among 5,233 female university students in Nigeria. Results: About 25.4% of th...

  19. Unintended effects of a Phytophtora-resistant cisgenic potato clone on the potato aphid Macrosiphum euphorbiae and its parasitoid Aphidius ervi

    NARCIS (Netherlands)

    Cascone, P.; Radkova, M.; Arpaia, S.; Errico, S.; Lotz, L.A.P.; Magarelli, R.A.; Djilianov, D.; Guerrieri, E.

    2018-01-01

    Genetically modified (GM) plants may show unintended differences compared to the original varieties, due to the modification process. Such differences might in some cases affect non-target organisms linked to the crop into an agro-ecosystem. In this paper, we aimed to study interactions of two

  20. Unintended consequences of biofuels production?The effects of large-scale crop conversion on water quality and quantity

    Science.gov (United States)

    Welch, Heather L.; Green, Christopher T.; Rebich, Richard A.; Barlow, Jeannie R.B.; Hicks, Matthew B.

    2010-01-01

    In the search for renewable fuel alternatives, biofuels have gained strong political momentum. In the last decade, extensive mandates, policies, and subsidies have been adopted to foster the development of a biofuels industry in the United States. The Biofuels Initiative in the Mississippi Delta resulted in a 47-percent decrease in cotton acreage with a concurrent 288-percent increase in corn acreage in 2007. Because corn uses 80 percent more water for irrigation than cotton, and more nitrogen fertilizer is recommended for corn cultivation than for cotton, this widespread shift in crop type has implications for water quantity and water quality in the Delta. Increased water use for corn is accelerating water-level declines in the Mississippi River Valley alluvial aquifer at a time when conservation is being encouraged because of concerns about sustainability of the groundwater resource. Results from a mathematical model calibrated to existing conditions in the Delta indicate that increased fertilizer application on corn also likely will increase the extent of nitrate-nitrogen movement into the alluvial aquifer. Preliminary estimates based on surface-water modeling results indicate that higher application rates of nitrogen increase the nitrogen exported from the Yazoo River Basin to the Mississippi River by about 7 percent. Thus, the shift from cotton to corn may further contribute to hypoxic (low dissolved oxygen) conditions in the Gulf of Mexico.

  1. Processing of intended and unintended strategic issues and integration into the strategic agenda.

    Science.gov (United States)

    Ridder, Hans-Gerd; Schrader, Jan Simon

    2017-11-01

    Strategic change is needed in hospitals due to external and internal pressures. However, research on strategic change, as a combination of management and medical expertise in hospitals, remains scarce. We analyze how intended strategic issues are processed into deliberate strategies and how unintended strategic issues are processed into emergent strategies in the management of strategy formation in hospitals. This study empirically investigates the integration of medical and management expertise in strategy formation. The longitudinal character of the case study enabled us to track patterns of intended and unintended strategic issues over 2 years. We triangulated data from interviews, observations, and documents. In accordance with the quality standards of qualitative research procedures, we analyzed the data by pattern matching and provided analytical generalization regarding strategy formation in hospitals. Our findings suggest that strategic issues are particularly successful within the strategy formation process if interest groups are concerned with the strategic issue, prospective profits are estimated, and relevant decisions makers are involved early on. Structure and interaction processes require clear criteria and transparent procedures for effective strategy formation. There is systematic neglect of medical expertise in processes of generating strategies. Our study reveals that the decentralized structure of medical centers is an adequate template for both the operationalization of intended strategic issues and the development of unintended strategic issues. However, tasks, roles, responsibility, resources, and administrative support are necessary for effective management of strategy formation. Similarly, criteria, procedures, and decision-making are prerequisites for effective strategy formation.

  2. Metabolite profiling of tomato (Lycopersicon esculentum) using 1H NMR spectroscopy as a tool to detect potential unintended effects following a genetic modification.

    Science.gov (United States)

    Le Gall, Gwénaëlle; Colquhoun, Ian J; Davis, Adrienne L; Collins, Geoff J; Verhoeyen, Martine E

    2003-04-23

    The maize transcription factors LC and C1 were simultaneously overexpressed in tomato with the aim of producing lines with increased amounts of flavonols. The metabolite composition of these genetically modified tomatoes has been compared with that of azygous (nonmodified) controls grown side-by-side under the same conditions. It has been possible to observe metabolic changes in both types at different stages of maturity. (1)H NMR spectra showed that the levels of glutamic acid, fructose, and some nucleosides and nucleotides gradually increase from the immature to the ripe stage, whereas some amino acids such as valine and gamma-aminobutyric acid were present in higher amounts in unripe tomatoes. Apart from the significantly increased content of six main flavonoid glycosides (mainly kaempferol-3-O-rutinoside, with additional increases in kaempferol-3,7-di-O-glucoside (1), kaempferol-3-O-rutinoside-7-O-glucoside (2), kaempferol-3-O-glucoside, a dihydrokaempferol-O-hexoside (3), and naringenin-7-O-glucoside), the levels of at least 15 other metabolites were found to be different between the two types of red tomato. Among them were citric acid, sucrose, phenylalanine, and trigonelline. However, although statistically significant, these changes in mean values were relatively minor (less than 3-fold) and within the natural variation that would be observed in a field-grown crop. Nevertheless, this study clearly showed that NMR combined with chemometrics and univariate statistics can successfully trace even small differences in metabolite levels between plants and therefore represents a powerful tool to detect potential unintended effects in genetically modified crops.

  3. Iranian Azeri women's perceptions of unintended pregnancy: A qualitative study.

    Science.gov (United States)

    Mohammadi, Easa; Nourizadeh, Roghaiyeh; Simbar, Masoumeh

    2015-01-01

    Many women, throughout their life cycle, experience unintended pregnancy and its subsequent induced abortion. Nonetheless, women's perceptions of this phenomenon - particularly in countries prohibiting elective abortion - are poorly known. The aim of this study was to explore Iranian Azeri women's perceptions of unintended pregnancy. This was a conventional content analysis study conducted in Tabriz, Iran. The data were collected through 31 semi-structured interviews with 23 women who had recently experienced an unintended pregnancy. The study participants were recruited using the purposive sampling method. Sampling started in March 2013 and continued until reaching data saturation, i.e. till August 2013. Data analysis was carried out concurrently with data collection. MAXQDA 10.0 software was employed for managing the study data. The study data analysis process yielded the formation of three main themes including negative effects of unintended pregnancy on daily life, fear of being stigmatized with violating social norms, and abortion panic, which in turn constituted the broader overarching theme of "threat supposition." In other words, following an unintended pregnancy, the study participants had experienced different levels of fear and threat depending on their personal, family, and socio-cultural backgrounds. Women perceive unintended pregnancy as a challenging and threatening situation. An unintended pregnancy can threaten women's lives through social deprivations, growing instability, and putting both mother and baby at risk for physical and psychosocial problems. On the other hand, an unsafe illegal abortion could have potentially life-threatening complications. To cope with such a situation, women need strong social support. Healthcare providers can fulfill such women's need for support by developing pre-abortion counseling services and providing them with professional counseling. Also, strengthening women's support system by policy-makers is recommended.

  4. Feasibility and effectiveness of unintended pregnancy prevention with low-dose mifepristone combined with misoprostol before expected menstruation.

    Science.gov (United States)

    Li, Cui-Lan; Chen, Dun-Jin; Deng, Yi-Fan; Song, Li-Ping; Mo, Xue-Tang; Liu, Kai-Jie

    2015-12-01

    What is the efficacy of maintaining or restoring non-pregnant status with low-dose mifepristone combined with misoprostol administered before expected menstruation? Low-dose mifepristone and misoprostol administered at the time of expected menstruation was effective and safe in maintaining or restoring non-pregnant status, with no obvious menstrual disturbance. Menstrual regulation involves the medical or mechanical stimulation of uterine sloughing in women with up to 2-3 weeks of menstrual delay. Low-dose mifepristone plus misoprostol is efficacious for termination of ultra-early pregnancy (≤ 35 days of amenorrhoea) with no obvious menstrual disturbance. A total of 678 women fulfilled all criteria and were recruited. Seventeen women dropped out after deciding to remain pregnant and 11 others were lost to follow-up. Thus, data from 650 women who completed the procedure were included in analyses. Participants were enrolled at any time during their menstrual cycle and administered medication 1 day before expected menstruation. The end of the study was defined on a per-patient basis as the date of completion of the post-treatment menstrual cycle. The primary outcome was the efficacy of abortion induction (for pregnant women) or menstrual regulation (for non-pregnant women). Women with regular menstrual cycles (25-35 days) were voluntarily recruited for this study between February 2012 and December 2014. Serum β-hCG was measured before mifepristone intake. Mifepristone (50 mg) was administered orally 1 day before expected menstruation and 200 µg misoprostol was administered orally on the day of expected menstruation. Efficacy, disturbance in bleeding patterns in the treatment and post-treatment cycles, satisfaction with the treatment, and subsequent contraception preference were analysed. Retrospective analysis of serum β-hCG levels at admission indicated that 23.3% (158/678) of the women were pregnant. The success rate for pregnancy termination was 98.6% (136

  5. Interventions for preventing unintended pregnancies among adolescents.

    Science.gov (United States)

    Oringanje, Chioma; Meremikwu, Martin M; Eko, Hokehe; Esu, Ekpereonne; Meremikwu, Anne; Ehiri, John E

    2016-02-03

    Unintended pregnancy among adolescents represents an important public health challenge in high-income countries, as well as middle- and low-income countries. Numerous prevention strategies such as health education, skills-building and improving accessibility to contraceptives have been employed by countries across the world, in an effort to address this problem. However, there is uncertainty regarding the effects of these interventions, hence the need to review the evidence-base. To assess the effects of primary prevention interventions (school-based, community/home-based, clinic-based, and faith-based) on unintended pregnancies among adolescents. We searched all relevant studies regardless of language or publication status up to November 2015. We searched the Cochrane Fertility Regulation Group Specialised trial register, The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2015 Issue 11), MEDLINE, EMBASE, LILACS, Social Science Citation Index and Science Citation Index, Dissertations Abstracts Online, The Gray Literature Network, HealthStar, PsycINFO, CINAHL and POPLINE and the reference lists of articles. We included both individual and cluster randomised controlled trials (RCTs) evaluating any interventions that aimed to increase knowledge and attitudes relating to risk of unintended pregnancies, promote delay in the initiation of sexual intercourse and encourage consistent use of birth control methods to reduce unintended pregnancies in adolescents aged 10 years to 19 years. Two authors independently assessed trial eligibility and risk of bias, and extracted data. Where appropriate, binary outcomes were pooled using a random-effects model with a 95% confidence interval (Cl). Where appropriate, we combined data in meta-analyses and assessed the quality of the evidence using the GRADE approach. We included 53 RCTs that enrolled 105,368 adolescents. Participants were ethnically diverse. Eighteen studies randomised individuals, 32

  6. Intervention Now to Eliminate Repeat Unintended Pregnancy in Teenagers (INTERUPT): a systematic review of intervention effectiveness and cost-effectiveness, and qualitative and realist synthesis of implementation factors and user engagement.

    Science.gov (United States)

    Aslam, Rabeea'h W; Hendry, Maggie; Booth, Andrew; Carter, Ben; Charles, Joanna M; Craine, Noel; Edwards, Rhiannon Tudor; Noyes, Jane; Ntambwe, Lupetu Ives; Pasterfield, Diana; Rycroft-Malone, Jo; Williams, Nefyn; Whitaker, Rhiannon

    2017-08-15

    Unintended repeat conceptions can result in emotional, psychological and educational harm to young women, often with enduring implications for their life chances. This study aimed to identify which young women are at the greatest risk of repeat unintended pregnancies; which interventions are effective and cost-effective; and what are the barriers to and facilitators for the uptake of these interventions. We conducted a mixed-methods systematic review which included meta-analysis, framework synthesis and application of realist principles, with stakeholder input and service user feedback to address this. We searched 20 electronic databases, including MEDLINE, Excerpta Medica database, Applied Social Sciences Index and Abstracts and Research Papers in Economics, to cover a broad range of health, social science, health economics and grey literature sources. Searches were conducted between May 2013 and June 2014 and updated in August 2015. Twelve randomised controlled trials (RCTs), two quasi-RCTs, 10 qualitative studies and 53 other quantitative studies were identified. The RCTs evaluated psychosocial interventions and an emergency contraception programme. The primary outcome was repeat conception rate: the event rate was 132 of 308 (43%) in the intervention group versus 140 of 289 (48%) for the control group, with a non-significant risk ratio (RR) of 0.92 [95% confidence interval (CI) 0.78-1.08]. Four studies reported subsequent birth rates: 29 of 237 (12%) events for the intervention arm versus 46 out of 224 (21%) for the control arm, with an RR of 0.60 (95% CI 0.39-0.93). Many repeat conceptions occurred in the context of poverty, low expectations and aspirations and negligible opportunities. Qualitative and realist evidence highlighted the importance of context, motivation, future planning and giving young women a central and active role in the development of new interventions. Little or no evidence for the effectiveness or cost-effectiveness of any of the

  7. Estimation of effective wind speed

    Science.gov (United States)

    Østergaard, K. Z.; Brath, P.; Stoustrup, J.

    2007-07-01

    The wind speed has a huge impact on the dynamic response of wind turbine. Because of this, many control algorithms use a measure of the wind speed to increase performance, e.g. by gain scheduling and feed forward. Unfortunately, no accurate measurement of the effective wind speed is online available from direct measurements, which means that it must be estimated in order to make such control methods applicable in practice. In this paper a new method is presented for the estimation of the effective wind speed. First, the rotor speed and aerodynamic torque are estimated by a combined state and input observer. These two variables combined with the measured pitch angle is then used to calculate the effective wind speed by an inversion of a static aerodynamic model.

  8. A systematic review of unintended pregnancy in cross-cultural ...

    African Journals Online (AJOL)

    Methods: Published and grey evidence available adverse effects of unintended pregnancy on children were extracted electronically using search engines: PubMed, EMBASE and Google Scholar for the period January 1981 through January 2017. The PRISMA checklist was used and qualities of eligible studies were ...

  9. People, planet and profit: Unintended consequences of legacy building materials.

    Science.gov (United States)

    Zimmer, Anthony T; Ha, HakSoo

    2017-12-15

    Although an explosion of new building materials are being introduced into today's market, adequate up-front research into their chemical and physical properties as well as their potential health and environmental consequences is lacking. History has provided us with several examples where building materials were broadly deployed into society only to find that health and environmental problems resulted in unintended sustainability consequences. In the following paper, we use lead and asbestos as legacy building materials to show their similar historical trends and sustainability consequences. Our research findings show unintended consequences such as: increased remediation and litigation costs; adverse health effects; offshoring of related industries; and impediments to urban revitalization. As numerous new building materials enter today's market, another building material may have already been deployed, representing the next "asbestos." This paper also proposes an alternative methodology that can be applied in a cost-effective way into existing and upcoming building materials, to minimize and prevent potential unintended consequences and create a pathway for sustainable communities. For instance, our findings show that this proposed methodology could have prevented the unintended incurred sustainability costs of approximately $272-$359 billion by investing roughly $24 million in constant 2014 U.S. dollars on up-front research into lead and asbestos. Published by Elsevier Ltd.

  10. Intimate partner violence and unintended pregnancy: prevalence and associated factors

    Directory of Open Access Journals (Sweden)

    Ana Carolina da C. Azevêdo

    2013-12-01

    Full Text Available This study investigated the association between unintended pregnancy and intimate partner violence before pregnancy. A cross-sectional study was carried out with 1,054 women, aged 18 to 49, in Recife, Northeastern Brazil, from July 2005 to March 2006. Non-conditional logistic regression analysis was performed with a hierarchical strategy for entering variables into the model, according to the conceptual framework defined. Unintended pregnancy was reported by 60.3% (636 women. Intimate partner violence prior to the pregnancy was associated with unintended pregnancy (ORadj = 1.57; 95%CI: 1.17-2.11, even when adjusted for the women's sociodemographic characteristics, the partner's behaviour, and the relationship dynamic. When the association was adjusted for the use of contraception and the partner's refusal to use contraception, the association was no longer significant, suggesting that the effect of partner violence on unintended pregnancy may be mediated by these variables. The findings point to the need of screening for intimate partner violence in reproductive health services.

  11. Unintended and unwanted pregnancy in St. Lucia.

    Science.gov (United States)

    Denton, A B; Chase, W M; Scott, K

    1994-09-01

    Among 200 mothers interviewed in St. Lucia, 82.5% described their pregnancy as unintended and 44% as unwanted; 80% of women having an intended pregnancy and 94.6% having an unintended pregnancy were unmarried and 18.5% were teenagers. Mothers of unintended pregnancies were significantly younger, were of significantly higher parity and had begun sexual relations at a significantly earlier age than mothers of intended pregnancies; and, unlike mothers of planned pregnancies, their desired interpregnancy interval was significantly longer than the actual interval. These results and the sporadic and ineffective use of contraception in St. Lucia emphasize the need for improvements in fertility regulation in that country.

  12. Correlates of unintended pregnancy among currently pregnant married women in Nepal

    Directory of Open Access Journals (Sweden)

    Soonthorndhada Kusol

    2009-08-01

    Full Text Available Abstract Background Women living in every country, irrespective of its development status, have been facing the problem of unintended pregnancy. Unintended pregnancy is an important public health issue in both developing and developed countries because of its negative association with the social and health outcomes for both mothers and children. This study aims to determine the prevalence and the factors influencing unintended pregnancy among currently pregnant married women in Nepal. Methods This paper reports on data drawn from Nepal Demographic and Health Survey (NDHS which is a nationally representative survey. The analysis is restricted to currently pregnant married women at the time of survey. Association between unintended pregnancy and the explanatory variables was assessed in bivariate analysis using Chi-square tests. Logistic regression was used to assess the net effect of several independent variables on unintended pregnancy. Results More than two-fifth of the currently pregnant women (41% reported that their current pregnancy was unintended. The results indicate that age of women, age at first marriage, ideal number of children, religion, exposure to radio and knowledge of family planning methods were key predictors of unintended pregnancy. Experience of unintended pregnancy augments with women's age (odds ratio, 1.11. Similarly, increase in the women's age at first marriage reduces the likelihood of unintended pregnancy (odds ratio, 0.93. Those who were exposed to the radio were less likely (odds ratio, 0.63 to have unintended pregnancy compared to those who were not. Furthermore, those women who had higher level of knowledge about family planning methods were less likely to experience unintended pregnancy (odds ratio, 0.60 compared to those having lower level of knowledge. Conclusion One of the important factors contributing to high level of maternal and infant mortality is unintended pregnancy. Programs should aim to reduce

  13. Unintended Positional Drift and Its Potential Solutions

    DEFF Research Database (Denmark)

    Nilsson, Niels Christian; Serafin, Stefania; Nordahl, Rolf

    2013-01-01

    many users unintentionally move forward while walking in place. We refer to this phenomenon accidental movement as Unintended Positional Drift. The poster presents evidence of the phenomenon's existence and subsequently discusses different design solutions which potentially could circumvent the problem....

  14. Intervention Now to Eliminate Repeat Unintended Pregnancy in Teenagers (INTERUPT): a systematic review of intervention effectiveness and cost-effectiveness, and qualitative and realist synthesis of implementation factors and user engagement.

    Science.gov (United States)

    Whitaker, Rhiannon; Hendry, Maggie; Aslam, Rabeea'h; Booth, Andrew; Carter, Ben; Charles, Joanna M; Craine, Noel; Tudor Edwards, Rhiannon; Noyes, Jane; Ives Ntambwe, Lupetu; Pasterfield, Diana; Rycroft-Malone, Jo; Williams, Nefyn

    2016-02-01

    The UK has one of the highest rates of teenage pregnancies in Western Europe. One-fifth of these are repeat pregnancies. Unintended conceptions can cause substantial emotional, psychological and educational harm to teenagers, often with enduring implications for life chances. Babies of teenage mothers have increased mortality and are at a significantly increased risk of poverty, educational underachievement and unemployment later in life, with associated costs to society. It is important to identify effective, cost-effective and acceptable interventions. To identify who is at the greatest risk of repeat unintended pregnancies; which interventions are effective and cost-effective; and what the barriers to and facilitators of the uptake of these interventions are. We conducted a multistreamed, mixed-methods systematic review informed by service user and provider consultation to examine worldwide peer-reviewed evidence and UK-generated grey literature to find and evaluate interventions to reduce repeat unintended teenage pregnancies. We searched the following electronic databases: MEDLINE and MEDLINE In-Process & Other Non-Indexed Citations, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, The Cochrane Library (Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and the Health Technology Assessment Database), EMBASE (Excerpta Medica database), British Nursing Index, Educational Resources Information Center, Sociological Abstracts, Applied Social Sciences Index and Abstracts, BiblioMap (the Evidence for Policy and Practice Information and Co-ordinating Centre register of health promotion and public health research), Social Sciences Citation Index (supported by Web of Knowledge), Research Papers in Economics, EconLit (American Economic Association's electronic bibliography), OpenGrey, Scopus, Scirus, Social Care Online, National Research Register, National Institute for Health Research Clinical Research Network

  15. Reports of unintended consequences of financial incentives to improve management of hypertension.

    Directory of Open Access Journals (Sweden)

    Sylvia J Hysong

    Full Text Available Given the increase in financial-incentive programs nationwide, many physicians and physician groups are concerned about potential unintended consequences of providing financial incentives to improve quality of care. However, few studies examine whether actual unintended consequences result from providing financial incentives to physicians. We sought to document the extent to which the unintended consequences discussed in the literature were observable in a randomized clinical trial (RCT of financial incentives.We conducted a qualitative observational study nested within a larger RCT of financial incentives to improve hypertension care. We conducted 30-minute telephone interviews with primary care personnel at facilities participating in the RCT housed at12 geographically dispersed Veterans Affairs Medical Centers nationwide. Participants answered questions about unintended effects, clinic team dynamics, organizational impact on care delivery, study participation. We employed a blend of inductive and deductive qualitative techniques for analysis.Sixty-five participants were recruited from RCT enrollees and personnel not enrolled in the larger RCT, plus one primary care leader per site.Emergent themes included possible patient harm, emphasis on documentation over improving care, reduced professional morale, and positive spillover. All discussions of unintended consequences involving patient harm were only concerns, not actual events. Several unintended consequences concerned ancillary initiatives for quality improvement (e.g., practice guidelines and performance measurement systems rather than financial incentives.Many unintended consequences of financial incentives noted were either only concerns or attributable to ancillary quality-improvement initiatives. Actual unintended consequences included improved documentation of care without necessarily improving actual care, and positive unintended consequences.Clinicaltrials.gov Identifier: NCT

  16. Intended and unintended consequences of mandatory IFRS adoption

    OpenAIRE

    Brüggemann, Ulf; Hitz, Jörg-Markus; Sellhorn, Thorsten

    2012-01-01

    This paper discusses empirical evidence on the economic consequences of mandatory adoption of International Financial Reporting Standards (IFRS) in the European Union (EU) and provides suggestions on how future research can add to our understanding of these effects. Based on the explicitly stated objectives of the EU‟s so-called „IAS Regulation‟, we distinguish between intended and unintended consequences of mandatory IFRS adoption. Empirical research on the intended consequences generally fa...

  17. Anticipating the unintended consequences of security dynamics.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.; Overfelt, James Robert; Malczynski, Leonard A.; Saltiel, David H.; Simon Paul Moulton

    2010-01-01

    In a globalized world, dramatic changes within any one nation causes ripple or even tsunamic effects within neighbor nations and nations geographically far removed. Multinational interventions to prevent or mitigate detrimental changes can easily cause secondary unintended consequences more detrimental and enduring than the feared change instigating the intervention. This LDRD research developed the foundations for a flexible geopolitical and socioeconomic simulation capability that focuses on the dynamic national security implications of natural and man-made trauma for a nation-state and the states linked to it through trade or treaty. The model developed contains a database for simulating all 229 recognized nation-states and sovereignties with the detail of 30 economic sectors including consumers and natural resources. The model explicitly simulates the interactions among the countries and their governments. Decisions among governments and populations is based on expectation formation. In the simulation model, failed expectations are used as a key metric for tension across states, among ethnic groups, and between population factions. This document provides the foundational documentation for the model.

  18. Factors associated with unintended pregnancy, poor birth outcomes and post-partum contraceptive use among HIV-positive female adolescents in Kenya

    Directory of Open Access Journals (Sweden)

    Obare Francis

    2012-10-01

    Full Text Available Abstract Background Although the experiences of unintended pregnancies and poor birth outcomes among adolescents aged 15–19 years in the general population are well documented, there is limited understanding of the same among those who are living with HIV. This paper examines the factors associated with experiencing unintended pregnancies, poor birth outcomes, and post-partum contraceptive use among HIV-positive female adolescents in Kenya. Methods Data are from a cross-sectional study that captured information on pregnancy histories of HIV-positive female adolescents in four regions of Kenya: Coast, Nairobi, Nyanza and Rift Valley provinces. Study participants were identified through HIV and AIDS programs in the four regions. Out of a total of 797 female participants, 394 had ever been pregnant with 24% of them experiencing multiple pregnancies. Analysis entails the estimation of random-effects logit models. Results Higher order pregnancies were just as likely to be unintended as lower order ones (odds ratios [OR]: 1.2; 95% confidence interval [CI]: 0.8–2.0 while pregnancies occurring within marital unions were significantly less likely to be unintended compared to those occurring outside such unions (OR: 0.1; 95% CI: 0.1–0.2. Higher order pregnancies were significantly more likely to result in poor outcomes compared to lower order ones (OR: 2.5; 95% CI: 1.6–4.0. In addition, pregnancies occurring within marital unions were significantly less likely to result in poor outcomes compared to those occurring outside such unions (OR: 0.3; 95% CI: 0.1–0.9. However, experiencing unintended pregnancy was not significantly associated with adverse birth outcomes (OR: 1.3; 95% CI: 0.5–3.3. There was also no significant difference in the likelihood of post-partum contraceptive use by whether the pregnancy was unintended (OR: 0.9; 95% CI: 0.5–1.5. Conclusions The experience of repeat unintended pregnancies among HIV-positive female adolescents

  19. Factors associated with unintended pregnancy, poor birth outcomes and post-partum contraceptive use among HIV-positive female adolescents in Kenya.

    Science.gov (United States)

    Obare, Francis; van der Kwaak, Anke; Birungi, Harriet

    2012-10-06

    Although the experiences of unintended pregnancies and poor birth outcomes among adolescents aged 15-19 years in the general population are well documented, there is limited understanding of the same among those who are living with HIV. This paper examines the factors associated with experiencing unintended pregnancies, poor birth outcomes, and post-partum contraceptive use among HIV-positive female adolescents in Kenya. Data are from a cross-sectional study that captured information on pregnancy histories of HIV-positive female adolescents in four regions of Kenya: Coast, Nairobi, Nyanza and Rift Valley provinces. Study participants were identified through HIV and AIDS programs in the four regions. Out of a total of 797 female participants, 394 had ever been pregnant with 24% of them experiencing multiple pregnancies. Analysis entails the estimation of random-effects logit models. Higher order pregnancies were just as likely to be unintended as lower order ones (odds ratios [OR]: 1.2; 95% confidence interval [CI]: 0.8-2.0) while pregnancies occurring within marital unions were significantly less likely to be unintended compared to those occurring outside such unions (OR: 0.1; 95% CI: 0.1-0.2). Higher order pregnancies were significantly more likely to result in poor outcomes compared to lower order ones (OR: 2.5; 95% CI: 1.6-4.0). In addition, pregnancies occurring within marital unions were significantly less likely to result in poor outcomes compared to those occurring outside such unions (OR: 0.3; 95% CI: 0.1-0.9). However, experiencing unintended pregnancy was not significantly associated with adverse birth outcomes (OR: 1.3; 95% CI: 0.5-3.3). There was also no significant difference in the likelihood of post-partum contraceptive use by whether the pregnancy was unintended (OR: 0.9; 95% CI: 0.5-1.5). The experience of repeat unintended pregnancies among HIV-positive female adolescents in the sample is partly due to inconsistent use of contraception to prevent

  20. The nature and causes of unintended events reported at ten emergency departments

    Directory of Open Access Journals (Sweden)

    van der Wal Gerrit

    2009-09-01

    Full Text Available Abstract Background Several studies on patient safety have shown that a substantial number of patients suffer from unintended harm caused by healthcare management in hospitals. Emergency departments (EDs are challenging hospital settings with regard to patient safety. There is an increased sense of urgency to take effective countermeasures in order to improve patient safety. This can only be achieved if interventions tackle the dominant underlying causes. The objectives of our study are to examine the nature and causes of unintended events in EDs and the relationship between type of event and causal factor structure. Methods Study at EDs of 10 hospitals in the Netherlands. The study period per ED was 8 to 14 weeks, in which staff were asked to report unintended events. Unintended events were broadly defined as all events, no matter how seemingly trivial or commonplace, that were unintended and could have harmed or did harm a patient. Reports were analysed with a Root Cause Analysis tool (PRISMA by an experienced researcher. Results 522 unintended events were reported. Of the events 25% was related to cooperation with other departments and 20% to problems with materials/equipment. More than half of the events had consequences for the patient, most often resulting in inconvenience or suboptimal care. Most root causes were human (60%, followed by organisational (25% and technical causes (11%. Nearly half of the root causes was external, i.e. attributable to other departments in or outside the hospital. Conclusion Event reporting gives insight into diverse unintended events. The information on unintended events may help target research and interventions to increase patient safety. It seems worthwhile to direct interventions on the collaboration between the ED and other hospital departments.

  1. Unintended pregnancies after Essure sterilization in the Netherlands

    NARCIS (Netherlands)

    Veersema, S.; Vleugels, M.P.; Moolenaar, L.M.; Janssen, C.A.; Brölmann, H.A.M.

    2010-01-01

    Objective: To analyze the data of cases of unintended pregnancies after Essure sterilization. Design: Retrospective case series analysis. Setting: National multicenter. Patient(s): Ten cases of unintended pregnancies after Essure sterilization in the Netherlands were reported from August 2002

  2. Education Differences in Intended and Unintended Fertility

    Science.gov (United States)

    Musick, Kelly; England, Paula; Edgington, Sarah; Kangas, Nicole

    2009-01-01

    Using a hazards framework and panel data from the National Longitudinal Survey of Youth (1979-2004), we analyze the fertility patterns of a recent cohort of white and black women in the United States. We examine how completed fertility varies by women's education, differentiating between intended and unintended births. We find that the education…

  3. Improving Evaluation to Address the Unintended Consequences of Health Information Technology:

    Science.gov (United States)

    Ammenwerth, E.; Hyppönen, H.; de Keizer, N.; Nykänen, P.; Rigby, M.; Scott, P.; Talmon, J.; Georgiou, A.

    2016-01-01

    Summary Background and objectives With growing use of IT by healthcare professionals and patients, the opportunity for any unintended effects of technology to disrupt care health processes and outcomes is intensified. The objectives of this position paper by the IMIA Working Group (WG) on Technology Assessment and Quality Development are to highlight how our ongoing initiatives to enhance evaluation are also addressing the unintended consequences of health IT. Methods Review of WG initiatives Results We argue that an evidence-based approach underpinned by rigorous evaluation is fundamental to the safe and effective use of IT, and for detecting and addressing its unintended consequences in a timely manner. We provide an overview of our ongoing initiatives to strengthen study design, execution and reporting by using evaluation frameworks and guidelines which can enable better characterization and monitoring of unintended consequences, including the Good Evaluation Practice Guideline in Health Informatics (GEP-HI) and the Statement on Reporting of Evaluation Studies in Health Informatics (STARE-HI). Indicators to benchmark the adoption and impact of IT can similarly be used to monitor unintended effects on healthcare structures, processes and outcome. We have also developed EvalDB, a web-based database of evaluation studies to promulgate evidence about unintended effects and are developing the content for courses to improve training in health IT evaluation. Conclusion Evaluation is an essential ingredient for the effective use of IT to improve healthcare quality and patient safety. WG resources and skills development initiatives can facilitate a proactive and evidence-based approach to detecting and addressing the unintended effects of health IT. PMID:27830232

  4. Unmet need for contraception and its association with unintended pregnancy in Bangladesh.

    Science.gov (United States)

    Bishwajit, Ghose; Tang, Shangfeng; Yaya, Sanni; Feng, Zhanchun

    2017-06-12

    Unmet need for contraception and unintended pregnancy are important public health concerns both in developing and developed countries. Previous researches have attempted to study the factors that influence unintended pregnancy. However, the association between unmet need for contraception and unwanted pregnancy is not studied adequately. The aim of the present study was to measure the prevalence of unmet need for contraception and unwanted pregnancy, and to explore the association between these two in a nationally representative sample in Bangladesh. Data for the present study were collected from Bangladesh demographic and health survey conducted in 2011. Participants were 7338 mothers ageing between 13 and 49 years selected from both rural and urban residencies. Planning status of last pregnancy was the main outcome variable and unmet need for contraception was the explanatory variable of primary interest. Cross tabulation, chi-square tests and logistic regression (Generalised estimating equations) methods were used for data analysis. Mean age of the sample population was 25.6 years (SD 6.4). Prevalence of unmet need for contraception was 13.5%, and about 30% of the women described their last pregnancy as unintended. In the adjusted model, the odds of unintended pregnancy were about 16 fold among women who reported facing unmet need for contraception compared to those who did not (95% CI = 11.63-23.79). National rates of unintended pregnancy and of unmet need for contraception remain considerably high and warrant increased policy attention. Findings suggests that programs targeting to reduce unmet need for contraception could contribute to a lower rate of unintended pregnancy in Bangladesh. More in-depth and qualitative studies on the underlying sociocultural causes of unmet need can help develop context specific solutions to unintended pregnancies.

  5. The frequency of unintended pregnancies at working and unworking women: why don’t they want to become pregnant?

    Directory of Open Access Journals (Sweden)

    Dilek Karaman

    2007-09-01

    Full Text Available OBJECTIVE: Unintended pregnancies and reasons of occurance should be analysed for socially and economically. The most important reason of unintended pregnancies is defects or failure at using contraception methods. Unintended pregnancies usually ended by dilatation and curratage for termination of pregnancies. The women use this method for limiting the child count and as one of the contraseption methods. Our study’s aims to investigate the frequency of unintended pregnancies at working and unworking women and the reasons of them.\tMaterials-METHODS: 507 healthy women who applied to Afyon Kocatepe University Ahmet Necdet Sezer Research and Training Hospital, Clinic of Obstetrics between July-Agust/2006 at reproductive age were enrolled. Frequency of their unintended pregnancies and the reason of them were asked. A questionnaire form which include 40 questions were used to collect data. The following outcomes were recorded using SPSS for Windows 11,0 programme. P\tRESULTS: This study shows that 44% women were had unintended pregnancy at least once. In our study group 84% women used one of the contraseption methods and 15.9% women didn’t use any methods. Unintended pregnancy frequency of unworking women 53.2 % and working women is 34.7%. The rates of unintended pregnancies in women who had no education were 66.7% and 28.9% in educated women. First unintended pregnancy often ended with 44% alive birth, second and third pregnancies usually ended with curettage.\tCONCLUSION: Contraception methods must be used effectively and correctly to prevent the unintended pregnancies. To make the all pregnancies intended more information about contraseption methods and their usage must be given.

  6. Unintended consequences of increasing block tariffs pricing policy in urban water

    Science.gov (United States)

    Dahan, Momi; Nisan, Udi

    2007-03-01

    We exploit a unique data set to estimate the degree of economies of scale in water consumption, controlling for the standard demand factors. We found a linear Engel curve in water consumption: each additional household member consumes the same water quantity regardless of household size, except for a single-person household. Our evidence suggests that the increasing block tariffs (IBT) structure, which is indifferent to household size, has unintended consequences. Large households, which are also likely to be poor given the negative correlation between income and household size, are charged a higher price for water. The degree of economies of scale found here erodes the effectiveness of IBT price structure as a way to introduce an equity consideration. This implication is important in view of the global trend toward the use of IBT.

  7. Intervention Now to Eliminate Repeat Unintended Pregnancy in Teenagers (INTERUPT): a systematic review of intervention effectiveness and cost-effectiveness, and qualitative and realist synthesis of implementation factors and user engagement

    OpenAIRE

    Aslam, Rabeea?h W.; Hendry, Maggie; Booth, Andrew; Carter, Ben; Charles, Joanna M.; Craine, Noel; Edwards, Rhiannon Tudor; Noyes, Jane; Ntambwe, Lupetu Ives; Pasterfield, Diana; Rycroft-Malone, Jo; Williams, Nefyn; Whitaker, Rhiannon

    2017-01-01

    Background\\ud The UK has one of the highest rates of teenage pregnancies in Western Europe. One-fifth of these are repeat pregnancies. Unintended conceptions can cause substantial emotional, psychological and educational harm to teenagers, often with enduring implications for life chances. Babies of teenage mothers have increased mortality and are at a significantly increased risk of poverty, educational underachievement and unemployment later in life, with associated costs to society. It is ...

  8. A Survey of the Literature on Unintended Consequences Associated with Health Information Technology: 2014–2015

    Science.gov (United States)

    Abraham, J.; Novak, L. L.; Reynolds, T. L.; Gettinger, A.

    2016-01-01

    Summary Objective To summarize recent research on unintended consequences associated with implementation and use of health information technology (health IT). Included in the review are original empirical investigations published in English between 2014 and 2015 that reported unintended effects introduced by adoption of digital interventions. Our analysis focuses on the trends of this steam of research, areas in which unintended consequences have continued to be reported, and common themes that emerge from the findings of these studies. Method Most of the papers reviewed were retrieved by searching three literature databases: MEDLINE, Embase, and CINAHL. Two rounds of searches were performed: the first round used more restrictive search terms specific to unintended consequences; the second round lifted the restrictions to include more generic health IT evaluation studies. Each paper was independently screened by at least two authors; differences were resolved through consensus development. Results The literature search identified 1,538 papers that were potentially relevant; 34 were deemed meeting our inclusion criteria after screening. Studies described in these 34 papers took place in a wide variety of care areas from emergency departments to ophthalmology clinics. Some papers reflected several previously unreported unintended consequences, such as staff attrition and patients’ withholding of information due to privacy and security concerns. A majority of these studies (71%) were quantitative investigations based on analysis of objectively recorded data. Several of them employed longitudinal or time series designs to distinguish between unintended consequences that had only transient impact, versus those that had persisting impact. Most of these unintended consequences resulted in adverse outcomes, even though instances of beneficial impact were also noted. While care areas covered were heterogeneous, over half of the studies were conducted at academic medical

  9. Estimating network effects in China's mobile telecommunications

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A model is proposed along with empirical investigation to prove the existence of network effects in China's mobile telecommunications market. Futhernore, network effects on China's mobile telecommunications are estimated with a dynamic model. The structural parameters are identified from regression coefficients and the results are analyzed and compared with another literature. Data and estimation issues are also discussed. Conclusions are drawn that network effects are significant in China's mobile telecommunications market, and that ignoring network effects leads to bad policy making.

  10. Unintended pregnancy among HIV positive couples receiving integrated HIV counseling, testing, and family planning services in Zambia.

    Science.gov (United States)

    Wall, Kristin M; Haddad, Lisa; Vwalika, Bellington; Htee Khu, Naw; Brill, Ilene; Kilembe, William; Stephenson, Rob; Chomba, Elwyn; Vwalika, Cheswa; Tichacek, Amanda; Allen, Susan

    2013-01-01

    We describe rates of unintended pregnancy among HIV positive couples in Lusaka, Zambia. We also identify factors associated with unintended pregnancy among oral contraceptive pill (OCP) using couples in this cohort. Data were analyzed from couples randomized in a factorial design to two family planning intervention videos. Rates of unintended pregnancy were stratified by contraceptive method used at time of pregnancy. Predictors of time to unintended pregnancy among OCP users were determined via multivariate Cox modeling. The highest rates of unintended pregnancy were observed among couples requesting condoms only (26.4/100CY) or OCPs (20.7/100CY); these rates were not significantly different. OCP users accounted for 37% of the couple-years (CY) observed and 87% of unintended pregnancies. Rates of unintended pregnancy for injectable (0.7/100CY) and intrauterine device (1.6/100CY) users were significantly lower relative to condom only users. No pregnancies occurred among contraceptive implant users or after tubal ligation. Factors associated (psex without a condom. Long-acting reversible contraceptive methods were effective in the context of integrated couples HIV prevention and contraceptive services. Injectable methods were also effective in this context. Given the high user failure rate of OCPs, family planning efforts should promote longer-acting methods among OCP users wishing to avoid pregnancy. Where other methods are not available or acceptable, OCP adherence counseling is needed, especially among younger and new OCP users. ClinicalTrials.gov NCT00067522.

  11. Social discrimination, stress, and risk of unintended pregnancy among young women.

    Science.gov (United States)

    Hall, Kelli Stidham; Kusunoki, Yasamin; Gatny, Heather; Barber, Jennifer

    2015-03-01

    Prior research linking young women's mental health to family planning outcomes has often failed to consider their social circumstances and the intersecting biosocial mechanisms that shape stress and depression as well as reproductive outcomes during adolescence and young adulthood. We extend our previous work to investigate relationships between social discrimination, stress and depression symptoms, and unintended pregnancy among adolescent and young adult women. Data were drawn from 794 women aged 18-20 years in a longitudinal cohort study. Baseline and weekly surveys assessed psychosocial information including discrimination (Everyday Discrimination Scale), stress (Perceived Stress Scale), depression (Center for Epidemiologic Studies-Depression Scale), and reproductive outcomes. Multilevel, mixed-effects logistic regression and discrete-time hazard models estimated associations between discrimination, mental health, and pregnancy. Baron and Kenny's method was used to test mediation effects of stress and depression on discrimination and pregnancy. The mean discrimination score was 19/45 points; 20% reported moderate/high discrimination. Discrimination scores were higher among women with stress and depression symptoms versus those without symptoms (21 vs. 18 points for both, p women with moderate/high (23%) versus low (11%) discrimination (p Discrimination was associated with stress (adjusted relative risk ratio, [aRR], 2.2; 95% confidence interval [CI], 1.4-3.4), depression (aRR, 2.4; CI, 1.5-3.7), and subsequent pregnancy (aRR, 1.8; CI, 1.1-3.0). Stress and depression symptoms did not mediate discrimination's effect on pregnancy. Discrimination was associated with an increased risk of mental health symptoms and unintended pregnancy among these young women. The interactive social and biological influences on reproductive outcomes during adolescence and young adulthood warrant further study. Copyright © 2015 Society for Adolescent Health and Medicine. Published

  12. The cost of unintended pregnancies for employer-sponsored health insurance plans.

    Science.gov (United States)

    Dieguez, Gabriela; Pyenson, Bruce S; Law, Amy W; Lynen, Richard; Trussell, James

    2015-04-01

    Pregnancy is associated with a significant cost for employers providing health insurance benefits to their employees. The latest study on the topic was published in 2002, estimating the unintended pregnancy rate for women covered by employer-sponsored insurance benefits to be approximately 29%. The primary objective of this study was to update the cost of unintended pregnancy to employer-sponsored health insurance plans with current data. The secondary objective was to develop a regression model to identify the factors and associated magnitude that contribute to unintended pregnancies in the employee benefits population. We developed stepwise multinomial logistic regression models using data from a national survey on maternal attitudes about pregnancy before and shortly after giving birth. The survey was conducted by the Centers for Disease Control and Prevention through mail and via telephone interviews between 2009 and 2011 of women who had had a live birth. The regression models were then applied to a large commercial health claims database from the Truven Health MarketScan to retrospectively assign the probability of pregnancy intention to each delivery. Based on the MarketScan database, we estimate that among employer-sponsored health insurance plans, 28.8% of pregnancies are unintended, which is consistent with national findings of 29% in a survey by the Centers for Disease Control and Prevention. These unintended pregnancies account for 27.4% of the annual delivery costs to employers in the United States, or approximately 1% of the typical employer's health benefits spending for 1 year. Using these findings, we present a regression model that employers could apply to their claims data to identify the risk for unintended pregnancies in their health insurance population. The availability of coverage for contraception without employee cost-sharing, as was required by the Affordable Care Act in 2012, combined with the ability to identify women who are at high

  13. The incidence of abortion and unintended pregnancy in India, 2015

    Science.gov (United States)

    Singh, Susheela; Shekhar, Chander; Acharya, Rajib; Moore, Ann M; Stillman, Melissa; Pradhan, Manas R; Frost, Jennifer J; Sahoo, Harihar; Alagarajan, Manoj; Hussain, Rubina; Sundaram, Aparna; Vlassoff, Michael; Kalyanwala, Shveta; Browne, Alyssa

    2018-01-01

    Summary Background Reliable information on the incidence of induced abortion in India is lacking. Official statistics and national surveys provide incomplete coverage. Since the early 2000s, medication abortion has become increasingly available, improving the way women obtain abortions. The aim of this study was to estimate the national incidence of abortion and unintended pregnancy for 2015. Methods National abortion incidence was estimated through three separate components: abortions (medication and surgical) in facilities (including private sector, public sector, and non-governmental organisations [NGOs]); medication abortions outside facilities; and abortions outside of facilities and with methods other than medication abortion. Facility-based abortions were estimated from the 2015 Health Facilities Survey of 4001 public and private health facilities in six Indian states (Assam, Bihar, Gujarat, Madhya Pradesh, Tamil Nadu, and Uttar Pradesh) and from NGO clinic data. National medication abortion drug sales and distribution data were obtained from IMS Health and six principal NGOs (DKT International, Marie Stopes International, Population Services International, World Health Partners, Parivar Seva Santha, and Janani). We estimated the total number of abortions that are not medication abortions and are not obtained in a health facility setting through an indirect technique based on findings from community-based study findings in two states in 2009, with adjustments to account for the rapid increase in use of medication abortion since 2009. The total number of women of reproductive age and livebirth data were obtained from UN population data, and the proportion of births from unplanned pregnancies and data on contraceptive use and need were obtained from the 2015–16 National Family Health Survey-4. Findings We estimate that 15·6 million abortions (14·1 million–17·3 million) occurred in India in 2015. The abortion rate was 47·0 abortions (42·2–52·1) per

  14. Climate change trade measures : estimating industry effects

    Science.gov (United States)

    2009-06-01

    Estimating the potential effects of domestic emissions pricing for industries in the United States is complex. If the United States were to regulate greenhouse gas emissions, production costs could rise for certain industries and could cause output, ...

  15. Genetic introgression of ethylene-suppressed, long shelf-life transgenic tomatoes with higher-polyamines trait overcomes many unintended effects due to reduced ethylene on metabolome

    Science.gov (United States)

    Ethylene regulates a myriad physiological and biochemical processes in ripening fruits and is accepted as the ripening hormone for the climacteric fruits. However, its effects on metabolome and resulting fruit quality are not yet fully understood, particularly when some of the ripening-associated bi...

  16. Does abortion reduce the mental health risks of unwanted or unintended pregnancy? A re-appraisal of the evidence.

    Science.gov (United States)

    Fergusson, David M; Horwood, L John; Boden, Joseph M

    2013-09-01

    There have been debates about the linkages between abortion and mental health. Few reviews have considered the extent to which abortion has therapeutic benefits that mitigate the mental health risks of abortion. The aim of this review was to conduct a re-appraisal of the evidence to examine the research hypothesis that abortion reduces rates of mental health problems in women having unwanted or unintended pregnancy. Analysis of recent reviews (Coleman, 2011; National Collaborating Centre for Mental Health, 2011) identified eight publications reporting 14 adjusted odds ratios (AORs) spanning five outcome domains: anxiety; depression; alcohol misuse; illicit drug use/misuse; and suicidal behaviour. For each outcome, pooled AORs were estimated using a random-effects model. There was consistent evidence to show that abortion was not associated with a reduction in rates of mental health problems (p>0.75). Abortion was associated with small to moderate increases in risks of anxiety (AOR 1.28, 95% CI 0.97-1.70; pabortion has therapeutic effects in reducing the mental health risks of unwanted or unintended pregnancy. There is suggestive evidence that abortion may be associated with small to moderate increases in risks of some mental health problems.

  17. Peacekeepers against ethnic and criminal violence : Unintended consequences of UN peacekeeping

    NARCIS (Netherlands)

    Di Salvatore, J.

    2017-01-01

    This dissertation examines the unintended and collateral effects of third-party interventions in war-torn countries. Building on the most recent findings in peacekeeping literature that suggests an overall conflict-reducing effect of military interventions, this thesis explores ways in which this

  18. Genetic introgression of ethylene-suppressed transgenic tomatoes with higher-polyamines trait overcomes many unintended effects due to reduced ethylene on the primary metabolome

    Directory of Open Access Journals (Sweden)

    Anatoly P Sobolev

    2014-12-01

    Full Text Available Ethylene regulates a myriad physiological and biochemical processes in ripening fruits and is accepted as the ripening hormone for the climacteric fruits. However, its effects on metabolome and resulting fruit quality are not yet fully understood, particularly when some of the ripening-associated biochemical changes are independent of ethylene action. We have generated a homozygous transgenic tomato genotype (2AS-AS that exhibits reduced ethylene production as a result of impaired expression of 1-aminocyclopropane-1-carboxylate synthase 2 gene by its antisense RNA and had a longer shelf life. Double transgenic hybrid (2AS-AS x 579HO developed through a genetic cross between 2AS-AS and 579HO (Mehta et al., 2002 lines resulted in significantly higher ethylene production than either the WT or 2AS-AS fruit. To determine the effects of reduced ethylene and introgression of higher polyamines’ trait, the metabolic profiles of ripening fruits from WT (556AZ, 2AS-AS, and 2AS-AS x 579HO lines were determined using 1H-NMR spectroscopy. The levels of Glu, Asp, AMP, Adenosine, Nucl1 and Nucl2 increased during ripening of the WT fruit. The increases in Glu, Asp, and AMP levels were attenuated in 2AS-AS fruit but recovered in the double hybrid with higher ethylene and polyamine levels. The ripening-associated decreases in Ala, Tyr, Val, Ile, Phe, malate and myo-inositol levels in the 2AS-AS line were not reversed in the double hybrid line suggesting a developmental/ripening regulated accumulation of these metabolites independent of ethylene. Significant increases in the levels of fumarate, formate, choline, Nucl1 and Nucl2 at most stages of ripening fruit were found in the double transgenic line due to introgression with higher-polyamines trait. Taken together these results show that the ripening-associated metabolic changes are both ethylene dependent and independent, and that the fruit metabolome is under the control of multiple regulators, including

  19. Estimating haplotype effects for survival data

    DEFF Research Database (Denmark)

    Scheike, Thomas; Martinussen, Torben; Silver, J

    2010-01-01

    Genetic association studies often investigate the effect of haplotypes on an outcome of interest. Haplotypes are not observed directly, and this complicates the inclusion of such effects in survival models. We describe a new estimating equations approach for Cox's regression model to assess haplo...

  20. Estimating haplotype effects for survival data.

    Science.gov (United States)

    Scheike, Thomas H; Martinussen, Torben; Silver, Jeremy D

    2010-09-01

    Genetic association studies often investigate the effect of haplotypes on an outcome of interest. Haplotypes are not observed directly, and this complicates the inclusion of such effects in survival models. We describe a new estimating equations approach for Cox's regression model to assess haplotype effects for survival data. These estimating equations are simple to implement and avoid the use of the EM algorithm, which may be slow in the context of the semiparametric Cox model with incomplete covariate information. These estimating equations also lead to easily computable, direct estimators of standard errors, and thus overcome some of the difficulty in obtaining variance estimators based on the EM algorithm in this setting. We also develop an easily implemented goodness-of-fit procedure for Cox's regression model including haplotype effects. Finally, we apply the procedures presented in this article to investigate possible haplotype effects of the PAF-receptor on cardiovascular events in patients with coronary artery disease, and compare our results to those based on the EM algorithm. © 2009, The International Biometric Society.

  1. A blessing I can't afford: factors underlying the paradox of happiness about unintended pregnancy.

    Science.gov (United States)

    Aiken, Abigail R A; Dillaway, Chloe; Mevs-Korff, Natasha

    2015-05-01

    An unresolved paradox in the measurement and interpretation of unintended pregnancy is that women frequently report feeling happy about pregnancies they also classify as unintended (i.e. they have incongruent intentions and feelings). This study explores the underlying reasons why women profess such happiness and how these relate to their motivations to avoid pregnancy. Between September 2013 and February 2014, semi-structured in-depth interviews were conducted with 27 women (8 white, 19 Latina) selected from a longitudinal study measuring prospective pregnancy intentions and feelings among 403 women in Austin, Texas. Women were selected for interview on the basis of wanting no more children and consistently professing either happiness (n = 17) or unhappiness (n = 10) at the prospect of pregnancy. Interviews were coded and analyzed following the principles of grounded theory. We found that it is possible for women to express happiness at the idea of pregnancy while simultaneously earnestly trying to prevent conception. Happiness at the idea of an unintended pregnancy was explained as the result of deep and heartfelt feelings about children taking precedence over practical considerations, the perception that the psychosocial stress resulting from another child would be low, and the ability to rationalize an unintended pregnancy as the result of fate or God's plan. The major exception to the sincerity of professed happiness was that conveyed as a result of social pressure despite truly negative feelings, predominantly expressed by foreign-born Latina women. Overall, equating incongruence with ambivalence about avoiding conception may undermine the sincerity of women's intentions and their desires for highly-effective contraception. At the same time, unintended pregnancies that are greeted with happiness may have different implications for maternal and child health outcomes compared to pregnancies that are greeted with unhappiness. Identifying which unintended

  2. Assessing the effectiveness of a patient-centred computer-based clinic intervention, Health-E You/Salud iTu, to reduce health disparities in unintended pregnancies among Hispanic adolescents: study protocol for a cluster randomised control trial.

    Science.gov (United States)

    Tebb, Kathleen P; Rodriguez, Felicia; Pollack, Lance M; Trieu, Sang Leng; Hwang, Loris; Puffer, Maryjane; Adams, Sally; Ozer, Elizabeth M; Brindis, Claire D

    2018-01-10

    Teen pregnancy rates in the USA remain higher than any other industrialised nation, and pregnancies among Hispanic adolescents are disproportionately high. Computer-based interventions represent a promising approach to address sexual health and contraceptive use disparities. Preliminary findings have demonstrated that the Health-E You/Salud iTu, computer application (app) is feasible to implement, acceptable to Latina adolescents and improves sexual health knowledge and interest in selecting an effective contraceptive method when used in conjunction with a healthcare visit. The app is now ready for efficacy testing. The purpose of this manuscript is to describe patient-centred approaches used both in developing and testing the Health-E You app and to present the research methods used to evaluate its effectiveness in improving intentions to use an effective method of contraception as well as actual contraceptive use. This study is designed to assess the effectiveness of a patient-centred computer-based clinic intervention, Health-E You/Salud  iTu, on its ability to reduce health disparities in unintended pregnancies among Latina adolescent girls. This study uses a cluster randomised control trial design in which 18 school-based health centers from the Los Angeles Unified School District were randomly assigned, at equal chance, to either the intervention ( Health-E You app) or control group. Analyses will examine differences between the control and intervention group's knowledge of and attitudes towards contraceptive use, receipt of contraception at the clinic visit and self-reported use of contraception at 3-month and 6-month follow-ups. The study began enrolling participants in August 2016, and a total of 1400 participants (700 per treatment group) are expected to be enrolled by March 2018. Ethics approval was obtained through the University of California, San Francisco Institutional Review Board. Results of this trial will be submitted for publication in peer

  3. Long-term intended and unintended experiences after Advanced Life Support training

    DEFF Research Database (Denmark)

    Rasmussen, M.B.; Dieckmann, Peter; Issenberg, Berry

    2012-01-01

    Highly structured simulation-based training (SBT) on managing emergency situations can have a significant effect on immediate satisfaction and learning. However, there are some indications of problems when applying learned skills to practice. The aim of this study was to identify long-term intended...... and unintended learner reactions, experiences and reflections after attending a simulation based Advanced Life Support (ALS) course....

  4. The Policy Delphi: A Method for Identifying Intended and Unintended Consequences of Educational Policy

    Science.gov (United States)

    Manley, R. Adam

    2013-01-01

    This article highlights a rarely utilized but effective technique for identifying intended and unintended consequences of past or current policy or policy change. The author guides the reader through the process of identifying potential participants, contacting participants, developing the policy Delphi instrument, and analyzing the findings by…

  5. Health effects estimation for contaminated properties

    International Nuclear Information System (INIS)

    Marks, S.; Denham, D.H.; Cross, F.T.; Kennedy, W.E. Jr.

    1984-05-01

    As part of an overall remedial action program to evaluate the need for and institute actions designed to minimize health hazards from inactive tailings piles and from displaced tailings, methods for estimating health effects from tailings were developed and applied to the Salt Lake City area. 2 references, 2 tables

  6. Nonuse of contraception among women at risk of unintended pregnancy in the United States.

    Science.gov (United States)

    Mosher, William; Jones, Jo; Abma, Joyce

    2015-08-01

    This paper seeks to determine factors associated with nonuse of contraception by women at risk of unintended pregnancy in the United States. This nonuse may be associated with about 900,000 unintended births in the US each year. The 2002 and 2006-2010 National Surveys of Family Growth were combined to yield a nationally representative sample of 9,445 women at risk of unintended pregnancy. Logistic regression analyses identified factors associated with nonuse of contraception. This analysis reveals previously undocumented patterns of nonuse: controlling for confounding variables, cohabiting women [adjusted odds ratio (AOR)=2.3, 95% confidence interval (CI)=1.45-3.52] had higher odds of nonuse than married women; women who reported a difficulty getting pregnant (AOR=2.5, 95% CI=2.01-3.01) had higher odds of nonuse than those who did not. Nonuse was also more common among women with a master's degree or more (AOR=1.5, 95% CI=1.11-2.08) compared with those with some college or bachelor's degree, and it was more common among women in their first year after first intercourse than after the first year (AOR 1.6, 95% CI=1.12-2.22). Among women who had a recent unintended birth, the most common reason for not using contraception prior to conception was that she did not think she could get pregnant. This study establishes national estimates of reasons for nonuse of contraception and identifies some new subgroups at risk of nonuse. These results may help better understand factors affecting nonuse of contraception and develop strategies for preventing unintended pregnancy in the United States. Published by Elsevier Inc.

  7. Prevalence and distribution of unintended pregnancy: the Understanding Fertility Management in Australia National Survey.

    Science.gov (United States)

    Rowe, Heather; Holton, Sara; Kirkman, Maggie; Bayly, Christine; Jordan, Lynne; McNamee, Kathleen; McBain, John; Sinnott, Vikki; Fisher, Jane

    2016-04-01

    Mistimed, unexpected or unwanted pregnancies occur in Australia, despite widespread contraception use. The objective was to estimate prevalence and ascertain modifiable social factors for prevention of unintended pregnancy. National population-based survey of women and men aged 18-51 years recruited from a random sample of electors on the Australian Electoral Roll in 2013. Data were weighted to reduce non-response bias. Factors associated with unintended pregnancy were identified in multivariable analyses. Data from 2,235 completed questionnaires were analysed (Women: 69%; Men: 31%). Of those ever pregnant or partner in pregnancy (59%), 40% had experienced an unintended pregnancy. Adjusting for other risks, ever having experienced sexual coercion (AOR, 95%CI=Women 1.948; 1.458-2.601; Men 1.657, 1.014-2.708); socioeconomic disadvantage (AOR, 95%CI=Women 1.808, 1.373, 2.381; Men 1.360, 1.004-1.841), living in a rural area (AOR, 95%CI=Women 1.403, 1.056-1.864; Men 1.583, 1.161-2.159), and for men being born overseas (AOR, 95%CI 1.989, 1.317-3.002) were significantly associated with unintended pregnancy. Experiences of sexual coercion, social disadvantage, rural residence and overseas birth are independently associated with unintended pregnancy in Australia. Public health policy and health service initiatives should prioritise prevention of sexual coercion, reduction of social inequality and reduction of geographic inequality for those in rural areas. © 2015 Public Health Association of Australia.

  8. Estimating the effects of wages on obesity.

    Science.gov (United States)

    Kim, DaeHwan; Leigh, John Paul

    2010-05-01

    To estimate the effects of wages on obesity and body mass. Data on household heads, aged 20 to 65 years, with full-time jobs, were drawn from the Panel Study of Income Dynamics for 2003 to 2007. The Panel Study of Income Dynamics is a nationally representative sample. Instrumental variables (IV) for wages were created using knowledge of computer software and state legal minimum wages. Least squares (linear regression) with corrected standard errors were used to estimate the equations. Statistical tests revealed both instruments were strong and tests for over-identifying restrictions were favorable. Wages were found to be predictive (P low wages increase obesity prevalence and body mass.

  9. Unintended and in situ amorphisation of pharmaceuticals

    DEFF Research Database (Denmark)

    Priemel, P A; Grohganz, H; Rades, T

    2016-01-01

    Amorphisation of poorly water-soluble drugs is one approach that can be applied to improve their solubility and thus their bioavailability. Amorphisation is a process that usually requires deliberate external energy input. However, amorphisation can happen both unintentionally, as in process......-induced amorphisation during manufacturing, or in situ during dissolution, vaporisation, or lipolysis. The systems in which unintended and in situ amorphisation has been observed normally contain a drug and a carrier. Common carriers include polymers and mesoporous silica particles. However, the precise mechanisms...... of in situ amorphisation can thus confer the advantages of the amorphous form, such as higher apparent solubility and faster dissolution rate, without the disadvantage of its physical instability....

  10. Unintended Pregnancy, Induced Abortion, and Mental Health.

    Science.gov (United States)

    Horvath, Sarah; Schreiber, Courtney A

    2017-09-14

    The early medical literature on mental health outcomes following abortion is fraught with methodological flaws that can improperly influence clinical practice. Our goal is to review the current medical literature on depression and other mental health outcomes for women obtaining abortions. The Turnaway Study prospectively enrolled 956 women seeking abortion in the USA and followed their mental health outcomes for 5 years. The control group was comprised of women denied abortions based on gestational age limits, thereby circumventing the major methodological flaw that had plagued earlier studies on the topic. Rates of depression are not significantly different between women obtaining abortion and those denied abortion. Rates of anxiety are initially higher in women denied abortion care. Counseling on decision-making for women with unintended pregnancies should reflect these findings.

  11. Quantitative Estimation for the Effectiveness of Automation

    International Nuclear Information System (INIS)

    Lee, Seung Min; Seong, Poong Hyun

    2012-01-01

    In advanced MCR, various automation systems are applied to enhance the human performance and reduce the human errors in industrial fields. It is expected that automation provides greater efficiency, lower workload, and fewer human errors. However, these promises are not always fulfilled. As the new types of events related to application of the imperfect and complex automation are occurred, it is required to analyze the effects of automation system for the performance of human operators. Therefore, we suggest the quantitative estimation method to analyze the effectiveness of the automation systems according to Level of Automation (LOA) classification, which has been developed over 30 years. The estimation of the effectiveness of automation will be achieved by calculating the failure probability of human performance related to the cognitive activities

  12. [Effect of speech estimation on social anxiety].

    Science.gov (United States)

    Shirotsuki, Kentaro; Sasagawa, Satoko; Nomura, Shinobu

    2009-02-01

    This study investigates the effect of speech estimation on social anxiety to further understanding of this characteristic of Social Anxiety Disorder (SAD). In the first study, we developed the Speech Estimation Scale (SES) to assess negative estimation before giving a speech which has been reported to be the most fearful social situation in SAD. Undergraduate students (n = 306) completed a set of questionnaires, which consisted of the Short Fear of Negative Evaluation Scale (SFNE), the Social Interaction Anxiety Scale (SIAS), the Social Phobia Scale (SPS), and the SES. Exploratory factor analysis showed an adequate one-factor structure with eight items. Further analysis indicated that the SES had good reliability and validity. In the second study, undergraduate students (n = 315) completed the SFNE, SIAS, SPS, SES, and the Self-reported Depression Scale (SDS). The results of path analysis showed that fear of negative evaluation from others (FNE) predicted social anxiety, and speech estimation mediated the relationship between FNE and social anxiety. These results suggest that speech estimation might maintain SAD symptoms, and could be used as a specific target for cognitive intervention in SAD.

  13. Estimating scaled treatment effects with multiple outcomes.

    Science.gov (United States)

    Kennedy, Edward H; Kangovi, Shreya; Mitra, Nandita

    2017-01-01

    In classical study designs, the aim is often to learn about the effects of a treatment or intervention on a single outcome; in many modern studies, however, data on multiple outcomes are collected and it is of interest to explore effects on multiple outcomes simultaneously. Such designs can be particularly useful in patient-centered research, where different outcomes might be more or less important to different patients. In this paper, we propose scaled effect measures (via potential outcomes) that translate effects on multiple outcomes to a common scale, using mean-variance and median-interquartile range based standardizations. We present efficient, nonparametric, doubly robust methods for estimating these scaled effects (and weighted average summary measures), and for testing the null hypothesis that treatment affects all outcomes equally. We also discuss methods for exploring how treatment effects depend on covariates (i.e., effect modification). In addition to describing efficiency theory for our estimands and the asymptotic behavior of our estimators, we illustrate the methods in a simulation study and a data analysis. Importantly, and in contrast to much of the literature concerning effects on multiple outcomes, our methods are nonparametric and can be used not only in randomized trials to yield increased efficiency, but also in observational studies with high-dimensional covariates to reduce confounding bias.

  14. Unintended consequences of atmospheric injection of sulphate aerosols.

    Energy Technology Data Exchange (ETDEWEB)

    Brady, Patrick Vane; Kobos, Peter Holmes; Goldstein, Barry

    2010-10-01

    Most climate scientists believe that climate geoengineering is best considered as a potential complement to the mitigation of CO{sub 2} emissions, rather than as an alternative to it. Strong mitigation could achieve the equivalent of up to -4Wm{sup -2} radiative forcing on the century timescale, relative to a worst case scenario for rising CO{sub 2}. However, to tackle the remaining 3Wm{sup -2}, which are likely even in a best case scenario of strongly mitigated CO{sub 2} releases, a number of geoengineering options show promise. Injecting stratospheric aerosols is one of the least expensive and, potentially, most effective approaches and for that reason an examination of the possible unintended consequences of the implementation of atmospheric injections of sulphate aerosols was made. Chief among these are: reductions in rainfall, slowing of atmospheric ozone rebound, and differential changes in weather patterns. At the same time, there will be an increase in plant productivity. Lastly, because atmospheric sulphate injection would not mitigate ocean acidification, another side effect of fossil fuel burning, it would provide only a partial solution. Future research should aim at ameliorating the possible negative unintended consequences of atmospheric injections of sulphate injection. This might include modeling the optimum rate and particle type and size of aerosol injection, as well as the latitudinal, longitudinal and altitude of injection sites, to balance radiative forcing to decrease negative regional impacts. Similarly, future research might include modeling the optimum rate of decrease and location of injection sites to be closed to reduce or slow rapid warming upon aerosol injection cessation. A fruitful area for future research might be system modeling to enhance the possible positive increases in agricultural productivity. All such modeling must be supported by data collection and laboratory and field testing to enable iterative modeling to increase the

  15. Direct costs of unintended pregnancy in the Russian federation.

    Science.gov (United States)

    Lowin, Julia; Jarrett, James; Dimova, Maria; Ignateva, Victoria; Omelyanovsky, Vitaly; Filonenko, Anna

    2015-02-01

    In 2010, almost every third pregnancy in Russia was terminated, indicating that unintended pregnancy (UP) is a public health problem. The aim of this study was to estimate the direct cost of UP to the healthcare system in Russia and the proportion attributable to using unreliable contraception. A cost model was built, adopting a generic payer perspective with a 1-year time horizon. The analysis cohort was defined as women of childbearing age between 18 and 44 years actively seeking to avoid pregnancy. Model inputs were derived from published sources or government statistics with a 2012 cost base. To estimate the number of UPs attributable to unreliable methods, the model combined annual typical use failure rates and age-adjusted utilization for each contraceptive method. Published survey data was used to adjust the total cost of UP by the number of UPs that were mistimed rather than unwanted. Scenario analysis considered alternate allocation of methods to the reliable and unreliable categories and estimate of the burden of UP in the target sub-group of women aged 18-29 years. The model estimated 1,646,799 UPs in the analysis cohort (women aged 18-44 years) with an associated annual cost of US$783 million. The model estimated 1,019,371 UPs in the target group of 18-29 years, of which 88 % were attributable to unreliable contraception. The total cost of UPs in the target group was estimated at approximately US$498 million, of which US$441 million could be considered attributable to the use of unreliable methods. The cost of UP attributable to use of unreliable contraception in Russia is substantial. Policies encouraging use of reliable contraceptive methods could reduce the burden of UP.

  16. Unintended pregnancy and subsequent use of modern contraceptive among slum and non-slum women in Nairobi, Kenya.

    Science.gov (United States)

    Fotso, Jean Christophe; Izugbara, Chimaraoke; Saliku, Teresa; Ochako, Rhoune

    2014-07-10

    In spite of major gains in contraceptive prevalence over the last few decades, many women in most parts of the developing world who would like to delay or avoid pregnancy do not use any method of contraception. This paper seeks to: a) examine whether experiencing an unintended pregnancy is associated with future use of contraception controlling for a number factors including poverty at the household and community levels; and b) investigate the mechanisms through which experiencing an unintended pregnancy leads to uptake of contraception. Quantitative and qualitative data from a cross-sectional research project conducted in 2009/10 in two slum settlements and two non-slum settings of Nairobi, Kenya are used. The quantitative component of the project was based on a random sample of 1,259 women aged 15-49 years. Logistic regression models were used to assess the effect of unintended pregnancy on future contraceptive use. The qualitative component of the project successfully interviewed a total of 80 women randomly selected from survey participants who had reported having at least one unintended pregnancy. Women whose last pregnancy was unintended were more likely to be using a modern method of contraception, compared to their peers whose last pregnancy was intended, especially among the wealthier group as shown in the interaction model. Among poor women, unintended pregnancy was not associated with subsequent use of contraception. The qualitative investigation with women who had an unplanned pregnancy reveals that experiencing an unintended pregnancy seems to have served as a "wake-up call", resulting in greater attention to personal risks, including increased interest in pregnancy prevention. For some women, unintended pregnancy was a consequence of strong opposition by their partners to family planning, while others reported they started using contraceptives following their unintended pregnancy, but discontinued after experiencing side effects. This study provides

  17. Facing HIV infection and unintended pregnancy: Rakai, Uganda, 2001-2013.

    Science.gov (United States)

    Grilo, Stephanie Ann; Song, Xiaoyu; Lutalo, Tom; Mullinax, Margo; Mathur, Sanyukta; Santelli, John

    2018-02-27

    Unintended pregnancy is a persistent and global issue with consequences for the health and well-being of mothers and babies. The aim of this paper is to examine unintended pregnancy over time in the context of substantial human immunodeficiency virus (HIV) prevalence and increasing access to anti-retro viral therapy (ART). Data are from the Rakai Community Cohort Study (RCCS) - a cohort of communities with 10,000-12,000 adults, ages 15-49, in Rakai District, Uganda. We examined prevalence of current pregnancies over time, intended pregnancy, and unintended pregnancies (unwanted, mistimed, ambivalent). We then examined risk factors for the different categories of unintended pregnancy among women who were currently pregnant. The full sample included 32,205 observations over 13 years. The prevalence of mistimed pregnancy and unwanted pregnancy both decreased significantly over time (p < .001). The prevalence of current pregnancies and intended pregnancy showed no significant changes over the thirteen year period. The same overall pattern was found when only examining HIV positive women in the sample; however, the trends were not significant. Out of the 2820 current pregnancies reported, 54.4% were intended, 29.8% were mistimed, 13.2% were unwanted, and 2.5% were ambivalent. After controlling for other predictors, HIV status had no independent effect on mistimed pregnancy but had a significant effect on unwanted pregnancy (RRR = 2.44, 95% CI = 1.65-3.61, p < .001] and ambivalent pregnancy [RRR = 2.07; CI: 1.03 to 4.18, p = 0.041]. In 2004, after the introduction of ART, there was a decreased risk in unintended pregnancy [RR = 0.75; CI: 0.66 to 0.84, p < .001]. Women with a secondary education or higher also had a decreased risk in unintended pregnancy [RR = 0.70; CI: 0.70 to 0.92, p = 0.002]. HIV was an important predictor of unwanted pregnancy. Unintended pregnancy decreased in the sample over time which may be due to an

  18. Unintended pregnancies among women serving in the Israeli military.

    Science.gov (United States)

    Rottenstreich, Misgav; Loitner, Limor; Dar, Shir; Kedem, Ron; Smorgick, Noam; Vaknin, Zvi

    2017-07-01

    The objective was to identify the prevalence of and variables associated with unintended pregnancy among young, unmarried women serving in the Israeli military. We performed a retrospective cohort study of unmarried women drafted by the Israeli military between 2013 and 2015 at the age of 18 years. We used multivariable logistic regression to examine associations between unintended pregnancy and women's education, IQ, immigration status, country of origin, neighborhood socioeconomic status and history of psychiatric illness. Most women (n=127,262) did not become pregnant while serving in the Israeli military. Unintended pregnancy was reported by 2365, with an additional 6 women reporting pregnancy resulting from sexual assault and 5 an intended pregnancy. Annual rates of unintended pregnancy among young women serving in the Israeli military declined from 1.69% in 2013 to 1.56% in 2014 and 1.33% in 2015. In multivariable models, unintended pregnancy was more common among women soldiers who had not graduated from high school (adjusted relative risk [RR], 5.3; 95% confidence interval [CI], 4.69-6.04) and those who were first-generation immigrants (adjusted RR, 2.1; 95% CI, 1.90-2.35). Unintended pregnancy is rare among women serving into the Israeli military. Increasing contraceptive use among women who have not graduated from high school may further reduce rates of unintended pregnancy among women serving in the Israeli military. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Estimating network effect in geocenter motion: Theory

    Science.gov (United States)

    Zannat, Umma Jamila; Tregoning, Paul

    2017-10-01

    Geophysical models and their interpretations of several processes of interest, such as sea level rise, postseismic relaxation, and glacial isostatic adjustment, are intertwined with the need to realize the International Terrestrial Reference Frame. However, this realization needs to take into account the geocenter motion, that is, the motion of the center of figure of the Earth surface, due to, for example, deformation of the surface by earthquakes or hydrological loading effects. Usually, there is also a discrepancy, known as the network effect, between the theoretically convenient center of figure and the physically accessible center of network frames, because of unavoidable factors such as uneven station distribution, lack of stations in the oceans, disparity in the coverage between the two hemispheres, and the existence of tectonically deforming zones. Here we develop a method to estimate the magnitude of the network effect, that is, the error introduced by the incomplete sampling of the Earth surface, in measuring the geocenter motion, for a network of space geodetic stations of a fixed size N. For this purpose, we use, as our proposed estimate, the standard deviations of the changes in Helmert parameters measured by a random network of the same size N. We show that our estimate scales as 1/√N and give an explicit formula for it in terms of the vector spherical harmonics expansion of the displacement field. In a complementary paper we apply this formalism to coseismic displacements and elastic deformations due to surface water movements.

  20. Unintended and in situ amorphisation of pharmaceuticals.

    Science.gov (United States)

    Priemel, P A; Grohganz, H; Rades, T

    2016-05-01

    Amorphisation of poorly water-soluble drugs is one approach that can be applied to improve their solubility and thus their bioavailability. Amorphisation is a process that usually requires deliberate external energy input. However, amorphisation can happen both unintentionally, as in process-induced amorphisation during manufacturing, or in situ during dissolution, vaporisation, or lipolysis. The systems in which unintended and in situ amorphisation has been observed normally contain a drug and a carrier. Common carriers include polymers and mesoporous silica particles. However, the precise mechanisms by which in situ amorphisation occurs are often not fully understood. In situ amorphisation can be exploited and performed before administration of the drug or possibly even within the gastrointestinal tract, as can be inferred from in situ amorphisation observed during in vitro lipolysis. The use of in situ amorphisation can thus confer the advantages of the amorphous form, such as higher apparent solubility and faster dissolution rate, without the disadvantage of its physical instability. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Attending unintended transformations of health care infrastructure

    Directory of Open Access Journals (Sweden)

    Helle Wentzer

    2007-11-01

    Full Text Available Introduction: Western health care is under pressure from growing demands on quality and efficiency. The development and implementation of information technology, IT is a key mean of health care authorities to improve on health care infrastructure. Theory and methods: Against a background of theories on human-computer interaction and IT-mediated communication, different empirical studies of IT implementation in health care are analyzed. The outcome is an analytical discernment between different relations of communication and levels of interaction with IT in health care infrastructure. These relations and levels are synthesized into a framework for identifying tensions and potential problems in the mediation of health care with the IT system. These problems are also known as unexpected adverse consequences, UACs, from IT implementation into clinical health care practices. Results: This paper develops a conceptual framework for addressing transformations of communication and workflow in health care as a result of implementing IT. Conclusion and discussion: The purpose of the conceptual framework is to support the attention to and continuous screening for errors and unintended consequences of IT implementation into health care practices and outcomes.

  2. Bayesian estimation of dose rate effectiveness

    International Nuclear Information System (INIS)

    Arnish, J.J.; Groer, P.G.

    2000-01-01

    A Bayesian statistical method was used to quantify the effectiveness of high dose rate 137 Cs gamma radiation at inducing fatal mammary tumours and increasing the overall mortality rate in BALB/c female mice. The Bayesian approach considers both the temporal and dose dependence of radiation carcinogenesis and total mortality. This paper provides the first direct estimation of dose rate effectiveness using Bayesian statistics. This statistical approach provides a quantitative description of the uncertainty of the factor characterising the dose rate in terms of a probability density function. The results show that a fixed dose from 137 Cs gamma radiation delivered at a high dose rate is more effective at inducing fatal mammary tumours and increasing the overall mortality rate in BALB/c female mice than the same dose delivered at a low dose rate. (author)

  3. Psychological Aspects of Contraception, Unintended Pregnancy, and Abortion

    OpenAIRE

    Steinberg, Julia R.; Rubin, Lisa R.

    2014-01-01

    The knowledge of important biopsychosocial factors linking women's reproductive health and mental health is increasing. This review focuses on psychological aspects of contraception, unintended pregnancy, and abortion because these are common reproductive health experiences in U.S. women's lives. This review addresses the mental-health antecedents and consequences of these experiences, mostly focusing on depression and depressive symptoms before and after unintended pregnancy and contraceptio...

  4. Factors associated with unintended pregnancy in Yamagata, Japan.

    Science.gov (United States)

    Goto, Aya; Yasumura, Seiji; Reich, Michael R; Fukao, Akira

    2002-04-01

    Data on unintended pregnancy are scarce in Japan. The purpose of this study is to examine the association of sociodemographic, reproductive, and other health behavioral factors with unintended pregnancy. A survey was conducted from May through November 1999 in Yamagata, Japan. We distributed anonymous self-administered questionnaires to cervical and breast cancer screening participants aged 35-49 years. There were 564 eligible women, and the number of respondents was 421 (74.6%). The proportion of women who had experienced unintended pregnancy was 46.2%, and 40.1% of them had repeated experiences. Among 312 pre-menopausal married women who did not want to become pregnant, 15.4% were not using any contraception. Factors that were significantly associated with the experience of unintended pregnancy were age of husband being 4 or more years older [Odds ratio (OR) = 1.83], and age at initiation of sexual intercourse (OR = 1.86) and marriage during teens (OR = 11.14). Analysis of 1255 pregnancies that the subjects had experienced showed that 51.2% and 25.9% of mistimed and unwanted pregnancies occurred as a result of no contraceptive use, and 39.5% and 71.1% of these ended in abortions. The number of past unintended pregnancies was significantly (p counseling for the prevention of repeated unintended pregnancies.

  5. Behavioral Interventions for Preventing Sexually Transmitted Infections and Unintended Pregnancies: An Overview of Systematic Reviews.

    Science.gov (United States)

    Macaya Pascual, A; Ferreres Riera, J R; Campoy Sánchez, A

    2016-05-01

    Countless sex education programs have been implemented worldwide in recent decades, but epidemiological data show no improvement in rates of sexually transmitted infections or unintended pregnancies. To summarize the evidence from higher-quality systematic reviews on the efficacy of behavioral interventions for the prevention of sexually transmitted infections and unintended pregnancies. We conducted an overview of reviews by selecting systematic reviews that met minimum quality criteria in terms of the design of the studies reviewed. We compared the results obtained when the effects of interventions were assessed on the basis of objective criteria (biological data) to those obtained when outcomes were assessed on the basis of subjective criteria (self-reports). The results of Cochrane and non-Cochrane reviews were also compared. We identified 55 systematic reviews. No overall effect on the sexual behavior of program participants was observed in 72.5% of the reviews that used objective criteria and in 48.1% of the reviews based on subjective criteria. In the Cochrane reviews, no evidence of an overall effect was observed in 86% of reviews based on objective variables and in 70.5% of those based on subjective variables. There is no evidence that behavioral interventions modify rates of sexually transmitted infections (including human immunodeficiency virus infections) or unintended pregnancies, particularly when effects are assessed using objective, biological data. Primary prevention strategies for sexually transmitted infections and unintended pregnancies need to be re-evaluated. Copyright © 2015 AEDV. Published by Elsevier España, S.L.U. All rights reserved.

  6. Unintended adverse consequences of introducing electronic health records in residential aged care homes.

    Science.gov (United States)

    Yu, Ping; Zhang, Yiting; Gong, Yang; Zhang, Jiajie

    2013-09-01

    burden, reduction of communication and the risks of lacking care follow-up, which may cause negative effects on aged care services. Further research can focus on investigating how the unintended adverse consequences can be mitigated or eliminated by understanding more about nursing staff's work as well as the information flow in RACH. This will help to improve the design, introduction and management of EHR systems in this setting. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. Happiness about unintended pregnancy and its relationship to contraceptive desires among a predominantly Latina cohort.

    Science.gov (United States)

    Aiken, Abigail R A

    2015-06-01

    Women frequently profess happiness about unintended pregnancies; such incongruence is associated with use of less effective contraceptive methods and inconsistent or incorrect method use. Yet, the methods women use may differ from those they desire. Data on 578 women were drawn from a prospective survey of postpartum women aged 18-44 recruited from three hospitals in Texas between 2012 and 2014. Jonckheere-Terpstra tests were used to compare women's feelings about a future pregnancy with their childbearing intentions. Fisher-Freeman-Halton tests compared distributions of contraceptive methods currently used and desired by women who professed happiness about a future unintended pregnancy, as well as distributions of desired methods by women's reported feelings. The proportion of women who reported happiness about a future pregnancy was 59% among those intending to wait two or three years for another child, 46% among those intending to wait four or more years, and 36% among those intending to have no more children. Among women who professed happiness, a greater proportion desired to use a highly effective contraceptive method than were currently using one (72% vs. 15% among those intending no more children; 55% vs. 23% among those intending to wait at least four years; and 36% vs. 10% among those intending to wait two or three years). Across intention categories, the types of methods desired did not differ by whether women professed happiness or unhappiness. Women who profess happiness about a future unintended pregnancy may nonetheless desire highly effective contraceptive methods. Copyright © 2015 by the Guttmacher Institute.

  8. Unintended exposure in radiotherapy: Identification of prominent causes

    International Nuclear Information System (INIS)

    Boadu, Mary; Rehani, Madan Mohan

    2009-01-01

    Background and purpose: Unintended exposures in radiotherapy are likely to occur when certain conditions that favour such exposures exist. Based on the frequency of occurrence of various causes of 100 events of unintended exposures in radiotherapy as derived from the analysis of published reports, a checklist for assessing the vulnerability of radiotherapy facilities for potential accidents has been prepared. The list presents items to be considered for safety critical assessments of a radiotherapy department for the improvement of patient safety and the entire radiotherapy processes. Materials and methods: The resources used for this paper consist of 100 unintended radiotherapy exposures and were derived from existing published reports. The analysis was performed by forming two templates: one consisting of 10 initiating events and another of 35 contributing factors. Results: Four most prominent initiating events were identified and together accounted for about 70% of all the unintended exposure events. Ten most prominent contributing factors were also identified and together accounted for about 70% of all the radiotherapy unintended exposure events covered under this study. Conclusion: With this knowledge of high frequency of occurrences, the identified four prominent initiating events and the 10 most prominent contributing factors must be checked and dealt with as a matter of priority when assessing the safety of a radiotherapy facility. A simple checklist for checking the quality assurance programmes of a radiotherapy department for every aspect of the design and delivery of radiation have been provided.

  9. Unintended pregnancy as a predictor of child maltreatment.

    Science.gov (United States)

    Guterman, Kai

    2015-10-01

    Whereas child maltreatment research has developed considerable evidence on post-natal risk-factors, pre-natal circumstances have been largely overlooked. The circumstances surrounding a pregnancy may considerably impact the environment in which later parenting behaviors occur. This study examines one of the earliest potentially identifiable risk-factors for child maltreatment: the intentions of a pregnancy. Utilizing both mother and father reports, this study focuses on maltreatment risk, as it relates with both parents' perspectives of the pregnancy's intention. Drawing upon data from the Fragile Families and Child Well Being study, a longitudinal, birth cohort study, survey questions were used that asked parents, at the time of the birth, whether they considered abortion for the child. Unintended pregnancy demonstrates predictive value as one of the earliest identifiable risk-factors for child maltreatment. Regardless of whether the mother or father reported the unintended pregnancy, the relationship with maltreating behavior is largely the same, although for different maltreatment types. Mothers' reports of unintended pregnancy are associated with psychological aggression, and neglect. Fathers' reports of unintended pregnancy are associated with physical aggression. Fathers' perspectives regarding pregnancy intentions matter just as much as mothers,' and accounting for their perspectives could be important in understanding the maltreating behaviors of both parents. Identifiable in the earliest stages of caregiving, unintended pregnancy may be an important risk-factor in predicting and understanding child maltreatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Estimation of effective dose during hysterosalpingography procedures

    International Nuclear Information System (INIS)

    Alzimamil, K.; Babikir, E.; Alkhorayef, M.; Sulieman, A.; Alsafi, K.; Omer, H.

    2014-08-01

    Hysterosalpingography (HSG) is the most frequently used diagnostic tool to evaluate the endometrial cavity and fallopian tube by using conventional x-ray or fluoroscopy. Determination of the patient radiation doses values from x-ray examinations provides useful guidance on where best to concentrate efforts on patient dose reduction in order to optimize the protection of the patients. The aims of this study were to measure the patients entrance surface air kerma doses (ESA K), effective doses and to compare practices between different hospitals in Sudan. ESA K were measured for patient using calibrated thermo luminance dosimeters (TLDs, Gr-200A). Effective doses were estimated using National Radiological Protection Board (NRPB) software. This study was conducted in five radiological departments: Two Teaching Hospitals (A and D), two private hospitals (B and C) and one University Hospital (E). The mean ESD was 20.1 mGy, 28.9 mGy, 13.6 mGy, 58.65 mGy, 35.7, 22.4 and 19.6 mGy for hospitals A,B,C,D, and E), respectively. The mean effective dose was 2.4 mSv, 3.5 mSv, 1.6 mSv, 7.1 mSv and 4.3 mSv in the same order. The study showed wide variations in the ESDs with three of the hospitals having values above the internationally reported values. Number of x-ray images, fluoroscopy time, operator skills x-ray machine type and clinical complexity of the procedures were shown to be major contributors to the variations reported. Results demonstrated the need for standardization of technique throughout the hospital. The results also suggest that there is a need to optimize the procedures. Local DRLs were proposed for the entire procedures. (author)

  11. Contraceptive Use and Unintended Pregnancies Among HIV-Infected Women in Mumbai

    Science.gov (United States)

    Joshi, Beena; Velhal, Gajanan; Chauhan, Sanjay; Kulkarni, Ragini; Begum, Shahina; Nandanwar, Y. S.; Fonseca, Michelle; Baweja, Sujata; Turbadkar, Dilip; Ramchandran, Anita; Dalal, Asha; Shastri, Jayanti; Agrawal, Sachee; Panhale, Manisha; More, Vasundhara; Sanap, Pravin; Panchal, Renuka; Kanougiya, Suman

    2015-01-01

    Background: Access to reproductive health services in Human Immunodeficiency Virus (HIV) programs can greatly enhance program's potential to limit the spread of disease, reduce unintended pregnancies and safeguard the health of infected people. Objectives: To assess (i) knowledge, attitude, and use regarding contraceptives; safe sex and dual protection; (ii) fertility desires and unintended pregnancies post HIV and (iii) symptoms of reproductive tract infection/sexually transmitted infection (RTI/STI) among women infected with HIV. Materials and Methods: A cross-sectional study among 300 currently married HIV-positive women who had not undergone permanent sterilization with no immediate desire for pregnancy. Study site was Integrated Counseling and Testing Centers (ICTC) in tertiary hospitals of Mumbai and women were interviewed using a semistructured questionnaire. Results: In spite of good awareness about modern methods, 42.7 felt that contraceptives other than condoms were harmful to use due to their HIV status. Knowledge on dual protection was limited to condom (75%). Condom use increased from 5.7% pre-HIV to 71.7% post-HIV, with 89.6% reporting regular use. Future fertility desire was expressed by 8.7% women. Induced abortions post-HIV was reported by16.6% women, as pregnancies were unintended. About 69% wished to use dual contraceptive methods for effective protection if it was not harmful to be used by people living with HIV (PLHIV). Conclusion: Data reveals a need to promote modern contraceptive methods along with regular condom use to prevent unintended pregnancies and improve health-seeking behavior for contraception. Health system models that converge or link HIV services with other reproductive health services need to be tested to provide comprehensive reproductive healthcare to infected women in India. PMID:26170540

  12. Contraceptive use and unintended pregnancies among HIV-infected women in Mumbai

    Directory of Open Access Journals (Sweden)

    Beena Joshi

    2015-01-01

    Full Text Available Background: Access to reproductive health services in Human Immunodeficiency Virus (HIV programs can greatly enhance program′s potential to limit the spread of disease, reduce unintended pregnancies and safeguard the health of infected people. Objectives: To assess (i knowledge, attitude, and use regarding contraceptives; safe sex and dual protection; (ii fertility desires and unintended pregnancies post HIV and (iii symptoms of reproductive tract infection/sexually transmitted infection (RTI/STI among women infected with HIV. Materials and Methods: A cross-sectional study among 300 currently married HIV-positive women who had not undergone permanent sterilization with no immediate desire for pregnancy. Study site was Integrated Counseling and Testing Centers (ICTC in tertiary hospitals of Mumbai and women were interviewed using a semistructured questionnaire. Results: In spite of good awareness about modern methods, 42.7 felt that contraceptives other than condoms were harmful to use due to their HIV status. Knowledge on dual protection was limited to condom (75%. Condom use increased from 5.7% pre-HIV to 71.7% post-HIV, with 89.6% reporting regular use. Future fertility desire was expressed by 8.7% women. Induced abortions post-HIV was reported by16.6% women, as pregnancies were unintended. About 69% wished to use dual contraceptive methods for effective protection if it was not harmful to be used by people living with HIV (PLHIV. Conclusion: Data reveals a need to promote modern contraceptive methods along with regular condom use to prevent unintended pregnancies and improve health-seeking behavior for contraception. Health system models that converge or link HIV services with other reproductive health services need to be tested to provide comprehensive reproductive healthcare to infected women in India.

  13. Mobile Phone Apps for the Prevention of Unintended Pregnancy: A Systematic Review and Content Analysis.

    Science.gov (United States)

    Mangone, Emily Rose; Lebrun, Victoria; Muessig, Kathryn E

    2016-01-19

    information (n=15), service or condom locators (n=12), pregnancy tests (n=10), and games (n=3). Twelve apps scored at least 50 points (out of 94) for overall number of features and at least 15 points (out of 21) for contraceptive information and pregnancy prevention best practices. Overall, 41% of apps did not mention any modern contraceptive methods and 23% mentioned only 1 method. Of apps that did mention a modern contraceptive method, fewer than 50% of these apps provided information on how to use it. YA SRH apps had the highest percentage of pregnancy prevention best practices in each app. Demographic and interface evaluation found that most apps (72%) did not target any race and only 10% explicitly targeted youth. Communication interface features were present in fewer than 50% of apps. This review identified several useful, evidence-based apps that support the prevention of unintended pregnancy. However, most apps miss opportunities to provide users with valuable information, interactive decision aids, and evidence-based interventions for unintended pregnancy prevention. Further, some apps in this space may increase the likelihood of unintended pregnancy due to the low effectiveness of the contraceptive methods promoted.

  14. Unintended rapid repeat pregnancy and low education status: any role for depression and contraceptive use?

    Science.gov (United States)

    Bennett, Ian M; Culhane, Jennifer F; McCollum, Kelly F; Elo, Irma T

    2006-03-01

    The purpose of this study was to assess the contribution of depressive symptoms and poor contraceptive use early in the first postpartum year to the risk of unintended repeat pregnancy at the end of that year among adults with low educational status ( or = 19) who enrolled prenatally (14.7 +/- 6.9 weeks gestational age) and were followed twice after delivery (3.3 +/- 1.3 months and 11.0 +/- 1.3 months). Associations were assessed by multivariate logistic regression. Low educational status (odds ratio, 2.32; 95% CI, 1.25-4.33) and less effective contraceptive use (odds ratio, 2.31; 95% CI, 1.05-4.51) were associated with unintended pregnancy. Neither depressive symptoms nor contraceptive use reduced the risk of pregnancy that was associated with low educational status. Low educational status was associated with more than twice the risk of unintended pregnancy 1 year after delivery. We found no evidence that depression or poor contraceptive use mediate this relationship.

  15. Potential unintended consequences of smoke-free policies in public places on pregnant women in China.

    Science.gov (United States)

    Yao, Tingting; Lee, Anita H; Mao, Zhengzhong

    2009-08-01

    Smoke-free policies in public places have become more common in China. Little is known, however, about the potential unintended consequences of such policies on pregnant women. The study was conducted in 2006 in Chengdu, China. Nonsmoking pregnant women (N=55) whose husband were smokers participated in a study of their knowledge about secondhand smoke and smoke-free policies, their exposure to secondhand smoke, and their husbands' smoking status at home. This study presents descriptive statistics, analyses based on family income and pregnant women's education level, and the findings of focus group discussions that examined the potential unintended consequences of the smoke-free policies on pregnant women. Exposure to secondhand smoke at home was reported by 69.1% of the pregnant women. Both family income and the education level of the pregnant women had a significant (ppolicies were: (1) increased exposure of pregnant women to secondhand smoke at home; (2) reduced work efficiency; (3) adverse effect on family harmony; and (4) poor air quality at home. Education is needed to increase knowledge of secondhand smoke among smokers and nonsmokers alike. When the smoking location is shifted from public places and workplaces to home, women, and in particular pregnant women, become the victims. Policymakers should recognize such potential unintended consequences and take necessary measures to increase awareness about the harms of secondhand smoke.

  16. Long-acting reversible contraceptive acceptability and unintended pregnancy among women presenting for short-acting methods: a randomized patient preference trial.

    Science.gov (United States)

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

    2017-02-01

    Measures of contraceptive effectiveness combine technology and user-related factors. Observational studies show higher effectiveness of long-acting reversible contraception compared with short-acting reversible contraception. Women who choose long-acting reversible contraception may differ in key ways from women who choose short-acting reversible contraception, and it may be these differences that are responsible for the high effectiveness of long-acting reversible contraception. Wider use of long-acting reversible contraception is recommended, but scientific evidence of acceptability and successful use is lacking in a population that typically opts for short-acting methods. The objective of the study was to reduce bias in measuring contraceptive effectiveness and better isolate the independent role that long-acting reversible contraception has in preventing unintended pregnancy relative to short-acting reversible contraception. We conducted a partially randomized patient preference trial and recruited women aged 18-29 years who were seeking a short-acting method (pills or injectable). Participants who agreed to randomization were assigned to 1 of 2 categories: long-acting reversible contraception or short-acting reversible contraception. Women who declined randomization but agreed to follow-up in the observational cohort chose their preferred method. Under randomization, participants chose a specific method in the category and received it for free, whereas participants in the preference cohort paid for the contraception in their usual fashion. Participants were followed up prospectively to measure primary outcomes of method continuation and unintended pregnancy at 12 months. Kaplan-Meier techniques were used to estimate method continuation probabilities. Intent-to-treat principles were applied after method initiation for comparing incidence of unintended pregnancy. We also measured acceptability in terms of level of happiness with the products. Of the 916

  17. Counseling in the clinical setting to prevent unintended pregnancy: an evidence-based research agenda.

    Science.gov (United States)

    Moos, Merry K; Bartholomew, Neva E; Lohr, Kathleen N

    2003-02-01

    Unintended pregnancies account for about half of all pregnancies in the United States and, in 1995, numbered nearly 3 million pregnancies. They pose appreciable medical, emotional, social and financial costs on women, their families and society. The US is not attaining national goals to decrease unintended pregnancies, and little is known about effective means for reducing unintended pregnancy rates in adults or adolescents.To examine the evidence about the effectiveness, benefits and harms of counseling in a clinical setting to prevent unintended pregnancy in adults and adolescents and to use the evidence to propose a research agenda.We identified English-language articles from comprehensive searches of the MEDLINE, CINAHL, PsychLit and other databases from 1985 through May 2000; the main clinical search terms included pregnancy (mistimed, unintended, unplanned, unwanted), family planning, contraceptive behavior, counseling, sex counseling, and knowledge, attitudes and behavior. We also used published systematic reviews, hand searching of relevant articles, the second Guide to Clinical Preventive Services and extensive peer review to identify important articles not otherwise found and to assure completeness. Of 673 abstracts examined, we retained 354 for full article review; of these, we used 74 for the systematic evidence review and abstracted data from 13 articles for evidence tables. Four studies addressed the effectiveness of counseling in a clinical setting in changing knowledge, skills and attitudes about contraception and pregnancy; all had poor internal validity and generalizability and collectively did not provide definitive guidance about effective counseling strategies. Nine studies (three in teenage populations) addressed the relationship of knowledge on contraceptive use and adherence. Knowledge of correct contraceptive methods may be positively associated with appropriate use, but reservations about the method itself, partner support of the method

  18. Preoperative unintended weight loss and low body mass index in relation to complications and length of stay after cardiac surgery

    NARCIS (Netherlands)

    van Venrooij, Lenny M. W.; de Vos, Rien; Borgmeijer-Hoelen, Mieke M. M. J.; Haaring, Cees; de Mol, Bas A. J. M.

    Background: Several studies reported increased adverse outcomes after cardiac surgery in patients with low body mass index (BMI; in kg/m(2)). Little is known yet, however, about the effect of preoperative unintended weight loss (UWL) in cardiac surgery patients. Objective: We explored the prevalence

  19. Preoperative unintended weight loss and low body mass index in relation to complications and length of stay after cardiac surgery

    NARCIS (Netherlands)

    van Venrooij, Lenny M. W.; de Vos, Rien; Borgmeijer-Hoelen, Mieke M. M. J.; Haaring, Cees; de Mol, Bas A. J. M.

    2008-01-01

    BACKGROUND: Several studies reported increased adverse outcomes after cardiac surgery in patients with low body mass index (BMI; in kg/m(2)). Little is known yet, however, about the effect of preoperative unintended weight loss (UWL) in cardiac surgery patients. OBJECTIVE: We explored the prevalence

  20. Unintended Sunburn: A Potential Target for Sun Protection Messages

    Directory of Open Access Journals (Sweden)

    Geraldine F. H. McLeod

    2017-01-01

    Full Text Available New Zealand (NZ has the highest melanoma incidence rate in the world. Primary prevention efforts focus on reducing sunburn incidence and increasing sun protective practices in the population. However, sunburn from excessive ultraviolet radiation (UVR remains common. To reduce sunburn incidence, it is important to examine those individuals who experience unintended sunburn. This study aims to use data from the NZ Triennial Sun Protection Survey to describe respondents who were not intending to tan but were sunburnt after outdoor UVR exposure. Information on sociodemographics, concurrent weather conditions, sun protection attitudes and knowledge, and outdoor behaviour was also collected. The results showed 13.5% of respondents’ experienced unintended sunburn during the survey weekend but had not attempted to obtain a tan that summer. Respondents who reported unintended sunburn were more likely than others to have been near water and in unshaded areas, used sunscreen, had higher SunSmart knowledge scores, had lower positive attitudes towards tanning, and were outdoors for a longer duration with less body coverage. As sunburn was unintended these respondents’ outdoor sun protective behaviours may be amenable to change. Future public health initiatives should focus on increasing sun protection (clothing and shade and reducing potential barriers to sun protection.

  1. Psychological Aspects of Contraception, Unintended Pregnancy, and Abortion.

    Science.gov (United States)

    Steinberg, Julia R; Rubin, Lisa R

    2014-10-01

    The knowledge of important biopsychosocial factors linking women's reproductive health and mental health is increasing. This review focuses on psychological aspects of contraception, unintended pregnancy, and abortion because these are common reproductive health experiences in U.S. women's lives. This review addresses the mental-health antecedents and consequences of these experiences, mostly focusing on depression and depressive symptoms before and after unintended pregnancy and contraception. As mental-health antecedents, depressive symptoms predict contraceptive behaviors that lead to unintended pregnancy, and mental-health disorders have been associated with having subsequent abortions. In examining the mental-health consequences, most sound research does not find abortion or contraceptive use to cause mental-health problems. Consequently, evidence does not support policies based on the notion that abortion harms women's mental health. Nevertheless, the abortion-care setting may be a place to integrate mental-health services. In contrast, women who have births resulting from unintended pregnancies may be at higher risk of postpartum depression. Social policies (e.g., paid maternity leave, subsidized child care) may protect women from mental-health problems and stress of unplanned children interrupting employment, education, and pre-existing family care responsibilities.

  2. Unintended Sunburn: A Potential Target for Sun Protection Messages.

    Science.gov (United States)

    McLeod, Geraldine F H; Reeder, Anthony I; Gray, Andrew R; McGee, Rob

    2017-01-01

    New Zealand (NZ) has the highest melanoma incidence rate in the world. Primary prevention efforts focus on reducing sunburn incidence and increasing sun protective practices in the population. However, sunburn from excessive ultraviolet radiation (UVR) remains common. To reduce sunburn incidence, it is important to examine those individuals who experience unintended sunburn. This study aims to use data from the NZ Triennial Sun Protection Survey to describe respondents who were not intending to tan but were sunburnt after outdoor UVR exposure. Information on sociodemographics, concurrent weather conditions, sun protection attitudes and knowledge, and outdoor behaviour was also collected. The results showed 13.5% of respondents' experienced unintended sunburn during the survey weekend but had not attempted to obtain a tan that summer. Respondents who reported unintended sunburn were more likely than others to have been near water and in unshaded areas, used sunscreen, had higher SunSmart knowledge scores, had lower positive attitudes towards tanning, and were outdoors for a longer duration with less body coverage. As sunburn was unintended these respondents' outdoor sun protective behaviours may be amenable to change. Future public health initiatives should focus on increasing sun protection (clothing and shade) and reducing potential barriers to sun protection.

  3. The Nature of Unintended Benefits in Health Information Systems

    DEFF Research Database (Denmark)

    Kuziemsky, Craig E.; Borycki, Elizabeth; Nøhr, Christian

    2012-01-01

    of healthcare delivery. This paper uses several case studies of HIS implementation to develop a model of unintended benefits of HIS usage with three categories of benefits: patient, service delivery and administrative. We also discuss the implications of these benefits on the design and evaluation of HISs....

  4. AACSB Accreditation and Possible Unintended Consequences: A Deming View

    Science.gov (United States)

    Stepanovich, Paul; Mueller, James; Benson, Dan

    2014-01-01

    The AACSB accreditation process reflects basic quality principles, providing standards and a process for feedback for continuous improvement. However, implementation can lead to unintended negative consequences. The literature shows that while institutionalism and critical theory have been used as a theoretical base for evaluating accreditation,…

  5. Estimating Equilibrium Effects of Job Search Assistance

    DEFF Research Database (Denmark)

    Gautier, Pieter; Muller, Paul; van der Klaauw, Bas

    that the nonparticipants in the experiment regions find jobs slower after the introduction of the activation program (relative to workers in other regions). We then estimate an equilibrium search model. This model shows that a large scale role out of the activation program decreases welfare, while a standard partial...... microeconometric cost-benefit analysis would conclude the opposite....

  6. Unintended Consequences of Wearable Sensor Use in Healthcare

    Science.gov (United States)

    McCaldin, D.; Wang, K.; Schreier, G.; Lovell, N. H.; Marschollek, M.; Redmond, S. J.

    2016-01-01

    Summary Objectives As wearable sensors take the consumer market by storm, and medical device manufacturers move to make their devices wireless and appropriate for ambulatory use, this revolution brings with it some unintended consequences, which we aim to discuss in this paper. Methods We discuss some important unintended consequences, both beneficial and unwanted, which relate to: modifications of behavior; creation and use of big data sets; new security vulnerabilities; and unforeseen challenges faced by regulatory authorities, struggling to keep pace with recent innovations. Where possible, we proposed potential solutions to unwanted consequences. Results Intelligent and inclusive design processes may mitigate unintended modifications in behavior. For big data, legislating access to and use of these data will be a legal and political challenge in the years ahead, as we trade the health benefits of wearable sensors against the risk to our privacy. The wireless and personal nature of wearable sensors also exposes them to a number of unique security vulnerabilities. Regulation plays an important role in managing these security risks, but also has the dual responsibility of ensuring that wearable devices are fit for purpose. However, the burden of validating the function and security of medical devices is becoming infeasible for regulators, given the many software apps and wearable sensors entering the market each year, which are only a subset of an even larger ‘internet of things’. Conclusion Wearable sensors may serve to improve wellbeing, but we must be vigilant against the occurrence of unintended consequences. With collaboration between device manufacturers, regulators, and end-users, we balance the risk of unintended consequences occurring against the incredible benefit that wearable sensors promise to bring to the world. PMID:27830234

  7. Comparing fixed effects and covariance structure estimators for panel data

    DEFF Research Database (Denmark)

    Ejrnæs, Mette; Holm, Anders

    2006-01-01

    In this article, the authors compare the traditional econometric fixed effect estimator with the maximum likelihood estimator implied by covariance structure models for panel data. Their findings are that the maximum like lipoid estimator is remarkably robust to certain types of misspecifications...

  8. Unintended cultivation, shifting baselines, and conflict between objectives for fisheries and conservation.

    Science.gov (United States)

    Brown, Christopher J; Trebilco, Rowan

    2014-06-01

    The effects of fisheries on marine ecosystems, and their capacity to drive shifts in ecosystem states, have been widely documented. Less well appreciated is that some commercially valuable species respond positively to fishing-induced ecosystem change and can become important fisheries resources in modified ecosystems. Thus, the ecological effects of one fishery can unintentionally increase the abundance and productivity of other fished species (i.e., cultivate). We reviewed examples of this effect in the peer-reviewed literature. We found 2 underlying ecosystem drivers of the effect: trophic release of prey species when predators are overfished and habitat change. Key ecological, social, and economic conditions required for one fishery to unintentionally cultivate another include strong top-down control of prey by predators, the value of the new fishery, and the capacity of fishers to adapt to a new fishery. These unintended cultivation effects imply strong trade-offs between short-term fishery success and conservation efforts to restore ecosystems toward baseline conditions because goals for fisheries and conservation may be incompatible. Conflicts are likely to be exacerbated if fisheries baselines shift relative to conservation baselines and there is investment in the new fishery. However, in the long-term, restoration toward ecosystem baselines may often benefit both fishery and conservation goals. Unintended cultivation can be identified and predicted using a combination of time-series data, dietary studies, models of food webs, and socioeconomic data. Identifying unintended cultivation is necessary for management to set compatible goals for fisheries and conservation. © 2014 Society for Conservation Biology.

  9. Estimating and Testing Mediation Effects with Censored Data

    Science.gov (United States)

    Wang, Lijuan; Zhang, Zhiyong

    2011-01-01

    This study investigated influences of censored data on mediation analysis. Mediation effect estimates can be biased and inefficient with censoring on any one of the input, mediation, and output variables. A Bayesian Tobit approach was introduced to estimate and test mediation effects with censored data. Simulation results showed that the Bayesian…

  10. ORIGINAL ARTICLE Estimation of annual occupational effective ...

    African Journals Online (AJOL)

    Nagasaki nuclear bomb survivors, who have demonstrated increased ... atomic numbers as soft tissue, and their energy responses to absorbed radiation show little ... suitable thermal treatment, making them cost-effective and viable in the long ...

  11. Unintended consequences of incentive provision for behaviour change and maintenance around childbirth.

    Science.gov (United States)

    Thomson, Gill; Morgan, Heather; Crossland, Nicola; Bauld, Linda; Dykes, Fiona; Hoddinott, Pat; Dombrowski, Stephan; MacLennan, Graeme; Rothnie, Kieran; Stewart, Fiona; Farrar, Shelley; Yi, Deokhee; Hislop, Jenni; Ludbrook, Anne; Campbell, Marion; Moran, Victoria Hall; Sniehotta, Falko; Tappin, David

    2014-01-01

    Financial (positive or negative) and non-financial incentives or rewards are increasingly used in attempts to influence health behaviours. While unintended consequences of incentive provision are discussed in the literature, evidence syntheses did not identify any primary research with the aim of investigating unintended consequences of incentive interventions for lifestyle behaviour change. Our objective was to investigate perceived positive and negative unintended consequences of incentive provision for a shortlist of seven promising incentive strategies for smoking cessation in pregnancy and breastfeeding. A multi-disciplinary, mixed-methods approach included involving two service-user mother and baby groups from disadvantaged areas with experience of the target behaviours as study co-investigators. Systematic reviews informed the shortlist of incentive strategies. Qualitative semi-structured interviews and a web-based survey of health professionals asked open questions on positive and negative consequences of incentives. The participants from three UK regions were a diverse sample with and without direct experience of incentive interventions: 88 pregnant women/recent mothers/partners/family members; 53 service providers; 24 experts/decision makers and interactive discussions with 63 conference attendees. Maternity and early years health professionals (n = 497) including doctors, midwives, health visitors, public health and related staff participated in the survey. Qualitative analysis identified ethical, political, cultural, social and psychological implications of incentive delivery at population and individual levels. Four key themes emerged: how incentives can address or create inequalities; enhance or diminish intrinsic motivation and wellbeing; have a positive or negative effect on relationships with others within personal networks or health providers; and can impact on health systems and resources by raising awareness and directing service delivery

  12. Unintended consequences of incentive provision for behaviour change and maintenance around childbirth.

    Directory of Open Access Journals (Sweden)

    Gill Thomson

    Full Text Available Financial (positive or negative and non-financial incentives or rewards are increasingly used in attempts to influence health behaviours. While unintended consequences of incentive provision are discussed in the literature, evidence syntheses did not identify any primary research with the aim of investigating unintended consequences of incentive interventions for lifestyle behaviour change. Our objective was to investigate perceived positive and negative unintended consequences of incentive provision for a shortlist of seven promising incentive strategies for smoking cessation in pregnancy and breastfeeding. A multi-disciplinary, mixed-methods approach included involving two service-user mother and baby groups from disadvantaged areas with experience of the target behaviours as study co-investigators. Systematic reviews informed the shortlist of incentive strategies. Qualitative semi-structured interviews and a web-based survey of health professionals asked open questions on positive and negative consequences of incentives. The participants from three UK regions were a diverse sample with and without direct experience of incentive interventions: 88 pregnant women/recent mothers/partners/family members; 53 service providers; 24 experts/decision makers and interactive discussions with 63 conference attendees. Maternity and early years health professionals (n = 497 including doctors, midwives, health visitors, public health and related staff participated in the survey. Qualitative analysis identified ethical, political, cultural, social and psychological implications of incentive delivery at population and individual levels. Four key themes emerged: how incentives can address or create inequalities; enhance or diminish intrinsic motivation and wellbeing; have a positive or negative effect on relationships with others within personal networks or health providers; and can impact on health systems and resources by raising awareness and directing

  13. Efficient nonparametric estimation of causal mediation effects

    OpenAIRE

    Chan, K. C. G.; Imai, K.; Yam, S. C. P.; Zhang, Z.

    2016-01-01

    An essential goal of program evaluation and scientific research is the investigation of causal mechanisms. Over the past several decades, causal mediation analysis has been used in medical and social sciences to decompose the treatment effect into the natural direct and indirect effects. However, all of the existing mediation analysis methods rely on parametric modeling assumptions in one way or another, typically requiring researchers to specify multiple regression models involving the treat...

  14. The effect of selection on genetic parameter estimates

    African Journals Online (AJOL)

    Unknown

    The South African Journal of Animal Science is available online at ... A simulation study was carried out to investigate the effect of selection on the estimation of genetic ... The model contained a fixed effect, random genetic and random.

  15. Can genetic estimators provide robust estimates of the effective number of breeders in small populations?

    Directory of Open Access Journals (Sweden)

    Marion Hoehn

    Full Text Available The effective population size (N(e is proportional to the loss of genetic diversity and the rate of inbreeding, and its accurate estimation is crucial for the monitoring of small populations. Here, we integrate temporal studies of the gecko Oedura reticulata, to compare genetic and demographic estimators of N(e. Because geckos have overlapping generations, our goal was to demographically estimate N(bI, the inbreeding effective number of breeders and to calculate the N(bI/N(a ratio (N(a =number of adults for four populations. Demographically estimated N(bI ranged from 1 to 65 individuals. The mean reduction in the effective number of breeders relative to census size (N(bI/N(a was 0.1 to 1.1. We identified the variance in reproductive success as the most important variable contributing to reduction of this ratio. We used four methods to estimate the genetic based inbreeding effective number of breeders N(bI(gen and the variance effective populations size N(eV(gen estimates from the genotype data. Two of these methods - a temporal moment-based (MBT and a likelihood-based approach (TM3 require at least two samples in time, while the other two were single-sample estimators - the linkage disequilibrium method with bias correction LDNe and the program ONeSAMP. The genetic based estimates were fairly similar across methods and also similar to the demographic estimates excluding those estimates, in which upper confidence interval boundaries were uninformative. For example, LDNe and ONeSAMP estimates ranged from 14-55 and 24-48 individuals, respectively. However, temporal methods suffered from a large variation in confidence intervals and concerns about the prior information. We conclude that the single-sample estimators are an acceptable short-cut to estimate N(bI for species such as geckos and will be of great importance for the monitoring of species in fragmented landscapes.

  16. Estimation of Biological Effects of Tritium.

    Science.gov (United States)

    Umata, Toshiyuki

    2017-01-01

    Nuclear fusion technology is expected to create new energy in the future. However, nuclear fusion requires a large amount of tritium as a fuel, leading to concern about the exposure of radiation workers to tritium beta radiation. Furthermore, countermeasures for tritium-polluted water produced in decommissioning of the reactor at Fukushima Daiichi Nuclear Power Station may potentially cause health problems in radiation workers. Although, internal exposure to tritium at a low dose/low dose rate can be assumed, biological effect of tritium exposure is not negligible, because tritiated water (HTO) intake to the body via the mouth/inhalation/skin would lead to homogeneous distribution throughout the whole body. Furthermore, organically-bound tritium (OBT) stays in the body as parts of the molecules that comprise living organisms resulting in long-term exposure, and the chemical form of tritium should be considered. To evaluate the biological effect of tritium, the effect should be compared with that of other radiation types. Many studies have examined the relative biological effectiveness (RBE) of tritium. Hence, we report the RBE, which was obtained with radiation carcinogenesis classified as a stochastic effect, and serves as a reference for cancer risk. We also introduce the outline of the tritium experiment and the principle of a recently developed animal experimental system using transgenic mouse to detect the biological influence of radiation exposure at a low dose/low dose rate.

  17. Malaysia's Education Policies and the Law of Unintended Consequences

    Directory of Open Access Journals (Sweden)

    Kee-Cheok Cheong

    2016-10-01

    Full Text Available Since gaining independence in 1957, the Federation of Malaya and now Malaysia has implemented education policies to broaden access, to unify an ethnically diverse population through a common curriculum and language, to enable the disadvantaged to catch up through affirmative action, and to build human capital as the country seeks to become an advanced country in the face of globalization. While some policies, such as enhancing access have achieved their objectives, others, such as unification and development of a national identity, have not. No less important are the unintended consequences of these policies. While some, like the expansion of private higher education and transnational higher education, have been a boon to Malaysian education, others, such as ethnic polarization in education, have been damaging. Some of these consequences, while unintended, have not been unexpected.

  18. ESTIMATING THE EFFECTS OF EXCHANGE AND INTEREST ...

    African Journals Online (AJOL)

    School of Management Technology,. Federal University of Technology Owerri,. Imo State, Nigeria. Abstract. The study examined the effects of exchange rate and interest rate on the ... the basic values of the firm like interest margin, sales etc. ... the economy, so it provides an easy way to gauge the performance of the entire ...

  19. Unintended Consequences of Products Liability: Evidence from the Pharmaceutical Market

    OpenAIRE

    Eric Helland; Darius N. Lakdawalla; Anup Malani; Seth A. Seabury

    2014-01-01

    In a complex economy, production is vertical and crosses jurisdictional lines. Goods are often produced by an upstream national or global firm and improved or distributed by local firms downstream. In this context, heightened products liability may have unintended consequences on product sales and consumer safety. Conventional wisdom holds that an increase in tort liability on the upstream firm will cause that firm to (weakly) increase investment in safety or disclosure. However, this may fai...

  20. Causes of unintended pregnancy among adolescents in Addis Abeba, Ethiopia

    OpenAIRE

    Nalenga, Georges Z.

    2012-01-01

    Unintended pregnancy among adolescents represents an important public health challenge in many countries, especially in developing countries. Numerous prevention strategies have been employed by countries across the world, in an effort to address this problem. However, the adolescent unwanted pregnancy still increasing in Africa, particularly in Ethiopia. It is why the researcher would like to assess the risk factors influencing the raise of this issue. The aim of the study was to identify...

  1. Logic Model Checking of Unintended Acceleration Claims in Toyota Vehicles

    Science.gov (United States)

    Gamble, Ed

    2012-01-01

    Part of the US Department of Transportation investigation of Toyota sudden unintended acceleration (SUA) involved analysis of the throttle control software, JPL Laboratory for Reliable Software applied several techniques including static analysis and logic model checking, to the software; A handful of logic models were build, Some weaknesses were identified; however, no cause for SUA was found; The full NASA report includes numerous other analyses

  2. A novel intravaginal ring to prevent HIV-1, HSV-2, HPV, and unintended pregnancy.

    Science.gov (United States)

    Ugaonkar, Shweta R; Wesenberg, Asa; Wilk, Jolanta; Seidor, Samantha; Mizenina, Olga; Kizima, Larisa; Rodriguez, Aixa; Zhang, Shimin; Levendosky, Keith; Kenney, Jessica; Aravantinou, Meropi; Derby, Nina; Grasperge, Brooke; Gettie, Agegnehu; Blanchard, James; Kumar, Narender; Roberts, Kevin; Robbiani, Melissa; Fernández-Romero, José A; Zydowsky, Thomas M

    2015-09-10

    Women urgently need a self-initiated, multipurpose prevention technology (MPT) that simultaneously reduces their risk of acquiring HIV-1, HSV-2, and HPV (latter two associated with increased risk of HIV-1 acquisition) and prevents unintended pregnancy. Here, we describe a novel core-matrix intravaginal ring (IVR), the MZCL IVR, which effectively delivered the MZC combination microbicide and a contraceptive. The MZCL IVR contains four active pharmaceutical ingredients (APIs): MIV-150 (targets HIV-1), zinc acetate (ZA; targets HIV-1 and HSV-2), carrageenan (CG; targets HPV and HSV-2), and levonorgestrel (LNG; targets unintended pregnancy). The elastomeric IVR body (matrix) was produced by hot melt extrusion of the non-water swellable elastomer, ethylene vinyl acetate (EVA-28), containing the hydrophobic small molecules, MIV-150 and LNG. The solid hydrophilic core, embedded within the IVR by compression, contained the small molecule ZA and the macromolecule CG. Hydrated ZA/CG from the core was released by diffusion via a pore on the IVR while the MIV-150/LNG diffused from the matrix continuously for 94 days (d) in vitro and up to 28 d (study period) in macaques. The APIs released in vitro and in vivo were active against HIV-1ADA-M, HSV-2, and HPV16 PsV in cell-based assays. Serum LNG was at levels associated with local contraceptive effects. The results demonstrate proof-of-concept of a novel core-matrix IVR for sustained and simultaneous delivery of diverse molecules for the prevention of HIV, HSV-2 and HPV acquisition, as well as unintended pregnancy. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Dosimetry in Interventional Radiology - Effective Dose Estimation

    International Nuclear Information System (INIS)

    Miljanic, S.; Buls, N.; Clerinx, P.; Jarvinen, H.; Nikodemova, D.; Ranogajec-Komor, M; D'Errico, F.

    2008-01-01

    Interventional radiological procedures can lead to significant radiation doses to patients and to staff members. In order to evaluate the personal doses with respect to the regulatory dose limits, doses measured by dosimeters have to be converted to effective doses (E). Measurement of personal dose equivalent Hp(10) using a single unshielded dosimeter above the lead apron can lead to significant overestimation of the effective dose, while the measurement with dosimeter under the apron can lead to underestimation. To improve the accuracy, measurements with two dosimeters, one above and the other under the apron have been suggested ( d ouble dosimetry ) . The ICRP has recommended that interventional radiology departments develop a policy that staff should wear two dosimeters. The aim of this study was to review the double dosimetry algorithms for the calculation of effective dose in high dose interventional radiology procedures. The results will be used to develop general guidelines for personal dosimetry in interventional radiology procedures. This work has been carried out by Working Group 9 (Radiation protection dosimetry of medical staff) of the CONRAD project, which is a Coordination Action supported by the European Commission within its 6th Framework Program.(author)

  4. Confirmation Testing of Essure Microinserts in Unintended Pregnancies Using a 10-Year Retrospective Database.

    Science.gov (United States)

    Rattray, Darrien; Thiel, Peter; Suchet, Ian; Thiel, John

    2016-01-01

    To examine the imaging modality used in cases of Essure failures and determine the cause of the unintended pregnancies (noncompliance to follow-up recommendations, misinterpretation of the imaging test, or device failure). Retrospective, single-center interventional cohort (Canadian Task Force classification II-2). Tertiary level hospital. Women who have had Essure placement and subsequent pregnancy. Coding data from the Regina General Hospital was examined for any pregnancy occurring after an Essure procedure. The hospital charts were then reviewed for data collection. A separate imaging database established over the same time frame was then reviewed to determine the imaging modality used in each case (transvaginal ultrasound [TVU], hysterosalpingogram [HSG], or none). Results of the imaging study were reviewed and the cause of the failure determined. Twenty-four pregnancies in 25 women were identified after Essure procedures from January 1, 2003 to March 31, 2013. There were 4 in vitro fertilization pregnancies and 4 pregnancies where the woman had been instructed not to rely on the devices because of incomplete placement noted at time of the procedure. Therefore, 17 unintended pregnancies occurred of a total 2080 procedures performed. Examination of the imaging studies revealed that 11 were due to patient noncompliance (either early cessation of backup contraception or failure to go for confirmatory imaging), 5 due to misinterpretation of the imaging tests (3 HSG, 2 TVU), and 1 device failure. This reveals a cumulative failure rate of 6 of 2080 or .29% over 10 years with only .04% (1/2080) being device related. Essure sterilization is an effective means of permanent contraception with a device failure rate of only .04%. Most unintended pregnancies after the Essure procedure result from a failure to comply with follow-up recommendations, and strategies to improve compliance should be emphasized. Copyright © 2016 AAGL. Published by Elsevier Inc. All rights

  5. Estimation of site effects in Beijing City

    International Nuclear Information System (INIS)

    Ding, Z.; Chen, Y.T.; Panza, G.F.

    2002-01-01

    For the realistic modeling of the seismic ground motion in lateral heterogeneous anelastic media, the database of 3-D geophysical structures for Beijing City has been built up to model the seismic ground motion in the City, caused by the 1976 Tangshan and the 1998 Zhangbei earthquakes. The hybrid method, that combines the modal summation and the finite difference algorithms, is used in the simulation. The modeling of the seismic ground motion for both the Tangshan and the Zhangbei earthquakes shows that the thick Quaternary sedimentary cover amplifies the peak values and increases the duration of the seismic ground motion in the northwest part of the City. Therefore the thickness of the Quaternary sediments in Beijing City is the key factor that controls the local ground effects, and four zones are defined on the base of the different thickness of the Quaternary sediments. The response spectra for each zone are computed, indicating that peak spectral values as high as 0.1g are compatible with past seismicity and can be well exceeded if an event similar to the 1697 Sanhe-Pinggu occurs. (author)

  6. Estimation of Site Effects in Beijing City

    Science.gov (United States)

    Ding, Z.; Chen, Y. T.; Panza, G. F.

    For the realistic modeling of the seismic ground motion in lateral heterogeneous anelastic media, the database of 3-D geophysical structures for Beijing City has been built up to model the seismic ground motion in the City, caused by the 1976 Tangshan and the 1998 Zhangbei earthquakes. The hybrid method, which combines the modal summation and the finite-difference algorithms, is used in the simulation. The modeling of the seismic ground motion, for both the Tangshan and the Zhangbei earthquakes, shows that the thick Quaternary sedimentary cover amplifies the peak values and increases the duration of the seismic ground motion in the northwestern part of the City. Therefore the thickness of the Quaternary sediments in Beijing City is the key factor controling the local ground effects. Four zones are defined on the base of the different thickness of the Quaternary sediments. The response spectra for each zone are computed, indicating that peak spectral values as high as 0.1 g are compatible with past seismicity and can be well exceeded if an event similar to the 1697 Sanhe-Pinggu occurs.

  7. Functional Mixed Effects Model for Small Area Estimation.

    Science.gov (United States)

    Maiti, Tapabrata; Sinha, Samiran; Zhong, Ping-Shou

    2016-09-01

    Functional data analysis has become an important area of research due to its ability of handling high dimensional and complex data structures. However, the development is limited in the context of linear mixed effect models, and in particular, for small area estimation. The linear mixed effect models are the backbone of small area estimation. In this article, we consider area level data, and fit a varying coefficient linear mixed effect model where the varying coefficients are semi-parametrically modeled via B-splines. We propose a method of estimating the fixed effect parameters and consider prediction of random effects that can be implemented using a standard software. For measuring prediction uncertainties, we derive an analytical expression for the mean squared errors, and propose a method of estimating the mean squared errors. The procedure is illustrated via a real data example, and operating characteristics of the method are judged using finite sample simulation studies.

  8. The problematic estimation of "imitation effects" in multilevel models

    Directory of Open Access Journals (Sweden)

    2003-09-01

    Full Text Available It seems plausible that a person's demographic behaviour may be influenced by that among other people in the community, for example because of an inclination to imitate. When estimating multilevel models from clustered individual data, some investigators might perhaps feel tempted to try to capture this effect by simply including on the right-hand side the average of the dependent variable, constructed by aggregation within the clusters. However, such modelling must be avoided. According to simulation experiments based on real fertility data from India, the estimated effect of this obviously endogenous variable can be very different from the true effect. Also the other community effect estimates can be strongly biased. An "imitation effect" can only be estimated under very special assumptions that in practice will be hard to defend.

  9. Unintended, but still blameworthy: the roles of awareness, desire, and anger in negligence, restitution, and punishment.

    Science.gov (United States)

    Laurent, Sean M; Nuñez, Narina L; Schweitzer, Kimberly A

    2016-11-01

    Two experiments (Experiment 1 N = 149, Experiment 2 N = 141) investigated how two mental states that underlie how perceivers reason about intentional action (awareness of action and desire for an outcome) influence blame and punishment for unintended (i.e., negligent) harms, and the role of anger in this process. Specifically, this research explores how the presence of awareness (of risk in acting, or simply of acting) and/or desire in an acting agent's mental states influences perceptions of negligence, judgements that the acting agent owes restitution to a victim, and the desire to punish the agent, mediated by anger. In both experiments, awareness and desire led to increased anger at the agent and increased perception of negligence. Anger mediated the effect of awareness and desire on negligence rather than negligence mediating the effect of mental states on anger. Anger also mediated punishment, and negligence mediated the effects of anger on restitution. We discuss how perceivers consider mental states such as awareness, desire, and knowledge when reasoning about blame and punishment for unintended harms, and the role of anger in this process.

  10. Estimating population effects of vaccination using large, routinely collected data.

    Science.gov (United States)

    Halloran, M Elizabeth; Hudgens, Michael G

    2018-01-30

    Vaccination in populations can have several kinds of effects. Establishing that vaccination produces population-level effects beyond the direct effects in the vaccinated individuals can have important consequences for public health policy. Formal methods have been developed for study designs and analysis that can estimate the different effects of vaccination. However, implementing field studies to evaluate the different effects of vaccination can be expensive, of limited generalizability, or unethical. It would be advantageous to use routinely collected data to estimate the different effects of vaccination. We consider how different types of data are needed to estimate different effects of vaccination. The examples include rotavirus vaccination of young children, influenza vaccination of elderly adults, and a targeted influenza vaccination campaign in schools. Directions for future research are discussed. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  11. The ineffectiveness and unintended consequences of the public health war on obesity.

    Science.gov (United States)

    Ramos Salas, Ximena

    2015-02-03

    The public health war on obesity has had little impact on obesity prevalence and has resulted in unintended consequences. Its ineffectiveness has been attributed to: 1) heavy focus on individual-based approaches and lack of scaled-up socio-environmental policies and programs, 2) modest effects of interventions in reducing and preventing obesity at the population level, and 3) inappropriate focus on weight rather than health. An unintended consequence of these policies and programs is excessive weight preoccupation among the population, which can lead to stigma, body dissatisfaction, dieting, disordered eating, and even death from effects of extreme dieting, anorexia, and obesity surgery complications, or from suicide that results from weight-based bullying. Future public health approaches should: a) avoid simplistic obesity messages that focus solely on individuals' responsibility for weight and health, b) focus on health outcomes rather than weight control, and c) address the complexity of obesity and target both individual-level and system-level determinants of health.

  12. Instrumental variables estimates of peer effects in social networks.

    Science.gov (United States)

    An, Weihua

    2015-03-01

    Estimating peer effects with observational data is very difficult because of contextual confounding, peer selection, simultaneity bias, and measurement error, etc. In this paper, I show that instrumental variables (IVs) can help to address these problems in order to provide causal estimates of peer effects. Based on data collected from over 4000 students in six middle schools in China, I use the IV methods to estimate peer effects on smoking. My design-based IV approach differs from previous ones in that it helps to construct potentially strong IVs and to directly test possible violation of exogeneity of the IVs. I show that measurement error in smoking can lead to both under- and imprecise estimations of peer effects. Based on a refined measure of smoking, I find consistent evidence for peer effects on smoking. If a student's best friend smoked within the past 30 days, the student was about one fifth (as indicated by the OLS estimate) or 40 percentage points (as indicated by the IV estimate) more likely to smoke in the same time period. The findings are robust to a variety of robustness checks. I also show that sharing cigarettes may be a mechanism for peer effects on smoking. A 10% increase in the number of cigarettes smoked by a student's best friend is associated with about 4% increase in the number of cigarettes smoked by the student in the same time period. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. How to Estimate and Interpret Various Effect Sizes

    Science.gov (United States)

    Vacha-Haase, Tammi; Thompson, Bruce

    2004-01-01

    The present article presents a tutorial on how to estimate and interpret various effect sizes. The 5th edition of the Publication Manual of the American Psychological Association (2001) described the failure to report effect sizes as a "defect" (p. 5), and 23 journals have published author guidelines requiring effect size reporting. Although…

  14. The trend of foreign direct investment movement: Did unintended nation brand of legal-families play an instrumental role?

    OpenAIRE

    Tse, Chin-Bun; Kam, Oi-Yan

    2018-01-01

    Combining the suggestion from Fan (2006) that a nation can have a brand image without deliberating efforts of nation branding and the work from Klerman et al. (2011) on Colonial History and effects on legal systems, we view that legal-systems could be an unintended nation brand that could instrumentally affect foreign direct investment (FDI) activities. We classify 193 countries according to their Colonial History or no-Colonial History into 5 legal-families. Applying Generalised Methods of M...

  15. Intended and unintended consequences of mandatory IFRS adoption: A review of extant evidence and suggestions for future research

    OpenAIRE

    Ulf Brüggemann; Jörg-Markus Hitz; Thorsten Sellhorn

    2012-01-01

    This paper discusses empirical evidence on the economic consequences of mandatory adoption of International Financial Reporting Standards (IFRS) in the European Union (EU) and provides suggestions on how future research can add to our understanding of these effects. Based on the explicitly stated objectives of the EU‟s so-called „IAS Regulation‟, we distinguish between intended and unintended consequences of mandatory IFRS adoption. Empirical research on the intended consequences genera...

  16. Effect size estimates: current use, calculations, and interpretation.

    Science.gov (United States)

    Fritz, Catherine O; Morris, Peter E; Richler, Jennifer J

    2012-02-01

    The Publication Manual of the American Psychological Association (American Psychological Association, 2001, American Psychological Association, 2010) calls for the reporting of effect sizes and their confidence intervals. Estimates of effect size are useful for determining the practical or theoretical importance of an effect, the relative contributions of factors, and the power of an analysis. We surveyed articles published in 2009 and 2010 in the Journal of Experimental Psychology: General, noting the statistical analyses reported and the associated reporting of effect size estimates. Effect sizes were reported for fewer than half of the analyses; no article reported a confidence interval for an effect size. The most often reported analysis was analysis of variance, and almost half of these reports were not accompanied by effect sizes. Partial η2 was the most commonly reported effect size estimate for analysis of variance. For t tests, 2/3 of the articles did not report an associated effect size estimate; Cohen's d was the most often reported. We provide a straightforward guide to understanding, selecting, calculating, and interpreting effect sizes for many types of data and to methods for calculating effect size confidence intervals and power analysis.

  17. Estimating linear effects in ANOVA designs: the easy way.

    Science.gov (United States)

    Pinhas, Michal; Tzelgov, Joseph; Ganor-Stern, Dana

    2012-09-01

    Research in cognitive science has documented numerous phenomena that are approximated by linear relationships. In the domain of numerical cognition, the use of linear regression for estimating linear effects (e.g., distance and SNARC effects) became common following Fias, Brysbaert, Geypens, and d'Ydewalle's (1996) study on the SNARC effect. While their work has become the model for analyzing linear effects in the field, it requires statistical analysis of individual participants and does not provide measures of the proportions of variability accounted for (cf. Lorch & Myers, 1990). In the present methodological note, using both the distance and SNARC effects as examples, we demonstrate how linear effects can be estimated in a simple way within the framework of repeated measures analysis of variance. This method allows for estimating effect sizes in terms of both slope and proportions of variability accounted for. Finally, we show that our method can easily be extended to estimate linear interaction effects, not just linear effects calculated as main effects.

  18. Menu labeling: the unintended consequences to the consumer.

    Science.gov (United States)

    Black, Ellen A

    2014-01-01

    The Affordable Care Act requires certain restaurants to provide nutritional information on their menus and menu boards, which is referred to as menu labeling. Menu labeling presupposes that providing consumers with the nutritional information about their food will cause them to reconsider their food choices by picking healthier food options over less healthy options, thereby reducing the nation's high obesity rate. However, several studies have shown that consumers do not make healthier food choices even when armed with menu labeling. The issue then becomes whether menu labeling provides a correlative benefit to consumers or whether there are unintended consequences that ultimately harm consumers.

  19. The Unintended Consequences of Social Media in Healthcare: New Problems and New Solutions.

    Science.gov (United States)

    Hors-Fraile, S; Atique, S; Mayer, M A; Denecke, K; Merolli, M; Househ, M

    2016-11-10

    Social media is increasingly being used in conjunction with health information technology (health IT). The objective of this paper is to identify some of the undesirable outcomes that arise from this integration and to suggest solutions to these problems. After a discussion with experts to elicit the topics that should be included in the survey, we performed a narrative review based on recent literature and interviewed multidisciplinary experts from different areas. In each case, we identified and analyzed the unintended effects of social media in health IT. Each analyzed topic provided a different set of unintended consequences. Most relevant consequences include lack of privacy with ethical and legal issues, patient confusion in disease management, poor information accuracy in crowdsourcing, unclear responsibilities, misleading and biased information in the prevention and detection of epidemics, and demotivation in gamified health solutions with social components. Using social media in healthcare offers several benefits, but it is not exempt of potential problems, and not all of these problems have clear solutions. We recommend careful design of digital systems in order to minimize patient's feelings of demotivation and frustration and we recommend following specific guidelines that should be created by all stakeholders in the healthcare ecosystem.

  20. ["Unintended consequences of scientific discoveries" or: "Heterogeny of purposes" as phenomena of the history of science].

    Science.gov (United States)

    Wittkau-Horgby, A

    2001-01-01

    This paper deals with an old observation in respect to man's action--the problem of unintended consequences of human action. It presents the scientific approaches to this phenomenon in the 18th century and focusses then on the problem of unintended consequences of scientific discoveries. Using the prominent examples of Copernicus and Darwin the author shows that the actual outcomes and final effects of scientific discoveries must not necessarily be the originally intended ones. On the contrary, especially those results of scientific discoveries which have affected the sphere of world view (Weltanschauung) like the research works of Copernicus and Darwin were originally meant to be only scientific studies. The final results in respect to the world view were on Copernicus' side not even realized and on Darwin's side neither intended nor welcomed. The conclusion of this analysis is that due to the fact that both scientists did not have the intention to change the world view they can only partly be regarded to be responsible for the fundamental changes they finally caused.

  1. Considerations regarding the unintended radiation exposure of the embryo, fetus or nursing child

    International Nuclear Information System (INIS)

    1994-01-01

    In Commentary No. 7, Misadministration of Radioactive Material in Medicine - Scientific Background (NCRP, 1991), the National Council on Radiation Protection and Measurements (NCRP) reviewed the misadministration of radioactive material in medicine. In that commentary, the number and variety of nuclear medicine procedures performed in the United States, administered activities and the resulting radiation doses were reviewed. Information on the reported frequency and nature of misadministrations was also summarized, as were the possible deterministic and stochastic effects that might occur as a result of the use in medicine of pharmaceuticals containing radioactive material. In addition, the basis for developing reporting requirements for the unintended administration of radioactive material to patients was also provided. The purpose of this Commentary is: (1) to draw special attention to problems in the protection of the embryo, fetus and nursing child that might result from the use, both externally and internally, of radioactive material in the medical diagnosis and treatment of the mother, and (2) to assist the Nuclear Regulatory Commission (NRC) in developing requirements appropriate to dealing with the unintended exposure of the embryo, fetus or nursing child as a result of such procedures. The sensitivity of humans during these stages of life justify separate consideration beyond that already given for adults in NCRP Commentary No. 7 (NCRP, 1991)

  2. Adult head CT scans: the uncertainties of effective dose estimates

    International Nuclear Information System (INIS)

    Gregory, Kent J.; Bibbo, Giovanni; Pattison, John E.

    2008-01-01

    Full Text: CT scanning is a high dose imaging modality. Effective dose estimates from CT scans can provide important information to patients and medical professionals. For example, medical practitioners can use the dose to estimate the risk to the patient, and judge whether this risk is outweighed by the benefits of the CT examination, while radiographers can gauge the effect of different scanning protocols on the patient effective dose, and take this into consideration when establishing routine scan settings. Dose estimates also form an important part of epidemiological studies examining the health effects of medical radiation exposures on the wider population. Medical physicists have been devoting significant effort towards estimating patient radiation doses from diagnostic CT scans for some years. The question arises: How accurate are these effective dose estimates? The need for a greater understanding and improvement of the uncertainties in CT dose estimates is now gaining recognition as an important issue (BEIR VII 2006). This study is an attempt to analyse and quantify the uncertainty components relating to effective dose estimates from adult head CT examinations that are calculated with four commonly used methods. The dose estimation methods analysed are the Nagel method, the ImpaCT method, the Wellhoefer method and the Dose-Length Product (DLP) method. The analysis of the uncertainties was performed in accordance with the International Standards Organisation's Guide to the Expression of Uncertainty in Measurement as discussed in Gregory et al (Australas. Phys. Eng. Sci. Med., 28: 131-139, 2005). The uncertainty components vary, depending on the method used to derive the effective dose estimate. Uncertainty components in this study include the statistical and other errors from Monte Carlo simulations, uncertainties in the CT settings and positions of patients in the CT gantry, calibration errors from pencil ionization chambers, the variations in the organ

  3. Socioeconomic inequality of unintended pregnancy in the Iranian population: a decomposition approach.

    Science.gov (United States)

    Omani-Samani, Reza; Amini Rarani, Mostafa; Sepidarkish, Mahdi; Khedmati Morasae, Esmaeil; Maroufizadeh, Saman; Almasi-Hashiani, Amir

    2018-05-09

    There are several studies regarding the predictors or risk factors of unintended pregnancy, but only a small number of studies have been carried out concerning the socio-economic factors influencing the unintended pregnancy rate. This study aimed to determine the socioeconomic inequality of unintended pregnancy in Tehran, Iran, as a developing country. In this hospital based cross-sectional study, 5152 deliveries from 103 hospitals in Tehran (the capital of Iran) were included in the analysis in July 2015. Socioeconomic status (SES) was measured through an asset-based method and principal component analysis was carried out to calculate the household SES. The concentration index and curve was used to measure SES inequality in unintended pregnancy, and then decomposed into its determinants. The data was analyzed by statistical Stata software. The Wagstaff normalized concentration index of unintended pregnancy (- 0.108 (95% Confidence Interval (CI) = - 0.119 ~ - 0.054)) endorses that unintended pregnancy is more concentrated among poorer mothers. The results showed that SES accounted for 27% of unintended pregnancy inequality, followed by the mother's nationality (19%), father's age (16%), mother's age (10%), father's education level (7%) and Body Mass Index (BMI) groups (5%). Unintended pregnancy is unequally distributed among Iranian women and is more concentrated among poor women. Economic status had the most positive contribution, explaining 27% of inequality in unintended pregnancy.

  4. Estimation of Nonlinear Dynamic Panel Data Models with Individual Effects

    Directory of Open Access Journals (Sweden)

    Yi Hu

    2014-01-01

    Full Text Available This paper suggests a generalized method of moments (GMM based estimation for dynamic panel data models with individual specific fixed effects and threshold effects simultaneously. We extend Hansen’s (Hansen, 1999 original setup to models including endogenous regressors, specifically, lagged dependent variables. To address the problem of endogeneity of these nonlinear dynamic panel data models, we prove that the orthogonality conditions proposed by Arellano and Bond (1991 are valid. The threshold and slope parameters are estimated by GMM, and asymptotic distribution of the slope parameters is derived. Finite sample performance of the estimation is investigated through Monte Carlo simulations. It shows that the threshold and slope parameter can be estimated accurately and also the finite sample distribution of slope parameters is well approximated by the asymptotic distribution.

  5. Estimating the Effects of Exchange Rate Volatility on Export Volumes

    OpenAIRE

    Wang, Kai-Li; Barrett, Christopher B.

    2007-01-01

    This paper takes a new empirical look at the long-standing question of the effect of exchange rate volatility on international trade flows by studying the case of Taiwan's exports to the United States from 1989-1998. In particular, we employ sectoral-level, monthly data and an innovative multivariate GARCH-M estimator with corrections for leptokurtic errors. This estimator allows for the possibility that traders' forward-looking contracting behavior might condition the way in which exchange r...

  6. Instrumental variable estimation of treatment effects for duration outcomes

    NARCIS (Netherlands)

    G.E. Bijwaard (Govert)

    2007-01-01

    textabstractIn this article we propose and implement an instrumental variable estimation procedure to obtain treatment effects on duration outcomes. The method can handle the typical complications that arise with duration data of time-varying treatment and censoring. The treatment effect we

  7. Estimation of the Continuous and Discontinuous Leverage Effects.

    Science.gov (United States)

    Aït-Sahalia, Yacine; Fan, Jianqing; Laeven, Roger J A; Wang, Christina Dan; Yang, Xiye

    2017-01-01

    This paper examines the leverage effect, or the generally negative covariation between asset returns and their changes in volatility, under a general setup that allows the log-price and volatility processes to be Itô semimartingales. We decompose the leverage effect into continuous and discontinuous parts and develop statistical methods to estimate them. We establish the asymptotic properties of these estimators. We also extend our methods and results (for the continuous leverage) to the situation where there is market microstructure noise in the observed returns. We show in Monte Carlo simulations that our estimators have good finite sample performance. When applying our methods to real data, our empirical results provide convincing evidence of the presence of the two leverage effects, especially the discontinuous one.

  8. Pension fund regulation: Unintended consequences of foreign investment restrictions in an emerging market economy

    Directory of Open Access Journals (Sweden)

    Coert Frederik Erasmus

    2016-12-01

    Full Text Available Retirement savings allow investors to earn income after retirement by saving while being part of the workforce. Retirement savings comprise the largest portion of retirement savings and should be safeguarded by effective regulation. To safeguard retirement savings, exposure to foreign asset investments is limited. However, in an emerging economy, limiting foreign asset investments, especially investment in developed markets, could hamper the potential investment returns due to the translation risk. To assess the effect of translation risk, a preservation provident fund was used in the present study to determine whether the returns of this preservation provident fund would be adversely affected by investment allocation regulation. The findings indicated how the translation effect affected the preservation provident fund, illustrating the adverse unintended consequences of investment regulation in emerging market economies. Consequently, regulators should reconsider the maximum allowed foreign asset investment in pension fund regulations to enhance investment returns from foreign asset investments

  9. Anticipating and addressing the unintended consequences of health IT and policy: a report from the AMIA 2009 Health Policy Meeting.

    Science.gov (United States)

    Bloomrosen, Meryl; Starren, Justin; Lorenzi, Nancy M; Ash, Joan S; Patel, Vimla L; Shortliffe, Edward H

    2011-01-01

    Federal legislation (Health Information Technology for Economic and Clinical Health (HITECH) Act) has provided funds to support an unprecedented increase in health information technology (HIT) adoption for healthcare provider organizations and professionals throughout the U.S. While recognizing the promise that widespread HIT adoption and meaningful use can bring to efforts to improve the quality, safety, and efficiency of healthcare, the American Medical Informatics Association devoted its 2009 Annual Health Policy Meeting to consideration of unanticipated consequences that could result with the increased implementation of HIT. Conference participants focused on possible unintended and unanticipated, as well as undesirable, consequences of HIT implementation. They employed an input-output model to guide discussion on occurrence of these consequences in four domains: technical, human/cognitive, organizational, and fiscal/policy and regulation. The authors outline the conference's recommendations: (1) an enhanced research agenda to guide study into the causes, manifestations, and mitigation of unintended consequences resulting from HIT implementations; (2) creation of a framework to promote sharing of HIT implementation experiences and the development of best practices that minimize unintended consequences; and (3) recognition of the key role of the Federal Government in providing leadership and oversight in analyzing the effects of HIT-related implementations and policies.

  10. Methodology development for the radioecological monitoring effectiveness estimation

    International Nuclear Information System (INIS)

    Gusev, A.E.; Kozlov, A.A.; Lavrov, K.N.; Sobolev, I.A.; Tsyplyakova, T.P.

    1997-01-01

    A general model for estimation of the programs assuring radiation and ecological public protection is described. The complex of purposes and criteria characterizing and giving an opportunity to estimate the effectiveness of environment protection program composition is selected. An algorithm for selecting the optimal management decision from the view point of work cost connected with population protection improvement is considered. The position of radiation-ecological monitoring in general problem of environment pollution is determined. It is shown that the monitoring organizing effectiveness is closely connected with population radiation and ecological protection

  11. Unintended pregnancy, contraceptive use, and childbearing desires among HIV-infected and HIV-uninfected women in Botswana: across-sectional study.

    Science.gov (United States)

    Mayondi, Gloria K; Wirth, Kathleen; Morroni, Chelsea; Moyo, Sikhulile; Ajibola, Gbolahan; Diseko, Modiegi; Sakoi, Maureen; Magetse, Jane Dipuo; Moabi, Kebaiphe; Leidner, Jean; Makhema, Joseph; Kammerer, Betsy; Lockman, Shahin

    2016-01-16

    pregnancy and contraceptive failure/misuse underscore an urgent need for better access to effective contraceptive methods for HIV-uninfected and HIV -infected women in Botswana. Lower socioeconomic status and lack of pre-conception HIV testing may indicate higher risk for unintended pregnancy in this setting.

  12. Improving Evaluation to Address the Unintended Consequences of Health Information Technology:. a Position Paper from the Working Group on Technology Assessment & Quality Development

    NARCIS (Netherlands)

    Magrabi, F.; Ammenwerth, E.; Hyppönen, H.; de Keizer, N.; Nykänen, P.; Rigby, M.; Scott, P.; Talmon, J.; Georgiou, A.

    2016-01-01

    With growing use of IT by healthcare professionals and patients, the opportunity for any unintended effects of technology to disrupt care health processes and outcomes is intensified. The objectives of this position paper by the IMIA Working Group (WG) on Technology Assessment and Quality

  13. The burden of unintended pregnancies in Brazil: a social and public health system cost analysis

    Directory of Open Access Journals (Sweden)

    Le HH

    2014-07-01

    Full Text Available Hoa H Le,1 Mark P Connolly,1,2 Luis Bahamondes,3 Jose G Cecatti,3 Jingbo Yu,4 Henry X Hu4 1Department of Pharmacoeconomics and Pharmacoepidemiology, University of Groningen, Groningen, the Netherlands; 2Global Market Access Solutions, Saint-Prex, Switzerland; 3Department of Obstetrics and Gynecology, School of Medical Sciences, University of Campinas, Campinas, Brazil; 4Merck & Co, Whitehouse Station, NJ, USA Background: Unintended pregnancy (UP is an unmet medical need with consequences worldwide. We evaluate the costs of UP based on pregnancies in Brazil from for the year 2010. Methods: The consequences of UP were evaluated using decision analysis based on pregnancy rates and outcomes as miscarriage, induced abortion, and live birth, which were factored into the analysis. The model discriminated between maternal and child outcomes and accounted for costs (in Brazilian currency [Real$, R$] within the Brazilian public health service attributed to preterm birth, neonatal admission, cerebral palsy, and neonatal and maternal mortality. Event probabilities were obtained from local resources. Results: We estimate that 1.8 million UPs resulted in 159,151 miscarriages, 48,769 induced abortions, 1.58 million live births, and 312 maternal deaths, including ten (3% attributed to unsafe abortions. The total estimated costs attributed to UP are R$4.1 billion annually, including R$32 million (0.8% and R$4.07 billion (99.2% attributed to miscarriages and births and complications, respectively. Direct birth costs accounted for approximately R$1.22 billion (30.0%, with labor and delivery responsible for most costs (R$988 million; 24.3% for the year 2010. The remainder of costs were for infant complications (R$2.84 billion; 72.3% with hospital readmission during the first year accounting for approximately R$2.15 billion (52.9%. Based on the national cost, we estimate the cost per UP to be R$2,293. Conclusion: Despite weaknesses in precise estimates in annual

  14. Risk estimates for the health effects of alpha radiation

    International Nuclear Information System (INIS)

    Thomas, D.C.; McNeill, K.G.

    1981-09-01

    This report provides risk estimates for various health effects of alpha radiation. Human and animal data have been used to characterize the shapes of dose-response relations and the effects of various modifying factors, but quantitative risk estimates are based solely on human data: for lung cancer, on miners in the Colorado plateau, Czechoslovakia, Sweden, Ontario and Newfoundland; for bone and head cancers, on radium dial painters and radium-injected patients. Slopes of dose-response relations for lung cancer show a tendency to decrease with increasing dose. Linear extrapolation is unlikely to underestimate the excess risk at low doses by more than a factor of l.5. Under the linear cell-killing model, our best estimate

  15. Time improvement of photoelectric effect calculation for absorbed dose estimation

    International Nuclear Information System (INIS)

    Massa, J M; Wainschenker, R S; Doorn, J H; Caselli, E E

    2007-01-01

    Ionizing radiation therapy is a very useful tool in cancer treatment. It is very important to determine absorbed dose in human tissue to accomplish an effective treatment. A mathematical model based on affected areas is the most suitable tool to estimate the absorbed dose. Lately, Monte Carlo based techniques have become the most reliable, but they are time expensive. Absorbed dose calculating programs using different strategies have to choose between estimation quality and calculating time. This paper describes an optimized method for the photoelectron polar angle calculation in photoelectric effect, which is significant to estimate deposited energy in human tissue. In the case studies, time cost reduction nearly reached 86%, meaning that the time needed to do the calculation is approximately 1/7 th of the non optimized approach. This has been done keeping precision invariant

  16. Unintended Learning in Primary School Practical Science Lessons from Polanyi's Perspective of Intellectual Passion

    Science.gov (United States)

    Park, Jisun; Song, Jinwoong; Abrahams, Ian

    2016-01-01

    This study explored, from the perspective of intellectual passion developed by Michael Polanyi, the unintended learning that occurred in primary practical science lessons. We use the term "unintended" learning to distinguish it from "intended" learning that appears in teachers' learning objectives. Data were collected using…

  17. Twelve-year retrospective review of unintended pregnancies after Essure sterilization in the Netherlands

    NARCIS (Netherlands)

    Hitzerd, Emilie; Schreuder, Henk W R; Vleugels, Michel P H; Veersema, Sebastiaan

    2016-01-01

    Objective To identify factors contributing to the occurrence of unintended pregnancies after Essure sterilization in the Netherlands. Even though Essure is a permanent method of contraception, unintended pregnancies have been reported.  Design  Retrospective case series analysis. Setting Not

  18. Digital Disturbances, Disorders, and Pathologies: A Discussion of Some Unintended Consequences of Technology in Higher Education

    Science.gov (United States)

    Haughton, Noela A.; Yeh, Kuo-Chuan; Nworie, John; Romero, Liz

    2013-01-01

    As with any innovation, the adoption and diffusion of digital technologies in higher education have also brought unintended consequences. This article discusses the unintended misuse of these technologies in the higher education setting. Depending upon severity, these consequences discussed--distraction, addiction, academic dishonesty, and…

  19. New Estimates of the Effect of Unemployment on Enlisted Retention

    Science.gov (United States)

    1985-07-01

    S14cw’tity lafication) New Estimates of the Effect of Umemployment on Enlisted Retention 12. PERSONAL AUTHOR(S) Ile, TYPE OF REPORT 3b~. TIME COVERED...wider swings in the umemployment rate during recent years, relative military pay has played at least as important a role as the unemployment rate in

  20. Sampling strategies for estimating brook trout effective population size

    Science.gov (United States)

    Andrew R. Whiteley; Jason A. Coombs; Mark Hudy; Zachary Robinson; Keith H. Nislow; Benjamin H. Letcher

    2012-01-01

    The influence of sampling strategy on estimates of effective population size (Ne) from single-sample genetic methods has not been rigorously examined, though these methods are increasingly used. For headwater salmonids, spatially close kin association among age-0 individuals suggests that sampling strategy (number of individuals and location from...

  1. Error Estimates for the Approximation of the Effective Hamiltonian

    International Nuclear Information System (INIS)

    Camilli, Fabio; Capuzzo Dolcetta, Italo; Gomes, Diogo A.

    2008-01-01

    We study approximation schemes for the cell problem arising in homogenization of Hamilton-Jacobi equations. We prove several error estimates concerning the rate of convergence of the approximation scheme to the effective Hamiltonian, both in the optimal control setting and as well as in the calculus of variations setting

  2. Efficient estimation of feedback effects with application to climate models

    International Nuclear Information System (INIS)

    Cacugi, D.G.; Hall, M.C.G.

    1984-01-01

    This work presents an efficient method for calculating the sensitivity of a mathematical model's result to feedback. Feedback is defined in terms of an operator acting on the model's dependent variables. The sensitivity to feedback is defined as a functional derivative, and a method is presented to evaluate this derivative using adjoint functions. Typically, this method allows the individual effect of many different feedbacks to be estimated with a total additional computing time comparable to only one recalculation. The effects on a CO 2 -doubling experiment of actually incorporating surface albedo and water vapor feedbacks in radiative-convective model are compared with sensivities calculated using adjoint functions. These sensitivities predict the actual effects of feedback with at least the correct sign and order of magnitude. It is anticipated that this method of estimation the effect of feedback will be useful for more complex models where extensive recalculations for each of a variety of different feedbacks is impractical

  3. Estimated effects of interfacial vaporization on fission product scrubbing

    International Nuclear Information System (INIS)

    Moody, F.J.; Nagy, S.G.

    1983-01-01

    When bubbles containing non-condensible gas rise through a water pool, interfacial evaporation causes a flow of vapor into the bubbles. The inflow reduces the outward particle motion toward the bubble wall, diminishing the effectiveness of fission product particle removal. This analysis provides an estimate of evaporation on pool scrubbing effectiveness. It is shown that hot gas, which boils water at the bubble wall, reduces the effective scrubbing height by less than five centimeters. Although the evaporative humidification in a rising bubble containing non-condensible gas has a diminishing effect on scrubbing mechanisms, substantial decontamination is still expected even for the limiting case of a saturated pool

  4. Respecting Intent and Dispelling Stereotypes by Reducing Unintended Pregnancy.

    Science.gov (United States)

    Johnsen, Dawn

    2015-01-01

    In "Expectant Fathers, Abortion, and Embryos," Dara Purvis evaluates the concepts of intent and gender stereotypes in connection with "expectational fathers" in the related contexts of abortion and assisted reproductive technologies. This comment seeks to build upon Purvis's own analysis to obviate her concern that abortion discourse promotes harmful stereotypes of men as disinterested fathers. To the contrary, for men — no less than for women — a desire to avoid or terminate pregnancy is fully consistent with loving and shared parenthood of existing or future children. The same individuals who choose to become parents at other times in their long reproductive lives will use contraception and have abortions. In fact, most women who have abortions already have children. Policies that empower men and women to avoid unintended pregnancy are the sensible, win-win, front-line approach to avoid disputes over abortion. © 2015 American Society of Law, Medicine & Ethics, Inc.

  5. Intended and unintended consequences of China's zero markup drug policy.

    Science.gov (United States)

    Yi, Hongmei; Miller, Grant; Zhang, Linxiu; Li, Shaoping; Rozelle, Scott

    2015-08-01

    Since economic liberalization in the late 1970s, China's health care providers have grown heavily reliant on revenue from drugs, which they both prescribe and sell. To curb abuse and to promote the availability, safety, and appropriate use of essential drugs, China introduced its national essential drug list in 2009 and implemented a zero markup policy designed to decouple provider compensation from drug prescription and sales. We collected and analyzed representative data from China's township health centers and their catchment-area populations both before and after the reform. We found large reductions in drug revenue, as intended by policy makers. However, we also found a doubling of inpatient care that appeared to be driven by supply, instead of demand. Thus, the reform had an important unintended consequence: China's health care providers have sought new, potentially inappropriate, forms of revenue. Project HOPE—The People-to-People Health Foundation, Inc.

  6. Robots and people with dementia: Unintended consequences and moral hazard.

    Science.gov (United States)

    O'Brolcháin, Fiachra

    2017-01-01

    The use of social robots in elder care is entering the mainstream as robots become more sophisticated and populations age. While there are many potential benefits to the use of social robots in care for the older people, there are ethical challenges as well. This article focuses on the societal consequences of the adoption of social robots in care for people with dementia. Making extensive use of Alasdair MacIntyre's Dependent Rational Animals to discuss issues of unintended consequences and moral hazard, we contend that in choosing to avoid the vulnerability and dependency of human existence, a society blinds itself from the animal reality of humankind. The consequence of this is that a flourishing society, in which each individual is helped to develop the virtues essential to her flourishing, becomes harder to achieve.

  7. Estimation of effective thermal conductivity tensor from composite microstructure images

    International Nuclear Information System (INIS)

    Thomas, M; Boyard, N; Jarny, Y; Delaunay, D

    2008-01-01

    The determination of the effective thermal properties of inhomogeneous materials is a long-standing problem of continuously interest. The impressive number of methods developed to measure or estimate the thermal properties of composite materials clearly exhibits the importance given to their knowledge. Homogenization models are a cheap way to determine or predict them. Many different approaches of homogenization were developed, but the last advances are credited to numerical methods. In this study, a new computational model is developed to estimate the 2D thermal conductivity tensor and the thermal main directions of a pure carbon/epoxy unidirectional composite. This tool is based on real composite microstructure.

  8. Cosmological perturbation effects on gravitational-wave luminosity distance estimates

    Science.gov (United States)

    Bertacca, Daniele; Raccanelli, Alvise; Bartolo, Nicola; Matarrese, Sabino

    2018-06-01

    Waveforms of gravitational waves provide information about a variety of parameters for the binary system merging. However, standard calculations have been performed assuming a FLRW universe with no perturbations. In reality this assumption should be dropped: we show that the inclusion of cosmological perturbations translates into corrections to the estimate of astrophysical parameters derived for the merging binary systems. We compute corrections to the estimate of the luminosity distance due to velocity, volume, lensing and gravitational potential effects. Our results show that the amplitude of the corrections will be negligible for current instruments, mildly important for experiments like the planned DECIGO, and very important for future ones such as the Big Bang Observer.

  9. Nonparametric Estimation of Distributions in Random Effects Models

    KAUST Repository

    Hart, Jeffrey D.

    2011-01-01

    We propose using minimum distance to obtain nonparametric estimates of the distributions of components in random effects models. A main setting considered is equivalent to having a large number of small datasets whose locations, and perhaps scales, vary randomly, but which otherwise have a common distribution. Interest focuses on estimating the distribution that is common to all datasets, knowledge of which is crucial in multiple testing problems where a location/scale invariant test is applied to every small dataset. A detailed algorithm for computing minimum distance estimates is proposed, and the usefulness of our methodology is illustrated by a simulation study and an analysis of microarray data. Supplemental materials for the article, including R-code and a dataset, are available online. © 2011 American Statistical Association.

  10. Unintended compositional changes in genetically modified (GM) crops: 20 years of research.

    Science.gov (United States)

    Herman, Rod A; Price, William D

    2013-12-04

    The compositional equivalency between genetically modified (GM) crops and nontransgenic comparators has been a fundamental component of human health safety assessment for 20 years. During this time, a large amount of information has been amassed on the compositional changes that accompany both the transgenesis process and traditional breeding methods; additionally, the genetic mechanisms behind these changes have been elucidated. After two decades, scientists are encouraged to objectively assess this body of literature and determine if sufficient scientific uncertainty still exists to continue the general requirement for these studies to support the safety assessment of transgenic crops. It is concluded that suspect unintended compositional effects that could be caused by genetic modification have not materialized on the basis of this substantial literature. Hence, compositional equivalence studies uniquely required for GM crops may no longer be justified on the basis of scientific uncertainty.

  11. A Curse of Coal? Exploring Unintended Regional Consequences of Coal Energy in The Czech Republic

    Directory of Open Access Journals (Sweden)

    Frantál Bohumil

    2014-07-01

    Full Text Available Focusing on coal energy from a geographical perspective, the unintended regional consequences of coal mining and combustion in the Czech Republic are discussed and analysed in terms of the environmental injustice and resource curse theories. The explorative case study attempts to identify significant associations between the spatially uneven distribution of coal power plants and the environmental and socioeconomic characteristics and development trends of affected areas. The findings indicate that the coal industries have contributed to slightly above average incomes and pensions, and have provided households with some technical services such as district heating. However, these positive effects have come at high environmental and health costs paid by the local populations. Above average rates of unemployment, homelessness and crime indicate that the benefits have been unevenly distributed economically. A higher proportion of uneducated people and ethnic minorities in affected districts suggest that coal energy is environmentally unjust.

  12. Lessons learned from unintended consequences about erasing the stigma of mental illness.

    Science.gov (United States)

    Corrigan, Patrick W

    2016-02-01

    Advocates and scientists have partnered to develop and evaluate programs meant to erase the egregious effects of the different forms of stigma. Enough evidence has been collected to yield lessons about approaches to stigma change. Some of the most insightful of these lessons emerge from unintended consequences of good intentioned approaches, and are the focus of this paper. They include the limited benefits of education especially when compared to contact, beating stigma is more than changing words, beware pity as a message, understand the competing agendas of stigma change, replace ideas of normalcy with solidarity, and avoid framing self-stigma as the problem of people with mental illness and not of society. The paper ends with consideration of the back seat role that psychiatrists and other mental health providers should have in stigma change. © 2015 World Psychiatric Association.

  13. Effect of stress on turbine fish passage mortality estimates

    International Nuclear Information System (INIS)

    Ruggles, C.P.

    1993-01-01

    Tests were conducted with juvenile alewife to determine the effects of four experimental protocols upon turbine fish passage mortality estimates. Three protocols determined the effect of cumulative stresses upon fish, while the fourth determined the effect of long range truck transportation prior to release into the penstock or tailrace. The wide range in results were attributed to the presence or absence of additional stress factors associated with the experiments. For instance, fish may survive passage through a turbine, or non-turbine related stresses imposed by the investigator; however, when both are imposed, the cumulative stresses may be lethal. The impact of protocol stress on turbine mortality estimates becomes almost exponential after control mortality exceeds 10%. Valid turbine related mortalities may be determined only after stresses associated with experimental protocol are adequately reduced. This is usually indicated by a control mortality of less than 10%. 14 refs., 5 figs., 6 tabs

  14. Estimating the rebound effect in US manufacturing energy consumption

    International Nuclear Information System (INIS)

    Bentzen, Jan

    2004-01-01

    The energy price shocks of the 1970s are usually assumed to have increased the search for new energy saving technologies where eventual gains in energy efficiencies will reduce the real per unit price of energy services and hence, the consumption of energy will rise and partially offset the initial reduction in the usage of energy sources. This is the 'rebound effect', which is estimated for the US manufacturing sector using time series data applying the dynamic OLS method (DOLS). When allowing for asymmetric price effects the rebound effect is found to be approximately 24% for the US manufacturing sector

  15. Measures to reduce car-fleet consumption - Estimation of effects

    International Nuclear Information System (INIS)

    Iten, R.; Hammer, S.; Keller, M.; Schmidt, N.; Sammer, K.; Wuestenhagen, R.

    2005-09-01

    This comprehensive report for the Swiss Federal Office of Energy (SFOE) takes a look at the results of a study that estimated the effects of measures that were to be taken in order to reduce the fuel consumption of fleets of vehicles as part of the SwissEnergy programme. The research reported on aimed to estimate the effects of the Energy Label on energy consumption and research concerning the results to be expected from the introduction of a bonus-malus system. Questions reviewed include the effect of fuel consumption data on making decisions concerning which vehicle to purchase, the effects of the Energy Label on consumption, the awareness of other appropriate information sources, the possible effects of a bonus-malus system and how the effectiveness of the Energy Label could be improved. The answers and results obtained are reviewed and commented on. Finally, an overall appraisal of the situation is presented and recommendations for increasing the effectiveness of the Energy Label are made

  16. Unintended effects and their detection in genetically modified crops

    NARCIS (Netherlands)

    Cellini, F.; Colquhoun, I.; Constable, A.; Davies, H.V.; Engel, K.H.; Gatehouse, A.M.R.; Kärenlampi, S.; Kok, E.J.; Leguay, J.J.; Lehesranta, S.; Noteborn, H.P.J.M.; Pedersen, J.; Smith, M.

    2004-01-01

    The commercialisation of GM crops in Europe is practically non-existent at the present time. The European Commission has instigated changes to the regulatory process to address the concerns of consumers and member states and to pave the way for removing the current moratorium. With regard to the

  17. Unintended effects were investigated in antioxidant activity between ...

    African Journals Online (AJOL)

    Jane

    2011-08-22

    Aug 22, 2011 ... modified organisms; POD, peroxidase; PPO, polyphenol oxidase; CAT ... the seeds powder were homogenized in 2 ml (for maize) or 3 ml (for canola) 100 mM .... was carried out using the Wiley GC-MS Library. The percent ...

  18. The Paradoxical and Unintended Effects of the War on Drugs

    Science.gov (United States)

    1993-04-01

    of coca leaves; 2) heroin, derived from the opium poppy; and, 3) marijuana and hashish from the cannabis plant. Cocaine and crack come into the U.S...example, is 28 to 43 per cent of its total exports, and generates more money than its major export, coffee . 52 Moreover, the drug business is a major source

  19. ESTIMATION OF AGING EFFECTS OF PILES IN MALAYSIAN OFFSHORE LOCATIONS

    Directory of Open Access Journals (Sweden)

    JERIN M. GEORGE

    2017-04-01

    Full Text Available An increasing demand for extending life and subsequently higher loading requirements of offshore jacket platforms are among the key problems faced by the offshore industry. The Aging effect has been proved to increase the axial capacity of piles, but proper methods to estimate and quantify these effects have not been developed. Borehole data from ten different Malaysian offshore locations have been analysed and they were employed to estimate the setup factor for different locations using AAU method. The setup factors found were used in the Skov and Denver equation to calculate capacity ratios of the offshore piles. The study showed that there will be an average improvement in the axial capacity of offshore piles by 42.2% and 34.9% for clayey and mixed soils respectively after a time equal to the normal design life (25 years of a jacket platform.

  20. Estimating the herd immunity effect of rotavirus vaccine.

    Science.gov (United States)

    Pollard, Suzanne L; Malpica-Llanos, Tanya; Friberg, Ingrid K; Fischer-Walker, Christa; Ashraf, Sania; Walker, Neff

    2015-07-31

    Diarrhea is one of the leading causes of death in children under 5, and an estimated 39% of these deaths are attributable to rotavirus. Currently two live, oral rotavirus vaccines have been introduced on the market; however, the herd immunity effect associated with rotavirus vaccine has not yet been quantified. The purpose of this meta-analysis was to estimate the herd immunity effects associated with rotavirus vaccines. We performed a systematic literature review of articles published between 2008 and 2014 that measured the impact of rotavirus vaccine on severe gastroenteritis (GE) morbidity or mortality. We assessed the quality of published studies using a standard protocol and conducted meta-analyses to estimate the herd immunity effect in children less than one year of age across all years presented in the studies. We conducted these analyses separately for studies reporting a rotavirus-specific GE outcome and those reporting an all-cause GE outcome. In studies reporting a rotavirus-specific GE outcome, four of five of which were conducted in the United States, the median herd effect across all study years was 22% [19-25%]. In studies reporting an all-cause GE outcome, all of which were conducted in Latin America, the median herd effect was 24.9% [11-30%]. There is evidence that rotavirus vaccination confers a herd immunity effect in children under one year of age in the United States and Latin American countries. Given the high variability in vaccine efficacy across regions, more studies are needed to better examine herd immunity effects in high mortality regions. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Estimation and Inference for Very Large Linear Mixed Effects Models

    OpenAIRE

    Gao, K.; Owen, A. B.

    2016-01-01

    Linear mixed models with large imbalanced crossed random effects structures pose severe computational problems for maximum likelihood estimation and for Bayesian analysis. The costs can grow as fast as $N^{3/2}$ when there are N observations. Such problems arise in any setting where the underlying factors satisfy a many to many relationship (instead of a nested one) and in electronic commerce applications, the N can be quite large. Methods that do not account for the correlation structure can...

  2. Estimating Effective Subsidy Rates of Student Aid Programs

    OpenAIRE

    Stacey H. CHEN

    2008-01-01

    Every year millions of high school students and their parents in the US are asked to fill out complicated financial aid application forms. However, few studies have estimated the responsiveness of government financial aid schemes to changes in financial needs of the students. This paper identifies the effective subsidy rate (ESR) of student aid, as defined by the coefficient of financial needs in the regression of financial aid. The ESR measures the proportion of subsidy of student aid under ...

  3. Evaluation of Rock Stress Estimation by the Kaiser effect

    International Nuclear Information System (INIS)

    Lehtonen, A.

    2005-11-01

    The knowledge of in situ stress is the key input parameter in many rock mechanics analyses. Information on stress allows the definition of boundary conditions for various modelling and engineering tasks. Presently, the estimation of stresses in bedrock is one of the most difficult, time-consuming and high-priced rock mechanical investigations. In addition, the methods used today have not evolved significantly in many years. This brings out a demand for novel, more economical and practical methods for stress estimation. In this study, one such method, Kaiser effect based on acoustic emission of core samples, has been evaluated. It can be described as a 'memory' in rock that is indicated by a change in acoustic emission emitted during uniaxial loading test. The most tempting feature of this method is the ability to estimate the in situ stress state from core specimens in laboratory conditions. This yields considerable cost savings compared to laborious borehole measurements. Kaiser effect has been studied in order to determine in situ stresses for decades without any major success. However, recent studies in Australia and China have been promising and made the estimation of stress tensor possible from differently oriented core samples. The aim of this work has been to develop a similar estimation method in Finland (including both equipment and data reduction), and to test it on samples obtained from Olkiluoto, Eurajoki. The developed measuring system proved to work well. The quality of obtained data varied, but they were still interpretable. The results obtained from these tests were compared with results of previous overcoring measurements, and they showed quite good correlation. Thus, the results were promising, but the method still needs further development and more testing before the final decision on its feasibility can be made. (orig.)

  4. Unintended consequences of human research ethics committees: au revoir workplace studies?

    Science.gov (United States)

    Bamber, Greg J; Sappey, Jennifer

    2007-07-01

    To protect the welfare and rights of participants in research and to facilitate research that will be of benefit, as well as protect them against litigation, universities and research-funding agencies in Australia adopted the National Statement on Ethical Conduct in Research Involving Humans (NHMRC 1999). In many other countries there are similar statements. However, the ways in which such statements are often implemented by Human Research Ethics Committees (HRECs) are in conflict with an important stream of industrial sociological research. This stream seeks to deconstruct workplaces and de-layer management rhetoric to understand the realities and complexities of the social relations of production. There is a pluralist basis for much industrial sociology that challenges the unitarist view of the workplace as essentially harmonious. While views of workplaces as being conflictual and exploitative have to be tempered with an understanding of the accommodative and cooperative nature of workplace relations, there is nevertheless a general recognition of acts of resistance, as well as those of cooperation. The way in which the National Statement is typically implemented in Australia means that many HRECs require written, informed consent, which in the first instance will usually be that of management. An unintended consequence is a research focus on consensus, which is at best one-sided and at worst seriously misleading. It is unlikely that managerial consent will be granted unless there is a 'good news story' guaranteed. This article explores the ways in which HRECs may influence workplace research. The publication of the revised National Statement provides a valuable opportunity not to be missed by HRECs to implement more effective and efficient practices which would not have the unintended consequences of the earlier version. This would deserve the support of researchers in industrial sociology and other branches of the social sciences.

  5. Unintended pregnancy and intimate partner violence around pregnancy in a population-based study.

    Science.gov (United States)

    Martin-de-las-Heras, Stella; Velasco, Casilda; Luna, Juan de Dios; Martin, Aurelia

    2015-06-01

    Intimate partner violence (IPV) and unintended pregnancy are public health issues that can affect the health and well-being of women and their children. However, the relationship between IPV and women's ability to control their fertility has not been adequately explored. To investigate the association between unintended pregnancy and emotional or physical violence perpetrated by partners around pregnancy. A population-based study was undertaken, recruiting women (n=779) at the hospital obstetric departments and gathering social and family data. IPV was diagnosed by using the Index of Spouse Abuse (ISA). Data were gathered by trained midwives in 15 public hospitals in southern Spain and multivariate logistic regression analysis was performed. The pregnancy was reported to be unintended by 118 (15.1%) of the study population. Unintended pregnancy was significantly associated with: physical and/or emotional IPV around pregnancy, age, marital status, cohabitation, educational level, and employment status. After adjusting for socio-demographic characteristics, emotional IPV around pregnancy was significantly associated with an unintended pregnancy (AOR=2.5; 95% CI=1.5-4.3). Being in a non-committed relationship was a risk factor (AOR=3.5; 95% CI=1.8-6.1) and being in employment a protective factor (AOR=0.4; 95% CI=0.2-0.8) for an unintended pregnancy. Women who report an unintended pregnancy may be experiencing emotional IPV. The risk of emotional IPV is higher if women reporting an unintended pregnancy are in a committed relationship, married, or in employment. A better understanding of the relationship between unintended pregnancy and violence can aid midwives about potential reproductive health risk factors associated with abuse. Copyright © 2015 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  6. Data error effects on net radiation and evapotranspiration estimation

    International Nuclear Information System (INIS)

    Llasat, M.C.; Snyder, R.L.

    1998-01-01

    The objective of this paper is to evaluate the potential error in estimating the net radiation and reference evapotranspiration resulting from errors in the measurement or estimation of weather parameters. A methodology for estimating the net radiation using hourly weather variables measured at a typical agrometeorological station (e.g., solar radiation, temperature and relative humidity) is presented. Then the error propagation analysis is made for net radiation and for reference evapotranspiration. Data from the Raimat weather station, which is located in the Catalonia region of Spain, are used to illustrate the error relationships. The results show that temperature, relative humidity and cloud cover errors have little effect on the net radiation or reference evapotranspiration. A 5°C error in estimating surface temperature leads to errors as big as 30 W m −2 at high temperature. A 4% solar radiation (R s ) error can cause a net radiation error as big as 26 W m −2 when R s ≈ 1000 W m −2 . However, the error is less when cloud cover is calculated as a function of the solar radiation. The absolute error in reference evapotranspiration (ET o ) equals the product of the net radiation error and the radiation term weighting factor [W = Δ(Δ1+γ)] in the ET o equation. Therefore, the ET o error varies between 65 and 85% of the R n error as air temperature increases from about 20° to 40°C. (author)

  7. A comparison of estimated and calculated effective porosity

    Science.gov (United States)

    Stephens, Daniel B.; Hsu, Kuo-Chin; Prieksat, Mark A.; Ankeny, Mark D.; Blandford, Neil; Roth, Tracy L.; Kelsey, James A.; Whitworth, Julia R.

    Effective porosity in solute-transport analyses is usually estimated rather than calculated from tracer tests in the field or laboratory. Calculated values of effective porosity in the laboratory on three different textured samples were compared to estimates derived from particle-size distributions and soil-water characteristic curves. The agreement was poor and it seems that no clear relationships exist between effective porosity calculated from laboratory tracer tests and effective porosity estimated from particle-size distributions and soil-water characteristic curves. A field tracer test in a sand-and-gravel aquifer produced a calculated effective porosity of approximately 0.17. By comparison, estimates of effective porosity from textural data, moisture retention, and published values were approximately 50-90% greater than the field calibrated value. Thus, estimation of effective porosity for chemical transport is highly dependent on the chosen transport model and is best obtained by laboratory or field tracer tests. Résumé La porosité effective dans les analyses de transport de soluté est habituellement estimée, plutôt que calculée à partir d'expériences de traçage sur le terrain ou au laboratoire. Les valeurs calculées de la porosité effective au laboratoire sur trois échantillons de textures différentes ont été comparées aux estimations provenant de distributions de taille de particules et de courbes caractéristiques sol-eau. La concordance était plutôt faible et il semble qu'il n'existe aucune relation claire entre la porosité effective calculée à partir des expériences de traçage au laboratoire et la porosité effective estimée à partir des distributions de taille de particules et de courbes caractéristiques sol-eau. Une expérience de traçage de terrain dans un aquifère de sables et de graviers a fourni une porosité effective calculée d'environ 0,17. En comparaison, les estimations de porosité effective de données de

  8. Unmet Need for Family Planning, Contraceptive Failure, and Unintended Pregnancy among HIV-Infected and HIV-Uninfected Women in Zimbabwe

    Science.gov (United States)

    McCoy, Sandra I.; Buzdugan, Raluca; Ralph, Lauren J.; Mushavi, Angela; Mahomva, Agnes; Hakobyan, Anna; Watadzaushe, Constancia; Dirawo, Jeffrey; Cowan, Frances M.; Padian, Nancy S.

    2014-01-01

    Background Prevention of unintended pregnancies among women living with HIV infection is a strategy recommended by the World Health Organization for prevention of mother-to-child transmission of HIV (PMTCT). We assessed pregnancy intentions and contraceptive use among HIV-positive and HIV-negative women with a recent pregnancy in Zimbabwe. Methods We analyzed baseline data from the evaluation of Zimbabwe’s Accelerated National PMTCT Program. Eligible women were randomly sampled from the catchment areas of 157 health facilities offering PMTCT services in five provinces. Eligible women were ≥16 years old and mothers of infants (alive or deceased) born 9 to 18 months prior to the interview. Participants were interviewed about their HIV status, intendedness of the birth, and contraceptive use. Results Of 8,797 women, the mean age was 26.7 years, 92.8% were married or had a regular sexual partner, and they had an average of 2.7 lifetime births. Overall, 3,090 (35.1%) reported that their births were unintended; of these women, 1,477 (47.8%) and 1,613 (52.2%) were and were not using a contraceptive method prior to learning that they were pregnant, respectively. Twelve percent of women reported that they were HIV-positive at the time of the survey; women who reported that they were HIV-infected were significantly more likely to report that their pregnancy was unintended compared to women who reported that they were HIV-uninfected (44.9% vs. 33.8%, pHIV status and lack of contraception use prior to pregnancy. Conclusions Unmet need for family planning and contraceptive failure contribute to unintended pregnancies among women in Zimbabwe. Both HIV-infected and HIV-uninfected women reported unintended pregnancies despite intending to avoid or delay pregnancy, highlighting the need for effective contraceptive methods that align with pregnancy intentions. PMID:25144229

  9. Health effects estimation code development for accident consequence analysis

    International Nuclear Information System (INIS)

    Togawa, O.; Homma, T.

    1992-01-01

    As part of a computer code system for nuclear reactor accident consequence analysis, two computer codes have been developed for estimating health effects expected to occur following an accident. Health effects models used in the codes are based on the models of NUREG/CR-4214 and are revised for the Japanese population on the basis of the data from the reassessment of the radiation dosimetry and information derived from epidemiological studies on atomic bomb survivors of Hiroshima and Nagasaki. The health effects models include early and continuing effects, late somatic effects and genetic effects. The values of some model parameters are revised for early mortality. The models are modified for predicting late somatic effects such as leukemia and various kinds of cancers. The models for genetic effects are the same as those of NUREG. In order to test the performance of one of these codes, it is applied to the U.S. and Japanese populations. This paper provides descriptions of health effects models used in the two codes and gives comparisons of the mortality risks from each type of cancer for the two populations. (author)

  10. On estimating the effective diffusive properties of hardened cement pastes

    International Nuclear Information System (INIS)

    Stora, E.; Bary, B.; Stora, E.; He, Qi-Chang

    2008-01-01

    The effective diffusion coefficients of hardened cement pastes can vary between a few orders of magnitude. The paper aims at building a homogenization model to estimate these macroscopic diffusivities and capture such strong variations. For this purpose, a three-scale description of the paste is proposed, relying mainly on the fact that the initial cement grains hydrate forming a complex microstructure with a multi-scale pore structure. In particular, porosity is found to be well connected at a fine scale. However, only a few homogenization schemes are shown to be adequate to account for such connectivity. Among them, the mixed composite spheres assemblage estimate (Stora, E., He, Q.-C., Bary, B.: J. Appl. Phys. 100(8), 084910, 2006a) seems to be the only one that always complies with rigorous bounds and is consequently employed to predict the effects of this fine porosity on the material effective diffusivities. The model proposed provides predictions in good agreement with experimental results and is consistent with the numerous measurements of critical pore diameters issued from mercury intrusion porosimetry tests. The evolution of the effective diffusivities of cement pastes subjected to leaching is also assessed by adopting a simplified scenario of the decalcification process. (authors)

  11. Effect of survey design and catch rate estimation on total catch estimates in Chinook salmon fisheries

    Science.gov (United States)

    McCormick, Joshua L.; Quist, Michael C.; Schill, Daniel J.

    2012-01-01

    Roving–roving and roving–access creel surveys are the primary techniques used to obtain information on harvest of Chinook salmon Oncorhynchus tshawytscha in Idaho sport fisheries. Once interviews are conducted using roving–roving or roving–access survey designs, mean catch rate can be estimated with the ratio-of-means (ROM) estimator, the mean-of-ratios (MOR) estimator, or the MOR estimator with exclusion of short-duration (≤0.5 h) trips. Our objective was to examine the relative bias and precision of total catch estimates obtained from use of the two survey designs and three catch rate estimators for Idaho Chinook salmon fisheries. Information on angling populations was obtained by direct visual observation of portions of Chinook salmon fisheries in three Idaho river systems over an 18-d period. Based on data from the angling populations, Monte Carlo simulations were performed to evaluate the properties of the catch rate estimators and survey designs. Among the three estimators, the ROM estimator provided the most accurate and precise estimates of mean catch rate and total catch for both roving–roving and roving–access surveys. On average, the root mean square error of simulated total catch estimates was 1.42 times greater and relative bias was 160.13 times greater for roving–roving surveys than for roving–access surveys. Length-of-stay bias and nonstationary catch rates in roving–roving surveys both appeared to affect catch rate and total catch estimates. Our results suggest that use of the ROM estimator in combination with an estimate of angler effort provided the least biased and most precise estimates of total catch for both survey designs. However, roving–access surveys were more accurate than roving–roving surveys for Chinook salmon fisheries in Idaho.

  12. Bayesian Estimation of Small Effects in Exercise and Sports Science.

    Directory of Open Access Journals (Sweden)

    Kerrie L Mengersen

    Full Text Available The aim of this paper is to provide a Bayesian formulation of the so-called magnitude-based inference approach to quantifying and interpreting effects, and in a case study example provide accurate probabilistic statements that correspond to the intended magnitude-based inferences. The model is described in the context of a published small-scale athlete study which employed a magnitude-based inference approach to compare the effect of two altitude training regimens (live high-train low (LHTL, and intermittent hypoxic exposure (IHE on running performance and blood measurements of elite triathletes. The posterior distributions, and corresponding point and interval estimates, for the parameters and associated effects and comparisons of interest, were estimated using Markov chain Monte Carlo simulations. The Bayesian analysis was shown to provide more direct probabilistic comparisons of treatments and able to identify small effects of interest. The approach avoided asymptotic assumptions and overcame issues such as multiple testing. Bayesian analysis of unscaled effects showed a probability of 0.96 that LHTL yields a substantially greater increase in hemoglobin mass than IHE, a 0.93 probability of a substantially greater improvement in running economy and a greater than 0.96 probability that both IHE and LHTL yield a substantially greater improvement in maximum blood lactate concentration compared to a Placebo. The conclusions are consistent with those obtained using a 'magnitude-based inference' approach that has been promoted in the field. The paper demonstrates that a fully Bayesian analysis is a simple and effective way of analysing small effects, providing a rich set of results that are straightforward to interpret in terms of probabilistic statements.

  13. Bayesian Estimation of Small Effects in Exercise and Sports Science.

    Science.gov (United States)

    Mengersen, Kerrie L; Drovandi, Christopher C; Robert, Christian P; Pyne, David B; Gore, Christopher J

    2016-01-01

    The aim of this paper is to provide a Bayesian formulation of the so-called magnitude-based inference approach to quantifying and interpreting effects, and in a case study example provide accurate probabilistic statements that correspond to the intended magnitude-based inferences. The model is described in the context of a published small-scale athlete study which employed a magnitude-based inference approach to compare the effect of two altitude training regimens (live high-train low (LHTL), and intermittent hypoxic exposure (IHE)) on running performance and blood measurements of elite triathletes. The posterior distributions, and corresponding point and interval estimates, for the parameters and associated effects and comparisons of interest, were estimated using Markov chain Monte Carlo simulations. The Bayesian analysis was shown to provide more direct probabilistic comparisons of treatments and able to identify small effects of interest. The approach avoided asymptotic assumptions and overcame issues such as multiple testing. Bayesian analysis of unscaled effects showed a probability of 0.96 that LHTL yields a substantially greater increase in hemoglobin mass than IHE, a 0.93 probability of a substantially greater improvement in running economy and a greater than 0.96 probability that both IHE and LHTL yield a substantially greater improvement in maximum blood lactate concentration compared to a Placebo. The conclusions are consistent with those obtained using a 'magnitude-based inference' approach that has been promoted in the field. The paper demonstrates that a fully Bayesian analysis is a simple and effective way of analysing small effects, providing a rich set of results that are straightforward to interpret in terms of probabilistic statements.

  14. System dynamics to model the unintended consequences of denying payment for venous thromboembolism after total knee arthroplasty.

    Science.gov (United States)

    Worni, Mathias; Pietrobon, Ricardo; Zammar, Guilherme Roberto; Shah, Jatin; Yoo, Bryan; Maldonato, Mauro; Takemoto, Steven; Vail, Thomas P

    2012-01-01

    The Hospital Acquired Condition Strategy (HACS) denies payment for venous thromboembolism (VTE) after total knee arthroplasty (TKA). The intention is to reduce complications and associated costs, while improving the quality of care by mandating VTE prophylaxis. We applied a system dynamics model to estimate the impact of HACS on VTE rates, and potential unintended consequences such as increased rates of bleeding and infection and decreased access for patients who might benefit from TKA. The system dynamics model uses a series of patient stocks including the number needing TKA, deemed ineligible, receiving TKA, and harmed due to surgical complication. The flow of patients between stocks is determined by a series of causal elements such as rates of exclusion, surgery and complications. The number of patients harmed due to VTE, bleeding or exclusion were modeled by year by comparing patient stocks that results in scenarios with and without HACS. The percentage of TKA patients experiencing VTE decreased approximately 3-fold with HACS. This decrease in VTE was offset by an increased rate of bleeding and infection. Moreover, results from the model suggest HACS could exclude 1.5% or half a million patients who might benefit from knee replacement through 2020. System dynamics modeling indicates HACS will have the intended consequence of reducing VTE rates. However, an unintended consequence of the policy might be increased potential harm resulting from over administration of prophylaxis, as well as exclusion of a large population of patients who might benefit from TKA.

  15. System Dynamics to Model the Unintended Consequences of Denying Payment for Venous Thromboembolism after Total Knee Arthroplasty

    Science.gov (United States)

    Worni, Mathias; Pietrobon, Ricardo; Zammar, Guilherme Roberto; Shah, Jatin; Yoo, Bryan; Maldonato, Mauro; Takemoto, Steven; Vail, Thomas P.

    2012-01-01

    Background The Hospital Acquired Condition Strategy (HACS) denies payment for venous thromboembolism (VTE) after total knee arthroplasty (TKA). The intention is to reduce complications and associated costs, while improving the quality of care by mandating VTE prophylaxis. We applied a system dynamics model to estimate the impact of HACS on VTE rates, and potential unintended consequences such as increased rates of bleeding and infection and decreased access for patients who might benefit from TKA. Methods and Findings The system dynamics model uses a series of patient stocks including the number needing TKA, deemed ineligible, receiving TKA, and harmed due to surgical complication. The flow of patients between stocks is determined by a series of causal elements such as rates of exclusion, surgery and complications. The number of patients harmed due to VTE, bleeding or exclusion were modeled by year by comparing patient stocks that results in scenarios with and without HACS. The percentage of TKA patients experiencing VTE decreased approximately 3-fold with HACS. This decrease in VTE was offset by an increased rate of bleeding and infection. Moreover, results from the model suggest HACS could exclude 1.5% or half a million patients who might benefit from knee replacement through 2020. Conclusion System dynamics modeling indicates HACS will have the intended consequence of reducing VTE rates. However, an unintended consequence of the policy might be increased potential harm resulting from over administration of prophylaxis, as well as exclusion of a large population of patients who might benefit from TKA. PMID:22536313

  16. Unintended consequences of changing accounting standards: the case of fair value accounting and mandatory dividends

    NARCIS (Netherlands)

    Goncharov, I.; van Triest, S.

    2014-01-01

    A growing body of literature investigates the interaction of changes in accounting standards with institutions such as investor protection laws and corporate governance mechanisms. We examine the unintended consequences of fair value accounting in determining mandated preferred dividends. We study

  17. A CFD-Model for prediction of unintended porosities in metal matrix composites

    DEFF Research Database (Denmark)

    Li, Shizhao; Spangenberg, Jon; Hattel, Jesper Henri

    2013-01-01

    This paper presents a numerical method that simulates the flow through the porous corridors of the preform, which in theory enables the prediction of unintended porosities at the end of the process....

  18. Chest X ray effective doses estimation in computed radiography

    International Nuclear Information System (INIS)

    Abdalla, Esra Abdalrhman Dfaalla

    2013-06-01

    Conventional chest radiography is technically difficult because of wide in tissue attenuations in the chest and limitations of screen-film systems. Computed radiography (CR) offers a different approach utilizing a photostimulable phosphor. photostimulable phosphors overcome some image quality limitations of chest imaging. The objective of this study was to estimate the effective dose in computed radiography at three hospitals in Khartoum. This study has been conducted in radiography departments in three centres Advanced Diagnostic Center, Nilain Diagnostic Center, Modern Diagnostic Center. The entrance surface dose (ESD) measurement was conducted for quality control of x-ray machines and survey of operators experimental techniques. The ESDs were measured by UNFORS dosimeter and mathematical equations to estimate patient doses during chest X rays. A total of 120 patients were examined in three centres, among them 62 were males and 58 were females. The overall mean and range of patient dosed was 0.073±0.037 (0.014-0.16) mGy per procedure while the effective dose was 3.4±01.7 (0.6-7.0) mSv per procedure. This study compared radiation doses to patients radiographic examinations of chest using computed radiology. The radiation dose was measured in three centres in Khartoum- Sudan. The results of the measured effective dose showed that the dose in chest radiography was lower in computed radiography compared to previous studies.(Author)

  19. Estimating intervention effects of prevention programs: accounting for noncompliance.

    Science.gov (United States)

    Stuart, Elizabeth A; Perry, Deborah F; Le, Huynh-Nhu; Ialongo, Nicholas S

    2008-12-01

    Individuals not fully complying with their assigned treatments is a common problem encountered in randomized evaluations of behavioral interventions. Treatment group members rarely attend all sessions or do all "required" activities; control group members sometimes find ways to participate in aspects of the intervention. As a result, there is often interest in estimating both the effect of being assigned to participate in the intervention, as well as the impact of actually participating and doing all of the required activities. Methods known broadly as "complier average causal effects" (CACE) or "instrumental variables" (IV) methods have been developed to estimate this latter effect, but they are more commonly applied in medical and treatment research. Since the use of these statistical techniques in prevention trials has been less widespread, many prevention scientists may not be familiar with the underlying assumptions and limitations of CACE and IV approaches. This paper provides an introduction to these methods, described in the context of randomized controlled trials of two preventive interventions: one for perinatal depression among at-risk women and the other for aggressive disruptive behavior in children. Through these case studies, the underlying assumptions and limitations of these methods are highlighted.

  20. Estimating effective doses to children from CT examinations

    International Nuclear Information System (INIS)

    Heron, J.C.L.

    2000-01-01

    Full text: Assessing doses to patients in diagnostic radiology is an integral part of implementing optimisation of radiation protection. Sources of normalised data are available for estimating doses to adults undergoing CT examinations, but for children this is not the case. This paper describes a simple method for estimating effective doses arising from paediatric CT examinations. First the effective dose to an adult is calculated, having anatomically matched the scanned regions of the child and the adult and also matched the irradiation conditions. A conversion factor is then applied to the adult effective dose, based on the region of the body being scanned - head, upper or lower trunk. This conversion factor is the child-to-adult ratio of the ratios of effective dose per entrance air kerma (in the absence of the patient) at the FAD. The values of these conversion factors were calculated by deriving effective dose per entrance air kerma at the FAD for new-born, 1, 5, 10, 15 and adult phantoms using four projections (AP, PA, left and right laterals) over a range of beam qualities and FADs.The program PCXMC was used for this purpose. Results to date suggest that the conversion factors to give effective doses for children undergoing CT examinations of the upper trunk are approximately 1.3, 1.2, 1.15, 1.1 and 1.05 for ages 0, 1, 5, 10 and 15 years respectively; CT of the lower trunk - 1.4, 1.3, 1.2, 1.2, 1.1; and CT of the head - 2.3, 2.0, 1.5, 1.3, 1.1. The dependence of these factors on beam quality (HVL from 4 to 10 mm Al) is less than 10%, with harder beams resulting in slightly smaller conversion factors. Dependence on FAD is also less than 10%. Major sources of uncertainties in the conversion factors include matching anatomical regions across the phantoms, and the presence of beam divergence in the z-direction when deriving the factors. The method described provides a simple means of estimating effective doses arising from paediatric CT examinations with

  1. Estimation of effective elastic constants for grid plate

    International Nuclear Information System (INIS)

    Shibanuma, Kiyoshi; Kuriyama, Masaaki; Okumura, Yoshikazu

    1980-07-01

    This article contains a method of estimation for the effective elastic constants of a grid plate, which is a flat perforated plate with pipes for cooling. The elastic constants of the grid plate are formulated for two symmetric axes. In the case of using OFCu(E 0 = 12500 kg/mm 2 , ν 0 = 0.34) as the material of the grid, the results are given as follows. E sub(L) = 3180 kg/mm 2 , E sub(T) = 3860 kg/mm 2 upsilon sub(LT) = 0.12, upsilon sub(TL) = 0.15 (author)

  2. The test-negative design for estimating influenza vaccine effectiveness.

    Science.gov (United States)

    Jackson, Michael L; Nelson, Jennifer C

    2013-04-19

    The test-negative design has emerged in recent years as the preferred method for estimating influenza vaccine effectiveness (VE) in observational studies. However, the methodologic basis of this design has not been formally developed. In this paper we develop the rationale and underlying assumptions of the test-negative study. Under the test-negative design for influenza VE, study subjects are all persons who seek care for an acute respiratory illness (ARI). All subjects are tested for influenza infection. Influenza VE is estimated from the ratio of the odds of vaccination among subjects testing positive for influenza to the odds of vaccination among subjects testing negative. With the assumptions that (a) the distribution of non-influenza causes of ARI does not vary by influenza vaccination status, and (b) VE does not vary by health care-seeking behavior, the VE estimate from the sample can generalized to the full source population that gave rise to the study sample. Based on our derivation of this design, we show that test-negative studies of influenza VE can produce biased VE estimates if they include persons seeking care for ARI when influenza is not circulating or do not adjust for calendar time. The test-negative design is less susceptible to bias due to misclassification of infection and to confounding by health care-seeking behavior, relative to traditional case-control or cohort studies. The cost of the test-negative design is the additional, difficult-to-test assumptions that incidence of non-influenza respiratory infections is similar between vaccinated and unvaccinated groups within any stratum of care-seeking behavior, and that influenza VE does not vary across care-seeking strata. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Determinants of accepting unintended pregnancies by Ukrainian women: Results of a 2007 survey

    Directory of Open Access Journals (Sweden)

    Barska, Julia

    2011-05-01

    Full Text Available BACKGROUND. In Ukraine, much public attention is given to adolescent girls and young women as a main ‘risk group’ for terminating an unplanned pregnancy in case it occurs. The objective of the study was to clarify whether this concern is substantiated.METHODS. Data from a nationally representative Demographic and Health Survey on women of reproductive age were used to examine the relationship of pregnancy order number, age when a woman became pregnant and her marital status to accepting unintended pregnancy. A subsample of 517 women having been pregnant within five years preceding the interview were divided into non-acceptors (unintended pregnancy was terminated and acceptors (pregnancy ended with live birth though was unintended at the time of conception. Independent variables included pregnancy- and childbearing-related, socio-demographic, and behavioral characteristics. Odds ratios were calculated using bivariate and multivariate logistic regression analysis. RESULTS. Controlling for all other factors, being 23 years and younger compared to 24-37 years old was positively associated with accepting an unintended pregnancy. With every next pregnancy, odds of accepting an unintended pregnancy decreased by 0.6. Being married compared to being unmarried was negatively associated with accepting an unintended pregnancy in bivariate analysis, which was attenuated in multivariate analysis because of predominance of the first pregnancies among never married women. Furthermore, women from all other regions of Ukraine compared to women from Western regions were less likely to accept an unintended pregnancy, and so did women of Christian Orthodox and no religion compared to women of other religions. CONCLUSIONS. Attention of public health programs and policies should be paid to the women with children, whose needs in reliable contraceptive methods are not met. Post-delivery contraceptive consultations may be a great tool in overcoming this gap. In

  4. Neonatal Nurses Experience Unintended Consequences and Risks to Patient Safety With Electronic Health Records.

    Science.gov (United States)

    Dudding, Katherine M; Gephart, Sheila M; Carrington, Jane M

    2018-04-01

    In this article, we examine the unintended consequences of nurses' use of electronic health records. We define these as unforeseen events, change in workflow, or an unanticipated result of implementation and use of electronic health records. Unintended consequences experienced by nurses while using electronic health records have been well researched. However, few studies have focused on neonatal nurses, and it is unclear to what extent unintended consequences threaten patient safety. A new instrument called the Carrington-Gephart Unintended Consequences of Electronic Health Record Questionnaire has been validated, and secondary analysis using the tool explored the phenomena among neonatal nurses (N = 40). The purposes of this study were to describe unintended consequences of use of electronic health records for neonatal nurses and to explore relationships between the phenomena and characteristics of the nurse and the electronic health record. The most frequent unintended consequences of electronic health record use were due to interruptions, followed by a heavier workload due to the electronic health record, changes to the workflow, and altered communication patterns. Neonatal nurses used workarounds most often with motivation to better assist patients. Teamwork was moderately related to higher unintended consequences including patient safety risks (r = 0.427, P = .007), system design (r = 0.419, P = .009), and technology barriers (r = 0.431, P = .007). Communication about patients was reduced when patient safety risks were high (r = -0.437, P = .003). By determining the frequency with which neonatal nurses experience unintended consequences of electronic health record use, future research can be targeted to improve electronic health record design through customization, integration, and refinement to support patient safety and better outcomes.

  5. Identification and estimation of survivor average causal effects.

    Science.gov (United States)

    Tchetgen Tchetgen, Eric J

    2014-09-20

    In longitudinal studies, outcomes ascertained at follow-up are typically undefined for individuals who die prior to the follow-up visit. In such settings, outcomes are said to be truncated by death and inference about the effects of a point treatment or exposure, restricted to individuals alive at the follow-up visit, could be biased even if as in experimental studies, treatment assignment were randomized. To account for truncation by death, the survivor average causal effect (SACE) defines the effect of treatment on the outcome for the subset of individuals who would have survived regardless of exposure status. In this paper, the author nonparametrically identifies SACE by leveraging post-exposure longitudinal correlates of survival and outcome that may also mediate the exposure effects on survival and outcome. Nonparametric identification is achieved by supposing that the longitudinal data arise from a certain nonparametric structural equations model and by making the monotonicity assumption that the effect of exposure on survival agrees in its direction across individuals. A novel weighted analysis involving a consistent estimate of the survival process is shown to produce consistent estimates of SACE. A data illustration is given, and the methods are extended to the context of time-varying exposures. We discuss a sensitivity analysis framework that relaxes assumptions about independent errors in the nonparametric structural equations model and may be used to assess the extent to which inference may be altered by a violation of key identifying assumptions. © 2014 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd.

  6. Estimating Effects of Species Interactions on Populations of Endangered Species.

    Science.gov (United States)

    Roth, Tobias; Bühler, Christoph; Amrhein, Valentin

    2016-04-01

    Global change causes community composition to change considerably through time, with ever-new combinations of interacting species. To study the consequences of newly established species interactions, one available source of data could be observational surveys from biodiversity monitoring. However, approaches using observational data would need to account for niche differences between species and for imperfect detection of individuals. To estimate population sizes of interacting species, we extended N-mixture models that were developed to estimate true population sizes in single species. Simulations revealed that our model is able to disentangle direct effects of dominant on subordinate species from indirect effects of dominant species on detection probability of subordinate species. For illustration, we applied our model to data from a Swiss amphibian monitoring program and showed that sizes of expanding water frog populations were negatively related to population sizes of endangered yellow-bellied toads and common midwife toads and partly of natterjack toads. Unlike other studies that analyzed presence and absence of species, our model suggests that the spread of water frogs in Central Europe is one of the reasons for the decline of endangered toad species. Thus, studying population impacts of dominant species on population sizes of endangered species using data from biodiversity monitoring programs should help to inform conservation policy and to decide whether competing species should be subject to population management.

  7. The Medicare Hospital Readmissions Reduction Program: potential unintended consequences for hospitals serving vulnerable populations.

    Science.gov (United States)

    Gu, Qian; Koenig, Lane; Faerberg, Jennifer; Steinberg, Caroline Rossi; Vaz, Christopher; Wheatley, Mary P

    2014-06-01

    To explore the impact of the Hospital Readmissions Reduction Program (HRRP) on hospitals serving vulnerable populations. Medicare inpatient claims to calculate condition-specific readmission rates. Medicare cost reports and other sources to determine a hospital's share of duals, profit margin, and characteristics. Regression analyses and projections were used to estimate risk-adjusted readmission rates and financial penalties under the HRRP. Findings were compared across groups of hospitals, determined based on their share of duals, to assess differential impacts of the HRRP. Both patient dual-eligible status and a hospital's dual-eligible share of Medicare discharges have a positive impact on risk-adjusted hospital readmission rates. Under current Centers for Medicare and Medicaid Service methodology, which does not adjust for socioeconomic status, high-dual hospitals are more likely to have excess readmissions than low-dual hospitals. As a result, HRRP penalties will disproportionately fall on high-dual hospitals, which are more likely to have negative all-payer margins, raising concerns of unintended consequences of the program for vulnerable populations. Policies to reduce hospital readmissions must balance the need to ensure continued access to quality care for vulnerable populations. © Health Research and Educational Trust.

  8. Estimation of effective dose equivalente from external irradiations

    International Nuclear Information System (INIS)

    Wakabayashi, T.

    1985-07-01

    A methodology for computing effective dose equivalent, derived from the computer code ALGAM: Monte Carlo Estimation of Internal Dose from Gamma-ray Sources in a Phantom Man, developed at Oak Ridge National Laboratory, is presented. The modified code was run for 12 different photon energy levels, from 0,010 Mev to 4.0 Mev, which provides computing the absorved dose, for these energy levels, in each one of the 97 organs of the original code. The code also was run for the principal energy levels used in the calibration of the dosimetric films. The results of the absorved doses per photon obtained for these levels of energy have been transformed in effective dose equivalents. (M.A.C.) [pt

  9. Estimation of the effective distribution coefficient from the solubility constant

    International Nuclear Information System (INIS)

    Wang, Yug-Yea; Yu, C.

    1994-01-01

    An updated version of RESRAD has been developed by Argonne National Laboratory for the US Department of Energy to derive site-specific soil guidelines for residual radioactive material. In this updated version, many new features have been added to the, RESRAD code. One of the options is that a user can input a solubility constant to limit the leaching of contaminants. The leaching model used in the code requires the input of an empirical distribution coefficient, K d , which represents the ratio of the solute concentration in soil to that in solution under equilibrium conditions. This paper describes the methodology developed to estimate an effective distribution coefficient, Kd, from the user-input solubility constant and the use of the effective K d for predicting the leaching of contaminants

  10. Model Specifications for Estimating Labor Market Returns to Associate Degrees: How Robust Are Fixed Effects Estimates? A CAPSEE Working Paper

    Science.gov (United States)

    Belfield, Clive; Bailey, Thomas

    2017-01-01

    Recently, studies have adopted fixed effects modeling to identify the returns to college. This method has the advantage over ordinary least squares estimates in that unobservable, individual-level characteristics that may bias the estimated returns are differenced out. But the method requires extensive longitudinal data and involves complex…

  11. A Conceptual Framework for Understanding Unintended Prolonged Opioid Use.

    Science.gov (United States)

    Hooten, W Michael; Brummett, Chad M; Sullivan, Mark D; Goesling, Jenna; Tilburt, Jon C; Merlin, Jessica S; St Sauver, Jennifer L; Wasan, Ajay D; Clauw, Daniel J; Warner, David O

    2017-12-01

    An urgent need exists to better understand the transition from short-term opioid use to unintended prolonged opioid use (UPOU). The purpose of this work is to propose a conceptual framework for understanding UPOU that posits the influence of 3 principal domains that include the characteristics of (1) individual patients, (2) the practice environment, and (3) opioid prescribers. Although no standardized method exists for developing a conceptual framework, the process often involves identifying corroborative evidence, leveraging expert opinion to identify factors for inclusion in the framework, and developing a graphic depiction of the relationships between the various factors and the clinical problem of interest. Key patient characteristics potentially associated with UPOU include (1) medical and mental health conditions; (2) pain etiology; (3) individual affective, behavioral, and neurophysiologic reactions to pain and opioids; and (4) sociodemographic factors. Also, UPOU could be influenced by structural and health care policy factors: (1) the practice environment, including the roles of prescribing clinicians, adoption of relevant practice guidelines, and clinician incentives or disincentives, and (2) the regulatory environment. Finally, characteristics inherent to clinicians that could influence prescribing practices include (1) training in pain management and opioid use; (2) personal attitudes, knowledge, and beliefs regarding the risks and benefits of opioids; and (3) professionalism. As the gatekeeper to opioid access, the behavior of prescribing clinicians directly mediates UPOU, with the 3 domains interacting to determine this behavior. This proposed conceptual framework could guide future research on the topic and allow plausible hypothesis-based interventions to reduce UPOU. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  12. Evaluating lidar point densities for effective estimation of aboveground biomass

    Science.gov (United States)

    Wu, Zhuoting; Dye, Dennis G.; Stoker, Jason M.; Vogel, John M.; Velasco, Miguel G.; Middleton, Barry R.

    2016-01-01

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) was recently established to provide airborne lidar data coverage on a national scale. As part of a broader research effort of the USGS to develop an effective remote sensing-based methodology for the creation of an operational biomass Essential Climate Variable (Biomass ECV) data product, we evaluated the performance of airborne lidar data at various pulse densities against Landsat 8 satellite imagery in estimating above ground biomass for forests and woodlands in a study area in east-central Arizona, U.S. High point density airborne lidar data, were randomly sampled to produce five lidar datasets with reduced densities ranging from 0.5 to 8 point(s)/m2, corresponding to the point density range of 3DEP to provide national lidar coverage over time. Lidar-derived aboveground biomass estimate errors showed an overall decreasing trend as lidar point density increased from 0.5 to 8 points/m2. Landsat 8-based aboveground biomass estimates produced errors larger than the lowest lidar point density of 0.5 point/m2, and therefore Landsat 8 observations alone were ineffective relative to airborne lidar for generating a Biomass ECV product, at least for the forest and woodland vegetation types of the Southwestern U.S. While a national Biomass ECV product with optimal accuracy could potentially be achieved with 3DEP data at 8 points/m2, our results indicate that even lower density lidar data could be sufficient to provide a national Biomass ECV product with accuracies significantly higher than that from Landsat observations alone.

  13. Impact of relativistic effects on cosmological parameter estimation

    Science.gov (United States)

    Lorenz, Christiane S.; Alonso, David; Ferreira, Pedro G.

    2018-01-01

    Future surveys will access large volumes of space and hence very long wavelength fluctuations of the matter density and gravitational field. It has been argued that the set of secondary effects that affect the galaxy distribution, relativistic in nature, will bring new, complementary cosmological constraints. We study this claim in detail by focusing on a subset of wide-area future surveys: Stage-4 cosmic microwave background experiments and photometric redshift surveys. In particular, we look at the magnification lensing contribution to galaxy clustering and general-relativistic corrections to all observables. We quantify the amount of information encoded in these effects in terms of the tightening of the final cosmological constraints as well as the potential bias in inferred parameters associated with neglecting them. We do so for a wide range of cosmological parameters, covering neutrino masses, standard dark-energy parametrizations and scalar-tensor gravity theories. Our results show that, while the effect of lensing magnification to number counts does not contain a significant amount of information when galaxy clustering is combined with cosmic shear measurements, this contribution does play a significant role in biasing estimates on a host of parameter families if unaccounted for. Since the amplitude of the magnification term is controlled by the slope of the source number counts with apparent magnitude, s (z ), we also estimate the accuracy to which this quantity must be known to avoid systematic parameter biases, finding that future surveys will need to determine s (z ) to the ˜5 %- 10 % level. On the contrary, large-scale general-relativistic corrections are irrelevant both in terms of information content and parameter bias for most cosmological parameters but significant for the level of primordial non-Gaussianity.

  14. Unintended Learning in Primary School Practical Science Lessons from Polanyi's Perspective of Intellectual Passion

    Science.gov (United States)

    Park, Jisun; Song, Jinwoong; Abrahams, Ian

    2016-03-01

    This study explored, from the perspective of intellectual passion developed by Michael Polanyi, the unintended learning that occurred in primary practical science lessons. We use the term `unintended' learning to distinguish it from `intended' learning that appears in teachers' learning objectives. Data were collected using video and audio recordings of a sample of twenty-four whole class practical science lessons, taught by five teachers, in Korean primary schools with 10- to 12-year-old students. In addition, video and audio recordings were made for each small group of students working together in order to capture their activities and intra-group discourse. Pre-lesson interviews with the teachers were undertaken and audio-recorded to ascertain their intended learning objectives. Selected key vignettes, including unintended learning, were analysed from the perspective of intellectual passion developed by Polanyi. What we found in this study is that unintended learning could occur when students got interested in something in the first place and could maintain their interest. In addition, students could get conceptual knowledge when they tried to connect their experience to their related prior knowledge. It was also found that the processes of intended learning and of unintended learning were different. Intended learning was characterized by having been planned by the teacher who then sought to generate students' interest in it. In contrast, unintended learning originated from students' spontaneous interest and curiosity as a result of unplanned opportunities. Whilst teachers' persuasive passion comes first in the process of intended learning, students' heuristic passion comes first in the process of unintended learning. Based on these findings, we argue that teachers need to be more aware that unintended learning, on the part of individual students, can occur during their lesson and to be able to better use this opportunity so that this unintended learning can be

  15. Estimation of Aging Effects on LOHS for CANDU-6

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yong Ki; Moon, Bok Ja; Kim, Seoung Rae [Nuclear Engineering Service and Solution Co. Ltd., Daejeon (Korea, Republic of)

    2014-05-15

    To evaluate the Wolsong Unit 1's capacity to respond to large-scale natural disaster exceeding design, the loss of heat sink(LOHS) accident accompanied by loss of all electric power is simulated as a beyond design basis accident. This analysis is considered the aging effects of plant as the consequences of LOHS accident. Various components of primary heat transport system(PHTS) get aged and some of the important aging effects of CANDU reactor are pressure tube(PT) diametral creep, steam generator(SG) U-tube fouling, increased feeder roughness, and feeder orifice degradation. These effects result in higher inlet header temperatures, reduced flows in some fuel channels, and higher void fraction in fuel channel outlets. Fresh and aged models are established for the analysis where fresh model is the circuit model simulating the conditions at retubing and aged model corresponds to the model reflecting the aged condition at 11 EFPY after retubing. CATHENA computer code[1] is used for the analysis of the system behavior under LOHS condition. The LOHS accident is analyzed for fresh and aged models using CATHENA thermal hydraulic computer code. The decay heat removal is one of the most important factors for mitigation of this accident. The major aging effect on decay heat removal is the reduction of heat transfer efficiency by steam generator. Thus, the channel failure time cannot be conservatively estimated if aged model is applied for the analysis of this accident.

  16. The intended and unintended consequences of communication systems on general internal medicine inpatient care delivery: a prospective observational case study of five teaching hospitals.

    Science.gov (United States)

    Wu, Robert C; Lo, Vivian; Morra, Dante; Wong, Brian M; Sargeant, Robert; Locke, Ken; Cavalcanti, Rodrigo; Quan, Sherman D; Rossos, Peter; Tran, Kim; Cheung, Mark

    2013-01-01

    Effective clinical communication is critical to providing high-quality patient care. Hospitals have used different types of interventions to improve communication between care teams, but there have been few studies of their effectiveness. To describe the effects of different communication interventions and their problems. Prospective observational case study using a mixed methods approach of quantitative and qualitative methods. General internal medicine (GIM) inpatient wards at five tertiary care academic teaching hospitals. Clinicians consisting of residents, attending physicians, nurses, and allied health (AH) staff working on the GIM wards. Ethnographic methods and interviews with clinical staff (doctors, nurses, medical students, and AH professionals) were conducted over a 16-month period from 2009 to 2010. We identified four categories that described the intended and unintended consequences of communication interventions: impacts on senders, receivers, interprofessional collaboration, and the use of informal communication processes. The use of alphanumeric pagers, smartphones, and web-based communication systems had positive effects for senders and receivers, but unintended consequences were seen with all interventions in all four categories. Interventions that aimed to improve clinical communications solved some but not all problems, and unintended effects were seen with all systems.

  17. Estimation of effective dose for children in interventional cardiology

    Directory of Open Access Journals (Sweden)

    S. S. Sarycheva

    2017-01-01

    Full Text Available This study is devoted to the estimation of effective dose for children undergoing interventional cardiology examinations. The conversion coefficients (CC from directly measured dose area product (DAP value to effective dose (ED were calculated within the approved effective dose assessment methodology (Guidelines 2.6.1. 2944-11. The CC, Ed K , [mSv / (Gy • cm2] for newborn infants and children of 1, 5, 10 and 15 years old (main(range were calculated as 2.5 (1.8-3.2; 1.1 (0.8-1.3; 0.6 (0.4-0.7; 0.4 (0.3-0.5; and 0,22 (0,18-0,30 respectively. A special Finnish computer program PCXMC 2.0 was used for calculating the dose CC. The series of calculations were made for different values of the physical and geometrical parameters based on their real-existing range of values. The value of CC from DAP to ED were calculated for all pediatric age groups. This work included 153 pediatric interventional studies carried out in two hospitals of the city of St. Petersburg for the period of one year from the summer of 2015. The dose CC dependency from the patient’s age and parameters of the examinations were under the study. The dependence from the beam quality (filtration and tube voltage and age of the patient were found. The younger is the patient, stronger is the filtration and higher is the voltage, the higher is the CC value. The CC in the younger (newborn and older (15 years age groups are different by the factor of 10. It was shown that the changes of the geometric parameters (in the scope of their real existing range have small effect on the value of the effective dose, not exceed 30-50% allowable for radiation protection purpose. The real values of effective doses of children undergoing cardiac interventions were estimated. In severe cases, the values of ED can reach several tens of mSv.

  18. Estimates of effective dose in adult CT examinations

    International Nuclear Information System (INIS)

    Mohamed, Mustafa Awad Elhaj.

    2015-12-01

    The goal of study was to estimate effective dose (E) in adult CT examinations for Toshiba X64 slice using CT. Exp version 2.5 software in Sudan. Using of CT in medical diagnosis delivers radiation doses to patients that are higher than those from other radiological procedures. lack of optimized protocols could be an additional source of increased dose in developing countries. In order to achieve these objectives, data of CT-scanner has been collected from three hospitals ( ANH, ZSH and MMH). Data collected included equipment information and scan parameters for individual patients, who were used to asses. 300 adult patients underwent head, chest, abdomen-pelvis and peivis CT examinations. The CT1_w , CTD1_vol, DLP, patient effective dos and organ doses were estimated, using CT exposure parameters and CT Exp version 2.5 software. A large variation of mean effective dose and organ doses among hospitals was observed for similar CT examinations. These variations largely originated from different CT scanning protocols used in different hospitals and scan length. The mean effective dose in this study in the Brain, PNS, Chest, pulmonary, Abdomen-pelvis, Pelvis, KUB and CTU were 3.2 mSv, 2.6 mSv, 18.9 mSv 17.6 mSv 27.1 mSv, 11.2 mSv, 9.6 mSv and 23.7 mSv respectively, and organ equivalent, doses presented in this study in this study for the eye lens (for head), lungs and thymus ( for chest) , liver, kidney and small intest ( for abdomen t-pelvis), bladder, uterus and gonads ( for pelvis), were 62.9 mSv, 39.5 mSv, 34.1 mSv, 53.9 mSv, 52.6 mSv, 58.1 mSv, 37 mSv, and 34.6 mSv, respectively. These values were mostly comparable to and slightly higher than the values of effective doses reported from similar studies the United Kingdom, Tanzania, Australia, Canada and Sudan. It was concluded that patient effective dose and organ doses could be substantially minimized through careful selection of scanning parameters based on clinical indications of study, patient size, and body

  19. Apollo Video Photogrammetry Estimation Of Plume Impingement Effects

    Science.gov (United States)

    Immer, Christopher; Lane, John; Metzger, Philip T.; Clements, Sandra

    2008-01-01

    The Constellation Project's planned return to the moon requires numerous landings at the same site. Since the top few centimeters are loosely packed regolith, plume impingement from the Lander ejects the granular material at high velocities. Much work is needed to understand the physics of plume impingement during landing in order to protect hardware surrounding the landing sites. While mostly qualitative in nature, the Apollo Lunar Module landing videos can provide a wealth of quantitative information using modem photogrammetry techniques. The authors have used the digitized videos to quantify plume impingement effects of the landing exhaust on the lunar surface. The dust ejection angle from the plume is estimated at 1-3 degrees. The lofted particle density is estimated at 10(exp 8)- 10(exp 13) particles per cubic meter. Additionally, evidence for ejection of large 10-15 cm sized objects and a dependence of ejection angle on thrust are presented. Further work is ongoing to continue quantitative analysis of the landing videos.

  20. Estimating effects of improved drinking water and sanitation on cholera.

    Science.gov (United States)

    Leidner, Andrew J; Adusumilli, Naveen C

    2013-12-01

    Demand for adequate provision of drinking-water and sanitation facilities to promote public health and economic growth is increasing in the rapidly urbanizing countries of the developing world. With a panel of data on Asia and Africa from 1990 to 2008, associations are estimated between the occurrence of cholera outbreaks, the case rates in given outbreaks, the mortality rates associated with cholera and two disease control mechanisms, drinking-water and sanitation services. A statistically significant and negative effect is found between drinking-water services and both cholera case rates as well as cholera-related mortality rates. A relatively weak statistical relationship is found between the occurrence of cholera outbreaks and sanitation services.

  1. The effects of global warming on fisheries: Simulation estimates

    Directory of Open Access Journals (Sweden)

    Carlos A. Medel

    2016-04-01

    Full Text Available This paper develops two fisheries models in order to estimate the effect of global warming (GW on firm value. GW is defined as an increase in the average temperature of the Earth’s surface as a result of emissions. It is assumed that (i GW exists, and (ii higher temperatures negatively affect biomass. CO2 The literature on biology and GW supporting these two crucial assumptions is reviewed. The main argument presented is that temperature increase has two effects on biomass, both of which have an impact on firm value. First, higher temperatures cause biomass to oscillate. To measure the effect of biomass oscillation on firm value the model in [1] is modified to include water temperature as a variable. The results indicate that a 1 to 20% variation in biomass causes firm value to fall from 6 to 44%, respectively. Second, higher temperatures reduce biomass, and a modification of the model in [2] reveals that an increase in temperature anomaly between +1 and +8°C causes fishing firm value to decrease by 8 to 10%.

  2. Contraception and Unintended Pregnancy among Unmarried Female University Students: A Cross-sectional Study from China

    Science.gov (United States)

    Wang, Hongjing; Long, Lu; Cai, Hui; Wu, Yue; Xu, Jing; Shu, Chang; Wang, Peng; Li, Bo; Wei, Qinyu; Shang, Xuejun; Wang, Xueyi; Zhang, Meimei; Xiong, Chengliang; Yin, Ping

    2015-01-01

    This study aims to understand the level of contraceptive knowledge and attitudes towards contraception, and then to explore the association between the contraceptive behavior and unintended pregnancy in unmarried female university students in China. A cross-sectional study was conducted of university students in 49 universities across 7 cities in China from September 2007 to January 2008. We distributed 74,800 questionnaires, of which 69,842 were returned. In this paper, the data from 35,383 unmarried female university students were analyzed. The prevalence of sexual intercourse in unmarried female university students was 10.2%. The prevalence of unintended pregnancy in those sexually active female university students, was 31.8%. Among students with pregnancy, 53.5% experienced two or more pregnancies. 28.3% of the students with sexual intercourse reported that they always adopted contraceptive methods, and of those 82.9% chose to use male condoms. The majority (83.9%) of students with unintended pregnancy chose to terminate the latest pregnancy by surgical abortion or medical abortion. The contraceptive knowledge level of students who experienced unintended pregnancy was lower than those who did not. In China, about one third of unmarried female students with sexual intercourse experience unintended pregnancy. A variety of contraceptive methods are adopted, but the frequency of contraceptive use is low. Most of unmarried female students who experienced unintended pregnancy would choose to terminate the pregnancy with surgical or medical abortion. University students, especially the ones who have experienced unintended pregnancy, lack contraceptive and reproductive health knowledge. PMID:26091505

  3. Unmet need for family planning, contraceptive failure, and unintended pregnancy among HIV-infected and HIV-uninfected women in Zimbabwe.

    Directory of Open Access Journals (Sweden)

    Sandra I McCoy

    Full Text Available Prevention of unintended pregnancies among women living with HIV infection is a strategy recommended by the World Health Organization for prevention of mother-to-child transmission of HIV (PMTCT. We assessed pregnancy intentions and contraceptive use among HIV-positive and HIV-negative women with a recent pregnancy in Zimbabwe.We analyzed baseline data from the evaluation of Zimbabwe's Accelerated National PMTCT Program. Eligible women were randomly sampled from the catchment areas of 157 health facilities offering PMTCT services in five provinces. Eligible women were ≥16 years old and mothers of infants (alive or deceased born 9 to 18 months prior to the interview. Participants were interviewed about their HIV status, intendedness of the birth, and contraceptive use.Of 8,797 women, the mean age was 26.7 years, 92.8% were married or had a regular sexual partner, and they had an average of 2.7 lifetime births. Overall, 3,090 (35.1% reported that their births were unintended; of these women, 1,477 (47.8% and 1,613 (52.2% were and were not using a contraceptive method prior to learning that they were pregnant, respectively. Twelve percent of women reported that they were HIV-positive at the time of the survey; women who reported that they were HIV-infected were significantly more likely to report that their pregnancy was unintended compared to women who reported that they were HIV-uninfected (44.9% vs. 33.8%, p<0.01. After adjustment for covariates, among women with unintended births, there was no association between self-reported HIV status and lack of contraception use prior to pregnancy.Unmet need for family planning and contraceptive failure contribute to unintended pregnancies among women in Zimbabwe. Both HIV-infected and HIV-uninfected women reported unintended pregnancies despite intending to avoid or delay pregnancy, highlighting the need for effective contraceptive methods that align with pregnancy intentions.

  4. Effects of exposure estimation errors on estimated exposure-response relations for PM2.5.

    Science.gov (United States)

    Cox, Louis Anthony Tony

    2018-07-01

    Associations between fine particulate matter (PM2.5) exposure concentrations and a wide variety of undesirable outcomes, from autism and auto theft to elderly mortality, suicide, and violent crime, have been widely reported. Influential articles have argued that reducing National Ambient Air Quality Standards for PM2.5 is desirable to reduce these outcomes. Yet, other studies have found that reducing black smoke and other particulate matter by as much as 70% and dozens of micrograms per cubic meter has not detectably affected all-cause mortality rates even after decades, despite strong, statistically significant positive exposure concentration-response (C-R) associations between them. This paper examines whether this disconnect between association and causation might be explained in part by ignored estimation errors in estimated exposure concentrations. We use EPA air quality monitor data from the Los Angeles area of California to examine the shapes of estimated C-R functions for PM2.5 when the true C-R functions are assumed to be step functions with well-defined response thresholds. The estimated C-R functions mistakenly show risk as smoothly increasing with concentrations even well below the response thresholds, thus incorrectly predicting substantial risk reductions from reductions in concentrations that do not affect health risks. We conclude that ignored estimation errors obscure the shapes of true C-R functions, including possible thresholds, possibly leading to unrealistic predictions of the changes in risk caused by changing exposures. Instead of estimating improvements in public health per unit reduction (e.g., per 10 µg/m 3 decrease) in average PM2.5 concentrations, it may be essential to consider how interventions change the distributions of exposure concentrations. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Mediation of adoption and use: a key strategy for mitigating unintended consequences of health IT implementation.

    Science.gov (United States)

    Novak, Laurie L; Anders, Shilo; Gadd, Cynthia S; Lorenzi, Nancy M

    2012-01-01

    Without careful attention to the work of users, implementation of health IT can produce new risks and inefficiencies in care. This paper uses the technology use mediation framework to examine the work of a group of nurses who serve as mediators of the adoption and use of a barcode medication administration (BCMA) system in an inpatient setting. The study uses ethnographic methods to explore the mediators' work. Data included field notes from observations, documents, and email communications. This variety of sources enabled triangulation of findings between activities observed, discussed in meetings, and reported in emails. Mediation work integrated the BCMA tool with nursing practice, anticipating and solving implementation problems. Three themes of mediation work include: resolving challenges related to coordination, integrating the physical aspects of BCMA into everyday practice, and advocacy work. Previous work suggests the following factors impact mediation effectiveness: proximity to the context of use, understanding of users' practices and norms, credibility with users, and knowledge of the technology and users' technical abilities. We describe three additional factors observed in this case: 'influence on system developers,' 'influence on institutional authorities,' and 'understanding the network of organizational relationships that shape the users' work.' Institutionally supported clinicians who facilitate adoption and use of health IT systems can improve the safety and effectiveness of implementation through the management of unintended consequences. Additional research on technology use mediation can advance the science of implementation by providing decision-makers with theoretically durable, empirically grounded evidence for designing implementations.

  6. Forest fire management to avoid unintended consequences: a case study of Portugal using system dynamics.

    Science.gov (United States)

    Collins, Ross D; de Neufville, Richard; Claro, João; Oliveira, Tiago; Pacheco, Abílio P

    2013-11-30

    Forest fires are a serious management challenge in many regions, complicating the appropriate allocation to suppression and prevention efforts. Using a System Dynamics (SD) model, this paper explores how interactions between physical and political systems in forest fire management impact the effectiveness of different allocations. A core issue is that apparently sound management can have unintended consequences. An instinctive management response to periods of worsening fire severity is to increase fire suppression capacity, an approach with immediate appeal as it directly treats the symptom of devastating fires and appeases the public. However, the SD analysis indicates that a policy emphasizing suppression can degrade the long-run effectiveness of forest fire management. By crowding out efforts to preventative fuel removal, it exacerbates fuel loads and leads to greater fires, which further balloon suppression budgets. The business management literature refers to this problem as the firefighting trap, wherein focus on fixing problems diverts attention from preventing them, and thus leads to inferior outcomes. The paper illustrates these phenomena through a case study of Portugal, showing that a balanced approach to suppression and prevention efforts can mitigate the self-reinforcing consequences of this trap, and better manage long-term fire damages. These insights can help policymakers and fire managers better appreciate the interconnected systems in which their authorities reside and the dynamics that may undermine seemingly rational management decisions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Improved quantum backtracking algorithms using effective resistance estimates

    Science.gov (United States)

    Jarret, Michael; Wan, Kianna

    2018-02-01

    We investigate quantum backtracking algorithms of the type introduced by Montanaro (Montanaro, arXiv:1509.02374). These algorithms explore trees of unknown structure and in certain settings exponentially outperform their classical counterparts. Some of the previous work focused on obtaining a quantum advantage for trees in which a unique marked vertex is promised to exist. We remove this restriction by recharacterizing the problem in terms of the effective resistance of the search space. In this paper, we present a generalization of one of Montanaro's algorithms to trees containing k marked vertices, where k is not necessarily known a priori. Our approach involves using amplitude estimation to determine a near-optimal weighting of a diffusion operator, which can then be applied to prepare a superposition state with support only on marked vertices and ancestors thereof. By repeatedly sampling this state and updating the input vertex, a marked vertex is reached in a logarithmic number of steps. The algorithm thereby achieves the conjectured bound of O ˜(√{T Rmax }) for finding a single marked vertex and O ˜(k √{T Rmax }) for finding all k marked vertices, where T is an upper bound on the tree size and Rmax is the maximum effective resistance encountered by the algorithm. This constitutes a speedup over Montanaro's original procedure in both the case of finding one and the case of finding multiple marked vertices in an arbitrary tree.

  8. Estimated effects of temperature on secondary organic aerosol concentrations.

    Science.gov (United States)

    Sheehan, P E; Bowman, F M

    2001-06-01

    The temperature-dependence of secondary organic aerosol (SOA) concentrations is explored using an absorptive-partitioning model under a variety of simplified atmospheric conditions. Experimentally determined partitioning parameters for high yield aromatics are used. Variation of vapor pressures with temperature is assumed to be the main source of temperature effects. Known semivolatile products are used to define a modeling range of vaporization enthalpy of 10-25 kcal/mol-1. The effect of diurnal temperature variations on model predictions for various assumed vaporization enthalpies, precursor emission rates, and primary organic concentrations is explored. Results show that temperature is likely to have a significant influence on SOA partitioning and resulting SOA concentrations. A 10 degrees C decrease in temperature is estimated to increase SOA yields by 20-150%, depending on the assumed vaporization enthalpy. In model simulations, high daytime temperatures tend to reduce SOA concentrations by 16-24%, while cooler nighttime temperatures lead to a 22-34% increase, compared to constant temperature conditions. Results suggest that currently available constant temperature partitioning coefficients do not adequately represent atmospheric SOA partitioning behavior. Air quality models neglecting the temperature dependence of partitioning are expected to underpredict peak SOA concentrations as well as mistime their occurrence.

  9. Estimation of effective dose from radionuclides contained in misch metal

    International Nuclear Information System (INIS)

    Furuta, Etsuko; Aburai, Tamaru; Nisizawa, Kunihide

    2003-01-01

    Radionuclides contained in three kinds of misch metal products and two kinds of ingots were analyzed using a Ge (Li) semiconductor detector. Lanthanum-138 ( 138 La) and several daughter nuclides derived from thorium and uranium series were detected in all samples. All misch metal products and ingots were determined to be radioactive consumer products (RCP), although they have not been regarded as RCP in Japan. 138 La showed the highest nuclide content rate of all the radionuclides, and the lanthanum metal ingots displayed the highest specific activity at 720 mBq·g -1 . The maximum external effective dose was estimated to be at 3.7 mSv when a metal match was carried for 8,760 hours at 1 mm from the skin. The calculated effective dose under some conditions exceeded 10 μSv per year. This value corresponded to the exemption standard proposed by the UK's National Radiological Protection Board. Individuals working with large amounts of RCP should be appropriately protected. (author)

  10. Estimating overall exposure effects for the clustered and censored outcome using random effect Tobit regression models.

    Science.gov (United States)

    Wang, Wei; Griswold, Michael E

    2016-11-30

    The random effect Tobit model is a regression model that accommodates both left- and/or right-censoring and within-cluster dependence of the outcome variable. Regression coefficients of random effect Tobit models have conditional interpretations on a constructed latent dependent variable and do not provide inference of overall exposure effects on the original outcome scale. Marginalized random effects model (MREM) permits likelihood-based estimation of marginal mean parameters for the clustered data. For random effect Tobit models, we extend the MREM to marginalize over both the random effects and the normal space and boundary components of the censored response to estimate overall exposure effects at population level. We also extend the 'Average Predicted Value' method to estimate the model-predicted marginal means for each person under different exposure status in a designated reference group by integrating over the random effects and then use the calculated difference to assess the overall exposure effect. The maximum likelihood estimation is proposed utilizing a quasi-Newton optimization algorithm with Gauss-Hermite quadrature to approximate the integration of the random effects. We use these methods to carefully analyze two real datasets. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Unintended pregnancy among HIV-positive pregnant women in Enugu, southeast Nigeria.

    Science.gov (United States)

    Ezugwu, Euzebus C; Iyoke, Chukwuemeka A; Nkwo, Peter O; Ezegwui, Hygenius U; Akabueze, Jude C; Agu, Polycap U

    2016-01-01

    To determine the prevalence and factors associated with unintended pregnancy among HIV-positive pregnant women in Enugu, southeast Nigeria. A questionnaire-based cross-sectional study was performed of HIV-positive pregnant women receiving prenatal care at two tertiary health institutions in Enugu between March 1 and August 31, 2012. The women were interviewed with a pretested questionnaire. Overall, 180 HIV-positive pregnant women were recruited, 67 (37.2%) of whom declared that their pregnancy was unintended. Overall, 174 (96.7%) patients were receiving antiretroviral therapy and 99 (55.0%) had future fertility intensions. Participants with regular partners (married or cohabiting) had a significantly higher rate of unintended pregnancy than those with unstable partners (40.3%, n=64/159 vs 14.3%, n=3/21 P=0.029). Age, parity, educational level, and current treatment with antiretroviral therapy did not significantly affect the prevalence of unintended pregnancy. A substantial number of HIV-positive pregnant women declared their pregnancies to be unintended. Modern contraceptives should be made readily available and accessible to HIV-positive women to help eliminate mother-to-child transmission of HIV and subsequent new pediatric HIV infections. Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  12. Facing the estimation of effective population size based on molecular markers: comparison of estimators

    DEFF Research Database (Denmark)

    Jimenez Mena, Belen; Verrier, Etienne; Hospital, Frederic

    an increase in the variability of values over time. The distance from the mean and the median to the true Ne increased over time too. This was caused by the fixation of alleles through time due to genetic drift and the changes in the distribution of allele frequencies. We compared the three estimators of Ne...

  13. Exploring the roots of unintended safety threats associated with the introduction of hospital ePrescribing systems and candidate avoidance and/or mitigation strategies: a qualitative study.

    Science.gov (United States)

    Mozaffar, Hajar; Cresswell, Kathrin M; Williams, Robin; Bates, David W; Sheikh, Aziz

    2017-09-01

    Hospital electronic prescribing (ePrescribing) systems offer a wide range of patient safety benefits. Like other hospital health information technology interventions, however, they may also introduce new areas of risk. Despite recent advances in identifying these risks, the development and use of ePrescribing systems is still leading to numerous unintended consequences, which may undermine improvement and threaten patient safety. These negative consequences need to be analysed in the design, implementation and use of these systems. We therefore aimed to understand the roots of these reported threats and identify candidate avoidance/mitigation strategies. We analysed a longitudinal, qualitative study of the implementation and adoption of ePrescribing systems in six English hospitals, each being conceptualised as a case study. Data included semistructured interviews, observations of implementation meetings and system use, and a collection of relevant documents. We analysed data first within and then across the case studies. Our dataset included 214 interviews, 24 observations and 18 documents. We developed a taxonomy of factors underlying unintended safety threats in: (1) suboptimal system design, including lack of support for complex medication administration regimens, lack of effective integration between different systems, and lack of effective automated decision support tools; (2) inappropriate use of systems-in particular, too much reliance on the system and introduction of workarounds; and (3) suboptimal implementation strategies resulting from partial roll-outs/dual systems and lack of appropriate training. We have identified a number of system and organisational strategies that could potentially avoid or reduce these risks. Imperfections in the design, implementation and use of ePrescribing systems can give rise to unintended consequences, including safety threats. Hospitals and suppliers need to implement short- and long-term strategies in terms of the

  14. Inferring Saving in Training Time From Effect Size Estimates

    National Research Council Canada - National Science Library

    Burright, Burke

    2000-01-01

    .... Students' time saving represents a major potential benefit of using them. This paper fills a methodology gap in estimating the students' timesaving benefit of asynchronous training technologies...

  15. A Monte Carlo estimation of effective dose in chest tomosynthesis

    International Nuclear Information System (INIS)

    Sabol, John M.

    2009-01-01

    calculated to be 0.124 mSv (ICRP60) [0.134 mSv (ICRP103)]. This is less than 75% of that predicted by scaling of the PA mA s ratio. This lower dose was due to changes in the focal-spot-to-skin distance, effective changes in collimation with projection angle, rounding down of the mA s step, and variations in organ exposure to the primary x-ray beam for each view. Large errors in dose estimation can occur if these factors are not accurately modeled. Conclusions: The effective dose of a chest examination with this chest tomosynthesis system is about twice that of a two-view chest examination and less than 2% of the published average values for thoracic CT. It is shown that complete consideration of the tomosynthesis acquisition technique and geometry is required for accurate determination of the effective dose to the patient. Tomosynthesis provides three-dimensional imaging at a dose level comparable to a two-view chest x-ray examination and may provide a low dose alternative to thoracic CT for obtaining depth information in chest imaging.

  16. Understanding peer effects : on the nature, estimation and channels of peer effects

    NARCIS (Netherlands)

    Feld, J.F.; Zölitz, U.N.

    2016-01-01

    This paper estimates peer effects in a university context where students are randomly assigned to sections. While students benefit from better peers on average, lowachieving students are harmed by high-achieving peers. Analyzing students’ course evaluations suggests that peer effects are driven by

  17. Understanding peer effects - On the nature, estimation and channels of peer effects

    NARCIS (Netherlands)

    Feld, J.F.; Zölitz, U.N.

    2016-01-01

    This paper estimates peer effects in a university context where students are randomly assigned to sections. While students benefit from better peers on average, low-achieving students are harmed by high-achieving peers. Analyzing students’ course evaluations suggests that peer effects are driven by

  18. Excessive Daytime Sleepiness and Unintended Sleep Episodes Associated with Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Fatai Salawu

    2015-01-01

    Full Text Available This article looks at the issues of excessive daytime sleepiness and unintended sleep episodes in patients with Parkinson’s disease (PD and explores the reasons why patients might suffer from these symptoms, and what steps could be taken to manage them. During the last decade, understanding of sleep/wake regulation has increased. Several brainstem nuclei and their communication pathways in the ascending arousing system through the hypothalamus and thalamus to the cortex play key roles in sleep disorders. Insomnia is the most common sleep disorder in PD patients, and excessive daytime sleepiness is also common. Excessive daytime sleepiness affects up to 50% of PD patients and a growing body of research has established this sleep disturbance as a marker of preclinical and premotor PD. It is a frequent and highly persistent feature in PD, with multifactorial underlying pathophysiology. Both age and disease-related disturbances of sleep-wake regulation contribute to hypersomnia in PD. Treatment with dopamine agonists also contribute to excessive daytime sleepiness. Effective management of sleep disturbances and excessive daytime sleepiness can greatly improve the quality of life for patients with PD.

  19. Racial/Ethnic Differences in Women's Experiences of Reproductive Coercion, Intimate Partner Violence, and Unintended Pregnancy.

    Science.gov (United States)

    Holliday, Charvonne N; McCauley, Heather L; Silverman, Jay G; Ricci, Edmund; Decker, Michele R; Tancredi, Daniel J; Burke, Jessica G; Documét, Patricia; Borrero, Sonya; Miller, Elizabeth

    2017-08-01

    To explore racial/ethnic differences in reproductive coercion (RC), intimate partner violence (IPV), and unintended pregnancy (UIP). We analyzed cross-sectional, baseline data from an intervention that was conducted between August 2008 and March 2009 in five family planning clinics in the San Francisco, California area, to examine the association of race/ethnicity with RC, IPV, and UIP among female patients aged 16-29 (n = 1234). RC was significantly associated with race/ethnicity, p women, with an overall range of 37.1%-50.3% among all racial/ethnic groups (p women (AOR = 1.72, 95% CI = 1.14-2.60). Black and multiracial women seeking care in family planning clinics have a disproportionately high prevalence of RC and UIP. RC may partially explain differences in UIP prevalence, with the effect of race/ethnicity slightly attenuated in RC-adjusted models. However, the impact of RC on risk for UIP was similar for White and Black women. Findings from this study support the need to understand and prevent RC, particularly among women of color. Results are foundational in understanding disparities in RC and UIP that may have implications for refinement of clinical care.

  20. IMPROVING THE METHODS OF ESTIMATION OF THE UNIT TRAIN EFFECTIVENESS

    Directory of Open Access Journals (Sweden)

    Dmytro KOZACHENKO

    2016-09-01

    Full Text Available The article presents the results of studies of freight transportation by unit trains. The article is aimed at developing the methods of the efficiency evaluation of unit train dispatch on the basis of full-scale experiments. Duration of the car turnover is a random variable when dispatching the single cars and group cars, as well as when dispatching them as a part of a unit train. The existing methodologies for evaluating the efficiency of unit trains’ make-up are based on the use of calculation methodologies and their results can give significant errors. The work presents a methodology that makes it possible to evaluate the efficiency of unit train shipments based on the processing of results of experimental travels using the methods of mathematical statistics. This approach provides probabilistic estimates of the rolling stock use efficiency for different approaches to the organization of car traffic volumes, as well as establishes the effect for each of the participants in the transportation process.

  1. Effect of Smart Meter Measurements Data On Distribution State Estimation

    DEFF Research Database (Denmark)

    Pokhrel, Basanta Raj; Nainar, Karthikeyan; Bak-Jensen, Birgitte

    2018-01-01

    Smart distribution grids with renewable energy based generators and demand response resources (DRR) requires accurate state estimators for real time control. Distribution grid state estimators are normally based on accumulated smart meter measurements. However, increase of measurements in the phy......Smart distribution grids with renewable energy based generators and demand response resources (DRR) requires accurate state estimators for real time control. Distribution grid state estimators are normally based on accumulated smart meter measurements. However, increase of measurements...... in the physical grid can enforce significant stress not only on the communication infrastructure but also in the control algorithms. This paper aims to propose a methodology to analyze needed real time smart meter data from low voltage distribution grids and their applicability in distribution state estimation...

  2. Estimating the Effects of Parental Divorce and Death With Fixed Effects Models

    OpenAIRE

    Amato, Paul R.; Anthony, Christopher J.

    2014-01-01

    The authors used child fixed effects models to estimate the effects of parental divorce and death on a variety of outcomes using 2 large national data sets: (a) the Early Childhood Longitudinal Study, Kindergarten Cohort (kindergarten through the 5th grade) and (b) the National Educational Longitudinal Study (8th grade to the senior year of high school). In both data sets, divorce and death were associated with multiple negative outcomes among children. Although evidence for a causal effect o...

  3. Estimating the hypothetical dual health impact and cost-effectiveness of the Woman’s Condom in selected sub-Saharan African countries

    Directory of Open Access Journals (Sweden)

    Mvundura M

    2015-03-01

    Full Text Available Mercy Mvundura, Neeti Nundy, Maggie Kilbourne-Brook, Patricia S Coffey Technology Solutions Global Program, PATH, Seattle, WA, USA Background: Female condoms are the only currently available woman-initiated option that offers dual protection from pregnancy and sexually transmitted infections, including HIV. The Woman’s Condom is a new female condom designed to provide dual protection and to be highly pleasurable and acceptable. Objective: We sought to estimate the potential dual health impact and cost-effectiveness of a Woman’s Condom distribution program in 13 sub-Saharan African countries with HIV prevalence rates >4% among adults aged 15–49 years. We used two separate, publicly available models for this analysis, the Impact 2 model developed by Marie Stopes International and the Population Services International disability-adjusted life years (DALY calculator program. We estimated the potential numbers of pregnancies and DALYs averted when the Woman’s Condom is used as a family planning method and the HIV infections and DALYs averted when it is used as an HIV prevention method. Results: Programming 100,000 Woman’s Condoms in each of 13 countries in sub-Saharan Africa during a 1-year period could potentially prevent 194 pregnancies and an average of 21 HIV infections in each country. When using the World Health Organization CHOosing Interventions that are Cost-Effective (WHO-CHOICE criteria as a threshold to infer the potential cost-effectiveness of the Woman’s Condom, we found that the Woman’s Condom would be considered cost-effective. Conclusion: This was a first and successful attempt to estimate the impact of dual protection of female condoms. The health impact is greater for the use of the Woman’s Condom as an HIV prevention method than for contraception. Dual use of the Woman’s Condom increases the overall health impact. The Woman’s Condom was found to be very cost-effective in all 13 countries in our sample. Keywords

  4. Nonparametric Estimation of Distributions in Random Effects Models

    KAUST Repository

    Hart, Jeffrey D.; Cañ ette, Isabel

    2011-01-01

    to every small dataset. A detailed algorithm for computing minimum distance estimates is proposed, and the usefulness of our methodology is illustrated by a simulation study and an analysis of microarray data. Supplemental materials for the article

  5. Estimating the Effects of Parental Divorce and Death With Fixed Effects Models.

    Science.gov (United States)

    Amato, Paul R; Anthony, Christopher J

    2014-04-01

    The authors used child fixed effects models to estimate the effects of parental divorce and death on a variety of outcomes using 2 large national data sets: (a) the Early Childhood Longitudinal Study, Kindergarten Cohort (kindergarten through the 5th grade) and (b) the National Educational Longitudinal Study (8th grade to the senior year of high school). In both data sets, divorce and death were associated with multiple negative outcomes among children. Although evidence for a causal effect of divorce on children was reasonably strong, effect sizes were small in magnitude. A second analysis revealed a substantial degree of variability in children's outcomes following parental divorce, with some children declining, others improving, and most not changing at all. The estimated effects of divorce appeared to be strongest among children with the highest propensity to experience parental divorce.

  6. Estimating the Effects of Parental Divorce and Death With Fixed Effects Models

    Science.gov (United States)

    Amato, Paul R.; Anthony, Christopher J.

    2014-01-01

    The authors used child fixed effects models to estimate the effects of parental divorce and death on a variety of outcomes using 2 large national data sets: (a) the Early Childhood Longitudinal Study, Kindergarten Cohort (kindergarten through the 5th grade) and (b) the National Educational Longitudinal Study (8th grade to the senior year of high school). In both data sets, divorce and death were associated with multiple negative outcomes among children. Although evidence for a causal effect of divorce on children was reasonably strong, effect sizes were small in magnitude. A second analysis revealed a substantial degree of variability in children’s outcomes following parental divorce, with some children declining, others improving, and most not changing at all. The estimated effects of divorce appeared to be strongest among children with the highest propensity to experience parental divorce. PMID:24659827

  7. Contact Estimation in Robot Interaction

    Directory of Open Access Journals (Sweden)

    Filippo D'Ippolito

    2014-07-01

    Full Text Available In the paper, safety issues are examined in a scenario in which a robot manipulator and a human perform the same task in the same workspace. During the task execution, the human should be able to physically interact with the robot, and in this case an estimation algorithm for both interaction forces and a contact point is proposed in order to guarantee safety conditions. The method, starting from residual joint torque estimation, allows both direct and adaptive computation of the contact point and force, based on a principle of equivalence of the contact forces. At the same time, all the unintended contacts must be avoided, and a suitable post-collision strategy is considered to move the robot away from the collision area or else to reduce impact effects. Proper experimental tests have demonstrated the applicability in practice of both the post-impact strategy and the estimation algorithms; furthermore, experiments demonstrate the different behaviour resulting from the adaptation of the contact point as opposed to direct calculation.

  8. Estimation of Lung Ventilation

    Science.gov (United States)

    Ding, Kai; Cao, Kunlin; Du, Kaifang; Amelon, Ryan; Christensen, Gary E.; Raghavan, Madhavan; Reinhardt, Joseph M.

    Since the primary function of the lung is gas exchange, ventilation can be interpreted as an index of lung function in addition to perfusion. Injury and disease processes can alter lung function on a global and/or a local level. MDCT can be used to acquire multiple static breath-hold CT images of the lung taken at different lung volumes, or with proper respiratory control, 4DCT images of the lung reconstructed at different respiratory phases. Image registration can be applied to this data to estimate a deformation field that transforms the lung from one volume configuration to the other. This deformation field can be analyzed to estimate local lung tissue expansion, calculate voxel-by-voxel intensity change, and make biomechanical measurements. The physiologic significance of the registration-based measures of respiratory function can be established by comparing to more conventional measurements, such as nuclear medicine or contrast wash-in/wash-out studies with CT or MR. An important emerging application of these methods is the detection of pulmonary function change in subjects undergoing radiation therapy (RT) for lung cancer. During RT, treatment is commonly limited to sub-therapeutic doses due to unintended toxicity to normal lung tissue. Measurement of pulmonary function may be useful as a planning tool during RT planning, may be useful for tracking the progression of toxicity to nearby normal tissue during RT, and can be used to evaluate the effectiveness of a treatment post-therapy. This chapter reviews the basic measures to estimate regional ventilation from image registration of CT images, the comparison of them to the existing golden standard and the application in radiation therapy.

  9. Uncertainties in effective dose estimates of adult CT head scans: The effect of head size

    International Nuclear Information System (INIS)

    Gregory, Kent J.; Bibbo, Giovanni; Pattison, John E.

    2009-01-01

    Purpose: This study is an extension of a previous study where the uncertainties in effective dose estimates from adult CT head scans were calculated using four CT effective dose estimation methods, three of which were computer programs (CT-EXPO, CTDOSIMETRY, and IMPACTDOSE) and one that involved the dose length product (DLP). However, that study did not include the uncertainty contribution due to variations in head sizes. Methods: The uncertainties due to head size variations were estimated by first using the computer program data to calculate doses to small and large heads. These doses were then compared with doses calculated for the phantom heads used by the computer programs. An uncertainty was then assigned based on the difference between the small and large head doses and the doses of the phantom heads. Results: The uncertainties due to head size variations alone were found to be between 4% and 26% depending on the method used and the patient gender. When these uncertainties were included with the results of the previous study, the overall uncertainties in effective dose estimates (stated at the 95% confidence interval) were 20%-31% (CT-EXPO), 15%-30% (CTDOSIMETRY), 20%-36% (IMPACTDOSE), and 31%-40% (DLP). Conclusions: For the computer programs, the lower overall uncertainties were still achieved when measured values of CT dose index were used rather than tabulated values. For DLP dose estimates, head size variations made the largest (for males) and second largest (for females) contributions to effective dose uncertainty. An improvement in the uncertainty of the DLP method dose estimates will be achieved if head size variation can be taken into account.

  10. Uncertainties in effective dose estimates of adult CT head scans: The effect of head size

    Energy Technology Data Exchange (ETDEWEB)

    Gregory, Kent J.; Bibbo, Giovanni; Pattison, John E. [Department of Medical Physics, Royal Adelaide Hospital, Adelaide, South Australia 5000 (Australia) and School of Electrical and Information Engineering (Applied Physics), University of South Australia, Mawson Lakes, South Australia 5095 (Australia); Division of Medical Imaging, Women' s and Children' s Hospital, North Adelaide, South Australia 5006 (Australia) and School of Electrical and Information Engineering (Applied Physics), University of South Australia, Mawson Lakes, South Australia 5095 (Australia); School of Electrical and Information Engineering (Applied Physics), University of South Australia, Mawson Lakes, South Australia 5095 (Australia)

    2009-09-15

    Purpose: This study is an extension of a previous study where the uncertainties in effective dose estimates from adult CT head scans were calculated using four CT effective dose estimation methods, three of which were computer programs (CT-EXPO, CTDOSIMETRY, and IMPACTDOSE) and one that involved the dose length product (DLP). However, that study did not include the uncertainty contribution due to variations in head sizes. Methods: The uncertainties due to head size variations were estimated by first using the computer program data to calculate doses to small and large heads. These doses were then compared with doses calculated for the phantom heads used by the computer programs. An uncertainty was then assigned based on the difference between the small and large head doses and the doses of the phantom heads. Results: The uncertainties due to head size variations alone were found to be between 4% and 26% depending on the method used and the patient gender. When these uncertainties were included with the results of the previous study, the overall uncertainties in effective dose estimates (stated at the 95% confidence interval) were 20%-31% (CT-EXPO), 15%-30% (CTDOSIMETRY), 20%-36% (IMPACTDOSE), and 31%-40% (DLP). Conclusions: For the computer programs, the lower overall uncertainties were still achieved when measured values of CT dose index were used rather than tabulated values. For DLP dose estimates, head size variations made the largest (for males) and second largest (for females) contributions to effective dose uncertainty. An improvement in the uncertainty of the DLP method dose estimates will be achieved if head size variation can be taken into account.

  11. Doing More for More: Unintended Consequences of Financial Incentives for Oncology Specialty Care.

    Science.gov (United States)

    O'Neil, Brock; Graves, Amy J; Barocas, Daniel A; Chang, Sam S; Penson, David F; Resnick, Matthew J

    2016-02-01

    Specialty care remains a significant contributor to health care spending but largely unaddressed in novel payment models aimed at promoting value-based delivery. Bladder cancer, chiefly managed by subspecialists, is among the most costly. In 2005, Centers for Medicare and Medicaid Services (CMS) dramatically increased physician payment for office-based interventions for bladder cancer to shift care from higher cost facilities, but the impact is unknown. This study evaluated the effect of financial incentives on patterns of fee-for-service (FFS) bladder cancer care. Data from a 5% sample of Medicare beneficiaries from 2001-2013 were evaluated using interrupted time-series analysis with segmented regression. Primary outcomes were the effects of CMS fee modifications on utilization and site of service for procedures associated with the diagnosis and treatment of bladder cancer. Rates of related bladder cancer procedures that were not affected by the fee change were concurrent controls. Finally, the effect of payment changes on both diagnostic yield and need for redundant procedures were studied. All statistical tests were two-sided. Utilization of clinic-based procedures increased by 644% (95% confidence interval [CI] = 584% to 704%) after the fee change, but without reciprocal decline in facility-based procedures. Procedures unaffected by the fee incentive remained unchanged throughout the study period. Diagnostic yield decreased by 17.0% (95% CI = 12.7% to 21.3%), and use of redundant office-based procedures increased by 76.0% (95% CI = 59% to 93%). Financial incentives in bladder cancer care have unintended and costly consequences in the current FFS environment. The observed price sensitivity is likely to remain a major issue in novel payment models failing to incorporate procedure-based specialty physicians. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  12. Estimates of the Economic Effects of Sea Level Rise

    International Nuclear Information System (INIS)

    Darwin, R.F.; Tol, R.S.J.

    2001-01-01

    Regional estimates of direct cost (DC) are commonly used to measure the economic damages of sea level rise. Such estimates suffer from three limitations: (1) values of threatened endowments are not well known, (2) loss of endowments does not affect consumer prices, and (3) international trade is disregarded. Results in this paper indicate that these limitations can significantly affect economic assessments of sea level rise. Current uncertainty regarding endowment values (as reflected in two alternative data sets), for example, leads to a 17 percent difference in coastal protection, a 36 percent difference in the amount of land protected, and a 36 percent difference in DC globally. Also, global losses in equivalent variation (EV), a welfare measure that accounts for price changes, are 13 percent higher than DC estimates. Regional EV losses may be up to 10 percent lower than regional DC, however, because international trade tends to redistribute losses from regions with relatively high damages to regions with relatively low damages. 43 refs

  13. Greenhouse effect: A first estimation of the emissions in Italy

    International Nuclear Information System (INIS)

    Gaudioso, D.; Onufrio, G.

    1991-03-01

    The estimate of the anthropogenic emissions of greenhouse gases and the selection of the relevant emission factors represents a preliminary condition to define policies aiming at curbing these emissions. In the first part of this paper there is an analysis of C0 2 emission factors, referred to the various fuels and energy technologies. The values at issue take into account the physico-chemical composition of the different fossil fuels, as well as the overall efficiency of energy production cycles and end uses patterns. As concerns the other greenhouse gases, the available information is summarized at a much more integrate level. The second part presents some estimates of carbon dioxide emissions in Italy, by sector and by fuel; some characteristic levels of specific emissions are also identified. A comparative estimate for CH 4 , N 2 O, CO and CFC's is also made, in order to set up a first reference table of the emissions of greenhouse gases in our country. (author)

  14. Estimating the effect of urban density on fuel demand

    Energy Technology Data Exchange (ETDEWEB)

    Karathodorou, Niovi; Graham, Daniel J. [Imperial College London, London, SW7 2AZ (United Kingdom); Noland, Robert B. [Rutgers University, New Brunswick, NJ 08901 (United States)

    2010-01-15

    Much of the empirical literature on fuel demand presents estimates derived from national data which do not permit any explicit consideration of the spatial structure of the economy. Intuitively we would expect the degree of spatial concentration of activities to have a strong link with transport fuel consumption. The present paper addresses this theme by estimating a fuel demand model for urban areas to provide a direct estimate of the elasticity of demand with respect to urban density. Fuel demand per capita is decomposed into car stock per capita, fuel consumption per kilometre and annual distance driven per car per year. Urban density is found to affect fuel consumption, mostly through variations in the car stock and in the distances travelled, rather than through fuel consumption per kilometre. (author)

  15. Uncertainty and validation. Effect of user interpretation on uncertainty estimates

    International Nuclear Information System (INIS)

    Kirchner, G.; Peterson, R.

    1996-11-01

    Uncertainty in predictions of environmental transfer models arises from, among other sources, the adequacy of the conceptual model, the approximations made in coding the conceptual model, the quality of the input data, the uncertainty in parameter values, and the assumptions made by the user. In recent years efforts to quantify the confidence that can be placed in predictions have been increasing, but have concentrated on a statistical propagation of the influence of parameter uncertainties on the calculational results. The primary objective of this Working Group of BIOMOVS II was to test user's influence on model predictions on a more systematic basis than has been done before. The main goals were as follows: To compare differences between predictions from different people all using the same model and the same scenario description with the statistical uncertainties calculated by the model. To investigate the main reasons for different interpretations by users. To create a better awareness of the potential influence of the user on the modeling results. Terrestrial food chain models driven by deposition of radionuclides from the atmosphere were used. Three codes were obtained and run with three scenarios by a maximum of 10 users. A number of conclusions can be drawn some of which are general and independent of the type of models and processes studied, while others are restricted to the few processes that were addressed directly: For any set of predictions, the variation in best estimates was greater than one order of magnitude. Often the range increased from deposition to pasture to milk probably due to additional transfer processes. The 95% confidence intervals about the predictions calculated from the parameter distributions prepared by the participants did not always overlap the observations; similarly, sometimes the confidence intervals on the predictions did not overlap. Often the 95% confidence intervals of individual predictions were smaller than the

  16. Uncertainty and validation. Effect of user interpretation on uncertainty estimates

    Energy Technology Data Exchange (ETDEWEB)

    Kirchner, G. [Univ. of Bremen (Germany); Peterson, R. [AECL, Chalk River, ON (Canada)] [and others

    1996-11-01

    Uncertainty in predictions of environmental transfer models arises from, among other sources, the adequacy of the conceptual model, the approximations made in coding the conceptual model, the quality of the input data, the uncertainty in parameter values, and the assumptions made by the user. In recent years efforts to quantify the confidence that can be placed in predictions have been increasing, but have concentrated on a statistical propagation of the influence of parameter uncertainties on the calculational results. The primary objective of this Working Group of BIOMOVS II was to test user's influence on model predictions on a more systematic basis than has been done before. The main goals were as follows: To compare differences between predictions from different people all using the same model and the same scenario description with the statistical uncertainties calculated by the model. To investigate the main reasons for different interpretations by users. To create a better awareness of the potential influence of the user on the modeling results. Terrestrial food chain models driven by deposition of radionuclides from the atmosphere were used. Three codes were obtained and run with three scenarios by a maximum of 10 users. A number of conclusions can be drawn some of which are general and independent of the type of models and processes studied, while others are restricted to the few processes that were addressed directly: For any set of predictions, the variation in best estimates was greater than one order of magnitude. Often the range increased from deposition to pasture to milk probably due to additional transfer processes. The 95% confidence intervals about the predictions calculated from the parameter distributions prepared by the participants did not always overlap the observations; similarly, sometimes the confidence intervals on the predictions did not overlap. Often the 95% confidence intervals of individual predictions were smaller than the

  17. Prevalence and factors associated with unintended pregnancy among married women in an urban and rural community, Khartoum state, Sudan

    Directory of Open Access Journals (Sweden)

    Majdi Mohammed Sabahelzain

    2014-01-01

    Full Text Available Introduction: Unintended or unplanned pregnancy has been a distressing reality among females in the reproductive age group particularly in developing countries. The repercussions of such events range from illegal abortions to various health related problems associated with pregnancy in mothers. The current study aimed to determine the prevalence of unintended pregnancy among married women in an urban and rural community in Khartoum state, to determine the associated factors of unintended pregnancy and to verify the reasons behind unintended pregnancy as perceived by the married women in the area. Methodology: It was a community?based; cross sectional study conducted in Riyadh and Alshekh Elfadni areas in Khartoum state. The sample size was calculated as 341. The study population were married women of reproductive age (15?49 years, selected by multistage stratified sampling. Data was collected by a pre?tested questionnaire and analysed by SPSS software. Chi square test was used to test the association between the dependent and independent variables. Level of significance was determined at 95% (P value < 0.05 was considered as significant. Results: Prevalence of unintended pregnancy was high at 30.2% among the study sample. Significant association (95% CI, p<0.05 was seen between unintended pregnancy and education, household size, parity and use of modern contraceptives methods Conclusion: This study concluded that the prevalence of unintended pregnancy among married women in rural and urban communities in Khartoum state is high. The unintended pregnancy increases as the level of education increases. Women with big household size and high parity are more likely to have experienced unintended pregnancy. The most important reason behind unintended pregnancy is less spacing between one pregnancy and the other.

  18. Economics: An Analysis of Unintended Consequences. Volume 1: Introduction to Microeconomics.

    Science.gov (United States)

    Schenk, Robert E.

    This curriculum guide introduces high school students to the basic principles of microeconomics. Chapter 1 provides a basic definition of economics, while chapter 2 introduces a number of important economic concepts and ideas and examines reasons for unintended or unexpected consequences of decision-making. Chapter 3 considers how individual…

  19. Investigations on human error hazards in recent unintended trip events of Korean nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sa Kil; Jang, Tong Il; Lee, Yong Hee; Shin, Kwang Hyeon [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    According to the Operational Performance Information System (OPIS) which has been operated to improve the public understanding by the KINS (Korea Institute of Nuclear Safety), unintended trip events by mainly human errors counted up to 38 cases (18.7%) from 2000 to 2011. Although the Nuclear Power Plant (NPP) industry in Korea has been making efforts to reduce the human errors which have largely contributed to trip events, the human error rate might keep increasing. Interestingly, digital based I and C systems is the one of the reduction factors of unintended reactor trips. Human errors, however, have occurred due to the digital based I and C systems because those systems require new or changed behaviors to the NPP operators. Therefore, it is necessary that the investigations of human errors consider a new methodology to find not only tangible behavior but also intangible behavior such as organizational behaviors. In this study we investigated human errors to find latent factors such as decisions and conditions in the all of the unintended reactor trip events during last dozen years. To find them, we applied the HFACS (Human Factors Analysis and Classification System) which is a commonly utilized tool for investigating human contributions to aviation accidents under a widespread evaluation scheme. The objective of this study is to find latent factors behind of human errors in nuclear reactor trip events. Therefore, a method to investigate unintended trip events by human errors and the results will be discussed in more detail.

  20. Unintended allergens in precautionary labelled and unlabelled products pose significant risks to UK allergic consumers

    NARCIS (Netherlands)

    Remington, B.C.; Baumert, J.L.; Blom, W.M.; Houben, G.F.; Taylor, S.L.; Kruizinga, A.G.

    2015-01-01

    Background Allergens in food may pose a risk to allergic consumers. While there is EU regulation for allergens present as an ingredient, this is not the case for unintended allergen presence (UAP). Food companies use precautionary allergen labels to inform allergic individuals of a potential risk

  1. Unintended pregnancy and the changing demography of American women, 1987-2008

    Directory of Open Access Journals (Sweden)

    Athena Tapales

    2015-12-01

    Full Text Available Background: In 1987, the U.S. unintended pregnancy rate was 59 per 1,000 women ages 15-44; the rate fell to 54 in 2008. Over this period, American women experienced dramatic demographic shifts, including an aging population that was better educated and more racially and ethnically diverse. Objective: This study aims to explain trends in unintended pregnancy and understand what factors contributed most strongly to changes in rates over time, focusing on population composition and group-specific changes. Methods: We used the 1988 and 2006-10 waves of the National Survey of Family Growth and employed a decomposition approach, looking jointly at age, relationship status and educational attainment. Results: When we decomposed by the demographic factors together, we found that changes in population composition contributed to an increase in the overall rate, but this was more than offset by group-specific rate declines, which had an impact nearly twice as great in the downward direction. Increases in the share of the population that was cohabiting and the share that was Hispanic were offset by declines in rates among married women. Conclusions: Our findings suggest that a combination of compositional shifts and changes in group-specific rates drove unintended pregnancy, sometimes acting as counterbalancing forces, other times operating in tandem. Contribution: This paper shows the importance of both changes in population composition and changes in group-specific behaviors to the changing unintended pregnancy rate in the United States.

  2. Cars Gone Wild: The Major Contributor to Unintended Acceleration in Automobiles is Pedal Error.

    Science.gov (United States)

    Schmidt, Richard A; Young, Douglas E

    2010-01-01

    "Unintended-acceleration" automobile accidents typically begin when the driver first enters the car, starts the engine, and intends to press his/her right foot on the brake while shifting from Park to a drive gear (Drive or Reverse). The driver reports an unintended (uncommanded) full-throttle acceleration, coupled with a loss of braking, until the episode ends in a crash. Pedal misapplications - where the right foot contacts the accelerator instead of the brake that was intended - have been linked to these accidents (Schmidt, 1989, 1993) which, in the 1980s, were thought to occur only at the start of a driving cycle (and/or with the car in Park). But, in 1997, we identified over 200 pedal errors as the cause of accidents reported in the North Carolina database; these crashes occurred during the driving cycle (Schmidt et al., 1997), and/or with the vehicle in a gear other than Park. Our present work provides a more thorough analysis of these North Carolina Police Accident Reports from 1979 to 1995. The vast majority of pedal misapplications (over 92%) (a) occurred during the driving cycle, (b) were generally in "unhurried" conditions, and (c) were categorically separate from those events referred to as unintended-acceleration episodes at start-up. These ideas are explanatory for the recent (2009-2010) surge of unintended-acceleration reports, perhaps even suggesting that all of these crashes are caused by pedal errors, and that none of them are based on some vehicle defect(s).

  3. Investigations on human error hazards in recent unintended trip events of Korean nuclear power plants

    International Nuclear Information System (INIS)

    Kim, Sa Kil; Jang, Tong Il; Lee, Yong Hee; Shin, Kwang Hyeon

    2012-01-01

    According to the Operational Performance Information System (OPIS) which has been operated to improve the public understanding by the KINS (Korea Institute of Nuclear Safety), unintended trip events by mainly human errors counted up to 38 cases (18.7%) from 2000 to 2011. Although the Nuclear Power Plant (NPP) industry in Korea has been making efforts to reduce the human errors which have largely contributed to trip events, the human error rate might keep increasing. Interestingly, digital based I and C systems is the one of the reduction factors of unintended reactor trips. Human errors, however, have occurred due to the digital based I and C systems because those systems require new or changed behaviors to the NPP operators. Therefore, it is necessary that the investigations of human errors consider a new methodology to find not only tangible behavior but also intangible behavior such as organizational behaviors. In this study we investigated human errors to find latent factors such as decisions and conditions in the all of the unintended reactor trip events during last dozen years. To find them, we applied the HFACS (Human Factors Analysis and Classification System) which is a commonly utilized tool for investigating human contributions to aviation accidents under a widespread evaluation scheme. The objective of this study is to find latent factors behind of human errors in nuclear reactor trip events. Therefore, a method to investigate unintended trip events by human errors and the results will be discussed in more detail

  4. The Unintended Consequences of Property Tax Relief: New York's STAR Program

    Science.gov (United States)

    Eom, Tae Ho; Duncombe, William; Nguyen-Hoang, Phuong; Yinger, John

    2014-01-01

    New York's School Tax Relief Program, STAR, provides state-funded property tax relief for homeowners. Like a matching grant, STAR changes the price of education, thereby altering the incentives of voters and school officials and leading to unintended consequences. Using data for New York State school districts before and after STAR was…

  5. The nature and causes of unintended events reported at 10 internal medicine departments.

    NARCIS (Netherlands)

    Lubberding, S.; Zwaan, L.; Timmermans, D.R.M.; Wagner, C.

    2011-01-01

    Objective: This study aimed to examine the nature and causes of unintended events (UEs) at internal medicine departments (IMD). Methods: An observational study was conducted at 10 IMDs in 8 Dutch hospitals. The study period per participating department was 5 to 14 weeks. During this period, staff

  6. Effective utilization of weighting adjustment for the estimates of ...

    African Journals Online (AJOL)

    The use of response propensity and the predicted mean of the outcome variable for cell creation are stressed .The results from our empirical study emphasize the efficacy of Weighting Adjustment over the Unadjusted estimates .We adopt the following criteria: Variance, Bias and Mean Square Error in reaching our ...

  7. ADHD and math - The differential effect on calculation and estimation.

    Science.gov (United States)

    Ganor-Stern, Dana; Steinhorn, Ofir

    2018-05-31

    Adults with ADHD were compared to controls when solving multiplication problems exactly and when estimating the results of multidigit multiplication problems relative to reference numbers. The ADHD participants were slower than controls in the exact calculation and in the estimation tasks, but not less accurate. The ADHD participants were similar to controls in showing enhanced accuracy and speed for smaller problem sizes, for trials in which the reference numbers were smaller (vs. larger) than the exact answers and for reference numbers that were far (vs. close) from the exact answer. The two groups similarly used the approximated calculation and the sense of magnitude strategies. They differed however in strategy execution, mainly of the approximated calculation strategy, which requires working memory resources. The increase in reaction time associated with using the approximated calculation strategy was larger for the ADHD compared to the control participants. Thus, ADHD seems to selectively impair calculation processes in estimation tasks that rely on working memory, but it does not hamper estimation skills that are based on sense of magnitude. The educational implications of these findings are discussed. Copyright © 2018. Published by Elsevier B.V.

  8. Effect of Smart Meter Measurements Data On Distribution State Estimation

    DEFF Research Database (Denmark)

    Pokhrel, Basanta Raj; Nainar, Karthikeyan; Bak-Jensen, Birgitte

    2018-01-01

    in the physical grid can enforce significant stress not only on the communication infrastructure but also in the control algorithms. This paper aims to propose a methodology to analyze needed real time smart meter data from low voltage distribution grids and their applicability in distribution state estimation...

  9. Effects of systematic sampling on satellite estimates of deforestation rates

    International Nuclear Information System (INIS)

    Steininger, M K; Godoy, F; Harper, G

    2009-01-01

    Options for satellite monitoring of deforestation rates over large areas include the use of sampling. Sampling may reduce the cost of monitoring but is also a source of error in estimates of areas and rates. A common sampling approach is systematic sampling, in which sample units of a constant size are distributed in some regular manner, such as a grid. The proposed approach for the 2010 Forest Resources Assessment (FRA) of the UN Food and Agriculture Organization (FAO) is a systematic sample of 10 km wide squares at every 1 deg. intersection of latitude and longitude. We assessed the outcome of this and other systematic samples for estimating deforestation at national, sub-national and continental levels. The study is based on digital data on deforestation patterns for the five Amazonian countries outside Brazil plus the Brazilian Amazon. We tested these schemes by varying sample-unit size and frequency. We calculated two estimates of sampling error. First we calculated the standard errors, based on the size, variance and covariance of the samples, and from this calculated the 95% confidence intervals (CI). Second, we calculated the actual errors, based on the difference between the sample-based estimates and the estimates from the full-coverage maps. At the continental level, the 1 deg., 10 km scheme had a CI of 21% and an actual error of 8%. At the national level, this scheme had CIs of 126% for Ecuador and up to 67% for other countries. At this level, increasing sampling density to every 0.25 deg. produced a CI of 32% for Ecuador and CIs of up to 25% for other countries, with only Brazil having a CI of less than 10%. Actual errors were within the limits of the CIs in all but two of the 56 cases. Actual errors were half or less of the CIs in all but eight of these cases. These results indicate that the FRA 2010 should have CIs of smaller than or close to 10% at the continental level. However, systematic sampling at the national level yields large CIs unless the

  10. Prevalence and Determinants of Unintended Pregnancy in Mchinji District, Malawi; Using a Conceptual Hierarchy to Inform Analysis.

    Science.gov (United States)

    Hall, Jennifer Anne; Barrett, Geraldine; Phiri, Tambosi; Copas, Andrew; Malata, Address; Stephenson, Judith

    2016-01-01

    In 2012 there were around 85 million unintended pregnancies globally. Unintended pregnancies unnecessarily expose women to the risks associated with pregnancy, unsafe abortion and childbirth, thereby contributing to maternal mortality and morbidity. Studies have identified a range of potential determinants of unplanned pregnancy but have used varying methodologies, measures of pregnancy intention and analysis techniques. Consequently there are many contradictions in their findings. Identifying women at risk of unplanned pregnancy is important as this information can be used to help with designing and targeting interventions and developing preventative policies. 4,244 pregnant women from Mchinji District, Malawi were interviewed at home between March and December 2013. They were asked about their pregnancy intention using the validated Chichewa version of the London Measure of Unplanned Pregnancy, as well as their socio-demographics and obstetric and psychiatric history. A conceptual hierarchical model of the determinants of pregnancy intention was developed and used to inform the analysis. Multiple random effects linear regression was used to explore the ways in which factors determine pregnancy intention leading to the identification of women at risk of unplanned pregnancies. 44.4% of pregnancies were planned. On univariate analyses pregnancy intention was associated with mother and father's age and education, marital status, number of live children, birth interval, socio-economic status, intimate partner violence and previous depression all at peffect is mediated through other factors in the model. Socio-demographic factors of importance were marital status, which was the factor in the model that had the largest effect on pregnancy intention, partner's age and mother's education level. The effect of mother's education level was mediated by maternal reproductive characteristics. Previous depression, abuse in the last year or sexual abuse, younger age, increasing

  11. Effects of uncertainty in model predictions of individual tree volume on large area volume estimates

    Science.gov (United States)

    Ronald E. McRoberts; James A. Westfall

    2014-01-01

    Forest inventory estimates of tree volume for large areas are typically calculated by adding model predictions of volumes for individual trees. However, the uncertainty in the model predictions is generally ignored with the result that the precision of the large area volume estimates is overestimated. The primary study objective was to estimate the effects of model...

  12. Semi-parametric estimation of random effects in a logistic regression model using conditional inference

    DEFF Research Database (Denmark)

    Petersen, Jørgen Holm

    2016-01-01

    This paper describes a new approach to the estimation in a logistic regression model with two crossed random effects where special interest is in estimating the variance of one of the effects while not making distributional assumptions about the other effect. A composite likelihood is studied...

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

    NARCIS (Netherlands)

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

    2017-01-01

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

  14. Estimating the effect of treatment rate changes when treatment benefits are heterogeneous: antibiotics and otitis media.

    Science.gov (United States)

    Park, Tae-Ryong; Brooks, John M; Chrischilles, Elizabeth A; Bergus, George

    2008-01-01

    Contrast methods to assess the health effects of a treatment rate change when treatment benefits are heterogeneous across patients. Antibiotic prescribing for children with otitis media (OM) in Iowa Medicaid is the empirical example. Instrumental variable (IV) and linear probability model (LPM) are used to estimate the effect of antibiotic treatments on cure probabilities for children with OM in Iowa Medicaid. Local area physician supply per capita is the instrument in the IV models. Estimates are contrasted in terms of their ability to make inferences for patients whose treatment choices may be affected by a change in population treatment rates. The instrument was positively related to the probability of being prescribed an antibiotic. LPM estimates showed a positive effect of antibiotics on OM patient cure probability while IV estimates showed no relationship between antibiotics and patient cure probability. Linear probability model estimation yields the average effects of the treatment on patients that were treated. IV estimation yields the average effects for patients whose treatment choices were affected by the instrument. As antibiotic treatment effects are heterogeneous across OM patients, our estimates from these approaches are aligned with clinical evidence and theory. The average estimate for treated patients (higher severity) from the LPM model is greater than estimates for patients whose treatment choices are affected by the instrument (lower severity) from the IV models. Based on our IV estimates it appears that lowering antibiotic use in OM patients in Iowa Medicaid did not result in lost cures.

  15. The effect of weak lensing on distance estimates from supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Mathew; Maartens, Roy [Department of Physics, University of the Western Cape, Cape Town 7535 (South Africa); Bacon, David J.; Nichol, Robert C.; Campbell, Heather; D' Andrea, Chris B. [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Clarkson, Chris [Astrophysics, Cosmology and Gravity Centre (ACGC), Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701 (South Africa); Bassett, Bruce A. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935 (South Africa); Cinabro, David [Wayne State University, Department of Physics and Astronomy, Detroit, MI 48202 (United States); Finley, David A.; Frieman, Joshua A. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Galbany, Lluis [CENTRA Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal); Garnavich, Peter M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Olmstead, Matthew D. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Shapiro, Charles [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, La Canada Flintridge, CA 91109 (United States); Sollerman, Jesper, E-mail: matsmith2@gmail.com [The Oskar Klein Centre, Department of Astronomy, AlbaNova, SE-106 91 Stockholm (Sweden)

    2014-01-01

    Using a sample of 608 Type Ia supernovae from the SDSS-II and BOSS surveys, combined with a sample of foreground galaxies from SDSS-II, we estimate the weak lensing convergence for each supernova line of sight. We find that the correlation between this measurement and the Hubble residuals is consistent with the prediction from lensing (at a significance of 1.7σ). Strong correlations are also found between the residuals and supernova nuisance parameters after a linear correction is applied. When these other correlations are taken into account, the lensing signal is detected at 1.4σ. We show, for the first time, that distance estimates from supernovae can be improved when lensing is incorporated, by including a new parameter in the SALT2 methodology for determining distance moduli. The recovered value of the new parameter is consistent with the lensing prediction. Using cosmic microwave background data from WMAP7, H {sub 0} data from Hubble Space Telescope and Sloan Digital Sky Survey (SDSS) Baryon acoustic oscillations measurements, we find the best-fit value of the new lensing parameter and show that the central values and uncertainties on Ω {sub m} and w are unaffected. The lensing of supernovae, while only seen at marginal significance in this low-redshift sample, will be of vital importance for the next generation of surveys, such as DES and LSST, which will be systematics-dominated.

  16. Method of estimating investment decisions effectiveness in power engineering

    International Nuclear Information System (INIS)

    Kamrat, W.

    1996-01-01

    A new concept of determining efficient power plants investment decision-making is proposed.The results of research on capital expenditures for building and modernization of power plants are presented. The model introduced is based on the well-known Annual Cost Model which is modified by adding annual risk costs. So the formula for annual costs is: K = K f + K v + K r , where: K f are annual fixed costs, K v - annual variables costs, K r -annual risk costs. The annual risk costs can be calculated by the expression: K r = e i x K c , where e i is the investment risk factor, and K c - leveled capital investment. The risk factor was created on the basis of some elements of the taxonometric method with a high level of estimation probability. The essential problem is the selection of risk investment variables, most important of which are economic, financial, technical, social, political, legal. These variables create a multidimensional space. A so called 'ideal' model of the power plant is created taking into account capacity, type, fuel used, etc. The values of the multidimensional risk factor e i lie within limit and make it possible to rank the planned plants in series according to the estimated level of risk. This method can be used not only for risk evaluation in power engineering but also for investment efficiency studies in different industrial branches

  17. The effect of response-delay on estimating reachability.

    Science.gov (United States)

    Gabbard, Carl; Ammar, Diala

    2008-11-01

    The experiment was conducted to compare visual imagery (VI) and motor imagery (MI) reaching tasks in a response-delay paradigm designed to explore the hypothesized dissociation between vision for perception and vision for action. Although the visual systems work cooperatively in motor control, theory suggests that they operate under different temporal constraints. From this perspective, we expected that delay would affect MI but not VI because MI operates in real time and VI is postulated to be memory-driven. Following measurement of actual reach, right-handers were presented seven (imagery) targets at midline in eight conditions: MI and VI with 0-, 1-, 2-, and 4-s delays. Results indicted that delay affected the ability to estimate reachability with MI but not with VI. These results are supportive of a general distinction between vision for perception and vision for action.

  18. The estimation of occupational effective dose in diagnostic radiology with two dosimeters

    International Nuclear Information System (INIS)

    Niklason, L.T.; Marx, M.V.; Chan, Heang-Ping

    1994-01-01

    Annual effective dose limits have been proposed by national and international radiation protection committees. Radiation protection agencies must decide upon a method of converting the radiation dose measured from dosimeters to an estimate of effective dose. A proposed method for the estimation of effective dose from the radiation dose to two dosimeters is presented. Correction factors are applied to an over-apron collar dose and an under-apron dose to estimate the effective dose. Correction factors are suggested for two cases, both with and without a thyroid shield. Effective dose may be estimated by the under-apron dose plus 6% of the over-collar dose if a thyroid shield is not worn or plus 2% of the over-collar dose if a thyroid shield is worn. This method provides a reasonable estimate of effective dose that is independent of lead apron thickness and accounts for the use of a thyroid shield. 17 refs., 3 tabs

  19. School Processes Mediate School Compositional Effects: Model Specification and Estimation

    Science.gov (United States)

    Liu, Hongqiang; Van Damme, Jan; Gielen, Sarah; Van Den Noortgate, Wim

    2015-01-01

    School composition effects have been consistently verified, but few studies ever attempted to study how school composition affects school achievement. Based on prior research findings, we employed multilevel mediation modeling to examine whether school processes mediate the effect of school composition upon school outcomes based on the data of 28…

  20. Estimation of biological effects of phytocenosis radioactive contamination

    International Nuclear Information System (INIS)

    Suvorova, L.I.; Smirnov, E.G.; Shejn, G.N.

    1990-01-01

    Biological effects of argicultural field contamination in the Chernobyl NPP 30-km zone in the period of 1986-1988 are studies. Depth of some kings of herbs is noted in spite of natural phytocenosis high stability. It is revealed that increased mutageneous effect is observed for seeds from phytocenosis subjected to radiation factor effects. The genetic radiation effects at cell level will be observed in the nearest years as the radiation factor will not disappear in the 30-km zone (chronic irradiation of plants in the dose range from 0.1x10 -4 up to 0.1 Gy/day). These injuries visually will not effect greatly on natural populations

  1. The effect of high leverage points on the logistic ridge regression estimator having multicollinearity

    Science.gov (United States)

    Ariffin, Syaiba Balqish; Midi, Habshah

    2014-06-01

    This article is concerned with the performance of logistic ridge regression estimation technique in the presence of multicollinearity and high leverage points. In logistic regression, multicollinearity exists among predictors and in the information matrix. The maximum likelihood estimator suffers a huge setback in the presence of multicollinearity which cause regression estimates to have unduly large standard errors. To remedy this problem, a logistic ridge regression estimator is put forward. It is evident that the logistic ridge regression estimator outperforms the maximum likelihood approach for handling multicollinearity. The effect of high leverage points are then investigated on the performance of the logistic ridge regression estimator through real data set and simulation study. The findings signify that logistic ridge regression estimator fails to provide better parameter estimates in the presence of both high leverage points and multicollinearity.

  2. The Effect of Some Estimators of Between-Study Variance on Random

    African Journals Online (AJOL)

    Samson Henry Dogo

    the first step to such objectivity (Schmidt, 1992), allows to combine results from many studies and accurately ... Schmidt, 2000) due to its ability to account for variation in effects across the studies. Random-effects model ... (2015), and each of the estimators differs in terms of their bias and precision in estimation. By definition ...

  3. Estimated nation wide effects of pesticide spray drift on terrestrial habitats in the Netherlands

    NARCIS (Netherlands)

    Jong, de F.M.W.; Snoo, de G.R.; Zande, van de J.C.

    2008-01-01

    This study estimated the potential effects of pesticide drift on terrestrial ecosystems outside target areas, for the Dutch situation. A series of field trials was conducted to estimate the effects of drift on different species groups at different distances from a treated plot for different

  4. Estimating the Population-Level Effectiveness of Vaccination Programs in the Netherlands.

    NARCIS (Netherlands)

    van Wijhe, Maarten; McDonald, Scott A; de Melker, Hester E; Postma, Maarten J; Wallinga, Jacco

    There are few estimates of the effectiveness of long-standing vaccination programs in developed countries. To fill this gap, we investigate the direct and indirect effectiveness of childhood vaccination programs on mortality at the population level in the Netherlands.

  5. Essential competencies in nursing education for prevention and care related to unintended pregnancy.

    Science.gov (United States)

    Hewitt, Caroline; Cappiello, Joyce

    2015-01-01

    To identify the essential competencies for prevention and care related to unintended pregnancy to develop program outcomes for nursing curricula. Modified Delphi study. National. Eighty-five nurse experts, including academic faculty and advanced practice nurses providing sexual and reproductive health care in primary or specialty care settings. Expert panelists completed a three-round Delphi study using an electronic survey. Eighty-five panelists completed the first round survey, and 72 panelists completed all three rounds. Twenty-seven items achieved consensus of at least 75% of the experts by the third round to comprise the educational competencies. Through an iterative process, experts in prevention and care related to unintended pregnancy reached consensus on 27 core educational competencies for nursing education. The competencies provide a framework for curricular development in an important area of nursing education. © 2015 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

  6. What to consider when regulating electronic cigarettes: Pros, cons and unintended consequences.

    Science.gov (United States)

    Caponnetto, Pasquale; Saitta, Daniela; Sweanor, David; Polosa, Riccardo

    2015-06-01

    Many public health experts, medical research societies, large health organizations and policy makers have expressed concerns about the increased popularity of electronic cigarettes and have pushed for more restrictive measures ranging from complete bans to tight regulations of these products either as medicines or as tobacco products. But these concerns have never been adequately qualified nor quantified. Without judicious assessment and thorough evaluation, regulations may have unintended consequences that can do more damage than good in public health terms. In this article, we will appraise the existing prominent regulatory frameworks for e-cigarettes, namely, general consumer product, medicinal product and tobacco product regulation, to highlight their pros and cons. Moreover, we provide concrete examples of the unintended consequences which may arise from inappropriate regulatory action. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Dose dependence on stochastic radiobiological effect in radiation risk estimation

    International Nuclear Information System (INIS)

    Komochkov, M.M.

    1999-01-01

    The analysis of the results in dose -- effect relationship observation has been carried out on the cell and organism levels, with the aim to obtain more precise data on the risk coefficients at low doses. The results are represented by two contrasting groups of dose dependence on effect: a downwards concave and a J-shaped curve. Both types of dependence are described by the equation solutions of an assumed unified protective mechanism, which comprises two components: constitutive and adaptive or inducible ones. The latest data analysis of the downwards concave dependence curves shows a considerable underestimation of radiation risk in all types of cancer, except leukemia, for a number of critical groups in a population, at low doses comparing to the ICRP recommendations. With the dose increase, the decrease of the effect value per dose unit is observed. It may be possibly related to the switching of the activity of the adaptive protective mechanism, with some threshold dose values being exceeded

  8. SAR image effects on coherence and coherence estimation.

    Energy Technology Data Exchange (ETDEWEB)

    Bickel, Douglas Lloyd

    2014-01-01

    Radar coherence is an important concept for imaging radar systems such as synthetic aperture radar (SAR). This document quantifies some of the effects in SAR which modify the coherence. Although these effects can disrupt the coherence within a single SAR image, this report will focus on the coherence between separate images, such as for coherent change detection (CCD) processing. There have been other presentations on aspects of this material in the past. The intent of this report is to bring various issues that affect the coherence together in a single report to support radar engineers in making decisions about these matters.

  9. Reducing the unintended consequence of overfishing due to open access: Learning from the Zamboanga experience

    OpenAIRE

    Israel, Danilo C.; Lunod-Carinan, Milva; Paqueo, Vicente B.

    2016-01-01

    The Philippines is blessed with rich marine fishing grounds that are valuable sources of food and livelihood for the population. Unfortunately, over the years, these fishing grounds have become increasingly less productive, and many are in danger of depletion. At the heart of the problem is the generally open-access nature of Philippine fisheries, which leads to the unintended consequence of overfishing. This paper reviews the basic theory of overfishing; institutions, laws, and policies rela...

  10. U.S. Agricultural Export Credits after the WTO Cotton Ruling: The Law of Unintended Consequences

    OpenAIRE

    Benitah, Marc

    2005-01-01

    The recent WTO cotton ruling has led to a paradoxical result for the United States, a result that seems a textbook illustration of the "law of unintended consequences". Indeed, during the Uruguay Round negotiations of the present WTO agreements, the United States refused to put agricultural export credits in the category of agricultural export subsidies, where they would then have been subject only to reduction commitments. Paradoxically, the United States finds itself now in a position where...

  11. Transformations, transport, and potential unintended consequences of high sulfur inputs to Napa Valley vineyards

    OpenAIRE

    Hinckley, Eve-Lyn S.; Matson, Pamela A.

    2011-01-01

    Unintended anthropogenic deposition of sulfur (S) to forest ecosystems has a range of negative consequences, identified through decades of research. There has been far less study of purposeful S use in agricultural systems around the world, including the application of elemental sulfur (S0) as a quick-reacting fungicide to prevent damage to crops. Here we report results from a three-year study of the transformations and flows of applied S0 in soils, vegetation, and hydrologic export pathways ...

  12. A CFD Approach for Prediction of Unintended Porosities in Aluminum Syntactic Foam: A Preliminary Study

    DEFF Research Database (Denmark)

    Li, Shizhao; Spangenberg, Jon; Hattel, Jesper Henri

    2013-01-01

    Aluminum Syntactic Foam (ASF) is a material with great potential in applications related to lightweight structures and structural damping. However, experimental investigations in literature report that the infiltration process to fabricate ASF often results in incomplete infiltration. Published...... calculates the pressure, velocity and free surface of the aluminum. The results of the numerical model illustrate that this method has great potential of predicting unintended porosities in ASF and thereby optimizing the parameters involved in the infiltration process....

  13. Semiparametric analysis to estimate the deal effect curve

    NARCIS (Netherlands)

    Van Heerde, HJ; Leeflang, PSH; Wittink, DR

    The marketing literature suggests several phenomena that may contribute to the nature of the relationship between sales and price discounts. These phenomena can produce complex nonlinearities and interactions in the deal effect curve that are best captured with a flexible approach. Because a fully

  14. Estimating the Effect of Personality on Male-Female Earnings

    NARCIS (Netherlands)

    G. Mueller; E.J.S. Plug (Erik)

    2004-01-01

    textabstractThis paper uses the Five-Factor Model of personality structure as an organizing framework to explore the effects of personality on earnings. Using data from a longitudinal survey of American high school graduates, we find that extroversion, agreeableness, conscientiousness, neuroticism

  15. Estimating the effect of fermentation yeast on distillers grains protein

    Science.gov (United States)

    Distillers dried grains with solubles (DDGS) is the key co-product of bio-ethanol production from grains. Major factors affecting its quality and market values include protein quantity (concentration) and quality (amino acid composition). Yet, the effect of fermentation yeast on DDGS quality has no...

  16. Effective single scattering albedo estimation using regional climate model

    CSIR Research Space (South Africa)

    Tesfaye, M

    2011-09-01

    Full Text Available In this study, by modifying the optical parameterization of Regional Climate model (RegCM), the authors have computed and compared the Effective Single-Scattering Albedo (ESSA) which is a representative of VIS spectral region. The arid, semi...

  17. Estimation of Rotor Effective Wind Speed: A Comparison

    DEFF Research Database (Denmark)

    Soltani, Mohsen; Knudsen, Torben; Svenstrup, Mikael

    2013-01-01

    Modern wind turbine controllers use wind speed information to improve power production and reduce loads on the turbine components. The turbine top wind speed measurement is unfortunately imprecise and not a good representative of the rotor effective wind speed. Consequently, many different model...... aero-servo-elastic turbine simulations and real turbine field experiments in different wind scenarios....

  18. Unintended costs and consequences of school closures implemented in preparation for Hurricane Isaac in Harrison County School District, Mississippi, August-September 2012.

    Directory of Open Access Journals (Sweden)

    Yenlik Zheteyeva

    Full Text Available School closures, while an effective measure against the spread of disease during a pandemic, may carry unintended social and economic consequences for students and families. We evaluated these costs and consequences following a 4-day school closure in Mississippi's Harrison County School District (HCSD.In a survey of all households with students enrolled in HCSD, we collected information on difficulties related to the school closure, including interruption of employment and pay, loss of access to subsidized school meals, and arrangement of alternative childcare. We analyzed this information in the context of certain demographic characteristics of the survey respondents and households, such as race, level of education, and income. We also estimated the average number of lost work days and documented the childcare alternatives chosen by households affected by the school closure.We received 2,229 (28.4% completed surveys from an estimated 7,851 households eligible to participate. About half (1,082 [48.5%] of the households experienced at least some difficulty during the closure, primarily in three areas: uncertainty about duration of the closure, lost income, and the effort of arranging alternate childcare. Adults working outside the home, particularly the major wage earner in the household, were more likely to suffer lost income while schools were closed, an effect mitigated by paid leave benefits. Difficulty arranging childcare was reported most frequently by respondents with lower levels of education and households with younger children. Beyond the top three concerns expressed by households in HCSD, the survey also shed light on the issue of food insecurity when subsidized school meals are not available. Reported by 17.9% of households participating in the subsidized school lunch program, difficulty providing meals during the closure was associated with higher numbers of dependent children, selection of "other" as the race of the household

  19. Infrared image simulation for estimating the effectiveness of camouflage measures

    Energy Technology Data Exchange (ETDEWEB)

    Jung, J.S. [Seoul National University Graduate School, Seoul (Korea); Kauh, S.K. [Seoul National University, Seoul (Korea); Yoo, H.S. [Soong Sil University, Seoul (Korea)

    1999-08-01

    Camouflage measures in military purpose utilize the apparent temperature difference between target and background, so it is essential to develop a thermal analysis program for apparent temperature predictions and to apply some camouflage measures to real military targets for camouflage purpose. In this study, a thermal analysis program including conduction, convection and radiation is developed and the validity of radiation heat transfer terms is examined. The results show that longwave radiation along with solar radiation should be included in order to predict the apparent temperature as well as the physical temperature precisely. Longwave emissivity variation as an effective surface treatment, such as painting of a less emissive material or camouflage clothing, may provide a temperature similarity or a spatial similarity, resulting in an effective camouflage. (author). 12 refs., 15 figs., 2 tabs.

  20. Estimation of several political action effects of energy prices

    Directory of Open Access Journals (Sweden)

    Andrew B. Whitford

    2016-01-01

    Full Text Available One important effect of price shocks in the United States has been increased political attention paid to the structure and performance of oil and natural gas markets, along with some governmental support for energy conservation. This article describes how price changes helped lead to the emergence of a political agenda accompanied by several interventions, as revealed through Granger causality tests on change in the legislative agenda.

  1. HFCs contribution to the greenhouse effect. Present and projected estimations

    Energy Technology Data Exchange (ETDEWEB)

    Libre, J.M.; Elf-Atochem, S.A. [Central Research & Development, Paris (France)

    1997-12-31

    This paper reviews data that can be used to calculate hydrofluorocarbon (HFC) contribution to the greenhouse effect and compare it to other trace gas contributions. Projections are made for 2010 and 2100 on the basis of available emission scenarios. Industrial judgement on the likelihood of those scenarios is also developed. Calculations can be made in two different ways: from Global Warming Potential weighted emissions of species or by direct calculation of radiative forcing based on measured and projected atmospheric concentrations of compounds. Results show that HFCs corresponding to commercial uses have a negligible contribution to the greenhouse effect in comparison with other trace gases. The projected contributions are also very small even if very high emission scenarios are maintained for decades. In 2010 this contribution remains below 1%. Longer term emissions projections are difficult. However, based on the IPCC scenario IS92a, in spite of huge emissions projected for the year 2100, the HFC contribution remains below 3%. Actually many factors indicate that the real UFC contribution to the greenhouse effect will be even smaller than presented here. Low emissive systems and small charges will likely improve sharply in the future and have drastically improved in the recent past. HFC technology implementation is likely to grow in the future, reach a maximum before the middle of the next century; the market will stabilise driven by recycling, closing of systems and competitive technologies. This hypothesis is supported by previous analysis of the demand for HTCs type applications which can be represented by {open_quotes}S{close_quotes} type curves and by recent analysis indicating that the level of substitution of old products by HFCs is growing slowly. On the basis of those data and best industrial judgement, the contribution of HFCs to the greenhouse effect is highly likely to remain below 1% during the next century. 11 refs., 2 figs., 5 tabs.

  2. Effective dose estimation to patients and staff during urethrography procedures

    International Nuclear Information System (INIS)

    Sulieman, A.; Barakat, H.; Alkhorayef, M.; Babikir, E.; Dalton, A.; Bradley, D.

    2015-10-01

    Medical-related radiation is the largest source of controllable radiation exposure to humans and it accounts for more than 95% of radiation exposure from man-made sources. Few data were available worldwide regarding patient and staff dose during urological ascending urethrography (ASU) procedure. The purposes of this study are to measure patient and staff entrance surface air kerma dose (ESAK) during ASU procedure and evaluate the effective doses. A total of 243 patients and 145 staff (Urologist) were examined in three Hospitals in Khartoum state. ESAKs were measured for patient and staff using thermoluminescent detectors (TLDs). Effective doses (E) were calculated using published conversion factors and methods recommended by the national Radiological Protection Board (NRPB). The mean ESAK dose for patients and staff dose were 7.79±6.7 mGy and 0.161±0.30 mGy per procedures respectively. The mean and range of the effective dose was 1.21 mSv per procedure. The radiation dose in this study is comparable with previous studies except Hospital C. It is obvious that high patient and staff exposure is due to the lack of experience and protective equipment s. Interventional procedures remain operator dependent; therefore continuous training is crucial. (Author)

  3. Effective dose estimation to patients and staff during urethrography procedures

    Energy Technology Data Exchange (ETDEWEB)

    Sulieman, A. [Prince Sattam bin Abdulaziz University, College of Applied Medical Sciences, Radiology and Medical Imaging Department, P. O- Box 422, Alkharj 11942 (Saudi Arabia); Barakat, H. [Neelain University, College of Science and Technology, Medical Physics Department, Khartoum (Sudan); Alkhorayef, M.; Babikir, E. [King Saud University, College of Applied Sciences, Radiological Sciences Department, P. O. Box 10219, Riyadh 11433 (Saudi Arabia); Dalton, A.; Bradley, D. [University of Surrey, Centre for Nuclear and Radiation Physics, Department of Physics, Surrey, GU2 7XH Guildford (United Kingdom)

    2015-10-15

    Medical-related radiation is the largest source of controllable radiation exposure to humans and it accounts for more than 95% of radiation exposure from man-made sources. Few data were available worldwide regarding patient and staff dose during urological ascending urethrography (ASU) procedure. The purposes of this study are to measure patient and staff entrance surface air kerma dose (ESAK) during ASU procedure and evaluate the effective doses. A total of 243 patients and 145 staff (Urologist) were examined in three Hospitals in Khartoum state. ESAKs were measured for patient and staff using thermoluminescent detectors (TLDs). Effective doses (E) were calculated using published conversion factors and methods recommended by the national Radiological Protection Board (NRPB). The mean ESAK dose for patients and staff dose were 7.79±6.7 mGy and 0.161±0.30 mGy per procedures respectively. The mean and range of the effective dose was 1.21 mSv per procedure. The radiation dose in this study is comparable with previous studies except Hospital C. It is obvious that high patient and staff exposure is due to the lack of experience and protective equipment s. Interventional procedures remain operator dependent; therefore continuous training is crucial. (Author)

  4. Unintended pregnancy and its correlates among currently pregnant women in the Kwango District, Democratic Republic of the Congo.

    Science.gov (United States)

    Dhakal, Sarita; Song, Jin Sung; Shin, Dong Eun; Lee, Tae Ho; So, Ae Young; Nam, Eun Woo

    2016-06-16

    Unintended pregnancy is an important reproductive health problem in both developed and developing countries and is most prominent in low-middle income countries. In the Democratic Republic of the Congo, the total fertility rate is high at 5.9 births per women, and a mother's probabily of dying at an age between 15-49 years is also high (53 %). Women with unintended pregnancies are less likely to utilize available necessary services for their own health and the health of their children. Therefore, unintended pregnancy is a crucial factor of maternal health in the Democratic Republic of the Congo. This study aims to identify the prevalence of unintended pregnancy and its associated factors in the Democratic Republic of the Congo. Data were collected from June 20 to 29, 2014 among women aged 15-49 years who had children younger than 5 years old. The women were from a representative sample of 602 households. Multiple logistic regression analysis was performed to evaluate the associations between the dependent variable and the explanatory variables. Unintended pregnancy was reported in 51.4 % of the respondents. Multivariate logistic regression showed an association between education status (AOR, 3.4; CI, 1.21-9.90) and age of the last child (AOR, 5.17; CI, 1.23-21.70) with an unintended pregnancy. Unintended pregnancies were low among women who owner a cell phone (AOR, 0.18; CI, 0.47-0.73) and those who were aware of family planning method (AOR 0.20; CI, 0.06-0.60). The unintended pregnancy rate high and was significantly associated with female education, previous use of family planning methods, ownership of cell phone, and age of the last child. Maternal health interventions should focus on increasing family planning service utilization, awareness of family planning, and access to communication and income.

  5. Some Unintended Consequences of "Top Down" Organization Development

    Science.gov (United States)

    White, Bernard J.; Ramsey, V. Jean

    1978-01-01

    An organizational development consultant is expected to perform a thorough and unbiased diagnosis of the organization's functioning. This is an account of a case study of the effect of top management influence on the consultant's awareness and definition of problems. (Author/MLF)

  6. Assessing Mediational Models: Testing and Interval Estimation for Indirect Effects.

    Science.gov (United States)

    Biesanz, Jeremy C; Falk, Carl F; Savalei, Victoria

    2010-08-06

    Theoretical models specifying indirect or mediated effects are common in the social sciences. An indirect effect exists when an independent variable's influence on the dependent variable is mediated through an intervening variable. Classic approaches to assessing such mediational hypotheses ( Baron & Kenny, 1986 ; Sobel, 1982 ) have in recent years been supplemented by computationally intensive methods such as bootstrapping, the distribution of the product methods, and hierarchical Bayesian Markov chain Monte Carlo (MCMC) methods. These different approaches for assessing mediation are illustrated using data from Dunn, Biesanz, Human, and Finn (2007). However, little is known about how these methods perform relative to each other, particularly in more challenging situations, such as with data that are incomplete and/or nonnormal. This article presents an extensive Monte Carlo simulation evaluating a host of approaches for assessing mediation. We examine Type I error rates, power, and coverage. We study normal and nonnormal data as well as complete and incomplete data. In addition, we adapt a method, recently proposed in statistical literature, that does not rely on confidence intervals (CIs) to test the null hypothesis of no indirect effect. The results suggest that the new inferential method-the partial posterior p value-slightly outperforms existing ones in terms of maintaining Type I error rates while maximizing power, especially with incomplete data. Among confidence interval approaches, the bias-corrected accelerated (BC a ) bootstrapping approach often has inflated Type I error rates and inconsistent coverage and is not recommended; In contrast, the bootstrapped percentile confidence interval and the hierarchical Bayesian MCMC method perform best overall, maintaining Type I error rates, exhibiting reasonable power, and producing stable and accurate coverage rates.

  7. LARF: Instrumental Variable Estimation of Causal Effects through Local Average Response Functions

    Directory of Open Access Journals (Sweden)

    Weihua An

    2016-07-01

    Full Text Available LARF is an R package that provides instrumental variable estimation of treatment effects when both the endogenous treatment and its instrument (i.e., the treatment inducement are binary. The method (Abadie 2003 involves two steps. First, pseudo-weights are constructed from the probability of receiving the treatment inducement. By default LARF estimates the probability by a probit regression. It also provides semiparametric power series estimation of the probability and allows users to employ other external methods to estimate the probability. Second, the pseudo-weights are used to estimate the local average response function conditional on treatment and covariates. LARF provides both least squares and maximum likelihood estimates of the conditional treatment effects.

  8. Estimates of dispersive effects in a bent NLC Main Linac

    International Nuclear Information System (INIS)

    Syphers, Michael; Michelotti, Leo

    2000-01-01

    An alternative being considered for the Next Linear Collider (NLC) is not to tunnel in a straight line but to bend the Main Linac into an arc so as to follow a gravitational equipotential. The authors begin here an examination of the effects that this would have on vertical dispersion, with its attendant consequences on synchrotron radiation and emittance growth by looking at two scenarios: a gentle continuous bending of the beam to follow an equipotential surface, and an introduction of sharp bends at a few sites in the linac so as to reduce the maximum sagitta produced

  9. Estimates of dispersive effects in a bent NLC main linac

    OpenAIRE

    Syphers, M.; Michelotti, L.

    2000-01-01

    An alternative being considered for the Next Linear Collider (NLC) is not to tunnel in a straight line but to bend the Main Linac into an arc so as to follow an equipotential. We begin here an examination of the effects that this would have on vertical dispersion, with its attendant consequences on synchrotron radiation and emittance growth by looking at two scenarios: a gentle continuous bending of the beam to follow an equipotential surface, and an introduction of sharp bends at a few sites...

  10. Using local multiplicity to improve effect estimation from a hypothesis-generating pharmacogenetics study.

    Science.gov (United States)

    Zou, W; Ouyang, H

    2016-02-01

    We propose a multiple estimation adjustment (MEA) method to correct effect overestimation due to selection bias from a hypothesis-generating study (HGS) in pharmacogenetics. MEA uses a hierarchical Bayesian approach to model individual effect estimates from maximal likelihood estimation (MLE) in a region jointly and shrinks them toward the regional effect. Unlike many methods that model a fixed selection scheme, MEA capitalizes on local multiplicity independent of selection. We compared mean square errors (MSEs) in simulated HGSs from naive MLE, MEA and a conditional likelihood adjustment (CLA) method that model threshold selection bias. We observed that MEA effectively reduced MSE from MLE on null effects with or without selection, and had a clear advantage over CLA on extreme MLE estimates from null effects under lenient threshold selection in small samples, which are common among 'top' associations from a pharmacogenetics HGS.

  11. The value of a registry negative urine pregnancy test for the prediction of a future unintended pregnancy among young women.

    Science.gov (United States)

    Rottenstreich, Misgav; Grisaru-Granovsky, Sorina; Rottenstreich, Amihai

    2018-05-15

    Performance of urine pregnancy test in general adolescents' clinic reflects caregiver or woman's concern that there might be a pregnancy. We aimed to assess whether young-unmarried women in whom a negative urine pregnancy test was registered would be at increased risk of a future unintended pregnancy. The study cohort included consecutive women drafted by the Israeli military between 2013 and 2015. The risk of unintended pregnancy was compared between women with a negative urine pregnancy test (n = 2774), the study group, and those in whom urine pregnancy test was not carried out (n = 126,659), the control group. During the study period, 2147 (1.7%) women experienced an unintended pregnancy. The risk of unintended pregnancy was significantly higher in patients in whom a past pregnancy test was negative 4.3% (n = 118), as compared with the control group 1.6% (n = 2028) (odds ratio [OR], 2.7; 95% confidence interval [CI], 2.23-3.26). In multivariate analysis history of a negative pregnancy test results was an independent predictor for a future unintended pregnancy (adjusted OR, 2.0; 95% CI, 1.63-2.52). A history of a negative pregnancy test among young conscripted women is a significant risk indicator for a future unintended pregnancy. Directed efforts should be made in this particular vulnerable group of patients.

  12. The stochastic system approach for estimating dynamic treatments effect.

    Science.gov (United States)

    Commenges, Daniel; Gégout-Petit, Anne

    2015-10-01

    The problem of assessing the effect of a treatment on a marker in observational studies raises the difficulty that attribution of the treatment may depend on the observed marker values. As an example, we focus on the analysis of the effect of a HAART on CD4 counts, where attribution of the treatment may depend on the observed marker values. This problem has been treated using marginal structural models relying on the counterfactual/potential response formalism. Another approach to causality is based on dynamical models, and causal influence has been formalized in the framework of the Doob-Meyer decomposition of stochastic processes. Causal inference however needs assumptions that we detail in this paper and we call this approach to causality the "stochastic system" approach. First we treat this problem in discrete time, then in continuous time. This approach allows incorporating biological knowledge naturally. When working in continuous time, the mechanistic approach involves distinguishing the model for the system and the model for the observations. Indeed, biological systems live in continuous time, and mechanisms can be expressed in the form of a system of differential equations, while observations are taken at discrete times. Inference in mechanistic models is challenging, particularly from a numerical point of view, but these models can yield much richer and reliable results.

  13. A Simple Method to Estimate Large Fixed Effects Models Applied to Wage Determinants and Matching

    OpenAIRE

    Mittag, Nikolas

    2016-01-01

    Models with high dimensional sets of fixed effects are frequently used to examine, among others, linked employer-employee data, student outcomes and migration. Estimating these models is computationally difficult, so simplifying assumptions that are likely to cause bias are often invoked to make computation feasible and specification tests are rarely conducted. I present a simple method to estimate large two-way fixed effects (TWFE) and worker-firm match effect models without additional assum...

  14. Modeling phytosanitary risk of unintended commodity use: the example of U.S. potato exports to Mexico.

    Science.gov (United States)

    Fowler, Glenn; Erikson, Lottie; Caton, Barney; Gutierrez, Walter; Griffin, Robert

    2014-09-01

    Diversion of commodities from their intended use to an unintended use, e.g., when commodities intended for consumption are used as seed for planting, is an important issue in agricultural trade that has implications for the establishment of pests and pathogens in an importing country and for the appropriate strength of plant health measures. Consequently, understanding and accurately characterizing the risk of diversion from intended use is highly relevant to policymakers, trading partners, and in trade dispute arbitration. To our knowledge, no risk assessments have ever accounted for the likelihood of diversion from intended use. Here we present an approach to analyzing this risk using diversion of U.S. table stock potatoes to seed for planting by Mexican potato producers as a case study. We use probabilistic pathway models to characterize the movement of white, yellow, and russet potatoes from the United States into Mexico at current and double export volumes. We then model the likelihood of these potatoes being diverted for seed and the subsequent establishment of bacteria, nematode, and virus pests in Mexico. Our approach demonstrates how diversion from intended use can be quantified in one scenario and, in particular, how it can be analyzed to estimate the magnitude of diversion required to produce a high risk of pest establishment. © 2014 Society for Risk Analysis Published 2014. This article is a U.S. Government work and is in the public domain for the U.S.A.

  15. Effects of exposure imprecision on estimation of the benchmark dose

    DEFF Research Database (Denmark)

    Budtz-Jørgensen, Esben; Keiding, Niels; Grandjean, Philippe

    2004-01-01

    In regression analysis failure to adjust for imprecision in the exposure variable is likely to lead to underestimation of the exposure effect. However, the consequences of exposure error for determination of safe doses of toxic substances have so far not received much attention. The benchmark...... approach is one of the most widely used methods for development of exposure limits. An important advantage of this approach is that it can be applied to observational data. However, in this type of data, exposure markers are seldom measured without error. It is shown that, if the exposure error is ignored......, then the benchmark approach produces results that are biased toward higher and less protective levels. It is therefore important to take exposure measurement error into account when calculating benchmark doses. Methods that allow this adjustment are described and illustrated in data from an epidemiological study...

  16. Confounding effects of phase delays on causality estimation.

    Directory of Open Access Journals (Sweden)

    Vasily A Vakorin

    Full Text Available Linear and non-linear techniques for inferring causal relations between the brain signals representing the underlying neuronal systems have become a powerful tool to extract the connectivity patterns in the brain. Typically these tools employ the idea of Granger causality, which is ultimately based on the temporal precedence between the signals. At the same time, phase synchronization between coupled neural ensembles is considered a mechanism implemented in the brain to integrate relevant neuronal ensembles to perform a cognitive or perceptual task. Phase synchronization can be studied by analyzing the effects of phase-locking between the brain signals. However, we should expect that there is no one-to-one mapping between the observed phase lag and the time precedence as specified by physically interacting systems. Specifically, phase lag observed between two signals may interfere with inferring causal relations. This could be of critical importance for the coupled non-linear oscillating systems, with possible time delays in coupling, when classical linear cross-spectrum strategies for solving phase ambiguity are not efficient. To demonstrate this, we used a prototypical model of coupled non-linear systems, and compared three typical pipelines of inferring Granger causality, as established in the literature. Specifically, we compared the performance of the spectral and information-theoretic Granger pipelines as well as standard Granger causality in their relations to the observed phase differences for frequencies at which the signals become synchronized to each other. We found that an information-theoretic approach, which takes into account different time lags between the past of one signal and the future of another signal, was the most robust to phase effects.

  17. Estimation of the global climate effect of brown carbon

    Science.gov (United States)

    Zhang, A.; Wang, Y.; Zhang, Y.; Weber, R. J.; Song, Y.

    2017-12-01

    Carbonaceous aerosols significantly affect global radiative forcing and climate through absorption and scattering of sunlight. Black carbon (BC) and brown carbon (BrC) are light-absorbing carbonaceous aerosols. The global distribution and climate effect of BrC is uncertain. A recent study suggests that BrC absorption is comparable to BC in the upper troposphere over biomass burning region and that the resulting heating tends to stabilize the atmosphere. Yet current climate models do not include proper treatments of BrC. In this study, we derived a BrC global biomass burning emission inventory from Global Fire Emissions Database 4 (GFED4) and developed a BrC module in the Community Atmosphere Model version 5 (CAM5) of Community Earth System Model (CESM) model. The model simulations compared well to BrC observations of the Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) and Deep Convective Clouds and Chemistry Project (DC-3) campaigns and includes BrC bleaching. Model results suggested that BrC in the upper troposphere due to convective transport is as important an absorber as BC globally. Upper tropospheric BrC radiative forcing is particularly significant over the tropics, affecting the atmosphere stability and Hadley circulation.

  18. Uncertainty and validation. Effect of model complexity on uncertainty estimates

    International Nuclear Information System (INIS)

    Elert, M.

    1996-09-01

    In the Model Complexity subgroup of BIOMOVS II, models of varying complexity have been applied to the problem of downward transport of radionuclides in soils. A scenario describing a case of surface contamination of a pasture soil was defined. Three different radionuclides with different environmental behavior and radioactive half-lives were considered: Cs-137, Sr-90 and I-129. The intention was to give a detailed specification of the parameters required by different kinds of model, together with reasonable values for the parameter uncertainty. A total of seven modelling teams participated in the study using 13 different models. Four of the modelling groups performed uncertainty calculations using nine different modelling approaches. The models used range in complexity from analytical solutions of a 2-box model using annual average data to numerical models coupling hydrology and transport using data varying on a daily basis. The complex models needed to consider all aspects of radionuclide transport in a soil with a variable hydrology are often impractical to use in safety assessments. Instead simpler models, often box models, are preferred. The comparison of predictions made with the complex models and the simple models for this scenario show that the predictions in many cases are very similar, e g in the predictions of the evolution of the root zone concentration. However, in other cases differences of many orders of magnitude can appear. One example is the prediction of the flux to the groundwater of radionuclides being transported through the soil column. Some issues that have come to focus in this study: There are large differences in the predicted soil hydrology and as a consequence also in the radionuclide transport, which suggests that there are large uncertainties in the calculation of effective precipitation and evapotranspiration. The approach used for modelling the water transport in the root zone has an impact on the predictions of the decline in root

  19. Effective network inference through multivariate information transfer estimation

    Science.gov (United States)

    Dahlqvist, Carl-Henrik; Gnabo, Jean-Yves

    2018-06-01

    Network representation has steadily gained in popularity over the past decades. In many disciplines such as finance, genetics, neuroscience or human travel to cite a few, the network may not directly be observable and needs to be inferred from time-series data, leading to the issue of separating direct interactions between two entities forming the network from indirect interactions coming through its remaining part. Drawing on recent contributions proposing strategies to deal with this problem such as the so-called "global silencing" approach of Barzel and Barabasi or "network deconvolution" of Feizi et al. (2013), we propose a novel methodology to infer an effective network structure from multivariate conditional information transfers. Its core principal is to test the information transfer between two nodes through a step-wise approach by conditioning the transfer for each pair on a specific set of relevant nodes as identified by our algorithm from the rest of the network. The methodology is model free and can be applied to high-dimensional networks with both inter-lag and intra-lag relationships. It outperforms state-of-the-art approaches for eliminating the redundancies and more generally retrieving simulated artificial networks in our Monte-Carlo experiments. We apply the method to stock market data at different frequencies (15 min, 1 h, 1 day) to retrieve the network of US largest financial institutions and then document how bank's centrality measurements relate to bank's systemic vulnerability.

  20. The estimation of effective doses using measurement of several relevant physical parameters from radon exposures

    International Nuclear Information System (INIS)

    Ridzikova, A; Fronka, A.; Maly, B.; Moucka, L.

    2003-01-01

    In the present investigation, we will be study the dose relevant factors from continual monitoring in real homes into account getting more accurate estimation of 222 Rn the effective dose. The dose relevant parameters include the radon concentration, the equilibrium factor (f), the fraction (fp) of unattached radon decay products and real time occupancy people in home. The result of the measurement are the time courses of radon concentration that are based on estimation effective doses together with assessment of the real time occupancy people indoor. We found out by analysis that year effective dose is lower than effective dose estimated by ICRP recommendation from the integral measurement that included only average radon concentration. Our analysis of estimation effective doses using measurement of several physical parameters was made only in one case and for the better specification is important to measure in different real occupancy houses. (authors)

  1. Estimating Causal Effects of Local Air Pollution on Daily Deaths: Effect of Low Levels.

    Science.gov (United States)

    Schwartz, Joel; Bind, Marie-Abele; Koutrakis, Petros

    2017-01-01

    , Koutrakis P. 2017. Estimating causal effects of local air pollution on daily deaths: effect of low levels. Environ Health Perspect 125:23-29; http://dx.doi.org/10.1289/EHP232.

  2. Analysis of jet flames and unignited jets from unintended releases of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Houf, W.G.; Evans, G.H.; Schefer, R.W. [Sandia National Laboratories, Livermore, CA 94551-0969 (United States)

    2009-07-15

    A combined experimental and modeling program is being carried out at Sandia National Laboratories to characterize and predict the behavior of unintended hydrogen releases. In the case where the hydrogen leak remains unignited, knowledge of the concentration field and flammability envelope is an issue of importance in determining consequence distances for the safe use of hydrogen. In the case where a high-pressure leak of hydrogen is ignited, a classic turbulent jet flame forms. Knowledge of the flame length and thermal radiation heat flux distribution is important to safety. Depending on the effective diameter of the leak and the tank source pressure, free jet flames can be extensive in length and pose significant radiation and impingement hazard, resulting in consequence distances that are unacceptably large. One possible mitigation strategy to potentially reduce the exposure to jet flames is to incorporate barriers around hydrogen storage equipment. The reasoning is that walls will reduce the extent of unacceptable consequences due to jet releases resulting from accidents involving high-pressure equipment. While reducing the jet extent, the walls may introduce other hazards if not configured properly. The goal of this work is to provide guidance on configuration and placement of these walls to minimize overall hazards using a quantitative risk assessment approach. The program includes detailed CFD calculations of jet flames and unignited jets to predict how hydrogen leaks and jet flames interact with barriers, complemented by an experimental validation program that considers the interaction of jet flames and unignited jets with barriers. As a first step in this work on barrier release interaction the Sandia CFD model has been validated by computing the concentration decay of unignited turbulent free jets and comparing the results with the classic concentration decay laws for turbulent free jets taken from experimental data. Computations for turbulent hydrogen

  3. Robust estimation and moment selection in dynamic fixed-effects panel data models

    NARCIS (Netherlands)

    Cizek, Pavel; Aquaro, Michele

    Considering linear dynamic panel data models with fixed effects, existing outlier–robust estimators based on the median ratio of two consecutive pairs of first-differenced data are extended to higher-order differencing. The estimation procedure is thus based on many pairwise differences and their

  4. The Effect of Error in Item Parameter Estimates on the Test Response Function Method of Linking.

    Science.gov (United States)

    Kaskowitz, Gary S.; De Ayala, R. J.

    2001-01-01

    Studied the effect of item parameter estimation for computation of linking coefficients for the test response function (TRF) linking/equating method. Simulation results showed that linking was more accurate when there was less error in the parameter estimates, and that 15 or 25 common items provided better results than 5 common items under both…

  5. Effects of EU dairy policy reform for Dutch dairy farming : a primal approach using GMM estimation

    NARCIS (Netherlands)

    Ooms, D.L.; Peerlings, J.H.M.

    2005-01-01

    This paper estimates a production function for milk using a generalised method of moments estimator to avoid the endogeneity problem. Using the first-order conditions for profit maximisation, the economic effects for individual Dutch dairy farms of the 2003 EU dairy policy reform are analysed. With

  6. Estimated allele substitution effects underlying genomic evaluation models depend on the scaling of allele counts

    NARCIS (Netherlands)

    Bouwman, Aniek C.; Hayes, Ben J.; Calus, Mario P.L.

    2017-01-01

    Background: Genomic evaluation is used to predict direct genomic values (DGV) for selection candidates in breeding programs, but also to estimate allele substitution effects (ASE) of single nucleotide polymorphisms (SNPs). Scaling of allele counts influences the estimated ASE, because scaling of

  7. Effect of Visual Field Presentation on Action Planning (Estimating Reach) in Children

    Science.gov (United States)

    Gabbard, Carl; Cordova, Alberto

    2012-01-01

    In this article, the authors examined the effects of target information presented in different visual fields (lower, upper, central) on estimates of reach via use of motor imagery in children (5-11 years old) and young adults. Results indicated an advantage for estimating reach movements for targets placed in lower visual field (LoVF), with all…

  8. Estimates of the rate and distribution of fitness effects of spontaneous mutation in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Zeyl, C.; Visser, de J.A.G.M.

    2001-01-01

    The per-genome, per-generation rate of spontaneous mutation affecting fitness (U) and the mean fitness cost per mutation (s) are important parameters in evolutionary genetics, but have been estimated for few species. We estimated U and sh (the heterozygous effect of mutations) for two diploid yeast

  9. Effects of satellite image spatial aggregation and resolution on estimates of forest land area

    Science.gov (United States)

    M.D. Nelson; R.E. McRoberts; G.R. Holden; M.E. Bauer

    2009-01-01

    Satellite imagery is being used increasingly in association with national forest inventories (NFIs) to produce maps and enhance estimates of forest attributes. We simulated several image spatial resolutions within sparsely and heavily forested study areas to assess resolution effects on estimates of forest land area, independent of other sensor characteristics. We...

  10. Estimating dose painting effects in radiotherapy: a mathematical model.

    Directory of Open Access Journals (Sweden)

    Juan Carlos López Alfonso

    Full Text Available Tumor heterogeneity is widely considered to be a determinant factor in tumor progression and in particular in its recurrence after therapy. Unfortunately, current medical techniques are unable to deduce clinically relevant information about tumor heterogeneity by means of non-invasive methods. As a consequence, when radiotherapy is used as a treatment of choice, radiation dosimetries are prescribed under the assumption that the malignancy targeted is of a homogeneous nature. In this work we discuss the effects of different radiation dose distributions on heterogeneous tumors by means of an individual cell-based model. To that end, a case is considered where two tumor cell phenotypes are present, which we assume to strongly differ in their respective cell cycle duration and radiosensitivity properties. We show herein that, as a result of such differences, the spatial distribution of the corresponding phenotypes, whence the resulting tumor heterogeneity can be predicted as growth proceeds. In particular, we show that if we start from a situation where a majority of ordinary cancer cells (CCs and a minority of cancer stem cells (CSCs are randomly distributed, and we assume that the length of CSC cycle is significantly longer than that of CCs, then CSCs become concentrated at an inner region as tumor grows. As a consequence we obtain that if CSCs are assumed to be more resistant to radiation than CCs, heterogeneous dosimetries can be selected to enhance tumor control by boosting radiation in the region occupied by the more radioresistant tumor cell phenotype. It is also shown that, when compared with homogeneous dose distributions as those being currently delivered in clinical practice, such heterogeneous radiation dosimetries fare always better than their homogeneous counterparts. Finally, limitations to our assumptions and their resulting clinical implications will be discussed.

  11. Living up to expectations: Estimating direct and indirect rebound effects for UK households

    International Nuclear Information System (INIS)

    Chitnis, Mona; Sorrell, Steve

    2015-01-01

    This study estimates the combined direct and indirect rebound effects from various types of energy efficiency improvement by UK households. In contrast to most studies of this topic, we base our estimates on cross-price elasticities and therefore capture both the income and substitution effects of energy efficiency improvements. Our approach involves estimating a household demand model to obtain price and expenditure elasticities of different goods and services, utilising a multiregional input–output model to estimate the GHG emission intensities of those goods and services, combining the two to estimate direct and indirect rebound effects, and decomposing those effects to reveal the relative contribution of different mechanisms and commodities. We estimate that the total rebound effects are 41% for measures that improve the efficiency of domestic gas use, 48% for electricity use and 78% for vehicle fuel use. The primary source of this rebound is increased consumption of the cheaper energy service (i.e. direct rebound) and this is primarily driven by substitution effects. Our results suggest that the neglect of substitution effects may have led prior research to underestimate the total rebound effect. However, we provide a number of caveats to this conclusion, as well as indicating priorities for future research.

  12. Effect of neural connectivity on autocovariance and cross covariance estimates

    Directory of Open Access Journals (Sweden)

    Stecker Mark M

    2007-01-01

    important to interpret measured auto and cross covariance functions cautiously in light of the long range nature of the electric fields. Using recording electrodes that are bipolar or quadrupolar minimizes or eliminates these effects and hence these electrodes are preferred when electrical recordings are made for the purpose of auto and cross correlation analysis of local electrical activity.

  13. Uncertainty and validation. Effect of model complexity on uncertainty estimates

    Energy Technology Data Exchange (ETDEWEB)

    Elert, M. [Kemakta Konsult AB, Stockholm (Sweden)] [ed.

    1996-09-01

    In the Model Complexity subgroup of BIOMOVS II, models of varying complexity have been applied to the problem of downward transport of radionuclides in soils. A scenario describing a case of surface contamination of a pasture soil was defined. Three different radionuclides with different environmental behavior and radioactive half-lives were considered: Cs-137, Sr-90 and I-129. The intention was to give a detailed specification of the parameters required by different kinds of model, together with reasonable values for the parameter uncertainty. A total of seven modelling teams participated in the study using 13 different models. Four of the modelling groups performed uncertainty calculations using nine different modelling approaches. The models used range in complexity from analytical solutions of a 2-box model using annual average data to numerical models coupling hydrology and transport using data varying on a daily basis. The complex models needed to consider all aspects of radionuclide transport in a soil with a variable hydrology are often impractical to use in safety assessments. Instead simpler models, often box models, are preferred. The comparison of predictions made with the complex models and the simple models for this scenario show that the predictions in many cases are very similar, e g in the predictions of the evolution of the root zone concentration. However, in other cases differences of many orders of magnitude can appear. One example is the prediction of the flux to the groundwater of radionuclides being transported through the soil column. Some issues that have come to focus in this study: There are large differences in the predicted soil hydrology and as a consequence also in the radionuclide transport, which suggests that there are large uncertainties in the calculation of effective precipitation and evapotranspiration. The approach used for modelling the water transport in the root zone has an impact on the predictions of the decline in root

  14. Estimating safety effects of pavement management factors utilizing Bayesian random effect models.

    Science.gov (United States)

    Jiang, Ximiao; Huang, Baoshan; Zaretzki, Russell L; Richards, Stephen; Yan, Xuedong

    2013-01-01

    Previous studies of pavement management factors that relate to the occurrence of traffic-related crashes are rare. Traditional research has mostly employed summary statistics of bidirectional pavement quality measurements in extended longitudinal road segments over a long time period, which may cause a loss of important information and result in biased parameter estimates. The research presented in this article focuses on crash risk of roadways with overall fair to good pavement quality. Real-time and location-specific data were employed to estimate the effects of pavement management factors on the occurrence of crashes. This research is based on the crash data and corresponding pavement quality data for the Tennessee state route highways from 2004 to 2009. The potential temporal and spatial correlations among observations caused by unobserved factors were considered. Overall 6 models were built accounting for no correlation, temporal correlation only, and both the temporal and spatial correlations. These models included Poisson, negative binomial (NB), one random effect Poisson and negative binomial (OREP, ORENB), and two random effect Poisson and negative binomial (TREP, TRENB) models. The Bayesian method was employed to construct these models. The inference is based on the posterior distribution from the Markov chain Monte Carlo (MCMC) simulation. These models were compared using the deviance information criterion. Analysis of the posterior distribution of parameter coefficients indicates that the pavement management factors indexed by Present Serviceability Index (PSI) and Pavement Distress Index (PDI) had significant impacts on the occurrence of crashes, whereas the variable rutting depth was not significant. Among other factors, lane width, median width, type of terrain, and posted speed limit were significant in affecting crash frequency. The findings of this study indicate that a reduction in pavement roughness would reduce the likelihood of traffic

  15. Torque-onset determination: Unintended consequences of the threshold method.

    Science.gov (United States)

    Dotan, Raffy; Jenkins, Glenn; O'Brien, Thomas D; Hansen, Steve; Falk, Bareket

    2016-12-01

    Compared with visual torque-onset-detection (TOD), threshold-based TOD produces onset bias, which increases with lower torques or rates of torque development (RTD). To compare the effects of differential TOD-bias on common contractile parameters in two torque-disparate groups. Fifteen boys and 12 men performed maximal, explosive, isometric knee-extensions. Torque and EMG were recorded for each contraction. Best contractions were selected by peak torque (MVC) and peak RTD. Visual-TOD-based torque-time traces, electromechanical delays (EMD), and times to peak RTD (tRTD) were compared with corresponding data derived from fixed 4-Nm- and relative 5%MVC-thresholds. The 5%MVC TOD-biases were similar for boys and men, but the corresponding 4-Nm-based biases were markedly different (40.3±14.1 vs. 18.4±7.1ms, respectively; ptorque kinetics tended to be faster than the boys' (NS), but the 4-Nm-based kinetics erroneously depicted the boys as being much faster to any given %MVC (p<0.001). When comparing contractile properties of dissimilar groups, e.g., children vs. adults, threshold-based TOD methods can misrepresent reality and lead to erroneous conclusions. Relative-thresholds (e.g., 5% MVC) still introduce error, but group-comparisons are not confounded. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. The Relationship between Contraceptive Use and Unintended Pregnancies among Married Women in Thatta District, Pakistan

    Directory of Open Access Journals (Sweden)

    Sumera Ali

    2017-07-01

    Full Text Available Background & aim: The rate of unintended pregnancy has decreased from 24% to 16% in the last four to five years in Pakistan. However, this rate stills varies among the women living in the rural and urban areas of Pakistan. The females residing in the rural areas are less likely to have many contraceptive choices and receive no/low-quality family planning services; as a result, they end up with birth control failure and unintended pregnancy. Regarding this, more studies are needed to investigate the association between the unintended pregnancy and contraceptive use, particularly in the rural areas of Pakistan.Therefore, the aim of the present study was to determine the relationship between contraceptive use and unintended pregnancy among the women at reproductive age living in Thatta district, Sindh, Pakistan. Methods:This nested case-control study was conducted on the women living in Thatta district during June 2011-July 2012. The pregnant women who did not want more children were considered as cases, and those who intended to have more children were considered as controls. The categorical and continuous variables were analyzed using the Chi-square test and independent t-tests, respectively. Results: According o the results of the present study, the use of contraceptive methods was significantly associated with increased risk of unintended pregnancy among the women living in Thatta district [OR: 2.77 (1.46-5.25]. Moreover, there was 14% increased risk of unintended pregnancy with one year increase in the age of the women [OR: 1.14 (1.10-1.19]. The age at marriage showed negative association with unintended pregnancy [OR: 0.92 (0.87-0.97]. The women having at least one son (alive were almost three times more likely to report their recent pregnancies as unintended, compared to those with no living son [OR: 2.97 (1.82-4.84]. In addition, the husband’s education and their opposition with the use of family planning methods [OR 2.16 (1.06-4.39] were

  17. Estimation of the effective population size (Ne) and its application in the management of small populations

    DEFF Research Database (Denmark)

    Jimenez Mena, Belen

    2016-01-01

    Effective population size (Ne) is an important concept to understand the evolution of a population. In conservation, Ne is used to assess the threat status of a population, evaluate its genetic viability in the future and set conservation priorities. An accurate estimation of Ne is thus essential....... The main objective of this thesis was to better understand how the estimation of Ne using molecular markers can be improved for use in conservation genetics. As a first step, we undertook a simulation study where three different methods to estimate Ne were investigated. We explored how well these three...... methods performed under different scenarios. This study showed that all three methods performed better when the number of unlinked loci used to make the estimation increased and the minimum number of loci need for an accurate estimation of Ne was 100 SNPs. A general assumption in the estimation of Ne...

  18. On the effect of correlated measurements on the performance of distributed estimation

    KAUST Repository

    Ahmed, Mohammed; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

    2013-01-01

    other as well. The correlation coefficient between two observations is exponentially decaying with the distance separation. The effect of the distance-based correlation on the estimation quality is demonstrated and compared with the case of unity

  19. Effects of spatial aggregation on the multi-scale estimation of evapotranspiration

    KAUST Repository

    Ershadi, Ali; McCabe, Matthew; Evans, Jason P.; Walker, Jeffrey P.

    2013-01-01

    The influence of spatial resolution on the estimation of land surface heat fluxes from remote sensing is poorly understood. In this study, the effects of aggregation from fine (< 100 m) to medium (approx. 1. km) scales are investigated using high

  20. Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes

    DEFF Research Database (Denmark)

    Wood, Lesley; Egger, Matthias; Gluud, Lise Lotte

    2008-01-01

    To examine whether the association of inadequate or unclear allocation concealment and lack of blinding with biased estimates of intervention effects varies with the nature of the intervention or outcome....

  1. Estimating the Effective Lower Bound for the Czech National Bank's Policy Rate

    OpenAIRE

    Kolcunova, Dominika; Havranek, Tomas

    2018-01-01

    The paper focuses on the estimation of the effective lower bound for the Czech National Bank's policy rate. The effective lower bound is determined by the value below which holding and using cash would be more convenient than deposits with negative yields. This bound is approximated based on storage, the insurance and transportation costs of cash and the costs associated with the loss of the convenience of cashless payments and complemented with the estimate based on interest charges, which p...

  2. Estimation of effective dose from Rn emanating from 'the minus ion' effect wallpaper

    International Nuclear Information System (INIS)

    Yoshizawa, Y.; Minowa, H.; Morita-Murase, Y.; Furuta, E.

    2006-01-01

    We have examined the wall papers which declared 'the minus ion' effect to estimate external and internal exposure dose from them. Results of gamma-ray spectrometry revealed that they contain 0.03 to 0.35 Bq·g -1 of Th-series nuclides, 208 Tl, 212 Pb, 212 Bi and 228 Ac, and U-series one, 214 Pb. Distributions of radioactive nuclides in the samples were measured using an imaging plate and a FLA-2000 (Fuji Photo Film). The radiation doses from the printed side of the wall papers were 5 to 15 times higher than that of the back side. The 222 Rn concentrations emanating from the wall papers in a sealed container of 50 liter were measured using the PICO-RAD radon detectors. One wall paper showed two to five times higher than the background value. (author)

  3. Atoms for peace and the nonproliferation treaty: unintended consequences

    International Nuclear Information System (INIS)

    Streeper, Charles Blamires

    2009-01-01

    In April 2009, President Obama revived nonproliferation and arms control efforts with a speech calling for the worldwide abolition of nuclear weapons. His speech correctly acknowledged the threat of nuclear terrorism and the vulnerabilities of the related unsecure nuclear materials. Unfortunately, the president did not mention and has not mentioned in any speech the threat posed by at-risk radiological materials. Nonproliferation efforts have a well documented history of focus on special nuclear materials (fissionable weapons usable materials or SNM), and other key materials (chemical and biological) and technologies for a Weapon of Mass Destruction (WMD). Such intense focus on WMD related materials/technologies is essential for international safety and security and merit continued attention and funding. However, the perception that radioactive sealed sources (sources) are of less concern than WMD is unfortunate. These perceptions are based solely on the potentially enormous and tragic consequences associated with their deliberate or accidental misuse and proliferation concerns. However, there is a documented history of overemphasis on the nuclear threat at the expense of ignoring the far more likely and also devastating chemical and biological threats. The radiological threat should not be minimized or excluded from policy discussions and decisions on these far ranging scopes of threat to the international community. Sources have a long history of use; and a wider distribution worldwide than fissile materials. Pair this with their broad ranges in isotopes/activities along with scant national and international attention and mechanisms for their safe and secure management and it is not difficult to envision a deadly threat. Arguments that minimize or divert attention away from sources may have the effect of distracting necessary policy attention on preventing/mitigating a radiological dispersal event. The terrorist attacks on 9/11 should be a clear reminder of the

  4. Factors associated with unintended pregnancy in Brazil: cross-sectional results from the Birth in Brazil National Survey, 2011/2012

    Directory of Open Access Journals (Sweden)

    Mariza Miranda Theme-Filha

    2016-10-01

    Full Text Available Abstract Background Unintended pregnancy, a pregnancy that have been either unwanted or mistimed, is a serious public health issue in Brazil. It is reported for more than half of women who gave birth in the country, but the characteristics of women who conceive unintentionally are rarely documented. The aim of this study is to analyse the prevalence and the association between unintended pregnancy and a set of sociodemographic characteristics, individual-level variables and history of obstetric outcomes. Methods Birth in Brazil is a cross-sectional study with countrywide representation that interviewed 23,894 women after birth. The information about intendedness of pregnancy was obtained after birth at the hospital and classified into three categories: intended, mistimed or unwanted. Multinomial regression analysis was used to estimate the associations between intendedness of a pregnancy, and sociodemographic and obstetric variables, calculating odds ratios and 95 % confidence intervals. All significant variables in the bivariate analysis were included in the multinomial multivariate model and the final model retaining variables that remained significant at the 5 % level. Results Unintended pregnancy was reported by 55.4 % of postpartum women. The following variables maintained positive and significant statistical associations with mistimed pregnancy: maternal age < 20 years (OR = 1.89, 95 % CI: 1.68–2.14; brown (OR = 1.15, 95 % CI: 1.04–1.27 or yellow skin color (OR = 1.56, 95 % CI: 1.05–2.32; having no partner (OR = 2.32, 95 % CI: 1.99–2.71; having no paid job (OR = 1.15, 95 % CI: 1.04–1.27; alcohol abuse with risk of alcoholism (OR = 1.25, 95 % CI: 1.04–1.50 and having had three or more births (OR = 2.01, 95 % CI: 1.63–2.47. The same factors were associated with unwanted pregnancy, though the strength of the associations was generally stronger. Women with three or more births were 14

  5. Wait time management strategies for total joint replacement surgery: sustainability and unintended consequences.

    Science.gov (United States)

    Pomey, Marie-Pascale; Clavel, Nathalie; Amar, Claudia; Sabogale-Olarte, Juan Carlos; Sanmartin, Claudia; De Coster, Carolyn; Noseworthy, Tom

    2017-09-07

    In Canada, long waiting times for core specialized services have consistently been identified as a key barrier to access. Governments and organizations have responded with strategies for better access management, notably for total joint replacement (TJR) of the hip and knee. While wait time management strategies (WTMS) are promising, the factors which influence their sustainable implementation at the organizational level are understudied. Consequently, this study examined organizational and systemic factors that made it possible to sustain waiting times for TJR within federally established limits and for at least 18 months or more. The research design is a multiple case study of WTMS implementation. Five cases were selected across five Canadian provinces. Three success levels were pre-defined: 1) the WTMS maintained compliance with requirements for more than 18 months; 2) the WTMS met requirements for 18 months but could not sustain the level thereafter; 3) the WTMS never met requirements. For each case, we collected documents and interviewed key informants. We analyzed systemic and organizational factors, with particular attention to governance and leadership, culture, resources, methods, and tools. We found that successful organizations had specific characteristics: 1) management of the whole care continuum, 2) strong clinical leadership; 3) dedicated committees to coordinate and sustain strategy; 4) a culture based on trust and innovation. All strategies led to relatively similar unintended consequences. The main negative consequence was an initial increase in waiting times for TJR and the main positive consequence was operational enhancement of other areas of specialization based on the TJR model. This study highlights important differences in factors which help to achieve and sustain waiting times. To be sustainable, a WTMS needs to generate greater synergies between contextual-level strategy (provincial or regional) and organizational objectives and

  6. Development of an intervention delivered by mobile phone aimed at decreasing unintended pregnancy among young people in three lower middle income countries.

    Science.gov (United States)

    McCarthy, Ona L; Wazwaz, Ola; Osorio Calderon, Veronica; Jado, Iman; Saibov, Salokhiddin; Stavridis, Amina; López Gallardo, Jhonny; Tokhirov, Ravshan; Adada, Samia; Huaynoca, Silvia; Makleff, Shelly; Vandewiele, Marieka; Standaert, Sarah; Free, Caroline

    2018-05-02

    Unintended pregnancies can result in poorer health outcomes for women, children and families. Young people in low and middle income countries are at particular risk of unintended pregnancies and could benefit from innovative contraceptive interventions. There is growing evidence that interventions delivered by mobile phone can be effective in improving a range of health behaviours. This paper describes the development of a contraceptive behavioural intervention delivered by mobile phone for young people in Tajikistan, Bolivia and Palestine, where unmet need for contraception is high among this group. Guided by Intervention Mapping, the following steps contributed to the development of the interventions: (1) needs assessment; (2) specifying behavioural change to result from the intervention; (3) selecting behaviour change methods to include in the intervention; (4) producing and refining the intervention content. The results of the needs assessment produced similar interventions across the countries. The interventions consist of short daily messages delivered over 4 months (delivered by text messaging in Palestine and mobile phone application instant messages in Bolivia and Tajikistan). The messages provide information about contraception, target attitudes that are barriers to contraceptive uptake and support young people in feeling that they can influence their reproductive health. The interventions each contain the same ten behaviour change methods, adapted for delivery by mobile phone. The development resulted in a well-specified, theory-based intervention, tailored to each country. It is feasible to develop an intervention delivered by mobile phone for young people in resource-limited settings.

  7. Social Norms and Stigma Regarding Unintended Pregnancy and Pregnancy Decisions: A Qualitative Study of Young Women in Alabama.

    Science.gov (United States)

    Smith, Whitney; Turan, Janet M; White, Kari; Stringer, Kristi L; Helova, Anna; Simpson, Tina; Cockrill, Kate

    2016-06-01

    Social norms and stigma may play important roles in reproductive health behavior and decision making among young women in the U.S. South, who disproportionately experience unintended pregnancies. No research has described the presence and manifestations of social norms and stigmas associated with unintended pregnancy and related decision making from the perspective of this population. Six focus groups and 12 cognitive interviews were conducted between December 2013 and July 2014 with 46 low-income women aged 19-24 living in Birmingham, Alabama; respondents were recruited from two public health department centers and a community college. Semistructured interview guides were used to facilitate discussion about social perceptions of unintended pregnancy and related pregnancy decisions. Sessions were audio-recorded, and transcripts were analyzed using a theme-based approach. Participants described community expectations that pregnancy occur in the context of monogamous relationships, in which both partners are mature, educated and financially stable. However, respondents reported that unintended pregnancy outside of these circumstances was common, and that the community expected young women faced with unintended pregnancies to bear and raise their children. Women who chose to do so were viewed more positively than were women who chose abortion or adoption. The community generally considered these alternatives to parenting unacceptable, and participants discussed them in terms of negative labels, social judgment and nondisclosure. Findings suggest a need to reduce stigma and create a social environment in which young women are empowered to make the best reproductive decisions for themselves. Copyright © 2016 by the Guttmacher Institute.

  8. Robust estimation of the proportion of treatment effect explained by surrogate marker information.

    Science.gov (United States)

    Parast, Layla; McDermott, Mary M; Tian, Lu

    2016-05-10

    In randomized treatment studies where the primary outcome requires long follow-up of patients and/or expensive or invasive obtainment procedures, the availability of a surrogate marker that could be used to estimate the treatment effect and could potentially be observed earlier than the primary outcome would allow researchers to make conclusions regarding the treatment effect with less required follow-up time and resources. The Prentice criterion for a valid surrogate marker requires that a test for treatment effect on the surrogate marker also be a valid test for treatment effect on the primary outcome of interest. Based on this criterion, methods have been developed to define and estimate the proportion of treatment effect on the primary outcome that is explained by the treatment effect on the surrogate marker. These methods aim to identify useful statistical surrogates that capture a large proportion of the treatment effect. However, current methods to estimate this proportion usually require restrictive model assumptions that may not hold in practice and thus may lead to biased estimates of this quantity. In this paper, we propose a nonparametric procedure to estimate the proportion of treatment effect on the primary outcome that is explained by the treatment effect on a potential surrogate marker and extend this procedure to a setting with multiple surrogate markers. We compare our approach with previously proposed model-based approaches and propose a variance estimation procedure based on a perturbation-resampling method. Simulation studies demonstrate that the procedure performs well in finite samples and outperforms model-based procedures when the specified models are not correct. We illustrate our proposed procedure using a data set from a randomized study investigating a group-mediated cognitive behavioral intervention for peripheral artery disease participants. Copyright © 2015 John Wiley & Sons, Ltd.

  9. Consistency in Estimation and Model Selection of Dynamic Panel Data Models with Fixed Effects

    Directory of Open Access Journals (Sweden)

    Guangjie Li

    2015-07-01

    Full Text Available We examine the relationship between consistent parameter estimation and model selection for autoregressive panel data models with fixed effects. We find that the transformation of fixed effects proposed by Lancaster (2002 does not necessarily lead to consistent estimation of common parameters when some true exogenous regressors are excluded. We propose a data dependent way to specify the prior of the autoregressive coefficient and argue for comparing different model specifications before parameter estimation. Model selection properties of Bayes factors and Bayesian information criterion (BIC are investigated. When model uncertainty is substantial, we recommend the use of Bayesian Model Averaging to obtain point estimators with lower root mean squared errors (RMSE. We also study the implications of different levels of inclusion probabilities by simulations.

  10. Genepleio software for effective estimation of gene pleiotropy from protein sequences.

    Science.gov (United States)

    Chen, Wenhai; Chen, Dandan; Zhao, Ming; Zou, Yangyun; Zeng, Yanwu; Gu, Xun

    2015-01-01

    Though pleiotropy, which refers to the phenomenon of a gene affecting multiple traits, has long played a central role in genetics, development, and evolution, estimation of the number of pleiotropy components remains a hard mission to accomplish. In this paper, we report a newly developed software package, Genepleio, to estimate the effective gene pleiotropy from phylogenetic analysis of protein sequences. Since this estimate can be interpreted as the minimum pleiotropy of a gene, it is used to play a role of reference for many empirical pleiotropy measures. This work would facilitate our understanding of how gene pleiotropy affects the pattern of genotype-phenotype map and the consequence of organismal evolution.

  11. The effect of tracking network configuration on GPS baseline estimates for the CASA Uno experiment

    Science.gov (United States)

    Wolf, S. Kornreich; Dixon, T. H.; Freymueller, J. T.

    1990-01-01

    The effect of the tracking network on long (greater than 100 km) GPS baseline estimates was estimated using various subsets of the global tracking network initiated by the first Central and South America (CASA Uno) experiment. It was found that best results could be obtained with a global tacking network consisting of three U.S. stations, two sites in the southwestern Pacific, and two sites in Europe. In comparison with smaller subsets, this global network improved the baseline repeatability, the resolution of carrier phase cycle ambiguities, and formal errors of the orbit estimates.

  12. Estimating the real-world effects of expanding antiretroviral treatment eligibility: Evidence from a regression discontinuity analysis in Zambia.

    Directory of Open Access Journals (Sweden)

    Aaloke Mody

    2018-06-01

    Full Text Available Although randomized trials have established the clinical efficacy of treating all persons living with HIV (PLWHs, expanding treatment eligibility in the real world may have additional behavioral effects (e.g., changes in retention or lead to unintended consequences (e.g., crowding out sicker patients owing to increased patient volume. Using a regression discontinuity design, we sought to assess the effects of a previous change to Zambia's HIV treatment guidelines increasing the threshold for treatment eligibility from 350 to 500 cells/μL to anticipate effects of current global efforts to treat all PLWHs.We analyzed antiretroviral therapy (ART-naïve adults who newly enrolled in HIV care in a network of 64 clinics operated by the Zambian Ministry of Health and supported by the Centre for Infectious Disease Research in Zambia (CIDRZ. Patients were restricted to those enrolling in a narrow window around the April 1, 2014 change to Zambian HIV treatment guidelines that raised the CD4 threshold for treatment from 350 to 500 cells/μL (i.e., August 1, 2013, to November 1, 2014. Clinical and sociodemographic data were obtained from an electronic medical record system used in routine care. We used a regression discontinuity design to estimate the effects of this change in treatment eligibility on ART initiation within 3 months of enrollment, retention in care at 6 months (defined as clinic attendance between 3 and 9 months after enrollment, and a composite of both ART initiation by 3 months and retention in care at 6 months in all new enrollees. We also performed an instrumental variable (IV analysis to quantify the effect of actually initiating ART because of this guideline change on retention. Overall, 34,857 ART-naïve patients (39.1% male, median age 34 years [IQR 28-41], median CD4 268 cells/μL [IQR 134-430] newly enrolled in HIV care during this period; 23,036 were analyzed after excluding patients around the threshold to allow for clinic

  13. ESTIMATION OF THE KNOWLEDGE SPILLOVER EFFECTS BETWEEN FIRMS IN BIO-RELATED INDUSTRIES

    OpenAIRE

    Kim, Hanho; Kim, Jae-Kyung

    2005-01-01

    Knowledge spillover is a kind of externality originating from imperfect appropriation of R&D performances, which implies that the knowledge created by one agent could be transmitted to other related agents by affecting their R&D or other economic performances. For the estimation of knowledge spillover effects based on firm-level patent data between firms in bio-related industries, patents production function, as a proxy of knowledge production function, is formulated and estimated. Knowledge ...

  14. Quantifying scaling effects on satellite-derived forest area estimates for the conterminous USA

    Science.gov (United States)

    Daolan Zheng; L.S. Heath; M.J. Ducey; J.E. Smith

    2009-01-01

    We quantified the scaling effects on forest area estimates for the conterminous USA using regression analysis and the National Land Cover Dataset 30m satellite-derived maps in 2001 and 1992. The original data were aggregated to: (1) broad cover types (forest vs. non-forest); and (2) coarser resolutions (1km and 10 km). Standard errors of the model estimates were 2.3%...

  15. Bias Corrections for Standardized Effect Size Estimates Used with Single-Subject Experimental Designs

    Science.gov (United States)

    Ugille, Maaike; Moeyaert, Mariola; Beretvas, S. Natasha; Ferron, John M.; Van den Noortgate, Wim

    2014-01-01

    A multilevel meta-analysis can combine the results of several single-subject experimental design studies. However, the estimated effects are biased if the effect sizes are standardized and the number of measurement occasions is small. In this study, the authors investigated 4 approaches to correct for this bias. First, the standardized effect…

  16. Preconception care: preliminary estimates of costs and effects of smoking cessation and folic acid supplementation.

    NARCIS (Netherlands)

    Weerd, S. de; Polder, J.J.; Cohen-Overbeek, T.E.; Zimmermann, L.J.; Steegers, E.A.P.

    2004-01-01

    OBJECTIVE: To assess costs and effectiveness of preconception counseling for all women planning pregnancy in The Netherlands with regard to folic acid supplementation and smoking cessation counseling. STUDY DESIGN: Costs and effects were estimated based on 200,000 women approached yearly and uptake

  17. Estimating the Effect of Entrepreneur Education on Graduates' Intention to Be Entrepreneurs

    Science.gov (United States)

    Mohamad, Noorkartina; Lim, Hock-Eam; Yusof, Norhafezah; Soon, Jan-Jan

    2015-01-01

    Purpose: Previous studies on the effect of entrepreneur education are not comprehensive. Thus, estimating the effect of entrepreneur education is imperative. According to the Malaysian Ministry of Education (MoE), only 1.7 percent (as of 2013) of university graduates are self-employed, that is managing one's own business or known as graduate…

  18. Revisiting the Effectiveness of African Economic Integration. A Meta-Analytic Review and Comparative Estimation Methods

    DEFF Research Database (Denmark)

    Afesorgbor, Sylvanus Kwaku

    The gravity model has extensively been used in estimating the effectiveness of a number of RTAs in the world. However, many previous studies that assess the effectiveness of African RTAs using gravity model produce contrasting results and are characterize by two main shortcomings. Firstly, these ...

  19. Accounting for One-Group Clustering in Effect-Size Estimation

    Science.gov (United States)

    Citkowicz, Martyna; Hedges, Larry V.

    2013-01-01

    In some instances, intentionally or not, study designs are such that there is clustering in one group but not in the other. This paper describes methods for computing effect size estimates and their variances when there is clustering in only one group and the analysis has not taken that clustering into account. The authors provide the effect size…

  20. Logistic Regression with Multiple Random Effects: A Simulation Study of Estimation Methods and Statistical Packages

    Science.gov (United States)

    Kim, Yoonsang; Emery, Sherry

    2013-01-01

    Several statistical packages are capable of estimating generalized linear mixed models and these packages provide one or more of three estimation methods: penalized quasi-likelihood, Laplace, and Gauss-Hermite. Many studies have investigated these methods’ performance for the mixed-effects logistic regression model. However, the authors focused on models with one or two random effects and assumed a simple covariance structure between them, which may not be realistic. When there are multiple correlated random effects in a model, the computation becomes intensive, and often an algorithm fails to converge. Moreover, in our analysis of smoking status and exposure to anti-tobacco advertisements, we have observed that when a model included multiple random effects, parameter estimates varied considerably from one statistical package to another even when using the same estimation method. This article presents a comprehensive review of the advantages and disadvantages of each estimation method. In addition, we compare the performances of the three methods across statistical packages via simulation, which involves two- and three-level logistic regression models with at least three correlated random effects. We apply our findings to a real dataset. Our results suggest that two packages—SAS GLIMMIX Laplace and SuperMix Gaussian quadrature—perform well in terms of accuracy, precision, convergence rates, and computing speed. We also discuss the strengths and weaknesses of the two packages in regard to sample sizes. PMID:24288415

  1. Logistic Regression with Multiple Random Effects: A Simulation Study of Estimation Methods and Statistical Packages.

    Science.gov (United States)

    Kim, Yoonsang; Choi, Young-Ku; Emery, Sherry

    2013-08-01

    Several statistical packages are capable of estimating generalized linear mixed models and these packages provide one or more of three estimation methods: penalized quasi-likelihood, Laplace, and Gauss-Hermite. Many studies have investigated these methods' performance for the mixed-effects logistic regression model. However, the authors focused on models with one or two random effects and assumed a simple covariance structure between them, which may not be realistic. When there are multiple correlated random effects in a model, the computation becomes intensive, and often an algorithm fails to converge. Moreover, in our analysis of smoking status and exposure to anti-tobacco advertisements, we have observed that when a model included multiple random effects, parameter estimates varied considerably from one statistical package to another even when using the same estimation method. This article presents a comprehensive review of the advantages and disadvantages of each estimation method. In addition, we compare the performances of the three methods across statistical packages via simulation, which involves two- and three-level logistic regression models with at least three correlated random effects. We apply our findings to a real dataset. Our results suggest that two packages-SAS GLIMMIX Laplace and SuperMix Gaussian quadrature-perform well in terms of accuracy, precision, convergence rates, and computing speed. We also discuss the strengths and weaknesses of the two packages in regard to sample sizes.

  2. Estimates of the Incidence of Induced Abortion And Consequences of Unsafe Abortion in Senegal

    Science.gov (United States)

    Sedgh, Gilda; Sylla, Amadou Hassane; Philbin, Jesse; Keogh, Sarah; Ndiaye, Salif

    2015-01-01

    CONTEXT Abortion is highly restricted by law in Senegal. Although women seek care for abortion complications, no national estimate of abortion incidence exists. METHODS Data on postabortion care and abortion in Senegal were collected in 2013 using surveys of a nationally representative sample of 168 health facilities that provide postabortion care and of 110 professionals knowledgeable about abortion service provision. Indirect estimation techniques were applied to the data to estimate the incidence of induced abortion in the country. Abortion rates and ratios were calculated for the nation and separately for the Dakar region and the rest of the country. The distribution of pregnancies by planning status and by outcome was estimated. RESULTS In 2012, an estimated 51,500 induced abortions were performed in Senegal, and 16,700 (32%) resulted in complications that were treated at health facilities. The estimated abortion rate was 17 per 1,000 women aged 15–44 and the abortion ratio was 10 per 100 live births. The rate was higher in Dakar (21 per 1,000) than in the rest of the country (16 per 1,000). Poor women were far more likely to experience abortion complications, and less likely to receive treatment for complications, than nonpoor women. About 31% of pregnancies were unintended, and 24% of unintended pregnancies (8% of all pregnancies) ended in abortion. CONCLUSIONS Unsafe abortion exacts a heavy toll on women in Senegal. Reducing the barriers to effective contraceptive use and ensuring access to postabortion care without the risk of legal consequences may reduce the incidence of and complications from unsafe abortion. PMID:25856233

  3. Estimates of the incidence of induced abortion and consequences of unsafe abortion in Senegal.

    Science.gov (United States)

    Sedgh, Gilda; Sylla, Amadou Hassane; Philbin, Jesse; Keogh, Sarah; Ndiaye, Salif

    2015-03-01

    Abortion is highly restricted by law in Senegal. Although women seek care for abortion complications, no national estimate of abortion incidence exists. Data on postabortion care and abortion in Senegal were collected in 2013 using surveys of a nationally representative sample of 168 health facilities that provide postabortion care and of 110 professionals knowledgeable about abortion service provision. Indirect estimation techniques were applied to the data to estimate the incidence of induced abortion in the country. Abortion rates and ratios were calculated for the nation and separately for the Dakar region and the rest of the country. The distribution of pregnancies by planning status and by outcome was estimated. In 2012, an estimated 51,500 induced abortions were performed in Senegal, and 16,700 (32%) resulted in complications that were treated at health facilities. The estimated abortion rate was 17 per 1,000 women aged 15-44 and the abortion ratio was 10 per 100 live births. The rate was higher in Dakar (21 per 1,000) than in the rest of the country (16 per 1,000). Poor women were far more likely to experience abortion complications, and less likely to receive treatment for complications, than nonpoor women. About 31% of pregnancies were unintended, and 24% of unintended pregnancies (8% of all pregnancies) ended in abortion. Unsafe abortion exacts a heavy toll on women in Senegal. Reducing the barriers to effective contraceptive use and ensuring access to postabortion care without the risk of legal consequences may reduce the incidence of and complications from unsafe abortion.

  4. Incidence of Induced Abortion in Uganda, 2013: New Estimates Since 2003.

    Science.gov (United States)

    Prada, Elena; Atuyambe, Lynn M; Blades, Nakeisha M; Bukenya, Justine N; Orach, Christopher Garimoi; Bankole, Akinrinola

    2016-01-01

    In Uganda, abortion is permitted only when the life of a woman is in danger. This restriction compels the perpetuation of the practice in secrecy and often under unsafe conditions. In 2003, 294,000 induced abortions were estimated to occur each year in Uganda. Since then, no other research on abortion incidence has been conducted in the country. Data from 418 health facilities were used to estimate the number and rate of induced abortion in 2013. An indirect estimation methodology was used to calculate the annual incidence of induced abortions ─ nationally and by major regions. The use of a comparable methodology in an earlier study permits assessment of trends between 2003 and 2013. In 2013, an estimated 128,682 women were treated for abortion complications and an estimated 314,304 induced abortions occurred, both slightly up from 110,000 and 294,000 in 2003, respectively. The national abortion rate was 39 abortions per 1,000 women aged 15-49, down from 51 in 2003. Regional variation in abortion rates is very large, from as high as an estimated 77 per 1,000 women 15-49 in Kampala region, to as low as 18 per 1,000 women in Western region. The overall pregnancy rate also declined from 326 to 288; however the proportion of pregnancies that were unintended increased slightly, from 49% to 52%. Unsafe abortion remains a major problem confronting Ugandan women. Although the overall pregnancy rate and the abortion rate declined in the past decade, the majority of pregnancies to Ugandan women are still unintended. These findings reflect the increase in the use of modern contraception but also suggest that a large proportion of women are still having difficulty practicing contraception effectively. Improved access to contraceptive services and abortion-related care are still needed.

  5. Young women's education and behavioural risk trajectories: clarifying their association with unintended-pregnancy resolution.

    Science.gov (United States)

    Gomez-Scott, Jessica; Cooney, Teresa M

    2014-06-01

    In the USA, most pregnancies occurring to teenage women are unplanned, making both the decisions regarding their resolution and the consequences of those decisions important topics of inquiry. Substantial debate surrounds the potential consequences for young women of either carrying an unintended pregnancy to term or voluntarily terminating it. The present study utilises data from The US National Longitudinal Study of Adolescent Health prospectively to examine the predictors of pregnancy resolution decisions in terms of young women's educational goals and their engagement in risk behaviours. Additionally, the long-term consequences of these decisions for education and risk-taking behaviours are identified. Results indicate that young women with strong educational goals have a greater likelihood of terminating an unintended pregnancy than those with low aspirations, and that pregnancy termination predicts higher educational attainment compared to motherhood. Risk behaviours did not predict pregnancy-resolution decisions, but young women who became mothers reported lower rates of subsequent substance use and fewer sexual partners post-pregnancy than those who terminated the pregnancy or who had never been pregnant. Motherhood appears to be a catalyst for lifestyle change among young women, limiting substance use and sexual partnering, in contrast to abortion, which appears to allow adolescents to continue risk-taking trajectories.

  6. Twelve-year retrospective review of unintended pregnancies after Essure sterilization in the Netherlands.

    Science.gov (United States)

    Hitzerd, Emilie; Schreuder, Henk W R; Vleugels, Michel P H; Veersema, Sebastiaan

    2016-04-01

    To identify factors contributing to the occurrence of unintended pregnancies after Essure sterilization in the Netherlands. Even though Essure is a permanent method of contraception, unintended pregnancies have been reported. Retrospective case series analysis. Not applicable. Thirty-five pregnancies were reported in the Netherlands after Essure sterilization from 2002 through 2014 out of 27,346 placements. Data regarding Essure placement procedure, confirmation tests, and pregnancy outcome of the reported cases were obtained and analyzed to identify a possible cause of failure. Four causes of failure were identified: perforation (n = 10), expulsion (n = 7), unilateral placement (n = 7), and luteal pregnancy (n = 2). The occurrence of most pregnancies was related to physician noncompliance (n = 14). The other cases were associated with patient noncompliance (n = 5) or misinterpretation of the confirmation test (n = 9). Most pregnancies occurred within the first 24 months after the 3-month confirmation test (n = 23). The results of this study show that the incidence of pregnancies after Essure sterilization is low. Most pregnancies were related to incorrect positioning of a device or unilateral placement, and seem therefore preventable. Unilateral placement without prior history of salpingectomy should always be considered as unsuccessful sterilization. Furthermore, interpretation of the confirmation tests should be done by trained physicians, and with caution. We want to emphasize the importance of strictly adhering to placement and follow-up protocols. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  7. Understanding and estimating effective population size for practical application in marine species management.

    Science.gov (United States)

    Hare, Matthew P; Nunney, Leonard; Schwartz, Michael K; Ruzzante, Daniel E; Burford, Martha; Waples, Robin S; Ruegg, Kristen; Palstra, Friso

    2011-06-01

    Effective population size (N(e)) determines the strength of genetic drift in a population and has long been recognized as an important parameter for evaluating conservation status and threats to genetic health of populations. Specifically, an estimate of N(e) is crucial to management because it integrates genetic effects with the life history of the species, allowing for predictions of a population's current and future viability. Nevertheless, compared with ecological and demographic parameters, N(e) has had limited influence on species management, beyond its application in very small populations. Recent developments have substantially improved N(e) estimation; however, some obstacles remain for the practical application of N(e) estimates. For example, the need to define the spatial and temporal scale of measurement makes the concept complex and sometimes difficult to interpret. We reviewed approaches to estimation of N(e) over both long-term and contemporary time frames, clarifying their interpretations with respect to local populations and the global metapopulation. We describe multiple experimental factors affecting robustness of contemporary N(e) estimates and suggest that different sampling designs can be combined to compare largely independent measures of N(e) for improved confidence in the result. Large populations with moderate gene flow pose the greatest challenges to robust estimation of contemporary N(e) and require careful consideration of sampling and analysis to minimize estimator bias. We emphasize the practical utility of estimating N(e) by highlighting its relevance to the adaptive potential of a population and describing applications in management of marine populations, where the focus is not always on critically endangered populations. Two cases discussed include the mechanisms generating N(e) estimates many orders of magnitude lower than census N in harvested marine fishes and the predicted reduction in N(e) from hatchery-based population

  8. Scent Lure Effect on Camera-Trap Based Leopard Density Estimates.

    Directory of Open Access Journals (Sweden)

    Alexander Richard Braczkowski

    Full Text Available Density estimates for large carnivores derived from camera surveys often have wide confidence intervals due to low detection rates. Such estimates are of limited value to authorities, which require precise population estimates to inform conservation strategies. Using lures can potentially increase detection, improving the precision of estimates. However, by altering the spatio-temporal patterning of individuals across the camera array, lures may violate closure, a fundamental assumption of capture-recapture. Here, we test the effect of scent lures on the precision and veracity of density estimates derived from camera-trap surveys of a protected African leopard population. We undertook two surveys (a 'control' and 'treatment' survey on Phinda Game Reserve, South Africa. Survey design remained consistent except a scent lure was applied at camera-trap stations during the treatment survey. Lures did not affect the maximum movement distances (p = 0.96 or temporal activity of female (p = 0.12 or male leopards (p = 0.79, and the assumption of geographic closure was met for both surveys (p >0.05. The numbers of photographic captures were also similar for control and treatment surveys (p = 0.90. Accordingly, density estimates were comparable between surveys (although estimates derived using non-spatial methods (7.28-9.28 leopards/100km2 were considerably higher than estimates from spatially-explicit methods (3.40-3.65 leopards/100km2. The precision of estimates from the control and treatment surveys, were also comparable and this applied to both non-spatial and spatial methods of estimation. Our findings suggest that at least in the context of leopard research in productive habitats, the use of lures is not warranted.

  9. Estimation of the ancestral effective population sizes of African great apes under different selection regimes.

    Science.gov (United States)

    Schrago, Carlos G

    2014-08-01

    Reliable estimates of ancestral effective population sizes are necessary to unveil the population-level phenomena that shaped the phylogeny and molecular evolution of the African great apes. Although several methods have previously been applied to infer ancestral effective population sizes, an analysis of the influence of the selective regime on the estimates of ancestral demography has not been thoroughly conducted. In this study, three independent data sets under different selective regimes were used were composed to tackle this issue. The results showed that selection had a significant impact on the estimates of ancestral effective population sizes of the African great apes. The inference of the ancestral demography of African great apes was affected by the selection regime. The effects, however, were not homogeneous along the ancestral populations of great apes. The effective population size of the ancestor of humans and chimpanzees was more impacted by the selection regime when compared to the same parameter in the ancestor of humans, chimpanzees and gorillas. Because the selection regime influenced the estimates of ancestral effective population size, it is reasonable to assume that a portion of the discrepancy found in previous studies that inferred the ancestral effective population size may be attributable to the differential action of selection on the genes sampled.

  10. Radiochemical separation and effective dose estimation due to ingestion of 90Sr

    International Nuclear Information System (INIS)

    Ilic, Z.; Vidic, A.; Deljkic, D.; Sirko, D.; Zovko, E.; Samek, D.

    2009-01-01

    Since 2007. Institute for Public Health of Federation of Bosnia and Herzegovina-Radiation Protection Centre, within the framework of monitoring of radioactivity of environment carried out measurement of specific activity of 90 Sr content in selected food and water samples. The paper described the methods of measurement and radiochemical separation. Presented results, as average values of specific activity of 90 Sr, were used for estimation of effective dose due to ingestion of 90 Sr for 2007. and 2008. Estimated effective dose for 2007. due to ingestion of 90 Sr for adults was 1,36 μSv and 2,03 μSv for children (10 year old), and for 2008. 0,67 μSv (adults) and 1,01 μSv (children 10 year old). Estimated effective doses for 2007. and 2008. are varied because of different average specific activity radionuclide 90 Sr in selected samples of food, their number, species and origin. (author) [sr

  11. Effect of tube current modulation for dose estimation using a simulation tool on body CT examination

    International Nuclear Information System (INIS)

    Kawaguchi, Ai; Matsunaga, Yuta; Kobayashi, Masanao; Suzuki, Shoichi; Matsubara, Kosuke; Chida, Koichi

    2015-01-01

    The purpose of this study was to evaluate the effect of tube current modulation for dose estimation of a body computed tomography (CT) examination using a simulation tool. The authors also compared longitudinal variations in tube current values between iterative reconstruction (IR) and filtered back-projection (FBP) reconstruction algorithms. One hundred patients underwent body CT examinations. The tube current values around 10 organ regions were recorded longitudinally from tube current information. The organ and effective doses were simulated by average tube current values and longitudinal modulated tube current values. The organ doses for the bladder and breast estimated by longitudinal modulated tube current values were 20 % higher and 25 % lower than those estimated using the average tube current values, respectively. The differences in effective doses were small (mean, 0.7 mSv). The longitudinal variations in tube current values were almost the same for the IR and FBP algorithms. (authors)

  12. Estimating Probable Maximum Precipitation by Considering Combined Effect of Typhoon and Southwesterly Air Flow

    Directory of Open Access Journals (Sweden)

    Cheng-Chin Liu

    2016-01-01

    Full Text Available Typhoon Morakot hit southern Taiwan in 2009, bringing 48-hr of heavy rainfall [close to the Probable Maximum Precipitation (PMP] to the Tsengwen Reservoir catchment. This extreme rainfall event resulted from the combined (co-movement effect of two climate systems (i.e., typhoon and southwesterly air flow. Based on the traditional PMP estimation method (i.e., the storm transposition method, STM, two PMP estimation approaches, i.e., Amplification Index (AI and Independent System (IS approaches, which consider the combined effect are proposed in this work. The AI approach assumes that the southwesterly air flow precipitation in a typhoon event could reach its maximum value. The IS approach assumes that the typhoon and southwesterly air flow are independent weather systems. Based on these assumptions, calculation procedures for the two approaches were constructed for a case study on the Tsengwen Reservoir catchment. The results show that the PMP estimates for 6- to 60-hr durations using the two approaches are approximately 30% larger than the PMP estimates using the traditional STM without considering the combined effect. This work is a pioneer PMP estimation method that considers the combined effect of a typhoon and southwesterly air flow. Further studies on this issue are essential and encouraged.

  13. Using cost-effectiveness estimates from survey data to guide commissioning: an application to home care.

    Science.gov (United States)

    Forder, Julien; Malley, Juliette; Towers, Ann-Marie; Netten, Ann

    2014-08-01

    The aim is to describe and trial a pragmatic method to produce estimates of the incremental cost-effectiveness of care services from survey data. The main challenge is in estimating the counterfactual; that is, what the patient's quality of life would be if they did not receive that level of service. A production function method is presented, which seeks to distinguish the variation in care-related quality of life in the data that is due to service use as opposed to other factors. A problem is that relevant need factors also affect the amount of service used and therefore any missing factors could create endogeneity bias. Instrumental variable estimation can mitigate this problem. This method was applied to a survey of older people using home care as a proof of concept. In the analysis, we were able to estimate a quality-of-life production function using survey data with the expected form and robust estimation diagnostics. The practical advantages with this method are clear, but there are limitations. It is computationally complex, and there is a risk of misspecification and biased results, particularly with IV estimation. One strategy would be to use this method to produce preliminary estimates, with a full trial conducted thereafter, if indicated. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Estimation of effective connectivity using multi-layer perceptron artificial neural network.

    Science.gov (United States)

    Talebi, Nasibeh; Nasrabadi, Ali Motie; Mohammad-Rezazadeh, Iman

    2018-02-01

    Studies on interactions between brain regions estimate effective connectivity, (usually) based on the causality inferences made on the basis of temporal precedence. In this study, the causal relationship is modeled by a multi-layer perceptron feed-forward artificial neural network, because of the ANN's ability to generate appropriate input-output mapping and to learn from training examples without the need of detailed knowledge of the underlying system. At any time instant, the past samples of data are placed in the network input, and the subsequent values are predicted at its output. To estimate the strength of interactions, the measure of " Causality coefficient " is defined based on the network structure, the connecting weights and the parameters of hidden layer activation function. Simulation analysis demonstrates that the method, called "CREANN" (Causal Relationship Estimation by Artificial Neural Network), can estimate time-invariant and time-varying effective connectivity in terms of MVAR coefficients. The method shows robustness with respect to noise level of data. Furthermore, the estimations are not significantly influenced by the model order (considered time-lag), and the different initial conditions (initial random weights and parameters of the network). CREANN is also applied to EEG data collected during a memory recognition task. The results implicate that it can show changes in the information flow between brain regions, involving in the episodic memory retrieval process. These convincing results emphasize that CREANN can be used as an appropriate method to estimate the causal relationship among brain signals.

  15. FY 2011 4th Quarter Metric: Estimate of Future Aerosol Direct and Indirect Effects

    Energy Technology Data Exchange (ETDEWEB)

    Koch, D

    2011-09-21

    The global and annual mean aerosol direct and indirect effects, relative to 1850 conditions, estimated from CESM simulations are 0.02 W m-2 and -0.39 W m-2, respectively, for emissions in year 2100 under the IPCC RCP8.5 scenario. The indirect effect is much smaller than that for 2000 emissions because of much smaller SO2 emissions in 2100; the direct effects are small due to compensation between warming by black carbon and cooling by sulfate.

  16. Estimating the economic effects of cystic echinococcosis: Uruguay, a developing country with upper-middle income.

    Science.gov (United States)

    Torgerson, P R; Carmona, C; Bonifacino, R

    2000-10-01

    Cost-benefit analyses, run before the commencement of a programme to control a parasitic disease, should include estimates of the economic losses attributable to the disease. Uruguay, a middle-income, developing country, has a recent history of persistent problems with cystic echinococcosis, in both its human population and livestock. The economic effects in Uruguay of this disease, caused by the larval stage of the canine tapeworm Echinococcus granulosus, have now been evaluated. Data on the incidence of the disease, in humans and livestock, were used to construct cost estimates. The estimated minimum cost (U.S.$2.9 million/year) was based on the condemnation costs of infected offal together with the actual costs of the hospital treatment of the human cases. The estimate of the maximum cost (U.S.$22.1 million/year) also included the production losses resulting from lower livestock efficiency and the reduced income of individuals with morbidity attributable to the disease.

  17. Effective Scheme of Channel Tracking and Estimation for Mobile WiMAX DL-PUSC System

    Directory of Open Access Journals (Sweden)

    Phuong Thi Thu Pham

    2010-01-01

    Full Text Available This paper introduces an effective joint scheme of channel estimation and tracking for downlink partial usage of subchannel (DL-PUSC mode of mobile WiMAX system. Based on the pilot pattern of this particular system, some channel estimation methods including conventional interpolations and a more favorable least-squares line fitting (LSLF technique are comparatively studied. Besides, channel estimation performance can be remarkably improved by taking advantage of channel tracking derived from the preamble symbol. System performances in terms of packet error rate (PER and user link throughput are investigated in various channels adopted from the well-known ITU models for mobile environments. Simulation results show a significant performance enhancement when the proposed joint scheme is utilized, at least 5 dB, compared to only commonly used channel estimation approaches.

  18. Estimation of stochastic effects risk in children from areas affected by the Chernobyl accident

    International Nuclear Information System (INIS)

    Jova S, L.; Garcia L, O.; Valdes R, M.

    1996-01-01

    Radiation risk estimation of stochastic effect was evaluated in a group of children assisted in the Cuba Republic as part of the program for medical attention with children from areas affected by the Chernobyl accident . Doses, received from different sources, were estimated for risk evaluation. The study shows total detrimental effects between 0,02 - 0,01% for different groups; values lower than expected for developed country (17-20%). Fatal thyroid cancer increased up to 0,07% in one of the studied groups. (authors). 8 refs., 4 tabs

  19. Estimation of genetic effects in the presence of multicollinearity in multibreed beef cattle evaluation.

    Science.gov (United States)

    Roso, V M; Schenkel, F S; Miller, S P; Schaeffer, L R

    2005-08-01

    Breed additive, dominance, and epistatic loss effects are of concern in the genetic evaluation of a multibreed population. Multiple regression equations used for fitting these effects may show a high degree of multicollinearity among predictor variables. Typically, when strong linear relationships exist, the regression coefficients have large SE and are sensitive to changes in the data file and to the addition or deletion of variables in the model. Generalized ridge regression methods were applied to obtain stable estimates of direct and maternal breed additive, dominance, and epistatic loss effects in the presence of multicollinearity among predictor variables. Preweaning weight gains of beef calves in Ontario, Canada, from 1986 to 1999 were analyzed. The genetic model included fixed direct and maternal breed additive, dominance, and epistatic loss effects, fixed environmental effects of age of the calf, contemporary group, and age of the dam x sex of the calf, random additive direct and maternal genetic effects, and random maternal permanent environment effect. The degree and the nature of the multicollinearity were identified and ridge regression methods were used as an alternative to ordinary least squares (LS). Ridge parameters were obtained using two different objective methods: 1) generalized ridge estimator of Hoerl and Kennard (R1); and 2) bootstrap in combination with cross-validation (R2). Both ridge regression methods outperformed the LS estimator with respect to mean squared error of predictions (MSEP) and variance inflation factors (VIF) computed over 100 bootstrap samples. The MSEP of R1 and R2 were similar, and they were 3% less than the MSEP of LS. The average VIF of LS, R1, and R2 were equal to 26.81, 6.10, and 4.18, respectively. Ridge regression methods were particularly effective in decreasing the multicollinearity involving predictor variables of breed additive effects. Because of a high degree of confounding between estimates of maternal

  20. An empirical comparison of effective concentration estimators for evaluating aquatic toxicity test responses

    Energy Technology Data Exchange (ETDEWEB)

    Bailer, A.J.; Hughes, M.R.; Denton, D.L.; Oris, J.T.

    2000-01-01

    Aquatic toxicity tests are statistically evaluated by either hypothesis testing procedures to derive a no-observed-effect concentration or by inverting regression models to calculate the concentration associated with a specific reduction from the control response. These latter methods can be described as potency estimation methods. Standard US Environmental Protection Agency (USEPA) potency estimation methods are based on two different techniques. For continuous or count response data, a nominally nonparametric method that assumes monotonic decreasing responses and piecewise linear patterns between successive concentration groups is used. For quantal responses, a probit regression model with a linear dose term is fit. These techniques were compared with a recently developed parametric regression-based estimator, the relative inhibition estimator, RIp. This method is based on fitting generalized linear models, followed by estimation of the concentration associated with a particular decrement relative to control responses. These estimators, with levels of inhibition (p) of 25 and 50%, were applied to a series of chronic toxicity tests in a US EPA region 9 database of reference toxicity tests. Biological responses evaluated in these toxicity tests included the number of young produced in three broods by the water flea (Ceriodaphnia dubia) and germination success and tube length data from the giant kelp (Macrocystis pyrifera). The greatest discrepancy between the RIp and standard US EPA estimators was observed for C. dubia. The concentration-response pattern for this biological endpoint exhibited nonmonotonicity more frequently than for any of the other endpoint. Future work should consider optimal experimental designs to estimate these quantities, methods for constructing confidence intervals, and simulation studies to explore the behavior of these estimators under known conditions.

  1. Estimating the effect of a rare time-dependent treatment on the recurrent event rate.

    Science.gov (United States)

    Smith, Abigail R; Zhu, Danting; Goodrich, Nathan P; Merion, Robert M; Schaubel, Douglas E

    2018-05-30

    In many observational studies, the objective is to estimate the effect of treatment or state-change on the recurrent event rate. If treatment is assigned after the start of follow-up, traditional methods (eg, adjustment for baseline-only covariates or fully conditional adjustment for time-dependent covariates) may give biased results. We propose a two-stage modeling approach using the method of sequential stratification to accurately estimate the effect of a time-dependent treatment on the recurrent event rate. At the first stage, we estimate the pretreatment recurrent event trajectory using a proportional rates model censored at the time of treatment. Prognostic scores are estimated from the linear predictor of this model and used to match treated patients to as yet untreated controls based on prognostic score at the time of treatment for the index patient. The final model is stratified on matched sets and compares the posttreatment recurrent event rate to the recurrent event rate of the matched controls. We demonstrate through simulation that bias due to dependent censoring is negligible, provided the treatment frequency is low, and we investigate a threshold at which correction for dependent censoring is needed. The method is applied to liver transplant (LT), where we estimate the effect of development of post-LT End Stage Renal Disease (ESRD) on rate of days hospitalized. Copyright © 2018 John Wiley & Sons, Ltd.

  2. Combined methodology for estimating dose rates and health effects from exposure to radioactive pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, D.E. Jr.; Leggett, R.W.; Yalcintas, M.G.

    1980-12-01

    The work described in the report is basically a synthesis of two previously existing computer codes: INREM II, developed at the Oak Ridge National Laboratory (ORNL); and CAIRD, developed by the Environmental Protection Agency (EPA). The INREM II code uses contemporary dosimetric methods to estimate doses to specified reference organs due to inhalation or ingestion of a radionuclide. The CAIRD code employs actuarial life tables to account for competing risks in estimating numbers of health effects resulting from exposure of a cohort to some incremental risk. The combined computer code, referred to as RADRISK, estimates numbers of health effects in a hypothetical cohort of 100,000 persons due to continuous lifetime inhalation or ingestion of a radionuclide. Also briefly discussed in this report is a method of estimating numbers of health effects in a hypothetical cohort due to continuous lifetime exposure to external radiation. This method employs the CAIRD methodology together with dose conversion factors generated by the computer code DOSFACTER, developed at ORNL; these dose conversion factors are used to estimate dose rates to persons due to radionuclides in the air or on the ground surface. The combination of the life table and dosimetric guidelines for the release of radioactive pollutants to the atmosphere, as required by the Clean Air Act Amendments of 1977.

  3. Estimating the Reference Incremental Cost-Effectiveness Ratio for the Australian Health System.

    Science.gov (United States)

    Edney, Laura Catherine; Haji Ali Afzali, Hossein; Cheng, Terence Chai; Karnon, Jonathan

    2018-02-01

    Spending on new healthcare technologies increases net population health when the benefits of a new technology are greater than their opportunity costs-the benefits of the best alternative use of the additional resources required to fund a new technology. The objective of this study was to estimate the expected incremental cost per quality-adjusted life-year (QALY) gained of increased government health expenditure as an empirical estimate of the average opportunity costs of decisions to fund new health technologies. The estimated incremental cost-effectiveness ratio (ICER) is proposed as a reference ICER to inform value-based decision making in Australia. Empirical top-down approaches were used to estimate the QALY effects of government health expenditure with respect to reduced mortality and morbidity. Instrumental variable two-stage least-squares regression was used to estimate the elasticity of mortality-related QALY losses to a marginal change in government health expenditure. Regression analysis of longitudinal survey data representative of the general population was used to isolate the effects of increased government health expenditure on morbidity-related, QALY gains. Clinical judgement informed the duration of health-related quality-of-life improvement from the annual increase in government health expenditure. The base-case reference ICER was estimated at AUD28,033 per QALY gained. Parametric uncertainty associated with the estimation of mortality- and morbidity-related QALYs generated a 95% confidence interval AUD20,758-37,667. Recent public summary documents suggest new technologies with ICERs above AUD40,000 per QALY gained are recommended for public funding. The empirical reference ICER reported in this article suggests more QALYs could be gained if resources were allocated to other forms of health spending.

  4. PREMIM and EMIM: tools for estimation of maternal, imprinting and interaction effects using multinomial modelling

    Directory of Open Access Journals (Sweden)

    Howey Richard

    2012-06-01

    Full Text Available Abstract Background Here we present two new computer tools, PREMIM and EMIM, for the estimation of parental and child genetic effects, based on genotype data from a variety of different child-parent configurations. PREMIM allows the extraction of child-parent genotype data from standard-format pedigree data files, while EMIM uses the extracted genotype data to perform subsequent statistical analysis. The use of genotype data from the parents as well as from the child in question allows the estimation of complex genetic effects such as maternal genotype effects, maternal-foetal interactions and parent-of-origin (imprinting effects. These effects are estimated by EMIM, incorporating chosen assumptions such as Hardy-Weinberg equilibrium or exchangeability of parental matings as required. Results In application to simulated data, we show that the inference provided by EMIM is essentially equivalent to that provided by alternative (competing software packages such as MENDEL and LEM. However, PREMIM and EMIM (used in combination considerably outperform MENDEL and LEM in terms of speed and ease of execution. Conclusions Together, EMIM and PREMIM provide easy-to-use command-line tools for the analysis of pedigree data, giving unbiased estimates of parental and child genotype relative risks.

  5. Revealing life-history traits by contrasting genetic estimations with predictions of effective population size.

    Science.gov (United States)

    Greenbaum, Gili; Renan, Sharon; Templeton, Alan R; Bouskila, Amos; Saltz, David; Rubenstein, Daniel I; Bar-David, Shirli

    2017-12-22

    Effective population size, a central concept in conservation biology, is now routinely estimated from genetic surveys and can also be theoretically predicted from demographic, life-history, and mating-system data. By evaluating the consistency of theoretical predictions with empirically estimated effective size, insights can be gained regarding life-history characteristics and the relative impact of different life-history traits on genetic drift. These insights can be used to design and inform management strategies aimed at increasing effective population size. We demonstrated this approach by addressing the conservation of a reintroduced population of Asiatic wild ass (Equus hemionus). We estimated the variance effective size (N ev ) from genetic data (N ev =24.3) and formulated predictions for the impacts on N ev of demography, polygyny, female variance in lifetime reproductive success (RS), and heritability of female RS. By contrasting the genetic estimation with theoretical predictions, we found that polygyny was the strongest factor affecting genetic drift because only when accounting for polygyny were predictions consistent with the genetically measured N ev . The comparison of effective-size estimation and predictions indicated that 10.6% of the males mated per generation when heritability of female RS was unaccounted for (polygyny responsible for 81% decrease in N ev ) and 19.5% mated when female RS was accounted for (polygyny responsible for 67% decrease in N ev ). Heritability of female RS also affected N ev ; hf2=0.91 (heritability responsible for 41% decrease in N ev ). The low effective size is of concern, and we suggest that management actions focus on factors identified as strongly affecting Nev, namely, increasing the availability of artificial water sources to increase number of dominant males contributing to the gene pool. This approach, evaluating life-history hypotheses in light of their impact on effective population size, and contrasting

  6. The economic costs of radiation-induced health effects: Estimation and simulation

    International Nuclear Information System (INIS)

    Nieves, L.A.; Tawil, J.J.

    1988-08-01

    This effort improves the quantitative information available for use in evaluating actions that alter health risks due to population exposure to ionizing radiation. To project the potential future costs of changes in health effects risks, Pacific Northwest Laboratory (PNL) constructed a probabilistic computer model, Health Effects Costs Model (HECOM), which utilizes the health effect incidence estimates from accident consequences models to calculate the discounted sum of the economic costs associated with population exposure to ionizing radiation. Application of HECOM to value-impact and environmental impact analyses should greatly increase the quality of the information available for regulatory decision making. Three major types of health effects present risks for any population sustaining a significant radiation exposure: acute radiation injuries (and fatalities), latent cancers, and impairments due to genetic effects. The literature pertaining to both incidence and treatment of these health effects was reviewed by PNL and provided the basis for developing economic cost estimates. The economic costs of health effects estimated by HECOM represent both the value of resources consumed in diagnosing, treating, and caring for the patient and the value of goods not produced because of illness or premature death due to the health effect. Additional costs to society, such as pain and suffering, are not included in the PNL economic cost measures since they do not divert resources from other uses, are difficult to quantify, and do not have a value observable in the marketplace. 83 refs., 3 figs., 19 tabs

  7. Estimating the direct rebound effect for on-road freight transportation

    International Nuclear Information System (INIS)

    Winebrake, James J.; Green, Erin H.; Comer, Bryan; Corbett, James J.; Froman, Sarah

    2012-01-01

    Energy and environmental concerns have spawned new policies aimed at reducing emissions and fuel consumption of heavy-duty vehicles (HDVs) worldwide. While such policies intend to reduce HDV energy consumption and emissions, energy savings that reduce transportation costs may lead to increased demand for HDV transportation services. Increased HDV transportation, in turn, can result in increased energy use and emissions—i.e., a direct “rebound effect.” This paper provides a critical review of the literature related to the HDV rebound effect. Results of this review demonstrate that the lack of focused studies in this area combined with the variability and heterogeneity of the trucking sector limit general understanding of the HDV rebound effect. Currently, the studies that do exist often create biased or erroneous rebound effect estimates by inappropriately relying on freight elasticities or applying metrics that omit important elements of fuel consumption. Research following a more transparent and coherent approach can improve estimates of the rebound effect from policy measures to improve HDV energy efficiency. - Highlights: ► Provides a critical review of HDV rebound effect literature. ► Demonstrates limitations of HDV rebound effect estimates. ► Provides framework for considering more complete HDV rebound effect.

  8. The economic costs of radiation-induced health effects: Estimation and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, L.A.; Tawil, J.J.

    1988-08-01

    This effort improves the quantitative information available for use in evaluating actions that alter health risks due to population exposure to ionizing radiation. To project the potential future costs of changes in health effects risks, Pacific Northwest Laboratory (PNL) constructed a probabilistic computer model, Health Effects Costs Model (HECOM), which utilizes the health effect incidence estimates from accident consequences models to calculate the discounted sum of the economic costs associated with population exposure to ionizing radiation. Application of HECOM to value-impact and environmental impact analyses should greatly increase the quality of the information available for regulatory decision making. Three major types of health effects present risks for any population sustaining a significant radiation exposure: acute radiation injuries (and fatalities), latent cancers, and impairments due to genetic effects. The literature pertaining to both incidence and treatment of these health effects was reviewed by PNL and provided the basis for developing economic cost estimates. The economic costs of health effects estimated by HECOM represent both the value of resources consumed in diagnosing, treating, and caring for the patient and the value of goods not produced because of illness or premature death due to the health effect. Additional costs to society, such as pain and suffering, are not included in the PNL economic cost measures since they do not divert resources from other uses, are difficult to quantify, and do not have a value observable in the marketplace. 83 refs., 3 figs., 19 tabs.

  9. Random forests of interaction trees for estimating individualized treatment effects in randomized trials.

    Science.gov (United States)

    Su, Xiaogang; Peña, Annette T; Liu, Lei; Levine, Richard A

    2018-04-29

    Assessing heterogeneous treatment effects is a growing interest in advancing precision medicine. Individualized treatment effects (ITEs) play a critical role in such an endeavor. Concerning experimental data collected from randomized trials, we put forward a method, termed random forests of interaction trees (RFIT), for estimating ITE on the basis of interaction trees. To this end, we propose a smooth sigmoid surrogate method, as an alternative to greedy search, to speed up tree construction. The RFIT outperforms the "separate regression" approach in estimating ITE. Furthermore, standard errors for the estimated ITE via RFIT are obtained with the infinitesimal jackknife method. We assess and illustrate the use of RFIT via both simulation and the analysis of data from an acupuncture headache trial. Copyright © 2018 John Wiley & Sons, Ltd.

  10. Effects of social organization, trap arrangement and density, sampling scale, and population density on bias in population size estimation using some common mark-recapture estimators.

    Directory of Open Access Journals (Sweden)

    Manan Gupta

    Full Text Available Mark-recapture estimators are commonly used for population size estimation, and typically yield unbiased estimates for most solitary species with low to moderate home range sizes. However, these methods assume independence of captures among individuals, an assumption that is clearly violated in social species that show fission-fusion dynamics, such as the Asian elephant. In the specific case of Asian elephants, doubts have been raised about the accuracy of population size estimates. More importantly, the potential problem for the use of mark-recapture methods posed by social organization in general has not been systematically addressed. We developed an individual-based simulation framework to systematically examine the potential effects of type of social organization, as well as other factors such as trap density and arrangement, spatial scale of sampling, and population density, on bias in population sizes estimated by POPAN, Robust Design, and Robust Design with detection heterogeneity. In the present study, we ran simulations with biological, demographic and ecological parameters relevant to Asian elephant populations, but the simulation framework is easily extended to address questions relevant to other social species. We collected capture history data from the simulations, and used those data to test for bias in population size estimation. Social organization significantly affected bias in most analyses, but the effect sizes were variable, depending on other factors. Social organization tended to introduce large bias when trap arrangement was uniform and sampling effort was low. POPAN clearly outperformed the two Robust Design models we tested, yielding close to zero bias if traps were arranged at random in the study area, and when population density and trap density were not too low. Social organization did not have a major effect on bias for these parameter combinations at which POPAN gave more or less unbiased population size estimates

  11. Do Individual Differences and Aging Effects in the Estimation of Geographical Slant Reflect Cognitive or Perceptual Effects?

    Directory of Open Access Journals (Sweden)

    Abigail M. Dean

    2016-07-01

    Full Text Available Several individual differences including age have been suggested to affect the perception of slant. A cross-sectional study of outdoor hill estimation (N = 106 was analyzed using individual difference measures of age, experiential knowledge, fitness, personality traits, and sex. Of particular note, it was found that for participants who reported any experiential knowledge about slant, estimates decreased (i.e., became more accurate as conscientiousness increased, suggesting that more conscientious individuals were more deliberate about taking their experiential knowledge (rather than perception into account. Effects of fitness were limited to those without experiential knowledge, suggesting that they, too, may be cognitive rather than perceptual. The observed effects of age, which tended to produce lower, more accurate estimates of hill slant, provide more evidence that older adults do not see hills as steeper. The main effect of age was to lower slant estimates; such effects may be due to implicit experiential knowledge acquired over a lifetime. The results indicate the impact of cognitive, rather than perceptual factors on individual differences in slant estimation.

  12. Estimation of the advection effects induced by surface heterogeneities in the surface energy budget

    NARCIS (Netherlands)

    Cuxart, J.; Wrenger, B.; Martinez-Villagrasa, D.; Reuder, J.; Jonassen, M.O.; Jimenez, M.A.; Lothon, M.; Hartogensis, O.K.; Dunnermann, J.; Conangla, L.; Garai, A.

    2016-01-01

    The effect of terrain heterogeneities in one-point
    measurements is a continuous subject of discussion. Here
    we focus on the order of magnitude of the advection term
    in the equation of the evolution of temperature as generated
    by documented terrain heterogeneities and we estimate

  13. Effects of stand density on top height estimation for ponderosa pine

    Science.gov (United States)

    Martin Ritchie; Jianwei Zhang; Todd Hamilton

    2012-01-01

    Site index, estimated as a function of dominant-tree height and age, is often used as an expression of site quality. This expression is assumed to be effectively independent of stand density. Observation of dominant height at two different ponderosa pine levels-of-growing-stock studies revealed that top height stability with respect to stand density depends on the...

  14. Systematic screening for Chlamydia trachomatis : Estimating cost-effectiveness using dynamic modeling and Dutch data

    NARCIS (Netherlands)

    de Vries, R.; Van Bergen, J.E.A.M.; de Jong-van den Berg, Lolkje; Postma, Maarten

    2006-01-01

    To estimate the cost-effectiveness of a systematic one-off Chlamydia trachomatis (CT) screening program including partner treatment for Dutch young adults. Data on infection prevalence, participation rates, and sexual behavior were obtained from a large pilot study conducted in The Netherlands.

  15. Systematic screening for Chlamydia trachomatis: estimating cost-effectiveness using dynamic modeling and Dutch data

    NARCIS (Netherlands)

    de Vries, Robin; van Bergen, Jan E. A. M.; de Jong-van den Berg, Lolkje T. W.; Postma, Maarten J.

    2006-01-01

    To estimate the cost-effectiveness of a systematic one-off Chlamydia trachomatis (CT) screening program including partner treatment for Dutch young adults. Data on infection prevalence, participation rates, and sexual behavior were obtained from a large pilot study conducted in The Netherlands.

  16. Effects of structural error on the estimates of parameters of dynamical systems

    Science.gov (United States)

    Hadaegh, F. Y.; Bekey, G. A.

    1986-01-01

    In this paper, the notion of 'near-equivalence in probability' is introduced for identifying a system in the presence of several error sources. Following some basic definitions, necessary and sufficient conditions for the identifiability of parameters are given. The effects of structural error on the parameter estimates for both the deterministic and stochastic cases are considered.

  17. Empirically Driven Variable Selection for the Estimation of Causal Effects with Observational Data

    Science.gov (United States)

    Keller, Bryan; Chen, Jianshen

    2016-01-01

    Observational studies are common in educational research, where subjects self-select or are otherwise non-randomly assigned to different interventions (e.g., educational programs, grade retention, special education). Unbiased estimation of a causal effect with observational data depends crucially on the assumption of ignorability, which specifies…

  18. Estimating climate change effects on net primary production of rangelands in the United States

    Science.gov (United States)

    Matthew C. Reeves; Adam L. Moreno; Karen E. Bagne; Steven W. Running

    2014-01-01

    The potential effects of climate change on net primary productivity (NPP) of U.S. rangelands were evaluated using estimated climate regimes from the A1B, A2 and B2 global change scenarios imposed on the biogeochemical cycling model, Biome-BGC from 2001 to 2100. Temperature, precipitation, vapor pressure deficit, day length, solar radiation, CO2 enrichment and nitrogen...

  19. Robust Estimation and Moment Selection in Dynamic Fixed-effects Panel Data Models

    NARCIS (Netherlands)

    Cizek, P.; Aquaro, M.

    2015-01-01

    This paper extends an existing outlier-robust estimator of linear dynamic panel data models with fixed effects, which is based on the median ratio of two consecutive pairs of first-differenced data. To improve its precision and robust properties, a general procedure based on many pairwise

  20. Effects of Training on the Estimation of Muscular Moment in Submaximal Exercise

    Science.gov (United States)

    Leverrier, Celine; Gauthier, Antoine; Nicolas, Arnaud; Molinaro, Corinne

    2011-01-01

    The purpose of this study was to observe the effects of a submaximal isometric training program on estimation capacity at 25, 50, and 75% of maximal contraction in isometric action and at two angular velocities. The second purpose was to study the variability of isometric action. To achieve these purposes, participants carried out an isokinetic…

  1. Estimation of effective brain connectivity with dual Kalman filter and EEG source localization methods.

    Science.gov (United States)

    Rajabioun, Mehdi; Nasrabadi, Ali Motie; Shamsollahi, Mohammad Bagher

    2017-09-01

    Effective connectivity is one of the most important considerations in brain functional mapping via EEG. It demonstrates the effects of a particular active brain region on others. In this paper, a new method is proposed which is based on dual Kalman filter. In this method, firstly by using a brain active localization method (standardized low resolution brain electromagnetic tomography) and applying it to EEG signal, active regions are extracted, and appropriate time model (multivariate autoregressive model) is fitted to extracted brain active sources for evaluating the activity and time dependence between sources. Then, dual Kalman filter is used to estimate model parameters or effective connectivity between active regions. The advantage of this method is the estimation of different brain parts activity simultaneously with the calculation of effective connectivity between active regions. By combining dual Kalman filter with brain source localization methods, in addition to the connectivity estimation between parts, source activity is updated during the time. The proposed method performance has been evaluated firstly by applying it to simulated EEG signals with interacting connectivity simulation between active parts. Noisy simulated signals with different signal to noise ratios are used for evaluating method sensitivity to noise and comparing proposed method performance with other methods. Then the method is applied to real signals and the estimation error during a sweeping window is calculated. By comparing proposed method results in different simulation (simulated and real signals), proposed method gives acceptable results with least mean square error in noisy or real conditions.

  2. Can i just check...? Effects of edit check questions on measurement error and survey estimates

    NARCIS (Netherlands)

    Lugtig, Peter; Jäckle, Annette

    2014-01-01

    Household income is difficult to measure, since it requires the collection of information about all potential income sources for each member of a household.Weassess the effects of two types of edit check questions on measurement error and survey estimates: within-wave edit checks use responses to

  3. Application of marker selection to enhance estimation of genetic effects and gene interaction in cattle

    Science.gov (United States)

    Selection on important genetic markers can improve estimates of additive and dominance association effects. A composite population of beef cattle was selected for intermediate frequencies of myostatin (GDF8) F94L and µ-calpain (CAPN1) polymorphisms. Important additive associations of the GDF8 locu...

  4. Estimation of effective population size in continuously distributed populations: There goes the neighborhood

    Science.gov (United States)

    M. C. Neel; K. McKelvey; N. Ryman; M. W. Lloyd; R. Short Bull; F. W. Allendorf; M. K. Schwartz; R. S. Waples

    2013-01-01

    Use of genetic methods to estimate effective population size (Ne) is rapidly increasing, but all approaches make simplifying assumptions unlikely to be met in real populations. In particular, all assume a single, unstructured population, and none has been evaluated for use with continuously distributed species. We simulated continuous populations with local mating...

  5. A Methodology of Health Effects Estimation from Air Pollution in Large Asian Cities

    Directory of Open Access Journals (Sweden)

    Keiko Hirota

    2017-09-01

    Full Text Available The increase of health effects caused by air pollution seems to be a growing concern in Asian cities with increasing motorization. This paper discusses methods of estimating the health effects of air pollution in large Asian cities. Due to the absence of statistical data in Asia, this paper carefully chooses the methodology using data of the Japanese compensation system. A basic idea of health effects will be captured from simple indicators, such as population and air quality, in a correlation model. This correlation model enables more estimation results of respiratory mortality caused by air pollution to be yielded than by using the relative model. The correlation model could be an alternative method to estimate mortality besides the relative risk model since the results of the correlation model are comparable with those of the relative model by city and by time series. The classification of respiratory diseases is not known from the statistical yearbooks in many countries. Estimation results could support policy decision-making with respect to public health in a cost-effective way.

  6. The Implications of Summer Learning Loss for Value-Added Estimates of Teacher Effectiveness

    Science.gov (United States)

    Gershenson, Seth; Hayes, Michael S.

    2018-01-01

    School districts across the United States increasingly use value-added models (VAMs) to evaluate teachers. In practice, VAMs typically rely on lagged test scores from the previous academic year, which necessarily conflate summer with school-year learning and potentially bias estimates of teacher effectiveness. We investigate the practical…

  7. Estimation of stochastic frontier models with fixed-effects through Monte Carlo Maximum Likelihood

    NARCIS (Netherlands)

    Emvalomatis, G.; Stefanou, S.E.; Oude Lansink, A.G.J.M.

    2011-01-01

    Estimation of nonlinear fixed-effects models is plagued by the incidental parameters problem. This paper proposes a procedure for choosing appropriate densities for integrating the incidental parameters from the likelihood function in a general context. The densities are based on priors that are

  8. Cost-effectiveness estimates for antenatal HIV testing in the Netherlands

    NARCIS (Netherlands)

    Rozenbaum, M. H.; Verweel, G.; Folkerts, D. K. F.; Dronkers, F.; van den Hoek, J. A. R.; Hartwig, N. G.; de Groot, R.; Postma, M. J.

    2008-01-01

    This paper provides an estimation of the lifetime health-care cost of HIV-infected children and an update of the cost-effectiveness of universal HIV-screening of pregnant women in Amsterdam (The Netherlands). During 2003-2005, we collected data concerning the prevalence of newly diagnosed

  9. An Introduction to Confidence Intervals for Both Statistical Estimates and Effect Sizes.

    Science.gov (United States)

    Capraro, Mary Margaret

    This paper summarizes methods of estimating confidence intervals, including classical intervals and intervals for effect sizes. The recent American Psychological Association (APA) Task Force on Statistical Inference report suggested that confidence intervals should always be reported, and the fifth edition of the APA "Publication Manual"…

  10. A Comparison of Methods for Estimating Quadratic Effects in Nonlinear Structural Equation Models

    Science.gov (United States)

    Harring, Jeffrey R.; Weiss, Brandi A.; Hsu, Jui-Chen

    2012-01-01

    Two Monte Carlo simulations were performed to compare methods for estimating and testing hypotheses of quadratic effects in latent variable regression models. The methods considered in the current study were (a) a 2-stage moderated regression approach using latent variable scores, (b) an unconstrained product indicator approach, (c) a latent…

  11. The Welfare Effects of Price Advertising with Basket Shopping: Structural Estimates from Supermarket Promotions

    DEFF Research Database (Denmark)

    Gao, Cixiu

    2015-01-01

    This paper empirically examines welfare effects of the informative price advertising in the supermarket retail industry, using structural estimation approaches and individual scanner data. Supermarket retailers use promotions (advertised price cuts) to announce sales as a competing instrument...... promotion intensities are socially excessive. Moreover, the welfare implications are determined by the two opposite effects of price advertising: (1) the informing and therefore welfare-improving effect, and (2) the welfare-harming effect that higher transportation costs incur when promotions are used....... Using a spatial model that accounts for consumer shopping behavior and retailer pricing behavior, I structurally estimate consumer demand and the marginal costs of promotion, following the discrete choice literature and moment inequality approach. The simulation results numerically show that the private...

  12. Analytical estimation of control rod shadowing effect for excess reactivity measurement of HTTR

    International Nuclear Information System (INIS)

    Nakano, Masaaki; Fujimoto, Nozomu; Yamashita, Kiyonobu

    1999-01-01

    The fuel addition method is generally used for the excess reactivity measurement of the initial core. The control rod shadowing effect for the excess reactivity measurement has been estimated analytically for High Temperature Engineering Test Reactor (HTTR). 3-dimensional whole core analyses were carried out. The movements of control rods in measurements were simulated in the calculation. It was made clear that the value of excess reactivity strongly depend on combinations of measuring control rods and compensating control rods. The differences in excess reactivity between combinations come from the control rod shadowing effect. The shadowing effect is reduced by the use of plural number of measuring and compensating control rods to prevent deep insertion of them into the core. The measured excess reactivity in the experiments is, however, smaller than the estimated value with shadowing effect. (author)

  13. The estimation of branching curves in the presence of subject-specific random effects.

    Science.gov (United States)

    Elmi, Angelo; Ratcliffe, Sarah J; Guo, Wensheng

    2014-12-20

    Branching curves are a technique for modeling curves that change trajectory at a change (branching) point. Currently, the estimation framework is limited to independent data, and smoothing splines are used for estimation. This article aims to extend the branching curve framework to the longitudinal data setting where the branching point varies by subject. If the branching point is modeled as a random effect, then the longitudinal branching curve framework is a semiparametric nonlinear mixed effects model. Given existing issues with using random effects within a smoothing spline, we express the model as a B-spline based semiparametric nonlinear mixed effects model. Simple, clever smoothness constraints are enforced on the B-splines at the change point. The method is applied to Women's Health data where we model the shape of the labor curve (cervical dilation measured longitudinally) before and after treatment with oxytocin (a labor stimulant). Copyright © 2014 John Wiley & Sons, Ltd.

  14. Estimation of average causal effect using the restricted mean residual lifetime as effect measure

    DEFF Research Database (Denmark)

    Mansourvar, Zahra; Martinussen, Torben

    2017-01-01

    with respect to their survival times. In observational studies where the factor of interest is not randomized, covariate adjustment is needed to take into account imbalances in confounding factors. In this article, we develop an estimator for the average causal treatment difference using the restricted mean...... residual lifetime as target parameter. We account for confounding factors using the Aalen additive hazards model. Large sample property of the proposed estimator is established and simulation studies are conducted in order to assess small sample performance of the resulting estimator. The method is also......Although mean residual lifetime is often of interest in biomedical studies, restricted mean residual lifetime must be considered in order to accommodate censoring. Differences in the restricted mean residual lifetime can be used as an appropriate quantity for comparing different treatment groups...

  15. Estimates of the effectiveness of automatic control in alleviating wake vortex induced roll excursions

    Science.gov (United States)

    Tinling, B. E.

    1977-01-01

    Estimates of the effectiveness of a model following type control system in reducing the roll excursion due to a wake vortex encounter were obtained from single degree of freedom computations with inputs derived from the results of wind tunnel, flight, and simulation experiments. The analysis indicates that the control power commanded by the automatic system must be roughly equal to the vortex induced roll acceleration if effective limiting of the maximum bank angle is to be achieved.

  16. Unintended benefits: the potential economic impact of addressing risk factors to prevent Alzheimer's disease.

    Science.gov (United States)

    Lin, Pei-Jung; Yang, Zhou; Fillit, Howard M; Cohen, Joshua T; Neumann, Peter J

    2014-04-01

    Certain chronic conditions appear to be modifiable risk factors of Alzheimer's disease and related dementias. To understand the potential health and economic impacts of addressing those risk factors, we used data on a Medicare cohort to simulate four scenarios: a 10 percent reduction in the prevalence of diabetes, hypertension, cardiovascular diseases, respectively, and a 10 percent reduction in body mass index among beneficiaries who were overweight or obese. Our simulation demonstrated that reducing the prevalence of these conditions may yield "unintended benefits" by lowering the risk, delaying the onset, reducing the duration, and lowering the costs of dementia. More research is needed to clarify the exact relationship between various other chronic diseases and dementia. However, our findings highlight potential health gains and savings opportunities stemming from the better management of other conditions associated with dementia.

  17. Pediatric Concerns Due to Expanded Cannabis Use: Unintended Consequences of Legalization.

    Science.gov (United States)

    Wang, George Sam

    2017-03-01

    An "unintended consequence" of marijuana legalization is the impact on the pediatric population. From prenatal exposure to unintentional childhood exposures, through concerns of adolescence abuse and marijuana use for medicinal indications in children, marijuana exposure can affect pediatric patients at every stage in childhood. Regardless of the stage or reason of exposure, concerns exist about short-term and long-term consequences in a child's physical and mental health. The use of cannabidiol (CBD) may have some benefit for the treatment of epilepsy, but emphasis needs to be on rigorous clinical trials to evaluate efficacy and safety. As more states allow both medical and recreational marijuana, availability and prevalence of use will likely increase and more surveillance and research is needed to evaluate the consequences on the pediatric population.

  18. Estimated effects of interfacial vaporization on fission product scrubbing: Chapter 11

    International Nuclear Information System (INIS)

    Moody, F.J.; Nagy, S.G.

    1983-01-01

    When bubbles containing non-condensible gas rise through a water pool, interfacial evaporation causes a flow of vapor into the bubbles. The inflow reduces the outward particle motion toward the bubble wall, diminishing the effectiveness of fission product particle removal. This analysis provides an estimate of evaporation on pool scrubbing effectiveness. It is shown that hot gas, which boils water at the bubble wall, reduces the effective scrubbing height by less than five centimeters. Although the evaporative humidification in a rising bubble containing non-condensible gas has a diminishing effect on scrubbing mechanisms, substantial decontamination is still expected even for the limiting case of a saturated pool

  19. A new way to estimate the direct and indirect rebound effect and other rebound indicators

    International Nuclear Information System (INIS)

    Freire-González, Jaume

    2017-01-01

    Some progress has been done during the last years on the methods and provision of empirical evidence on the direct and indirect rebound effect. However, these methods are complex, and sometimes require some specific economic knowledge. The development of risk and vulnerability rebound indicators for economies can be a useful tool to help the research community, policy-makers and other practitioners to understand and tackle the rebound effect. This research shows a new analytical way to obtain the direct and indirect rebound effect from the direct rebound effect and the use of energy input-output coefficients, and proposes three risk and vulnerability rebound indicators to show the effects of energy efficiency improvements in households on overall energy consumption. An estimation of these indicators has been conducted for the EU-27 countries. - Highlights: • A new method to estimate direct and indirect rebound effect is shown. • Three indicators are developed to assess risk and vulnerability to rebound. • An estimation of rebound indicators has been carried out for the EU-27 economies.

  20. Estimated collective effective dose to the population from nuclear medicine examinations in Slovenia

    International Nuclear Information System (INIS)

    Skrk, Damijan; Zontar, Dejan

    2013-01-01

    A national survey of patient exposure from nuclear medicine diagnostic procedures was performed by Slovenian Radiation Protection Administration in order to estimate their contribution to the collective effective dose to the population of Slovenia. A set of 36 examinations with the highest contributions to the collective effective dose was identified. Data about frequencies and average administered activities of radioisotopes used for those examinations were collected from all nuclear medicine departments in Slovenia. A collective effective dose to the population and an effective dose per capita were estimated from the collected data using dose conversion factors. The total collective effective dose to the population from nuclear medicine diagnostic procedures in 2011 was estimated to 102 manSv, giving an effective dose per capita of 0.05 mSv. The comparison of results of this study with studies performed in other countries indicates that the nuclear medicine providers in Slovenia are well aware of the importance of patient protection measures and of optimisation of procedures

  1. We can do better than effective dose for estimating or comparing low-dose radiation risks

    International Nuclear Information System (INIS)

    Brenner, D.J.

    2012-01-01

    The effective dose concept was designed to compare the generic risks of exposure to different radiation fields. More commonly these days, it is used to estimate or compare radiation-induced cancer risks. For various reasons, effective dose represents flawed science: for instance, the tissue-specific weighting factors used to calculate effective dose are a subjective mix of different endpoints; and the marked and differing age and gender dependencies for different health detriment endpoints are not taken into account. This paper suggests that effective dose could be replaced with a new quantity, ‘effective risk’, which, like effective dose, is a weighted sum of equivalent doses to different tissues. Unlike effective dose, where the tissue-dependent weighting factors are a set of generic, subjective committee-defined numbers, the weighting factors for effective risk are simply evaluated tissue-specific lifetime cancer risks per unit equivalent dose. Effective risk, which has the potential to be age and gender specific if desired, would perform the same comparative role as effective dose, be just as easy to estimate, be less prone to misuse, be more directly understandable, and would be based on solid science. An added major advantage is that it gives the users some feel for the actual numerical values of the radiation risks they are trying to control.

  2. Exploring shifts in the characteristics of US government-funded science curriculum materials and their (unintended) consequences

    NARCIS (Netherlands)

    Pareja Roblin, Natalie; Schunn, Christian; Bernstein, Debra; McKenney, Susan

    2018-01-01

    Grant-funded curriculum development efforts can substantially impact practice and research in science education. Therefore, understanding the sometimes-unintended consequences of changes in grant priorities is crucial. Using the case of two large funding agencies in the United States, the current

  3. Unintended Pregnancy and Intimate Partner Violence before and during Pregnancy among Latina Women in Los Angeles, California

    Science.gov (United States)

    Martin, Kathryn R.; Garcia, Lorena

    2011-01-01

    The purpose of this paper was to examine the relationship between unintended pregnancy and intimate partner violence (IPV) before and during pregnancy among Latinas. A cross-sectional interview measuring pregnancy intent, IPV, and acculturation, using the Acculturation Rating Scale for Mexican Americans (ARSMA-II), was conducted among Latina women…

  4. A comparison of different methods for reducing the unintended positional drift accompanying walking-in-place locomotion

    DEFF Research Database (Denmark)

    Nilsson, Niels Christian; Serafin, Stefania; Nordahl, Rolf

    2014-01-01

    If Walking-in-place (WIP) techniques are to be considered a useful way of facilitating virtual locomotion, it is crucial that the user remains stationary with respect to the physical environment. However, it has recently been documented that WIP locmotion may lead to Unintended Positional Drift...

  5. Analysis of unintended events in hospitals: inter-rater reliability of constructing causal trees and classifying root causes

    NARCIS (Netherlands)

    Smits, M.; Janssen, J.; Vet, de H.C.W.; Zwaan, L.; Timmermans, D.R.M.; Groenewegen, P.P.; Wagner, C.

    2009-01-01

    BACKGROUND: Root cause analysis is a method to examine causes of unintended events. PRISMA (Prevention and Recovery Information System for Monitoring and Analysis: is a root cause analysis tool. With PRISMA, events are described in causal trees and root causes are subsequently classified with the

  6. Analysis of unintended events in hospitals : inter-rater reliability of constructing causal trees and classifying root causes

    NARCIS (Netherlands)

    Smits, M.; Janssen, J.; Vet, R. de; Zwaan, L.; Groenewegen, P.P.; Timmermans, D.

    2009-01-01

    Background. Root cause analysis is a method to examine causes of unintended events. PRISMA (Prevention and Recovery Information System for Monitoring and Analysis) is a root cause analysis tool. With PRISMA, events are described in causal trees and root causes are subsequently classified with the

  7. Analysis of unintended events in hospitals: inter-rater reliability of constructing causal trees and classifying root causes.

    NARCIS (Netherlands)

    Smits, M.; Janssen, J.; Vet, R. de; Zwaan, L.; Timmermans, D.; Groenewegen, P.; Wagner, C.

    2009-01-01

    Background: Root cause analysis is a method to examine causes of unintended events. PRISMA (Prevention and Recovery Information System for Monitoring and Analysis) is a root cause analysis tool. With PRISMA, events are described in causal trees and root causes are subsequently classified with the

  8. Estimation of Genetic Effects from Generation Means in Maize (Zea mays L.)

    International Nuclear Information System (INIS)

    Ligeyo, D.O.; Ayiecho, P.O.

    1999-01-01

    Estimates of mean, additive, dominance, additive * additive, additive * dominance and dominance * dominance genetic effects were obtained for six crosses from four inbred lines of maize for grain yield. All the genetic effects contributed to the inheritance of yield. However not all genetic effects are present in all crosses at all locations. Both additive dominance genetic effects were responsible for the manifestation variability in grain yield, though the dominance genetic effect was preponderant in all cases. In most cases additive * additive and additive * dominance effects were more important contributors to inheritance than dominance * dominance gene effects at all locations.In all cases the manifestation of various genetic effects varied according to crosses and experimental sites

  9. Union women, the tobacco industry, and excise taxes: a lesson in unintended consequences.

    Science.gov (United States)

    Balbach, Edith D; Campbell, Richard B

    2009-08-01

    Between 1987 and 1997, the tobacco industry used the issue of cigarette excise tax increases to create a political partnership with the Coalition of Labor Union Women (CLUW), a group representing female trade unionists in the U.S. This paper documents how the industry created this relationship and the lessons tobacco-control advocates can learn from the industry's example, in order to mitigate possible unintended consequences of advocating excise tax increases. In 1998, under the terms of the Master Settlement Agreement, the tobacco industry began making documents produced in litigation available publicly. Currently, approximately 50 million pages are available online, including substantial documentation of the industry-CLUW relationship. For this study, a comprehensive search of these documents was conducted. The tobacco industry encouraged CLUW's opposition to excise tax increases by emphasizing the economic regressivity of these taxes, discussing excise taxes generically to deflect attention from cigarettes, and encouraging opposition to earmarking cigarette taxes to pay for specific programs. In addition, CLUW received at least $221,500 in financial support between 1987 and 1997 and in-kind support for its conferences, membership materials, and other services. Excise tax increases, if pursued without considering the impacts they may have on low-SES populations, may have unintended consequences. In this case, such proposals may have helped to create a relationship between CLUW and the tobacco industry. Because excise taxes are endorsed in the Framework Convention on Tobacco Control, tobacco-control advocates must understand how to build relationships with low-SES populations and mitigate potential alliances with the tobacco industry.

  10. Transformations, transport, and potential unintended consequences of high sulfur inputs to Napa Valley vineyards.

    Science.gov (United States)

    Hinckley, Eve-Lyn S; Matson, Pamela A

    2011-08-23

    Unintended anthropogenic deposition of sulfur (S) to forest ecosystems has a range of negative consequences, identified through decades of research. There has been far less study of purposeful S use in agricultural systems around the world, including the application of elemental sulfur (S(0)) as a quick-reacting fungicide to prevent damage to crops. Here we report results from a three-year study of the transformations and flows of applied S(0) in soils, vegetation, and hydrologic export pathways of Napa Valley, CA vineyards, documenting that all applied S is lost from the vineyard ecosystem on an annual basis. We found that S(0) oxidizes rapidly to sulfate ( ) on the soil surface where it then accumulates over the course of the growing season. Leaf and grape tissues accounted for only 7-13% of applied S whereas dormant season cover crops accounted for 4-10% of applications. Soil S inventories were largely and ester-bonded sulfates; they decreased from 1,623 ± 354 kg ha(-1) during the dry growing season to 981 ± 526 kg ha(-1) (0-0.5 m) during the dormant wet season. Nearly all S applied to the vineyard soils is transported offsite in dissolved oxidized forms during dormant season rainstorms. Thus, the residence time of reactive S is brief in these systems, and largely driven by hydrology. Our results provide new insight into how S use in vineyards constitutes a substantial perturbation of the S cycle in Northern California winegrowing regions and points to the unintended consequences that agricultural S use may have at larger scales.

  11. Estimates of effective equivalent dose commitments for Slovene population following the Chernobyl accident

    International Nuclear Information System (INIS)

    Kanduc, M.; Jovanowic, O.; Kuhar, B.

    2004-01-01

    This paper shows the estimates of effective equivalent dose commitments for the two groups of Slovene population, 5 years old children and adults. Doses were calculated on the basis of the ICRP 30 methodology, first from the measurements of the concentrations of the radionuclides in air, water and food samples and then compared with the results of the measurements of radionuclides in composite samples of the prepared food, taken in the kindergarten nearby. Results show that there is certain degree of conservatism hidden in the calculation of the doses on the basis of measurements of the activity concentration in the elements of the biosphere and is estimated to be roughly 50%. (author)

  12. EFFECTS OF OCEAN TIDE MODELS ON GNSS-ESTIMATED ZTD AND PWV IN TURKEY

    Directory of Open Access Journals (Sweden)

    G. Gurbuz

    2015-12-01

    Full Text Available Global Navigation Satellite System (GNSS observations can precisely estimate the total zenith tropospheric delay (ZTD and precipitable water vapour (PWV for weather prediction and atmospheric research as a continuous and all-weather technique. However, apart from GNSS technique itself, estimations of ZTD and PWV are subject to effects of geophysical models with large uncertainties, particularly imprecise ocean tide models in Turkey. In this paper, GNSS data from Jan. 1st to Dec. 31st of 2014 are processed at 4 co-located GNSS stations (GISM, DIYB, GANM, and ADAN with radiosonde from Turkish Met-Office along with several nearby IGS stations. The GAMIT/GLOBK software has been used to process GNSS data of 30-second sample using the Vienna Mapping Function and 10° elevation cut-off angle. Also tidal and non-tidal atmospheric pressure loadings (ATML at the observation level are also applied in GAMIT/GLOBK. Several widely used ocean tide models are used to evaluate their effects on GNSS-estimated ZTD and PWV estimation, such as IERS recommended FES2004, NAO99b from a barotropic hydrodynamic model, CSR4.0 obtained from TOPEX/Poseidon altimetry with the model FES94.1 as the reference model and GOT00 which is again long wavelength adjustments of FES94.1 using TOPEX/Poseidon data at 0.5 by 0.5 degree grid. The ZTD and PWV computed from radiosonde profile observations are regarded as reference values for the comparison and validation. In the processing phase, five different strategies are taken without ocean tide model and with four aforementioned ocean tide models, respectively, which are used to evaluate ocean tide models effects on GNSS-estimated ZTD and PWV estimation through comparing with co-located Radiosonde. Results showed that ocean tide models have greatly affected the estimation of the ZTD in centimeter level and thus the precipitable water vapour in millimeter level, respectively at stations near coasts. The ocean tide model FES2004 that is

  13. Turning lights into flights: Estimating direct and indirect rebound effects for UK households

    International Nuclear Information System (INIS)

    Chitnis, Mona; Sorrell, Steve; Druckman, Angela; Firth, Steven K.; Jackson, Tim

    2013-01-01

    Energy efficiency improvements by households lead to rebound effects that offset the potential energy and emissions savings. Direct rebound effects result from increased demand for cheaper energy services, while indirect rebound effects result from increased demand for other goods and services that also require energy to provide. Research to date has focused upon the former, but both are important for climate change. This study estimates the combined direct and indirect rebound effects from seven measures that improve the energy efficiency of UK dwellings. The methodology is based upon estimates of the income elasticity and greenhouse gas (GHG) intensity of 16 categories of household goods and services, and allows for the embodied emissions of the energy efficiency measures themselves, as well as the capital cost of the measures. Rebound effects are measured in GHG terms and relate to the adoption of these measures by an average UK household. The study finds that the rebound effects from these measures are typically in the range 5–15% and arise mostly from indirect effects. This is largely because expenditure on gas and electricity is more GHG-intensive than expenditure on other goods and services. However, the anticipated shift towards a low carbon electricity system in the UK may lead to much larger rebound effects. - Highlights: ► We estimate the direct and indirect rebound effects from energy efficiency improvements by UK households. ► We allow for the capital cost of the improvement, together with the emissions embodied in the relevant equipment. ► We find rebound effects to be relatively modest, in the range 5–15%. ► The anticipated shift towards a low carbon electricity system will lead to larger rebound effects

  14. On the uncertainties in effective dose estimates of adult CT head scans

    International Nuclear Information System (INIS)

    Gregory, Kent J.; Bibbo, Giovanni; Pattison, John E.

    2008-01-01

    Estimates of the effective dose to adult patients from computed tomography (CT) head scanning can be calculated using a number of different methods. These estimates can be used for a variety of purposes, such as improving scanning protocols, comparing different CT imaging centers, and weighing the benefits of the scan against the risk of radiation-induced cancer. The question arises: What is the uncertainty in these effective dose estimates? This study calculates the uncertainty of effective dose estimates produced by three computer programs (CT-EXPO, CTDosimetry, and ImpactDose) and one method that makes use of dose-length product (DLP) values. Uncertainties were calculated in accordance with an internationally recognized uncertainty analysis guide. For each of the four methods, the smallest and largest overall uncertainties (stated at the 95% confidence interval) were: 20%-31% (CT-EXPO), 15%-28% (CTDosimetry), 20%-36% (ImpactDose), and 22%-32% (DLP), respectively. The overall uncertainties for each method vary due to differences in the uncertainties of factors used in each method. The smallest uncertainties apply when the CT dose index for the scanner has been measured using a calibrated pencil ionization chamber

  15. Informing Estimates of Program Effects for Studies of Mathematics Professional Development Using Teacher Content Knowledge Outcomes.

    Science.gov (United States)

    Phelps, Geoffrey; Kelcey, Benjamin; Jones, Nathan; Liu, Shuangshuang

    2016-10-03

    Mathematics professional development is widely offered, typically with the goal of improving teachers' content knowledge, the quality of teaching, and ultimately students' achievement. Recently, new assessments focused on mathematical knowledge for teaching (MKT) have been developed to assist in the evaluation and improvement of mathematics professional development. This study presents empirical estimates of average program change in MKT and its variation with the goal of supporting the design of experimental trials that are adequately powered to detect a specified program effect. The study drew on a large database representing five different assessments of MKT and collectively 326 professional development programs and 9,365 teachers. Results from cross-classified hierarchical growth models found that standardized average change estimates across the five assessments ranged from a low of 0.16 standard deviations (SDs) to a high of 0.26 SDs. Power analyses using the estimated pre- and posttest change estimates indicated that hundreds of teachers are needed to detect changes in knowledge at the lower end of the distribution. Even studies powered to detect effects at the higher end of the distribution will require substantial resources to conduct rigorous experimental trials. Empirical benchmarks that describe average program change and its variation provide a useful preliminary resource for interpreting the relative magnitude of effect sizes associated with professional development programs and for designing adequately powered trials. © The Author(s) 2016.

  16. Estimating the cost-effectiveness of stroke units in France compared with conventional care.

    Science.gov (United States)

    Launois, R; Giroud, M; Mégnigbêto, A C; Le Lay, K; Présenté, G; Mahagne, M H; Durand, I; Gaudin, A F

    2004-03-01

    The incidence of stroke in France is estimated at between 120 000 and 150 000 cases per year. This modeling study assessed the clinical and economic benefits of establishing specialized stroke units compared with conventional care. Data from the Dijon stroke registry were used to determine healthcare trajectories according to the degree of autonomy and organization of patient care. The relative risks of death or institutionalization or death or dependence after passage through a stroke unit were compared with conventional care. These risks were then inserted with the costing data into a Markov model to estimate the cost-effectiveness of stroke units. Patients cared for in a stroke unit survive more trimesters without sequelae in the 5 years after hospitalization than those cared for conventionally (11.6 versus 8.28 trimesters). The mean cost per patient at 5 years was estimated at 30 983 for conventional care and 34 638 in a stroke unit. An incremental cost-effectiveness ratio for stroke units of 1359 per year of life gained without disability was estimated. The cost-effectiveness ratio for stroke units is much lower than the threshold (53 400 ) of acceptability recognized by the international scientific community. This finding justifies organizational changes in the management of stroke patients and the establishment of stroke units in France.

  17. Covariate adjustments in randomized controlled trials increased study power and reduced biasedness of effect size estimation.

    Science.gov (United States)

    Lee, Paul H

    2016-08-01

    This study aims to show that under several assumptions, in randomized controlled trials (RCTs), unadjusted, crude analysis will underestimate the Cohen's d effect size of the treatment, and an unbiased estimate of effect size can be obtained only by adjusting for all predictors of the outcome. Four simulations were performed to examine the effects of adjustment on the estimated effect size of the treatment and power of the analysis. In addition, we analyzed data from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study (older adults aged 65-94), an RCT with three treatment arms and one control arm. We showed that (1) the number of unadjusted covariates was associated with the effect size of the treatment; (2) the biasedness of effect size estimation was minimized if all covariates were adjusted for; (3) the power of the statistical analysis slightly decreased with the number of adjusted noise variables; and (4) exhaustively searching the covariates and noise variables adjusted for can lead to exaggeration of the true effect size. Analysis of the ACTIVE study data showed that the effect sizes adjusting for covariates of all three treatments were 7.39-24.70% larger than their unadjusted counterparts, whereas the effect size would be elevated by at most 57.92% by exhaustively searching the variables adjusted for. All covariates of the outcome in RCTs should be adjusted for, and if the effect of a particular variable on the outcome is unknown, adjustment will do more good than harm. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. A Bayesian localized conditional autoregressive model for estimating the health effects of air pollution.

    Science.gov (United States)

    Lee, Duncan; Rushworth, Alastair; Sahu, Sujit K

    2014-06-01

    Estimation of the long-term health effects of air pollution is a challenging task, especially when modeling spatial small-area disease incidence data in an ecological study design. The challenge comes from the unobserved underlying spatial autocorrelation structure in these data, which is accounted for using random effects modeled by a globally smooth conditional autoregressive model. These smooth random effects confound the effects of air pollution, which are also globally smooth. To avoid this collinearity a Bayesian localized conditional autoregressive model is developed for the random effects. This localized model is flexible spatially, in the sense that it is not only able to model areas of spatial smoothness, but also it is able to capture step changes in the random effects surface. This methodological development allows us to improve the estimation performance of the covariate effects, compared to using traditional conditional auto-regressive models. These results are established using a simulation study, and are then illustrated with our motivating study on air pollution and respiratory ill health in Greater Glasgow, Scotland in 2011. The model shows substantial health effects of particulate matter air pollution and nitrogen dioxide, whose effects have been consistently attenuated by the currently available globally smooth models. © 2014, The Authors Biometrics published by Wiley Periodicals, Inc. on behalf of International Biometric Society.

  19. The burden of secrecy? No effect on hill slant estimation and beanbag throwing.

    Science.gov (United States)

    Pecher, Diane; van Mierlo, Heleen; Cañal-Bruland, Rouwen; Zeelenberg, René

    2015-08-01

    Slepian, Masicampo, Toosi, and Ambady (2012, Experiment 1) reported that participants who recalled a big secret estimated a hill as steeper than participants who recalled a small secret. This finding was interpreted as evidence that secrets are experienced as physical burdens. In 2 experiments, we tried to replicate this finding, but, despite larger power, did not find a difference in slant estimates between participants who recalled a big secret and those who recalled a small secret. This finding was further corroborated by a meta-analysis that included 8 published data sets of exact replications, which indicates that thinking of a big secret does not affect hill slant estimation. In a third experiment, we also failed to replicate the effect of recalling a secret on throwing a beanbag at a target (Slepian et al., 2012, Experiment 2). Together, our findings question the robustness of the original empirical findings. (c) 2015 APA, all rights reserved).

  20. On the effect of correlated measurements on the performance of distributed estimation

    KAUST Repository

    Ahmed, Mohammed

    2013-06-01

    We address the distributed estimation of an unknown scalar parameter in Wireless Sensor Networks (WSNs). Sensor nodes transmit their noisy observations over multiple access channel to a Fusion Center (FC) that reconstructs the source parameter. The received signal is corrupted by noise and channel fading, so that the FC objective is to minimize the Mean-Square Error (MSE) of the estimate. In this paper, we assume sensor node observations to be correlated with the source signal and correlated with each other as well. The correlation coefficient between two observations is exponentially decaying with the distance separation. The effect of the distance-based correlation on the estimation quality is demonstrated and compared with the case of unity correlated observations. Moreover, a closed-form expression for the outage probability is derived and its dependency on the correlation coefficients is investigated. Numerical simulations are provided to verify our analytic results. © 2013 IEEE.

  1. Genepleio Software for Effective Estimation of Gene Pleiotropy from Protein Sequences

    Directory of Open Access Journals (Sweden)

    Wenhai Chen

    2015-01-01

    Full Text Available Though pleiotropy, which refers to the phenomenon of a gene affecting multiple traits, has long played a central role in genetics, development, and evolution, estimation of the number of pleiotropy components remains a hard mission to accomplish. In this paper, we report a newly developed software package, Genepleio, to estimate the effective gene pleiotropy from phylogenetic analysis of protein sequences. Since this estimate can be interpreted as the minimum pleiotropy of a gene, it is used to play a role of reference for many empirical pleiotropy measures. This work would facilitate our understanding of how gene pleiotropy affects the pattern of genotype-phenotype map and the consequence of organismal evolution.

  2. Estimating effectiveness in HIV prevention trials with a Bayesian hierarchical compound Poisson frailty model

    Science.gov (United States)

    Coley, Rebecca Yates; Browna, Elizabeth R.

    2016-01-01

    Inconsistent results in recent HIV prevention trials of pre-exposure prophylactic interventions may be due to heterogeneity in risk among study participants. Intervention effectiveness is most commonly estimated with the Cox model, which compares event times between populations. When heterogeneity is present, this population-level measure underestimates intervention effectiveness for individuals who are at risk. We propose a likelihood-based Bayesian hierarchical model that estimates the individual-level effectiveness of candidate interventions by accounting for heterogeneity in risk with a compound Poisson-distributed frailty term. This model reflects the mechanisms of HIV risk and allows that some participants are not exposed to HIV and, therefore, have no risk of seroconversion during the study. We assess model performance via simulation and apply the model to data from an HIV prevention trial. PMID:26869051

  3. Quantifying the Effects of Historical Land Cover Conversion Uncertainty on Global Carbon and Climate Estimates

    Science.gov (United States)

    Di Vittorio, A. V.; Mao, J.; Shi, X.; Chini, L.; Hurtt, G.; Collins, W. D.

    2018-01-01

    Previous studies have examined land use change as a driver of global change, but the translation of land use change into land cover conversion has been largely unconstrained. Here we quantify the effects of land cover conversion uncertainty on the global carbon and climate system using the integrated Earth System Model. Our experiments use identical land use change data and vary land cover conversions to quantify associated uncertainty in carbon and climate estimates. Land cover conversion uncertainty is large, constitutes a 5 ppmv range in estimated atmospheric CO2 in 2004, and generates carbon uncertainty that is equivalent to 80% of the net effects of CO2 and climate and 124% of the effects of nitrogen deposition during 1850-2004. Additionally, land cover uncertainty generates differences in local surface temperature of over 1°C. We conclude that future studies addressing land use, carbon, and climate need to constrain and reduce land cover conversion uncertainties.

  4. Effective charge versus bare charge: an analytical estimate for colloids in the infinite dilution limit

    International Nuclear Information System (INIS)

    Aubouy, Miguel; Trizac, Emmanuel; Bocquet, Lyderic

    2003-01-01

    We propose an analytical approximation for the dependence of the effective charge on the bare charge for spherical and cylindrical macro-ions as a function of the size of the colloid and salt content, for the situation of a unique colloid immersed in a sea of electrolyte (where the definition of an effective charge is non-ambiguous). Our approach is based on the Poisson-Boltzmann (PB) mean-field theory. Mathematically speaking, our estimate is asymptotically exact in the limit κa >> 1, where a is the radius of the colloid and κ is the inverse screening length. In practice, a careful comparison with effective charge parameters, obtained by numerically solving the full nonlinear PB theory, proves that our estimate is good down to κa ∼ 1. This is precisely the limit appropriate to treat colloidal suspensions. A particular emphasis is put on the range of parameters suitable to describe both single and double strand DNA molecules under physiological conditions

  5. Probability of Neutralization Estimation for APR1400 Physical Protection System Design Effectiveness Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myungsu; Lim, Heoksoon; Na, Janghwan; Chi, Moongoo [Korea Hydro and Nuclear Power Co. Ltd. Central Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    It is focusing on development of a new designing process which can be compatible to international standards such as IAEA1 and NRC2 suggest. Evaluation for the design effectiveness was found as one of the areas to improve. If a design doesn't meet a certain level of effectiveness, it should be re-designed accordingly. The effectiveness can be calculated with combination of probability of Interruption and probability of neutralization. System Analysis of Vulnerability to Intrusion (SAVI) has been developed by Sandia National Laboratories for that purpose. With SNL's timely detection methodology, SAVI has been used by U.S. nuclear utilities to meet the NRC requirements for PPS design effectiveness evaluation. For the SAVI calculation, probability of neutralization is a vital input element that must be supplied. This paper describes the elements to consider for neutralization, probability estimation methodology, and the estimation for APR1400 PPS design effectiveness evaluation process. Markov chain and Monte Carlo simulation are often used for simple numerical calculation to estimate P{sub N}. The results from both methods are not always identical even for the same situation. P{sub N} values for APR1400 evaluation were calculated based on Markov chain method and modified to be applicable for guards/adversaries ratio based analysis.

  6. Effectiveness of external respiratory surrogates for in vivo liver motion estimation

    International Nuclear Information System (INIS)

    Chang, Kai-Hsiang; Ho, Ming-Chih; Yeh, Chi-Chuan; Chen, Yu-Chien; Lian, Feng-Li; Lin, Win-Li; Yen, Jia-Yush; Chen, Yung-Yaw

    2012-01-01

    Purpose: Due to low frame rate of MRI and high radiation damage from fluoroscopy and CT, liver motion estimation using external respiratory surrogate signals seems to be a better approach to track liver motion in real-time for liver tumor treatments in radiotherapy and thermotherapy. This work proposes a liver motion estimation method based on external respiratory surrogate signals. Animal experiments are also conducted to investigate related issues, such as the sensor arrangement, multisensor fusion, and the effective time period. Methods: Liver motion and abdominal motion are both induced by respiration and are proved to be highly correlated. Contrary to the difficult direct measurement of the liver motion, the abdominal motion can be easily accessed. Based on this idea, our study is split into the model-fitting stage and the motion estimation stage. In the first stage, the correlation between the surrogates and the liver motion is studied and established via linear regression method. In the second stage, the liver motion is estimated by the surrogate signals with the correlation model. Animal experiments on cases of single surrogate signal, multisurrogate signals, and long-term surrogate signals are conducted and discussed to verify the practical use of this approach. Results: The results show that the best single sensor location is at the middle of the upper abdomen, while multisurrogate models are generally better than the single ones. The estimation error is reduced from 0.6 mm for the single surrogate models to 0.4 mm for the multisurrogate models. The long-term validity of the estimation models is quite satisfactory within the period of 10 min with the estimation error less than 1.4 mm. Conclusions: External respiratory surrogate signals from the abdomen motion produces good performance for liver motion estimation in real-time. Multisurrogate signals enhance estimation accuracy, and the estimation model can maintain its accuracy for at least 10 min. This

  7. Application of a multistate model to estimate culvert effects on movement of small fishes

    Science.gov (United States)

    Norman, J.R.; Hagler, M.M.; Freeman, Mary C.; Freeman, B.J.

    2009-01-01

    While it is widely acknowledged that culverted road-stream crossings may impede fish passage, effects of culverts on movement of nongame and small-bodied fishes have not been extensively studied and studies generally have not accounted for spatial variation in capture probabilities. We estimated probabilities for upstream and downstream movement of small (30-120 mm standard length) benthic and water column fishes across stream reaches with and without culverts at four road-stream crossings over a 4-6-week period. Movement and reach-specific capture probabilities were estimated using multistate capture-recapture models. Although none of the culverts were complete barriers to passage, only a bottomless-box culvert appeared to permit unrestricted upstream and downstream movements by benthic fishes based on model estimates of movement probabilities. At two box culverts that were perched above the water surface at base flow, observed movements were limited to water column fishes and to intervals when runoff from storm events raised water levels above the perched level. Only a single fish was observed to move through a partially embedded pipe culvert. Estimates for probabilities of movement over distances equal to at least the length of one culvert were low (e.g., generally ???0.03, estimated for 1-2-week intervals) and had wide 95% confidence intervals as a consequence of few observed movements to nonadjacent reaches. Estimates of capture probabilities varied among reaches by a factor of 2 to over 10, illustrating the importance of accounting for spatially variable capture rates when estimating movement probabilities with capture-recapture data. Longer-term studies are needed to evaluate temporal variability in stream fish passage at culverts (e.g., in relation to streamflow variability) and to thereby better quantify the degree of population fragmentation caused by road-stream crossings with culverts. ?? American Fisheries Society 2009.

  8. Effects of sample size on estimates of population growth rates calculated with matrix models.

    Directory of Open Access Journals (Sweden)

    Ian J Fiske

    Full Text Available BACKGROUND: Matrix models are widely used to study the dynamics and demography of populations. An important but overlooked issue is how the number of individuals sampled influences estimates of the population growth rate (lambda calculated with matrix models. Even unbiased estimates of vital rates do not ensure unbiased estimates of lambda-Jensen's Inequality implies that even when the estimates of the vital rates are accurate, small sample sizes lead to biased estimates of lambda due to increased sampling variance. We investigated if sampling variability and the distribution of sampling effort among size classes lead to biases in estimates of lambda. METHODOLOGY/PRINCIPAL FINDINGS: Using data from a long-term field study of plant demography, we simulated the effects of sampling variance by drawing vital rates and calculating lambda for increasingly larger populations drawn from a total population of 3842 plants. We then compared these estimates of lambda with those based on the entire population and calculated the resulting bias. Finally, we conducted a review of the literature to determine the sample sizes typically used when parameterizing matrix models used to study plant demography. CONCLUSIONS/SIGNIFICANCE: We found significant bias at small sample sizes when survival was low (survival = 0.5, and that sampling with a more-realistic inverse J-shaped population structure exacerbated this bias. However our simulations also demonstrate that these biases rapidly become negligible with increasing sample sizes or as survival increases. For many of the sample sizes used in demographic studies, matrix models are probably robust to the biases resulting from sampling variance of vital rates. However, this conclusion may depend on the structure of populations or the distribution of sampling effort in ways that are unexplored. We suggest more intensive sampling of populations when individual survival is low and greater sampling of stages with high

  9. Effects of sample size on estimates of population growth rates calculated with matrix models.

    Science.gov (United States)

    Fiske, Ian J; Bruna, Emilio M; Bolker, Benjamin M

    2008-08-28

    Matrix models are widely used to study the dynamics and demography of populations. An important but overlooked issue is how the number of individuals sampled influences estimates of the population growth rate (lambda) calculated with matrix models. Even unbiased estimates of vital rates do not ensure unbiased estimates of lambda-Jensen's Inequality implies that even when the estimates of the vital rates are accurate, small sample sizes lead to biased estimates of lambda due to increased sampling variance. We investigated if sampling variability and the distribution of sampling effort among size classes lead to biases in estimates of lambda. Using data from a long-term field study of plant demography, we simulated the effects of sampling variance by drawing vital rates and calculating lambda for increasingly larger populations drawn from a total population of 3842 plants. We then compared these estimates of lambda with those based on the entire population and calculated the resulting bias. Finally, we conducted a review of the literature to determine the sample sizes typically used when parameterizing matrix models used to study plant demography. We found significant bias at small sample sizes when survival was low (survival = 0.5), and that sampling with a more-realistic inverse J-shaped population structure exacerbated this bias. However our simulations also demonstrate that these biases rapidly become negligible with increasing sample sizes or as survival increases. For many of the sample sizes used in demographic studies, matrix models are probably robust to the biases resulting from sampling variance of vital rates. However, this conclusion may depend on the structure of populations or the distribution of sampling effort in ways that are unexplored. We suggest more intensive sampling of populations when individual survival is low and greater sampling of stages with high elasticities.

  10. Unintended Consequences of Wearable Sensor Use in Healthcare. Contribution of the IMIA Wearable Sensors in Healthcare WG.

    Science.gov (United States)

    Schukat, M; McCaldin, D; Wang, K; Schreier, G; Lovell, N H; Marschollek, M; Redmond, S J

    2016-11-10

    As wearable sensors take the consumer market by storm, and medical device manufacturers move to make their devices wireless and appropriate for ambulatory use, this revolution brings with it some unintended consequences, which we aim to discuss in this paper. We discuss some important unintended consequences, both beneficial and unwanted, which relate to: modifications of behavior; creation and use of big data sets; new security vulnerabilities; and unforeseen challenges faced by regulatory authorities, struggling to keep pace with recent innovations. Where possible, we proposed potential solutions to unwanted consequences. Intelligent and inclusive design processes may mitigate unintended modifications in behavior. For big data, legislating access to and use of these data will be a legal and political challenge in the years ahead, as we trade the health benefits of wearable sensors against the risk to our privacy. The wireless and personal nature of wearable sensors also exposes them to a number of unique security vulnerabilities. Regulation plays an important role in managing these security risks, but also has the dual responsibility of ensuring that wearable devices are fit for purpose. However, the burden of validating the function and security of medical devices is becoming infeasible for regulators, given the many software apps and wearable sensors entering the market each year, which are only a subset of an even larger 'internet of things'. Wearable sensors may serve to improve wellbeing, but we must be vigilant against the occurrence of unintended consequences. With collaboration between device manufacturers, regulators, and end-users, we balance the risk of unintended consequences occurring against the incredible benefit that wearable sensors promise to bring to the world.

  11. Key issues for estimating the impact and cost-effectiveness of seasonal influenza vaccination strategies.

    Science.gov (United States)

    Jit, Mark; Newall, Anthony T; Beutels, Philippe

    2013-04-01

    Many countries have considered or are considering modifying their seasonal influenza immunization policies. Estimating the impact of such changes requires understanding the existing clinical and economic burden of influenza, as well as the potential impact of different vaccination options. Previous studies suggest that vaccinating clinical risk groups, health care workers, children and the elderly may be cost-effective. However, challenges in such estimation include: (1) potential cases are not usually virologically tested; (2) cases have non-specific symptoms and are rarely reported to surveillance systems; (3) endpoints for influenza proxies (such as influenza-like illness) need to be matched to case definitions for treatment costs, (4) disease burden estimates vary from year to year with strain transmissibility, virulence and prior immunity, (5) methods to estimate productivity losses due to influenza vary, (6) vaccine efficacy estimates from trials differ due to variation in subtype prevalence, vaccine match and case ascertainment, and (7) indirect (herd) protection from vaccination depends on setting-specific variables that are difficult to directly measure. Given the importance of knowing the impact of changes to influenza policy, such complexities need careful treatment using tools such as population-based trial designs, meta-analyses, time-series analyses and transmission dynamic models.

  12. GONe: Software for estimating effective population size in species with generational overlap

    Science.gov (United States)

    Coombs, J.A.; Letcher, B.H.; Nislow, K.H.

    2012-01-01

    GONe is a user-friendly, Windows-based program for estimating effective size (N e) in populations with overlapping generations. It uses the Jorde-Ryman modification to the temporal method to account for age structure in populations. This method requires estimates of age-specific survival and birth rate and allele frequencies measured in two or more consecutive cohorts. Allele frequencies are acquired by reading in genotypic data from files formatted for either GENEPOP or TEMPOFS. For each interval between consecutive cohorts, N e is estimated at each locus and over all loci. Furthermore, N e estimates are output for three different genetic drift estimators (F s, F c and F k). Confidence intervals are derived from a chi-square distribution with degrees of freedom equal to the number of independent alleles. GONe has been validated over a wide range of N e values, and for scenarios where survival and birth rates differ between sexes, sex ratios are unequal and reproductive variances differ. GONe is freely available for download at. ?? 2011 Blackwell Publishing Ltd.

  13. Do Health Promotion Messages Integrate Unintended Pregnancy and STI Prevention? A Content Analysis of Online Information for Adolescents and Young Adults.

    Science.gov (United States)

    Steiner, Riley J; Rasberry, Catherine N; Sales, Jessica M; Gaydos, Laura M; Pazol, Karen; Kramer, Michael; Swartzendruber, Andrea

    2018-04-20

    Recently there have been calls to strengthen integration of unintended pregnancy and sexually transmitted infection (STI) prevention messages, spurred by increasing use of long-acting reversible contraception. To assess the extent to which public health/clinical messages about unintended pregnancy prevention also address STI prevention, we conducted a content analysis of web-based health promotion information for young people. Websites identified through a systematic Google search were eligible for inclusion if they were operated by a United States-based organization with a mission related to public health/clinical services and the URL included: 1) original content; 2) about sexual and reproductive health; 3) explicitly for adolescents and/or young adults. Using defined protocols, URLs were screened and content was selected and analyzed thematically. Many of the 32 eligible websites presented information about pregnancy and STI prevention separately. Concurrent discussion of the two topics was often limited to statements about (1) strategies that can prevent both outcomes (abstinence, condoms only, condoms plus moderate or highly effective contraceptive methods) and (2) contraceptive methods that confer no STI protection. We also identified framing of condom use with moderate or highly effective contraceptive method for back-up pregnancy prevention but not STI prevention. STI prevention methods in addition to condoms, such as STI/HIV testing, vaccination, or pre-exposure or post-exposure prophylaxis, were typically not addressed with pregnancy prevention information. There may be missed opportunities for promoting STI prevention online in the context of increasing awareness of and access to a full range of contraceptive methods. Strengthening messages that integrate pregnancy and STI prevention may include: describing STI prevention strategies when noting that birth control methods do not prevent STIs; promoting a full complement of STI prevention strategies; and

  14. Estimation of indirect effect when the mediator is a censored variable.

    Science.gov (United States)

    Wang, Jian; Shete, Sanjay

    2017-01-01

    A mediation model explores the direct and indirect effects of an initial variable ( X) on an outcome variable ( Y) by including a mediator ( M). In many realistic scenarios, investigators observe censored data instead of the complete data. Current research in mediation analysis for censored data focuses mainly on censored outcomes, but not censored mediators. In this study, we proposed a strategy based on the accelerated failure time model and a multiple imputation approach. We adapted a measure of the indirect effect for the mediation model with a censored mediator, which can assess the indirect effect at both the group and individual levels. Based on simulation, we established the bias in the estimations of different paths (i.e. the effects of X on M [ a], of M on Y [ b] and of X on Y given mediator M [ c']) and indirect effects when analyzing the data using the existing approaches, including a naïve approach implemented in software such as Mplus, complete-case analysis, and the Tobit mediation model. We conducted simulation studies to investigate the performance of the proposed strategy compared to that of the existing approaches. The proposed strategy accurately estimates the coefficients of different paths, indirect effects and percentages of the total effects mediated. We applied these mediation approaches to the study of SNPs, age at menopause and fasting glucose levels. Our results indicate that there is no indirect effect of association between SNPs and fasting glucose level that is mediated through the age at menopause.

  15. The effect of volume-of-interest misregistration on quantitative planar activity and dose estimation

    International Nuclear Information System (INIS)

    Song, N; Frey, E C; He, B

    2010-01-01

    In targeted radionuclide therapy (TRT), dose estimation is essential for treatment planning and tumor dose response studies. Dose estimates are typically based on a time series of whole-body conjugate view planar or SPECT scans of the patient acquired after administration of a planning dose. Quantifying the activity in the organs from these studies is an essential part of dose estimation. The quantitative planar (QPlanar) processing method involves accurate compensation for image degrading factors and correction for organ and background overlap via the combination of computational models of the image formation process and 3D volumes of interest defining the organs to be quantified. When the organ VOIs are accurately defined, the method intrinsically compensates for attenuation, scatter and partial volume effects, as well as overlap with other organs and the background. However, alignment between the 3D organ volume of interest (VOIs) used in QPlanar processing and the true organ projections in the planar images is required. The aim of this research was to study the effects of VOI misregistration on the accuracy and precision of organ activity estimates obtained using the QPlanar method. In this work, we modeled the degree of residual misregistration that would be expected after an automated registration procedure by randomly misaligning 3D SPECT/CT images, from which the VOI information was derived, and planar images. Mutual information-based image registration was used to align the realistic simulated 3D SPECT images with the 2D planar images. The residual image misregistration was used to simulate realistic levels of misregistration and allow investigation of the effects of misregistration on the accuracy and precision of the QPlanar method. We observed that accurate registration is especially important for small organs or ones with low activity concentrations compared to neighboring organs. In addition, residual misregistration gave rise to a loss of precision

  16. Foreground effect on the J-factor estimation of ultra-faint dwarf spheroidal galaxies

    Science.gov (United States)

    Ichikawa, Koji; Horigome, Shun-ichi; Ishigaki, Miho N.; Matsumoto, Shigeki; Ibe, Masahiro; Sugai, Hajime; Hayashi, Kohei

    2018-05-01

    Dwarf spheroidal galaxies (dSphs) are promising targets for the gamma-ray dark matter (DM) search. In particular, DM annihilation signal is expected to be strong in some of the recently discovered nearby ultra-faint dSphs, which potentially give stringent constraints on the O(1) TeV WIMP DM. However, various non-negligible systematic uncertainties complicate the estimation of the astrophysical factors relevant for the DM search in these objects. Among them, the effects of foreground stars particularly attract attention because the contamination is unavoidable even for the future kinematical survey. In this article, we assess the effects of the foreground contamination on the astrophysical J-factor estimation by generating mock samples of stars in the four ultra-faint dSphs and using a model of future spectrographs. We investigate various data cuts to optimize the quality of the data and apply a likelihood analysis which takes member and foreground stellar distributions into account. We show that the foreground star contaminations in the signal region (the region of interest) and their statistical uncertainty can be estimated by interpolating the foreground star distribution in the control region where the foreground stars dominate the member stars. Such regions can be secured at future spectroscopic observations utilizing a multiple object spectrograph with a large field of view; e.g. the Prime Focus Spectrograph mounted on Subaru Telescope. The above estimation has several advantages: The data-driven estimation of the contamination makes the analysis of the astrophysical factor stable against the complicated foreground distribution. Besides, foreground contamination effect is considered in the likelihood analysis.

  17. A new balance formula to estimate new particle formation rate: reevaluating the effect of coagulation scavenging

    Directory of Open Access Journals (Sweden)

    R. Cai

    2017-10-01

    Full Text Available A new balance formula to estimate new particle formation rate is proposed. It is derived from the aerosol general dynamic equation in the discrete form and then converted into an approximately continuous form for analyzing data from new particle formation (NPF field campaigns. The new formula corrects the underestimation of the coagulation scavenging effect that occurred in the previously used formulae. It also clarifies the criteria for determining the upper size bound in measured aerosol size distributions for estimating new particle formation rate. An NPF field campaign was carried out from 7 March to 7 April 2016 in urban Beijing, and a diethylene glycol scanning mobility particle spectrometer equipped with a miniature cylindrical differential mobility analyzer was used to measure aerosol size distributions down to ∼ 1 nm. Eleven typical NPF events were observed during this period. Measured aerosol size distributions from 1 nm to 10 µm were used to test the new formula and the formulae widely used in the literature. The previously used formulae that perform well in a relatively clean atmosphere in which nucleation intensity is not strong were found to underestimate the comparatively high new particle formation rate in urban Beijing because of their underestimation or neglect of the coagulation scavenging effect. The coagulation sink term is the governing component of the estimated formation rate in the observed NPF events in Beijing, and coagulation among newly formed particles contributes a large fraction to the coagulation sink term. Previously reported formation rates in Beijing and in other locations with intense NPF events might be underestimated because the coagulation scavenging effect was not fully considered; e.g., estimated formation rates of 1.5 nm particles in this campaign using the new formula are 1.3–4.3 times those estimated using the formula neglecting coagulation among particles in the nucleation mode.

  18. Reduction of Topographic Effect for Curve Number Estimated from Remotely Sensed Imagery

    Science.gov (United States)

    Zhang, Wen-Yan; Lin, Chao-Yuan

    2016-04-01

    The Soil Conservation Service Curve Number (SCS-CN) method is commonly used in hydrology to estimate direct runoff volume. The CN is the empirical parameter which corresponding to land use/land cover, hydrologic soil group and antecedent soil moisture condition. In large watersheds with complex topography, satellite remote sensing is the appropriate approach to acquire the land use change information. However, the topographic effect have been usually found in the remotely sensed imageries and resulted in land use classification. This research selected summer and winter scenes of Landsat-5 TM during 2008 to classified land use in Chen-You-Lan Watershed, Taiwan. The b-correction, the empirical topographic correction method, was applied to Landsat-5 TM data. Land use were categorized using K-mean classification into 4 groups i.e. forest, grassland, agriculture and river. Accuracy assessment of image classification was performed with national land use map. The results showed that after topographic correction, the overall accuracy of classification was increased from 68.0% to 74.5%. The average CN estimated from remotely sensed imagery decreased from 48.69 to 45.35 where the average CN estimated from national LULC map was 44.11. Therefore, the topographic correction method was recommended to normalize the topographic effect from the satellite remote sensing data before estimating the CN.

  19. Estimating the average treatment effect on survival based on observational data and using partly conditional modeling.

    Science.gov (United States)

    Gong, Qi; Schaubel, Douglas E

    2017-03-01

    Treatments are frequently evaluated in terms of their effect on patient survival. In settings where randomization of treatment is not feasible, observational data are employed, necessitating correction for covariate imbalances. Treatments are usually compared using a hazard ratio. Most existing methods which quantify the treatment effect through the survival function are applicable to treatments assigned at time 0. In the data structure of our interest, subjects typically begin follow-up untreated; time-until-treatment, and the pretreatment death hazard are both heavily influenced by longitudinal covariates; and subjects may experience periods of treatment ineligibility. We propose semiparametric methods for estimating the average difference in restricted mean survival time attributable to a time-dependent treatment, the average effect of treatment among the treated, under current treatment assignment patterns. The pre- and posttreatment models are partly conditional, in that they use the covariate history up to the time of treatment. The pre-treatment model is estimated through recently developed landmark analysis methods. For each treated patient, fitted pre- and posttreatment survival curves are projected out, then averaged in a manner which accounts for the censoring of treatment times. Asymptotic properties are derived and evaluated through simulation. The proposed methods are applied to liver transplant data in order to estimate the effect of liver transplantation on survival among transplant recipients under current practice patterns. © 2016, The International Biometric Society.

  20. Robust Wavelet Estimation to Eliminate Simultaneously the Effects of Boundary Problems, Outliers, and Correlated Noise

    Directory of Open Access Journals (Sweden)

    Alsaidi M. Altaher

    2012-01-01

    Full Text Available Classical wavelet thresholding methods suffer from boundary problems caused by the application of the wavelet transformations to a finite signal. As a result, large bias at the edges and artificial wiggles occur when the classical boundary assumptions are not satisfied. Although polynomial wavelet regression and local polynomial wavelet regression effectively reduce the risk of this problem, the estimates from these two methods can be easily affected by the presence of correlated noise and outliers, giving inaccurate estimates. This paper introduces two robust methods in which the effects of boundary problems, outliers, and correlated noise are simultaneously taken into account. The proposed methods combine thresholding estimator with either a local polynomial model or a polynomial model using the generalized least squares method instead of the ordinary one. A primary step that involves removing the outlying observations through a statistical function is considered as well. The practical performance of the proposed methods has been evaluated through simulation experiments and real data examples. The results are strong evidence that the proposed method is extremely effective in terms of correcting the boundary bias and eliminating the effects of outliers and correlated noise.