Iron Deficiency in COPD Associates with Increased Pulmonary Artery Pressure Estimated by Echocardiography

DEFF Research Database (Denmark)

Plesner, Louis L; Schoos, Mikkel M; Dalsgaard, Morten

2017-01-01

OBJECTIVES: Iron deficiency (ID) might augment chronic pulmonary hypertension in chronic obstructive pulmonary disease (COPD). This observational study investigates the association between ID and systolic pulmonary artery pressure estimated by echocardiography in non-anaemic COPD outpatients...

PEPIS: A Pipeline for Estimating Epistatic Effects in Quantitative Trait Locus Mapping and Genome-Wide Association Studies.

Directory of Open Access Journals (Sweden)

Wenchao Zhang

2016-05-01

Full Text Available The term epistasis refers to interactions between multiple genetic loci. Genetic epistasis is important in regulating biological function and is considered to explain part of the 'missing heritability,' which involves marginal genetic effects that cannot be accounted for in genome-wide association studies. Thus, the study of epistasis is of great interest to geneticists. However, estimating epistatic effects for quantitative traits is challenging due to the large number of interaction effects that must be estimated, thus significantly increasing computing demands. Here, we present a new web server-based tool, the Pipeline for estimating EPIStatic genetic effects (PEPIS, for analyzing polygenic epistatic effects. The PEPIS software package is based on a new linear mixed model that has been used to predict the performance of hybrid rice. The PEPIS includes two main sub-pipelines: the first for kinship matrix calculation, and the second for polygenic component analyses and genome scanning for main and epistatic effects. To accommodate the demand for high-performance computation, the PEPIS utilizes C/C++ for mathematical matrix computing. In addition, the modules for kinship matrix calculations and main and epistatic-effect genome scanning employ parallel computing technology that effectively utilizes multiple computer nodes across our networked cluster, thus significantly improving the computational speed. For example, when analyzing the same immortalized F2 rice population genotypic data examined in a previous study, the PEPIS returned identical results at each analysis step with the original prototype R code, but the computational time was reduced from more than one month to about five minutes. These advances will help overcome the bottleneck frequently encountered in genome wide epistatic genetic effect analysis and enable accommodation of the high computational demand. The PEPIS is publically available at http://bioinfo.noble.org/PolyGenic_QTL/.

PEPIS: A Pipeline for Estimating Epistatic Effects in Quantitative Trait Locus Mapping and Genome-Wide Association Studies.

Science.gov (United States)

Zhang, Wenchao; Dai, Xinbin; Wang, Qishan; Xu, Shizhong; Zhao, Patrick X

2016-05-01

The term epistasis refers to interactions between multiple genetic loci. Genetic epistasis is important in regulating biological function and is considered to explain part of the 'missing heritability,' which involves marginal genetic effects that cannot be accounted for in genome-wide association studies. Thus, the study of epistasis is of great interest to geneticists. However, estimating epistatic effects for quantitative traits is challenging due to the large number of interaction effects that must be estimated, thus significantly increasing computing demands. Here, we present a new web server-based tool, the Pipeline for estimating EPIStatic genetic effects (PEPIS), for analyzing polygenic epistatic effects. The PEPIS software package is based on a new linear mixed model that has been used to predict the performance of hybrid rice. The PEPIS includes two main sub-pipelines: the first for kinship matrix calculation, and the second for polygenic component analyses and genome scanning for main and epistatic effects. To accommodate the demand for high-performance computation, the PEPIS utilizes C/C++ for mathematical matrix computing. In addition, the modules for kinship matrix calculations and main and epistatic-effect genome scanning employ parallel computing technology that effectively utilizes multiple computer nodes across our networked cluster, thus significantly improving the computational speed. For example, when analyzing the same immortalized F2 rice population genotypic data examined in a previous study, the PEPIS returned identical results at each analysis step with the original prototype R code, but the computational time was reduced from more than one month to about five minutes. These advances will help overcome the bottleneck frequently encountered in genome wide epistatic genetic effect analysis and enable accommodation of the high computational demand. The PEPIS is publically available at http://bioinfo.noble.org/PolyGenic_QTL/.

Bias in estimating the cross-sectional smoking, alcohol, obesity and diabetes associations with moderate-severe periodontitis in the Atherosclerosis Risk in Communities study: comparison of full versus partial-mouth estimates.

Science.gov (United States)

Akinkugbe, Aderonke A; Saraiya, Veeral M; Preisser, John S; Offenbacher, Steven; Beck, James D

2015-07-01

To assess whether partial-mouth protocols (PRPs) result in biased estimates of the associations between smoking, alcohol, obesity and diabetes with periodontitis. Using a sample (n = 6129) of the 1996-1998 Atherosclerosis Risk in Communities study, we used measures of probing pocket depth and clinical attachment level to identify moderate-severe periodontitis. Adjusting for confounders, unconditional binary logistic regression estimated prevalence odds ratios (POR) and 95% confidence limits. Specifically, we compared POR for smoking, alcohol, obesity and diabetes with periodontitis derived from full-mouth to those derived from 4-PRPs (Ramfjörd, National Health and Nutrition Examination survey-III, modified-NHANES-IV and 42-site-Random-site selection-method). Finally, we conducted a simple sensitivity analysis of periodontitis misclassification by changing the case definition threshold for each PRP. In comparison to full-mouth PORs, PRP PORs were biased in terms of magnitude and direction. Holding the full-mouth case definition at moderate-severe periodontitis and setting it at mild-moderate-severe for the PRPs did not consistently produce POR estimates that were either biased towards or away from the null in comparison to full-mouth estimates. Partial-mouth protocols result in misclassification of periodontitis and may bias epidemiologic measures of association. The magnitude and direction of this bias depends on choice of PRP and case definition threshold used. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Reported estimates of diagnostic accuracy in ophthalmology conference abstracts were not associated with full-text publication.

Science.gov (United States)

Korevaar, Daniël A; Cohen, Jérémie F; Spijker, René; Saldanha, Ian J; Dickersin, Kay; Virgili, Gianni; Hooft, Lotty; Bossuyt, Patrick M M

2016-11-01

To assess whether conference abstracts that report higher estimates of diagnostic accuracy are more likely to reach full-text publication in a peer-reviewed journal. We identified abstracts describing diagnostic accuracy studies, presented between 2007 and 2010 at the Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting. We extracted reported estimates of sensitivity, specificity, area under the receiver operating characteristic curve (AUC), and diagnostic odds ratio (DOR). Between May and July 2015, we searched MEDLINE and EMBASE to identify corresponding full-text publications; if needed, we contacted abstract authors. Cox regression was performed to estimate associations with full-text publication, where sensitivity, specificity, and AUC were logit transformed, and DOR was log transformed. A full-text publication was found for 226/399 (57%) included abstracts. There was no association between reported estimates of sensitivity and full-text publication (hazard ratio [HR] 1.09 [95% confidence interval {CI} 0.98, 1.22]). The same applied to specificity (HR 1.00 [95% CI 0.88, 1.14]), AUC (HR 0.91 [95% CI 0.75, 1.09]), and DOR (HR 1.01 [95% CI 0.94, 1.09]). Almost half of the ARVO conference abstracts describing diagnostic accuracy studies did not reach full-text publication. Studies in abstracts that mentioned higher accuracy estimates were not more likely to be reported in a full-text publication. Copyright © 2016 Elsevier Inc. All rights reserved.

Study on Top-Down Estimation Method of Software Project Planning

Institute of Scientific and Technical Information of China (English)

ZHANG Jun-guang; L(U) Ting-jie; ZHAO Yu-mei

2006-01-01

This paper studies a new software project planning method under some actual project data in order to make software project plans more effective. From the perspective of system theory, our new method regards a software project plan as an associative unit for study. During a top-down estimation of a software project, Program Evaluation and Review Technique (PERT) method and analogy method are combined to estimate its size, then effort estimation and specific schedules are obtained according to distributions of the phase effort. This allows a set of practical and feasible planning methods to be constructed. Actual data indicate that this set of methods can lead to effective software project planning.

Improving Accuracy of Influenza-Associated Hospitalization Rate Estimates

Science.gov (United States)

Reed, Carrie; Kirley, Pam Daily; Aragon, Deborah; Meek, James; Farley, Monica M.; Ryan, Patricia; Collins, Jim; Lynfield, Ruth; Baumbach, Joan; Zansky, Shelley; Bennett, Nancy M.; Fowler, Brian; Thomas, Ann; Lindegren, Mary L.; Atkinson, Annette; Finelli, Lyn; Chaves, Sandra S.

2015-01-01

Diagnostic test sensitivity affects rate estimates for laboratory-confirmed influenza–associated hospitalizations. We used data from FluSurv-NET, a national population-based surveillance system for laboratory-confirmed influenza hospitalizations, to capture diagnostic test type by patient age and influenza season. We calculated observed rates by age group and adjusted rates by test sensitivity. Test sensitivity was lowest in adults >65 years of age. For all ages, reverse transcription PCR was the most sensitive test, and use increased from 65 years. After 2009, hospitalization rates adjusted by test sensitivity were ≈15% higher for children 65 years of age. Test sensitivity adjustments improve the accuracy of hospitalization rate estimates. PMID:26292017

Estimating the Burden of Maternal and Neonatal Deaths Associated With Jaundice in Bangladesh: Possible Role of Hepatitis E Infection

Science.gov (United States)

Halder, Amal K.; Streatfield, Peter K.; Sazzad, Hossain M.S.; Nurul Huda, Tarique M.; Hossain, M. Jahangir; Luby, Stephen P.

2012-01-01

Objectives. We estimated the population-based incidence of maternal and neonatal mortality associated with hepatitis E virus (HEV) in Bangladesh. Methods. We analyzed verbal autopsy data from 4 population-based studies in Bangladesh to calculate the maternal and neonatal mortality ratios associated with jaundice during pregnancy. We then reviewed the published literature to estimate the proportion of maternal deaths associated with liver disease during pregnancy that were the result of HEV in hospitals. Results. We found that 19% to 25% of all maternal deaths and 7% to 13% of all neonatal deaths in Bangladesh were associated with jaundice in pregnant women. In the published literature, 58% of deaths in pregnant women with acute liver disease in hospitals were associated with HEV. Conclusions. Jaundice is frequently associated with maternal and neonatal deaths in Bangladesh, and the published literature suggests that HEV may cause many of these deaths. HEV is preventable, and studies to estimate the burden of HEV in endemic countries are urgently needed. PMID:23078501

A prospective longitudinal study to estimate the prevalence of ...

African Journals Online (AJOL)

A prospective longitudinal study to estimate the prevalence of obesity in Egyptian children with nocturnal enuresis and the association between body mass index and ... Egyptian Journal of Medical Human Genetics ... Response to the treatment was evaluated statistically and correlated with body mass index percentile.

Associations between Salivary Testosterone Levels, Androgen‐Related Genetic Polymorphisms, and Self‐Estimated Ejaculation Latency Time

Directory of Open Access Journals (Sweden)

Patrick Jern, PhD

2014-08-01

Conclusions: We were unable to find support for the hypothesis suggesting an association between T levels and ELT, possibly because of the low number of phenotypically extreme cases (the sample used in the present study was population based. Our results concerning genetic associations should be interpreted with caution until replication studies have been conducted. Jern P, Westberg L, Ankarberg‐Lindgren C, Johansson A, Gunst A, Sandnabba NK, and Santtila P. Associations between salivary testosterone levels, androgen‐related genetic polymorphisms, and self‐estimated ejaculation latency time. Sex Med 2014;2:107–114.

Preliminary estimates of the abundance and fidelity of dolphins associating with a demersal trawl fishery.

Science.gov (United States)

Allen, Simon J; Pollock, Kenneth H; Bouchet, Phil J; Kobryn, Halina T; McElligott, Deirdre B; Nicholson, Krista E; Smith, Joshua N; Loneragan, Neil R

2017-07-10

The incidental capture of wildlife in fishing gear presents a global conservation challenge. As a baseline to inform assessments of the impact of bycatch on bottlenose dolphins (Tursiops truncatus) interacting with an Australian trawl fishery, we conducted an aerial survey to estimate dolphin abundance across the fishery. Concurrently, we carried out boat-based dolphin photo-identification to assess short-term fidelity to foraging around trawlers, and used photographic and genetic data to infer longer-term fidelity to the fishery. We estimated abundance at ≈ 2,300 dolphins (95% CI = 1,247-4,214) over the ≈ 25,880-km 2 fishery. Mark-recapture estimates yielded 226 (SE = 38.5) dolphins associating with one trawler and some individuals photographed up to seven times over 12 capture periods. Moreover, photographic and genetic re-sampling over three years confirmed that some individuals show long-term fidelity to trawler-associated foraging. Our study presents the first abundance estimate for any Australian pelagic dolphin community and documents individuals associating with trawlers over days, months and years. Without trend data or correction factors for dolphin availability, the impact of bycatch on this dolphin population's conservation status remains unknown. These results should be taken into account by management agencies assessing the impact of fisheries-related mortality on this protected species.

Genome-wide association study identifies 74 loci associated with educational attainment

NARCIS (Netherlands)

A. Okbay (Aysu); J.P. Beauchamp (Jonathan); Fontana, M.A. (Mark Alan); J.J. Lee (James J.); T.H. Pers (Tune); Rietveld, C.A. (Cornelius A.); P. Turley (Patrick); Chen, G.-B. (Guo-Bo); V. Emilsson (Valur); Meddens, S.F.W. (S. Fleur W.); Oskarsson, S. (Sven); Pickrell, J.K. (Joseph K.); Thom, K. (Kevin); Timshel, P. (Pascal); R. de Vlaming (Ronald); A. Abdellaoui (Abdel); T.S. Ahluwalia (Tarunveer Singh); J. Bacelis (Jonas); C. Baumbach (Clemens); Bjornsdottir, G. (Gyda); J.H. Brandsma (Johan); Pina Concas, M. (Maria); J. Derringer; Furlotte, N.A. (Nicholas A.); T.E. Galesloot (Tessel); S. Girotto; Gupta, R. (Richa); L.M. Hall (Leanne M.); S.E. Harris (Sarah); E. Hofer; Horikoshi, M. (Momoko); J.E. Huffman (Jennifer E.); Kaasik, K. (Kadri); I.-P. Kalafati (Ioanna-Panagiota); R. Karlsson (Robert); A. Kong (Augustine); J. Lahti (Jari); S.J. van der Lee (Sven); Deleeuw, C. (Christiaan); P.A. Lind (Penelope); Lindgren, K.-O. (Karl-Oskar); Liu, T. (Tian); M. Mangino (Massimo); J. Marten (Jonathan); E. Mihailov (Evelin); M. Miller (Mike); P.J. van der Most (Peter); C. Oldmeadow (Christopher); A. Payton (Antony); N. Pervjakova (Natalia); W.J. Peyrot (Wouter ); Qian, Y. (Yong); O. Raitakari (Olli); Rueedi, R. (Rico); Salvi, E. (Erika); Schmidt, B. (Börge); Schraut, K.E. (Katharina E.); Shi, J. (Jianxin); A.V. Smith (Albert Vernon); R.A. Poot (Raymond); B. St Pourcain (Beate); A. Teumer (Alexander); G. Thorleifsson (Gudmar); N. Verweij (Niek); D. Vuckovic (Dragana); Wellmann, J. (Juergen); H.J. Westra (Harm-Jan); Yang, J. (Jingyun); Zhao, W. (Wei); Zhu, Z. (Zhihong); B.Z. Alizadeh (Behrooz); N. Amin (Najaf); Bakshi, A. (Andrew); S.E. Baumeister (Sebastian); G. Biino (Ginevra); K. Bønnelykke (Klaus); P.A. Boyle (Patricia); H. Campbell (Harry); Cappuccio, F.P. (Francesco P.); G. Davies (Gail); J.E. de Neve (Jan-Emmanuel); P. Deloukas (Panagiotis); I. Demuth (Ilja); Ding, J. (Jun); Eibich, P. (Peter); Eisele, L. (Lewin); N. Eklund (Niina); D.M. Evans (David); J.D. Faul (Jessica D.); M.F. Feitosa (Mary Furlan); A.J. Forstner (Andreas); I. Gandin (Ilaria); Gunnarsson, B. (Bjarni); B.V. Halldorsson (Bjarni); T.B. Harris (Tamara); E.G. Holliday (Elizabeth); A.C. Heath (Andrew C.); L.J. Hocking; G. Homuth (Georg); M. Horan (Mike); J.J. Hottenga (Jouke Jan); P.L. de Jager (Philip); P.K. Joshi (Peter); A. Juqessur (Astanand); M. Kaakinen (Marika); M. Kähönen (Mika); S. Kanoni (Stavroula); Keltigangas-Järvinen, L. (Liisa); L.A.L.M. Kiemeney (Bart); I. Kolcic (Ivana); Koskinen, S. (Seppo); A. Kraja (Aldi); Kroh, M. (Martin); Z. Kutalik (Zoltán); A. Latvala (Antti); L.J. Launer (Lenore); Lebreton, M.P. (Maël P.); D.F. Levinson (Douglas F.); P. Lichtenstein (Paul); P. Lichtner (Peter); D.C. Liewald (David C.); A. Loukola (Anu); P.A. Madden (Pamela); R. Mägi (Reedik); Mäki-Opas, T. (Tomi); R.E. Marioni (Riccardo); P. Marques-Vidal; Meddens, G.A. (Gerardus A.); G. Mcmahon (George); C. Meisinger (Christa); T. Meitinger (Thomas); Milaneschi, Y. (Yusplitri); L. Milani (Lili); G.W. Montgomery (Grant); R. Myhre (Ronny); C.P. Nelson (Christopher P.); D.R. Nyholt (Dale); W.E.R. Ollier (William); A. Palotie (Aarno); L. Paternoster (Lavinia); N.L. Pedersen (Nancy); K. Petrovic (Katja); D.J. Porteous (David J.); K. Räikkönen (Katri); Ring, S.M. (Susan M.); A. Robino (Antonietta); O. Rostapshova (Olga); I. Rudan (Igor); A. Rustichini (Aldo); V. Salomaa (Veikko); Sanders, A.R. (Alan R.); A.-P. Sarin; R. Schmidt (Reinhold); R.J. Scott (Rodney); B.H. Smith (Blair); J.A. Smith (Jennifer A); J.A. Staessen (Jan); E. Steinhagen-Thiessen (Elisabeth); K. Strauch (Konstantin); A. Terracciano; M.D. Tobin (Martin); S. Ulivi (Shelia); S. Vaccargiu (Simona); L. Quaye (Lydia); F.J.A. van Rooij (Frank); C. Venturini (Cristina); A.A.E. Vinkhuyzen (Anna A.); U. Völker (Uwe); Völzke, H. (Henry); J.M. Vonk (Judith); D. Vozzi (Diego); J. Waage (Johannes); E.B. Ware (Erin B.); G.A.H.M. Willemsen (Gonneke); J. Attia (John); D.A. Bennett (David A.); Berger, K. (Klaus); L. Bertram (Lars); H. Bisgaard (Hans); D.I. Boomsma (Dorret); I.B. Borecki (Ingrid); U. Bültmann (Ute); C.F. Chabris (Christopher F.); F. Cucca (Francesco); D. Cusi (Daniele); I.J. Deary (Ian J.); G.V. Dedoussis (George); C.M. van Duijn (Cornelia); K. Hagen (Knut); B. Franke (Barbara); L. Franke (Lude); P. Gasparini (Paolo); P.V. Gejman (Pablo); C. Gieger (Christian); H.J. Grabe (Hans Jörgen); J. Gratten (Jacob); P.J.F. Groenen (Patrick); V. Gudnason (Vilmundur); P. van der Harst (Pim); C. Hayward (Caroline); D.A. Hinds (David A.); W. Hoffmann (Wolfgang); E. Hypponen (Elina); W.G. Iacono (William); B. Jacobsson (Bo); M.-R. Jarvelin (Marjo-Riitta); K.-H. JöCkel (Karl-Heinz); J. Kaprio (Jaakko); S.L.R. Kardia (Sharon); T. Lehtimäki (Terho); Lehrer, S.F. (Steven F.); P.K. Magnusson (Patrik); N.G. Martin (Nicholas); M. McGue (Matt); A. Metspalu (Andres); N. Pendleton (Neil); B.W.J.H. Penninx (Brenda); M. Perola (Markus); N. Pirastu (Nicola); M. Pirastu (Mario); O. Polasek (Ozren); D. Posthuma (Danielle); C. Power (Christopher); M.A. Province (Mike); N.J. Samani (Nilesh); Schlessinger, D. (David); R. Schmidt (Reinhold); T.I.A. Sørensen (Thorkild); T.D. Spector (Timothy); J-A. Zwart (John-Anker); U. Thorsteinsdottir (Unnur); A.R. Thurik (Roy); Timpson, N.J. (Nicholas J.); H.W. Tiemeier (Henning); J.Y. Tung (Joyce Y.); A.G. Uitterlinden (André); Vitart, V. (Veronique); P. Vollenweider (Peter); D.R. Weir (David); J.F. Wilson (James F.); A.F. Wright (Alan); Conley, D.C. (Dalton C.); R.F. Krueger; G.D. Smith; Hofman, A. (Albert); D. Laibson (David); S.E. Medland (Sarah Elizabeth); M.N. Meyer (Michelle N.); J. Yang (Joanna); M. Johannesson (Magnus); P.M. Visscher (Peter); T. Esko (Tõnu); Ph.D. Koellinger (Philipp); D. Cesarini (David); D.J. Benjamin (Daniel J.)

2016-01-01

textabstractEducational attainment is strongly influenced by social and other environmental factors, but genetic factors are estimated to account for at least 20% of the variation across individuals. Here we report the results of a genome-wide association study (GWAS) for educational attainment that

Genome-wide association study identifies 74 loci associated with educational attainment

NARCIS (Netherlands)

Okbay, A.; Beauchamp, J.; Fontana, M.A.; Lee, J.J.; Pers, T.H.; Rietveld, C.A.; Turley, P.; Chen, G.B.; Emilsson, V.; Meddens, S.F.W.; de Vlaming, R.; Abdellaoui, A.; Peyrot, W.; Vinkhuyzen, A.A.E.; Hottenga, J.J.; Willemsen, G.; Boomsma, D.I.; Penninx, B.W.J.H.; Laibson, D.; Medland, S.E.; Meyer, M.N.; Yang, J.; Johannesson, M.; Visscher, P.M.; Esko, T.; Koellinger, P.D.; Cesarini, D.; Benjamin, D.J.

2016-01-01

Educational attainment is strongly influenced by social and other environmental factors, but genetic factors are estimated to account for at least 20% of the variation across individuals. Here we report the results of a genome-wide association study (GWAS) for educational attainment that extends our

Genome-wide association study identifies 74 loci associated with educational attainment

NARCIS (Netherlands)

Okbay, Aysu; Beauchamp, Jonathan P.; Fontana, Mark Alan; Lee, James J.; Pers, Tune H.; Rietveld, Cornelius A.; Turley, Patrick; Chen, Guo-Bo; Emilsson, Valur; Meddens, S. Fleur W.; Oskarsson, Sven; Pickrell, Joseph K.; Thom, Kevin; Timshel, Pascal; de Vlaming, Ronald; Abdellaoui, Abdel; Ahluwalia, Tarunveer S.; Bacelis, Jonas; Baumbach, Clemens; Bjornsdottir, Gyda; Brandsma, Johannes H.; Concas, Maria Pina; Derringer, Jaime; Furlotte, Nicholas A.; Galesloot, Tessel E.; Girotto, Giorgia; Gupta, Richa; Hall, Leanne M.; Harris, Sarah E.; Hofer, Edith; Horikoshi, Momoko; Huffman, Jennifer E.; Kaasik, Kadri; Kalafati, Ioanna P.; Karlsson, Robert; Kong, Augustine; Lahti, Jari; van der Lee, Sven J.; de Leeuw, Christiaan; Lind, Penelope A.; Lindgren, Karl-Oskar; Liu, Tian; van der Most, Peter J.; Verweij, Niek; Alizadeh, Behrooz Z.; Vonk, Judith M.; Bultmann, Ute; Franke, Lude; van der Harst, Pim; Penninx, Brenda W. J. H.

2016-01-01

Educational attainment is strongly influenced by social and other environmental factors, but genetic factors are estimated to account for at least 20% of the variation across individuals(1). Here we report the results of a genome-wide association study (GWAS) for educational attainment that extends

Genome-association analysis of Korean Holstein milk traits using genomic estimated breeding value

Directory of Open Access Journals (Sweden)

Donghyun Shin

2017-03-01

Full Text Available Objective Holsteins are known as the world’s highest-milk producing dairy cattle. The purpose of this study was to identify genetic regions strongly associated with milk traits (milk production, fat, and protein using Korean Holstein data. Methods This study was performed using single nucleotide polymorphism (SNP chip data (Illumina BovineSNP50 Beadchip of 911 Korean Holstein individuals. We inferred each genomic estimated breeding values based on best linear unbiased prediction (BLUP and ridge regression using BLUPF90 and R. We then performed a genome-wide association study and identified genetic regions related to milk traits. Results We identified 9, 6, and 17 significant genetic regions related to milk production, fat and protein, respectively. These genes are newly reported in the genetic association with milk traits of Holstein. Conclusion This study complements a recent Holstein genome-wide association studies that identified other SNPs and genes as the most significant variants. These results will help to expand the knowledge of the polygenic nature of milk production in Holsteins.

Estimate of the economy-wide financial risk associated with a serious nuclear reactor accident

International Nuclear Information System (INIS)

Heising, C.D.; George, V.P.

1985-01-01

Since the accident at Three Mile Island, considerable attention has focused on the financial risks associated with nuclear reactor accidents. Previous studies have calculated the plant-specific financial risk due to primarily off-site consequences, including most probabilistic risk assessments (PRAs) beginning first with the Reactor Safety Study. Previous studies, however, have not studied the possible economy-wide costs of a severe reactor accident due to such considerations as adverse public opinion, enhanced concern in the financial community, and, particularly, regulatory constraints placed on the industry subsequent to an accident. These considerations could lead to a spectrum of scenarios, including partial or complete nuclear moratoria, which may have far reaching economy-wide effects. It is the purpose of this study to provide an estimate of these effects, and to compare these estimates with the plant-specific financial risks calculated earlier by others. First, a model is presented for including the impact of various regulatory response options on the nuclear industry, followed by a discussion of how the economy-wide costs associated with these options may be calculated. Then, results of series of calculations are presented, and finally, conclusions are given

Arm-associated measurements as estimates of true height in black ...

African Journals Online (AJOL)

arm-associated measurements to true height included that of the World Health ... Conclusion: Findings indicate the need for gender and race-specific height estimation ..... New. York, NY: Springer; 2012. 12. Golshan M, Amra B, Hoghoghi MA.

Estimates of Maternal Mortality Ratio and the associated medical causes in Orissa and Rajasthan States - A cross sectional study

Directory of Open Access Journals (Sweden)

Abha Rani Aggarwal

2015-03-01

Full Text Available Background: Maternal Mortality Ratio (MMR is an important indicator of reproductive health and its reduction remains a challenge in India. Aims &Objective: This study was conducted with the aim of estimating MMR in two states Orissa and Rajasthan having high MMR as well as to identify the associated medical causes of maternal mortality. Material Methods: This survey was conducted from October 2010-June 2012 on a sample of 13 Primary Health Centres (PHCs in Orissa and 15 PHCs in Rajasthan. These numbers have been derived after estimating the total number of live births using MMR and birth rate from Sample Registration System. 1997-2003.An adapted snowball technique was adopted wherein maternal deaths were captured by snowball technique and the numbers of live births were taken from the available records from the various health facilities in the study.  Results: The overall birth rate in Orissa was found to be 19 per 1000 population while in Rajasthan it was 24 per 1000 population. The study revealed that 17% additional maternal deaths could be captured by snowball technique as against the official record. The overall weighted estimate of MMR was 252 per one lakh live births (95% CI: 246-259 per 1,00,000 live births in Orissa and 209 per one lakh live births (95% CI: 207-211 per one lakh live births in Rajasthan. The main causes of maternal deaths were post-partum haemorrhage, anaemia and septicaemia. More than 25% maternal deaths could be attributed to indirect causes including suicide, accident and infectious diseases. Conclusion: There appears to be a positive trend towards reduction of maternal mortality in Orissa and Rajasthan. Greater care is essential to reduce medical as well as incidental causes of death during pregnancy.

Estimates of Maternal Mortality Ratio and the associated medical causes in Orissa and Rajasthan States - A cross sectional study

Directory of Open Access Journals (Sweden)

Abha Rani Aggarwal

2015-03-01

Full Text Available Background: Maternal Mortality Ratio (MMR is an important indicator of reproductive health and its reduction remains a challenge in India. Aims &Objective: This study was conducted with the aim of estimating MMR in two states Orissa and Rajasthan having high MMR as well as to identify the associated medical causes of maternal mortality. Material Methods: This survey was conducted from October 2010-June 2012 on a sample of 13 Primary Health Centres (PHCs in Orissa and 15 PHCs in Rajasthan. These numbers have been derived after estimating the total number of live births using MMR and birth rate from Sample Registration System. 1997-2003.An adapted snowball technique was adopted wherein maternal deaths were captured by snowball technique and the numbers of live births were taken from the available records from the various health facilities in the study.  Results: The overall birth rate in Orissa was found to be 19 per 1000 population while in Rajasthan it was 24 per 1000 population. The study revealed that 17% additional maternal deaths could be captured by snowball technique as against the official record. The overall weighted estimate of MMR was 252 per one lakh live births (95% CI: 246-259 per 1,00,000 live births in Orissa and 209 per one lakh live births (95% CI: 207-211 per one lakh live births in Rajasthan. The main causes of maternal deaths were post-partum haemorrhage, anaemia and septicaemia. More than 25% maternal deaths could be attributed to indirect causes including suicide, accident and infectious diseases. Conclusion: There appears to be a positive trend towards reduction of maternal mortality in Orissa and Rajasthan. Greater care is essential to reduce medical as well as incidental causes of death during pregnancy.

Integration of external estimated breeding values and associated reliabilities using correlations among traits and effects

NARCIS (Netherlands)

Vandenplas, J.; Colinet, F.G.; Glorieux, G.; Bertozzi, C.; Gengler, N.

2015-01-01

Based on a Bayesian view of linear mixed models, several studies showed the possibilities to integrate estimated breeding values (EBV) and associated reliabilities (REL) provided by genetic evaluations performed outside a given evaluation system into this genetic evaluation. Hereafter, the term

Estimation of Damage Costs Associated with Flood Events

Science.gov (United States)

Andrews, T. A.; Wauthier, C.; Zipp, K.

2017-12-01

This study investigates the possibility of creating a mathematical function that enables the estimation of flood-damage costs. We begin by examining the costs associated with past flood events in the United States. The data on these tropical storms and hurricanes are provided by the National Oceanic and Atmospheric Administration. With the location, extent of flooding, and damage reparation costs identified, we analyze variables such as: number of inches rained, land elevation, type of landscape, region development in regards to building density and infrastructure, and population concentration. We seek to identify the leading drivers of high flood-damage costs and understand which variables play a large role in the costliness of these weather events. Upon completion of our mathematical analysis, we turn out attention to the 2017 natural disaster of Texas. We divide the region, as we did above, by land elevation, type of landscape, region development in regards to building density and infrastructure, and population concentration. Then, we overlay the number of inches rained in those regions onto the divided landscape and apply our function. We hope to use these findings to estimate the potential flood-damage costs of Hurricane Harvey. This information is then transformed into a hazard map that could provide citizens and businesses of flood-stricken zones additional resources for their insurance selection process.

Estimates o the risks associated with dam failure

Energy Technology Data Exchange (ETDEWEB)

Ayyaswamy, P.; Hauss, B.; Hseih, T.; Moscati, A.; Hicks, T.E.; Okrent, D.

1974-03-01

The probabilities and potential consequences of dam failure in California, primarily due to large earthquakes, was estimated, taking as examples eleven dams having a relatively large population downstream. Mortalities in the event of dam failure range from 11,000 to 260,000, while damage to property may be as high as $720 million. It was assumed that an intensity IX or X earthquake (on the Modified Mercalli Scale) would be sufficient to completely fail earthen dams. Predictions of dam failure were based on the recurrence times of such earthquakes. For the dams studied, the recurrence intervals for an intensity IX earthquake varied between 20 and 800 years; for an intensity X between 50 and 30,000 years. For the Lake Chabot and San Pablo dams (respectively 20, 30 years recurrent earthquake times for a intensity X) the associated consequences are: 34,000 (Lake Chabot) and 30,000 (San Pablo) people killed; damage $140 million and $77 million. Evaculation was found to ameliorate the consequences slightly in most cases because of the short time available. Calculations are based on demography, and assume 10 foot floodwaters will drown all in their path and destroy all one-unit homes in the flood area. Damage estimates reflect losses incurred by structural damage to buildings and do not include loss of income. Hence the economic impact is probably understated.

On estimation of time-dependent attributable fraction from population-based case-control studies.

Science.gov (United States)

Zhao, Wei; Chen, Ying Qing; Hsu, Li

2017-09-01

Population attributable fraction (PAF) is widely used to quantify the disease burden associated with a modifiable exposure in a population. It has been extended to a time-varying measure that provides additional information on when and how the exposure's impact varies over time for cohort studies. However, there is no estimation procedure for PAF using data that are collected from population-based case-control studies, which, because of time and cost efficiency, are commonly used for studying genetic and environmental risk factors of disease incidences. In this article, we show that time-varying PAF is identifiable from a case-control study and develop a novel estimator of PAF. Our estimator combines odds ratio estimates from logistic regression models and density estimates of the risk factor distribution conditional on failure times in cases from a kernel smoother. The proposed estimator is shown to be consistent and asymptotically normal with asymptotic variance that can be estimated empirically from the data. Simulation studies demonstrate that the proposed estimator performs well in finite sample sizes. Finally, the method is illustrated by a population-based case-control study of colorectal cancer. © 2017, The International Biometric Society.

Estimates of state-level health-care expenditures associated with disability.

Science.gov (United States)

Anderson, Wayne L; Armour, Brian S; Finkelstein, Eric A; Wiener, Joshua M

2010-01-01

We estimated state-level disability-associated health-care expenditures (DAHE) for the U.S. adult population. We used a two-part model to estimate DAHE for the noninstitutionalized U.S. civilian adult population using data from the 2002-2003 Medical Expenditure Panel Survey and state-level data from the Behavioral Risk Factor Surveillance System. Administrative data for people in institutions were added to generate estimates for the total adult noninstitutionalized population. Individual-level data on total health-care expenditures along with demographic, socioeconomic, geographic, and payer characteristics were used in the models. The DAHE for all U.S. adults totaled $397.8 billion in 2006, with state expenditures ranging from $598 million in Wyoming to $40.1 billion in New York. Of the national total, the DAHE were $118.9 billion for the Medicare population, $161.1 billion for Medicaid recipients, and $117.8 billion for the privately insured and uninsured populations. For the total U.S. adult population, 26.7% of health-care expenditures were associated with disability, with proportions by state ranging from 16.9% in Hawaii to 32.8% in New York. This proportion varied greatly by payer, with 38.1% for Medicare expenditures, 68.7% for Medicaid expenditures, and 12.5% for nonpublic health-care expenditures associated with disability. DAHE vary greatly by state and are borne largely by the public sector, and particularly by Medicaid. Policy makers need to consider initiatives that will help reduce the prevalence of disabilities and disability-related health disparities, as well as improve the lives of people with disabilities.

EOQ estimation for imperfect quality items using association rule mining with clustering

Directory of Open Access Journals (Sweden)

Mandeep Mittal

2015-09-01

Full Text Available Timely identification of newly emerging trends is needed in business process. Data mining techniques like clustering, association rule mining, classification, etc. are very important for business support and decision making. This paper presents a method for redesigning the ordering policy by including cross-selling effect. Initially, association rules are mined on the transactional database and EOQ is estimated with revenue earned. Then, transactions are clustered to obtain homogeneous clusters and association rules are mined in each cluster to estimate EOQ with revenue earned for each cluster. Further, this paper compares ordering policy for imperfect quality items which is developed by applying rules derived from apriori algorithm viz. a without clustering the transactions, and b after clustering the transactions. A numerical example is illustrated to validate the results.

Genome-wide association study of swine farrowing traits. Part I: genetic and genomic parameter estimates.

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Schneider, J F; Rempel, L A; Rohrer, G A

2012-10-01

The primary objective of this study was to determine genetic and genomic parameters among swine (Sus scrofa) farrowing traits. Genetic parameters were obtained using MTDFREML. Genomic parameters were obtained using GENSEL. Genetic and residual variances obtained from MTDFREML were used as priors for the Bayes C analysis of GENSEL. Farrowing traits included total number born (TNB), number born alive (NBA), number born dead (NBD), number stillborn (NSB), number of mummies (MUM), litter birth weight (LBW), and average piglet birth weight (ABW). Statistically significant heritabilities included TNB (0.09, P = 0.048), NBA (0.09, P = 0.041), LBW (0.20, P = 0.002), and ABW (0.26, P NBA (0.97, P NBA-LBW (0.56, P NBA (0.06), NBD (0.00), NSB (0.01), MUM (0.00), LBW (0.11), and ABW (0.31). Limited information is available in the literature about genomic parameters. Only the GP estimate for NSB is significantly lower than what has been published. The GP estimate for ABW is greater than the estimate for heritability found in this study. Other traits with significant heritability had GP estimates half the value of heritability. This research indicates that significant genetic markers will be found for TNB, NBA, LBW, and ABW that will have either immediate use in industry or provide a roadmap to further research with fine mapping or sequencing of areas of significance. Furthermore, these results indicate that genomic selection implemented at an early age would have similar annual progress as traditional selection, and could be incorporated along with traditional selection procedures to improve genetic progress of litter traits.

The associations between birth outcomes and satellite-estimated maternal PM2.5 exposure in Shanghai, China

Science.gov (United States)

Xiao, Q.; Liu, Y.; Strickland, M. J.; Chang, H. H.; Kan, H.

2017-12-01

Background: Satellite remote sensing data have been employed for air pollution exposure assessment, with the intent of better characterizing exposure spatio-temproal variations. However, non-random missingness in satellite data may lead to exposure error. Objectives: We explored the differences in health effect estimates due to different exposure metrics, with and without satellite data, when analyzing the associations between maternal PM2.5 exposure and birth outcomes. Methods: We obtained birth registration records of 132,783 singleton live births during 2011-2014 in Shanghai. Trimester-specific and total pregnancy exposures were estimated from satellite PM2.5 predictions with missingness, gap-filled satellite PM2.5 predictions with complete coverage and regional average PM2.5 measurements from monitoring stations. Linear regressions estimated associations between birth weight and maternal PM2.5 exposure. Logistic regressions estimated associations between preterm birth and the first and second trimester exposure. Discrete-time models estimated third trimester and total pregnancy associations with preterm birth. Effect modifications by maternal age and parental education levels were investigated. Results: we observed statistically significant associations between maternal PM2.5 exposure during all exposure windows and adverse birth outcomes. A 10 µg/m3 increase in pregnancy PM2.5 exposure was associated with a 12.85 g (95% CI: 18.44, 7.27) decrease in birth weight for term births, and a 27% (95% CI: 20%, 36%) increase in the risk of preterm birth. Greater effects were observed between first and third trimester exposure and birth weight, as well as between first trimester exposure and preterm birth. Mothers older than 35 years and without college education tended to have higher associations with preterm birth. Conclusions: Gap-filled satellite data derived PM2.5 exposure estimates resulted in reduced exposure error and more precise health effect estimates.

Association of blood lead and mercury with estimated GFR in herbalists after the ban of herbs containing aristolochic acids in Taiwan.

Science.gov (United States)

Lin, Hsing-Hua; Chou, Shan-An; Yang, Hsiao-Yu; Hwang, Yaw-Huei; Kuo, Ching-Hua; Kao, Tze-Wah; Lo, Tsai-Chang; Chen, Pau-Chung

2013-08-01

This study was undertaken to explore the association of estimated glomerular filtration rate (GFR) with exposure to aristolochic acids (ALAs) and nephrotoxic metals in herbalists after the ban of herbs containing ALAs in Taiwan. This cross-sectional study recruited a total of 138 herbalists without end-stage renal disease or urothelial carcinoma from the Occupational Union of Chinese Herbalists in Taiwan in 2007. Aristolochic acid I (ALA-I) was measured by ultra-high-pressure liquid chromatography/ tandem mass spectrometry (UHPLC-MS/MS) and heavy metals in blood samples were analysed by Agilent 7500C inductively coupled plasma-mass spectrometry. Renal function was assessed by using a simplified Modification of Diet in Renal Disease Study equation to estimate GFR. Blood lead was higher in herbal dispensing procedures (p=0.053) and in subjects who self-prescribe herbal medicine (p=0.057); mercury was also higher in subjects living in the workplace (p=0.03). Lower estimated GFR was significantly associated with lead (β=-10.66, 95% CI -18.7 to -2.6) and mercury (β=-12.52, 95% CI -24.3 to -0.8) with a significant interaction (p=0.01) between mercury and lead; however, estimated GFR was not significantly associated with high ALA-I level groups, arsenic and cadmium after adjusting for other confounding factors. We found that lower estimated GFR was associated with blood lead and mercury in herbalists after the ban of herbs containing ALAs in Taiwan. The ALA-I exposure did not show a significant negative association of estimated GFR, which might due to herbalists having known how to distinguish ALA herbs after the banning policy. Rigorous monitoring is still needed to protect herbalists and the general population who take herbs.

Associations between the intake of miso soup and Japanese pickles and the estimated 24-hour urinary sodium excretion: a population-based cross-sectional study.

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Wakasugi, Minako; James Kazama, Junichiro; Narita, Ichiei

2015-01-01

In Japan, reducing the consumption of miso soup and Japanese pickles, both traditional Japanese dishes, is recommended in order to decrease dietary salt intake. With the Westernization of dietary habits, however, these dishes are now consumed less frequently, and thus a reduction in their effect on sodium intake is suspected. This study examined cross-sectional associations between the frequency of intake of miso soup and Japanese pickles and the estimated 24-hour urine sodium excretion using data obtained from health examination surveys conducted in 2013 in Sado City, Japan. The level of daily salt intake was estimated based on spot urine sodium and creatinine measurements. The frequency of intake of miso soup and Japanese pickles was determined using a self-reported questionnaire. Multiple linear regression models were used to assess associations. Among a total of 8,821 participants (3,956 men; age range, 19-97 years), the mean daily salt intake was 9.4 g/day. The frequency of intake of miso soup and Japanese pickles increased with age and was associated with the level of daily salt intake (p for trend soup (psoup and Japanese pickles may be an effective approach for decreasing the level of dietary salt intake in the general Japanese population, although not in octogenarians or nonagenarians.

[Estimation of the excess of lung cancer mortality risk associated to environmental tobacco smoke exposure of hospitality workers].

Science.gov (United States)

López, M José; Nebot, Manel; Juárez, Olga; Ariza, Carles; Salles, Joan; Serrahima, Eulàlia

2006-01-14

To estimate the excess lung cancer mortality risk associated with environmental tobacco (ETS) smoke exposure among hospitality workers. The estimation was done using objective measures in several hospitality settings in Barcelona. Vapour phase nicotine was measured in several hospitality settings. These measurements were used to estimate the excess lung cancer mortality risk associated with ETS exposure for a 40 year working life, using the formula developed by Repace and Lowrey. Excess lung cancer mortality risk associated with ETS exposure was higher than 145 deaths per 100,000 workers in all places studied, except for cafeterias in hospitals, where excess lung cancer mortality risk was 22 per 100,000. In discoteques, for comparison, excess lung cancer mortality risk is 1,733 deaths per 100,000 workers. Hospitality workers are exposed to ETS levels related to a very high excess lung cancer mortality risk. These data confirm that ETS control measures are needed to protect hospital workers.

Shrinkage Estimators for Robust and Efficient Inference in Haplotype-Based Case-Control Studies

KAUST Repository

Chen, Yi-Hau; Chatterjee, Nilanjan; Carroll, Raymond J.

2009-01-01

Case-control association studies often aim to investigate the role of genes and gene-environment interactions in terms of the underlying haplotypes (i.e., the combinations of alleles at multiple genetic loci along chromosomal regions). The goal of this article is to develop robust but efficient approaches to the estimation of disease odds-ratio parameters associated with haplotypes and haplotype-environment interactions. We consider "shrinkage" estimation techniques that can adaptively relax the model assumptions of Hardy-Weinberg-Equilibrium and gene-environment independence required by recently proposed efficient "retrospective" methods. Our proposal involves first development of a novel retrospective approach to the analysis of case-control data, one that is robust to the nature of the gene-environment distribution in the underlying population. Next, it involves shrinkage of the robust retrospective estimator toward a more precise, but model-dependent, retrospective estimator using novel empirical Bayes and penalized regression techniques. Methods for variance estimation are proposed based on asymptotic theories. Simulations and two data examples illustrate both the robustness and efficiency of the proposed methods.

Shrinkage Estimators for Robust and Efficient Inference in Haplotype-Based Case-Control Studies

KAUST Repository

Chen, Yi-Hau

2009-03-01

Case-control association studies often aim to investigate the role of genes and gene-environment interactions in terms of the underlying haplotypes (i.e., the combinations of alleles at multiple genetic loci along chromosomal regions). The goal of this article is to develop robust but efficient approaches to the estimation of disease odds-ratio parameters associated with haplotypes and haplotype-environment interactions. We consider "shrinkage" estimation techniques that can adaptively relax the model assumptions of Hardy-Weinberg-Equilibrium and gene-environment independence required by recently proposed efficient "retrospective" methods. Our proposal involves first development of a novel retrospective approach to the analysis of case-control data, one that is robust to the nature of the gene-environment distribution in the underlying population. Next, it involves shrinkage of the robust retrospective estimator toward a more precise, but model-dependent, retrospective estimator using novel empirical Bayes and penalized regression techniques. Methods for variance estimation are proposed based on asymptotic theories. Simulations and two data examples illustrate both the robustness and efficiency of the proposed methods.

Retinal vessel diameter and estimated cerebrospinal fluid pressure in arterial hypertension: the Beijing Eye Study.

Science.gov (United States)

Jonas, Jost B; Wang, Ningli; Wang, Shuang; Wang, Ya Xing; You, Qi Sheng; Yang, Diya; Wei, Wen Bin; Xu, Liang

2014-09-01

Hypertensive retinal microvascular abnormalities include an increased retinal vein-to-artery diameter ratio. Because central retinal vein pressure depends on cerebrospinal fluid pressure (CSFP), we examined whether the retinal vein-to-artery diameter ratio and other retinal hypertensive signs are associated with CSFP. Participants of the population-based Beijing Eye Study (n = 1,574 subjects) underwent measurement of the temporal inferior and superior retinal artery and vein diameter. CSFP was calculated as 0.44 × body mass index (kg/m(2)) + 0.16 × diastolic blood pressure (mm Hg) - 0.18 × age (years) - 1.91. Larger retinal vein diameters and higher vein-to-artery diameter ratios were significantly associated with higher estimated CSFP (P = 0.001) in multivariable analysis. In contrast, temporal inferior retinal arterial diameter was marginally associated (P = 0.03) with estimated CSFP, and temporal superior artery diameter was not significantly associated (P = 0.10) with estimated CSFP; other microvascular abnormalities, such as arteriovenous crossing signs, were also not significantly associated with estimated CSFP. In a reverse manner, higher estimated CSFP as a dependent variable in the multivariable analysis was associated with wider retinal veins and higher vein-to-artery diameter ratio. In the same model, estimated CSFP was not significantly correlated with retinal artery diameters or other retinal microvascular abnormalities. Correspondingly, arterial hypertension was associated with retinal microvascular abnormalities such as arteriovenous crossing signs (P = 0.003), thinner temporal retinal arteries (P arterial hypertension, an increased retinal vein-to-artery diameter ratio depends on elevated CSFP, which is correlated with blood pressure. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Genome-wide association study identifies 74 loci associated with educational attainment

OpenAIRE

Okbay, Aysu; Beauchamp, Jonathan; Fontana, M.A. (Mark Alan); Lee, James J.; Pers, Tune; Rietveld, C.A. (Cornelius A.); Turley, Patrick; Chen, G.-B. (Guo-Bo); Emilsson, Valur; Meddens, S.F.W. (S. Fleur W.); Oskarsson, S. (Sven); Pickrell, J.K. (Joseph K.); Thom, K. (Kevin); Timshel, P. (Pascal); Vlaming, Ronald

2016-01-01

textabstractEducational attainment is strongly influenced by social and other environmental factors, but genetic factors are estimated to account for at least 20% of the variation across individuals. Here we report the results of a genome-wide association study (GWAS) for educational attainment that extends our earlier discovery sample of 101,069 individuals to 293,723 individuals, and a replication study in an independent sample of 111,349 individuals from the UK Biobank. We identify 74 geno...

Consumption of seafood and its estimated heavy metals are associated with lipid profile and oxidative lipid damage on healthy adults from a Spanish Mediterranean area: A cross-sectional study.

Science.gov (United States)

Aranda, N; Valls, R M; Romeu, M; Sánchez-Martos, V; Albaladejo, R; Fernández-Castillejo, S; Nogués, R; Catalán, Ú; Pedret, A; Espinel, A; Delgado, M A; Arija, V; Sola, R; Giralt, M

2017-07-01

The association between the consumption of seafood and its benefits on cardiovascular (CVD) risk can be challenged by its heavy metal (HM) content. This study aimed to explore the association of seafood consumption and its estimated HM contents with the lipid profile and lipid oxidation biomarkers in adults from a Spanish Mediterranean area who do not present risk factors for CVD. In this cross-sectional study, the clinical history, three-day dietary record, lipid profile (LDLc, HDLc, APOB/A, and triglyceride levels), plasma oxidised LDL (oxLDL) and 8-isoprostane levels of 81 adults without risk factors for CVD [43% men, with a mean age of 43.6 years (95%CI: 40.1-47.1)] were assessed. The HM [arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb)] contents of seafood were estimated according to data from analyses of marine species in the same Mediterranean area. Moderate adherence to the Mediterranean diet (score: 4.6 of 9) with a mean seafood consumption of 74.9g/day (95%CI: 59.9-89.9), including 22.7g of shellfish per day (95%CI: 13.5-31.9), was observed. The estimated HM contents were lower than the provisional tolerable weekly intakes (PTWIs): 21.12µg/kg/week As, 0.57µg/kg/week InAs, 0.15µg/kg/week Cd, 1.11µg/kg/week Hg and 0.28µg/kg/week Pb. After adjusting by confounder variables, an increase in shellfish consumption was associated with increases in the levels of LDLc (P=0.013), non-HDLc (P=0.015), APOB/A (P=0.02) and plasma oxLDL (P=0.002). Moreover, an increase in the estimated As and Hg levels in shellfish was associated with an increase in LDLc (P=0.015 and P=0.018, respectively), non-HDLc (Pconsumption, even by a moderate amount, could favour a pro-atherogenic lipid profile and a higher level of oxidised LDL. These associations are likely influenced by the estimated exposure to As and Hg from shellfish despite these values are lower than the PTWIs. Copyright © 2017 Elsevier Inc. All rights reserved.

Parental and Child Factors Associated with Under-Estimation of Children with Excess Weight in Spain.

Science.gov (United States)

de Ruiter, Ingrid; Olmedo-Requena, Rocío; Jiménez-Moleón, José Juan

2017-11-01

Objective Understanding obesity misperception and associated factors can improve strategies to increase obesity identification and intervention. We investigate underestimation of child excess weight with a broader perspective, incorporating perceptions, views, and psychosocial aspects associated with obesity. Methods This study used cross-sectional data from the Spanish National Health Survey in 2011-2012 for children aged 2-14 years who are overweight or obese. Percentages of parental misperceived excess weight were calculated. Crude and adjusted analyses were performed for both child and parental factors analyzing associations with underestimation. Results Two-five year olds have the highest prevalence of misperceived overweight or obesity around 90%. In the 10-14 year old age group approximately 63% of overweight teens were misperceived as normal weight and 35.7 and 40% of obese males and females. Child gender did not affect underestimation, whereas a younger age did. Aspects of child social and mental health were associated with under-estimation, as was short sleep duration. Exercise, weekend TV and videogames, and food habits had no effect on underestimation. Fathers were more likely to misperceive their child´s weight status; however parent's age had no effect. Smokers and parents with excess weight were less likely to misperceive their child´s weight status. Parents being on a diet also decreased odds of underestimation. Conclusions for practice This study identifies some characteristics of both parents and children which are associated with under-estimation of child excess weight. These characteristics can be used for consideration in primary care, prevention strategies and for further research.

Estimation of transient increases in bleeding risk associated with physical activity in children with haemophilia

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Latimer Jane

2008-06-01

Full Text Available Abstract Background Although it is widely appreciated that vigorous physical activity can increase the risk of bleeding episodes in children with haemophilia, the magnitude of the increase in risk is not known. Accurate risk estimates could inform decisions made by children with haemophilia and their parents about participation in physical activity and aid the development of optimal prophylactic schedules. The aim of this study is to provide an accurate estimate of the risks of bleeding associated with vigorous physical activity in children with haemophilia. Methods/Design The study will be a case-crossover study nested within a prospective cohort study. Children with moderate or severe haemophilia A or B, recruited from two paediatric haematology departments in Australia, will participate in the study. The child, or the child's parent or guardian, will report bleeding episodes experienced over a 12-month period. Following a bleeding episode, the participant will be interviewed by telephone about exposures to physical activity in the case period (8 hours before the bleed and 2 control periods (an 8 hour period at the same time on the day preceding the bleed and an 8 hour period two days preceding the bleed. Conditional logistic regression will be used to estimate the risk of participating in vigorous physical activity from measures of exposure to physical activity in the case and control periods. Discussion This case-control study will provide estimates of the risk of participation in vigorous physical activity in children with haemophilia.

Estimation of Aerobic Capacity and Determination of Its Associated Factors among Male Workers of Industrial Sector of Shiraz City, 2010

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A. Rajaei Fard

2011-12-01

Full Text Available Background and aims   In order to physiologically fit the job to the worker’s capability, maximum aerobic capacity (VO2-max is used. This study was conducted to estimate VO2-max and determine its associated factors among workers of industrial sector of Shiraz city.   Methods  In this cross-sectional study, 500 healthy male workers employed in Shiraz city industries participated voluntarily. Subjects’ aerobic capacity was assessed by ergocycle test according to Astrand protocol for 6 minutes. A questionnaire consisted of two parts covering demographic, anthropometric and physiological characteristics was used as data collecting tool.   Results    Mean and standard deviation of age of workers was 32.01 and 7.66 years, respectively. Worker’s aerobic capacity was estimated to be 2.69±0.263 1.min-1 . The results showed that there was association between VO2-max and age, weight and BMI while no association was found between VO2-max and height. Also, statistical analysis revealed association between VO2-max and smoking and exercise per week (P<0.05. Nature of work , shift working, job satisfaction and fatigue had no association with aerobic capacity. Based on the results, regression equations were developed for estimation of aerobic capacity.  Conclusion  Aerobic capacity had association with age, weight, BMI, exercise and smoking.  

Genome-wide association study identifies 74 loci associated with educational attainment

DEFF Research Database (Denmark)

Okbay, Aysu; P. Beauchamp, Jonathan; Alan Fontana, Mark

2016-01-01

-nucleotide polymorphisms associated with educational attainment are disproportionately found in genomic regions regulating gene expression in the fetal brain. Candidate genes are preferentially expressed in neural tissue, especially during the prenatal period, and enriched for biological pathways involved in neural......Educational attainment is strongly influenced by social and other environmental factors, but genetic factors are estimated to account for at least 20% of the variation across individuals1. Here we report the results of a genome-wide association study (GWAS) for educational attainment that extends...... development. Our findings demonstrate that, even for a behavioural phenotype that is mostly environmentally determined, a well-powered GWAS identifies replicable associated genetic variants that suggest biologically relevant pathways. Because educational attainment is measured in large numbers of individuals...

Estimation of Rainfall Associated with Typhoons over the Ocean Using TRMM/TMI and Numerical Models

Directory of Open Access Journals (Sweden)

Nan-Ching Yeh

2015-11-01

Full Text Available This study quantitatively estimated the precipitation associated with a typhoon in the northwestern Pacific Ocean by using a physical algorithm which included the Weather Research and Forecasting model, Radiative Transfer for TIROS Operational Vertical Sounder model, and data from the Tropical Rainfall Measuring Mission (TRMM/TRMM Microwave Imager (TMI and TRMM/Precipitation Radar (PR. First, a prior probability distribution function (PDF was constructed using over three million rain rate retrievals from the TRMM/PR data for the period 2002–2010 over the northwestern Pacific Ocean. Subsequently, brightness temperatures for 15 typhoons that occurred over the northwestern Pacific Ocean were simulated using a microwave radiative transfer model and a conditional PDF was obtained for these typhoons. The aforementioned physical algorithm involved using a posterior PDF. A posterior PDF was obtained by combining the prior and conditional PDFs. Finally, the rain rate associated with a typhoon was estimated by inputting the observations of the TMI (attenuation indices at 10, 19, 37 GHz into the posterior PDF (lookup table. Results based on rain rate retrievals indicated that rainband locations with the heaviest rainfall showed qualitatively similar horizontal distributions. The correlation coefficient and root-mean-square error of the rain rate estimation were 0.63 and 4.45 mm·h−1, respectively. Furthermore, the correlation coefficient and root-mean-square error for convective rainfall were 0.78 and 7.25 mm·h−1, respectively, and those for stratiform rainfall were 0.58 and 9.60 mm·h−1, respectively. The main contribution of this study is introducing an approach to quickly and accurately estimate the typhoon precipitation, and remove the need for complex calculations.

High Dietary Sodium Intake Assessed by Estimated 24-h Urinary Sodium Excretion Is Associated with NAFLD and Hepatic Fibrosis.

Science.gov (United States)

Huh, Ji Hye; Lee, Kyong Joo; Lim, Jung Soo; Lee, Mi Young; Park, Hong Jun; Kim, Moon Young; Kim, Jae Woo; Chung, Choon Hee; Shin, Jang Yel; Kim, Hyun-Soo; Kwon, Sang Ok; Baik, Soon Koo

2015-01-01

Although high sodium intake is associated with obesity and hypertension, few studies have investigated the relationship between sodium intake and non-alcoholic fatty liver disease (NAFLD). We evaluated the association between sodium intake assessed by estimated 24-h urinary sodium excretion and NAFLD in healthy Koreans. We analyzed data from 27,433 participants in the Korea National Health and Nutrition Examination Surveys (2008-2010). The total amount of sodium excretion in 24-h urine was estimated using Tanaka's equations from spot urine specimens. Subjects were defined as having NAFLD when they had high scores in previously validated NAFLD prediction models such as the hepatic steatosis index (HSI) and fatty liver index (FLI). BARD scores and FIB-4 were used to define advanced fibrosis in subjects with NAFLD. The participants were classified into three groups according to estimated 24-h urinary excretion tertiles. The prevalence of NAFLD as assessed by both FLI and HSI was significantly higher in the highest estimated 24-h urinary sodium excretion tertile group. Even after adjustment for confounding factors including body fat and hypertension, the association between higher estimated 24-h urinary sodium excretion and NAFLD remained significant (Odds ratios (OR) 1.39, 95% confidence interval (CI) 1.26-1.55, in HSI; OR 1.75, CI 1.39-2.20, in FLI, both P sodium values. High sodium intake was independently associated with an increased risk of NAFLD and advanced liver fibrosis.

Association of type D personality with unhealthy lifestyle, and estimated risk of coronary events in the general Icelandic population.

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Svansdottir, Erla; Denollet, Johan; Thorsson, Bolli; Gudnason, Thorarinn; Halldorsdottir, Sigrun; Gudnason, Vilmundur; van den Broek, Krista C; Karlsson, Hrobjartur D

2013-04-01

Type D personality is associated with an increased morbidity and mortality risk in cardiovascular disease patients, but the mechanisms explaining this risk are unclear. We examined whether Type D was associated with coronary artery disease (CAD) risk factors, estimated risk of developing CAD, and previous cardiac events. Cross-sectional study in the general Icelandic population. A random sample of 4753 individuals (mean age 49.1 ± 12.0 years; 49% men) from the REFINE-Reykjavik study completed assessments for Type D personality and conventional CAD risk factors. Ten-year risk of developing CAD was estimated with the Icelandic risk calculator. Type D personality (22% of sample) was associated with a higher prevalence of hypertension (35 vs. 31%, p = 0.009), but less use of hypertension medication (58 vs. 65%, p = 0.013) in hypertensives, more diabetes (6 vs. 4%, p = 0.023), wider waist circumference (p = 0.007), and elevated body mass index (p = 0.025) and blood lipids (p lifestyle-related CAD risk factors, a higher estimated risk of developing CAD, and higher incidence of previous cardiac events. Unhealthy lifestyles may partly explain the adverse cardiovascular effect of Type D personality.

Proenkephalin, Neutrophil Gelatinase-Associated Lipocalin, and Estimated Glomerular Filtration Rates in Patients With Sepsis.

Science.gov (United States)

Kim, Hanah; Hur, Mina; Lee, Seungho; Marino, Rossella; Magrini, Laura; Cardelli, Patrizia; Struck, Joachim; Bergmann, Andreas; Hartmann, Oliver; Di Somma, Salvatore

2017-09-01

Proenkephalin (PENK) has been suggested as a novel biomarker for kidney function. We investigated the diagnostic and prognostic utility of plasma PENK in comparison with neutrophil gelatinase-associated lipocalin (NGAL) and estimated glomerular filtration rates (eGFR) in septic patients. A total of 167 septic patients were enrolled: 99 with sepsis, 37 with septic shock, and 31 with suspected sepsis. PENK and NGAL concentrations were measured and GFR was estimated by using the isotope dilution mass spectrometry traceable-Modification of Diet in Renal Disease (MDRD) Study and three Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations: CKD-EPI(Cr), CDK-EPI(CysC), and CKD-EPI(Cr-CysC). The PENK, NGAL, and eGFR results were compared according to sepsis severity, presence or absence of acute kidney injury (AKI), and clinical outcomes. The PENK, NGAL, and eGFR results were significantly associated with sepsis severity and differed significantly between patients with and without AKI only in the sepsis group (all Psepsis. © The Korean Society for Laboratory Medicine

Estimated incidence of influenza-associated severe acute respiratory infections in Indonesia, 2013-2016.

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Susilarini, Ni K; Haryanto, Edy; Praptiningsih, Catharina Y; Mangiri, Amalya; Kipuw, Natalie; Tarya, Irmawati; Rusli, Roselinda; Sumardi, Gestafiana; Widuri, Endang; Sembiring, Masri M; Noviyanti, Widya; Widaningrum, Christina; Lafond, Kathryn E; Samaan, Gina; Setiawaty, Vivi

2018-01-01

Indonesia's hospital-based Severe Acute Respiratory Infection (SARI) surveillance system, Surveilans Infeksi Saluran Pernafasan Akut Berat Indonesia (SIBI), was established in 2013. While respiratory illnesses such as SARI pose a significant problem, there are limited incidence-based data on influenza disease burden in Indonesia. This study aimed to estimate the incidence of influenza-associated SARI in Indonesia during 2013-2016 at three existing SIBI surveillance sites. From May 2013 to April 2016, inpatients from sentinel hospitals in three districts of Indonesia (Gunung Kidul, Balikpapan, Deli Serdang) were screened for SARI. Respiratory specimens were collected from eligible inpatients and screened for influenza viruses. Annual incidence rates were calculated using these SIBI-enrolled influenza-positive SARI cases as a numerator, with a denominator catchment population defined through hospital admission survey (HAS) to identify respiratory-coded admissions by age to hospitals in the sentinel site districts. From May 2013 to April 2016, there were 1527 SARI cases enrolled, of whom 1392 (91%) had specimens tested and 199 (14%) were influenza-positive. The overall estimated annual incidence of influenza-associated SARI ranged from 13 to 19 per 100 000 population. Incidence was highest in children aged 0-4 years (82-114 per 100 000 population), followed by children 5-14 years (22-36 per 100 000 population). Incidence rates of influenza-associated SARI in these districts indicate a substantial burden of influenza hospitalizations in young children in Indonesia. Further studies are needed to examine the influenza burden in other potential risk groups such as pregnant women and the elderly. © 2017 The Authors. Influenza and Other Respiratory Viruses. Published by John Wiley & Sons Ltd.

Imputation-based analysis of association studies: candidate regions and quantitative traits.

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Bertrand Servin

2007-07-01

Full Text Available We introduce a new framework for the analysis of association studies, designed to allow untyped variants to be more effectively and directly tested for association with a phenotype. The idea is to combine knowledge on patterns of correlation among SNPs (e.g., from the International HapMap project or resequencing data in a candidate region of interest with genotype data at tag SNPs collected on a phenotyped study sample, to estimate ("impute" unmeasured genotypes, and then assess association between the phenotype and these estimated genotypes. Compared with standard single-SNP tests, this approach results in increased power to detect association, even in cases in which the causal variant is typed, with the greatest gain occurring when multiple causal variants are present. It also provides more interpretable explanations for observed associations, including assessing, for each SNP, the strength of the evidence that it (rather than another correlated SNP is causal. Although we focus on association studies with quantitative phenotype and a relatively restricted region (e.g., a candidate gene, the framework is applicable and computationally practical for whole genome association studies. Methods described here are implemented in a software package, Bim-Bam, available from the Stephens Lab website http://stephenslab.uchicago.edu/software.html.

Improved children's motor learning of the basketball free shooting pattern by associating subjective error estimation and extrinsic feedback.

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Silva, Leandro de Carvalho da; Pereira-Monfredini, Carla Ferro; Teixeira, Luis Augusto

2017-09-01

This study aimed at assessing the interaction between subjective error estimation and frequency of extrinsic feedback in the learning of the basketball free shooting pattern by children. 10- to 12-year olds were assigned to 1 of 4 groups combining subjective error estimation and relative frequency of extrinsic feedback (33% × 100%). Analysis of performance was based on quality of movement pattern. Analysis showed superior learning of the group combining error estimation and 100% feedback frequency, both groups receiving feedback on 33% of trials achieved intermediate results, and the group combining no requirement of error estimation and 100% feedback frequency had the poorest learning. Our results show the benefit of subjective error estimation in association with high frequency of extrinsic feedback in children's motor learning of a sport motor pattern.

Considerations for Pharmacoepidemiological Studies of Drug-Cancer Associations

DEFF Research Database (Denmark)

Pottegård, Anton; Friis, Søren; Stürmer, Til

2018-01-01

and future perspectives. Aspects of data sources include assessment of complete history of drug use and data on dose and duration of drug use, allowing estimates of cumulative exposure. Outcome data from formal cancer registries are preferable, but cancer data from other sources, for example, patient......In this MiniReview, we provide general considerations for the planning and conduct of pharmacoepidemiological studies of associations between drug use and cancer development. We address data sources, study design, assessment of drug exposure, ascertainment of cancer outcomes, confounder adjustment...... or pathology registries, medical records or claims are also suitable. The two principal designs for observational studies evaluating drug-cancer associations are the cohort and case-control designs. A key challenge in studies of drug-cancer associations is the exposure assessment due to the typically long...

Bias analysis applied to Agricultural Health Study publications to estimate non-random sources of uncertainty.

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Lash, Timothy L

2007-11-26

The associations of pesticide exposure with disease outcomes are estimated without the benefit of a randomized design. For this reason and others, these studies are susceptible to systematic errors. I analyzed studies of the associations between alachlor and glyphosate exposure and cancer incidence, both derived from the Agricultural Health Study cohort, to quantify the bias and uncertainty potentially attributable to systematic error. For each study, I identified the prominent result and important sources of systematic error that might affect it. I assigned probability distributions to the bias parameters that allow quantification of the bias, drew a value at random from each assigned distribution, and calculated the estimate of effect adjusted for the biases. By repeating the draw and adjustment process over multiple iterations, I generated a frequency distribution of adjusted results, from which I obtained a point estimate and simulation interval. These methods were applied without access to the primary record-level dataset. The conventional estimates of effect associating alachlor and glyphosate exposure with cancer incidence were likely biased away from the null and understated the uncertainty by quantifying only random error. For example, the conventional p-value for a test of trend in the alachlor study equaled 0.02, whereas fewer than 20% of the bias analysis iterations yielded a p-value of 0.02 or lower. Similarly, the conventional fully-adjusted result associating glyphosate exposure with multiple myleoma equaled 2.6 with 95% confidence interval of 0.7 to 9.4. The frequency distribution generated by the bias analysis yielded a median hazard ratio equal to 1.5 with 95% simulation interval of 0.4 to 8.9, which was 66% wider than the conventional interval. Bias analysis provides a more complete picture of true uncertainty than conventional frequentist statistical analysis accompanied by a qualitative description of study limitations. The latter approach is

Bias analysis applied to Agricultural Health Study publications to estimate non-random sources of uncertainty

Directory of Open Access Journals (Sweden)

Lash Timothy L

2007-11-01

Full Text Available Abstract Background The associations of pesticide exposure with disease outcomes are estimated without the benefit of a randomized design. For this reason and others, these studies are susceptible to systematic errors. I analyzed studies of the associations between alachlor and glyphosate exposure and cancer incidence, both derived from the Agricultural Health Study cohort, to quantify the bias and uncertainty potentially attributable to systematic error. Methods For each study, I identified the prominent result and important sources of systematic error that might affect it. I assigned probability distributions to the bias parameters that allow quantification of the bias, drew a value at random from each assigned distribution, and calculated the estimate of effect adjusted for the biases. By repeating the draw and adjustment process over multiple iterations, I generated a frequency distribution of adjusted results, from which I obtained a point estimate and simulation interval. These methods were applied without access to the primary record-level dataset. Results The conventional estimates of effect associating alachlor and glyphosate exposure with cancer incidence were likely biased away from the null and understated the uncertainty by quantifying only random error. For example, the conventional p-value for a test of trend in the alachlor study equaled 0.02, whereas fewer than 20% of the bias analysis iterations yielded a p-value of 0.02 or lower. Similarly, the conventional fully-adjusted result associating glyphosate exposure with multiple myleoma equaled 2.6 with 95% confidence interval of 0.7 to 9.4. The frequency distribution generated by the bias analysis yielded a median hazard ratio equal to 1.5 with 95% simulation interval of 0.4 to 8.9, which was 66% wider than the conventional interval. Conclusion Bias analysis provides a more complete picture of true uncertainty than conventional frequentist statistical analysis accompanied by a

Borderline features are associated with inaccurate trait self-estimations.

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Morey, Leslie C

2014-01-01

Many treatments for Borderline Personality Disorder (BPD) are based upon the hypothesis that gross distortion in perceptions and attributions related to self and others represent a core mechanism for the enduring difficulties displayed by such patients. However, available experimental evidence of such distortions provides equivocal results, with some studies suggesting that BPD is related to inaccuracy in such perceptions and others indicative of enhanced accuracy in some judgments. The current study uses a novel methodology to explore whether individuals with BPD features are less accurate in estimating their levels of universal personality characteristics as compared to community norms. One hundred and four students received course instruction on the Five Factor Model of personality, and then were asked to estimate their levels of these five traits relative to community norms. They then completed the NEO-Five Factor Inventory and the Personality Assessment Inventory-Borderline Features scale (PAI-BOR). Accuracy of estimates was calculated by computing squared differences between self-estimated trait levels and norm-referenced standardized scores in the NEO-FFI. There was a moderately strong relationship between PAI-BOR score and inaccuracy of trait level estimates. In particular, high BOR individuals dramatically overestimated their levels of Agreeableness and Conscientiousness, estimating themselves to be slightly above average on each of these characteristics but actually scoring well below average on both. The accuracy of estimates of levels of Neuroticism were unrelated to BOR scores, despite the fact that BOR scores were highly correlated with Neuroticism. These findings support the hypothesis that a key feature of BPD involves marked perceptual distortions of various aspects of self in relationship to others. However, the results also indicate that this is not a global perceptual deficit, as high BOR scorers accurately estimated that their emotional

Association studies using family pools of outcrossing crops based on allele-frequency estimates from DNA sequencing

DEFF Research Database (Denmark)

Ashraf, Bilal; Jensen, Just; Asp, Torben

2014-01-01

effect from F2-family pools was verified and it was shown that the underestimation of the allele effect is correctly described. The optimal design for an association study when sequencing budget would be fixed is obtained using large sample size and lower sequence depth, and using higher SNP density......F2 families are frequently used in breeding of outcrossing species, for instance to obtain trait measurements on plots. We propose to perform association studies by obtaining a matching “family genotype” from sequencing a pooled sample of the family, and to directly use allele frequencies computed...... (resulting in higher LD with causative mutations) and lower sequencing depth. Therefore, association studies using genotyping by sequencing are optimal and use low sequencing depth per sample. The developed framework for association studies using allele frequencies from sequencing can be modified for other...

Microcephaly Case Fatality Rate Associated with Zika Virus Infection in Brazil: Current Estimates.

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Cunha, Antonio José Ledo Alves da; de Magalhães-Barbosa, Maria Clara; Lima-Setta, Fernanda; Medronho, Roberto de Andrade; Prata-Barbosa, Arnaldo

2017-05-01

Considering the currently confirmed cases of microcephaly and related deaths associated with Zika virus in Brazil, the estimated case fatality rate is 8.3% (95% confidence interval: 7.2-9.6). However, a third of the reported cases remain under investigation. If the confirmation rates of cases and deaths are the same in the future, the estimated case fatality rate will be as high as 10.5% (95% confidence interval: 9.5-11.7).

Elastic Thickness Estimates for Coronae Associated with Chasmata on Venus

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Hoogenboom, T.; Martin, P.; Housean, G. A.

2005-01-01

Coronae are large-scale circular tectonic features surrounded by annular ridges. They are generally considered unique to Venus and may offer insights into the differences in lithospheric structure or mantle convective pattern between Venus and Earth. 68% of all coronae are associated with chasmata or fracture belts. The remaining 32% are located at volcanic rises or in the plains. Chasmata are linear to arcuate troughs, with trough parallel fractures and faults which extend for 1000 s of kilometers. Estimates of the elastic thickness of the lithosphere (T(sub e)) have been calculated in a number of gravity/topography studies of Venus and for coronae specifically. None of these studies, however, have explored the dependence of T(sub e) on the tectonic history of the region, as implied from the interpretation of relative timing relationships between coronae and surrounding features. We examine the relationship between the local T(sub e) and the relative ages of coronae and chasmata with the aim of further constraining the origin and evolution of coronae and chasmata systems.

Beyond Crowd Judgments: Data-driven Estimation of Market Value in Association Football

DEFF Research Database (Denmark)

Müller, Oliver; Simons, Alexander; Weinmann, Markus

2017-01-01

concern. Market values can be understood as estimates of transfer fees—that is, prices that could be paid for a player on the football market—so they play an important role in transfer negotiations. These values have traditionally been estimated by football experts, but crowdsourcing has emerged......Association football is a popular sport, but it is also a big business. From a managerial perspective, the most important decisions that team managers make concern player transfers, so issues related to player valuation, especially the determination of transfer fees and market values, are of major......’ market values using multilevel regression analysis. The regression results suggest that data-driven estimates of market value can overcome several of the crowd's practical limitations while producing comparably accurate numbers. Our results have important implications for football managers and scouts...

Integration of external estimated breeding values and associated reliabilities using correlations among traits and effects.

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Vandenplas, J; Colinet, F G; Glorieux, G; Bertozzi, C; Gengler, N

2015-12-01

Based on a Bayesian view of linear mixed models, several studies showed the possibilities to integrate estimated breeding values (EBV) and associated reliabilities (REL) provided by genetic evaluations performed outside a given evaluation system into this genetic evaluation. Hereafter, the term "internal" refers to this given genetic evaluation system, and the term "external" refers to all other genetic evaluations performed outside the internal evaluation system. Bayesian approaches integrate external information (i.e., external EBV and associated REL) by altering both the mean and (co)variance of the prior distributions of the additive genetic effects based on the knowledge of this external information. Extensions of the Bayesian approaches to multivariate settings are interesting because external information expressed on other scales, measurement units, or trait definitions, or associated with different heritabilities and genetic parameters than the internal traits, could be integrated into a multivariate genetic evaluation without the need to convert external information to the internal traits. Therefore, the aim of this study was to test the integration of external EBV and associated REL, expressed on a 305-d basis and genetically correlated with a trait of interest, into a multivariate genetic evaluation using a random regression test-day model for the trait of interest. The approach we used was a multivariate Bayesian approach. Results showed that the integration of external information led to a genetic evaluation for the trait of interest for, at least, animals associated with external information, as accurate as a bivariate evaluation including all available phenotypic information. In conclusion, the multivariate Bayesian approaches have the potential to integrate external information correlated with the internal phenotypic traits, and potentially to the different random regressions, into a multivariate genetic evaluation. This allows the use of different

Potential Selection Effects when Estimating Associations Between the Infancy Peak or Adiposity Rebound and Later Body Mass Index in Children

DEFF Research Database (Denmark)

Börnhorst, Claudia; Siani, Alfonso; Tornaritis, Michalis

2017-01-01

Introduction:This study aims to evaluate a potential selection effect caused by exclusion of children with non-identifiable infancy peak (IP) and adiposity rebound (AR) when estimating associations between age and BMI at IP and AR and later weight status. Subjects and methods: In 4 744 children.......98). In the total study group, BMI values in infancy and childhood were positively associated with later BMI z-scores where associations increased with age. Associations between BMI velocities and later BMI z-scores were largest at ages 5 and 6. Results differed for children with non-identifiable IP and AR...

Sequential recruitment of study participants may inflate genetic heritability estimates.

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Noce, Damia; Gögele, Martin; Schwienbacher, Christine; Caprioli, Giulia; De Grandi, Alessandro; Foco, Luisa; Platzgummer, Stefan; Pramstaller, Peter P; Pattaro, Cristian

2017-06-01

After the success of genome-wide association studies to uncover complex trait loci, attempts to explain the remaining genetic heritability (h 2 ) are mainly focused on unraveling rare variant associations and gene-gene or gene-environment interactions. Little attention is paid to the possibility that h 2 estimates are inflated as a consequence of the epidemiological study design. We studied the time series of 54 biochemical traits in 4373 individuals from the Cooperative Health Research In South Tyrol (CHRIS) study, a pedigree-based study enrolling ten participants/day over several years, with close relatives preferentially invited within the same day. We observed distributional changes of measured traits over time. We hypothesized that the combination of such changes with the pedigree structure might generate a shared-environment component with consequent h 2 inflation. We performed variance components (VC) h 2 estimation for all traits after accounting for the enrollment period in a linear mixed model (two-stage approach). Accounting for the enrollment period caused a median h 2 reduction of 4%. For 9 traits, the reduction was of >20%. Results were confirmed by a Bayesian Markov chain Monte Carlo analysis with all VCs included at the same time (one-stage approach). The electrolytes were the traits most affected by the enrollment period. The h 2 inflation was independent of the h 2 magnitude, laboratory protocol changes, and length of the enrollment period. The enrollment process may induce shared-environment effects even under very stringent and standardized operating procedures, causing h 2 inflation. Including the day of participation as a random effect is a sensitive way to avoid overestimation.

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

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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.

Development of Methodologies for the Estimation of Thermal Properties Associated with Aerospace Vehicles

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Scott, Elaine P.

1996-01-01

A thermal stress analysis is an important aspect in the design of aerospace structures and vehicles such as the High Speed Civil Transport (HSCT) at the National Aeronautics and Space Administration Langley Research Center (NASA-LaRC). These structures are complex and are often composed of numerous components fabricated from a variety of different materials. The thermal loads on these structures induce temperature variations within the structure, which in turn result in the development of thermal stresses. Therefore, a thermal stress analysis requires knowledge of the temperature distributions within the structures which consequently necessitates the need for accurate knowledge of the thermal properties, boundary conditions and thermal interface conditions associated with the structural materials. The goal of this proposed multi-year research effort was to develop estimation methodologies for the determination of the thermal properties and interface conditions associated with aerospace vehicles. Specific objectives focused on the development and implementation of optimal experimental design strategies and methodologies for the estimation of thermal properties associated with simple composite and honeycomb structures. The strategy used in this multi-year research effort was to first develop methodologies for relatively simple systems and then systematically modify these methodologies to analyze complex structures. This can be thought of as a building block approach. This strategy was intended to promote maximum usability of the resulting estimation procedure by NASA-LARC researchers through the design of in-house experimentation procedures and through the use of an existing general purpose finite element software.

Quantifying the underestimation of relative risks from genome-wide association studies.

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Chris Spencer

2011-03-01

Full Text Available Genome-wide association studies (GWAS have identified hundreds of associated loci across many common diseases. Most risk variants identified by GWAS will merely be tags for as-yet-unknown causal variants. It is therefore possible that identification of the causal variant, by fine mapping, will identify alleles with larger effects on genetic risk than those currently estimated from GWAS replication studies. We show that under plausible assumptions, whilst the majority of the per-allele relative risks (RR estimated from GWAS data will be close to the true risk at the causal variant, some could be considerable underestimates. For example, for an estimated RR in the range 1.2-1.3, there is approximately a 38% chance that it exceeds 1.4 and a 10% chance that it is over 2. We show how these probabilities can vary depending on the true effects associated with low-frequency variants and on the minor allele frequency (MAF of the most associated SNP. We investigate the consequences of the underestimation of effect sizes for predictions of an individual's disease risk and interpret our results for the design of fine mapping experiments. Although these effects mean that the amount of heritability explained by known GWAS loci is expected to be larger than current projections, this increase is likely to explain a relatively small amount of the so-called "missing" heritability.

Estimate of uncertainties correlated and no correlated associated to performance tests of activity meters

International Nuclear Information System (INIS)

Sousa, C.H.S.; Teixeira, G.J.; Peixoto, J.G.P.

2014-01-01

Activimeters should undergo performance for verifying the functionality tests as technical recommendations. This study estimated the associated expanded uncertainties uncorrelated to the results conducted on three instruments, two detectors with ionization chamber and one with Geiger Mueller tubes. For this we used a standard reference source and screened certified by the National Institute of Technology and Standardization. The methodology of this research was based on the protocols listed in the technical document of the International Atomic Energy Agency. Later two quantities were correlated presenting real correlation and improving expanded uncertainty 3.7%. (author)

A prevalence-based association test for case-control studies.

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Ryckman, Kelli K; Jiang, Lan; Li, Chun; Bartlett, Jacquelaine; Haines, Jonathan L; Williams, Scott M

2008-11-01

Genetic association is often determined in case-control studies by the differential distribution of alleles or genotypes. Recent work has demonstrated that association can also be assessed by deviations from the expected distributions of alleles or genotypes. Specifically, multiple methods motivated by the principles of Hardy-Weinberg equilibrium (HWE) have been developed. However, these methods do not take into account many of the assumptions of HWE. Therefore, we have developed a prevalence-based association test (PRAT) as an alternative method for detecting association in case-control studies. This method, also motivated by the principles of HWE, uses an estimated population allele frequency to generate expected genotype frequencies instead of using the case and control frequencies separately. Our method often has greater power, under a wide variety of genetic models, to detect association than genotypic, allelic or Cochran-Armitage trend association tests. Therefore, we propose PRAT as a powerful alternative method of testing for association.

Residential Lighting End-Use Consumption Study: Estimation Framework and Initial Estimates

Energy Technology Data Exchange (ETDEWEB)

Gifford, Will R.; Goldberg, Miriam L.; Tanimoto, Paulo M.; Celnicker, Dane R.; Poplawski, Michael E.

2012-12-01

The U.S. DOE Residential Lighting End-Use Consumption Study is an initiative of the U.S. Department of Energy’s (DOE’s) Solid-State Lighting Program that aims to improve the understanding of lighting energy usage in residential dwellings. The study has developed a regional estimation framework within a national sample design that allows for the estimation of lamp usage and energy consumption 1) nationally and by region of the United States, 2) by certain household characteristics, 3) by location within the home, 4) by certain lamp characteristics, and 5) by certain categorical cross-classifications (e.g., by dwelling type AND lamp type or fixture type AND control type).

Estimates of Parainfluenza Virus-Associated Hospitalizations and Cost Among Children Aged Less Than 5 Years in the United States, 1998–2010

Science.gov (United States)

Abedi, Glen R.; Prill, Mila M.; Langley, Gayle E.; Wikswo, Mary E.; Weinberg, Geoffrey A.; Curns, Aaron T.; Schneider, Eileen

2018-01-01

Background Parainfluenza virus (PIV) is the second leading cause of hospitalization for respiratory illness in young children in the United States. Infection can result in a full range of respiratory illness, including bronchiolitis, croup, and pneumonia. The recognized human subtypes of PIV are numbered 1–4. This study calculates estimates of PIV-associated hospitalizations among US children younger than 5 years using the latest available data. Methods Data from the National Respiratory and Enteric Virus Surveillance System were used to characterize seasonal PIV trends from July 2004 through June 2010. To estimate the number of PIV-associated hospitalizations that occurred annually among US children aged PIV among young children enrolled in the New Vaccine Surveillance Network. Estimates of hospitalization charges attributable to PIV infection were also calculated. Results Parainfluenza virus seasonality follows type-specific seasonal patterns, with PIV-1 circulating in odd-numbered years and PIV-2 and -3 circulating annually. The average annual estimates of PIV-associated bronchiolitis, croup, and pneumonia hospitalizations among children aged PIV-associated bronchiolitis, croup, and pneumonia hospitalizations were approximately $43 million, $58 million, and $158 million, respectively. Conclusions The majority of PIV-associated hospitalizations in young children occur among those aged 0 to 2 years. When vaccines for PIV become available, immunization would be most effective if realized within the first year of life. PMID:26908486

Study on drug costs associated with COPD prescription medicine in Denmark.

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Jakobsen, Marie; Anker, Niels; Dollerup, Jens; Poulsen, Peter Bo; Lange, Peter

2013-10-01

Spirometric studies of the general population estimate that 430 000 Danes have chronic obstructive pulmonary disease (COPD). COPD is mainly caused by smoking, and smoking cessation is the most important intervention to prevent disease progression. Cost-of-illness studies conclude that the costs associated with COPD in Denmark are significant, but costs of prescription medicine for COPD were not analysed. To analyse the societal costs associated with prescription medicine for COPD in Denmark. The study was designed as a nationwide retrospective register study of the drug costs (ATC group R03) associated with COPD in the period 2001-2010. Data were retrieved from the Prescription Database, the National Patient Register and the Centralised Civil Register. The population comprised individuals (40+ years) who had at least one prescription of selected R03 drugs and who had been either hospitalised with a COPD diagnosis or had at least one prescription for drugs primarily used for COPD. The study population comprised 166 462 individuals of which 97 916 were alive on 31 December 2010. The average annual drug costs (R03) were DKK 7842 (EUR 1055) per patient in 2010 with total costs of DKK 685 million (EUR 92 million). The average lifetime costs associated with COPD prescription medicine were estimated to be DKK 70 000-75 000 (EUR 9416-10 089) per patient (2010 prices). The costs associated with prescription medicine for COPD in Denmark are significant. © 2012 John Wiley & Sons Ltd.

Estimated Under-Five Deaths Associated with Poor-Quality Antimalarials in Sub-Saharan Africa

Science.gov (United States)

Renschler, John P.; Walters, Kelsey M.; Newton, Paul N.; Laxminarayan, Ramanan

2015-01-01

Many antimalarials sold in sub-Saharan Africa are poor-quality (falsified, substandard, or degraded), and the burden of disease caused by this problem is inadequately quantified. In this article, we estimate the number of under-five deaths caused by ineffective treatment of malaria associated with consumption of poor-quality antimalarials in 39 sub-Saharan countries. Using Latin hypercube sampling our estimates were calculated as the product of the number of private sector antimalarials consumed by malaria-positive children in 2013; the proportion of private sector antimalarials consumed that were of poor-quality; and the case fatality rate (CFR) of under-five malaria-positive children who did not receive appropriate treatment. An estimated 122,350 (interquartile range [IQR]: 91,577–154,736) under-five malaria deaths were associated with consumption of poor-quality antimalarials, representing 3.75% (IQR: 2.81–4.75%) of all under-five deaths in our sample of 39 countries. There is considerable uncertainty surrounding our results because of gaps in data on case fatality rates and prevalence of poor-quality antimalarials. Our analysis highlights the need for further investigation into the distribution of poor-quality antimalarials and the need for stronger surveillance and regulatory efforts to prevent the sale of poor-quality antimalarials. PMID:25897068

Estimating the variation in need for community-based social care by body mass index in England and associated cost: population-based cross-sectional study

Directory of Open Access Journals (Sweden)

Vicky R. Copley

2017-08-01

Full Text Available Abstract Background Adult obesity is linked to a greater need for social care because of its association with the development of long term conditions and because obese adults can have physical and social difficulties which inhibit daily living. Obesity thus has considerable social care cost implications but the magnitude of these costs is currently unknown. This paper outlines an approach to estimating obesity-related social care costs in adults aged over 65 in England. Methods We used univariable and multivariable logistic regression models to investigate the relation between the self-reported need for social care and potential determinants, including body mass index (BMI, using data from Health Survey for England. We combined these modelled estimates of need for social care with the mean hours of help received, conditional on receiving any help, to calculate the expected hours of social care received per adult by BMI. Results BMI is positively associated with self-reported need for social care. A one unit (ie 1 kg/m2 increase in BMI is on average associated with a 5% increase in the odds of need for help with social care (odds ratio 1.05, 95% CI 1.04 to 1.07 in an unadjusted model. Adjusting for long term illness and sociodemographic characteristics we estimate the annual cost of local authority funded care for those who receive it is £599 at a BMI of 23 but £1086 at a BMI of 40. Conclusion BMI is positively associated with self-reported need for social care after adjustment for sociodemographic factors and limiting long term illness. The increase in need for care with BMI gives rise to additional costs in social care provision which should be borne in mind when calculating the cost-effectiveness of interventions aimed at reducing obesity.

GM-PHD Filter Combined with Track-Estimate Association and Numerical Interpolation

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Jinguang Chen

2015-01-01

Full Text Available For the standard Gaussian mixture probability hypothesis density (GM-PHD filter, the number of targets can be overestimated if the clutter rate is too high or underestimated if the detection rate is too low. These problems seriously affect the accuracy of multitarget tracking for the number and the value of measurements and clutters cannot be distinguished and recognized. Therefore, we proposed an improved GM-PHD filter to tackle these problems. Firstly, a track-estimate association was implemented in the filtering process to detect and remove false-alarm targets. Secondly, a numerical interpolation technique was used to compensate the missing targets caused by low detection rate. At the end of this paper, simulation results were presented to demonstrate the proposed GM-PHD algorithm is more effective in estimating the number and state of targets than the previous ones.

Robust Maximum Association Estimators

NARCIS (Netherlands)

A. Alfons (Andreas); C. Croux (Christophe); P. Filzmoser (Peter)

2017-01-01

textabstractThe maximum association between two multivariate variables X and Y is defined as the maximal value that a bivariate association measure between one-dimensional projections αX and αY can attain. Taking the Pearson correlation as projection index results in the first canonical correlation

Exposure to Traffic-related Air Pollution During Pregnancy and Term Low Birth Weight: Estimation of Causal Associations in a Semiparametric Model

Science.gov (United States)

Padula, Amy M.; Mortimer, Kathleen; Hubbard, Alan; Lurmann, Frederick; Jerrett, Michael; Tager, Ira B.

2012-01-01

Traffic-related air pollution is recognized as an important contributor to health problems. Epidemiologic analyses suggest that prenatal exposure to traffic-related air pollutants may be associated with adverse birth outcomes; however, there is insufficient evidence to conclude that the relation is causal. The Study of Air Pollution, Genetics and Early Life Events comprises all births to women living in 4 counties in California's San Joaquin Valley during the years 2000–2006. The probability of low birth weight among full-term infants in the population was estimated using machine learning and targeted maximum likelihood estimation for each quartile of traffic exposure during pregnancy. If everyone lived near high-volume freeways (approximated as the fourth quartile of traffic density), the estimated probability of term low birth weight would be 2.27% (95% confidence interval: 2.16, 2.38) as compared with 2.02% (95% confidence interval: 1.90, 2.12) if everyone lived near smaller local roads (first quartile of traffic density). Assessment of potentially causal associations, in the absence of arbitrary model assumptions applied to the data, should result in relatively unbiased estimates. The current results support findings from previous studies that prenatal exposure to traffic-related air pollution may adversely affect birth weight among full-term infants. PMID:23045474

Estimation of avoidable skin cancers and cost-savings to government associated with regulation of the solarium industry in Australia.

Science.gov (United States)

Hirst, Nicholas; Gordon, Louisa; Gies, Peter; Green, Adèle C

2009-03-01

In Australia there is growing concern about the expanding solarium industry, and the additive effect of persons seeking exposure to artificial ultraviolet radiation (UVR) against already intense background levels of solar UVR. We estimated the numbers of potential skin cancers prevented through regulation of solaria and the associated cost-savings to the Federal Government. A lifetime decision-analytic model was created using relative risk estimates based on a meta-analysis of the literature assessing the link between skin cancer risk and solarium use. The costs were limited to those incurred by Medicare Australia, for the medical care of individuals treated for skin cancer. With stricter regulations, we estimated between 18 and 31 melanomas, 200-251 squamous cell carcinomas and associated costs of $AU 256,054 would be avoided per 100,000 persons. Our base findings were sensitive to estimates for prevalence of use, skin cancer risk and discounting rates. Continued growth in the Australian solarium industry is likely to inflate the already substantial skin cancer burden. Subject to some limitations, our study indicates that by successfully enforcing solarium regulations to prohibit use by minors and by those with fair skin colour, the Federal Government could expect favourable cost and health benefits.

Influence of reported study design characteristics on intervention effect estimates from randomized, controlled trials

DEFF Research Database (Denmark)

Savović, Jelena; Jones, Hayley E; Altman, Douglas G

2012-01-01

bias and increases in between-trial heterogeneity were driven primarily by trials with subjective outcomes, with little evidence of bias in trials with objective and mortality outcomes. This study is limited by incomplete trial reporting, and findings may be confounded by other study design...... characteristics. Bias associated with study design characteristics may lead to exaggeration of intervention effect estimates and increases in between-trial heterogeneity in trials reporting subjectively assessed outcomes....

Genome-wide association study identifies 74 loci associated with educational attainment

Science.gov (United States)

Okbay, Aysu; Beauchamp, Jonathan P.; Fontana, Mark A.; Lee, James J.; Pers, Tune H.; Rietveld, Cornelius A.; Turley, Patrick; Chen, Guo-Bo; Emilsson, Valur; Meddens, S. Fleur W.; Oskarsson, Sven; Pickrell, Joseph K.; Thom, Kevin; Timshel, Pascal; de Vlaming, Ronald; Abdellaoui, Abdel; Ahluwalia, Tarunveer S.; Bacelis, Jonas; Baumbach, Clemens; Bjornsdottir, Gyda; Brandsma, Johannes H.; Concas, Maria Pina; Derringer, Jaime; Furlotte, Nicholas A.; Galesloot, Tessel E.; Girotto, Giorgia; Gupta, Richa; Hall, Leanne M.; Harris, Sarah E.; Hofer, Edith; Horikoshi, Momoko; Huffman, Jennifer E.; Kaasik, Kadri; Kalafati, Ioanna P.; Karlsson, Robert; Kong, Augustine; Lahti, Jari; van der Lee, Sven J.; de Leeuw, Christiaan; Lind, Penelope A.; Lindgren, Karl-Oskar; Liu, Tian; Mangino, Massimo; Marten, Jonathan; Mihailov, Evelin; Miller, Michael B.; van der Most, Peter J.; Oldmeadow, Christopher; Payton, Antony; Pervjakova, Natalia; Peyrot, Wouter J.; Qian, Yong; Raitakari, Olli; Rueedi, Rico; Salvi, Erika; Schmidt, Börge; Schraut, Katharina E.; Shi, Jianxin; Smith, Albert V.; Poot, Raymond A.; Pourcain, Beate; Teumer, Alexander; Thorleifsson, Gudmar; Verweij, Niek; Vuckovic, Dragana; Wellmann, Juergen; Westra, Harm-Jan; Yang, Jingyun; Zhao, Wei; Zhu, Zhihong; Alizadeh, Behrooz Z.; Amin, Najaf; Bakshi, Andrew; Baumeister, Sebastian E.; Biino, Ginevra; Bønnelykke, Klaus; Boyle, Patricia A.; Campbell, Harry; Cappuccio, Francesco P.; Davies, Gail; De Neve, Jan-Emmanuel; Deloukas, Panos; Demuth, Ilja; Ding, Jun; Eibich, Peter; Eisele, Lewin; Eklund, Niina; Evans68, David M.; Faul, Jessica D.; Feitosa, Mary F.; Forstner, Andreas J.; Gandin, Ilaria; Gunnarsson, Bjarni; Halldórsson, Bjarni V.; Harris, Tamara B.; Heath, Andrew C.; Hocking, Lynne J.; Holliday, Elizabeth G.; Homuth, Georg; Horan, Michael A.; Hottenga, Jouke-Jan; de Jager, Philip L.; Joshi, Peter K.; Jugessur, Astanand; Kaakinen, Marika A.; Kähönen, Mika; Kanoni, Stavroula; Keltigangas-Järvinen, Liisa; Kiemeney, Lambertus A.L.M.; Kolcic, Ivana; Koskinen, Seppo; Kraja, Aldi T.; Kroh, Martin; Kutalik, Zoltan; Latvala, Antti; Launer, Lenore J.; Lebreton, Maël P.; Levinson, Douglas F.; Lichtenstein, Paul; Lichtner, Peter; Liewald, David C.M.; Loukola, Anu; Madden, Pamela A.; Mägi, Reedik; Mäki-Opas, Tomi; Marioni, Riccardo E.; Marques-Vidal, Pedro; Meddens, Gerardus A.; McMahon, George; Meisinger, Christa; Meitinger, Thomas; Milaneschi, Yusplitri; Milani, Lili; Montgomery, Grant W.; Myhre, Ronny; Nelson, Christopher P.; Nyholt, Dale R.; Ollier, William E.R.; Palotie, Aarno; Paternoster, Lavinia; Pedersen, Nancy L.; Petrovic, Katja E.; Porteous, David J.; Räikkönen, Katri; Ring, Susan M.; Robino, Antonietta; Rostapshova, Olga; Rudan, Igor; Rustichini, Aldo; Salomaa, Veikko; Sanders, Alan R.; Sarin, Antti-Pekka; Schmidt, Helena; Scott, Rodney J.; Smith, Blair H.; Smith, Jennifer A.; Staessen, Jan A.; Steinhagen-Thiessen, Elisabeth; Strauch, Konstantin; Terracciano, Antonio; Tobin, Martin D.; Ulivi, Sheila; Vaccargiu, Simona; Quaye, Lydia; van Rooij, Frank J.A.; Venturini, Cristina; Vinkhuyzen, Anna A.E.; Völker, Uwe; Völzke, Henry; Vonk, Judith M.; Vozzi, Diego; Waage, Johannes; Ware, Erin B.; Willemsen, Gonneke; Attia, John R.; Bennett, David A.; Berger, Klaus; Bertram, Lars; Bisgaard, Hans; Boomsma, Dorret I.; Borecki, Ingrid B.; Bultmann, Ute; Chabris, Christopher F.; Cucca, Francesco; Cusi, Daniele; Deary, Ian J.; Dedoussis, George V.; van Duijn, Cornelia M.; Eriksson, Johan G.; Franke, Barbara; Franke, Lude; Gasparini, Paolo; Gejman, Pablo V.; Gieger, Christian; Grabe, Hans-Jörgen; Gratten, Jacob; Groenen, Patrick J.F.; Gudnason, Vilmundur; van der Harst, Pim; Hayward, Caroline; Hinds, David A.; Hoffmann, Wolfgang; Hyppönen, Elina; Iacono, William G.; Jacobsson, Bo; Järvelin, Marjo-Riitta; Jöckel, Karl-Heinz; Kaprio, Jaakko; Kardia, Sharon L.R.; Lehtimäki, Terho; Lehrer, Steven F.; Magnusson, Patrik K.E.; Martin, Nicholas G.; McGue, Matt; Metspalu, Andres; Pendleton, Neil; Penninx, Brenda W.J.H.; Perola, Markus; Pirastu, Nicola; Pirastu, Mario; Polasek, Ozren; Posthuma, Danielle; Power, Christine; Province, Michael A.; Samani, Nilesh J.; Schlessinger, David; Schmidt, Reinhold; Sørensen, Thorkild I.A.; Spector, Tim D.; Stefansson, Kari; Thorsteinsdottir, Unnur; Thurik, A. Roy; Timpson, Nicholas J.; Tiemeier, Henning; Tung, Joyce Y.; Uitterlinden, André G.; Vitart, Veronique; Vollenweider, Peter; Weir, David R.; Wilson, James F.; Wright, Alan F.; Conley, Dalton C.; Krueger, Robert F.; Smith, George Davey; Hofman, Albert; Laibson, David I.; Medland, Sarah E.; Meyer, Michelle N.; Yang, Jian; Johannesson, Magnus; Visscher, Peter M.; Esko, Tõnu; Koellinger, Philipp D.; Cesarini, David; Benjamin, Daniel J.

2016-01-01

Summary Educational attainment (EA) is strongly influenced by social and other environmental factors, but genetic factors are also estimated to account for at least 20% of the variation across individuals1. We report the results of a genome-wide association study (GWAS) for EA that extends our earlier discovery sample1,2 of 101,069 individuals to 293,723 individuals, and a replication in an independent sample of 111,349 individuals from the UK Biobank. We now identify 74 genome-wide significant loci associated with number of years of schooling completed. Single-nucleotide polymorphisms (SNPs) associated with educational attainment are disproportionately found in genomic regions regulating gene expression in the fetal brain. Candidate genes are preferentially expressed in neural tissue, especially during the prenatal period, and enriched for biological pathways involved in neural development. Our findings demonstrate that, even for a behavioral phenotype that is mostly environmentally determined, a well-powered GWAS identifies replicable associated genetic variants that suggest biologically relevant pathways. Because EA is measured in large numbers of individuals, it will continue to be useful as a proxy phenotype in efforts to characterize the genetic influences of related phenotypes, including cognition and neuropsychiatric disease. PMID:27225129

Store turnover as a predictor of food and beverage provider turnover and associated dietary intake estimates in very remote Indigenous communities.

Science.gov (United States)

Wycherley, Thomas; Ferguson, Megan; O'Dea, Kerin; McMahon, Emma; Liberato, Selma; Brimblecombe, Julie

2016-12-01

Determine how very-remote Indigenous community (RIC) food and beverage (F&B) turnover quantities and associated dietary intake estimates derived from only stores, compare with values derived from all community F&B providers. F&B turnover quantity and associated dietary intake estimates (energy, micro/macronutrients and major contributing food types) were derived from 12-months transaction data of all F&B providers in three RICs (NT, Australia). F&B turnover quantities and dietary intake estimates from only stores (plus only the primary store in multiple-store communities) were expressed as a proportion of complete F&B provider turnover values. Food types and macronutrient distribution (%E) estimates were quantitatively compared. Combined stores F&B turnover accounted for the majority of F&B quantity (98.1%) and absolute dietary intake estimates (energy [97.8%], macronutrients [≥96.7%] and micronutrients [≥83.8%]). Macronutrient distribution estimates from combined stores and only the primary store closely aligned complete provider estimates (≤0.9% absolute). Food types were similar using combined stores, primary store or complete provider turnover. Evaluating combined stores F&B turnover represents an efficient method to estimate total F&B turnover quantity and associated dietary intake in RICs. In multiple-store communities, evaluating only primary store F&B turnover provides an efficient estimate of macronutrient distribution and major food types. © 2016 Public Health Association of Australia.

Identification of Promising Mutants Associated with Egg Production Traits Revealed by Genome-Wide Association Study.

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Jingwei Yuan

Full Text Available Egg number (EN, egg laying rate (LR and age at first egg (AFE are important production traits related to egg production in poultry industry. To better understand the knowledge of genetic architecture of dynamic EN during the whole laying cycle and provide the precise positions of associated variants for EN, LR and AFE, laying records from 21 to 72 weeks of age were collected individually for 1,534 F2 hens produced by reciprocal crosses between White Leghorn and Dongxiang Blue-shelled chicken, and their genotypes were assayed by chicken 600 K Affymetrix high density genotyping arrays. Subsequently, pedigree and SNP-based genetic parameters were estimated and a genome-wide association study (GWAS was conducted on EN, LR and AFE. The heritability estimates were similar between pedigree and SNP-based estimates varying from 0.17 to 0.36. In the GWA analysis, we identified nine genome-wide significant loci associated with EN of the laying periods from 21 to 26 weeks, 27 to 36 weeks and 37 to 72 weeks. Analysis of GTF2A1 and CLSPN suggested that they influenced the function of ovary and uterus, and may be considered as relevant candidates. The identified SNP rs314448799 for accumulative EN from 21 to 40 weeks on chromosome 5 created phenotypic differences of 6.86 eggs between two homozygous genotypes, which could be potentially applied to the molecular breeding for EN selection. Moreover, our finding showed that LR was a moderate polygenic trait. The suggestive significant region on chromosome 16 for AFE suggested the relationship between sex maturity and immune in the current population. The present study comprehensively evaluates the role of genetic variants in the development of egg laying. The findings will be helpful to investigation of causative genes function and future marker-assisted selection and genomic selection in chickens.

Estimation of the externalities associated with atmospheric emissions of the electric power production cycle

International Nuclear Information System (INIS)

Jacomino, Vanusa Maria Feliciano; Barreto, Alberto Avelar; Pereira, Maria Cristina; Branco, Otavio Eurico de Aquino; Aronne, Ivan Dionysio; Pinheiro, Ricardo Brant

2000-01-01

Nowadays the activities connected to energy generation and distribution are those that most contribute to local, regional and global degradation of the environment. One of the most important contribution for externalities estimation is the ExternE Project, which has established a methodological framework called damage function approach to quantify both health and environmental impacts from electricity generation as well as to quantify in monetary terms the damage resulting from these physical impacts. In order to incorporate economic, social and environmental aspects in the decision process of energy planning in Brazil, a joint research project sponsored by the International Atomic Energy Agency is being carried out. The primary objective of this Project is to perform a comparative assessment of external costs of alternative fuel cycles for electricity production. It includes not only the quantification of the physical impacts and damage costs associated with airborne emissions from the traditional fossil fuels (coal, gas and oil) and nuclear energy, but also those from renewable resources, most specifically from hydroelectric. The main objective of this paper is to present preliminary results of the external costs associated to atmospheric emissions of an oil fired plant. Applying the Damage Function Approach methodology the quantification of healthy impacts and damage cost was performed. These results will later be compared with those from nuclear energy option. Atmospheric dispersion studies were carried out using the Industrial Complex Source Model. The healthy impacts were estimated using the exposure-response curves recommended by the ExternE Project. The monetary unit cost for different public health endpoints considered in this study were obtained indirectly by using unit cost values taken from Contingent Valuation studies sponsored by the World Bank, which are specific for developing countries. (author)

Automated estimation of hip prosthesis migration: a feasibility study

Science.gov (United States)

Vandemeulebroucke, Jef; Deklerck, Rudi; Temmermans, Frederik; Van Gompel, Gert; Buls, Nico; Scheerlinck, Thierry; de Mey, Johan

2013-09-01

A common complication associated with hip arthoplasty is prosthesis migration, and for most cemented components a migration greater than 0.85 mm within the first six months after surgery, are an indicator for prosthesis failure. Currently, prosthesis migration is evaluated using X-ray images, which can only reliably estimate migrations larger than 5 mm. We propose an automated method for estimating prosthesis migration more accurately, using CT images and image registration techniques. We report on the results obtained using an experimental set-up, in which a metal prosthesis can be translated and rotated with respect to a cadaver femur, over distances and angles applied using a combination of positioning stages. Images are first preprocessed to reduce artefacts. Bone and prosthesis are extracted using consecutive thresholding and morphological operations. Two registrations are performed, one aligning the bones and the other aligning the prostheses. The migration is estimated as the difference between the found transformations. We use a robust, multi-resolution, stochastic optimization approach, and compare the mean squared intensity differences (MS) to mutual information (MI). 30 high-resolution helical CT scans were acquired for prosthesis translations ranging from 0.05 mm to 4 mm, and rotations ranging from 0.3° to 3° . For the translations, the mean 3D registration error was found to be 0.22 mm for MS, and 0.15 mm for MI. For the rotations, the standard deviation of the estimation error was 0.18° for MS, and 0.08° for MI. The results show that the proposed approach is feasible and that clinically acceptable accuracies can be obtained. Clinical validation studies on patient images will now be undertaken.

Vaccine-associated paralytic poliomyelitis: a review of the epidemiology and estimation of the global burden.

Science.gov (United States)

Platt, Lauren R; Estívariz, Concepción F; Sutter, Roland W

2014-11-01

Vaccine-associated paralytic poliomyelitis (VAPP) is a rare adverse event associated with oral poliovirus vaccine (OPV). This review summarizes the epidemiology and provides a global burden estimate. A literature review was conducted to abstract the epidemiology and calculate the risk of VAPP. A bootstrap method was applied to calculate global VAPP burden estimates. Trends in VAPP epidemiology varied by country income level. In the low-income country, the majority of cases occurred in individuals who had received >3 doses of OPV (63%), whereas in middle and high-income countries, most cases occurred in recipients after their first OPV dose or unvaccinated contacts (81%). Using all risk estimates, VAPP risk was 4.7 cases per million births (range, 2.4-9.7), leading to a global annual burden estimate of 498 cases (range, 255-1018). If the analysis is limited to estimates from countries that currently use OPV, the VAPP risk is 3.8 cases per million births (range, 2.9-4.7) and a burden of 399 cases (range, 306-490). Because many high-income countries have replaced OPV with inactivated poliovirus vaccine, the VAPP burden is concentrated in lower-income countries. The planned universal introduction of inactivated poliovirus vaccine is likely to substantially decrease the global VAPP burden by 80%-90%. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Application of microwave radiometer and wind profiler data in the estimation of wind gust associated with intense convective weather

International Nuclear Information System (INIS)

Chan, P W; Wong, K H

2008-01-01

Estimates of the wind gusts associated with intense convective weather could be obtained using empirical relationships such as GUSTEX based on radiosonde measurements. However, such data are only available a couple of times a day and may not reflect the rapidly changing atmospheric condition in spring and summer times. The feasibility of combining the thermodynamic profiles from a ground-based microwave radiometer and wind profiles given by radar wind profilers in the continuous estimation of wind gusts is studied in this paper. Based on the results of a 4-month trial of a microwave radiometer in Hong Kong in 2004, the estimated and the actual gusts are reasonably well correlated. It is also found that the wind gusts so estimated provide better indications of the strength of squalls compared with those based on radiosonde measurements and with a lead time of about one hour

Study on Posture Estimation Using Delayed Measurements for Mobile Robots

Institute of Scientific and Technical Information of China (English)

无

2005-01-01

When associating data from various sensors to estimate the posture of mobile robots, a crucial problem to be solved is that there may be some delayed measurements. Furthermore, the general multi-sensor data fusion algorithm is a Kalman filter. In order to handle the problem concerning delayed measurements, this paper investigates a Kalman filter modified to account for the delays. Based on the interpolating measurement, a fusion system is applied to estimate the posture of a mobile robot which fuses the data from the encoder and laser global position system using the extended Kalman filter algorithm. Finally, the posture estimation experiment of the mobile robot is given whose result verifies the feasibility and efficiency of the algorithm.

Visual estimation versus gravimetric measurement of postpartum blood loss: a prospective cohort study.

Science.gov (United States)

Al Kadri, Hanan M F; Al Anazi, Bedayah K; Tamim, Hani M

2011-06-01

One of the major problems in international literature is how to measure postpartum blood loss with accuracy. We aimed in this research to assess the accuracy of visual estimation of postpartum blood loss (by each of two main health-care providers) compared with the gravimetric calculation method. We carried out a prospective cohort study at King Abdulaziz Medical City, Riyadh, Saudi Arabia between 1 November 2009 and 31 December 2009. All women who were admitted to labor and delivery suite and delivered vaginally were included in the study. Postpartum blood loss was visually estimated by the attending physician and obstetrics nurse and then objectively calculated by a gravimetric machine. Comparison between the three methods of blood loss calculation was carried out. A total of 150 patients were included in this study. There was a significant difference between the gravimetric calculated blood loss and both health-care providers' estimation with a tendency to underestimate the loss by about 30%. The background and seniority of the assessing health-care provider did not affect the accuracy of the estimation. The corrected incidence of postpartum hemorrhage in Saudi Arabia was found to be 1.47%. Health-care providers tend to underestimate the volume of postpartum blood loss by about 30%. Training and continuous auditing of the diagnosis of postpartum hemorrhage is needed to avoid missing cases and thus preventing associated morbidity and mortality.

Are risk estimates biased in follow-up studies of psychosocial factors with low base-line participation?

Directory of Open Access Journals (Sweden)

Andersen Johan

2011-07-01

Full Text Available Abstract Background Low participation in population-based follow-up studies addressing psychosocial risk factors may cause biased estimation of health risk but the issue has seldom been examined. We compared risk estimates for selected health outcomes among respondents and the entire source population. Methods In a Danish cohort study of associations between psychosocial characteristics of the work environment and mental health, the source population of public service workers comprised 10,036 employees in 502 work units of which 4,489 participated (participation rate 45%. Data on the psychosocial work environment were obtained for each work unit by calculating the average of the employee self-reports. The average values were assigned all employees and non-respondent at the work unit. Outcome data on sick leave and prescription of antidepressant medication during the follow-up period (1.4.2007-31.12.2008 was obtained by linkage to national registries. Results Respondents differed at baseline from non-respondents by gender, age, employment status, sick leave and hospitalization for affective disorders. However, risk estimates for sick leave and prescription of antidepressant medication, during follow-up, based on the subset of participants, did only differ marginally from risk estimates based upon the entire population. Conclusions We found no indications that low participation at baseline distorts the estimates of associations between the work unit level of psychosocial work environment and mental health outcomes during follow-up. These results may not be valid for other exposures or outcomes.

Bayesian estimates of linkage disequilibrium

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Abad-Grau María M

2007-06-01

Full Text Available Abstract Background The maximum likelihood estimator of D' – a standard measure of linkage disequilibrium – is biased toward disequilibrium, and the bias is particularly evident in small samples and rare haplotypes. Results This paper proposes a Bayesian estimation of D' to address this problem. The reduction of the bias is achieved by using a prior distribution on the pair-wise associations between single nucleotide polymorphisms (SNPs that increases the likelihood of equilibrium with increasing physical distances between pairs of SNPs. We show how to compute the Bayesian estimate using a stochastic estimation based on MCMC methods, and also propose a numerical approximation to the Bayesian estimates that can be used to estimate patterns of LD in large datasets of SNPs. Conclusion Our Bayesian estimator of D' corrects the bias toward disequilibrium that affects the maximum likelihood estimator. A consequence of this feature is a more objective view about the extent of linkage disequilibrium in the human genome, and a more realistic number of tagging SNPs to fully exploit the power of genome wide association studies.

Robust state estimation for uncertain fuzzy bidirectional associative memory networks with time-varying delays

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Vadivel, P.; Sakthivel, R.; Mathiyalagan, K.; Arunkumar, A.

2013-09-01

This paper addresses the issue of robust state estimation for a class of fuzzy bidirectional associative memory (BAM) neural networks with time-varying delays and parameter uncertainties. By constructing the Lyapunov-Krasovskii functional, which contains the triple-integral term and using the free-weighting matrix technique, a set of sufficient conditions are derived in terms of linear matrix inequalities (LMIs) to estimate the neuron states through available output measurements such that the dynamics of the estimation error system is robustly asymptotically stable. In particular, we consider a generalized activation function in which the traditional assumptions on the boundedness, monotony and differentiability of the activation functions are removed. More precisely, the design of the state estimator for such BAM neural networks can be obtained by solving some LMIs, which are dependent on the size of the time derivative of the time-varying delays. Finally, a numerical example with simulation result is given to illustrate the obtained theoretical results.

Robust state estimation for uncertain fuzzy bidirectional associative memory networks with time-varying delays

International Nuclear Information System (INIS)

Vadivel, P; Sakthivel, R; Mathiyalagan, K; Arunkumar, A

2013-01-01

This paper addresses the issue of robust state estimation for a class of fuzzy bidirectional associative memory (BAM) neural networks with time-varying delays and parameter uncertainties. By constructing the Lyapunov–Krasovskii functional, which contains the triple-integral term and using the free-weighting matrix technique, a set of sufficient conditions are derived in terms of linear matrix inequalities (LMIs) to estimate the neuron states through available output measurements such that the dynamics of the estimation error system is robustly asymptotically stable. In particular, we consider a generalized activation function in which the traditional assumptions on the boundedness, monotony and differentiability of the activation functions are removed. More precisely, the design of the state estimator for such BAM neural networks can be obtained by solving some LMIs, which are dependent on the size of the time derivative of the time-varying delays. Finally, a numerical example with simulation result is given to illustrate the obtained theoretical results. (paper)

An Empirical Bayes Mixture Model for Effect Size Distributions in Genome-Wide Association Studies

DEFF Research Database (Denmark)

Thompson, Wesley K.; Wang, Yunpeng; Schork, Andrew J.

2015-01-01

-wide association study (GWAS) test statistics. Test statistics corresponding to null associations are modeled as random draws from a normal distribution with zero mean; test statistics corresponding to non-null associations are also modeled as normal with zero mean, but with larger variance. The model is fit via...... analytically and in simulations. We apply this approach to meta-analysis test statistics from two large GWAS, one for Crohn’s disease (CD) and the other for schizophrenia (SZ). A scale mixture of two normals distribution provides an excellent fit to the SZ nonparametric replication effect size estimates. While...... minimizing discrepancies between the parametric mixture model and resampling-based nonparametric estimates of replication effect sizes and variances. We describe in detail the implications of this model for estimation of the non-null proportion, the probability of replication in de novo samples, the local...

A Comprehensive Study of Costs Associated With Recurrent Clostridium difficile Infection.

Science.gov (United States)

Rodrigues, Rodrigo; Barber, Grant E; Ananthakrishnan, Ashwin N

2017-02-01

BACKGROUND Clostridium difficile infection (CDI) is the most common healthcare-associated infection and is associated with considerable morbidity. Recurrent CDI is a key contributing factor to this morbidity. Despite an estimated 83,000 recurrences annually in the United States, there are few accurate estimates of costs associated with recurrent CDI. OBJECTIVE We performed this study (1) to identify the health consequences of recurrent CDI including need for repeat hospitalization, intensive care unit (ICU) stay, and surgery; (2) to determine costs associated with recurrent CDI and identify determinants of such costs; and (3) to compare the outcomes and costs of recurrent CDI to those who develop reinfection. METHODS We identified all patients with confirmed recurrent CDI between January to December 2013 at a single referral center. Healthcare burden associated with recurrence including diagnostic testing, pharmacologic treatment, and inpatient and outpatient healthcare visits were identified in the 12 months following the first recurrence. Total healthcare costs were calculated, and the predictors of high healthcare utilization were identified. RESULTS Our study population included 98 patients with recurrent CDI. The median interval between the initial infection and recurrence was 37 days. The mean age of the cohort was 67 years, two-thirds were women (62%), and the mean Charlson index was 8.6. During the year following the first recurrence of CDI, each patient underwent a mean of 4.4 stool C. difficile toxin tests and received a mean of 2.5 prescriptions for oral vancomycin (range, 0-6). Most patients (84%) with recurrence had a CDI-related hospitalization, and 6% underwent colectomy. The mean total CDI-associated cost was $34,104 per patient, with hospitalization costs accounting for 68%, surgery 20%, and drug treatment 8% of this cost, respectively. Extrapolating to the United States overall, we estimate an annual cost of $2.8 billion related to recurrent CDI

A novel approach for estimating ingested dose associated with paracetamol overdose.

Science.gov (United States)

Zurlinden, Todd J; Heard, Kennon; Reisfeld, Brad

2016-04-01

In cases of paracetamol (acetaminophen, APAP) overdose, an accurate estimate of tissue-specific paracetamol pharmacokinetics (PK) and ingested dose can offer health care providers important information for the individualized treatment and follow-up of affected patients. Here a novel methodology is presented to make such estimates using a standard serum paracetamol measurement and a computational framework. The core component of the computational framework was a physiologically-based pharmacokinetic (PBPK) model developed and evaluated using an extensive set of human PK data. Bayesian inference was used for parameter and dose estimation, allowing the incorporation of inter-study variability, and facilitating the calculation of uncertainty in model outputs. Simulations of paracetamol time course concentrations in the blood were in close agreement with experimental data under a wide range of dosing conditions. Also, predictions of administered dose showed good agreement with a large collection of clinical and emergency setting PK data over a broad dose range. In addition to dose estimation, the platform was applied for the determination of optimal blood sampling times for dose reconstruction and quantitation of the potential role of paracetamol conjugate measurement on dose estimation. Current therapies for paracetamol overdose rely on a generic methodology involving the use of a clinical nomogram. By using the computational framework developed in this study, serum sample data, and the individual patient's anthropometric and physiological information, personalized serum and liver pharmacokinetic profiles and dose estimate could be generated to help inform an individualized overdose treatment and follow-up plan. © 2015 The British Pharmacological Society.

Inverse estimation of source parameters of oceanic radioactivity dispersion models associated with the Fukushima accident

Directory of Open Access Journals (Sweden)

Y. Miyazawa

2013-04-01

Full Text Available With combined use of the ocean–atmosphere simulation models and field observation data, we evaluate the parameters associated with the total caesium-137 amounts of the direct release into the ocean and atmospheric deposition over the western North Pacific caused by the accident of Fukushima Daiichi nuclear power plant (FNPP that occurred in March 2011. The Green's function approach is adopted for the estimation of two parameters determining the total emission amounts for the period from 12 March to 6 May 2011. It is confirmed that the validity of the estimation depends on the simulation skill near FNPP. The total amount of the direct release is estimated as 5.5–5.9 × 1015 Bq, while that of the atmospheric deposition is estimated as 5.5–9.7 × 1015 Bq, which indicates broader range of the estimate than that of the direct release owing to uncertainty of the dispersion widely spread over the western North Pacific.

Estimation of community-level influenza-associated illness in a low resource rural setting in India.

Directory of Open Access Journals (Sweden)

Siddhartha Saha

Full Text Available To estimate rates of community-level influenza-like-illness (ILI and influenza-associated ILI in rural north India.During 2011, we conducted household-based healthcare utilization surveys (HUS for any acute medical illness (AMI in preceding 14days among residents of 28villages of Ballabgarh, in north India. Concurrently, we conducted clinic-based surveillance (CBS in the area for AMI episodes with illness onset ≤3days and collected nasal and throat swabs for influenza virus testing using real-time polymerase chain reaction. Retrospectively, we applied ILI case definition (measured/reported fever and cough to HUS and CBS data. We attributed 14days of risk-time per person surveyed in HUS and estimated community ILI rate by dividing the number of ILI cases in HUS by total risk-time. We used CBS data on influenza positivity and applied it to HUS-based community ILI rates by age, month, and clinic type, to estimate the community influenza-associated ILI rates.The HUS of 69,369 residents during the year generated risk-time of 3945 person-years (p-y and identified 150 (5%, 95%CI: 4-6 ILI episodes (38 ILI episodes/1,000 p-y; 95% CI 32-44. Among 1,372 ILI cases enrolled from clinics, 126 (9%; 95% CI 8-11 had laboratory-confirmed influenza (A (H3N2 = 72; B = 54. After adjusting for age, month, and clinic type, overall influenza-associated ILI rate was 4.8/1,000 p-y; rates were highest among children <5 years (13; 95% CI: 4-29 and persons≥60 years (11; 95%CI: 2-30.We present a novel way to use HUS and CBS data to generate estimates of community burden of influenza. Although the confidence intervals overlapped considerably, higher point estimates for burden among young children and older adults shows the utility for exploring the value of influenza vaccination among target groups.

Reef-associated crustacean fauna: biodiversity estimates using semi-quantitative sampling and DNA barcoding

Science.gov (United States)

Plaisance, L.; Knowlton, N.; Paulay, G.; Meyer, C.

2009-12-01

The cryptofauna associated with coral reefs accounts for a major part of the biodiversity in these ecosystems but has been largely overlooked in biodiversity estimates because the organisms are hard to collect and identify. We combine a semi-quantitative sampling design and a DNA barcoding approach to provide metrics for the diversity of reef-associated crustacean. Twenty-two similar-sized dead heads of Pocillopora were sampled at 10 m depth from five central Pacific Ocean localities (four atolls in the Northern Line Islands and in Moorea, French Polynesia). All crustaceans were removed, and partial cytochrome oxidase subunit I was sequenced from 403 individuals, yielding 135 distinct taxa using a species-level criterion of 5% similarity. Most crustacean species were rare; 44% of the OTUs were represented by a single individual, and an additional 33% were represented by several specimens found only in one of the five localities. The Northern Line Islands and Moorea shared only 11 OTUs. Total numbers estimated by species richness statistics (Chao1 and ACE) suggest at least 90 species of crustaceans in Moorea and 150 in the Northern Line Islands for this habitat type. However, rarefaction curves for each region failed to approach an asymptote, and Chao1 and ACE estimators did not stabilize after sampling eight heads in Moorea, so even these diversity figures are underestimates. Nevertheless, even this modest sampling effort from a very limited habitat resulted in surprisingly high species numbers.

Dense Descriptors for Optical Flow Estimation: A Comparative Study

Directory of Open Access Journals (Sweden)

Ahmadreza Baghaie

2017-02-01

Full Text Available Estimating the displacements of intensity patterns between sequential frames is a very well-studied problem, which is usually referred to as optical flow estimation. The first assumption among many of the methods in the field is the brightness constancy during movements of pixels between frames. This assumption is proven to be not true in general, and therefore, the use of photometric invariant constraints has been studied in the past. One other solution can be sought by use of structural descriptors rather than pixels for estimating the optical flow. Unlike sparse feature detection/description techniques and since the problem of optical flow estimation tries to find a dense flow field, a dense structural representation of individual pixels and their neighbors is computed and then used for matching and optical flow estimation. Here, a comparative study is carried out by extending the framework of SIFT-flow to include more dense descriptors, and comprehensive comparisons are given. Overall, the work can be considered as a baseline for stimulating more interest in the use of dense descriptors for optical flow estimation.

Negative control exposure studies in the presence of measurement error: implications for attempted effect estimate calibration.

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Sanderson, Eleanor; Macdonald-Wallis, Corrie; Davey Smith, George

2018-04-01

Negative control exposure studies are increasingly being used in epidemiological studies to strengthen causal inference regarding an exposure-outcome association when unobserved confounding is thought to be present. Negative control exposure studies contrast the magnitude of association of the negative control, which has no causal effect on the outcome but is associated with the unmeasured confounders in the same way as the exposure, with the magnitude of the association of the exposure with the outcome. A markedly larger effect of the exposure on the outcome than the negative control on the outcome strengthens inference that the exposure has a causal effect on the outcome. We investigate the effect of measurement error in the exposure and negative control variables on the results obtained from a negative control exposure study. We do this in models with continuous and binary exposure and negative control variables using analysis of the bias of the estimated coefficients and Monte Carlo simulations. Our results show that measurement error in either the exposure or negative control variables can bias the estimated results from the negative control exposure study. Measurement error is common in the variables used in epidemiological studies; these results show that negative control exposure studies cannot be used to precisely determine the size of the effect of the exposure variable, or adequately adjust for unobserved confounding; however, they can be used as part of a body of evidence to aid inference as to whether a causal effect of the exposure on the outcome is present.

The association of estimated salt intake with blood pressure in a Viet Nam national survey.

Directory of Open Access Journals (Sweden)

Paul N Jensen

Full Text Available To evaluate the association of salt consumption with blood pressure in Viet Nam, a developing country with a high level of salt consumption.Analysis of a nationally representative sample of Vietnamese adults 25-65 years of age who were surveyed using the World Health Organization STEPwise approach to Surveillance protocol. Participants who reported acute illness, pregnancy, or current use of antihypertensive medications were excluded. Daily salt consumption was estimated from fasting mid-morning spot urine samples. Associations of salt consumption with systolic blood pressure and prevalent hypertension were assessed using adjusted linear and generalized linear models. Interaction terms were tested to assess differences by age, smoking, alcohol consumption, and rural/urban status.The analysis included 2,333 participants (mean age: 37 years, 46% male, 33% urban. The average estimated salt consumption was 10g/day. No associations of salt consumption with blood pressure or prevalent hypertension were observed at a national scale in men or women. The associations did not differ in subgroups defined by age, smoking, or alcohol consumption; however, associations differed between urban and rural participants (p-value for interaction of urban/rural status with salt consumption, p = 0.02, suggesting that higher salt consumption may be associated with higher systolic blood pressure in urban residents but lower systolic blood pressure in rural residents.Although there was no evidence of an association at a national level, associations of salt consumption with blood pressure differed between urban and rural residents in Viet Nam. The reasons for this differential association are not clear, and given the large rate of rural to urban migration experienced in Viet Nam, this topic warrants further investigation.

The association of estimated salt intake with blood pressure in a Viet Nam national survey.

Science.gov (United States)

Jensen, Paul N; Bao, Tran Quoc; Huong, Tran Thi Thanh; Heckbert, Susan R; Fitzpatrick, Annette L; LoGerfo, James P; Ngoc, Truong Le Van; Mokdad, Ali H

2018-01-01

To evaluate the association of salt consumption with blood pressure in Viet Nam, a developing country with a high level of salt consumption. Analysis of a nationally representative sample of Vietnamese adults 25-65 years of age who were surveyed using the World Health Organization STEPwise approach to Surveillance protocol. Participants who reported acute illness, pregnancy, or current use of antihypertensive medications were excluded. Daily salt consumption was estimated from fasting mid-morning spot urine samples. Associations of salt consumption with systolic blood pressure and prevalent hypertension were assessed using adjusted linear and generalized linear models. Interaction terms were tested to assess differences by age, smoking, alcohol consumption, and rural/urban status. The analysis included 2,333 participants (mean age: 37 years, 46% male, 33% urban). The average estimated salt consumption was 10g/day. No associations of salt consumption with blood pressure or prevalent hypertension were observed at a national scale in men or women. The associations did not differ in subgroups defined by age, smoking, or alcohol consumption; however, associations differed between urban and rural participants (p-value for interaction of urban/rural status with salt consumption, p = 0.02), suggesting that higher salt consumption may be associated with higher systolic blood pressure in urban residents but lower systolic blood pressure in rural residents. Although there was no evidence of an association at a national level, associations of salt consumption with blood pressure differed between urban and rural residents in Viet Nam. The reasons for this differential association are not clear, and given the large rate of rural to urban migration experienced in Viet Nam, this topic warrants further investigation.

Prevalence of prediabetes and its association with obesity among college students in Kuwait: A cross-sectional study.

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Ben Haider, Nour Y; Ziyab, Ali H

2016-09-01

This cross-sectional study sought to estimate the prevalence of prediabetes and assess its association with obesity among young adults in Kuwait; a country with a high prevalence of obesity and diabetes. The estimated prevalence of prediabetes was 6.3% (95% CI: 4.8-8.1) and obesity was associated with elevated prediabetes prevalence. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Occupational heat stress and associated productivity loss estimation using the PHS model (ISO 7933): a case study from workplaces in Chennai, India

Science.gov (United States)

Lundgren, Karin; Kuklane, Kalev; Venugopal, Vidhya

2014-01-01

Background Heat stress is a major occupational problem in India that can cause adverse health effects and reduce work productivity. This paper explores this problem and its impacts in selected workplaces, including industrial, service, and agricultural sectors in Chennai, India. Design Quantitative measurements of heat stress, workload estimations, and clothing testing, and qualitative information on health impacts, productivity loss, etc., were collected. Heat strain and associated impacts on labour productivity between the seasons were assessed using the International Standard ISO 7933:2004, which applies the Predicted Heat Strain (PHS) model. Results and conclusions All workplaces surveyed had very high heat exposure in the hot season (Wet Bulb Globe Temperature x¯ =29.7), often reaching the international standard safe work values (ISO 7243:1989). Most workers had moderate to high workloads (170–220 W/m2), with some exposed to direct sun. Clothing was found to be problematic, with high insulation values in relation to the heat exposure. Females were found to be more vulnerable because of the extra insulation added from wearing a protective shirt on top of traditional clothing (0.96 clo) while working. When analysing heat strain – in terms of core temperature and dehydration – and associated productivity loss in the PHS model, the parameters showed significant impacts that affected productivity in all workplaces, apart from the laundry facility, especially during the hot season. For example, in the canteen, the core temperature limit of 38°C predicted by the model was reached in only 64 min for women. With the expected increases in temperature due to climate change, additional preventive actions have to be implemented to prevent further productivity losses and adverse health impacts. Overall, this study presented insight into using a thermo-physiological model to estimate productivity loss due to heat exposure in workplaces. This is the first time the PHS

Occupational heat stress and associated productivity loss estimation using the PHS model (ISO 7933): a case study from workplaces in Chennai, India.

Science.gov (United States)

Lundgren, Karin; Kuklane, Kalev; Venugopal, Vidhya

2014-01-01

Heat stress is a major occupational problem in India that can cause adverse health effects and reduce work productivity. This paper explores this problem and its impacts in selected workplaces, including industrial, service, and agricultural sectors in Chennai, India. Quantitative measurements of heat stress, workload estimations, and clothing testing, and qualitative information on health impacts, productivity loss, etc., were collected. Heat strain and associated impacts on labour productivity between the seasons were assessed using the International Standard ISO 7933:2004, which applies the Predicted Heat Strain (PHS) model. All workplaces surveyed had very high heat exposure in the hot season (Wet Bulb Globe Temperature =29.7), often reaching the international standard safe work values (ISO 7243:1989). Most workers had moderate to high workloads (170-220 W/m2), with some exposed to direct sun. Clothing was found to be problematic, with high insulation values in relation to the heat exposure. Females were found to be more vulnerable because of the extra insulation added from wearing a protective shirt on top of traditional clothing (0.96 clo) while working. When analysing heat strain--in terms of core temperature and dehydration--and associated productivity loss in the PHS model, the parameters showed significant impacts that affected productivity in all workplaces, apart from the laundry facility, especially during the hot season. For example, in the canteen, the core temperature limit of 38°C predicted by the model was reached in only 64 min for women. With the expected increases in temperature due to climate change, additional preventive actions have to be implemented to prevent further productivity losses and adverse health impacts. Overall, this study presented insight into using a thermo-physiological model to estimate productivity loss due to heat exposure in workplaces. This is the first time the PHS model has been used for this purpose. An exploratory

Occupational heat stress and associated productivity loss estimation using the PHS model (ISO 7933: a case study from workplaces in Chennai, India

Directory of Open Access Journals (Sweden)

Karin Lundgren

2014-11-01

Full Text Available Background: Heat stress is a major occupational problem in India that can cause adverse health effects and reduce work productivity. This paper explores this problem and its impacts in selected workplaces, including industrial, service, and agricultural sectors in Chennai, India. Design: Quantitative measurements of heat stress, workload estimations, and clothing testing, and qualitative information on health impacts, productivity loss, etc., were collected. Heat strain and associated impacts on labour productivity between the seasons were assessed using the International Standard ISO 7933:2004, which applies the Predicted Heat Strain (PHS model. Results and conclusions: All workplaces surveyed had very high heat exposure in the hot season (Wet Bulb Globe Temperature x¯ =29.7, often reaching the international standard safe work values (ISO 7243:1989. Most workers had moderate to high workloads (170–220 W/m2, with some exposed to direct sun. Clothing was found to be problematic, with high insulation values in relation to the heat exposure. Females were found to be more vulnerable because of the extra insulation added from wearing a protective shirt on top of traditional clothing (0.96 clo while working. When analysing heat strain – in terms of core temperature and dehydration – and associated productivity loss in the PHS model, the parameters showed significant impacts that affected productivity in all workplaces, apart from the laundry facility, especially during the hot season. For example, in the canteen, the core temperature limit of 38°C predicted by the model was reached in only 64 min for women. With the expected increases in temperature due to climate change, additional preventive actions have to be implemented to prevent further productivity losses and adverse health impacts. Overall, this study presented insight into using a thermo-physiological model to estimate productivity loss due to heat exposure in workplaces. This is the

a comparative study of some robust ridge and liu estimators

African Journals Online (AJOL)

Dr A.B.Ahmed

estimation techniques such as Ridge and Liu Estimators are preferable to Ordinary Least Square. On the other hand, when outliers exist in the data, robust estimators like M, MM, LTS and S. Estimators, are preferred. To handle these two problems jointly, the study combines the Ridge and Liu Estimators with Robust.

Forensic Entomology: Evaluating Uncertainty Associated With Postmortem Interval (PMI) Estimates With Ecological Models.

Science.gov (United States)

Faris, A M; Wang, H-H; Tarone, A M; Grant, W E

2016-05-31

Estimates of insect age can be informative in death investigations and, when certain assumptions are met, can be useful for estimating the postmortem interval (PMI). Currently, the accuracy and precision of PMI estimates is unknown, as error can arise from sources of variation such as measurement error, environmental variation, or genetic variation. Ecological models are an abstract, mathematical representation of an ecological system that can make predictions about the dynamics of the real system. To quantify the variation associated with the pre-appearance interval (PAI), we developed an ecological model that simulates the colonization of vertebrate remains by Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae), a primary colonizer in the southern United States. The model is based on a development data set derived from a local population and represents the uncertainty in local temperature variability to address PMI estimates at local sites. After a PMI estimate is calculated for each individual, the model calculates the maximum, minimum, and mean PMI, as well as the range and standard deviation for stadia collected. The model framework presented here is one manner by which errors in PMI estimates can be addressed in court when no empirical data are available for the parameter of interest. We show that PAI is a potential important source of error and that an ecological model is one way to evaluate its impact. Such models can be re-parameterized with any development data set, PAI function, temperature regime, assumption of interest, etc., to estimate PMI and quantify uncertainty that arises from specific prediction systems. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

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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…

Genome-wide association study of primary tooth eruption identifies pleiotropic loci associated with height and craniofacial distances

DEFF Research Database (Denmark)

Fatemifar, Ghazaleh; Hoggart, Clive J; Paternoster, Lavinia

2013-01-01

Twin and family studies indicate that the timing of primary tooth eruption is highly heritable, with estimates typically exceeding 80%. To identify variants involved in primary tooth eruption, we performed a population-based genome-wide association study of 'age at first tooth' and 'number of teeth......' using 5998 and 6609 individuals, respectively, from the Avon Longitudinal Study of Parents and Children (ALSPAC) and 5403 individuals from the 1966 Northern Finland Birth Cohort (NFBC1966). We tested 2 446 724 SNPs imputed in both studies. Analyses were controlled for the effect of gestational age, sex...

On the analysis of genome-wide association studies in family-based designs: a universal, robust analysis approach and an application to four genome-wide association studies.

Directory of Open Access Journals (Sweden)

Sungho Won

2009-11-01

Full Text Available For genome-wide association studies in family-based designs, we propose a new, universally applicable approach. The new test statistic exploits all available information about the association, while, by virtue of its design, it maintains the same robustness against population admixture as traditional family-based approaches that are based exclusively on the within-family information. The approach is suitable for the analysis of almost any trait type, e.g. binary, continuous, time-to-onset, multivariate, etc., and combinations of those. We use simulation studies to verify all theoretically derived properties of the approach, estimate its power, and compare it with other standard approaches. We illustrate the practical implications of the new analysis method by an application to a lung-function phenotype, forced expiratory volume in one second (FEV1 in 4 genome-wide association studies.

Estimating pesticide exposure from dietary intake and organic food choices: the Multi-Ethnic Study of Atherosclerosis (MESA).

Science.gov (United States)

Curl, Cynthia L; Beresford, Shirley A A; Fenske, Richard A; Fitzpatrick, Annette L; Lu, Chensheng; Nettleton, Jennifer A; Kaufman, Joel D

2015-05-01

Organophosphate pesticide (OP) exposure to the U.S. population is dominated by dietary intake. The magnitude of exposure from diet depends partly on personal decisions such as which foods to eat and whether to choose organic food. Most studies of OP exposure rely on urinary biomarkers, which are limited by short half-lives and often lack specificity to parent compounds. A reliable means of estimating long-term dietary exposure to individual OPs is needed to assess the potential relationship with adverse health effects. We assessed long-term dietary exposure to 14 OPs among 4,466 participants in the Multi-Ethnic Study of Atherosclerosis, and examined the influence of organic produce consumption on this exposure. Individual-level exposure was estimated by combining information on typical intake of specific food items with average OP residue levels on those items. In an analysis restricted to a subset of participants who reported rarely or never eating organic produce ("conventional consumers"), we assessed urinary dialkylphosphate (DAP) levels across tertiles of estimated exposure (n = 480). In a second analysis, we compared DAP levels across subgroups with differing self-reported organic produce consumption habits (n = 240). Among conventional consumers, increasing tertile of estimated dietary OP exposure was associated with higher DAP concentrations (p organic produce (p organic produce was associated with lower DAPs.

Estimate of dose in interventional radiology: a study of cases

International Nuclear Information System (INIS)

Pinto, N.; Braz, D.; Lopes, R.; Vallim, M.; Padilha, L.; Azevedo, F.; Barroso, R.

2006-01-01

Values of absorbed dose taken by patients and professionals involved in interventional radiology can be significant mainly for the reason of these proceedings taking long time of fluoroscopy There are many methods to estimate and reduce doses of radiation in the interventional radiology, particularly because the fluoroscopy is responsible for the high dose contribution in the patient and in the professional. The aim of this work is the thermoluminescent dosimetry to estimate the dose values of the extremities of the professionals involved in the interventional radiology and the product dose-area was investigated using a Diamentor. This evaluation is particularly useful for proceedings that interest multiple parts of the organism. In this study were used thermoluminescent dosimeters (LiF:Mg, Ti - Harshaw) to estimate the dose values of the extremities of the professionals and to calibrate them. They were irradiated with X rays at 50 mGy, in Kerma in air and read in the reader Harshaw-5500. The product dose-area (D.A.P.) were obtained through the Diamentor (M2-P.T.W.) calibrated in Cgy.cm 2 fixed in the exit of the X-rays tube. The patients of these study were divided in three groups: individuals submitted to proceedings of embolization, individuals submitted to cerebral and renal arteriography and individuals submitted to proceedings of Transjungular Inthahepatic Porta Systemic Stent Shunt (TIPS). The texts were always carried out by the same group: radiologist doctor), an auxiliary doctor and a nursing auxiliary. The section of interventional radiology has an Angiostar Plus Siemens equipment type arc C, in which there is trifocal Megalix X-ray tube and a intensifier of image from Sirecon 40-4 HDR/33 HDR. In this work the dose estimated values were 137.25 mSv/year for the doctors, 40.27 mSv/year for the nursing and 51.95 mSv/year for the auxiliary doctor and they are below the rule, but in this study it was not taken in consideration the emergency texts as they were

Estimation of community-level influenza-associated illness in a low resource rural setting in India.

Science.gov (United States)

Saha, Siddhartha; Gupta, Vivek; Dawood, Fatimah S; Broor, Shobha; Lafond, Kathryn E; Chadha, Mandeep S; Rai, Sanjay K; Krishnan, Anand

2018-01-01

To estimate rates of community-level influenza-like-illness (ILI) and influenza-associated ILI in rural north India. During 2011, we conducted household-based healthcare utilization surveys (HUS) for any acute medical illness (AMI) in preceding 14days among residents of 28villages of Ballabgarh, in north India. Concurrently, we conducted clinic-based surveillance (CBS) in the area for AMI episodes with illness onset ≤3days and collected nasal and throat swabs for influenza virus testing using real-time polymerase chain reaction. Retrospectively, we applied ILI case definition (measured/reported fever and cough) to HUS and CBS data. We attributed 14days of risk-time per person surveyed in HUS and estimated community ILI rate by dividing the number of ILI cases in HUS by total risk-time. We used CBS data on influenza positivity and applied it to HUS-based community ILI rates by age, month, and clinic type, to estimate the community influenza-associated ILI rates. The HUS of 69,369 residents during the year generated risk-time of 3945 person-years (p-y) and identified 150 (5%, 95%CI: 4-6) ILI episodes (38 ILI episodes/1,000 p-y; 95% CI 32-44). Among 1,372 ILI cases enrolled from clinics, 126 (9%; 95% CI 8-11) had laboratory-confirmed influenza (A (H3N2) = 72; B = 54). After adjusting for age, month, and clinic type, overall influenza-associated ILI rate was 4.8/1,000 p-y; rates were highest among children value of influenza vaccination among target groups.

Study on drug costs associated with COPD prescription medicine in Denmark

DEFF Research Database (Denmark)

Jakobsen, M; Anker, N; Dollerup, J

2013-01-01

that the costs associated with COPD in Denmark are significant, but costs of prescription medicine for COPD were not analysed. OBJECTIVES: To analyse the societal costs associated with prescription medicine for COPD in Denmark. METHODS: The study was designed as a nationwide retrospective register study...... in 2010 with total costs of DKK 685 million (EUR 92 million). The average lifetime costs associated with COPD prescription medicine were estimated to be DKK 70,000-75,000 (EUR 9,416-10,089) per patient (2010 prices). CONCLUSION: The costs associated with prescription medicine for COPD in Denmark...... of the drug costs (ATC group R03) associated with COPD in the period 2001-2010. Data were retrieved from the Prescription Database, the National Patient Register and the Centralised Civil Register. The population comprised individuals (40+ years) who had at least one prescription of selected R03 drugs and who...

STUDY ON DRUG COSTS ASSOCIATED WITH COPD PRESCRIPTION MEDICINE IN DENMARK

DEFF Research Database (Denmark)

Jakobsen, Iris Marie; Anker, Niels; Dolleru, Jens

2012-01-01

that the costs associated with COPD in Denmark are significant, but costs of prescription medicine for COPD were not analysed. OBJECTIVES: To analyse the societal costs associated with prescription medicine for COPD in Denmark. METHODS: The study was designed as a nationwide retrospective register study...... in 2010 with total costs of DKK 685 million (EUR 92 million). The average lifetime costs associated with COPD prescription medicine were estimated to be DKK 70,000-75,000 (EUR 9,416-10,089) per patient (2010 prices). CONCLUSION: The costs associated with prescription medicine for COPD in Denmark...... of the drug costs (ATC group R03) associated with COPD in the period 2001-2010. Data were retrieved from the Prescription Database, the National Patient Register and the Centralised Civil Register. The population comprised individuals (40+ years) who had at least one prescription of selected R03 drugs and who...

An evaluation of different target enrichment methods in pooled sequencing designs for complex disease association studies.

Directory of Open Access Journals (Sweden)

Aaron G Day-Williams

Full Text Available Pooled sequencing can be a cost-effective approach to disease variant discovery, but its applicability in association studies remains unclear. We compare sequence enrichment methods coupled to next-generation sequencing in non-indexed pools of 1, 2, 10, 20 and 50 individuals and assess their ability to discover variants and to estimate their allele frequencies. We find that pooled resequencing is most usefully applied as a variant discovery tool due to limitations in estimating allele frequency with high enough accuracy for association studies, and that in-solution hybrid-capture performs best among the enrichment methods examined regardless of pool size.

Longtime napping is associated with cardiovascular risk estimation according to Framingham risk score in postmenopausal women.

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Li, Feng; Sun, Kan; Lin, Diaozhu; Qi, Yiqin; Li, Yan; Yan, Li; Ren, Meng

2016-09-01

Menopause can affect the physiological timing system, which could result in circadian rhythm changes and development of napping habits. Whether longtime napping in postmenopausal women is associated with cardiovascular disease is, however, still debated. The present study aims to investigate this association. We conducted a population-based study in 4,616 postmenopausal Chinese women. Information on sleep duration was self-reported. The Framingham General Cardiovascular Risk Score was calculated and used to identify participants at high risk of coronary heart disease (CHD). Increased daytime napping hours were positively associated with cardiovascular disease risk factors in postmenopausal women, such as age, waist circumference, systolic blood pressure, triglycerides, fasting glucose, postload glucose, and hemoglobin A1C (all P for trend napping hours, and was 3.7%, 4.3%, and 6.9% in the no daytime napping group, the 0.1 to 1 hour group, and the more than 1 hour group, respectively (P for trend = 0.005). Compared with the no daytime napping group, postmenopausal women with daytime napping more than 1 hour had higher risk of CHD in both univariate (odds ratio 1.94, 95% CI, 1.29-2.95) and multivariate (odds ratio 1.61, 95% CI, 1.03-2.52) logistic regression analyses. No statistically significant association was detected between night sleeping hours and high risk of CHD in postmenopausal participants. Daytime napping is positively associated with estimated 10-year CHD risk in postmenopausal Chinese women.

Importance of tree basic density in biomass estimation and associated uncertainties

DEFF Research Database (Denmark)

Njana, Marco Andrew; Meilby, Henrik; Eid, Tron

2016-01-01

Key message Aboveground and belowground tree basic densities varied between and within the three mangrove species. If appropriately determined and applied, basic density may be useful in estimation of tree biomass. Predictive accuracy of the common (i.e. multi-species) models including aboveground...... of sustainable forest management, conservation and enhancement of carbon stocks (REDD+) initiatives offer an opportunity for sustainable management of forests including mangroves. In carbon accounting for REDD+, it is required that carbon estimates prepared for monitoring reporting and verification schemes...... and examine uncertainties in estimation of tree biomass using indirect methods. Methods This study focused on three dominant mangrove species (Avicennia marina (Forssk.) Vierh, Sonneratia alba J. Smith and Rhizophora mucronata Lam.) in Tanzania. A total of 120 trees were destructively sampled for aboveground...

Genome-wide association study identifies novel breast cancer susceptibility loci

Science.gov (United States)

Easton, Douglas F.; Pooley, Karen A.; Dunning, Alison M.; Pharoah, Paul D. P.; Thompson, Deborah; Ballinger, Dennis G.; Struewing, Jeffery P.; Morrison, Jonathan; Field, Helen; Luben, Robert; Wareham, Nicholas; Ahmed, Shahana; Healey, Catherine S.; Bowman, Richard; Meyer, Kerstin B.; Haiman, Christopher A.; Kolonel, Laurence K.; Henderson, Brian E.; Marchand, Loic Le; Brennan, Paul; Sangrajrang, Suleeporn; Gaborieau, Valerie; Odefrey, Fabrice; Shen, Chen-Yang; Wu, Pei-Ei; Wang, Hui-Chun; Eccles, Diana; Evans, D. Gareth; Peto, Julian; Fletcher, Olivia; Johnson, Nichola; Seal, Sheila; Stratton, Michael R.; Rahman, Nazneen; Chenevix-Trench, Georgia; Bojesen, Stig E.; Nordestgaard, Børge G.; Axelsson, Christen K.; Garcia-Closas, Montserrat; Brinton, Louise; Chanock, Stephen; Lissowska, Jolanta; Peplonska, Beata; Nevanlinna, Heli; Fagerholm, Rainer; Eerola, Hannaleena; Kang, Daehee; Yoo, Keun-Young; Noh, Dong-Young; Ahn, Sei-Hyun; Hunter, David J.; Hankinson, Susan E.; Cox, David G.; Hall, Per; Wedren, Sara; Liu, Jianjun; Low, Yen-Ling; Bogdanova, Natalia; Schürmann, Peter; Dörk, Thilo; Tollenaar, Rob A. E. M.; Jacobi, Catharina E.; Devilee, Peter; Klijn, Jan G. M.; Sigurdson, Alice J.; Doody, Michele M.; Alexander, Bruce H.; Zhang, Jinghui; Cox, Angela; Brock, Ian W.; MacPherson, Gordon; Reed, Malcolm W. R.; Couch, Fergus J.; Goode, Ellen L.; Olson, Janet E.; Meijers-Heijboer, Hanne; van den Ouweland, Ans; Uitterlinden, André; Rivadeneira, Fernando; Milne, Roger L.; Ribas, Gloria; Gonzalez-Neira, Anna; Benitez, Javier; Hopper, John L.; McCredie, Margaret; Southey, Melissa; Giles, Graham G.; Schroen, Chris; Justenhoven, Christina; Brauch, Hiltrud; Hamann, Ute; Ko, Yon-Dschun; Spurdle, Amanda B.; Beesley, Jonathan; Chen, Xiaoqing; Mannermaa, Arto; Kosma, Veli-Matti; Kataja, Vesa; Hartikainen, Jaana; Day, Nicholas E.; Cox, David R.; Ponder, Bruce A. J.; Luccarini, Craig; Conroy, Don; Shah, Mitul; Munday, Hannah; Jordan, Clare; Perkins, Barbara; West, Judy; Redman, Karen; Driver, Kristy; Aghmesheh, Morteza; Amor, David; Andrews, Lesley; Antill, Yoland; Armes, Jane; Armitage, Shane; Arnold, Leanne; Balleine, Rosemary; Begley, Glenn; Beilby, John; Bennett, Ian; Bennett, Barbara; Berry, Geoffrey; Blackburn, Anneke; Brennan, Meagan; Brown, Melissa; Buckley, Michael; Burke, Jo; Butow, Phyllis; Byron, Keith; Callen, David; Campbell, Ian; Chenevix-Trench, Georgia; Clarke, Christine; Colley, Alison; Cotton, Dick; Cui, Jisheng; Culling, Bronwyn; Cummings, Margaret; Dawson, Sarah-Jane; Dixon, Joanne; Dobrovic, Alexander; Dudding, Tracy; Edkins, Ted; Eisenbruch, Maurice; Farshid, Gelareh; Fawcett, Susan; Field, Michael; Firgaira, Frank; Fleming, Jean; Forbes, John; Friedlander, Michael; Gaff, Clara; Gardner, Mac; Gattas, Mike; George, Peter; Giles, Graham; Gill, Grantley; Goldblatt, Jack; Greening, Sian; Grist, Scott; Haan, Eric; Harris, Marion; Hart, Stewart; Hayward, Nick; Hopper, John; Humphrey, Evelyn; Jenkins, Mark; Jones, Alison; Kefford, Rick; Kirk, Judy; Kollias, James; Kovalenko, Sergey; Lakhani, Sunil; Leary, Jennifer; Lim, Jacqueline; Lindeman, Geoff; Lipton, Lara; Lobb, Liz; Maclurcan, Mariette; Mann, Graham; Marsh, Deborah; McCredie, Margaret; McKay, Michael; McLachlan, Sue Anne; Meiser, Bettina; Milne, Roger; Mitchell, Gillian; Newman, Beth; O'Loughlin, Imelda; Osborne, Richard; Peters, Lester; Phillips, Kelly; Price, Melanie; Reeve, Jeanne; Reeve, Tony; Richards, Robert; Rinehart, Gina; Robinson, Bridget; Rudzki, Barney; Salisbury, Elizabeth; Sambrook, Joe; Saunders, Christobel; Scott, Clare; Scott, Elizabeth; Scott, Rodney; Seshadri, Ram; Shelling, Andrew; Southey, Melissa; Spurdle, Amanda; Suthers, Graeme; Taylor, Donna; Tennant, Christopher; Thorne, Heather; Townshend, Sharron; Tucker, Kathy; Tyler, Janet; Venter, Deon; Visvader, Jane; Walpole, Ian; Ward, Robin; Waring, Paul; Warner, Bev; Warren, Graham; Watson, Elizabeth; Williams, Rachael; Wilson, Judy; Winship, Ingrid; Young, Mary Ann; Bowtell, David; Green, Adele; deFazio, Anna; Chenevix-Trench, Georgia; Gertig, Dorota; Webb, Penny

2009-01-01

Breast cancer exhibits familial aggregation, consistent with variation in genetic susceptibility to the disease. Known susceptibility genes account for less than 25% of the familial risk of breast cancer, and the residual genetic variance is likely to be due to variants conferring more moderate risks. To identify further susceptibility alleles, we conducted a two-stage genome-wide association study in 4,398 breast cancer cases and 4,316 controls, followed by a third stage in which 30 single nucleotide polymorphisms (SNPs) were tested for confirmation in 21,860 cases and 22,578 controls from 22 studies. We used 227,876 SNPs that were estimated to correlate with 77% of known common SNPs in Europeans at r2>0.5. SNPs in five novel independent loci exhibited strong and consistent evidence of association with breast cancer (P<10−7). Four of these contain plausible causative genes (FGFR2, TNRC9, MAP3K1 and LSP1). At the second stage, 1,792 SNPs were significant at the P<0.05 level compared with an estimated 1,343 that would be expected by chance, indicating that many additional common susceptibility alleles may be identifiable by this approach. PMID:17529967

Kernel bandwidth estimation for non-parametric density estimation: a comparative study

CSIR Research Space (South Africa)

Van der Walt, CM

2013-12-01

Full Text Available We investigate the performance of conventional bandwidth estimators for non-parametric kernel density estimation on a number of representative pattern-recognition tasks, to gain a better understanding of the behaviour of these estimators in high...

Improving estimation of flight altitude in wildlife telemetry studies

Science.gov (United States)

Poessel, Sharon; Duerr, Adam E.; Hall, Jonathan C.; Braham, Melissa A.; Katzner, Todd

2018-01-01

Altitude measurements from wildlife tracking devices, combined with elevation data, are commonly used to estimate the flight altitude of volant animals. However, these data often include measurement error. Understanding this error may improve estimation of flight altitude and benefit applied ecology.There are a number of different approaches that have been used to address this measurement error. These include filtering based on GPS data, filtering based on behaviour of the study species, and use of state-space models to correct measurement error. The effectiveness of these approaches is highly variable.Recent studies have based inference of flight altitude on misunderstandings about avian natural history and technical or analytical tools. In this Commentary, we discuss these misunderstandings and suggest alternative strategies both to resolve some of these issues and to improve estimation of flight altitude. These strategies also can be applied to other measures derived from telemetry data.Synthesis and applications. Our Commentary is intended to clarify and improve upon some of the assumptions made when estimating flight altitude and, more broadly, when using GPS telemetry data. We also suggest best practices for identifying flight behaviour, addressing GPS error, and using flight altitudes to estimate collision risk with anthropogenic structures. Addressing the issues we describe would help improve estimates of flight altitude and advance understanding of the treatment of error in wildlife telemetry studies.

Software engineering the mixed model for genome-wide association studies on large samples.

Science.gov (United States)

Zhang, Zhiwu; Buckler, Edward S; Casstevens, Terry M; Bradbury, Peter J

2009-11-01

Mixed models improve the ability to detect phenotype-genotype associations in the presence of population stratification and multiple levels of relatedness in genome-wide association studies (GWAS), but for large data sets the resource consumption becomes impractical. At the same time, the sample size and number of markers used for GWAS is increasing dramatically, resulting in greater statistical power to detect those associations. The use of mixed models with increasingly large data sets depends on the availability of software for analyzing those models. While multiple software packages implement the mixed model method, no single package provides the best combination of fast computation, ability to handle large samples, flexible modeling and ease of use. Key elements of association analysis with mixed models are reviewed, including modeling phenotype-genotype associations using mixed models, population stratification, kinship and its estimation, variance component estimation, use of best linear unbiased predictors or residuals in place of raw phenotype, improving efficiency and software-user interaction. The available software packages are evaluated, and suggestions made for future software development.

Walkability and cardiometabolic risk factors: Cross-sectional and longitudinal associations from the Multi-Ethnic Study of Atherosclerosis.

Science.gov (United States)

Braun, Lindsay M; Rodríguez, Daniel A; Evenson, Kelly R; Hirsch, Jana A; Moore, Kari A; Diez Roux, Ana V

2016-05-01

We used data from 3227 older adults in the Multi-Ethnic Study of Atherosclerosis (2004-2012) to explore cross-sectional and longitudinal associations between walkability and cardiometabolic risk factors. In cross-sectional analyses, linear regression was used to estimate associations of Street Smart Walk Score® with glucose, triglycerides, HDL and LDL cholesterol, systolic and diastolic blood pressure, and waist circumference, while logistic regression was used to estimate associations with odds of metabolic syndrome. Econometric fixed effects models were used to estimate longitudinal associations of changes in walkability with changes in each risk factor among participants who moved residential locations between 2004 and 2012 (n=583). Most cross-sectional and longitudinal associations were small and statistically non-significant. We found limited evidence that higher walkability was cross-sectionally associated with lower blood pressure but that increases in walkability were associated with increases in triglycerides and blood pressure over time. Further research over longer time periods is needed to understand the potential for built environment interventions to improve cardiometabolic health. Copyright © 2016 Elsevier Ltd. All rights reserved.

Consequences of Secondary Calibrations on Divergence Time Estimates.

Directory of Open Access Journals (Sweden)

John J Schenk

Full Text Available Secondary calibrations (calibrations based on the results of previous molecular dating studies are commonly applied in divergence time analyses in groups that lack fossil data; however, the consequences of applying secondary calibrations in a relaxed-clock approach are not fully understood. I tested whether applying the posterior estimate from a primary study as a prior distribution in a secondary study results in consistent age and uncertainty estimates. I compared age estimates from simulations with 100 randomly replicated secondary trees. On average, the 95% credible intervals of node ages for secondary estimates were significantly younger and narrower than primary estimates. The primary and secondary age estimates were significantly different in 97% of the replicates after Bonferroni corrections. Greater error in magnitude was associated with deeper than shallower nodes, but the opposite was found when standardized by median node age, and a significant positive relationship was determined between the number of tips/age of secondary trees and the total amount of error. When two secondary calibrated nodes were analyzed, estimates remained significantly different, and although the minimum and median estimates were associated with less error, maximum age estimates and credible interval widths had greater error. The shape of the prior also influenced error, in which applying a normal, rather than uniform, prior distribution resulted in greater error. Secondary calibrations, in summary, lead to a false impression of precision and the distribution of age estimates shift away from those that would be inferred by the primary analysis. These results suggest that secondary calibrations should not be applied as the only source of calibration in divergence time analyses that test time-dependent hypotheses until the additional error associated with secondary calibrations is more properly modeled to take into account increased uncertainty in age estimates.

Model-based estimation for dynamic cardiac studies using ECT.

Science.gov (United States)

Chiao, P C; Rogers, W L; Clinthorne, N H; Fessler, J A; Hero, A O

1994-01-01

The authors develop a strategy for joint estimation of physiological parameters and myocardial boundaries using ECT (emission computed tomography). They construct an observation model to relate parameters of interest to the projection data and to account for limited ECT system resolution and measurement noise. The authors then use a maximum likelihood (ML) estimator to jointly estimate all the parameters directly from the projection data without reconstruction of intermediate images. They also simulate myocardial perfusion studies based on a simplified heart model to evaluate the performance of the model-based joint ML estimator and compare this performance to the Cramer-Rao lower bound. Finally, the authors discuss model assumptions and potential uses of the joint estimation strategy.

Population-Based Estimates of Decreases in Quality-Adjusted Life Expectancy Associated with Unhealthy Body Mass Index.

Science.gov (United States)

Jia, Haomiao; Zack, Matthew M; Thompson, William W

2016-01-01

Being classified as outside the normal range for body mass index (BMI) has been associated with increased risk for chronic health conditions, poor health-related quality of life (HRQOL), and premature death. To assess the impact of BMI on HRQOL and mortality, we compared quality-adjusted life expectancy (QALE) by BMI levels. We obtained HRQOL data from the 1993-2010 Behavioral Risk Factor Surveillance System and life table estimates from the National Center for Health Statistics national mortality files to estimate QALE among U.S. adults by BMI categories: underweight (BMI overweight (BMI 25.0-29.9 kg/m(2)), obese (BMI 30.0-34.9 kg/m(2)), and severely obese (BMI ≥35.0 kg/m(2)). In 2010 in the United States, the highest estimated QALE for adults at 18 years of age was 54.1 years for individuals classified as normal weight. The two lowest QALE estimates were for those classified as either underweight (48.9 years) or severely obese (48.2 years). For individuals who were overweight or obese, the QALE estimates fell between those classified as either normal weight (54.1 years) or severely obese (48.2 years). The difference in QALE between adults classified as normal weight and those classified as either overweight or obese was significantly higher among women than among men, irrespective of race/ethnicity. Using population-based data, we found significant differences in QALE loss by BMI category. These findings are valuable for setting national and state targets to reduce health risks associated with severe obesity, and could be used for cost-effectiveness evaluations of weight-reduction interventions.

Lack of association between level of Plasminogen Activator Inhibitor-1 and estimates of tumor angiogenesis in early breast cancer

DEFF Research Database (Denmark)

Offersen, Birgitte Vrou; Riisbro, Rikke; Knoop, Ann

2007-01-01

Plasminogen Activator Inhibitor type-1 (PAI-1) is involved in tumor invasion and progression. High levels of PAI-1 are associated with poor prognosis in breast cancer, and PAI-1 has been shown to play a role in angiogenic processes. Since estimates of tumor angiogenesis may predict poor prognosis...... we studied the relationship between PAI-1 and estimates of angiogenesis in breast cancer. Tumor tissue specimens from 438 breast cancer patients were included. Median follow-up was 10.3 years. Protein levels of PAI-1 were measured using an ELISA. Angiogenesis scores were performed using a Chalkley.......009) were independent markers of death from breast cancer. This study confirms high PAI-1 or high Chalkley counts as markers of poor prognosis in breast cancer patients, and suggests that the prognostic impact of PAI-1 is independent of its supposed involvement in tumor angiogenesis. Udgivelsesdato: 2007...

Epigenome-wide association studies without the need for cell-type composition.

Science.gov (United States)

Zou, James; Lippert, Christoph; Heckerman, David; Aryee, Martin; Listgarten, Jennifer

2014-03-01

In epigenome-wide association studies, cell-type composition often differs between cases and controls, yielding associations that simply tag cell type rather than reveal fundamental biology. Current solutions require actual or estimated cell-type composition--information not easily obtainable for many samples of interest. We propose a method, FaST-LMM-EWASher, that automatically corrects for cell-type composition without the need for explicit knowledge of it, and then validate our method by comparison with the state-of-the-art approach. Corresponding software is available from http://www.microsoft.com/science/.

Association of Body Mass Index with Depression, Anxiety and Suicide-An Instrumental Variable Analysis of the HUNT Study.

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Johan Håkon Bjørngaard

Full Text Available While high body mass index is associated with an increased risk of depression and anxiety, cumulative evidence indicates that it is a protective factor for suicide. The associations from conventional observational studies of body mass index with mental health outcomes are likely to be influenced by reverse causality or confounding by ill-health. In the present study, we investigated the associations between offspring body mass index and parental anxiety, depression and suicide in order to avoid problems with reverse causality and confounding by ill-health.We used data from 32,457 mother-offspring and 27,753 father-offspring pairs from the Norwegian HUNT-study. Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale and suicide death from national registers. Associations between offspring and own body mass index and symptoms of anxiety and depression and suicide mortality were estimated using logistic and Cox regression. Causal effect estimates were estimated with a two sample instrument variable approach using offspring body mass index as an instrument for parental body mass index.Both own and offspring body mass index were positively associated with depression, while the results did not indicate any substantial association between body mass index and anxiety. Although precision was low, suicide mortality was inversely associated with own body mass index and the results from the analysis using offspring body mass index supported these results. Adjusted odds ratios per standard deviation body mass index from the instrumental variable analysis were 1.22 (95% CI: 1.05, 1.43 for depression, 1.10 (95% CI: 0.95, 1.27 for anxiety, and the instrumental variable estimated hazard ratios for suicide was 0.69 (95% CI: 0.30, 1.63.The present study's results indicate that suicide mortality is inversely associated with body mass index. We also found support for a positive association between body mass index and depression, but not

Estimating the Health Risk Associated with the Use of Ecological Sanitation Toilets in Malawi

Directory of Open Access Journals (Sweden)

Save Kumwenda

2017-01-01

Full Text Available Use of Ecological Sanitation (EcoSan sludge is becoming popular due to increasing price of organic fertilizers in Malawi; however, there is little evidence on the associated risks. Quantitative microbiological risk assessment (QMRA was done to determine health risks associated with use of EcoSan. Pathogens considered included Escherichia coli (E. coli, Salmonella, and soil transmitted helminths (STHs. Exponential and Beta Poisson models were used to estimate the risk from helminthic and bacterial pathogens, respectively. Main exposure pathways were through poor storage of sludge, contamination of foods during drying, walking barefoot on the ground contaminated with sludge, pit emptying without protection, and application of sludge in the fields. Estimated annual risk for Ascaris lumbricoides, Taenia, and hookworms was approximately over 5.6 × 10−1 for both Fossa Alternas (FAs and Urine Diverting Dry Toilet (UDDTs. Risk from E. coli and Salmonella was 8.9 × 10−2 and above. The risks were higher than WHO acceptable risk for use of faecal sludge in crops of 10−4 infections per year. Promoters and users of EcoSan latrines need to consider advocating for strict guidelines to reduce the risk.

Associated with aerospace vehicles development of methodologies for the estimation of thermal properties

Science.gov (United States)

Scott, Elaine P.

1994-01-01

was related to the development of the experimental techniques. Initial experiments required a resistance heater placed between two samples. The design was modified such that the heater was placed on the surface of only one sample, as would be necessary in the analysis of built up structures. Experiments using the modified technique were conducted on the composite sample used previously at different temperatures. The results were within 5 percent of those found using two samples. Finally, an initial heat transfer analysis, including conduction, convection and radiation components, was completed on a titanium sandwich structural sample. Experiments utilizing this sample are currently being designed and will be used to first estimate the material's effective thermal conductivity and later to determine the properties associated with each individual heat transfer component.

A Study on Parametric Wave Estimation Based on Measured Ship Motions

DEFF Research Database (Denmark)

Nielsen, Ulrik Dam; Iseki, Toshio

2011-01-01

The paper studies parametric wave estimation based on the ‘wave buoy analogy’, and data and results obtained from the training ship Shioji-maru are compared with estimates of the sea states obtained from other measurements and observations. Furthermore, the estimating characteristics of the param......The paper studies parametric wave estimation based on the ‘wave buoy analogy’, and data and results obtained from the training ship Shioji-maru are compared with estimates of the sea states obtained from other measurements and observations. Furthermore, the estimating characteristics...... of the parametric model are discussed by considering the results of a similar estimation concept based on Bayesian modelling. The purpose of the latter comparison is not to favour the one estimation approach to the other but rather to highlight some of the advantages and disadvantages of the two approaches....

Model-based estimation for dynamic cardiac studies using ECT

International Nuclear Information System (INIS)

Chiao, P.C.; Rogers, W.L.; Clinthorne, N.H.; Fessler, J.A.; Hero, A.O.

1994-01-01

In this paper, the authors develop a strategy for joint estimation of physiological parameters and myocardial boundaries using ECT (Emission Computed Tomography). The authors construct an observation model to relate parameters of interest to the projection data and to account for limited ECT system resolution and measurement noise. The authors then use a maximum likelihood (ML) estimator to jointly estimate all the parameters directly from the projection data without reconstruction of intermediate images. The authors also simulate myocardial perfusion studies based on a simplified heart model to evaluate the performance of the model-based joint ML estimator and compare this performance to the Cramer-Rao lower bound. Finally, model assumptions and potential uses of the joint estimation strategy are discussed

Estimation development cost, study case: Quality Management System Reactor TRIGA Mark III

International Nuclear Information System (INIS)

Antúnez Barbosa, Tereso Antonio; Valdovinos Rosas, Rosa María; Marcial Romero, José Raymundo; Ramos Corchado, Marco Antonio; Edgar Herrera Arriaga

2016-01-01

The process of estimating costs in software engineering is not a simple task, it must be addressed carefully to obtain an efficient strategy to solve problems associated with the effort, cost and time of activities that are performed in the development of an information system project. In this context the main goal for both developers and customers is the cost, since developers are worry about the effort pay-load and customers are worry about the product pay-load. However, in other fields the cost of goods depends on the activity or process that is performed, thereby deduce that the main cost of the final product of a development project software project is undoubtedly its size. In this paper a comparative study of common models for estimating costs are developed. These models are used today in order to create a structured analysis to provide the necessary information about cost, time and effort for making decisions in a software development project. Finally the models are applied to a case study, which is a system called Monitorizacion Automatica del Sistema de Gestion de Calidad del Reactor TRIGA Mark III. (author)

Factors Associated with Remission of Eczema in Children: a Population-based Follow-up Study.

OpenAIRE

von Kobyletzki, Laura; Bornehag, Carl-Gustaf; Breeze, Elizabeth; Larsson, Malin; Boman Lindström, Cecilia; Svensson, Åke

2014-01-01

The aim of this study was to analyse factors associated with remission of atopic dermatitis (AD) in childhood. A population-based AD cohort of 894 children aged 1-3 years from a cross-sectional baseline study in 2000 was followed up in 2005. The association between remission, background, health, lifestyle, and environmental variables was estimated with crude and multivariable logistic regression. At follow-up, 52% of the children had remission. Independent factors at baseline predicting remis...

Genetic association study of common mitochondrial variants on body fat mass.

Directory of Open Access Journals (Sweden)

Tie-Lin Yang

Full Text Available Mitochondria play a central role in ATP production and energy metabolism. Previous studies suggest that common variants in mtDNA are associated with several common complex diseases, including obesity. To test the hypothesis that common mtDNA variants influence obesity-related phenotypes, including BMI and body fat mass, we genotyped a total of 445 mtSNPs across the whole mitochondrial genome in a large sample of 2,286 unrelated Caucasian subjects. 72 of these 445 mtSNPs passed quality control criteria, and were used for subsequent analyses. We also classified all subjects into nine common European haplogroups. Association analyses were conducted for both BMI and body fat mass with single mtSNPs and mtDNA haplogroups. Two mtSNPs, mt4823 and mt8873 were detected to be significantly associated with body fat mass, with adjusted P values of 4.94 × 10⁻³ and 4.58 × 10⁻², respectively. The minor alleles mt4823 C and mt8873 A were associated with reduced fat mass values and the effect size (β was estimated to be 3.52 and 3.18, respectively. These two mtSNPs also achieved nominally significant levels for association with BMI. For haplogroup analyses, we found that haplogroup X was strongly associated with both BMI (adjusted P = 8.31 × 10⁻³ and body fat mass (adjusted P = 5.67×10⁻⁴ Subjects classified as haplogroup X had lower BMI and fat mass values, with the β estimated to be 2.86 and 6.03, respectively. Our findings suggest that common variants in mitochondria might play a role in variations of body fat mass. Further molecular and functional studies will be needed to clarify the potential mechanism.

Composite likelihood and two-stage estimation in family studies

DEFF Research Database (Denmark)

Andersen, Elisabeth Anne Wreford

2004-01-01

In this paper register based family studies provide the motivation for linking a two-stage estimation procedure in copula models for multivariate failure time data with a composite likelihood approach. The asymptotic properties of the estimators in both parametric and semi-parametric models are d...

Association between perceived racial discrimination and hypertension: findings from the ELSA-Brasil study.

Science.gov (United States)

Mendes, Patrícia Miranda; Nobre, Aline Araújo; Griep, Rosane Härter; Guimarães, Joanna Miguez Nery; Juvanhol, Leidjaira Lopes; Barreto, Sandhi Maria; Pereira, Alexandre; Chor, Dóra

2018-03-01

"Pardos" and blacks in Brazil and blacks in the USA are at greater risk of developing arterial hypertension than whites, and the causes of this inequality are still little understood. Psychosocial and contextual factors, including racial discrimination, are indicated as conditions associated with this inequality. The aim of this study was to identify the association between perceived racial discrimination and hypertension. The study evaluated 14,012 workers from the ELSA-Brazil baseline population. Perceived discrimination was measured by the Lifetime Major Events Scale, adapted to Portuguese. Classification by race/color followed the categories proposed by Brazilian Institute of Geography and Statistics (IBGE). Hypertension was defined by standard criteria. The association between the compound variable - race/racial discrimination - and hypertension was estimated by Poisson regression with robust variance and stratified by the categories of body mass index (BMI) and sex. Choosing white women as the reference group, in the BMI 25kg/m2 and men in any BMI category, no effect of racial discrimination was identified. Despite the differences in point estimates of prevalence of hypertension between "pardo" women who reported and those who did not report discrimination, our results are insufficient to assert that an association exists between racial discrimination and hypertension.

Estimation of beverage consumption and associated caloric intake in adult Czech population. An observational study.

Science.gov (United States)

Adámková, Věra; Hubáček, Jaroslav A; Zimmelová, Petra; Velemínský, Miloš

2011-01-01

Food intake is a commonly monitored issue in many studies. In contrast, almost no information has been published on beverage intake in adults. To evaluate beverage intake, we studied a population of 1, 200 adults (656 males and 544 females, aged 18-54 years). The volumes and types of beverages were obtained from self-reported questionnaires. The mean beverage intake was highly variable, with a minimum of 450 mL/day and a maximum of 5,330 mL/day. A mean of 1,575 mL/day was found in the entire population (2,300 mL in males and 840 mL in females). Different patterns in the consumption of beverage types were observed between the males and females. For both males and females, the most common beverage consumed was water followed by tea. The next preferable beverages were alcoholic beer, coffee, and non-alcoholic beer in males and coffee, milk, and alcoholic beer in females. The estimated caloric intake from beverages covers, in most individuals, 10-30% of the recommended daily caloric intake. There is substantial variation among individuals, both in beverage intake and in caloric intake through beverages. The caloric intake from beverages reaches, in some individuals, one-third of the recommended daily caloric rate. © 2011 Neuroendocrinology Letters

Genome-wide association study of pancreatic cancer in Japanese population.

Directory of Open Access Journals (Sweden)

Siew-Kee Low

Full Text Available Pancreatic cancer shows very poor prognosis and is the fifth leading cause of cancer death in Japan. Previous studies indicated some genetic factors contributing to the development and progression of pancreatic cancer; however, there are limited reports for common genetic variants to be associated with this disease, especially in the Asian population. We have conducted a genome-wide association study (GWAS using 991 invasive pancreatic ductal adenocarcinoma cases and 5,209 controls, and identified three loci showing significant association (P-value<5x10(-7 with susceptibility to pancreatic cancer. The SNPs that showed significant association carried estimated odds ratios of 1.29, 1.32, and 3.73 with 95% confidence intervals of 1.17-1.43, 1.19-1.47, and 2.24-6.21; P-value of 3.30x10(-7, 3.30x10(-7, and 4.41x10(-7; located on chromosomes 6p25.3, 12p11.21 and 7q36.2, respectively. These associated SNPs are located within linkage disequilibrium blocks containing genes that have been implicated some roles in the oncogenesis of pancreatic cancer.

Association of Type D personality with unhealthy lifestyle, and estimated risk of coronary events in the general Icelandic population

NARCIS (Netherlands)

Svansdóttir, E.; Denollet, J.; Thorsson, B.; Gudnason, T.; Halldorsdottir, S.; Gudnason, V.; van den Broek, K.C.; Karlsson, D.

2013-01-01

Background: Type D personality is associated with an increased morbidity and mortality risk in cardiovascular disease patients, but the mechanisms explaining this risk are unclear. We examined whether Type D was associated with coronary artery disease (CAD) risk factors, estimated risk of developing

Estimated drinking water fluoride exposure and risk of hip fracture: a cohort study.

Science.gov (United States)

Näsman, P; Ekstrand, J; Granath, F; Ekbom, A; Fored, C M

2013-11-01

The cariostatic benefit from water fluoridation is indisputable, but the knowledge of possible adverse effects on bone and fracture risk due to fluoride exposure is ambiguous. The association between long-term (chronic) drinking water fluoride exposure and hip fracture (ICD-7-9: '820' and ICD-10: 'S72.0-S72.2') was assessed in Sweden using nationwide registers. All individuals born in Sweden between January 1, 1900 and December 31, 1919, alive and living in their municipality of birth at the time of start of follow-up, were eligible for this study. Information on the study population (n = 473,277) was linked among the Swedish National In-Patient Register (IPR), the Swedish Cause of Death Register, and the Register of Population and Population Changes. Estimated individual drinking water fluoride exposure was stratified into 4 categories: very low, hip fracture. The risk estimates did not change in analyses restricted to only low-trauma osteoporotic hip fractures. Chronic fluoride exposure from drinking water does not seem to have any important effects on the risk of hip fracture, in the investigated exposure range.

A comparative study of the performances of some estimators of ...

African Journals Online (AJOL)

These estimators are compared using the finite properties of estimators' criteria namely; sum of biases, sum of variances and sum of the mean squared error of the estimated parameter of the model at different levels of autocorrelation and sample size through Monte – Carlo studies. Results show that at each level of ...

Estimating the Direct Medical Economic Burden of Health Care-Associated Infections in Public Tertiary Hospitals in Hubei Province, China.

Science.gov (United States)

Li, Hao; Liu, Xinliang; Cui, Dan; Wang, Quan; Mao, Zongfu; Fang, Liang; Zhang, Furong; Yang, Ping; Wu, Huiling; Ren, Nili; He, Jianyun; Sun, Jing

2017-07-01

This study estimated the attributable direct medical economic burden of health care-associated infections (HAIs) in China. Data were extracted from hospitals' information systems. Inpatient cases with HAIs and non-HAIs were grouped by the propensity score matching (PSM) method. Attributable hospitalization expenditures and length of hospital stay were measured to estimate the direct medical economic burden of HAIs. STATA 12.0 was used to conduct descriptive analysis, bivariate χ 2 test, paired Z test, PSM ( r = 0.25σ, nearest neighbor 1:1 matching), and logistic regress analysis. The statistically significant level was set at .05. The HAIs group had statistically significant higher expenditures and longer hospitalization stay than the non-HAIs group during 2013 to 2015 ( P economic burden of HAIs calls for more effective HAI surveillance and better control with appropriate incentives.

Multiethnic meta-analysis of genome-wide association studies in >100 000 subjects identifies 23 fibrinogen-associated Loci but no strong evidence of a causal association between circulating fibrinogen and cardiovascular disease

NARCIS (Netherlands)

Sabater-Lleal, M.; Huang, J.; Chasman, D.I.; Naitza, S.; Dehghan, A.; Johnson, A.D.; Teumer, A.; Reiner, A.P.; Folkersen, L.; Basu, S.; Rudnicka, A.R.; Trompet, S.; Mälarstig, A.; Baumert, J.; Bis, J.C.; Guo, X.; Hottenga, J.J.; Shin, S.Y.; Lopez, L.M.; Lahti, J.; Tanaka, T.; Yanek, L.R.; Oudot-Mellakh, T.; Wilson, J.F.; Navarro, P.; Huffman, J.E.; Zemunik, T.; Redline, S.; Mehra, R.; Pulanic, D.; Rudan, I.; Wright, A.F.; Kolcic, I.; Polasek, O.; Wild, S.H.; Campbell, H.; Curb, J.D.; Wallace, R.; Liu, S.; Eaton, C.B.; Becker, D.M.; Becker, L.C.; Bandinelli, S.; Räikkönen, K.; Widén, E.; Palotie, A.; Fornage, M.; Green, D.; Gross, M.; Davies, G.E.; Harris, S.E.; Liewald, D.C.; Starr, J.M.; Williams, F.M.; Grant, P.J.; Spector, T.D.; Strawbridge, R.J.; Silveira, A.; Sennblad, B.; Rivadeneira, F.; Uitterlinden, A.G.; Franco, O.H.; Hofman, A.; van Dongen, J.; Willemsen, G.; Boomsma, D.I.; Yao, J.; Swords Jenny, N.; Haritunians, T.; McKnight, B.; Lumley, T.; Taylor, K.D.; Rotter, J.I.; Psaty, B.M.; Peters, A.; Gieger, C.; Illig, T.; Grotevendt, A.; Homuth, G.; Völzke, H.; Kocher, T.; Goel, A.; Franzosi, M.G.; Seedorf, U.; Clarke, R.; Steri, M.; Tarasov, K.V.; Sanna, S.; Schlessinger, D.; Stott, D.J.; Sattar, N.; Buckley, B.M.; Rumley, A.; Lowe, G.D.; McArdle, W.L.; Chen, M.H.; Tofler, G.H.; Song, J.; Boerwinkle, E.; Folsom, A.R.; Rose, L.M.; Franco-Cereceda, A.; Teichert, M.; Ikram, M.A.; Mosley, T.H.; Bevan, S.; Dichgans, M.; Rothwell, P.M.; Sudlow, C.L.; Hopewell, J.C.; Chambers, J.C.; Saleheen, D.; Kooner, J.S.; Danesh, J.; Nelson, C.P.; Erdmann, J.; Reilly, M.P.; Kathiresan, S.; Schunkert, H.; Morange, P.E.; Ferrucci, L.; Eriksson, J.G.; Jacobs, D.; Deary, I.J.; Soranzo, N.; Witteman, J.C.; de Geus, E.J.C.; Tracy, R.P.; Hayward, C.; Koenig, W.; Cucca, F.; Jukema, J.W.; Eriksson, P.; Seshadri, S.; Markus, H.S.; Watkins, H.; Samani, N.J.; Wallaschofski, H.; Smith, N.L.; Tregouet, D.A.; Ridker, P.M.; Tang, W.; Strachan, D.P.; Hamsten, A.; O'Donnell, C.J.

2013-01-01

BACKGROUND-: Estimates of the heritability of plasma fibrinogen concentration, an established predictor of cardiovascular disease, range from 34% to 50%. Genetic variants so far identified by genome-wide association studies explain only a small proportion (<2%) of its variation. METHODS AND

Estimates of Enhanced Outcomes in Employment, Income, Health, and Volunteerism for the Association of Boarding Schools Member School Graduates

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Steel, Allison; Erhardt, Robert; Phelps, Richard; Upham, Peter

2015-01-01

We analyzed data from 65 schools that are U.S. members of The Association of Boarding Schools (TABS) to estimate how TABS member school graduates who enter college compare with college entrants from non-boarding schools on several long-term quality-of-life estimates. Although TABS students are more likely to graduate college than the population of…

Association between serum bilirubin levels and decline in estimated glomerular filtration rate among patients with type 2 diabetes.

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Wang, Jing; Li, Yaru; Han, Xu; Hu, Hua; Wang, Fei; Yu, Caizheng; Li, Xiulou; Yang, Kun; Yuan, Jing; Yao, Ping; Miao, Xiaoping; Wei, Sheng; Wang, Youjie; Chen, Weihong; Liang, Yuan; Zhang, Xiaomin; Guo, Huan; Pan, An; Yang, Handong; Wu, Tangchun; He, Meian

2016-01-01

Studies indicate that elevated serum total bilirubin (TBil) levels are associated with lower risk of diabetic kidney disease (DKD). Few studies examined the associations of direct bilirubin (DBil) and indirect bilirubin (IBil) with the development of DKD. Type 2 diabetes patients (n=2,958) with estimated glomerular filtration (eGFR)≥60mlmin(-1) 1.73m(-2) from the Dongfeng-Tongji cohort were selected and followed up for 5years. Development of DKD was defined as decline in eGFR≥30% during follow-up. Generalize linear model was used to assess the associations of bilirubin levels with DKD development. Compared with those in the first tertile of serum TBil, the relative risks (RRs) and 95% confidence intervals (CIs) of incident eGFR decline for tertile 2 to 3 were 0.83 (0.64-1.09) and 0.74 (0.56-0.98), Ptrend=0.04. The counterpart RRs (95% CIs) in IBil were 0.74 (0.57-0.97) and 0.75 (0.57-0.98), Ptrend=0.04. No significant associations were observed in DBil. Moreover, TBil and IBil interacted with smoking, the bilirubin-DKD associations were evident in ever smokers. Our findings suggest that elevation of serum TBil or IBil levels are independent protective factors for development of DKD, particularly in smokers. Copyright © 2016 Elsevier Inc. All rights reserved.

The Estimation of Gestational Age at Birth in Database Studies.

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Eberg, Maria; Platt, Robert W; Filion, Kristian B

2017-11-01

Studies on the safety of prenatal medication use require valid estimation of the pregnancy duration. However, gestational age is often incompletely recorded in administrative and clinical databases. Our objective was to compare different approaches to estimating the pregnancy duration. Using data from the Clinical Practice Research Datalink and Hospital Episode Statistics, we examined the following four approaches to estimating missing gestational age: (1) generalized estimating equations for longitudinal data; (2) multiple imputation; (3) estimation based on fetal birth weight and sex; and (4) conventional approaches that assigned a fixed value (39 weeks for all or 39 weeks for full term and 35 weeks for preterm). The gestational age recorded in Hospital Episode Statistics was considered the gold standard. We conducted a simulation study comparing the described approaches in terms of estimated bias and mean square error. A total of 25,929 infants from 22,774 mothers were included in our "gold standard" cohort. The smallest average absolute bias was observed for the generalized estimating equation that included birth weight, while the largest absolute bias occurred when assigning 39-week gestation to all those with missing values. The smallest mean square errors were detected with generalized estimating equations while multiple imputation had the highest mean square errors. The use of generalized estimating equations resulted in the most accurate estimation of missing gestational age when birth weight information was available. In the absence of birth weight, assignment of fixed gestational age based on term/preterm status may be the optimal approach.

Beyond Attributable Burden: Estimating the Avoidable Burden of Disease Associated with Household Air Pollution.

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Randall Kuhn

Full Text Available The Global Burden of Disease (GBD studies have transformed global understanding of health risks by producing comprehensive estimates of attributable disease burden, or the current disease that would be eliminated if a risk factor did not exist. Yet many have noted the greater policy significance of avoidable burden, or the future disease that could actually be eliminated if a risk factor were eliminated today. Avoidable risk may be considerably lower than attributable risk if baseline levels of exposure or disease are declining, or if a risk factor carries lagged effects on disease. As global efforts to deliver clean cookstoves accelerate, a temporal estimation of avoidable risk due to household air pollution (HAP becomes increasingly important, particularly in light of the rapid uptake of modern stoves and ongoing epidemiologic transitions in regions like South and Southeast Asia.We estimate the avoidable burden associated with HAP using International Futures (IFs, an integrated forecasting system that has been used to model future global disease burdens and risk factors. Building on GBD and other estimates, we integrated a detailed HAP exposure estimation and exposure-response model into IFs. We then conducted a counterfactual experiment in which HAP exposure is reduced to theoretical minimum levels in 2015. We evaluated avoidable mortality and DALY reductions for the years 2015 to 2024 relative to a Base Case scenario in which only endogenous changes occurred. We present results by cause and region, looking at impacts on acute lower respiratory infection (ALRI and four noncommunicable diseases (NCDs. We found that just 2.6% of global DALYs would be averted between 2015 and 2024, compared to 4.5% of global DALYs attributed to HAP in the 2010 GBD study, due in large part to the endogenous tendency towards declining traditional stove usage in the IFs base case forecast. The extent of diminished impact was comparable for ALRI and affected NCDs

Trick or treat: The effect of placebo on the power of pharmacogenetic association studies

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Singer Clara

2005-03-01

Full Text Available Abstract The genetic mapping of drug-response traits is often characterised by a poor signal-to-noise ratio that is placebo related and which distinguishes pharmacogenetic association studies from classical case-control studies for disease susceptibility. The goal of this study was to evaluate the statistical power of candidate gene association studies under different pharmacogenetic scenarios, with special emphasis on the placebo effect. Genotype/phenotype data were simulated, mimicking samples from clinical trials, and response to the drug was modelled as a binary trait. Association was evaluated by a logistic regression model. Statistical power was estimated as a function of the number of single nucleotide polymorphisms (SNPs genotyped, the frequency of the placebo 'response', the genotype relative risk (GRR of the response polymorphism, the strategy for selecting SNPs for genotyping, the number of individuals in the trial and the ratio of placebo-treated to drugtreated patients. We show that: (i the placebo 'response' strongly affects the statistical power of association studies -- even a highly penetrant drug-response allele requires at least a 500-patient trial in order to reach 80 per cent power, several-fold more than the value estimated by standard tools that are not calibrated to pharmacogenetics; (ii the power of a pharmacogenetic association study depends primarily on the penetrance of the response genotype and, when this penetrance is fixed, power decreases for larger placebo effects; (iii power is dramatically increased when adding markers; (iv an optimal study design includes a similar number of placebo- and drugtreated patients; and (v in this setting, straightforward haplotype analysis does not seem to have an advantage over single marker analysis.

Estimation of age of Dali-Ganis rifting and associated volcanic activity, Venus

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Basilevsky, A. T.

1993-01-01

This paper deals with the estimation of age for the Dali and Ganis Chasma rift zones and their associated volcanism based on photogeologic analysis of stratigraphic relations of rift-associated features with impact craters which have associated features indicative of their age. The features are radar-dark and parabolic, and they are believed to be mantles of debris derived from fallout of the craters' ejecta. They are thought to be among the youngest features on the Venusian surface, so their 'parent' craters must also be very young, evidently among the youngest 10 percent of Venus' crater population. Dali Chasma and Ganis Chasma are a part of a system of rift zones contained within eastern Aphrodite and Atla Regio which is a significant component of Venus tectonics. The rifts of this system are fracture belts which dissect typical Venusian plains with rare islands of tessera terrain. The rift zone system consists of several segments following each other (Diane, Dali, Ganis) and forming the major rift zone line, about 10,000 km long, which has junctions with several other rift zones, including Parga Chasma Rift. The junctions are usually locations of rift-associated volcanism in the form of volcanic edifices (Maat and Ozza Montes) or plain-forming flows flooding some areas within the rift zones and the adjacent plains.

Association between chronic kidney disease and urinary calculus by stone location: a population-based study.

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Keller, Joseph J; Chen, Yi-Kuang; Lin, Herng-Ching

2012-12-01

Study Type--Disease prevalence study (cohort design) Level of Evidence 2a. What's known on the subject? and What does the study add? Several studies have estimated the potential association of urinary calculus (UC) with chronic kidney disease (CKD). However, previous literature focusing on this issue tended to evaluate the impact of kidney stones alone on incident CKD, with no studies having been conducted investigating the association between CKD and stone formation in other portions of the urological system. We found that patients with CKD were consistently more likely than comparison subjects to have been previously diagnosed with kidney calculus (odds ratio [OR] 2.10, 95% confidence interval [CI] 1.95-2.27), ureter calculus (OR 1.68, 95% CI 1.51-1.85), bladder calculus (OR 1.49, 95% CI 1.13-1.98), and unspecified calculus (OR 1.89, 95% CI 1.74-2.06). We concluded that there was an association between CKD and UC regardless of stone location. • To explore the association of chronic kidney disease (CKD) with prior kidney calculus, ureter calculus, and bladder calculus using a population-based dataset in Taiwan. Several studies have estimated the potential association of urinary calculus (UC) with CKD. However, previous literature focusing on this issue tended to evaluate the impact of kidney stones alone on incident CKD, with no studies having been conducted investigating the association between CKD and stone formation in other portions of the urological system. • We identified 21,474 patients who received their first-time diagnosis of CKD between 2001 and 2009. • The 21,474 controls were frequency-matched with cases for sex, age group, and index year. • We used conditional logistic regression analyses to compute the odds ratio (OR) and corresponding 95% confidence interval (CI) as an estimation of association between CKD and having been previously diagnosed with UC. • The results show that compared with controls, the OR of prior UC for cases was 1

Lower estimated glomerular filtration rate and higher albuminuria are associated with mortality and end-stage renal disease. A collaborative meta-analysis of kidney disease population cohorts

DEFF Research Database (Denmark)

Astor, Brad C; Matsushita, Kunihiro; Gansevoort, Ron T

2011-01-01

We studied here the independent associations of estimated glomerular filtration rate (eGFR) and albuminuria with mortality and end-stage renal disease (ESRD) in individuals with chronic kidney disease (CKD). We performed a collaborative meta-analysis of 13 studies totaling 21,688 patients selected...

A new evaluation of the uncertainty associated with CDIAC estimates of fossil fuel carbon dioxide emission

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Robert J. Andres

2014-07-01

Full Text Available Three uncertainty assessments associated with the global total of carbon dioxide emitted from fossil fuel use and cement production are presented. Each assessment has its own strengths and weaknesses and none give a full uncertainty assessment of the emission estimates. This approach grew out of the lack of independent measurements at the spatial and temporal scales of interest. Issues of dependent and independent data are considered as well as the temporal and spatial relationships of the data. The result is a multifaceted examination of the uncertainty associated with fossil fuel carbon dioxide emission estimates. The three assessments collectively give a range that spans from 1.0 to 13% (2 σ. Greatly simplifying the assessments give a global fossil fuel carbon dioxide uncertainty value of 8.4% (2 σ. In the largest context presented, the determination of fossil fuel emission uncertainty is important for a better understanding of the global carbon cycle and its implications for the physical, economic and political world.

Multiethnic meta-analysis of genome-wide association studies in >100 000 subjects identifies 23 fibrinogen-associated Loci but no strong evidence of a causal association between circulating fibrinogen and cardiovascular disease

NARCIS (Netherlands)

Sabater-Lleal, M.; Huang, J.; Chasman, D.; Naitza, S.; Dehghan, A.; Johnson, A.D.; Teumer, A.; Reiner, A.P.; Folkersen, L.; Basu, S.; Rudnicka, A.R.; Trompet, S.; Malarstig, A.; Baumert, J.; Bis, J.C.; Guo, X.; Hottenga, J.J.; Shin, S.Y.; Lopez, L.M.; Lahti, J.; Tanaka, T.; Yanek, L.R.; Oudot-Mellakh, T.; Wilson, J.F.; Navarro, P.; Huffman, J.E.; Zemunik, T.; Redline, S.; Mehra, R.; Pulanic, D.; Rudan, I.; Wright, A.F.; Kolcic, I.; Polasek, O.; Wild, S.H.; Campbell, H.; Curb, J.D.; Wallace, R.; Liu, S.; Eaton, C.B.; Becker, D.M.; Becker, L.C.; Bandinelli, S.; Raikkonen, K.; Widen, E.; Palotie, A.; Fornage, M.; Green, D.; Gross, M.; Davies, G.; Harris, S.E.; Liewald, D.C.; Starr, J.M.; Williams, F.M.; Grant, P.J.; Spector, T.D.; Strawbridge, R.J.; Silveira, A.; Sennblad, B.; Rivadeneira, F.; Uitterlinden, A.G.; Franco, O.H.; Hofman, A.; Dongen, J. Van; Willemsen, G.; Boomsma, D.I.; Yao, J.; Jenny, N. Swords; Haritunians, T.; McKnight, B.; Lumley, T.; Taylor, K.D.; Rotter, J.I.; Psaty, B.M.; Peters, A.; Gieger, C.; Illig, T.; Grotevendt, A.; Homuth, G.; Volzke, H.; Kocher, T.; Goel, A.; Franzosi, M.G.; Seedorf, U.; Clarke, R.; Steri, M.; Tarasov, K.V.; Sanna, S.; Schlessinger, D.; Stott, D.J.; Sattar, N.; Buckley, B.M.; Rumley, A.; Lowe, G.D.; McArdle, W.L.; Chen, M.H.; Tofler, G.H.; Song, J.; Boerwinkle, E.; Folsom, A.R.; Teichert, M.; et al.,

2013-01-01

BACKGROUND: Estimates of the heritability of plasma fibrinogen concentration, an established predictor of cardiovascular disease, range from 34% to 50%. Genetic variants so far identified by genome-wide association studies explain only a small proportion (<2%) of its variation. METHODS AND RESULTS:

Defining and Estimating Healthy Aging in Spain: A Cross-sectional Study.

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Rodriguez-Laso, Angel; McLaughlin, Sara J; Urdaneta, Elena; Yanguas, Javier

2018-03-19

Using an operational continuum of healthy aging developed by U.S. researchers, we sought to estimate the prevalence of healthy aging among older Spaniards, inform the development of a definition of healthy aging in Spain, and foster cross-national research on healthy aging. The ELES pilot study is a nationwide, cross-sectional survey of community-dwelling Spaniards 50 years and older. The prevalence of healthy aging was calculated for the 65 and over population using varying definitions. To evaluate their validity, we examined the association of healthy aging with the 8 foot up & go test, quality of life scores and self-perceived health using multiple linear and logistic regression. The estimated prevalence of healthy aging varied across the operational continuum, from 4.5% to 49.2%. Prevalence figures were greater for men and those aged 65 to 79 years and were higher than in the United States. Predicted mean physical performance scores were similar for 3 of the 4 definitions, suggesting that stringent definitions of healthy aging offer little advantage over a more moderate one. Similar to U.S. researchers, we recommend a definition of healthy aging that incorporates measures of functional health and limiting disease as opposed to definitions requiring the absence of all disease in studies designed to assess the effect of policy initiatives on healthy aging.

Informing Estimates of Program Effects for Studies of Mathematics Professional Development Using Teacher Content Knowledge Outcomes.

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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.

Hyperuricemia and associated factors: a cross-sectional study of Japanese-Brazilians

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Juliana Poletto

2011-02-01

Full Text Available This cross-sectional study aimed to estimate the prevalence of hyperuricemia and associated risk factors among Japanese-Brazilians. We obtained data on demographic, health history, food intake, and laboratory variables. Chi-square and prevalence ratios were used as measures of association. 35.3% of the subjects presented hyperuricemia, which was more frequent in smokers, males, age > 55 years, with co-morbidities, individuals on uric acid-increasing medication, serum creatinine > 1.4mg/dL, high alcohol consumption, and low consumption of milk and dairy products. In the multivariate analysis, the associations remained significant with gender, overweight, central obesity, hypertriglyceridemia, and use of specific drugs. Among males, low intake of saturated fat was associated with hyperuricemia. Individuals with hypertension showed a negative association with dairy product consumption. The high hyperuricemia prevalence suggests that changes in nutritional profile and control of associated co-morbidities could help minimize occurrence of this condition.

Prevalence and associated factors of DSM-V insomnia in Norway: the Nord-Trøndelag Health Study (HUNT 3).

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Uhlig, Benjamin Langsæter; Sand, Trond; Odegård, Siv Steinsmo; Hagen, Knut

2014-06-01

Many studies have assessed the prevalence of insomnia, but the influence of non-participants has largely been ignored. The objective of the present study was to estimate the prevalence and associated factors of insomnia in a large adult population using DSM-V (diagnostic and statistical manual of mental disorders, 5th ed.) criteria, also taking non-participants into account. This cross-sectional study used data from a questionnaire in The Nord-Trøndelag Health Study (HUNT 3) performed in 2006-2008, and a subsequent non-participant study. The total adult population (n=93,860 aged > or =20 years) of Nord-Trøndelag County, Norway, was invited. Of these, 40,535 responded to the insomnia questionnaire. Among 42,024 eligible non-participants, 6918 (17%) responded to two insomnia questions. Insomnia was diagnosed by applying modified DSM-V criteria. The age-adjusted insomnia prevalence was estimated using the age distribution of all adult inhabitants of Nord-Trøndelag. Supplementary prevalence data were estimated by extrapolating data from the non-participant study. Additionally, the association between insomnia and self-reported health was estimated, adjusting for known confounders. The total age-adjusted prevalence of insomnia was 7.1% (95% confidence interval [CI], 6.9-7.4) (8.6% for women, 5.5% for men). Adjusting for non-participants, the prevalence estimate changed to 7.9% (95% CI, 7.3-8.6) (9.4% for women, 6.4% for men). Insomnia was more than eight times more likely (OR, 8.3; 95% CI, 6.2-11.1) among individuals with very poor versus very good self-reported health, adjusting for age, gender, employment status, chronic musculoskeletal complaints, anxiety and depression. The adjusted insomnia prevalence estimate in Nord-Trøndelag was 7.9%. Insomnia was strongly associated with poor self-reported health. Copyright © 2014 Elsevier B.V. All rights reserved.

Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes: meta-epidemiological study

DEFF Research Database (Denmark)

Wood, L.; Egger, M.; Gluud, L.L.

2008-01-01

OBJECTIVE: 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. DESIGN: Combined analysis of data from three meta-epidemiological studies based o...

Association between subjective risk perception and objective risk estimation in patients with atrial fibrillation: a cross-sectional study.

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Zweiker, David; Zweiker, Robert; Winkler, Elisabeth; Roesch, Konstantina; Schumacher, Martin; Stepan, Vinzenz; Krippl, Peter; Bauer, Norbert; Heine, Martin; Reicht, Gerhard; Zweiker, Gudrun; Sprenger, Martin; Watzinger, Norbert

2017-09-25

Oral anticoagulation (OAC) is state-of-the-art therapy for atrial fibrillation (AF), the most common arrhythmia worldwide. However, little is known about the perception of patients with AF and how it correlates with risk scores used by their physicians. Therefore, we correlated patients' estimates of their own stroke and bleeding risk with the objectively predicted individual risk using CHA 2 DS 2 -VASc and HAS-BLED scores. Cross-sectional prevalence study using convenience sampling and telephone follow-up. Eight hospital departments and one general practitioner in Austria. Patients' perception of stroke and bleeding risk was opposed to commonly used risk scoring. Patients with newly diagnosed AF and indication for anticoagulation. Comparison of subjective risk perception with CHA 2 DS 2 -VASc and HAS-BLED scores showing possible discrepancies between subjective and objective risk estimation. Patients' judgement of their own knowledge on AF and education were also correlated with accuracy of subjective risk appraisal. Ninety-one patients (age 73±11 years, 45% female) were included in this study. Subjective stroke and bleeding risk estimation did not correlate with risk scores (ρ=0.08 and ρ=0.17). The majority of patients (57%) underestimated the individual stroke risk. Patients feared stroke more than bleeding (67% vs 10%). There was no relationship between accurate perception of stroke and bleeding risks and education level. However, we found a correlation between the patients' judgement of their own knowledge of AF and correct assessment of individual stroke risk (ρ=0.24, p=0.02). During follow-up, patients experienced the following events: death (n=5), stroke (n=2), bleeding (n=1). OAC discontinuation rate despite indication was 3%. In this cross-sectional analysis of OAC-naive patients with AF, we found major differences between patients' perceptions and physicians' assessments of risks and benefits of OAC. To ensure shared decision-making and informed

Power Estimation for Gene-Longevity Association Analysis Using Concordant Twins

DEFF Research Database (Denmark)

Tan, Qihua; Zhao, Jing Hua; Kruse, Torben A

2014-01-01

Statistical power is one of the major concerns in genetic association studies. Related individuals such as twins are valuable samples for genetic studies because of their genetic relatedness. Phenotype similarity in twin pairs provides evidence of genetic control over the phenotype variation...... in a population. The genetic association study on human longevity, a complex trait that is under control of both genetic and environmental factors, has been confronted by the small sample sizes of longevity subjects which limit statistical power. Twin pairs concordant for longevity have increased probability...... an approximate of 2- to 3-fold increase in sample sizes needed for longevity cutoff at age 90 as compared with that at age 95. Overall, our results showed high value of twins in genetic association studies on human longevity....

Problematic video game use: estimated prevalence and associations with mental and physical health.

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Mentzoni, Rune Aune; Brunborg, Geir Scott; Molde, Helge; Myrseth, Helga; Skouverøe, Knut Joachim Mår; Hetland, Jørn; Pallesen, Ståle

2011-10-01

A nationwide survey was conducted to investigate the prevalence of video game addiction and problematic video game use and their association with physical and mental health. An initial sample comprising 2,500 individuals was randomly selected from the Norwegian National Registry. A total of 816 (34.0 percent) individuals completed and returned the questionnaire. The majority (56.3 percent) of respondents used video games on a regular basis. The prevalence of video game addiction was estimated to be 0.6 percent, with problematic use of video games reported by 4.1 percent of the sample. Gender (male) and age group (young) were strong predictors for problematic use of video games. A higher proportion of high frequency compared with low frequency players preferred massively multiplayer online role-playing games, although the majority of high frequency players preferred other game types. Problematic use of video games was associated with lower scores on life satisfaction and with elevated levels of anxiety and depression. Video game use was not associated with reported amount of physical exercise.

Estimating the clinical and economic benefit associated with incremental improvements in sustained virologic response in chronic hepatitis C.

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McEwan, Phil; Ward, Thomas; Bennett, Hayley; Kalsekar, Anupama; Webster, Samantha; Brenner, Michael; Yuan, Yong

2015-01-01

Hepatitis C virus (HCV) infection is one of the principle causes of chronic liver disease. Successful treatment significantly decreases the risk of hepatic morbidity and mortality. Current standard of care achieves sustained virologic response (SVR) rates of 40-80%; however, the HCV therapy landscape is rapidly evolving. The objective of this study was to quantify the clinical and economic benefit associated with increasing levels of SVR. A published Markov model (MONARCH) that simulates the natural history of hepatitis C over a lifetime horizon was used. Discounted and non-discounted life-years (LYs), quality-adjusted life-years (QALYs) and cost of complication management were estimated for various plausible SVR rates. To demonstrate the robustness of projections obtained, the model was validated to ten UK-specific HCV studies. QALY estimates ranged from 18.0 years for those treated successfully in fibrosis stage F0 to 7.5 years (discounted) for patients in fibrosis stage F4 who remain untreated. Predicted QALY gains per 10% improvement in SVR ranged from 0.23 (F0) to 0.64 (F4) and 0.58 (F0) to 1.35 (F4) in 40 year old patients (discounted and non-discounted results respectively). In those aged 40, projected discounted HCV-related costs are minimised with successful treatment in F0/F1 (at approximately £ 300), increasing to £ 49,300 in F4 patients who remain untreated. Validation of the model to published UK cost-effectiveness studies produce R2 goodness of fit statistics of 0.988, 0.978 and of 0.973 for total costs, QALYs and incremental cost effectiveness ratios, respectively. Projecting the long-term clinical and economic consequences associated with chronic hepatitis C is a necessary requirement for the evaluation of new treatments. The principle analysis demonstrates the significant impact on expected costs, LYs and QALYs associated with increasing SVR. A validation analysis demonstrated the robustness of the results reported.

Estimation and Control in Agile Methods for Software Development: a Case Study

Directory of Open Access Journals (Sweden)

Mitre-Hernández Hugo A.

2014-07-01

Full Text Available The development of software (SW using agile methods is growing due to the productivity associated with these methodologies, in addition to the flexibility shown in small teams. However, these methods have clear weaknesses of software development in cost estimation and management, as well as the fact that project managers do not have enough evidence to verify the budget spending on a project due to the poor documentation generated and the lack of monitoring of resource spending. A proposal estimation and cost control in agile methods to solve these shortcomings. To this end, a case study was conducted in an agile software development company using the proposal for Software as a Service (SaaS and Web application projects. The results found were that the proposal generates a high degree of evidence for project managers, but it has shortcomings in the administration of the evidence for the control and decision making, which led to a definition of a decision making process to be coupled with the measurement proposal.

Estimating Externalities of Hydro Fuel Cycles, Report 6

Energy Technology Data Exchange (ETDEWEB)

Barnthouse, L.W.; Cada, G.F.; Cheng, M.-D.; Easterly, C.E.; Kroodsma, R.L.; Lee, R.; Shriner, D.S.; Tolbert, V.R.; Turner, R.S.

1994-12-01

There are three major objectives of this hydropower study: (1) to implement the methodological concepts that were developed in the background document (ORNL/RFF 1992) as a means of estimating the external costs and benefits of fuel cycles and, by so doing, to demonstrate their application to the hydroelectric fuel cycle (different fuel cycles have unique characteristics that need to be addressed in different ways); (2) to develop, given the time and resources, the best range of estimates of externalities associated with hydroelectric projects, using two benchmark projects at two reference sites in the US; and (3) to assess the state of the information that is available to support the estimation of externalities associated with the hydroelectric fuel cycle and, by so doing, to assist in identifying gaps in knowledge and in setting future research agendas. The main consideration in defining these objectives was a desire to have more information about externalities and a better method for estimating them. As set forth in the agreement between the US and the EC, the study is explicitly and intentionally not directed at any one audience. This study is about a methodology for estimating externalities. It is not about how to use estimates of externalities in a particular policy context.

Estimation of organ doses and risk of cancer associated with CT examination

International Nuclear Information System (INIS)

Ahmed, Nagla Nooraldaim

2017-11-01

The purpose of this study to estimate the organ closes and risk of cancer associated with CT examinations in Khartoum state, where the study conducted in three hospitals; Alzytouna , royal scan and Royal Care. From April to November 2017, and the data collected from 120 patients, 40 patents from each hospital undergoing CT brain and abdomen examinations. The data were entered to CT - Expo version 2.4 software for calculation the effective dose and organ dose and by Xray risk web site for calculate the risk factor associated with CT examinations. Results have shown the values of effective dose that found 9.73 mSv for all patients and for female and male 9.9 mSv respectively. The effective dose from Brain examinations in three hospitals Alzytouna Royal scan and Royal Care was 16.9 mSv, 3.7 mSv, 3.8 mSv respectively, and from abdomen examinations was 4.2 mSv, 7.6 mSv, 22.2 mSv respectively. Comparing te effective dose from the hospitals, for Ct. Brain in Alzytouna hospital was higher than other hospitals; and for CT Abdomen in Royal Care hospital was higher than other hospitals, but still under the risk levels according to the ICRP report. For organ doses results, the most organs exposed from CT. brain was brain, salivary gland, thyroid gland, Bone marrow, Bone surface, Extra thoracic tissue, Eye lens and oral mucosa received ( 70,2, 66.4,15.04, 10.9, 24.9, 14.8,89.5,65.07) mSv respectively. The most organs exposed from CT. Abdomen were liver, stomach, low, Large intestine, Bladder, Bone surface, upper , Large intestine, spleen, kidney, small intestine and prostate received (16.53, 12.8, 33.43, 41.01,20.5, 38.4, 14.7, 28.9, 37.5,30.5 ) mSv respectively. This study found that te ability of cancer induced i the female was higher from the male; dut to body component of the female. (Author)

Gastroschisis and associated defects: an international study.

LENUS (Irish Health Repository)

Mastroiacovo, Pierpaolo

2007-04-01

Our objective was to evaluate the frequency and type of malformations associated with gastroschisis in a large pool of international data, to identify malformation patterns, and to evaluate the role of maternal age in non-isolated cases. Case-by-case information from 24 registries, all members of the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR), were evaluated. After the exclusion of other abdominal wall defects cases were classified as: (a) isolated; (b) recognizable syndrome, chromosomal or not; (c) multiple congenital anomalies (MCA). Our results showed that out of 3,322 total cases 469 non-isolated cases were registered (14.1%): 41 chromosomal syndromes, 24 other syndromes, and 404 MCA. Among MCA four groups of anomalies were most frequent: CNS (4.5%), cardio-vascular (2.5%), limb (2.2%), and kidney anomalies (1.9%). No similar patterns emerged except two patterns resembling limb-body wall complex and OEIS. In both of them the gastroschisis could be however misclassified. Chromosomal trisomies and possibly non-syndromic MCA are associated with an older maternal age more than isolated cases. On consideration of our data and the most valid studies published in the literature, the best estimate of the proportion of gastroschisis associated with major unrelated defects is about 10%, with a few cases associated to recognizable syndromes. Recognized syndromes with gastroschisis seem to be so exceptional that the well documented and validated cases are worth being published as interesting case report. An appropriate case definition in etiological studies should include only isolated gastroschisis after an appropriate definition of isolated and non-isolated cases and a thorough case-by-case review.

Comparative Study of Online Open Circuit Voltage Estimation Techniques for State of Charge Estimation of Lithium-Ion Batteries

Directory of Open Access Journals (Sweden)

Hicham Chaoui

2017-04-01

Full Text Available Online estimation techniques are extensively used to determine the parameters of various uncertain dynamic systems. In this paper, online estimation of the open-circuit voltage (OCV of lithium-ion batteries is proposed by two different adaptive filtering methods (i.e., recursive least square, RLS, and least mean square, LMS, along with an adaptive observer. The proposed techniques use the battery’s terminal voltage and current to estimate the OCV, which is correlated to the state of charge (SOC. Experimental results highlight the effectiveness of the proposed methods in online estimation at different charge/discharge conditions and temperatures. The comparative study illustrates the advantages and limitations of each online estimation method.

Estimating the Hospital Delivery Costs Associated With Severe Maternal Morbidity in New York City, 2008-2012.

Science.gov (United States)

Howland, Renata E; Angley, Meghan; Won, Sang Hee; Wilcox, Wendy; Searing, Hannah; Tsao, Tsu-Yu

2018-02-01

To quantify the average and total hospital delivery costs associated with severe maternal morbidity in excess of nonsevere maternal morbidity deliveries over a 5-year period in New York City adjusting for other sociodemographic and clinical factors. We conducted a population-based cross-sectional study using linked birth certificates and hospital discharge data for New York City deliveries from 2008 to 2012. Severe maternal morbidity was defined using a published algorithm of International Classification of Diseases, 9 Revision, Clinical Modification disease and procedure codes. Hospital costs were estimated by converting hospital charges using factors specific to each year and hospital and to each diagnosis. These estimates approximate what it costs the hospital to provide services (excluding professional fees) and were used in all subsequent analyses. To estimate adjusted mean costs associated with severe maternal morbidity, we used multivariable regression models with a log link, gamma distribution, robust standard errors, and hospital fixed effects, controlling for age, race and ethnicity, neighborhood poverty, primary payer, number of deliveries, method of delivery, comorbidities, and year. We used the adjusted mean cost to determine the average and total hospital delivery costs associated with severe maternal morbidity in excess of nonsevere maternal morbidity deliveries from 2008 to 2012. Approximately 2.3% (n=13,502) of all New York City delivery hospitalizations were complicated by severe maternal morbidity. Compared with nonsevere maternal morbidity deliveries, these hospitalizations were clinically complicated, required more and intensive clinical services, and had a longer stay in the hospital. The average cost of delivery with severe maternal morbidity was $14,442 (95% CI $14,128-14,756), compared with $7,289 (95% CI $7,276-7,302) among deliveries without severe maternal morbidity. After adjusting for other factors, the difference between deliveries

Source-specific pollution exposure and associations with pulmonary response in the Atlanta Commuters Exposure Studies.

Science.gov (United States)

Krall, Jenna R; Ladva, Chandresh N; Russell, Armistead G; Golan, Rachel; Peng, Xing; Shi, Guoliang; Greenwald, Roby; Raysoni, Amit U; Waller, Lance A; Sarnat, Jeremy A

2018-01-03

Concentrations of traffic-related air pollutants are frequently higher within commuting vehicles than in ambient air. Pollutants found within vehicles may include those generated by tailpipe exhaust, brake wear, and road dust sources, as well as pollutants from in-cabin sources. Source-specific pollution, compared to total pollution, may represent regulation targets that can better protect human health. We estimated source-specific pollution exposures and corresponding pulmonary response in a panel study of commuters. We used constrained positive matrix factorization to estimate source-specific pollution factors and, subsequently, mixed effects models to estimate associations between source-specific pollution and pulmonary response. We identified four pollution factors that we named: crustal, primary tailpipe traffic, non-tailpipe traffic, and secondary. Among asthmatic subjects (N = 48), interquartile range increases in crustal and secondary pollution were associated with changes in lung function of -1.33% (95% confidence interval (CI): -2.45, -0.22) and -2.19% (95% CI: -3.46, -0.92) relative to baseline, respectively. Among non-asthmatic subjects (N = 51), non-tailpipe pollution was associated with pulmonary response only at 2.5 h post-commute. We found no significant associations between pulmonary response and primary tailpipe pollution. Health effects associated with traffic-related pollution may vary by source, and therefore some traffic pollution sources may require targeted interventions to protect health.

A Comparative Study of Distribution System Parameter Estimation Methods

Energy Technology Data Exchange (ETDEWEB)

Sun, Yannan; Williams, Tess L.; Gourisetti, Sri Nikhil Gup

2016-07-17

In this paper, we compare two parameter estimation methods for distribution systems: residual sensitivity analysis and state-vector augmentation with a Kalman filter. These two methods were originally proposed for transmission systems, and are still the most commonly used methods for parameter estimation. Distribution systems have much lower measurement redundancy than transmission systems. Therefore, estimating parameters is much more difficult. To increase the robustness of parameter estimation, the two methods are applied with combined measurement snapshots (measurement sets taken at different points in time), so that the redundancy for computing the parameter values is increased. The advantages and disadvantages of both methods are discussed. The results of this paper show that state-vector augmentation is a better approach for parameter estimation in distribution systems. Simulation studies are done on a modified version of IEEE 13-Node Test Feeder with varying levels of measurement noise and non-zero error in the other system model parameters.

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.

Estimating the non-monetary burden of neurocysticercosis in Mexico.

Directory of Open Access Journals (Sweden)

Rachana Bhattarai

Full Text Available BACKGROUND: Neurocysticercosis (NCC is a major public health problem in many developing countries where health education, sanitation, and meat inspection infrastructure are insufficient. The condition occurs when humans ingest eggs of the pork tapeworm Taenia solium, which then develop into larvae in the central nervous system. Although NCC is endemic in many areas of the world and is associated with considerable socio-economic losses, the burden of NCC remains largely unknown. This study provides the first estimate of disability adjusted life years (DALYs associated with NCC in Mexico. METHODS: DALYs lost for symptomatic cases of NCC in Mexico were estimated by incorporating morbidity and mortality due to NCC-associated epilepsy, and morbidity due to NCC-associated severe chronic headaches. Latin hypercube sampling methods were employed to sample the distributions of uncertain parameters and to estimate 95% credible regions (95% CRs. FINDINGS: In Mexico, 144,433 and 98,520 individuals are estimated to suffer from NCC-associated epilepsy and NCC-associated severe chronic headaches, respectively. A total of 25,341 (95% CR: 12,569-46,640 DALYs were estimated to be lost due to these clinical manifestations, with 0.25 (95% CR: 0.12-0.46 DALY lost per 1,000 person-years of which 90% was due to NCC-associated epilepsy. CONCLUSION: This is the first estimate of DALYs associated with NCC in Mexico. However, this value is likely to be underestimated since only the clinical manifestations of epilepsy and severe chronic headaches were included. In addition, due to limited country specific data, some parameters used in the analysis were based on systematic reviews of the literature or primary research from other geographic locations. Even with these limitations, our estimates suggest that healthy years of life are being lost due to NCC in Mexico.

Methods to estimate the between‐study variance and its uncertainty in meta‐analysis†

Science.gov (United States)

Jackson, Dan; Viechtbauer, Wolfgang; Bender, Ralf; Bowden, Jack; Knapp, Guido; Kuss, Oliver; Higgins, Julian PT; Langan, Dean; Salanti, Georgia

2015-01-01

Meta‐analyses are typically used to estimate the overall/mean of an outcome of interest. However, inference about between‐study variability, which is typically modelled using a between‐study variance parameter, is usually an additional aim. The DerSimonian and Laird method, currently widely used by default to estimate the between‐study variance, has been long challenged. Our aim is to identify known methods for estimation of the between‐study variance and its corresponding uncertainty, and to summarise the simulation and empirical evidence that compares them. We identified 16 estimators for the between‐study variance, seven methods to calculate confidence intervals, and several comparative studies. Simulation studies suggest that for both dichotomous and continuous data the estimator proposed by Paule and Mandel and for continuous data the restricted maximum likelihood estimator are better alternatives to estimate the between‐study variance. Based on the scenarios and results presented in the published studies, we recommend the Q‐profile method and the alternative approach based on a ‘generalised Cochran between‐study variance statistic’ to compute corresponding confidence intervals around the resulting estimates. Our recommendations are based on a qualitative evaluation of the existing literature and expert consensus. Evidence‐based recommendations require an extensive simulation study where all methods would be compared under the same scenarios. © 2015 The Authors. Research Synthesis Methods published by John Wiley & Sons Ltd. PMID:26332144

Comparative study of approaches to estimate pipe break frequencies

Energy Technology Data Exchange (ETDEWEB)

Simola, K.; Pulkkinen, U.; Talja, H.; Saarenheimo, A.; Karjalainen-Roikonen, P. [VTT Industrial Systems (Finland)

2002-12-01

The report describes the comparative study of two approaches to estimate pipe leak and rupture frequencies for piping. One method is based on a probabilistic fracture mechanistic (PFM) model while the other one is based on statistical estimation of rupture frequencies from a large database. In order to be able to compare the approaches and their results, the rupture frequencies of some selected welds have been estimated using both of these methods. This paper highlights the differences both in methods, input data, need and use of plant specific information and need of expert judgement. The study focuses on one specific degradation mechanism, namely the intergranular stress corrosion cracking (IGSCC). This is the major degradation mechanism in old stainless steel piping in BWR environment, and its growth is influenced by material properties, stresses and water chemistry. (au)

Sources of heterogeneity in studies of the BMI-mortality association.

Science.gov (United States)

Peter, Raphael Simon; Nagel, Gabriele

2017-06-01

To date, the amount of heterogeneity among studies of the body mass index-mortality association attributable to differences in the age distribution and length of follow-up has not been quantified. Therefore, we wanted to quantify the amount of heterogeneity attributable to age and follow-up in results of studies on the body mass index-mortality relation. We used optima of the body mass index mortality association reported for 30 populations and performed meta-regression to estimate the amount of heterogeneity attributable to sex, ethnicity, mean age at baseline, percentage smokers, and length of follow-up. Ethnicity as single factor accounted for 36% (95% CI, 11-56%) of heterogeneity. Mean age and length of follow-up had an interactive effect and together accounted for 56% (95% CI, 24-74%) of the remaining heterogeneity. Sex did not significantly contribute to the heterogeneity, after controlling for ethnicity, age, and length of follow-up. A considerable amount of heterogeneity in studies of the body mass index-mortality association is attributable to ethnicity, age, and length of follow-up. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Incorporating Functional Genomic Information in Genetic Association Studies Using an Empirical Bayes Approach.

Science.gov (United States)

Spencer, Amy V; Cox, Angela; Lin, Wei-Yu; Easton, Douglas F; Michailidou, Kyriaki; Walters, Kevin

2016-04-01

There is a large amount of functional genetic data available, which can be used to inform fine-mapping association studies (in diseases with well-characterised disease pathways). Single nucleotide polymorphism (SNP) prioritization via Bayes factors is attractive because prior information can inform the effect size or the prior probability of causal association. This approach requires the specification of the effect size. If the information needed to estimate a priori the probability density for the effect sizes for causal SNPs in a genomic region isn't consistent or isn't available, then specifying a prior variance for the effect sizes is challenging. We propose both an empirical method to estimate this prior variance, and a coherent approach to using SNP-level functional data, to inform the prior probability of causal association. Through simulation we show that when ranking SNPs by our empirical Bayes factor in a fine-mapping study, the causal SNP rank is generally as high or higher than the rank using Bayes factors with other plausible values of the prior variance. Importantly, we also show that assigning SNP-specific prior probabilities of association based on expert prior functional knowledge of the disease mechanism can lead to improved causal SNPs ranks compared to ranking with identical prior probabilities of association. We demonstrate the use of our methods by applying the methods to the fine mapping of the CASP8 region of chromosome 2 using genotype data from the Collaborative Oncological Gene-Environment Study (COGS) Consortium. The data we analysed included approximately 46,000 breast cancer case and 43,000 healthy control samples. © 2016 The Authors. *Genetic Epidemiology published by Wiley Periodicals, Inc.

Two-stage estimation in copula models used in family studies

DEFF Research Database (Denmark)

Andersen, Elisabeth Anne Wreford

2005-01-01

by Shih and Louis (Biometrics vol. 51, pp. 1384-1399, 1995b) and Glidden (Lifetime Data Analysis vol. 6, pp. 141-156, 2000). Because register based family studies often involve very large cohorts a method for analysing a sampled cohort is also derived together with the asymptotic properties...... of the estimators. The proposed methods are studied in simulations and the estimators are found to be highly efficient. Finally, the methods are applied to a study of mortality in twins....

An Updated Algorithm for Estimation of Pesticide Exposure Intensity in the Agricultural Health Study

Directory of Open Access Journals (Sweden)

Aaron Blair

2011-12-01

Full Text Available An algorithm developed to estimate pesticide exposure intensity for use in epidemiologic analyses was revised based on data from two exposure monitoring studies. In the first study, we estimated relative exposure intensity based on the results of measurements taken during the application of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D (n = 88 and the insecticide chlorpyrifos (n = 17. Modifications to the algorithm weighting factors were based on geometric means (GM of post-application urine concentrations for applicators grouped by application method and use of chemically-resistant (CR gloves. Measurement data from a second study were also used to evaluate relative exposure levels associated with airblast as compared to hand spray application methods. Algorithm modifications included an increase in the exposure reduction factor for use of CR gloves from 40% to 60%, an increase in the application method weight for boom spray relative to in-furrow and for air blast relative to hand spray, and a decrease in the weight for mixing relative to the new weights assigned for application methods. The weighting factors for the revised algorithm now incorporate exposure measurements taken on Agricultural Health Study (AHS participants for the application methods and personal protective equipment (PPE commonly reported by study participants.

A study on the estimation method of nuclear accident risk cost

International Nuclear Information System (INIS)

Matsuo, Yuji

2016-01-01

The methodology of estimating nuclear accident risk cost, as a part of nuclear power generation cost, has hardly been established due mainly to the extremely wide range of the estimation of the accident frequency. This study estimates the expected nuclear accident frequency for Japan, making use of the method of Bayesian statistics, which exploits both the information obtained by Probabilistic Risk Assessment (PRA) and the observed historical accident frequencies. Using the PRA estimation of the Containment Failure Frequency (CFF) for Tomari nuclear power plant unit 3 of Hokkaido Electric Power Company (average: 2.1 x 10 -4 , 95th percentile: 7.7 x 10 -4 ) and the actual large-scale accident frequency (once in 1,460 reactor-years), the posterior CFF was estimated at 3.8 x 10 -4 . This study also took into account the 'external' factor causing unexpected nuclear accidents, concluding that such factor could result in higher CFF estimations, especially with larger observed accident numbers. (author)

Association between Empirically Estimated Monsoon Dynamics and Other Weather Factors and Historical Tea Yields in China: Results from a Yield Response Model

Directory of Open Access Journals (Sweden)

Rebecca Boehm

2016-04-01

Full Text Available Farmers in China’s tea-growing regions report that monsoon dynamics and other weather factors are changing and that this is affecting tea harvest decisions. To assess the effect of climate change on tea production in China, this study uses historical weather and production data from 1980 to 2011 to construct a yield response model that estimates the partial effect of weather factors on tea yields in China, with a specific focus on East Asian Monsoon dynamics. Tea (Camellia sinensis (L. Kunze has not been studied using these methods even though it is an important crop for human nutrition and the economic well-being of rural communities in many countries. Previous studies have approximated the monsoon period using historical average onset and retreat dates, which we believe limits our understanding of how changing monsoon patterns affect crop productivity. In our analysis, we instead estimate the monsoon season across China’s tea growing regions empirically by identifying the unknown breakpoints in the year-by-province cumulative precipitation. We find that a 1% increase in the monsoon retreat date is associated with 0.481%–0.535% reduction in tea yield. In the previous year, we also find that a 1% increase in the date of the monsoon retreat is associated with a 0.604% decrease in tea yields. For precipitation, we find that a 1% increase in average daily precipitation occurring during the monsoon period is associated with a 0.184%–0.262% reduction in tea yields. In addition, our models show that 1% increase in the average daily monsoon precipitation from the previous growing season is associated with 0.258%–0.327% decline in yields. We also find that a 1% decrease in solar radiation in the previous growing season is associated with 0.554%-0.864% decrease in tea yields. These findings suggest the need for adaptive management and harvesting strategies given climate change projections and the known negative association between excess

Estimated Aortic Stiffness is Independently Associated with Cardiac Baroreflex Sensitivity in Humans: Role of Aging and Habitual Endurance Exercise

Science.gov (United States)

Pierce, Gary L.; Harris, Stephen A.; Seals, Douglas R.; Casey, Darren P.; Barlow, Patrick B.; Stauss, Harald M.

2016-01-01

We hypothesized that differences in cardiac baroreflex sensitivity (BRS) would be independently associated with aortic stiffness and augmentation index (AI), clinical biomarkers of cardiovascular disease (CVD) risk, among young sedentary and middle-aged/older sedentary and endurance-trained adults. A total of 36 healthy middle-aged/older (age 55-76 years, n=22 sedentary; n=14 endurance-trained) and 5 young sedentary (age 18-31 years) adults were included in a cross-sectional study. A subset of the middle-aged/older sedentary adults (n=12) completed an 8-week aerobic exercise intervention. Invasive brachial artery blood pressure waveforms were used to compute spontaneous cardiac BRS (via sequence technique) and estimated aortic pulse wave velocity (PWV) and AI (AI, via brachial-aortic transfer function and wave separation analysis). In the cross-sectional study, cardiac BRS was 71% lower in older compared with young sedentary adults (Pendurance exercise (P=0.03). In a regression model that included age, sex, resting heart rate, mean arterial pressure (MAP), body mass index and maximal exercise oxygen uptake, estimated aortic PWV (β±SE = −5.76 ± 2.01, P=0.01) was the strongest predictor of BRS (Model R2=0.59, Pendurance exercise-related differences in cardiac BRS are independently associated with corresponding alterations in aortic PWV among healthy adults, consistent with a mechanistic link between variations in the sensitivity of the baroreflex and aortic stiffness with age and exercise. PMID:26911535

Estimated aortic stiffness is independently associated with cardiac baroreflex sensitivity in humans: role of ageing and habitual endurance exercise.

Science.gov (United States)

Pierce, G L; Harris, S A; Seals, D R; Casey, D P; Barlow, P B; Stauss, H M

2016-09-01

We hypothesised that differences in cardiac baroreflex sensitivity (BRS) would be independently associated with aortic stiffness and augmentation index (AI), clinical biomarkers of cardiovascular disease risk, among young sedentary and middle-aged/older sedentary and endurance-trained adults. A total of 36 healthy middle-aged/older (age 55-76 years, n=22 sedentary and n=14 endurance-trained) and 5 young sedentary (age 18-31 years) adults were included in a cross-sectional study. A subset of the middle-aged/older sedentary adults (n=12) completed an 8-week-aerobic exercise intervention. Invasive brachial artery blood pressure waveforms were used to compute spontaneous cardiac BRS (via sequence technique), estimated aortic pulse wave velocity (PWV) and AI (AI, via brachial-aortic transfer function and wave separation analysis). In the cross-sectional study, cardiac BRS was 71% lower in older compared with young sedentary adults (Pendurance exercise (P=0.03). In a regression model that included age, sex, resting heart rate, mean arterial pressure (MAP), body mass index and maximal exercise oxygen uptake, estimated aortic PWV (β±s.e.=-5.76±2.01, P=0.01) was the strongest predictor of BRS (model R(2)=0.59, Pendurance-exercise-related differences in cardiac BRS are independently associated with corresponding alterations in aortic PWV among healthy adults, consistent with a mechanistic link between variations in the sensitivity of the baroreflex and aortic stiffness with age and exercise.

A model for fine mapping in family based association studies.

Science.gov (United States)

Boehringer, Stefan; Pfeiffer, Ruth M

2009-01-01

Genome wide association studies for complex diseases are typically followed by more focused characterization of the identified genetic region. We propose a latent class model to evaluate a candidate region with several measured markers using observations on families. The main goal is to estimate linkage disequilibrium (LD) between the observed markers and the putative true but unobserved disease locus in the region. Based on this model, we estimate the joint distribution of alleles at the observed markers and the unobserved true disease locus, and a penetrance parameter measuring the impact of the disease allele on disease risk. A family specific random effect allows for varying baseline disease prevalences for different families. We present a likelihood framework for our model and assess its properties in simulations. We apply the model to an Alzheimer data set and confirm previous findings in the ApoE region.

Factors associated with voice disorders among teachers: a case-control study.

Science.gov (United States)

Giannini, Susana Pimentel Pinto; Latorre, Maria do Rosário Dias de Oliveira; Ferreira, Léslie Piccolotto

2013-01-01

We aimed at verifying an association between voice disorders/stress and loss of work ability among female teachers who work in São Paulo's public school system. This is a paired case- control study. The case group was composed offiteachers with alterations in speech and larynges assessments, and the control group was formed by teachers without alterations in these evaluations who work in the same schools. Both groups answered the following questionnaires: Conditions of Vocal Production-Teachers, Job Stress Scale, and Work Ability Index. The analysis was performed using the chi-square association test and logistic regression models with the purpose of estimating the association between independent variables and voice disorders. We found differences between the groups in relation to stress in the workplace under high demand, a situation that poses greater risks of adverse reactions to the workers' physical and mental health. Regarding the ability to work, the categories poor and moderate ability for work are associated with voice disorders, regardless of job stress factors, age, and the unsatisfactory acoustic properties of the classrooms. This study confirmed the association between voice disorders and job stress, as well as between voice disorders and loss of work ability.

Association of Microalbuminuria and Estimated Glomerular Filtration Rate With Carotid Intima-Media Thickness in Patients With Type 2 Diabetes Mellitus

Directory of Open Access Journals (Sweden)

Dehdashti Shahrokh

2015-04-01

Full Text Available Background Atherosclerosis is the main cause of cardiovascular diseases, and its risk enhances in type 2 diabetes mellitus. Objectives This study aimed to evaluate Carotid Intima-Media Thickness (CIMT by carotid artery ultrasonography and assess its correlation with microalbuminuria and estimated Glomerular Filtration Rate (eGFR in the patients with type 2 diabetes mellitus. Patients and Methods This cross-sectional study was included 205 patients with Type 2 Diabetes Mellitus (T2DM. We recorded clinical and biochemical data such as FBS, lipid profile, and urinary albumin. Intima-media thickness of carotid arteries was measured in all patients by high frequency ultrasound. Results In simple correlation coefficients analysis, CIMT was significantly associated with total cholesterol (r = 0.197, P = 0.008, serum creatinine (r = 0.240, P = 0.001, and urinary albumin (r = 0.420, P = 0.000. Also, CIMT elevated significantly with the stage progression of chronic kidney disease (0.67 ± 0.15 mm in stage 1, 0.73 ± 0.22 mm in stage 2, and 0.82 ± 0.21 mm in stage 3 (P value = 0.024. In multivariate linear regression analysis, the duration of diabetes, weight, HDL, serum creatinine, urinary albumin, and estimated Glomerular Filtration Rate (eGFR were independently associated with CIMT (P value < 0.05 for all. Conclusions Our study shows a relationship between CIMT and renal parameters, including eGFR and albuminuria. This study confirms the importance of intensive examinations for early detection of atherosclerosis and treatment of risk factors.

Genome-wide association study of telomere length among South Asians identifies a second RTEL1 association signal.

Science.gov (United States)

Delgado, Dayana A; Zhang, Chenan; Chen, Lin S; Gao, Jianjun; Roy, Shantanu; Shinkle, Justin; Sabarinathan, Mekala; Argos, Maria; Tong, Lin; Ahmed, Alauddin; Islam, Tariqul; Rakibuz-Zaman, Muhammad; Sarwar, Golam; Shahriar, Hasan; Rahman, Mahfuzar; Yunus, Mohammad; Jasmine, Farzana; Kibriya, Muhammad G; Ahsan, Habibul; Pierce, Brandon L

2018-01-01

Leucocyte telomere length (TL) is a potential biomarker of ageing and risk for age-related disease. Leucocyte TL is heritable and shows substantial differences by race/ethnicity. Recent genome-wide association studies (GWAS) report ~10 loci harbouring SNPs associated with leucocyte TL, but these studies focus primarily on populations of European ancestry. This study aims to enhance our understanding of genetic determinants of TL across populations. We performed a GWAS of TL using data on 5075 Bangladeshi adults. We measured TL using one of two technologies (qPCR or a Luminex-based method) and used standardised variables as TL phenotypes. Our results replicate previously reported associations in the TERC and TERT regions (P=2.2×10 -8 and P=6.4×10 -6 , respectively). We observed a novel association signal in the RTEL1 gene (intronic SNP rs2297439; P=2.82×10 -7 ) that is independent of previously reported TL-associated SNPs in this region. The minor allele for rs2297439 is common in South Asian populations (≥0.25) but at lower frequencies in other populations (eg, 0.07 in Northern Europeans). Among the eight other previously reported association signals, all were directionally consistent with our study, but only rs8105767 ( ZNF208 ) was nominally significant (P=0.003). SNP-based heritability estimates were as high as 44% when analysing close relatives but much lower when analysing distant relatives only. In this first GWAS of TL in a South Asian population, we replicate some, but not all, of the loci reported in prior GWAS of individuals of European ancestry, and we identify a novel second association signal at the RTEL1 locus. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Post-Colonization Interval Estimates Using Multi-Species Calliphoridae Larval Masses and Spatially Distinct Temperature Data Sets: A Case Study

Science.gov (United States)

Weatherbee, Courtney R.; Pechal, Jennifer L.; Stamper, Trevor; Benbow, M. Eric

2017-01-01

Common forensic entomology practice has been to collect the largest Diptera larvae from a scene and use published developmental data, with temperature data from the nearest weather station, to estimate larval development time and post-colonization intervals (PCIs). To evaluate the accuracy of PCI estimates among Calliphoridae species and spatially distinct temperature sources, larval communities and ambient air temperature were collected at replicate swine carcasses (N = 6) throughout decomposition. Expected accumulated degree hours (ADH) associated with Cochliomyia macellaria and Phormia regina third instars (presence and length) were calculated using published developmental data sets. Actual ADH ranges were calculated using temperatures recorded from multiple sources at varying distances (0.90 m–7.61 km) from the study carcasses: individual temperature loggers at each carcass, a local weather station, and a regional weather station. Third instars greatly varied in length and abundance. The expected ADH range for each species successfully encompassed the average actual ADH for each temperature source, but overall under-represented the range. For both calliphorid species, weather station data were associated with more accurate PCI estimates than temperature loggers associated with each carcass. These results provide an important step towards improving entomological evidence collection and analysis techniques, and developing forensic error rates. PMID:28375172

Post-Colonization Interval Estimates Using Multi-Species Calliphoridae Larval Masses and Spatially Distinct Temperature Data Sets: A Case Study

Directory of Open Access Journals (Sweden)

Courtney R. Weatherbee

2017-04-01

Full Text Available Common forensic entomology practice has been to collect the largest Diptera larvae from a scene and use published developmental data, with temperature data from the nearest weather station, to estimate larval development time and post-colonization intervals (PCIs. To evaluate the accuracy of PCI estimates among Calliphoridae species and spatially distinct temperature sources, larval communities and ambient air temperature were collected at replicate swine carcasses (N = 6 throughout decomposition. Expected accumulated degree hours (ADH associated with Cochliomyia macellaria and Phormia regina third instars (presence and length were calculated using published developmental data sets. Actual ADH ranges were calculated using temperatures recorded from multiple sources at varying distances (0.90 m–7.61 km from the study carcasses: individual temperature loggers at each carcass, a local weather station, and a regional weather station. Third instars greatly varied in length and abundance. The expected ADH range for each species successfully encompassed the average actual ADH for each temperature source, but overall under-represented the range. For both calliphorid species, weather station data were associated with more accurate PCI estimates than temperature loggers associated with each carcass. These results provide an important step towards improving entomological evidence collection and analysis techniques, and developing forensic error rates.

Economic burden associated with alcohol dependence in a German primary care sample: a bottom-up study

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Jakob Manthey

2016-08-01

Full Text Available Abstract Background A considerable economic burden has been repeatedly associated with alcohol dependence (AD – mostly calculated using aggregate data and alcohol-attributable fractions (top-down approach. However, this approach is limited by a number of assumptions, which are hard to test. Thus, cost estimates should ideally be validated with studies using individual data to estimate the same costs (bottom-up approach. However, bottom-up studies on the economic burden associated with AD are lacking. Our study aimed to fill this gap using the bottom-up approach to examine costs for AD, and also stratified the results by the following subgroups: sex, age, diagnostic approach and severity of AD, as relevant variations could be expected by these factors. Methods Sample: 1356 primary health care patients, representative for two German regions. AD was diagnosed by a standardized instrument and treating physicians. Individual costs were calculated by combining resource use and productivity data representing a period of six months prior to the time of interview, with unit costs derived from the literature or official statistics. The economic burden associated with AD was determined via excess costs by comparing utilization of various health care resources and impaired productivity between people with and without AD, controlling for relevant confounders. Additional analyses for several AD characteristics were performed. Results Mean costs among alcohol dependent patients were 50 % higher compared to the remaining patients, resulting in 1836 € excess costs per alcohol dependent patient in 6 months. More than half of these excess costs incurred through increased productivity loss among alcohol dependent patients. Treatment for alcohol problems represents only 6 % of these costs. The economic burden associated with AD incurred mainly among males and among 30 to 49 year old patients. Both diagnostic approaches were significantly related to the

Using linked educational attainment data to reduce bias due to missing outcome data in estimates of the association between the duration of breastfeeding and IQ at 15 years.

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Cornish, Rosie P; Tilling, Kate; Boyd, Andy; Davies, Amy; Macleod, John

2015-06-01

Most epidemiological studies have missing information, leading to reduced power and potential bias. Estimates of exposure-outcome associations will generally be biased if the outcome variable is missing not at random (MNAR). Linkage to administrative data containing a proxy for the missing study outcome allows assessment of whether this outcome is MNAR and the evaluation of bias. We examined this in relation to the association between infant breastfeeding and IQ at 15 years, where a proxy for IQ was available through linkage to school attainment data. Subjects were those who enrolled in the Avon Longitudinal Study of Parents and Children in 1990-91 (n = 13 795), of whom 5023 had IQ measured at age 15. For those with missing IQ, 7030 (79%) had information on educational attainment at age 16 obtained through linkage to the National Pupil Database. The association between duration of breastfeeding and IQ was estimated using a complete case analysis, multiple imputation and inverse probability-of-missingness weighting; these estimates were then compared with those derived from analyses informed by the linkage. IQ at 15 was MNAR-individuals with higher attainment were less likely to have missing IQ data, even after adjusting for socio-demographic factors. All the approaches underestimated the association between breastfeeding and IQ compared with analyses informed by linkage. Linkage to administrative data containing a proxy for the outcome variable allows the MNAR assumption to be tested and more efficient analyses to be performed. Under certain circumstances, this may produce unbiased results. © The Author 2015. Published by Oxford University Press on behalf of the International Epidemiological Association.

Estimating burden of influenza-associated influenza-like illness and severe acute respiratory infection at public healthcare facilities in Romania during the 2011/12-2015/16 influenza seasons.

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Gefenaite, Giedre; Pistol, Adriana; Popescu, Rodica; Popovici, Odette; Ciurea, Daniel; Dolk, Christiaan; Jit, Mark; Gross, Diane

2018-01-01

Influenza is responsible for substantial morbidity and mortality, but there is limited information on reliable disease burden estimates, especially from middle-income countries in the WHO European Region. To estimate the incidence of medically attended influenza-associated influenza-like illness (ILI) and hospitalizations due to severe acute respiratory infection (SARI) presenting to public healthcare facilities in Romania. Sentinel influenza surveillance data for ILI and SARI from 2011/12-2015/16, including virological data, were used to estimate influenza-associated ILI and SARI incidence/100 000 and their 95% confidence intervals (95% CI). The overall annual incidence of ILI and influenza-associated ILI per 100 000 persons in Romania varied between 68 (95% CI: 61-76) and 318 (95% CI: 298-338) and between 23 (95% CI: 19-29) and 189 (95% CI: 149-240), respectively. The highest ILI and influenza incidence was among children aged 0-4 years. We estimated that SARI incidence per 100 000 persons was 6 (95% CI: 5-7) to 9 (95% CI: 8-10), of which 2 (95% CI: 1-2) to 3 (95% CI: 2-4) were due to influenza. Up to 0.3% of the Romanian population were annually reported with ILI, and 0.01% was hospitalized with SARI, of which as much as one-third could be explained by influenza. This evaluation was the first study estimating influenza burden in Romania. We found that during each influenza season, a substantial number of persons in Romania suffer from influenza-related ILI or are hospitalized due to influenza-associated SARI. © 2017 The World Health Organization. Influenza and Other Respiratory Viruses. Published by John Wiley & Sons Ltd.

Estimating the causal influence of body mass index on risk of Parkinson disease: A Mendelian randomisation study.

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Alastair J Noyce

2017-06-01

Full Text Available Both positive and negative associations between higher body mass index (BMI and Parkinson disease (PD have been reported in observational studies, but it has been difficult to establish causality because of the possibility of residual confounding or reverse causation. To our knowledge, Mendelian randomisation (MR-the use of genetic instrumental variables (IVs to explore causal effects-has not previously been used to test the effect of BMI on PD.Two-sample MR was undertaken using genome-wide association (GWA study data. The associations between the genetic instruments and BMI were obtained from the GIANT consortium and consisted of the per-allele difference in mean BMI for 77 independent variants that reached genome-wide significance. The per-allele difference in log-odds of PD for each of these variants was estimated from a recent meta-analysis, which included 13,708 cases of PD and 95,282 controls. The inverse-variance weighted method was used to estimate a pooled odds ratio (OR for the effect of a 5-kg/m2 higher BMI on PD. Evidence of directional pleiotropy averaged across all variants was sought using MR-Egger regression. Frailty simulations were used to assess whether causal associations were affected by mortality selection. A combined genetic IV expected to confer a lifetime exposure of 5-kg/m2 higher BMI was associated with a lower risk of PD (OR 0.82, 95% CI 0.69-0.98. MR-Egger regression gave similar results, suggesting that directional pleiotropy was unlikely to be biasing the result (intercept 0.002; p = 0.654. However, the apparent protective influence of higher BMI could be at least partially induced by survival bias in the PD GWA study, as demonstrated by frailty simulations. Other important limitations of this application of MR include the inability to analyse non-linear associations, to undertake subgroup analyses, and to gain mechanistic insights.In this large study using two-sample MR, we found that variants known to influence

Age estimation using exfoliative cytology and radiovisiography: A comparative study.

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Nallamala, Shilpa; Guttikonda, Venkateswara Rao; Manchikatla, Praveen Kumar; Taneeru, Sravya

2017-01-01

Age estimation is one of the essential factors in establishing the identity of an individual. Among various methods, exfoliative cytology (EC) is a unique, noninvasive technique, involving simple, and pain-free collection of intact cells from the oral cavity for microscopic examination. The study was undertaken with an aim to estimate the age of an individual from the average cell size of their buccal smears calculated using image analysis morphometric software and the pulp-tooth area ratio in mandibular canine of the same individual using radiovisiography (RVG). Buccal smears were collected from 100 apparently healthy individuals. After fixation in 95% alcohol, the smears were stained using Papanicolaou stain. The average cell size was measured using image analysis software (Image-Pro Insight 8.0). The RVG images of mandibular canines were obtained, pulp and tooth areas were traced using AutoCAD 2010 software, and area ratio was calculated. The estimated age was then calculated using regression analysis. The paired t -test between chronological age and estimated age by cell size and pulp-tooth area ratio was statistically nonsignificant ( P > 0.05). In the present study, age estimated by pulp-tooth area ratio and EC yielded good results.

Risk of hip fractures associated with benzodiazepines: Applying common protocol to a multi-database nested case-control study. The protect project

NARCIS (Netherlands)

Requena, Gema; Logie, John; González-González, Rocío; Gardarsdottir, Helga|info:eu-repo/dai/nl/321858131; Afonso, Ana; Souverein, Patrick C.|info:eu-repo/dai/nl/243074948; Merino, Elisa Martin; Boudiaf, Nada; Huerta, Consuelo; Bate, Andrew; Alvarez, Yolanda; García-Rodríguez, Luis A.; Reynolds, Robert; Schlienger, Raymond G.; De Groot, Mark C.H.|info:eu-repo/dai/nl/313936455; Klungel, Olaf H.|info:eu-repo/dai/nl/181447649; De Abajo, Francisco J.

2014-01-01

Background: The association between benzodiazepines (BZD) and hip fractures has been estimated in several observational studies although diverse methodologies and definitions have hampered comparability. Objectives: To evaluate the discrepancies in the risk estimates of hip/femur fractures

Fat Mass Is Positively Associated with Estimated Hip Bone Strength among Chinese Men Aged 50 Years and above with Low Levels of Lean Mass

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Guiyuan Han

2017-04-01

Full Text Available This study investigated the relationships of fat mass (FM and lean mass (LM with estimated hip bone strength in Chinese men aged 50–80 years (median value: 62.0 years. A cross-sectional study including 889 men was conducted in Guangzhou, China. Body composition and hip bone parameters were generated by dual-energy X-ray absorptiometry (DXA. The relationships of the LM index (LMI and the FM index (FMI with bone phenotypes were detected by generalised additive models and multiple linear regression. The associations between the FMI and the bone variables in LMI tertiles were further analysed. The FMI possessed a linear relationship with greater estimated hip bone strength after adjustment for the potential confounders (p < 0.05. Linear relationships were also observed for the LMI with most bone phenotypes, except for the cross-sectional area (p < 0.05. The contribution of the LMI (4.0%–12.8% was greater than that of the FMI (2.0%–5.7%. The associations between the FMI and bone phenotypes became weaker after controlling for LMI. Further analyses showed that estimated bone strength ascended with FMI in the lowest LMI tertile (p < 0.05, but not in the subgroups with a higher LMI. This study suggested that LM played a critical role in bone health in middle-aged and elderly Chinese men, and that the maintenance of adequate FM could help to promote bone acquisition in relatively thin men.

Urinary neutrophil gelatinase-associated lipocalin for diagnosis and estimating activity in lupus nephritis: a meta-analysis.

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Fang, Y G; Chen, N N; Cheng, Y B; Sun, S J; Li, H X; Sun, F; Xiang, Y

2015-12-01

Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is relatively specific in lupus nephritis (LN) patients. However, its diagnostic value has not been evaluated. The aim of this review was to determine the value of uNGAL for diagnosis and estimating activity in LN. A comprehensive search was performed on PubMed, EMBASE, Web of Knowledge, Cochrane electronic databases through December 2014. Meta-analysis of sensitivity and specificity was performed with a random-effects model. Additionally, summary receiver operating characteristic (SROC) curves and area under the curve (AUC) values were calculated. Fourteen studies were selected for this review. With respect to diagnosing LN, the pooled sensitivity and specificity were 73.6% (95% confidence interval (CI), 61.9-83.3) and 78.1% (95% CI, 69.0-85.6), respectively. The SROC-AUC value was 0.8632. Regarding estimating LN activity, the pooled sensitivity and specificity were 66.2% (95% CI, 60.4-71.7) and 62.1% (95% CI, 57.9-66.3), respectively. The SROC-AUC value was 0.7583. In predicting renal flares, the pooled sensitivity and specificity were 77.5% (95% CI, 68.1-85.1) and 65.3% (95% CI, 60.0-70.3), respectively. The SROC-AUC value was 0.7756. In conclusion, this meta-analysis indicates that uNGAL has relatively fair sensitivity and specificity in diagnosing LN, estimating LN activity and predicting renal flares, suggesting that uNGAL is a potential biomarker in diagnosing LN and monitoring LN activity. © The Author(s) 2015.

Time Delay Estimation Algoritms for Echo Cancellation

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Kirill Sakhnov

2011-01-01

Full Text Available The following case study describes how to eliminate echo in a VoIP network using delay estimation algorithms. It is known that echo with long transmission delays becomes more noticeable to users. Thus, time delay estimation, as a part of echo cancellation, is an important topic during transmission of voice signals over packetswitching telecommunication systems. An echo delay problem associated with IP-based transport networks is discussed in the following text. The paper introduces the comparative study of time delay estimation algorithm, used for estimation of the true time delay between two speech signals. Experimental results of MATLab simulations that describe the performance of several methods based on cross-correlation, normalized crosscorrelation and generalized cross-correlation are also presented in the paper.

Excess cases of prostate cancer and estimated overdiagnosis associated with PSA testing in East Anglia

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Pashayan, N; Powles, J; Brown, C; Duffy, S W

2006-01-01

This study aimed to estimate the extent of ‘overdiagnosis' of prostate cancer attributable to prostate-specific antigen (PSA) testing in the Cambridge area between 1996 and 2002. Overdiagnosis was defined conceptually as detection of prostate cancer through PSA testing that otherwise would not have been diagnosed within the patient's lifetime. Records of PSA tests in Addenbrookes Hospital were linked to prostate cancer registrations by NHS number. Differences in prostate cancer registration rates between those receiving and not receiving prediagnosis PSA tests were calculated. The proportion of men aged 40 years or over with a prediagnosis PSA test increased from 1.4 to 5.2% from 1996 to 2002. The rate of diagnosis of prostate cancer was 45% higher (rate ratios (RR)=1.45, 95% confidence intervals (CI) 1.02–2.07) in men with a history of prediagnosis PSA testing. Assuming average lead times of 5 to 10 years, 40–64% of the PSA-detected cases were estimated to be overdiagnosed. In East Anglia, from 1996 to 2000, a 1.6% excess of cases was associated with PSA testing (around a quarter of the 5.3% excess incidence cases observed in East Anglia from 1996 to 2000). Further quantification of the overdiagnosis will result from continued surveillance and from linkage of incidence to testing in other hospitals. PMID:16832417

A Multilevel Model to Estimate the Within- and the Between-Center Components of the Exposure/Disease Association in the EPIC Study

OpenAIRE

Sera, Francesco; Ferrari, Pietro

2015-01-01

In a multicenter study, the overall relationship between exposure and the risk of cancer can be broken down into a within-center component, which reflects the individual level association, and a between-center relationship, which captures the association at the aggregate level. A piecewise exponential proportional hazards model with random effects was used to evaluate the association between dietary fiber intake and colorectal cancer (CRC) risk in the EPIC study. During an average follow-up o...

On Estimating Marginal Tax Rates for U.S. States

OpenAIRE

Reed, W. Robert; Rogers, Cynthia L; Skidmore, Mark

2011-01-01

This paper presents a procedure for generating state-specific time-varying estimates of marginal tax rates (MTRs). Most estimates of MTRs follow a procedure developed by Koester and Kormendi (1989) (K&K). Unfortunately, the time-invariant nature of the K&K estimates precludes their use as explanatory variables in panel data studies with fixed effects. Furthermore, the associated MTR estimates are not explicitly linked to statutory tax parameters. Our approach addresses both shortcomings. Usin...

Regional and longitudinal estimation of product lifespan distribution: a case study for automobiles and a simplified estimation method.

Science.gov (United States)

Oguchi, Masahiro; Fuse, Masaaki

2015-02-03

Product lifespan estimates are important information for understanding progress toward sustainable consumption and estimating the stocks and end-of-life flows of products. Publications reported actual lifespan of products; however, quantitative data are still limited for many countries and years. This study presents regional and longitudinal estimation of lifespan distribution of consumer durables, taking passenger cars as an example, and proposes a simplified method for estimating product lifespan distribution. We estimated lifespan distribution parameters for 17 countries based on the age profile of in-use cars. Sensitivity analysis demonstrated that the shape parameter of the lifespan distribution can be replaced by a constant value for all the countries and years. This enabled a simplified estimation that does not require detailed data on the age profile. Applying the simplified method, we estimated the trend in average lifespans of passenger cars from 2000 to 2009 for 20 countries. Average lifespan differed greatly between countries (9-23 years) and was increasing in many countries. This suggests consumer behavior differs greatly among countries and has changed over time, even in developed countries. The results suggest that inappropriate assumptions of average lifespan may cause significant inaccuracy in estimating the stocks and end-of-life flows of products.

Estimating Pesticide Exposure from Dietary Intake and Organic Food Choices: The Multi-Ethnic Study of Atherosclerosis (MESA)

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Beresford, Shirley A.A.; Fenske, Richard A.; Fitzpatrick, Annette L.; Lu, Chensheng; Nettleton, Jennifer A.; Kaufman, Joel D.

2015-01-01

Background Organophosphate pesticide (OP) exposure to the U.S. population is dominated by dietary intake. The magnitude of exposure from diet depends partly on personal decisions such as which foods to eat and whether to choose organic food. Most studies of OP exposure rely on urinary biomarkers, which are limited by short half-lives and often lack specificity to parent compounds. A reliable means of estimating long-term dietary exposure to individual OPs is needed to assess the potential relationship with adverse health effects. Objectives We assessed long-term dietary exposure to 14 OPs among 4,466 participants in the Multi-Ethnic Study of Atherosclerosis, and examined the influence of organic produce consumption on this exposure. Methods Individual-level exposure was estimated by combining information on typical intake of specific food items with average OP residue levels on those items. In an analysis restricted to a subset of participants who reported rarely or never eating organic produce (“conventional consumers”), we assessed urinary dialkylphosphate (DAP) levels across tertiles of estimated exposure (n = 480). In a second analysis, we compared DAP levels across subgroups with differing self-reported organic produce consumption habits (n = 240). Results Among conventional consumers, increasing tertile of estimated dietary OP exposure was associated with higher DAP concentrations (p Fenske RA, Fitzpatrick AL, Lu C, Nettleton JA, Kaufman JD. 2015. Estimating pesticide exposure from dietary intake and organic food choices: the Multi-Ethnic Study of Atherosclerosis (MESA). Environ Health Perspect 123:475–483; http://dx.doi.org/10.1289/ehp.1408197 PMID:25650532

Estimating the direct costs of ischemic heart disease: evidence from a teaching hospital in BRAZIL, a retrospective cohort study.

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Schlatter, Rosane Paixão; Hirakata, Vânia Naomi; Polanczyk, Carisi Anne

2017-07-04

Coronary artery disease is the most prevalent cardiovascular disease. In the United States, 7% of adults over 20 years of age are estimated to have coronary artery disease. In Brazil, a prevalence of 5 to 8% has been estimated in adults over 40 years of age, with an increased number of hospitalizations associated with both stable and acute clinical manifestations; and health care costs have quadrupled in the last decade. To estimate the direct costs of managing ischemic heart disease patient care in a teaching hospital in Brazil from the perspective of the service payer, the Brazilian Unified Health System. This study was a retrospective cohort study for the identification and valuation of resources used at both the outpatient and in-hospital levels in a sample of 330 patients selected from the hospital's ischemic heart disease clinic. Data were collected from computerized hospital records and patients' hospital bills from January 2000 to October 2015. A bivariate analysis and binary logistic regression were performed with p cost of outpatient management was US $1,521 per patient. The mean cost per hospitalization was US $1,976, and the expenses were higher in the first and last years of follow-up. Unstable angina, revascularization procedures, diabetes, hypertension and obesity were predictors of higher hospitalization costs (p cost estimates in this study indicate a high proportion of drug treatment costs in the treatment of ischemic heart disease. Treatment costs are higher in the first year and at the end of treatment, and some clinical factors are associated with greater hospital care costs. These results may serve as a basis for the evaluation of existing public policies and inputs for cost-effectiveness studies in coronary artery disease. CEP HCPA 11-0460 . Ethics Committee of Hospital de Clínicas de Porto Alegre.

Born to Lead? A Twin Design and Genetic Association Study of Leadership Role Occupancy*

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De Neve, Jan-Emmanuel; Mikhaylov, Slava; Dawes, Christopher T.; Christakis, Nicholas A.; Fowler, James H.

2013-01-01

We address leadership emergence and the possibility that there is a partially innate predisposition to occupy a leadership role. Employing twin design methods on data from the National Longitudinal Study of Adolescent Health, we estimate the heritability of leadership role occupancy at 24%. Twin studies do not point to specific genes or neurological processes that might be involved. We therefore also conduct association analysis on the available genetic markers. The results show that leadership role occupancy is associated with rs4950, a single nucleotide polymorphism (SNP) residing on a neuronal acetylcholine receptor gene (CHRNB3). We replicate this family-based genetic association result on an independent sample in the Framingham Heart Study. This is the first study to identify a specific genotype associated with the tendency to occupy a leadership position. The results suggest that what determines whether an individual occupies a leadership position is the complex product of genetic and environmental influences; with a particular role for rs4950. PMID:23459689

Augmented cross-sectional studies with abbreviated follow-up for estimating HIV incidence.

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Claggett, B; Lagakos, S W; Wang, R

2012-03-01

Cross-sectional HIV incidence estimation based on a sensitive and less-sensitive test offers great advantages over the traditional cohort study. However, its use has been limited due to concerns about the false negative rate of the less-sensitive test, reflecting the phenomenon that some subjects may remain negative permanently on the less-sensitive test. Wang and Lagakos (2010, Biometrics 66, 864-874) propose an augmented cross-sectional design that provides one way to estimate the size of the infected population who remain negative permanently and subsequently incorporate this information in the cross-sectional incidence estimator. In an augmented cross-sectional study, subjects who test negative on the less-sensitive test in the cross-sectional survey are followed forward for transition into the nonrecent state, at which time they would test positive on the less-sensitive test. However, considerable uncertainty exists regarding the appropriate length of follow-up and the size of the infected population who remain nonreactive permanently to the less-sensitive test. In this article, we assess the impact of varying follow-up time on the resulting incidence estimators from an augmented cross-sectional study, evaluate the robustness of cross-sectional estimators to assumptions about the existence and the size of the subpopulation who will remain negative permanently, and propose a new estimator based on abbreviated follow-up time (AF). Compared to the original estimator from an augmented cross-sectional study, the AF estimator allows shorter follow-up time and does not require estimation of the mean window period, defined as the average time between detectability of HIV infection with the sensitive and less-sensitive tests. It is shown to perform well in a wide range of settings. We discuss when the AF estimator would be expected to perform well and offer design considerations for an augmented cross-sectional study with abbreviated follow-up. © 2011, The

Review of comparative studies of health hazards associated with electric power generation

International Nuclear Information System (INIS)

Paskievici, W.

1982-01-01

Twenty comparative studies on health hazards associated with different methods of energy production were reviewed in order to highlight the methodological problems which are characteristic of this type of study and attempt to bring the results obtained closer together by using a more consistent methodological approach. The main conceptual difficulties lie in the delineation of the boundaries of a fuel cycle, the choice of technologies, dose-effect relationships and health hazard estimates, and in finding equivalent values in the case of real and hypothetical risks and of present and future risks. Practical limitations in predicting the number and gravity of illnesses and accidents both in workers and the population were also reviewed. The health effects associated with the coal, oil, natural gas and uranium cycles were estimated with the following assumptions: exclusion of risks associated with non-fuel resources, use of advanced technologies, use of linear non-threshold dose-effect relationships, exclusion of hypothetical accidents and exclusion or discounting to present worth of long-term risks (>500 years). It can be concluded from these calculations that the health hazards from all the energy sources considered are relatively low and therefore acceptable, natural gas being the safest source followed by uranium, oil and coal in that order. The uncertainty factors are discussed and methods to improve the results are proposed. It is also shown that the radiological risks to workers in the PHWR cycle are approximately half those of the LWR cycle. (author)

The association between stress and headache: A longitudinal population-based study.

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Schramm, Sara H; Moebus, Susanne; Lehmann, Nils; Galli, Ursula; Obermann, Mark; Bock, Eva; Yoon, Min-Suk; Diener, Hans-Christoph; Katsarava, Zaza

2015-09-01

We studied the association between stress intensity and headache frequency for tension-type headache (TTH), migraine and migraine with coexisting TTH (MigTTH). We studied a population-based sample of 5159 participants (21-71 years) who were asked quarterly between March 2010 and April 2012 about headache and stress. Log-linear regression in the framework of generalized estimating equations was used to estimate regression coefficients presented as percent changes to describe the association between stress intensity (modified visual analog scale (VAS) from 0 to 100) and headache frequency (days/month) stratified by headache subtypes and age groups and adjusted for sex, age, frequent intake of acute pain drugs, drinking, smoking, BMI and education. TTH was reported in 31% participants (48.1 ± 12.5years, 51.5% women, 2.2 ± 3.9 mean headache days/month, 52.3 ± 26.7 mean stress), migraine in 14% (44.8 ± 11.3years, 73.3%, 4.5 ± 5.2 days/month, 62.4 ± 23.3), MigTTH in 10.6% (43.5 ± 11.5 years, 61.0%, 3.6 ± 4.8 days/month, 58.6 ± 24.1), 23.6% were unclassifiable, and 20.8% had no headache. In participants with TTH an increase of 10 points on VAS was associated with an increase of headaches days/month of 6.0% (adjusted). Higher effects were observed in younger age groups (21-30/31-40/41-50/51-60/61-71 years: 9.8/10.2/7.0/6.5/3.5%). Slightly lower effects were observed for migraine (4.3%, 8.1/5.1/3.4/6.3/0.3%) and MigTTH (4.2%, 5.5/6.8/6.9/5.8/-0.7%). Our study provides evidence for an association between stress intensity and headache frequency. © International Headache Society 2014.

Sniffing out significant "Pee values": genome wide association study of asparagus anosmia.

Science.gov (United States)

Markt, Sarah C; Nuttall, Elizabeth; Turman, Constance; Sinnott, Jennifer; Rimm, Eric B; Ecsedy, Ethan; Unger, Robert H; Fall, Katja; Finn, Stephen; Jensen, Majken K; Rider, Jennifer R; Kraft, Peter; Mucci, Lorelei A

2016-12-13

 To determine the inherited factors associated with the ability to smell asparagus metabolites in urine.  Genome wide association study.  Nurses' Health Study and Health Professionals Follow-up Study cohorts.  6909 men and women of European-American descent with available genetic data from genome wide association studies.  Participants were characterized as asparagus smellers if they strongly agreed with the prompt "after eating asparagus, you notice a strong characteristic odor in your urine," and anosmic if otherwise. We calculated per-allele estimates of asparagus anosmia for about nine million single nucleotide polymorphisms using logistic regression. P values asparagus anosmia, all in a region on chromosome 1 (1q44: 248139851-248595299) containing multiple genes in the olfactory receptor 2 (OR2) family. Conditional analyses revealed three independent markers associated with asparagus anosmia: rs13373863, rs71538191, and rs6689553.  A large proportion of people have asparagus anosmia. Genetic variation near multiple olfactory receptor genes is associated with the ability of an individual to smell the metabolites of asparagus in urine. Future replication studies are necessary before considering targeted therapies to help anosmic people discover what they are missing. 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.

Associations Between Fast-Food Consumption and Body Mass Index: A Cross-Sectional Study in Adult Twins.

Science.gov (United States)

Cohen-Cline, Hannah; Lau, Richard; Moudon, Anne V; Turkheimer, Eric; Duncan, Glen E

2015-08-01

Obesity is a substantial health problem in the United States, and is associated with many chronic diseases. Previous studies have linked poor dietary habits to obesity. This cross-sectional study aimed to identify the association between body mass index (BMI) and fast-food consumption among 669 same-sex adult twin pairs residing in the Puget Sound region around Seattle, Washington. We calculated twin-pair correlations for BMI and fast-food consumption. We next regressed BMI on fast-food consumption using generalized estimating equations (GEE), and finally estimated the within-pair difference in BMI associated with a difference in fast-food consumption, which controls for all potential genetic and environment characteristics shared between twins within a pair. Twin-pair correlations for fast-food consumption were similar for identical (monozygotic; MZ) and fraternal (dizygotic; DZ) twins, but were substantially higher in MZ than DZ twins for BMI. In the unadjusted GEE model, greater fast-food consumption was associated with larger BMI. For twin pairs overall, and for MZ twins, there was no association between within-pair differences in fast-food consumption and BMI in any model. In contrast, there was a significant association between within-pair differences in fast-food consumption and BMI among DZ twins, suggesting that genetic factors play a role in the observed association. Thus, although variance in fast-food consumption itself is largely driven by environmental factors, the overall association between this specific eating behavior and BMI is largely due to genetic factors.

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 ...

Bias correction of risk estimates in vaccine safety studies with rare adverse events using a self-controlled case series design.

Science.gov (United States)

Zeng, Chan; Newcomer, Sophia R; Glanz, Jason M; Shoup, Jo Ann; Daley, Matthew F; Hambidge, Simon J; Xu, Stanley

2013-12-15

The self-controlled case series (SCCS) method is often used to examine the temporal association between vaccination and adverse events using only data from patients who experienced such events. Conditional Poisson regression models are used to estimate incidence rate ratios, and these models perform well with large or medium-sized case samples. However, in some vaccine safety studies, the adverse events studied are rare and the maximum likelihood estimates may be biased. Several bias correction methods have been examined in case-control studies using conditional logistic regression, but none of these methods have been evaluated in studies using the SCCS design. In this study, we used simulations to evaluate 2 bias correction approaches-the Firth penalized maximum likelihood method and Cordeiro and McCullagh's bias reduction after maximum likelihood estimation-with small sample sizes in studies using the SCCS design. The simulations showed that the bias under the SCCS design with a small number of cases can be large and is also sensitive to a short risk period. The Firth correction method provides finite and less biased estimates than the maximum likelihood method and Cordeiro and McCullagh's method. However, limitations still exist when the risk period in the SCCS design is short relative to the entire observation period.

Association of glucose homeostasis measures with heart rate variability among Hispanic/Latino adults without diabetes: the Hispanic Community Health Study/Study of Latinos (HCHS/SOL).

Science.gov (United States)

Meyer, Michelle L; Gotman, Nathan M; Soliman, Elsayed Z; Whitsel, Eric A; Arens, Raanan; Cai, Jianwen; Daviglus, Martha L; Denes, Pablo; González, Hector M; Moreiras, Juan; Talavera, Gregory A; Heiss, Gerardo

2016-03-16

Reduced heart rate variability (HRV), a measure of cardiac autonomic function, is associated with an increased risk of cardiovascular disease (CVD) and mortality. Glucose homeostasis measures are associated with reduced cardiac autonomic function among those with diabetes, but inconsistent associations have been reported among those without diabetes. This study aimed to examine the association of glucose homeostasis measures with cardiac autonomic function among diverse Hispanic/Latino adults without diabetes. The Hispanic community Health Study/Study of Latinos (HCHS/SOL; 2008-2011) used two-stage area probability sampling of households to enroll 16,415 self-identified Hispanics/Latinos aged 18-74 years from four USA communities. Resting, standard 12-lead electrocardiogram recordings were used to estimate the following ultrashort-term measures of HRV: RR interval (RR), standard deviation of all normal to normal RR (SDNN) and root mean square of successive differences in RR intervals (RMSSD). Multivariable regression analysis was used to estimate associations between glucose homeostasis measures with HRV using data from 11,994 adults without diabetes (mean age 39 years; 52 % women). Higher fasting glucose was associated with lower RR, SDNN, and RMSSD. Fasting insulin and the homeostasis model assessment of insulin resistance was negatively associated with RR, SDNN, and RMSSD, and the association was stronger among men compared with women. RMSSD was, on average, 26 % lower in men with higher fasting insulin and 29 % lower in men with lower insulin resistance; for women, the corresponding estimates were smaller at 4 and 9 %, respectively. Higher glycated hemoglobin was associated with lower RR, SDNN, and RMSSD in those with abdominal adiposity, defined by sex-specific cut-points for waist circumference, after adjusting for demographics and medication use. There were no associations between glycated hemoglobin and HRV measures among those without abdominal adiposity

Further Improvements to Linear Mixed Models for Genome-Wide Association Studies

Science.gov (United States)

Widmer, Christian; Lippert, Christoph; Weissbrod, Omer; Fusi, Nicolo; Kadie, Carl; Davidson, Robert; Listgarten, Jennifer; Heckerman, David

2014-11-01

We examine improvements to the linear mixed model (LMM) that better correct for population structure and family relatedness in genome-wide association studies (GWAS). LMMs rely on the estimation of a genetic similarity matrix (GSM), which encodes the pairwise similarity between every two individuals in a cohort. These similarities are estimated from single nucleotide polymorphisms (SNPs) or other genetic variants. Traditionally, all available SNPs are used to estimate the GSM. In empirical studies across a wide range of synthetic and real data, we find that modifications to this approach improve GWAS performance as measured by type I error control and power. Specifically, when only population structure is present, a GSM constructed from SNPs that well predict the phenotype in combination with principal components as covariates controls type I error and yields more power than the traditional LMM. In any setting, with or without population structure or family relatedness, a GSM consisting of a mixture of two component GSMs, one constructed from all SNPs and another constructed from SNPs that well predict the phenotype again controls type I error and yields more power than the traditional LMM. Software implementing these improvements and the experimental comparisons are available at http://microsoft.com/science.

Hydrogen Station Cost Estimates: Comparing Hydrogen Station Cost Calculator Results with other Recent Estimates

Energy Technology Data Exchange (ETDEWEB)

Melaina, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Penev, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2013-09-01

This report compares hydrogen station cost estimates conveyed by expert stakeholders through the Hydrogen Station Cost Calculation (HSCC) to a select number of other cost estimates. These other cost estimates include projections based upon cost models and costs associated with recently funded stations.

Disease-Concordant Twins Empower Genetic Association Studies

DEFF Research Database (Denmark)

Tan, Qihua; Li, Weilong; Vandin, Fabio

2017-01-01

and ordinary healthy samples as controls. We examined the power gain of the twin-based design for various scenarios (i.e., cases from monozygotic and dizygotic twin pairs concordant for a disease) and compared the power with the ordinary case-control design with cases collected from the unrelated patient...... concordant for a disease, should confer increased power in genetic association analysis because of their genetic relatedness. We conducted a computer simulation study to explore the power advantage of the disease-concordant twin design, which uses singletons from disease-concordant twin pairs as cases...... population. Simulation was done by assigning various allele frequencies and allelic relative risks for different mode of genetic inheritance. In general, for achieving a power estimate of 80%, the sample sizes needed for dizygotic and monozygotic twin cases were one half and one fourth of the sample size...

On the a priori estimation of collocation error covariance functions: a feasibility study

DEFF Research Database (Denmark)

Arabelos, D.N.; Forsberg, René; Tscherning, C.C.

2007-01-01

and the associated error covariance functions were conducted in the Arctic region north of 64 degrees latitude. The correlation between the known features of the data and the parameters variance and correlation length of the computed error covariance functions was estimated using multiple regression analysis...

A simulation study on estimating biomarker-treatment interaction effects in randomized trials with prognostic variables.

Science.gov (United States)

Haller, Bernhard; Ulm, Kurt

2018-02-20

To individualize treatment decisions based on patient characteristics, identification of an interaction between a biomarker and treatment is necessary. Often such potential interactions are analysed using data from randomized clinical trials intended for comparison of two treatments. Tests of interactions are often lacking statistical power and we investigated if and how a consideration of further prognostic variables can improve power and decrease the bias of estimated biomarker-treatment interactions in randomized clinical trials with time-to-event outcomes. A simulation study was performed to assess how prognostic factors affect the estimate of the biomarker-treatment interaction for a time-to-event outcome, when different approaches, like ignoring other prognostic factors, including all available covariates or using variable selection strategies, are applied. Different scenarios regarding the proportion of censored observations, the correlation structure between the covariate of interest and further potential prognostic variables, and the strength of the interaction were considered. The simulation study revealed that in a regression model for estimating a biomarker-treatment interaction, the probability of detecting a biomarker-treatment interaction can be increased by including prognostic variables that are associated with the outcome, and that the interaction estimate is biased when relevant prognostic variables are not considered. However, the probability of a false-positive finding increases if too many potential predictors are included or if variable selection is performed inadequately. We recommend undertaking an adequate literature search before data analysis to derive information about potential prognostic variables and to gain power for detecting true interaction effects and pre-specifying analyses to avoid selective reporting and increased false-positive rates.

Necrotizing Fasciitis Associated with Pregnancy: a Population-Based Cohort Study.

Science.gov (United States)

Oud, Lavi; Watkins, Phillip

2014-12-01

Necrotizing fasciitis (NF) is a rare complication in pregnant women. There have been no population-level data reported to date on its epidemiology, clinical features, resource utilization, and outcomes. This was a retrospective, population-based cohort study, using the Texas Inpatient Public Use Data File to identify pregnancy-associated hospitalizations for the years 2001-2010. Hospitalizations with a diagnosis of NF were then identified using the International Classification of Diseases, Ninth Revision, Clinical Modification code 728.86. Denominator data for incidence estimates were derived from the Texas Center for Health Statistics reports of live births, abortions and fetal deaths, and previously reported population-based, age-specific linkage data on miscarriage, and were used to estimate the annual total number of pregnancies (TEP). The incidence of pregnancy-associated NF (PANF), hospitalization type, clinical features, resource utilization and outcomes were examined. There were 4,060,201 pregnancy-associated hospitalizations and 148 PANF hospitalizations during study period. Postpartum hospitalizations accounted for 82.4% of all PANF events, and intensive care unit care was required in 61.5%. The key trends noted between 2001-2002 and 2009-2010 included rising incidence of PANF from 1.1 vs. 3.8 per 100,000 TEP-years (P = 0.0001), chronic comorbidities 0% vs. 31.7% (P = 0.0777), and development of organ failure in 9.1% vs. 31.7% (P = 0.0302). There was no significant change in total hospital charges or hospital length of stay. Three patients (2%) died in the hospital and 55% of survivors had routine home discharge. The present cohort of PANF is the largest reported to date. The incidence of PANF rose nearly 3.5-fold over the past decade, with most events developing following delivery hospitalization. Chronic illness has been increasingly present, along with rising severity of illness. The majority of patients required ICU care. Hospital mortality was

Mortality and hospital stay associated with resistant Staphylococcus aureus and Escherichia coli bacteremia: estimating the burden of antibiotic resistance in Europe.

Directory of Open Access Journals (Sweden)

Marlieke E A de Kraker

2011-10-01

Full Text Available The relative importance of human diseases is conventionally assessed by cause-specific mortality, morbidity, and economic impact. Current estimates for infections caused by antibiotic-resistant bacteria are not sufficiently supported by quantitative empirical data. This study determined the excess number of deaths, bed-days, and hospital costs associated with blood stream infections (BSIs caused by methicillin-resistant Staphylococcus aureus (MRSA and third-generation cephalosporin-resistant Escherichia coli (G3CREC in 31 countries that participated in the European Antimicrobial Resistance Surveillance System (EARSS.The number of BSIs caused by MRSA and G3CREC was extrapolated from EARSS prevalence data and national health care statistics. Prospective cohort studies, carried out in hospitals participating in EARSS in 2007, provided the parameters for estimating the excess 30-d mortality and hospital stay associated with BSIs caused by either MRSA or G3CREC. Hospital expenditure was derived from a publicly available cost model. Trends established by EARSS were used to determine the trajectories for MRSA and G3CREC prevalence until 2015. In 2007, 27,711 episodes of MRSA BSIs were associated with 5,503 excess deaths and 255,683 excess hospital days in the participating countries, whereas 15,183 episodes of G3CREC BSIs were associated with 2,712 excess deaths and 120,065 extra hospital days. The total costs attributable to excess hospital stays for MRSA and G3CREC BSIs were 44.0 and 18.1 million Euros (63.1 and 29.7 million international dollars, respectively. Based on prevailing trends, the number of BSIs caused by G3CREC is likely to rapidly increase, outnumbering the number of MRSA BSIs in the near future.Excess mortality associated with BSIs caused by MRSA and G3CREC is significant, and the prolongation of hospital stay imposes a considerable burden on health care systems. A foreseeable shift in the burden of antibiotic resistance from Gram

Association between bisphenol A exposure and body mass index in Chinese school children: a cross-sectional study

Directory of Open Access Journals (Sweden)

Wang He-xing

2012-10-01

Full Text Available Abstract Background There is increasing evidence suggesting that Bisphenol A (BPA, one of the highest volume chemicals produced worldwide, can interfere with the body’s natural weight control mechanisms to promote obesity. However, epidemiological studies for this are limited, especially for children. Methods A cross-sectional study was conducted to investigate the association between BPA exposure and body mass index (BMI in school children. Three primary and three middle schools were randomly selected from 26 primary and 30 middle candidate schools in Changning District of Shanghai City in China. According to the BMI-based criteria by age and sex for screening of overweight or obese children, we randomly chose 20 obese, 10 overweight, and 30 normal weight children aged 8-15 years of age from each selected school. First morning urine was collected and total urine BPA concentrations were determined by ultra-performance liquid chromatography tandem mass spectrometry. Multiple linear regression analysis was conducted to examine the association of urine BPA concentrations and daily intake estimates with BMI. Results BPA was detected in 84.9% of urine samples with a geometric mean of 0.45 ng/mL. The daily intake estimates ranged from 0.03 μg/day to 1.96 μg/day with a geometric mean of 0.37 μg/day. The average urine BPA concentrations and daily intake estimates were similar for boys and girls, but significantly higher in older children than younger ones, and showed an increasing trend with BMI. Multiple linear regression analyses showed that urine BPA concentrations were significantly associated with increasing BMI values in all subjects after adjustment for age and sex and the results were similar before and after corrected by urine specific gravity. When stratified by age or sex, the associations remained significant in females and in those 8-11 years of age before corrected by specific gravity. Similar results were shown for the association

Resting State Network Estimation in Individual Subjects

Science.gov (United States)

Hacker, Carl D.; Laumann, Timothy O.; Szrama, Nicholas P.; Baldassarre, Antonello; Snyder, Abraham Z.

2014-01-01

Resting-state functional magnetic resonance imaging (fMRI) has been used to study brain networks associated with both normal and pathological cognitive function. The objective of this work is to reliably compute resting state network (RSN) topography in single participants. We trained a supervised classifier (multi-layer perceptron; MLP) to associate blood oxygen level dependent (BOLD) correlation maps corresponding to pre-defined seeds with specific RSN identities. Hard classification of maps obtained from a priori seeds was highly reliable across new participants. Interestingly, continuous estimates of RSN membership retained substantial residual error. This result is consistent with the view that RSNs are hierarchically organized, and therefore not fully separable into spatially independent components. After training on a priori seed-based maps, we propagated voxel-wise correlation maps through the MLP to produce estimates of RSN membership throughout the brain. The MLP generated RSN topography estimates in individuals consistent with previous studies, even in brain regions not represented in the training data. This method could be used in future studies to relate RSN topography to other measures of functional brain organization (e.g., task-evoked responses, stimulation mapping, and deficits associated with lesions) in individuals. The multi-layer perceptron was directly compared to two alternative voxel classification procedures, specifically, dual regression and linear discriminant analysis; the perceptron generated more spatially specific RSN maps than either alternative. PMID:23735260

The association of depressive symptoms and physical diseases in Switzerland: a cross-sectional general population study

Directory of Open Access Journals (Sweden)

Donja eRodic

2015-03-01

Full Text Available Objective: To estimate the association between depressive symptoms and physical diseases in Switzerland, as respective findings might inform about future estimates of mental and physical health care costs.Methods: A population-based study, using data from the Swiss Health Survey collected by computer assisted telephone interviews and additional written questionnaires during the year 2007 (n = 18,760 in Switzerland. The multistage stratified random sample included subjects aged 15 and older, living in a private Swiss household with a telephone connection. Complete data was available for 14,348 subjects (51% of all subjects reached by telephone. Logistic regression analyses were used to estimate the associations between depressive symptoms and any physical disease, or a specific physical disease out of 13 non-communicable physical diseases assessed with a self-report checklist on common physical diseases. Analyses were adjusted for sex, age, education, occupation and household income. Results: In the adjusted models depressive symptoms were associated with arthrosis and arthritis (Odds Ratio [OR] = 1.79, 95% Confidence Interval [CI] = 1.28−2.50 and any physical disease (OR = 1.67, 95% CI = 1.33−2.10 after controlling for multiple testing.Conclusion: Our findings contribute to a better understanding of the comorbidity of depressive symptoms and arthrosis and arthritis in Switzerland and might have implications for more precise future estimates of mental and physical health care costs.

Sniffing out significant “Pee values”: genome wide association study of asparagus anosmia

Science.gov (United States)

Markt, Sarah C; Nuttall, Elizabeth; Turman, Constance; Sinnott, Jennifer; Rimm, Eric B; Ecsedy, Ethan; Unger, Robert H; Fall, Katja; Finn, Stephen; Jensen, Majken K; Rider, Jennifer R; Kraft, Peter

2016-01-01

Objective To determine the inherited factors associated with the ability to smell asparagus metabolites in urine. Design Genome wide association study. Setting Nurses’ Health Study and Health Professionals Follow-up Study cohorts. Participants 6909 men and women of European-American descent with available genetic data from genome wide association studies. Main outcome measure Participants were characterized as asparagus smellers if they strongly agreed with the prompt “after eating asparagus, you notice a strong characteristic odor in your urine,” and anosmic if otherwise. We calculated per-allele estimates of asparagus anosmia for about nine million single nucleotide polymorphisms using logistic regression. P values asparagus anosmia, all in a region on chromosome 1 (1q44: 248139851-248595299) containing multiple genes in the olfactory receptor 2 (OR2) family. Conditional analyses revealed three independent markers associated with asparagus anosmia: rs13373863, rs71538191, and rs6689553. Conclusion A large proportion of people have asparagus anosmia. Genetic variation near multiple olfactory receptor genes is associated with the ability of an individual to smell the metabolites of asparagus in urine. Future replication studies are necessary before considering targeted therapies to help anosmic people discover what they are missing. PMID:27965198

Ethnic disparities in educational and occupational gradients of estimated cardiovascular disease risk: The Healthy Life in an Urban Setting study.

Science.gov (United States)

Perini, Wilco; Agyemang, Charles; Snijder, Marieke B; Peters, Ron J G; Kunst, Anton E

2018-03-01

European societies are becoming increasingly ethnically diverse. This may have important implications for socio-economic inequalities in health due to the often disadvantaged position of ethnic minority groups in both socio-economic status (SES) and disease, especially cardiovascular disease (CVD). The aim of this study was to determine whether the socio-economic gradient of estimated CVD risk differs between ethnic groups. Using the Healthy Life in an Urban Setting study, we obtained data on SES and CVD risk factors among participants from six ethnic backgrounds residing in Amsterdam. SES was measured using educational level and occupational level. CVD risk was estimated based on the occurrence of CVD risk factors using the Dutch version of the systematic coronary risk evaluation algorithm. Ethnic disparities in socio-economic gradients for estimated CVD risk were determined using the relative index of inequality (RII). Among Dutch-origin men, the RII for estimated CVD risk according to educational level was 6.15% (95% confidence interval [CI] 4.35-7.96%), indicating that those at the bottom of the educational hierarchy had a 6.15% higher estimated CVD risk relative than those at the top. Among Dutch-origin women, the RII was 4.49% (CI 2.45-6.52%). The RII was lower among ethnic minority groups, ranging from 0.83% to 3.13% among men and -0.29% to 5.12% among women, indicating weaker associations among these groups. Results were similar based on occupational level. Ethnic background needs to be considered in associations between SES and disease. The predictive value of SES varies between ethnic groups and may be quite poor for some groups.

[Potentials in the regionalization of health indicators using small-area estimation methods : Exemplary results based on the 2009, 2010 and 2012 GEDA studies].

Science.gov (United States)

Kroll, Lars Eric; Schumann, Maria; Müters, Stephan; Lampert, Thomas

2017-12-01

Nationwide health surveys can be used to estimate regional differences in health. Using traditional estimation techniques, the spatial depth for these estimates is limited due to the constrained sample size. So far - without special refreshment samples - results have only been available for larger populated federal states of Germany. An alternative is regression-based small-area estimation techniques. These models can generate smaller-scale data, but are also subject to greater statistical uncertainties because of the model assumptions. In the present article, exemplary regionalized results based on the studies "Gesundheit in Deutschland aktuell" (GEDA studies) 2009, 2010 and 2012, are compared to the self-rated health status of the respondents. The aim of the article is to analyze the range of regional estimates in order to assess the usefulness of the techniques for health reporting more adequately. The results show that the estimated prevalence is relatively stable when using different samples. Important determinants of the variation of the estimates are the achieved sample size on the district level and the type of the district (cities vs. rural regions). Overall, the present study shows that small-area modeling of prevalence is associated with additional uncertainties compared to conventional estimates, which should be taken into account when interpreting the corresponding findings.

Severe maternal morbidity: A population-based study of an expanded measure and associated factors.

Directory of Open Access Journals (Sweden)

Victoria Lazariu

Full Text Available Severe maternal morbidity conditions such as sepsis, embolism and cardiac arrest during the delivery hospitalization period can lead to extended length of hospital stays, life-long maternal health problems, and high medical costs. Most importantly, these conditions also contribute to the risk of maternal death. This population-based observational study proposed and evaluated the impact of expanding the Centers for Disease Control and Prevention (CDC measure of severe maternal morbidity by including additional comorbidities and intensive care admissions during delivery hospitalizations and examined associated factors. A New York State linked hospitalization and birth record database was used. Study participants included all New York State female residents, ages 10 to 55 years, who delivered a live infant in a New York acute care hospital between 2008 and 2013, inclusive. Incidence trends for both severe maternal morbidity measures were evaluated longitudinally. Associations between covariates and the two severe maternal morbidity measures were examined with logistic regression models, solved using generalized estimating equations and stratified by method of delivery. The New York expanded severe maternal morbidity measure identified 34,478 cases among 1,352,600 hospital deliveries (estimated incidence 2.55% representing a 3% increase in the number of cases compared to the CDC measure. Both estimates increased over the study period (p 1.5 included most measured comorbidities (e.g., pregnancy-induced hypertension, placentation disorder, multiple births, preterm birth, no prenatal care, hospitalization prior to delivery, higher levels of perinatal care birthing facilities and race/ethnicity. Expanding the measure for severe maternal morbidity during delivery to capture intensive care admissions provides a more sensitive estimate of disease burden. Perinatal regionalization in New York appears effective in routing high risk pregnancies to higher

Study on interference of technetium in spectrophotometric estimation of uranium

International Nuclear Information System (INIS)

Revathi, P.; Saipriya, K.; Madhavan Kutty, V.K.; Srinivasa Rao, G.; Vijayakumar, N.; Kumar, T.

2015-01-01

Estimation of uranium is essential for process control purposes as well as to arrive optimum parameters for further waste management in reprocessing industry. Uranium estimation is done by spectrophotometry using ammonium thiocyanate, DBM, PAR and Br-PADAP as chromogenic reagents for colour development. Extractive spectrophotometry can also be used to eliminate some of the interfering ions. During inter method comparison, technetium was found to be interfering in the thiocyanate spectrophotometry. This study is an effort to find out the extent of technetium interference in the estimation of uranium by spectrophotometry using the above said chromogenic reagents. (author)

Association of body flexibility and carotid atherosclerosis in Japanese middle-aged men: a cross-sectional study

Science.gov (United States)

Imoto, Takayuki; Kida, Akira; Yokochi, Takashi; Iwase, Mitsunori; Kozawa, Kenji

2018-01-01

Objective This study examined the associations of body flexibility with carotid arterial remodelling, including intima–media thickness (IMT) and plaque formation in middle-aged men. Methods The subjects of this cross-sectional study included 1354 Japanese men aged 35–59 years without histories of stroke or cardiac diseases. The arm extensibility test, which can estimate flexibility of the upper extremity (composed of shoulder external rotation and forearm supination), and the sit-and-reach test were performed. Common carotid IMT and plaque formation (≥1.1 mm) were estimated by ultrasound. Results The proportion of subjects who fully completed the arm extensibility test was 55.0%, and who had plaques in the common carotid artery was 37.8%. IMT was associated with poor arm extensibility (β=–0.073, 95% CI –0.02224 to –0.00041, P=0.004), while plaque formation was associated with poor sit-and-reach (OR 0.98579, 95% CI 0.97257 to 0.99919, P=0.038) after adjustment by all covariates. Conclusions This study demonstrated that poor upper extremity and trunk flexibility were associated with characteristics of early onset of atherosclerosis. Furthermore, these associations were independent of covariates such as age, blood pressure, blood lipids glucose levels and abdominal fat accumulation, handgrip strength and lifestyle, including sleeping, drinking, exercise and smoking habits. Poor flexibility may reflect subclinical atherosclerosis in middle-aged men. PMID:29306892

Genome-wide association study meta-analysis of European and Asian-ancestry samples identifies three novel loci associated with bipolar disorder.

Science.gov (United States)

Chen, D T; Jiang, X; Akula, N; Shugart, Y Y; Wendland, J R; Steele, C J M; Kassem, L; Park, J-H; Chatterjee, N; Jamain, S; Cheng, A; Leboyer, M; Muglia, P; Schulze, T G; Cichon, S; Nöthen, M M; Rietschel, M; McMahon, F J; Farmer, A; McGuffin, P; Craig, I; Lewis, C; Hosang, G; Cohen-Woods, S; Vincent, J B; Kennedy, J L; Strauss, J

2013-02-01

Meta-analyses of bipolar disorder (BD) genome-wide association studies (GWAS) have identified several genome-wide significant signals in European-ancestry samples, but so far account for little of the inherited risk. We performed a meta-analysis of ∼750,000 high-quality genetic markers on a combined sample of ∼14,000 subjects of European and Asian-ancestry (phase I). The most significant findings were further tested in an extended sample of ∼17,700 cases and controls (phase II). The results suggest novel association findings near the genes TRANK1 (LBA1), LMAN2L and PTGFR. In phase I, the most significant single nucleotide polymorphism (SNP), rs9834970 near TRANK1, was significant at the P=2.4 × 10(-11) level, with no heterogeneity. Supportive evidence for prior association findings near ANK3 and a locus on chromosome 3p21.1 was also observed. The phase II results were similar, although the heterogeneity test became significant for several SNPs. On the basis of these results and other established risk loci, we used the method developed by Park et al. to estimate the number, and the effect size distribution, of BD risk loci that could still be found by GWAS methods. We estimate that >63,000 case-control samples would be needed to identify the ∼105 BD risk loci discoverable by GWAS, and that these will together explain <6% of the inherited risk. These results support previous GWAS findings and identify three new candidate genes for BD. Further studies are needed to replicate these findings and may potentially lead to identification of functional variants. Sample size will remain a limiting factor in the discovery of common alleles associated with BD.

Model uncertainty of various settlement estimation methods in shallow tunnels excavation; case study: Qom subway tunnel

Science.gov (United States)

Khademian, Amir; Abdollahipour, Hamed; Bagherpour, Raheb; Faramarzi, Lohrasb

2017-10-01

In addition to the numerous planning and executive challenges, underground excavation in urban areas is always followed by certain destructive effects especially on the ground surface; ground settlement is the most important of these effects for which estimation there exist different empirical, analytical and numerical methods. Since geotechnical models are associated with considerable model uncertainty, this study characterized the model uncertainty of settlement estimation models through a systematic comparison between model predictions and past performance data derived from instrumentation. To do so, the amount of surface settlement induced by excavation of the Qom subway tunnel was estimated via empirical (Peck), analytical (Loganathan and Poulos) and numerical (FDM) methods; the resulting maximum settlement value of each model were 1.86, 2.02 and 1.52 cm, respectively. The comparison of these predicted amounts with the actual data from instrumentation was employed to specify the uncertainty of each model. The numerical model outcomes, with a relative error of 3.8%, best matched the reality and the analytical method, with a relative error of 27.8%, yielded the highest level of model uncertainty.

COPATH - a spreadsheet model for the estimation of carbon flows associated with the use of forest resources

International Nuclear Information System (INIS)

Makundi, W.; Sathaye, J.; Ketoff, A.

1995-01-01

The forest sector plays a key role in the global climate change process. A significant amount of net greenhouse gas emissions emanate from land use changes, and the sector offers a unique opportunity to sequester carbon in vegetation, detritus, soils and forest products. However, the estimates of carbon flows associated with the use of forest resources have been quite imprecise. This paper describes a methodological framework-COPATH-which is a spreadsheet model for estimating carbon emissions and sequestration from deforestation and harvesting of forests. The model has two parts, the first estimates carbon stocks, emissions and uptake in the base year, while the second part forecasts future emissions and the uptake under various scenarios. The forecast module is structured after the main modes of forest conversion, i.e. agriculture, pasture, forest harvesting and other land uses. The model can be used by countries which may not possess an abundance of pertinent data, and allows for the use of forest inventory data to estimate carbon stocks. The choice of the most likely scenario provides the country with a carbon flux profile necessary to formulate GHG mitigation strategies. (Author)

Small-Area Estimation with Zero-Inflated Data – a Simulation Study

Directory of Open Access Journals (Sweden)

Krieg Sabine

2016-12-01

Full Text Available Many target variables in official statistics follow a semicontinuous distribution with a mixture of zeros and continuously distributed positive values. Such variables are called zero inflated. When reliable estimates for subpopulations with small sample sizes are required, model-based small-area estimators can be used, which improve the accuracy of the estimates by borrowing information from other subpopulations. In this article, three small-area estimators are investigated. The first estimator is the EBLUP, which can be considered the most common small-area estimator and is based on a linear mixed model that assumes normal distributions. Therefore, the EBLUP is model misspecified in the case of zero-inflated variables. The other two small-area estimators are based on a model that takes zero inflation explicitly into account. Both the Bayesian and the frequentist approach are considered. These small-area estimators are compared with each other and with design-based estimation in a simulation study with zero-inflated target variables. Both a simulation with artificial data and a simulation with real data from the Dutch Household Budget Survey are carried out. It is found that the small-area estimators improve the accuracy compared to the design-based estimator. The amount of improvement strongly depends on the properties of the population and the subpopulations of interest.

[Gastric cancer risk estimate in patients with chronic gastritis associated with Helicobacter pylori infection in a clinical setting].

Science.gov (United States)

Arismendi-Morillo, G; Hernández, I; Mengual, E; Abreu, N; Molero, N; Fuenmayor, A; Romero, G; Lizarzábal, M

2013-01-01

Severity of chronic gastritis associated with Helicobacter pylori infection (CGAHpI) could play a role in evaluating the potential risk to develop gastric cancer. Our aim was to estimate the risk for gastric cancer in a clinical setting, according to histopathologic criteria, by applying the gastric cancer risk index (GCRI) METHODS: Histopathologic study of the gastric biopsies (corpus-antrum) from consecutive adult patients that underwent gastroesophageal duodenoscopy was carried out, and the GCRI was applied in patients presenting with CGAHpI. One hundred eleven patients (77% female) with a mean age of 38.6±13.1 years were included. Active Helicobacter pylori infection (aHpi) was diagnosed in 77 cases (69.40%). In 45% of the cases with aHpi, pangastritis (23%) or corpus-predominant gastritis (22%) was diagnosed. Nine cases were diagnosed with intestinal metaplasia (8%), 7 of which (77.70%) were in the aHpi group. Twenty one percent of the patients with aHpi had a GCRI of 2 (18.10%) or 3 (2.50%) points (high risk index), while 79.10% accumulated a GCRI of 0 or 1 points (low risk index). Of the patients with no aHpi, none of them had 3 points (p=0.001). Of the 18 patients that accumulated 2 or 3 points, 6 (33.30%) presented with intestinal metaplasia (all with pangastritis and corpus-predominant gastritis), of which 4 cases (66.60%) had aHpi. The estimated gastric cancer risk in patients with CGAHpI in the clinical setting studied was relatively low and 5% of the patients had a histopathologic phenotype associated with an elevated risk for developing gastric cancer. Copyright © 2012 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.

Estimating PM2.5-associated mortality increase in California due to the Volkswagen emission control defeat device

Science.gov (United States)

Wang, Tianyang; Jerrett, Michael; Sinsheimer, Peter; Zhu, Yifang

2016-11-01

The Volkswagen Group of America (VW) was found by the US Environmental Protection Agency (EPA) and the California Air Resources Board (CARB) to have installed "defeat devices" and emit more oxides of nitrogen (NOx) than permitted under current EPA standards. In this paper, we quantify the hidden NOx emissions from this so-called VW scandal and the resulting public health impacts in California. The NOx emissions are calculated based on VW road test data and the CARB Emission Factors (EMFAC) model. Cumulative hidden NOx emissions from 2009 to 2015 were estimated to be over 3500 tons. Adult mortality changes were estimated based on ambient fine particulate matter (PM2.5) change due to secondary nitrate formation and the related concentration-response functions. We estimated that hidden NOx emissions from 2009 to 2015 have resulted in a total of 12 PM2.5-associated adult mortality increases in California. Most of the mortality increase happened in metropolitan areas, due to their high population and vehicle density.

Fat Mass Is Positively Associated with Estimated Hip Bone Strength among Chinese Men Aged 50 Years and above with Low Levels of Lean Mass.

Science.gov (United States)

Han, Guiyuan; Chen, Yu-Ming; Huang, Hua; Chen, Zhanyong; Jing, Lipeng; Xiao, Su-Mei

2017-04-24

This study investigated the relationships of fat mass (FM) and lean mass (LM) with estimated hip bone strength in Chinese men aged 50-80 years (median value: 62.0 years). A cross-sectional study including 889 men was conducted in Guangzhou, China. Body composition and hip bone parameters were generated by dual-energy X-ray absorptiometry (DXA). The relationships of the LM index (LMI) and the FM index (FMI) with bone phenotypes were detected by generalised additive models and multiple linear regression. The associations between the FMI and the bone variables in LMI tertiles were further analysed. The FMI possessed a linear relationship with greater estimated hip bone strength after adjustment for the potential confounders ( p maintenance of adequate FM could help to promote bone acquisition in relatively thin men.

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...

Study on estimation of evacuation distances for nuclear emergency

International Nuclear Information System (INIS)

Sato, Sohei; Homma, Toshimitsu

2005-09-01

Japan Atomic Energy Research Institute (JAERI) have conducted the analytical studies on the Probabilistic Safety Assessment (PSA), the severe accidents, and the optimization of protective actions. Based on the results of these studies, JAERI are investigating the method for taking urgent protective actions more reasonably. If an accident occurs in a nuclear power plant (NPP), early protective actions are carried out. To implement these actions more effectively, emergency preparedness and emergency planning are important, and especially prompt evacuation is expected to reduce a large amount of radiation exposures. To examine the effect of early protective measures by using a PSA method, estimation of the parameter uncertainty related in the time for early protective actions is needed. For this purpose, we have developed an analytical method for urgent protective actions using geographic information, and estimated the movement distance based on gathering points arrangement an population distribution. For this analysis, we used the gathering point data shown on each regional plans for disaster prevention which will be used in actual emergency situation and targeted the population inside Emergency Planning Zone (EPZ). By applying this method for the existing sixteen commercial NPP sites, we estimated the average value and distribution of the movement distance for each sites. This report provides a brief description of the method for estimating the movement distance, input data for this analysis, and the result. Moreover, the problem on the method of evacuation distance analysis and usefulness of this method for emergency planning were discussed. (author)

High performance computing enabling exhaustive analysis of higher order single nucleotide polymorphism interaction in Genome Wide Association Studies.

Science.gov (United States)

Goudey, Benjamin; Abedini, Mani; Hopper, John L; Inouye, Michael; Makalic, Enes; Schmidt, Daniel F; Wagner, John; Zhou, Zeyu; Zobel, Justin; Reumann, Matthias

2015-01-01

Genome-wide association studies (GWAS) are a common approach for systematic discovery of single nucleotide polymorphisms (SNPs) which are associated with a given disease. Univariate analysis approaches commonly employed may miss important SNP associations that only appear through multivariate analysis in complex diseases. However, multivariate SNP analysis is currently limited by its inherent computational complexity. In this work, we present a computational framework that harnesses supercomputers. Based on our results, we estimate a three-way interaction analysis on 1.1 million SNP GWAS data requiring over 5.8 years on the full "Avoca" IBM Blue Gene/Q installation at the Victorian Life Sciences Computation Initiative. This is hundreds of times faster than estimates for other CPU based methods and four times faster than runtimes estimated for GPU methods, indicating how the improvement in the level of hardware applied to interaction analysis may alter the types of analysis that can be performed. Furthermore, the same analysis would take under 3 months on the currently largest IBM Blue Gene/Q supercomputer "Sequoia" at the Lawrence Livermore National Laboratory assuming linear scaling is maintained as our results suggest. Given that the implementation used in this study can be further optimised, this runtime means it is becoming feasible to carry out exhaustive analysis of higher order interaction studies on large modern GWAS.

Risk of lung cancer associated with domestic use of coal in Xuanwei, China: retrospective cohort study

NARCIS (Netherlands)

Barone-Adesi, F.; Chapman, R.S.; Silverman, D.T.; He, X.; Hu, W.; Vermeulen, R.; Ning, B.; Fraumeni, J.F.; Rothman, N.; Lan, Q.

2012-01-01

OBJECTIVE: To estimate the risk of lung cancer associated with the use of different types of coal for household cooking and heating. SETTING: Xuanwei County, Yunnan Province, China. DESIGN: Retrospective cohort study (follow-up 1976-96) comparing mortality from lung cancer between lifelong users of

Estimation of dose and exposure at sentinel node study

International Nuclear Information System (INIS)

Skopljak, A.; Kucukalic-Selimovic, E.; Beslic, N.; Begic, A.; Begovic-Hadzimuratovic, S.; Drazeta, Z.; Beganovic, A.

2005-01-01

The purpose of this study was to estimate the dose end exposure in staff involved in sentinel node procedure for breast cancer patients. The Institute of Nuclear Medicine in Sarajevo uses a protocol for lymphoscintigraphy of the sentinel node whereby 13 MBq of 9 9mT c nanocoll are used. In this study, we measured radiation doses and exposure of a nuclear medicine physician and a technologist, as well as a surgeon performing sentinel node lymphoscintigraphy and biopsy. Dose and exposure were calculated using the equation in which we have gamma constant for 9 9mT c. Calculations were made for different times of exposure and distance. In Table 1. we estimated the dose and exposure during sentinel node study. Radiation levels were very low and the most exposed hospital staff performing sentinel node study were nuclear medicine physicians. The doses on the hands of surgeons were negligible 8 hours after exposure.(author)

Association study of FOXO3A SNPs and aging phenotypes in Danish oldest-old individuals

DEFF Research Database (Denmark)

Soerensen, Mette; Nygaard, Marianne; Dato, Serena

2015-01-01

-old Danes (age 92-93) with 4 phenotypes known to predict their survival: cognitive function, hand grip strength, activity of daily living (ADL), and self-rated health. Based on previous studies in humans and foxo animal models, we also explore self-reported diabetes, cancer, cardiovascular disease......FOXO3A variation has repeatedly been reported to associate with human longevity, yet only few studies have investigated whether FOXO3A variation also associates with aging-related traits. Here, we investigate the association of 15 FOXO3A tagging single nucleotide polymorphisms (SNPs) in 1088 oldest...... borderline significance (P = 0.054), while ADL did not (P = 0.396). Although the single-SNP associations did not formally replicate in another study population of oldest-old Danes (n = 1279, age 94-100), the estimates were of similar direction of effect as observed in the Discovery sample. A pooled analysis...

Wide-area estimates of evapotranspiration by red gum (Eucalyptus camaldulensis) and associated vegetation in the Murray-Darling River Basin, Australia

Science.gov (United States)

Nagler, Pamela L.; Doody, Tanya M.; Glenn, Edward P.; Jarchow, Christopher J.; Barreto-Munoz, Armando; Didan, Kamel

2016-01-01

Floodplain red gum forests (Eucalyptus camaldulensis plus associated grasses, reeds and sedges) are sites of high biodiversity in otherwise arid regions of southeastern Australia. They depend on periodic floods from rivers, but dams and diversions have reduced flood frequencies and volumes, leading to deterioration of trees and associated biota. There is a need to determine their water requirements so environmental flows can be administered to maintain or restore the forests. Their water requirements include the frequency and extent of overbank flooding, which recharges the floodplain soils with water, as well as the actual amount of water consumed in evapotranspiration (ET). We estimated the flooding requirements and ET for a 38 134 ha area of red gum forest fed by the Murrumbidgee River in Yanga National Park, New South Wales. ET was estimated by three methods: sap flux sensors placed in individual trees; a remote sensing method based on the Enhanced Vegetation Index from MODIS satellite imagery and a water balance method based on differences between river flows into and out of the forest. The methods gave comparable estimates yet covered different spatial and temporal scales. We estimated flood frequency and volume requirements by comparing Normalized Difference Vegetation Index values from Landsat images with flood history from 1995 to 2014, which included both wet periods and dry periods. ET during wet years is about 50% of potential ET but is much less in dry years because of the trees' ability to control stomatal conductance. Based on our analyses plus other studies, red gum trees at this location require environmental flows of 2000 GL yr−1 every other year, with peak flows of 20 000 ML d−1, to produce flooding sufficient to keep them in good condition. However, only about 120–200 GL yr−1 of river water is consumed in ET, with the remainder flowing out of the forest where it enters the Murray River system.

The association between estimated average glucose levels and fasting plasma glucose levels

Directory of Open Access Journals (Sweden)

Giray Bozkaya

2010-01-01

Full Text Available OBJECTIVE: The level of hemoglobin A1c (HbA1c, also known as glycated hemoglobin, determines how well a patient's blood glucose level has been controlled over the previous 8-12 weeks. HbA1c levels help patients and doctors understand whether a particular diabetes treatment is working and whether adjustments need to be made to the treatment. Because the HbA1c level is a marker of blood glucose for the previous 120 days, average blood glucose levels can be estimated using HbA1c levels. Our aim in the present study was to investigate the relationship between estimated average glucose levels, as calculated by HbA1c levels, and fasting plasma glucose levels. METHODS: The fasting plasma glucose levels of 3891 diabetic patient samples (1497 male, 2394 female were obtained from the laboratory information system used for HbA1c testing by the Department of Internal Medicine at the Izmir Bozyaka Training and Research Hospital in Turkey. These samples were selected from patient samples that had hemoglobin levels between 12 and 16 g/dL. The estimated glucose levels were calculated using the following formula: 28.7 x HbA1c - 46.7. Glucose and HbA1c levels were determined using hexokinase and high performance liquid chromatography (HPLC methods, respectively. RESULTS: A strong positive correlation between fasting plasma glucose levels and estimated average blood glucose levels (r=0.757, p<0.05 was observed. The difference was statistically significant. CONCLUSION: Reporting the estimated average glucose level together with the HbA1c level is believed to assist patients and doctors determine the effectiveness of blood glucose control measures.

Assessing the Probability that a Finding Is Genuine for Large-Scale Genetic Association Studies.

Science.gov (United States)

Kuo, Chia-Ling; Vsevolozhskaya, Olga A; Zaykin, Dmitri V

2015-01-01

Genetic association studies routinely involve massive numbers of statistical tests accompanied by P-values. Whole genome sequencing technologies increased the potential number of tested variants to tens of millions. The more tests are performed, the smaller P-value is required to be deemed significant. However, a small P-value is not equivalent to small chances of a spurious finding and significance thresholds may fail to serve as efficient filters against false results. While the Bayesian approach can provide a direct assessment of the probability that a finding is spurious, its adoption in association studies has been slow, due in part to the ubiquity of P-values and the automated way they are, as a rule, produced by software packages. Attempts to design simple ways to convert an association P-value into the probability that a finding is spurious have been met with difficulties. The False Positive Report Probability (FPRP) method has gained increasing popularity. However, FPRP is not designed to estimate the probability for a particular finding, because it is defined for an entire region of hypothetical findings with P-values at least as small as the one observed for that finding. Here we propose a method that lets researchers extract probability that a finding is spurious directly from a P-value. Considering the counterpart of that probability, we term this method POFIG: the Probability that a Finding is Genuine. Our approach shares FPRP's simplicity, but gives a valid probability that a finding is spurious given a P-value. In addition to straightforward interpretation, POFIG has desirable statistical properties. The POFIG average across a set of tentative associations provides an estimated proportion of false discoveries in that set. POFIGs are easily combined across studies and are immune to multiple testing and selection bias. We illustrate an application of POFIG method via analysis of GWAS associations with Crohn's disease.

Extremity fractures associated with ATVs and dirt bikes: a 10-year national epidemiologic study.

Science.gov (United States)

Lombardo, D J; Jelsema, T; Gambone, A; Weisman, M; Petersen-Fitts, G; Whaley, J D; Sabesan, V J

2017-08-01

Morbidity and mortality of all-terrain vehicles and dirt bikes have been studied, as well as the association of helmet use and head injury. The purpose of this study is to compare and contrast the patterns of extremity fractures associated with ATVs and dirt bikes. We believe there will be unique and potentially preventable injury patterns associated with dirt bikes and three-wheeled ATVs due to the poor stability of these vehicles. Descriptive epidemiology study. The National Electronic Injury Surveillance System (NEISS) was used to acquire data for extremity fractures related to ATV (three wheels, four wheels, and number of wheels undefined) and dirt bike use from 2007 to 2012. Nationwide estimation of injury incidence was determined using NEISS weight calculations. The database yielded an estimate of 229,362 extremity fractures from 2007 to 2012. The incidence rates of extremity fractures associated with ATV and dirt bike use were 3.87 and 6.85 per 1000 participant-years. The largest proportion of all fractures occurred in the shoulder (27.2%), followed by the wrist and lower leg (13.8 and 12.4%, respectively). There were no differences in the distribution of the location of fractures among four-wheeled or unspecified ATVs. However, three-wheeled ATVs and dirt bikes had much larger proportion of lower leg, foot, and ankle fractures compared to the other vehicle types. While upper extremity fractures were the most commonly observed in this database, three-wheeled ATVs and dirt bikes showed increased proportions of lower extremity fractures. Several organizations have previously advocated for better regulation of the sale and use of these specific vehicles due to increased risks. These findings help illustrate some of the specific risks associated with these commonly used vehicles.

Dietary patterns and chronic kidney disease: a cross-sectional association in the Irish Nun Eye Study.

Science.gov (United States)

Paterson, Euan N; Neville, Charlotte E; Silvestri, Giuliana; Montgomery, Shannon; Moore, Evelyn; Silvestri, Vittorio; Cardwell, Christopher R; MacGillivray, Tom J; Maxwell, Alexander P; Woodside, Jayne V; McKay, Gareth J

2018-04-27

Associations between dietary patterns and chronic kidney disease are not well established, especially in European populations. We conducted a cross-sectional study of 1033 older Irish women (age range 56-100 years) with a restricted lifestyle. Dietary intake was assessed using a food frequency questionnaire. Renal function was determined by estimated glomerular filtration rate. Two dietary patterns were identified within the study population using factor analysis. A significant negative association was found between unhealthy dietary pattern adherence and renal function in both unadjusted and adjusted models controlling for potential confounding variables (p for trend <0.001), with a mean difference in estimated glomerular filtration rate of -6 ml/min/1.73 m 2 between those in the highest fifth of adherence to the unhealthy dietary pattern compared to the lowest, in the fully adjusted model. Chronic kidney disease risk was significantly greater for the highest fifth, compared to the lowest fifth of unhealthy dietary pattern adherence in adjusted models (adjusted odds ratio = 2.62, p < 0.001). Adherence to the healthy dietary pattern was not associated with renal function or chronic kidney disease in adjusted models. In this cohort, an unhealthy dietary pattern was associated with lower renal function and greater prevalence of chronic kidney disease.

Impact of varying the definition of myopia on estimates of prevalence and associations with risk factors: time for an approach that serves research, practice and policy.

Science.gov (United States)

Cumberland, Phillippa M; Bountziouka, Vasiliki; Rahi, Jugnoo S

2018-02-03

Refractive error is an increasing global public health concern that requires robust and reliable research to identify modifiable risk factors and provide accurate estimates of population burden. We investigated the impact of reclassification of individuals when using different threshold values of spherical equivalent (SE) to define myopia, on estimates of frequency, distribution and associations with risk factors, to inform current international initiatives to standardise definitions. A random sample of 1985 individuals from the 1958 British birth cohort, at age 44, had autorefraction and self-reported on educational attainment and social class.Refraction status assigned in three different models using SE: (A) moderate to high myopia -3 diopters (D) or more extreme (≤-3.00D), (B) hypermetropia +1.00D or more extreme (≥+1.00D) and (C) mild myopia using three different thresholds: -1.00D, -0.75D or -0.50D, hence reciprocal changes in definition of emmetropia. Frequency estimates and associations with risk factors altered significantly as the threshold value for myopia moved towards SE 0.0D: prevalence of mild myopia increased from 28% to 47%, the association with highest educational attainment attenuated and with higher social class strengthened, with changes in risk ratios of approximately 20%. Even small changes in the threshold definition of myopia (±0.25D) can significantly affect the conclusions of epidemiological studies, creating both false-positive and false-negative associations for specific risk factors. An international classification for refractive error, empirically evidenced and cognisant of the question(s) being addressed and the population(s) being studied, is needed to serve better translational research, practice and policy. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Comparing computing formulas for estimating concentration ratios

International Nuclear Information System (INIS)

Gilbert, R.O.; Simpson, J.C.

1984-03-01

This paper provides guidance on the choice of computing formulas (estimators) for estimating concentration ratios and other ratio-type measures of radionuclides and other environmental contaminant transfers between ecosystem components. Mathematical expressions for the expected value of three commonly used estimators (arithmetic mean of ratios, geometric mean of ratios, and the ratio of means) are obtained when the multivariate lognormal distribution is assumed. These expressions are used to explain why these estimators will not in general give the same estimate of the average concentration ratio. They illustrate that the magnitude of the discrepancies depends on the magnitude of measurement biases, and on the variances and correlations associated with spatial heterogeneity and measurement errors. This paper also reports on a computer simulation study that compares the accuracy of eight computing formulas for estimating a ratio relationship that is constant over time and/or space. Statistical models appropriate for both controlled spiking experiments and observational field studies for either normal or lognormal distributions are considered. 24 references, 15 figures, 7 tables

Scientific and Engineering Studies; Spectral Estimation.

Science.gov (United States)

1977-01-01

L NIfN-l DE6X.I,/N ISZN/16 S=IS0ED. 114-zINTI|L0OG(|FL0t.O(M)) *1.ti427,5) CALL OTRCOS(CNe,) CAL QTRCO$(cMr*t) CA6 .L "ODEUS(ZvO) CAL StBJEi,(Z5. -00...6lNES6(Z#,PLAT(IP)emLOO.) CALL SLTS*6(Zo~nelo) CALL 6141S&(Z#O.SseemLOO) CALL LLCSLL5e. CA6 .L L1NLSa(Zokl 16*einLOO.) CALL 61N4ESS(Z@1L.0-1000OO) CA6L...square error of the MC estimate § can be obtained. A significant difference now exists between treatment of the MC estimate and the MSC estimate: whereas

Estimating population exposure to power plant emissions using CALPUFF: a case study in Beijing, China

Energy Technology Data Exchange (ETDEWEB)

Ying Zhou; Levy, J.I. [Harvard School of Public Health, Boston, MA (United States); Hammitt, J.K.; Evans, J.S. [Harvard Center for Risk Analysis, Boston, MA (United States)

2003-02-01

Epidemiological studies have shown a significant association between ambient particulate matter (PM) exposures and increased mortality and morbidity risk. Power plants are significant emitters of precursor gases of fine particulate matter. To evaluate the public health risk posed by power plants, it is necessary to evaluate population exposure to different pollutants. The concept of intake fraction (the fraction of a pollutant emitted that is eventually inhaled or ingested by a population) has been proposed to provide a simple summary measure of the relationship between emissions and exposure. Currently available intake fraction estimates from developing countries used models that look only at the near field impacts, which may not capture the full impact of a pollution source. This case study demonstrated how the intake fraction of power plant emissions in China can be calculated using a detailed long-range atmospheric dispersion model-CALPUFF. We found that the intake fraction of primary fine particles is roughly on the order of 10{sup -5}, while the intake fractions of sulfur dioxide, sulfate and nitrate are on the order of 10{sup -6}. These estimates are an order of magnitude higher than the US estimates. We also tested how sensitive the results were to key assumptions within the model. The size distribution of primary particles has a large impact on the intake fraction for primary particles while the background ammonia concentration is an important factor influencing the intake fraction of nitrate. The background ozone concentration has a moderate impact on the intake fraction of sulfate and nitrate. Our analysis shows that this approach is applicable to a developing country and it provides reasonable population exposure estimates. (author)

Estimation of the simple correlation coefficient.

Science.gov (United States)

Shieh, Gwowen

2010-11-01

This article investigates some unfamiliar properties of the Pearson product-moment correlation coefficient for the estimation of simple correlation coefficient. Although Pearson's r is biased, except for limited situations, and the minimum variance unbiased estimator has been proposed in the literature, researchers routinely employ the sample correlation coefficient in their practical applications, because of its simplicity and popularity. In order to support such practice, this study examines the mean squared errors of r and several prominent formulas. The results reveal specific situations in which the sample correlation coefficient performs better than the unbiased and nearly unbiased estimators, facilitating recommendation of r as an effect size index for the strength of linear association between two variables. In addition, related issues of estimating the squared simple correlation coefficient are also considered.

Estimating the geoeffectiveness of halo CMEs from associated solar and IP parameters using neural networks

Directory of Open Access Journals (Sweden)

J. Uwamahoro

2012-06-01

Full Text Available Estimating the geoeffectiveness of solar events is of significant importance for space weather modelling and prediction. This paper describes the development of a neural network-based model for estimating the probability occurrence of geomagnetic storms following halo coronal mass ejection (CME and related interplanetary (IP events. This model incorporates both solar and IP variable inputs that characterize geoeffective halo CMEs. Solar inputs include numeric values of the halo CME angular width (AW, the CME speed (Vcme, and the comprehensive flare index (cfi, which represents the flaring activity associated with halo CMEs. IP parameters used as inputs are the numeric peak values of the solar wind speed (Vsw and the southward Z-component of the interplanetary magnetic field (IMF or Bs. IP inputs were considered within a 5-day time window after a halo CME eruption. The neural network (NN model training and testing data sets were constructed based on 1202 halo CMEs (both full and partial halo and their properties observed between 1997 and 2006. The performance of the developed NN model was tested using a validation data set (not part of the training data set covering the years 2000 and 2005. Under the condition of halo CME occurrence, this model could capture 100% of the subsequent intense geomagnetic storms (Dst ≤ −100 nT. For moderate storms (−100 < Dst ≤ −50, the model is successful up to 75%. This model's estimate of the storm occurrence rate from halo CMEs is estimated at a probability of 86%.

Estimated radiation dose from timepieces containing tritium

International Nuclear Information System (INIS)

McDowell-Boyer, L.M.

1980-01-01

Luminescent timepieces containing radioactive tritium, either in elemental form or incorporated into paint, are available to the general public. The purpose of this study was to estimate potential radiation dose commitments received by the public annually as a result of exposure to tritium which may escape from the timepieces during their distribution, use, repair, and disposal. Much uncertainty is associated with final dose estimates due to limitations of empirical data from which exposure parameters were derived. Maximum individual dose estimates were generally less than 3 μSv/yr, but ranged up to 2 mSv under worst-case conditions postulated. Estimated annual collective (population) doses were less than 5 person/Sv per million timepieces distributed

The association between dietary energy density and type 2 diabetes in Europe: results from the EPIC-InterAct Study.

Directory of Open Access Journals (Sweden)

Saskia W van den Berg

Full Text Available Observational studies implicate higher dietary energy density (DED as a potential risk factor for weight gain and obesity. It has been hypothesized that DED may also be associated with risk of type 2 diabetes (T2D, but limited evidence exists. Therefore, we investigated the association between DED and risk of T2D in a large prospective study with heterogeneity of dietary intake.A case-cohort study was nested within the European Prospective Investigation into Cancer (EPIC study of 340,234 participants contributing 3.99 million person years of follow-up, identifying 12,403 incident diabetes cases and a random subcohort of 16,835 individuals from 8 European countries. DED was calculated as energy (kcal from foods (except beverages divided by the weight (gram of foods estimated from dietary questionnaires. Prentice-weighted Cox proportional hazard regression models were fitted by country. Risk estimates were pooled by random effects meta-analysis and heterogeneity was evaluated. Estimated mean (sd DED was 1.5 (0.3 kcal/g among cases and subcohort members, varying across countries (range 1.4-1.7 kcal/g. After adjustment for age, sex, smoking, physical activity, alcohol intake, energy intake from beverages and misreporting of dietary intake, no association was observed between DED and T2D (HR 1.02 (95% CI: 0.93-1.13, which was consistent across countries (I(2 = 2.9%.In this large European case-cohort study no association between DED of solid and semi-solid foods and risk of T2D was observed. However, despite the fact that there currently is no conclusive evidence for an association between DED and T2DM risk, choosing low energy dense foods should be promoted as they support current WHO recommendations to prevent chronic diseases.

Exploratory Study for Continuous-time Parameter Estimation of Ankle Dynamics

Science.gov (United States)

Kukreja, Sunil L.; Boyle, Richard D.

2014-01-01

Recently, a parallel pathway model to describe ankle dynamics was proposed. This model provides a relationship between ankle angle and net ankle torque as the sum of a linear and nonlinear contribution. A technique to identify parameters of this model in discrete-time has been developed. However, these parameters are a nonlinear combination of the continuous-time physiology, making insight into the underlying physiology impossible. The stable and accurate estimation of continuous-time parameters is critical for accurate disease modeling, clinical diagnosis, robotic control strategies, development of optimal exercise protocols for longterm space exploration, sports medicine, etc. This paper explores the development of a system identification technique to estimate the continuous-time parameters of ankle dynamics. The effectiveness of this approach is assessed via simulation of a continuous-time model of ankle dynamics with typical parameters found in clinical studies. The results show that although this technique improves estimates, it does not provide robust estimates of continuous-time parameters of ankle dynamics. Due to this we conclude that alternative modeling strategies and more advanced estimation techniques be considered for future work.

A feasibility study on wavelet transform for reactivity coefficient estimation

International Nuclear Information System (INIS)

Shimazu, Yoichiro

2000-01-01

Recently, a new method using Fourier transform has been introduced in place of the conventional method in order to reduce the time required for the measurement of moderator temperature coefficient in domestic PWRs. The basic concept of these methods is to eliminate noise in the reactivity signal. From this point of view, wavelet analysis is also known as an effective method. In this paper, we tried to apply this method to estimate reactivity coefficients of a nuclear reactor. The basic idea of the reactivity coefficient estimation is to analyze the ratios themselves of the corresponding expansion coefficients of the wavelet transform of the signals of reactivity and the relevant parameter. The concept requires no inverse wavelet transform. Based on numerical simulations, it is found that the method can reasonably estimate reactivity coefficient, for example moderator temperature coefficient, with less length of time sequence data than those required for Fourier transform method. We will continue this study to examine the validity of the estimation procedure for the actual reactor data and further to estimate the other reactivity coefficients. (author)

A comparison of Cox and logistic regression for use in genome-wide association studies of cohort and case-cohort design.

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Staley, James R; Jones, Edmund; Kaptoge, Stephen; Butterworth, Adam S; Sweeting, Michael J; Wood, Angela M; Howson, Joanna M M

2017-06-01

Logistic regression is often used instead of Cox regression to analyse genome-wide association studies (GWAS) of single-nucleotide polymorphisms (SNPs) and disease outcomes with cohort and case-cohort designs, as it is less computationally expensive. Although Cox and logistic regression models have been compared previously in cohort studies, this work does not completely cover the GWAS setting nor extend to the case-cohort study design. Here, we evaluated Cox and logistic regression applied to cohort and case-cohort genetic association studies using simulated data and genetic data from the EPIC-CVD study. In the cohort setting, there was a modest improvement in power to detect SNP-disease associations using Cox regression compared with logistic regression, which increased as the disease incidence increased. In contrast, logistic regression had more power than (Prentice weighted) Cox regression in the case-cohort setting. Logistic regression yielded inflated effect estimates (assuming the hazard ratio is the underlying measure of association) for both study designs, especially for SNPs with greater effect on disease. Given logistic regression is substantially more computationally efficient than Cox regression in both settings, we propose a two-step approach to GWAS in cohort and case-cohort studies. First to analyse all SNPs with logistic regression to identify associated variants below a pre-defined P-value threshold, and second to fit Cox regression (appropriately weighted in case-cohort studies) to those identified SNPs to ensure accurate estimation of association with disease.

Study of non-Hodgkin's lymphoma mortality associated with industrial pollution in Spain, using Poisson models

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Lope Virginia

2009-01-01

Full Text Available Abstract Background Non-Hodgkin's lymphomas (NHLs have been linked to proximity to industrial areas, but evidence regarding the health risk posed by residence near pollutant industries is very limited. The European Pollutant Emission Register (EPER is a public register that furnishes valuable information on industries that release pollutants to air and water, along with their geographical location. This study sought to explore the relationship between NHL mortality in small areas in Spain and environmental exposure to pollutant emissions from EPER-registered industries, using three Poisson-regression-based mathematical models. Methods Observed cases were drawn from mortality registries in Spain for the period 1994–2003. Industries were grouped into the following sectors: energy; metal; mineral; organic chemicals; waste; paper; food; and use of solvents. Populations having an industry within a radius of 1, 1.5, or 2 kilometres from the municipal centroid were deemed to be exposed. Municipalities outside those radii were considered as reference populations. The relative risks (RRs associated with proximity to pollutant industries were estimated using the following methods: Poisson Regression; mixed Poisson model with random provincial effect; and spatial autoregressive modelling (BYM model. Results Only proximity of paper industries to population centres (>2 km could be associated with a greater risk of NHL mortality (mixed model: RR:1.24, 95% CI:1.09–1.42; BYM model: RR:1.21, 95% CI:1.01–1.45; Poisson model: RR:1.16, 95% CI:1.06–1.27. Spatial models yielded higher estimates. Conclusion The reported association between exposure to air pollution from the paper, pulp and board industry and NHL mortality is independent of the model used. Inclusion of spatial random effects terms in the risk estimate improves the study of associations between environmental exposures and mortality. The EPER could be of great utility when studying the effects of

Biodiversity estimates from different camera trap surveys: a case study from Osogovo Mt., Bulgaria

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Diana P. Zlatanova

2018-06-01

Full Text Available Inventorying mammal assemblages is vital for their conservation and management, especially when they include rare or endangered species. However, obtaining a correct estimation of the species diversity in a particular area can be challenging due to uncertainties regarding study design and duration. In this paper, we present the biodiversity estimates derived from three unrelated camera trap studies in Osogovo Mt., Bulgaria. They have different duration and positioning schemes of the camera trap locations: Study 1 – grid based, 34 days; Study 2 – random points based, 138 days; Study 3 – locations based on expert opinion, 1437 days. Utilising EstimateS, we compare a number of estimators (Shannon diversity index, Coleman rarefaction curve, ACE (Abundance-based Coverage Estimator, ICE (Incidence-based Coverage Estimator, Chao 1, Chao 2 and Jackknife estimators to the number of present and confirmed and/or potentially present mammals (excluding bats in the mountains. A total of 17 mammal species were registered in the three studies, which represents around 76% of the permanently present mammals in the mountain that inhabit its forested area and can be detected by a camera trap. The results point to some guidelines that can aid future camera trap research in temperate forested areas. A grid-based design works best for very short study periods (e.g. 10 days, while the opportunistic expert-based positioning scheme provides good results for longer studies (approx. a month. However, the grid-based design needs to be further tested for longer periods. Generally, the random points approach does not yield satisfactory results. In agreement with other studies, analysis based on the Jackknife procedure (Jack 2 appears to result in the best estimate of species richness. When performing camera trap studies, special care should be taken to minimise the number of unidentifiable photos and to take into account «trap-shy» individuals. The results from this

Methodological issues of genetic association studies.

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Simundic, Ana-Maria

2010-12-01

Genetic association studies explore the association between genetic polymorphisms and a certain trait, disease or predisposition to disease. It has long been acknowledged that many genetic association studies fail to replicate their initial positive findings. This raises concern about the methodological quality of these reports. Case-control genetic association studies often suffer from various methodological flaws in study design and data analysis, and are often reported poorly. Flawed methodology and poor reporting leads to distorted results and incorrect conclusions. Many journals have adopted guidelines for reporting genetic association studies. In this review, some major methodological determinants of genetic association studies will be discussed.

Fusion reactor design studies: standard accounts for cost estimates

International Nuclear Information System (INIS)

Schulte, S.C.; Willke, T.L.; Young, J.R.

1978-05-01

The fusion reactor design studies--standard accounts for cost estimates provides a common format from which to assess the economic character of magnetically confined fusion reactor design concepts. The format will aid designers in the preparation of design concept costs estimates and also provide policymakers with a tool to assist in appraising which design concept may be economically promising. The format sets forth a categorization and accounting procedure to be used when estimating fusion reactor busbar energy cost that can be easily and consistently applied. Reasons for developing the procedure, explanations of the procedure, justifications for assumptions made in the procedure, and the applicability of the procedure are described in this document. Adherence to the format when evaluating prospective fusion reactor design concepts will result in the identification of the more promising design concepts thus enabling the fusion power alternatives with better economic potential to be quickly and efficiently developed

Associated Variables of Myositis in Systemic Lupus Erythematosus: A Cross-Sectional Study.

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Liang, Yan; Leng, Rui-Xue; Pan, Hai-Feng; Ye, Dong-Qing

2017-05-26

BACKGROUND This study aimed to estimate the point prevalence of myositis and identify associated variables of myositis in systemic lupus erythematosus (SLE). MATERIAL AND METHODS Clinical date of patients hospitalized with lupus at the First Affiliated Hospital of Anhui Medical University and Anhui Provincial Hospital were collected. Patients were defined as having myositis if they reported the presence of persistent invalidating muscular weakness combined with increased levels of creatine phosphokinase (CPK) and abnormal electromyography (EMG). RESULTS The study sample comprised 1701 lupus patients, of which 44 had myositis. Patients with SLE-associated myositis are more likely to have skin rash, alopecia, pericarditis, vasculitis, anti-Sm, anti-RNP, anti-dsDNA, thrombocytopenia, leukopenia, low C3, low C4, high erythrocyte sedimentation rate (ESR), high D-dimer, and active disease. Multivariate logistic regression found positive associations between leukopenia, alopecia, and active disease with myositis. Negative associations between myositis with the use of corticosteroids or immunosuppressive drugs were revealed in univariate and multivariate analysis. CONCLUSIONS The point prevalence of myositis was 2.6% in SLE patients. The significant association of alopecia, leukopenia, and active disease with myositis suggests that organ damage, hematological abnormality, and high disease activity promote the progression of myositis in lupus patients.

Associations between physical and cognitive doping--a cross-sectional study in 2.997 triathletes.

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Pavel Dietz

Full Text Available PURPOSE: This study assessed, for the first time, prevalence estimates for physical and cognitive doping within a single collective of athletes using the randomized response technique (RRT. Furthermore, associations between the use of legal and freely available substances to improve physical and cognitive performance (enhancement and illicit or banned substances to improve physical and cognitive performance (doping were examined. METHODS: An anonymous questionnaire using the unrelated question RRT was used to survey 2,997 recreational triathletes in three sports events (Frankfurt, Regensburg, and Wiesbaden in Germany. Prior to the survey, statistical power analyses were performed to determine sample size. Logistic regression was used to predict physical and cognitive enhancement and the bootstrap method was used to evaluate differences between the estimated prevalences of physical and cognitive doping. RESULTS: 2,987 questionnaires were returned (99.7%. 12-month prevalences for physical and cognitive doping were 13.0% and 15.1%, respectively. The prevalence estimate for physical doping was significantly higher in athletes who also used physical enhancers, as well as in athletes who took part in the European Championship in Frankfurt compared to those who did not. The prevalence estimate for cognitive doping was significantly higher in athletes who also used physical and cognitive enhancers. Moreover, the use of physical and cognitive enhancers were significantly associated and also the use of physical and cognitive doping. DISCUSSION: The use of substances to improve physical and cognitive performance was associated on both levels of legality (enhancement vs. doping suggesting that athletes do not use substances for a specific goal but may have a general propensity to enhance. This finding is important for understanding why people use such substances. Consequently, more effective prevention programs against substance abuse and doping could be

An efficient Bayesian meta-analysis approach for studying cross-phenotype genetic associations.

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Arunabha Majumdar

2018-02-01

Full Text Available Simultaneous analysis of genetic associations with multiple phenotypes may reveal shared genetic susceptibility across traits (pleiotropy. For a locus exhibiting overall pleiotropy, it is important to identify which specific traits underlie this association. We propose a Bayesian meta-analysis approach (termed CPBayes that uses summary-level data across multiple phenotypes to simultaneously measure the evidence of aggregate-level pleiotropic association and estimate an optimal subset of traits associated with the risk locus. This method uses a unified Bayesian statistical framework based on a spike and slab prior. CPBayes performs a fully Bayesian analysis by employing the Markov Chain Monte Carlo (MCMC technique Gibbs sampling. It takes into account heterogeneity in the size and direction of the genetic effects across traits. It can be applied to both cohort data and separate studies of multiple traits having overlapping or non-overlapping subjects. Simulations show that CPBayes can produce higher accuracy in the selection of associated traits underlying a pleiotropic signal than the subset-based meta-analysis ASSET. We used CPBayes to undertake a genome-wide pleiotropic association study of 22 traits in the large Kaiser GERA cohort and detected six independent pleiotropic loci associated with at least two phenotypes. This includes a locus at chromosomal region 1q24.2 which exhibits an association simultaneously with the risk of five different diseases: Dermatophytosis, Hemorrhoids, Iron Deficiency, Osteoporosis and Peripheral Vascular Disease. We provide an R-package 'CPBayes' implementing the proposed method.

Soluble tumor necrosis factor receptor 1 is associated with diminished estimated glomerular filtration rate in colombian patients with type 2 diabetes.

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Gómez-Banoy, Nicolás; Cuevas, Virginia; Higuita, Andrea; Aranzález, Luz Helena; Mockus, Ismena

2016-07-01

The tumor necrosis factor α (TNF-α) family of inflammatory molecules plays a crucial role in the pathogenesis of type 2 diabetes mellitus (DM2) complications. TNF-α soluble receptors 1 (sTNFR1) and 2 (sTNFR2) have been associated with chronic kidney disease in DM2 patients. This cross-sectional study intended to determine serum concentrations of sTNFR1 and sTNFR2 in Colombian patients and correlated them with various clinical variables, especially kidney function. 92 Colombian patients with DM2 were recruited. Anthropometric variables, glycemic control parameters, lipid profile and renal function were assessed for each patient. Levels of sTNFR1 and sTNFR2 were determined using ELISA. Patients were stratified in two groups according to reduced estimated glomerular filtration rate (eGFR) (studies should focus on social and genetic determinants of inflammation and their association with CKD in this ethnicity. Copyright © 2016 Elsevier Inc. All rights reserved.

Risk estimation in association with diagnostic techniques in the nuclear medicine service of the Camaguey Ciego de Avila Territory

International Nuclear Information System (INIS)

Barrerras, C.A.; Brigido, F.O.; Naranjo, L.A.; Lasserra, S.O.; Hernandez Garcia, J.

1999-01-01

The nuclear medicine service at the Maria Curie Oncological Hospital, Camaguey, has experience of over three decades in using radiofarmaceutical imaging agents for diagnosis. Although the clinical risk associated with these techniques is negligible, it is necessary to evaluate the effective dose administered to the patient due to the introduction of radioactive substances into the body. The study of the dose administered to the patient provides useful data for evaluating the detriment associated with this medical practice, its subsequently optimization and consequently, for minimizing the stochastic effects on the patient. The aim of our paper is to study the collective effective dose administered by nuclear medicine service to Camaguey and Ciego de Avila population from 1995 to 1998 and the relative contribution to the total annual effective collective dose of the different diagnostic examinations. The studies were conducted on the basis of statistics from nuclear medicine examinations given to a population of 1102353 inhabitants since 1995. The results show that the nuclear medicine techniques of neck examinations with 1168.8 Sv man (1.11 Sv/expl), thyroid explorations with 119.6 Sv man (55.5 mSv/expl) and iodide uptake with 113.7 Sv man (14.0 mSv/expl) are the main techniques implicated in the relative contribution to the total annual effective collective dose of 1419.5 Sv man. The risk estimation in association with diagnostic techniques in the nuclear medicine service studied is globally low (total detriment: 103.6 as a result of 16232 explorations), similar to other published data

Dental age estimation using Willems method: A digital orthopantomographic study

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Rezwana Begum Mohammed

2014-01-01

Full Text Available In recent years, age estimation has become increasingly important in living people for a variety of reasons, including identifying criminal and legal responsibility, and for many other social events such as a birth certificate, marriage, beginning a job, joining the army, and retirement. Objectives: The aim of this study was to assess the developmental stages of left seven mandibular teeth for estimation of dental age (DA in different age groups and to evaluate the possible correlation between DA and chronological age (CA in South Indian population using Willems method. Materials and Methods: Digital Orthopantomogram of 332 subjects (166 males, 166 females who fit the study and the criteria were obtained. Assessment of mandibular teeth (from central incisor to the second molar on left quadrant development was undertaken and DA was assessed using Willems method. Results and Discussion: The present study showed a significant correlation between DA and CA in both males (r = 0.71 and females (r = 0.88. The overall mean difference between the estimated DA and CA for males was 0.69 ± 2.14 years (P 0.05. Willems method underestimated the mean age of males by 0.69 years and females by 0.08 years and showed that females mature earlier than males in selected population. The mean difference between DA and CA according to Willems method was 0.39 years and is statistically significant (P < 0.05. Conclusion: This study showed significant relation between DA and CA. Thus, digital radiographic assessment of mandibular teeth development can be used to generate mean DA using Willems method and also the estimated age range for an individual of unknown CA.

Estimating the Cost of Preeclampsia in the Healthcare System: Cross-Sectional Study Using Data From SCOPE Study (Screening for Pregnancy End Points).

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Fox, Aimée; McHugh, Sheena; Browne, John; Kenny, Louise C; Fitzgerald, Anthony; Khashan, Ali S; Dempsey, Eugene; Fahy, Ciara; O'Neill, Ciaran; Kearney, Patricia M

2017-12-01

To estimate the cost of preeclampsia from the national health payer's perspective using secondary data from the SCOPE study (Screening for Pregnancy End Points). SCOPE is an international observational prospective study of healthy nulliparous women with singleton pregnancies. Using data from the Irish cohort recruited between November 2008 and February 2011, all women with preeclampsia and a 10% random sample of women without preeclampsia were selected. Additional health service use data were extracted from the consenting participants' medical records for maternity services which were not included in SCOPE. Unit costs were based on estimates from 3 existing Irish studies. Costs were extrapolated to a national level using a prevalence rate of 5% to 7% among nulliparous pregnancies. Within the cohort of 1774 women, 68 developed preeclampsia (3.8%) and 171 women were randomly selected as controls. Women with preeclampsia used higher levels of maternity services. The average cost of a pregnancy complicated by preeclampsia was €5243 per case compared with €2452 per case for an uncomplicated pregnancy. The national cost of preeclampsia is between €6.5 and €9.1 million per annum based on the 5% to 7% prevalence rate. Postpartum care was the largest contributor to these costs (€4.9-€6.9 million), followed by antepartum care (€0.9-€1.3 million) and peripartum care (€0.6-€0.7 million). Women with preeclampsia generate significantly higher maternity costs than women without preeclampsia. These cost estimates will allow policy-makers to efficiently allocate resources for this pregnancy-specific condition. Moreover, these estimates are useful for future research assessing the cost-effectiveness of preeclampsia screening and treatment. © 2017 American Heart Association, Inc.

Replication of prostate cancer risk loci in a Japanese case-control association study.

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Yamada, Hiroki; Penney, Kathryn L; Takahashi, Hiroyuki; Katoh, Takahiko; Yamano, Yuko; Yamakado, Minoru; Kimura, Takahiro; Kuruma, Hidetoshi; Kamata, Yuko; Egawa, Shin; Freedman, Matthew L

2009-10-07

Two prostate cancer genome-wide scans in populations of European ancestry identified several genetic variants that are strongly associated with prostate cancer risk. The effect of these risk variants and their cumulative effect in other populations are unknown. We evaluated the association of 23 risk single-nucleotide polymorphisms (SNPs) with prostate cancer risk and clinical covariates (Gleason score, tumor aggressiveness, and age at diagnosis) in men of Japanese ancestry (311 case subjects and 1035 control subjects) using unconditional logistic regression. We also used logistic regression to test the association between increasing numbers of independently associated risk alleles and the risk of prostate cancer, prostate cancer aggressiveness, and age at diagnosis. All statistical tests were two-sided. Seven of the 23 SNPs (five independent loci) were associated with prostate cancer risk (P values ranged from .0084 to 2.3 x 10(-8) and effect sizes [estimated as odds ratios, ORs] ranged from 1.35 to 1.82). None of the seven SNPs was associated with Gleason score or aggressive disease. rs6983561 and rs4430796 were associated with age at diagnosis (Ps = .0188 and .0339, respectively). Men with six or more risk alleles (27% of case patients and 11% of control subjects) had a higher risk of prostate cancer than men with two or fewer risk alleles (7% of case patients and 20% of control subjects) (OR = 6.22, P = 1.5 x 10(-12)). These results highlight the critical importance of considering ancestry in understanding how risk alleles influence disease and suggest that risk estimates and variants differ across populations. It is important to perform studies in multiple ancestral populations so that the composite genetic architecture of prostate cancer can be rigorously addressed.

The Growth-Inequality Association:

DEFF Research Database (Denmark)

Bjørnskov, Christian

2008-01-01

This note suggests that the association between income inequality and economic growth rates might arguably depend on the political ideology of incumbent governments. Estimates indicate that under leftwing governments, inequality is negatively associated with growth while the association is positive...... under rightwing governments. This may provide a qualification to recent studies of inequality....

Estimation of sex and age of ''virtual skeletons''-a feasibility study

International Nuclear Information System (INIS)

Grabherr, Silke; Cooper, Christine; Ulrich-Bochsler, Susi; Uldin, Tanya; Ross, Steffen; Oesterhelweg, Lars; Bolliger, Stephan; Thali, Michael J.; Christe, Andreas; Schnyder, Pierre; Mangin, Patrice

2009-01-01

This article presents a feasibility study with the objective of investigating the potential of multi-detector computed tomography (MDCT) to estimate the bone age and sex of deceased persons. To obtain virtual skeletons, the bodies of 22 deceased persons with known age at death were scanned by MDCT using a special protocol that consisted of high-resolution imaging of the skull, shoulder girdle (including the upper half of the humeri), the symphysis pubis and the upper halves of the femora. Bone and soft-tissue reconstructions were performed in two and three dimensions. The resulting data were investigated by three anthropologists with different professional experience. Sex was determined by investigating three-dimensional models of the skull and pelvis. As a basic orientation for the age estimation, the complex method according to Nemeskeri and co-workers was applied. The final estimation was effected using additional parameters like the state of dentition, degeneration of the spine, etc., which where chosen individually by the three observers according to their experience. The results of the study show that the estimation of sex and age is possible by the use of MDCT. Virtual skeletons present an ideal collection for anthropological studies, because they are obtained in a non-invasive way and can be investigated ad infinitum. (orig.)

A state-space modeling approach to estimating canopy conductance and associated uncertainties from sap flux density data.

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Bell, David M; Ward, Eric J; Oishi, A Christopher; Oren, Ram; Flikkema, Paul G; Clark, James S

2015-07-01

Uncertainties in ecophysiological responses to environment, such as the impact of atmospheric and soil moisture conditions on plant water regulation, limit our ability to estimate key inputs for ecosystem models. Advanced statistical frameworks provide coherent methodologies for relating observed data, such as stem sap flux density, to unobserved processes, such as canopy conductance and transpiration. To address this need, we developed a hierarchical Bayesian State-Space Canopy Conductance (StaCC) model linking canopy conductance and transpiration to tree sap flux density from a 4-year experiment in the North Carolina Piedmont, USA. Our model builds on existing ecophysiological knowledge, but explicitly incorporates uncertainty in canopy conductance, internal tree hydraulics and observation error to improve estimation of canopy conductance responses to atmospheric drought (i.e., vapor pressure deficit), soil drought (i.e., soil moisture) and above canopy light. Our statistical framework not only predicted sap flux observations well, but it also allowed us to simultaneously gap-fill missing data as we made inference on canopy processes, marking a substantial advance over traditional methods. The predicted and observed sap flux data were highly correlated (mean sensor-level Pearson correlation coefficient = 0.88). Variations in canopy conductance and transpiration associated with environmental variation across days to years were many times greater than the variation associated with model uncertainties. Because some variables, such as vapor pressure deficit and soil moisture, were correlated at the scale of days to weeks, canopy conductance responses to individual environmental variables were difficult to interpret in isolation. Still, our results highlight the importance of accounting for uncertainty in models of ecophysiological and ecosystem function where the process of interest, canopy conductance in this case, is not observed directly. The StaCC modeling

Genome-wide association study identifies novel locus for neuroticism and shows polygenic association with Major Depressive Disorder

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de Moor, Marleen H.M.; van den Berg, Stéphanie M.; Verweij, Karin J.H.; Krueger, Robert F.; Luciano, Michelle; Vasquez, Alejandro Arias; Matteson, Lindsay K.; Derringer, Jaime; Esko, Tõnu; Amin, Najaf; Gordon, Scott D.; Hansell, Narelle K.; Hart, Amy B.; Seppälä, Ilkka; Huffman, Jennifer E.; Konte, Bettina; Lahti, Jari; Lee, Minyoung; Miller, Mike; Nutile, Teresa; Tanaka, Toshiko; Teumer, Alexander; Viktorin, Alexander; Wedenoja, Juho; Abecasis, Goncalo R.; Adkins, Daniel E.; Agrawal, Arpana; Allik, Jüri; Appel, Katja; Bigdeli, Timothy B.; Busonero, Fabio; Campbell, Harry; Costa, Paul T.; Smith, George Davey; Davies, Gail; de Wit, Harriet; Ding, Jun; Engelhardt, Barbara E.; Eriksson, Johan G.; Fedko, Iryna O.; Ferrucci, Luigi; Franke, Barbara; Giegling, Ina; Grucza, Richard; Hartmann, Annette M.; Heath, Andrew C.; Heinonen, Kati; Henders, Anjali K.; Homuth, Georg; Hottenga, Jouke-Jan; Janzing, Joost; Jokela, Markus; Karlsson, Robert; Kemp, John P.; Kirkpatrick, Matthew G.; Latvala, Antti; Lehtimäki, Terho; Liewald, David C.; Madden, Pamela A.F.; Magri, Chiara; Magnusson, Patrik K.E.; Marten, Jonathan; Maschio, Andrea; Medland, Sarah E.; Mihailov, Evelin; Milaneschi, Yuri; Montgomery, Grant W.; Nauck, Matthias; Ouwens, Klaasjan G.; Palotie, Aarno; Pettersson, Erik; Polasek, Ozren; Qian, Yong; Pulkki-Råback, Laura; Raitakari, Olli T.; Realo, Anu; Rose, Richard J.; Ruggiero, Daniela; Schmidt, Carsten O.; Slutske, Wendy S.; Sorice, Rossella; Starr, John M.; Pourcain, Beate St; Sutin, Angelina R.; Timpson, Nicholas J.; Trochet, Holly; Vermeulen, Sita; Vuoksimaa, Eero; Widen, Elisabeth; Wouda, Jasper; Wright, Margaret J.; Zgaga, Lina; Scotland, Generation; Porteous, David; Minelli, Alessandra; Palmer, Abraham A.; Rujescu, Dan; Ciullo, Marina; Hayward, Caroline; Rudan, Igor; Metspalu, Andres; Kaprio, Jaakko; Deary, Ian J.; Räikkönen, Katri; Wilson, James F.; Keltikangas-Järvinen, Liisa; Bierut, Laura J.; Hettema, John M.; Grabe, Hans J.; van Duijn, Cornelia M.; Evans, David M.; Schlessinger, David; Pedersen, Nancy L.; Terracciano, Antonio; McGue, Matt; Penninx, Brenda W.J.H.; Martin, Nicholas G.; Boomsma, Dorret I.

2015-01-01

Importance Neuroticism is a personality trait that is briefly defined by emotional instability. It is a robust genetic risk factor for Major Depressive Disorder (MDD) and other psychiatric disorders. Hence, neuroticism is an important phenotype for psychiatric genetics. The Genetics of Personality Consortium (GPC) has created a resource for genome-wide association analyses of personality traits in over 63,000 participants (including MDD cases). Objective To identify genetic variants associated with neuroticism by performing a meta-analysis of genome-wide association (GWA) results based on 1000Genomes imputation, to evaluate if common genetic variants as assessed by Single Nucleotide Polymorphisms (SNPs) explain variation in neuroticism by estimating SNP-based heritability, and to examine whether SNPs that predict neuroticism also predict MDD. Setting 30 cohorts with genome-wide genotype, personality and MDD data from the GPC. Participants The study included 63,661 participants from 29 discovery cohorts and 9,786 participants from a replication cohort. Participants came from Europe, the United States or Australia. Main outcome measure(s) Neuroticism scores harmonized across all cohorts by Item Response Theory (IRT) analysis, and clinically assessed MDD case-control status. Results A genome-wide significant SNP was found in the MAGI1 gene (rs35855737; P=9.26 × 10−9 in the discovery meta-analysis, and P=2.38 × 10−8 in the meta-analysis of all 30 cohorts). Common genetic variants explain 15% of the variance in neuroticism. Polygenic scores based on the meta-analysis of neuroticism in 27 of the discovery cohorts significantly predicted neuroticism in 2 independent cohorts. Importantly, polygenic scores also predicted MDD in these cohorts. Conclusions and relevance This study identifies a novel locus for neuroticism. The variant is located in a known gene that has been associated with bipolar disorder and schizophrenia in previous studies. In addition, the study

Meta-analysis of the INSIG2 association with obesity including 74,345 individuals: does heterogeneity of estimates relate to study design?

DEFF Research Database (Denmark)

Heid, Iris M; Huth, Cornelia; Loos, Ruth J F

2009-01-01

with subjects selected for conditions related to a better health status ('healthy population', HP), and obesity studies (OB). We tested five hypotheses to explore potential sources of heterogeneity. The meta-analysis of 27 studies on Caucasian adults (n = 66,213) combining the different study designs did......The INSIG2 rs7566605 polymorphism was identified for obesity (BMI> or =30 kg/m(2)) in one of the first genome-wide association studies, but replications were inconsistent. We collected statistics from 34 studies (n = 74,345), including general population (GP) studies, population-based studies...... not support overall association of the CC-genotype with obesity, yielding an odds ratio (OR) of 1.05 (p-value = 0.27). The I(2) measure of 41% (p-value = 0.015) indicated between-study heterogeneity. Restricting to GP studies resulted in a declined I(2) measure of 11% (p-value = 0.33) and an OR of 1.10 (p...

Investigating causal associations between use of nicotine, alcohol, caffeine and cannabis: a two-sample bidirectional Mendelian randomization study.

Science.gov (United States)

Verweij, Karin J H; Treur, Jorien L; Vink, Jacqueline M

2018-07-01

Epidemiological studies consistently show co-occurrence of use of different addictive substances. Whether these associations are causal or due to overlapping underlying influences remains an important question in addiction research. Methodological advances have made it possible to use published genetic associations to infer causal relationships between phenotypes. In this exploratory study, we used Mendelian randomization (MR) to examine the causality of well-established associations between nicotine, alcohol, caffeine and cannabis use. Two-sample MR was employed to estimate bidirectional causal effects between four addictive substances: nicotine (smoking initiation and cigarettes smoked per day), caffeine (cups of coffee per day), alcohol (units per week) and cannabis (initiation). Based on existing genome-wide association results we selected genetic variants associated with the exposure measure as an instrument to estimate causal effects. Where possible we applied sensitivity analyses (MR-Egger and weighted median) more robust to horizontal pleiotropy. Most MR tests did not reveal causal associations. There was some weak evidence for a causal positive effect of genetically instrumented alcohol use on smoking initiation and of cigarettes per day on caffeine use, but these were not supported by the sensitivity analyses. There was also some suggestive evidence for a positive effect of alcohol use on caffeine use (only with MR-Egger) and smoking initiation on cannabis initiation (only with weighted median). None of the suggestive causal associations survived corrections for multiple testing. Two-sample Mendelian randomization analyses found little evidence for causal relationships between nicotine, alcohol, caffeine and cannabis use. © 2018 Society for the Study of Addiction.

A constrained polynomial regression procedure for estimating the local False Discovery Rate

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Broët Philippe

2007-06-01

Full Text Available Abstract Background In the context of genomic association studies, for which a large number of statistical tests are performed simultaneously, the local False Discovery Rate (lFDR, which quantifies the evidence of a specific gene association with a clinical or biological variable of interest, is a relevant criterion for taking into account the multiple testing problem. The lFDR not only allows an inference to be made for each gene through its specific value, but also an estimate of Benjamini-Hochberg's False Discovery Rate (FDR for subsets of genes. Results In the framework of estimating procedures without any distributional assumption under the alternative hypothesis, a new and efficient procedure for estimating the lFDR is described. The results of a simulation study indicated good performances for the proposed estimator in comparison to four published ones. The five different procedures were applied to real datasets. Conclusion A novel and efficient procedure for estimating lFDR was developed and evaluated.

Improving Focal Depth Estimates: Studies of Depth Phase Detection at Regional Distances

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Stroujkova, A.; Reiter, D. T.; Shumway, R. H.

2006-12-01

The accurate estimation of the depth of small, regionally recorded events continues to be an important and difficult explosion monitoring research problem. Depth phases (free surface reflections) are the primary tool that seismologists use to constrain the depth of a seismic event. When depth phases from an event are detected, an accurate source depth is easily found by using the delay times of the depth phases relative to the P wave and a velocity profile near the source. Cepstral techniques, including cepstral F-statistics, represent a class of methods designed for the depth-phase detection and identification; however, they offer only a moderate level of success at epicentral distances less than 15°. This is due to complexities in the Pn coda, which can lead to numerous false detections in addition to the true phase detection. Therefore, cepstral methods cannot be used independently to reliably identify depth phases. Other evidence, such as apparent velocities, amplitudes and frequency content, must be used to confirm whether the phase is truly a depth phase. In this study we used a variety of array methods to estimate apparent phase velocities and arrival azimuths, including beam-forming, semblance analysis, MUltiple SIgnal Classification (MUSIC) (e.g., Schmidt, 1979), and cross-correlation (e.g., Cansi, 1995; Tibuleac and Herrin, 1997). To facilitate the processing and comparison of results, we developed a MATLAB-based processing tool, which allows application of all of these techniques (i.e., augmented cepstral processing) in a single environment. The main objective of this research was to combine the results of three focal-depth estimation techniques and their associated standard errors into a statistically valid unified depth estimate. The three techniques include: 1. Direct focal depth estimate from the depth-phase arrival times picked via augmented cepstral processing. 2. Hypocenter location from direct and surface-reflected arrivals observed on sparse

Estimating 24-h urinary sodium/potassium ratio from casual ('spot') urinary sodium/potassium ratio: the INTERSALT Study.

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Iwahori, Toshiyuki; Miura, Katsuyuki; Ueshima, Hirotsugu; Chan, Queenie; Dyer, Alan R; Elliott, Paul; Stamler, Jeremiah

2017-10-01

Association between casual and 24-h urinary sodium-to-potassium (Na/K) ratio is well recognized, although it has not been validated in diverse demographic groups. Our aim was to assess utility across and within populations of casual urine to estimate 24-h urinary Na/K ratio using data from the INTERSALT Study. The INTERSALT Study collected cross-sectional standardized data on casual urinary sodium and potassium and also on timed 24-h urinary sodium and potassium for 10 065 individuals from 52 population samples in 32 countries (1985-87). Pearson correlation coefficients and agreement were computed for Na/K ratio of casual urine against 24-h urinary Na/K ratio both at population and individual levels. Pearson correlation coefficients relating means of 24-h urine and casual urine Na/K ratio were r = 0.96 and r = 0.69 in analyses across populations and individuals, respectively. Correlations of casual urine Na/creatinine and K/creatinine ratios with 24-h urinary Na and K excretion, respectively, were lower than correlation of casual and 24-h urinary Na/K ratio in analyses across populations and individuals. The bias estimate with the Bland-Altman method, defined as the difference between Na/K ratio of 24-h urine and casual urine, was approximately 0.4 across both populations and individuals. Spread around, the mean bias was higher for individuals than populations. With appropriate bias correction, casual urine Na/K ratio may be a useful, low-burden alternative method to 24-h urine for estimation of population urinary Na/K ratio. It may also be applicable for assessment of the urinary Na/K ratio of individuals, with use of repeated measurements to reduce measurement error and increase precision. © The Author 2016. Published by Oxford University Press on behalf of the International Epidemiological Association

Does the choice of neighbourhood supermarket access measure influence associations with individual-level fruit and vegetable consumption? A case study from Glasgow.

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Thornton, Lukar E; Pearce, Jamie R; Macdonald, Laura; Lamb, Karen E; Ellaway, Anne

2012-07-27

Previous studies have provided mixed evidence with regards to associations between food store access and dietary outcomes. This study examines the most commonly applied measures of locational access to assess whether associations between supermarket access and fruit and vegetable consumption are affected by the choice of access measure and scale. Supermarket location data from Glasgow, UK (n = 119), and fruit and vegetable intake data from the 'Health and Well-Being' Survey (n = 1041) were used to compare various measures of locational access. These exposure variables included proximity estimates (with different points-of-origin used to vary levels of aggregation) and density measures using three approaches (Euclidean and road network buffers and Kernel density estimation) at distances ranging from 0.4 km to 5 km. Further analysis was conducted to assess the impact of using smaller buffer sizes for individuals who did not own a car. Associations between these multiple access measures and fruit and vegetable consumption were estimated using linear regression models. Levels of spatial aggregation did not impact on the proximity estimates. Counts of supermarkets within Euclidean buffers were associated with fruit and vegetable consumption at 1 km, 2 km and 3 km, and for our road network buffers at 2 km, 3 km, and 4 km. Kernel density estimates provided the strongest associations and were significant at a distance of 2 km, 3 km, 4 km and 5 km. Presence of a supermarket within 0.4 km of road network distance from where people lived was positively associated with fruit consumption amongst those without a car (coef. 0.657; s.e. 0.247; p0.008). The associations between locational access to supermarkets and individual-level dietary behaviour are sensitive to the method by which the food environment variable is captured. Care needs to be taken to ensure robust and conceptually appropriate measures of access are used and these should be

Efficient multiple-trait association and estimation of genetic correlation using the matrix-variate linear mixed model.

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Furlotte, Nicholas A; Eskin, Eleazar

2015-05-01

Multiple-trait association mapping, in which multiple traits are used simultaneously in the identification of genetic variants affecting those traits, has recently attracted interest. One class of approaches for this problem builds on classical variance component methodology, utilizing a multitrait version of a linear mixed model. These approaches both increase power and provide insights into the genetic architecture of multiple traits. In particular, it is possible to estimate the genetic correlation, which is a measure of the portion of the total correlation between traits that is due to additive genetic effects. Unfortunately, the practical utility of these methods is limited since they are computationally intractable for large sample sizes. In this article, we introduce a reformulation of the multiple-trait association mapping approach by defining the matrix-variate linear mixed model. Our approach reduces the computational time necessary to perform maximum-likelihood inference in a multiple-trait model by utilizing a data transformation. By utilizing a well-studied human cohort, we show that our approach provides more than a 10-fold speedup, making multiple-trait association feasible in a large population cohort on the genome-wide scale. We take advantage of the efficiency of our approach to analyze gene expression data. By decomposing gene coexpression into a genetic and environmental component, we show that our method provides fundamental insights into the nature of coexpressed genes. An implementation of this method is available at http://genetics.cs.ucla.edu/mvLMM. Copyright © 2015 by the Genetics Society of America.

Lung cancer among coal miners, ore miners and quarrymen : smoking-adjusted risk estimates from the synergy pooled analysis of case-control studies

NARCIS (Netherlands)

Taeger, Dirk; Pesch, Beate; Kendzia, Benjamin; Behrens, Thomas; Jöckel, Karl-Heinz; Dahmann, Dirk; Siemiatycki, Jack; Kromhout, Hans; Vermeulen, Roel; Peters, Susan; Olsson, Ann; Brüske, Irene; Wichmann, Heinz-Erich; Stücker, Isabelle; Guida, Florence; Tardón, Adonina; Merletti, Franco; Mirabelli, Dario; Richiardi, Lorenzo; Pohlabeln, Hermann; Ahrens, Wolfgang; Landi, Maria Teresa; Caporaso, Neil; Pesatori, Angela Cecilia; Mukeriya, Anush; Szeszenia-Dabrowska, Neonila; Lissowska, Jolanta; Gustavsson, Per; Field, John; Marcus, Michael W; Fabianova, Eleonora; 't Mannetje, Andrea; Pearce, Neil; Rudnai, Peter; Bencko, Vladimir; Janout, Vladimir; Dumitru, Rodica Stanescu; Foretova, Lenka; Forastiere, Francesco; John McLaughlin, John McLaughlin; Paul Demers, Paul Demers; Bas Bueno-de-Mesquita, Bas Bueno-de-Mesquita; Joachim Schüz, Joachim Schüz; Kurt Straif, Kurt Straif; Brüning, Thomas

2015-01-01

OBJECTIVES: Working in mines and quarries has been associated with an elevated lung cancer risk but with inconsistent results for coal miners. This study aimed to estimate the smoking-adjusted lung cancer risk among coal miners and compare the risk pattern with lung cancer risks among ore miners and

Estimating Large Area Forest Carbon Stocks—A Pragmatic Design Based Strategy

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Andrew Haywood

2017-03-01

Full Text Available Reducing uncertainty in forest carbon estimates at local and regional scales has become increasingly important due to the centrality of the terrestrial carbon cycle in issues of climate change. In Victoria, Australia, public natural forests extend over 7.2 M ha and constitute a significant and important carbon stock. Recently, a wide range of approaches to estimate carbon stocks within these forests have been developed and applied. However, there are a number of data and estimation limitations associated with these studies. In response, over the last five years, the State of Victoria has implemented a pragmatic plot-based design consisting of pre-stratified permanent observational units located on a state-wide grid. Using the ground sampling grid, we estimated aboveground and belowground carbon stocks (including soil to 0.3 m depth in both National Parks and State Forests, across a wide range of bioregions. Estimates of carbon stocks and associated uncertainty were conducted using simple design based estimators. We detected significantly more carbon in total aboveground and belowground components in State Forests (408.9 t ha−1, 95% confidence interval 388.8–428.9 t ha−1 than National Parks (267.6 t ha−1, 251.9–283.3 t ha−1. We were also able to estimate forest carbon stocks (and associated uncertainty for 21 strata that represent all of Victoria’s bioregions and public tenures. It is anticipated that the lessons learnt from this study may support the discussion on planning and implementing low cost large area forest carbon stock sampling in other jurisdictions.

Higher freshwater fish and sea fish intake is inversely associated with colorectal cancer risk among Chinese population: a case-control study.

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Xu, Ming; Fang, Yu-Jing; Chen, Yu-Ming; Lu, Min-Shan; Pan, Zhi-Zhong; Yan, Bo; Zhong, Xiao; Zhang, Cai-Xia

2015-08-12

The association between specific fish intake and colorectal cancer risk remains controversial. This study aimed to examine the association between specific fish intake and colorectal cancer risk in Chinese population in a large case control study. During July 2010 to November 2014, 1189 eligible colorectal cancer cases and 1189 frequency-matched controls (age and sex) completed in-person interviews. A validated food frequency questionnaire was used to estimate dietary intake. Multivariate logistical regression models were used to estimate the odds ratio (OR) and 95% confidence interval (95% CI) after adjusting for various confounders. A strong inverse association was found between freshwater fish intake and colorectal cancer risk. Compared with the lowest quartile, the highest quartile intake showed a risk reduction of 53% (OR 0.47, 95% CI = 0.36-0.60, Ptrend colorectal cancer risk. These results indicate that higher consumption of freshwater fish, sea fish and fresh fish is associated with a lower risk of colorectal caner.

Review of uncertainty estimates associated with models for assessing the impact of breeder reactor radioactivity releases

International Nuclear Information System (INIS)

Miller, C.; Little, C.A.

1982-08-01

The purpose is to summarize estimates based on currently available data of the uncertainty associated with radiological assessment models. The models being examined herein are those recommended previously for use in breeder reactor assessments. Uncertainty estimates are presented for models of atmospheric and hydrologic transport, terrestrial and aquatic food-chain bioaccumulation, and internal and external dosimetry. Both long-term and short-term release conditions are discussed. The uncertainty estimates presented in this report indicate that, for many sites, generic models and representative parameter values may be used to calculate doses from annual average radionuclide releases when these calculated doses are on the order of one-tenth or less of a relevant dose limit. For short-term, accidental releases, especially those from breeder reactors located in sites dominated by complex terrain and/or coastal meteorology, the uncertainty in the dose calculations may be much larger than an order of magnitude. As a result, it may be necessary to incorporate site-specific information into the dose calculation under these circumstances to reduce this uncertainty. However, even using site-specific information, natural variability and the uncertainties in the dose conversion factor will likely result in an overall uncertainty of greater than an order of magnitude for predictions of dose or concentration in environmental media following shortterm releases

Preterm-associated visual impairment and estimates of retinopathy of prematurity at regional and global levels for 2010

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Blencowe, Hannah; Lawn, Joy E.; Vazquez, Thomas; Fielder, Alistair; Gilbert, Clare

2013-01-01

Background: Retinopathy of prematurity (ROP) is a leading cause of potentially avoidable childhood blindness worldwide. We estimated ROP burden at the global and regional levels to inform screening and treatment programs, research, and data priorities. Methods: Systematic reviews and meta-analyses were undertaken to estimate the risk of ROP and subsequent visual impairment for surviving preterm babies by level of neonatal care, access to ROP screening, and treatment. A compartmental model was used to estimate ROP cases and numbers of visually impaired survivors. Results: In 2010, an estimated 184,700 (uncertainty range: 169,600–214,500) preterm babies developed any stage of ROP, 20,000 (15,500–27,200) of whom became blind or severely visually impaired from ROP, and a further 12,300 (8,300–18,400) developed mild/moderate visual impairment. Sixty-five percent of those visually impaired from ROP were born in middle-income regions; 6.2% (4.3–8.9%) of all ROP visually impaired infants were born at >32-wk gestation. Visual impairment from other conditions associated with preterm birth will affect larger numbers of survivors. Conclusion: Improved care, including oxygen delivery and monitoring, for preterm babies in all facility settings would reduce the number of babies affected with ROP. Improved data tracking and coverage of locally adapted screening/treatment programs are urgently required. PMID:24366462

Genome-wide association study of blood pressure extremes identifies variant near UMOD associated with hypertension.

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Sandosh Padmanabhan

2010-10-01

Full Text Available Hypertension is a heritable and major contributor to the global burden of disease. The sum of rare and common genetic variants robustly identified so far explain only 1%-2% of the population variation in BP and hypertension. This suggests the existence of more undiscovered common variants. We conducted a genome-wide association study in 1,621 hypertensive cases and 1,699 controls and follow-up validation analyses in 19,845 cases and 16,541 controls using an extreme case-control design. We identified a locus on chromosome 16 in the 5' region of Uromodulin (UMOD; rs13333226, combined P value of 3.6 × 10⁻¹¹. The minor G allele is associated with a lower risk of hypertension (OR [95%CI]: 0.87 [0.84-0.91], reduced urinary uromodulin excretion, better renal function; and each copy of the G allele is associated with a 7.7% reduction in risk of CVD events after adjusting for age, sex, BMI, and smoking status (H.R. = 0.923, 95% CI 0.860-0.991; p = 0.027. In a subset of 13,446 individuals with estimated glomerular filtration rate (eGFR measurements, we show that rs13333226 is independently associated with hypertension (unadjusted for eGFR: 0.89 [0.83-0.96], p = 0.004; after eGFR adjustment: 0.89 [0.83-0.96], p = 0.003. In clinical functional studies, we also consistently show the minor G allele is associated with lower urinary uromodulin excretion. The exclusive expression of uromodulin in the thick portion of the ascending limb of Henle suggests a putative role of this variant in hypertension through an effect on sodium homeostasis. The newly discovered UMOD locus for hypertension has the potential to give new insights into the role of uromodulin in BP regulation and to identify novel drugable targets for reducing cardiovascular risk.

Estimated cost of asthma in outpatient treatment: a real-world study

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Costa, Eduardo; Caetano, Rosangela; Werneck, Guilherme Loureiro; Bregman, Maurício; Araújo, Denizar Vianna; Rufino, Rogério

2018-01-01

ABSTRACT OBJECTIVE To estimate the cost of diagnosis and treatment of asthma. METHODS We used the perspective of society. We sequentially included for 12 months, in 2011-2012, 117 individuals over five years of age who were treated for asthma in the Pneumology and Allergy-Immunology Services of the Piquet Carneiro Polyclinic, Universidade do Estado do Rio de Janeiro. All of them were interviewed twice with a six-month interval for data collection, covering 12 months. The cost units were identified and valued according to defined methods. We carried out a sensitivity analysis and applied statistical methods with a significance level of 5% for cost comparisons between subgroups. RESULTS The study consisted of 108 patients, and 73.8% of them were women. Median age was 49.5 years. Rhinitis was present in 83.3% of the individuals, and more than half were overweight or obese. Mean family income was U$915.90/month (SD = 879.12). Most workers and students had absenteeism related to asthma. Total annual mean cost was U$1,291.20/patient (SD = 1,298.57). The cost related to isolated asthma was U$1,155.43/patient-year (SD = 1,305.58). Obese, severe, and uncontrolled asthmatic patients had higher costs than non-obese, non-severe, and controlled asthmatics, respectively. Severity and control level were independently associated with higher cost (p = 0.001 and 0.000, respectively). The direct cost accounted for 82.3% of the estimated total cost. The cost of medications for asthma accounted for 62.2% of the direct costs of asthma. CONCLUSIONS Asthma medications, environmental control measures, and long-term health leaves had the greatest potential impact on total cost variation. The results are an estimate of the cost of treating asthma at a secondary level in the Brazilian Unified Health System, assuming that the treatment used represents the ideal approach to the disease. PMID:29641652

Large-scale genome-wide association studies and meta-analyses of longitudinal change in adult lung function.

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Wenbo Tang

Full Text Available Genome-wide association studies (GWAS have identified numerous loci influencing cross-sectional lung function, but less is known about genes influencing longitudinal change in lung function.We performed GWAS of the rate of change in forced expiratory volume in the first second (FEV1 in 14 longitudinal, population-based cohort studies comprising 27,249 adults of European ancestry using linear mixed effects model and combined cohort-specific results using fixed effect meta-analysis to identify novel genetic loci associated with longitudinal change in lung function. Gene expression analyses were subsequently performed for identified genetic loci. As a secondary aim, we estimated the mean rate of decline in FEV1 by smoking pattern, irrespective of genotypes, across these 14 studies using meta-analysis.The overall meta-analysis produced suggestive evidence for association at the novel IL16/STARD5/TMC3 locus on chromosome 15 (P  =  5.71 × 10(-7. In addition, meta-analysis using the five cohorts with ≥3 FEV1 measurements per participant identified the novel ME3 locus on chromosome 11 (P  =  2.18 × 10(-8 at genome-wide significance. Neither locus was associated with FEV1 decline in two additional cohort studies. We confirmed gene expression of IL16, STARD5, and ME3 in multiple lung tissues. Publicly available microarray data confirmed differential expression of all three genes in lung samples from COPD patients compared with controls. Irrespective of genotypes, the combined estimate for FEV1 decline was 26.9, 29.2 and 35.7 mL/year in never, former, and persistent smokers, respectively.In this large-scale GWAS, we identified two novel genetic loci in association with the rate of change in FEV1 that harbor candidate genes with biologically plausible functional links to lung function.

Prevalence, associated factors and heritabilities of metabolic syndrome and its individual components in African Americans: the Jackson Heart Study.

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Khan, Rumana J; Gebreab, Samson Y; Sims, Mario; Riestra, Pia; Xu, Ruihua; Davis, Sharon K

2015-11-01

Both environmental and genetic factors play important roles in the development of metabolic syndrome (MetS). Studies about its associated factors and genetic contribution in African Americans (AA) are sparse. Our aim was to report the prevalence, associated factors and heritability estimates of MetS and its components in AA men and women. Data of this cross-sectional study come from a large community-based Jackson Heart Study (JHS). We analysed a total of 5227 participants, of whom 1636 from 281 families were part of a family study subset of JHS. Participants were classified as having MetS according to the Adult Treatment Panel III criteria. Multiple logistic regression analysis was performed to isolate independently associated factors of MetS (n=5227). Heritability was estimated from the family study subset using variance component methods (n=1636). About 27% of men and 40% of women had MetS. For men, associated factors with having MetS were older age, lower physical activity, higher body mass index, and higher homocysteine and adiponectin levels (pmetabolism playing a central role in the development of MetS and encourage additional efforts to identify the underlying susceptibility genes for this syndrome in AA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Study on the Leak Rate Estimation of SG Tubes and Residual Stress Estimation based on Plastic Deformation

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Jin; Chang, Yoon Suk; Lee, Dock Jin; Lee, Tae Rin; Choi, Shin Beom; Jeong, Jae Uk; Yeum, Seung Won [Sungkyunkwan University, Seoul (Korea, Republic of)

2009-02-15

In this research project, a leak rate estimation model was developed for steam generator tubes with through wall cracks. The modelling was based on the leak data from 23 tube specimens. Also, the procedure of finite element analysis was developed for residual stress calculation of dissimilar metal weld in a bottom mounted instrumentation. The effect of geometric variables related with the residual stress in penetration weld part was investigated by using the developed analysis procedure. The key subjects dealt in this research are: 1. Development of leak rate estimation model for steam generator tubes with through wall cracks 2. Development of the program which can perform the structure and leakage integrity evaluation for steam generator tubes 3. Development of analysis procedure for bottom mounted instrumentation weld residual stress 4. Analysis on the effects of geometric variables on weld residual stress It is anticipated that the technologies developed in this study are applicable for integrity estimation of steam generator tubes and weld part in NPP.

Covariate adjustments in randomized controlled trials increased study power and reduced biasedness of effect size estimation.

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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.

Estimating one's own and one's relatives' multiple intelligence: a study from Argentina.

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Furnham, Adrian; Chamorro-Premuzic, Tomas

2005-05-01

Participants from Argentina (N = 217) estimated their own, their partner's, their parents' and their grandparents' overall and multiple intelligences. The Argentinean data showed that men gave higher overall estimates than women (M = 110.4 vs. 105.1) as well as higher estimates on mathematical and spatial intelligence. Participants thought themselves slightly less bright than their fathers (2 IQ points) but brighter than their mothers (6 points), their grandfathers (8 points), but especially their grandmothers (11 points). Regressions showed that participants thought verbal and mathematical IQ to be the best predictors of overall IQ. Results were broadly in agreement with other studies in the area. A comparison was also made with British data using the same questionnaire. British participants tended to give significantly higher self-estimates than for relatives, though the pattern was generally similar. Results are discussed in terms of the studies in the field.

Accuracy of prognosis estimates by four palliative care teams: a prospective cohort study

Directory of Open Access Journals (Sweden)

Costantini Massimo

2002-03-01

Full Text Available Abstract Background Prognosis estimates are used to access services, but are often inaccurate. This study aimed to determine the accuracy of giving a prognosis range. Methods and measurements A prospective cohort study in four multi-professional palliative care teams in England collected data on 275 consecutive cancer referrals who died. Prognosis estimates (minimum – maximum at referral, patient characteristics, were recorded by staff, and later compared with actual survival. Results Minimum survival estimates ranged Conclusions Offering a prognosis range has higher levels of accuracy (about double than traditional estimates, but is still very often inaccurate, except very close to death. Where possible clinicians should discuss scenarios with patients, rather than giving a prognosis range.

A Minimum Fuel Based Estimator for Maneuver and Natrual Dynamics Reconstruction

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Lubey, D.; Scheeres, D.

2013-09-01

The vast and growing population of objects in Earth orbit (active and defunct spacecraft, orbital debris, etc.) offers many unique challenges when it comes to tracking these objects and associating the resulting observations. Complicating these challenges are the inaccurate natural dynamical models of these objects, the active maneuvers of spacecraft that deviate them from their ballistic trajectories, and the fact that spacecraft are tracked and operated by separate agencies. Maneuver detection and reconstruction algorithms can help with each of these issues by estimating mismodeled and unmodeled dynamics through indirect observation of spacecraft. It also helps to verify the associations made by an object correlation algorithm or aid in making those associations, which is essential when tracking objects in orbit. The algorithm developed in this study applies an Optimal Control Problem (OCP) Distance Metric approach to the problems of Maneuver Reconstruction and Dynamics Estimation. This was first developed by Holzinger, Scheeres, and Alfriend (2011), with a subsequent study by Singh, Horwood, and Poore (2012). This method estimates the minimum fuel control policy rather than the state as a typical Kalman Filter would. This difference ensures that the states are connected through a given dynamical model and allows for automatic covariance manipulation, which can help to prevent filter saturation. Using a string of measurements (either verified or hypothesized to correlate with one another), the algorithm outputs a corresponding string of adjoint and state estimates with associated noise. Post-processing techniques are implemented, which when applied to the adjoint estimates can remove noise and expose unmodeled maneuvers and mismodeled natural dynamics. Specifically, the estimated controls are used to determine spacecraft dependent accelerations (atmospheric drag and solar radiation pressure) using an adapted form of the Optimal Control based natural dynamics

No Reliable Association between Runs of Homozygosity and Schizophrenia in a Well-Powered Replication Study

Science.gov (United States)

Bjelland, Douglas W.; Howrigan, Daniel P.; Abdellaoui, Abdel; Breen, Gerome; Borglum, Anders; Cichon, Sven; Degenhardt, Franziska; Forstner, Andreas J.; Genovese, Giulio; Heilmann-Heimbach, Stefanie; Hoffman, Per; Maier, Wolfgang; Mattheisen, Manuel; Morris, Derek; Mowry, Bryan; Müller-Mhysok, Betram; Neale, Benjamin; Nenadic, Igor; Nöthen, Markus M.; O’Dushlaine, Colm; Rietschel, Marcella; Ruderfer, Douglas M.; Rujescu, Dan; Schulze, Thomas G.; Simonson, Matthew A.; Stahl, Eli; Strohmaier, Jana; Sullivan, Patrick F.; Keller, Matthew C.

2016-01-01

It is well known that inbreeding increases the risk of recessive monogenic diseases, but it is less certain whether it contributes to the etiology of complex diseases such as schizophrenia. One way to estimate the effects of inbreeding is to examine the association between disease diagnosis and genome-wide autozygosity estimated using runs of homozygosity (ROH) in genome-wide single nucleotide polymorphism arrays. Using data for schizophrenia from the Psychiatric Genomics Consortium (n = 21,868), Keller et al. (2012) estimated that the odds of developing schizophrenia increased by approximately 17% for every additional percent of the genome that is autozygous (β = 16.1, CI(β) = [6.93, 25.7], Z = 3.44, p = 0.0006). Here we describe replication results from 22 independent schizophrenia case-control datasets from the Psychiatric Genomics Consortium (n = 39,830). Using the same ROH calling thresholds and procedures as Keller et al. (2012), we were unable to replicate the significant association between ROH burden and schizophrenia in the independent PGC phase II data, although the effect was in the predicted direction, and the combined (original + replication) dataset yielded an attenuated but significant relationship between Froh and schizophrenia (β = 4.86,CI(β) = [0.90,8.83],Z = 2.40,p = 0.02). Since Keller et al. (2012), several studies reported inconsistent association of ROH burden with complex traits, particularly in case-control data. These conflicting results might suggest that the effects of autozygosity are confounded by various factors, such as socioeconomic status, education, urbanicity, and religiosity, which may be associated with both real inbreeding and the outcome measures of interest. PMID:27792727

Quantifying Uncertainty in Soil Volume Estimates

International Nuclear Information System (INIS)

Roos, A.D.; Hays, D.C.; Johnson, R.L.; Durham, L.A.; Winters, M.

2009-01-01

Proper planning and design for remediating contaminated environmental media require an adequate understanding of the types of contaminants and the lateral and vertical extent of contamination. In the case of contaminated soils, this generally takes the form of volume estimates that are prepared as part of a Feasibility Study for Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites and/or as part of the remedial design. These estimates are typically single values representing what is believed to be the most likely volume of contaminated soil present at the site. These single-value estimates, however, do not convey the level of confidence associated with the estimates. Unfortunately, the experience has been that pre-remediation soil volume estimates often significantly underestimate the actual volume of contaminated soils that are encountered during the course of remediation. This underestimation has significant implications, both technically (e.g., inappropriate remedial designs) and programmatically (e.g., establishing technically defensible budget and schedule baselines). Argonne National Laboratory (Argonne) has developed a joint Bayesian/geostatistical methodology for estimating contaminated soil volumes based on sampling results, that also provides upper and lower probabilistic bounds on those volumes. This paper evaluates the performance of this method in a retrospective study that compares volume estimates derived using this technique with actual excavated soil volumes for select Formerly Utilized Sites Remedial Action Program (FUSRAP) Maywood properties that have completed remedial action by the U.S. Army Corps of Engineers (USACE) New York District. (authors)

Associations of Coffee Drinking and Cancer Mortality in the Cancer Prevention Study-II.

Science.gov (United States)

Gapstur, Susan M; Anderson, Rebecca L; Campbell, Peter T; Jacobs, Eric J; Hartman, Terryl J; Hildebrand, Janet S; Wang, Ying; McCullough, Marjorie L

2017-10-01

Background: Associations of coffee consumption with cancer mortality are inconsistent for many types of cancer, and confounding by smoking is an important concern. Methods: Cox proportional hazards regression was used to estimate multivariable-adjusted HRs for coffee consumption associated with death from all cancers combined and from specific cancer types among 922,896 Cancer Prevention Study-II participants ages 28-94 years who completed a four-page questionnaire and were cancer free at baseline in 1982. Results: During follow-up through 2012, there were 118,738 cancer-related deaths. There was a nonlinear association between coffee consumption and all-cancer death among current smokers and former smokers and no association among never smokers. Among nonsmokers, a 2 cup/day increase in coffee consumption was inversely associated with death from colorectal [HR = 0.97; 95% confidence interval (CI) 0.95-0.99], liver [HR = 0.92; 95% CI, 0.88-0.96], and female breast (HR = 0.97; 95% CI, 0.94-0.99) cancers, and positively associated with esophageal cancer-related death (HR = 1.07; 95% CI, 1.02-1.12). For head and neck cancer, a nonlinear inverse association was observed starting at 2-3 cups per day (HR = 0.72; 95% CI, 0.55-0.95), with similar associations observed at higher levels of consumption. Conclusions: These findings are consistent with many other studies that suggest coffee drinking is associated with a lower risk of colorectal, liver, female breast, and head and neck cancer. The association of coffee consumption with higher risk of esophageal cancer among nonsmokers in our study should be confirmed. Impact: These results underscore the importance of assessing associations between coffee consumption and cancer mortality by smoking status. Cancer Epidemiol Biomarkers Prev; 26(10); 1477-86. ©2017 AACR . ©2017 American Association for Cancer Research.

Elastic-net regularization approaches for genome-wide association studies of rheumatoid arthritis.

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Cho, Seoae; Kim, Haseong; Oh, Sohee; Kim, Kyunga; Park, Taesung

2009-12-15

The current trend in genome-wide association studies is to identify regions where the true disease-causing genes may lie by evaluating thousands of single-nucleotide polymorphisms (SNPs) across the whole genome. However, many challenges exist in detecting disease-causing genes among the thousands of SNPs. Examples include multicollinearity and multiple testing issues, especially when a large number of correlated SNPs are simultaneously tested. Multicollinearity can often occur when predictor variables in a multiple regression model are highly correlated, and can cause imprecise estimation of association. In this study, we propose a simple stepwise procedure that identifies disease-causing SNPs simultaneously by employing elastic-net regularization, a variable selection method that allows one to address multicollinearity. At Step 1, the single-marker association analysis was conducted to screen SNPs. At Step 2, the multiple-marker association was scanned based on the elastic-net regularization. The proposed approach was applied to the rheumatoid arthritis (RA) case-control data set of Genetic Analysis Workshop 16. While the selected SNPs at the screening step are located mostly on chromosome 6, the elastic-net approach identified putative RA-related SNPs on other chromosomes in an increased proportion. For some of those putative RA-related SNPs, we identified the interactions with sex, a well known factor affecting RA susceptibility.

Arterial wave reflections and kidney function decline among persons with preserved estimated glomerular filtration rate: the Multi-Ethnic Study of Atherosclerosis.

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Hsu, Jeffrey J; Katz, Ronit; Chirinos, Julio A; Jacobs, David R; Duprez, Daniel A; Peralta, Carmen A

2016-05-01

Differences in arterial wave reflections have been associated with increased risk for heart failure and mortality. Whether these measures are also associated with kidney function decline is not well established. Reflection magnitude (RM, defined as the ratio of the backward wave [Pb] to that of the forward wave [Pf]), augmentation index (AIx), and pulse pressure amplification (PPA) were derived from radial tonometry measures among 5232 participants free of cardiovascular disease who were enrolled in the Multiethnic Study of Atherosclerosis. Kidney function was estimated by creatinine and cystatin C measurements, as well as albumin-to-creatinine ratio. We evaluated the associations of Pb, Pf, RM, AIx, and PPA with annualized estimated glomerular filtration rate (eGFR) change and rapid kidney function decline over 5 years, using generalized linear mixed models and logistic regression, respectively. Of the study participants, 48% were male, mean age was 62 years, mean eGFR and median albumin-to-creatinine ratio at baseline were 84 mL/min/1.73 m(2) and 5.3 mg/g, respectively. In demographically adjusted models, both Pb and Pf had similarly strong associations with kidney function decline; compared to those in the lowest tertiles, the persons in the highest tertiles of Pb and Pf had a 1.01 and 0.99 mL/min/1.73 m(2)/year faster eGFR decline, respectively (P function decline. In conclusion, the reflected and forward wave components were similarly associated with kidney function decline, and these associations were explained by differences in systolic blood pressure. Copyright © 2016 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Association between ABO and Rh Blood Groups and Risk of Preeclampsia: A Case-Control Study from Iran.

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Aghasadeghi, Firoozeh; Saadat, Mostafa

2017-04-15

Preeclampsia (PE) is a major cause of maternal and neonatal morbidity and mortality. There is a genetic component in the development of PE with estimated heritability around 0.47. Several studies have investigated the association between maternal ABO blood groups (OMIM 110300) and risk of PE, with contradictory results have emerged. Considering that there is no study in this filed from Iranian population, the present case-control study was carried out at Shiraz (south-west Iran). In this study 331 women; 121 pregnant with PE and 210 normotensive pregnant women were included. Using blood group O (for ABO blood groups) or Rh+ (for Rh blood groups) as a reference, odds ratios (ORs) and its 95% confidence intervals (95% CI) of PE risk were estimated from logistic regression analysis. Although the A (OR = 0.67, 95% CI = 0.39-1.17, P = 0.165), B (OR = 0.86, 95% CI = 0.48-1.53, P = 0.615) and AB (OR = 1.14, 95% CI = 0.37-3.45, P = 0.812) phenotypes showed lower risks compared with the O blood group, statistical analysis indicated that there was no significant association between ABO phenotypes and risk of PE. The frequency of Rh- phenotype was higher among PE patients compared with the control group. However, the association was not significant (OR = 1.79, 95% CI = 0.69-4.65, P = 0.229). Adjusted ORs for age of participants and parity did not change the above-mentioned associations. Our present findings indicate that there is no association between ABO and Rh blood groups and risk of PE in Iranian population.

Mitochondrial DNA single nucleotide polymorphism associated with weight estimated breeding values in Nelore cattle (Bos indicus

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Fernando Henrique Biase

2007-01-01

Full Text Available We sampled 119 Nelore cattle (Bos indicus, 69 harboring B. indicus mtDNA plus 50 carrying Bos taurus mtDNA, to estimate the frequencies of putative mtDNA single nucleotide polymorphisms (SNPs and investigate their association with Nelore weight and scrotal circumference estimated breeding values (EBVs. The PCR restriction fragment length polymorphism (PCR-RFLP method was used to detect polymorphisms in the mitochondrial asparagine, cysteine, glycine, leucine and proline transporter RNA (tRNA genes (tRNAasn, tRNAcys, tRNAgly, tRNAleu and tRNApro. The 50 cattle carrying B. taurus mtDNA were monomorphic for all the tRNA gene SNPs analyzed, suggesting that they are specific to mtDNA from B. indicus cattle. No tRNAcys or tRNAgly polymorphisms were detected in any of the cattle but we did detect polymorphic SNPs in the tRNAasn, tRNAleu and tRNApro genes in the cattle harboring B. indicus mtDNA, with the same allele observed in the B. taurus sequence being present in the following percentage of cattle harboring B. indicus mtDNA: 72.46% for tRNAasn, 95.23% for tRNAleu and 90.62% for tRNApro. Analyses of variance using the tRNAasn SNP as the independent variable and EBVs as the dependent variable showed that the G -> T SNP was significantly associated (p < 0.05 with maternal EBVs for weight at 120 and 210 days (p < 0.05 and animal's EBVs for weight at 210, 365 and 455 days. There was no association of the tRNAasn SNP with the scrotal circumference EBVs. These results confirm that mtDNA can affect weight and that mtDNA polymorphisms can be a source of genetic variation for quantitative traits.

Ability of self-reported estimates of dietary sodium, potassium and protein to detect an association with general and abdominal obesity: comparison with the estimates derived from 24 h urinary excretion.

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Murakami, Kentaro; Livingstone, M Barbara E; Sasaki, Satoshi; Uenishi, Kazuhiro

2015-04-28

As under-reporting of dietary intake, particularly by overweight and obese subjects, is common in dietary surveys, biases inherent in the use of self-reported dietary information may distort true diet-obesity relationships or even create spurious ones. However, empirical evidence of this possibility is limited. The present cross-sectional study compared the relationships of 24 h urine-derived and self-reported intakes of Na, K and protein with obesity. A total of 1043 Japanese women aged 18-22 years completed a 24 h urine collection and a self-administered diet history questionnaire. After adjustment for potential confounders, 24 h urine-derived Na intake was associated with a higher risk of general obesity (BMI≥25 kg/m2) and abdominal obesity (waist circumference≥80 cm; both P for trend=0·04). For 24 h urine-derived protein intake, positive associations with general and abdominal obesity were observed (P for trend=0·02 and 0·053, respectively). For 24 h urine-derived K intake, there was an inverse association with abdominal obesity (P for trend=0·01). Conversely, when self-reported dietary information was used, only inverse associations between K intake and general and abdominal obesity were observed (P for trend=0·04 and 0·02, respectively), with no associations of Na or protein intake. In conclusion, we found positive associations of Na and protein intakes and inverse associations of K intake with obesity when using 24 h urinary excretion for estimating dietary intakes. However, no association was observed based on using self-reported dietary intakes, except for inverse association of K intake, suggesting that the ability of self-reported dietary information using the diet history questionnaire for investigating diet-obesity relationships is limited.

Associations between Physical and Cognitive Doping – A Cross-Sectional Study in 2.997 Triathletes

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Dietz, Pavel; Ulrich, Rolf; Dalaker, Robert; Striegel, Heiko; Franke, Andreas G.; Lieb, Klaus; Simon, Perikles

2013-01-01

Purpose This study assessed, for the first time, prevalence estimates for physical and cognitive doping within a single collective of athletes using the randomized response technique (RRT). Furthermore, associations between the use of legal and freely available substances to improve physical and cognitive performance (enhancement) and illicit or banned substances to improve physical and cognitive performance (doping) were examined. Methods An anonymous questionnaire using the unrelated question RRT was used to survey 2,997 recreational triathletes in three sports events (Frankfurt, Regensburg, and Wiesbaden) in Germany. Prior to the survey, statistical power analyses were performed to determine sample size. Logistic regression was used to predict physical and cognitive enhancement and the bootstrap method was used to evaluate differences between the estimated prevalences of physical and cognitive doping. Results 2,987 questionnaires were returned (99.7%). 12-month prevalences for physical and cognitive doping were 13.0% and 15.1%, respectively. The prevalence estimate for physical doping was significantly higher in athletes who also used physical enhancers, as well as in athletes who took part in the European Championship in Frankfurt compared to those who did not. The prevalence estimate for cognitive doping was significantly higher in athletes who also used physical and cognitive enhancers. Moreover, the use of physical and cognitive enhancers were significantly associated and also the use of physical and cognitive doping. Discussion The use of substances to improve physical and cognitive performance was associated on both levels of legality (enhancement vs. doping) suggesting that athletes do not use substances for a specific goal but may have a general propensity to enhance. This finding is important for understanding why people use such substances. Consequently, more effective prevention programs against substance abuse and doping could be developed. PMID

Accounting for Time-Varying Confounding in the Relationship Between Obesity and Coronary Heart Disease: Analysis With G-Estimation: The ARIC Study.

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Shakiba, Maryam; Mansournia, Mohammad Ali; Salari, Arsalan; Soori, Hamid; Mansournia, Nasrin; Kaufman, Jay S

2018-06-01

In longitudinal studies, standard analysis may yield biased estimates of exposure effect in the presence of time-varying confounders that are also intermediate variables. We aimed to quantify the relationship between obesity and coronary heart disease (CHD) by appropriately adjusting for time-varying confounders. This study was performed in a subset of participants from the Atherosclerosis Risk in Communities (ARIC) Study (1987-2010), a US study designed to investigate risk factors for atherosclerosis. General obesity was defined as body mass index (weight (kg)/height (m)2) ≥30, and abdominal obesity (AOB) was defined according to either waist circumference (≥102 cm in men and ≥88 cm in women) or waist:hip ratio (≥0.9 in men and ≥0.85 in women). The association of obesity with CHD was estimated by G-estimation and compared with results from accelerated failure-time models using 3 specifications. The first model, which adjusted for baseline covariates, excluding metabolic mediators of obesity, showed increased risk of CHD for all obesity measures. Further adjustment for metabolic mediators in the second model and time-varying variables in the third model produced negligible changes in the hazard ratios. The hazard ratios estimated by G-estimation were 1.15 (95% confidence interval (CI): 0.83, 1.47) for general obesity, 1.65 (95% CI: 1.35, 1.92) for AOB based on waist circumference, and 1.38 (95% CI: 1.13, 1.99) for AOB based on waist:hip ratio, suggesting that AOB increased the risk of CHD. The G-estimated hazard ratios for both measures were further from the null than those derived from standard models.

A Study on Fuel Estimation Algorithms for a Geostationary Communication & Broadcasting Satellite

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Jong Won Eun

2000-12-01

Full Text Available It has been developed to calculate fuel budget for a geostationary communication and broadcasting satellite. It is quite essential that the pre-launch fuel budget estimation must account for the deterministic transfer and drift orbit maneuver requirements. After on-station, the calculation of satellite lifetime should be based on the estimation of remaining fuel and assessment of actual performance. These estimations step from the proper algorithms to produce the prediction of satellite lifetime. This paper concentrates on the fuel estimation method that was studied for calculation of the propellant budget by using the given algorithms. Applications of this method are discussed for a communication and broadcasting satellite.

Admixture mapping in the Hispanic Community Health Study/Study of Latinos reveals regions of genetic associations with blood pressure traits.

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Tamar Sofer

Full Text Available Admixture mapping can be used to detect genetic association regions in admixed populations, such as Hispanics/Latinos, by estimating associations between local ancestry allele counts and the trait of interest. We performed admixture mapping of the blood pressure traits systolic and diastolic blood pressure (SBP, DBP, mean arterial pressure (MAP, and pulse pressure (PP, in a dataset of 12,116 participants from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL. Hispanics/Latinos have three predominant ancestral populations (European, African, and Amerindian, for each of which we separately tested local ancestry intervals across the genome. We identified four regions that were significantly associated with a blood pressure trait at the genome-wide admixture mapping level. A 6p21.31 Amerindian ancestry association region has multiple known associations, but none explained the admixture mapping signal. We identified variants that completely explained this signal. One of these variants had p-values of 0.02 (MAP and 0.04 (SBP in replication testing in Pima Indians. A 11q13.4 Amerindian ancestry association region spans a variant that was previously reported (p-value = 0.001 in a targeted association study of Blood Pressure (BP traits and variants in the vitamin D pathway. There was no replication evidence supporting an association in the identified 17q25.3 Amerindian ancestry association region. For a region on 6p12.3, associated with African ancestry, we did not identify any candidate variants driving the association. It may be driven by rare variants. Whole genome sequence data may be necessary to fine map these association signals, which may contribute to disparities in BP traits between diverse populations.

An Empirical Bayes Mixture Model for Effect Size Distributions in Genome-Wide Association Studies.

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Wesley K Thompson

2015-12-01

Full Text Available Characterizing the distribution of effects from genome-wide genotyping data is crucial for understanding important aspects of the genetic architecture of complex traits, such as number or proportion of non-null loci, average proportion of phenotypic variance explained per non-null effect, power for discovery, and polygenic risk prediction. To this end, previous work has used effect-size models based on various distributions, including the normal and normal mixture distributions, among others. In this paper we propose a scale mixture of two normals model for effect size distributions of genome-wide association study (GWAS test statistics. Test statistics corresponding to null associations are modeled as random draws from a normal distribution with zero mean; test statistics corresponding to non-null associations are also modeled as normal with zero mean, but with larger variance. The model is fit via minimizing discrepancies between the parametric mixture model and resampling-based nonparametric estimates of replication effect sizes and variances. We describe in detail the implications of this model for estimation of the non-null proportion, the probability of replication in de novo samples, the local false discovery rate, and power for discovery of a specified proportion of phenotypic variance explained from additive effects of loci surpassing a given significance threshold. We also examine the crucial issue of the impact of linkage disequilibrium (LD on effect sizes and parameter estimates, both analytically and in simulations. We apply this approach to meta-analysis test statistics from two large GWAS, one for Crohn's disease (CD and the other for schizophrenia (SZ. A scale mixture of two normals distribution provides an excellent fit to the SZ nonparametric replication effect size estimates. While capturing the general behavior of the data, this mixture model underestimates the tails of the CD effect size distribution. We discuss the

An Empirical Bayes Mixture Model for Effect Size Distributions in Genome-Wide Association Studies.

Science.gov (United States)

Thompson, Wesley K; Wang, Yunpeng; Schork, Andrew J; Witoelar, Aree; Zuber, Verena; Xu, Shujing; Werge, Thomas; Holland, Dominic; Andreassen, Ole A; Dale, Anders M

2015-12-01

Characterizing the distribution of effects from genome-wide genotyping data is crucial for understanding important aspects of the genetic architecture of complex traits, such as number or proportion of non-null loci, average proportion of phenotypic variance explained per non-null effect, power for discovery, and polygenic risk prediction. To this end, previous work has used effect-size models based on various distributions, including the normal and normal mixture distributions, among others. In this paper we propose a scale mixture of two normals model for effect size distributions of genome-wide association study (GWAS) test statistics. Test statistics corresponding to null associations are modeled as random draws from a normal distribution with zero mean; test statistics corresponding to non-null associations are also modeled as normal with zero mean, but with larger variance. The model is fit via minimizing discrepancies between the parametric mixture model and resampling-based nonparametric estimates of replication effect sizes and variances. We describe in detail the implications of this model for estimation of the non-null proportion, the probability of replication in de novo samples, the local false discovery rate, and power for discovery of a specified proportion of phenotypic variance explained from additive effects of loci surpassing a given significance threshold. We also examine the crucial issue of the impact of linkage disequilibrium (LD) on effect sizes and parameter estimates, both analytically and in simulations. We apply this approach to meta-analysis test statistics from two large GWAS, one for Crohn's disease (CD) and the other for schizophrenia (SZ). A scale mixture of two normals distribution provides an excellent fit to the SZ nonparametric replication effect size estimates. While capturing the general behavior of the data, this mixture model underestimates the tails of the CD effect size distribution. We discuss the implications of

Estimate of the economic impact of mastitis: A case study in a Holstein dairy herd under tropical conditions.

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Guimarães, Juliana L B; Brito, Maria A V P; Lange, Carla C; Silva, Márcio R; Ribeiro, João B; Mendonça, Letícia C; Mendonça, Juliana F M; Souza, Guilherme N

2017-07-01

The aim of this study was to estimate the economic impact of mastitis at the herd level and the weight (percent) of the components of this impact in a Holstein dairy herd under tropical conditions. Three estimates of the economic impact of mastitis were performed. In estimates 1 and 2 the real production and economic indices from February 2011 to January 2012 were considered. In the estimate 1, indices for mastitis classified as ideal were considered, whereas in the estimate 2, the mastitis indices used were those recorded at the farm and at Holstein Cattle Association of Minas Gerais State database (real indices). Ideal mastitis indices were bulk milk somatic cell counts less than 250,000 cells/mL, incidence of clinical mastitis less than 25 cases/100 cows/year, number of culls due to udder health problems less than 5% and the percentage of cows with somatic cell counts greater than 200,000 cells/mL less than 20%. Considering the ideal indices of mastitis, the economic impact was US$19,132.35. The three main components of the economic impact were culling cows (39.4%) and the reduction in milk production due to subclinical and clinical mastitis (32.3% and 18.2%, respectively). Estimate 2 using real mastitis indices showed an economic impact of US$61,623.13 and the reduction in milk production due to mastitis (77.7%) and milk disposal (14.0%) were the most relevant components. The real impact of culling cows was approximately 16 times less than the weight that was considered ideal, indicating that this procedure could have been more frequently adopted. The reduction in milk production was 27.2% higher than the reduction in Estimate 1, indicating a need to control and prevent mastitis. The estimate 3 considered the same indices as estimate 2, but for the period from February 2012 to January 2013. Its economic impact was US$91,552.69. During this period, 161 treatments of cows with an intramammary antibiotic were performed to eliminate Streptococcus agalactiae, and

Estimating haplotype effects for survival data.

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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.

Coupled land surface-subsurface hydrogeophysical inverse modeling to estimate soil organic carbon content and explore associated hydrological and thermal dynamics in the Arctic tundra

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Phuong Tran, Anh; Dafflon, Baptiste; Hubbard, Susan S.

2017-09-01

Quantitative characterization of soil organic carbon (OC) content is essential due to its significant impacts on surface-subsurface hydrological-thermal processes and microbial decomposition of OC, which both in turn are important for predicting carbon-climate feedbacks. While such quantification is particularly important in the vulnerable organic-rich Arctic region, it is challenging to achieve due to the general limitations of conventional core sampling and analysis methods, and to the extremely dynamic nature of hydrological-thermal processes associated with annual freeze-thaw events. In this study, we develop and test an inversion scheme that can flexibly use single or multiple datasets - including soil liquid water content, temperature and electrical resistivity tomography (ERT) data - to estimate the vertical distribution of OC content. Our approach relies on the fact that OC content strongly influences soil hydrological-thermal parameters and, therefore, indirectly controls the spatiotemporal dynamics of soil liquid water content, temperature and their correlated electrical resistivity. We employ the Community Land Model to simulate nonisothermal surface-subsurface hydrological dynamics from the bedrock to the top of canopy, with consideration of land surface processes (e.g., solar radiation balance, evapotranspiration, snow accumulation and melting) and ice-liquid water phase transitions. For inversion, we combine a deterministic and an adaptive Markov chain Monte Carlo (MCMC) optimization algorithm to estimate a posteriori distributions of desired model parameters. For hydrological-thermal-to-geophysical variable transformation, the simulated subsurface temperature, liquid water content and ice content are explicitly linked to soil electrical resistivity via petrophysical and geophysical models. We validate the developed scheme using different numerical experiments and evaluate the influence of measurement errors and benefit of joint inversion on the

Coupled land surface–subsurface hydrogeophysical inverse modeling to estimate soil organic carbon content and explore associated hydrological and thermal dynamics in the Arctic tundra

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A. P. Tran

2017-09-01

Full Text Available Quantitative characterization of soil organic carbon (OC content is essential due to its significant impacts on surface–subsurface hydrological–thermal processes and microbial decomposition of OC, which both in turn are important for predicting carbon–climate feedbacks. While such quantification is particularly important in the vulnerable organic-rich Arctic region, it is challenging to achieve due to the general limitations of conventional core sampling and analysis methods, and to the extremely dynamic nature of hydrological–thermal processes associated with annual freeze–thaw events. In this study, we develop and test an inversion scheme that can flexibly use single or multiple datasets – including soil liquid water content, temperature and electrical resistivity tomography (ERT data – to estimate the vertical distribution of OC content. Our approach relies on the fact that OC content strongly influences soil hydrological–thermal parameters and, therefore, indirectly controls the spatiotemporal dynamics of soil liquid water content, temperature and their correlated electrical resistivity. We employ the Community Land Model to simulate nonisothermal surface–subsurface hydrological dynamics from the bedrock to the top of canopy, with consideration of land surface processes (e.g., solar radiation balance, evapotranspiration, snow accumulation and melting and ice–liquid water phase transitions. For inversion, we combine a deterministic and an adaptive Markov chain Monte Carlo (MCMC optimization algorithm to estimate a posteriori distributions of desired model parameters. For hydrological–thermal-to-geophysical variable transformation, the simulated subsurface temperature, liquid water content and ice content are explicitly linked to soil electrical resistivity via petrophysical and geophysical models. We validate the developed scheme using different numerical experiments and evaluate the influence of measurement errors and

MANTEL-HAENSZEL TYPE ESTIMATORS FOR THE COUNTER-MATCHED SAMPLING DESIGN IN NESTED CASE-CONTROL STUDY

OpenAIRE

Fujii, Yoshinori; Zhang, Zhong-Zhan; 藤井, 良宜

2001-01-01

We are concerned with a counter-matched nested case-control study. Assuming the proportional hazards model, the Mantel-Haenszel estimators of hazard rates are presented in two situations. The proposed estimators can be calculated without estimating the nuisance parameter. Consistent estimators of the variance of the proposed hazard rate estimators are also developed. We compare these estimators to the maximum partial likelihood estimators in the asymptotic variance. The methods are illustrate...

A hierarchical model for estimating density in camera-trap studies

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Royle, J. Andrew; Nichols, James D.; Karanth, K.Ullas; Gopalaswamy, Arjun M.

2009-01-01

Estimating animal density using capture–recapture data from arrays of detection devices such as camera traps has been problematic due to the movement of individuals and heterogeneity in capture probability among them induced by differential exposure to trapping.We develop a spatial capture–recapture model for estimating density from camera-trapping data which contains explicit models for the spatial point process governing the distribution of individuals and their exposure to and detection by traps.We adopt a Bayesian approach to analysis of the hierarchical model using the technique of data augmentation.The model is applied to photographic capture–recapture data on tigers Panthera tigris in Nagarahole reserve, India. Using this model, we estimate the density of tigers to be 14·3 animals per 100 km2 during 2004.Synthesis and applications. Our modelling framework largely overcomes several weaknesses in conventional approaches to the estimation of animal density from trap arrays. It effectively deals with key problems such as individual heterogeneity in capture probabilities, movement of traps, presence of potential ‘holes’ in the array and ad hoc estimation of sample area. The formulation, thus, greatly enhances flexibility in the conduct of field surveys as well as in the analysis of data, from studies that may involve physical, photographic or DNA-based ‘captures’ of individual animals.

Four Susceptibility Loci for Gallstone Disease Identified in a Meta-analysis of Genome-Wide Association Studies

DEFF Research Database (Denmark)

Joshi, Amit D; Andersson, Charlotte; Buch, Stephan

2016-01-01

discovery studies (8720 cases and 55,152 controls). We performed an inverse variance weighted, fixed-effects meta-analysis of study-specific estimates to identify single-nucleotide polymorphisms that were associated independently with gallstone disease. Associations were replicated in 6489 cases and 62...... in TM4SF4 (OR, 1.12; 95% CI, 1.08-1.16; P = 6.09 × 10(-11)), rs2547231 in SULT2A1 (encodes a sulfoconjugation enzyme that acts on hydroxysteroids and cholesterol-derived sterol bile acids) (OR, 1.17; 95% CI, 1.12-1.21; P = 2.24 × 10(-10)), rs1260326 in glucokinase regulatory protein (OR, 1.12; 95% CI, 1...

A population-based national estimate of the prevalence and risk factors associated with hypertension in Rwanda: implications for prevention and control.

Science.gov (United States)

Nahimana, Marie-Rosette; Nyandwi, Alypio; Muhimpundu, Marie Aimee; Olu, Olushayo; Condo, Jeanine Umutesi; Rusanganwa, Andre; Koama, Jean Baptiste; Ngoc, Candide Tran; Gasherebuka, Jean Bosco; Ota, Martin O; Okeibunor, Joseph C

2017-07-10

Hypertension is a leading cause of cardiovascular diseases and a growing public health problem in many developed and developing countries. However, population-based data to inform policy development are scarce in Rwanda. This nationally representative study aimed to determine population-based estimates of the prevalence and risk factors associated with hypertension in Rwanda. We conducted secondary epidemiological analysis of data collected from a cross-sectional population-based study to assess the risk factors for NCDs using the WHO STEPwise approach to Surveillance of non-communicable diseases (STEPS). Adjusted odds ratios at 95% confidence interval were used to establish association between hypertension, socio-demographic characteristics and health risk behaviors. Of the 7116 study participants, 62.8% were females and 38.2% were males. The mean age of study participants was 35.3 years (SD 12.5). The overall prevalence of hypertension was 15.3% (16.4% for males and 14.4% for females). Twenty two percent of hypertensive participants were previously diagnosed. A logistic regression model revealed that age (AOR: 8.02, 95% CI: 5.63-11.42, p Rwanda, suggesting the need for prevention and control interventions aimed at decreasing the incidence taking into consideration the risk factors documented in this and other similar studies.

Impaired Fertility Associated with Subclinical Hypothyroidism and Thyroid Autoimmunity: The Danish General Suburban Population Study

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Anne-Dorthe Feldthusen

2015-01-01

Full Text Available Introduction. The aim of this study was to estimate the significance of TSH, thyroid peroxidase antibody (TPOAb, and mild (subclinical hypothyroidism in women from The Danish General Suburban Population Study (GESUS on the number of children born, the number of pregnancies, and the number of spontaneous abortions. Methods. Retrospective cross sectional study of 11254 women participating in GESUS. Data included biochemical measurements and a self-administrated questionnaire. Results. 6.7% had mild (subclinical hypothyroidism and 9.4% prevalent hypothyroidism. In women with mild hypothyroidism TPOAb was significantly elevated and age at first child was older compared to controls. TSH and TPOAb were negatively linearly associated with the number of children born and the number of pregnancies in the full cohort in age-adjusted and multiadjusted models. TSH or TPOAb was not associated with spontaneous abortions. Mild (subclinical hypothyroidism was associated with a risk of not having children and a risk of not getting pregnant in age-adjusted and multiadjusted models. Prevalent hypothyroidism was not associated with the number of children born, the number of pregnancies, or spontaneous abortions. Conclusion. Impaired fertility is associated with TSH, TPOAb, and mild (subclinical hypothyroidism in a Danish population of women.

Is sarcopenia associated with depression? A systematic review and meta-analysis of observational studies.

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Chang, Ke-Vin; Hsu, Tsai-Hsuan; Wu, Wei-Ting; Huang, Kuo-Chin; Han, Der-Sheng

2017-09-01

to explore whether sarcopenia is associated with depression. electronic literature databases from PubMed, Scopus, Embase and Google Scholar were searched. A systematic review and meta-analysis of observational studies was conducted. community and outpatient clinic. people with and without diagnoses of sarcopenia. outcome measures of depression. about 15 articles were included, 5 of which were retrieved for narrative review. The crude odds ratios (ORs) between sarcopenia and depression were extracted from the remaining 10 studies, 6 of which also included adjusted ORs. Sarcopenia was associated with depression without adjusting covariates (crude OR, 1.640; 95% confidence interval (CI), 1.247-2.155). After adjusting for potential confounders such as age, gender, cognitive performance and physical activity, sarcopenia still demonstrated a significant positive association with depression (adjusted OR, 1.821; 95% CI, 1.160-2.859). A stratified analysis showed that the studies that used bioelectrical impedance analysis for measurement of body composition tended to have an elevated association between sarcopenia and depression compared with those that used dual-energy X-ray absorptiometry or equation estimation. sarcopenia was independently associated with depression. The causal relationship between the two clinical conditions requires future validation with cohort studies. © The Author 2017. Published by Oxford University Press on behalf of the British Geriatrics Society.All rights reserved. For permissions, please email: journals.permissions@oup.com

Neighborhood Disadvantage, Neighborhood Safety and Cardiometabolic Risk Factors in African Americans: Biosocial Associations in the Jackson Heart Study

Science.gov (United States)

Clark, Cheryl R.; Ommerborn, Mark J.; Hickson, DeMarc A.; Grooms, Kya N.; Sims, Mario; Taylor, Herman A.; Albert, Michelle A.

2013-01-01

Objective We examined associations between neighborhood socioeconomic disadvantage, perceived neighborhood safety and cardiometabolic risk factors, adjusting for health behaviors and socioeconomic status (SES) among African Americans. Methods Study participants were non-diabetic African Americans (n = 3,909) in the baseline examination (2000–2004) of the Jackson Heart Study. We measured eight risk factors: the metabolic syndrome, its five components, insulin resistance and cardiovascular inflammation. We assessed neighborhood socioeconomic disadvantage with US Census 2000 data. We assessed perceived neighborhood safety, health behaviors and SES via survey. We used generalized estimating equations to estimate associations with a random intercept model for neighborhood effects. Results After adjustment for health behaviors and SES, neighborhood socioeconomic disadvantage was associated with the metabolic syndrome in women (PR 1.13, 95% CI 1.01, 1.27). Lack of perceived safety was associated with elevated glucose (OR 1.36, 95% CI 1.03, 1.80) and waist circumference (PR 1.06, 95% CI 1.02, 1.11) among women, and with elevated glucose (PR 1.30, 95% CI 1.02, 1.66) and insulin resistance (PR 1.25, 95% CI 1.08, 1.46) among men. Conclusions Neighborhood socioeconomic disadvantage and perceived safety should be considered as targets for intervention to reduce cardiometabolic risks among African Americans. PMID:23691005

Heritability and confirmation of genetic association studies for childhood asthma in twins.

Science.gov (United States)

Ullemar, V; Magnusson, P K E; Lundholm, C; Zettergren, A; Melén, E; Lichtenstein, P; Almqvist, C

2016-02-01

Although the genetics of asthma has been extensively studied using both quantitative and molecular genetic analysis methods, both approaches lack studies specific to the childhood phenotype and including other allergic diseases. This study aimed to give specific estimates for the heritability of childhood asthma and other allergic diseases, to attempt to replicate findings from genomewide association studies (GWAS) for childhood asthma and to test the same variants against other allergic diseases. In a cohort of 25 306 Swedish twins aged 9 or 12 years, data on asthma were available from parental interviews and population-based registers. The interviews also inquired about wheeze, hay fever, eczema, and food allergy. Through structural equation modeling, the heritability of all phenotypes was calculated. A subset of 10 075 twins was genotyped for 16 single nucleotide polymorphisms (SNPs) selected from previous GWAS; these were first tested for association with asthma and significant findings also against the other allergic diseases. The heritability of any childhood asthma was 0.82 (95% CI 0.79-0.85). For the other allergic diseases, the range was approximately 0.60-0.80. Associations for six SNPs with asthma were replicated, including rs2305480 in the GSDMB gene (OR 0.80, 95% CI 0.74-0.86, P = 1.5*10(-8) ; other significant associations all below P = 3.5*10(-4) ). Of these, only rs3771180 in IL1RL1 was associated with any other allergic disease (for hay fever, OR 0.64, 95% CI 0.53-0.77, P = 2.5*10(-6) ). Asthma and allergic diseases of childhood are highly heritable, and these high-risk genetic variants associated specifically with childhood asthma, except for one SNP shared with hay fever. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Association between Herpesviruses and Chronic Periodontitis: A Meta-Analysis Based on Case-Control Studies.

Science.gov (United States)

Zhu, Ce; Li, Fei; Wong, May Chun Mei; Feng, Xi-Ping; Lu, Hai-Xia; Xu, Wei

2015-01-01

Numerous studies have investigated the associations between herpesviruses and chronic periodontitis; however, the results remain controversial. To derive a more precise estimation, a meta-analysis on all available studies was performed to identify the association between herpesviruses and chronic periodontitis. A computerized literature search was conducted in December 2014 to identify eligible case-control studies from the PUBMED and EMBASE databases according to inclusion and exclusion criteria. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were used to assess the association between herpesviruses and risk of chronic periodontitis. A fixed or random effects model was determined based on a heterogeneity test. Sensitivity analysis was conducted to investigate stability and reliability. Publication bias was investigated using the Begg rank correlation test and Egger's funnel plot. Ten eligible studies were included to investigate the association between Epstein-Barr virus (EBV) and chronic periodontitis. The results showed that EBV has a significant association with chronic periodontitis compared with periodontally healthy group (OR = 5.74, 95% CI = 2.53-13.00, Pchronic periodontitis was analyzed in 10 studies. The pooled result showed that HCMV also has a significant association with chronic periodontitis (OR = 3.59, 95% CI = 1.41-9.16, P = 0.007). Similar results were found in the sensitivity analyses. No significant publication bias was observed. Two eligible studies were included to investigate the association between herpes simplex virus (HSV) and chronic periodontitis risk. The association between HSV and chronic periodontitis was inconclusive (OR = 2.81 95% CI = 0.95-8.27, P = 0.06). Only one included study investigated the association between human herpesvirus 7 (HHV-7) and chronic periodontitis risk (OR = 1.00, 95% CI = 0.21-4.86). The findings of this meta-analysis suggest that two members of the herpesvirus family, EBV

Estimating the cost of a smoking employee.

Science.gov (United States)

Berman, Micah; Crane, Rob; Seiber, Eric; Munur, Mehmet

2014-09-01

We attempted to estimate the excess annual costs that a US private employer may attribute to employing an individual who smokes tobacco as compared to a non-smoking employee. Reviewing and synthesising previous literature estimating certain discrete costs associated with smoking employees, we developed a cost estimation approach that approximates the total of such costs for U.S. employers. We examined absenteeism, presenteesim, smoking breaks, healthcare costs and pension benefits for smokers. Our best estimate of the annual excess cost to employ a smoker is $5816. This estimate should be taken as a general indicator of the extent of excess costs, not as a predictive point value. Employees who smoke impose significant excess costs on private employers. The results of this study may help inform employer decisions about tobacco-related policies. 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.

Methods for developing useful estimates of the costs associated with birth defects.

Science.gov (United States)

Case, Amy P; Canfield, Mark A

2009-11-01

Cost estimates for birth defects are useful to policy makers in deciding the best use of resources to prevent these conditions. Much of the effort in this area has focused on spina bifida, in part because cost savings can be estimated from folic acid-preventable cases. However, comprehensive cost-of-illness estimates for this condition may be too outdated, too general, or not applicable to individual states' environments. Using the live birth prevalence for spina bifida in Texas, we applied recent spina bifida cost estimates to approximate total lifetime medical and other costs for an average live birth cohort of spina bifida cases in Texas. In addition, we queried various government programs that provide services for persons with spina bifida to provide program-specific annual costs for this condition. Applying a recently published average lifetime medical cost of $635,000 per case of spina bifida to the average annual birth cohort of 120 Texas cases, an estimated $76 million in direct and indirect medical and other costs will be incurred in Texas over the life span of that cohort. Examples of estimated medical costs for one year are $5 million for infants using actual employer-paid insurance claims data and $6 million combined for children in two public sector programs. Stakeholders and state policy makers may look to state birth defects registries for useful cost data. Although comprehensive state-specific figures are not available, applying prevalence data to existing estimates and obtaining actual claims and program expenditures may help close this information gap.

Methodology for estimating biomass energy potential and its application to Colombia

International Nuclear Information System (INIS)

Gonzalez-Salazar, Miguel Angel; Morini, Mirko; Pinelli, Michele; Spina, Pier Ruggero; Venturini, Mauro; Finkenrath, Matthias; Poganietz, Witold-Roger

2014-01-01

Highlights: • Methodology to estimate the biomass energy potential and its uncertainty at a country level. • Harmonization of approaches and assumptions in existing assessment studies. • The theoretical and technical biomass energy potential in Colombia are estimated in 2010. - Abstract: This paper presents a methodology to estimate the biomass energy potential and its associated uncertainty at a country level when quality and availability of data are limited. The current biomass energy potential in Colombia is assessed following the proposed methodology and results are compared to existing assessment studies. The proposed methodology is a bottom-up resource-focused approach with statistical analysis that uses a Monte Carlo algorithm to stochastically estimate the theoretical and the technical biomass energy potential. The paper also includes a proposed approach to quantify uncertainty combining a probabilistic propagation of uncertainty, a sensitivity analysis and a set of disaggregated sub-models to estimate reliability of predictions and reduce the associated uncertainty. Results predict a theoretical energy potential of 0.744 EJ and a technical potential of 0.059 EJ in 2010, which might account for 1.2% of the annual primary energy production (4.93 EJ)

Uncertainty Estimate in Resources Assessment: A Geostatistical Contribution

International Nuclear Information System (INIS)

Souza, Luis Eduardo de; Costa, Joao Felipe C. L.; Koppe, Jair C.

2004-01-01

For many decades the mining industry regarded resources/reserves estimation and classification as a mere calculation requiring basic mathematical and geological knowledge. Most methods were based on geometrical procedures and spatial data distribution. Therefore, uncertainty associated with tonnages and grades either were ignored or mishandled, although various mining codes require a measure of confidence in the values reported. Traditional methods fail in reporting the level of confidence in the quantities and grades. Conversely, kriging is known to provide the best estimate and its associated variance. Among kriging methods, Ordinary Kriging (OK) probably is the most widely used one for mineral resource/reserve estimation, mainly because of its robustness and its facility in uncertainty assessment by using the kriging variance. It also is known that OK variance is unable to recognize local data variability, an important issue when heterogeneous mineral deposits with higher and poorer grade zones are being evaluated. Alternatively, stochastic simulation are used to build local or global uncertainty about a geological attribute respecting its statistical moments. This study investigates methods capable of incorporating uncertainty to the estimates of resources and reserves via OK and sequential gaussian and sequential indicator simulation The results showed that for the type of mineralization studied all methods classified the tonnages similarly. The methods are illustrated using an exploration drill hole data sets from a large Brazilian coal deposit

'I feel better when…': An analysis of the memory-experience gap for peoples' estimates of the relationship between health behaviours and experiences.

Science.gov (United States)

Gloster, Andrew T; Meyer, Andrea H; Witthauer, Cornelia; Lieb, Roselind; Mata, Jutta

2017-09-01

People often overestimate how strongly behaviours and experiences are related. This memory-experience gap might have important implications for health care settings, which often require people to estimate associations, such as "my mood is better when I exercise". This study examines how subjective correlation estimates between health behaviours and experiences relate to calculated correlations from online reports and whether subjective estimates are associated with engagement in actual health behaviour. Seven-month online study on physical activity, sleep, affect and stress, with 61 online assessments. University students (N = 168) retrospectively estimated correlations between physical activity, sleep, positive affect and stress over the seven-month study period. Correlations between experiences and behaviours (online data) were small (r = -.12-.14), estimated correlations moderate (r = -.35-.24). Correspondence between calculated and estimated correlations was low. Importantly, estimated correlations of physical activity with stress, positive affect and sleep were associated with actual engagement in physical activity. Estimation accuracy of relations between health behaviours and experiences is low. However, association estimates could be an important predictor of actual health behaviours. This study identifies and quantifies estimation inaccuracies in health behaviours and points towards potential systematic biases in health settings, which might seriously impair intervention efficacy.

Estimating the health and economic benefits associated with reducing air pollution in the Barcelona metropolitan area (Spain).

Science.gov (United States)

Pérez, Laura; Sunyer, Jordi; Künzli, Nino

2009-01-01

To estimate the health and economic benefits that would result from two scenarios of improved air quality in 57 municipalities of the metropolitan area of Barcelona. We used attributable fractions and life tables to quantify the benefits for selected health outcomes, based on published concentration-response functions and economic unit values. The mean weighted concentration of PM(10) for the study population was estimated through concentration surface maps developed by the local government. The annual mean health benefits of reducing the mean PM(10) exposure estimated for the population in the study area (50microg/m(3)) to the annual mean value recommended by the World Health Organization (20microg/m(3)) were estimated to be 3,500 fewer deaths (representing an average increase in life expectancy of 14 months), 1,800 fewer hospitalizations for cardio-respiratory diseases, 5,100 fewer cases of chronic bronchitis among adults, 31,100 fewer cases of acute bronchitis among children, and 54,000 fewer asthma attacks among children and adults. The mean total monetary benefits were estimated to be 6,400 million euros per year. Reducing PM(10) to comply with the current European Union regulatory annual mean level (40microg/m(3)) would yield approximately one third of these benefits. This study shows that reducing air pollution in the metropolitan area of Barcelona would result in substantial health and economic benefits. The benefits are probably underestimated due to the assumptions made in this study. Assessment of the health impact of local air pollution is a useful tool in public health.

Effort estimation for enterprise resource planning implementation projects using social choice - a comparative study

Science.gov (United States)

Koch, Stefan; Mitlöhner, Johann

2010-08-01

ERP implementation projects have received enormous attention in the last years, due to their importance for organisations, as well as the costs and risks involved. The estimation of effort and costs associated with new projects therefore is an important topic. Unfortunately, there is still a lack of models that can cope with the special characteristics of these projects. As the main focus lies in adapting and customising a complex system, and even changing the organisation, traditional models like COCOMO can not easily be applied. In this article, we will apply effort estimation based on social choice in this context. Social choice deals with aggregating the preferences of a number of voters into a collective preference, and we will apply this idea by substituting the voters by project attributes. Therefore, instead of supplying numeric values for various project attributes, a new project only needs to be placed into rankings per attribute, necessitating only ordinal values, and the resulting aggregate ranking can be used to derive an estimation. We will describe the estimation process using a data set of 39 projects, and compare the results to other approaches proposed in the literature.

Global estimates of syphilis in pregnancy and associated adverse outcomes: analysis of multinational antenatal surveillance data.

Directory of Open Access Journals (Sweden)

Lori Newman

Full Text Available The World Health Organization initiative to eliminate mother-to-child transmission of syphilis aims for ≥ 90% of pregnant women to be tested for syphilis and ≥ 90% to receive treatment by 2015. We calculated global and regional estimates of syphilis in pregnancy and associated adverse outcomes for 2008, as well as antenatal care (ANC coverage for women with syphilis.Estimates were based upon a health service delivery model. National syphilis seropositivity data from 97 of 193 countries and ANC coverage from 147 countries were obtained from World Health Organization databases. Proportions of adverse outcomes and effectiveness of screening and treatment were from published literature. Regional estimates of ANC syphilis testing and treatment were examined through sensitivity analysis. In 2008, approximately 1.36 million (range: 1.16 to 1.56 million pregnant women globally were estimated to have probable active syphilis; of these, 80% had attended ANC. Globally, 520,905 (best case: 425,847; worst case: 615,963 adverse outcomes were estimated to be caused by maternal syphilis, including approximately 212,327 (174,938; 249,716 stillbirths (>28 wk or early fetal deaths (22 to 28 wk, 91,764 (76,141; 107,397 neonatal deaths, 65,267 (56,929; 73,605 preterm or low birth weight infants, and 151,547 (117,848; 185,245 infected newborns. Approximately 66% of adverse outcomes occurred in ANC attendees who were not tested or were not treated for syphilis. In 2008, based on the middle case scenario, clinical services likely averted 26% of all adverse outcomes. Limitations include missing syphilis seropositivity data for many countries in Europe, the Mediterranean, and North America, and use of estimates for the proportion of syphilis that was "probable active," and for testing and treatment coverage.Syphilis continues to affect large numbers of pregnant women, causing substantial perinatal morbidity and mortality that could be prevented by early testing and

Association of pediatric obstructive sleep apnea with poor academic performance: A school-based study from India

OpenAIRE

Abhishek Goyal; Abhijit P Pakhare; Girish C Bhatt; Bharat Choudhary; Rajesh Patil

2018-01-01

Background: Pediatric obstructive sleep apnea (OSA) is a highly prevalent but often neglected disorder. There is paucity of reports on the prevalence of pediatric OSA from India. This study was done to estimate the prevalence of OSA in school children aged 5–10 years and its association with academic performance. Methodology: This school-based cross-sectional epidemiological study was conducted from July 2015 to November 2015. A questionnaire seeking information on sociodemographic variables,...

Estimates of mean consequences and confidence bounds on the mean associated with low-probability seismic events in total system performance assessments

International Nuclear Information System (INIS)

Pensado, Osvaldo; Mancillas, James

2007-01-01

An approach is described to estimate mean consequences and confidence bounds on the mean of seismic events with low probability of breaching components of the engineered barrier system. The approach is aimed at complementing total system performance assessment models used to understand consequences of scenarios leading to radionuclide releases in geologic nuclear waste repository systems. The objective is to develop an efficient approach to estimate mean consequences associated with seismic events of low probability, employing data from a performance assessment model with a modest number of Monte Carlo realizations. The derived equations and formulas were tested with results from a specific performance assessment model. The derived equations appear to be one method to estimate mean consequences without having to use a large number of realizations. (authors)

Personnel exposure estimates associated with nuclear fuel reprocessing waste

International Nuclear Information System (INIS)

Boone, F.W.; Rogers, B.W.

1983-08-01

The operation design of the Barnwell Nuclear Fuel Plant (BNFP) calls for shipment of its wastes to either a low-level waste disposal site or to a Federal repository. This study analyzes the probable radiation dose accrued to the personnel involved in handling waste packages from all identified waste streams of the BNFP from generation to reception at destination and including transportation. The shielding characteristics of the transport packages were derived by assuming packaging in existing or prototyped casks. Possible combinations of waste forms and packages for which the projected dose exceeded DOT or NRC regulations for transport of radioactive materials were rejected. Legal weight truck and legal weight rail transport modes were assumed. Potential ways for reducing overall personnel exposure are considered, concentrating on the particular streams with the largest dose contributions. The personnel exposure estimates were determined using a computer program specifically designed for this purpose. This program is described in Appendix A. 9 references, 3 figures, 19 tables

Association of General and Abdominal Obesity With Hypertension, Dyslipidemia and Prediabetes in the PREDAPS Study.

Science.gov (United States)

Sangrós, F Javier; Torrecilla, Jesús; Giráldez-García, Carolina; Carrillo, Lourdes; Mancera, José; Mur, Teresa; Franch, Josep; Díez, Javier; Goday, Albert; Serrano, Rosario; García-Soidán, F Javier; Cuatrecasas, Gabriel; Igual, Dimas; Moreno, Ana; Millaruelo, J Manuel; Carramiñana, Francisco; Ruiz, Manuel Antonio; Pérez, Francisco Carlos; Iriarte, Yon; Lorenzo, Ángela; González, María; Álvarez, Beatriz; Barutell, Lourdes; Mayayo, M Soledad; Del Castillo, Mercedes; Navarro, Emma; Malo, Fernando; Cambra, Ainhoa; López, Riánsares; Gutiérrez, M Ángel; Gutiérrez, Luisa; Boente, Carmen; Mediavilla, J Javier; Prieto, Luis; Mendo, Luis; Mansilla, M José; Ortega, Francisco Javier; Borras, Antonia; Sánchez, L Gabriel; Obaya, J Carlos; Alonso, Margarita; García, Francisco; Gutiérrez, Ángela Trinidad; Hernández, Ana M; Suárez, Dulce; Álvarez, J Carlos; Sáenz, Isabel; Martínez, F Javier; Casorrán, Ana; Ripoll, Jazmín; Salanova, Alejandro; Marín, M Teresa; Gutiérrez, Félix; Innerárity, Jaime; Álvarez, M Del Mar; Artola, Sara; Bedoya, M Jesús; Poveda, Santiago; Álvarez, Fernando; Brito, M Jesús; Iglesias, Rosario; Paniagua, Francisca; Nogales, Pedro; Gómez, Ángel; Rubio, José Félix; Durán, M Carmen; Sagredo, Julio; Gijón, M Teresa; Rollán, M Ángeles; Pérez, Pedro P; Gamarra, Javier; Carbonell, Francisco; García-Giralda, Luis; Antón, J Joaquín; de la Flor, Manuel; Martínez, Rosario; Pardo, José Luis; Ruiz, Antonio; Plana, Raquel; Macía, Ramón; Villaró, Mercè; Babace, Carmen; Torres, José Luis; Blanco, Concepción; Jurado, Ángeles; Martín, José Luis; Navarro, Jorge; Sanz, Gloria; Colas, Rafael; Cordero, Blanca; de Castro, Cristina; Ibáñez, Mercedes; Monzón, Alicia; Porta, Nuria; Gómez, María Del Carmen; Llanes, Rafael; Rodríguez, J José; Granero, Esteban; Sánchez, Manuel; Martínez, Juan; Ezkurra, Patxi; Ávila, Luis; de la Sen, Carlos; Rodríguez, Antonio; Buil, Pilar; Gabriel, Paula; Roura, Pilar; Tarragó, Eduard; Mundet, Xavier; Bosch, Remei; González, J Carles; Bobé, M Isabel; Mata, Manel; Ruiz, Irene; López, Flora; Birules, Marti; Armengol, Oriol; de Miguel, Rosa Mar; Romera, Laura; Benito, Belén; Piulats, Neus; Bilbeny, Beatriz; Cabré, J José; Cos, Xavier; Pujol, Ramón; Seguí, Mateu; Losada, Carmen; de Santiago, A María; Muñoz, Pedro; Regidor, Enrique

2018-03-01

Some anthropometric measurements show a greater capacity than others to identify the presence of cardiovascular risk factors. This study estimated the magnitude of the association of different anthropometric indicators of obesity with hypertension, dyslipidemia, and prediabetes (altered fasting plasma glucose and/or glycosylated hemoglobin). Cross-sectional analysis of information collected from 2022 participants in the PREDAPS study (baseline phase). General obesity was defined as body mass index ≥ 30kg/m 2 and abdominal obesity was defined with 2 criteria: a) waist circumference (WC) ≥ 102cm in men/WC ≥ 88cm in women, and b) waist-height ratio (WHtR) ≥ 0.55. The magnitude of the association was estimated by logistic regression. Hypertension showed the strongest association with general obesity in women (OR, 3.01; 95%CI, 2.24-4.04) and with abdominal obesity based on the WHtR criterion in men (OR, 3.65; 95%CI, 2.66-5.01). Hypertriglyceridemia and low levels of high-density lipoprotein cholesterol showed the strongest association with abdominal obesity based on the WHtR criterion in women (OR, 2.49; 95%CI, 1.68-3.67 and OR, 2.70; 95%CI, 1.89-3.86) and with general obesity in men (OR, 2.06; 95%CI, 1.56-2.73 and OR, 1.68; 95%CI, 1.21-2.33). Prediabetes showed the strongest association with abdominal obesity based on the WHtR criterion in women (OR, 2.48; 95%CI, 1.85-3.33) and with abdominal obesity based on the WC criterion in men (OR, 2.33; 95%CI, 1.75-3.08). Abdominal obesity indicators showed the strongest association with the presence of prediabetes. The association of anthropometric indicators with hypertension and dyslipidemia showed heterogeneous results. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Are we under-estimating the association between autism symptoms?: The importance of considering simultaneous selection when using samples of individuals who meet diagnostic criteria for an autism spectrum disorder.

Science.gov (United States)

Murray, Aja Louise; McKenzie, Karen; Kuenssberg, Renate; O'Donnell, Michael

2014-11-01

The magnitude of symptom inter-correlations in diagnosed individuals has contributed to the evidence that autism spectrum disorders (ASD) is a fractionable disorder. Such correlations may substantially under-estimate the population correlations among symptoms due to simultaneous selection on the areas of deficit required for diagnosis. Using statistical simulations of this selection mechanism, we provide estimates of the extent of this bias, given different levels of population correlation between symptoms. We then use real data to compare domain inter-correlations in the Autism Spectrum Quotient, in those with ASD versus a combined ASD and non-ASD sample. Results from both studies indicate that samples restricted to individuals with a diagnosis of ASD potentially substantially under-estimate the magnitude of association between features of ASD.

Estimating soil zinc concentrations using reflectance spectroscopy

Science.gov (United States)

Sun, Weichao; Zhang, Xia

2017-06-01

Soil contamination by heavy metals has been an increasingly severe threat to nature environment and human health. Efficiently investigation of contamination status is essential to soil protection and remediation. Visible and near-infrared reflectance spectroscopy (VNIRS) has been regarded as an alternative for monitoring soil contamination by heavy metals. Generally, the entire VNIR spectral bands are employed to estimate heavy metal concentration, which lacks interpretability and requires much calculation. In this study, 74 soil samples were collected from Hunan Province, China and their reflectance spectra were used to estimate zinc (Zn) concentration in soil. Organic matter and clay minerals have strong adsorption for Zn in soil. Spectral bands associated with organic matter and clay minerals were used for estimation with genetic algorithm based partial least square regression (GA-PLSR). The entire VNIR spectral bands, the bands associated with organic matter and the bands associated with clay minerals were incorporated as comparisons. Root mean square error of prediction, residual prediction deviation, and coefficient of determination (R2) for the model developed using combined bands of organic matter and clay minerals were 329.65 mg kg-1, 1.96 and 0.73, which is better than 341.88 mg kg-1, 1.89 and 0.71 for the entire VNIR spectral bands, 492.65 mg kg-1, 1.31 and 0.40 for the organic matter, and 430.26 mg kg-1, 1.50 and 0.54 for the clay minerals. Additionally, in consideration of atmospheric water vapor absorption in field spectra measurement, combined bands of organic matter and absorption around 2200 nm were used for estimation and achieved high prediction accuracy with R2 reached 0.640. The results indicate huge potential of soil reflectance spectroscopy in estimating Zn concentrations in soil.

Web-based genome-wide association study identifies two novel loci and a substantial genetic component for Parkinson's disease.

Directory of Open Access Journals (Sweden)

Chuong B Do

2011-06-01

Full Text Available Although the causes of Parkinson's disease (PD are thought to be primarily environmental, recent studies suggest that a number of genes influence susceptibility. Using targeted case recruitment and online survey instruments, we conducted the largest case-control genome-wide association study (GWAS of PD based on a single collection of individuals to date (3,426 cases and 29,624 controls. We discovered two novel, genome-wide significant associations with PD-rs6812193 near SCARB2 (p = 7.6 × 10(-10, OR = 0.84 and rs11868035 near SREBF1/RAI1 (p = 5.6 × 10(-8, OR = 0.85-both replicated in an independent cohort. We also replicated 20 previously discovered genetic associations (including LRRK2, GBA, SNCA, MAPT, GAK, and the HLA region, providing support for our novel study design. Relying on a recently proposed method based on genome-wide sharing estimates between distantly related individuals, we estimated the heritability of PD to be at least 0.27. Finally, using sparse regression techniques, we constructed predictive models that account for 6%-7% of the total variance in liability and that suggest the presence of true associations just beyond genome-wide significance, as confirmed through both internal and external cross-validation. These results indicate a substantial, but by no means total, contribution of genetics underlying susceptibility to both early-onset and late-onset PD, suggesting that, despite the novel associations discovered here and elsewhere, the majority of the genetic component for Parkinson's disease remains to be discovered.

Analysis of Case-Control Association Studies: SNPs, Imputation and Haplotypes

KAUST Repository

Chatterjee, Nilanjan; Chen, Yi-Hau; Luo, Sheng; Carroll, Raymond J.

2009-01-01

Although prospective logistic regression is the standard method of analysis for case-control data, it has been recently noted that in genetic epidemiologic studies one can use the "retrospective" likelihood to gain major power by incorporating various population genetics model assumptions such as Hardy-Weinberg-Equilibrium (HWE), gene-gene and gene-environment independence. In this article we review these modern methods and contrast them with the more classical approaches through two types of applications (i) association tests for typed and untyped single nucleotide polymorphisms (SNPs) and (ii) estimation of haplotype effects and haplotype-environment interactions in the presence of haplotype-phase ambiguity. We provide novel insights to existing methods by construction of various score-tests and pseudo-likelihoods. In addition, we describe a novel two-stage method for analysis of untyped SNPs that can use any flexible external algorithm for genotype imputation followed by a powerful association test based on the retrospective likelihood. We illustrate applications of the methods using simulated and real data. © Institute of Mathematical Statistics, 2009.

Analysis of Case-Control Association Studies: SNPs, Imputation and Haplotypes

KAUST Repository

Chatterjee, Nilanjan

2009-11-01

Although prospective logistic regression is the standard method of analysis for case-control data, it has been recently noted that in genetic epidemiologic studies one can use the "retrospective" likelihood to gain major power by incorporating various population genetics model assumptions such as Hardy-Weinberg-Equilibrium (HWE), gene-gene and gene-environment independence. In this article we review these modern methods and contrast them with the more classical approaches through two types of applications (i) association tests for typed and untyped single nucleotide polymorphisms (SNPs) and (ii) estimation of haplotype effects and haplotype-environment interactions in the presence of haplotype-phase ambiguity. We provide novel insights to existing methods by construction of various score-tests and pseudo-likelihoods. In addition, we describe a novel two-stage method for analysis of untyped SNPs that can use any flexible external algorithm for genotype imputation followed by a powerful association test based on the retrospective likelihood. We illustrate applications of the methods using simulated and real data. © Institute of Mathematical Statistics, 2009.

Discretization of Lévy semistationary processes with application to estimation

DEFF Research Database (Denmark)

Bennedsen, Mikkel; Lunde, Asger; Pakkanen, Mikko

Motivated by the construction of the Ito stochastic integral, we consider a step function method to discretize and simulate volatility modulated Lévy semistationary processes. Moreover, we assess the accuracy of the method with a particular focus on integrating kernels with a singularity...... at the origin. Using the simulation method, we study the finite sample properties of some recently developed estimators of realized volatility and associated parametric estimators for Brownian semistationary processes. Although the theoretical properties of these estimators have been established under high...

The Association Between Oxidative Stress and Depressive Symptom Scores in Elderly Population: A Repeated Panel Study

Directory of Open Access Journals (Sweden)

Changwoo Han

2016-09-01

Full Text Available Objectives Previous epidemiological studies about oxidative stress and depression are limited by hospital-based case-control design, single-time measurements of oxidative stress biomarkers, and the small number of study participants. Therefore, in this study, we analyzed the association between biomarker of oxidative stress and depressive symptom scores using repeatedly measured panel data from a community-dwelling elderly population. Methods From 2008 to 2010, a total of 478 elderly participants residing in Seoul, Korea, were evaluated three times. Participants underwent the Korean version of the Short Form Generic Depression Scale (SGDS-K test for screening depression, and urinary malondialdehyde (MDA levels were measured as an oxidative stress biomarker. We used a generalized estimating equation with a compound symmetry covariance structure to estimate the effects of oxidative stress on depressive symptom scores. Results A two-fold increase in urinary MDA concentration was significantly associated with a 33.88% (95% confidence interval [CI], 21.59% to 47.42% increase in total SGDS-K scores. In subgroup analyses by gender, a two-fold increase in urinary MDA concentration was significantly associated with increased SGDS-K scores in both men and women (men: 30.88%; 95% CI, 10.24% to 55.37%; women: 34.77%; 95% CI, 20.09% to 51.25%. In bivariate analysis after an SGDS-K score ≥8 was defined as depression, the third and the fourth urinary MDA quartiles showed a significantly increased odds ratio(OR of depression compared to the lowest urinary MDA quartile (third quartile OR, 6.51; 95% CI, 1.77 to 24.00; fourth quartile OR, 7.11; 95% CI, 1.99 to 25.42. Conclusions Our study suggests a significant association between oxidative stress and depressive symptoms in the elderly population.

Comparative Study of Complex Survey Estimation Software in ONS

Directory of Open Access Journals (Sweden)

Andy Fallows

2015-09-01

Full Text Available Many official statistics across the UK Government Statistical Service (GSS are produced using data collected from sample surveys. These survey data are used to estimate population statistics through weighting and calibration techniques. For surveys with complex or unusual sample designs, the weighting can be fairly complicated. Even in more simple cases, appropriate software is required to implement survey weighting and estimation. As with other stages of the survey process, it is preferable to use a standard, generic calibration tool wherever possible. Standard tools allow for efficient use of resources and assist with the harmonisation of methods. In the case of calibration, the Office for National Statistics (ONS has experience of using the Statistics Canada Generalized Estimation System (GES across a range of business and social surveys. GES is a SAS-based system and so is only available in conjunction with an appropriate SAS licence. Given recent initiatives and encouragement to investigate open source solutions across government, it is appropriate to determine whether there are any open source calibration tools available that can provide the same service as GES. This study compares the use of GES with the calibration tool ‘R evolved Generalized software for sampling estimates and errors in surveys’ (ReGenesees available in R, an open source statistical programming language which is beginning to be used in many statistical offices. ReGenesees is a free R package which has been developed by the Italian statistics office (Istat and includes functionality to calibrate survey estimates using similar techniques to GES. This report describes analysis of the performance of ReGenesees in comparison to GES to calibrate a representative selection of ONS surveys. Section 1.1 provides a brief introduction to the current use of SAS and R in ONS. Section 2 describes GES and ReGenesees in more detail. Sections 3.1 and 3.2 consider methods for

Temporal validation for landsat-based volume estimation model

Science.gov (United States)

Renaldo J. Arroyo; Emily B. Schultz; Thomas G. Matney; David L. Evans; Zhaofei Fan

2015-01-01

Satellite imagery can potentially reduce the costs and time associated with ground-based forest inventories; however, for satellite imagery to provide reliable forest inventory data, it must produce consistent results from one time period to the next. The objective of this study was to temporally validate a Landsat-based volume estimation model in a four county study...

A simulation study to quantify the impacts of exposure measurement error on air pollution health risk estimates in copollutant time-series models.

Science.gov (United States)

Dionisio, Kathie L; Chang, Howard H; Baxter, Lisa K

2016-11-25

Exposure measurement error in copollutant epidemiologic models has the potential to introduce bias in relative risk (RR) estimates. A simulation study was conducted using empirical data to quantify the impact of correlated measurement errors in time-series analyses of air pollution and health. ZIP-code level estimates of exposure for six pollutants (CO, NO x , EC, PM 2.5 , SO 4 , O 3 ) from 1999 to 2002 in the Atlanta metropolitan area were used to calculate spatial, population (i.e. ambient versus personal), and total exposure measurement error. Empirically determined covariance of pollutant concentration pairs and the associated measurement errors were used to simulate true exposure (exposure without error) from observed exposure. Daily emergency department visits for respiratory diseases were simulated using a Poisson time-series model with a main pollutant RR = 1.05 per interquartile range, and a null association for the copollutant (RR = 1). Monte Carlo experiments were used to evaluate the impacts of correlated exposure errors of different copollutant pairs. Substantial attenuation of RRs due to exposure error was evident in nearly all copollutant pairs studied, ranging from 10 to 40% attenuation for spatial error, 3-85% for population error, and 31-85% for total error. When CO, NO x or EC is the main pollutant, we demonstrated the possibility of false positives, specifically identifying significant, positive associations for copollutants based on the estimated type I error rate. The impact of exposure error must be considered when interpreting results of copollutant epidemiologic models, due to the possibility of attenuation of main pollutant RRs and the increased probability of false positives when measurement error is present.

Power assessment for genetic association study of human longevity using offspring of long-lived subjects

DEFF Research Database (Denmark)

Tan, Qihua; Zhao, Jing Hua; Li, Shuxia

2010-01-01

and the proportional hazard model for generating individual lifespan. Family genotype data is generated using a genetic linkage program for given SNP allele frequency. Power is estimated by setting the type I error rate at 0.05 and by calculating the Armitage's chi-squared test statistic for 200 replicate samples...... the direct approach. It also has low power in detecting non-additive effect genes. Indirect genetic association using offspring from families with both parents as nonagenarians is nearly as powerful as using offspring from families with one centenarian parent. In conclusion, the indirect design can be a good......Recently, an indirect genetic association approach that compares genotype frequencies in offspring of long-lived subjects and offspring from random families has been introduced to study gene-longevity associations. Although the indirect genetic association has certain advantages over the direct...

HMGCR-associated myositis: a New Zealand case series and estimate of incidence.

Science.gov (United States)

Kennedy, N; Keating, P; O'Donnell, J

2016-05-01

Statins are one of the most commonly prescribed drugs in New Zealand, with 525 772 or 16.5% of the adult New Zealand population prescribed a statin between June 2013 and July 2014. While generally well-tolerated, statins are known to cause a range of muscle-related side effects, ranging from myalgia to life-threatening rhabdomyolysis. Recently, it has been recognised that in rare instances, statins can induce an immune-mediated necrotising myositis with antibodies against 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), the enzymatic target of statins. In 2014, anti-HMGCR antibody testing was introduced to Canterbury Health Laboratories (CHL), with this being the only laboratory in New Zealand performing this test during the period of this case series. This article describes an index case and characterises the clinical features of a subsequent 12-month series. From this series, we estimated the yearly incidence of HMGCR-associated myositis at 1.7/million/year or ~1/90 000 New Zealand statin users. © 2016 Royal Australasian College of Physicians.

A study on the estimation of economic consequence of severe accident

International Nuclear Information System (INIS)

Hong, Dae Seok; Lee, Kun Jai; Jeong, Jong Tae

1996-01-01

A model to estimate economic consequence of severe accident provides some measure of the impact on the accident and enables to know the different effects of the accident described as same terms of cost and combined as necessary. Techniques to assess the consequences of accidents in terms of cost have many applications, for instance in examining countermeasure options, as part of either emergency planning or decision making after an accident. In this study, a model to estimate the accident economic consequence is developed appropriate to our country focused on PWR accident costs from a societal viewpoint. Societal costs are estimated by accounting for losses that directly affect the plant licensee, the public, the nuclear industry, or the electric utility industry after PWR accident

Estimated maximal and current brain volume predict cognitive ability in old age

Science.gov (United States)

Royle, Natalie A.; Booth, Tom; Valdés Hernández, Maria C.; Penke, Lars; Murray, Catherine; Gow, Alan J.; Maniega, Susana Muñoz; Starr, John; Bastin, Mark E.; Deary, Ian J.; Wardlaw, Joanna M.

2013-01-01

Brain tissue deterioration is a significant contributor to lower cognitive ability in later life; however, few studies have appropriate data to establish how much influence prior brain volume and prior cognitive performance have on this association. We investigated the associations between structural brain imaging biomarkers, including an estimate of maximal brain volume, and detailed measures of cognitive ability at age 73 years in a large (N = 620), generally healthy, community-dwelling population. Cognitive ability data were available from age 11 years. We found positive associations (r) between general cognitive ability and estimated brain volume in youth (male, 0.28; females, 0.12), and in measured brain volume in later life (males, 0.27; females, 0.26). Our findings show that cognitive ability in youth is a strong predictor of estimated prior and measured current brain volume in old age but that these effects were the same for both white and gray matter. As 1 of the largest studies of associations between brain volume and cognitive ability with normal aging, this work contributes to the wider understanding of how some early-life factors influence cognitive aging. PMID:23850342

Estimating the direct costs of ischemic heart disease: evidence from a teaching hospital in BRAZIL, a retrospective cohort study

OpenAIRE

Schlatter, Rosane Paix?o; Hirakata, V?nia Naomi; Polanczyk, Carisi Anne

2017-01-01

Background Coronary artery disease is the most prevalent cardiovascular disease. In the United States, 7% of adults over 20 years of age are estimated to have coronary artery disease. In Brazil, a prevalence of 5 to 8% has been estimated in adults over 40 years of age, with an increased number of hospitalizations associated with both stable and acute clinical manifestations; and health care costs have quadrupled in the last decade. To estimate the direct costs of managing ischemic heart disea...

Estimating retrospective exposure of household humidifier disinfectants.

Science.gov (United States)

Park, D U; Friesen, M C; Roh, H S; Choi, Y Y; Ahn, J J; Lim, H K; Kim, S K; Koh, D H; Jung, H J; Lee, J H; Cheong, H K; Lim, S Y; Leem, J H; Kim, Y H; Paek, D M

2015-12-01

We conducted a comprehensive humidifier disinfectant exposure characterization for 374 subjects with lung disease who presumed their disease was related to humidifier disinfectant use (patient group) and for 303 of their family members (family group) for an ongoing epidemiological study. We visited the homes of the registered patients to investigate disinfectant use characteristics. Probability of exposure to disinfectants was determined from the questionnaire and supporting evidence from photographs demonstrating the use of humidifier disinfectant, disinfectant purchase receipts, any residual disinfectant, and the consistency of their statements. Exposure duration was estimated as cumulative disinfectant use hours from the questionnaire. Airborne disinfectant exposure intensity (μg/m(3)) was estimated based on the disinfectant volume (ml) and frequency added to the humidifier per day, disinfectant bulk level (μg/ml), the volume of the room (m(3)) with humidifier disinfectant, and the degree of ventilation. Overall, the distribution patterns of the intensity, duration, and cumulative exposure to humidifier disinfectants for the patient group were higher than those of the family group, especially for pregnant women and patients ≤6 years old. Further study is underway to evaluate the association between the disinfectant exposures estimated here with clinically diagnosed lung disease. Retrospective exposure to household humidifier disinfectant as estimated here can be used to evaluate associations with clinically diagnosed lung disease due to the use of humidifier disinfectant in Korea. The framework, with modifications to account for dispersion and use patterns, can also be potentially adapted to assessment of other household chemical exposures. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Study on Comparison of Bidding and Pricing Behavior Distinction between Estimate Methods

Science.gov (United States)

Morimoto, Emi; Namerikawa, Susumu

The most characteristic trend on bidding and pricing behavior distinction in recent years is the increasing number of bidders just above the criteria for low-price bidding investigations. The contractor's markup is the difference between the bidding price and the execution price. Therefore, the contractor's markup is the difference between criteria for low-price bidding investigations price and the execution price in the public works bid in Japan. Virtually, bidder's strategies and behavior have been controlled by public engineer's budgets. Estimation and bid are inseparably linked in the Japanese public works procurement system. The trial of the unit price-type estimation method begins in 2004. On another front, accumulated estimation method is one of the general methods in public works. So, there are two types of standard estimation methods in Japan. In this study, we did a statistical analysis on the bid information of civil engineering works for the Ministry of Land, Infrastructure, and Transportation in 2008. It presents several issues that bidding and pricing behavior is related to an estimation method (several estimation methods) for public works bid in Japan. The two types of standard estimation methods produce different results that number of bidders (decide on bid-no bid strategy) and distribution of bid price (decide on mark-up strategy).The comparison on the distribution of bid prices showed that the percentage of the bid concentrated on the criteria for low-price bidding investigations have had a tendency to get higher in the large-sized public works by the unit price-type estimation method, comparing with the accumulated estimation method. On one hand, the number of bidders who bids for public works estimated unit-price tends to increase significantly Public works estimated unit-price is likely to have been one of the factors for the construction companies to decide if they participate in the biddings.

Reliability of different sampling densities for estimating and mapping lichen diversity in biomonitoring studies

International Nuclear Information System (INIS)

Ferretti, M.; Brambilla, E.; Brunialti, G.; Fornasier, F.; Mazzali, C.; Giordani, P.; Nimis, P.L.

2004-01-01

Sampling requirements related to lichen biomonitoring include optimal sampling density for obtaining precise and unbiased estimates of population parameters and maps of known reliability. Two available datasets on a sub-national scale in Italy were used to determine a cost-effective sampling density to be adopted in medium-to-large-scale biomonitoring studies. As expected, the relative error in the mean Lichen Biodiversity (Italian acronym: BL) values and the error associated with the interpolation of BL values for (unmeasured) grid cells increased as the sampling density decreased. However, the increase in size of the error was not linear and even a considerable reduction (up to 50%) in the original sampling effort led to a far smaller increase in errors in the mean estimates (<6%) and in mapping (<18%) as compared with the original sampling densities. A reduction in the sampling effort can result in considerable savings of resources, which can then be used for a more detailed investigation of potentially problematic areas. It is, however, necessary to decide the acceptable level of precision at the design stage of the investigation, so as to select the proper sampling density. - An acceptable level of precision must be decided before determining a sampling design

Implications of a valuation study for ecological and social indicators associated with Everglades restoration.

Science.gov (United States)

Seeteram, Nadia A; Engel, Victor; Mozumder, Pallab

2018-06-15

The Everglades of south Florida, although degraded, imparts vital ecosystem benefits, including contributions to high quality drinking water supplies and habitat for a number of threatened and endangered species. Restoration of the Everglades can improve the provision of these benefits but also may impose tradeoffs with competing societal demands. This study focuses on understanding public preferences for Everglades restoration and estimating the willingness to pay (WTP) values for restored ecosystem services (ES) through the implementation of a discrete choice experiment (DCE). We collected data from 2302 respondents from the general public from an online survey designed to elicit WTP values for selected ecological and social attributes associated with Everglades restoration scenarios. We compare the findings to results from earlier studies (Milon et al., 1999; Milon and Scrogin, 2005), which also estimated WTP values among Floridians for Everglades restoration. For some attributes, WTP for Everglades restoration appears to have slightly increased while for others WTP appears to have decreased. We estimated statewide aggregate WTP values for components of species population restoration up to $2B over 10 years. Several factors impeded a direct comparison of current and historical WTP values, including time elapsed, different samples and sampling methods- which may have implications for integrating ecosystem service valuation studies into water management decisions. Copyright © 2018 Elsevier B.V. All rights reserved.

A case-control study estimating accident risk for alcohol, medicines and illegal drugs.

Directory of Open Access Journals (Sweden)

Kim Paula Colette Kuypers

Full Text Available The aim of the present study was to assess the risk of having a traffic accident after using alcohol, single drugs, or a combination, and to determine the concentrations at which this risk is significantly increased.A population-based case-control study was carried out, collecting whole blood samples of both cases and controls, in which a number of drugs were detected. The risk of having an accident when under the influence of drugs was estimated using logistic regression adjusting for gender, age and time period of accident (cases/sampling (controls. The main outcome measures were odds ratio (OR for accident risk associated with single and multiple drug use. In total, 337 cases (negative: 176; positive: 161 and 2726 controls (negative: 2425; positive: 301 were included in the study.Main findings were that 1 alcohol in general (all the concentrations together caused an elevated crash risk; 2 cannabis in general also caused an increase in accident risk; at a cut-off of 2 ng/mL THC the risk of having an accident was four times the risk associated with the lowest THC concentrations; 3 when ranking the adjusted OR from lowest to highest risk, alcohol alone or in combination with other drugs was related to a very elevated crash risk, with the highest risk for stimulants combined with sedatives.The study demonstrated a concentration-dependent crash risk for THC positive drivers. Alcohol and alcohol-drug combinations are by far the most prevalent substances in drivers and subsequently pose the largest risk in traffic, both in terms of risk and scope.

Assessing the Association between Natural Food Folate Intake and Blood Folate Concentrations: A Systematic Review and Bayesian Meta-Analysis of Trials and Observational Studies

Directory of Open Access Journals (Sweden)

Claire M. Marchetta

2015-04-01

Full Text Available Folate is found naturally in foods or as synthetic folic acid in dietary supplements and fortified foods. Adequate periconceptional folic acid intake can prevent neural tube defects. Folate intake impacts blood folate concentration; however, the dose-response between natural food folate and blood folate concentrations has not been well described. We estimated this association among healthy females. A systematic literature review identified studies (1 1992–3 2014 with both natural food folate intake alone and blood folate concentration among females aged 12–49 years. Bayesian methods were used to estimate regression model parameters describing the association between natural food folate intake and subsequent blood folate concentration. Seven controlled trials and 29 observational studies met the inclusion criteria. For the six studies using microbiologic assay (MA included in the meta-analysis, we estimate that a 6% (95% Credible Interval (CrI: 4%, 9% increase in red blood cell (RBC folate concentration and a 7% (95% CrI: 1%, 12% increase in serum/plasma folate concentration can occur for every 10% increase in natural food folate intake. Using modeled results, we estimate that a natural food folate intake of ≥450 μg dietary folate equivalents (DFE/day could achieve the lower bound of an RBC folate concentration (~1050 nmol/L associated with the lowest risk of a neural tube defect. Natural food folate intake affects blood folate concentration and adequate intakes could help women achieve a RBC folate concentration associated with a risk of 6 neural tube defects/10,000 live births.

Assessing the association between natural food folate intake and blood folate concentrations: a systematic review and Bayesian meta-analysis of trials and observational studies.

Science.gov (United States)

Marchetta, Claire M; Devine, Owen J; Crider, Krista S; Tsang, Becky L; Cordero, Amy M; Qi, Yan Ping; Guo, Jing; Berry, Robert J; Rosenthal, Jorge; Mulinare, Joseph; Mersereau, Patricia; Hamner, Heather C

2015-04-10

Folate is found naturally in foods or as synthetic folic acid in dietary supplements and fortified foods. Adequate periconceptional folic acid intake can prevent neural tube defects. Folate intake impacts blood folate concentration; however, the dose-response between natural food folate and blood folate concentrations has not been well described. We estimated this association among healthy females. A systematic literature review identified studies (1 1992-3 2014) with both natural food folate intake alone and blood folate concentration among females aged 12-49 years. Bayesian methods were used to estimate regression model parameters describing the association between natural food folate intake and subsequent blood folate concentration. Seven controlled trials and 29 observational studies met the inclusion criteria. For the six studies using microbiologic assay (MA) included in the meta-analysis, we estimate that a 6% (95% Credible Interval (CrI): 4%, 9%) increase in red blood cell (RBC) folate concentration and a 7% (95% CrI: 1%, 12%) increase in serum/plasma folate concentration can occur for every 10% increase in natural food folate intake. Using modeled results, we estimate that a natural food folate intake of ≥ 450 μg dietary folate equivalents (DFE)/day could achieve the lower bound of an RBC folate concentration (~ 1050 nmol/L) associated with the lowest risk of a neural tube defect. Natural food folate intake affects blood folate concentration and adequate intakes could help women achieve a RBC folate concentration associated with a risk of 6 neural tube defects/10,000 live births.

Association between Myocardial Infarction and Periodontitis: a Meta-Analysis of Case-Control Studies

Directory of Open Access Journals (Sweden)

Quan Shi

2016-11-01

Full Text Available AbstractBackground and Objective: Many clinical researches have been carried out to investigate the relationship between myocardial infarction (MI and periodontitis. Despite most of them indicated that the periodontitis may be associated with an increased risk of MI, the findings and study types of these studies have been inconsistent. The goal of this meta-analysis was to critically assess the strength of the association between MI and periodontitis in case-control studies.Methods: PubMed and the Cochrane Library were searched for eligible case-control studies reporting relevant parameters that compared periodontal status between MI and control subjects. The odds ratios (ORs and 95% confidence intervals (CIs from each study were pooled to estimate the strength of the association between MI and periodontitis. The mean differences and 95% CIs for periodontal-related parameters were calculated to determine their overall effects.Results: Seventeen studies including a total of 3456 MI patients and 3875 non-MI control subjects were included. The pooled OR for the association between MI and periodontitis was 2.531 (95% CI: 1.927-3.324. The mean differences (95% CIs for clinical attachment loss, probing depth, bleeding on probing, plaque index, and the number of missing teeth were 1.000 (0.726-1.247, 1.209 (0.538-1.880, 0.342 (0.129-0.555, 0.383 (0.205-0.560, and 4.122 (2.012-6.232, respectively. Conclusion: With the current evidence, the results support the presence of a significant association between MI and periodontitis. Moreover, MI patients had worse periodontal and oral hygiene status and fewer teeth than did control subjects. More high-quality and well-designed studies focusing on the casual relationship between MI and periodontitis should be conducted in the future.

Associations of advanced glycation end-products with cognitive functions in individuals with and without type 2 diabetes: the maastricht study.

Science.gov (United States)

Spauwen, P J J; van Eupen, M G A; Köhler, S; Stehouwer, C D A; Verhey, F R J; van der Kallen, C J H; Sep, S J S; Koster, A; Schaper, N C; Dagnelie, P C; Schalkwijk, C G; Schram, M T; van Boxtel, M P J

2015-03-01

Advanced glycation end-products (AGEs) are thought to be involved in the pathogenesis of Alzheimer's disease. AGEs are products resulting from nonenzymatic chemical reactions between reduced sugars and proteins, which accumulate during natural aging, and their accumulation is accelerated in hyperglycemic conditions such as type 2 diabetes mellitus. The objective of the study was to examine associations between AGEs and cognitive functions. This study was performed as part of the Maastricht Study, a population-based cohort study in which, by design, 215 participants (28.1%) had type 2 diabetes mellitus. We examined associations of skin autofluorescence (SAF) (n = 764), an overall estimate of skin AGEs, and specific plasma protein-bound AGEs (n = 781) with performance on tests for global cognitive functioning, information processing speed, verbal memory (immediate and delayed word recall), and response inhibition. After adjustment for demographics, diabetes, smoking, alcohol, waist circumference, total cholesterol/high-density lipoprotein cholesterol ratio, triglycerides, and lipid-lowering medication use, higher SAF was significantly associated with worse delayed word recall (regression coefficient, b = -0.44; P = .04), and response inhibition (b = 0.03; P = .04). After further adjustment for systolic blood pressure, cardiovascular disease, estimated glomerular filtration rate, and depression, associations were attenuated (delayed word recall, b = -0.38, P = .07; response inhibition, b = 0.02, P = .07). Higher pentosidine levels were associated with worse global cognitive functioning (b = -0.61; P = .04) after full adjustment, but other plasma AGEs were not. Associations did not differ between individuals with and without diabetes. We found inverse associations of SAF (a noninvasive marker for tissue AGEs) with cognitive performance, which were attenuated after adjustment for vascular risk factors and depression.

Higher freshwater fish and sea fish intake is inversely associated with colorectal cancer risk among Chinese population: a case-control study

OpenAIRE

Xu, Ming; Fang, Yu-Jing; Chen, Yu-Ming; Lu, Min-Shan; Pan, Zhi-Zhong; Yan, Bo; Zhong, Xiao; Zhang, Cai-Xia

2015-01-01

The association between specific fish intake and colorectal cancer risk remains controversial. This study aimed to examine the association between specific fish intake and colorectal cancer risk in Chinese population in a large case control study. During July 2010 to November 2014, 1189 eligible colorectal cancer cases and 1189 frequency-matched controls (age and sex) completed in-person interviews. A validated food frequency questionnaire was used to estimate dietary intake. Multivariate log...

A Generalized Estimating Equations Approach to Model Heterogeneity and Time Dependence in Capture-Recapture Studies

Directory of Open Access Journals (Sweden)

Akanda Md. Abdus Salam

2017-03-01

Full Text Available Individual heterogeneity in capture probabilities and time dependence are fundamentally important for estimating the closed animal population parameters in capture-recapture studies. A generalized estimating equations (GEE approach accounts for linear correlation among capture-recapture occasions, and individual heterogeneity in capture probabilities in a closed population capture-recapture individual heterogeneity and time variation model. The estimated capture probabilities are used to estimate animal population parameters. Two real data sets are used for illustrative purposes. A simulation study is carried out to assess the performance of the GEE estimator. A Quasi-Likelihood Information Criterion (QIC is applied for the selection of the best fitting model. This approach performs well when the estimated population parameters depend on the individual heterogeneity and the nature of linear correlation among capture-recapture occasions.

A nationwide study of the association between celiac disease and the risk of autistic spectrum disorders.

Science.gov (United States)

Ludvigsson, Jonas F; Reichenberg, Abraham; Hultman, Christina M; Murray, Joseph A

2013-11-01

Most case reports suggest an association between autistic spectrum disorders (ASDs) and celiac disease (CD) or positive CD serologic test results, but larger studies are contradictory. To examine the association between ASDs and CD according to small intestinal histopathologic findings. Nationwide case-control study in Sweden. Through 28 Swedish biopsy registers, we collected data about 26,995 individuals with CD (equal to villous atrophy, Marsh stage 3), 12,304 individuals with inflammation (Marsh stages 1-2), and 3719 individuals with normal mucosa (Marsh stage 0) but positive CD serologic test results (IgA/IgG gliadin, endomysium, or tissue transglutaminase) and compared them with 213,208 age- and sex-matched controls. Conditional logistic regression estimated odds ratios (ORs) for having a prior diagnosis of an ASD according to the Swedish National Patient Register. In another analysis, we used the Cox proportional hazards regression model to estimate hazard ratios (HRs) for future ASDs in individuals undergoing small intestinal biopsy. A prior ASD was not associated with CD (OR, 0.93; 95% CI, 0.51-1.68) or inflammation (OR 1.03; 95% CI, 0.40-2.64) but was associated with a markedly increased risk of having a normal mucosa but a positive CD serologic test result (OR, 4.57; 95% CI, 1.58-13.22). Restricting our data to individuals without a diagnosis of an ASD at the time of biopsy, CD (HR, 1.39; 95% CI, 1.13-1.71) and inflammation (HR, 2.01; 95% CI, 1.29-3.13) were both associated with moderate excess risks of later ASDs, whereas the HR for later ASDs in individuals with normal mucosa but positive CD serologic test results was 3.09 (95% CI, 1.99-4.80). Although this study found no association between CD or inflammation and earlier ASDs, there was a markedly increased risk of ASDs in individuals with normal mucosa but a positive CD serologic test result.

Estimates of global HIV/AIDS mortality, prevalence and incidence rates, and their association with the Human Development Index

OpenAIRE

Kamyar Mansori; Erfan Ayubi; Fatemeh Khosravi Shadmani; Shiva Mansouri Hanis; Somayeh Khazaei; Mohadeseh Sani; Yousef Moradi; Salman Khazaei; Abolfazl Mohammadbeigi

2017-01-01

Background: HIV/AIDS is one of greatest global public health concerns today due to the high incidence, prevalence and mortality rates. The aim of this research was investigate and estimate the global HIV/AIDS mortality, prevalence and incidence rates, and explore their associations with the Human Development Index. Methods: The global age-standardized rates of mortality, prevalence and incidence of HIV/AIDS were obtained from the UNAIDS for different countries in 2015. The human developm...

Impact of urine concentration adjustment method on associations between urine metals and estimated glomerular filtration rates (eGFR) in adolescents

International Nuclear Information System (INIS)

Weaver, Virginia M.; Vargas, Gonzalo García; Silbergeld, Ellen K.; Rothenberg, Stephen J.; Fadrowski, Jeffrey J.; Rubio-Andrade, Marisela; Parsons, Patrick J.; Steuerwald, Amy J.

2014-01-01

Positive associations between urine toxicant levels and measures of glomerular filtration rate (GFR) have been reported recently in a range of populations. The explanation for these associations, in a direction opposite that of traditional nephrotoxicity, is uncertain. Variation in associations by urine concentration adjustment approach has also been observed. Associations of urine cadmium, thallium and uranium in models of serum creatinine- and cystatin-C-based estimated GFR (eGFR) were examined using multiple linear regression in a cross-sectional study of adolescents residing near a lead smelter complex. Urine concentration adjustment approaches compared included urine creatinine, urine osmolality and no adjustment. Median age, blood lead and urine cadmium, thallium and uranium were 13.9 years, 4.0 μg/dL, 0.22, 0.27 and 0.04 g/g creatinine, respectively, in 512 adolescents. Urine cadmium and thallium were positively associated with serum creatinine-based eGFR only when urine creatinine was used to adjust for urine concentration (β coefficient=3.1 mL/min/1.73 m 2 ; 95% confidence interval=1.4, 4.8 per each doubling of urine cadmium). Weaker positive associations, also only with urine creatinine adjustment, were observed between these metals and serum cystatin-C-based eGFR and between urine uranium and serum creatinine-based eGFR. Additional research using non-creatinine-based methods of adjustment for urine concentration is necessary. - Highlights: • Positive associations between urine metals and creatinine-based eGFR are unexpected. • Optimal approach to urine concentration adjustment for urine biomarkers uncertain. • We compared urine concentration adjustment methods. • Positive associations observed only with urine creatinine adjustment. • Additional research using non-creatinine-based methods of adjustment needed

Impact of urine concentration adjustment method on associations between urine metals and estimated glomerular filtration rates (eGFR) in adolescents

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Weaver, Virginia M., E-mail: vweaver@jhsph.edu [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD (United States); Johns Hopkins University School of Medicine, Baltimore, MD (United States); Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD (United States); Vargas, Gonzalo García [Faculty of Medicine, University of Juárez of Durango State, Durango (Mexico); Secretaría de Salud del Estado de Coahuila, Coahuila, México (Mexico); Silbergeld, Ellen K. [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD (United States); Rothenberg, Stephen J. [Instituto Nacional de Salud Publica, Centro de Investigacion en Salud Poblacional, Cuernavaca, Morelos (Mexico); Fadrowski, Jeffrey J. [Johns Hopkins University School of Medicine, Baltimore, MD (United States); Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD (United States); Rubio-Andrade, Marisela [Faculty of Medicine, University of Juárez of Durango State, Durango (Mexico); Parsons, Patrick J. [Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY (United States); Department of Environmental Health Sciences, School of Public Health, University at Albany, Albany, NY (United States); Steuerwald, Amy J. [Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY (United States); and others

2014-07-15

Positive associations between urine toxicant levels and measures of glomerular filtration rate (GFR) have been reported recently in a range of populations. The explanation for these associations, in a direction opposite that of traditional nephrotoxicity, is uncertain. Variation in associations by urine concentration adjustment approach has also been observed. Associations of urine cadmium, thallium and uranium in models of serum creatinine- and cystatin-C-based estimated GFR (eGFR) were examined using multiple linear regression in a cross-sectional study of adolescents residing near a lead smelter complex. Urine concentration adjustment approaches compared included urine creatinine, urine osmolality and no adjustment. Median age, blood lead and urine cadmium, thallium and uranium were 13.9 years, 4.0 μg/dL, 0.22, 0.27 and 0.04 g/g creatinine, respectively, in 512 adolescents. Urine cadmium and thallium were positively associated with serum creatinine-based eGFR only when urine creatinine was used to adjust for urine concentration (β coefficient=3.1 mL/min/1.73 m{sup 2}; 95% confidence interval=1.4, 4.8 per each doubling of urine cadmium). Weaker positive associations, also only with urine creatinine adjustment, were observed between these metals and serum cystatin-C-based eGFR and between urine uranium and serum creatinine-based eGFR. Additional research using non-creatinine-based methods of adjustment for urine concentration is necessary. - Highlights: • Positive associations between urine metals and creatinine-based eGFR are unexpected. • Optimal approach to urine concentration adjustment for urine biomarkers uncertain. • We compared urine concentration adjustment methods. • Positive associations observed only with urine creatinine adjustment. • Additional research using non-creatinine-based methods of adjustment needed.

The association between physical activity and healthcare costs in children--results from the GINIplus and LISAplus cohort studies.

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Idler, Nadja; Teuner, Christina M; Hunger, Matthias; Holle, Rolf; Ortlieb, Sandra; Schulz, Holger; Bauer, Carl-Peter; Hoffmann, Ute; Koletzko, Sibylle; Lehmann, Irina; von Berg, Andrea; Berdel, Dietrich; Hoffmann, Barbara; Schaaf, Beate; Heinrich, Joachim; Wolfenstetter, Silke B

2015-04-29

Physical inactivity in children is an important risk factor for the development of various morbidities and mortality in adulthood, physical activity already has preventive effects during childhood. The objective of this study is to estimate the association between physical activity, healthcare utilization and costs in children. Cross-sectional data of 3356 children aged 9 to 12 years were taken from the 10-year follow-up of the birth cohort studies GINIplus and LISAplus, including information on healthcare utilization and physical activity given by parents via self-administered questionnaires. Using a bottom-up approach, direct costs due to healthcare utilization and indirect costs resulting from parental work absence were estimated for the base year 2007. A two-step regression model compared effects on healthcare utilization and costs for a higher (≥ 7 h/week) versus a lower (physical activity (MVPA) adjusted for age, gender, BMI, education and income of parents, single parenthood and study region. Recycled predictions estimated adjusted mean costs per child and activity group. The analyses for the association between physical activity, healthcare utilization and costs showed no statistically significant results. Different directions of estimates were noticeable throughout cost components in the first step as well as the second step of the regression model. For higher MVPA (≥ 7 h/week) compared with lower MVPA (physical activity on healthcare utilization and costs, as diseases attributable to lacking physical activity might first occur later in life. This underpins the importance of clarifying the long-term effects of physical activity as it may strengthen the promotion of physical activity in children from a health economic perspective.

New methods for estimating follow-up rates in cohort studies

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Xiaonan Xue

2017-12-01

Full Text Available Abstract Background The follow-up rate, a standard index of the completeness of follow-up, is important for assessing the validity of a cohort study. A common method for estimating the follow-up rate, the “Percentage Method”, defined as the fraction of all enrollees who developed the event of interest or had complete follow-up, can severely underestimate the degree of follow-up. Alternatively, the median follow-up time does not indicate the completeness of follow-up, and the reverse Kaplan-Meier based method and Clark’s Completeness Index (CCI also have limitations. Methods We propose a new definition for the follow-up rate, the Person-Time Follow-up Rate (PTFR, which is the observed person-time divided by total person-time assuming no dropouts. The PTFR cannot be calculated directly since the event times for dropouts are not observed. Therefore, two estimation methods are proposed: a formal person-time method (FPT in which the expected total follow-up time is calculated using the event rate estimated from the observed data, and a simplified person-time method (SPT that avoids estimation of the event rate by assigning full follow-up time to all events. Simulations were conducted to measure the accuracy of each method, and each method was applied to a prostate cancer recurrence study dataset. Results Simulation results showed that the FPT has the highest accuracy overall. In most situations, the computationally simpler SPT and CCI methods are only slightly biased. When applied to a retrospective cohort study of cancer recurrence, the FPT, CCI and SPT showed substantially greater 5-year follow-up than the Percentage Method (92%, 92% and 93% vs 68%. Conclusions The Person-time methods correct a systematic error in the standard Percentage Method for calculating follow-up rates. The easy to use SPT and CCI methods can be used in tandem to obtain an accurate and tight interval for PTFR. However, the FPT is recommended when event rates and

Population estimates of extended family structure and size.

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Garceau, Anne; Wideroff, Louise; McNeel, Timothy; Dunn, Marsha; Graubard, Barry I

2008-01-01

Population-based estimates of biological family size can be useful for planning genetic studies, assessing how distributions of relatives affect disease associations with family history and estimating prevalence of potential family support. Mean family size per person is estimated from a population-based telephone survey (n = 1,019). After multivariate adjustment for demographic variables, older and non-White respondents reported greater mean numbers of total, first- and second-degree relatives. Females reported more total and first-degree relatives, while less educated respondents reported more second-degree relatives. Demographic differences in family size have implications for genetic research. Therefore, periodic collection of family structure data in representative populations would be useful. Copyright 2008 S. Karger AG, Basel.

Genomewide association study of methane emissions in Angus beef cattle with validation in dairy cattle.

Science.gov (United States)

Manzanilla-Pech, C I V; De Haas, Y; Hayes, B J; Veerkamp, R F; Khansefid, M; Donoghue, K A; Arthur, P F; Pryce, J E

2016-10-01

Methane (CH) is a product of enteric fermentation in ruminants, and it represents around 17% of global CH emissions. There has been substantial effort from the livestock scientific community toward tools that can help reduce this percentage. One approach is to select for lower emitting animals. To achieve this, accurate genetic parameters and identification of the genomic basis of CH traits are required. Therefore, the objectives of this study were 1) to perform a genomewide association study to identify SNP associated with several CH traits in Angus beef cattle (1,020 animals) and validate them in a lactating Holstein population (population 1 [POP1]; 205 animals); 2) to validate significant SNP for DMI and weight at test (WT) from a second Holstein population, from a previous study (population 2 [POP2]; 903 animals), in an Angus population; and 3) to evaluate 2 different residual CH traits and determine if the genes associated with CH also control residual CH traits. Phenotypes calculated for the genotyped Angus population included CH production (MeP), CH yield (MeY), CH intensity (MI), DMI, and WT. The Holstein population (POP1) was multiparous, with phenotypes on CH traits (MeP, MeY, and MI) plus genotypes. Additionally, 2 CH traits, residual genetic CH (RGM) and residual phenotypic CH (RPM), were calculated by adjusting MeP for DMI and WT. Estimated heritabilities in the Angus population were 0.30, 0.19, and 0.15 for MeP, RGM, and RPM, respectively, and genetic correlations of MeP with DMI and WT were 0.83 and 0.80, respectively. Estimated heritabilities in Holstein POP1 were 0.23, 0.30, and 0.42 for MeP, MeY, and MI, respectively. Strong associations with MeP were found on chromosomes 4, 12, 14, 20, and 30 at Angus population, the number of significant SNP for MeP at Angus population was used to estimate genetic parameters for MeP and MeY in Holstein POP1, the genetic variance and, consequently, the heritability slightly increased, meaning that most of the

Global Estimates of Syphilis in Pregnancy and Associated Adverse Outcomes: Analysis of Multinational Antenatal Surveillance Data

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Newman, Lori; Kamb, Mary; Hawkes, Sarah; Gomez, Gabriela; Say, Lale; Seuc, Armando; Broutet, Nathalie

2013-01-01

Background The World Health Organization initiative to eliminate mother-to-child transmission of syphilis aims for ≥90% of pregnant women to be tested for syphilis and ≥90% to receive treatment by 2015. We calculated global and regional estimates of syphilis in pregnancy and associated adverse outcomes for 2008, as well as antenatal care (ANC) coverage for women with syphilis. Methods and Findings Estimates were based upon a health service delivery model. National syphilis seropositivity data from 97 of 193 countries and ANC coverage from 147 countries were obtained from World Health Organization databases. Proportions of adverse outcomes and effectiveness of screening and treatment were from published literature. Regional estimates of ANC syphilis testing and treatment were examined through sensitivity analysis. In 2008, approximately 1.36 million (range: 1.16 to 1.56 million) pregnant women globally were estimated to have probable active syphilis; of these, 80% had attended ANC. Globally, 520,905 (best case: 425,847; worst case: 615,963) adverse outcomes were estimated to be caused by maternal syphilis, including approximately 212,327 (174,938; 249,716) stillbirths (>28 wk) or early fetal deaths (22 to 28 wk), 91,764 (76,141; 107,397) neonatal deaths, 65,267 (56,929; 73,605) preterm or low birth weight infants, and 151,547 (117,848; 185,245) infected newborns. Approximately 66% of adverse outcomes occurred in ANC attendees who were not tested or were not treated for syphilis. In 2008, based on the middle case scenario, clinical services likely averted 26% of all adverse outcomes. Limitations include missing syphilis seropositivity data for many countries in Europe, the Mediterranean, and North America, and use of estimates for the proportion of syphilis that was “probable active,” and for testing and treatment coverage. Conclusions Syphilis continues to affect large numbers of pregnant women, causing substantial perinatal morbidity and mortality that

Reporting of HIV-infected pregnant women: estimates from a Brazilian study.

Science.gov (United States)

Domingues, Rosa Maria Soares Madeira; Saraceni, Valéria; Leal, Maria do Carmo

2018-01-01

To estimate the coverage of the reporting of cases of HIV-infected pregnant women, to estimate the increase in the coverage of the reporting with the routine search of data in other Brazilian health information systems, and to identify missed opportunities for identification of HIV-infected pregnant women in Brazilian maternity hospitals. This is a descriptive study on the linkage of Brazilian databases with primary data from the "Nascer no Brasil" study and secondary database collection from national health information systems. The "Nascer no Brasil" is a national-based study carried out in 2011-2012 with 23,894 pregnant women, which identified HIV-infected pregnant women using prenatal and medical records. We searched for cases of HIV-infected pregnant women identified in the "Nascer no Brasil" study in the Information System of Notifiable Diseases, the Control System for Laboratory Tests of the National CD4+/CD8+ Lymphocyte Count and HIV Viral Load Network, and the Logistics Control System for Medications. We used the OpenRecLink software for the linkage of databases. We estimated the notification coverage, with the respective confidence interval, of the evaluated Brazilian health information systems. We estimated the coverage of the reporting of HIV-infected pregnant women in the Information System of Notifiable Diseases as 57.1% (95%CI 42.9-70.2), and we located 89.3% of the HIV-infected pregnant women (95%CI 81.2-94.2) in some of the Brazilian health information systems researched. The search in other national health information systems would result in an increase of 57.1% of the reported cases. We identified no missed opportunities for the diagnosis of HIV+ in pregnant women in the maternity hospitals evaluated by the "Nascer no Brasil" study. The routine search for information in other Brazilian health information systems, a procedure carried out by the Ministry of Health for cases of AIDS in adults and children, should be adopted for cases of HIV in

Economic costs associated with moderate and late preterm birth: a prospective population-based study.