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Sample records for population-based lifetime modeling

  1. Lifetime sexual violence and childbirth expectations - A Norwegian population based cohort study.

    PubMed

    Henriksen, Lena; Schei, Berit; Lukasse, Mirjam

    2016-05-01

    this study aimed to explore the association between lifetime sexual violence and expectations about childbirth. Norwegian population-based cohort study. women presenting for routine ultrasound examinations were recruited to the Norwegian Mother and Child Cohort Study between 1999 and 2008. 78,660 pregnant women. sexual violence and expectations about childbirth were self-reported during pregnancy using postal questionnaires. Risk estimations were performed using multivariable logistic regression analysis and stratified by parity. fear of childbirth, the thoughts about pain relief, worries about the infant's health and looking forward to the arrival of the infant. of 78,660 women, 18.4% reported a history of sexual violence and 0.9% were exposed to sexual violence within the last 12 months, including during the current pregnancy. We found that nulliparous women who reported previous or recent sexual violence had a decrease in the odds of looking forward to the arrival of the infant with an AOR of 0.8 (95% CI 0.7-0.9) and 0.4 (95% CI 0.3-0.6), respectively, compared to non-abused women. The same pattern was observed among multiparous women and they were more likely to report worries about the infant's health. Severe sexual violence (rape) was associated with concerns about childbirth, especially for nulliparous women that were more likely to express fear of birth, a hope for a pain-free birth, a desire for caesarean section and worries about the infant's health than non-exposed women. women with a lifetime exposure to sexual violence, both past experiences and within the last 12 months, were less likely to look forward to the arrival of the infant than non-exposed women, and they were more likely to worry about the infant's health. Women with experiences of severe sexual violence (rape) had more concerns about childbirth than women without this experience. This finding shows that exploring women's attitudes toward childbirth may work as an approach when examining

  2. Occupational self-coding and automatic recording (OSCAR): a novel web-based tool to collect and code lifetime job histories in large population-based studies.

    PubMed

    De Matteis, Sara; Jarvis, Deborah; Young, Heather; Young, Alan; Allen, Naomi; Potts, James; Darnton, Andrew; Rushton, Lesley; Cullinan, Paul

    2017-03-01

    Objectives The standard approach to the assessment of occupational exposures is through the manual collection and coding of job histories. This method is time-consuming and costly and makes it potentially unfeasible to perform high quality analyses on occupational exposures in large population-based studies. Our aim was to develop a novel, efficient web-based tool to collect and code lifetime job histories in the UK Biobank, a population-based cohort of over 500 000 participants. Methods We developed OSCAR (occupations self-coding automatic recording) based on the hierarchical structure of the UK Standard Occupational Classification (SOC) 2000, which allows individuals to collect and automatically code their lifetime job histories via a simple decision-tree model. Participants were asked to find each of their jobs by selecting appropriate job categories until they identified their job title, which was linked to a hidden 4-digit SOC code. For each occupation a job title in free text was also collected to estimate Cohen's kappa (κ) inter-rater agreement between SOC codes assigned by OSCAR and an expert manual coder. Results OSCAR was administered to 324 653 UK Biobank participants with an existing email address between June and September 2015. Complete 4-digit SOC-coded lifetime job histories were collected for 108 784 participants (response rate: 34%). Agreement between the 4-digit SOC codes assigned by OSCAR and the manual coder for a random sample of 400 job titles was moderately good [κ=0.45, 95% confidence interval (95% CI) 0.42-0.49], and improved when broader job categories were considered (κ=0.64, 95% CI 0.61-0.69 at a 1-digit SOC-code level). Conclusions OSCAR is a novel, efficient, and reasonably reliable web-based tool for collecting and automatically coding lifetime job histories in large population-based studies. Further application in other research projects for external validation purposes is warranted.

  3. Lifetime exposure to arsenic in drinking water and bladder cancer: a population-based case–control study in Michigan, USA

    PubMed Central

    Slotnick, Melissa J.; AvRuskin, Gillian A.; Schottenfeld, David; Jacquez, Geoffrey M.; Wilson, Mark L.; Goovaerts, Pierre; Franzblau, Alfred; Nriagu, Jerome O.

    2014-01-01

    Objective Arsenic in drinking water has been linked with the risk of urinary bladder cancer, but the dose–response relationships for arsenic exposures below 100 µg/L remain equivocal. We conducted a population-based case–control study in southeastern Michigan, USA, where approximately 230,000 people were exposed to arsenic concentrations between 10 and 100 µg/L. Methods This study included 411 bladder cancer cases diagnosed between 2000 and 2004, and 566 controls recruited during the same period. Individual lifetime exposure profiles were reconstructed, and residential water source histories, water consumption practices, and water arsenic measurements or modeled estimates were determined at all residences. Arsenic exposure was estimated for 99% of participants’ person-years. Results Overall, an increase in bladder cancer risk was not found for time-weighted average lifetime arsenic exposure >10 µg/L when compared with a reference group exposed to <1 µg/L (odds ratio (OR) = 1.10; 95% confidence interval (CI): 0.65, 1.86). Among ever-smokers, risks from arsenic exposure >10 µg/L were similarly not elevated when compared to the reference group (OR = 0.94; 95% CI: 0.50, 1.78). Conclusions We did not find persuasive evidence of an association between low-level arsenic exposure and bladder cancer. Selecting the appropriate exposure metric needs to be thoughtfully considered when investigating risk from low-level arsenic exposure. PMID:20084543

  4. Adult lifetime alcohol consumption and invasive epithelial ovarian cancer risk in a population-based case-control study.

    PubMed

    Cook, Linda S; Leung, Andy C Y; Swenerton, Kenneth; Gallagher, Richard P; Magliocco, Anthony; Steed, Helen; Koebel, Martin; Nation, Jill; Eshragh, Sima; Brooks-Wilson, Angela; Le, Nhu D

    2016-02-01

    Meta-analyses report a null association between recent alcohol consumption and ovarian cancer risk. However, because few studies investigated different types of alcohol over adult ages, we investigated adult lifetime and type (beer, wine, spirits) of consumption and risk. Consumption after age 20years was ascertained in 1144 invasive epithelial ovarian cancer cases and 2513 controls in a population-based case-control study (Alberta and British Columbia, Canada, 2001-2012). Non-drinkers consumed any types of alcohol <12 times per year on average. Logistic regression was use to estimate adjusted odds ratios [aOR] and 95% confidence intervals [CIs]. Wine consumption was associated with a risk reduction (aOR=0.67, 95% CI: 0.50-0.88) relative to non-drinkers, but not beer (aOR=1.06, 95% CI: 0.71-1.58) or spirits (aOR=0.98, 95% CI: 0.69-1.39). The reduced risk was stronger for exclusive red wine drinkers (aOR=0.44, 95% CI: 0.19-0.92) than white wine drinkers (aOR=0.79, 95% CI: 0.46-1.34), although most women drank both types of wine. Risk decreased with increasing cumulative consumption of any wine (P-trend<0.05) and was evident for the serous histotype. Wine consumption initiated prior to age 50 was associated with a risk reduction (e.g., at 40-49years, aOR=0.58, 95% CI: 0.42-0.78), but not drinking initiated after 50years of age. For any type, level, or age at initiation of alcohol consumption, we found no increased risks. For the moderate consumption in this study, higher levels of wine consumption were generally associated with risk reductions; reductions may be stronger for red wine. Our results suggest that alcohol consumption that is guideline concordant will not increase epithelial ovarian cancer risk. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Implications from Under-reporting at Lifetime, Death Certificate Notifications and Trace-back on the Recorded Incidence of a "Newly" Established Population-based Cancer Registry.

    PubMed

    Holleczek, B; Brenner, H

    2016-01-01

    Population-based cancer registries (CRs) are powerful tools for measuring cancer burden and progress against cancer. The study's objective was to investigate the effects of under-reporting at lifetime, death certificate notifications, and trace-back on the incidence a newly established population-based CR may record during its initial 15 years of operation. Using cancer data of nine CRs of the SEER programme we performed model calculations to investigate temporal trends of the recorded incidence that might be expected if registration started in 1995 with gradually increasing proportions of cancers reported to the CR. It was assumed that the CR obtains all death certificates providing cancer as the underlying cause of death. Different scenarios with regard to the development of the proportions of cancers reported to the CR and the use of trace-back were evaluated. Our model calculations demonstrated that the inclusion of cancers notified from death certificates which were diagnosed prior to the start of registration and which attribute to the incidence estimates of the year of death ('prevalent' cases) may compensate under-reporting typically observed right after the start of a CR. The recorded incidence may even be overestimated during the first years of registration, if large amounts of prevalent cancers are notified from death certificates (e.g. overestimation of lung cancer incidence by 8% and 21% in the first year of registration, if the proportions of cases reported were 50% and 70% in that year, overestimation of myeloma incidence still exceeding 5% after eight years of registration, if the proportion of cases reported to the CR had reached 97.5% after six years). Trace-back may effectively reduce the recorded surplus cancer cases. During the initial years of registration, the inclusion of prevalent cancers from death certificates may compensate the higher amount of underreporting right after the start of a CR. Accurate incidence estimates may nevertheless be

  6. Modelling lifetime data with multivariate Tweedie distribution

    NASA Astrophysics Data System (ADS)

    Nor, Siti Rohani Mohd; Yusof, Fadhilah; Bahar, Arifah

    2017-05-01

    This study aims to measure the dependence between individual lifetimes by applying multivariate Tweedie distribution to the lifetime data. Dependence between lifetimes incorporated in the mortality model is a new form of idea that gives significant impact on the risk of the annuity portfolio which is actually against the idea of standard actuarial methods that assumes independent between lifetimes. Hence, this paper applies Tweedie family distribution to the portfolio of lifetimes to induce the dependence between lives. Tweedie distribution is chosen since it contains symmetric and non-symmetric, as well as light-tailed and heavy-tailed distributions. Parameter estimation is modified in order to fit the Tweedie distribution to the data. This procedure is developed by using method of moments. In addition, the comparison stage is made to check for the adequacy between the observed mortality and expected mortality. Finally, the importance of including systematic mortality risk in the model is justified by the Pearson's chi-squared test.

  7. Remaining Lifetime After Recognition of Terminal Illness Depends on Diagnosis: A Nationwide Population-Based Cohort Study.

    PubMed

    Bell, Cathrine; Nielsen, Mette K; Neergaard, Mette A; Guldin, Mai-Britt; Jensen, Anders B

    2017-01-01

    Timely recognition of the terminal phase of life will benefit patients and caregivers as it may facilitate advance care planning and support. The objective of this study was to investigate the remaining lifetime of patients entering a physician-assessed terminal phase and to analyze variation in remaining lifetime according to diagnosis and sociodemographic factors. Danish National Health Registers were used to establish a prospective cohort of adult patients formally registered with drug reimbursement due to terminal illness in 2012 and followed until June 2014. Of the 11,062 included patients, the median remaining lifetime was 55 days and 37% of the patients died within the first month. The majority suffered from cancer (89%). Patients with a noncancer disease had the shortest remaining lifetime (17 days), considerably shorter than patients with cancer (59 days). Patients with prostate cancer had the longest remaining lifetime (76 days), whereas those with hematologic cancer had the shortest among cancer patients (41 days). Compared with lung cancer patients, the probability of death within 30 days were higher for patients with noncancer disease and lower for those with prostate or colorectal cancer. Male gender and high age were associated with higher risk of dying within 30 days. This study found a median remaining lifetime of 55 days after recognition of terminal illness. Remaining lifetime differed between cancer and noncancer patients and according to age and gender. Increased attention should be directed toward timely recognition of the transition into the terminal phase, especially for patients with noncancer disease. Copyright © 2016 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

  8. Development and validation of a new population-based simulation model of osteoarthritis in New Zealand.

    PubMed

    Wilson, R; Abbott, J H

    2018-04-01

    To describe the construction and preliminary validation of a new population-based microsimulation model developed to analyse the health and economic burden and cost-effectiveness of treatments for knee osteoarthritis (OA) in New Zealand (NZ). We developed the New Zealand Management of Osteoarthritis (NZ-MOA) model, a discrete-time state-transition microsimulation model of the natural history of radiographic knee OA. In this article, we report on the model structure, derivation of input data, validation of baseline model parameters against external data sources, and validation of model outputs by comparison of the predicted population health loss with previous estimates. The NZ-MOA model simulates both the structural progression of radiographic knee OA and the stochastic development of multiple disease symptoms. Input parameters were sourced from NZ population-based data where possible, and from international sources where NZ-specific data were not available. The predicted distributions of structural OA severity and health utility detriments associated with OA were externally validated against other sources of evidence, and uncertainty resulting from key input parameters was quantified. The resulting lifetime and current population health-loss burden was consistent with estimates of previous studies. The new NZ-MOA model provides reliable estimates of the health loss associated with knee OA in the NZ population. The model structure is suitable for analysis of the effects of a range of potential treatments, and will be used in future work to evaluate the cost-effectiveness of recommended interventions within the NZ healthcare system. Copyright © 2018 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  9. Reduced memory and attention performance in a population-based sample of young adults with a moderate lifetime use of cannabis, ecstasy and alcohol.

    PubMed

    Indlekofer, F; Piechatzek, M; Daamen, M; Glasmacher, C; Lieb, R; Pfister, H; Tucha, O; Lange, K W; Wittchen, H U; Schütz, C G

    2009-07-01

    reaction time was found. The results are consistent with decrements of memory and attentional performance described in previous studies. These effects are relatively small; however, it must be kept in mind that this study focussed on assessing young adults with moderate drug use from a population-based study.

  10. POPULATION-BASED EXPOSURE MODELING FOR AIR POLLUTANTS AT EPA'S NATIONAL EXPOSURE RESEARCH LABORATORY

    EPA Science Inventory

    The US EPA's National Exposure Research Laboratory (NERL) has been developing, applying, and evaluating population-based exposure models to improve our understanding of the variability in personal exposure to air pollutants. Estimates of population variability are needed for E...

  11. Heuristic Modeling for TRMM Lifetime Predictions

    NASA Technical Reports Server (NTRS)

    Jordan, P. S.; Sharer, P. J.; DeFazio, R. L.

    1996-01-01

    Analysis time for computing the expected mission lifetimes of proposed frequently maneuvering, tightly altitude constrained, Earth orbiting spacecraft have been significantly reduced by means of a heuristic modeling method implemented in a commercial-off-the-shelf spreadsheet product (QuattroPro) running on a personal computer (PC). The method uses a look-up table to estimate the maneuver frequency per month as a function of the spacecraft ballistic coefficient and the solar flux index, then computes the associated fuel use by a simple engine model. Maneuver frequency data points are produced by means of a single 1-month run of traditional mission analysis software for each of the 12 to 25 data points required for the table. As the data point computations are required only a mission design start-up and on the occasion of significant mission redesigns, the dependence on time consuming traditional modeling methods is dramatically reduced. Results to date have agreed with traditional methods to within 1 to 1.5 percent. The spreadsheet approach is applicable to a wide variety of Earth orbiting spacecraft with tight altitude constraints. It will be particularly useful to such missions as the Tropical Rainfall Measurement Mission scheduled for launch in 1997, whose mission lifetime calculations are heavily dependent on frequently revised solar flux predictions.

  12. Estimating and modeling the cure fraction in population-based cancer survival analysis.

    PubMed

    Lambert, Paul C; Thompson, John R; Weston, Claire L; Dickman, Paul W

    2007-07-01

    In population-based cancer studies, cure is said to occur when the mortality (hazard) rate in the diseased group of individuals returns to the same level as that expected in the general population. The cure fraction (the proportion of patients cured of disease) is of interest to patients and is a useful measure to monitor trends in survival of curable disease. There are 2 main types of cure fraction model, the mixture cure fraction model and the non-mixture cure fraction model, with most previous work concentrating on the mixture cure fraction model. In this paper, we extend the parametric non-mixture cure fraction model to incorporate background mortality, thus providing estimates of the cure fraction in population-based cancer studies. We compare the estimates of relative survival and the cure fraction between the 2 types of model and also investigate the importance of modeling the ancillary parameters in the selected parametric distribution for both types of model.

  13. Probabilistic estimation of residential air exchange rates for population-based human exposure modeling

    EPA Science Inventory

    Residential air exchange rates (AERs) are a key determinant in the infiltration of ambient air pollution indoors. Population-based human exposure models using probabilistic approaches to estimate personal exposure to air pollutants have relied on input distributions from AER meas...

  14. Socioeconomic status during lifetime and cognitive impairment no-dementia in late life: the population-based aging in the Chianti Area (InCHIANTI) Study.

    PubMed

    Marengoni, Alessandra; Fratiglioni, Laura; Bandinelli, Stefania; Ferrucci, Luigi

    2011-01-01

    Thousand and twelve dementia-free elderly (60–98 years old) enrolled in the InChianti Study (Italy) were evaluated at baseline (1998–2000) and at 3-year follow-up (2001–2003) with the aim of analyzing the association of lifetime socioeconomic status (SES) with prevalent and incident cognitive impairment no-dementia (CIND). SES was defined from information on formal education, longest held occupation, and financial conditions through life. CIND was defined as age-adjusted Mini-Mental State Examination score one standard deviation below the baseline mean score of participants without dementia. Logistic regression and Cox proportional-hazards models were used to estimate the association of SES with CIND. Demographics,occupation characteristics (i.e., job stress and physical demand), cardiovascular diseases, diabetes, apolipoprotein E (APOE)genotype, smoking, alcohol consumption, depressive symptoms, and C-reactive protein were considered potential confounders.Prevalence of CIND was 17.7%. In the fully adjusted model, low education (OR = 2.1; 95% confidence intervals, CI = 1.4 to 3.2)was associated with prevalent CIND. Incidence rate of CIND was 66.0 per 1000 person-years. Low education (HR = 1.7; 95% CI = 1.04 to 2.6) and manual occupation (HR = 1.9; 95% CI = 1.0 to 3.6) were associated with incident CIND. Among covariates,high job-related physical demand was associated with both prevalent and incident CIND (OR = 1.6; 95% CI = 1.1 to 2.4 and HR= 1.5; 95% CI = 1.0 to 2.3). After stratification for education, manual occupation was still associated with CIND among participants with high education (HR = 2.2; 95% CI = 1.2 to 4.3 versus HR= 1.4; 95% CI = 0.2 to 10.4 among those with low education). Proxy markers of lifetime SES (low education, manual occupation and high physical demand) are cross-sectional correlates of CIND and predict incident CIND over a three-year follow-up.

  15. Lifetime risk of renal replacement therapy in Europe: a population-based study using data from the ERA-EDTA Registry.

    PubMed

    van den Brand, Jan A J G; Pippias, Maria; Stel, Vianda S; Caskey, Fergus J; Collart, Frederic; Finne, Partik; Heaf, James; Jais, Jean-Philippe; Kramar, Reinhard; Massy, Ziad A; De Meester, Johan; Traynor, Jamie P; Reisæter, Anna Varberg; Wetzels, Jack F M; Jager, Kitty J

    2017-02-01

    Upcoming KDIGO guidelines for the evaluation of living kidney donors are expected to move towards a personal risk-based evaluation of potential donors. We present the age and sex-specific lifetime risk of renal replacement therapy (RRT) for end-stage renal disease in 10 European countries. We defined lifetime risk of RRT as the cumulative incidence of RRT up to age 90 years. We obtained RRT incidence rates per million population by 5-year age groups and sex using data from the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry, and used these to estimate the cumulative incidence of RRT, adjusting for competing mortality risk. Lifetime risk of RRT varied from 0.44% to 2.05% at age 20 years and from 0.17% to 1.59% at age 70 years across countries, and was twice as high in men as in women. Lifetime RRT risk decreased with age, ranging from an average of 0.77% to 0.44% in 20- to- 70-year-old women, and from 1.45% to 0.96% in 20- to- 70-year-old men. The lifetime risk of RRT increased slightly over the past decade, more so in men than in women. However, it appears to have stabilized or even decreased slightly in more recent years. The lifetime risk of RRT decreased with age, was lower in women as compared with men of equal age and varied considerably throughout Europe. Given the substantial differences in lifetime risk of RRT between the USA and Europe, country-specific estimates should be used in the evaluation and communication of the risk of RRT for potential living kidney donors. © The Author 2016. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  16. Lifetime occupational exposure to metals and welding fumes, and risk of glioma: a 7-country population-based case-control study.

    PubMed

    Parent, Marie-Elise; Turner, Michelle C; Lavoué, Jérôme; Richard, Hugues; Figuerola, Jordi; Kincl, Laurel; Richardson, Lesley; Benke, Geza; Blettner, Maria; Fleming, Sarah; Hours, Martine; Krewski, Daniel; McLean, David; Sadetzki, Siegal; Schlaefer, Klaus; Schlehofer, Brigitte; Schüz, Joachim; Siemiatycki, Jack; van Tongeren, Martie; Cardis, Elisabeth

    2017-08-25

    Brain tumor etiology is poorly understood. Based on their ability to pass through the blood-brain barrier, it has been hypothesized that exposure to metals may increase the risk of brain cancer. Results from the few epidemiological studies on this issue are limited and inconsistent. We investigated the relationship between glioma risk and occupational exposure to five metals - lead, cadmium, nickel, chromium and iron- as well as to welding fumes, using data from the seven-country INTEROCC study. A total of 1800 incident glioma cases and 5160 controls aged 30-69 years were included in the analysis. Lifetime occupational exposure to the agents was assessed using the INTEROCC JEM, a modified version of the Finnish job exposure matrix FINJEM. In general, cases had a slightly higher prevalence of exposure to the various metals and welding fumes than did controls, with the prevalence among ever exposed ranging between 1.7 and 2.2% for cadmium to 10.2 and 13.6% for iron among controls and cases, respectively. However, in multivariable logistic regression analyses, there was no association between ever exposure to any of the agents and risk of glioma with odds ratios (95% confidence intervals) ranging from 0.8 (0.7-1.0) for lead to 1.1 (0.7-1.6) for cadmium. Results were consistent across models considering cumulative exposure or duration, as well as in all sensitivity analyses conducted. Findings from this large-scale international study provide no evidence for an association between occupational exposure to any of the metals under scrutiny or welding fumes, and risk of glioma.

  17. Population-based prevention of eating disorders: an application of the Rose prevention model.

    PubMed

    Austin, S B

    2001-03-01

    Several decades of concerted research on eating disorders have generated a broad range of proposed causal influences, but much of this etiologic research does not elucidate practical avenues for preventive interventions. Translating etiologic theory into community health interventions depends on the identification of key leverage points, factors that are amenable to public health intervention and provide an opportunity to maximize impact on the outcome of interest. Population-based preventive strategies, elaborated by epidemiologist Geoffrey Rose, can maximize the impact of public health interventions. In the case of eating disorders, Rose's model is instructive: Dieting stands out as risk behavior that may both fit Rose's model well and be a key leverage point for preventive intervention. Grounded in Rose's work, this article lodges a theoretical argument for the population-based prevention of eating disorders. In the introductory section, existing research on the epidemiology of dieting is reviewed, showing that it is extremely common among adolescent girls and women and that the behavior has been implicated as a causal factor for disordered eating. Next, new evidence is offered to build a case for how a population-wide reduction in dieting may be an effective strategy for prevention of eating pathology. Finally Rose's prevention framework is used to introduce a unique and provocative perspective on the prevention of eating disorders. Dieting is a normative behavior in our culture with psychological and physiological effects in the causal chain leading to eating pathology. This behavior may represent an ideal target for population-based prevention. Theoretical and empirical evidence suggests that a population-wide reduction in dieting may be a justifiable and effective strategy for prevention of eating pathology. Copyright 2001 American Health Foundation and Academic Press.

  18. The lifetime cost of spinal cord injury in Ontario, Canada: A population-based study from the perspective of the public health care payer.

    PubMed

    Chan, Brian Chun-Fai; Cadarette, Suzanne M; Wodchis, Walter P; Krahn, Murray D; Mittmann, Nicole

    2018-06-20

    To determine the publicly funded health care system lifetime cost-of-illness of spinal cord injury (SCI) from the perspective of the Ontario Ministry of Health and Long-term Care. Individuals hospitalized for their first SCI between the years 2005 and 2011 were identified and their health care costs were calculated using Ontario administrative health care data. From this information, lifetime costs were estimated using phase-based costing methods. The spinal cord injured cohort was matched to a non-spinal cord injured using propensity score matching. Net costs were determined by calculating the difference in costs between the two matched groups. Net costs were also presented for subgroups stratified by demographic characteristics. A total of 1,716 individuals with SCI were identified and matched in our study. The net lifetime cost of SCI was $336,000 per person. Much of the costs were observed in the first year post-SCI. The lifetime cost of SCI for individuals with a concurrent pressure ulcer at the initial hospitalization rises to $479,600. Costs were also higher for individuals with cervical or thoracic injury or requiring inpatient rehabilitation. Spinal cord injury is a substantial burden to the health care system. Our results are limited to the direct health care costs from the publicly funded health care payer perspective. Further analysis with a broader perspective is needed to understand the full economic impact of this catastrophic condition.

  19. Empirical membrane lifetime model for heavy duty fuel cell systems

    NASA Astrophysics Data System (ADS)

    Macauley, Natalia; Watson, Mark; Lauritzen, Michael; Knights, Shanna; Wang, G. Gary; Kjeang, Erik

    2016-12-01

    Heavy duty fuel cells used in transportation system applications such as transit buses expose the fuel cell membranes to conditions that can lead to lifetime-limiting membrane failure via combined chemical and mechanical degradation. Highly durable membranes and reliable predictive models are therefore needed in order to achieve the ultimate heavy duty fuel cell lifetime target of 25,000 h. In the present work, an empirical membrane lifetime model was developed based on laboratory data from a suite of accelerated membrane durability tests. The model considers the effects of cell voltage, temperature, oxygen concentration, humidity cycling, humidity level, and platinum in the membrane using inverse power law and exponential relationships within the framework of a general log-linear Weibull life-stress statistical distribution. The obtained model is capable of extrapolating the membrane lifetime from accelerated test conditions to use level conditions during field operation. Based on typical conditions for the Whistler, British Columbia fuel cell transit bus fleet, the model predicts a stack lifetime of 17,500 h and a membrane leak initiation time of 9200 h. Validation performed with the aid of a field operated stack confirmed the initial goal of the model to predict membrane lifetime within 20% of the actual operating time.

  20. Lifetime and 12-month prevalence of eating disorders amongst women in mid-life: a population-based study of diagnoses and risk factors.

    PubMed

    Micali, Nadia; Martini, Maria G; Thomas, Jennifer J; Eddy, Kamryn T; Kothari, Radha; Russell, Ellie; Bulik, Cynthia M; Treasure, Janet

    2017-01-17

    Eating disorders (EDs) are common amongst women; however, no research has specifically investigated the lifetime/12-month prevalence of eating disorders amongst women in mid-life (i.e., fourth and fifth decade of life) and the relevant longitudinal risk factors. We aimed to investigate the lifetime and 12-month prevalence of EDs and lifetime health service use and to identify childhood, parenting, and personality risk factors. This is a two-phase prevalence study, nested within an existing longitudinal community-based sample of women in mid-life. A total of 5658 women from the UK Avon Longitudinal Study of Parents and Children (ALSPAC; enrolled 20 years earlier) participated. ED diagnoses were obtained using validated structured interviews. Weighted analyses were carried out accounting for the two-phase methodology to obtain prevalence figures and to carry out risk factor regression analyses. By mid-life, 15.3% (95% confidence intervals, 13.5-17.4%) of women had met criteria for a lifetime ED. The 12-month prevalence of EDs was 3.6%. Childhood sexual abuse was prospectively associated with all binge/purge type disorders and an external locus of control was associated with binge-eating disorder. Better maternal care was protective for bulimia nervosa. Childhood life events and interpersonal sensitivity were associated with all EDs. By mid-life a significant proportion of women will experience an ED, and few women accessed healthcare. Active EDs are common in mid-life, both due to new onset and chronic disorders. Increased awareness of the full spectrum of EDs in this stage of life and adequate service provision is important. This is the first study to investigate childhood and personality risk factors for full threshold and sub-threshold EDs and to identify common predictors for full and sub-threshold EDs. Further research should clarify the role of preventable risk factors on both full and sub-threshold EDs.

  1. Scalable Entity-Based Modeling of Population-Based Systems, Final LDRD Report

    SciTech Connect

    Cleary, A J; Smith, S G; Vassilevska, T K

    2005-01-27

    The goal of this project has been to develop tools, capabilities and expertise in the modeling of complex population-based systems via scalable entity-based modeling (EBM). Our initial focal application domain has been the dynamics of large populations exposed to disease-causing agents, a topic of interest to the Department of Homeland Security in the context of bioterrorism. In the academic community, discrete simulation technology based on individual entities has shown initial success, but the technology has not been scaled to the problem sizes or computational resources of LLNL. Our developmental emphasis has been on the extension of this technology to parallelmore » computers and maturation of the technology from an academic to a lab setting.« less

  2. Measurements and modeling of charge carrier lifetime in compressed xenon

    NASA Astrophysics Data System (ADS)

    Pudov, A. O.; Abyzov, A. S.; Sokolov, S. A.; Davydov, L. N.; Rybka, A. V.; Kutny, V. E.; Melnikov, S. I.; Kholomyeyev, G. A.; Leonov, S. A.; Turchin, A. A.

    2018-06-01

    Gamma-spectrometers based on high-pressure xenon gas (HPXe) are proving themselves as a great potential alternative to the spectrometers based on high-purity germanium crystals and scintillators. The working medium for the high-resolution HPXe detectors, that is, xenon gas compressed up to pressure ∼50 bar and sometimes doped with hydrogen, methane or others gases, needs to be of very high purity. The gas purity level can be determined by direct measurements or, alternatively, its usability in gamma-spectrometers can be evaluated indirectly through the charge carrier (electron) lifetime measurements. Different approaches and specific setups have been used for the lifetime determination, most of those methods involve the measurement and analyses of individual pulses from ionizing particles registered in an ionization chamber filled with Xe. In the present paper, we report on the HPXe electron lifetime study carried out by using measurements in a cylindrical ionization chamber and the respective analytical charge transport model. Our results support the possibility of carrier lifetime determination in the cylindrical configuration. In addition, the voltage regimes for the use of the chamber in the spectroscopic mode were determined. The measurements were conducted in a two-electrode configuration for a range of pressure values (5 to 50 bar) for the Xe+0.25%H2 gas mixture of ∼6N purity. It is shown that in gases with relatively high values of the electron drift velocity and the electron lifetime, for example low-density gases, the charge collection time measurements can give significantly underestimated lifetime assessment. On the other hand, for the low drift velocity gases, they give much more accurate results. With the use of the analytical model, the electron lifetime was determined more precisely.

  3. Remaining lifetime modeling using State-of-Health estimation

    NASA Astrophysics Data System (ADS)

    Beganovic, Nejra; Söffker, Dirk

    2017-08-01

    Technical systems and system's components undergo gradual degradation over time. Continuous degradation occurred in system is reflected in decreased system's reliability and unavoidably lead to a system failure. Therefore, continuous evaluation of State-of-Health (SoH) is inevitable to provide at least predefined lifetime of the system defined by manufacturer, or even better, to extend the lifetime given by manufacturer. However, precondition for lifetime extension is accurate estimation of SoH as well as the estimation and prediction of Remaining Useful Lifetime (RUL). For this purpose, lifetime models describing the relation between system/component degradation and consumed lifetime have to be established. In this contribution modeling and selection of suitable lifetime models from database based on current SoH conditions are discussed. Main contribution of this paper is the development of new modeling strategies capable to describe complex relations between measurable system variables, related system degradation, and RUL. Two approaches with accompanying advantages and disadvantages are introduced and compared. Both approaches are capable to model stochastic aging processes of a system by simultaneous adaption of RUL models to current SoH. The first approach requires a priori knowledge about aging processes in the system and accurate estimation of SoH. An estimation of SoH here is conditioned by tracking actual accumulated damage into the system, so that particular model parameters are defined according to a priori known assumptions about system's aging. Prediction accuracy in this case is highly dependent on accurate estimation of SoH but includes high number of degrees of freedom. The second approach in this contribution does not require a priori knowledge about system's aging as particular model parameters are defined in accordance to multi-objective optimization procedure. Prediction accuracy of this model does not highly depend on estimated SoH. This model

  4. Measuring and modeling the lifetime of nitrous oxide including its variability: NITROUS OXIDE AND ITS CHANGING LIFETIME

    DOE PAGES

    Prather, Michael J.; Hsu, Juno; DeLuca, Nicole M.; ...

    2015-06-05

    The lifetime of nitrous oxide, the third‐most‐important human‐emitted greenhouse gas, is based to date primarily on model studies or scaling to other gases. This work calculates a semiempirical lifetime based on Microwave Limb Sounder satellite measurements of stratospheric profiles of nitrous oxide, ozone, and temperature; laboratory cross‐section data for ozone and molecular oxygen plus kinetics for O(1D); the observed solar spectrum; and a simple radiative transfer model. The result is 116 ± 9 years. The observed monthly‐to‐biennial variations in lifetime and tropical abundance are well matched by four independent chemistry‐transport models driven by reanalysis meteorological fields for the period of observation (2005–2010), butmore » all these models overestimate the lifetime due to lower abundances in the critical loss region near 32 km in the tropics. These models plus a chemistry‐climate model agree on the nitrous oxide feedback factor on its own lifetime of 0.94 ± 0.01, giving N2O perturbations an effective residence time of 109 years. Combining this new empirical lifetime with model estimates of residence time and preindustrial lifetime (123 years) adjusts our best estimates of the human‐natural balance of emissions today and improves the accuracy of projected nitrous oxide increases over this century.« less

  5. Physically based DC lifetime model for lead zirconate titanate films

    NASA Astrophysics Data System (ADS)

    Garten, Lauren M.; Hagiwara, Manabu; Ko, Song Won; Trolier-McKinstry, Susan

    2017-09-01

    Accurate lifetime predictions for Pb(Zr0.52Ti0.48)O3 thin films are critical for a number of applications, but current reliability models are not consistent with the resistance degradation mechanisms in lead zirconate titanate. In this work, the reliability and lifetime of chemical solution deposited (CSD) and sputtered Pb(Zr0.52Ti0.48)O3 thin films are characterized using highly accelerated lifetime testing (HALT) and leakage current-voltage (I-V) measurements. Temperature dependent HALT results and impedance spectroscopy show activation energies of approximately 1.2 eV for the CSD films and 0.6 eV for the sputtered films. The voltage dependent HALT results are consistent with previous reports, but do not clearly indicate what causes device failure. To understand more about the underlying physical mechanisms leading to degradation, the I-V data are fit to known conduction mechanisms, with Schottky emission having the best-fit and realistic extracted material parameters. Using the Schottky emission equation as a base, a unique model is developed to predict the lifetime under highly accelerated testing conditions based on the physical mechanisms of degradation.

  6. Calculating excess lifetime risk in relative risk models.

    PubMed

    Vaeth, M; Pierce, D A

    1990-07-01

    When assessing the impact of radiation exposure it is common practice to present the final conclusions in terms of excess lifetime cancer risk in a population exposed to a given dose. The present investigation is mainly a methodological study focusing on some of the major issues and uncertainties involved in calculating such excess lifetime risks and related risk projection methods. The age-constant relative risk model used in the recent analyses of the cancer mortality that was observed in the follow-up of the cohort of A-bomb survivors in Hiroshima and Nagasaki is used to describe the effect of the exposure on the cancer mortality. In this type of model the excess relative risk is constant in age-at-risk, but depends on the age-at-exposure. Calculation of excess lifetime risks usually requires rather complicated life-table computations. In this paper we propose a simple approximation to the excess lifetime risk; the validity of the approximation for low levels of exposure is justified empirically as well as theoretically. This approximation provides important guidance in understanding the influence of the various factors involved in risk projections. Among the further topics considered are the influence of a latent period, the additional problems involved in calculations of site-specific excess lifetime cancer risks, the consequences of a leveling off or a plateau in the excess relative risk, and the uncertainties involved in transferring results from one population to another. The main part of this study relates to the situation with a single, instantaneous exposure, but a brief discussion is also given of the problem with a continuous exposure at a low-dose rate.

  7. Calculating excess lifetime risk in relative risk models.

    PubMed Central

    Vaeth, M; Pierce, D A

    1990-01-01

    When assessing the impact of radiation exposure it is common practice to present the final conclusions in terms of excess lifetime cancer risk in a population exposed to a given dose. The present investigation is mainly a methodological study focusing on some of the major issues and uncertainties involved in calculating such excess lifetime risks and related risk projection methods. The age-constant relative risk model used in the recent analyses of the cancer mortality that was observed in the follow-up of the cohort of A-bomb survivors in Hiroshima and Nagasaki is used to describe the effect of the exposure on the cancer mortality. In this type of model the excess relative risk is constant in age-at-risk, but depends on the age-at-exposure. Calculation of excess lifetime risks usually requires rather complicated life-table computations. In this paper we propose a simple approximation to the excess lifetime risk; the validity of the approximation for low levels of exposure is justified empirically as well as theoretically. This approximation provides important guidance in understanding the influence of the various factors involved in risk projections. Among the further topics considered are the influence of a latent period, the additional problems involved in calculations of site-specific excess lifetime cancer risks, the consequences of a leveling off or a plateau in the excess relative risk, and the uncertainties involved in transferring results from one population to another. The main part of this study relates to the situation with a single, instantaneous exposure, but a brief discussion is also given of the problem with a continuous exposure at a low-dose rate. PMID:2269245

  8. Classification of customer lifetime value models using Markov chain

    NASA Astrophysics Data System (ADS)

    Permana, Dony; Pasaribu, Udjianna S.; Indratno, Sapto W.; Suprayogi

    2017-10-01

    A firm’s potential reward in future time from a customer can be determined by customer lifetime value (CLV). There are some mathematic methods to calculate it. One method is using Markov chain stochastic model. Here, a customer is assumed through some states. Transition inter the states follow Markovian properties. If we are given some states for a customer and the relationships inter states, then we can make some Markov models to describe the properties of the customer. As Markov models, CLV is defined as a vector contains CLV for a customer in the first state. In this paper we make a classification of Markov Models to calculate CLV. Start from two states of customer model, we make develop in many states models. The development a model is based on weaknesses in previous model. Some last models can be expected to describe how real characters of customers in a firm.

  9. Policy evaluation in diabetes prevention and treatment using a population-based macro simulation model: the MICADO model.

    PubMed

    van der Heijden, A A W A; Feenstra, T L; Hoogenveen, R T; Niessen, L W; de Bruijne, M C; Dekker, J M; Baan, C A; Nijpels, G

    2015-12-01

    To test a simulation model, the MICADO model, for estimating the long-term effects of interventions in people with and without diabetes. The MICADO model includes micro- and macrovascular diseases in relation to their risk factors. The strengths of this model are its population scope and the possibility to assess parameter uncertainty using probabilistic sensitivity analyses. Outcomes include incidence and prevalence of complications, quality of life, costs and cost-effectiveness. We externally validated MICADO's estimates of micro- and macrovascular complications in a Dutch cohort with diabetes (n = 498,400) by comparing these estimates with national and international empirical data. For the annual number of people undergoing amputations, MICADO's estimate was 592 (95% interquantile range 291-842), which compared well with the registered number of people with diabetes-related amputations in the Netherlands (728). The incidence of end-stage renal disease estimated using the MICADO model was 247 people (95% interquartile range 120-363), which was also similar to the registered incidence in the Netherlands (277 people). MICADO performed well in the validation of macrovascular outcomes of population-based cohorts, while it had more difficulty in reflecting a highly selected trial population. Validation by comparison with independent empirical data showed that the MICADO model simulates the natural course of diabetes and its micro- and macrovascular complications well. As a population-based model, MICADO can be applied for projections as well as scenario analyses to evaluate the long-term (cost-)effectiveness of population-level interventions targeting diabetes and its complications in the Netherlands or similar countries. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

  10. A Constitutive Model for Creep Lifetime of PBO Braided Cord

    NASA Technical Reports Server (NTRS)

    Sterling, W. J.

    2007-01-01

    A constitutive model to describe the creep lifetime of PBO braided cord has been developed and fit to laboratory data. The model follows an approach proposed for p-aramid cord in similar applications, and has a Boltzman-type representation that arises from consideration of the failure phenomenon mechanism. The data were obtained using a hydraulic-type universal testing machine, and were analyzed according to Weibull statistics using commercially-available software. The application of concern to the author is NASA's Ultra- Long Duration Balloon and other gossamer spacecraft, but the motivations for the related p-aramid works suggest broader interest.

  11. Lifetime pharmacokinetic model for hydrophobic contaminants in marine mammals

    SciTech Connect

    Hickie, B.E.; Mackay, D.; Koning, J. de

    1999-11-01

    A physiologically based pharmacokinetic model is developed that describes the uptake and release of a hydrophobic organic chemical by a marine mammal over its entire lifetime, i.e., from birth to death. This model is applied to polychlorinated biphenyls (PCBs) in the beluga whale (Delphinapterus leucas). The processes treated are growth; uptake from food, milk, and air; disposition of the chemical among arterial and venous blood, liver, muscle, blubber, and rapidly perfused tissues; and losses by metabolism, release in exhaled air; and by egestion. A separate model is developed for females, which includes pregnancy, birth, and lactation. Food consumption is deducedmore » from size, growth, and from activity-dependent bioenergetic data. The results obtained by simulating continuous PCB exposure over a 30-year period are in accordance with reported concentrations and show the importance of milk transfer to both mother and progeny and the tendency for continued accumulation over the animal's lifetime. Implications of the results are discussed, especially the need for improved data on diets, gut absorption characteristics, and various physiological parameters used in the model.« less

  12. Estimating and modelling cure in population-based cancer studies within the framework of flexible parametric survival models.

    PubMed

    Andersson, Therese M L; Dickman, Paul W; Eloranta, Sandra; Lambert, Paul C

    2011-06-22

    When the mortality among a cancer patient group returns to the same level as in the general population, that is, the patients no longer experience excess mortality, the patients still alive are considered "statistically cured". Cure models can be used to estimate the cure proportion as well as the survival function of the "uncured". One limitation of parametric cure models is that the functional form of the survival of the "uncured" has to be specified. It can sometimes be hard to find a survival function flexible enough to fit the observed data, for example, when there is high excess hazard within a few months from diagnosis, which is common among older age groups. This has led to the exclusion of older age groups in population-based cancer studies using cure models. Here we have extended the flexible parametric survival model to incorporate cure as a special case to estimate the cure proportion and the survival of the "uncured". Flexible parametric survival models use splines to model the underlying hazard function, and therefore no parametric distribution has to be specified. We have compared the fit from standard cure models to our flexible cure model, using data on colon cancer patients in Finland. This new method gives similar results to a standard cure model, when it is reliable, and better fit when the standard cure model gives biased estimates. Cure models within the framework of flexible parametric models enables cure modelling when standard models give biased estimates. These flexible cure models enable inclusion of older age groups and can give stage-specific estimates, which is not always possible from parametric cure models. © 2011 Andersson et al; licensee BioMed Central Ltd.

  13. Estimating and modelling cure in population-based cancer studies within the framework of flexible parametric survival models

    PubMed Central

    2011-01-01

    Background When the mortality among a cancer patient group returns to the same level as in the general population, that is, the patients no longer experience excess mortality, the patients still alive are considered "statistically cured". Cure models can be used to estimate the cure proportion as well as the survival function of the "uncured". One limitation of parametric cure models is that the functional form of the survival of the "uncured" has to be specified. It can sometimes be hard to find a survival function flexible enough to fit the observed data, for example, when there is high excess hazard within a few months from diagnosis, which is common among older age groups. This has led to the exclusion of older age groups in population-based cancer studies using cure models. Methods Here we have extended the flexible parametric survival model to incorporate cure as a special case to estimate the cure proportion and the survival of the "uncured". Flexible parametric survival models use splines to model the underlying hazard function, and therefore no parametric distribution has to be specified. Results We have compared the fit from standard cure models to our flexible cure model, using data on colon cancer patients in Finland. This new method gives similar results to a standard cure model, when it is reliable, and better fit when the standard cure model gives biased estimates. Conclusions Cure models within the framework of flexible parametric models enables cure modelling when standard models give biased estimates. These flexible cure models enable inclusion of older age groups and can give stage-specific estimates, which is not always possible from parametric cure models. PMID:21696598

  14. LCP- LIFETIME COST AND PERFORMANCE MODEL FOR DISTRIBUTED PHOTOVOLTAIC SYSTEMS

    NASA Technical Reports Server (NTRS)

    Borden, C. S.

    1994-01-01

    The Lifetime Cost and Performance (LCP) Model was developed to assist in the assessment of Photovoltaic (PV) system design options. LCP is a simulation of the performance, cost, and revenue streams associated with distributed PV power systems. LCP provides the user with substantial flexibility in specifying the technical and economic environment of the PV application. User-specified input parameters are available to describe PV system characteristics, site climatic conditions, utility purchase and sellback rate structures, discount and escalation rates, construction timing, and lifetime of the system. Such details as PV array orientation and tilt angle, PV module and balance-of-system performance attributes, and the mode of utility interconnection are user-specified. LCP assumes that the distributed PV system is utility grid interactive without dedicated electrical storage. In combination with a suitable economic model, LCP can provide an estimate of the expected net present worth of a PV system to the owner, as compared to electricity purchased from a utility grid. Similarly, LCP might be used to perform sensitivity analyses to identify those PV system parameters having significant impact on net worth. The user describes the PV system configuration to LCP via the basic electrical components. The module is the smallest entity in the PV system which is modeled. A PV module is defined in the simulation by its short circuit current, which varies over the system lifetime due to degradation and failure. Modules are wired in series to form a branch circuit. Bypass diodes are allowed between modules in the branch circuits. Branch circuits are then connected in parallel to form a bus. A collection of buses is connected in parallel to form an increment to capacity of the system. By choosing the appropriate series-parallel wiring design, the user can specify the current, voltage, and reliability characteristics of the system. LCP simulation of system performance is site

  15. Atmospheric drag model calibrations for spacecraft lifetime prediction

    NASA Technical Reports Server (NTRS)

    Binebrink, A. L.; Radomski, M. S.; Samii, M. V.

    1989-01-01

    Although solar activity prediction uncertainty normally dominates decay prediction error budget for near-Earth spacecraft, the effect of drag force modeling errors for given levels of solar activity needs to be considered. Two atmospheric density models, the modified Harris-Priester model and the Jacchia-Roberts model, to reproduce the decay histories of the Solar Mesosphere Explorer (SME) and Solar Maximum Mission (SMM) spacecraft in the 490- to 540-kilometer altitude range were analyzed. Historical solar activity data were used in the input to the density computations. For each spacecraft and atmospheric model, a drag scaling adjustment factor was determined for a high-solar-activity year, such that the observed annual decay in the mean semimajor axis was reproduced by an averaged variation-of-parameters (VOP) orbit propagation. The SME (SMM) calibration was performed using calendar year 1983 (1982). The resulting calibration factors differ by 20 to 40 percent from the predictions of the prelaunch ballistic coefficients. The orbit propagations for each spacecraft were extended to the middle of 1988 using the calibrated drag models. For the Jaccia-Roberts density model, the observed decay in the mean semimajor axis of SME (SMM) over the 4.5-year (5.5-year) predictive period was reproduced to within 1.5 (4.4) percent. The corresponding figure for the Harris-Priester model was 8.6 (20.6) percent. Detailed results and conclusions regarding the importance of accurate drag force modeling for lifetime predictions are presented.

  16. Determinants of political trust: a lifetime learning model.

    PubMed

    Schoon, Ingrid; Cheng, Helen

    2011-05-01

    This article addresses questions regarding the origins of individual variations in political trust. Using 2 prospective longitudinal studies, we examine the associations between family background, general cognitive ability (g) and school motivation at early age, educational and occupational attainment in adulthood, and political trust measured in early and mid-adulthood in 2 large representative samples of the British population born in 1958 (N = 8,804) and in 1970 (N = 7,194). A lifetime learning model of political trust is tested using structural equation modeling to map the pathways linking early experiences to adult outcomes. Results show that political trust is shaped by both early and later experiences with institutions in society. Individuals who have accumulated more socioeconomic, educational, and motivational resources throughout their life course express higher levels of political trust than do those with fewer resources. (c) 2011 APA, all rights reserved.

  17. How are population-based funding formulae for healthcare composed? A comparative analysis of seven models.

    PubMed

    Penno, Erin; Gauld, Robin; Audas, Rick

    2013-11-08

    Population-based funding formulae act as an important means of promoting equitable health funding structures. To evaluate how policy makers in different jurisdictions construct health funding formulae and build an understanding of contextual influences underpinning formula construction we carried out a comparative analysis of key components of funding formulae across seven high-income and predominantly publically financed health systems: New Zealand, England, Scotland, the Netherlands, the state of New South Wales in Australia, the Canadian province of Ontario, and the city of Stockholm, Sweden. Core components from each formula were summarised and key similarities and differences evaluated from a compositional perspective. We categorised approaches to constructing funding formulae under three main themes: identifying factors which predict differential need amongst populations; adjusting for cost factors outside of needs factors; and engaging in normative correction of allocations for 'unmet' need. We found significant congruence in the factors used to guide need and cost adjustments. However, there is considerable variation in interpretation and implementation of these factors. Despite broadly similar frameworks, there are distinct differences in the composition of the formulae across the seven health systems. Ultimately, the development of funding formulae is a dynamic process, subject to availability of data reflecting health needs, the influence of wider socio-political objectives and health system determinants.

  18. The demand control model and circadian saliva cortisol variations in a Swedish population based sample (The PART study)

    PubMed Central

    Alderling, Magnus; Theorell, Töres; de la Torre, Bartolomé; Lundberg, Ingvar

    2006-01-01

    Background Previous studies of the relationship between job strain and blood or saliva cortisol levels have been small and based on selected occupational groups. Our aim was to examine the association between job strain and saliva cortisol levels in a population-based study in which a number of potential confounders could be adjusted for. Methods The material derives from a population-based study in Stockholm on mental health and its potential determinants. Two data collections were performed three years apart with more than 8500 subjects responding to a questionnaire in both waves. In this paper our analyses are based on 529 individuals who held a job, participated in both waves as well as in an interview linked to the second wave. They gave saliva samples at awakening, half an hour later, at lunchtime and before going to bed on a weekday in close connection with the interview. Job control and job demands were assessed from the questionnaire in the second wave. Mixed models were used to analyse the association between the demand control model and saliva cortisol. Results Women in low strain jobs (high control and low demands) had significantly lower cortisol levels half an hour after awakening than women in high strain (low control and high demands), active (high control and high demands) or passive jobs (low control and low demands). There were no significant differences between the groups during other parts of the day and furthermore there was no difference between the job strain, active and passive groups. For men, no differences were found between demand control groups. Conclusion This population-based study, on a relatively large sample, weakly support the hypothesis that the demand control model is associated with saliva cortisol concentrations. PMID:17129377

  19. [Prediction of schistosomiasis infection rates of population based on ARIMA-NARNN model].

    PubMed

    Ke-Wei, Wang; Yu, Wu; Jin-Ping, Li; Yu-Yu, Jiang

    2016-07-12

    To explore the effect of the autoregressive integrated moving average model-nonlinear auto-regressive neural network (ARIMA-NARNN) model on predicting schistosomiasis infection rates of population. The ARIMA model, NARNN model and ARIMA-NARNN model were established based on monthly schistosomiasis infection rates from January 2005 to February 2015 in Jiangsu Province, China. The fitting and prediction performances of the three models were compared. Compared to the ARIMA model and NARNN model, the mean square error (MSE), mean absolute error (MAE) and mean absolute percentage error (MAPE) of the ARIMA-NARNN model were the least with the values of 0.011 1, 0.090 0 and 0.282 4, respectively. The ARIMA-NARNN model could effectively fit and predict schistosomiasis infection rates of population, which might have a great application value for the prevention and control of schistosomiasis.

  20. Simulation of population-based commuter exposure to NO₂ using different air pollution models.

    PubMed

    Ragettli, Martina S; Tsai, Ming-Yi; Braun-Fahrländer, Charlotte; de Nazelle, Audrey; Schindler, Christian; Ineichen, Alex; Ducret-Stich, Regina E; Perez, Laura; Probst-Hensch, Nicole; Künzli, Nino; Phuleria, Harish C

    2014-05-12

    We simulated commuter routes and long-term exposure to traffic-related air pollution during commute in a representative population sample in Basel (Switzerland), and evaluated three air pollution models with different spatial resolution for estimating commute exposures to nitrogen dioxide (NO2) as a marker of long-term exposure to traffic-related air pollution. Our approach includes spatially and temporally resolved data on actual commuter routes, travel modes and three air pollution models. Annual mean NO2 commuter exposures were similar between models. However, we found more within-city and within-subject variability in annual mean (±SD) NO2 commuter exposure with a high resolution dispersion model (40 ± 7 µg m(-3), range: 21-61) than with a dispersion model with a lower resolution (39 ± 5 µg m(-3); range: 24-51), and a land use regression model (41 ± 5 µg m(-3); range: 24-54). Highest median cumulative exposures were calculated along motorized transport and bicycle routes, and the lowest for walking. For estimating commuter exposure within a city and being interested also in small-scale variability between roads, a model with a high resolution is recommended. For larger scale epidemiological health assessment studies, models with a coarser spatial resolution are likely sufficient, especially when study areas include suburban and rural areas.

  1. Simulation of Population-Based Commuter Exposure to NO2 Using Different Air Pollution Models

    PubMed Central

    Ragettli, Martina S.; Tsai, Ming-Yi; Braun-Fahrländer, Charlotte; de Nazelle, Audrey; Schindler, Christian; Ineichen, Alex; Ducret-Stich, Regina E.; Perez, Laura; Probst-Hensch, Nicole; Künzli, Nino; Phuleria, Harish C.

    2014-01-01

    We simulated commuter routes and long-term exposure to traffic-related air pollution during commute in a representative population sample in Basel (Switzerland), and evaluated three air pollution models with different spatial resolution for estimating commute exposures to nitrogen dioxide (NO2) as a marker of long-term exposure to traffic-related air pollution. Our approach includes spatially and temporally resolved data on actual commuter routes, travel modes and three air pollution models. Annual mean NO2 commuter exposures were similar between models. However, we found more within-city and within-subject variability in annual mean (±SD) NO2 commuter exposure with a high resolution dispersion model (40 ± 7 µg m−3, range: 21–61) than with a dispersion model with a lower resolution (39 ± 5 µg m−3; range: 24–51), and a land use regression model (41 ± 5 µg m−3; range: 24–54). Highest median cumulative exposures were calculated along motorized transport and bicycle routes, and the lowest for walking. For estimating commuter exposure within a city and being interested also in small-scale variability between roads, a model with a high resolution is recommended. For larger scale epidemiological health assessment studies, models with a coarser spatial resolution are likely sufficient, especially when study areas include suburban and rural areas. PMID:24823664

  2. Quality of asthma care under different primary care models in Canada: a population-based study.

    PubMed

    To, Teresa; Guan, Jun; Zhu, Jingqin; Lougheed, M Diane; Kaplan, Alan; Tamari, Itamar; Stanbrook, Matthew B; Simatovic, Jacqueline; Feldman, Laura; Gershon, Andrea S

    2015-02-14

    Previous research has shown variations in quality of care and patient outcomes under different primary care models. The objective of this study was to use previously validated, evidence-based performance indicators to measure quality of asthma care over time and to compare quality of care between different primary care models. Data were obtained for years 2006 to 2010 from the Ontario Asthma Surveillance Information System, which uses health administrative databases to track individuals with asthma living in the province of Ontario, Canada. Individuals with asthma (n=1,813,922) were divided into groups based on the practice model of their primary care provider (i.e., fee-for-service, blended fee-for-service, blended capitation). Quality of asthma care was measured using six validated, evidence-based asthma care performance indicators. All of the asthma performance indicators improved over time within each of the primary care models. Compared to the traditional fee-for-service model, the blended fee-for-service and blended capitation models had higher use of spirometry for asthma diagnosis and monitoring, higher rates of inhaled corticosteroid prescription, and lower outpatient claims. Emergency department visits were lowest in the blended fee-for-service group. Quality of asthma care improved over time within each of the primary care models. However, the amount by which they improved differed between the models. The newer primary care models (i.e., blended fee-for-service, blended capitation) appear to provide better quality of asthma care compared to the traditional fee-for-service model.

  3. A population-based model for priority setting across the care continuum and across modalities

    PubMed Central

    Segal, Leonie; Mortimer, Duncan

    2006-01-01

    Background The Health-sector Wide (HsW) priority setting model is designed to shift the focus of priority setting away from 'program budgets' – that are typically defined by modality or disease-stage – and towards well-defined target populations with a particular disease/health problem. Methods The key features of the HsW model are i) a disease/health problem framework, ii) a sequential approach to covering the entire health sector, iii) comprehensiveness of scope in identifying intervention options and iv) the use of objective evidence. The HsW model redefines the unit of analysis over which priorities are set to include all mutually exclusive and complementary interventions for the prevention and treatment of each disease/health problem under consideration. The HsW model is therefore incompatible with the fragmented approach to priority setting across multiple program budgets that currently characterises allocation in many health systems. The HsW model employs standard cost-utility analyses and decision-rules with the aim of maximising QALYs contingent upon the global budget constraint for the set of diseases/health problems under consideration. It is recognised that the objective function may include non-health arguments that would imply a departure from simple QALY maximisation and that political constraints frequently limit degrees of freedom. In addressing these broader considerations, the HsW model can be modified to maximise value-weighted QALYs contingent upon the global budget constraint and any political constraints bearing upon allocation decisions. Results The HsW model has been applied in several contexts, recently to osteoarthritis, that has demonstrated both its practical application and its capacity to derive clear evidenced-based policy recommendations. Conclusion Comparisons with other approaches to priority setting, such as Programme Budgeting and Marginal Analysis (PBMA) and modality-based cost-effectiveness comparisons, as typified by

  4. Development of a paediatric population-based model of the pharmacokinetics of rivaroxaban.

    PubMed

    Willmann, Stefan; Becker, Corina; Burghaus, Rolf; Coboeken, Katrin; Edginton, Andrea; Lippert, Jörg; Siegmund, Hans-Ulrich; Thelen, Kirstin; Mück, Wolfgang

    2014-01-01

    Venous thromboembolism has been increasingly recognised as a clinical problem in the paediatric population. Guideline recommendations for antithrombotic therapy in paediatric patients are based mainly on extrapolation from adult clinical trial data, owing to the limited number of clinical trials in paediatric populations. The oral, direct Factor Xa inhibitor rivaroxaban has been approved in adult patients for several thromboembolic disorders, and its well-defined pharmacokinetic and pharmacodynamic characteristics and efficacy and safety profiles in adults warrant further investigation of this agent in the paediatric population. The objective of this study was to develop and qualify a physiologically based pharmacokinetic (PBPK) model for rivaroxaban doses of 10 and 20 mg in adults and to scale this model to the paediatric population (0-18 years) to inform the dosing regimen for a clinical study of rivaroxaban in paediatric patients. Experimental data sets from phase I studies supported the development and qualification of an adult PBPK model. This adult PBPK model was then scaled to the paediatric population by including anthropometric and physiological information, age-dependent clearance and age-dependent protein binding. The pharmacokinetic properties of rivaroxaban in virtual populations of children were simulated for two body weight-related dosing regimens equivalent to 10 and 20 mg once daily in adults. The quality of the model was judged by means of a visual predictive check. Subsequently, paediatric simulations of the area under the plasma concentration-time curve (AUC), maximum (peak) plasma drug concentration (C max) and concentration in plasma after 24 h (C 24h) were compared with the adult reference simulations. Simulations for AUC, C max and C 24h throughout the investigated age range largely overlapped with values obtained for the corresponding dose in the adult reference simulation for both body weight-related dosing regimens. However

  5. Peristomal Skin Complications Are Common, Expensive, and Difficult to Manage: A Population Based Cost Modeling Study

    PubMed Central

    Meisner, Søren; Lehur, Paul-Antoine; Moran, Brendan; Martins, Lina; Jemec, Gregor Borut Ernst

    2012-01-01

    Background Peristomal skin complications (PSCs) are the most common post-operative complications following creation of a stoma. Living with a stoma is a challenge, not only for the patient and their carers, but also for society as a whole. Due to methodological problems of PSC assessment, the associated health-economic burden of medium to longterm complications has been poorly described. Aim The aim of the present study was to create a model to estimate treatment costs of PSCs using the standardized assessment Ostomy Skin Tool as a reference. The resultant model was applied to a real-life global data set of stoma patients (n = 3017) to determine the prevalence and financial burden of PSCs. Methods Eleven experienced stoma care nurses were interviewed to get a global understanding of a treatment algorithm that formed the basis of the cost analysis. The estimated costs were based on a seven week treatment period. PSC costs were estimated for five underlying diagnostic categories and three levels of severity. The estimated treatment costs of severe cases of PSCs were increased 2–5 fold for the different diagnostic categories of PSCs compared with mild cases. French unit costs were applied to the global data set. Results The estimated total average cost for a seven week treatment period (including appliances and accessories) was 263€ for those with PSCs (n = 1742) compared to 215€ for those without PSCs (n = 1172). A co-variance analysis showed that leakage level had a significant impact on PSC cost from ‘rarely/never’ to ‘always/often’ p<0.00001 and from ‘rarely/never’ to ‘sometimes’ p = 0.0115. Conclusion PSCs are common and troublesome and the consequences are substantial, both for the patient and from a health economic viewpoint. PSCs should be diagnosed and treated at an early stage to prevent long term, debilitating and expensive complications. PMID:22679479

  6. Adjusting for overdispersion in piecewise exponential regression models to estimate excess mortality rate in population-based research.

    PubMed

    Luque-Fernandez, Miguel Angel; Belot, Aurélien; Quaresma, Manuela; Maringe, Camille; Coleman, Michel P; Rachet, Bernard

    2016-10-01

    In population-based cancer research, piecewise exponential regression models are used to derive adjusted estimates of excess mortality due to cancer using the Poisson generalized linear modelling framework. However, the assumption that the conditional mean and variance of the rate parameter given the set of covariates x i are equal is strong and may fail to account for overdispersion given the variability of the rate parameter (the variance exceeds the mean). Using an empirical example, we aimed to describe simple methods to test and correct for overdispersion. We used a regression-based score test for overdispersion under the relative survival framework and proposed different approaches to correct for overdispersion including a quasi-likelihood, robust standard errors estimation, negative binomial regression and flexible piecewise modelling. All piecewise exponential regression models showed the presence of significant inherent overdispersion (p-value <0.001). However, the flexible piecewise exponential model showed the smallest overdispersion parameter (3.2 versus 21.3) for non-flexible piecewise exponential models. We showed that there were no major differences between methods. However, using a flexible piecewise regression modelling, with either a quasi-likelihood or robust standard errors, was the best approach as it deals with both, overdispersion due to model misspecification and true or inherent overdispersion.

  7. Analysis of amyotrophic lateral sclerosis as a multistep process: a population-based modelling study.

    PubMed

    Al-Chalabi, Ammar; Calvo, Andrea; Chio, Adriano; Colville, Shuna; Ellis, Cathy M; Hardiman, Orla; Heverin, Mark; Howard, Robin S; Huisman, Mark H B; Keren, Noa; Leigh, P Nigel; Mazzini, Letizia; Mora, Gabriele; Orrell, Richard W; Rooney, James; Scott, Kirsten M; Scotton, William J; Seelen, Meinie; Shaw, Christopher E; Sidle, Katie S; Swingler, Robert; Tsuda, Miho; Veldink, Jan H; Visser, Anne E; van den Berg, Leonard H; Pearce, Neil

    2014-11-01

    Amyotrophic lateral sclerosis shares characteristics with some cancers, such as onset being more common in later life, progression usually being rapid, the disease affecting a particular cell type, and showing complex inheritance. We used a model originally applied to cancer epidemiology to investigate the hypothesis that amyotrophic lateral sclerosis is a multistep process. We generated incidence data by age and sex from amyotrophic lateral sclerosis population registers in Ireland (registration dates 1995-2012), the Netherlands (2006-12), Italy (1995-2004), Scotland (1989-98), and England (2002-09), and calculated age and sex-adjusted incidences for each register. We regressed the log of age-specific incidence against the log of age with least squares regression. We did the analyses within each register, and also did a combined analysis, adjusting for register. We identified 6274 cases of amyotrophic lateral sclerosis from a catchment population of about 34 million people. We noted a linear relationship between log incidence and log age in all five registers: England r(2)=0·95, Ireland r(2)=0·99, Italy r(2)=0·95, the Netherlands r(2)=0·99, and Scotland r(2)=0·97; overall r(2)=0·99. All five registers gave similar estimates of the linear slope ranging from 4·5 to 5·1, with overlapping confidence intervals. The combination of all five registers gave an overall slope of 4·8 (95% CI 4·5-5·0), with similar estimates for men (4·6, 4·3-4·9) and women (5·0, 4·5-5·5). A linear relationship between the log incidence and log age of onset of amyotrophic lateral sclerosis is consistent with a multistage model of disease. The slope estimate suggests that amyotrophic lateral sclerosis is a six-step process. Identification of these steps could lead to preventive and therapeutic avenues. UK Medical Research Council; UK Economic and Social Research Council; Ireland Health Research Board; The Netherlands Organisation for Health Research and Development (ZonMw); the

  8. Public Preferences Regarding Informed Consent Models for Participation in Population-based Genomic Research

    PubMed Central

    Platt, Jodyn; Bollinger, Juli; Dvoskin, Rachel; Kardia, Sharon LR; Kaufman, David

    2013-01-01

    Purpose Some large population biobanks that house biospecimens and health information for research seek broad consent from participants, while others re-consent for specific new studies. Understanding research participants’ attitudes and preferences about broad and narrow consent may improve recruitment, retention, and public support. Methods An online survey was conducted among a representative sample of 4,659 US adults to examine relationships between consent preferences and demographic factors, beliefs about privacy, the value of research, and the perceived trustworthiness of researchers. Results Participants preferred broad consent (52%) over study-by-study consent models (48%). Higher preferences for study-by-study consent observed among Black non-Hispanic respondents, and respondents with lower income and education were explained by differences in the prevalence of one or more beliefs about the study. Respondents with fears about research and those that would feel respected if asked for permission for each research use preferred study-by-study consent. Preference for broad consent was related to the desire not to be bothered with multiple requests and the belief that the study could lead to improved treatments, cures, and lives saved. Conclusion These data suggest that support for broad consent is contingent on sufficient information about data use. Work with research participants and community leaders to understand, respond to, and influence opinions about a given, ongoing study may improve uptake of broad consent. PMID:23660530

  9. Modeling of BN Lifetime Prediction of a System Based on Integrated Multi-Level Information

    PubMed Central

    Wang, Xiaohong; Wang, Lizhi

    2017-01-01

    Predicting system lifetime is important to ensure safe and reliable operation of products, which requires integrated modeling based on multi-level, multi-sensor information. However, lifetime characteristics of equipment in a system are different and failure mechanisms are inter-coupled, which leads to complex logical correlations and the lack of a uniform lifetime measure. Based on a Bayesian network (BN), a lifetime prediction method for systems that combine multi-level sensor information is proposed. The method considers the correlation between accidental failures and degradation failure mechanisms, and achieves system modeling and lifetime prediction under complex logic correlations. This method is applied in the lifetime prediction of a multi-level solar-powered unmanned system, and the predicted results can provide guidance for the improvement of system reliability and for the maintenance and protection of the system. PMID:28926930

  10. Modeling of BN Lifetime Prediction of a System Based on Integrated Multi-Level Information.

    PubMed

    Wang, Jingbin; Wang, Xiaohong; Wang, Lizhi

    2017-09-15

    Predicting system lifetime is important to ensure safe and reliable operation of products, which requires integrated modeling based on multi-level, multi-sensor information. However, lifetime characteristics of equipment in a system are different and failure mechanisms are inter-coupled, which leads to complex logical correlations and the lack of a uniform lifetime measure. Based on a Bayesian network (BN), a lifetime prediction method for systems that combine multi-level sensor information is proposed. The method considers the correlation between accidental failures and degradation failure mechanisms, and achieves system modeling and lifetime prediction under complex logic correlations. This method is applied in the lifetime prediction of a multi-level solar-powered unmanned system, and the predicted results can provide guidance for the improvement of system reliability and for the maintenance and protection of the system.

  11. Performance and Cost-Effectiveness of Computed Tomography Lung Cancer Screening Scenarios in a Population-Based Setting: A Microsimulation Modeling Analysis in Ontario, Canada.

    PubMed

    Ten Haaf, Kevin; Tammemägi, Martin C; Bondy, Susan J; van der Aalst, Carlijn M; Gu, Sumei; McGregor, S Elizabeth; Nicholas, Garth; de Koning, Harry J; Paszat, Lawrence F

    2017-02-01

    The National Lung Screening Trial (NLST) results indicate that computed tomography (CT) lung cancer screening for current and former smokers with three annual screens can be cost-effective in a trial setting. However, the cost-effectiveness in a population-based setting with >3 screening rounds is uncertain. Therefore, the objective of this study was to estimate the cost-effectiveness of lung cancer screening in a population-based setting in Ontario, Canada, and evaluate the effects of screening eligibility criteria. This study used microsimulation modeling informed by various data sources, including the Ontario Health Insurance Plan (OHIP), Ontario Cancer Registry, smoking behavior surveys, and the NLST. Persons, born between 1940 and 1969, were examined from a third-party health care payer perspective across a lifetime horizon. Starting in 2015, 576 CT screening scenarios were examined, varying by age to start and end screening, smoking eligibility criteria, and screening interval. Among the examined outcome measures were lung cancer deaths averted, life-years gained, percentage ever screened, costs (in 2015 Canadian dollars), and overdiagnosis. The results of the base-case analysis indicated that annual screening was more cost-effective than biennial screening. Scenarios with eligibility criteria that required as few as 20 pack-years were dominated by scenarios that required higher numbers of accumulated pack-years. In general, scenarios that applied stringent smoking eligibility criteria (i.e., requiring higher levels of accumulated smoking exposure) were more cost-effective than scenarios with less stringent smoking eligibility criteria, with modest differences in life-years gained. Annual screening between ages 55-75 for persons who smoked ≥40 pack-years and who currently smoke or quit ≤10 y ago yielded an incremental cost-effectiveness ratio of $41,136 Canadian dollars ($33,825 in May 1, 2015, United States dollars) per life-year gained (compared to

  12. Stratospheric lifetime ratio of CFC-11 and CFC-12 from satellite and model climatologies

    NASA Astrophysics Data System (ADS)

    Hoffmann, L.; Hoppe, C. M.; Müller, R.; Dutton, G. S.; Gille, J. C.; Griessbach, S.; Jones, A.; Meyer, C. I.; Spang, R.; Volk, C. M.; Walker, K. A.

    2014-06-01

    Chlorofluorocarbons (CFCs) play a key role in stratospheric ozone loss and are strong infrared absorbers that contribute to global warming. The stratospheric lifetimes of CFCs are a measure of their global loss rates that are needed to determine global warming and ozone depletion potentials. We applied the tracer-tracer correlation approach to zonal mean climatologies from satellite measurements and model data to assess the lifetimes of CFCl3 (CFC-11) and CF2Cl2 (CFC-12). We present estimates of the CFC-11/CFC-12 lifetime ratio and the absolute lifetime of CFC-12, based on a reference lifetime of 52 yr for CFC-11. We analyzed climatologies from three satellite missions, the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS), the HIgh Resolution Dynamics Limb Sounder (HIRDLS), and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). We found a CFC-11/CFC-12 lifetime ratio of 0.47±0.08 and a CFC-12 lifetime of 111(96-132) yr for ACE-FTS, a ratio of 0.46±0.07 and a lifetime of 112(97-133) yr for HIRDLS, and a ratio of 0.46±0.08 and a lifetime of 112(96-135) yr for MIPAS. The error-weighted, combined CFC-11/CFC-12 lifetime ratio is 0.47±0.04 and the CFC-12 lifetime estimate is 112(102-123) yr. These results agree with the recent Stratosphere-troposphere Processes And their Role in Climate (SPARC) reassessment, which recommends lifetimes of 52(43-67) yr and 102(88-122) yr, respectively. Having smaller uncertainties than the results from other recent studies, our estimates can help to better constrain CFC-11 and CFC-12 lifetime recommendations in future scientific studies and assessments. Furthermore, the satellite observations were used to validate first simulation results from a new coupled model system, which integrates a Lagrangian chemistry transport model into a climate model. For the coupled model we found a CFC-11/CFC-12 lifetime ratio of 0.48±0.07 and a CFC-12 lifetime of 110(95-129) yr, based on a ten-year perpetual

  13. Stratospheric lifetime ratio of CFC-11 and CFC-12 from satellite and model climatologies

    NASA Astrophysics Data System (ADS)

    Hoffmann, L.; Hoppe, C. M.; Müller, R.; Dutton, G. S.; Gille, J. C.; Griessbach, S.; Jones, A.; Meyer, C. I.; Spang, R.; Volk, C. M.; Walker, K. A.

    2014-11-01

    Chlorofluorocarbons (CFCs) play a key role in stratospheric ozone loss and are strong infrared absorbers that contribute to global warming. The stratospheric lifetimes of CFCs are a measure of their stratospheric loss rates that are needed to determine global warming and ozone depletion potentials. We applied the tracer-tracer correlation approach to zonal mean climatologies from satellite measurements and model data to assess the lifetimes of CFCl3 (CFC-11) and CF2Cl2 (CFC-12). We present estimates of the CFC-11/CFC-12 lifetime ratio and the absolute lifetime of CFC-12, based on a reference lifetime of 52 years for CFC-11. We analyzed climatologies from three satellite missions, the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS), the HIgh Resolution Dynamics Limb Sounder (HIRDLS), and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). We found a CFC-11/CFC-12 lifetime ratio of 0.47±0.08 and a CFC-12 lifetime of 112(96-133) years for ACE-FTS, a ratio of 0.46±0.07 and a lifetime of 113(97-134) years for HIRDLS, and a ratio of 0.46±0.08 and a lifetime of 114(98-136) years for MIPAS. The error-weighted, combined CFC-11/CFC-12 lifetime ratio is 0.46±0.04 and the CFC-12 lifetime estimate is 113(103-124) years. These results agree with the recent Stratosphere-troposphere Processes And their Role in Climate (SPARC) reassessment, which recommends lifetimes of 52(43-67) years and 102(88-122) years, respectively. Having smaller uncertainties than the results from other recent studies, our estimates can help to better constrain CFC-11 and CFC-12 lifetime recommendations in future scientific studies and assessments. Furthermore, the satellite observations were used to validate first simulation results from a new coupled model system, which integrates a Lagrangian chemistry transport model into a climate model. For the coupled model we found a CFC-11/CFC-12 lifetime ratio of 0.48±0.07 and a CFC-12 lifetime of 110(95-129) years

  14. Radiation-induced aging of PDMS Elastomer TR-55: a summary of constitutive, mesoscale, and population-based models

    SciTech Connect

    Maiti, A; Weisgraber, T. H.; Dinh, L. N.

    Filled and cross-linked elastomeric rubbers are versatile network materials with a multitude of applications ranging from artificial organs and biomedical devices to cushions, coatings, adhesives, interconnects, and seismic-isolation-, thermal-, and electrical barriers. External factors like mechanical stress, temperature fluctuations, or radiation are known to create chemical changes in such materials that can directly affect the molecular weight distribution (MWD) of the polymer between cross-links and alter the structural and mechanical properties. From a Materials Science point of view it is highly desirable to understand, effect, and manipulate such property changes in a controlled manner. In this report we summarize ourmore » modeling efforts on a polysiloxane elastomer TR-55, which is an important component in several of our systems, and representative of a wide class of filled rubber materials. The primary aging driver in this work has been γ-radiation, and a variety of modeling approaches have been employed, including constitutive, mesoscale, and population-based models. The work utilizes diverse experimental data, including mechanical stress-strain and compression set measurements, as well as MWD measurements using multiquantum NMR.« less

  15. Are immigrants and nationals born to immigrants at higher risk for delayed or no lifetime breast and cervical cancer screening? The results from a population-based survey in Paris metropolitan area in 2010.

    PubMed

    Rondet, Claire; Lapostolle, Annabelle; Soler, Marion; Grillo, Francesca; Parizot, Isabelle; Chauvin, Pierre

    2014-01-01

    This study aims to compare breast cancer screening (BCS) and cervical cancer screening (CCS) practices of French women born to French parents with those of immigrants and nationals born to immigrants, taking their socioeconomic status into account. The study is based on data collected in 2010 in the Paris metropolitan area among a representative sample of 3000 French-speaking adults. For women with no history of breast or cervical cancer, multivariate logistic regressions and structural equation models were used to investigate the factors associated with never having undergone BCS or CCS. We confirmed the existence of a strong gradient, with respect to migration origin, for delaying or never having undergone BCS or CCS. Thus, being a foreign immigrant or being French of immigrant parentage were risk factors for delayed and no lifetime screening. Interestingly, we found that this gradient persisted (at least partially) after adjusting for the women's socioeconomic characteristics. Only the level of income seemed to play a mediating role, but only partially. We observed differences between BCS and CCS which suggest that organized CCS could be effective in reducing socioeconomic and/or ethnic inequities. Socioeconomic status partially explained the screening nonparticipation on the part of French women of immigrant origin and foreign immigrants. This was more so the case with CCS than with BCS, which suggests that organized prevention programs might reduce social inequalities.

  16. Measuring and modeling the lifetime of nitrous oxide including its variability

    NASA Astrophysics Data System (ADS)

    Prather, Michael J.; Hsu, Juno; DeLuca, Nicole M.; Jackman, Charles H.; Oman, Luke D.; Douglass, Anne R.; Fleming, Eric L.; Strahan, Susan E.; Steenrod, Stephen D.; Søvde, O. Amund; Isaksen, Ivar S. A.; Froidevaux, Lucien; Funke, Bernd

    2015-06-01

    The lifetime of nitrous oxide, the third-most-important human-emitted greenhouse gas, is based to date primarily on model studies or scaling to other gases. This work calculates a semiempirical lifetime based on Microwave Limb Sounder satellite measurements of stratospheric profiles of nitrous oxide, ozone, and temperature; laboratory cross-section data for ozone and molecular oxygen plus kinetics for O(1D); the observed solar spectrum; and a simple radiative transfer model. The result is 116 ± 9 years. The observed monthly-to-biennial variations in lifetime and tropical abundance are well matched by four independent chemistry-transport models driven by reanalysis meteorological fields for the period of observation (2005-2010), but all these models overestimate the lifetime due to lower abundances in the critical loss region near 32 km in the tropics. These models plus a chemistry-climate model agree on the nitrous oxide feedback factor on its own lifetime of 0.94 ± 0.01, giving N2O perturbations an effective residence time of 109 years. Combining this new empirical lifetime with model estimates of residence time and preindustrial lifetime (123 years) adjusts our best estimates of the human-natural balance of emissions today and improves the accuracy of projected nitrous oxide increases over this century.

  17. Measuring and modeling the lifetime of nitrous oxide including its variability

    DOE PAGES

    Prather, Michael J.; Hsu, Juno; DeLuca, Nicole M.; ...

    2015-05-14

    The lifetime of nitrous oxide, the third-most-important human-emitted greenhouse gas, is based to date primarily on model studies or scaling to other gases. This work calculates a semiempirical lifetime based on Microwave Limb Sounder satellite measurements of stratospheric profiles of nitrous oxide, ozone, and temperature; laboratory cross-section data for ozone and molecular oxygen plus kinetics for O( 1D); the observed solar spectrum; and a simple radiative transfer model. The result is 116 ± 9 years. The observed monthly-to-biennial variations in lifetime and tropical abundance are well matched by four independent chemistry-transport models driven by reanalysis meteorological fields for the periodmore » of observation (2005–2010), but all these models overestimate the lifetime due to lower abundances in the critical loss region near 32 km in the tropics. These models plus a chemistry-climate model agree on the nitrous oxide feedback factor on its own lifetime of 0.94 ± 0.01, giving N 2O perturbations an effective residence time of 109 years. Combining this new empirical lifetime with model estimates of residence time and preindustrial lifetime (123 years) adjusts our best estimates of the human-natural balance of emissions today and improves the accuracy of projected nitrous oxide increases over this century.« less

  18. Applying the effort-reward imbalance model to household and family work: a population-based study of German mothers

    PubMed Central

    2012-01-01

    Background This paper reports on results of a newly developed questionnaire for the assessment of effort-reward imbalance (ERI) in unpaid household and family work. Methods: Using a cross-sectional population-based survey of German mothers (n = 3129) the dimensional structure of the theoretical ERI model was validated by means of Confirmatory Factor Analysis (CFA). Analyses of Variance were computed to examine relationships between ERI and social factors and health outcomes. Results CFA revealed good psychometric properties indicating that the subscale 'effort' is based on one latent factor and the subscale 'reward' is composed of four dimensions: 'intrinsic value of family and household work', 'societal esteem', 'recognition from the partner', and 'affection from the child(ren)'. About 19.3% of mothers perceived lack of reciprocity and 23.8% showed high rates of overcommitment in terms of inability to withdraw from household and family obligations. Socially disadvantaged mothers were at higher risk of ERI, in particular with respect to the perception of low societal esteem. Gender inequality in the division of household and family work and work-family conflict accounted most for ERI in household and family work. Analogous to ERI in paid work we could demonstrate that ERI affects self-rated health, somatic complaints, mental health and, to some extent, hypertension. Conclusions The newly developed questionnaire demonstrates satisfied validity and promising results for extending the ERI model to household and family work. PMID:22221851

  19. Lifetime indirect cost of childhood overweight and obesity: A decision analytic model.

    PubMed

    Sonntag, Diana; Ali, Shehzad; De Bock, Freia

    2016-01-01

    To estimate the indirect lifetime cost of childhood overweight and obesity for Germany. The lifetime cohort model consisted of two parts: (a) Model I used data from the German Interview and Examination Survey for Children on prevalence of BMI categories during childhood to evaluate BMI trajectories before the age of 18; and (b) Model II estimated lifetime excess indirect cost based on the history of childhood BMI. Indirect costs were defined as the opportunity cost of lost productivity due to mortality and morbidity and were identified through a systematic literature review. Our analysis showed that the majority of children with overweight and obesity remained in the same BMI category during their adult life, resulting in significant indirect lifetime costs. We estimated that overweight and obesity during childhood resulted in an excess lifetime cost per person of €4,209 (men) and €2,445 (women). For the current prevalent German population, the excess lifetime cost was €145 billion. Our study showed that childhood obesity results in significant economic burden on the society. Therefore, cost-effective strategies targeted at reducing the prevalence of obesity during the early years of life can significantly reduce both healthcare and nonhealthcare costs over the lifetime. © 2015 The Obesity Society.

  20. [Epidemiology of homicides in Cali, Colombia, 1993-1998: six years of a population-based model].

    PubMed

    Concha-Eastman, Alberto; Espitia, Victoria E; Espinosa, Rafael; Guerrero, Rodrigo

    2002-10-01

    the benefits of a population-based surveillance model are discussed, particularly their usefulness for identifying risk factors and the measures that can be applied to prevent and control this form of violence.

  1. Stratospheric lifetime ratio of CFC-11 and CFC-12 from satellite and model climatologies

    NASA Astrophysics Data System (ADS)

    Hoffmann, Lars; Hoppe, Charlotte; Müller, Rolf; Dutton, Geoffrey S.; Gille, John C.; Griessbach, Sabine; Jones, Ashley; Meyer, Catrin I.; Spang, Reinhold; Volk, C. Michael; Walker, Kaley A.

    2015-04-01

    Chlorofluorocarbons (CFCs) play a key role in stratospheric ozone loss and are strong infrared absorbers that contribute to global warming. The stratospheric lifetimes of CFCs are a measure of their stratospheric loss rates that are needed to determine global warming and ozone depletion potentials. We applied the tracer-tracer correlation approach to zonal mean climatologies from satellite measurements and model data to assess the lifetimes of CFCl3 (CFC-11) and CF2Cl2 (CFC-12). We present new estimates of the CFC-11/CFC-12 lifetime ratio and the absolute lifetime of CFC-12, based on a reference lifetime of 52 yr for CFC-11. We analyzed climatologies from three satellite missions, the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS), the HIgh Resolution Dynamics Limb Sounder (HIRDLS), and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). We found a CFC-11/CFC-12 lifetime ratio of 0.47 ± 0.08 and a CFC-12 lifetime of 112(96 - 133) yr for ACE-FTS, a ratio of 0.46 ± 0.07 and a lifetime of 113(97 - 134) yr for HIRDLS, and a ratio of 0.46 ± 0.08 and a lifetime of 114(98 - 136) yr for MIPAS. The error-weighted, combined CFC-11/CFC-12 lifetime ratio is 0.46 ± 0.04 and the CFC-12 lifetime estimate is 113(103 - 124) yr. These results are in excellent agreement with the recent Stratosphere-troposphere Processes And their Role in Climate (SPARC) reassessment, which recommends lifetimes of 52(43 - 67) yr for CFC-11 and 102(88 - 122) yr for CFC-12, respectively. Having smaller uncertainties than the results from other recent studies, our estimates can help to better constrain CFC-11 and CFC-12 lifetime recommendations in future scientific studies and assessments. Furthermore, the satellite observations were used to validate first simulation results from a new coupled model system, which integrates a Lagrangian chemistry transport model into a climate model. For the coupled EMAC/CLaMS model we found a CFC-11/CFC-12 lifetime ratio

  2. Deployment-based lifetime optimization model for homogeneous Wireless Sensor Network under retransmission.

    PubMed

    Li, Ruiying; Liu, Xiaoxi; Xie, Wei; Huang, Ning

    2014-12-10

    Sensor-deployment-based lifetime optimization is one of the most effective methods used to prolong the lifetime of Wireless Sensor Network (WSN) by reducing the distance-sensitive energy consumption. In this paper, data retransmission, a major consumption factor that is usually neglected in the previous work, is considered. For a homogeneous WSN, monitoring a circular target area with a centered base station, a sensor deployment model based on regular hexagonal grids is analyzed. To maximize the WSN lifetime, optimization models for both uniform and non-uniform deployment schemes are proposed by constraining on coverage, connectivity and success transmission rate. Based on the data transmission analysis in a data gathering cycle, the WSN lifetime in the model can be obtained through quantifying the energy consumption at each sensor location. The results of case studies show that it is meaningful to consider data retransmission in the lifetime optimization. In particular, our investigations indicate that, with the same lifetime requirement, the number of sensors needed in a non-uniform topology is much less than that in a uniform one. Finally, compared with a random scheme, simulation results further verify the advantage of our deployment model.

  3. Youth and Work: Toward a Model of Lifetime Economic Prospects.

    ERIC Educational Resources Information Center

    Carroll, Stephen J.; Pascal, Anthony H.

    As part of an effort to reduce inequalities in economic opportunities confronting the young, this general model of youth behavior and opportunity was developed. Underlying the model are three sets of variables which influence economic opportunities: experience, perceptions, and opportunities. The relations between behavior at a point in time and…

  4. FPGA implementation of predictive degradation model for engine oil lifetime

    NASA Astrophysics Data System (ADS)

    Idros, M. F. M.; Razak, A. H. A.; Junid, S. A. M. Al; Suliman, S. I.; Halim, A. K.

    2018-03-01

    This paper presents the implementation of linear regression model for degradation prediction on Register Transfer Logic (RTL) using QuartusII. A stationary model had been identified in the degradation trend for the engine oil in a vehicle in time series method. As for RTL implementation, the degradation model is written in Verilog HDL and the data input are taken at a certain time. Clock divider had been designed to support the timing sequence of input data. At every five data, a regression analysis is adapted for slope variation determination and prediction calculation. Here, only the negative value are taken as the consideration for the prediction purposes for less number of logic gate. Least Square Method is adapted to get the best linear model based on the mean values of time series data. The coded algorithm has been implemented on FPGA for validation purposes. The result shows the prediction time to change the engine oil.

  5. Maternal lifetime history of depression and depressive symptoms in the prenatal and early postnatal period do not predict infant-mother attachment quality in a large, population-based Dutch cohort study.

    PubMed

    Tharner, Anne; Luijk, Maartje P C M; van Ijzendoorn, Marinus H; Bakermans-Kranenburg, Marian J; Jaddoe, Vincent W V; Hofman, Albert; Verhulst, Frank C; Tiemeier, Henning

    2012-01-01

    We examined the effects of maternal history of depressive disorder and the effects of depressive symptoms during pregnancy and the early postpartum period on attachment insecurity and disorganization. A total of 627 mother-infant dyads from the Generation R Study participated in a population-based cohort from fetal life onwards. Maternal history of depression was assessed by diagnostic interviews during pregnancy; maternal peri- and postnatal depressive symptoms were assessed with questionnaires in 506 of these women at 20 weeks pregnancy and two months postpartum; and infant-mother attachment security was observed when infants were aged 14 months. A history of maternal depressive disorder, regardless of severity or psychiatric comorbidity, was not associated with an increased risk of infant attachment insecurity or disorganization. Likewise, maternal peri- and postnatal depressive symptoms were not related to attachment insecurity or disorganization at 14 months. These results are important because mothers from otherwise low risk backgrounds often have previously been depressed or are struggling with non-clinical depressive symptoms during pregnancy and after giving birth. Our findings are discussed in terms of protective factors that may limit the potentially negative effects of maternal depressive symptoms on the infant-mother attachment relationship in the general population. The role of selective attrition and lack of information about the mothers' attachment status for the current null-findings are also discussed.

  6. Modeling of Hall Thruster Lifetime and Erosion Mechanisms (Preprint)

    DTIC Science & Technology

    2007-09-01

    Hall thruster plasma discharge has been upgraded to simulate the erosion of the thruster acceleration channel, the degradation of which is the main life-limiting factor of the propulsion system. Evolution of the thruster geometry as a result of material removal due to sputtering is modeled by calculating wall erosion rates, stepping the grid boundary by a chosen time step and altering the computational mesh between simulation runs. The code is first tuned to predict the nose cone erosion of a 200 W Busek Hall thruster , the BHT-200. Simulated erosion

  7. A simple shape-free model for pore-size estimation with positron annihilation lifetime spectroscopy

    NASA Astrophysics Data System (ADS)

    Wada, Ken; Hyodo, Toshio

    2013-06-01

    Positron annihilation lifetime spectroscopy is one of the methods for estimating pore size in insulating materials. We present a shape-free model to be used conveniently for such analysis. A basic model in classical picture is modified by introducing a parameter corresponding to an effective size of the positronium (Ps). This parameter is adjusted so that its Ps-lifetime to pore-size relation merges smoothly with that of the well-established Tao-Eldrup model (with modification involving the intrinsic Ps annihilation rate) applicable to very small pores. The combined model, i.e., modified Tao-Eldrup model for smaller pores and the modified classical model for larger pores, agrees surprisingly well with the quantum-mechanics based extended Tao-Eldrup model, which deals with Ps trapped in and thermally equilibrium with a rectangular pore.

  8. Model of electron lifetimes inside the plasmasphere calculated using a CRRES derived hiss wave amplitude model

    NASA Astrophysics Data System (ADS)

    Orlova, Ksenia; Spasojevic, Maria; Shprits, Yuri

    Particle populations in the inner magnetosphere can change by orders of magnitude on very short time scales. For the last decade observations and theoretical computations showed that resonant interaction of electrons with various plasma waves plays an important role in acceleration and loss mechanisms. Using data from the CRRES plasma wave experiment, we develop quadratic fits to the mean of the wave amplitude squared for plasmaspheric hiss as a function of geomagnetic activity (Kp) and magnetic latitude (lambda) for the dayside (6model is valid for lambda<25(°) , Kp<=6, and for 3lifetimes of electrons are then calculated from the diffusion coefficients. The obtained lifetimes are parameterized as a function of energy, Kp-index, L-shell and can be used in 2D/3D/4D convection and particle tracing codes.

  9. Lifetime prediction for the subsurface crack propagation using three-dimensional dynamic FEA model

    NASA Astrophysics Data System (ADS)

    Yin, Yuan; Chen, Yun-Xia; Liu, Le

    2017-03-01

    The subsurface crack propagation is one of the major interests for gear system research. The subsurface crack propagation lifetime is the number of cycles remaining for a spall to appear, which can be obtained through either stress intensity factor or accumulated plastic strain analysis. In this paper, the heavy loads are applied to the gear system. When choosing stress intensity factor, the high compressive stress suppresses Mode I stress intensities and severely reduces Mode II stress intensities in the heavily loaded lubricated contacts. Such that, the accumulated plastic strain is selected to calculate the subsurface crack propagation lifetime from the three-dimensional FEA model through ANSYS Workbench transient analysis. The three-dimensional gear FEA dynamic model with the subsurface crack is built through dividing the gears into several small elements. The calculation of the total cycles of the elements is proposed based on the time-varying accumulated plastic strain, which then will be used to calculate the subsurface crack propagation lifetime. During this process, the demonstration from a subsurface crack to a spall can be uncovered. In addition, different sizes of the elements around the subsurface crack are compared in this paper. The influences of the frictional coefficient and external torque on the crack propagation lifetime are also discussed. The results show that the lifetime of crack propagation decreases significantly when the external load T increasing from 100 N m to 150 N m. Given from the distributions of the accumulated plastic strain, the lifetime shares no significant difference when the frictional coefficient f ranging in 0.04-0.06.

  10. Comparison of Accelerated Testing with Modeling to Predict Lifetime of CPV Solder Layers (Presentation)

    SciTech Connect

    Silverman, T. J.; Bosco, N.; Kurtz, S.

    2012-03-01

    Concentrating photovoltaic (CPV) cell assemblies can fail due to thermomechanical fatigue in the die-attach layer. In this presentation, we show the latest results from our computational model of thermomechanical fatigue. The model is used to estimate the relative lifetime of cell assemblies exposed to various temperature histories consistent with service and with accelerated testing. We also present early results from thermal cycling experiments designed to help validate the computational model.

  11. Phase of care prevalence for prostate cancer in New South Wales, Australia: A population-based modelling study.

    PubMed

    Yu, Xue Qin; Luo, Qingwei; Smith, David P; Clements, Mark S; Patel, Manish I; O'Connell, Dianne L

    2017-01-01

    To develop a method for estimating the future numbers of prostate cancer survivors requiring different levels of care. Analysis of population-based cancer registry data for prostate cancer cases (aged 18-84 years) diagnosed in 1996-2007, and a linked dataset with hospital admission data for men with prostate cancer diagnosed during 2005-2007 in New South Wales (NSW), Australia. Cancer registry data (1996-2007) were used to project complete prostate cancer prevalence in NSW, Australia for 2008-2017, and treatment information from hospital records (2005-2007) was used to estimate the inpatient care needs during the first year after diagnosis. The projected complete prevalence was divided into care needs-based groups. We first divided the cohort into two groups based on patient's age (<75 and 75-84 years). The younger cohort was further divided into initial care and monitoring phases. Cause of death data were used as a proxy for patients requiring last year of life prostate cancer care. Finally, episode data were used to estimate the future number of cases with metastatic progression. Of the estimated total of 60,910 men with a previous diagnosis of prostate cancer in 2017, the largest groups will be older patients (52.0%) and younger men who require monitoring (42.5%). If current treatment patterns continue, in the first year post-diagnosis 41% (1380) of patients (<75 years) will have a radical prostatectomy, and 52.6% (1752) will be likely to have either active surveillance, external beam radiotherapy or androgen deprivation therapy. About 3% will require care for subsequent metastases, and 1288 men with prostate cancer are likely to die from the disease in 2017. This method extends the application of routinely collected population-based data, and can contribute much to the knowledge of the number of men with prostate cancer and their health care requirements. This could be of significant use in planning future cancer care services and facilities in Australia.

  12. Bilayer Suspension Plasma-Sprayed Thermal Barrier Coatings with Enhanced Thermal Cyclic Lifetime: Experiments and Modeling

    NASA Astrophysics Data System (ADS)

    Gupta, Mohit; Kumara, Chamara; Nylén, Per

    2017-08-01

    Suspension plasma spraying (SPS) has been shown as a promising process to produce porous columnar strain tolerant coatings for thermal barrier coatings (TBCs) in gas turbine engines. However, the highly porous structure is vulnerable to crack propagation, especially near the topcoat-bondcoat interface where high stresses are generated due to thermal cycling. A topcoat layer with high toughness near the topcoat-bondcoat interface could be beneficial to enhance thermal cyclic lifetime of SPS TBCs. In this work, a bilayer coating system consisting of first a dense layer near the topcoat-bondcoat interface followed by a porous columnar layer was fabricated by SPS using Yttria-stabilised zirconia suspension. The objective of this work was to investigate if the bilayer topcoat architecture could enhance the thermal cyclic lifetime of SPS TBCs through experiments and to understand the effect of the column gaps/vertical cracks and the dense layer on the generated stresses in the TBC during thermal cyclic loading through finite element modeling. The experimental results show that the bilayer TBC had significantly higher lifetime than the single-layer TBC. The modeling results show that the dense layer and vertical cracks are beneficial as they reduce the thermally induced stresses which thus increase the lifetime.

  13. A practical model of thin disk regenerative amplifier based on analytical expression of ASE lifetime

    NASA Astrophysics Data System (ADS)

    Zhou, Huang; Chyla, Michal; Nagisetty, Siva Sankar; Chen, Liyuan; Endo, Akira; Smrz, Martin; Mocek, Tomas

    2017-12-01

    In this paper, a practical model of a thin disk regenerative amplifier has been developed based on an analytical approach, in which Drew A. Copeland [1] had evaluated the loss rate of the upper state laser level due to ASE and derived the analytical expression of the effective life-time of the upper-state laser level by taking the Lorentzian stimulated emission line-shape and total internal reflection into account. By adopting the analytical expression of effective life-time in the rate equations, we have developed a less numerically intensive model for predicting and analyzing the performance of a thin disk regenerative amplifier. Thanks to the model, optimized combination of various parameters can be obtained to avoid saturation, period-doubling bifurcation or first pulse suppression prior to experiments. The effective life-time due to ASE is also analyzed against various parameters. The simulated results fit well with experimental data. By fitting more experimental results with numerical model, we can improve the parameters of the model, such as reflective factor which is used to determine the weight of boundary reflection within the influence of ASE. This practical model will be used to explore the scaling limits imposed by ASE of the thin disk regenerative amplifier being developed in HiLASE Centre.

  14. Predicting the breakdown strength and lifetime of nanocomposites using a multi-scale modeling approach

    NASA Astrophysics Data System (ADS)

    Huang, Yanhui; Zhao, He; Wang, Yixing; Ratcliff, Tyree; Breneman, Curt; Brinson, L. Catherine; Chen, Wei; Schadler, Linda S.

    2017-08-01

    It has been found that doping dielectric polymers with a small amount of nanofiller or molecular additive can stabilize the material under a high field and lead to increased breakdown strength and lifetime. Choosing appropriate fillers is critical to optimizing the material performance, but current research largely relies on experimental trial and error. The employment of computer simulations for nanodielectric design is rarely reported. In this work, we propose a multi-scale modeling approach that employs ab initio, Monte Carlo, and continuum scales to predict the breakdown strength and lifetime of polymer nanocomposites based on the charge trapping effect of the nanofillers. The charge transfer, charge energy relaxation, and space charge effects are modeled in respective hierarchical scales by distinctive simulation techniques, and these models are connected together for high fidelity and robustness. The preliminary results show good agreement with the experimental data, suggesting its promise for use in the computer aided material design of high performance dielectrics.

  15. Beyond R 0: Demographic Models for Variability of Lifetime Reproductive Output

    PubMed Central

    Caswell, Hal

    2011-01-01

    The net reproductive rate measures the expected lifetime reproductive output of an individual, and plays an important role in demography, ecology, evolution, and epidemiology. Well-established methods exist to calculate it from age- or stage-classified demographic data. As an expectation, provides no information on variability; empirical measurements of lifetime reproduction universally show high levels of variability, and often positive skewness among individuals. This is often interpreted as evidence of heterogeneity, and thus of an opportunity for natural selection. However, variability provides evidence of heterogeneity only if it exceeds the level of variability to be expected in a cohort of identical individuals all experiencing the same vital rates. Such comparisons require a way to calculate the statistics of lifetime reproduction from demographic data. Here, a new approach is presented, using the theory of Markov chains with rewards, obtaining all the moments of the distribution of lifetime reproduction. The approach applies to age- or stage-classified models, to constant, periodic, or stochastic environments, and to any kind of reproductive schedule. As examples, I analyze data from six empirical studies, of a variety of animal and plant taxa (nematodes, polychaetes, humans, and several species of perennial plants). PMID:21738586

  16. A health economic lifetime treatment pathway model for low back pain in Sweden.

    PubMed

    Olafsson, Gylfi; Jonsson, Emma; Fritzell, Peter; Hägg, Olle; Borgström, Fredrik

    2017-12-01

    To develop a health economic model to evaluate the long-term costs and outcomes over the healthcare treatment pathway for patients with low back pain (LBP). A health economic model, consisting of a decision tree structure with a Markov microsimulation model at the end of each branch, was created. Patients were followed from first observed clinical presentation with LBP until the age of 100 years or death. The underlying data to populate the model were based on Swedish national and regional registry data on healthcare resource use and sickness insurance in patients presenting with LBP in the Swedish region Västra Götaland during 2008-2012. Costs (outpatient healthcare visits, inpatient bed days, pharmaceuticals, productivity loss), EUR 2016, and quality-of-life based on EQ-5D data from the registries and published estimates were summarized over the lifetime of the patients with 3% annual discount. A lost quality-adjusted life year (QALY) was valued at €70,000. Mean lifetime total cost was estimated at €47,452/patient, of which indirect costs were 57%. Total lifetime economic burden for all patients coming to clinical presentation in Sweden per year was €8.8bn. The average LBP patient was estimated to face a loss of 2.7 QALYs over their lifetime compared with the general population. For all patients in Sweden coming to clinical presentation in 1 year this gives 505,407 QALYs lost, valued at €35.3bn. Adding the economic burden, the total societal burden amounts to €44.1bn. This pathway model shows that most patients with LBP receive conservative care, and a minority consume high-cost healthcare interventions like surgery. The model could be used to see broad economic effects of different patterns of healthcare provision in sub-groups with LBP and to estimate where it is possible to influence these pathways to increase utility for patients and for society.

  17. Regional differences in population-based cancer survival between six prefectures in Japan: application of relative survival models with funnel plots.

    PubMed

    Ito, Yuri; Ioka, Akiko; Tsukuma, Hideaki; Ajiki, Wakiko; Sugimoto, Tomoyuki; Rachet, Bernard; Coleman, Michel P

    2009-07-01

    We used new methods to examine differences in population-based cancer survival between six prefectures in Japan, after adjustment for age and stage at diagnosis. We applied regression models for relative survival to data from population-based cancer registries covering each prefecture for patients diagnosed with stomach, lung, or breast cancer during 1993-1996. Funnel plots were used to display the excess hazard ratio (EHR) for each prefecture, defined as the excess hazard of death from each cancer within 5 years of diagnosis relative to the mean excess hazard (in excess of national background mortality by age and sex) in all six prefectures combined. The contribution of age and stage to the EHR in each prefecture was assessed from differences in deviance-based R(2) between the various models. No significant differences were seen between prefectures in 5-year survival from breast cancer. For cancers of the stomach and lung, EHR in Osaka prefecture were above the upper 95% control limits. For stomach cancer, the age- and stage-adjusted EHR in Osaka were 1.29 for men and 1.43 for women, compared with Fukui and Yamagata. Differences in the stage at diagnosis of stomach cancer appeared to explain most of this excess hazard (61.3% for men, 56.8% for women), whereas differences in age at diagnosis explained very little (0.8%, 1.3%). This approach offers the potential to quantify the impact of differences in stage at diagnosis on time trends and regional differences in cancer survival. It underlines the utility of population-based cancer registries for improving cancer control.

  18. Evaluation of Observed and Modelled Aerosol Lifetimes Using Radioactive Tracers of Opportunity and an Ensemble of 19 Global Models

    NASA Technical Reports Server (NTRS)

    Kristiansen, N. I.; Stohl, A.; Olivie, D. J. L.; Croft, B.; Sovde, O. A.; Klein, H.; Christoudias, T.; Kunkel, D.; Leadbetter, S. J.; Lee, Y. H.; hide

    2016-01-01

    Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 (Cs-137) and xenon-133 (Xe-133) were released in large quantities. Cesium attached to particles in the ambient air, approximately according to their available aerosol surface area. Cs-137 size distribution measurements taken close to the power plant suggested that accumulation mode (AM) sulfate aerosols were the main carriers of cesium. Hence, Cs-137 can be used as a proxy tracer for the AM sulfate aerosol's fate in the atmosphere. In contrast, the noble gas Xe-133 behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of Cs-137that were assigned to an aerosol tracer with each model's default properties of AM sulfate, and Xe-133 emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulfate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled Cs-137and Xe-133 concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime e, calculated from station measurement data taken between 2 and 9 weeks after the start of the emissions, is 14.3 days (95

  19. Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models

    DOE PAGES

    Kristiansen, N. I.; Stohl, A.; Olivie, D. J. L.; ...

    2016-03-17

    Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 ( 137Cs) and xenon-133 ( 133Xe) were released in large quantities. Cesium attached to particles in the ambient air, approximately according to theirmore » available aerosol surface area. 137Cs size distribution measurements taken close to the power plant suggested that accumulation-mode (AM) sulfate aerosols were the main carriers of cesium. Hence, 137Cs can be used as a proxy tracer for the AM sulfate aerosol's fate in the atmosphere. In contrast, the noble gas 133Xe behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of 137Cs that were assigned to an aerosol tracer with each model's default properties of AM sulfate, and 133Xe emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulfate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled 137Cs and 133Xe concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime τ e, calculated from station measurement data taken between 2 and 9 weeks after the start of the emissions, is 14.3 days

  20. A new lifetime estimation model for a quicker LED reliability prediction

    NASA Astrophysics Data System (ADS)

    Hamon, B. H.; Mendizabal, L.; Feuillet, G.; Gasse, A.; Bataillou, B.

    2014-09-01

    LED reliability and lifetime prediction is a key point for Solid State Lighting adoption. For this purpose, one hundred and fifty LEDs have been aged for a reliability analysis. LEDs have been grouped following nine current-temperature stress conditions. Stress driving current was fixed between 350mA and 1A and ambient temperature between 85C and 120°C. Using integrating sphere and I(V) measurements, a cross study of the evolution of electrical and optical characteristics has been done. Results show two main failure mechanisms regarding lumen maintenance. The first one is the typically observed lumen depreciation and the second one is a much more quicker depreciation related to an increase of the leakage and non radiative currents. Models of the typical lumen depreciation and leakage resistance depreciation have been made using electrical and optical measurements during the aging tests. The combination of those models allows a new method toward a quicker LED lifetime prediction. These two models have been used for lifetime predictions for LEDs.

  1. Studies on Mathematical Models of Wet Adhesion and Lifetime Prediction of Organic Coating/Steel by Grey System Theory.

    PubMed

    Meng, Fandi; Liu, Ying; Liu, Li; Li, Ying; Wang, Fuhui

    2017-06-28

    A rapid degradation of wet adhesion is the key factor controlling coating lifetime, for the organic coatings under marine hydrostatic pressure. The mathematical models of wet adhesion have been studied by Grey System Theory (GST). Grey models (GM) (1, 1) of epoxy varnish (EV) coating/steel and epoxy glass flake (EGF) coating/steel have been established, and a lifetime prediction formula has been proposed on the basis of these models. The precision assessments indicate that the established models are accurate, and the prediction formula is capable of making precise lifetime forecasting of the coatings.

  2. Studies on Mathematical Models of Wet Adhesion and Lifetime Prediction of Organic Coating/Steel by Grey System Theory

    PubMed Central

    Meng, Fandi; Liu, Ying; Liu, Li; Li, Ying; Wang, Fuhui

    2017-01-01

    A rapid degradation of wet adhesion is the key factor controlling coating lifetime, for the organic coatings under marine hydrostatic pressure. The mathematical models of wet adhesion have been studied by Grey System Theory (GST). Grey models (GM) (1, 1) of epoxy varnish (EV) coating/steel and epoxy glass flake (EGF) coating/steel have been established, and a lifetime prediction formula has been proposed on the basis of these models. The precision assessments indicate that the established models are accurate, and the prediction formula is capable of making precise lifetime forecasting of the coatings. PMID:28773073

  3. The application of cure models in the presence of competing risks: a tool for improved risk communication in population-based cancer patient survival.

    PubMed

    Eloranta, Sandra; Lambert, Paul C; Andersson, Therese M-L; Björkholm, Magnus; Dickman, Paul W

    2014-09-01

    Quantifying cancer patient survival from the perspective of cure is clinically relevant. However, most cure models estimate cure assuming no competing causes of death. We use a relative survival framework to demonstrate how flexible parametric cure models can be used in combination with competing-risks theory to incorporate noncancer deaths. Under a model that incorporates statistical cure, we present the probabilities that cancer patients (1) have died from their cancer, (2) have died from other causes, (3) will eventually die from their cancer, or (4) will eventually die from other causes, all as a function of time since diagnosis. We further demonstrate how conditional probabilities can be used to update the prognosis among survivors (eg, at 1 or 5 years after diagnosis) by summarizing the proportion of patients who will not die from their cancer. The proposed method is applied to Swedish population-based data for persons diagnosed with melanoma, colon cancer, or acute myeloid leukemia between 1973 and 2007.

  4. Effectiveness of integrated care model for type 2 diabetes: A population-based study in Reggio Emilia (Italy).

    PubMed

    Ballotari, Paola; Venturelli, Francesco; Manicardi, Valeria; Ferrari, Francesca; Vicentini, Massimo; Greci, Marina; Pignatti, Fabio; Storani, Simone; Giorgi Rossi, Paolo

    2018-01-01

    To compare the effectiveness of integrated care with that of the diabetes clinic care model in terms of mortality and hospitalisation of type 2 diabetes patients with low risk of complications. Out of 27234 people with type 2 diabetes residing in the province of Reggio Emilia on 31/12/2011, 3071 were included in this cohort study as eligible for integrated care (i.e., low risk of complications) and cared for with the same care model for at least two years. These patients were followed up from 2012 to 2016, for all-cause and diabetes-related mortality and hospital admissions. We performed a Poisson regression model, using the proportion of eligible patients included in the integrated care model for each general practitioner as an instrumental variable. 1700 patients were cared for by integrated care and 1371 by diabetes clinics. Mortality rate ratios were 0.83 (95%CI 0.60-1.13) and 0.95 (95%CI 0.54-1.70) for all-cause and cardiovascular mortality, respectively, and incidence rate ratios were 0.90 (95%CI 0.76-1.06) and 0.91 (95%CI 0.69-1.20) for all-cause and cardiovascular disease hospitalisation, respectively. For low risk patients with type 2 diabetes, the integrated care model involving both general practitioner and diabetes clinic professionals showed similar mortality and hospitalisation as a model with higher use of specialized care in an exclusively diabetes clinic setting.

  5. Study of behavior and determination of customer lifetime value(CLV) using Markov chain model

    NASA Astrophysics Data System (ADS)

    Permana, Dony; Indratno, Sapto Wahyu; Pasaribu, Udjianna S.

    2014-03-01

    Customer Lifetime Value or CLV is a restriction on interactive marketing to help a company in arranging financial for the marketing of new customer acquisition and customer retention. Additionally CLV can be able to segment customers for financial arrangements. Stochastic models for the fairly new CLV used a Markov chain. In this model customer retention probability and new customer acquisition probability play an important role. This model is originally introduced by Pfeifer and Carraway in 2000 [1]. They introduced several CLV models, one of them only involves customer and former customer. In this paper we expand the model by adding the assumption of the transition from former customer to customer. In the proposed model, the CLV value is higher than the CLV value obtained by Pfeifer and Caraway model. But our model still requires a longer convergence time.

  6. Study of behavior and determination of customer lifetime value(CLV) using Markov chain model

    SciTech Connect

    Permana, Dony, E-mail: donypermana@students.itb.ac.id; Indratno, Sapto Wahyu; Pasaribu, Udjianna S.

    Customer Lifetime Value or CLV is a restriction on interactive marketing to help a company in arranging financial for the marketing of new customer acquisition and customer retention. Additionally CLV can be able to segment customers for financial arrangements. Stochastic models for the fairly new CLV used a Markov chain. In this model customer retention probability and new customer acquisition probability play an important role. This model is originally introduced by Pfeifer and Carraway in 2000 [1]. They introduced several CLV models, one of them only involves customer and former customer. In this paper we expand the model by addingmore » the assumption of the transition from former customer to customer. In the proposed model, the CLV value is higher than the CLV value obtained by Pfeifer and Caraway model. But our model still requires a longer convergence time.« less

  7. Electromigration model for the prediction of lifetime based on the failure unit statistics in aluminum metallization

    NASA Astrophysics Data System (ADS)

    Park, Jong Ho; Ahn, Byung Tae

    2003-01-01

    A failure model for electromigration based on the "failure unit model" was presented for the prediction of lifetime in metal lines.The failure unit model, which consists of failure units in parallel and series, can predict both the median time to failure (MTTF) and the deviation in the time to failure (DTTF) in Al metal lines. The model can describe them only qualitatively. In our model, both the probability function of the failure unit in single grain segments and polygrain segments are considered instead of in polygrain segments alone. Based on our model, we calculated MTTF, DTTF, and activation energy for different median grain sizes, grain size distributions, linewidths, line lengths, current densities, and temperatures. Comparisons between our results and published experimental data showed good agreements and our model could explain the previously unexplained phenomena. Our advanced failure unit model might be further applied to other electromigration characteristics of metal lines.

  8. Effectiveness of integrated care model for type 2 diabetes: A population-based study in Reggio Emilia (Italy)

    PubMed Central

    Ballotari, Paola; Manicardi, Valeria; Ferrari, Francesca; Vicentini, Massimo; Greci, Marina; Pignatti, Fabio; Storani, Simone; Giorgi Rossi, Paolo

    2018-01-01

    Aims To compare the effectiveness of integrated care with that of the diabetes clinic care model in terms of mortality and hospitalisation of type 2 diabetes patients with low risk of complications. Methods Out of 27234 people with type 2 diabetes residing in the province of Reggio Emilia on 31/12/2011, 3071 were included in this cohort study as eligible for integrated care (i.e., low risk of complications) and cared for with the same care model for at least two years. These patients were followed up from 2012 to 2016, for all-cause and diabetes-related mortality and hospital admissions. We performed a Poisson regression model, using the proportion of eligible patients included in the integrated care model for each general practitioner as an instrumental variable. Results 1700 patients were cared for by integrated care and 1371 by diabetes clinics. Mortality rate ratios were 0.83 (95%CI 0.60–1.13) and 0.95 (95%CI 0.54–1.70) for all-cause and cardiovascular mortality, respectively, and incidence rate ratios were 0.90 (95%CI 0.76–1.06) and 0.91 (95%CI 0.69–1.20) for all-cause and cardiovascular disease hospitalisation, respectively. Conclusion For low risk patients with type 2 diabetes, the integrated care model involving both general practitioner and diabetes clinic professionals showed similar mortality and hospitalisation as a model with higher use of specialized care in an exclusively diabetes clinic setting. PMID:29584749

  9. Capitation and enhanced fee-for-service models for primary care reform: a population-based evaluation

    PubMed Central

    Glazier, Richard H.; Klein-Geltink, Julie; Kopp, Alexander; Sibley, Lyn M.

    2009-01-01

    Background Primary care reform in Ontario, Canada, included the initiation of a blended capitation model in 2001–2002 and an enhanced fee-for-service model in 2003. Both models involve patient rostering, incentives for preventive care and requirements for after-hours care. We evaluated practice characteristics and patterns of care under both models. Methods Using administrative data, we identified physicians belonging to either the capitation or the enhanced fee-for-service group throughout the period from Sept. 1, 2005, to Aug. 31, 2006, and their enrolled patients. Practices were stratified by location (urban v. rural). We compared the groups in terms of practice characteristics and patterns of care, including comprehensiveness of care, continuity of care, after-hours care, visits to the emergency department and uptake of new patients. Results Patients in the capitation and enhanced fee-for-service practices had similar demographic characteristics. Patients in capitation practices had lower morbidity and comorbidity indices. Comprehensiveness and continuity of care were similar between the 2 groups. Compared with patients in enhanced fee-for-service practices, those in capitation practices had less after-hours care (adjusted rate ratio [RR] 0.68, 95% confidence interval [CI] 0.61–0.75) and more visits to emergency departments (adjusted RR 1.20, 95% CI 1.15–1.25). Overall, physicians in the capitation group enrolled fewer new patients than did physicians in the enhanced fee-for-service group (37.0 v. 52.0 per physician); the same was true of new graduates (60.3 v. 72.1 per physician). Interpretation Physicians enrolled in the capitation model had different practice characteristics than those in the enhanced fee-for-service model. These characteristics appeared to be pre-existing and not due to enrolment in a new model. Although the capitation model provides an alternative to fee-for-service practice, its characteristics should be the focus of future policy

  10. Application of a dynamic population-based model for evaluation of exposure reduction strategies in the baking industry

    NASA Astrophysics Data System (ADS)

    Meijster, Tim; Warren, Nick; Heederik, Dick; Tielemans, Erik

    2009-02-01

    Recently a dynamic population model was developed that simulates a population of bakery workers longitudinally through time and tracks the development of work-related sensitisation and respiratory symptoms in each worker. Input for this model comes from cross-sectional and longitudinal epidemiological studies which allowed estimation of exposure response relationships and disease transition probabilities This model allows us to study the development of diseases and transitions between disease states over time in relation to determinants of disease including flour dust and/or allergen exposure. Furthermore it enables more realistic modelling of the health impact of different intervention strategies at the workplace (e.g. changes in exposure may take several years to impact on ill-health and often occur as a gradual trend). A large dataset of individual full-shift exposure measurements and real-time exposure measurements were used to obtain detailed insight into the effectiveness of control measures and other determinants of exposure. Given this information a population wide reduction of the median exposure with 50% was evaluated in this paper.

  11. Diagnosis of Parkinson’s disease on the basis of clinical–genetic classification: a population-based modelling study

    PubMed Central

    Nalls, Mike A.; McLean, Cory Y.; Rick, Jacqueline; Eberly, Shirley; Hutten, Samantha J.; Gwinn, Katrina; Sutherland, Margaret; Martinez, Maria; Heutink, Peter; Williams, Nigel; Hardy, John; Gasser, Thomas; Brice, Alexis; Price, T. Ryan; Nicolas, Aude; Keller, Margaux F.; Molony, Cliona; Gibbs, J. Raphael; Chen-Plotkin, Alice; Suh, Eunran; Letson, Christopher; Fiandaca, Massimo S.; Mapstone, Mark; Federoff, Howard J.; Noyce, Alastair J; Morris, Huw; Van Deerlin, Vivianna M.; Weintraub, Daniel; Zabetian, Cyrus; Hernandez, Dena G.; Lesage, Suzanne; Mullins, Meghan; Conley, Emily Drabant; Northover, Carrie; Frasier, Mark; Marek, Ken; Day-Williams, Aaron G.; Stone, David J.; Ioannidis, John P. A.; Singleton, Andrew B.

    2015-01-01

    Background Accurate diagnosis and early detection of complex disease has the potential to be of enormous benefit to clinical trialists, patients, and researchers alike. We sought to create a non-invasive, low-cost, and accurate classification model for diagnosing Parkinson’s disease risk to serve as a basis for future disease prediction studies in prospective longitudinal cohorts. Methods We developed a simple disease classifying model within 367 patients with Parkinson’s disease and phenotypically typical imaging data and 165 controls without neurological disease of the Parkinson’s Progression Marker Initiative (PPMI) study. Olfactory function, genetic risk, family history of PD, age and gender were algorithmically selected as significant contributors to our classifying model. This model was developed using the PPMI study then tested in 825 patients with Parkinson’s disease and 261 controls from five independent studies with varying recruitment strategies and designs including the Parkinson’s Disease Biomarkers Program (PDBP), Parkinson’s Associated Risk Study (PARS), 23andMe, Longitudinal and Biomarker Study in PD (LABS-PD), and Morris K. Udall Parkinson’s Disease Research Center of Excellence (Penn-Udall). Findings Our initial model correctly distinguished patients with Parkinson’s disease from controls at an area under the curve (AUC) of 0.923 (95% CI = 0.900 – 0.946) with high sensitivity (0.834, 95% CI = 0.711 – 0.883) and specificity (0.903, 95% CI = 0.824 – 0.946) in PPMI at its optimal AUC threshold (0.655). The model is also well-calibrated with all Hosmer-Lemeshow simulations suggesting that when parsed into random subgroups, the actual data mirrors that of the larger expected data, demonstrating that our model is robust and fits well. Likewise external validation shows excellent classification of PD with AUCs of 0.894 in PDBP, 0.998 in PARS, 0.955 in 23andMe, 0.929 in LABS-PD, and 0.939 in Penn-Udall. Additionally, when our model

  12. Diagnosis of Parkinson's disease on the basis of clinical and genetic classification: a population-based modelling study.

    PubMed

    Nalls, Mike A; McLean, Cory Y; Rick, Jacqueline; Eberly, Shirley; Hutten, Samantha J; Gwinn, Katrina; Sutherland, Margaret; Martinez, Maria; Heutink, Peter; Williams, Nigel M; Hardy, John; Gasser, Thomas; Brice, Alexis; Price, T Ryan; Nicolas, Aude; Keller, Margaux F; Molony, Cliona; Gibbs, J Raphael; Chen-Plotkin, Alice; Suh, Eunran; Letson, Christopher; Fiandaca, Massimo S; Mapstone, Mark; Federoff, Howard J; Noyce, Alastair J; Morris, Huw; Van Deerlin, Vivianna M; Weintraub, Daniel; Zabetian, Cyrus; Hernandez, Dena G; Lesage, Suzanne; Mullins, Meghan; Conley, Emily Drabant; Northover, Carrie A M; Frasier, Mark; Marek, Ken; Day-Williams, Aaron G; Stone, David J; Ioannidis, John P A; Singleton, Andrew B

    2015-10-01

    Accurate diagnosis and early detection of complex diseases, such as Parkinson's disease, has the potential to be of great benefit for researchers and clinical practice. We aimed to create a non-invasive, accurate classification model for the diagnosis of Parkinson's disease, which could serve as a basis for future disease prediction studies in longitudinal cohorts. We developed a model for disease classification using data from the Parkinson's Progression Marker Initiative (PPMI) study for 367 patients with Parkinson's disease and phenotypically typical imaging data and 165 controls without neurological disease. Olfactory function, genetic risk, family history of Parkinson's disease, age, and gender were algorithmically selected by stepwise logistic regression as significant contributors to our classifying model. We then tested the model with data from 825 patients with Parkinson's disease and 261 controls from five independent cohorts with varying recruitment strategies and designs: the Parkinson's Disease Biomarkers Program (PDBP), the Parkinson's Associated Risk Study (PARS), 23andMe, the Longitudinal and Biomarker Study in PD (LABS-PD), and the Morris K Udall Parkinson's Disease Research Center of Excellence cohort (Penn-Udall). Additionally, we used our model to investigate patients who had imaging scans without evidence of dopaminergic deficit (SWEDD). In the population from PPMI, our initial model correctly distinguished patients with Parkinson's disease from controls at an area under the curve (AUC) of 0·923 (95% CI 0·900-0·946) with high sensitivity (0·834, 95% CI 0·711-0·883) and specificity (0·903, 95% CI 0·824-0·946) at its optimum AUC threshold (0·655). All Hosmer-Lemeshow simulations suggested that when parsed into random subgroups, the subgroup data matched that of the overall cohort. External validation showed good classification of Parkinson's disease, with AUCs of 0·894 (95% CI 0·867-0·921) in the PDBP cohort, 0·998 (0·992-1·000

  13. Of Mice and Men: Empirical Support for the Population-Based Social Epistasis Amplification Model (a Comment on ).

    PubMed

    Sarraf, Matthew Alexandar; Woodley Of Menie, Michael Anthony

    2017-01-01

    This commentary article offers new perspective on recent research investigating the behavioral and social ecological effects of a mutation related to autism spectrum disorders in mice. The authors explain the consistency of this research on mice with predictions advanced by a theory of the role of mutations in altering interorganismal gene-gene interactions (social epistasis) in social species including humans, known as the social epistasis amplification model. The potential significance of the mouse research for understanding contemporary human behavioral trends is explored.

  14. Assessing the impact of the Lebanese National Polio Immunization Campaign using a population-based computational model.

    PubMed

    Alawieh, Ali; Sabra, Zahraa; Langley, E Farris; Bizri, Abdul Rahman; Hamadeh, Randa; Zaraket, Fadi A

    2017-11-25

    After the re-introduction of poliovirus to Syria in 2013, Lebanon was considered at high transmission risk due to its proximity to Syria and the high number of Syrian refugees. However, after a large-scale national immunization initiative, Lebanon was able to prevent a potential outbreak of polio among nationals and refugees. In this work, we used a computational individual-simulation model to assess the risk of poliovirus threat to Lebanon prior and after the immunization campaign and to quantitatively assess the healthcare impact of the campaign and the required standards that need to be maintained nationally to prevent a future outbreak. Acute poliomyelitis surveillance in Lebanon was along with the design and coverage rate of the recent national polio immunization campaign were reviewed from the records of the Lebanese Ministry of Public Health. Lebanese population demographics including Syrian and Palestinian refugees were reviewed to design individual-based models that predicts the consequences of polio spread to Lebanon and evaluate the outcome of immunization campaigns. The model takes into account geographic, demographic and health-related features. Our simulations confirmed the high risk of polio outbreaks in Lebanon within 10 days of case introduction prior to the immunization campaign, and showed that the current immunization campaign significantly reduced the speed of the infection in the event poliomyelitis cases enter the country. A minimum of 90% national immunization coverage was found to be required to prevent exponential propagation of potential transmission. Both surveillance and immunization efforts should be maintained at high standards in Lebanon and other countries in the area to detect and limit any potential outbreak. The use of computational population simulation models can provide a quantitative approach to assess the impact of immunization campaigns and the burden of infectious diseases even in the context of population migration.

  15. Fluorescence lifetime imaging of endogenous molecules in live mouse cancer models (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Svindrych, Zdenek; Wang, Tianxiong; Hu, Song; Periasamy, Ammasi

    2017-02-01

    NADH and FAD are important endogenous fluorescent coenzymes participating in key enzymatic reactions of cellular metabolism. While fluorescence intensities of NADH and FAD have been used to determine the redox state of cells and tissues, this simple approach breaks down in the case of deep-tissue intravital imaging due to depth- and wavelength-dependent light absorption and scattering. To circumvent this limitation, our research focuses on fluorescence lifetimes of two-photon excited NADH and FAD emission to study the metabolic state of live tissues. In our custom-built scanning microscope we combine tunable femtosecond Ti:sapphire laser (operating at 740 nm for NADH excitation and 890 nm for FAD excitation), two GaAsP hybrid detectors for registering individual fluorescence photons and two Becker and Hickl time correlator boards for high precision lifetime measurements. Together with our rigorous FLIM analysis approach (including image segmentation, multi-exponential decay fitting and detailed statistical analysis) we are able to detect metabolic changes in cancer xenografts (human pancreatic cancer MPanc96 cells injected subcutaneously into the ear of an immunodeficient nude mouse), relative to surrounding healthy tissue. Advantageously, with the same instrumentation we can also take high-resolution and high-contrast images of second harmonic signal (SHG) originating from collagen fibers of both the healthy skin and the growing tumor. The combination of metabolic measurements (NADH and FAD lifetime) and morphological information (collagen SHG) allows us to follow the tumor growth in live mouse model and the changes in tumor microenvironment.

  16. Atmospheric Muon Lifetime, Standard Model of Particles and the Lead Stopping Power for Muons

    NASA Astrophysics Data System (ADS)

    Gutarra-Leon, Angel; Barazandeh, Cioli; Majewski, Walerian

    2017-01-01

    The muon is a fundamental particles of matter. It decays into three other leptons through an exchange of the weak vector bosons W +/W-. Muons are present in the atmosphere from cosmic ray showers. By detecting the time delay between arrival of the muon and an appearance of the decay electron in our detector, we'll measure muon's lifetime at rest. From the lifetime we should be able to find the ratio gw /MW of the weak coupling constant gw (a weak analog of the electric charge) to the mass of the W-boson MW. Vacuum expectation value v of the Higg's field, which determines the masses of all particles of the Standard Model (SM), could be then calculated from our muon experiment as v =2MWc2/gw =(τ m μc2/6 π3ĥ)1/4m μc2 in terms of muon mass mµand muon lifetime τ only. Using known experimental value for MWc2 = 80.4 GeV we'll find the weak coupling constant gw. Using the SM relation e =gwsin θ√ hc ɛ0 with the experimental value of the Z0-photon weak mixing angle θ = 29o we could find from our muon lifetime the value of the elementary electric charge e. We'll determine the sea-level fluxes of low-energy and high-energy cosmic muons, then we'll shield the detector with varying thicknesses of lead plates and find the energy-dependent muon stopping power in lead.

  17. Treatment cost and life expectancy of diffuse large B-cell lymphoma (DLBCL): a discrete event simulation model on a UK population-based observational cohort.

    PubMed

    Wang, Han-I; Smith, Alexandra; Aas, Eline; Roman, Eve; Crouch, Simon; Burton, Cathy; Patmore, Russell

    2017-03-01

    Diffuse large B-cell lymphoma (DLBCL) is the commonest non-Hodgkin lymphoma. Previous studies examining the cost of treating DLBCL have generally focused on a specific first-line therapy alone; meaning that their findings can neither be extrapolated to the general patient population nor to other points along the treatment pathway. Based on empirical data from a representative population-based patient cohort, the objective of this study was to develop a simulation model that could predict costs and life expectancy of treating DLBCL. All patients newly diagnosed with DLBCL in the UK's population-based Haematological Malignancy Research Network ( www.hmrn.org ) in 2007 were followed until 2013 (n = 271). Mapped treatment pathways, alongside cost information derived from the National Tariff 2013/14, were incorporated into a patient-level simulation model in order to reflect the heterogeneities of patient characteristics and treatment options. The NHS and social services perspective was adopted, and all outcomes were discounted at 3.5 % per annum. Overall, the expected total medical costs were £22,122 for those treated with curative intent, and £2930 for those managed palliatively. For curative chemotherapy, the predicted medical costs were £14,966, £23,449 and £7376 for first-, second- and third-line treatments, respectively. The estimated annual cost for treating DLBCL across the UK was around £88-92 million. This is the first cost modelling study using empirical data to provide 'real world' evidence throughout the DLBCL treatment pathway. Future application of the model could include evaluation of new technologies/treatments to support healthcare decision makers, especially in the era of personalised medicine.

  18. Nonparametric evaluation of quantitative traits in population-based association studies when the genetic model is unknown.

    PubMed

    Konietschke, Frank; Libiger, Ondrej; Hothorn, Ludwig A

    2012-01-01

    Statistical association between a single nucleotide polymorphism (SNP) genotype and a quantitative trait in genome-wide association studies is usually assessed using a linear regression model, or, in the case of non-normally distributed trait values, using the Kruskal-Wallis test. While linear regression models assume an additive mode of inheritance via equi-distant genotype scores, Kruskal-Wallis test merely tests global differences in trait values associated with the three genotype groups. Both approaches thus exhibit suboptimal power when the underlying inheritance mode is dominant or recessive. Furthermore, these tests do not perform well in the common situations when only a few trait values are available in a rare genotype category (disbalance), or when the values associated with the three genotype categories exhibit unequal variance (variance heterogeneity). We propose a maximum test based on Marcus-type multiple contrast test for relative effect sizes. This test allows model-specific testing of either dominant, additive or recessive mode of inheritance, and it is robust against variance heterogeneity. We show how to obtain mode-specific simultaneous confidence intervals for the relative effect sizes to aid in interpreting the biological relevance of the results. Further, we discuss the use of a related all-pairwise comparisons contrast test with range preserving confidence intervals as an alternative to Kruskal-Wallis heterogeneity test. We applied the proposed maximum test to the Bogalusa Heart Study dataset, and gained a remarkable increase in the power to detect association, particularly for rare genotypes. Our simulation study also demonstrated that the proposed non-parametric tests control family-wise error rate in the presence of non-normality and variance heterogeneity contrary to the standard parametric approaches. We provide a publicly available R library nparcomp that can be used to estimate simultaneous confidence intervals or compatible

  19. Expectation Maximization Algorithm for Box-Cox Transformation Cure Rate Model and Assessment of Model Misspecification Under Weibull Lifetimes.

    PubMed

    Pal, Suvra; Balakrishnan, Narayanaswamy

    2018-05-01

    In this paper, we develop likelihood inference based on the expectation maximization algorithm for the Box-Cox transformation cure rate model assuming the lifetimes to follow a Weibull distribution. A simulation study is carried out to demonstrate the performance of the proposed estimation method. Through Monte Carlo simulations, we also study the effect of model misspecification on the estimate of cure rate. Finally, we analyze a well-known data on melanoma with the model and the inferential method developed here.

  20. A model measuring therapeutic inertia and the associated factors among diabetes patients: A nationwide population-based study in Taiwan.

    PubMed

    Huang, Li-Ying; Shau, Wen-Yi; Yeh, Hseng-Long; Chen, Tsung-Tai; Hsieh, Jun Yi; Su, Syi; Lai, Mei-Shu

    2015-01-01

    This article presents an analysis conducted on the patterns related to therapeutic inertia with the aim of uncovering how variables at the patient level and the healthcare provider level influence the intensification of therapy when it is clinically indicated. A cohort study was conducted on 899,135 HbA1c results from 168,876 adult diabetes patients with poorly controlled HbA1c levels. HbA1c results were used to identify variations in the prescription of hypoglycemic drugs. Logistic regression and hierarchical linear models (HLMs) were used to determine how differences among healthcare providers and patient characteristics influence therapeutic inertia. We estimated that 38.5% of the patients in this study were subject to therapeutic inertia. The odds ratio of cardiologists choosing to intensify therapy was 0.708 times that of endocrinologists. Furthermore, patients in medical centers were shown to be 1.077 times more likely to be prescribed intensified treatment than patients in primary clinics. The HLMs presented results similar to those of the logistic model. Overall, we determined that 88.92% of the variation in the application of intensified treatment was at the within-physician level. Reducing therapeutic inertia will likely require educational initiatives aimed at ensuring adherence to clinical practice guidelines in the care of diabetes patients. © 2014, The American College of Clinical Pharmacology.

  1. Population-based pharmacoeconomic model for adopting capecitabine/docetaxel combination treatment for anthracycline-pretreated metastatic breast cancer.

    PubMed

    Verma, Shailendra; Ilersich, A Lane

    2003-01-01

    To model the cost-effectiveness of adopting capecitabine/docetaxel combination therapy in place of single-agent taxane therapy for women in the province of Ontario, Canada, receiving treatment for anthracycline-pretreated metastatic breast cancer. Clinical effectiveness and economic data were combined in a population model, from the perspective of a universal health care system. Estimates of clinical effectiveness and medical resource utilization were derived prospectively during a phase III randomized controlled trial comparing single-agent docetaxel with capecitabine/docetaxel combination therapy. Population data were obtained from the Cancer Care Ontario Registry and provincial prescription claims data. During 1999-2000, 542 patients were eligible for taxane monotherapy. As capecitabine/docetaxel treatment confers a median 3-month survival benefit compared with docetaxel monotherapy, the projected survival gain in these patients was 136 life-years. The results of the cost-effectiveness analysis demonstrate that the survival benefit provided by the addition of capecitabine to single-agent docetaxel is afforded at a small incremental cost of Canadian $3,691 per life-year gained. Hospitalization costs for treatment of adverse events were less for patients receiving capecitabine/docetaxel combination therapy than for those receiving docetaxel monotherapy. The results were robust for adjustments in treatment costs and adverse effects costs. Due to its 3-month survival gain and small incremental treatment cost, capecitabine/docetaxel is judged to be a highly cost-effective treatment in anthracycline-pretreated advanced breast cancer. From the perspective of the Ontario health care system, the addition of capecitabine to docetaxel in this patient population is a clinically appropriate and economically acceptable treatment strategy.

  2. Approaches in methodology for population-based longitudinal study on neuroprotective model for healthy longevity (TUA) among Malaysian Older Adults.

    PubMed

    Shahar, Suzana; Omar, Azahadi; Vanoh, Divya; Hamid, Tengku Aizan; Mukari, Siti Zamratol Mai-Sarah; Din, Normah Che; Rajab, Nor Fadilah; Mohammed, Zainora; Ibrahim, Rahimah; Loo, Won Hui; Meramat, Asheila; Kamaruddin, Mohd Zul Amin; Bagat, Mohamad Fazdillah; Razali, Rosdinom

    2016-12-01

    A number of longitudinal studies on aging have been designed to determine the predictors of healthy longevity, including the neuroprotective factors, however, relatively few studies included a wide range of factors and highlighted the challenges faced during data collection. Thus, the longitudinal study on neuroprotective model for healthy longevity (LRGS TUA) has been designed to prospectively investigate the magnitude of cognitive decline and its risk factors through a comprehensive multidimensional assessment comprising of biophysical health, auditory and visual function, nutrition and dietary pattern and psychosocial aspects. At baseline, subjects were interviewed for their status on sociodemographic, health, neuropsychological test, psychosocial and dietary intake. Subjects were also measured for anthropometric and physical function and fitness. Biospecimens including blood, buccal swap, hair and toenail were collected, processed and stored. A subsample was assessed for sensory function, i.e., vision and auditory. During follow-up, at 18 and 36 months, most of the measurements, along with morbidity and mortality outcomes will be collected. The description of mild cognitive impairment, successful aging and usual aging process is presented here. A total 2322 respondents were recruited in the data analysis at baseline. Most of the respondents were categorized as experiencing usual aging (73 %), followed by successful aging (11 %) and mild cognitive impairment (16 %). The LRGS TUA study is the most comprehensive longitudinal study on aging in Malaysia, and will contribute to the understanding of the aging process and factors associated with healthy aging and mental well-being of a multiethnic population in Malaysia.

  3. [Development of Markov models for economics evaluation of strategies on hepatitis B vaccination and population-based antiviral treatment in China].

    PubMed

    Yang, P C; Zhang, S X; Sun, P P; Cai, Y L; Lin, Y; Zou, Y H

    2017-07-10

    Objective: To construct the Markov models to reflect the reality of prevention and treatment interventions against hepatitis B virus (HBV) infection, simulate the natural history of HBV infection in different age groups and provide evidence for the economics evaluations of hepatitis B vaccination and population-based antiviral treatment in China. Methods: According to the theory and techniques of Markov chain, the Markov models of Chinese HBV epidemic were developed based on the national data and related literature both at home and abroad, including the settings of Markov model states, allowable transitions and initial and transition probabilities. The model construction, operation and verification were conducted by using software TreeAge Pro 2015. Results: Several types of Markov models were constructed to describe the disease progression of HBV infection in neonatal period, perinatal period or adulthood, the progression of chronic hepatitis B after antiviral therapy, hepatitis B prevention and control in adults, chronic hepatitis B antiviral treatment and the natural progression of chronic hepatitis B in general population. The model for the newborn was fundamental which included ten states, i.e . susceptiblity to HBV, HBsAg clearance, immune tolerance, immune clearance, low replication, HBeAg negative CHB, compensated cirrhosis, decompensated cirrhosis, hepatocellular carcinoma (HCC) and death. The susceptible state to HBV was excluded in the perinatal period model, and the immune tolerance state was excluded in the adulthood model. The model for general population only included two states, survive and death. Among the 5 types of models, there were 9 initial states assigned with initial probabilities, and 27 states for transition probabilities. The results of model verifications showed that the probability curves were basically consistent with the situation of HBV epidemic in China. Conclusion: The Markov models developed can be used in economics evaluation of

  4. The role of perceived air pollution and health risk perception in health symptoms and disease: a population-based study combined with modelled levels of PM10.

    PubMed

    Orru, Kati; Nordin, Steven; Harzia, Hedi; Orru, Hans

    2018-07-01

    Adverse health impact of air pollution on health may not only be associated with the level of exposure, but rather mediated by perception of the pollution and by top-down processing (e.g. beliefs of the exposure being hazardous), especially in areas with relatively low levels of pollutants. The aim of this study was to test a model that describes interrelations between air pollution (particles < 10 [Formula: see text]m, PM 10 ), perceived pollution, health risk perception, health symptoms and diseases. A population-based questionnaire study was conducted among 1000 Estonian residents (sample was stratified by age, sex, and geographical location) about health risk perception and coping. The PM 10 levels were modelled in 1 × 1 km grids using a Eulerian air quality dispersion model. Respondents were ascribed their annual mean PM 10 exposure according to their home address. Path analysis was performed to test the validity of the model. The data refute the model proposing that exposure level significantly influences symptoms and disease. Instead, the perceived exposure influences symptoms and the effect of perceived exposure on disease is mediated by health risk perception. This relationship is more pronounced in large cities compared to smaller towns or rural areas. Perceived pollution and health risk perception, in particular in large cities, play important roles in understanding and predicting environmentally induced symptoms and diseases at relatively low levels of air pollution.

  5. Budget impact analysis of switching to digital mammography in a population-based breast cancer screening program: a discrete event simulation model.

    PubMed

    Comas, Mercè; Arrospide, Arantzazu; Mar, Javier; Sala, Maria; Vilaprinyó, Ester; Hernández, Cristina; Cots, Francesc; Martínez, Juan; Castells, Xavier

    2014-01-01

    To assess the budgetary impact of switching from screen-film mammography to full-field digital mammography in a population-based breast cancer screening program. A discrete-event simulation model was built to reproduce the breast cancer screening process (biennial mammographic screening of women aged 50 to 69 years) combined with the natural history of breast cancer. The simulation started with 100,000 women and, during a 20-year simulation horizon, new women were dynamically entered according to the aging of the Spanish population. Data on screening were obtained from Spanish breast cancer screening programs. Data on the natural history of breast cancer were based on US data adapted to our population. A budget impact analysis comparing digital with screen-film screening mammography was performed in a sample of 2,000 simulation runs. A sensitivity analysis was performed for crucial screening-related parameters. Distinct scenarios for recall and detection rates were compared. Statistically significant savings were found for overall costs, treatment costs and the costs of additional tests in the long term. The overall cost saving was 1,115,857€ (95%CI from 932,147 to 1,299,567) in the 10th year and 2,866,124€ (95%CI from 2,492,610 to 3,239,638) in the 20th year, representing 4.5% and 8.1% of the overall cost associated with screen-film mammography. The sensitivity analysis showed net savings in the long term. Switching to digital mammography in a population-based breast cancer screening program saves long-term budget expense, in addition to providing technical advantages. Our results were consistent across distinct scenarios representing the different results obtained in European breast cancer screening programs.

  6. Budget Impact Analysis of Switching to Digital Mammography in a Population-Based Breast Cancer Screening Program: A Discrete Event Simulation Model

    PubMed Central

    Comas, Mercè; Arrospide, Arantzazu; Mar, Javier; Sala, Maria; Vilaprinyó, Ester; Hernández, Cristina; Cots, Francesc; Martínez, Juan; Castells, Xavier

    2014-01-01

    Objective To assess the budgetary impact of switching from screen-film mammography to full-field digital mammography in a population-based breast cancer screening program. Methods A discrete-event simulation model was built to reproduce the breast cancer screening process (biennial mammographic screening of women aged 50 to 69 years) combined with the natural history of breast cancer. The simulation started with 100,000 women and, during a 20-year simulation horizon, new women were dynamically entered according to the aging of the Spanish population. Data on screening were obtained from Spanish breast cancer screening programs. Data on the natural history of breast cancer were based on US data adapted to our population. A budget impact analysis comparing digital with screen-film screening mammography was performed in a sample of 2,000 simulation runs. A sensitivity analysis was performed for crucial screening-related parameters. Distinct scenarios for recall and detection rates were compared. Results Statistically significant savings were found for overall costs, treatment costs and the costs of additional tests in the long term. The overall cost saving was 1,115,857€ (95%CI from 932,147 to 1,299,567) in the 10th year and 2,866,124€ (95%CI from 2,492,610 to 3,239,638) in the 20th year, representing 4.5% and 8.1% of the overall cost associated with screen-film mammography. The sensitivity analysis showed net savings in the long term. Conclusions Switching to digital mammography in a population-based breast cancer screening program saves long-term budget expense, in addition to providing technical advantages. Our results were consistent across distinct scenarios representing the different results obtained in European breast cancer screening programs. PMID:24832200

  7. Profit-Based Model Selection for Customer Retention Using Individual Customer Lifetime Values.

    PubMed

    Óskarsdóttir, María; Baesens, Bart; Vanthienen, Jan

    2018-03-01

    The goal of customer retention campaigns, by design, is to add value and enhance the operational efficiency of businesses. For organizations that strive to retain their customers in saturated, and sometimes fast moving, markets such as the telecommunication and banking industries, implementing customer churn prediction models that perform well and in accordance with the business goals is vital. The expected maximum profit (EMP) measure is tailored toward this problem by taking into account the costs and benefits of a retention campaign and estimating its worth for the organization. Unfortunately, the measure assumes fixed and equal customer lifetime value (CLV) for all customers, which has been shown to not correspond well with reality. In this article, we extend the EMP measure to take into account the variability in the lifetime values of customers, thereby basing it on individual characteristics. We demonstrate how to incorporate the heterogeneity of CLVs when CLVs are known, when their prior distribution is known, and when neither is known. By taking into account individual CLVs, our proposed approach of measuring model performance gives novel insights when deciding on a customer retention campaign. The method is dependent on the characteristics of the customer base as is compliant with modern business analytics and accommodates the data-driven culture that has manifested itself within organizations.

  8. Modeling the impact of biota on polychlorinated biphenyls (PCBs) fate and transport in Lake Ontario using a population-based multi-compartment fugacity approach.

    PubMed

    Sun, Xiangfei; Ng, Carla A; Small, Mitchell J

    2018-06-12

    Organisms have long been treated as receptors in exposure studies of polychlorinated biphenyls (PCBs) and other persistent organic pollutants (POPs). The influences of environmental pollution on organisms are well recognized. However, the impact of biota on PCB transport in an environmental system has not been considered in sufficient detail. In this study, a population-based multi-compartment fugacity model is developed by reconfiguring the organisms as populated compartments and reconstructing all the exchange processes between the organism compartments and environmental compartments, especially the previously ignored feedback routes from biota to the environment. We evaluate the model performance by simulating the PCB concentration distribution in Lake Ontario using published loading records. The lake system is divided into three environment compartments (air, water, and sediment) and several organism groups according to the dominant local biotic species. The comparison indicates that the simulated results are well-matched by a list of published field measurements from different years. We identify a new process, called Facilitated Biotic Intermedia Transport (FBIT), to describe the enhanced pollution transport that occurs between environmental media and organisms. As the hydrophobicity of PCB congener increases, the organism population exerts greater influence on PCB mass flows. In a high biomass scenario, the model simulation indicates significant FBIT effects and biotic storage effects with hydrophobic PCB congeners, which also lead to significant shifts in systemic contaminant exchange rates between organisms and the environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Lifetime maps for orbits around Callisto using a double-averaged model

    NASA Astrophysics Data System (ADS)

    Cardoso dos Santos, Josué; Carvalho, Jean P. S.; Prado, Antônio F. B. A.; Vilhena de Moraes, Rodolpho

    2017-12-01

    The present paper studies the lifetime of orbits around a moon that is in orbit around its mother planet. In the context of the inner restricted three-body problem, the dynamical model considered in the present study uses the double-averaged dynamics of a spacecraft moving around a moon under the gravitational pulling of a disturbing third body in an elliptical orbit. The non-uniform distribution of the mass of the moon is also considered. Applications are performed using numerical experiments for the Callisto-spacecraft-Jupiter system, and lifetime maps for different values of the eccentricity of the disturbing body (Jupiter) are presented, in order to investigate the role of this parameter in these maps. The idea is to simulate a system with the same physical parameters as the Jupiter-Callisto system, but with larger eccentricities. These maps are also useful for validation and improvements in the results available in the literature, such as to find conditions to extend the available time for a massless orbiting body to be in highly inclined orbits under gravitational disturbances coming from the other bodies of the system.

  10. Development of a lifetime prediction model for lithium-ion batteries based on extended accelerated aging test data

    NASA Astrophysics Data System (ADS)

    Ecker, Madeleine; Gerschler, Jochen B.; Vogel, Jan; Käbitz, Stefan; Hust, Friedrich; Dechent, Philipp; Sauer, Dirk Uwe

    2012-10-01

    Battery lifetime prognosis is a key requirement for successful market introduction of electric and hybrid vehicles. This work aims at the development of a lifetime prediction approach based on an aging model for lithium-ion batteries. A multivariable analysis of a detailed series of accelerated lifetime experiments representing typical operating conditions in hybrid electric vehicle is presented. The impact of temperature and state of charge on impedance rise and capacity loss is quantified. The investigations are based on a high-power NMC/graphite lithium-ion battery with good cycle lifetime. The resulting mathematical functions are physically motivated by the occurring aging effects and are used for the parameterization of a semi-empirical aging model. An impedance-based electric-thermal model is coupled to the aging model to simulate the dynamic interaction between aging of the battery and the thermal as well as electric behavior. Based on these models different drive cycles and management strategies can be analyzed with regard to their impact on lifetime. It is an important tool for vehicle designers and for the implementation of business models. A key contribution of the paper is the parameterization of the aging model by experimental data, while aging simulation in the literature usually lacks a robust empirical foundation.

  11. Estimation of iodine nutrition and thyroid function status in late-gestation pregnant women in the United States: Development and application of a population-based pregnancy model

    SciTech Connect

    Lumen, A., E-mail: Annie.Lumen@fda.hhs.gov

    Previously, a deterministic biologically-based dose-response (BBDR) pregnancy model was developed to evaluate moderate thyroid axis disturbances with and without thyroid-active chemical exposure in a near-term pregnant woman and fetus. In the current study, the existing BBDR model was adapted to include a wider functional range of iodine nutrition, including more severe iodine deficiency conditions, and to incorporate empirically the effects of homeostatic mechanisms. The extended model was further developed into a population-based model and was constructed using a Monte Carlo-based probabilistic framework. In order to characterize total (T4) and free (fT4) thyroxine levels for a given iodine status at themore » population-level, the distribution of iodine intake for late-gestation pregnant women in the U.S was reconstructed using various reverse dosimetry methods and available biomonitoring data. The range of median (mean) iodine intake values resulting from three different methods of reverse dosimetry tested was 196.5–219.9 μg of iodine/day (228.2–392.9 μg of iodine/day). There was minimal variation in model-predicted maternal serum T4 and ft4 thyroxine levels from use of the three reconstructed distributions of iodine intake; the range of geometric mean for T4 and fT4, was 138–151.7 nmol/L and 7.9–8.7 pmol/L, respectively. The average value of the ratio of the 97.5th percentile to the 2.5th percentile equaled 3.1 and agreed well with similar estimates from recent observations in third-trimester pregnant women in the U.S. In addition, the reconstructed distributions of iodine intake allowed us to estimate nutrient inadequacy for late-gestation pregnant women in the U.S. via the probability approach. The prevalence of iodine inadequacy for third-trimester pregnant women in the U.S. was estimated to be between 21% and 44%. Taken together, the current work provides an improved tool for evaluating iodine nutritional status and the corresponding thyroid

  12. Injury risk functions based on population-based finite element model responses: Application to femurs under dynamic three-point bending.

    PubMed

    Park, Gwansik; Forman, Jason; Kim, Taewung; Panzer, Matthew B; Crandall, Jeff R

    2018-02-28

    The goal of this study was to explore a framework for developing injury risk functions (IRFs) in a bottom-up approach based on responses of parametrically variable finite element (FE) models representing exemplar populations. First, a parametric femur modeling tool was developed and validated using a subject-specific (SS)-FE modeling approach. Second, principal component analysis and regression were used to identify parametric geometric descriptors of the human femur and the distribution of those factors for 3 target occupant sizes (5th, 50th, and 95th percentile males). Third, distributions of material parameters of cortical bone were obtained from the literature for 3 target occupant ages (25, 50, and 75 years) using regression analysis. A Monte Carlo method was then implemented to generate populations of FE models of the femur for target occupants, using a parametric femur modeling tool. Simulations were conducted with each of these models under 3-point dynamic bending. Finally, model-based IRFs were developed using logistic regression analysis, based on the moment at fracture observed in the FE simulation. In total, 100 femur FE models incorporating the variation in the population of interest were generated, and 500,000 moments at fracture were observed (applying 5,000 ultimate strains for each synthesized 100 femur FE models) for each target occupant characteristics. Using the proposed framework on this study, the model-based IRFs for 3 target male occupant sizes (5th, 50th, and 95th percentiles) and ages (25, 50, and 75 years) were developed. The model-based IRF was located in the 95% confidence interval of the test-based IRF for the range of 15 to 70% injury risks. The 95% confidence interval of the developed IRF was almost in line with the mean curve due to a large number of data points. The framework proposed in this study would be beneficial for developing the IRFs in a bottom-up manner, whose range of variabilities is informed by the population-based

  13. The relationship between the Five-Factor Model personality traits and peptic ulcer disease in a large population-based adult sample.

    PubMed

    Realo, Anu; Teras, Andero; Kööts-Ausmees, Liisi; Esko, Tõnu; Metspalu, Andres; Allik, Jüri

    2015-12-01

    The current study examined the relationship between the Five-Factor Model personality traits and physician-confirmed peptic ulcer disease (PUD) diagnosis in a large population-based adult sample, controlling for the relevant behavioral and sociodemographic factors. Personality traits were assessed by participants themselves and by knowledgeable informants using the NEO Personality Inventory-3 (NEO PI-3). When controlling for age, sex, education, and cigarette smoking, only one of the five NEO PI-3 domain scales - higher Neuroticism - and two facet scales - lower A1: Trust and higher C1: Competence - made a small, yet significant contribution (p < 0.01) to predicting PUD in logistic regression analyses. In the light of these relatively modest associations, our findings imply that it is certain behavior (such as smoking) and sociodemographic variables (such as age, gender, and education) rather than personality traits that are associated with the diagnosis of PUD at a particular point in time. Further prospective studies with a longitudinal design and multiple assessments would be needed to fully understand if the FFM personality traits serve as risk factors for the development of PUD. © 2015 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  14. Solving inverse problem for Markov chain model of customer lifetime value using flower pollination algorithm

    NASA Astrophysics Data System (ADS)

    Al-Ma'shumah, Fathimah; Permana, Dony; Sidarto, Kuntjoro Adji

    2015-12-01

    Customer Lifetime Value is an important and useful concept in marketing. One of its benefits is to help a company for budgeting marketing expenditure for customer acquisition and customer retention. Many mathematical models have been introduced to calculate CLV considering the customer retention/migration classification scheme. A fairly new class of these models which will be described in this paper uses Markov Chain Models (MCM). This class of models has the major advantage for its flexibility to be modified to several different cases/classification schemes. In this model, the probabilities of customer retention and acquisition play an important role. From Pfeifer and Carraway, 2000, the final formula of CLV obtained from MCM usually contains nonlinear form of the transition probability matrix. This nonlinearity makes the inverse problem of CLV difficult to solve. This paper aims to solve this inverse problem, yielding the approximate transition probabilities for the customers, by applying metaheuristic optimization algorithm developed by Yang, 2013, Flower Pollination Algorithm. The major interpretation of obtaining the transition probabilities are to set goals for marketing teams in keeping the relative frequencies of customer acquisition and customer retention.

  15. Species abundance distributions in neutral models with immigration or mutation and general lifetimes.

    PubMed

    Lambert, Amaury

    2011-07-01

    We consider a general, neutral, dynamical model of biodiversity. Individuals have i.i.d. lifetime durations, which are not necessarily exponentially distributed, and each individual gives birth independently at constant rate λ. Thus, the population size is a homogeneous, binary Crump-Mode-Jagers process (which is not necessarily a Markov process). We assume that types are clonally inherited. We consider two classes of speciation models in this setting. In the immigration model, new individuals of an entirely new species singly enter the population at constant rate μ (e.g., from the mainland into the island). In the mutation model, each individual independently experiences point mutations in its germ line, at constant rate θ. We are interested in the species abundance distribution, i.e., in the numbers, denoted I(n)(k) in the immigration model and A(n)(k) in the mutation model, of species represented by k individuals, k = 1, 2, . . . , n, when there are n individuals in the total population. In the immigration model, we prove that the numbers (I(t)(k); k ≥ 1) of species represented by k individuals at time t, are independent Poisson variables with parameters as in Fisher's log-series. When conditioning on the total size of the population to equal n, this results in species abundance distributions given by Ewens' sampling formula. In particular, I(n)(k) converges as n → ∞ to a Poisson r.v. with mean γ/k, where γ : = μ/λ. In the mutation model, as n → ∞, we obtain the almost sure convergence of n (-1) A(n)(k) to a nonrandom explicit constant. In the case of a critical, linear birth-death process, this constant is given by Fisher's log-series, namely n(-1) A(n)(k) converges to α(k)/k, where α : = λ/(λ + θ). In both models, the abundances of the most abundant species are briefly discussed.

  16. Feasibility of using limited-population-based average R10 for pharmacokinetic modeling of osteosarcoma dynamic contrast-enhanced magnetic resonance imaging data.

    PubMed

    Huang, Wei; Wang, Ya; Panicek, David M; Schwartz, Lawrence H; Koutcher, Jason A

    2009-07-01

    Retrospective analyses of clinical dynamic contrast-enhanced (DCE) MRI studies may be limited by failure to measure the longitudinal relaxation rate constant (R(1)) initially, which is necessary for quantitative analysis. In addition, errors in R(1) estimation in each individual experiment can cause inconsistent results in derivations of pharmacokinetic parameters, K(trans) and v(e), by kinetic modeling of the DCE-MRI time course data. A total of 18 patients with lower extremity osteosarcomas underwent multislice DCE-MRI prior to surgery. For the individual R(1) measurement approach, the R(1) time course was obtained using the two-point R(1) determination method. For the average R(10) (precontrast R(1)) approach, the R(1) time course was derived using the DCE-MRI pulse sequence signal intensity equation and the average R(10) value of this population. The whole tumor and histogram median K(trans) (0.57+/-0.37 and 0.45+/-0.32 min(-1)) and v(e) (0.59+/-0.20 and 0.56+/-0.17) obtained with the individual R(1) measurement approach are not significantly different (paired t test) from those (K(trans): 0.61+/-0.46 and 0.44+/-0.33 min(-1); v(e): 0.61+/-0.19 and 0.55+/-0.14) obtained with the average R(10) approach. The results suggest that it is feasible, as well as practical, to use a limited-population-based average R(10) for pharmacokinetic modeling of osteosarcoma DCE-MRI data.

  17. Development of a population-based threshold model of conidial germination for analysing the effects of physiological manipulation on the stress tolerance and infectivity of insect pathogenic fungi.

    PubMed

    Andersen, M; Magan, N; Mead, A; Chandler, D

    2006-09-01

    Entomopathogenic fungi are being used as biocontrol agents of insect pests, but their efficacy can be poor in environments where water availability is reduced. In this study, the potential to improve biocontrol by physiologically manipulating fungal inoculum was investigated. Cultures of Beauveria bassiana, Lecanicillium muscarium, Lecanicillium longisporum, Metarhizium anisopliae and Paecilomyces fumosoroseus were manipulated by growing them under conditions of water stress, which produced conidia with increased concentrations of erythritol. The time-course of germination of conidia at different water activities (water activity, aw) was described using a generalized linear model, and in most cases reducing the water activity of the germination medium delayed the onset of germination without affecting the distribution of germination times. The germination of M. anisopliae, L. muscarium, L. longisporum and P. fumosoroseus was accelerated over a range of aw levels as a result of physiological manipulation. However, the relationship between the effect of physiological manipulation on germination and the osmolyte content of conidia varied according to fungal species. There was a linear relationship between germination rate, expressed as the reciprocal of germination time, and aw of the germination medium, but there was no significant effect of fungal species or physiological manipulation on the aw threshold for germination. In bioassays with M. anisopliae, physiologically manipulated conidia germinated more rapidly on the surface of an insect host, the melon cotton aphid Aphis gossypii, and fungal virulence was increased even when relative humidity was reduced after an initial high period. It is concluded that physiological manipulation may lead to improvements in biocontrol in the field, but choice of fungal species/isolate will be critical. In addition, the population-based threshold model used in this study, which considered germination in terms of physiological

  18. Estimation of iodine nutrition and thyroid function status in late-gestation pregnant women in the United States: Development and application of a population-based pregnancy model.

    PubMed

    Lumen, A; George, N I

    2017-01-01

    Previously, a deterministic biologically-based dose-response (BBDR) pregnancy model was developed to evaluate moderate thyroid axis disturbances with and without thyroid-active chemical exposure in a near-term pregnant woman and fetus. In the current study, the existing BBDR model was adapted to include a wider functional range of iodine nutrition, including more severe iodine deficiency conditions, and to incorporate empirically the effects of homeostatic mechanisms. The extended model was further developed into a population-based model and was constructed using a Monte Carlo-based probabilistic framework. In order to characterize total (T4) and free (fT4) thyroxine levels for a given iodine status at the population-level, the distribution of iodine intake for late-gestation pregnant women in the U.S was reconstructed using various reverse dosimetry methods and available biomonitoring data. The range of median (mean) iodine intake values resulting from three different methods of reverse dosimetry tested was 196.5-219.9μg of iodine/day (228.2-392.9μg of iodine/day). There was minimal variation in model-predicted maternal serum T4 and ft4 thyroxine levels from use of the three reconstructed distributions of iodine intake; the range of geometric mean for T4 and fT4, was 138-151.7nmol/L and 7.9-8.7pmol/L, respectively. The average value of the ratio of the 97.5th percentile to the 2.5th percentile equaled 3.1 and agreed well with similar estimates from recent observations in third-trimester pregnant women in the U.S. In addition, the reconstructed distributions of iodine intake allowed us to estimate nutrient inadequacy for late-gestation pregnant women in the U.S. via the probability approach. The prevalence of iodine inadequacy for third-trimester pregnant women in the U.S. was estimated to be between 21% and 44%. Taken together, the current work provides an improved tool for evaluating iodine nutritional status and the corresponding thyroid function status in

  19. Prediction of liver disease in patients whose liver function tests have been checked in primary care: model development and validation using population-based observational cohorts.

    PubMed

    McLernon, David J; Donnan, Peter T; Sullivan, Frank M; Roderick, Paul; Rosenberg, William M; Ryder, Steve D; Dillon, John F

    2014-06-02

    To derive and validate a clinical prediction model to estimate the risk of liver disease diagnosis following liver function tests (LFTs) and to convert the model to a simplified scoring tool for use in primary care. Population-based observational cohort study of patients in Tayside Scotland identified as having their LFTs performed in primary care and followed for 2 years. Biochemistry data were linked to secondary care, prescriptions and mortality data to ascertain baseline characteristics of the derivation cohort. A separate validation cohort was obtained from 19 general practices across the rest of Scotland to externally validate the final model. Primary care, Tayside, Scotland. Derivation cohort: LFT results from 310 511 patients. After exclusions (including: patients under 16 years, patients having initial LFTs measured in secondary care, bilirubin >35 μmol/L, liver complications within 6 weeks and history of a liver condition), the derivation cohort contained 95 977 patients with no clinically apparent liver condition. Validation cohort: after exclusions, this cohort contained 11 653 patients. Diagnosis of a liver condition within 2 years. From the derivation cohort (n=95 977), 481 (0.5%) were diagnosed with a liver disease. The model showed good discrimination (C-statistic=0.78). Given the low prevalence of liver disease, the negative predictive values were high. Positive predictive values were low but rose to 20-30% for high-risk patients. This study successfully developed and validated a clinical prediction model and subsequent scoring tool, the Algorithm for Liver Function Investigations (ALFI), which can predict liver disease risk in patients with no clinically obvious liver disease who had their initial LFTs taken in primary care. ALFI can help general practitioners focus referral on a small subset of patients with higher predicted risk while continuing to address modifiable liver disease risk factors in those at lower risk. Published

  20. Natural History of Dependency in the Elderly: A 24-Year Population-Based Study Using a Longitudinal Item Response Theory Model.

    PubMed

    Edjolo, Arlette; Proust-Lima, Cécile; Delva, Fleur; Dartigues, Jean-François; Pérès, Karine

    2016-02-15

    We aimed to describe the hierarchical structure of Instrumental Activities of Daily Living (IADL) and basic Activities of Daily Living (ADL) and trajectories of dependency before death in an elderly population using item response theory methodology. Data were obtained from a population-based French cohort study, the Personnes Agées QUID (PAQUID) Study, of persons aged ≥65 years at baseline in 1988 who were recruited from 75 randomly selected areas in Gironde and Dordogne. We evaluated IADL and ADL data collected at home every 2-3 years over a 24-year period (1988-2012) for 3,238 deceased participants (43.9% men). We used a longitudinal item response theory model to investigate the item sequence of 11 IADL and ADL combined into a single scale and functional trajectories adjusted for education, sex, and age at death. The findings confirmed the earliest losses in IADL (shopping, transporting, finances) at the partial limitation level, and then an overlapping of concomitant IADL and ADL, with bathing and dressing being the earliest ADL losses, and finally total losses for toileting, continence, eating, and transferring. Functional trajectories were sex-specific, with a benefit of high education that persisted until death in men but was only transient in women. An in-depth understanding of this sequence provides an early warning of functional decline for better adaptation of medical and social care in the elderly. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Estimated incidence of cardiovascular complications related to type 2 diabetes in Mexico using the UKPDS outcome model and a population-based survey

    PubMed Central

    2011-01-01

    Background To estimate the incidence of complications, life expectancy and diabetes related mortality in the Mexican diabetic population over the next two decades using data from a nation-wide, population based survey and the United Kingdom Prospective Diabetes Study (UKPDS) outcome model Methods The cohort included all patients with type 2 diabetes evaluated during the National Health and Nutrition Survey (ENSANut) 2006. ENSANut is a probabilistic multistage stratified survey whose aim was to measure the prevalence of chronic diseases. A total of 47,152 households were visited. Results are shown stratified by gender, time since diagnosis (> or ≤ to 10 years) and age at the time of diagnosis (> or ≤ 40 years). Results The prevalence of diabetes in our cohort was 14.4%. The predicted 20 year-incidence for chronic complications per 1000 individuals are: ischemic heart disease 112, myocardial infarction 260, heart failure 113, stroke 101, and amputation 62. Furthermore, 539 per 1000 patients will have a diabetes-related premature death. The average life expectancy for the diabetic population is 10.9 years (95%CI 10.7-11.2); this decreases to 8.3 years after adjusting for quality of life (CI95% 8.1-8.5). Male sex and cases diagnosed after age 40 have the highest risk for developing at least one major complication during the next 20 years. Conclusions Based on the current clinical profile of Mexican patients with diabetes, the burden of disease related complications will be tremendous over the next two decades. PMID:21214916

  2. Cost-Effectiveness of Orthogeriatric and Fracture Liaison Service Models of Care for Hip Fracture Patients: A Population-Based Study.

    PubMed

    Leal, Jose; Gray, Alastair M; Hawley, Samuel; Prieto-Alhambra, Daniel; Delmestri, Antonella; Arden, Nigel K; Cooper, Cyrus; Javaid, M Kassim; Judge, Andrew

    2017-02-01

    Fracture liaison services are recommended as a model of best practice for organizing patient care and secondary fracture prevention for hip fracture patients, although variation exists in how such services are structured. There is considerable uncertainty as to which model is most cost-effective and should therefore be mandated. This study evaluated the cost- effectiveness of orthogeriatric (OG)- and nurse-led fracture liaison service (FLS) models of post-hip fracture care compared with usual care. Analyses were conducted from a health care and personal social services payer perspective, using a Markov model to estimate the lifetime impact of the models of care. The base-case population consisted of men and women aged 83 years with a hip fracture. The risk and costs of hip and non-hip fractures were derived from large primary and hospital care data sets in the UK. Utilities were informed by a meta-regression of 32 studies. In the base-case analysis, the orthogeriatric-led service was the most effective and cost-effective model of care at a threshold of £30,000 per quality-adjusted life years gained (QALY). For women aged 83 years, the OG-led service was the most cost-effective at £22,709/QALY. If only health care costs are considered, OG-led service was cost-effective at £12,860/QALY and £14,525/QALY for women and men aged 83 years, respectively. Irrespective of how patients were stratified in terms of their age, sex, and Charlson comorbidity score at index hip fracture, our results suggest that introducing an orthogeriatrician-led or a nurse-led FLS is cost-effective when compared with usual care. Although considerable uncertainty remains concerning which of the models of care should be preferred, introducing an orthogeriatrician-led service seems to be the most cost-effective service to pursue. © 2016 American Society for Bone and Mineral Research. © 2016 American Society for Bone and Mineral Research.

  3. Adding smoking to the Fardal model of cost-effectiveness for the life-time treatment of periodontal diseases.

    PubMed

    Fardal, Øystein; Grytten, Jostein; Martin, John; Ellingsen, Stig; Fardal, Patrick; Heasman, Peter; Linden, Gerard J

    2018-05-16

    Little is known about the financial costs that smoking adds to the life-time treatment of periodontal disease. The total life-time cost of periodontal treatment was modelled using data from private periodontal practice. The costs of initial and supportive therapy, re-treatment and tooth replacements (with bridgework or implants) were identified using average dental charges from the American Dental Association survey. Smoking costs at $6 and $10 for 20 cigarettes were compared to the costs of life-time periodontal treatment for stable and unstable compliant patients. Smoking added 8.8% to the financial cost of the life-time cost of periodontal therapy in stable maintenance patients, 40.1% in patients who needed one extra maintenance visit and 71.4% in patients who needed two extra maintenance visits per year in addition to added re-treatment. The cost of smoking far exceeded the cost of periodontal treatment; For patients who smoked 10 to 40 cigarettes per day at the cost of $6 or $10 a pack, the cost of smoking exceeded the cost of life-time periodontal treatment by between 2.7 and 17.9 times. Smoking 40 cigarettes at $10 a packet for 3.4 years would pay for the entire life-time cost of periodontal treatment. Smoking adds considerable extra financial costs to the life-time treatment of periodontal diseases. The cost of smoking itself exceeds the cost of periodontal therapy. This article is protected by copyright. All rights reserved. © 2018 American Academy of Periodontology.

  4. A CTRW-based model of time-resolved fluorescence lifetime imaging in a turbid medium

    NASA Astrophysics Data System (ADS)

    Chernomordik, Victor; Gandjbakhche, Amir H.; Hassan, Moinuddin; Pajevic, Sinisa; Weiss, George H.

    2010-12-01

    We develop an analytic model of time-resolved fluorescent imaging of photons migrating through a semi-infinite turbid medium bounded by an infinite plane in the presence of a single stationary point fluorophore embedded in the medium. In contrast to earlier models of fluorescent imaging in which photon motion is assumed to be some form of continuous diffusion process, the present analysis is based on a continuous-time random walk (CTRW) on a simple cubic lattice, the objective being to estimate the position and lifetime of the fluorophore. This can provide information related to local variations in pH and temperature with potential medical significance. Aspects of the theory were tested using time-resolved measurements of the fluorescence from small inclusions inside tissue-like phantoms. The experimental results were found to be in good agreement with theoretical predictions provided that the fluorophore was not located too close to the planar boundary, a common problem in many diffusive systems.

  5. Optical damage performance of conductive widegap semiconductors: spatial, temporal, and lifetime modeling

    DOE PAGES

    Elhadj, Selim; Yoo, Jae-hyuck; Negres, Raluca A.; ...

    2016-12-19

    The optical damage performance of electrically conductive gallium nitride (GaN) and indium tin oxide (ITO) films is addressed using large area, high power laser beam exposures at 1064 nm sub-bandgap wavelength. Analysis of the laser damage process assumes that onset of damage (threshold) is determined by the absorption and heating of a nanoscale region of a characteristic size reaching a critical temperature. We use this model to rationalize semi-quantitatively the pulse width scaling of the damage threshold from picosecond to nanosecond timescales, along with the pulse width dependence of the damage threshold probability derived by fitting large beam damage densitymore » data. Multi-shot exposures were used to address lifetime performance degradation described by an empirical expression based on the single exposure damage model. A damage threshold degradation of at least 50% was observed for both materials. Overall, the GaN films tested had 5-10 × higher optical damage thresholds than the ITO films tested for comparable transmission and electrical conductivity. This route to optically robust, large aperture transparent electrodes and power optoelectronics may thus involve use of next generation widegap semiconductors such as GaN.« less

  6. Global-mean BC lifetime as an indicator of model skill? Constraining the vertical aerosol distribution using aircraft observations

    NASA Astrophysics Data System (ADS)

    Lund, M. T.; Samset, B. H.; Skeie, R. B.; Berntsen, T.

    2017-12-01

    Several recent studies have used observations from the HIPPO flight campaigns to constrain the modeled vertical distribution of black carbon (BC) over the Pacific. Results indicate a relatively linear relationship between global-mean atmospheric BC residence time, or lifetime, and bias in current models. A lifetime of less than 5 days is necessary for models to reasonably reproduce these observations. This is shorter than what many global models predict, which will in turn affect their estimates of BC climate impacts. Here we use the chemistry-transport model OsloCTM to examine whether this relationship between global BC lifetime and model skill also holds for a broader a set of flight campaigns from 2009-2013 covering both remote marine and continental regions at a range of latitudes. We perform four sets of simulations with varying scavenging efficiency to obtain a spread in the modeled global BC lifetime and calculate the model error and bias for each campaign and region. Vertical BC profiles are constructed using an online flight simulator, as well by averaging and interpolating monthly mean model output, allowing us to quantify sampling errors arising when measurements are compared with model output at different spatial and temporal resolutions. Using the OsloCTM coupled with a microphysical aerosol parameterization, we investigate the sensitivity of modeled BC vertical distribution to uncertainties in the aerosol aging and scavenging processes in more detail. From this, we can quantify how model uncertainties in the BC life cycle propagate into uncertainties in its climate impacts. For most campaigns and regions, a short global-mean BC lifetime corresponds with the lowest model error and bias. On an aggregated level, sampling errors appear to be small, but larger differences are seen in individual regions. However, we also find that model-measurement discrepancies in BC vertical profiles cannot be uniquely attributed to uncertainties in a single process or

  7. Lifetime of a spacecraft around a synchronous system of asteroids using a dipole model

    NASA Astrophysics Data System (ADS)

    dos Santos, Leonardo Barbosa Torres; de Almeida Prado, Antonio F. Bertachini; Sanchez, Diogo Merguizo

    2017-11-01

    Space missions allow us to expand our knowledge about the origin of the solar system. It is believed that asteroids and comets preserve the physical characteristics from the time that the solar system was created. For this reason, there was an increase of missions to asteroids in the past few years. To send spacecraft to asteroids or comets is challenging, since these objects have their own characteristics in several aspects, such as size, shape, physical properties, etc., which are often only discovered after the approach and even after the landing of the spacecraft. These missions must be developed with sufficient flexibility to adjust to these parameters, which are better determined only when the spacecraft reaches the system. Therefore, conducting a dynamic investigation of a spacecraft around a multiple asteroid system offers an extremely rich environment. Extracting accurate information through analytical approaches is quite challenging and requires a significant number of restrictive assumptions. For this reason, a numerical approach to the dynamics of a spacecraft in the vicinity of a binary asteroid system is offered in this paper. In the present work, the equations of the Restricted Synchronous Four-Body Problem (RSFBP) are used to model a binary asteroid system. The main objective of this work is to construct grids of initial conditions, which relates semi-major axis and eccentricity, in order to quantify the lifetime of a spacecraft when released close to the less massive body of the binary system (modeled as a rotating mass dipole). We performed an analysis of the lifetime of the spacecraft considering several mass ratios of a binary system of asteroids and investigating the behavior of a spacecraft in the vicinity of this system. We analyze direct and retrograde orbits. This study investigated orbits that survive for at least 500 orbital periods of the system (which is approximately one year), then not colliding or escaping from the system during this

  8. Endurance degradation and lifetime model of p-channel floating gate flash memory device with 2T structure

    NASA Astrophysics Data System (ADS)

    Wei, Jiaxing; Liu, Siyang; Liu, Xiaoqiang; Sun, Weifeng; Liu, Yuwei; Liu, Xiaohong; Hou, Bo

    2017-08-01

    The endurance degradation mechanisms of p-channel floating gate flash memory device with two-transistor (2T) structure are investigated in detail in this work. With the help of charge pumping (CP) measurements and Sentaurus TCAD simulations, the damages in the drain overlap region along the tunnel oxide interface caused by band-to-band (BTB) tunneling programming and the damages in the channel region resulted from Fowler-Nordheim (FN) tunneling erasure are verified respectively. Furthermore, the lifetime model of endurance characteristic is extracted, which can extrapolate the endurance degradation tendency and predict the lifetime of the device.

  9. LIFETIME LUNG CANCER RISKS ASSOCIATED WITH INDOOR RADON EXPOSURE BASED ON VARIOUS RADON RISK MODELS FOR CANADIAN POPULATION.

    PubMed

    Chen, Jing

    2017-04-01

    This study calculates and compares the lifetime lung cancer risks associated with indoor radon exposure based on well-known risk models in the literature; two risk models are from joint studies among miners and the other three models were developed from pooling studies on residential radon exposure from China, Europe and North America respectively. The aim of this article is to make clear that the various models are mathematical descriptions of epidemiologically observed real risks in different environmental settings. The risk from exposure to indoor radon is real and it is normal that variations could exist among different risk models even when they were applied to the same dataset. The results show that lifetime risk estimates vary significantly between the various risk models considered here: the model based on the European residential data provides the lowest risk estimates, while models based on the European miners and Chinese residential pooling with complete dosimetry give the highest values. The lifetime risk estimates based on the EPA/BEIR-VI model lie within this range and agree reasonably well with the averages of risk estimates from the five risk models considered in this study. © Crown copyright 2016.

  10. Quasiparticle energies and lifetimes in a metallic chain model of a tunnel junction.

    PubMed

    Szepieniec, Mark; Yeriskin, Irene; Greer, J C

    2013-04-14

    As electronics devices scale to sub-10 nm lengths, the distinction between "device" and "electrodes" becomes blurred. Here, we study a simple model of a molecular tunnel junction, consisting of an atomic gold chain partitioned into left and right electrodes, and a central "molecule." Using a complex absorbing potential, we are able to reproduce the single-particle energy levels of the device region including a description of the effects of the semi-infinite electrodes. We then use the method of configuration interaction to explore the effect of correlations on the system's quasiparticle peaks. We find that when excitations on the leads are excluded, the device's highest occupied molecular orbital and lowest unoccupied molecular orbital quasiparticle states when including correlation are bracketed by their respective values in the Hartree-Fock (Koopmans) and ΔSCF approximations. In contrast, when excitations on the leads are included, the bracketing property no longer holds, and both the positions and the lifetimes of the quasiparticle levels change considerably, indicating that the combined effect of coupling and correlation is to alter the quasiparticle spectrum significantly relative to an isolated molecule.

  11. The inverse power law model for the lifetime of a mylar-polyurethane laminated dc hv insulating structure

    NASA Astrophysics Data System (ADS)

    Kalkanis, G.; Rosso, E.

    1989-09-01

    Results of an accelerated test on the lifetime of a mylar-polyurethane laminated dc high voltage insulating structure are reported. This structure consists of mylar ribbons placed side by side in a number of layers, staggered and glued together with a polyurethane adhesive. The lifetime until breakdown as a function of extremely high values of voltage stress is measured and represented by a mathematical model, the inverse power law model with a 2-parameter Weibull lifetime distribution. The statistical treatment of the data — either by graphical or by analytical methods — allowed us to estimate the lifetime distribution and confidence bounds for any required normal voltage stress. The laminated structure under consideration is, according to the analysis, a very reliable dc hv insulating material, with a very good life performance according to the inverse power law model, and with an exponent of voltage stress equal to 6. A large insulator of cylindrical shape with this kind of laminated structure can be constructed by winding helically a mylar ribbon in a number of layers.

  12. DC-Obesity: A New Model for Estimating Differential Lifetime Costs of Overweight and Obesity by Socioeconomic Status.

    PubMed

    Sonntag, Diana; Jarczok, Marc N; Ali, Shehzad

    2017-09-01

    The aim of this study was to quantify the magnitude of lifetime costs of overweight and obesity by socioeconomic status (SES). Differential Costs (DC)-Obesity is a new model that uses time-to-event simulation and the Markov modeling approach to compare lifetime excess costs of overweight and obesity among individuals with low, middle, and high SES. SES was measured by a multidimensional aggregated index based on level of education, occupational class, and income by using longitudinal data of the German Socioeconomic Panel (SOEP). Random-effects meta-analysis was applied to combine estimates of (in)direct costs of overweight and obesity. DC-Obesity brings attention to opposite socioeconomic gradients in lifetime costs due to obesity compared to overweight. Compared to individuals with obesity and high SES, individuals with obesity and low SES had lifetime excess costs that were two times higher (€8,526). In contrast, these costs were 20% higher in groups with overweight and high SES than in groups with overweight and low SES (€2,711). The results of this study indicate that SES may play a pivotal role in designing cost-effective and sustainable interventions to prevent and treat overweight and obesity. DC-Obesity may help public policy planners to make informed decisions about obesity programs targeted at vulnerable SES groups. © 2017 The Obesity Society.

  13. Historical human exposure to perfluoroalkyl acids in the United States and Australia reconstructed from biomonitoring data using population-based pharmacokinetic modelling.

    PubMed

    Gomis, Melissa I; Vestergren, Robin; MacLeod, Matthew; Mueller, Jochen F; Cousins, Ian T

    2017-11-01

    Perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) are found in the blood of humans and wildlife worldwide. Since the beginning of the 21st century, a downward trend in the human body burden, especially for PFOS and PFOA, has been observed while there is no clear temporal trend in wildlife. The inconsistency between the concentration decline in human serum and in wildlife could be indicative of a historical exposure pathway for humans linked to consumer products that has been reduced or eliminated. In this study, we reconstruct the past human exposure trends in two different regions, USA and Australia, by inferring the historical intake from cross-sectional biomonitoring data of PFOS, PFOA and PFHxS using a population-based pharmacokinetic model. For PFOS in the USA, the reconstructed daily intake peaked at 4.5ng/kg-bw/day between 1988 and 1999 while in Australia it peaked at 4.0ng/kg-bw/day between 1984 and 1996. For PFOA in the USA and Australia, the peak reconstructed daily intake was 1.1ng/kg-bw/day in 1995 and 3.6ng/kg-bw/day in 1992, respectively, and started to decline in 2000 and 1995, respectively. The model could not be satisfactorily fitted to the biomonitoring data for PFHxS within reasonable boundaries for its intrinsic elimination half-life, and thus reconstructing intakes of PFHxS was not possible. Our results indicate that humans experienced similar exposure levels and trends to PFOS and PFOA in the USA and Australia. Our findings support the hypothesis that near-field consumer product exposure pathways were likely dominant prior to the phase-out in industrialized countries. The intrinsic elimination half-life, which represents elimination processes that are common for all humans, and elimination processes unique to women (i.e., menstruation, cord-blood transfer and breastfeeding) were also investigated. The intrinsic elimination half-lives for PFOS and PFOA derived from model fitting for men

  14. Modelling lifetime cost consequences of ReSTOR® in cataract surgery in four European countries

    PubMed Central

    Lafuma, Antoine; Berdeaux, Gilles

    2008-01-01

    Background To compare the lifetime costs of liberating patients from spectacles after cataract surgery by implanting the multifocal intraocular lens (IOL) 'ReSTOR®' versus monofocal IOLs in France, Italy, Germany and Spain. Methods A Markov model was created to follow patient cohorts from cataract surgery until death. Prevalence rates of patients not needing spectacles after cataract surgery were obtained from clinical trials. Resource utilisation included implant surgery, IOLs, spectacles, visits to ophthalmologists and eye centres, transport, and time lost by patients. Economic perspectives were those of Society and Sickness Funds (SFs). Results The mean number of spectacles purchased after ReSTOR® was 1.34–1.61 and after monofocal IOLs 6.05–7.27. From the societal perspective, total cost estimates discounted by 3% were between €3,551 and €4,052 with ReSTOR® compared to €3,989 and €5,548 with monofocal IOLs. Undiscounted savings related to ReSTOR® ranged from €815 to €2,164. From the SFs' perspective total cost estimates discounted by 3% were between €2,150 and €2,524 with ReSTOR® compared to €2,324 and €2,610 with monofocal IOLs. Savings related to ReSTOR®, once costs discounted, ranged from €61 to €219. Discount and spectacle freedom prevalence rates were the most sensitive parameters. Conclusion The bulk of the savings related to ReSTOR® were realized outside the SF. From both a societal and SF perspective, savings, after a 3% discounting, achieved by liberating patients from spectacles counterbalanced the initially higher cost of ReSTOR®. ReSTOR® is a cost saving alternative to spectacles for patients requiring cataract surgery. PMID:18627594

  15. External validation and comparison with other models of the International Metastatic Renal-Cell Carcinoma Database Consortium prognostic model: a population-based study

    PubMed Central

    Heng, Daniel Y C; Xie, Wanling; Regan, Meredith M; Harshman, Lauren C; Bjarnason, Georg A; Vaishampayan, Ulka N; Mackenzie, Mary; Wood, Lori; Donskov, Frede; Tan, Min-Han; Rha, Sun-Young; Agarwal, Neeraj; Kollmannsberger, Christian; Rini, Brian I; Choueiri, Toni K

    2014-01-01

    Summary Background The International Metastatic Renal-Cell Carcinoma Database Consortium model offers prognostic information for patients with metastatic renal-cell carcinoma. We tested the accuracy of the model in an external population and compared it with other prognostic models. Methods We included patients with metastatic renal-cell carcinoma who were treated with first-line VEGF-targeted treatment at 13 international cancer centres and who were registered in the Consortium’s database but had not contributed to the initial development of the Consortium Database model. The primary endpoint was overall survival. We compared the Database Consortium model with the Cleveland Clinic Foundation (CCF) model, the International Kidney Cancer Working Group (IKCWG) model, the French model, and the Memorial Sloan-Kettering Cancer Center (MSKCC) model by concordance indices and other measures of model fit. Findings Overall, 1028 patients were included in this study, of whom 849 had complete data to assess the Database Consortium model. Median overall survival was 18·8 months (95% 17·6–21·4). The predefined Database Consortium risk factors (anaemia, thrombocytosis, neutrophilia, hypercalcaemia, Karnofsky performance status <80%, and <1 year from diagnosis to treatment) were independent predictors of poor overall survival in the external validation set (hazard ratios ranged between 1·27 and 2·08, concordance index 0·71, 95% CI 0·68–0·73). When patients were segregated into three risk categories, median overall survival was 43·2 months (95% CI 31·4–50·1) in the favourable risk group (no risk factors; 157 patients), 22·5 months (18·7–25·1) in the intermediate risk group (one to two risk factors; 440 patients), and 7·8 months (6·5–9·7) in the poor risk group (three or more risk factors; 252 patients; p<0·0001; concordance index 0·664, 95% CI 0·639–0·689). 672 patients had complete data to test all five models. The concordance index of the CCF

  16. Lifetime and 5 years risk of breast cancer and attributable risk factor according to Gail model in Iranian women

    PubMed Central

    Mohammadbeigi, Abolfazl; Mohammadsalehi, Narges; Valizadeh, Razieh; Momtaheni, Zeinab; Mokhtari, Mohsen; Ansari, Hossein

    2015-01-01

    Introduction: Breast cancer is the most commonly diagnosed cancers in women worldwide and in Iran. It is expected to account for 29% of all new cancers in women at 2015. This study aimed to assess the 5 years and lifetime risk of breast cancer according to Gail model, and to evaluate the effect of other additional risk factors on the Gail risk. Materials and Methods: A cross sectional study conducted on 296 women aged more than 34-year-old in Qom, Center of Iran. Breast Cancer Risk Assessment Tool calculated the Gail risk for each subject. Data were analyzed by paired t-test, independent t-test, and analysis of variance in bivariate approach to evaluate the effect of each factor on Gail risk. Multiple linear regression models with stepwise method were used to predict the effect of each variable on the Gail risk. Results: The mean age of the participants was 47.8 ± 8.8-year-old and 47% have Fars ethnicity. The 5 years and lifetime risk was 0.37 ± 0.18 and 4.48 ± 0.925%, respectively. It was lower than the average risk in same race and age women (P < 0.001). Being single, positive family history of breast cancer, positive history of biopsy, and radiotherapy as well as using nonhormonal contraceptives were related to higher lifetime risk (P < 0.05). Moreover, a significant direct correlation observed between lifetime risk and body mass index, age of first live birth, and menarche age. While an inversely correlation observed between lifetimes risk of breast cancer and total month of breast feeding duration and age. Conclusion: Based on our results, the 5 years and lifetime risk of breast cancer according to Gail model was lower than the same race and age. Moreover, by comparison with national epidemiologic indicators about morbidity and mortality of breast cancer, it seems that the Gail model overestimate the risk of breast cancer in Iranian women. PMID:26229355

  17. Desired lifetime and end-of-life desires across adulthood from 20 to 90: a dual-source information model.

    PubMed

    Lang, Frieder R; Baltes, Paul B; Wagner, Gert G

    2007-09-01

    How long do people want to live, and how does scientific research on aging affect such desires? A dual-source information model proposes that aging expectations and desires are informed differently by two sources: personal experiences on the one hand, and scientific and societal influences on the other. Two studies with independent German national samples explored desires regarding length of life and end of life among adults between the ages of 20 and 90. FINDINGS ARE: First, desired lifetime is consistent at around 85 years with few age differences. Second, experimental induction of good or bad news from research on aging has little effect in Study 1. Third, interest in science has moderating effects on desired lifetime in Study 2. Fourth, there is a high prevalence of a strong desire to control the "when and how" of one's death, although only 11% of the individuals completed a living will. Findings are consistent with the dual-source information model.

  18. Chasing quicksilver: modeling the atmospheric lifetime of Hg(0)(g) in the marine boundary layer at various latitudes.

    PubMed

    Hedgecock, Ian M; Pirrone, Nicola

    2004-01-01

    The lifetime of elemental mercury in the marine boundary layer(MBL) has been studied using AMCOTS (Atmospheric Mercury Chemistry Over The Sea), a box model of MBL photochemistry including aerosols and detailed mercury chemistry. Recently measured Hg(0)(g) oxidation reactions have been included, and the studies were performed as a function of latitude, time of year, boundary layer liquid water content (LWC) and cloud optical depth. The results show that Hg has the shortest lifetime when air temperatures are low and sunlight and deliquescent aerosol particles are plentiful. Thus the modeled lifetime for clear-sky conditions is actually shorter at mid-latitudes and high latitudes than near the equator, and for a given latitude and time of year, cooler temperatures enhance the rate of Hg oxidation. Under typical summer conditions (for a given latitude) of temperature and cloudiness, the lifetime (tau) of Hg(0)(g) in the MBL is calculated to be around 10 days at all latitudes between the equator and 60 degrees N. This is much shorter than the generally accepted atmospheric residence time for Hg(0)(g) of a year or more. Given the relatively stable background concentrations of Hg(0)(g) which have been measured, continual replenishment of Hg(0)(g) must take place, suggesting a "multihop" mechanism for the distribution of Hg, rather than solely aeolian transport with little or no chemical transformation between source and receptor. Inclusion of an empirical Hg(0)(g) emission factor related to insolation was used to stabilize the Hg(0)(g) concentration in the model, and the emission rates necessarily agree well with estimated emission fluxes for the open ocean.

  19. Lifetimes of excited states in 196, 198Pt; Application of interacting boson approximation model to even Pt isotopes systematics

    NASA Astrophysics Data System (ADS)

    Bolotin, H. H.; Stuchbery, A. E.; Morrison, I.; Kennedy, D. L.; Ryan, C. G.; Sie, S. H.

    1981-11-01

    The lifetimes and lifetime limits of the low-lying excited states up to and including the 6 1+ levels in 196, 198Pt were determined by the recoil-distance method (RDM). Gamma-ray angular distributions in 198Pt were also measured. These states were populated by multiple Coulomb excitation using 220 MeV 58Ni ion beams and the measurements were carried out in coincidence with back-scattered projectiles. The measured mean lives of the states and B(E2) values inferred for the transitions between levels are presented. These specific findings, and the observed structure systematics obtained from the combination of the present results and those of prior workers for the even 194-198Pt isotopes, are critically compared with our structure calculations employing the interacting boson approximation (IBA) model incorporating a symmetry-breaking quadrupole force; evaluative comparisons are also made with boson expansion theory (BET) calculations.

  20. Monte Carlo mixture model of lifetime cancer incidence risk from radiation exposure on shuttle and international space station

    NASA Technical Reports Server (NTRS)

    Peterson, L. E.; Cucinotta, F. A.; Wilson, J. W. (Principal Investigator)

    1999-01-01

    Estimating uncertainty in lifetime cancer risk for human exposure to space radiation is a unique challenge. Conventional risk assessment with low-linear-energy-transfer (LET)-based risk from Japanese atomic bomb survivor studies may be inappropriate for relativistic protons and nuclei in space due to track structure effects. This paper develops a Monte Carlo mixture model (MCMM) for transferring additive, National Institutes of Health multiplicative, and multiplicative excess cancer incidence risks based on Japanese atomic bomb survivor data to determine excess incidence risk for various US astronaut exposure profiles. The MCMM serves as an anchor point for future risk projection methods involving biophysical models of DNA damage from space radiation. Lifetime incidence risks of radiation-induced cancer for the MCMM based on low-LET Japanese data for nonleukemia (all cancers except leukemia) were 2.77 (90% confidence limit, 0.75-11.34) for males exposed to 1 Sv at age 45 and 2.20 (90% confidence limit, 0.59-10.12) for males exposed at age 55. For females, mixture model risks for nonleukemia exposed separately to 1 Sv at ages of 45 and 55 were 2.98 (90% confidence limit, 0.90-11.70) and 2.44 (90% confidence limit, 0.70-10.30), respectively. Risks for high-LET 200 MeV protons (LET=0.45 keV/micrometer), 1 MeV alpha-particles (LET=100 keV/micrometer), and 600 MeV iron particles (LET=180 keV/micrometer) were scored on a per particle basis by determining the particle fluence required for an average of one particle per cell nucleus of area 100 micrometer(2). Lifetime risk per proton was 2.68x10(-2)% (90% confidence limit, 0.79x10(-3)%-0. 514x10(-2)%). For alpha-particles, lifetime risk was 14.2% (90% confidence limit, 2.5%-31.2%). Conversely, lifetime risk per iron particle was 23.7% (90% confidence limit, 4.5%-53.0%). Uncertainty in the DDREF for high-LET particles may be less than that for low-LET radiation because typically there is very little dose-rate dependence

  1. Creating a Simian Model of Guam ALS/PDC Which Reflects Chamorro Lifetime BMAA Exposures.

    PubMed

    Banack, Sandra Anne; Cox, Paul Alan

    2018-01-01

    The theory that β-N-methylamino-L-alanine (BMAA), a cyanobacterial toxin, contaminates traditional food supplies of the Chamorro people of Guam is supported by the recent finding that chronic dietary exposure to L-BMAA in vervets (Chlorocebus sabaeus) triggers the formation of neurofibrillary tangles (NFT) and β-amyloid plaques in the brain. In the first experiment, we found that all four vervets receiving a 210 mg/kg dose for 140 days developed NFT and sparse amyloid deposits. In the second experiment, all eight vervets receiving a 210 mg/kg dose for 140 days developed NFT and amyloid deposits, as well as all eight vervets that received only 21 mg/kg. Based on dietary surveys of the Chamorro people, we estimated lifetime chronic BMAA exposure at a high and a low level: 1) adult male Chamorros eating two flying foxes per month plus one 30 g serving of cycad flour per week; and 2) adult male Chamorros eating one 30 g serving of cycad flour per day combined with the consumption of eight flying foxes per month. The resultant cumulative lifetime Chamorro exposures ranged from 1 to 41 g/kg and are comparable to the total lifetime vervet exposures in our experiments of 2 and 22 g/kg, respectively. Furthermore, measured protein-bound BMAA concentrations of vervets fed L-BMAA powder are comparable to measured protein-bound BMAA concentrations in postmortem brain tissues of Chamorros who died with ALS/PDC.

  2. Coupled modeling of the competitive gettering of transition metals and impact on performance of lifetime sensitive devices

    NASA Astrophysics Data System (ADS)

    Yazdani, Armin; Chen, Renyu; Dunham, Scott T.

    2017-03-01

    This work models competitive gettering of metals (Cu, Ni, Fe, Mo, and W) by boron, phosphorus, and dislocation loops, and connects those results directly to device performance. Density functional theory calculations were first performed to determine the binding energies of metals to the gettering sites, and based on that, continuum models were developed to model the redistribution and trapping of the metals. Our models found that Fe is most strongly trapped by the dislocation loops while Cu and Ni are most strongly trapped by the P4V clusters formed in high phosphorus concentrations. In addition, it is found that none of the mentioned gettering sites are effective in gettering Mo and W. The calculated metal redistribution along with the associated capture cross sections and trap energy levels are passed to device simulation via the recombination models to calculate carrier lifetime and the resulting device performance. Thereby, a comprehensive and predictive TCAD framework is developed to optimize the processing conditions to maximize performance of lifetime sensitive devices.

  3. Effects of Orbital Lifetime Reduction on the Long-Term Earth Satellite Population as Modeled by EVOLVE 4.0

    NASA Technical Reports Server (NTRS)

    Krisko, Paula H.; Opiela, John N.; Liou, Jer-Chyi; Anz-Meador, Phillip D.; Theall, Jeffrey R.

    1999-01-01

    The latest update of the NASA orbital debris environment model, EVOLVE 4.0, has been used to study the effect of various proposed debris mitigation measures, including the NASA 25-year guideline. EVOLVE 4.0, which includes updates of the NASA breakup, solar activity, and the orbit propagator models, a GEO analysis option, and non-fragmentation debris source models, allows for the statistical modeling and predicted growth of the particle population >1 mm in characteristic length in LEO and GEO orbits. The initial implementation of this &odel has been to study the sensitivity of the overall LEO debris environment to mitigation measures designed to limit the lifetime of intact objects in LEO orbits. The mitigation measures test matrix for this study included several commonly accepted testing schemes, i.e., the variance of the maximum LEO lifetime from 10 to 50 years, the date of the initial implementation of this policy, the shut off of all explosions at some specified date, and the inclusion of disposal orbits. All are timely studies in that all scenarios have been suggested by researchers and satellite operators as options for the removal of debris from LEO orbits.

  4. Modeling lifetime costs and health outcomes attributable to secondhand smoke exposure at home among Korean adult women.

    PubMed

    Lee, Jiyae; Han, Ah Ram; Choi, Dalwoong; Lim, Kyung-Min; Bae, SeungJin

    2017-05-17

    The aim of this research is to estimate lifetime costs and health consequences for Korean adult women who were exposed to secondhand smoke (SHS) at home. A Markov model was developed to project the lifetime healthcare costs and health outcomes of a hypothetical cohort of Korean women who are 40 years old and were married to current smokers. The Korean epidemiological data were used to reflect the natural history of SHS-exposed and non-exposed women. The direct healthcare costs (in 2014 US dollars) and quality-adjusted life years (QALYs) were annually discounted at 5% to reflect time preference. The time horizon of the analysis was lifetime and the cycle length was 1 year. Deterministic and probabilistic sensitivity analyses were conducted. In the absence of SHS exposure, Korean women will live 41.32 years or 34.56 QALYs before discount, which corresponded to 17.29 years or 15.35 QALYs after discount. The SHS-exposed women were predicted to live 37.91 years and 31.08 QALYs before discount and 16.76 years and 14.62 QALYs after discount. The estimated lifetime healthcare cost per woman in the SHS non-exposed group was US$11 214 before the discount and US$2465 after discount. The negative impact of SHS exposure on health outcomes and healthcare costs escalated as the time horizon increased, suggesting that the adverse impact of SHS exposure may have higher impact on the later part of the lifetime. The result was consistent across a wide range of assumptions. Life expectancy might underestimate the impact of SHS exposure on health outcomes, especially if the time horizon of the analysis is not long enough. Early intervention on smoking behaviour could substantially reduce direct healthcare costs and improve quality of life attributable to SHS exposure. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. Neutron lifetimes behavior analysis considering the two-region kinetic model in the IPEN/MB-01 reactor

    SciTech Connect

    Gonnelli, Eduardo; Diniz, Ricardo

    2014-11-11

    This is a complementary work about the behavior analysis of the neutron lifetimes that was developed in the IPEN/MB-01 nuclear reactor facility. The macroscopic neutron noise technique was experimentally employed using pulse mode detectors for two stages of control rods insertion, where a total of twenty levels of subcriticality have been carried out. It was also considered that the neutron reflector density was treated as an additional group of delayed neutrons, being a sophisticated approach in the two-region kinetic theoretical model.

  6. Modeling the expected lifetime and evolution of a deme's principal genetic sequence.

    NASA Astrophysics Data System (ADS)

    Clark, Brian

    2014-03-01

    The principal genetic sequence (PGS) is the most common genetic sequence in a deme. The PGS changes over time because new genetic sequences are created by inversions, compete with the current PGS, and a small fraction become PGSs. A set of coupled difference equations provides a description of the evolution of the PGS distribution function in an ensemble of demes. Solving the set of equations produces the survival probability of a new genetic sequence and the expected lifetime of an existing PGS as a function of inversion size and rate, recombination rate, and deme size. Additionally, the PGS distribution function is used to explain the transition pathway from old to new PGSs. We compare these results to a cellular automaton based representation of a deme and the drosophila species, D. melanogaster and D. yakuba.

  7. Variation in Adenoma Detection Rate and the Lifetime Benefits and Cost of Colorectal Cancer Screening: A Microsimulation Model

    PubMed Central

    Meester, Reinier G.S.; Doubeni, Chyke A.; Lansdorp-Vogelaar, Iris; Jensen, Christopher D.; van der Meulen, Miriam P.; Levin, Theodore R.; Quinn, Virginia P.; Schottinger, Joanne E.; Zauber, Ann G.; Corley, Douglas A.; van Ballegooijen, Marjolein

    2015-01-01

    IMPORTANCE Colonoscopy is the most commonly used colorectal cancer screening test in the United States. Its quality, as measured by adenoma detection rates, varies widely between physicians with unknown consequences for the cost and benefits of screening programs. OBJECTIVE To estimate the lifetime benefits, complications and costs of a colonoscopy screening program at different levels of adenoma detection. DESIGN, SETTING and PARTICIPANTS This study used microsimulation modeling with data from a community-based healthcare system on adenoma detection rate variation and cancer risk among 136 physicians and 57,588 patients for 1998–2010. EXPOSURE Using modeling, no screening was compared to screening initiation with colonoscopy according to adenoma detection rate quintiles (averages 15.3, 21.3, 25.6, 30.9, and 38.7%) at ages 50, 60 and 70 with appropriate surveillance of adenoma patients. MAIN OUTCOMES Estimated lifetime colorectal cancer incidence, mortality, number of colonoscopies, complications and costs per 1,000 patients, all discounted at 3% per year and including 95% confidence intervals from multiway probabilistic sensitivity analysis (95%CI). RESULTS In simulation modeling, among unscreened patients, the lifetime risks of colorectal cancer incidence and mortality were 34.2 (95%CI:25.9–43.6) and 13.4 (95%CI:10.0–17.6) per 1,000, respectively. Among screened patients, simulated lifetime incidence decreased with lower to higher adenoma detection rates (quintile 1 versus 5: 26.6, 95%CI:20.0–34.3 versus 12.5, 95%CI:9.3–16.5) as did mortality (5.7, 95%CI:4.2–7.7 versus 2.3, 95%CI:1.7–3.1). Compared to quintile 1, simulated lifetime incidence and mortality were on average 11.4% (95%CI:10.3–11.9) and 12.8% (95%CI:11.1–13.7) lower, respectively, for every 5 percentage-point higher adenoma detection rate. Total colonoscopies and associated complications were higher from quintile 1 (2,777, 95%CI:2,626–2,943 and 6.0, 95%CI:4.0–8.5) to subsequent

  8. Simulating star clusters with the AMUSE software framework. I. Dependence of cluster lifetimes on model assumptions and cluster dissolution modes

    SciTech Connect

    Whitehead, Alfred J.; McMillan, Stephen L. W.; Vesperini, Enrico

    2013-12-01

    We perform a series of simulations of evolving star clusters using the Astrophysical Multipurpose Software Environment (AMUSE), a new community-based multi-physics simulation package, and compare our results to existing work. These simulations model a star cluster beginning with a King model distribution and a selection of power-law initial mass functions and contain a tidal cutoff. They are evolved using collisional stellar dynamics and include mass loss due to stellar evolution. After studying and understanding that the differences between AMUSE results and results from previous studies are understood, we explored the variation in cluster lifetimes due to the random realization noisemore » introduced by transforming a King model to specific initial conditions. This random realization noise can affect the lifetime of a simulated star cluster by up to 30%. Two modes of star cluster dissolution were identified: a mass evolution curve that contains a runaway cluster dissolution with a sudden loss of mass, and a dissolution mode that does not contain this feature. We refer to these dissolution modes as 'dynamical' and 'relaxation' dominated, respectively. For Salpeter-like initial mass functions, we determined the boundary between these two modes in terms of the dynamical and relaxation timescales.« less

  9. Robust Bayesian Fluorescence Lifetime Estimation, Decay Model Selection and Instrument Response Determination for Low-Intensity FLIM Imaging

    PubMed Central

    Rowley, Mark I.; Coolen, Anthonius C. C.; Vojnovic, Borivoj; Barber, Paul R.

    2016-01-01

    We present novel Bayesian methods for the analysis of exponential decay data that exploit the evidence carried by every detected decay event and enables robust extension to advanced processing. Our algorithms are presented in the context of fluorescence lifetime imaging microscopy (FLIM) and particular attention has been paid to model the time-domain system (based on time-correlated single photon counting) with unprecedented accuracy. We present estimates of decay parameters for mono- and bi-exponential systems, offering up to a factor of two improvement in accuracy compared to previous popular techniques. Results of the analysis of synthetic and experimental data are presented, and areas where the superior precision of our techniques can be exploited in Förster Resonance Energy Transfer (FRET) experiments are described. Furthermore, we demonstrate two advanced processing methods: decay model selection to choose between differing models such as mono- and bi-exponential, and the simultaneous estimation of instrument and decay parameters. PMID:27355322

  10. Scale-invariant instantons and the complete lifetime of the standard model

    NASA Astrophysics Data System (ADS)

    Andreassen, Anders; Frost, William; Schwartz, Matthew D.

    2018-03-01

    In a classically scale-invariant quantum field theory, tunneling rates are infrared divergent due to the existence of instantons of any size. While one expects such divergences to be resolved by quantum effects, it has been unclear how higher-loop corrections can resolve a problem appearing already at one loop. With a careful power counting, we uncover a series of loop contributions that dominate over the one-loop result and sum all the necessary terms. We also clarify previously incomplete treatments of related issues pertaining to global symmetries, gauge fixing, and finite mass effects. In addition, we produce exact closed-form solutions for the functional determinants over scalars, fermions, and vector bosons around the scale-invariant bounce, demonstrating manifest gauge invariance in the vector case. With these problems solved, we produce the first complete calculation of the lifetime of our Universe: 1 0139 years . With 95% confidence, we expect our Universe to last more than 1 058 years . The uncertainty is part experimental uncertainty on the top quark mass and on αs and part theory uncertainty from electroweak threshold corrections. Using our complete result, we provide phase diagrams in the mt/mh and the mt/αs planes, with uncertainty bands. To rule out absolute stability to 3 σ confidence, the uncertainty on the top quark pole mass would have to be pushed below 250 MeV or the uncertainty on αs(mZ) pushed below 0.00025.

  11. Uncertainties in models of tropospheric ozone based on Monte Carlo analysis: Tropospheric ozone burdens, atmospheric lifetimes and surface distributions

    NASA Astrophysics Data System (ADS)

    Derwent, Richard G.; Parrish, David D.; Galbally, Ian E.; Stevenson, David S.; Doherty, Ruth M.; Naik, Vaishali; Young, Paul J.

    2018-05-01

    Recognising that global tropospheric ozone models have many uncertain input parameters, an attempt has been made to employ Monte Carlo sampling to quantify the uncertainties in model output that arise from global tropospheric ozone precursor emissions and from ozone production and destruction in a global Lagrangian chemistry-transport model. Ninety eight quasi-randomly Monte Carlo sampled model runs were completed and the uncertainties were quantified in tropospheric burdens and lifetimes of ozone, carbon monoxide and methane, together with the surface distribution and seasonal cycle in ozone. The results have shown a satisfactory degree of convergence and provide a first estimate of the likely uncertainties in tropospheric ozone model outputs. There are likely to be diminishing returns in carrying out many more Monte Carlo runs in order to refine further these outputs. Uncertainties due to model formulation were separately addressed using the results from 14 Atmospheric Chemistry Coupled Climate Model Intercomparison Project (ACCMIP) chemistry-climate models. The 95% confidence ranges surrounding the ACCMIP model burdens and lifetimes for ozone, carbon monoxide and methane were somewhat smaller than for the Monte Carlo estimates. This reflected the situation where the ACCMIP models used harmonised emissions data and differed only in their meteorological data and model formulations whereas a conscious effort was made to describe the uncertainties in the ozone precursor emissions and in the kinetic and photochemical data in the Monte Carlo runs. Attention was focussed on the model predictions of the ozone seasonal cycles at three marine boundary layer stations: Mace Head, Ireland, Trinidad Head, California and Cape Grim, Tasmania. Despite comprehensively addressing the uncertainties due to global emissions and ozone sources and sinks, none of the Monte Carlo runs were able to generate seasonal cycles that matched the observations at all three MBL stations. Although

  12. NOx Lifetime During WINTER

    NASA Astrophysics Data System (ADS)

    Kenagy, H. S.; Sparks, T.; Ebben, C. J.; Wooldridge, P. J.; Lopez-Hilfiker, F.; Lee, B. H.; Thornton, J. A.; McDuffie, E. E.; Fibiger, D. L.; Brown, S. S.; Montzka, D. D.; Weinheimer, A. J.; Apel, E. C.; Jaegle, L.; Cohen, R. C.

    2017-12-01

    The study of the lifetime and fate of NOx (=NO + NO2) is important for understanding its persistence and distribution. This requires an understanding of the balance of NOx sinks. Although urban NOx lifetimes are relatively well understood during summertime conditions, wintertime NOx chemistry has been comparatively less studied. We used measurements of NOx and its oxidation products from the aircraft-based WINTER (Wintertime INvestigation of Transport, Emissions, and Reactivity) campaign over the northeastern US during February-March 2015 to help constrain NOx lifetime during wintertime conditions when days are shorter, actinic flux is reduced, and temperatures are colder. By analyzing the marine outflow from the NYC-DC corridor, we learn that wintertime NOx has a long lifetime, is much longer-lived during the day than at night, and its lifetime is controlled during both periods by NOx conversion to nitric acid (HNO3) as the primary NOx sink. We also employ a two-box model to constrain the wintertime plume dilution rate and HNO3 deposition rate. Additionally, analysis of the nighttime Ox budget suggests that approximately 10% of O3 is lost overnight through N2O5 dark reactions that produce HNO3.

  13. Development of a transformation model to derive general population-based utility: Mapping the pruritus-visual analog scale (VAS) to the EQ-5D utility.

    PubMed

    Park, Sun-Young; Park, Eun-Ja; Suh, Hae Sun; Ha, Dongmun; Lee, Eui-Kyung

    2017-08-01

    Although nonpreference-based disease-specific measures are widely used in clinical studies, they cannot generate utilities for economic evaluation. A solution to this problem is to estimate utilities from disease-specific instruments using the mapping function. This study aimed to develop a transformation model for mapping the pruritus-visual analog scale (VAS) to the EuroQol 5-Dimension 3-Level (EQ-5D-3L) utility index in pruritus. A cross-sectional survey was conducted with a sample (n = 268) drawn from the general population of South Korea. Data were randomly divided into 2 groups, one for estimating and the other for validating mapping models. To select the best model, we developed and compared 3 separate models using demographic information and the pruritus-VAS as independent variables. The predictive performance was assessed using the mean absolute deviation and root mean square error in a separate dataset. Among the 3 models, model 2 using age, age squared, sex, and the pruritus-VAS as independent variables had the best performance based on the goodness of fit and model simplicity, with a log likelihood of 187.13. The 3 models had similar precision errors based on mean absolute deviation and root mean square error in the validation dataset. No statistically significant difference was observed between the mean observed and predicted values in all models. In conclusion, model 2 was chosen as the preferred mapping model. Outcomes measured as the pruritus-VAS can be transformed into the EQ-5D-3L utility index using this mapping model, which makes an economic evaluation possible when only pruritus-VAS data are available. © 2017 John Wiley & Sons, Ltd.

  14. Benefits and costs of substance abuse treatment programs for state prison inmates: results from a lifetime simulation model.

    PubMed

    Zarkin, Gary A; Cowell, Alexander J; Hicks, Katherine A; Mills, Michael J; Belenko, Steven; Dunlap, Laura J; Houser, Kimberly A; Keyes, Vince

    2012-06-01

    Reflecting drug use patterns and criminal justice policies throughout the 1990s and 2000s, prisons hold a disproportionate number of society's drug abusers. Approximately 50% of state prisoners meet the criteria for a diagnosis of drug abuse or dependence, but only 10% receive medically based drug treatment. Because of the link between substance abuse and crime, treating substance abusing and dependent state prisoners while incarcerated has the potential to yield substantial economic benefits. In this paper, we simulate the lifetime costs and benefits of improving prison-based substance abuse treatment and post-release aftercare for a cohort of state prisoners. Our model captures the dynamics of substance abuse as a chronic disease; estimates the benefits of substance abuse treatment over individuals' lifetimes; and tracks the costs of crime and criminal justice costs related to policing, adjudication, and incarceration. We estimate net societal benefits and cost savings to the criminal justice system of the current treatment system and five policy scenarios. We find that four of the five policy scenarios provide positive net societal benefits and cost savings to the criminal justice system relative to the current treatment system. Our study demonstrates the societal gains to improving the drug treatment system for state prisoners. Copyright © 2011 John Wiley & Sons, Ltd.

  15. BENEFITS AND COSTS OF SUBSTANCE ABUSE TREATMENT PROGRAMS FOR STATE PRISON INMATES: RESULTS FROM A LIFETIME SIMULATION MODEL

    PubMed Central

    ZARKIN, GARY A.; COWELL, ALEXANDER J.; HICKS, KATHERINE A.; MILLS, MICHAEL J.; BELENKO, STEVEN; DUNLAP, LAURA J.; HOUSER, KIMBERLY A.; KEYES, VINCE

    2011-01-01

    SUMMARY Reflecting drug use patterns and criminal justice policies throughout the 1990s and 2000s, prisons hold a disproportionate number of society’s drug abusers. Approximately 50% of state prisoners meet the criteria for a diagnosis of drug abuse or dependence, but only 10% receive medically based drug treatment. Because of the link between substance abuse and crime, treating substance abusing and dependent state prisoners while incarcerated has the potential to yield substantial economic benefits. In this paper, we simulate the lifetime costs and benefits of improving prison-based substance abuse treatment and post-release aftercare for a cohort of state prisoners. Our model captures the dynamics of substance abuse as a chronic disease; estimates the benefits of substance abuse treatment over individuals’ lifetimes; and tracks the costs of crime and criminal justice costs related to policing, adjudication, and incarceration. We estimate net societal benefits and cost savings to the criminal justice system of the current treatment system and five policy scenarios. We find that four of the five policy scenarios provide positive net societal benefits and cost savings to the criminal justice system relative to the current treatment system. Our study demonstrates the societal gains to improving the drug treatment system for state prisoners. PMID:21506193

  16. Evaluating the Number of Stages in Development of Squamous Cell and Adenocarcinomas across Cancer Sites Using Human Population-Based Cancer Modeling

    PubMed Central

    Kravchenko, Julia; Akushevich, Igor; Abernethy, Amy P.; Lyerly, H. Kim

    2012-01-01

    Background Adenocarcinomas (ACs) and squamous cell carcinomas (SCCs) differ by clinical and molecular characteristics. We evaluated the characteristics of carcinogenesis by modeling the age patterns of incidence rates of ACs and SCCs of various organs to test whether these characteristics differed between cancer subtypes. Methodology/Principal Findings Histotype-specific incidence rates of 14 ACs and 12 SCCs from the SEER Registry (1973–2003) were analyzed by fitting several biologically motivated models to observed age patterns. A frailty model with the Weibull baseline was applied to each age pattern to provide the best fit for the majority of cancers. For each cancer, model parameters describing the underlying mechanisms of carcinogenesis including the number of stages occurring during an individual’s life and leading to cancer (m-stages) were estimated. For sensitivity analysis, the age-period-cohort model was incorporated into the carcinogenesis model to test the stability of the estimates. For the majority of studied cancers, the numbers of m-stages were similar within each group (i.e., AC and SCC). When cancers of the same organs were compared (i.e., lung, esophagus, and cervix uteri), the number of m-stages were more strongly associated with the AC/SCC subtype than with the organ: 9.79±0.09, 9.93±0.19 and 8.80±0.10 for lung, esophagus, and cervical ACs, compared to 11.41±0.10, 12.86±0.34 and 12.01±0.51 for SCCs of the respective organs (p<0.05 between subtypes). Most SCCs had more than ten m-stages while ACs had fewer than ten m-stages. The sensitivity analyses of the model parameters demonstrated the stability of the obtained estimates. Conclusions/Significance A model containing parameters capable of representing the number of stages of cancer development occurring during individual’s life was applied to the large population data on incidence of ACs and SCCs. The model revealed that the number of m-stages differed by cancer subtype being more

  17. Association between intake of less-healthy foods defined by the United Kingdom's nutrient profile model and cardiovascular disease: A population-based cohort study

    PubMed Central

    Scarborough, Peter; Lentjes, Marleen; Khaw, Kay Tee

    2018-01-01

    Background In the United Kingdom, the Food Standards Agency-Ofcom nutrient profiling model (FSA-Ofcom model) is used to define less-healthy foods that cannot be advertised to children. However, there has been limited investigation of whether less-healthy foods defined by this model are associated with prospective health outcomes. The objective of this study was to test whether consumption of less-healthy food as defined by the FSA-Ofcom model is associated with cardiovascular disease (CVD). Methods and findings We used data from the European Prospective Investigation of Cancer (EPIC)-Norfolk cohort study in adults (n = 25,639) aged 40–79 years who completed a 7-day diet diary between 1993 and 1997. Incident CVD (primary outcome), cardiovascular mortality, and all-cause mortality (secondary outcomes) were identified using record linkage to hospital admissions data and death certificates up to 31 March 2015. Each food and beverage item reported was coded and given a continuous score, using the FSA-Ofcom model, based on the consumption of energy; saturated fat; total sugar; sodium; nonsoluble fibre; protein; and fruits, vegetables, and nuts. Items were classified as less-healthy using Ofcom regulation thresholds. We used Cox proportional hazards regression to test for an association between consumption of less-healthy food and incident CVD. Sensitivity analyses explored whether the results differed based on the definition of the exposure. Analyses were adjusted for age, sex, behavioural risk factors, clinical risk factors, and socioeconomic status. Participants were followed up for a mean of 16.4 years. During follow-up, there were 4,965 incident cases of CVD (1,524 fatal within 30 days). In the unadjusted analyses, we observed an association between consumption of less-healthy food and incident CVD (test for linear trend over quintile groups, p < 0.01). After adjustment for covariates (sociodemographic, behavioural, and indices of cardiovascular risk), we found no

  18. Population based screening for chronic kidney disease: cost effectiveness study.

    PubMed

    Manns, Braden; Hemmelgarn, Brenda; Tonelli, Marcello; Au, Flora; Chiasson, T Carter; Dong, James; Klarenbach, Scott

    2010-11-08

    To determine the cost effectiveness of one-off population based screening for chronic kidney disease based on estimated glomerular filtration rate. Cost utility analysis of screening with estimated glomerular filtration rate alone compared with no screening (with allowance for incidental finding of cases of chronic kidney disease). Analyses were stratified by age, diabetes, and the presence or absence of proteinuria. Scenario and sensitivity analyses, including probabilistic sensitivity analysis, were performed. Costs were estimated in all adults and in subgroups defined by age, diabetes, and hypertension. Publicly funded Canadian healthcare system. Large population based laboratory cohort used to estimate mortality rates and incidence of end stage renal disease for patients with chronic kidney disease over a five year follow-up period. Patients had not previously undergone assessment of glomerular filtration rate. Lifetime costs, end stage renal disease, quality adjusted life years (QALYs) gained, and incremental cost per QALY gained. Compared with no screening, population based screening for chronic kidney disease was associated with an incremental cost of $C463 (Canadian dollars in 2009; equivalent to about £275, €308, US $382) and a gain of 0.0044 QALYs per patient overall, representing a cost per QALY gained of $C104 900. In a cohort of 100 000 people, screening for chronic kidney disease would be expected to reduce the number of people who develop end stage renal disease over their lifetime from 675 to 657. In subgroups of people with and without diabetes, the cost per QALY gained was $C22 600 and $C572 000, respectively. In a cohort of 100 000 people with diabetes, screening would be expected to reduce the number of people who develop end stage renal disease over their lifetime from 1796 to 1741. In people without diabetes with and without hypertension, the cost per QALY gained was $C334 000 and $C1 411 100, respectively. Population based

  19. A comparison of linear demographic models and fraction of lifetime egg production for assessing sustainability in sharks.

    PubMed

    Chapple, Taylor K; Botsford, Louis W

    2013-06-01

    Conventional methods for management of data-rich fisheries maintain sustainable populations by assuring that lifetime reproduction is adequate for individuals to replace themselves and accounting for density-dependent recruitment. Fishing is not allowed to reduce relative lifetime reproduction, the fraction of current egg production relative to unfished egg production (FLEP), below a sustainable level. Because most shark fisheries are data poor, other representations of persistence status have been used, including linear demographic models, which incorporate life-history characteristics in age-structured models with no density dependence. We tested how well measures of sustainability from 3 linear demographic methods (rebound potential, stochastic growth rate, and potential population increase) reflect actual population persistence by comparing values of these measures with FLEP for 26 shark species. We also calculated the value of fishing mortality (F) that would allow all 26 species to maintain an accepted precautionary threshold for sharks of FLEP = 60%, expressing F as a fraction of natural mortality (M). Values of stochastic growth rate and potential population growth did not covary in rank order with FLEP (p = 0.057 and p = 0.077, respectively) and neither was significantly correlated with FLEP. Ordinal ranking of rebound potential positively covaried with FLEP (p = 0.00013), but the relative rankings of some species were substantially out of order. Adopting a sustainable limit of F = 0.16M would maintain all 26 species above the precautionary minimum value of FLEP (60%). We concluded that shark-fishery and conservation policies should rely on calculation of replacement (i.e., FLEP), and that sharks should be fished at a precautionary level that would protect all stocks (i.e., F< 0.16M). © 2013 Society for Conservation Biology.

  20. Multistate transitional models for measuring adherence to breast cancer screening: A population-based longitudinal cohort study with over two million women.

    PubMed

    Sutradhar, R; Gu, S; Paszat, L F

    2017-06-01

    Objective Prior work on the disparities among women in breast cancer screening adherence has been methodologically limited. This longitudinal study determines and examines the factors associated with becoming adherent. Methods In a cohort of Canadian women aged 50-74, a three-state transitional model was used to examine adherence to screening for breast cancer. The proportion of time spent being non-adherent with screening was calculated for each woman during her observation window. Using age as the time scale, a relative rate multivariable regression was implemented under the three-state transitional model, to examine the association between covariates (all time-varying) and the rate of becoming adherent. Results The cohort consisted of 2,537,960 women with a median follow-up of 8.46 years. Nearly 31% of women were continually up-to-date with breast screening. Once a woman was non-adherent, the rate of becoming adherent was higher among longer term residents (relative rate = 1.289, 95% confidence interval 1.275-1.302), those from wealthier neighbourhoods, and those who had an identifiable primary care provider who was female or had graduated in Canada. Conclusion Individual and physician-level characteristics play an important role in a woman's adherence to screening. This work improves the quality of evidence regarding disparities among women in adherence to breast cancer screening and provides a novel methodological foundation to investigate adherence for other types of screening, including cervix and colorectal cancer screening.

  1. Why do general circulation models overestimate the aerosol cloud lifetime effect? A case study comparing CAM5 and a CRM

    DOE PAGES

    Zhou, Cheng; Penner, Joyce E.

    2017-01-02

    Observation-based studies have shown that the aerosol cloud lifetime effect or the increase of cloud liquid water path (LWP) with increased aerosol loading may have been overestimated in climate models. Here, we simulate shallow warm clouds on 27 May 2011 at the southern Great Plains (SGP) measurement site established by the Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) program using a single-column version of a global climate model (Community Atmosphere Model or CAM) and a cloud resolving model (CRM). The LWP simulated by CAM increases substantially with aerosol loading while that in the CRM does not. The increase of LWP inmore » CAM is caused by a large decrease of the autoconversion rate when cloud droplet number increases. In the CRM, the autoconversion rate is also reduced, but this is offset or even outweighed by the increased evaporation of cloud droplets near the cloud top, resulting in an overall decrease in LWP. Lastly, our results suggest that climate models need to include the dependence of cloud top growth and the evaporation/condensation process on cloud droplet number concentrations.« less

  2. Why do general circulation models overestimate the aerosol cloud lifetime effect? A case study comparing CAM5 and a CRM

    SciTech Connect

    Zhou, Cheng; Penner, Joyce E.

    Observation-based studies have shown that the aerosol cloud lifetime effect or the increase of cloud liquid water path (LWP) with increased aerosol loading may have been overestimated in climate models. Here, we simulate shallow warm clouds on 27 May 2011 at the southern Great Plains (SGP) measurement site established by the Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) program using a single-column version of a global climate model (Community Atmosphere Model or CAM) and a cloud resolving model (CRM). The LWP simulated by CAM increases substantially with aerosol loading while that in the CRM does not. The increase of LWP inmore » CAM is caused by a large decrease of the autoconversion rate when cloud droplet number increases. In the CRM, the autoconversion rate is also reduced, but this is offset or even outweighed by the increased evaporation of cloud droplets near the cloud top, resulting in an overall decrease in LWP. Lastly, our results suggest that climate models need to include the dependence of cloud top growth and the evaporation/condensation process on cloud droplet number concentrations.« less

  3. Why do general circulation models overestimate the aerosol cloud lifetime effect? A case study comparing CAM5 and a CRM

    NASA Astrophysics Data System (ADS)

    Zhou, Cheng; Penner, Joyce E.

    2017-01-01

    Observation-based studies have shown that the aerosol cloud lifetime effect or the increase of cloud liquid water path (LWP) with increased aerosol loading may have been overestimated in climate models. Here, we simulate shallow warm clouds on 27 May 2011 at the southern Great Plains (SGP) measurement site established by the Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) program using a single-column version of a global climate model (Community Atmosphere Model or CAM) and a cloud resolving model (CRM). The LWP simulated by CAM increases substantially with aerosol loading while that in the CRM does not. The increase of LWP in CAM is caused by a large decrease of the autoconversion rate when cloud droplet number increases. In the CRM, the autoconversion rate is also reduced, but this is offset or even outweighed by the increased evaporation of cloud droplets near the cloud top, resulting in an overall decrease in LWP. Our results suggest that climate models need to include the dependence of cloud top growth and the evaporation/condensation process on cloud droplet number concentrations.

  4. Improved survival time: what can survival cure models tell us about population-based survival improvements in late-stage colorectal, ovarian, and testicular cancer?

    PubMed

    Huang, Lan; Cronin, Kathleen A; Johnson, Karen A; Mariotto, Angela B; Feuer, Eric J

    2008-05-15

    The objective of the current study was to investigate the long-term impact of treatment advances on the survival of patients with late-stage ovarian, colorectal (American Joint Committee on Cancer stage III, men), and testicular cancers by estimating the increase in the percentage cured from their disease and the change in survival time of uncured patients. Cause-specific survival data from 1973 to 2000 were obtained from the Surveillance, Epidemiology, and End Results Program. Survival cure models were fit and were used to estimate the gain in life expectancy (GLE) attributed to an increase in the fraction of cured patients and to prolonged survival among noncured patients. Treatment improvement for ovarian cancer resulted in a total GLE of 2 years, and 80% of that GLE was because of an extension of survival time in uncured patients (from 0.9 years to 2.1 years) rather than an increased cure fraction (from 12% to 14%). In contrast, the cure rate rose from 29% to 47% for colorectal cancer, representing 82% of a 2.8-year GLE, and from 23% to 81% for testicular cancer, representing 100% of a 24-year GLE. The current results suggested that treatment benefits for testicular and colorectal cancer in men with late-stage disease primarily are the result of increases in cure fraction, whereas survival gains for ovarian cancer occur despite persisting disease. Cure models, in combination with population-level data, provide insight into how treatment advances are changing survival and ultimately impacting mortality. Survival patterns reflect the underlying biology of response to cancer treatment and suggest promising directions for future research.

  5. Sulfate geoengineering impact on methane transport and lifetime: results from the Geoengineering Model Intercomparison Project (GeoMIP)

    NASA Astrophysics Data System (ADS)

    Visioni, Daniele; Pitari, Giovanni; Aquila, Valentina; Tilmes, Simone; Cionni, Irene; Di Genova, Glauco; Mancini, Eva

    2017-09-01

    Sulfate geoengineering (SG), made by sustained injection of SO2 in the tropical lower stratosphere, may impact the CH4 abundance through several photochemical mechanisms affecting tropospheric OH and hence the methane lifetime. (a) The reflection of incoming solar radiation increases the planetary albedo and cools the surface, with a tropospheric H2O decrease. (b) The tropospheric UV budget is upset by the additional aerosol scattering and stratospheric ozone changes: the net effect is meridionally not uniform, with a net decrease in the tropics, thus producing less tropospheric O(1D). (c) The extratropical downwelling motion from the lower stratosphere tends to increase the sulfate aerosol surface area density available for heterogeneous chemical reactions in the mid-to-upper troposphere, thus reducing the amount of NOx and O3 production. (d) The tropical lower stratosphere is warmed by solar and planetary radiation absorption by the aerosols. The heating rate perturbation is highly latitude dependent, producing a stronger meridional component of the Brewer-Dobson circulation. The net effect on tropospheric OH due to the enhanced stratosphere-troposphere exchange may be positive or negative depending on the net result of different superimposed species perturbations (CH4, NOy, O3, SO4) in the extratropical upper troposphere and lower stratosphere (UTLS). In addition, the atmospheric stabilization resulting from the tropospheric cooling and lower stratospheric warming favors an additional decrease of the UTLS extratropical CH4 by lowering the horizontal eddy mixing. Two climate-chemistry coupled models are used to explore the above radiative, chemical and dynamical mechanisms affecting CH4 transport and lifetime (ULAQ-CCM and GEOSCCM). The CH4 lifetime may become significantly longer (by approximately 16 %) with a sustained injection of 8 Tg-SO2 yr-1 starting in the year 2020, which implies an increase of tropospheric CH4 (200 ppbv) and a positive indirect radiative

  6. Modelling impacts of performance on the probability of reproducing, and thereby on productive lifespan, allow prediction of lifetime efficiency in dairy cows.

    PubMed

    Phuong, H N; Blavy, P; Martin, O; Schmidely, P; Friggens, N C

    2016-01-01

    Reproductive success is a key component of lifetime efficiency - which is the ratio of energy in milk (MJ) to energy intake (MJ) over the lifespan, of cows. At the animal level, breeding and feeding management can substantially impact milk yield, body condition and energy balance of cows, which are known as major contributors to reproductive failure in dairy cattle. This study extended an existing lifetime performance model to incorporate the impacts that performance changes due to changing breeding and feeding strategies have on the probability of reproducing and thereby on the productive lifespan, and thus allow the prediction of a cow's lifetime efficiency. The model is dynamic and stochastic, with an individual cow being the unit modelled and one day being the unit of time. To evaluate the model, data from a French study including Holstein and Normande cows fed high-concentrate diets and data from a Scottish study including Holstein cows selected for high and average genetic merit for fat plus protein that were fed high- v. low-concentrate diets were used. Generally, the model consistently simulated productive and reproductive performance of various genotypes of cows across feeding systems. In the French data, the model adequately simulated the reproductive performance of Holsteins but significantly under-predicted that of Normande cows. In the Scottish data, conception to first service was comparably simulated, whereas interval traits were slightly under-predicted. Selection for greater milk production impaired the reproductive performance and lifespan but not lifetime efficiency. The definition of lifetime efficiency used in this model did not include associated costs or herd-level effects. Further works should include such economic indicators to allow more accurate simulation of lifetime profitability in different production scenarios.

  7. Expectation maximization-based likelihood inference for flexible cure rate models with Weibull lifetimes.

    PubMed

    Balakrishnan, Narayanaswamy; Pal, Suvra

    2016-08-01

    Recently, a flexible cure rate survival model has been developed by assuming the number of competing causes of the event of interest to follow the Conway-Maxwell-Poisson distribution. This model includes some of the well-known cure rate models discussed in the literature as special cases. Data obtained from cancer clinical trials are often right censored and expectation maximization algorithm can be used in this case to efficiently estimate the model parameters based on right censored data. In this paper, we consider the competing cause scenario and assuming the time-to-event to follow the Weibull distribution, we derive the necessary steps of the expectation maximization algorithm for estimating the parameters of different cure rate survival models. The standard errors of the maximum likelihood estimates are obtained by inverting the observed information matrix. The method of inference developed here is examined by means of an extensive Monte Carlo simulation study. Finally, we illustrate the proposed methodology with a real data on cancer recurrence. © The Author(s) 2013.

  8. Zero-Inflated Models for Identifying Relationships Between Body Mass Index and Gastroesophageal Reflux Symptoms: A Nationwide Population-Based Study in China.

    PubMed

    Xu, Qin; Zhang, Wei; Zhang, Tianyi; Zhang, Ruijie; Zhao, Yanfang; Zhang, Yuan; Guo, Yibin; Wang, Rui; Ma, Xiuqiang; He, Jia

    2016-07-01

    That obesity leads to gastroesophageal reflux is a widespread notion. However, scientific evidence for this association is limited, with no rigorous epidemiological approach conducted to address this question. This study examined the relationship between body mass index (BMI) and gastroesophageal reflux symptoms in a large population-representative sample from China. We performed a cross-sectional study in an age- and gender-stratified random sample of the population of five central regions in China. Participants aged 18-80 years completed a general information questionnaire and a Chinese version of the Reflux Disease Questionnaire. The zero-inflated Poisson regression model estimated the relationship between body mass index and gastroesophageal reflux symptoms. Overall, 16,091 (89.4 %) of the 18,000 eligible participants responded. 638 (3.97 %) and 1738 (10.81 %) experienced at least weekly heartburn and weekly acid regurgitation, respectively. After adjusting for potential risk factors in the zero-inflated part, the frequency [odds ratio (OR) 0.66, 95 % confidence interval (95 % CI) 0.50-0.86, p = 0.002] and severity (OR 0.66, 95 % CI 0.50-088, p = 0.004) of heartburn in obese participants were statistically significant compared to those in normal participants. In the Poisson part, the frequency of acid regurgitation, overweight (OR 1.10, 95 % CI 1.01-1.21, p = 0.038) and obesity (OR 1.19, 95 % CI 1.04-1.37, p = 0.013) were statistically significant. BMI was strongly and positively related to the frequency and severity of gastroesophageal reflux symptoms. Additionally, gender exerted strong specific effects on the relationship between BMI and gastroesophageal reflux symptoms. The severity and frequency of heartburn were positively correlated with obesity. This relationship was presented distinct in male participants only.

  9. Testicular cancer incidence to rise by 25% by 2025 in Europe? Model-based predictions in 40 countries using population-based registry data.

    PubMed

    Le Cornet, Charlotte; Lortet-Tieulent, Joannie; Forman, David; Béranger, Rémi; Flechon, Aude; Fervers, Béatrice; Schüz, Joachim; Bray, Freddie

    2014-03-01

    Testicular cancer mainly affects White Caucasian populations, accounts for 1% of all male cancers, and is frequently the most common malignancy among young adult men. In light of the escalating rates of testicular cancer incidence in Europe, and in support of future planning to ensure optimal care of patients with what can be a curable disease, we predict the future burden in 40 European countries around 2025. Current observed trends were extrapolated with the NORDPRED model to estimate the future burden of testicular cancer in the context of changes in risk versus changes in demographics. Despite substantial heterogeneity in the rates, the vast majority of European countries will see an increasing burden over the next two decades. We estimate there will be 23,000 new cases of testicular cancer annually in Europe by 2025, a rise of 24% from 2005. Some of the most rapid increases in testicular cancer are observed in Croatia, Slovenia, Italy and Spain, and a transition is underway, whereby recent attenuations and declines in rates in certain high-risk countries in Northern Europe contrast with the increasing trends and escalating burden in Southern Europe. According to our estimates for 2025, around one in 100 men will be diagnosed with the disease annually in the highest risk countries of Europe (Croatia, Slovenia and Norway). Elucidating the key determinants of testicular cancer and the equitable provision of optimal care for patients across Europe are priorities given the steady rise in the number of patients by 2025, and an absence of primary prevention opportunities. None. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. A statistical regression model for the estimation of acrylamide concentrations in French fries for excess lifetime cancer risk assessment.

    PubMed

    Chen, Ming-Jen; Hsu, Hui-Tsung; Lin, Cheng-Li; Ju, Wei-Yuan

    2012-10-01

    Human exposure to acrylamide (AA) through consumption of French fries and other foods has been recognized as a potential health concern. Here, we used a statistical non-linear regression model, based on the two most influential factors, cooking temperature and time, to estimate AA concentrations in French fries. The R(2) of the predictive model is 0.83, suggesting the developed model was significant and valid. Based on French fry intake survey data conducted in this study and eight frying temperature-time schemes which can produce tasty and visually appealing French fries, the Monte Carlo simulation results showed that if AA concentration is higher than 168 ppb, the estimated cancer risk for adolescents aged 13-18 years in Taichung City would be already higher than the target excess lifetime cancer risk (ELCR), and that by taking into account this limited life span only. In order to reduce the cancer risk associated with AA intake, the AA levels in French fries might have to be reduced even further if the epidemiological observations are valid. Our mathematical model can serve as basis for further investigations on ELCR including different life stages and behavior and population groups. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Model-observational bridging study on the effectiveness of ezetimibe on cardiovascular morbidity and mortality in France: A population-based study.

    PubMed

    Ferrières, Jean; Dallongeville, Jean; Rossignol, Michel; Bénichou, Jacques; Caro, J Jaime; Getsios, Denis; Hernandez, Luis; Abenhaim, Lucien; Grimaldi-Bensouda, Lamiae

    To evaluate the real-life impact of ezetimibe on cardiovascular (CV) morbidity and mortality in France. To estimate the number of non-fatal and fatal CV events that could be prevented and corresponding number of patients needed to treat (NNT) with ezetimibe to prevent one CV event over 5 years. Non-interventional 48-month follow-up cohort conducted in hypercholesterolemic patients starting on ezetimibe <3 months at study entry, either as monotherapy or combined with statins. Prediction modeling using discrete event simulation with calibrated Framingham CV risk equations was applied to data from pivotal clinical trials on ezetimibe and real-life data derived from the cohort. A total of 3215 patients in the cohort accumulated 9314 person-years of follow-up for an average of 2.9 years. Mean age was 61.5 (standard deviation [SD] = 10.7), 54.6% were males, and 27.0% had a history of CV disease. Baseline LDL-cholesterol averaged 4.1 mmol/L (159 mg/dL; SD = 1.0) and HDL-C 1.6 mmol/L (62 mg/dL; SD = 0.5). LDL-C decreased in the first 12 months in ezetimibe-LLT (lipid-lowering therapy) initiators, switchers (monotherapy), and combination therapy with a statin by respectively 21.3%, 6.4%, and 29.1%. The corresponding predicted rate reductions of CV events (non-fatal and fatal) compared to no treatment or to a statin (combination therapy) were respectively 8, 2, and 12 per 1000 patients treated over 5 years, with a global NNT of 143 patients over 5 years. These results, accounting for observed CV event rates, risk factors evolution over time and adherence to treatment in real life, were consistent with those from clinical trials. Copyright © 2016 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  12. Constraints from Airborne (210)Pb Observations on Aerosol Scavenging and Lifetime in a Global Chemical Transport Model

    NASA Technical Reports Server (NTRS)

    Zhang, Bo; Liu, Hongyu; Crawford, James H.; Fairlie, Duncan T.; Chen, Gao; Dibb, Jack E.; Shah, Viral; Sulprizio, Melissa P.; Yantosca, Robert M.

    2016-01-01

    Lead-210 distribution and lifetime in the atmosphere are not sensitive to ice in-cloud scavenging in convective updraft. Ice in-cloud scavenging in stratiform clouds reduce tropospheric (210)Pb lifetime by approximately 1 day and results in better agreements with observed surface observations and aircraft measured profiles. However, the process results in significant underestimate of (210)Pb in UT/LS.

  13. A lifetime Markov model for the economic evaluation of chronic obstructive pulmonary disease.

    PubMed

    Menn, Petra; Leidl, Reiner; Holle, Rolf

    2012-09-01

    Chronic obstructive pulmonary disease (COPD) is currently the fourth leading cause of death worldwide. It has serious health effects and causes substantial costs for society. The aim of the present paper was to develop a state-of-the-art decision-analytic model of COPD whereby the cost effectiveness of interventions in Germany can be estimated. To demonstrate the applicability of the model, a smoking cessation programme was evaluated against usual care. A seven-stage Markov model (disease stages I to IV according to the GOLD [Global Initiative for Chronic Obstructive Lung Disease] classification, states after lung-volume reduction surgery and lung transplantation, death) was developed to conduct a cost-utility analysis from the societal perspective over a time horizon of 10, 40 and 60 years. Patients entered the cohort model at the age of 45 with mild COPD. Exacerbations were classified into three levels: mild, moderate and severe. Estimation of stage-specific probabilities (for smokers and quitters), utilities and costs was based on German data where possible. Data on effectiveness of the intervention was retrieved from the literature. A discount rate of 3% was applied to costs and effects. Probabilistic sensitivity analysis was used to assess the robustness of the results. The smoking cessation programme was the dominant strategy compared with usual care, and the intervention resulted in an increase in health effects of 0.54 QALYs and a cost reduction of &U20AC;1115 per patient (year 2007 prices) after 60 years. In the probabilistic analysis, the intervention dominated in about 95% of the simulations. Sensitivity analyses showed that uncertainty primarily originated from data on disease progression and treatment cost in the early stages of disease. The model developed allows the long-term cost effectiveness of interventions to be estimated, and has been adapted to Germany. The model suggests that the smoking cessation programme evaluated was more effective than

  14. Likelihood inference for COM-Poisson cure rate model with interval-censored data and Weibull lifetimes.

    PubMed

    Pal, Suvra; Balakrishnan, N

    2017-10-01

    In this paper, we consider a competing cause scenario and assume the number of competing causes to follow a Conway-Maxwell Poisson distribution which can capture both over and under dispersion that is usually encountered in discrete data. Assuming the population of interest having a component cure and the form of the data to be interval censored, as opposed to the usually considered right-censored data, the main contribution is in developing the steps of the expectation maximization algorithm for the determination of the maximum likelihood estimates of the model parameters of the flexible Conway-Maxwell Poisson cure rate model with Weibull lifetimes. An extensive Monte Carlo simulation study is carried out to demonstrate the performance of the proposed estimation method. Model discrimination within the Conway-Maxwell Poisson distribution is addressed using the likelihood ratio test and information-based criteria to select a suitable competing cause distribution that provides the best fit to the data. A simulation study is also carried out to demonstrate the loss in efficiency when selecting an improper competing cause distribution which justifies the use of a flexible family of distributions for the number of competing causes. Finally, the proposed methodology and the flexibility of the Conway-Maxwell Poisson distribution are illustrated with two known data sets from the literature: smoking cessation data and breast cosmesis data.

  15. Modelling lifetime cost consequences of toric compared with standard IOLs in cataract surgery of astigmatic patients in four European countries.

    PubMed

    Laurendeau, C; Lafuma, A; Berdeaux, G

    2009-09-01

    To compare the lifetime costs of freeing astigmatic patients from spectacles after bilateral cataract surgery implanting toric intraocular lenses (IOLs: i.e., Acrysof Toric) versus monofocal IOLs, in France, Italy, Germany and Spain. A Markov model followed patient cohorts from cataract surgery until death. Prevalence rates of patients not needing spectacles and the types of spectacles prescribed for those requiring them were obtained from clinical trials and national surveys. The economic perspective was societal. Mortality rates were incorporated into the model. Discount rates were applied. A sensitivity analysis was performed on non-discounted costs. Fewer patients with toric IOLs needed spectacles for distance vision than patients with monofocal IOLs. With monofocal IOLs more than 66% of patients needed complex spectacles compared to less than 25% implanted with toric IOLs. In France and Italy, toric IOLs reduced overall costs relative to otherwise high spectacle costs after cataract surgery. Savings were 897.0 euros (France), 822.5 euros (Germany), 895.8 euros (Italy) and 391.6 euros (Spain), without discounting. On applying a 3% discount rate the costs became 691.7 euros, 646.4 euros, 693.9 euros and 308.2 euros, respectively. Bilateral toric IOL implants in astigmatic patients decreased spectacle dependence for distance vision and the need for complex spectacles. The economic consequences for patients depended on the national spectacle costs usually incurred after cataract surgery.

  16. Establishment of primary cultures for mouse ameloblasts as a model of their lifetime

    SciTech Connect

    Suzawa, Tetsuo; Itoh, Nao; Department of Clinical Pharmacy, School of Pharmaceutical Science, Showa University

    2006-07-07

    To understand how the properties of ameloblasts are spatiotemporally regulated during amelogenesis, two primary cultures of ameloblasts in different stages of differentiation were established from mouse enamel epithelium. Mouse primary ameloblasts (MPAs) prepared from immature enamel epithelium (MPA-I) could proliferate, whereas those from mature enamel epithelium (MPA-M) could not. MPA-M but not MPA-I caused apoptosis during culture. The mRNA expression of amelogenin, a marker of immature ameloblasts, was down-regulated, and that of enamel matrix serine proteiase-1, a marker of mature ameloblasts, was induced in MPA-I during culture. Using green fluorescence protein as a reporter, a visualized reporter system was establishedmore » to analyze the promoter activity of the amelogenin gene. The region between -1102 bp and -261 bp was required for the reporter expression in MPA-I. These results suggest that MPAs are valuable in vitro models for investigation of ameloblast biology, and that the visualized system is useful for promoter analysis in MPAs.« less

  17. Preconception stress and the secondary sex ratio in a population-based preconception cohort.

    PubMed

    Bae, Jisuk; Lynch, Courtney D; Kim, Sungduk; Sundaram, Rajeshwari; Sapra, Katherine J; Buck Louis, Germaine M

    2017-03-01

    To examine the association between preconception parental stress and the secondary sex ratio, defined as the ratio of males to females at birth. A population-based preconception cohort. Not applicable. A total of 235 couples who were enrolled before conception in Michigan and Texas between 2005 and 2009 and who had a singleton birth during the follow-up period. Couples were interviewed separately at baseline to obtain information on perceived stress (Cohen's Perceived Stress Scale) and lifetime history of physician-diagnosed anxiety and/or mood disorders. Female partners were also trained to collect basal saliva samples for the measurement of salivary stress markers, alpha-amylase and cortisol. None. Birth outcome data including infant sex were collected upon delivery. Modified Poisson regression models were used to estimate the relative risks (RRs) of a male birth for each stress marker. After adjusting for potential confounders, we observed a 76% increase in the risk of fathering a male infant (RR 1.76; 95% confidence interval 1.17-2.65) in men diagnosed with anxiety disorders compared with those who were not diagnosed. When lifetime history of physician-diagnosed anxiety disorders was modeled jointly for the couple, the association was slightly strengthened (RR 2.03; 95% confidence interval 1.46-2.84). This prospective cohort study suggests that paternal lifetime history of physician-diagnosed anxiety disorders may be associated with an increase in the secondary sex ratio, resulting in an excess of male births. Copyright © 2016 American Society for Reproductive Medicine. All rights reserved.

  18. Analytic solutions to modelling exponential and harmonic functions using Chebyshev polynomials: fitting frequency-domain lifetime images with photobleaching.

    PubMed

    Malachowski, George C; Clegg, Robert M; Redford, Glen I

    2007-12-01

    A novel approach is introduced for modelling linear dynamic systems composed of exponentials and harmonics. The method improves the speed of current numerical techniques up to 1000-fold for problems that have solutions of multiple exponentials plus harmonics and decaying components. Such signals are common in fluorescence microscopy experiments. Selective constraints of the parameters being fitted are allowed. This method, using discrete Chebyshev transforms, will correctly fit large volumes of data using a noniterative, single-pass routine that is fast enough to analyse images in real time. The method is applied to fluorescence lifetime imaging data in the frequency domain with varying degrees of photobleaching over the time of total data acquisition. The accuracy of the Chebyshev method is compared to a simple rapid discrete Fourier transform (equivalent to least-squares fitting) that does not take the photobleaching into account. The method can be extended to other linear systems composed of different functions. Simulations are performed and applications are described showing the utility of the method, in particular in the area of fluorescence microscopy.

  19. How are physicians delivering palliative care? A population-based retrospective cohort study describing the mix of generalist and specialist palliative care models in the last year of life.

    PubMed

    Brown, Catherine Rl; Hsu, Amy T; Kendall, Claire; Marshall, Denise; Pereira, Jose; Prentice, Michelle; Rice, Jill; Seow, Hsien-Yeang; Smith, Glenys A; Ying, Irene; Tanuseputro, Peter

    2018-06-01

    To enable coordinated palliative care delivery, all clinicians should have basic palliative care skill sets ('generalist palliative care'). Specialists should have skills for managing complex and difficult cases ('specialist palliative care') and co-exist to support generalists through consultation care and transfer of care. Little information exists about the actual mixes of generalist and specialist palliative care. To describe the models of physician-based palliative care services delivered to patients in the last 12 months of life. This is a population-based retrospective cohort study using linked health care administrative data. Physicians providing palliative care services to a decedent cohort in Ontario, Canada. The decedent cohort consisted of all adults (18+ years) who died in Ontario, Canada between April 2011 and March 2015 ( n = 361,951). We describe four major models of palliative care services: (1) 53.0% of decedents received no physician-based palliative care, (2) 21.2% received only generalist palliative care, (3) 14.7% received consultation palliative care (i.e. care from both specialists and generalists), and (4) 11.1% received only specialist palliative care. Among physicians providing palliative care ( n = 11,006), 95.3% had a generalist palliative care focus and 4.7% a specialist focus; 74.2% were trained as family physicians. We examined how often a coordinated palliative care model is delivered to a large decedent cohort and identified that few actually received consultation care. The majority of care, in both the palliative care generalist and specialist models, was delivered by family physicians. Further research should evaluate how different models of care impact patient outcomes and costs.

  20. Using non-empirically tuned range-separated functionals with simulated emission bands to model fluorescence lifetimes.

    PubMed

    Wong, Z C; Fan, W Y; Chwee, T S; Sullivan, Michael B

    2017-08-09

    Fluorescence lifetimes were evaluated using TD-DFT under different approximations for the emitting molecule and various exchange-correlation functionals, such as B3LYP, BMK, CAM-B3LYP, LC-BLYP, M06, M06-2X, M11, PBE0, ωB97, ωB97X, LC-BLYP*, and ωB97X* where the range-separation parameters in the last two functionals were tuned in a non-empirical fashion. Changes in the optimised molecular geometries between the ground and electronically excited states were found to affect the quality of the calculated lifetimes significantly, while the inclusion of vibronic features led to further improvements over the assumption of a vertical electronic transition. The LC-BLYP* functional was found to return the most accurate fluorescence lifetimes with unsigned errors that are mostly within 1.5 ns of experimental values.

  1. Cost effectiveness of population based BRCA1 founder mutation testing in Sephardi Jewish women.

    PubMed

    Patel, Shreeya; Legood, Rosa; Evans, D Gareth; Turnbull, Clare; Antoniou, Antonis C; Menon, Usha; Jacobs, Ian; Manchanda, Ranjit

    2018-04-01

    Population-based BRCA1/BRCA2 founder-mutation testing has been demonstrated as cost effective compared with family history based testing in Ashkenazi Jewish women. However, only 1 of the 3 Ashkenazi Jewish BRCA1/BRCA2 founder mutations (185delAG[c.68_69delAG]), 5382insC[c.5266dupC]), and 6174delT[c.5946delT]) is found in the Sephardi Jewish population (185delAG[c.68_69delAG]), and the overall prevalence of BRCA mutations in the Sephardi Jewish population is accordingly lower (0.7% compared with 2.5% in the Ashkenazi Jewish population). Cost-effectiveness analyses of BRCA testing have not previously been performed at these lower BRCA prevalence levels seen in the Sephardi Jewish population. Here we present a cost-effectiveness analysis for UK and US populations comparing population testing with clinical criteria/family history-based testing in Sephardi Jewish women. A Markov model was built comparing the lifetime costs and effects of population-based BRCA1 testing, with testing using family history-based clinical criteria in Sephardi Jewish women aged ≥30 years. BRCA1 carriers identified were offered magnetic resonance imaging/mammograms and risk-reducing surgery. Costs are reported at 2015 prices. Outcomes include breast cancer, ovarian cancer, and excess deaths from heart disease. All costs and outcomes are discounted at 3.5%. The time horizon is lifetime, and perspective is payer. The incremental cost-effectiveness ratio per quality-adjusted life-year was calculated. Parameter uncertainty was evaluated through 1-way and probabilistic sensitivity analysis. Population testing resulted in gain in life expectancy of 12 months (quality-adjusted life-year = 1.00). The baseline discounted incremental cost-effectiveness ratio for UK population-based testing was £67.04/quality-adjusted life-year and for US population was $308.42/quality-adjusted life-year. Results were robust in the 1-way sensitivity analysis. The probabilistic sensitivity analysis showed 100% of

  2. Urbanization factors associated with childhood asthma and prematurity: a population-based analysis aged from 0 to 5 years in Taiwan by using Cox regression within a hospital cluster model.

    PubMed

    Lin, Sheng-Chieh; Lin, Hui-Wen

    2015-04-01

    Childhood asthma and premature birth are both common; however, no studies have reported urbanization association between asthma and prematurity and the duration of prematurity affect asthma development. We use Taiwan Longitudinal Health Insurance Database (LHID) to explore association between asthma and prematurity among children by using a population-based analysis. This is a retrospective cohort study with registration data derived from Taiwan LHID. We evaluated prematurely born infants and children aged <5 years (n = 532) and age-matched control patients (n = 60505) using Cox proportional hazard regression analysis within a hospital cluster model. Of the 61 037 examinees, 14 012 experienced asthma during the 5-year follow-up, including 161 (72.26 per 1000 person-years) infants and children born prematurely and 13 851 (40.27 per 1000 person-years) controls. The hazard ratio for asthma during 5-year follow-up period was 1.95 (95% confidence interval = 1.67-2.28) among children born prematurely. Boys born prematurely aged 0-2 years were associated with higher asthma rates compared with girls in non-premature and premature groups. Living in urban areas, those born prematurely were associated with higher rates of asthma compared with non-prematurity. Those born prematurely lived in northern region had higher asthma hazard ratio than other regions. Our analyses indicated that sex, age, urbanization level, and geographic region are significantly associated with prematurity and asthma. Based on cumulative asthma-free survival curve generated using the Kaplan-Meier method, infants born prematurely should be closely monitored to see if they would develop asthma until the age of 6 years.

  3. Expected lifetime numbers and costs of fractures in postmenopausal women with and without osteoporosis in Germany: a discrete event simulation model

    PubMed Central

    2014-01-01

    Background Osteoporotic fractures cause a large health burden and substantial costs. This study estimated the expected fracture numbers and costs for the remaining lifetime of postmenopausal women in Germany. Methods A discrete event simulation (DES) model which tracks changes in fracture risk due to osteoporosis, a previous fracture or institutionalization in a nursing home was developed. Expected lifetime fracture numbers and costs per capita were estimated for postmenopausal women (aged 50 and older) at average osteoporosis risk (AOR) and for those never suffering from osteoporosis. Direct and indirect costs were modeled. Deterministic univariate and probabilistic sensitivity analyses were conducted. Results The expected fracture numbers over the remaining lifetime of a 50 year old woman with AOR for each fracture type (% attributable to osteoporosis) were: hip 0.282 (57.9%), wrist 0.229 (18.2%), clinical vertebral 0.206 (39.2%), humerus 0.147 (43.5%), pelvis 0.105 (47.5%), and other femur 0.033 (52.1%). Expected discounted fracture lifetime costs (excess cost attributable to osteoporosis) per 50 year old woman with AOR amounted to €4,479 (€1,995). Most costs were accrued in the hospital €1,743 (€751) and long-term care sectors €1,210 (€620). Univariate sensitivity analysis resulted in percentage changes between -48.4% (if fracture rates decreased by 2% per year) and +83.5% (if fracture rates increased by 2% per year) compared to base case excess costs. Costs for women with osteoporosis were about 3.3 times of those never getting osteoporosis (€7,463 vs. €2,247), and were markedly increased for women with a previous fracture. Conclusion The results of this study indicate that osteoporosis causes a substantial share of fracture costs in postmenopausal women, which strongly increase with age and previous fractures. PMID:24981316

  4. Expected lifetime numbers and costs of fractures in postmenopausal women with and without osteoporosis in Germany: a discrete event simulation model.

    PubMed

    Bleibler, Florian; Rapp, Kilian; Jaensch, Andrea; Becker, Clemens; König, Hans-Helmut

    2014-06-30

    Osteoporotic fractures cause a large health burden and substantial costs. This study estimated the expected fracture numbers and costs for the remaining lifetime of postmenopausal women in Germany. A discrete event simulation (DES) model which tracks changes in fracture risk due to osteoporosis, a previous fracture or institutionalization in a nursing home was developed. Expected lifetime fracture numbers and costs per capita were estimated for postmenopausal women (aged 50 and older) at average osteoporosis risk (AOR) and for those never suffering from osteoporosis. Direct and indirect costs were modeled. Deterministic univariate and probabilistic sensitivity analyses were conducted. The expected fracture numbers over the remaining lifetime of a 50 year old woman with AOR for each fracture type (% attributable to osteoporosis) were: hip 0.282 (57.9%), wrist 0.229 (18.2%), clinical vertebral 0.206 (39.2%), humerus 0.147 (43.5%), pelvis 0.105 (47.5%), and other femur 0.033 (52.1%). Expected discounted fracture lifetime costs (excess cost attributable to osteoporosis) per 50 year old woman with AOR amounted to € 4,479 (€ 1,995). Most costs were accrued in the hospital € 1,743 (€ 751) and long-term care sectors € 1,210 (€ 620). Univariate sensitivity analysis resulted in percentage changes between -48.4% (if fracture rates decreased by 2% per year) and +83.5% (if fracture rates increased by 2% per year) compared to base case excess costs. Costs for women with osteoporosis were about 3.3 times of those never getting osteoporosis (€ 7,463 vs. € 2,247), and were markedly increased for women with a previous fracture. The results of this study indicate that osteoporosis causes a substantial share of fracture costs in postmenopausal women, which strongly increase with age and previous fractures.

  5. Physical comorbidities in men with mood and anxiety disorders: a population-based study

    PubMed Central

    2013-01-01

    Background The mind-body nexus has been a topic of growing interest. Further data are however required to understand the specific relationship between mood and anxiety disorders and individual physical health conditions, and to verify whether these psychiatric disorders are linked to overall medical burden. Methods This study examined data collected from 942 men, 20 to 97 years old, participating in the Geelong Osteoporosis Study. A lifetime history of mood and anxiety disorders was identified using the Structured Clinical Interview for DSM-IV-TR Research Version, Non-patient edition (SCID-I/NP). The presence of medical conditions (lifetime) was self-reported and confirmed by medical records, medication use or clinical data. Anthropometric measurements and socioeconomic status (SES) were determined and information on medication use and lifestyle was obtained via questionnaire. Logistic regression models were used to test the associations. Results After adjustment for age, socioeconomic status, and health risk factors (body mass index, physical activity and smoking), mood disorders were associated with gastro oesophageal reflux disease (GORD), recurrent headaches, blackouts and/or epilepsy, liver disorders and pulmonary disease in older people, whilst anxiety disorders were significantly associated with thyroid, GORD and other gastrointestinal disorders, and psoriasis. Increased odds of high medical burden were associated with both mood and anxiety disorders. Conclusions Our study provides further population-based evidence supporting the link between mental and physical illness in men. Understanding these associations is not only necessary for individual management, but also to inform the delivery of health promotion messages and health care. PMID:23618390

  6. The costs of inequality: whole-population modelling study of lifetime inpatient hospital costs in the English National Health Service by level of neighbourhood deprivation

    PubMed Central

    Doran, Tim; Cookson, Richard

    2016-01-01

    Background There are substantial socioeconomic inequalities in both life expectancy and healthcare use in England. In this study, we describe how these two sets of inequalities interact by estimating the social gradient in hospital costs across the life course. Methods Hospital episode statistics, population and index of multiple deprivation data were combined at lower-layer super output area level to estimate inpatient hospital costs for 2011/2012 by age, sex and deprivation quintile. Survival curves were estimated for each of the deprivation groups and used to estimate expected annual costs and cumulative lifetime costs. Results A steep social gradient was observed in overall inpatient hospital admissions, with rates ranging from 31 298/100 000 population in the most affluent fifth of areas to 43 385 in the most deprived fifth. This gradient was steeper for emergency than for elective admissions. The total cost associated with this inequality in 2011/2012 was £4.8 billion. A social gradient was also observed in the modelled lifetime costs where the lower life expectancy was not sufficient to outweigh the higher average costs in the more deprived populations. Lifetime costs for women were 14% greater than for men, due to higher costs in the reproductive years and greater life expectancy. Conclusions Socioeconomic inequalities result in increased morbidity and decreased life expectancy. Interventions to reduce inequality and improve health in more deprived neighbourhoods have the potential to save money for health systems not only within years but across peoples’ entire lifetimes, despite increased costs due to longer life expectancies. PMID:27189975

  7. Using Hierarchical Cluster Models to Systematically Identify Groups of Jobs With Similar Occupational Questionnaire Response Patterns to Assist Rule-Based Expert Exposure Assessment in Population-Based Studies

    PubMed Central

    Friesen, Melissa C.; Shortreed, Susan M.; Wheeler, David C.; Burstyn, Igor; Vermeulen, Roel; Pronk, Anjoeka; Colt, Joanne S.; Baris, Dalsu; Karagas, Margaret R.; Schwenn, Molly; Johnson, Alison; Armenti, Karla R.; Silverman, Debra T.; Yu, Kai

    2015-01-01

    Objectives: Rule-based expert exposure assessment based on questionnaire response patterns in population-based studies improves the transparency of the decisions. The number of unique response patterns, however, can be nearly equal to the number of jobs. An expert may reduce the number of patterns that need assessment using expert opinion, but each expert may identify different patterns of responses that identify an exposure scenario. Here, hierarchical clustering methods are proposed as a systematic data reduction step to reproducibly identify similar questionnaire response patterns prior to obtaining expert estimates. As a proof-of-concept, we used hierarchical clustering methods to identify groups of jobs (clusters) with similar responses to diesel exhaust-related questions and then evaluated whether the jobs within a cluster had similar (previously assessed) estimates of occupational diesel exhaust exposure. Methods: Using the New England Bladder Cancer Study as a case study, we applied hierarchical cluster models to the diesel-related variables extracted from the occupational history and job- and industry-specific questionnaires (modules). Cluster models were separately developed for two subsets: (i) 5395 jobs with ≥1 variable extracted from the occupational history indicating a potential diesel exposure scenario, but without a module with diesel-related questions; and (ii) 5929 jobs with both occupational history and module responses to diesel-relevant questions. For each subset, we varied the numbers of clusters extracted from the cluster tree developed for each model from 100 to 1000 groups of jobs. Using previously made estimates of the probability (ordinal), intensity (µg m−3 respirable elemental carbon), and frequency (hours per week) of occupational exposure to diesel exhaust, we examined the similarity of the exposure estimates for jobs within the same cluster in two ways. First, the clusters’ homogeneity (defined as >75% with the same estimate

  8. Using hierarchical cluster models to systematically identify groups of jobs with similar occupational questionnaire response patterns to assist rule-based expert exposure assessment in population-based studies.

    PubMed

    Friesen, Melissa C; Shortreed, Susan M; Wheeler, David C; Burstyn, Igor; Vermeulen, Roel; Pronk, Anjoeka; Colt, Joanne S; Baris, Dalsu; Karagas, Margaret R; Schwenn, Molly; Johnson, Alison; Armenti, Karla R; Silverman, Debra T; Yu, Kai

    2015-05-01

    Rule-based expert exposure assessment based on questionnaire response patterns in population-based studies improves the transparency of the decisions. The number of unique response patterns, however, can be nearly equal to the number of jobs. An expert may reduce the number of patterns that need assessment using expert opinion, but each expert may identify different patterns of responses that identify an exposure scenario. Here, hierarchical clustering methods are proposed as a systematic data reduction step to reproducibly identify similar questionnaire response patterns prior to obtaining expert estimates. As a proof-of-concept, we used hierarchical clustering methods to identify groups of jobs (clusters) with similar responses to diesel exhaust-related questions and then evaluated whether the jobs within a cluster had similar (previously assessed) estimates of occupational diesel exhaust exposure. Using the New England Bladder Cancer Study as a case study, we applied hierarchical cluster models to the diesel-related variables extracted from the occupational history and job- and industry-specific questionnaires (modules). Cluster models were separately developed for two subsets: (i) 5395 jobs with ≥1 variable extracted from the occupational history indicating a potential diesel exposure scenario, but without a module with diesel-related questions; and (ii) 5929 jobs with both occupational history and module responses to diesel-relevant questions. For each subset, we varied the numbers of clusters extracted from the cluster tree developed for each model from 100 to 1000 groups of jobs. Using previously made estimates of the probability (ordinal), intensity (µg m(-3) respirable elemental carbon), and frequency (hours per week) of occupational exposure to diesel exhaust, we examined the similarity of the exposure estimates for jobs within the same cluster in two ways. First, the clusters' homogeneity (defined as >75% with the same estimate) was examined compared

  9. Thermo-mechanical and neutron lifetime modelling and design of Be pebbles in the neutron multiplier for the LIFE engine

    NASA Astrophysics Data System (ADS)

    DeMange, P.; Marian, J.; Caro, M.; Caro, A.

    2009-11-01

    Concept designs for the laser inertial fusion/fission energy (LIFE) engine include a neutron multiplication blanket containing Be pebbles flowing in a molten salt coolant. These pebbles must be designed to withstand the extreme irradiation and temperature conditions in the blanket to enable a reliable and cost-effective operation of LIFE. In this work, we develop design criteria for spherical Be pebbles on the basis of their thermo-mechanical behaviour under continued neutron exposure. We consider the effects of high fluence and fast fluxes on the elastic, thermal and mechanical properties of nuclear-grade Be. Our results suggest a maximum pebble diameter of 30 mm to avoid tensile failure, coated with an anti-corrosive, high-strength metallic shell to avoid failure by pebble contact. Moreover, we find that the operation temperature must always be kept above 450 °C to enable creep to relax the stresses induced by swelling. Under these circumstances, we estimate the pebble lifetime to be at least 16 months if uncoated, and up to six years when coated. We identify the sources of uncertainty on the properties used and discuss the advantages of new intermetallic beryllides and their use in LIFE's neutron multiplier. To establish Be-pebble lifetimes with improved confidence, reliable experiments to measure irradiation creep must be performed.

  10. Preindustrial to Present-Day Changes in Tropospheric Hydroxyl Radical and Methane Lifetime from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

    NASA Technical Reports Server (NTRS)

    Naik, V.; Voulgarakis, A.; Fiore, A. M.; Horowitz, L. W.; Lamarque, J.-F.; Lin, M.; Prather, M. J.; Young, P. J.; Bergmann, D.; Cameron-Smith, P. J.; hide

    2013-01-01

    We have analysed time-slice simulations from 17 global models, participating in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), to explore changes in present-day (2000) hydroxyl radical (OH) concentration and methane (CH4) lifetime relative to preindustrial times (1850) and to 1980. A comparison of modeled and observation-derived methane and methyl chloroform lifetimes suggests that the present-day global multi-model mean OH concentration is overestimated by 5 to 10% but is within the range of uncertainties. The models consistently simulate higher OH concentrations in the Northern Hemisphere (NH) compared with the Southern Hemisphere (SH) for the present-day (2000; inter-hemispheric ratios of 1.13 to 1.42), in contrast to observation-based approaches which generally indicate higher OH in the SH although uncertainties are large. Evaluation of simulated carbon monoxide (CO) concentrations, the primary sink for OH, against ground-based and satellite observations suggests low biases in the NH that may contribute to the high north–south OH asymmetry in the models. The models vary widely in their regional distribution of present-day OH concentrations (up to 34%). Despite large regional changes, the multi-model global mean (mass-weighted) OH concentration changes little over the past 150 yr, due to concurrent increases in factors that enhance OH (humidity, tropospheric ozone, nitrogen oxide (NOx) emissions, and UV radiation due to decreases in stratospheric ozone), compensated by increases in OH sinks (methane abundance, carbon monoxide and non-methane volatile organic carbon (NMVOC) emissions). The large inter-model diversity in the sign and magnitude of preindustrial to present-day OH changes (ranging from a decrease of 12.7% to an increase of 14.6%) indicate that uncertainty remains in our understanding of the long-term trends in OH and methane lifetime. We show that this diversity is largely explained by the different ratio of the

  11. Cost-effectiveness analysis of population-based screening of hepatocellular carcinoma: Comparing ultrasonography with two-stage screening

    PubMed Central

    Kuo, Ming-Jeng; Chen, Hsiu-Hsi; Chen, Chi-Ling; Fann, Jean Ching-Yuan; Chen, Sam Li-Sheng; Chiu, Sherry Yueh-Hsia; Lin, Yu-Min; Liao, Chao-Sheng; Chang, Hung-Chuen; Lin, Yueh-Shih; Yen, Amy Ming-Fang

    2016-01-01

    AIM: To assess the cost-effectiveness of two population-based hepatocellular carcinoma (HCC) screening programs, two-stage biomarker-ultrasound method and mass screening using abdominal ultrasonography (AUS). METHODS: In this study, we applied a Markov decision model with a societal perspective and a lifetime horizon for the general population-based cohorts in an area with high HCC incidence, such as Taiwan. The accuracy of biomarkers and ultrasonography was estimated from published meta-analyses. The costs of surveillance, diagnosis, and treatment were based on a combination of published literature, Medicare payments, and medical expenditure at the National Taiwan University Hospital. The main outcome measure was cost per life-year gained with a 3% annual discount rate. RESULTS: The results show that the mass screening using AUS was associated with an incremental cost-effectiveness ratio of USD39825 per life-year gained, whereas two-stage screening was associated with an incremental cost-effectiveness ratio of USD49733 per life-year gained, as compared with no screening. Screening programs with an initial screening age of 50 years old and biennial screening interval were the most cost-effective. These findings were sensitive to the costs of screening tools and the specificity of biomarker screening. CONCLUSION: Mass screening using AUS is more cost effective than two-stage biomarker-ultrasound screening. The most optimal strategy is an initial screening age at 50 years old with a 2-year inter-screening interval. PMID:27022228

  12. On the reduced lifetime of nitrous oxide due to climate change induced acceleration of the Brewer-Dobson circulation as simulated by the MPI Earth System Model

    NASA Astrophysics Data System (ADS)

    Kracher, D.; Manzini, E.; Reick, C. H.; Schultz, M. G.; Stein, O.

    2014-12-01

    Greenhouse gas induced climate change will modify the physical conditions of the atmosphere. One of the projected changes is an acceleration of the Brewer-Dobson circulation in the stratosphere, as it has been shown in many model studies. This change in the stratospheric circulation consequently bears an effect on the transport and distribution of atmospheric components such as N2O. Since N2O is involved in ozone destruction, a modified distribution of N2O can be of importance for ozone chemistry. N2O is inert in the troposphere and decays only in the stratosphere. Thus, changes in the exchange between troposphere and stratosphere can also affect the stratospheric sink of N2O, and consequently its atmospheric lifetime. N2O is a potent greenhouse gas with a global warming potential of currently approximately 300 CO2-equivalents in a 100-year perspective. A faster decay in atmospheric N2O mixing ratios, i.e. a decreased atmospheric lifetime of N2O, will also reduce its global warming potential. In order to assess the impact of climate change on atmospheric circulation and implied effects on the distribution and lifetime of atmospheric N2O, we apply the Max Planck Institute Earth System Model, MPI-ESM. MPI-ESM consists of the atmospheric general circulation model ECHAM, the land surface model JSBACH, and MPIOM/HAMOCC representing ocean circulation and ocean biogeochemistry. Prognostic atmospheric N2O concentrations in MPI-ESM are determined by land N2O emissions, ocean-atmosphere N2O exchange and atmospheric tracer transport. As stratospheric chemistry is not explicitly represented in MPI-ESM, stratospheric decay rates of N2O are prescribed from a MACC MOZART simulation. Increasing surface temperatures and CO2 concentrations in the stratosphere impact atmospheric circulation differently. Thus, we conduct a series of transient runs with the atmospheric model of MPI-ESM to isolate different factors governing a shift in atmospheric circulation. From those transient

  13. Fluorescence lifetime imaging ophthalmoscopy.

    PubMed

    Dysli, Chantal; Wolf, Sebastian; Berezin, Mikhail Y; Sauer, Lydia; Hammer, Martin; Zinkernagel, Martin S

    2017-09-01

    Imaging techniques based on retinal autofluorescence have found broad applications in ophthalmology because they are extremely sensitive and noninvasive. Conventional fundus autofluorescence imaging measures fluorescence intensity of endogenous retinal fluorophores. It mainly derives its signal from lipofuscin at the level of the retinal pigment epithelium. Fundus autofluorescence, however, can not only be characterized by the spatial distribution of the fluorescence intensity or emission spectrum, but also by a characteristic fluorescence lifetime function. The fluorescence lifetime is the average amount of time a fluorophore remains in the excited state following excitation. Fluorescence lifetime imaging ophthalmoscopy (FLIO) is an emerging imaging modality for in vivo measurement of lifetimes of endogenous retinal fluorophores. Recent reports in this field have contributed to our understanding of the pathophysiology of various macular and retinal diseases. Within this review, the basic concept of fluorescence lifetime imaging is provided. It includes technical background information and correlation with in vitro measurements of individual retinal metabolites. In a second part, clinical applications of fluorescence lifetime imaging and fluorescence lifetime features of selected retinal diseases such as Stargardt disease, age-related macular degeneration, choroideremia, central serous chorioretinopathy, macular holes, diabetic retinopathy, and retinal artery occlusion are discussed. Potential areas of use for fluorescence lifetime imaging ophthalmoscopy will be outlined at the end of this review. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Validity of LIDAS (LIfetime Depression Assessment Self-report): a self-report online assessment of lifetime major depressive disorder.

    PubMed

    Bot, M; Middeldorp, C M; de Geus, E J C; Lau, H M; Sinke, M; van Nieuwenhuizen, B; Smit, J H; Boomsma, D I; Penninx, B W J H

    2017-01-01

    There is a paucity of valid, brief instruments for the assessment of lifetime major depressive disorder (MDD) that can be used in, for example, large-scale genomics, imaging or biomarker studies on depression. We developed the LIfetime Depression Assessment Self-report (LIDAS), which assesses lifetime MDD diagnosis according to DSM criteria, and is largely based on the widely used Composite International Diagnostic Interview (CIDI). Here, we tested the feasibility and determined the sensitivity and specificity for measuring lifetime MDD with this new questionnaire, with a regular CIDI as reference. Sensitivity and specificity analyses of the online lifetime MDD questionnaire were performed in adults with (n = 177) and without (n = 87) lifetime MDD according to regular index CIDIs, selected from the Netherlands Study of Depression and Anxiety (NESDA) and Netherlands Twin Register (NTR). Feasibility was tested in an additional non-selective, population-based sample of NTR participants (n = 245). Of the 753 invited persons, 509 (68%) completed the LIDAS, of which 419 (82%) did this online. User-friendliness of the instrument was rated high. Median completion time was 6.2 min. Sensitivity and specificity for lifetime MDD were 85% [95% confidence interval (CI) 80-91%] and 80% (95% CI 72-89%), respectively. This LIDAS instrument gave a lifetime MDD prevalence of 20.8% in the population-based sample. Measuring lifetime MDD with an online instrument was feasible. Sensitivity and specificity were adequate. The instrument gave a prevalence of lifetime MDD in line with reported population prevalences. LIDAS is a promising tool for rapid determination of lifetime MDD status in large samples, such as needed for genomics studies.

  15. Polymer damage mitigation---predictive lifetime models of polymer insulation degradation and biorenewable thermosets through cationic polymerization for self-healing applications

    NASA Astrophysics Data System (ADS)

    Hondred, Peter Raymond

    Over the past 50 years, the industrial development and applications for polymers and polymer composites has become expansive. However, as with any young technology, the techniques for predicting material damage and resolving material failure are in need of continued development and refinement. This thesis work takes two approaches to polymer damage mitigation---material lifetime prediction and spontaneous damage repair through self-healing while incorporating bio-renewable feedstock. First, material lifetime prediction offers the benefit of identifying and isolating material failures before the effects of damage results in catastrophic failure. Second, self-healing provides a systematic approach to repairing damaged polymer composites, specifically in applications where a hands-on approach or removing the part from service are not feasible. With regard to lifetime prediction, we investigated three specific polymeric materials---polytetrafluoroethylene (PTFE), poly(ethylene-alt-tetrafluoroethylene) (ETFE), and Kapton. All three have been utilized extensively in the aerospace field as a wire insulation coating. Because of the vast amount of electrical wiring used in aerospace constructions and the potential for electrical and thermal failure, this work develops mathematical models for both the thermal degradation kinetics as well as a lifetime prediction model for electrothermal breakdown. Isoconversional kinetic methods, which plot activation energy as a function of the extent of degradation, present insight into the development each kinetic model. The models for PTFE, ETFE, and Kapton are one step, consecutive three-step, and competitive and consecutive five-step respectively. Statistical analysis shows that an nth order autocatalytic reaction best defined the reaction kinetics for each polymer's degradation. Self-healing polymers arrest crack propagation through the use of an imbedded adhesive that reacts when cracks form. This form of damage mitigation focuses on

  16. Adatom lifetime in film growth at solid surfaces in the framework of the Johnson Mehl Avrami Kolmogorov model

    NASA Astrophysics Data System (ADS)

    Tomellini, M.; Fanfoni, M.

    1999-10-01

    On the basis of the quasi-static approximation and for simultaneous nucleation the adatom lifetime, τ, during film growth at solid surfaces has been computed by Monte Carlo (MC) simulation. The quantity DN0τ, N0 and D being respectively the cluster density and the adatom diffusion coefficient, is found to depend upon the portion of surface covered by clusters and, very weakly, on N0. Moreover, a stochastic approach based on the Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory has been developed to obtain the analytical expression of the MC curve. The collision factor of the mean island has been calculated and compared with those previously obtained from the uniform depletion approximation and the lattice approximation.

  17. Deriving estimates of individual variability in genetic potentials of performance traits for 3 dairy breeds, using a model of lifetime nutrient partitioning.

    PubMed

    Phuong, H N; Martin, O; de Boer, I J M; Ingvartsen, K L; Schmidely, Ph; Friggens, N C

    2015-01-01

    This study explored the ability of an existing lifetime nutrient partitioning model for simulating individual variability in genetic potentials of dairy cows. Generally, the model assumes a universal trajectory of dynamic partitioning of priority between life functions and genetic scaling parameters are then incorporated to simulate individual difference in performance. Data of 102 cows including 180 lactations of 3 breeds: Danish Red, Danish Holstein, and Jersey, which were completely independent from those used previously for model development, were used. Individual cow performance records through sequential lactations were used to derive genetic scaling parameters for each animal by calibrating the model to achieve best fit, cow by cow. The model was able to fit individual curves of body weight, and milk fat, milk protein, and milk lactose concentrations with a high degree of accuracy. Daily milk yield and dry matter intake were satisfactorily predicted in early and mid lactation, but underpredictions were found in late lactation. Breeds and parities did not significantly affect the prediction accuracy. The means of genetic scaling parameters between Danish Red and Danish Holstein were similar but significantly different from those of Jersey. The extent of correlations between the genetic scaling parameters was consistent with that reported in the literature. In conclusion, this model is of value as a tool to derive estimates of genetic potentials of milk yield, milk composition, body reserve usage, and growth for different genotypes of cow. Moreover, it can be used to separate genetic variability in performance between individual cows from environmental noise. The model enables simulation of the effects of a genetic selection strategy on lifetime efficiency of individual cows, which has a main advantage of including the rearing costs, and thus, can be used to explore the impact of future selection on animal performance and efficiency. Copyright © 2015 American

  18. Stochastic Analysis of Orbital Lifetimes of Spacecraft

    NASA Technical Reports Server (NTRS)

    Sasamoto, Washito; Goodliff, Kandyce; Cornelius, David

    2008-01-01

    A document discusses (1) a Monte-Carlo-based methodology for probabilistic prediction and analysis of orbital lifetimes of spacecraft and (2) Orbital Lifetime Monte Carlo (OLMC)--a Fortran computer program, consisting of a previously developed long-term orbit-propagator integrated with a Monte Carlo engine. OLMC enables modeling of variances of key physical parameters that affect orbital lifetimes through the use of probability distributions. These parameters include altitude, speed, and flight-path angle at insertion into orbit; solar flux; and launch delays. The products of OLMC are predicted lifetimes (durations above specified minimum altitudes) for the number of user-specified cases. Histograms generated from such predictions can be used to determine the probabilities that spacecraft will satisfy lifetime requirements. The document discusses uncertainties that affect modeling of orbital lifetimes. Issues of repeatability, smoothness of distributions, and code run time are considered for the purpose of establishing values of code-specific parameters and number of Monte Carlo runs. Results from test cases are interpreted as demonstrating that solar-flux predictions are primary sources of variations in predicted lifetimes. Therefore, it is concluded, multiple sets of predictions should be utilized to fully characterize the lifetime range of a spacecraft.

  19. Febrile seizures: a population-based study.

    PubMed

    Dalbem, Juliane S; Siqueira, Heloise H; Espinosa, Mariano M; Alvarenga, Regina P

    2015-01-01

    To determine the prevalence of benign febrile seizures of childhood and describe the clinical and epidemiological profile of this population. This was a population-based, cross-sectional study, carried out in the city of Barra do Bugres, MT, Brazil, from August 2012 to August 2013. Data were collected in two phases. In the first phase, a questionnaire that was previously validated in another Brazilian study was used to identify suspected cases of seizures. In the second phase, a neurological evaluation was performed to confirm diagnosis. The prevalence was 6.4/1000 inhabitants (95% CI: 3.8-10.1). There was no difference between genders. Simple febrile seizures were found in 88.8% of cases. A family history of febrile seizures in first-degree relatives and history of epilepsy was present in 33.3% and 11.1% of patients, respectively. The prevalence of febrile seizures in Midwestern Brazil was lower than that found in other Brazilian regions, probably due to the inclusion only of febrile seizures with motor manifestations and differences in socioeconomic factors among the evaluated areas. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  20. Mapping population-based structural connectomes.

    PubMed

    Zhang, Zhengwu; Descoteaux, Maxime; Zhang, Jingwen; Girard, Gabriel; Chamberland, Maxime; Dunson, David; Srivastava, Anuj; Zhu, Hongtu

    2018-05-15

    Advances in understanding the structural connectomes of human brain require improved approaches for the construction, comparison and integration of high-dimensional whole-brain tractography data from a large number of individuals. This article develops a population-based structural connectome (PSC) mapping framework to address these challenges. PSC simultaneously characterizes a large number of white matter bundles within and across different subjects by registering different subjects' brains based on coarse cortical parcellations, compressing the bundles of each connection, and extracting novel connection weights. A robust tractography algorithm and streamline post-processing techniques, including dilation of gray matter regions, streamline cutting, and outlier streamline removal are applied to improve the robustness of the extracted structural connectomes. The developed PSC framework can be used to reproducibly extract binary networks, weighted networks and streamline-based brain connectomes. We apply the PSC to Human Connectome Project data to illustrate its application in characterizing normal variations and heritability of structural connectomes in healthy subjects. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Population-based study on infant mortality.

    PubMed

    Lima, Jaqueline Costa; Mingarelli, Alexandre Marchezoni; Segri, Neuber José; Zavala, Arturo Alejandro Zavala; Takano, Olga Akiko

    2017-03-01

    Although Brazil has reduced social, economic and health indicators disparities in the last decade, intra- and inter-regional differences in child mortality rates (CMR) persist in regions such as the state capital of Mato Grosso. This population-based study aimed to investigate factors associated with child mortality in five cohorts of live births (LB) of mothers living in Cuiabá (MT), Brazil, 2006-2010, through probabilistic linkage in 47,018 LB. We used hierarchical logistic regression analysis. Of the 617 child deaths, 48% occurred in the early neonatal period. CMR ranged from 14.6 to 12.0 deaths per thousand LB. The following remained independently associated with death: mothers without companion (OR = 1.32); low number of prenatal consultations (OR = 1.65); low birthweight (OR = 4.83); prematurity (OR = 3.05); Apgar ≤ 7 at the first minute (OR = 3.19); Apgar ≤ 7 at the fifth minute (OR = 4.95); congenital malformations (OR = 14.91) and male gender (OR = 1.26). CMR has declined in Cuiabá, however, there is need to guide public healthcare policies in the prenatal and perinatal period to reduce early neonatal mortality and further studies to identify the causes of preventable deaths.

  2. Heritability of lifetime ecstasy use.

    PubMed

    Verweij, Karin J H; Treur, Jorien L; Vreeker, Annabel; Brunt, Tibor M; Willemsen, Gonneke; Boomsma, Dorret I; Vink, Jacqueline M

    2017-09-01

    Ecstasy is a widely used psychoactive drug that users often take because they experience positive effects such as increased euphoria, sociability, elevated mood, and heightened sensations. Ecstasy use is not harmless and several immediate and long term side effects have been identified. Lifetime ecstasy use is likely to be partly influenced by genetic factors, but no twin study has determined the heritability. Here, we apply a classical twin design to a large sample of twins and siblings to estimate the heritability of lifetime ecstasy use. The sample comprised 8500 twins and siblings aged between 18 and 45 years from 5402 families registered at the Netherlands Twin Registry. In 2013-2014 participants filled out a questionnaire including a question whether they had ever used ecstasy. We used the classical twin design to partition the individual differences in liability to ecstasy use into that due to genetic, shared environmental, and residual components. Overall, 10.4% of the sample had used ecstasy during their lifetime, with a somewhat higher prevalence in males than females. Twin modelling indicated that individual differences in liability to lifetime ecstasy use are for 74% due to genetic differences between individuals, whereas shared environmental and residual factors explain a small proportion of its liability (5% and 21%, respectively). Although heritability estimates appeared to be higher for females than males, this difference was not significant. Lifetime ecstasy use is a highly heritable trait, which indicates that some people are genetically more vulnerable to start using ecstasy than others. Copyright © 2017. Published by Elsevier B.V.

  3. SO2 Emissions and Lifetimes: Estimates from Inverse Modeling Using In Situ and Global, Space-Based (SCIAMACHY and OMI) Observations

    NASA Technical Reports Server (NTRS)

    Lee, Chulkyu; Martin Randall V.; vanDonkelaar, Aaron; Lee, Hanlim; Dickerson, RUssell R.; Hains, Jennifer C.; Krotkov, Nickolay; Richter, Andreas; Vinnikov, Konstantine; Schwab, James J.

    2011-01-01

    Top-down constraints on global sulfur dioxide (SO2) emissions are inferred through inverse modeling using SO2 column observations from two satellite instruments (SCIAMACHY and OMI). We first evaluated the S02 column observations with surface SO2 measurements by applying local scaling factors from a global chemical transport model (GEOS-Chem) to SO2 columns retrieved from the satellite instruments. The resulting annual mean surface SO2 mixing ratios for 2006 exhibit a significant spatial correlation (r=0.86, slope=0.91 for SCIAMACHY and r=0.80, slope = 0.79 for OMI) with coincident in situ measurements from monitoring networks throughout the United States and Canada. We evaluate the GEOS-Chem simulation of the SO2 lifetime with that inferred from in situ measurements to verity the applicability of GEOS-Chem for inversion of SO2 columns to emissions. The seasonal mean SO2 lifetime calculated with the GEOS-Chem model over the eastern United States is 13 h in summer and 48 h in winter, compared to lifetimes inferred from in situ measurements of 19 +/- 7 h in summer and 58 +/- 20 h in winter. We apply SO2 columns from SCIAMACHY and OMI to derive a top-down anthropogenic SO2 emission inventory over land by using the local GEOS-Chem relationship between SO2 columns and emissions. There is little seasonal variation in the top-down emissions (<15%) over most major industrial regions providing some confidence in the method. Our global estimate for annual land surface anthropogenic SO2 emissions (52.4 Tg S/yr from SCIAMACHY and 49.9 Tg S / yr from OMI) closely agrees with the bottom-up emissions (54.6 Tg S/yr) in the GEOS-Chem model and exhibits consistency in global distributions with the bottom-up emissions (r = 0.78 for SCIAMACHY, and r = 0.77 for OMI). However, there are significant regional differences.

  4. Lifetime Risk of Symptomatic Hand Osteoarthritis: The Johnston County Osteoarthritis Project

    PubMed Central

    Qin, Jin; Barbour, Kamil E.; Murphy, Louise B.; Nelson, Amanda E.; Schwartz, Todd A.; Helmick, Charles G.; Allen, Kelli D.; Renner, Jordan B.; Baker, Nancy A; Jordan, Joanne M.

    2017-01-01

    Objective Symptomatic hand osteoarthritis (SHOA) is a common condition that affects hand strength and function, and causes disability in activities of daily living. Prior studies have estimated lifetime risk for symptomatic knee and hip osteoarthritis to be 45% and 25% respectively. The objective of this study is to estimate overall lifetime risk for SHOA and stratified lifetime risk by potential risk factors. Methods We analyzed data for 2,218 adults ≥ 45 years in the Johnston County Osteoarthritis Project, a population-based prospective cohort study in residents of Johnston County, North Carolina. Data were collected in two cycles (1999–2004 and 2005–2010). SHOA was defined as having both self-reported symptoms and radiographic OA in the same hand. Lifetime risk, defined as the proportion of the population who will develop SHOA in at least one hand by age 85, was estimated from models using generalized estimating equations methodology. Results Overall, the lifetime risk of SHOA is 39.8% (95% confidence interval (CI): 34.4, 45.3). Nearly one in two women (47.2%; 95% CI: 40.6, 53.9) will develop SHOA by age 85 compared with one in four men (24.6%; 95% CI: 19.5, 30.5). Race-specific estimates are 41.4% (95% CI: 35.5, 47.6) among whites and 29.2% (95% CI: 20.5, 39.7) among blacks. Lifetime risk among individuals with obesity (47.1%, 95% CI: 37.8, 56.7) is 11 percentage point higher than those without obesity (36.1%, 95% CI: 29.7, 42.9). Conclusion These findings demonstrate the substantial burden of SHOA overall and in subgroups. Increased use of public health and clinical interventions is needed to address its impact. PMID:28470947

  5. [Population-based cancer registration in Germany. Essentials and perspectives].

    PubMed

    Katalinic, A

    2004-05-01

    Although cancer registration has a long tradition in Germany, wide areas remained blank spaces on the map concerning population-based cancer registration. The situation changed completely when a federal law on cancer registration (KRG, 1995-1999) took effect. Now all federal states have established population-based cancer registries on a legal basis. In spite of the uniform model of cancer registration anchored in the KRG, 16 different models have developed in Germany. Completeness of cancer registration was constantly improved over the last several years. In addition to the Saarland cancer registry, further registries can now provide a high grade of registration for all cancer sites. Essential tasks, such as public reporting and support of cancer research, can now be better fulfilled. Even taking the great developments in cancer registration in Germany into consideration, some deficits still continue to exist. These deficits are mostly caused by heterogeneity and missing compatibility of the cancer registry laws of the federal states. After the focus of cancer registration was on developing valid registries,now the focus has to be changed to the usability of cancer registry data. These data can be used e. g. for research on etiology and evaluation of programs on early cancer detection. Scientists in the field of cancer epidemiology, public health, and cancer care are invited to use data of cancer registries for research and evaluation projects intensively.

  6. Oral Sex and HPV: Population Based Indications.

    PubMed

    Mishra, Anupam; Verma, Veerendra

    2015-03-01

    Human pappilloma virus (HPV) is well established in etiology of uterine cervical cancers, but its role in head and neck cancer is strongly suggested through many epidemiological and laboratory studies. Although HPV-16 induced oropharyngeal cancer is a distinct molecular entity, its role at other sub-sites (oral cavity, larynx, nasopharynx, hypopharynx) is less well established. Oral sex is supposedly the most commonly practiced unnatural sex across the globe and may prove to be a potential transmitting link between cancers of the uterine cervix and the oropharynx in males particularly in those 10-15% non-smokers. In India with the second largest population (higher population density than China) the oral sex is likely to be a common 'recreation-tool' amongst the majority (poor) and with the concurrent highly prevalent bad cervical/oral hygiene the HPV is likely to synergize other carcinogens. Hence in accordance (or coincidently), in India the cervical cancer happens to be the commonest cancer amongst females while oral/oropharyngeal cancer amongst males. Oral sex as a link between these two cancer types, can largely be argued considering a poor level of evidence in the existing literature. The modern world has even commercialized oral sex in the form of flavored condoms. The inadequate world literature currently is of a low level of evidence to conclude such a relationship because no such specific prospective study has been carried out and also due to wide (and unpredictable) variety of sexual practices, such a relationship can only be speculated. This article briefly reviews the existing literature on various modes and population based indications for HPV to be implicated in head and neck cancer with reference to oral sexual practice.

  7. Lifetime assessment by intermittent inspection under the mixture Weibull power law model with application to XLPE cables.

    PubMed

    Hirose, H

    1997-01-01

    This paper proposes a new treatment for electrical insulation degradation. Some types of insulation which have been used under various circumstances are considered to degrade at various rates in accordance with their stress circumstances. The cross-linked polyethylene (XLPE) insulated cables inspected by major Japanese electric companies clearly indicate such phenomena. By assuming that the inspected specimen is sampled from one of the clustered groups, a mixed degradation model can be constructed. Since the degradation of the insulation under common circumstances is considered to follow a Weibull distribution, a mixture model and a Weibull power law can be combined. This is called The mixture Weibull power law model. By using the maximum likelihood estimation for the newly proposed model to Japanese 22 and 33 kV insulation class cables, they are clustered into a certain number of groups by using the AIC and the generalized likelihood ratio test method. The reliability of the cables at specified years are assessed.

  8. Heterogeneity in Risk of Pelvic Inflammatory Diseases After Chlamydia Infection: A Population-Based Study in Manitoba, Canada

    PubMed Central

    Davies, Bethan; Ward, Helen; Leung, Stella; Turner, Katy M. E.; Garnett, Geoff P.; Blanchard, James F.; Yu, B. Nancy

    2014-01-01

    Background. The association between chlamydia infection and pelvic inflammatory disease (PID) is a key parameter for models evaluating the impact of chlamydia control programs. We quantified this association using a retrospective population-based cohort. Methods. We used administrative health data sets to construct a retrospective population-based cohort of women and girls aged 12–24 years who were resident in Manitoba, Canada, between 1992 and 1996. We performed survival analysis on a subcohort of individuals who were tested for chlamydia to estimate the risk of PID diagnosed in a primary care, outpatient, or inpatient setting after ≥1 positive chlamydia test. Results. A total of 73 883 individuals contributed 625 621 person years of follow-up. Those with a diagnosis of chlamydia had an increased risk of PID over their reproductive lifetime compared with those who tested negative (adjusted hazard ratio [AHR], 1.55; 95% confidence interval [CI], 1.43–1.70). This risk increased with each subsequent infection: the AHR was 1.17 for first reinfection (95% CI, 1.06–1.30) and 1.35 for the second (95% CI, 1.04–1.75). The increased risk of PID from reinfection was highest in younger individuals (AHR, 4.55 (95% CI, 3.59–5.78) in individuals aged 12–15 years at the time of their second reinfection, compared with individuals older than 30 years). Conclusions. There is heterogeneity in the risk of PID after a chlamydia infection. Describing the progression to PID in mathematical models as an average rate may be an oversimplification; more accurate estimates of the cost-effectiveness of screening may be obtained by using an individual-based measure of risk. Health inequalities may be reduced by targeting health promotion interventions at sexually active girls younger than 16 years and those with a history of chlamydia. PMID:25381374

  9. Heterogeneity in risk of pelvic inflammatory diseases after chlamydia infection: a population-based study in Manitoba, Canada.

    PubMed

    Davies, Bethan; Ward, Helen; Leung, Stella; Turner, Katy M E; Garnett, Geoff P; Blanchard, James F; Yu, B Nancy

    2014-12-01

    The association between chlamydia infection and pelvic inflammatory disease (PID) is a key parameter for models evaluating the impact of chlamydia control programs. We quantified this association using a retrospective population-based cohort. We used administrative health data sets to construct a retrospective population-based cohort of women and girls aged 12-24 years who were resident in Manitoba, Canada, between 1992 and 1996. We performed survival analysis on a subcohort of individuals who were tested for chlamydia to estimate the risk of PID diagnosed in a primary care, outpatient, or inpatient setting after ≥ 1 positive chlamydia test. A total of 73 883 individuals contributed 625 621 person years of follow-up. Those with a diagnosis of chlamydia had an increased risk of PID over their reproductive lifetime compared with those who tested negative (adjusted hazard ratio [AHR], 1.55; 95% confidence interval [CI], 1.43-1.70). This risk increased with each subsequent infection: the AHR was 1.17 for first reinfection (95% CI, 1.06-1.30) and 1.35 for the second (95% CI, 1.04-1.75). The increased risk of PID from reinfection was highest in younger individuals (AHR, 4.55 (95% CI, 3.59-5.78) in individuals aged 12-15 years at the time of their second reinfection, compared with individuals older than 30 years). There is heterogeneity in the risk of PID after a chlamydia infection. Describing the progression to PID in mathematical models as an average rate may be an oversimplification; more accurate estimates of the cost-effectiveness of screening may be obtained by using an individual-based measure of risk. Health inequalities may be reduced by targeting health promotion interventions at sexually active girls younger than 16 years and those with a history of chlamydia. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

  10. Implementation of Remaining Useful Lifetime Transformer Models in the Fleet-Wide Prognostic and Health Management Suite

    SciTech Connect

    Agarwal, Vivek; Lybeck, Nancy J.; Pham, Binh

    Research and development efforts are required to address aging and reliability concerns of the existing fleet of nuclear power plants. As most plants continue to operate beyond the license life (i.e., towards 60 or 80 years), plant components are more likely to incur age-related degradation mechanisms. To assess and manage the health of aging plant assets across the nuclear industry, the Electric Power Research Institute has developed a web-based Fleet-Wide Prognostic and Health Management (FW-PHM) Suite for diagnosis and prognosis. FW-PHM is a set of web-based diagnostic and prognostic tools and databases, comprised of the Diagnostic Advisor, the Asset Faultmore » Signature Database, the Remaining Useful Life Advisor, and the Remaining Useful Life Database, that serves as an integrated health monitoring architecture. The main focus of this paper is the implementation of prognostic models for generator step-up transformers in the FW-PHM Suite. One prognostic model discussed is based on the functional relationship between degree of polymerization, (the most commonly used metrics to assess the health of the winding insulation in a transformer) and furfural concentration in the insulating oil. The other model is based on thermal-induced degradation of the transformer insulation. By utilizing transformer loading information, established thermal models are used to estimate the hot spot temperature inside the transformer winding. Both models are implemented in the Remaining Useful Life Database of the FW-PHM Suite. The Remaining Useful Life Advisor utilizes the implemented prognostic models to estimate the remaining useful life of the paper winding insulation in the transformer based on actual oil testing and operational data.« less

  11. Prevalence and determinants of male partner violence against Mexican women: a population-based study.

    PubMed

    Rivera-Rivera, Leonor; Lazcano-Ponce, Eduardo; Salmerón-Castro, Jorge; Salazar-Martínez, Eduardo; Castro, Roberto; Hernández-Avila, Mauricio

    2004-01-01

    To determine the prevalence of and risk factors for violence against women, inflicted by their male partners, in a representative sample of women residing in the metropolitan area of Cuernavaca Morelos, Mexico. A population-based study was conducted from June to September 1998, among 1,535 women aged 15 to 49 years. Principal components analysis was used to determine the domains of violence that served as the dependent variable. Polynomial logistic regression models were used to estimate odds ratios (OR), with 95% confidence intervals (CI). Prevalence of low-moderate level violence was 35.8%, while prevalence of severe violence was 9.5%. The lifetime prevalence of reported rape was 5.9%. The main factors associated with violence were socio-economic status (OR=0.57; 95% CI=0.34-0.95); education level, both of the women studied (test for trend p=0.01) and of the male partner (test for trend p=0.002); number of years living with partner (OR=2.63; 95% CI=1.55-4.45), alcohol use (OR=2.56; 95% CI=2.02-3.25), illegal drug use by partner (OR=6.17; 95% CI=2.37-16.03); violence during childhood (OR=3.40; 95% CI=2.23-5.18), and a history of rape (OR=5.89; 95% CI=2.78-12.5). Study findings confirm that violence against women is a prevalent phenomenon in Mexico. Awareness-raising campaigns about male partner violence should bring this important issue to the front of public discussion. Such efforts will help assure that future generations do not experience partner violence to the extent that contemporary Mexican women do.

  12. Induced abortion, pregnancy loss and intimate partner violence in Tanzania: a population based study

    PubMed Central

    2012-01-01

    Background Violence by an intimate partner is increasingly recognized as an important public and reproductive health issue. The aim of this study is to investigate the extent to which physical and/or sexual intimate partner violence is associated with induced abortion and pregnancy loss from other causes and to compare this with other, more commonly recognized explanatory factors. Methods This study analyzes the data of the Tanzania section of the WHO Multi-Country Study on Women's Health and Domestic Violence, a large population-based cross-sectional survey of women of reproductive age in Dar es Salaam and Mbeya, Tanzania, conducted from 2001 to 2002. All women who answered positively to at least one of the questions about specific acts of physical or sexual violence committed by a partner towards her at any point in her life were considered to have experienced intimate partner violence. Associations between self reported induced abortion and pregnancy loss with intimate partner violence were analysed using multiple regression models. Results Lifetime physical and/or sexual intimate partner violence was reported by 41% and 56% of ever partnered, ever pregnant women in Dar es Salaam and Mbeya respectively. Among the ever pregnant, ever partnered women, 23% experienced involuntary pregnancy loss, while 7% reported induced abortion. Even after adjusting for other explanatory factors, women who experienced intimate partner violence were 1.6 (95%CI: 1.06,1.60) times more likely to report an pregnancy loss and 1.9 (95%CI: 1.30,2.89) times more likely to report an induced abortion. Intimate partner violence had a stronger influence on induced abortion and pregnancy loss than women's age, socio-economic status, and number of live born children. Conclusions Intimate partner violence is likely to be an important influence on levels of induced abortion and pregnancy loss in Tanzania. Preventing intimate partner violence may therefore be beneficial for maternal health and

  13. Cost-effectiveness of dronedarone and standard of care compared with standard of care alone: US results of an ATHENA lifetime model.

    PubMed

    Reynolds, Matthew R; Nilsson, Jonas; Akerborg, Orjan; Jhaveri, Mehul; Lindgren, Peter

    2013-01-01

    The first antiarrhythmic drug to demonstrate a reduced rate of cardiovascular hospitalization in atrial fibrillation/flutter (AF/AFL) patients was dronedarone in a placebo-controlled, double-blind, parallel arm Trial to assess the efficacy of dronedarone 400 mg bid for the prevention of cardiovascular Hospitalization or death from any cause in patiENts with Atrial fibrillation/atrial flutter (ATHENA trial). The potential cost-effectiveness of dronedarone in this patient population has not been reported in a US context. This study assesses the cost-effectiveness of dronedarone from a US health care payers' perspective. ATHENA patient data were applied to a patient-level health state transition model. Probabilities of health state transitions were derived from ATHENA and published data. Associated costs used in the model (2010 values) were obtained from published sources when trial data were not available. The base-case model assumed that patients were treated with dronedarone for the duration of ATHENA (mean 21 months) and were followed over a lifetime. Cost-effectiveness, from the payers' perspective, was determined using a Monte Carlo microsimulation (1 million fictitious patients). Dronedarone plus standard care provided 0.13 life years gained (LYG), and 0.11 quality-adjusted life years (QALYs), over standard care alone; cost/QALY was $19,520 and cost/LYG was $16,930. Compared to lower risk patients, patients at higher risk of stroke (Congestive heart failure, history of Hypertension, Age ≥ 75 years, Diabetes mellitus, and past history of Stroke or transient ischemic attack (CHADS(2)) scores 3-6 versus 0) had a lower cost/QALY ($9580-$16,000 versus $26,450). Cost/QALY was highest in scenarios assuming lifetime dronedarone therapy, no cardiovascular mortality benefit, no cost associated with AF/AFL recurrence on standard care, and when discounting of 5% was compared with 0%. By extrapolating the results of a large, multicenter, randomized clinical trial (ATHENA

  14. Estimating the long-term effects of in vitro fertilization in Greece: an analysis based on a lifetime-investment model

    PubMed Central

    Fragoulakis, Vassilis; Maniadakis, Nikolaos

    2013-01-01

    Objective To quantify the economic effects of a child conceived by in vitro fertilization (IVF) in terms of net tax revenue from the state’s perspective in Greece. Methods Based on previous international experience, a mathematical model was developed to assess the lifetime productivity of a single individual and his/her lifetime transactions with governmental agencies. The model distinguished among three periods in the economic life cycle of an individual: (1) early life, when the government primarily contributes resources through child tax credits, health care, and educational expenses; (2) employment, when individuals begin returning resources through taxes; and (3) retirement, when the government expends additional resources on pensions and health care. The cost of a live birth with IVF was based on the modification of a previously published model developed by the authors. All outcomes were discounted at a 3% discount rate. The data inputs – namely, the economic or demographic variables – were derived from the National Statistical Secretariat of Greece and other relevant sources. To deal with uncertainty, bias-corrected uncertainty intervals (UIs) were calculated based on 5000 Monte Carlo simulations. In addition, to examine the robustness of our results, other one-way sensitivity analyses were also employed. Results The cost of IVF per birth was estimated at €17,015 (95% UI: €13,932–€20,200). The average projected income generated by an individual throughout his/her productive life was €258,070 (95% UI: €185,376–€339,831). In addition, his/her life tax contribution was estimated at €133,947 (95% UI: €100,126–€177,375), while the discounted governmental expenses for elderly and underage individuals were €67,624 (95% UI: €55,211–€83,930). Hence, the net present value of IVF was €60,435 (95% UI: €33,651–€94,330), representing a 182% net return on investment. Results remained constant under various assumptions for the

  15. Population-based absolute risk estimation with survey data

    PubMed Central

    Kovalchik, Stephanie A.; Pfeiffer, Ruth M.

    2013-01-01

    Absolute risk is the probability that a cause-specific event occurs in a given time interval in the presence of competing events. We present methods to estimate population-based absolute risk from a complex survey cohort that can accommodate multiple exposure-specific competing risks. The hazard function for each event type consists of an individualized relative risk multiplied by a baseline hazard function, which is modeled nonparametrically or parametrically with a piecewise exponential model. An influence method is used to derive a Taylor-linearized variance estimate for the absolute risk estimates. We introduce novel measures of the cause-specific influences that can guide modeling choices for the competing event components of the model. To illustrate our methodology, we build and validate cause-specific absolute risk models for cardiovascular and cancer deaths using data from the National Health and Nutrition Examination Survey. Our applications demonstrate the usefulness of survey-based risk prediction models for predicting health outcomes and quantifying the potential impact of disease prevention programs at the population level. PMID:23686614

  16. Perceived discrimination among men and women with normal weight and obesity. A population-based study from Sweden.

    PubMed

    Hansson, Lena M; Näslund, Erik; Rasmussen, Finn

    2010-08-01

    We examined whether men and women with obesity reported different types of discrimination to a greater extent than those with normal weight, and explored whether these associations were modified by socioeconomic position. National representative sample of men and women, with normal weight (n = 2,000), moderate obesity (n = 2,461) and severe obesity (n = 557). Participants were identified in a yearly population-based survey (1996-2006) and data on perceived discrimination and potential confounding factors were measured in 2008. Logistic regression models tested whether obesity was associated with perceived lifetime, workplace, healthcare and interpersonal discrimination. The overall response rate was 56%. For men, moderate obesity was associated with workplace discrimination, while severely obese women were more likely to report this sort of discrimination than normal weight women. Severely obese individuals were twice as likely to report healthcare discrimination than normal weight individuals. Women, regardless of weight status group, were in turn twice as likely to report healthcare discrimination as men. Women with severe obesity were significantly more likely to report interpersonal discrimination compared with normal weight women. Socioeconomic position modified the association between weight status and healthcare discrimination. Highly educated individuals with moderate and severe obesity were more likely to report healthcare discrimination than their normal weight counterparts, whereas low educated individuals with normal weight, moderate and severe obesity were equally likely to report discrimination. In this large, population-based study, discrimination was more likely to be reported by obese individuals compared with those of normal weight. The associations, however, varied according to gender and socioeconomic position.

  17. The atmospheric lifetime of black carbon

    NASA Astrophysics Data System (ADS)

    Cape, J. N.; Coyle, M.; Dumitrean, P.

    2012-11-01

    Black carbon (BC) in the atmosphere contributes to the human health effects of particulate matter and contributes to radiative forcing of climate. The lifetime of BC, particularly the smaller particle sizes (PM2.5) which can be transported over long distances, is therefore an important factor in determining the range of such effects, and the spatial footprint of emission controls. Theory and models suggest that the typical lifetime of BC is around one week. The frequency distributions of measurements of a range of hydrocarbons at a remote rural site in southern Scotland (Auchencorth Moss) between 2007 and 2010 have been used to quantify the relationship between atmospheric lifetime and the geometric standard deviation of observed concentration. The analysis relies on an assumed common major emission source for hydrocarbons and BC, namely diesel-engined vehicles. The logarithm of the standard deviation of the log-transformed concentration data is linearly related to hydrocarbon lifetime, and the same statistic for BC can be used to assess the lifetime of BC relative to the hydrocarbons. Annual average data show BC lifetimes in the range 4-12 days, for an assumed OH concentration of 7 × 105 cm-3. At this site there is little difference in BC lifetime between winter and summer, despite a 3-fold difference in relative hydrocarbon lifetimes. This observation confirms the role of wet deposition as an important removal process for BC, as there is no difference in precipitation between winter and summer at this site. BC lifetime was significantly greater in 2010, which had 23% less rainfall than the preceding 3 years.

  18. Filter replacement lifetime prediction

    DOEpatents

    Hamann, Hendrik F.; Klein, Levente I.; Manzer, Dennis G.; Marianno, Fernando J.

    2017-10-25

    Methods and systems for predicting a filter lifetime include building a filter effectiveness history based on contaminant sensor information associated with a filter; determining a rate of filter consumption with a processor based on the filter effectiveness history; and determining a remaining filter lifetime based on the determined rate of filter consumption. Methods and systems for increasing filter economy include measuring contaminants in an internal and an external environment; determining a cost of a corrosion rate increase if unfiltered external air intake is increased for cooling; determining a cost of increased air pressure to filter external air; and if the cost of filtering external air exceeds the cost of the corrosion rate increase, increasing an intake of unfiltered external air.

  19. Characterizing Fibrosis in Mouse Kidney using Label Free Fluorescence Lifetime and Second Harmonic Generation Imaging Microscopy in Unilateral Ureteral Obstruction Model

    PubMed Central

    Ranjit, Suman; Dobrinskikh, Evgenia; Montford, John; Dvornikov, Alexander; Lehman, Allison; Orlicky, David J.; Nemenoff, Raphael; Gratton, Enrico; Levi, Moshe; Furgeson, Seth

    2017-01-01

    All forms of progressive renal diseases develop a final pathway of tubulointerstitial fibrosis and glomerulosclerosis. Renal fibrosis is usually quantified using histological staining, a process that is time-consuming and pathologist dependent. The work described here shows the development of a fast and operator-independent method to measure fibrosis. To study renal fibrosis, the unilateral ureteral obstruction (UUO) model was chosen. Mice develop a time-dependent increase in obstructed kidneys; contralateral kidneys are used as controls. After UUO, kidneys were analyzed at three time points: 7 days, 14 days, and 21 days. Fibrosis was investigated using FLIM (Fluorescence Lifetime Imaging) and SHG (Second Harmonic Generation) in the deep tissue imaging microscope called DIVER (Deep Imaging via Enhanced photon Recovery). This microscope was developed for deep tissue and SHG and THG (Third Harmonic Generation) imaging and has extraordinary sensitivity towards harmonic generation. SHG data suggests the presence of more fibrillar collagen in the diseased kidneys. The combinations of short wavelength FLIM and SHG analysis results in a robust analysis procedure independent of observer interpretation and let us create a criterion to quantify the extent of fibrosis directly from the image. The progression of fibrosis in UUO model has been studied using this new FLIM-SHG technique and it shows remarkable improvement in quantification of fibrosis compared to standard histological techniques. PMID:27555119

  20. Parenting and risk for mood, anxiety and substance use disorders: a study in population-based male twins.

    PubMed

    Otowa, Takeshi; Gardner, Charles O; Kendler, Kenneth S; Hettema, John M

    2013-11-01

    Previous studies consistently identified a relationship between parenting behavior and psychopathology. In this study, we extended prior analyses performed in female twins to a large sample of twins from male-male pairs. We used interview data on 2,609 adult male twins from a population-based twin registry. We examined the association between three retrospectively reported parenting dimensions (coldness, protectiveness, and authoritarianism) and lifetime history of seven common psychiatric and substance use disorders. Using univariate structural equation modeling, we also examined the influence of the genetic and environmental factors on parenting. Examined individually, coldness was consistently associated with risk for a broad range of adult psychopathology. Averaged odds of psychiatric disorders associated with parenting were increased between 26 and 36 %. When the three parenting dimensions were examined together, coldness remained significant for major depression, phobia, and generalized anxiety disorder. Controlling for other disorders, the associations between the parenting dimensions and psychopathology were non-specific. Twin fitting model demonstrated that modest heritability accounted for parenting, whereas most variance resulted from the non-shared environment. Based on our current and prior findings, there is broad similarity in the impact of parenting on adult psychopathology between men and women.

  1. Parenting and risk for mood, anxiety and substance use disorders: a study in population-based male twins

    PubMed Central

    Gardner, Charles O.; Kendler, Kenneth S.; Hettema, John M.

    2013-01-01

    Background Previous studies consistently identified a relationship between parenting behavior and psychopathology. In this study, we extended prior analyses performed in female twins to a large sample of twins from male–male pairs. Methods We used interview data on 2,609 adult male twins from a population-based twin registry. We examined the association between three retrospectively reported parenting dimensions (coldness, protectiveness, and authoritarianism) and lifetime history of seven common psychiatric and substance use disorders. Using univariate structural equation modeling, we also examined the influence of the genetic and environmental factors on parenting. Results Examined individually, coldness was consistently associated with risk for a broad range of adult psychopathology. Averaged odds of psychiatric disorders associated with parenting were increased between 26 and 36 %. When the three parenting dimensions were examined together, coldness remained significant for major depression, phobia, and generalized anxiety disorder. Controlling for other disorders, the associations between the parenting dimensions and psychopathology were non-specific. Twin fitting model demonstrated that modest heritability accounted for parenting, whereas most variance resulted from the non-shared environment. Conclusions Based on our current and prior findings, there is broad similarity in the impact of parenting on adult psychopathology between men and women. PMID:23344783

  2. Lifetime interpersonal violence and self-reported chlamydia trachomatis diagnosis among California women.

    PubMed

    Alvarez, Jennifer; Pavao, Joanne; Mack, Katelyn P; Chow, Joan M; Baumrind, Nikki; Kimerling, Rachel

    2009-01-01

    To examine the relationship between cumulative exposure to various types of interpersonal violence throughout the life span and self-reported history of Chlamydia trachomatis (CT) diagnosis in a population-based sample of California women. This was a cross-sectional analysis of a population-based survey of California women aged 18-44 years (n = 3521). Participants reported their experience of multiple types of interpersonal violence: physical or sexual abuse in childhood or adulthood and intimate partner violence (IPV) in the past 12 months. Current posttraumatic stress disorder (PTSD) and depressive symptoms were also reported. Separate logistic regression models assessed the association between experiencing each type of interpersonal violence, as well as women's cumulative exposure to violence, and past CT diagnosis, adjusting for age, race/ethnicity, and poverty, as well as mental health problems. Six percent of women reported a past diagnosis of CT, and 40.8% reported experiencing at least one type of interpersonal violence in their lifetime. All types of violence were significantly associated with higher odds of having a past CT diagnosis even after controlling for sociodemographics. Women who reported experiencing four or more types of violence experiences had over five times the odds of reporting a lifetime CT diagnosis compared with women who never experienced interpersonal violence (adjusted odds ratio = 5.71, 95% CI 3.27-9.58). Current PTSD and depressive symptoms did not significantly affect the relationship between a woman's cumulative experience of violence and her risk of past CT diagnosis. There is a robust association between experiencing multiple forms of violence and having been diagnosed with CT. Women who seek treatment for sexually transmitted diseases (STDs), such as CT, should be assessed for their lifetime history of violence, especially violence in their current intimate relationships. Sexual risk reduction counseling may also be important

  3. Recoil distance lifetime measurements in82Kr

    NASA Astrophysics Data System (ADS)

    Brüssermann, S.; Keinonen, J.; Hellmeister, H. P.; Lieb, K. P.

    1982-12-01

    The lifetimes τ=124±12, 6{-2/+4} and 380±100 ps of the E x ( I π )=3.46(8+), 2.92(6+) and 3.04(6-) MeV states, respectively, populated by the reaction76Ge(12C, α2 n) were measured with the recoil distance method. In addition upper lifetime limits were obtained for nine states. The measured lifetimes and energies indicate a band crossing at about I π =8+, probably arising from the alignment of two g 9/2 neutrons. For the 3.04 MeV 6- state as a second member of a band built on the 2.65 MeV 4- state the measured lifetime points to a two-quasiparticle configuration. The positive-parity states have been discussed in the frame of the interacting boson approximation, nuclear field theory and the cranked shell model.

  4. Design and implementation of population-based specialty care programs.

    PubMed

    Botts, Sheila R; Gee, Michael T; Chang, Christopher C; Young, Iris; Saito, Logan; Lyman, Alfred E

    2017-09-15

    The development, implementation, and scaling of 3 population-based specialty care programs in a large integrated healthcare system are reviewed, and the role of clinical pharmacy services in ensuring safe, effective, and affordable care is highlighted. The Kaiser Permanente (KP) integrated healthcare delivery model allows for rapid development and expansion of innovative population management programs involving pharmacy services. Clinical pharmacists have assumed integral roles in improving the safety and effectiveness of high-complexity, high-cost care for specialty populations. These roles require an appropriate practice scope and are supported by an advanced electronic health record with disease registries and electronic surveillance tools for care-gap identification. The 3 specialty population programs described were implemented to address variation or unrecognized gaps in care for at-risk specialty populations. The Home Phototherapy Program has leveraged internal partnerships with clinical pharmacists to improve access to cost-effective nonpharmacologic interventions for psoriasis and other skin disorders. The Multiple Sclerosis Care Program has incorporated clinical pharmacists into neurology care in order to apply clinical guidelines in a systematic manner. The KP SureNet program has used clinical pharmacists and data analytics to identify opportunities to prevent drug-related adverse outcomes and ensure timely follow-up. Specialty care programs improve quality, cost outcomes, and the patient experience by appropriating resources to provide systematic and targeted care to high-risk patients. KP leverages an integration of people, processes, and technology to develop and scale population-based specialty care. Copyright © 2017 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  5. Scleroderma prevalence: demographic variations in a population-based sample.

    PubMed

    Bernatsky, S; Joseph, L; Pineau, C A; Belisle, P; Hudson, M; Clarke, A E

    2009-03-15

    To estimate the prevalence of systemic sclerosis (SSc) using population-based administrative data, and to assess the sensitivity of case ascertainment approaches. We ascertained SSc cases from Quebec physician billing and hospitalization databases (covering approximately 7.5 million individuals). Three case definition algorithms were compared, and statistical methods accounting for imperfect case ascertainment were used to estimate SSc prevalence and case ascertainment sensitivity. A hierarchical Bayesian latent class regression model that accounted for possible between-test dependence conditional on disease status estimated the effect of patient characteristics on SSc prevalence and the sensitivity of the 3 ascertainment algorithms. Accounting for error inherent in both the billing and the hospitalization data, we estimated SSc prevalence in 2003 at 74.4 cases per 100,000 women (95% credible interval [95% CrI] 69.3-79.7) and 13.3 cases per 100,000 men (95% CrI 11.1-16.1). Prevalence was higher for older individuals, particularly in urban women (161.2 cases per 100,000, 95% CrI 148.6-175.0). Prevalence was lowest in young men (in rural areas, as low as 2.8 cases per 100,000, 95% CrI 1.4-4.8). In general, no single algorithm was very sensitive, with point estimates for sensitivity ranging from 20-73%. We found marked differences in SSc prevalence according to age, sex, and region. In general, no single case ascertainment approach was very sensitive for SSc. Therefore, using data from multiple sources, with adjustment for the imperfect nature of each, is an important strategy in population-based studies of SSc and similar conditions.

  6. Health economic evaluation of Human Papillomavirus vaccines in women from Venezuela by a lifetime Markov cohort model.

    PubMed

    Bardach, Ariel Esteban; Garay, Osvaldo Ulises; Calderón, María; Pichón-Riviére, Andrés; Augustovski, Federico; Martí, Sebastián García; Cortiñas, Paula; Gonzalez, Marino; Naranjo, Laura T; Gomez, Jorge Alberto; Caporale, Joaquín Enzo

    2017-02-02

    Cervical cancer (CC) and genital warts (GW) are a significant public health issue in Venezuela. Our objective was to assess the cost-effectiveness of the two available vaccines, bivalent and quadrivalent, against Human Papillomavirus (HPV) in Venezuelan girls in order to inform decision-makers. A previously published Markov cohort model, informed by the best available evidence, was adapted to the Venezuelan context to evaluate the effects of vaccination on health and healthcare costs from the perspective of the healthcare payer in an 11-year-old girls cohort of 264,489. Costs and quality-adjusted life years (QALYs) were discounted at 5%. Eight scenarios were analyzed to depict the cost-effectiveness under alternative vaccine prices, exchange rates and dosing schemes. Deterministic and probabilistic sensitivity analyses were performed. Compared to screening only, the bivalent and quadrivalent vaccines were cost-saving in all scenarios, avoiding 2,310 and 2,143 deaths, 4,781 and 4,431 CCs up to 18,459 GW for the quadrivalent vaccine and gaining 4,486 and 4,395 discounted QALYs respectively. For both vaccines, the main determinants of variations in the incremental costs-effectiveness ratio after running deterministic and probabilistic sensitivity analyses were transition probabilities, vaccine and cancer-treatment costs and HPV 16 and 18 distribution in CC cases. When comparing vaccines, none of them was consistently more cost-effective than the other. In sensitivity analyses, for these comparisons, the main determinants were GW incidence, the level of cross-protection and, for some scenarios, vaccines costs. Immunization with the bivalent or quadrivalent HPV vaccines showed to be cost-saving or cost-effective in Venezuela, falling below the threshold of one Gross Domestic Product (GDP) per capita (104,404 VEF) per QALY gained. Deterministic and probabilistic sensitivity analyses confirmed the robustness of these results.

  7. The simcyp population based simulator: architecture, implementation, and quality assurance.

    PubMed

    Jamei, Masoud; Marciniak, Steve; Edwards, Duncan; Wragg, Kris; Feng, Kairui; Barnett, Adrian; Rostami-Hodjegan, Amin

    2013-01-01

    Developing a user-friendly platform that can handle a vast number of complex physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) models both for conventional small molecules and larger biologic drugs is a substantial challenge. Over the last decade the Simcyp Population Based Simulator has gained popularity in major pharmaceutical companies (70% of top 40 - in term of R&D spending). Under the Simcyp Consortium guidance, it has evolved from a simple drug-drug interaction tool to a sophisticated and comprehensive Model Based Drug Development (MBDD) platform that covers a broad range of applications spanning from early drug discovery to late drug development. This article provides an update on the latest architectural and implementation developments within the Simulator. Interconnection between peripheral modules, the dynamic model building process and compound and population data handling are all described. The Simcyp Data Management (SDM) system, which contains the system and drug databases, can help with implementing quality standards by seamless integration and tracking of any changes. This also helps with internal approval procedures, validation and auto-testing of the new implemented models and algorithms, an area of high interest to regulatory bodies.

  8. Adult Prevalence of Epilepsy in Spain: EPIBERIA, a Population-Based Study

    PubMed Central

    Serrano-Castro, Pedro J.; Mauri-Llerda, Jose Angel; Hernández-Ramos, Francisco José; Sánchez-Alvarez, Juan Carlos; Parejo-Carbonell, Beatriz; Quiroga-Subirana, Pablo; Vázquez-Gutierrez, Fernando; Santos-Lasaosa, Sonia; Mendez-Lucena, Carolina; Redondo-Verge, Luis; Tejero-Juste, Carlos; Morandeira-Rivas, Clara; Sancho-Rieger, Jerónimo; Matías-Guiu, Jorge

    2015-01-01

    Background. This study assesses the lifetime and active prevalence of epilepsy in Spain in people older than 18 years. Methods. EPIBERIA is a population-based epidemiological study of epilepsy prevalence using data from three representative Spanish regions (health districts in Zaragoza, Almería, and Seville) between 2012 and 2013. The study consisted of two phases: screening and confirmation. Participants completed a previously validated questionnaire (EPIBERIA questionnaire) over the telephone. Results. A total of 1741 valid questionnaires were obtained, including 261 (14.99%) raising a suspicion of epilepsy. Of these suspected cases, 216 (82.75%) agreed to participate in phase 2. Of the phase 2 participants, 22 met the International League Against Epilepsy's diagnostic criteria for epilepsy. The estimated lifetime prevalence, adjusted by age and sex per 1,000 people, was 14.87 (95% CI: 9.8–21.9). Active prevalence was 5.79 (95% CI: 2.8–10.6). No significant age, sex, or regional differences in prevalence were detected. Conclusions. EPIBERIA provides the most accurate estimate of epilepsy prevalence in the Mediterranean region based on its original methodology and its adherence to ILAE recommendations. We highlight that the lifetime prevalence and inactive epilepsy prevalence figures observed here were compared to other epidemiological studies. PMID:26783554

  9. Cost-effectiveness of population based BRCA testing with varying Ashkenazi Jewish ancestry.

    PubMed

    Manchanda, Ranjit; Patel, Shreeya; Antoniou, Antonis C; Levy-Lahad, Ephrat; Turnbull, Clare; Evans, D Gareth; Hopper, John L; Macinnis, Robert J; Menon, Usha; Jacobs, Ian; Legood, Rosa

    2017-11-01

    Population-based BRCA1/BRCA2 testing has been found to be cost-effective compared with family history-based testing in Ashkenazi-Jewish women were >30 years old with 4 Ashkenazi-Jewish grandparents. However, individuals may have 1, 2, or 3 Ashkenazi-Jewish grandparents, and cost-effectiveness data are lacking at these lower BRCA prevalence estimates. We present an updated cost-effectiveness analysis of population BRCA1/BRCA2 testing for women with 1, 2, and 3 Ashkenazi-Jewish grandparents. Decision analysis model. Lifetime costs and effects of population and family history-based testing were compared with the use of a decision analysis model. 56% BRCA carriers are missed by family history criteria alone. Analyses were conducted for United Kingdom and United States populations. Model parameters were obtained from the Genetic Cancer Prediction through Population Screening trial and published literature. Model parameters and BRCA population prevalence for individuals with 3, 2, or 1 Ashkenazi-Jewish grandparent were adjusted for the relative frequency of BRCA mutations in the Ashkenazi-Jewish and general populations. Incremental cost-effectiveness ratios were calculated for all Ashkenazi-Jewish grandparent scenarios. Costs, along with outcomes, were discounted at 3.5%. The time horizon of the analysis is "life-time," and perspective is "payer." Probabilistic sensitivity analysis evaluated model uncertainty. Population testing for BRCA mutations is cost-saving in Ashkenazi-Jewish women with 2, 3, or 4 grandparents (22-33 days life-gained) in the United Kingdom and 1, 2, 3, or 4 grandparents (12-26 days life-gained) in the United States populations, respectively. It is also extremely cost-effective in women in the United Kingdom with just 1 Ashkenazi-Jewish grandparent with an incremental cost-effectiveness ratio of £863 per quality-adjusted life-years and 15 days life gained. Results show that population-testing remains cost-effective at the £20,000-30000 per quality

  10. Potential for adult-based epidemiological studies to characterize overall cancer risks associated with a lifetime of CT scans.

    PubMed

    Shuryak, Igor; Lubin, Jay H; Brenner, David J

    2014-06-01

    Recent epidemiological studies have suggested that radiation exposure from pediatric CT scanning is associated with small excess cancer risks. However, the majority of CT scans are performed on adults, and most radiation-induced cancers appear during middle or old age, in the same age range as background cancers. Consequently, a logical next step is to investigate the effects of CT scanning in adulthood on lifetime cancer risks by conducting adult-based, appropriately designed epidemiological studies. Here we estimate the sample size required for such studies to detect CT-associated risks. This was achieved by incorporating different age-, sex-, time- and cancer type-dependent models of radiation carcinogenesis into an in silico simulation of a population-based cohort study. This approach simulated individual histories of chest and abdominal CT exposures, deaths and cancer diagnoses. The resultant sample sizes suggest that epidemiological studies of realistically sized cohorts can detect excess lifetime cancer risks from adult CT exposures. For example, retrospective analysis of CT exposure and cancer incidence data from a population-based cohort of 0.4 to 1.3 million (depending on the carcinogenic model) CT-exposed UK adults, aged 25-65 in 1980 and followed until 2015, provides 80% power for detecting cancer risks from chest and abdominal CT scans.

  11. Fluorescence lifetime based bioassays

    NASA Astrophysics Data System (ADS)

    Meyer-Almes, Franz-Josef

    2017-12-01

    Fluorescence lifetime (FLT) is a robust intrinsic property and material constant of fluorescent matter. Measuring this important physical indicator has evolved from a laboratory curiosity to a powerful and established technique for a variety of applications in drug discovery, medical diagnostics and basic biological research. This distinct trend was mainly driven by improved and meanwhile affordable laser and detection instrumentation on the one hand, and the development of suitable FLT probes and biological assays on the other. In this process two essential working approaches emerged. The first one is primarily focused on high throughput applications employing biochemical in vitro assays with no requirement for high spatial resolution. The second even more dynamic trend is the significant expansion of assay methods combining highly time and spatially resolved fluorescence data by fluorescence lifetime imaging. The latter approach is currently pursued to enable not only the investigation of immortal tumor cell lines, but also specific tissues or even organs in living animals. This review tries to give an actual overview about the current status of FLT based bioassays and the wide range of application opportunities in biomedical and life science areas. In addition, future trends of FLT technologies will be discussed.

  12. A Satellite Mortality Study to Support Space Systems Lifetime Prediction

    NASA Technical Reports Server (NTRS)

    Fox, George; Salazar, Ronald; Habib-Agahi, Hamid; Dubos, Gregory

    2013-01-01

    Estimating the operational lifetime of satellites and spacecraft is a complex process. Operational lifetime can differ from mission design lifetime for a variety of reasons. Unexpected mortality can occur due to human errors in design and fabrication, to human errors in launch and operations, to random anomalies of hardware and software or even satellite function degradation or technology change, leading to unrealized economic or mission return. This study focuses on data collection of public information using, for the first time, a large, publically available dataset, and preliminary analysis of satellite lifetimes, both operational lifetime and design lifetime. The objective of this study is the illustration of the relationship of design life to actual lifetime for some representative classes of satellites and spacecraft. First, a Weibull and Exponential lifetime analysis comparison is performed on the ratio of mission operating lifetime to design life, accounting for terminated and ongoing missions. Next a Kaplan-Meier survivor function, standard practice for clinical trials analysis, is estimated from operating lifetime. Bootstrap resampling is used to provide uncertainty estimates of selected survival probabilities. This study highlights the need for more detailed databases and engineering reliability models of satellite lifetime that include satellite systems and subsystems, operations procedures and environmental characteristics to support the design of complex, multi-generation, long-lived space systems in Earth orbit.

  13. Protective effect of Aronia melanocarpa polyphenols against cadmium-induced disorders in bone metabolism: a study in a rat model of lifetime human exposure to this heavy metal.

    PubMed

    Brzóska, Malgorzata M; Rogalska, Joanna; Galazyn-Sidorczuk, Malgorzata; Jurczuk, Maria; Roszczenko, Alicja; Tomczyk, Michal

    2015-03-05

    It was investigated, in a female rat model of low and moderate lifetime human exposure to cadmium (Cd), whether polyphenols from Aronia melanocarpa berries (chokeberry; AMP) may offer protection from this heavy metal-induced disorders in bone metabolism. For this purpose, numerous indices of bone formation (osteocalcin, alkaline phosphatase, osteoprotegerin) and resorption (carboxy-terminal cross-linking telopeptides of type I collagen, soluble receptor activator of nuclear factor-κB ligand) in the serum and/or distal femur epiphysis (trabecular bone region), as well as bone mineral status (volumetric bone mineral density of the femur and content of mineral components, including calcium, in the bone tissue at the distal femur epiphysis) were evaluated in female Wistar rats that received a 0.1% aqueous extract of AMP, as the only drinking fluid (prepared from lyophilized extract by Adamed Consumer Healthcare), and/or Cd in diet (1 and 5mg/kg) for 3, 10, 17, and 24 months. Examination of the phytochemical profile of the aronia extract revealed high content of polyphenols (612.40 ± 3.33 mg/g), including anthocyanins, proanthocyanidins, phenolic acids, and flavonoids. Among detected compounds anthocyanins were identified as dominating. The exposure to Cd, dose- and duration-dependently, enhanced resorption and inhibited formation of the bone tissue resulting in its decreased mineralization. The administration of AMP under the exposure to 1 and 5 mgCd/kg diet provided important protection from this heavy metal-induced disturbances in the bone turnover and changes in the bone mineral status, and the beneficial impact of polyphenols resulted from their independent action and interaction with Cd. These findings suggest that consumption of Aronia melanocarpa polyphenols may play a role in prevention against female skeleton damage due to chronic exposure to Cd and that chokeberry represents the good natural plant candidate for further investigations of its prophylactic use

  14. Population-based contracting (population health): part II.

    PubMed

    Jacofsky, D J

    2017-11-01

    Modern healthcare contracting is shifting the responsibility for improving quality, enhancing community health and controlling the total cost of care for patient populations from payers to providers. Population-based contracting involves capitated risk taken across an entire population, such that any included services within the contract are paid for by the risk-bearing entity throughout the term of the agreement. Under such contracts, a risk-bearing entity, which may be a provider group, a hospital or another payer, administers the contract and assumes risk for contractually defined services. These contracts can be structured in various ways, from professional fee capitation to full global per member per month diagnosis-based risk. The entity contracting with the payer must have downstream network contracts to provide the care and facilities that it has agreed to provide. Population health is a very powerful model to reduce waste and costs. It requires a deep understanding of the nuances of such contracting and the appropriate infrastructure to manage both networks and risk. Cite this article: Bone Joint J 2017;99-B:1431-4. ©2017 The British Editorial Society of Bone & Joint Surgery.

  15. Progress toward a new measurement of the neutron lifetime

    NASA Astrophysics Data System (ADS)

    Grammer, Kyle

    2015-04-01

    Free neutron decay is the simplest nuclear beta decay. A precise value for the neutron lifetime is valuable for standard model consistency tests and Big Bang Nucleosynthesis models. There is a disagreement between the measured neutron lifetime from cold neutron beam experiments and ultracold neutron storage experiments. A new measurement of the neutron lifetime using the beam method is planned at the National Institute of Standards and Technology Center for Neutron Research. Experimental improvements should result in a 1s uncertainty measurement of the neutron lifetime. The technical improvements and the path towards the new measurement will be discussed. This work is supported by DOE Office of Science, NIST, and NSF.

  16. Lifetime secondhand smoke exposure and childhood and adolescent asthma: findings from the PIAMA cohort.

    PubMed

    Milanzi, Edith B; Brunekreef, Bert; Koppelman, Gerard H; Wijga, Alet H; van Rossem, Lenie; Vonk, Judith M; Smit, Henriëtte A; Gehring, Ulrike

    2017-02-23

    Secondhand smoke (SHS) exposure is a modifiable risk factor associated with childhood asthma. Associations with adolescent asthma and the relevance of the timing and patterns of exposure are unclear. Knowledge of critical windows of exposure is important for targeted interventions. We used data until age 17 from 1454 children of the Dutch population-based PIAMA birth cohort. Residential SHS exposure was assessed through parental questionnaires completed at ages 3 months, 1-8 (yearly), 11, 14, and 17 years. Lifetime exposure was determined as; a) time window-specific exposure (prenatal, infancy, preschool, primary school, and secondary school); b) lifetime cumulative exposure; c) longitudinal exposure patterns using latent class growth modeling (LCGM). Generalized estimation equations and logistic regression were used to analyze associations between exposure and asthma at ages 4 to 17 years, adjusting for potential confounders. With all three methods, we consistently found no association between SHS exposure and asthma at ages 4 to 17 years e.g. adjusted overall odds ratio (95% confidence interval) 0.67 (0.41-1.12), 1.00 (0.66-1.51) and 0.67 (0.41-1.11) for prenatal maternal active smoking, infancy, and preschool school time window exposures, respectively. We assessed lifetime SHS exposure using different methods. Different timing and patterns of SHS exposure were not associated with an increased risk of asthma in childhood and adolescence in our study. More longitudinal studies could investigate effects of lifetime SHS exposure on asthma in adolescence and later life.

  17. Evaluation of nationwide supplementary immunization in Lao People's Democratic Republic: Population-based seroprevalence survey of anti-measles and anti-rubella IgG in children and adults, mathematical modelling and a stability testing of the vaccine

    PubMed Central

    Miyano, Shinsuke; Mori, Yoshio; Vynnycky, Emilia; Keungsaneth, Phath; Vongphrachanh, Phengta; Xeuatvongsa, Anonh; Sisouk, Thongchanh; Som-Oulay, Vilasak; Khamphaphongphane, Bouaphan; Sengkeopaseuth, Bounthanom; Pathammavong, Chansay; Phounphenghak, Kongxay; Kitamura, Tomomi; Takeda, Makoto; Komase, Katsuhiro

    2018-01-01

    Background Measles outbreaks have occurred in some countries despite supplementary immunization activities (SIA) using measles-containing vaccine with high vaccination coverage. We conducted a cross-sectional seroprevalence survey to estimate population immunity in Lao People's Democratic Republic where repeated mass immunization has failed to eliminate measles. Methods and findings In this nationwide multistage cluster sampling survey conducted in 2014 based on probability proportionate to size sampling, blood samples were collected from 2,135 children and adults living in 52 randomly selected villages. Anti-measles and anti-rubella IgG were measured, and IgG prevalence was calculated. We applied mathematical modelling to estimate the number of cases of congenital rubella syndrome (CRS) in 2013 that were averted by the 2011 SIA. A stability testing was applied to the MR vaccine at 4°C, 25°C, and 35°C to examine stability differences between measles and rubella vaccine components. Measles IgG prevalence was significantly lower in the target age groups (5–21 years) of the 2011 SIA using a combination vaccine for measles and rubella vaccine (MR vaccine) than in young adults (22–39 years) (86.8% [95% CI: 83.0–90.6] vs. 99.0% [98.3–99.8]; p<0.001), whereas rubella IgG prevalence was significantly higher (88.2% [84.5–91.8] vs. 74.6% [70.7–78.5]; p<0.001). In the SIA target age groups, prevalence of measles IgG, but not rubella IgG, increased with age. CRS cases prevented in 2013 ranged from 16 [0–50] to 92 [32–180] if the force of infection had remained unchanged or had been reduced by 75%, respectively. In freeze-dried conditions, the measles vaccine component was more heat sensitive than the rubella component. Conclusions Inconsistent IgG prevalence between measles and rubella in Lao PDR can be partly explained by different stability of the measles and rubella vaccine components under heat exposure. Suboptimal vaccine handling may cause insufficient

  18. Evaluation of nationwide supplementary immunization in Lao People's Democratic Republic: Population-based seroprevalence survey of anti-measles and anti-rubella IgG in children and adults, mathematical modelling and a stability testing of the vaccine.

    PubMed

    Hachiya, Masahiko; Miyano, Shinsuke; Mori, Yoshio; Vynnycky, Emilia; Keungsaneth, Phath; Vongphrachanh, Phengta; Xeuatvongsa, Anonh; Sisouk, Thongchanh; Som-Oulay, Vilasak; Khamphaphongphane, Bouaphan; Sengkeopaseuth, Bounthanom; Pathammavong, Chansay; Phounphenghak, Kongxay; Kitamura, Tomomi; Takeda, Makoto; Komase, Katsuhiro

    2018-01-01

    Measles outbreaks have occurred in some countries despite supplementary immunization activities (SIA) using measles-containing vaccine with high vaccination coverage. We conducted a cross-sectional seroprevalence survey to estimate population immunity in Lao People's Democratic Republic where repeated mass immunization has failed to eliminate measles. In this nationwide multistage cluster sampling survey conducted in 2014 based on probability proportionate to size sampling, blood samples were collected from 2,135 children and adults living in 52 randomly selected villages. Anti-measles and anti-rubella IgG were measured, and IgG prevalence was calculated. We applied mathematical modelling to estimate the number of cases of congenital rubella syndrome (CRS) in 2013 that were averted by the 2011 SIA. A stability testing was applied to the MR vaccine at 4°C, 25°C, and 35°C to examine stability differences between measles and rubella vaccine components. Measles IgG prevalence was significantly lower in the target age groups (5-21 years) of the 2011 SIA using a combination vaccine for measles and rubella vaccine (MR vaccine) than in young adults (22-39 years) (86.8% [95% CI: 83.0-90.6] vs. 99.0% [98.3-99.8]; p<0.001), whereas rubella IgG prevalence was significantly higher (88.2% [84.5-91.8] vs. 74.6% [70.7-78.5]; p<0.001). In the SIA target age groups, prevalence of measles IgG, but not rubella IgG, increased with age. CRS cases prevented in 2013 ranged from 16 [0-50] to 92 [32-180] if the force of infection had remained unchanged or had been reduced by 75%, respectively. In freeze-dried conditions, the measles vaccine component was more heat sensitive than the rubella component. Inconsistent IgG prevalence between measles and rubella in Lao PDR can be partly explained by different stability of the measles and rubella vaccine components under heat exposure. Suboptimal vaccine handling may cause insufficient immunogenicity for measles, which subsequently leads to an

  19. Protochlorophyll complexes with similar steady-state fluorescence characteristics can differ in fluorescence lifetimes. A model study in Triton X-100.

    PubMed

    Myśliwa-Kurdziel, Beata; Solymosi, Katalin; Kruk, Jerzy; Böddi, Béla; Strzałka, Kazimierz

    2007-03-01

    The steady-state and time-resolved fluorescence characteristics of protochlorophyll (Pchl) dissolved in neat Triton X-100 and in Triton X-100 micelles were investigated, and the fluorescence lifetimes of different Pchl spectral forms were studied. Varying the concentration of Pchl or diluting the micellar solutions either with a buffer or with a micellar solution, 631-634, 645-655, 680-692 and above 700 nm emitting Pchl complexes were prepared, the ratios of which varied from one another. The fluorescence decay of the 631-634 nm emitting (monomeric) form had a mono-exponential character with a 5.4-ns fluorescence lifetime. The long-wavelength Pchl complexes (aggregates) had two fluorescence lifetime values within a range of 1.4-3.9 ns and 0.15-0.84 ns, which showed high variability in different environments. Depending on the conditions, either mono- or double-exponential fluorescence decay was found for a fluorescence band at 680-685 nm. These data show that despite their very similar steady-state fluorescence properties, Pchl complexes can differ in fluorescence lifetimes, which may reflect different molecular structures, intrinsic geometries or different molecular interactions. This underlines the importance of complex spectroscopic analysis for a precise description of native and artificial chlorophyllous pigment forms.

  20. Photoacoustic lifetime contrast between methylene blue monomers and self-quenched dimers as a model for dual-labeled activatable probes

    NASA Astrophysics Data System (ADS)

    Morgounova, Ekaterina; Shao, Qi; Hackel, Benjamin J.; Thomas, David D.; Ashkenazi, Shai

    2013-05-01

    Activatable photoacoustic probes efficiently combine the high spatial resolution and penetration depth of ultrasound with the high optical contrast and versatility of molecular imaging agents. Our approach is based on photoacoustic probing of the excited-state lifetime of methylene blue (MB), a fluorophore widely used in clinical therapeutic and diagnostic applications. Upon aggregation, static quenching between the bound molecules dramatically shortens their lifetime by three orders of magnitude. We present preliminary results demonstrating the ability of photoacoustic imaging to probe the lifetime contrast between monomers and dimers with high sensitivity in cylindrical phantoms. Gradual dimerization enhancement, driven by the addition of increasing concentrations of sodium sulfate to a MB solution, showed that lifetime-based photoacoustic probing decreases linearly with monomer concentration. Similarly, the addition of 4 mM sodium dodecyl sulfate, a concentration that amplifies MB aggregation and reduces the monomer concentration by more than 20-fold, led to a signal decrease of more than 20 dB compared to a solution free of surfactant. These results suggest that photoacoustic imaging can be used to selectively detect the presence of monomers. We conclude by discussing the implementation of the monomer-dimer contrast mechanism for the development of an enzyme-specific activatable probe.

  1. Lifetime measurement of high spin states in (75) Kr

    SciTech Connect

    Sheikh, Javid; Trivedi, T.; Maurya, K.

    2010-01-01

    The lifetimes of high spin states of {sup 75}Kr have been determined via {sup 50}Cr ({sup 28}Si, 2pn) {sup 75}Kr reaction in positive parity band using the Doppler-shift attenuation method. The transition quadrupole moments Q deduced from lifetime measurements have been compared with {sup 75}Br. Experimental results obtained from lifetime measurement are interpreted in the framework of projected shell model.

  2. Insight into carrier lifetime impact on band-modulation devices

    NASA Astrophysics Data System (ADS)

    Parihar, Mukta Singh; Lee, Kyung Hwa; Park, Hyung Jin; Lacord, Joris; Martinie, Sébastien; Barbé, Jean-Charles; Xu, Yue; El Dirani, Hassan; Taur, Yuan; Cristoloveanu, Sorin; Bawedin, Maryline

    2018-05-01

    A systematic study to model and characterize the band-modulation Z2-FET device is developed bringing light to the relevance of the carrier lifetime influence. This work provides guidelines to optimize the Z2-FETs for sharp switching, ESD protection, and 1T-DRAM applications. Lower carrier lifetime in the Z2-FET helps in attaining the sharp switch. We provide new insights into the correlation between generation/recombination, diffusion, electrostatic barriers and carrier lifetime.

  3. Induced abortion, pregnancy loss and intimate partner violence in Tanzania: a population based study.

    PubMed

    Stöckl, Heidi; Filippi, Veronique; Watts, Charlotte; Mbwambo, Jessie K K

    2012-03-05

    Violence by an intimate partner is increasingly recognized as an important public and reproductive health issue. The aim of this study is to investigate the extent to which physical and/or sexual intimate partner violence is associated with induced abortion and pregnancy loss from other causes and to compare this with other, more commonly recognized explanatory factors. This study analyzes the data of the Tanzania section of the WHO Multi-Country Study on Women's Health and Domestic Violence, a large population-based cross-sectional survey of women of reproductive age in Dar es Salaam and Mbeya, Tanzania, conducted from 2001 to 2002. All women who answered positively to at least one of the questions about specific acts of physical or sexual violence committed by a partner towards her at any point in her life were considered to have experienced intimate partner violence. Associations between self reported induced abortion and pregnancy loss with intimate partner violence were analysed using multiple regression models. Lifetime physical and/or sexual intimate partner violence was reported by 41% and 56% of ever partnered, ever pregnant women in Dar es Salaam and Mbeya respectively. Among the ever pregnant, ever partnered women, 23% experienced involuntary pregnancy loss, while 7% reported induced abortion. Even after adjusting for other explanatory factors, women who experienced intimate partner violence were 1.6 (95%CI: 1.06,1.60) times more likely to report an pregnancy loss and 1.9 (95%CI: 1.30,2.89) times more likely to report an induced abortion. Intimate partner violence had a stronger influence on induced abortion and pregnancy loss than women's age, socio-economic status, and number of live born children. Intimate partner violence is likely to be an important influence on levels of induced abortion and pregnancy loss in Tanzania. Preventing intimate partner violence may therefore be beneficial for maternal health and pregnancy outcomes. © 2012 Stöckl et al

  4. Clinical and social outcomes of adolescent self harm: population based birth cohort study

    PubMed Central

    Heron, Jon; Crane, Catherine; Hawton, Keith; Lewis, Glyn; Macleod, John; Tilling, Kate; Gunnell, David

    2014-01-01

    Objectives To investigate the mental health, substance use, educational, and occupational outcomes of adolescents who self harm in a general population sample, and to examine whether these outcomes differ according to self reported suicidal intent. Design Population based birth cohort study. Setting Avon Longitudinal Study of Parents and Children (ALSPAC), a UK birth cohort of children born in 1991-92. Participants Data on lifetime history of self harm with and without suicidal intent were available for 4799 respondents who completed a detailed self harm questionnaire at age 16 years. Multiple imputation was used to account for missing data. Main outcome measures Mental health problems (depression and anxiety disorder), assessed using the clinical interview schedule-revised at age 18 years, self reported substance use (alcohol, cannabis, cigarette smoking, and illicit drugs) at age 18 years, educational attainment at age 16 and 19 years, occupational outcomes at age 19 years, and self harm at age 21 years. Results Participants who self harmed with and without suicidal intent at age 16 years were at increased risk of developing mental health problems, future self harm, and problem substance misuse, with stronger associations for suicidal self harm than for non-suicidal self harm. For example, in models adjusted for confounders the odds ratio for depression at age 18 years was 2.21 (95% confidence interval 1.55 to 3.15) in participants who had self harmed without suicidal intent at age 16 years and 3.94 (2.67 to 5.83) in those who had self harmed with suicidal intent. Suicidal self harm, but not self harm without suicidal intent, was also associated with poorer educational and employment outcomes. Conclusions Adolescents who self harm seem to be vulnerable to a range of adverse outcomes in early adulthood. Risks were generally stronger in those who had self harmed with suicidal intent, but outcomes were also poor among those who had self harmed without suicidal

  5. Higher speed VCSELs by photon lifetime reduction

    NASA Astrophysics Data System (ADS)

    Westbergh, Petter; Gustavsson, Johan S.; Kögel, Benjamin; Haglund, Åsa; Larsson, Anders; Joel, Andrew

    2011-03-01

    The impedance characteristics and the effects of photon lifetime reduction on the performance of high-speed 850 nm VCSELs are investigated. Through S11 measurements and equivalent circuit modeling we show that the parasitic mesa capacitance can be significantly reduced by using multiple oxide layers. By performing a shallow surface etch (25 - 55 nm) on the fabricated VCSELs, we are able to reduce the photon lifetime by up to 80% and thereby significantly improve both static and dynamic properties of the VCSELs. By optimizing the photon lifetime we are able to enhance the 3dB modulation bandwidth of 7 μm oxide aperture VCSELs from 15 GHz to 23 GHz and finally demonstrate errorfree transmission at up to 40 Gbit/s.

  6. Photovoltaic Lifetime Project | Photovoltaic Research | NREL

    Science.gov Websites

    PV & Solar Resource Testing Accelerated Testing & Analysis Systems Engineering Project Sandia National Laboratories' PV Performance Modeling Collaborative website. Jinko Solar. PV systems mounted on the ground. Jinko Solar PV Lifetime installation at NREL. need-alt Light-induced degradation

  7. Guiding principles and checklist for population-based quality metrics.

    PubMed

    Krishnan, Mahesh; Brunelli, Steven M; Maddux, Franklin W; Parker, Thomas F; Johnson, Douglas; Nissenson, Allen R; Collins, Allan; Lacson, Eduardo

    2014-06-06

    The Centers for Medicare and Medicaid Services oversees the ESRD Quality Incentive Program to ensure that the highest quality of health care is provided by outpatient dialysis facilities that treat patients with ESRD. To that end, Centers for Medicare and Medicaid Services uses clinical performance measures to evaluate quality of care under a pay-for-performance or value-based purchasing model. Now more than ever, the ESRD therapeutic area serves as the vanguard of health care delivery. By translating medical evidence into clinical performance measures, the ESRD Prospective Payment System became the first disease-specific sector using the pay-for-performance model. A major challenge for the creation and implementation of clinical performance measures is the adjustments that are necessary to transition from taking care of individual patients to managing the care of patient populations. The National Quality Forum and others have developed effective and appropriate population-based clinical performance measures quality metrics that can be aggregated at the physician, hospital, dialysis facility, nursing home, or surgery center level. Clinical performance measures considered for endorsement by the National Quality Forum are evaluated using five key criteria: evidence, performance gap, and priority (impact); reliability; validity; feasibility; and usability and use. We have developed a checklist of special considerations for clinical performance measure development according to these National Quality Forum criteria. Although the checklist is focused on ESRD, it could also have broad application to chronic disease states, where health care delivery organizations seek to enhance quality, safety, and efficiency of their services. Clinical performance measures are likely to become the norm for tracking performance for health care insurers. Thus, it is critical that the methodologies used to develop such metrics serve the payer and the provider and most importantly, reflect

  8. Guiding Principles and Checklist for Population-Based Quality Metrics

    PubMed Central

    Brunelli, Steven M.; Maddux, Franklin W.; Parker, Thomas F.; Johnson, Douglas; Nissenson, Allen R.; Collins, Allan; Lacson, Eduardo

    2014-01-01

    The Centers for Medicare and Medicaid Services oversees the ESRD Quality Incentive Program to ensure that the highest quality of health care is provided by outpatient dialysis facilities that treat patients with ESRD. To that end, Centers for Medicare and Medicaid Services uses clinical performance measures to evaluate quality of care under a pay-for-performance or value-based purchasing model. Now more than ever, the ESRD therapeutic area serves as the vanguard of health care delivery. By translating medical evidence into clinical performance measures, the ESRD Prospective Payment System became the first disease-specific sector using the pay-for-performance model. A major challenge for the creation and implementation of clinical performance measures is the adjustments that are necessary to transition from taking care of individual patients to managing the care of patient populations. The National Quality Forum and others have developed effective and appropriate population-based clinical performance measures quality metrics that can be aggregated at the physician, hospital, dialysis facility, nursing home, or surgery center level. Clinical performance measures considered for endorsement by the National Quality Forum are evaluated using five key criteria: evidence, performance gap, and priority (impact); reliability; validity; feasibility; and usability and use. We have developed a checklist of special considerations for clinical performance measure development according to these National Quality Forum criteria. Although the checklist is focused on ESRD, it could also have broad application to chronic disease states, where health care delivery organizations seek to enhance quality, safety, and efficiency of their services. Clinical performance measures are likely to become the norm for tracking performance for health care insurers. Thus, it is critical that the methodologies used to develop such metrics serve the payer and the provider and most importantly, reflect

  9. Association between serotonin 5-HT-2C receptor gene (HTR2C) polymorphisms and obesity- and mental health-related phenotypes in a large population-based cohort.

    PubMed

    Vimaleswaran, K S; Zhao, J H; Wainwright, N W; Surtees, P G; Wareham, N J; Loos, R J F

    2010-06-01

    Studies have shown that common single-nucleotide polymorphisms (SNPs) in the serotonin 5-HT-2C receptor (HTR2C) are associated with antipsychotic agent-induced weight gain and the development of behavioural and psychological symptoms. We aimed to analyse whether variation in the HTR2C is associated with obesity- and mental health-related phenotypes in a large population-based cohort. Six tagSNPs, which capture all common genetic variation in the HTR2C gene, were genotyped in 4978 men and women from the European Prospective Investigation into Cancer (EPIC)-Norfolk study, an ongoing prospective population-based cohort study in the United Kingdom. To confirm borderline significant associations, the -759C/T SNP (rs3813929) was genotyped in the remaining 16 003 individuals from the EPIC-Norfolk study. We assessed social and psychological circumstances using the Health and Life Experiences Questionnaire. Genmod models were used to test associations between the SNPs and the outcomes. Logistic regression was performed to test for association of SNPs with obesity- and mental health- related phenotypes. Of the six HTR2C SNPs, only the T allele of the -759C/T SNP showed borderline significant associations with higher body mass index (BMI) (0.23 kg m(-2); (95% confidence interval (CI): 0.01-0.44); P=0.051) and increased risk of lifetime major depressive disorder (MDD) (Odds ratio (OR): 1.13 (95% CI: 1.01-1.22), P=0.02). The associations between the -759C/T and BMI and lifetime MDD were independent. As associations only achieved borderline significance, we aimed to validate our findings on the -759C/T SNP in the full EPIC-Norfolk cohort (n=20 981). Although the association with BMI remained borderline significant (beta=0.20 kg m(-2); 95% CI: 0.04-0.44, P=0.09), that with lifetime MDD (OR: 1.01; 95% CI: 0.94-1.09, P=0.73) was not replicated. Our findings suggest that common HTR2C gene variants are unlikely to have a major role in obesity- and mental health-related traits in the

  10. Comparison of lifetime incremental cost:utility ratios of surgery relative to failed medical management for the treatment of hip, knee and spine osteoarthritis modelled using 2-year postsurgical values

    PubMed Central

    Tso, Peggy; Walker, Kevin; Mahomed, Nizar; Coyte, Peter C.; Rampersaud, Y. Raja

    2012-01-01

    Background Demand for surgery to treat osteoarthritis (OA) of the hip, knee and spine has risen dramatically. Whereas total hip (THA) and total knee arthroplasty (TKA) have been widely accepted as cost-effective, spine surgeries (decompression, decompression with fusion) to treat degenerative conditions remain underfunded compared with other surgeries. Methods An incremental cost–utility analysis comparing decompression and decompression with fusion to THA and TKA, from the perspective of the provincial health insurance system, was based on an observational matched-cohort study of prospectively collected outcomes and retrospectively collected costs. Patient outcomes were measured using short-form (SF)-36 surveys over a 2-year follow-up period. Utility was modelled over the lifetime, and quality-adjusted life years (QALYs) were determined. We calculated the incremental cost per QALY gained by estimating mean incremental lifetime costs and QALYs of surgery compared with medical management of each diagnosis group after discounting costs and QALYs at 3%. Sensitivity analyses were also conducted. Results The lifetime incremental cost:utility ratios (ICURs) discounted at 3% were $5321 per QALY for THA, $11 275 per QALY for TKA, $2307 per QALY for spinal decompression and $7153 per QALY for spinal decompression with fusion. The sensitivity analyses did not alter the ranking of the lifetime ICURs. Conclusion In appropriately selected patients with leg-dominant symptoms secondary to focal lumbar spinal stenosis who have failed medical management, the lifetime ICUR for surgical treatment of lumbar spinal stenosis is similar to those of THA and TKA for the treatment of OA. PMID:22630061

  11. Lifetime income patterns and alcohol consumption: Investigating the association between long- and short-term income trajectories and drinking

    PubMed Central

    Cerdá, Magdalena; Johnson-Lawrence, Vicki; Galea, Sandro

    2011-01-01

    Lifetime patterns of income may be an important driver of alcohol use. In this study, we evaluated the relationship between long-term and short-term measures of income and the relative odds of abstaining, drinking lightly-moderately and drinking heavily. We used data from the US Panel Study on Income Dynamics (PSID), a national population-based cohort that has been followed annually or biannually since 1968. We examined 3111 adult respondents aged 30-44 in 1997. Latent class growth mixture models with a censored normal distribution were used to estimate income trajectories followed by the respondent families from 1968-1997, while repeated measures multinomial generalized logit models estimated the odds of abstinence (no drinks per day) or heavy drinking (at least 3 drinks a day), relative to light/moderate drinking (<1-2 drinks a day), in 1999-2003. Lower income was associated with higher odds of abstinence and of heavy drinking, relative to light/moderate drinking. For example, belonging to a household with stable low income ($11-20,000) over 30 years was associated with 1.57 odds of abstinence, and 2.14 odds of heavy drinking in adulthood. The association between lifetime income patterns and alcohol use decreased in magnitude and became non-significant once we controlled for past-year income, education and occupation. Lifetime income patterns may have an indirect association with alcohol use, mediated through current socioeconomic conditions. PMID:21890256

  12. Pinhole shifting lifetime imaging microscopy

    PubMed Central

    Ramshesh, Venkat K.; Lemasters, John J.

    2009-01-01

    Lifetime imaging microscopy is a powerful tool to probe biological phenomena independent of luminescence intensity and fluorophore concentration. We describe time-resolved imaging of long-lifetime luminescence with an unmodified commercial laser scanning confocal/multiphoton microscope. The principle of the measurement is displacement of the detection pinhole to collect delayed luminescence from a position lagging the rasting laser beam. As proof of principle, luminescence from microspheres containing europium (Eu3+), a red emitting probe, was compared to that of short-lifetime green-fluorescing microspheres and/or fluorescein and rhodamine in solution. Using 720-nm two-photon excitation and a pinhole diameter of 1 Airy unit, the short-lifetime fluorescence of fluorescein, rhodamine and green microspheres disappeared much more rapidly than the long-lifetime phosphorescence of Eu3+ microspheres as the pinhole was repositioned in the lagging direction. In contrast, repositioning of the pinhole in the leading and orthogonal directions caused equal loss of short- and long-lifetime luminescence. From measurements at different lag pinhole positions, a lifetime of 270 μs was estimated for the Eu3+ microspheres, consistent with independent measurements. This simple adaptation is the basis for quantitative 3-D lifetime imaging microscopy. PMID:19123648

  13. Mathematical modeling of elementary trapping-reduction processes in positron annihilation lifetime spectroscopy: methodology of Ps-to-positron trapping conversion

    NASA Astrophysics Data System (ADS)

    Shpotyuk, Ya; Cebulski, J.; Ingram, A.; Shpotyuk, O.

    2017-12-01

    Methodological possibilities of positron annihilation lifetime (PAL) spectroscopy in application to nanostructurized substances treated within three-term fitting procedure are reconsidered to parameterize their atomic-deficient structural arrangement. In contrast to conventional three-term fitting analysis of the detected PAL spectra based on admixed positron trapping and positronium (Ps) decaying, the nanostructurization due to guest nanoparticles embedded in host matrix is considered as producing modified trapping, which involves conversion between these channels. The developed approach referred to as x3-x2-coupling decomposition algorithm allows estimation free volumes of interfacial voids responsible for positron trapping and bulk lifetimes in nanoparticle-embedded substances. This methodology is validated using experimental data of Chakraverty et al. [Phys. Rev. B71 (2005) 024115] on PAL study of composites formed by guest NiFe2O4 nanocrystals grown in host SiO2 matrix.

  14. Young adults' trajectories of Ecstasy use: a population based study.

    PubMed

    Smirnov, Andrew; Najman, Jake M; Hayatbakhsh, Reza; Plotnikova, Maria; Wells, Helene; Legosz, Margot; Kemp, Robert

    2013-11-01

    Young adults' Ecstasy use trajectories have important implications for individual and population-level consequences of Ecstasy use, but little relevant research has been conducted. This study prospectively examines Ecstasy trajectories in a population-based sample. Data are from the Natural History Study of Drug Use, a retrospective/prospective cohort study conducted in Australia. Population screening identified a probability sample of Ecstasy users aged 19-23 years. Complete data for 30 months of follow-up, comprising 4 time intervals, were available for 297 participants (88.4% of sample). Trajectories were derived using cluster analysis based on recent Ecstasy use at each interval. Trajectory predictors were examined using a generalized ordered logit model and included Ecstasy dependence (World Mental Health Composite International Diagnostic Instrument), psychological distress (Hospital Anxiety Depression Scale), aggression (Young Adult Self Report) and contextual factors (e.g. attendance at electronic/dance music events). Three Ecstasy trajectories were identified (low, intermediate and high use). At its peak, the high-use trajectory involved 1-2 days Ecstasy use per week. Decreasing frequency of use was observed for intermediate and high-use trajectories from 12 months, independently of market factors. Intermediate and high-use trajectory membership was predicted by past Ecstasy consumption (>70 pills) and attendance at electronic/dance music events. High-use trajectory members were unlikely to have used Ecstasy for more than 3 years and tended to report consistently positive subjective effects at baseline. Given the social context and temporal course of Ecstasy use, Ecstasy trajectories might be better understood in terms of instrumental rather than addictive drug use patterns. © 2013 Elsevier Ltd. All rights reserved.

  15. The first large population based twin study of coeliac disease

    PubMed Central

    Greco, L; Romino, R; Coto, I; Di Cosmo, N; Percopo, S; Maglio, M; Paparo, F; Gasperi, V; Limongelli, M G; Cotichini, R; D'Agate, C; Tinto, N; Sacchetti, L; Tosi, R; Stazi, M A

    2002-01-01

    Background and aims: The genetic load in coeliac disease has hitherto been inferred from case series or anecdotally referred twin pairs. We have evaluated the genetic component in coeliac disease by estimating the concordance rate for the disease among twin pairs in a large population based study. Methods: The Italian Twin Registry was matched with the membership lists of a patient support group. Forty seven twin pairs were recruited and screened for antiendomysial (EMA) and antihuman-tissue transglutaminase (anti-tTG) antibodies; zygosity was verified by DNA fingerprinting and twins were typed for HLA class II DRB1 and DQB1 molecules. Results: Concordance rates for coeliac disease differ significantly between monozygotic (MZ) (0.86 probandwise and 0.75 pairwise) and dizygotic (DZ) (0.20 probandwise and 0.11 pairwise) twins. This is the highest concordance so far reported for a multifactorial disease. A logistic regression model, adjusted for age, sex, number of shared HLA haplotypes, and zygosity, showed that genotypes DQA1*0501/DQB1*0201 and DQA1*0301/DQB1*0302 (encoding for heterodimers DQ2 and DQ8, respectively) conferred to the non-index twin a risk of contracting the disease of 3.3 and 1.4, respectively. The risk of being concordant for coeliac disease estimated for the non-index twin of MZ pairs was 17 (95% confidence interval 2.1–134), independent of the DQ at risk genotype. Conclusion: This study provides substantial evidence for a very strong genetic component in coeliac disease, which is only partially due to the HLA region. PMID:11950806

  16. Predictors of fibromyalgia: a population-based twin cohort study.

    PubMed

    Markkula, Ritva A; Kalso, Eija A; Kaprio, Jaakko A

    2016-01-15

    Fibromyalgia (FM) is a pain syndrome, the mechanisms and predictors of which are still unclear. We have earlier validated a set of FM-symptom questions for detecting possible FM in an epidemiological survey and thereby identified a cluster with "possible FM". This study explores prospectively predictors for membership of that FM-symptom cluster. A population-based sample of 8343 subjects of the older Finnish Twin Cohort replied to health questionnaires in 1975, 1981, and 1990. Their answers to the set of FM-symptom questions in 1990 classified them in three latent classes (LC): LC1 with no or few symptoms, LC2 with some symptoms, and LC3 with many FM symptoms. We analysed putative predictors for these symptom classes using baseline (1975 and 1981) data on regional pain, headache, migraine, sleeping, body mass index (BMI), physical activity, smoking, and zygosity, adjusted for age, gender, and education. Those with a high likelihood of having fibromyalgia at baseline were excluded from the analysis. In the final multivariate regression model, regional pain, sleeping problems, and overweight were all predictors for membership in the class with many FM symptoms. The strongest non-genetic predictor was frequent headache (OR 8.6, CI 95% 3.8-19.2), followed by persistent back pain (OR 4.7, CI 95% 3.3-6.7) and persistent neck pain (OR 3.3, CI 95% 1.8-6.0). Regional pain, frequent headache, and persistent back or neck pain, sleeping problems, and overweight are predictors for having a cluster of symptoms consistent with fibromyalgia.

  17. Association of serum homocysteine with major depressive disorder: results from a large population-based study.

    PubMed

    Nabi, Hermann; Bochud, Murielle; Glaus, Jennifer; Lasserre, Aurélie M; Waeber, Gérard; Vollenweider, Peter; Preisig, Martin

    2013-10-01

    Studies on the association between homocysteine levels and depression have shown conflicting results. To examine the association between serum total homocysteine (tHcy) levels and major depressive disorder (MDD) in a large community sample with an extended age range. A total of 3392 men and women aged 35-66 years participating in the CoLaus study and its psychiatric arm (PsyCoLaus) were included in the analyses. High tHcy measured from fasting blood samples was defined as a concentration ≥15μmol/L. MDD was assessed using the semi-structured Diagnostic Interview for Genetics Studies. In multivariate analyses, elevated tHcy levels were associated with greater odds of meeting the diagnostic criteria for lifetime MDD among men (OR=1.71; 95% CI, 1.18-2.50). This was particularly the case for remitted MDD. Among women, there was no significant association between tHcy levels and MDD and the association tended to be in the opposite direction (OR=0.61; 95% CI, 0.34-1.08). In this large population-based study, elevated tHcy concentrations are associated with lifetime MDD and particularly with remitted MDD among men. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. The association between adverse childhood experiences (ACEs) and suicide attempts in a population-based study.

    PubMed

    Fuller-Thomson, E; Baird, S L; Dhrodia, R; Brennenstuhl, S

    2016-09-01

    To further our understanding of the relationship between Adverse Childhood Experiences (ACEs) and suicidal behaviour, this study investigates the association between three types of ACEs and lifetime suicide attempts, while considering potential gender-specific and mediating effects. Data were obtained from the 2012 Canadian Community Health Survey-Mental Health (CCHS-MH), a cross-sectional, population-based survey comprised of respondents aged 18 or older who provided self-reported data on past experiences of suicide attempts, as well as childhood sexual abuse (CSA), childhood physical abuse (CPA) and parental domestic violence (PDV) (n = 22 559). After testing for ACE by gender interactions, we estimated the odds of lifetime suicide attempts for each ACE and then investigated whether depression, anxiety, substance abuse and chronic pain acted as mediators of the relationship. The odds of suicide attempts are significantly higher among those with a history of CPA (OR = 3.29; 99.9% CI 2.33-4.64), CSA (OR = 4.42; 99.9% CI 3.14-6.23) or PDV (OR = 2.52; 99.9% CI 1.69-3.76), when ACEs are mutually adjusted. There is little evidence that gender acts as a moderator; however, depression, anxiety, substance abuse and chronic pain appear to partially mediate the associations. Depression alone accounts for about a quarter of the associations with CSA and CPA. Mental health factors and chronic pain appear only to partially mediate relationships between ACEs and lifetime suicide attempts. Future research should look at other pathways with the goal of developing multi-level interventions. © 2016 John Wiley & Sons Ltd.

  19. Dynamical lifetimes of asteroids in retrograde orbits

    NASA Astrophysics Data System (ADS)

    Kankiewicz, Paweł; Włodarczyk, Ireneusz

    2017-07-01

    The population of known minor bodies in retrograde orbits (I > 90°) that are classified as asteroids is still growing. The aim of our study was to estimate the dynamical lifetimes of these bodies using the latest observational data, including astrometry and physical properties. We selected 25 asteroids with the best-determined orbital elements. We studied their dynamical evolution in the past and future for ±100 Myr (±1 Gyr for three particular cases). We first used orbit determination and cloning to produce swarms of test particles. These swarms were then input into long-term numerical integrations, and the orbital elements were averaged. Next, we collected the available thermal properties of our objects and we used them in an enhanced dynamical model with Yarkovsky forces. We also used a gravitational model for comparison. Finally, we estimated the median lifetimes of 25 asteroids. We found three objects whose retrograde orbits were stable with a dynamical lifetime τ ˜ 10-100 Myr. A large portion of the objects studied displayed smaller values of τ (τ ˜ 1 Myr). In addition, we studied the possible influence of the Yarkovsky effect on our results. We found that the Yarkovsky effect can have a significant influence on the lifetimes of asteroids in retrograde orbits. Because of the presence of this effect, it is possible that the median lifetimes of these objects are extended. Additionally, the changes in orbital elements, caused by Yarkovsky forces, appear to depend on the integration direction. To explain this more precisely, the same model based on new physical parameters, determined from future observations, will be required.

  20. SIRTF thermal design modifications to increase lifetime

    NASA Astrophysics Data System (ADS)

    Petrick, S. W.

    1993-01-01

    An effort was made to increase the predicted lifetime of the SIRTF dewar by lowering the exterior shell temperature, increasing the radiated energy from the vapor cooled shields and reconfiguring the vapor cooled shields. The lifetime increases can be used to increase the scientific return from the mission and as a trade-off against mass and cost. This paper describes the configurations studied, the steady state thermal model used, the analytical methods and the results of the analysis. Much of the heat input to the outside dewar shell is radiative heat transfer from the solar panel. To lower the shell temperature, radiative cooled shields were placed between the solar panel and the dewar shell and between the bus and the dewar shell. Analysis showed that placing a radiator on the outer vapor cooled shield had a significant effect on lifetime. Lengthening the distance between the outer shell and the point where the vapor cooled shields are attached to the support straps also improved lifetime.

  1. Lifetime Measurements in 178Hf

    PubMed Central

    de Haan, R. C.; Aprahamian, A.; Börner, H. G.; Doll, C.; Jentschel, M.; Bruce, A. M.; Lesher, S. R.

    2000-01-01

    Lifetimes of levels from Kπ = 2+, Kπ = 4+ and several Kπ = 0+ bands have been measured in the 178Hf nucleus using the GRID technique. Lifetimes of the 2+ and 3+ levels were measured within the Kπ = 2+ γ band. A lower limit was established for the lifetime of the 4+ level of the Kπ = 4+ band. The resulting upper limits for the absolute B(E2) values exclude collective transitions from the Kπ = 4+ to the ground state band but not to the Kπ= 2+ band. Level lifetimes were also measured for several states within three separate Kπ= 0+ bands. Evidence is presented for a previously unobserved case of two excited Kπ= 0+ bands being connected via collective E2 transitions. PMID:27551596

  2. Energy Savings Lifetimes and Persistence

    SciTech Connect

    Hoffman, Ian M.; Schiller, Steven R.; Todd, Annika

    2016-02-01

    This technical brief explains the concepts of energy savings lifetimes and savings persistence and discusses how program administrators use these factors to calculate savings for efficiency measures, programs and portfolios. Savings lifetime is the length of time that one or more energy efficiency measures or activities save energy, and savings persistence is the change in savings throughout the functional life of a given efficiency measure or activity. Savings lifetimes are essential for assessing the lifecycle benefits and cost effectiveness of efficiency activities and for forecasting loads in resource planning. The brief also provides estimates of savings lifetimes derived from amore » national collection of costs and savings for electric efficiency programs and portfolios.« less

  3. Lifetime and magnetic moment measurements

    NASA Astrophysics Data System (ADS)

    Werner, V.; Ilie, G.; Radeck, D.; Ahn, T.; Beausang, C. W.; Bettermann, L.; Casperson, R. J.; Chevrier, R.; Cooper, N.; Bonniwell, T. C.; Heinz, A.; Holland, E.; McCarthy, D.; Pauerstein, B.; Smith, M. K.; Terry, J. R.; Williams, E.

    2012-05-01

    The g-Plunger technique has been introduced, which allows for the simultaneous measurement of lifetimes and absolute values of g-factors using a plunger device in inverse kinematics. Experiments on the 104,106,108Pd isotopes using Coulomb excitation resulted in g-factors in agreement with literature data. Lifetimes of 2+1 states have in part significantly changed in this work.

  4. Tomographic Positron Annihilation Lifetime Spectroscopy

    NASA Astrophysics Data System (ADS)

    Wagner, A.; Anwand, W.; Butterling, M.; Fiedler, F.; Fritz, F.; Kempe, M.; Cowan, T. E.

    2014-04-01

    Positron annihilation lifetime spectroscopy serves as a perfect tool for studies of open-volume defects in solid materials such as vacancies, vacancy agglomerates, and dislocations. Moreover, structures in porous media can be investigated ranging from 0.3 nm to 30 nm employing the variation of the Positronium lifetime with the pore size. While lifetime measurements close to the material's surface can be performed at positron-beam installations bulk materials, fluids, bio-materials or composite structures cannot or only destructively accessed by positron beams. Targeting those problems, a new method of non-destructive positron annihilation lifetime spectroscopy has been developed which features even a 3-dimensional tomographic reconstruction of the spatial lifetime distribution. A beam of intense bremsstrahlung is provided by the superconducting electron linear accelerator ELBE (Electron Linear Accelerator with high Brilliance and low Emittance) at Helmholtz-Zentrum Dresden-Rossendorf. Since the generation of bremsstrahlung and the transport to the sample preserves the sharp timing of the electron beam, positrons generated inside the entire sample volume by pair production feature a sharp start time stamp for lifetime studies. In addition to the existing technique of in-situ production of positrons inside large (cm3) bulk samples using high-energy photons up to 16 MeV from bremsstrahlung production, granular position-sensitive photon detectors have been employed. The detector system will be described and results for experiments using samples with increasing complexity will be presented. The Lu2SiO5:Ce scintillation crystals allow resolving the total energy to 5.1 % (root-mean-square, RMS) and the annihilation lifetime to 225 ps (RMS). 3-dimensional annihilation lifetime maps have been created in an offline-analysis employing well-known techniques from PET.

  5. Intergenerational teen pregnancy: a population-based cohort study.

    PubMed

    Liu, Ning; Vigod, Simone N; Farrugia, M Michèle; Urquia, Marcelo L; Ray, Joel G

    2018-05-22

    To estimate the intergenerational association in teenage pregnancy, and whether there is a coupling tendency between a mother and daughter in how their teen pregnancies end, such as an induced abortion (IA) vs. a livebirth. Population-based cohort study. Ontario, Canada. 15,097 mothers and their 16,177 daughters. Generalized estimating equations generated adjusted odds ratios (aOR) of a daughter experiencing a teen pregnancy in relation to the number of teen pregnancies her mother had. Multinomial logistic regression estimated the odds that a teen pregnancy ended with IA among both mother and daughter. All models were adjusted for maternal age and world region of origin, the daughter's socio-demographic characteristics and comorbidities, mother-daughter cohabitation, and neighborhood-level teen pregnancy rate. Teen pregnancy in the daughter, between ages 15-19 years, and also the nature of the daughter's teen pregnancy, categorized as i) no teen pregnancy, ii) at least one teen pregnancy, all exclusively ending with a livebirth, and iii) at least one teen pregnancy, with at least one teen pregnancy ending with an IA. The proportion of daughters having a teen pregnancy among those whose mother had 0, 1, 2, or ≥ 3 teen pregnancies was 16.3%, 24.9%, 33.5% and 36.3%, respectively. The aOR of a daughter having a teen pregnancy was 1.42 (95% CI 1.25-1.61) if her mother had 1, 1.97 (95% CI 1.71-2.26) if she had 2, and 2.17 (95% CI 1.84-2.56) if her mother had ≥ 3 teen pregnancies, relative to none. If a mother had ≥ 1 teen pregnancy ending with IA, then her daughter had an aOR of 2.12 (95% CI 1.76-2.56) for having a teen pregnancy also ending with IA; whereas, if a mother had ≥ 1 teen pregnancy, all ending with a livebirth, then her daughter had an aOR of 1.73 (95% CI 1.46-2.05) for that same outcome. There is a strong intergenerational occurrence of teenage pregnancy between a mother and daughter, including a coupling tendency in how the pregnancy ends. This

  6. Shifting the lens: the introduction of population-based funding in Alberta.

    PubMed

    Smith, Neale; Church, John

    2008-01-01

    This paper offers a detailed historical description of the development of Alberta's population-based funding model for Regional Health Authorities (RHAs). It focuses on key political factors that may have facilitated this transition--in particular, the role of institutions, organized interests, and ideas and values. Understanding the politics of policy change as exemplified in this case can be useful in assessing future prospects for health system reform in Canada and laying the groundwork for further comparative study.

  7. The prevalence of ADHD in a population-based sample

    PubMed Central

    Rowland, Andrew S.; Skipper, Betty J.; Umbach, David M.; Rabiner, David L.; Campbell, Richard A.; Naftel, A. Jack; Sandler, Dale P.

    2014-01-01

    Objective Few studies of ADHD prevalence have used population-based samples, multiple informants, and DSM-IV criteria. In addition, children who are asymptomatic while receiving ADHD mediction often have been misclassified. Therefore, we conducted a population-based study to estimate the prevalence of ADHD in elementary school children using DSM-IV critera. Methods We screened 7587 children for ADHD. Teachers of 81% of the children completed a DSM-IV checklist. We then interviewed parents using a structured interview (DISC). Of these, 72% participated. Parent and teacher ratings were combined to determine ADHD status. We also estimated the proportion of cases attributable to other conditions. Results Overall, 15.5% of our sample (95% confidence interval (C.I.) 14.6%-16.4%) met DSM-IV-TR criteria for ADHD. Over 40% of cases reported no previous diagnosis. With additional information, other conditions explained about 9% of cases. Conclusions The prevalence of ADHD in this population-based sample was higher than the 3-7% commonly reported. To compare study results, the methods used to implement the DSM criteria need to be standardized. PMID:24336124

  8. Importance of population-based studies in clinical practice

    PubMed Central

    Ronnie, George; Ve, Ramesh Sathyamangalam; Velumuri, Lokapavani; Asokan, Rashima; Vijaya, Lingam

    2011-01-01

    In the last decade, there have been reports on the prevalence of glaucoma from the Vellore Eye Survey, Andhra Pradesh Eye Diseases Survey, Aravind Comprehensive Eye Survey, Chennai Glaucoma Study and West Bengal Glaucoma Study. Population-based studies provide important information regarding the prevalence and risk factors for glaucoma. They also highlight regional differences in the prevalence of various types of glaucoma. It is possible to gather important insights regarding the number of persons affected with glaucoma and the proportion with undiagnosed disease. We reviewed the different population-based studies from India and compare their findings. The lacunae in ophthalmic care that can be inferred from these studies are identified and possible reasons and solutions are discussed. We also discuss the clinical relevance of the various findings, and how it reflects on clinical practice in the country. Since India has a significantly high disease burden, we examine the possibility of population-based screening for disease in the Indian context. PMID:21150021

  9. Same-Sex Behavior and its Relationship with Sexual and Health-Related Practices Among a Population-Based Sample of Women in Puerto Rico: Implications for Cancer Prevention and Control.

    PubMed

    Soto-Salgado, Marievelisse; Colón-López, Vivian; Perez, Cynthia; Muñoz-Masso, Cristina; Marrero, Edmir; Suárez, Erick; Ortiz, Ana P

    2016-01-01

    This secondary data analysis aimed to estimate the prevalence of same-sex behavior and sexual and health-related practices of a population-based sample (n=560) of women aged 16-64 years in Puerto Rico (PR). Data collection included interviews and biologic samples. Seven percent of the sample had had sex with other women (WSW). Age-adjusted logistic regression models indicated that WSW had higher odds of history of cancer, having ≥ 7 lifetime sexual partners, using sex toys and sharing them, and use of tobacco and illicit drugs. Future research is needed to address the health needs of WSW, including cancer-related risk factors and sexual practices.

  10. Cost-effectiveness of population-based screening for colorectal cancer: a comparison of guaiac-based faecal occult blood testing, faecal immunochemical testing and flexible sigmoidoscopy

    PubMed Central

    Sharp, L; Tilson, L; Whyte, S; O'Ceilleachair, A; Walsh, C; Usher, C; Tappenden, P; Chilcott, J; Staines, A; Barry, M; Comber, H

    2012-01-01

    Background: Several colorectal cancer-screening tests are available, but it is uncertain which provides the best balance of risks and benefits within a screening programme. We evaluated cost-effectiveness of a population-based screening programme in Ireland based on (i) biennial guaiac-based faecal occult blood testing (gFOBT) at ages 55–74, with reflex faecal immunochemical testing (FIT); (ii) biennial FIT at ages 55–74; and (iii) once-only flexible sigmoidoscopy (FSIG) at age 60. Methods: A state-transition model was used to estimate costs and outcomes for each screening scenario vs no screening. A third party payer perspective was adopted. Probabilistic sensitivity analyses were undertaken. Results: All scenarios would be considered highly cost-effective compared with no screening. The lowest incremental cost-effectiveness ratio (ICER vs no screening €589 per quality-adjusted life-year (QALY) gained) was found for FSIG, followed by FIT (€1696) and gFOBT (€4428); gFOBT was dominated. Compared with FSIG, FIT was associated with greater gains in QALYs and reductions in lifetime cancer incidence and mortality, but was more costly, required considerably more colonoscopies and resulted in more complications. Results were robust to variations in parameter estimates. Conclusion: Population-based screening based on FIT is expected to result in greater health gains than a policy of gFOBT (with reflex FIT) or once-only FSIG, but would require significantly more colonoscopy resources and result in more individuals experiencing adverse effects. Weighing these advantages and disadvantages presents a considerable challenge to policy makers. PMID:22343624

  11. Quantile based Tsallis entropy in residual lifetime

    NASA Astrophysics Data System (ADS)

    Khammar, A. H.; Jahanshahi, S. M. A.

    2018-02-01

    Tsallis entropy is a generalization of type α of the Shannon entropy, that is a nonadditive entropy unlike the Shannon entropy. Shannon entropy may be negative for some distributions, but Tsallis entropy can always be made nonnegative by choosing appropriate value of α. In this paper, we derive the quantile form of this nonadditive's entropy function in the residual lifetime, namely the residual quantile Tsallis entropy (RQTE) and get the bounds for it, depending on the Renyi's residual quantile entropy. Also, we obtain relationship between RQTE and concept of proportional hazards model in the quantile setup. Based on the new measure, we propose a stochastic order and aging classes, and study its properties. Finally, we prove characterizations theorems for some well known lifetime distributions. It is shown that RQTE uniquely determines the parent distribution unlike the residual Tsallis entropy.

  12. Population-based strategies to control manufacturing epidemics.

    PubMed

    Gorini, Giuseppe

    2017-01-01

    "The multinational corporations producing tobacco, alcohol, soft drinks, and processed foods have a role of vectors in the increase of chronic diseases, so that one can speak of manufacturing epidemics. The main aim of this paper is to conduct a literature review on different approaches in population-based interventions to stem the rise in consumption of unhealthy products. Different approaches were found: • command-and-control regulations: the route is definitely more advanced for tobacco with the implementation of an international treaty, which requires 180 ratifying states to implement a series of tobacco control policies. Similar regulations have been partially adopted to reduce alcohol use and to increase taxes of sugar-sweetened beverages; • multinational corporations in few Countries can voluntarily adopt recommendations on media campaigns and on labelling of soft drinks and processed foods; • in order to reduce salt in foods, many Countries developed voluntary agreements with industries with monitoring systems to assess compliance. Population-based interventions to try to align the interests of multinational corporations with those of public health are described in literature: • the "Health Footprint" programme; • the performance-based regulation which could oblige industry to take responsibility to reduce the harmful consequences of the use of their unhealthy commodities; • the price-cap regulation, usually applied to the utilities sector, would set a cap on the price of the tobacco industry, raising the tobacco taxes by 500 million euros per year. In order to reduce the burden of chronic disease, one of the objectives of the Italian National Prevention Plan, a working group including non-governmental organizations and experts in communication, social marketing, and lifestyles should be organized by the Ministry of Health in order to identify which population-based interventions could be implemented in Italy in next years to stem the rise of

  13. A population based study of herpes simplex virus 2 seroprevalence in rural Costa Rica

    PubMed Central

    Rodriguez, A; Castle, P; Smith, J; Bratti, C; Hildesheim, A; Schiffman, M; Viscidi, R; Burk, R; Ashley, R; Castellsague, X; Herrero, R

    2003-01-01

    Objectives: To determine seroprevalence and determinants of herpes simplex virus 2 (HSV-2) seropositivity, in a random sample of a population based cohort of 10 049 women of Guanacaste, Costa Rica, using a highly sensitive and specific serological assay. Methods: Seroprevalence was determined by a type specific HSV-2 ELISA assay in an age stratified random sample of 1100 women. Univariate and multivariate logistic regression was used to calculate odds ratios and 95% confidence intervals for risk factors of seropositivity. Results: Overall age adjusted HSV-2 seroprevalence was 38.5% (95% CI, 37.5 to 39.5), and it was strongly associated with increasing age (pTrend<0.0001), both among monogamous women and women with multiple sexual partners. A greater number of lifetime sexual partners increased the risk of seropositivity, with a 28.2% (95% CI, 24.4 to 32.2) seroprevalence among monogamous women and 75% (95% CI, 65.6 to 83.0) seroprevalence for those with four or more partners (OR = 7.6 95% CI, 4.7 to 12.4 pTrend<0.0001). Barrier contraceptive use was negatively associated with HSV-2 seropositivity (OR 0.54, 95% CI, 0.31 to 0.94). Women with antibodies against HPV 16, 18, or 31 were 1.6 times more likely to be HSV-2 seropositive (OR 1.6, 95% CI, 1.2 to 2.1). Conclusions: HSV-2 infection is highly endemic in Guanacaste, even among lifetime monogamous women, suggesting a role of male behaviour in the transmission of the infection. Until vaccination against HSV-2 is available, education to prevent high risk sexual behaviour and the use of condoms appear as preventive measures against HSV-2. PMID:14663121

  14. Estimating lifetime healthcare costs with morbidity data.

    PubMed

    Carreras, Marc; Ibern, Pere; Coderch, Jordi; Sánchez, Inma; Inoriza, Jose M

    2013-10-25

    In many developed countries, the economic crisis started in 2008 producing a serious contraction of the financial resources spent on healthcare. Identifying which individuals will require more resources and the moment in their lives these resources have to be allocated becomes essential. It is well known that a small number of individuals with complex healthcare needs consume a high percentage of health expenditures. Conversely, little is known on how morbidity evolves throughout life. The aim of this study is to introduce a longitudinal perspective to chronic disease management. Data used relate to the population of the county of Baix Empordà in Catalonia for the period 2004-2007 (average population was N = 88,858). The database included individual information on morbidity, resource consumption, costs and activity records. The population was classified using the Clinical Risk Groups (CRG) model. Future morbidity evolution was simulated under different assumptions using a stationary Markov chain. We obtained morbidity patterns for the lifetime and the distribution function of the random variable lifetime costs. Individual information on acute episodes, chronic conditions and multimorbidity patterns were included in the model. The probability of having a specific health status in the future (healthy, acute process or different combinations of chronic illness) and the distribution function of healthcare costs for the individual lifetime were obtained for the sample population. The mean lifetime cost for women was €111,936, a third higher than for men, at €81,566 (all amounts calculated in 2007 Euros). Healthy life expectancy at birth for females was 46.99, lower than for males (50.22). Females also spent 28.41 years of life suffering from some type of chronic disease, a longer period than men (21.9). Future morbidity and whole population costs can be reasonably predicted, combining stochastic microsimulation with a morbidity classification system. Potential

  15. Fluorescence lifetime in cardiovascular diagnostics

    NASA Astrophysics Data System (ADS)

    Marcu, Laura

    2010-01-01

    We review fluorescence lifetime techniques including time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) and fluorescence lifetime imaging microscopy (FLIM) instrumentation and associated methodologies that allow for characterization and diagnosis of atherosclerotic plaques. Emphasis is placed on the translational research potential of TR-LIFS and FLIM and on determining whether intrinsic fluorescence signals can be used to provide useful contrast for the diagnosis of high-risk atherosclerotic plaque. Our results demonstrate that these techniques allow for the discrimination of important biochemical features involved in atherosclerotic plaque instability and rupture and show their potential for future intravascular applications.

  16. Fluorescence lifetime in cardiovascular diagnostics.

    PubMed

    Marcu, Laura

    2010-01-01

    We review fluorescence lifetime techniques including time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) and fluorescence lifetime imaging microscopy (FLIM) instrumentation and associated methodologies that allow for characterization and diagnosis of atherosclerotic plaques. Emphasis is placed on the translational research potential of TR-LIFS and FLIM and on determining whether intrinsic fluorescence signals can be used to provide useful contrast for the diagnosis of high-risk atherosclerotic plaque. Our results demonstrate that these techniques allow for the discrimination of important biochemical features involved in atherosclerotic plaque instability and rupture and show their potential for future intravascular applications.

  17. Fluorescence lifetime in cardiovascular diagnostics

    PubMed Central

    Marcu, Laura

    2010-01-01

    We review fluorescence lifetime techniques including time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) and fluorescence lifetime imaging microscopy (FLIM) instrumentation and associated methodologies that allow for characterization and diagnosis of atherosclerotic plaques. Emphasis is placed on the translational research potential of TR-LIFS and FLIM and on determining whether intrinsic fluorescence signals can be used to provide useful contrast for the diagnosis of high-risk atherosclerotic plaque. Our results demonstrate that these techniques allow for the discrimination of important biochemical features involved in atherosclerotic plaque instability and rupture and show their potential for future intravascular applications. PMID:20210432

  18. Occupations associated with COPD risk in the large population-based UK Biobank cohort study.

    PubMed

    De Matteis, Sara; Jarvis, Deborah; Hutchings, Sally; Darnton, Andy; Fishwick, David; Sadhra, Steven; Rushton, Lesley; Cullinan, Paul

    2016-06-01

    Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Exposure to occupational hazards is an important preventable risk factor but the contribution of specific occupations to COPD risk in a general population is uncertain. Our aim was to investigate the association of COPD with occupation in the UK population. In 2006-2010, the UK Biobank cohort recruited 502 649 adults aged 40-69 years. COPD cases were identified by prebronchodilator forced expiratory volume in 1 s/forced vital capacitymodel adjusted for sex, age, recruitment centre and lifetime tobacco smoking. Analyses restricted to never-smokers and non-asthmatics were also performed. Of the 353 occupations reported by 228 614 current working participants, several showed significantly increased COPD risk. Those at highest COPD risk were seafarers (PR=2.64; 95% CI 1.59 to 4.38), coal mine operatives (PR=2.30; 95% CI 1.00 to 5.31), cleaners (industrial: PR=1.96; 95% CI 1.16 to 3.31 and domestic: PR=1.43; 95% CI 1.28 to 1.59), roofers/tilers (PR=1.86; 95% CI 1.29 to 2.67), packers/bottlers/canners/fillers (PR=1.60; 95% CI 1.15 to 2.22), horticultural trades (PR=1.55; 95% CI 0.97 to 2.50), food/drink/tobacco process operatives (PR=1.46; 95% CI 1.11 to 1.93), floorers/wall tilers (PR=1.41; 95% CI 1.00 to 2.00), chemical/related process operatives (PR=1.39; 95% CI 0.98 to 1.97), postal workers/couriers (PR=1.35; 95% CI 1.15 to 1.59), labourers in building/woodworking trades (PR=1.32; 95% CI 1.04 to 1.68), school mid-day assistants (PR=1.32; 95% CI 1.01 to 1.74) and kitchen/catering assistants (PR=1.30; 95% CI 1.10 to 1.53). Associations were similar in

  19. On the method of positron lifetime measurement

    NASA Technical Reports Server (NTRS)

    Nishiyama, F.; Shizuma, K.; Nasai, H.; Nishi, M.

    1983-01-01

    A fast-slow coincidence system was constructed for the measurement of positron lifetimes in material. The time resolution of this system was 270 ps for the (60)Co gamma rays. Positron lifetime spectra for 14 kinds of alkali halides were measured with this system. Two lifetime components and their intensities were derived from analyses of the lifetime spectra.

  20. An obesity/cardiometabolic risk reduction disease management program: a population-based approach.

    PubMed

    Villagra, Victor G

    2009-04-01

    Obesity is a critical health concern that has captured the attention of public and private healthcare payers who are interested in controlling costs and mitigating the long-term economic consequences of the obesity epidemic. Population-based approaches to obesity management have been proposed that take advantage of a chronic care model (CCM), including patient self-care, the use of community-based resources, and the realization of care continuity through ongoing communications with patients, information technology, and public policy changes. Payer-sponsored disease management programs represent an important conduit to delivering population-based care founded on similar CCM concepts. Disease management is founded on population-based disease identification, evidence-based care protocols, and collaborative practices between clinicians. While substantial clinician training, technology infrastructure commitments, and financial support at the payer level will be needed for the success of disease management programs in obesity and cardiometabolic risk reduction, these barriers can be overcome with the proper commitment. Disease management programs represent an important tool to combat the growing societal risks of overweight and obesity.

  1. Lifetime earnings for physicians across specialties.

    PubMed

    Leigh, J Paul; Tancredi, Daniel; Jerant, Anthony; Romano, Patrick S; Kravitz, Richard L

    2012-12-01

    Earlier studies estimated annual income differences across specialties, but lifetime income may be more relevant given physicians' long-term commitments to specialties. Annual income and work hours data were collected from 6381 physicians in the nationally representative 2004-2005 Community Tracking Study. Data regarding years of residency were collected from AMA FREIDA. Present value models were constructed assuming 3% discount rates. Estimates were adjusted for demographic and market covariates. Sensitivity analyses included 4 alternative models involving work hours, retirement, exogenous variables, and 1% discount rate. Estimates were generated for 4 broad specialty categories (Primary Care, Surgery, Internal Medicine and Pediatric Subspecialties, and Other), and for 41 specific specialties. The estimates of lifetime earnings for the broad categories of Surgery, Internal Medicine and Pediatric Subspecialties, and Other specialties were $1,587,722, $1,099,655, and $761,402 more than for Primary Care. For the 41 specific specialties, the top 3 (with family medicine as reference) were neurological surgery ($2,880,601), medical oncology ($2,772,665), and radiation oncology ($2,659,657). The estimates from models with varying rates of retirement and including only exogenous variables were similar to those in the preferred model. The 1% discount model generated estimates that were roughly 150% larger than the 3% model. There was considerable variation in the lifetime earnings across physician specialties. After accounting for varying residency years and discounting future earnings, primary care specialties earned roughly $1-3 million less than other specialties. Earnings' differences across specialties may undermine health reform efforts to control costs and ensure adequate numbers of primary care physicians.

  2. Occupational UV-Exposure is a Major Risk Factor for Basal Cell Carcinoma: Results of the Population-Based Case-Control Study FB-181.

    PubMed

    Schmitt, Jochen; Haufe, Eva; Trautmann, Freya; Schulze, Hans-Joachim; Elsner, Peter; Drexler, Hans; Bauer, Andrea; Letzel, Stephan; John, Swen Malte; Fartasch, Manigé; Brüning, Thomas; Seidler, Andreas; Dugas-Breit, Susanne; Gina, Michal; Weistenhöfer, Wobbeke; Bachmann, Klaus; Bruhn, Ilka; Lang, Berenice Mareen; Bonness, Sonja; Allam, Jean Pierre; Grobe, William; Stange, Thoralf; Westerhausen, Stephan; Knuschke, Peter; Wittlich, Marc; Diepgen, Thomas Ludwig

    2018-01-01

    The aim of this study was to investigate the role of occupational and nonoccupational ultraviolet (UV)-exposure concerning the development of basal cell carcinoma (BCC). We undertook a population-based multicenter case-control study. Patients with first incident BCC (n = 836) were propensity score matched by age and sex to controls without skin cancer (n = 836). Sociodemographic characteristics, clinical characteristics, and lifetime UV-exposure were assessed by trained investigators. The differential estimation of occupational and nonoccupational UV-exposure dosages was based on validated instruments and established reference values. Associations were assessed using multivariable-adjusted conditional logistic regression models. Individuals with high levels of occupational UV-exposure were at significantly increased BCC-risk compared with individuals with low [odds ratio (OR) 1.84; 95% confidence interval (95% CI) 1.19 to 2.83 and moderate (OR 1.97; 95% CI 1.20 to 3.22) occupational UV-exposure. Nonoccupational UV-exposure was not independently associated with BCC. Skin cancer prevention strategies should be expanded to the occupational setting.

  3. The impact of childhood parental loss on risk for mood, anxiety and substance use disorders in a population-based sample of male twins.

    PubMed

    Otowa, Takeshi; York, Timothy P; Gardner, Charles O; Kendler, Kenneth S; Hettema, John M

    2014-12-15

    Previous studies have identified the relationship between parental loss and psychopathology later in life. However, this relationship varied depending on the kind of loss, the parent involved, and the type of psychopathology. In the present study, we examined the association between parental loss (any loss, death, and separation) during childhood and lifetime risk for seven common psychiatric and substance use disorders in a sample of 2605 male twins from the Virginia population-based twin registry. Using structural equation modeling (SEM), we also examined the extent to which the influence of parental loss contributes to adult psychopathology. Parental separation was associated with a wide range of adult psychopathology, whereas parental death was specifically associated with phobia and alcohol dependence. Maternal and paternal separations were almost equally associated with most forms of psychopathology. SEM suggested that parental loss accounted for about 10% of the variance of adult psychopathology, of which parental separation had the strongest impacts on risk for depression and drug abuse/dependence (11% of the total variance). Our findings suggest that early parental separation has stronger and wider effects on adult psychopathology than parental death. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Resolving the neutron lifetime puzzle

    NASA Astrophysics Data System (ADS)

    Mumm, Pieter

    2018-05-01

    Free electrons and protons are stable, but outside atomic nuclei, free neutrons decay into a proton, electron, and antineutrino through the weak interaction, with a lifetime of ∼880 s (see the figure). The most precise measurements have stated uncertainties below 1 s (0.1%), but different techniques, although internally consistent, disagree by 4 standard deviations given the quoted uncertainties. Resolving this “neutron lifetime puzzle” has spawned much experimental effort as well as exotic theoretical mechanisms, thus far without a clear explanation. On page 627 of this issue, Pattie et al. (1) present the most precise measurement of the neutron lifetime to date. A new method of measuring trapped neutrons in situ allows a more detailed exploration of one of the more pernicious systematic effects in neutron traps, neutron phase-space evolution (the changing orbits of neutrons in the trap), than do previous methods. The precision achieved, combined with a very different set of systematic uncertainties, gives hope that experiments such as this one can help resolve the current situation with the neutron lifetime.

  5. The Work of a Lifetime

    ERIC Educational Resources Information Center

    Olson, Cathy Applefeld

    2012-01-01

    If there's one message that Joan Hillsman wants to get across to music directors, it's this: Teaching is a lifetime commitment. Hillsman is a longtime music educator, African-American music historian, author, consultant, music producer, clinician, radio show host, and current member of the Academic Board of the James Cleveland Gospel Music…

  6. Habitable zone lifetimes of exoplanets around main sequence stars.

    PubMed

    Rushby, Andrew J; Claire, Mark W; Osborn, Hugh; Watson, Andrew J

    2013-09-01

    The potential habitability of newly discovered exoplanets is initially assessed by determining whether their orbits fall within the circumstellar habitable zone of their star. However, the habitable zone (HZ) is not static in time or space, and its boundaries migrate outward at a rate proportional to the increase in luminosity of a star undergoing stellar evolution, possibly including or excluding planets over the course of the star's main sequence lifetime. We describe the time that a planet spends within the HZ as its "habitable zone lifetime." The HZ lifetime of a planet has strong astrobiological implications and is especially important when considering the evolution of complex life, which is likely to require a longer residence time within the HZ. Here, we present results from a simple model built to investigate the evolution of the "classic" HZ over time, while also providing estimates for the evolution of stellar luminosity over time in order to develop a "hybrid" HZ model. These models return estimates for the HZ lifetimes of Earth and 7 confirmed HZ exoplanets and 27 unconfirmed Kepler candidates. The HZ lifetime for Earth ranges between 6.29 and 7.79×10⁹ years (Gyr). The 7 exoplanets fall in a range between ∼1 and 54.72 Gyr, while the 27 Kepler candidate planets' HZ lifetimes range between 0.43 and 18.8 Gyr. Our results show that exoplanet HD 85512b is no longer within the HZ, assuming it has an Earth analog atmosphere. The HZ lifetime should be considered in future models of planetary habitability as setting an upper limit on the lifetime of any potential exoplanetary biosphere, and also for identifying planets of high astrobiological potential for continued observational or modeling campaigns.

  7. Lifetime measurements in 162Dy

    NASA Astrophysics Data System (ADS)

    Aprahamian, A.; Lesher, S. R.; Casarella, C.; Börner, H. G.; Jentschel, M.

    2017-02-01

    Background: The nature of oscillations or excitations around the equilibrium deformed nuclear shape remains an open question in nuclear structure. The 162Dy nucleus is one of the most extensively studied nuclei with the (n ,γ ), (n ,e- ), (α ,2 n ) reactions and most recently the (p ,t ) pickup reaction adding 11 0+ states to an excitation energy of 2.8 MeV to an already-well-developed level scheme. However, a major shortfall for a better understanding of the nature of the plethora of bands and levels in this nucleus has been the lack of lifetime measurements. Purpose: To determine the character of the low-lying excited bands in this 162Dy nucleus, we set out to measure the level lifetimes. Method: Lifetimes were measured in the 162Dy nucleus following neutron capture using the Gamma-Ray-Induced Doppler (GRID) broadening technique at the Institut Laue-Langevin in Grenoble, France. Results: In total, we have measured the lifetimes of 12 levels belonging to a number of excited positive- and negative-parity bands in the low-lying spectrum of the 162Dy nucleus. The lifetime of the Kπ=2+ bandhead at 888.16 keV was previously measured. We confirm this value and measure lifetimes of the 3+ and 4+ members of this band yielding B (E 2 ) values that are consistent with a single γ -vibrational phonon of several Weisskopf units. The first excited Kπ=4+ band, with a bandhead at 1535.66 keV, is strongly connected to the Kπ=2+ band with enhanced collective B (E 2 ) values and it is consistent with a double phonon vibrational (γ γ ) excitation. Lifetime of Kπ=0+ band members have also been measured, including the 4Kπ=02+ state at 1574.29 keV and the 2Kπ= 03+ state at 1728.31 keV. This latter state also displays the characteristics of a double phonon excitation built on the Kπ=2+ band. Conclusions: We discuss our findings in terms of the presence or absence of collective quadrupole and octupole vibrational excitations. We find two positive-parity excited bands at 1535

  8. Occupation and leukemia: a population-based case-control study in Iowa and Minnesota.

    PubMed

    Blair, A; Zheng, T; Linos, A; Stewart, P A; Zhang, Y W; Cantor, K P

    2001-07-01

    Studies have suggested that risk of leukemia may be associated with occupational or industrial exposures and risk may vary by the histological type of the disease. A population-based case-control study was conducted in Iowa and Minnesota to evaluate the association between various occupations, industries, and occupational exposures and leukemia risk. A total of 513 cases and 1,087 controls was included in the study. A lifetime occupational history and other risk factor information were collected through in-person interviews, and a job-exposure matrix was used to assess possible risks associated with specific exposures. A significantly increased risk of leukemia was observed among agricultural service industries and among nursing and healthcare workers. Janitors, cleaners, and light truck drivers also experienced increased risk. Those employed in plumbing, heating and air conditioning industries, and sales of nondurable goods (such as paints and varnishes) had an increased risk. Printers, painters, and workers in the food and metal industries had a nonsignificantly increased risk of leukemia. Analyses by specific exposures and histology of leukemia showed that risk of leukemia associated with occupational or industrial exposures may vary by histological type of the disease. An increased risk of leukemia among workers employed in agricultural industries, nursing and healthcare workers, and in a few occupations with possible exposure to solvents is consistent with earlier studies. Associations of risk with occupations not observed previously deserve further assessment. Published 2001 Wiley-Liss, Inc.

  9. Prevalence of different forms of child maltreatment among Taiwanese adolescents: a population-based study.

    PubMed

    Feng, Jui-Ying; Chang, Yi-Ting; Chang, Hsin-Yi; Fetzer, Susan; Wang, Jung-Der

    2015-04-01

    Reported cases of child maltreatment are increasing in Taiwan. Yet, comprehensive epidemiological characteristics of adolescents' exposure over the wide spectrum of violence are still lacking. The purpose of this study was to estimate the prevalence and magnitude of child maltreatment among Taiwanese adolescents. A population-based study was conducted with 5,276 adolescents aged 12-18 from 35 schools in 17 cities and townships to determine the prevalence of five forms of child maltreatment in Taiwan. A total of 5,236 adolescents completed anonymous, self-report, structured questionnaires. Most adolescents (91%, n=4,788) experienced at least one form of maltreatment with 83% (n=4,347) exposed during the previous year. Violence exposure was the most common type of child maltreatment experienced, followed by psychological abuse, physical abuse, neglect, and sexual abuse. Adolescents reported an average of 7.4 (SD=5.87) victimizations over their lifetime and 4.8 (SD=4.82) victimizations during the past year. Females reported a higher rate of neglect, while males reported a higher rate of sexual abuse. Most of the sexual abuse perpetrators were known by their victims. Adolescents' victimization and polyvictimization from child maltreatment in Taiwan deserves a review and modification of national control and prevention policies. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Lung Cancer and Occupation in a Population-based Case-Control Study

    PubMed Central

    Consonni, Dario; De Matteis, Sara; Lubin, Jay H.; Wacholder, Sholom; Tucker, Margaret; Pesatori, Angela Cecilia; Caporaso, Neil E.; Bertazzi, Pier Alberto; Landi, Maria Teresa

    2010-01-01

    The authors examined the relation between occupation and lung cancer in the large, population-based Environment And Genetics in Lung cancer Etiology (EAGLE) case-control study. In 2002–2005 in the Lombardy region of northern Italy, 2,100 incident lung cancer cases and 2,120 randomly selected population controls were enrolled. Lifetime occupational histories (industry and job title) were coded by using standard international classifications and were translated into occupations known (list A) or suspected (list B) to be associated with lung cancer. Smoking-adjusted odds ratios and 95% confidence intervals were calculated with logistic regression. For men, an increased risk was found for list A (177 exposed cases and 100 controls; odds ratio = 1.74, 95% confidence interval: 1.27, 2.38) and most occupations therein. No overall excess was found for list B with the exception of filling station attendants and bus and truck drivers (men) and launderers and dry cleaners (women). The authors estimated that 4.9% (95% confidence interval: 2.0, 7.8) of lung cancers in men were attributable to occupation. Among those in other occupations, risk excesses were found for metal workers, barbers and hairdressers, and other motor vehicle drivers. These results indicate that past exposure to occupational carcinogens remains an important determinant of lung cancer occurrence. PMID:20047975

  11. Progress toward a new measurement of the neutron lifetime

    NASA Astrophysics Data System (ADS)

    Grammer, Kyle

    2015-10-01

    Free neutron decay is the simplest nuclear beta decay. A precise value for the neutron lifetime is valuable for standard model consistency tests and Big Bang Nucleosynthesis models. There is a disagreement between the measured neutron lifetime from cold neutron beam experiments and ultracold neutron storage experiments. A new measurement of the neutron lifetime using the beam method is planned at the National Institute of Standards and Technology Center for Neutron Research. Experimental improvements should result in a 1s uncertainty measurement of the neutron lifetime. The technical improvements, recent apparatus tests, and the path towards the new measurement will be discussed. This work is supported by DOE Office of Science, NIST, and NSF.

  12. Time-dependent breakdown of fiber networks: Uncertainty of lifetime

    NASA Astrophysics Data System (ADS)

    Mattsson, Amanda; Uesaka, Tetsu

    2017-05-01

    Materials often fail when subjected to stresses over a prolonged period. The time to failure, also called the lifetime, is known to exhibit large variability of many materials, particularly brittle and quasibrittle materials. For example, a coefficient of variation reaches 100% or even more. Its distribution shape is highly skewed toward zero lifetime, implying a large number of premature failures. This behavior contrasts with that of normal strength, which shows a variation of only 4%-10% and a nearly bell-shaped distribution. The fundamental cause of this large and unique variability of lifetime is not well understood because of the complex interplay between stochastic processes taking place on the molecular level and the hierarchical and disordered structure of the material. We have constructed fiber network models, both regular and random, as a paradigm for general material structures. With such networks, we have performed Monte Carlo simulations of creep failure to establish explicit relationships among fiber characteristics, network structures, system size, and lifetime distribution. We found that fiber characteristics have large, sometimes dominating, influences on the lifetime variability of a network. Among the factors investigated, geometrical disorders of the network were found to be essential to explain the large variability and highly skewed shape of the lifetime distribution. With increasing network size, the distribution asymptotically approaches a double-exponential form. The implication of this result is that, so-called "infant mortality," which is often predicted by the Weibull approximation of the lifetime distribution, may not exist for a large system.

  13. Etiology and clinical presentation of birth defects: population based study

    PubMed Central

    Carey, John C; Byrne, Janice L B; Krikov, Sergey; Botto, Lorenzo D

    2017-01-01

    Objective To assess causation and clinical presentation of major birth defects. Design Population based case cohort. Setting Cases of birth defects in children born 2005-09 to resident women, ascertained through Utah’s population based surveillance system. All records underwent clinical re-review. Participants 5504 cases among 270 878 births (prevalence 2.03%), excluding mild isolated conditions (such as muscular ventricular septal defects, distal hypospadias). Main outcome measures The primary outcomes were the proportion of birth defects with a known etiology (chromosomal, genetic, human teratogen, twinning) or unknown etiology, by morphology (isolated, multiple, minors only), and by pathogenesis (sequence, developmental field defect, or known pattern of birth defects). Results Definite cause was assigned in 20.2% (n=1114) of cases: chromosomal or genetic conditions accounted for 94.4% (n=1052), teratogens for 4.1% (n=46, mostly poorly controlled pregestational diabetes), and twinning for 1.4% (n=16, conjoined or acardiac). The 79.8% (n=4390) remaining were classified as unknown etiology; of these 88.2% (n=3874) were isolated birth defects. Family history (similarly affected first degree relative) was documented in 4.8% (n=266). In this cohort, 92.1% (5067/5504) were live born infants (isolated and non-isolated birth defects): 75.3% (4147/5504) were classified as having an isolated birth defect (unknown or known etiology). Conclusions These findings underscore the gaps in our knowledge regarding the causes of birth defects. For the causes that are known, such as smoking or diabetes, assigning causation in individual cases remains challenging. Nevertheless, the ongoing impact of these exposures on fetal development highlights the urgency and benefits of population based preventive interventions. For the causes that are still unknown, better strategies are needed. These can include greater integration of the key elements of etiology, morphology, and

  14. Multiphoton fluorescence lifetime imaging of chemotherapy distribution in solid tumors

    NASA Astrophysics Data System (ADS)

    Carlson, Marjorie; Watson, Adrienne L.; Anderson, Leah; Largaespada, David A.; Provenzano, Paolo P.

    2017-11-01

    Doxorubicin is a commonly used chemotherapeutic employed to treat multiple human cancers, including numerous sarcomas and carcinomas. Furthermore, doxorubicin possesses strong fluorescent properties that make it an ideal reagent for modeling drug delivery by examining its distribution in cells and tissues. However, while doxorubicin fluorescence and lifetime have been imaged in live tissue, its behavior in archival samples that frequently result from drug and treatment studies in human and animal patients, and murine models of human cancer, has to date been largely unexplored. Here, we demonstrate imaging of doxorubicin intensity and lifetimes in archival formalin-fixed paraffin-embedded sections from mouse models of human cancer with multiphoton excitation and multiphoton fluorescence lifetime imaging microscopy (FLIM). Multiphoton excitation imaging reveals robust doxorubicin emission in tissue sections and captures spatial heterogeneity in cells and tissues. However, quantifying the amount of doxorubicin signal in distinct cell compartments, particularly the nucleus, often remains challenging due to strong signals in multiple compartments. The addition of FLIM analysis to display the spatial distribution of excited state lifetimes clearly distinguishes between signals in distinct compartments such as the cell nuclei versus cytoplasm and allows for quantification of doxorubicin signal in each compartment. Furthermore, we observed a shift in lifetime values in the nuclei of transformed cells versus nontransformed cells, suggesting a possible diagnostic role for doxorubicin lifetime imaging to distinguish normal versus transformed cells. Thus, data here demonstrate that multiphoton FLIM is a highly sensitive platform for imaging doxorubicin distribution in normal and diseased archival tissues.

  15. Exits in order: How crowding affects particle lifetimes

    SciTech Connect

    Penington, Catherine J.; Simpson, Matthew J.; Baker, Ruth E.

    2016-06-28

    Diffusive processes are often represented using stochastic random walk frameworks. The amount of time taken for an individual in a random walk to intersect with an absorbing boundary is a fundamental property that is often referred to as the particle lifetime, or the first passage time. The mean lifetime of particles in a random walk model of diffusion is related to the amount of time required for the diffusive process to reach a steady state. Mathematical analysis describing the mean lifetime of particles in a standard model of diffusion without crowding is well known. However, the lifetime of agents inmore » a random walk with crowding has received much less attention. Since many applications of diffusion in biology and biophysics include crowding effects, here we study a discrete model of diffusion that incorporates crowding. Using simulations, we show that crowding has a dramatic effect on agent lifetimes, and we derive an approximate expression for the mean agent lifetime that includes crowding effects. Our expression matches simulation results very well, and highlights the importance of crowding effects that are sometimes overlooked.« less

  16. Incidence of Radiologically Isolated Syndrome: A Population-Based Study.

    PubMed

    Forslin, Y; Granberg, T; Jumah, A Antwan; Shams, S; Aspelin, P; Kristoffersen-Wiberg, M; Martola, J; Fredrikson, S

    2016-06-01

    Incidental MR imaging findings resembling MS in asymptomatic individuals, fulfilling the Okuda criteria, are termed "radiologically isolated syndrome." Those with radiologically isolated syndrome are at high risk of their condition converting to MS. The epidemiology of radiologically isolated syndrome remains largely unknown, and there are no population-based studies, to our knowledge. Our aim was to study the population-based incidence of radiologically isolated syndrome in a high-incidence region for MS and to evaluate the effect on radiologically isolated syndrome incidence when revising the original radiologically isolated syndrome criteria by using the latest radiologic classification for dissemination in space. All 2272 brain MR imaging scans in 1907 persons obtained during 2013 in the Swedish county of Västmanland, with a population of 259,000 inhabitants, were blindly evaluated by a senior radiologist and a senior neuroradiologist. The Okuda criteria for radiologically isolated syndrome were applied by using both the Barkhof and Swanton classifications for dissemination in space. Assessments of clinical data were performed by a radiology resident and a senior neurologist. The cumulative incidence of radiologically isolated syndrome was 2 patients (0.1%), equaling an incidence rate of 0.8 cases per 100,000 person-years, in a region with an incidence rate of MS of 10.2 cases per 100,000 person-years. There was no difference in the radiologically isolated syndrome incidence rate when applying a modified version of the Okuda criteria by using the newer Swanton classification for dissemination in space. Radiologically isolated syndrome is uncommon in a high-incidence region for MS. Adapting the Okuda criteria to use the dissemination in space-Swanton classification may be feasible. Future studies on radiologically isolated syndrome may benefit from a collaborative approach to ensure adequate numbers of participants. © 2016 by American Journal of Neuroradiology.

  17. Enhancing the Value of Population-Based Risk Scores for Institutional-Level Use.

    PubMed

    Raza, Sajjad; Sabik, Joseph F; Rajeswaran, Jeevanantham; Idrees, Jay J; Trezzi, Matteo; Riaz, Haris; Javadikasgari, Hoda; Nowicki, Edward R; Svensson, Lars G; Blackstone, Eugene H

    2016-07-01

    We hypothesized that factors associated with an institution's residual risk unaccounted for by population-based models may be identifiable and used to enhance the value of population-based risk scores for quality improvement. From January 2000 to January 2010, 4,971 patients underwent aortic valve replacement (AVR), either isolated (n = 2,660) or with concomitant coronary artery bypass grafting (AVR+CABG; n = 2,311). Operative mortality and major morbidity and mortality predicted by The Society of Thoracic Surgeons (STS) risk models were compared with observed values. After adjusting for patients' STS score, additional and refined risk factors were sought to explain residual risk. Differences between STS model coefficients (risk-factor strength) and those specific to our institution were calculated. Observed operative mortality was less than predicted for AVR (1.6% [42 of 2,660] vs 2.8%, p < 0.0001) and AVR+CABG (2.6% [59 of 2,311] vs 4.9%, p < 0.0001). Observed major morbidity and mortality was also lower than predicted for isolated AVR (14.6% [389 of 2,660] vs 17.5%, p < 0.0001) and AVR+CABG (20.0% [462 of 2,311] vs 25.8%, p < 0.0001). Shorter height, higher bilirubin, and lower albumin were identified as additional institution-specific risk factors, and body surface area, creatinine, glomerular filtration rate, blood urea nitrogen, and heart failure across all levels of functional class were identified as refined risk-factor variables associated with residual risk. In many instances, risk-factor strength differed substantially from that of STS models. Scores derived from population-based models can be enhanced for institutional level use by adjusting for institution-specific additional and refined risk factors. Identifying these and measuring differences in institution-specific versus population-based risk-factor strength can identify areas to target for quality improvement initiatives. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier

  18. Psychopathy, traumatic exposure, and lifetime posttraumatic stress.

    PubMed

    Willemsen, Jochem; De Ganck, Julie; Verhaeghe, Paul

    2012-06-01

    This study examined two theoretical models on the interaction between psychopathy, traumatic exposure, and lifetime posttraumatic stress in a sample of 81 male detainees. In Model 1, the interpersonal and affective features of psychopathy were assumed to protect against posttraumatic stress. In Model 2, the lifestyle and antisocial traits of psychopathy were assumed to lead to a lifestyle that increases the risk of traumatic exposure and subsequent posttraumatic stress. The authors found significant negative bivariate associations between Psychopathy Checklist-Revised (PCL-R) total, Interpersonal and Affective facet scores, and posttraumatic stress. Model 1 was confirmed, as they found the interaction between the Affective facet and traumatic exposure had a significant negative effect on posttraumatic stress. Model 2 was rejected. The authors' findings confirm that the interpersonal and affective features of psychopathy are associated with an emotional deficit and that the affective features of psychopathy are crucial for understanding the relationship between psychopathy and anxiety.

  19. Population-based respiratory 4D motion atlas construction and its application for VR simulations of liver punctures

    NASA Astrophysics Data System (ADS)

    Mastmeyer, Andre; Wilms, Matthias; Handels, Heinz

    2018-03-01

    Virtual reality (VR) training simulators of liver needle insertion in the hepatic area of breathing virtual patients often need 4D image data acquisitions as a prerequisite. Here, first a population-based breathing virtual patient 4D atlas is built and second the requirement of a dose-relevant or expensive acquisition of a 4D CT or MRI data set for a new patient can be mitigated by warping the mean atlas motion. The breakthrough contribution of this work is the construction and reuse of population-based, learned 4D motion models.

  20. Early childhood measles vaccinations are not associated with paediatric IBD: a population-based analysis.

    PubMed

    Shaw, Souradet Y; Blanchard, James F; Bernstein, Charles N

    2015-04-01

    Early childhood vaccinations have been hypothesized to contribute to the emergence of paediatric inflammatory bowel disease [IBD] in developed countries. Using linked population-based administrative databases, we aimed to explore the association between vaccination with measles-containing vaccines and the risk for IBD. This was a case-control study using the University of Manitoba IBD Epidemiology Database [UMIBDED]. The UMIBDED was linked to the Manitoba Immunization Monitoring System [MIMS], a population-based database of immunizations administered in Manitoba. All paediatric IBD cases in Manitoba, born after 1989 and diagnosed before March 31, 2008, were included. Controls were matched to cases on the basis of age, sex, and region of residence at time of diagnosis. Measles-containing vaccinations received in the first 2 years of life were documented, with vaccinations categorized as 'None' or 'Complete', with completeness defined according to Manitoba's vaccination schedule. Conditional logistic regression models were fitted to the data, with models adjusted for physician visits in the first 2 years of life and area-level socioeconomic status at case date. A total of 951 individuals [117 cases and 834 controls] met eligibility criteria, with average age of diagnosis among cases at 11 years. The proportion of IBD cases with completed vaccinations was 97%, compared with 94% of controls. In models adjusted for physician visits and area-level socioeconomic status, no statistically significant association was detected between completed measles vaccinations and the risk of IBD (adjusted odds ratio [AOR]: 1.5; 95% confidence interval [CI]: 0.5-4.4; p = 0.419]. No significant association between completed measles-containing vaccination in the first 2 years of life and paediatric IBD could be demonstrated in this population-based study. Copyright © 2015 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For

  1. Predicting sample lifetimes in creep fracture of heterogeneous materials

    NASA Astrophysics Data System (ADS)

    Koivisto, Juha; Ovaska, Markus; Miksic, Amandine; Laurson, Lasse; Alava, Mikko J.

    2016-08-01

    Materials flow—under creep or constant loads—and, finally, fail. The prediction of sample lifetimes is an important and highly challenging problem because of the inherently heterogeneous nature of most materials that results in large sample-to-sample lifetime fluctuations, even under the same conditions. We study creep deformation of paper sheets as one heterogeneous material and thus show how to predict lifetimes of individual samples by exploiting the "universal" features in the sample-inherent creep curves, particularly the passage to an accelerating creep rate. Using simulations of a viscoelastic fiber bundle model, we illustrate how deformation localization controls the shape of the creep curve and thus the degree of lifetime predictability.

  2. Recoil distance lifetime measurements in 122,124Xe

    NASA Astrophysics Data System (ADS)

    Govil, I. M.; Kumar, A.; Iyer, H.; Li, H.; Garg, U.; Ghugre, S. S.; Johnson, T.; Kaczarowski, R.; Kharraja, B.; Naguleswaran, S.; Walpe, J. C.

    1998-02-01

    Lifetimes of the lower-excited states in 122,124Xe are measured using the recoil-distance Doppler-shift technique. The reactions 110Pd(16O,4n)122Xe and 110Pd(18O,4n)124Xe at a beam energy of 66 MeV were used for this experiment. The lifetimes of the 2+, 4+, 6+, and 8+ states of the ground state band were extracted using the computer code LIFETIME including the corrections due to the side feeding and the nuclear deorientation effects. The lifetime of the 2+ state in 122Xe agrees with the recoil distance method (RDM) measurements but for the 124Xe it does not agree with the RDM measurements but agrees with the Coulomb-excitation experiment. The measured B(E2) values for both the nuclei are compared with the standard algebraic and the multishell models.

  3. Measurement and Perturbation of Morphogen Lifetime: Effects on Gradient Shape

    PubMed Central

    Drocco, Jeffrey A.; Grimm, Oliver; Tank, David W.; Wieschaus, Eric

    2011-01-01

    Protein lifetime is of critical importance for most biological processes and plays a central role in cell signaling and embryonic development, where it impacts the absolute concentration of signaling molecules and, potentially, the shape of morphogen gradients. Early conceptual and mathematical models of gradient formation proposed that steady-state gradients are established by an equilibration between the lifetime of a morphogen and its rates of synthesis and diffusion, though whether gradients in fact reach steady state before being read out is a matter of controversy. In any case, this class of models predicts that protein lifetime is a key determinant of both the time to steady state and the spatial extent of a gradient. Using a method that employs repeated photoswitching of a fusion of the morphogen Bicoid (Bcd) and the photoconvertible fluorescent protein Dronpa, we measure and modify the lifetime of Dronpa-Bcd in living Drosophila embryos. We find that the lifetime of Bcd is dynamic, changing from 50 min before mitotic cycle 14 to 15 min during cellularization. Moreover, by measuring total quantities of Bcd over time, we find that the gradient does not reach steady state. Finally, using a nearly continuous low-level conversion to the dark state of Dronpa-Bcd to mimic the effect of increased degradation, we demonstrate that perturbation of protein lifetime changes the characteristic length of the gradient, providing direct support for a mechanism based on synthesis, diffusion, and degradation. PMID:22004733

  4. Lifetime Assessment of the NEXT Ion Thruster

    NASA Technical Reports Server (NTRS)

    VanNoord, Jonathan L.

    2010-01-01

    Ion thrusters are low thrust, high specific impulse devices with required operational lifetimes on the order of 10,000 to 100,000 hr. The NEXT ion thruster is the latest generation of ion thrusters under development. The NEXT ion thruster currently has a qualification level propellant throughput requirement of 450 kg of xenon, which corresponds to roughly 22,000 hr of operation at the highest throttling point. Currently, a NEXT engineering model ion thruster with prototype model ion optics is undergoing a long duration test to determine wear characteristics and establish propellant throughput capability. The NEXT thruster includes many improvements over previous generations of ion thrusters, but two of its component improvements have a larger effect on thruster lifetime. These include the ion optics with tighter tolerances, a masked region and better gap control, and the discharge cathode keeper material change to graphite. Data from the NEXT 2000 hr wear test, the NEXT long duration test, and further analysis is used to determine the expected lifetime of the NEXT ion thruster. This paper will review the predictions for all of the anticipated failure mechanisms. The mechanisms will include wear of the ion optics and cathode s orifice plate and keeper from the plasma, depletion of low work function material in each cathode s insert, and spalling of material in the discharge chamber leading to arcing. Based on the analysis of the NEXT ion thruster, the first failure mode for operation above a specific impulse of 2000 sec is expected to be the structural failure of the ion optics at 750 kg of propellant throughput, 1.7 times the qualification requirement. An assessment based on mission analyses for operation below a specific impulse of 2000 sec indicates that the NEXT thruster is capable of double the propellant throughput required by these missions.

  5. A non-invasive approach to study lifetime exposure and bioaccumulation of PCBs in protected marine mammals: PBPK modeling in harbor porpoises

    SciTech Connect

    Weijs, Liesbeth, E-mail: liesbeth.weijs@ua.ac.be; Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk; Covaci, Adrian

    2011-10-15

    In the last decade, physiologically based pharmacokinetic (PBPK) models have increasingly been developed to explain the kinetics of environmental pollutants in wildlife. For marine mammals specifically, these models provide a new, non-destructive tool that enables the integration of biomonitoring activities and in vitro studies. The goals of the present study were firstly to develop PBPK models for several environmental relevant PCB congeners in harbor porpoises (Phocoena phocoena), a species that is sensitive to pollution because of its limited metabolic capacity for pollutant transformation. These models were tested using tissue data of porpoises from the Black Sea. Secondly, the predictive powermore » of the models was investigated for time trends in the PCB concentrations in North Sea harbor porpoises between 1990 and 2008. Thirdly, attempts were made to assess metabolic capacities of harbor porpoises for the investigated PCBs. In general, results show that parameter values from other species (rodents, humans) are not always suitable in marine mammal models, most probably due to differences in physiology and exposure. The PCB 149 levels decrease the fastest in male harbor porpoises from the North Sea in a time period of 18 years, whereas the PCB 101 levels decrease the slowest. According to the models, metabolic breakdown of PCB 118 is probably of lesser importance compared to other elimination pathways. For PCB 101 and 149 however, the presence of their metabolites can be attributed to bioaccumulation of metabolites from the prey and to metabolic breakdown of the parent compounds in the harbor porpoises. - Highlights: > PBPK modeling was used to study the kinetics of several PCBs in a marine mammal. > Harbor porpoises are sensitive to pollution and therefore ideal model organisms. > Black Sea data were used for parameterization. > North Sea data for assessing temporal trends (1990-2008). > PBPK modeling is a non-invasive and non-destructive tool.« less

  6. Visual loss after spine surgery: a population-based study.

    PubMed

    Patil, Chirag G; Lad, Eleonora M; Lad, Shivanand P; Ho, Chris; Boakye, Maxwell

    2008-06-01

    Retrospective cohort study using National inpatient sample administrative data. To determine national estimates of visual impairment and ischemic optic neuropathy after spine surgery. Loss of vision after spine surgery is rare but has devastating complications that has gained increasing recognition in the recent literature. National population-based studies of visual complications after spine surgery are lacking. All patients from 1993 to 2002 who underwent spine surgery (Clinical Classifications software procedure code: 3, 158) and who had ischemic optic neuropathy (ION) (ICD9-CM code 377.41), central retinal artery occlusion (CRAO) (ICD9-CM code 362.31) or non-ION, non-CRAO perioperative visual impairment (ICD9-CM codes: 369, 368.4, 368.8-9368.11-13) were included. Univariate and multivariate analysis were performed to identify potential risk factors. The overall incidence of visual disturbance after spine surgery was 0.094%. Spine surgery for scoliosis correction and posterior lumbar fusion had the highest rates of postoperative visual loss of 0.28% and 0.14% respectively. Pediatric patients (<18 years) were 5.8 times and elderly patients (>84 years) were 3.2 times more likely than, patients 18 to 44 years of age to develop non-ION, non-CRAO visual loss after spine surgery. Patients with peripheral vascular disease (OR = 2.0), hypertension (OR = 1.3), and those who received blood transfusion (OR = 2.2) were more likely to develop non-ION, non-CRAO vision loss after spine surgery. Ischemic optic neuropathy was present in 0.006% of patients. Hypotension (OR = 10.1), peripheral vascular disease (OR = 6.3) and anemia (OR = 5.9) were the strongest risk factors identified for the development of ION. We used multivariate analysis to identify significant risk factors for visual loss after spine surgery. National population-based estimate of visual impairment after spine surgery confirms that ophthalmic complications after spine surgery are rare. Since visual loss may be

  7. Population-based birth weight reference percentiles for Chinese twins.

    PubMed

    Dai, Li; Deng, Changfei; Li, Yanhua; Yi, Ling; Li, Xiaohong; Mu, Yi; Li, Qi; Yao, Qiang; Wang, Yanping

    2017-09-01

    Birth weight percentiles by gestational age are important for assessing prenatal growth and predicting postnatal outcomes of newborns. Several countries have developed nation-specific birth weight references for twins, but China still lacks such references. Birth weight data for twins born between October 2006 and September 2015 were abstracted from the China National Population-based Birth Defects Surveillance System. A total of 54,786 live twin births aged ≥28 weeks of gestation without birth defects were included in the analysis. The LMS method was adopted to generate gestational age-specific birth weight percentiles and curves for male and female twins separately. Significant differences were observed between the current reference and other references developed for Chinese or non-Chinese twins. The neonatal mortality rate in this cohort was 12.3‰, and much higher rates at very early gestation weeks were identified in small-for-gestational-age twins grouped by the newly developed reference cutoffs. The established birth weight centiles represent the first birth weight norm for contemporary Chinese twins and can be a useful tool to assess growth of twins in clinical and research settings. Key Messages There have been no population-based birth weight percentiles for Chinese twins prior to this study. The established birth weight centiles for female and male twins are markedly lower than those for Chinese singletons. Twin-specific curves should be used for determining inappropriate for gestational age in twins rather than using existing singleton reference. The birth weight percentiles for twins differed significantly from those for non-Chinese twins. In addition to ethnic influences, the observed differences could be ascribed to variations in prenatal care, fetal or maternal nutrition status or other environmental factors. Neonatal mortality rates varied considerably among twins grouped by the newly developed reference percentiles. Small

  8. Neighborhood socioeconomic status and the prevalence of stroke and coronary heart disease in rural China: a population-based study

    PubMed Central

    Tang, Xun; Laskowitz, Daniel T.; He, Liu; Østbye, Truls; Bettger, Janet Prvu; Cao, Yang; Li, Na; Li, Jingrong; Zhang, Zongxin; Liu, Jianjiang; Yu, Liping; Xu, Haitao; Hu, Yonghua; Goldstein, Larry B.

    2014-01-01

    Background Lower neighborhood-level socioeconomic status (SES) is associated with an increased risk of vascular disease in developed countries. Aims This study aims to identify village- and individual-level determinants of stroke and coronary heart disease (CHD) in a rural Chinese population. Methods We analyzed data from a population-based survey of 14,424 rural Chinese adults aged over 40-years from 54 villages. Primary outcomes were stroke and CHD prevalence. Village-level SES was determined from the Chinese government's official statistical yearbook. Individual-level characteristics were obtained by in-person interviews. Prevalence rate ratios (RR) and 95% confidence intervals (95% CI) were calculated using generalized linear mixed models with log link function to explore associations of village-level SES and individual social, demographic, and cardiovascular risk factors with stroke or CHD. Variance was expressed using the median rate ratio (MRR) and interval rate ratio (IRR). Results Villages accounted for significant variability in the prevalence of stroke (MRR=1.70; 95% CI:1.42-1.94; P<0.05) and CHD (MRR=1.59; 95% CI:1.35-1.78, P<0.05) with village-level income alone accounted for 10% and 13.5% of between-village variation in stroke and CHD, respectively. High-income villages were at higher risk of both stroke (RR=1.69, 95% CI:1.09∼2.62) and CHD (RR=1.63, 95% CI:1.13∼2.34) than lower-income villages. Among individual-level risk factors, hypertension was associated with a higher prevalence of stroke (RR=2.33, 95% CI:1.93-2.80) than CHD (RR=1.58, 95% CI:1.38-1.82), whereas obesity was only associated with CHD (RR=1.43, 95% CI:1.23-1.66). In addition, there was an interaction between age and income; residents of higher income villages age<60 had a higher prevalence of CHD (RR=1.58, 95% CI:1.15-2.18), but not stroke. Conclusions There were differences in vascular risk across rural villages in China, with higher lifetime stroke and CHD prevalence in higher

  9. Calcium intake by adolescents: a population-based health survey.

    PubMed

    de Assumpção, Daniela; Dias, Marcia Regina Messaggi Gomes; de Azevedo Barros, Marilisa Berti; Fisberg, Regina Mara; de Azevedo Barros Filho, Antonio

    2016-01-01

    To analyze calcium intake in adolescents according to sociodemographic variables, health-related behaviors, morbidities, and body mass index. This was a cross-sectional population-based study, with a two-stage cluster sampling that used data from a survey conducted in Campinas, São Paulo, Brazil, between 2008 and 2009. Food intake was assessed using a 24-hour dietary recall. The study included 913 adolescents aged 10-19 years. Average nutrient intake was significantly lower in the segment with lower education of the head of the family and lower per capita family income, in individuals from other cities or states, those who consumed fruit less than four times a week, those who did not drink milk daily, those who were smokers, and those who reported the occurrence of headaches and dizziness. Higher mean calcium intake was found in individuals that slept less than seven hours a day. The prevalence of calcium intake below the recommendation was 88.6% (95% CI: 85.4-91.2). The results alert to an insufficient calcium intake and suggest that certain subgroups of adolescents need specific strategies to increase the intake of this nutrient. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  10. Screening and cervical cancer cure: population based cohort study

    PubMed Central

    Andersson, Therese M-L; Lambert, Paul C; Kemetli, Levent; Silfverdal, Lena; Strander, Björn; Ryd, Walter; Dillner, Joakim; Törnberg, Sven; Sparén, Pär

    2012-01-01

    Objective To determine whether detection of invasive cervical cancer by screening results in better prognosis or merely increases the lead time until death. Design Nationwide population based cohort study. Setting Sweden. Participants All 1230 women with cervical cancer diagnosed during 1999-2001 in Sweden prospectively followed up for an average of 8.5 years. Main outcome measures Cure proportions and five year relative survival ratios, stratified by screening history, mode of detection, age, histopathological type, and FIGO (International Federation of Gynecology and Obstetrics) stage. Results In the screening ages, the cure proportion for women with screen detected invasive cancer was 92% (95% confidence interval 75% to 98%) and for symptomatic women was 66% (62% to 70%), a statistically significant difference in cure of 26% (16% to 36%). Among symptomatic women, the cure proportion was significantly higher for those who had been screened according to recommendations (interval cancers) than among those overdue for screening: difference in cure 14% (95% confidence interval 6% to 23%). Cure proportions were similar for all histopathological types except small cell carcinomas and were closely related to FIGO stage. A significantly higher cure proportion for screen detected cancers remained after adjustment for stage at diagnosis (difference 15%, 7% to 22%). Conclusions Screening is associated with improved cure of cervical cancer. Confounding cannot be ruled out, but the effect was not attributable to lead time bias and was larger than what is reflected by down-staging. Evaluations of screening programmes should consider the assessment of cure proportions. PMID:22381677

  11. Screening and cervical cancer cure: population based cohort study.

    PubMed

    Andrae, Bengt; Andersson, Therese M-L; Lambert, Paul C; Kemetli, Levent; Silfverdal, Lena; Strander, Björn; Ryd, Walter; Dillner, Joakim; Törnberg, Sven; Sparén, Pär

    2012-03-01

    To determine whether detection of invasive cervical cancer by screening results in better prognosis or merely increases the lead time until death. Nationwide population based cohort study. Sweden. All 1230 women with cervical cancer diagnosed during 1999-2001 in Sweden prospectively followed up for an average of 8.5 years. Cure proportions and five year relative survival ratios, stratified by screening history, mode of detection, age, histopathological type, and FIGO (International Federation of Gynecology and Obstetrics) stage. In the screening ages, the cure proportion for women with screen detected invasive cancer was 92% (95% confidence interval 75% to 98%) and for symptomatic women was 66% (62% to 70%), a statistically significant difference in cure of 26% (16% to 36%). Among symptomatic women, the cure proportion was significantly higher for those who had been screened according to recommendations (interval cancers) than among those overdue for screening: difference in cure 14% (95% confidence interval 6% to 23%). Cure proportions were similar for all histopathological types except small cell carcinomas and were closely related to FIGO stage. A significantly higher cure proportion for screen detected cancers remained after adjustment for stage at diagnosis (difference 15%, 7% to 22%). Screening is associated with improved cure of cervical cancer. Confounding cannot be ruled out, but the effect was not attributable to lead time bias and was larger than what is reflected by down-staging. Evaluations of screening programmes should consider the assessment of cure proportions.

  12. Economic costs of social phobia: a population-based study.

    PubMed

    Acarturk, C; Smit, Filip; de Graaf, R; van Straten, A; Ten Have, M; Cuijpers, P

    2009-06-01

    Information about the economic costs of social phobia is scant. In this study, we examine the economic costs of social phobia and subthreshold social phobia. Data were derived from the Netherlands Mental Health Survey and Incidence Study (NEMESIS) which is a population-based prospective study (n=4,789). Costs related to health service uptake, patients' out-of-pocket expenses, and costs arising from production losses were calculated for the reference year 2003. The costs for people with social phobia were compared with the costs for people with no mental disorder. The annual per capita total costs of social phobia were euro 11,952 (95% CI=7,891-16,013) which is significantly higher than the total costs for people with no mental disorder, euro 2957 (95% CI=2690-3224). When adjusting for mental and somatic co-morbidity, the costs decreased to euro 6,100 (95% CI=2681-9519), or 136 million euro per year per 1 million inhabitants, which was still significantly higher than the costs for people with no mental disorder. The costs of subthreshold social phobia were also significantly higher than the costs for people without any mental disorder, at euro 4,687 (95% CI=2557-6816). The costs presented here are conservative lower estimates because we only included costs related to mental health services. The economic costs associated with social phobia are substantial, and those of subthreshold social phobia approach those of the full-blown disorder.

  13. Respiratory cancer population-based survival in Mumbai, India.

    PubMed

    Yeole, Balkrishna B

    2005-01-01

    Survival experience of patients with cancer of the larynx (ICD-32) or lung (ICD-34) registered by the Mumbai (Bombay) population based cancer registry, India, during the years 1992-94 was determined. The vital statistics of the patients were established by matching with death certificates from the Mumbai Municipal death register and by active methods such as telephone enquiry, reply-paid postal enquiry, house visits and scrutiny of case records. Of the 1905 (675 larynx and 1230 lung) eligible cases for analysis, 1480 were dead (450 larynx and 1030 lung) and 425 were alive (225 larynx and 200 lung). The overall 5-year observed and relative survival rates for laryngeal cancers were 29.1% and 36.4%, and for lung cancers were 12.5% and 15.9% respectively. On multivariate analysis, age, treatment and clinical extent of disease emerged as independent predictors of survival with both cancers. People aged 55 years and above had a relative risk of four or more for laryngeal cancer and 2.3 times and more for lung cancer death as compared to those aged less than 35 years. Early detection and prompt treatment should improve overall survival from lung as well as laryngeal cancer.

  14. Population-Based Study of Trachoma in Guatemala.

    PubMed

    Silva, Juan Carlos; Diaz, Marco Antonio; Maul, Eugenio; Munoz, Beatriz E; West, Sheila K

    2015-01-01

    A prevalence survey for active trachoma in children aged under 10 years and trichiasis in women aged 40 years and older was carried out in four districts in the Sololá region in Guatemala, which is suspected of still having a trachoma problem. Population-based surveys were undertaken in three districts, within 15 randomly selected communities in each district. In addition, in a fourth district that borders the third district chosen, we surveyed the small northern sub-district, by randomly selecting three communities in each community, 100 children aged under 10 years were randomly selected, and all females over 40 years. Five survey teams were trained and standardized. Trachoma was graded using the World Health Organization simplified grading scheme and ocular swabs were taken in cases of clinical follicular or inflammatory trachoma. Prevalence estimates were calculated at district and sub-district level. Trachoma rates at district level varied from 0-5.1%. There were only two sub-districts where active trachoma approached 10% (Nahualá Costa, 8.1%, and Santa Catarina Costa, 7.3%). Trichiasis rates in females aged 40 years and older varied from 0-3%. Trachoma was likely a problem in the past. Trachoma is disappearing in the Sololá region in Guatemala. Health leadership may consider further mapping of villages around the areas with an especially high rate of trachoma and infection, and instituting trichiasis surgery and active trachoma intervention where needed.

  15. Histocompatibility antigens in a population based silicosis series.

    PubMed Central

    Kreiss, K; Danilovs, J A; Newman, L S

    1989-01-01

    Individual susceptibility to silicosis is suggested by the lack of a uniform dose response relation and by the presence of immunological epiphenomena, such as increased antibody levels and associated diseases that reflect altered immune regulation. Human leucocyte antigens (HLA) are linked with immune response capability and might indicate a possible genetic susceptibility to silicosis. Forty nine silicotic subjects were identified from chest radiographs in a population based study in Leadville, Colorado. They were interviewed for symptoms and occupational history and gave a blood specimen for HLA-A, -B, -DR, and -DQ typing and for antinuclear antibody, immune complexes, immunoglobulins, and rheumatoid factor. Silicotic subjects had twice the prevalence of B44 (45%) of the reference population and had triple the prevalence of A29 (20%), both of which were statistically significant when corrected for the number of comparisons made. No perturbations in D-region antigen frequencies were detected. B44-positive subjects were older at diagnosis and had less dyspnoea than other subjects. A29-positive subjects were more likely to have abnormal levels of IgA and had higher levels of immune complexes. This study is the first to find significant HLA antigen excesses among a series of silicotic cases and extends earlier reported hypotheses that were based on groups of antigens of which B44 and A29 are components. PMID:2818968

  16. Optimal inverse functions created via population-based optimization.

    PubMed

    Jennings, Alan L; Ordóñez, Raúl

    2014-06-01

    Finding optimal inputs for a multiple-input, single-output system is taxing for a system operator. Population-based optimization is used to create sets of functions that produce a locally optimal input based on a desired output. An operator or higher level planner could use one of the functions in real time. For the optimization, each agent in the population uses the cost and output gradients to take steps lowering the cost while maintaining their current output. When an agent reaches an optimal input for its current output, additional agents are generated in the output gradient directions. The new agents then settle to the local optima for the new output values. The set of associated optimal points forms an inverse function, via spline interpolation, from a desired output to an optimal input. In this manner, multiple locally optimal functions can be created. These functions are naturally clustered in input and output spaces allowing for a continuous inverse function. The operator selects the best cluster over the anticipated range of desired outputs and adjusts the set point (desired output) while maintaining optimality. This reduces the demand from controlling multiple inputs, to controlling a single set point with no loss in performance. Results are demonstrated on a sample set of functions and on a robot control problem.

  17. Aligning population-based care management with chronic disease complexity.

    PubMed

    Hewner, Sharon; Seo, Jin Young; Gothard, Sandra E; Johnson, Barbara J

    2014-01-01

    Risk-stratified care management requires knowledge of the complexity of chronic disease and comorbidity, information that is often not readily available in the primary care setting. The purpose of this article was to describe a population-based approach to risk-stratified care management that could be applied in primary care. Three populations (Medicaid, Medicare, and privately insured) at a regional health plan were divided into risk-stratified cohorts based on chronic disease and complexity, and utilization was compared before and after the implementation of population-specific care management teams of nurses. Risk-stratified care management was associated with reductions in hospitalization rates in all three populations, but the opportunities to avoid admissions were different. Knowledge of population complexity is critical to the development of risk-stratified care management in primary care, and a complexity matrix can help nurses identify gaps in care and align interventions to cohort and population needs. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Experimental analysis of the bearing greases lifetime

    NASA Astrophysics Data System (ADS)

    Albagachiev, A. U.; Smirnov, N. I.; Prozhega, M. V.; Smirnov, N. N.

    2018-04-01

    The purpose of the presented work is to increase the lifetime of space mechanisms bearings. The authors reviewed the studies of the bearings and linear mechanisms operating in air and in vacuum. A testing equipment is developed to assess the lubricity and lifetime of greases in the air. Criteria for the evaluation of relative lifetime are defined. Four types of space greases are tested.

  19. Estimating lifetime healthcare costs with morbidity data

    PubMed Central

    2013-01-01

    Background In many developed countries, the economic crisis started in 2008 producing a serious contraction of the financial resources spent on healthcare. Identifying which individuals will require more resources and the moment in their lives these resources have to be allocated becomes essential. It is well known that a small number of individuals with complex healthcare needs consume a high percentage of health expenditures. Conversely, little is known on how morbidity evolves throughout life. The aim of this study is to introduce a longitudinal perspective to chronic disease management. Methods Data used relate to the population of the county of Baix Empordà in Catalonia for the period 2004–2007 (average population was N = 88,858). The database included individual information on morbidity, resource consumption, costs and activity records. The population was classified using the Clinical Risk Groups (CRG) model. Future morbidity evolution was simulated under different assumptions using a stationary Markov chain. We obtained morbidity patterns for the lifetime and the distribution function of the random variable lifetime costs. Individual information on acute episodes, chronic conditions and multimorbidity patterns were included in the model. Results The probability of having a specific health status in the future (healthy, acute process or different combinations of chronic illness) and the distribution function of healthcare costs for the individual lifetime were obtained for the sample population. The mean lifetime cost for women was €111,936, a third higher than for men, at €81,566 (all amounts calculated in 2007 Euros). Healthy life expectancy at birth for females was 46.99, lower than for males (50.22). Females also spent 28.41 years of life suffering from some type of chronic disease, a longer period than men (21.9). Conclusions Future morbidity and whole population costs can be reasonably predicted, combining stochastic microsimulation with a

  20. Probabilistic Prediction of Lifetimes of Ceramic Parts

    NASA Technical Reports Server (NTRS)

    Nemeth, Noel N.; Gyekenyesi, John P.; Jadaan, Osama M.; Palfi, Tamas; Powers, Lynn; Reh, Stefan; Baker, Eric H.

    2006-01-01

    ANSYS/CARES/PDS is a software system that combines the ANSYS Probabilistic Design System (PDS) software with a modified version of the Ceramics Analysis and Reliability Evaluation of Structures Life (CARES/Life) Version 6.0 software. [A prior version of CARES/Life was reported in Program for Evaluation of Reliability of Ceramic Parts (LEW-16018), NASA Tech Briefs, Vol. 20, No. 3 (March 1996), page 28.] CARES/Life models effects of stochastic strength, slow crack growth, and stress distribution on the overall reliability of a ceramic component. The essence of the enhancement in CARES/Life 6.0 is the capability to predict the probability of failure using results from transient finite-element analysis. ANSYS PDS models the effects of uncertainty in material properties, dimensions, and loading on the stress distribution and deformation. ANSYS/CARES/PDS accounts for the effects of probabilistic strength, probabilistic loads, probabilistic material properties, and probabilistic tolerances on the lifetime and reliability of the component. Even failure probability becomes a stochastic quantity that can be tracked as a response variable. ANSYS/CARES/PDS enables tracking of all stochastic quantities in the design space, thereby enabling more precise probabilistic prediction of lifetimes of ceramic components.

  1. Association of education and receiving social transfers with allostatic load in the Swiss population-based CoLaus study.

    PubMed

    Nicod, Edouard; Stringhini, Silvia; Marques-Vidal, Pedro; Paccaud, Fred; Waeber, Gérard; Lamiraud, Karine; Vollenweider, Peter; Bochud, Murielle

    2014-06-01

    Allostatic load reflects cumulative exposure to stressors throughout lifetime and has been associated with several adverse health outcomes. It is hypothesized that people with low socioeconomic status (SES) are exposed to higher chronic stress and have therefore greater levels of allostatic load. To assess the association of receiving social transfers and low education with allostatic load. We included 3589 participants (1812 women) aged over 35years and under retirement age from the population-based CoLaus study (Lausanne, Switzerland, 2003-2006). We computed an allostatic load index aggregating cardiovascular, metabolic, dyslipidemic and inflammatory markers. A novel index additionally including markers of oxidative stress was also examined. Men with low vs. high SES were more likely to have higher levels of allostatic load (odds ratio (OR)=1.93/2.34 for social transfers/education, 95%CI from 1.45 to 4.17). The same patterns were observed among women. Associations persisted after controlling for health behaviors and marital status. Low education and receiving social transfers independently and cumulatively predict high allostatic load and dysregulation of several homeostatic systems in a Swiss population-based study. Participants with low SES are at higher risk of oxidative stress, which may justify its inclusion as a separate component of allostatic load. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Lifetime Traumatic Experiences and Leisure Physical Inactivity among Adolescent Boys.

    PubMed

    Malinauskas, Romualdas; Malinauskiene, Vilija; Malinauskas, Mindaugas

    2018-03-01

    The aim of this study was to examine the associations between lifetime traumatic experiences and leisure physical inactivity among adolescent boys and to determine to what extent those associations are mediated by posttraumatic stress symptoms, unhealthy behaviors (smoking, alcohol use), the daily consumption of fresh fruit, and sense of coherence. A self-administered questionnaire combining 3 instruments measured leisure physical activity level (Godin and Shephard), symptoms of posttraumatic stress (IES-revised), lifetime traumatic experiences, sense of coherence (SOC-13, from Antonovsky), and behavioral and dietary patterns in a representative sample of eighth grade boys from a number of Kaunas, Lithuania, secondary schools (N = 885; response rate 88.6%). Fifty-six point eight percent of boys had experienced at least 1 lifetime traumatic event, with a 20.5% prevalence of PTS symptoms, and 5.4% were inactive during leisure time. In the logistic regression models, leisure physical inactivity was associated with lifetime traumatic experiences (adjusted OR = 2.33; 95% CI: 1.09-4.98). Sense of coherence and posttraumatic stress symptoms did not mediate those associations. Less-than-daily consumption of fresh fruit showed an independent effect, while smoking and weekly consumption of alcohol did not. Consistent associations between lifetime traumatic experiences and leisure physical inactivity among adolescent boys indicate that the presence of lifetime traumatic events should be taken into account when employing intervention and prevention programs on unhealthy lifestyles (physical inactivity, smoking, and alcohol).

  3. What is the most cost-effective population-based cancer screening program for Chinese women?

    PubMed

    Woo, Pauline P S; Kim, Jane J; Leung, Gabriel M

    2007-02-20

    To develop a policy-relevant generalized cost-effectiveness (CE) model of population-based cancer screening for Chinese women. Disability-adjusted life-years (DALYs) averted and associated screening and treatment costs under population-based screening using cervical cytology (cervical cancer), mammography (breast cancer), and fecal occult blood testing (FOBT), sigmoidoscopy, FOBT plus sigmoidoscopy, or colonoscopy (colorectal cancer) were estimated, from which average and incremental CE ratios were generated. Probabilistic sensitivity analysis was undertaken to assess stochasticity, parameter uncertainty, and model assumptions. Cervical, breast, and colorectal cancers were together responsible for 13,556 DALYs (in a 1:4:3 ratio, respectively) in Hong Kong's 3.4 million female population annually. All status quo strategies were dominated, thus confirming the suboptimal efficiency of opportunistic screening. Current patterns of screening averted 471 DALYs every year, which could potentially be more than doubled to 1,161 DALYs under the same screening and treatment budgetary threshold of US $50 million with 100% Pap coverage every 4 years and 30% coverage of colonoscopy every 10 years. With higher budgetary caps, biennial mammographic screening starting at age 50 years can be introduced. Our findings have informed how best to achieve allocative efficiency in deploying scarce cancer care dollars but must be coupled with better integrated care planning, improved intersectoral coordination, increased resources, and stronger political will to realize the potential health and economic gains as demonstrated.

  4. Alcohol consumption and cardiorespiratory fitness in five population-based studies.

    PubMed

    Baumeister, Sebastian E; Finger, Jonas D; Gläser, Sven; Dörr, Marcus; Markus, Marcello Rp; Ewert, Ralf; Felix, Stephan B; Grabe, Hans-Jörgen; Bahls, Martin; Mensink, Gert Bm; Völzke, Henry; Piontek, Katharina; Leitzmann, Michael F

    2018-01-01

    Background Poor cardiorespiratory fitness is a risk factor for cardiovascular morbidity. Alcohol consumption contributes substantially to the burden of disease, but its association with cardiorespiratory fitness is not well described. We examined associations between average alcohol consumption, heavy episodic drinking and cardiorespiratory fitness. Design The design of this study was as a cross-sectional population-based random sample. Methods We analysed data from five independent population-based studies (Study of Health in Pomerania (2008-2012); German Health Interview and Examination Survey (2008-2011); US National Health and Nutrition Examination Survey (NHANES) 1999-2000; NHANES 2001-2002; NHANES 2003-2004) including 7358 men and women aged 20-85 years, free of lung disease or asthma. Cardiorespiratory fitness, quantified by peak oxygen uptake, was assessed using exercise testing. Information regarding average alcohol consumption (ethanol in grams per day (g/d)) and heavy episodic drinking (5+ or 6+ drinks/occasion) was obtained from self-reports. Fractional polynomial regression models were used to determine the best-fitting dose-response relationship. Results Average alcohol consumption displayed an inverted U-type relation with peak oxygen uptake ( p-value<0.0001), after adjustment for age, sex, education, smoking and physical activity. Compared to individuals consuming 10 g/d (moderate consumption), current abstainers and individuals consuming 50 and 60 g/d had significantly lower peak oxygen uptake values (ml/kg/min) (β coefficients = -1.90, β = -0.06, β = -0.31, respectively). Heavy episodic drinking was not associated with peak oxygen uptake. Conclusions Across multiple adult population-based samples, moderate drinkers displayed better fitness than current abstainers and individuals with higher average alcohol consumption.

  5. Stressful psychosocial factors and symptoms of gastroesophageal reflux disease: a population-based study in Norway.

    PubMed

    Jansson, Catarina; Wallander, Mari-Ann; Johansson, Saga; Johnsen, Roar; Hveem, Kristian

    2010-01-01

    Adverse psychosocial factors, including work-related stress, are, like gastroesophageal reflux disease (GERD), increasing health problems in industrialized countries. The importance of clarifying the relation between psychosocial factors and GERD has been stressed, but there are few population-based studies. This was a population-based, cross-sectional, case-control study based on two health surveys conducted in the Norwegian county Nord-Trondelag in 1984-86 and 1995-97. GERD symptoms were assessed in the second survey, which included 65,333 participants, representing 70% of the county's adult population. The 3153 persons reporting severe GERD symptoms were defined as cases and the 40,210 persons without such symptoms were defined as controls. Data on psychosocial factors and potential confounders were collected using questionnaires. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using unconditional logistic regression. In models adjusted for age, sex, smoking, obesity and socioeconomic status, positive associations were observed between high job demands (OR 1.9, 95% CI 1.6-2.2), low job control (OR 1.1, 95% CI 1.0-1.2) and job strain (OR 1.9, 95% CI 1.6-2.4) and risk of GERD symptoms. Persons reporting low job satisfaction had a twofold (95% CI 1.6-2.5) increased risk of GERD compared to persons reporting high job satisfaction. Self pressure (OR 1.8, 95% CI 1.6-2.1) and time pressure (OR 2.0, 95% CI 1.7-2.4) were positively associated with GERD symptoms. These associations were attenuated after further adjustment for anxiety, depression, myocardial infarction, angina pectoris, stroke and insomnia, but remained statistically significant. This population-based study reveals a link between stressful psychosocial factors, including job strain, and GERD symptoms.

  6. Neighborhood deprivation is strongly associated with participation in a population-based health check.

    PubMed

    Bender, Anne Mette; Kawachi, Ichiro; Jørgensen, Torben; Pisinger, Charlotta

    2015-01-01

    We sought to examine whether neighborhood deprivation is associated with participation in a large population-based health check. Such analyses will help answer the question whether health checks, which are designed to meet the needs of residents in deprived neighborhoods, may increase participation and prove to be more effective in preventing disease. In Europe, no study has previously looked at the association between neighborhood deprivation and participation in a population-based health check. The study population comprised 12,768 persons invited for a health check including screening for ischemic heart disease and lifestyle counseling. The study population was randomly drawn from a population of 179,097 persons living in 73 neighborhoods in Denmark. Data on neighborhood deprivation (percentage with basic education, with low income and not in work) and individual socioeconomic position were retrieved from national administrative registers. Multilevel regression analyses with log links and binary distributions were conducted to obtain relative risks, intraclass correlation coefficients and proportional change in variance. Large differences between neighborhoods existed in both deprivation levels and neighborhood health check participation rate (mean 53%; range 35-84%). In multilevel analyses adjusted for age and sex, higher levels of all three indicators of neighborhood deprivation and a deprivation score were associated with lower participation in a dose-response fashion. Persons living in the most deprived neighborhoods had up to 37% decreased probability of participating compared to those living in the least deprived neighborhoods. Inclusion of individual socioeconomic position in the model attenuated the neighborhood deprivation coefficients, but all except for income deprivation remained statistically significant. Neighborhood deprivation was associated with participation in a population-based health check in a dose-response manner, in which increasing

  7. Exposure to childhood adversity and deficits in emotion recognition: results from a large, population-based sample.

    PubMed

    Dunn, Erin C; Crawford, Katherine M; Soare, Thomas W; Button, Katherine S; Raffeld, Miriam R; Smith, Andrew D A C; Penton-Voak, Ian S; Munafò, Marcus R

    2018-03-07

    Emotion recognition skills are essential for social communication. Deficits in these skills have been implicated in mental disorders. Prior studies of clinical and high-risk samples have consistently shown that children exposed to adversity are more likely than their unexposed peers to have emotion recognition skills deficits. However, only one population-based study has examined this association. We analyzed data from children participating in the Avon Longitudinal Study of Parents and Children, a prospective birth cohort (n = 6,506). We examined the association between eight adversities, assessed repeatedly from birth to age 8 (caregiver physical or emotional abuse; sexual or physical abuse; maternal psychopathology; one adult in the household; family instability; financial stress; parent legal problems; neighborhood disadvantage) and the ability to recognize facial displays of emotion measured using the faces subtest of the Diagnostic Assessment of Non-Verbal Accuracy (DANVA) at age 8.5 years. In addition to examining the role of exposure (vs. nonexposure) to each type of adversity, we also evaluated the role of the timing, duration, and recency of each adversity using a Least Angle Regression variable selection procedure. Over three-quarters of the sample experienced at least one adversity. We found no evidence to support an association between emotion recognition deficits and previous exposure to adversity, either in terms of total lifetime exposure, timing, duration, or recency, or when stratifying by sex. Results from the largest population-based sample suggest that even extreme forms of adversity are unrelated to emotion recognition deficits as measured by the DANVA, suggesting the possible immutability of emotion recognition in the general population. These findings emphasize the importance of population-based studies to generate generalizable results. © 2018 Association for Child and Adolescent Mental Health.

  8. A population-based exposure assessment methodology for carbon monoxide: Development of a carbon monoxide passive sampler and occupational dosimeter

    SciTech Connect

    Apte, Michael G.

    Two devices, an occupational carbon monoxide (CO) dosimeter (LOCD), and an indoor air quality (IAQ) passive sampler were developed for use in population-based CO exposure assessment studies. CO exposure is a serious public health problem in the U.S., causing both morbidity and mortality (lifetime mortality risk approximately 10{sup -4}). Sparse data from population-based CO exposure assessments indicate that approximately 10% of the U.S. population is exposed to CO above the national ambient air quality standard. No CO exposure measurement technology is presently available for affordable population-based CO exposure assessment studies. The LOCD and IAQ Passive Sampler were tested in themore » laboratory and field. The palladium-molybdenum based CO sensor was designed into a compact diffusion tube sampler that can be worn. Time-weighted-average (TWA) CO exposure of the device is quantified by a simple spectrophotometric measurement. The LOCD and IAQ Passive Sampler were tested over an exposure range of 40 to 700 ppm-hours and 200 to 4200 ppm-hours, respectively. Both devices were capable of measuring precisely (relative standard deviation <20%), with low bias (<10%). The LOCD was screened for interferences by temperature, humidity, and organic and inorganic gases. Temperature effects were small in the range of 10°C to 30°C. Humidity effects were low between 20% and 90% RH. Ethylene (200 ppm) caused a positive interference and nitric oxide (50 ppm) caused a negative response without the presence of CO but not with CO.« less

  9. The mass-lifetime relation

    NASA Astrophysics Data System (ADS)

    LoPresto, Michael C.

    2018-05-01

    In a recent "AstroNote," I described a simple exercise on the mass-luminosity relation for main sequence stars as an example of exposing students in a general education science course of lower mathematical level to the use of quantitative skills such as collecting and analyzing data. Here I present another attempt at a meaningful experience for such students that again involves both the gathering and analysis of numerical data and comparison with accepted result, this time on the relationship of the mass and lifetimes of main sequence stars. This experiment can stand alone or be used as an extension of the previous mass-luminosity relationship experiment.

  10. Discriminating Famous from Fictional Names Based on Lifetime Experience: Evidence in Support of a Signal-Detection Model Based on Finite Mixture Distributions

    ERIC Educational Resources Information Center

    Bowles, Ben; Harlow, Iain M.; Meeking, Melissa M.; Kohler, Stefan

    2012-01-01

    It is widely accepted that signal-detection mechanisms contribute to item-recognition memory decisions that involve discriminations between targets and lures based on a controlled laboratory study episode. Here, the authors employed mathematical modeling of receiver operating characteristics (ROC) to determine whether and how a signal-detection…

  11. District nursing: the cost benefits of a population-based practice.

    PubMed Central

    Dreher, M

    1984-01-01

    This paper presents some serendipitous findings from an ethnohistorical study of public health nursing in rural New England. In the course of that study, a model of population-based nursing revealed itself that some would condemn as antiquated; it may, however, hold great possibilities for addressing the nation's current and future health problems, particularly health maintenance of the elderly and care of the chronically ill. In keeping with the criteria used to evaluate primary health care, the model is examined for the extent to which it is accessible, available, accountable, acceptable, comprehensive, coordinated, and cost-effective. The policy implications of this model for the organization and financing of community health care are explored. PMID:6476165

  12. Falls and Depression in Men: A Population-Based Study.

    PubMed

    Stuart, Amanda L; Pasco, Julie A; Jacka, Felice N; Berk, Michael; Williams, Lana J

    2018-01-01

    The link between falls and depression has been researched in the elderly; however, little information is available on this association in younger adults, particularly men. This study sought to investigate the link between major depressive disorder (MDD) and falls in a population-based sample of 952 men (24-97 years). MDD was diagnosed utilizing the Structured Clinical Interview for DSM-IV-TR Research Version, Non-Patient edition, and categorized as 12-month/past/never. Body mass index and gait were measured; falls, smoking status, psychotropic medication use, and alcohol intake were self-reported as part of the Geelong Osteoporosis Study 5-year follow-up assessment. Thirty-four (3.6%) men met criteria for 12-month MDD, and 110 (11.6%) for past MDD. Of the 952 men, 175 (18.4%) reported falling at least once during the past 12 months. Fallers were older (66 [interquartile range: 48-79] vs. 59 [45-72] years, p = .001) and more likely to have uneven gait ( n = 16, 10% vs. n = 31, 4%, p = .003) than nonfallers. Participants with 12-month MDD had more than twice the odds of falling (age-adjusted odds ratio: 2.22, 95% confidence interval [1.03, 4.80]). The odds of falling were not associated with past depression ( p = .4). Further adjustments for psychotropic drug use, gait, body mass index, smoking status, blood pressure, and alcohol did not explain these associations. Given the 2.2-fold greater likelihood of falling associated with depression was not explained by age or psychotropic drug use, further research is warranted.

  13. [Population-based study of diabetic retinopathy in Wolfsburg].

    PubMed

    Hesse, L; Grüsser, M; Hoffstadt, K; Jörgens, V; Hartmann, P; Kroll, P

    2001-11-01

    Since November 1997 the complete documentation of an ophthalmological examination of diabetics has been annually subsidized by the Volkswagen Corporation Health Maintenance Organization (VW-HMO). The results of an annual ophthalmological examination were recorded in a standardised history sheet developed by the Initiative Group for Early Detection of Diabetic Eye Diseases. These data included visual acuity, intraocular pressure, lens status and a description of fundus abnormalities. Within 26 months ophthalmological examinations of 2,801 patients were completed which represented 4.5% of all VW-HMO insured patients. On average, patients suffered from diabetes for 9.6 years (SD +/- 8.3), artificial intraocular lenses were present in 357 eyes (6.4%) and 1,216 eyes (12.0%) were diagnosed with cataract or posterior capsule opacification impairing visual acuity. Out of 263 patients younger than 40 years old, 18.8% had a mild or moderate and 3.3% a severe non-proliferative diabetic retinopathy (NPDR). A proliferative diabetic retinopathy (PDR) was found in 2.2% of the younger patients. Of 2,228 patients aged 40 years and older, 11.9% had a mild or moderate and 2.6% a severe NPDR. In 0.9% of this group PDR was diagnosed. An annual ophthalmological screening based on a survey sheet of the Initiative Group was successfully introduced. For the first time a population-based evaluation on the prevalence of diabetic retinopathy was carried out for inhabitants of a German city. The prevalence of PDR was found to be lower than previously published in comparable studied.

  14. Hypervolemia for hypertension pathophysiology: a population-based study.

    PubMed

    Hür, Ender; Özişik, Melih; Ural, Cihan; Yildiz, Gürsel; Mağden, Kemal; Köse, Sennur Budak; Köktürk, Füruzan; Büyükuysal, Çağatay; Yildirim, Ibrahim; Süleymanlar, Gültekin; Ateş, Kenan; Duman, Soner

    2014-01-01

    Hypertension and hypervolemia relationship was proven among renal disease, although it is not known in normal population. Present study determines the fluid distribution defects in relation to blood pressure. In a population-based survey in Turkey demographics, height, weight, blood pressure, urine analysis, and serum creatinine measurements were recorded. Bioimpedance measured with the Body Composition Monitor. Total 2034 population of 71.6% male, mean age 47 ± 12.6 (18-89) years, systolic blood pressure (SBP) 134.7 ± 20, diastolic blood pressure 77.9 ± 11.6 mmHg. Body mass index (BMI) was 28.5 ± 4.5 (15.8-50.6) kg/m(2); overhydration was 0.05 ± 1.05 L. There was a correlation between extracellular water (ECW)/height and SBP (r = 0.21, P < 0.001). Receiver operating characteristic (ROC) curve with the performance of 0.60 (P < 0.001) that showed cut-off value of ECW/height was 10.06 L/m, with the 69% sensitivity and 45% specificity for SBP: 140 mmHg values. Risk factors for high SBP were increase of ECW/Height, age, BMI and presence of diabetes. ECW/height, SBP, and fat tissue index (FTI) increased in BMI categories (low, normal, and obese) and in diabetics. SBP and FTI were lower in smokers. High blood pressure may be accompanied by increased extracellular volume indices. In the future volume status assessment could be of use in evaluating the effectiveness of pharmacological intervention in the treatment of hypertension.

  15. Laryngeal adenoid cystic carcinoma: A population-based perspective.

    PubMed

    Dubal, Pariket M; Svider, Peter F; Folbe, Adam J; Lin, Ho-Sheng; Park, Richard C; Baredes, Soly; Eloy, Jean Anderson

    2015-11-01

    Adenoid cystic carcinoma (ACC) occurs infrequently in the larynx. Consequently, no large samples describing its clinical behavior are available in the literature. Our objective was to use a nationally representative population-based resource to evaluate clinical behavior, patient demographics, and outcomes among patients diagnosed with laryngeal ACC (LACC). Retrospective database analysis. The National Cancer Institute's Surveillance, Epidemiology, and End Results database was analyzed for patients diagnosed with LACC between 1973 and 2011. Patient demographics, incidence, treatment, and survival between LACC and other laryngeal malignancies were compared. Of 69 LACC patients, 63.8% were female, 78.2% Caucasian, and the median age was 54 years. LACC patients were much more likely to have subglottic lesions (44.9%) than individuals with other malignancies (1.6%). The incidence of LACC was 0.005/100,000 individuals. The majority of patients with LACC harbored T4 lesions at initial diagnosis, although 87.9% had N0 disease, and only 6.1% had distant metastasis at diagnosis. Disease-specific survival (DSS) was greater at 1 year for LACC compared to other laryngeal malignancies, but not at 5 or 10 years. Five-year DSS was greater for LACC patients who underwent surgery versus those who did not undergo surgery. This analysis notes that LACC has a low incidence with no significant change in incidence over the study period. Compared to other laryngeal malignancies, LACC has a female preponderance, is much more common in the subglottis, presents at a younger age, and more often presents with T4 disease. Surgery was noted to confer a survival advantage in LACC. 4. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  16. Fetal Growth and Childhood Cancer: A Population-Based Study

    PubMed Central

    Sørensen, Henrik Toft; Grotmol, Tom; Engeland, Anders; Stephansson, Olof; Gissler, Mika; Tretli, Steinar; Troisi, Rebecca

    2013-01-01

    OBJECTIVE: The etiology of childhood cancers is largely unknown. Studies have suggested that birth characteristics may be associated with risk. Our goal was to evaluate the risk of childhood cancers in relation to fetal growth. METHODS: We conducted a case-control study nested within Nordic birth registries. The study included cancer cases diagnosed in Denmark, Finland, Norway, and Sweden among children born from 1967 to 2010 and up to 10 matched controls per case, totaling 17 698 cases and 172 422 controls. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were derived from conditional logistic regression. RESULTS: Risks of all childhood cancers increased with increasing birth weight (Ptrend ≤ .001). Risks of acute lymphoid leukemia and Wilms tumor were elevated when birth weight was >4000 g and of central nervous system tumors when birth weight was >4500 g. Newborns large for gestational age were at increased risk of Wilms tumor (OR: 2.1 [95% CI: 1.2–3.6]) and connective/soft tissue tumors (OR: 2.1 [95% CI: 1.1–4.4]). In contrast, the risk of acute myeloid leukemia was increased among children born small for gestational age (OR: 1.8 [95% CI: 1.1–3.1]). Children diagnosed with central nervous system tumors at <1 year of age had elevated risk with increasing head circumference (Ptrend < .001). Those with head circumference >39 cm had the highest risk (OR: 4.7 [95% CI: 2.5–8.7]). CONCLUSIONS: In this large, Nordic population-based study, increased risks for several childhood tumors were associated with measures of fetal growth, supporting the hypothesis that tumorigenesis manifesting in childhood is initiated in utero. PMID:24167169

  17. Worry about breast cancer recurrence: a population-based analysis.

    PubMed

    Tewari, Apoorva; Chagpar, Anees B

    2014-07-01

    As more patients with breast cancer survive treatment, the importance of their long-term quality of life is increasing. One important concern for many survivors is fear of recurrence. To better understand worry about recurrence, we conducted a population-based statistical analysis. The National Health Interview Survey (NHIS) is the largest annual source of health information for the U.S. population. We obtained data from the 2010 survey, which asked breast cancer survivors about their fear of recurrence and quality of life. Data were analyzed using SUDAAN software. The 2010 NHIS sample represented 2,668,697 breast cancer survivors. On univariate analysis, worry about recurrence was correlated with current age (P = 0.03) and radiation therapy (P = 0.04). Worry was strongly associated with perceived risk of recurrence (P < 0.01) and decreased overall quality of life (P < 0.01) as well as lower self-reported physical (P < 0.01) and mental (P < 0.01) health and poor satisfaction with social activities and relationships (P < 0.01). On multivariate analysis, worry was not independently associated with decreased quality of life (P = 0.09). However, those who "always worried" about recurrence had a lower quality of life (odds ratio, 0.06; 95% confidence interval, 0.01 to 0.45). Worry about recurrence among breast cancer survivors is associated with age and radiation therapy and is correlated with self-reported physical health, mental health, social relationships, and overall quality of life. It is a significant predictor of decreased quality of life in those who worry the most. Screening for worry about recurrence is an important measure for the improvement of quality of life among breast cancer survivors.

  18. Repetition of intentional drug overdose: a population-based study.

    PubMed

    Finkelstein, Yaron; Macdonald, Erin M; Hollands, Simon; Sivilotti, Marco L A; Hutson, Janine R; Mamdani, Muhammad M; Koren, Gideon; Juurlink, David N

    2016-08-01

    Intentional overdose is a leading method of self-harm and suicide, and repeat attempts strongly predict eventual death by suicide. To determine the risk of recurrence after a first intentional overdose. Secondary objectives included characterization of the temporal course and potential predictors of repeat overdose, a strong risk factor for death from suicide. Population-based cohort study. Ontario, Canada, from 1 April 2002 to 31 March 2013. All Ontario residents presenting to an emergency department after a first intentional overdose. The incidence and timing of recurrent overdose. We followed 81,675 patients discharged from hospital after a first intentional overdose. Overall, 13,903 (17.0%) returned with a repeat overdose after a median interval of 288 (inter-quartile range: 62 to 834) days. Of these, 4493 (5.5%) had multiple repeat episodes. Factors associated with repeat self-poisoning included psychiatric care in the preceding year (adjusted hazard ratio [aHR] 1.55; 95% confidence interval [CI] 1.50 to 1.61), alcohol dependence (aHR 1.41; 95% CI 1.35 to 1.46) and documented depression (aHR 1.39; 95% CI 1.34 to 1.44). Female sex, rural residence, lower socioeconomic status, ingestion of psychoactive drugs and younger age were also weakly associated with repeat overdose. Hospital presentation for repetition of intentional overdose is common, with recurrent episodes often far removed from the first. While several factors predict overdose repetition, none is particularly strong. Secondary prevention initiatives should be implemented for all individuals who present to the emergency department and survive intentional overdose.

  19. Population-based study of presbyopia in Shahroud, Iran.

    PubMed

    Hashemi, Hassan; Khabazkhoob, Mehdi; Jafarzadehpur, Ebrahim; Mehravaran, Shiva; Emamian, Mohammad Hassan; Yekta, AbbasAli; Shariati, Mohammad; Fotouhi, Akbar

    2012-12-01

    There is limited information regarding the prevalence of presbyopia in different parts of the world. The add power and the prevalence of presbyopia by age and gender in general population of Shahroud, north of Iran, were studied. Population-based cross-sectional study. Using random cluster sampling, 6311 people from the 40- to 64-year-old population of Shahroud were invited. Of the invited population, 5190 individuals (82.2%) participated in the study. Presbyopia was defined as the correction of near vision to logMAR 1 (N8 point) with at least 1 D of add power. Near visual acuity of participants was evaluated with a logMAR chart at a distance of 40 cm. Mean add power in the age groups of 40-44, 45-49, 50-54, 55-59 and 60-64 years was 0.65, 1.30, 1.70, 1.87 and 2.08 D, respectively. For each 5-year increase in age, a 0.35 D increase in add power was noted. The prevalence of presbyopia was 58.15% (95% confidence interval: 56.46-59.84). Presbyopia was more prevalent in women (P < 0.001) and increased with ageing more in women than in men (P < 0.001). Furthermore, in the 60-64-year-old age group, 11% of men and 23% of women were not presbyopic. Compared with other reports, the add power in different age groups was 0.5 D less, and presbyopia was less prevalent. More than 50% of the over 45-year-old individuals were presbyopic and 17% of the over 60 individuals were free of this condition. © 2012 The Authors. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.

  20. Heritability of Autism Spectrum Disorder in a UK Population-Based Twin Sample

    PubMed Central

    Colvert, Emma; Tick, Beata; McEwen, Fiona; Stewart, Catherine; Curran, Sarah R.; Woodhouse, Emma; Gillan, Nicola; Hallett, Victoria; Lietz, Stephanie; Garnett, Tracy; Ronald, Angelica; Plomin, Robert; Rijsdijk, Frühling; Happé, Francesca; Bolton, Patrick

    2016-01-01

    IMPORTANCE Most evidence to date highlights the importance of genetic influences on the liability to autism and related traits. However, most of these findings are derived from clinically ascertained samples, possibly missing individuals with subtler manifestations, and obtained estimates may not be representative of the population. OBJECTIVES To establish the relative contributions of genetic and environmental factors in liability to autism spectrum disorder (ASD) and a broader autism phenotype in a large population-based twin sample and to ascertain the genetic/environmental relationship between dimensional trait measures and categorical diagnostic constructs of ASD. DESIGN, SETTING, AND PARTICIPANTS We used data from the population-based cohort Twins Early Development Study, which included all twin pairs born in England and Wales from January 1, 1994, through December 31, 1996. We performed joint continuous-ordinal liability threshold model fitting using the full information maximum likelihood method to estimate genetic and environmental parameters of covariance. Twin pairs underwent the following assessments: the Childhood Autism Spectrum Test (CAST) (6423 pairs; mean age, 7.9 years), the Development and Well-being Assessment (DAWBA) (359 pairs; mean age, 10.3 years), the Autism Diagnostic Observation Schedule (ADOS) (203 pairs; mean age, 13.2 years), the Autism Diagnostic Interview–Revised (ADI-R) (205 pairs; mean age, 13.2 years), and a best-estimate diagnosis (207 pairs). MAIN OUTCOMES AND MEASURES Participants underwent screening using a population-based measure of autistic traits (CAST assessment), structured diagnostic assessments (DAWBA, ADI-R, and ADOS), and a best-estimate diagnosis. RESULTS On all ASD measures, correlations among monozygotic twins (range, 0.77-0.99) were significantly higher than those for dizygotic twins (range, 0.22-0.65), giving heritability estimates of 56% to 95%. The covariance of CAST and ASD diagnostic status (DAWBA, ADOS

  1. Depression, antidepressants, and bone mineral density in a population-based cohort.

    PubMed

    Mezuk, Briana; Eaton, William W; Golden, Sherita Hill; Wand, Gary; Lee, Hochang Benjamin

    2008-12-01

    It is uncertain whether depression and antidepressant use are associated with decreased bone mineral density (BMD) and whether these relationships differ for men and women. The study used a case-cohort design within the Baltimore Epidemiologic Catchment Area Study, a population-based sample of adults that recently completed its 23-year follow-up. Depression was measured at four time points during the follow-up period by the Diagnostic Interview Schedule. Lower spine BMD was measured at the fourth wave by dual-energy x-ray absorptiometry. The association of BMD with lifetime history of depression and antidepressant medication use was studied using linear regression with bootstrap standard errors. A history of depression was associated with lower spine BMD after controlling for age, sex, race, calcium intake, alcohol use, smoking status, level of physical activity, percent body fat, and antidepressant medication use (-0.140 g/cm(2); p <.002). After controlling for depression, antidepressant medication use was associated with decreased BMD in women but not in men (-0.218 g/cm(2); p <.016). A history of depression predicted decreased lumbar spine BMD in men and women, and antidepressant use predicted decreased BMD in women even after controlling for depression. The magnitude of the effect of depression on BMD was approximately equivalent to 1 standard deviation in BMD and was therefore clinically significant. Providers should be aware of the physiologic consequences of depression as well as the possible risks to bone strength associated with antidepressant use in older patients.

  2. Early sexual debut in Norwegian youth with epilepsy: A population-based study.

    PubMed

    Lossius, Morten I; Alfstad, Kristin Å; Van Roy, Betty; Mowinckel, Petter; Clench-Aas, Jocelyne; Gjerstad, Leif; Nakken, Karl O

    2016-03-01

    In comparison with controls, youth with epilepsy (YWE) have greater psychosocial problems. However, information about their sexual behavior is sparse. We have performed a large, population-based questionnaire study to examine differences in sexual behavior between YWE and controls. A randomly chosen cohort of youth (13-19 years) from Akershus county, Norway (n=19,995) was asked to complete a questionnaire anonymously with questions on epilepsy and sexual activity. The response rate was 85%. Two hundred forty-seven participants reported having or having had epilepsy, i.e., a lifetime epilepsy prevalence of 1.2%. Compared with controls, a higher proportion of YWE reported having had sexual intercourse (43.6% vs. 35.3%, p=0.009). The mean age at sexual debut was significantly lower in YWE than in controls (14.0 years vs. 15.0 years, p<0.001), and this was particularly marked among boys. A higher proportion of YWE reported not having used contraceptives at their last sexual intercourse compared with controls (31.6% vs. 22.3%, p=0.03). Ten percent of YWE, compared with 2% of the controls, reported that they had been forced into their first sexual intercourse. In YWE, some aspects of sexual behavior differ from those of their peers, with earlier sexual debut and less frequent use of contraceptives. More attention should be directed toward this subject, aiming at avoiding unwanted pregnancies and potential emotional traumas in this already vulnerable patient group. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Cognitive lifestyle in older persons: the population-based Sydney Memory and Ageing Study.

    PubMed

    Valenzuela, Michael J; Leon, Irene; Suo, Chao; Piamba, Diana Martinez; Kochan, Nicole; Brodaty, Henry; Sachdev, Perminder

    2013-01-01

    Cognitive lifestyle may be an important modifiable risk factor for dementia but has not yet been comprehensively studied in healthy elderly. To examine gender- and lifespan-related differences in cognitive lifestyle in a population-based cohort. 872 individuals from the second wave of the Sydney Memory and Ageing Study (MAS) cohort were invited to complete the Lifetime of Experiences Questionnaire (LEQ), a validated measure of cognitive lifestyle. Of 555 questionnaires returned (64%), 253 were excluded due to prior diagnosis of mild cognitive impairment, leaving n = 302 cognitively-intact elders (mean age 80.1 years, ±SD 4.7, 40.1% men). Total LEQ was significantly higher in men (97.9 ± 20.0) than women (90.0 ± 24.5), resulting mainly from midlife LEQ differences. Men were more likely to have worked in managerial or professional jobs (73.8% versus 39.5% women), and twice as likely to have supervised large groups of workers. In late life, women were significantly more likely to be living alone (68.1% versus 25.4% men), but otherwise significantly more engaged in specific cognitive activities, including reading novels (72.3% versus 52.0% men) and incorporating volunteer work (31.9% versus 19.7% men) and socializing (59.0% versus 37.0% men) into their typical day. Over the adult lifespan, it was more common for men and women to transition between LEQ tertiles than remain the same. Cognitive lifestyle changes over the adult lifespan and exhibits a range of gender-based differences. While older women are more likely to be living alone they generally lead a more active current cognitive lifestyle.

  4. The Prevalence and Causes of Primary Infertility in Iran: A Population-Based Study.

    PubMed

    Kazemijaliseh, Hadigheh; Ramezani Tehrani, Fahimeh; Behboudi-Gandevani, Samira; Hosseinpanah, Farhad; Khalili, Davood; Azizi, Fereidoun

    2015-04-19

    Primary infertility is a health issue among women over the world. The aim of this study was to investigate the prevalence and causes of primary infertility based on a population-based study in an urban area of Iran. In a cross-sectional study, a total of 1067 married women who participated in the Tehran Lipid and Glucose Study were randomly selected using systematic random sampling. Unmarried women, those with unwilling pregnancy and duration of marriage below one year were excluded from the study. Data was collected by using validated ad-hoc questionnaires. Descriptive and inferential statistics were used for data analysis. The mean (SD) of age and marriage age of the studied women were 40.3 (9.3) and 20.6 (4.49) years, respectively; the overall prevalence of lifetime primary infertility among couples was 17.3% (185/1067). Ovulatory disorder (39.7%) and male factors (29.1%) were the main causes of primary infertility. In addition, 31 (17%) of the women were diagnosed with more than one cause. According to the logistic regression analysis, primary infertility was independently related to the old age of women (OR: 1.37; 95% CI: 1.14-13.63, P.value: 0.001), higher BMI (OR: 1.95; 95% CI: 1.87-4.14, P.value: 0.003), active smoking (OR: 1.47; 95% CI: 1.38-3.53, P.value: 0.012) and higher educational level (OR: 2.23; 95% CI: 1.12-5.53, P.value: 0.03). The prevalence of primary infertility in Iran was higher than the worldwide trends of infertility, indicating that understanding such risks help healthcare providers and policy makers to design and implement interventions to slow down this trend.

  5. Using Sport Education to Teach the Lifetime Sport of Golf

    ERIC Educational Resources Information Center

    Scarboro, Shot; Pritchard, Tony

    2015-01-01

    Golf is a lifetime sport activity that can be taught in physical education classes. How one teaches golf in physical education could influence whether students will want to continue to participate outside of physical education. The sport education model (SEM) is an instructional model that promotes student learning in all three domains by ensuring…

  6. Corrosion Preventive Compounds Lifetime Testing

    NASA Technical Reports Server (NTRS)

    Hale, Stephanie M.; Kammerer, Catherine C.; Copp, Tracy L.

    2007-01-01

    Lifetime Testing of Corrosion Preventive Compounds (CPCs) was performed to quantify performance in the various environments to which the Space Shuttle Orbiter is exposed during a flight cycle. Three CPCs are approved for use on the Orbiter: RD Calcium Grease, Dinitrol AV-30, and Braycote 601 EF. These CPCs have been rigorously tested to prove that they mitigate corrosion in typical environments, but little information is available on how they perform in the unique combination of the coastal environment at the launch pad, the vacuum of low-earth orbit, and the extreme heat of reentry. Currently, there is no lifetime or reapplication schedule established for these compounds that is based on this combination of environmental conditions. Aluminum 2024 coupons were coated with the three CPCs and exposed to conditions that simulate the environments to which the Orbiter is exposed. Uncoated Aluminum 2024 coupons were exposed to the environmental conditions as a control. Visual inspection and Electro- Impedance Spectroscopy (EIS) were performed on the samples in order to determine the effectiveness of the CPCs. The samples were processed through five mission life cycles or until the visual inspection revealed the initiation of corrosion and EIS indicated severe degradation of the coating.

  7. Corrosion Preventive Compounds Lifetime Testing

    NASA Technical Reports Server (NTRS)

    Hale, Stephanie M.; Kammerer, Catherine C.

    2007-01-01

    Lifetime Testing of Corrosion Preventive Compounds (CPCs) was performed to quantify performance in the various environments to which the Space Shuttle Orbiter is exposed during a flight cycle. Three CPCs are approved for use on the Orbiter: HD Calcium Grease, Dinitrol AV-30, and Braycote 601 EF. These CPCs have been rigorously tested to prove that they mitigate corrosion in typical environments, but little information is available on how they perform in the unique combination of the coastal environment at the launch pad, the vacuum of low-earth orbit, and the extreme heat of reentry. Currently, there is no lifetime or reapplication schedule established for these compounds that is based on this combination of environmental conditions. Aluminum 2024 coupons were coated with the three CPCs and exposed to conditions that simulate the environments to which the Orbiter is exposed. Uncoated Aluminum 2024 coupons were exposed to the environmental conditions as a control. Visual inspection and Electro- Impedance Spectroscopy (EIS) were performed on the samples in order to determine the effectiveness of the CPCs. The samples were processed through five mission life cycles or until the visual inspection revealed the initiation of corrosion and EIS indicated severe degradation of the coating.

  8. Environmental Tobacco Smoke and Adult-Onset Asthma: A Population-Based Incident Case–Control Study

    PubMed Central

    Jaakkola, Maritta S.; Piipari, Ritva; Jaakkola, Niina; Jaakkola, Jouni J. K.

    2003-01-01

    Objectives. The authors assessed the effects of environmental tobacco smoke (ETS) on the development of asthma in adults. Methods. In the Pirkanmaa district of South Finland, all 21- to 63-year-old adults with new cases of asthma diagnosed during a 2.5-year period (n = 521 case patients, out of 441 000 inhabitants) and a random sample of control subjects from the source population (932 control subjects) participated in a population-based incident case–control study. Results. Risk of asthma was related to workplace ETS exposure (adjusted odds ratio [OR] = 2.16; 95% confidence interval [CI] = 1.26, 3.72) and home exposure (OR = 4.77; 95% CI = 1.29, 17.7) in the past year. Cumulative ETS exposure over a lifetime at work and at home increased the risk. Conclusions. This study indicates for the first time that both cumulative lifetime and recent ETS exposures increase the risk of adult-onset asthma. PMID:14652334

  9. Fragility fractures and bone mineral density in HIV positive women: a case-control population-based study.

    PubMed

    Prior, J; Burdge, D; Maan, E; Milner, R; Hankins, C; Klein, M; Walmsley, S

    2007-10-01

    This Canadian study of bone health showed that HIV+ women were more likely to have had fragility fractures (OR 1.7) but had BMD values that were not different than women from a national population-based cohort. Given that 17.5 million women globally are HIV-infected and living longer on anti-retroviral therapy (ART+), it is essential to determine whether they are at risk for osteoporosis as is currently assumed. Assessment of osteoporosis risk factors and lifetime low-trauma (fragility) fracture history used a common interviewer-administered questionnaire and phantom-adjusted bone mineral density (BMD). This study compared HIV+ Canadian women with age- and region-matched control women (1:3) from a national population-based study of osteoporosis. One hundred and thirty-eight HIV+ women (100 ART+, 38 ART-) were compared with 402 controls. There were no differences in age (37.7 vs. 38.0 years), BMI (25.0 vs. 26.2), family history of osteoporosis, exercise history, alcohol or calcium intakes, age at menarche, oral contraceptive use or parity. HIV+ cases included more Aboriginal and Black women (12.5% and 16.2 vs. 2% and 1%, respectively), smoked and used injection drugs (53%) more, were more often treated with glucocorticoids, had oligomenorrhea, and reported 10-kg weight cycling. Significantly more HIV+ women reported lifetime fragility fractures (26.1% vs. 17.3; OR 1.7, 95% CI 1.1, 2.6). HIV+ and control women did not differ in BMD: spine 1.0 +/- 0.12 vs.1.0 +/- 0.14 g/cm(2) (diff. 0.0, 95% CI -0.27, 0.27) or total femur 0.91 +/- 0.15 vs. 0.93 +/- 0.12 g/cm(2) (diff 0.02, 95% CI +0.005, -0.045). HIV+ women reported significantly more past osteoporotic fractures than population-based controls despite normal BMD. Research is needed to assess bone microarchitecture and develop a reliable fracture risk assessment tool for HIV+ women.

  10. Calibrating a population-based job-exposure matrix using inspection measurements to estimate historical occupational exposure to lead for a population-based cohort in Shanghai, China

    PubMed Central

    Koh, Dong-Hee; Bhatti, Parveen; Coble, Joseph B.; Stewart, Patricia A; Lu, Wei; Shu, Xiao-Ou; Ji, Bu-Tian; Xue, Shouzheng; Locke, Sarah J.; Portengen, Lutzen; Yang, Gong; Chow, Wong-Ho; Gao, Yu-Tang; Rothman, Nathaniel; Vermeulen, Roel; Friesen, Melissa C.

    2012-01-01

    The epidemiologic evidence for the carcinogenicity of lead is inconsistent and requires improved exposure assessment to estimate risk. We evaluated historical occupational lead exposure for a population-based cohort of women (n=74,942) by calibrating a job-exposure matrix (JEM) with lead fume (n=20,084) and lead dust (n=5,383) measurements collected over four decades in Shanghai, China. Using mixed-effect models, we calibrated intensity JEM ratings to the measurements using fixed-effects terms for year and JEM rating. We developed job/industry-specific estimates from the random-effects terms for job and industry. The model estimates were applied to subjects’ jobs when the JEM probability rating was high for either job or industry; remaining jobs were considered unexposed. The models predicted that exposure increased monotonically with JEM intensity rating and decreased 20–50-fold over time. The cumulative calibrated JEM estimates and job/industry-specific estimates were highly correlated (Pearson correlation=0.79–0.84). Overall, 5% of the person-years and 8% of the women were exposed to lead fume; 2% of the person-years and 4% of the women were exposed to lead dust. The most common lead-exposed jobs were manufacturing electronic equipment. These historical lead estimates should enhance our ability to detect associations between lead exposure and cancer risk in future epidemiologic analyses. PMID:22910004

  11. Atmospheric lifetime of SF5CF3

    NASA Astrophysics Data System (ADS)

    Takahashi, K.; Nakayama, T.; Matsumi, Y.; Solomon, S.; Gejo, T.; Shigemasa, E.; Wallington, T. J.

    2002-08-01

    The vacuum ultraviolet (VUV) absorption spectrum of SF5CF3 was measured over the range 106-200 nm. At 121.6 nm, σ(base e) = (7.8 +/- 0.6) × 10-18 cm2 molecule-1, in which quoted uncertainty includes two standard deviation from the least-square fit in the Beer-Lambert plot and our estimate of potential systematic errors associated with measurements of the reactant concentrations. The VUV spectrum and literature data for electron attachment and ion-molecule reactions were incorporated into a model of the stratosphere, mesosphere, and lower thermosphere. This information provides better constraints on the atmospheric lifetime and hence on the potential of this highly radiatively-active trace gas to influence the climate system. The atmospheric lifetime of SF5CF3 is dominated by dissociative electron attachment and is estimated to be approximately 950 years. Solar proton events could reduce this to a lower limit of 650 years.

  12. New detectors to explore the lifetime frontier

    NASA Astrophysics Data System (ADS)

    Chou, John Paul; Curtin, David; Lubatti, H. J.

    2017-04-01

    Long-lived particles (LLPs) are a common feature in many beyond the Standard Model theories, including supersymmetry, and are generically produced in exotic Higgs decays. Unfortunately, no existing or proposed search strategy will be able to observe the decay of non-hadronic electrically neutral LLPs with masses above ∼ GeV and lifetimes near the limit set by Big Bang Nucleosynthesis (BBN), cτ ≲107-108 m. We propose the MATHUSLA surface detector concept (MAssive Timing Hodoscope for Ultra Stable neutraL pArticles), which can be implemented with existing technology and in time for the high luminosity LHC upgrade to find such ultra-long-lived particles (ULLPs), whether produced in exotic Higgs decays or more general production modes. We also advocate a dedicated LLP detector at a future 100 TeV collider, where a modestly sized underground design can discover ULLPs with lifetimes at the BBN limit produced in sub-percent level exotic Higgs decays.

  13. Epoch Lifetimes in the Dynamics of a Competing Population

    NASA Astrophysics Data System (ADS)

    Yeung, C. H.; Ma, Y. P.; Wong, K. Y. Michael

    We propose a dynamical model of a competing population whose agents have a tendency to balance their decisions in time. The model is applicable to financial markets in which the agents trade with finite capital, or other multiagent systems such as routers in communication networks attempting to transmit multiclass traffic in a fair way. We find an oscillatory behavior due to the segregation of agents into two groups. Each group remains winning over epochs. The aggregation of smart agents is able to explain the lifetime distribution of epochs to 8 decades of probability. The existence of the super agents further refines the lifetime distribution of short epochs.

  14. Statin use after esophageal cancer diagnosis and survival: A population based cohort study.

    PubMed

    Cardwell, Chris R; Spence, Andrew D; Hughes, Carmel M; Murray, Liam J

    2017-06-01

    A recent epidemiological study of esophageal cancer patients concluded statin use post-diagnosis was associated with large (38%) and significant reductions in cancer-specific mortality. We investigated statin use and cancer-specific mortality in a large population-based cohort of esophageal cancer patients. Newly diagnosed [2009-2012] esophageal cancer patients were identified from the Scottish Cancer Registry and linked with the Prescribing Information System and Scotland Death Records (to January 2015). Time-dependent Cox regression models were used to calculate hazard ratios (HR) for cancer-specific mortality and 95% confidence intervals (CIs) by post-diagnostic statin use (using a 6 month lag to reduce reverse causation) and to adjust these HRs for potential confounders. 1921 esophageal cancer patients were included in the main analysis, of whom 651 (34%) used statins after diagnosis. There was little evidence of a reduction in esophageal cancer-specific mortality in statin users compared with non-users after diagnosis (adjusted HR=0.93, 95% CI, 0.81, 1.07) and no dose response associations were seen. However, statin users compared with non-users in the year before diagnosis had a weak reduction in esophageal cancer-specific mortality (adjusted HR=0.88, 95% CI, 0.79, 0.99). In this large population-based esophageal cancer cohort, there was little evidence of a reduction in esophageal cancer-specific mortality with statin use after diagnosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Colorectal Cancer Prognosis Following Obesity Surgery in a Population-Based Cohort Study.

    PubMed

    Tao, Wenjing; Konings, Peter; Hull, Mark A; Adami, Hans-Olov; Mattsson, Fredrik; Lagergren, Jesper

    2017-05-01

    Obesity surgery involves mechanical and physiological changes of the gastrointestinal tract that might promote colorectal cancer progression. Thus, we hypothesised that obesity surgery is associated with poorer prognosis in patients with colorectal cancer. This nationwide population-based cohort study included all patients with an obesity diagnosis who subsequently developed colorectal cancer in Sweden from 1980 to 2012. The exposure was obesity surgery, and the main and secondary outcomes were disease-specific mortality and all-cause mortality, respectively. Cox proportional hazard survival models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs), adjusted for sex, age, calendar year and education level. The exposed and unexposed cohort included 131 obesity surgery and 1332 non-obesity surgery patients with colorectal cancer. There was a statistically significant increased rate of colorectal cancer deaths following obesity surgery (disease-specific HR 1.50, 95% CI 1.00-2.19). When analysed separately, the mortality rate was more than threefold increased in rectal cancer patients with prior obesity surgery (disease-specific HR 3.70, 95% CI 2.00-6.90), while no increased mortality rate was found in colon cancer patients (disease-specific HR 1.10, 85% CI 0.67-1.70). This population-based study among obese individuals found a poorer prognosis in colorectal cancer following obesity surgery, which was primarily driven by the higher mortality rate in rectal cancer.

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

    PubMed

    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.

  17. Sunlight Exposure and Breast Density: A Population-Based Study

    PubMed Central

    Wu, Sheng-Hui; So, Edwin; Lam, Tsz-ping; Woo, Jean; Yuen, PY; Qin, Ling; Ku, Susanna

    2013-01-01

    Purpose This study aims to assess the association of sunlight exposure with breast cancer risk, measured by the breast density assessed from Tabár's mammographic pattern in Chinese women. Methods A total of 676 premenopausal women were recruited to participate in this study, in which 650 completed a validated sunlight exposure questionnaire via telephone. The mammograms were classified according to Tabár's classification for parenchyma, and patterns IV & V and I, II & III indicated respectively high and low risk mammographic patterns for breast cancer. The odds ratios (OR) and 95% confidence intervals (CIs) for sun exposure-related variables were estimated using unconditional logistic regression with adjustment for potential confounders. Results Among 646 participants, women with high breast cancer risk (Tabár's patterns IV &V) had less hours spent in the sun than those with low risk (I, II & III) at any age stage. A higher level of sunlight exposure was associated with a significantly lower risk having high risk Tabár's pattern. Women aged 40 to 44 years who were in the highest tertile of lifetime total hours spent in the sun had a multi-adjusted OR of 0.41 (95% CI, 0.18-0.92; p for trend=0.03) compared with those in the lowest tertile (>2.19 hr/day vs. <1.32 hr/day). For hours spent in the sun across the ages of 6 to 12 years, the comparable OR was 0.37 (95% CI, 0.15-0.91; p for trend=0.03). Conclusion These findings suggest that higher sunlight exposure is related to a lower risk of having high risk breast density pattern in premenopausal women. Our results also suggest the most relevant period of exposure is during earlier life. PMID:23843849

  18. Progress toward a new beam measurement of the neutron lifetime

    NASA Astrophysics Data System (ADS)

    Hoogerheide, Shannon Fogwell

    2016-09-01

    Neutron beta decay is the simplest example of nuclear beta decay. A precise value of the neutron lifetime is important for consistency tests of the Standard Model and Big Bang Nucleosysnthesis models. The beam neutron lifetime method requires the absolute counting of the decay protons in a neutron beam of precisely known flux. Recent work has resulted in improvements in both the neutron and proton detection systems that should permit a significant reduction in systematic uncertainties. A new measurement of the neutron lifetime using the beam method will be performed at the National Institute of Standards and Technology Center for Neutron Research. The projected uncertainty of this new measurement is 1 s. An overview of the measurement and the technical improvements will be discussed.

  19. Progress toward a new beam measurement of the neutron lifetime

    NASA Astrophysics Data System (ADS)

    Hoogerheide, Shannon Fogwell; BL2 Collaboration

    2017-01-01

    Neutron beta decay is the simplest example of nuclear beta decay. A precise value of the neutron lifetime is important for consistency tests of the Standard Model and Big Bang Nucleosynthesis models. The beam neutron lifetime method requires the absolute counting of the decay protons in a neutron beam of precisely known flux. Recent work has resulted in improvements in both the neutron and proton detection systems that should permit a significant reduction in systematic uncertainties. A new measurement of the neutron lifetime using the beam method is underway at the National Institute of Standards and Technology Center for Neutron Research. The projected uncertainty of this new measurement is 1 s. An overview of the measurement, its current status, and the technical improvements will be discussed.

  20. Sexuality after a cancer diagnosis: A population-based study.

    PubMed

    Jackson, Sarah E; Wardle, Jane; Steptoe, Andrew; Fisher, Abigail

    2016-12-15

    This study explored differences in sexual activity, function, and concerns between cancer survivors and cancer-free controls in a population-based study. The data were from 2982 men and 3708 women who were 50 years old or older and were participating in the English Longitudinal Study of Ageing. Sexual well-being was assessed with the Sexual Relationships and Activities Questionnaire, and cancer diagnoses were self-reported. There were no differences between cancer survivors and controls in levels of sexual activity (76.0% vs 78.5% for men and 58.2% vs 55.5% for women) or sexual function. Men and women with cancer diagnoses were more dissatisfied with their sex lives than controls (age-adjusted percentages: 30.9% vs 19.8% for men [P = .023] and 18.2% vs 11.8% for women [P = .034]), and women with cancer were more concerned about levels of sexual desire (10.2% vs 7.1%; P = .006). Women diagnosed < 5 years ago were more likely to report difficulty with becoming aroused (55.4% vs 31.8%; P = .016) and achieving orgasm (60.6% vs 28.3%; P < .001) and were more concerned about sexual desire (14.8% vs 7.1%; P = .007) and orgasmic experience (17.6% vs 7.1%; P = .042) than controls, but there were no differences in men. Self-reports of sexual activity and functioning in older people with cancer are broadly comparable to age-matched, cancer-free controls. There is a need to identify the causes of sexual dissatisfaction among long-term cancer survivors despite apparently normal levels of sexual activity and function for their age. The development of interventions addressing low sexual desire and problems with sexual functioning in women is also important and may be particularly relevant for cancer survivors after treatment. Cancer 2016;122:3883-3891. © 2016 American Cancer Society. © 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

  1. Cyberbullying among Finnish adolescents – a population-based study

    PubMed Central

    2012-01-01

    Background Cyberbullying, threatening or harassing another via the internet or mobile phones, does not cause physically harm and thus the consequences are less visible. Little research has been performed on the occurrence of cyberbullying among adolescents or the perception of its seriousness. Only a few population-based studies have been published, none of which included research on the witnessing of cyberbullying. Here, we examined exposure to cyberbullying during the last year, and its frequency and perceived seriousness among 12 to 18-year-old adolescents in Finland. We studied four dimensions of cyberbullying: being a victim, bully, or both victim and bully of cyberbullying, and witnessing the cyberbullying of friends. Methods Self-administered questionnaires, including four questions on cyberbullying, were mailed to a representative sample of 12-, 14-, 16-, and 18-year-old Finns in 2009 (the Adolescent Health and Lifestyle Survey). The respondents could answer via the internet or paper questionnaire. Results The number of respondents was 5516 and the response rate was 56%. Girls more often than boys reported experiencing at least one dimension of cyberbullying during the last year. The proportion was highest among 14-year-olds and lowest among 18-year-olds of both sexes. Among girls, the most commonly encountered dimension was witnessing the cyberbullying of friends (16%); and being a victim was slightly more common than being a bully (11% vs. 9%). Among boys, an equal proportion, approximately 10%, had been a victim, a bully, or had witnessed cyberbullying. The proportion of bully-victims was 4%. Serious and disruptive cyberbullying was experienced by 2% of respondents and weekly cyberbullying by 1%; only 0.5% of respondents had been bullied weekly and considered bullying serious and disruptive. Conclusions Adolescents are commonly exposed to cyberbullying, but it is rarely frequent or considered serious or disruptive. Cyberbullying exposure differed between

  2. Population-based study of Hodgkin's lymphoma in Kuwait.

    PubMed

    Alshemmari, S; Sajnani, K P; Refaat, S; Albassami, A

    2011-01-01

    Hodgkin lymphoma (HL) comprises about 25% of all malignant nodal lymphomas worldwide. Incidence of HL has been increasing in many countries around the world, in the western countries in particular. Cancer incidence variations in different ethnic groups in the same country can lead to some important information about the search of etiological factors. Some researchers found an association between ethnicity and increased risk of HL. In this study, we evaluated the epidemiologic and clinical characteristics of patients with HL and the HL subtypes in Kuwait who were diagnosed between 1998 and 2006 and we analyzed the changes in the incidence of HL over time based on age, sex, and ethnicity. The Kuwait Cancer Control Center is a tertiary referral hospital and the only cancer hospital in the entire state of Kuwait. We identified 293 patients who were newly diagnosed with HL by histopathology between January 1, 1998, and December 31, 2006, at the Kuwait Cancer Control Center. Incidence data were crossvalidated with the population-based Cancer Registry of Kuwait. Clinical data were obtained by reviewing the patients' medical records. The median age at diagnosis was 39 years (range, 10-85 years) for patients with cHL and 36 years (range, 14-51 years) for patients with NLPHL. The age-adjusted incidence rate was 2.1 cases (range, 1.2-2.9) per 100,000 people per year in the period between 1998 and 2006. NLPHL and cHL were predominant in men with a male to female ratio of 2:1. However, the mean annual percentage change in HL incidence among Kuwaiti patients and non-Kuwaiti patients per year showed unexplained higher percentage in females both Kuwaiti and non-Kuwaiti. cHL comprised 92.5% of all HL cases and NLPHL comprised 7.5%. Nodular sclerosis was the predominant histologic subtype of cHL (58.9%), whereas mixed cellularity was the second most frequent histologic subtype of cHL, (25.9%). Although the incidence of HL was slightly lower in Kuwait than the worldwide incidence; it

  3. Familial risk of cerebral palsy: population based cohort study.

    PubMed

    Tollånes, Mette C; Wilcox, Allen J; Lie, Rolv T; Moster, Dag

    2014-07-15

    To investigate risks of recurrence of cerebral palsy in family members with various degrees of relatedness to elucidate patterns of hereditability. Population based cohort study. Data from the Medical Birth Registry of Norway, linked to the Norwegian social insurance scheme to identify cases of cerebral palsy and to databases of Statistics Norway to identify relatives. 2,036,741 Norwegians born during 1967-2002, 3649 of whom had a diagnosis of cerebral palsy; 22,558 pairs of twins, 1,851,144 pairs of first degree relatives, 1,699,856 pairs of second degree relatives, and 5,165,968 pairs of third degree relatives were identified. Cerebral palsy. If one twin had cerebral palsy, the relative risk of recurrence of cerebral palsy was 15.6 (95% confidence interval 9.8 to 25) in the other twin. In families with an affected singleton child, risk was increased 9.2 (6.4 to 13)-fold in a subsequent full sibling and 3.0 (1.1 to 8.6)-fold in a half sibling. Affected parents were also at increased risk of having an affected child (6.5 (1.6 to 26)-fold). No evidence was found of differential transmission through mothers or fathers, although the study had limited power to detect such differences. For people with an affected first cousin, only weak evidence existed for an increased risk (1.5 (0.9 to 2.7)-fold). Risks in siblings or cousins were independent of sex of the index case. After exclusion of preterm births (an important risk factor for cerebral palsy), familial risks remained and were often stronger. People born into families in which someone already has cerebral palsy are themselves at elevated risk, depending on their degree of relatedness. Elevated risk may extend even to third degree relatives (first cousins). The patterns of risk suggest multifactorial inheritance, in which multiple genes interact with each other and with environmental factors. These data offer additional evidence that the underlying causes of cerebral palsy extend beyond the clinical management of

  4. Cardiovascular mortality after pre-eclampsia in one child mothers: prospective, population based cohort study.

    PubMed

    Skjaerven, Rolv; Wilcox, Allen J; Klungsøyr, Kari; Irgens, Lorentz M; Vikse, Bjørn Egil; Vatten, Lars J; Lie, Rolv Terje

    2012-11-27

    To assess the association of pre-eclampsia with later cardiovascular death in mothers according to their lifetime number of pregnancies, and particularly after only one child. Prospective, population based cohort study. Medical Birth Registry of Norway. We followed 836,147 Norwegian women with a first singleton birth between 1967 and 2002 for cardiovascular mortality through linkage to the national Cause of Death Registry. About 23,000 women died by 2009, of whom 3891 died from cardiovascular causes. Associations between pre-eclampsia and cardiovascular death were assessed by hazard ratios, estimated by Cox regression analyses. Hazard ratios were adjusted for maternal education (three categories), maternal age at first birth, and year of first birth The rate of cardiovascular mortality among women with preterm pre-eclampsia was 9.2% after having only one child, falling to 1.1% for those with two or more children. With term pre-eclampsia, the rates were 2.8% and 1.1%, respectively. Women with pre-eclampsia in their first pregnancy had higher rates of cardiovascular death than those who did not have the condition at first birth (adjusted hazard ratio 1.6 (95% confidence interval 1.4 to 2.0) after term pre-eclampsia; 3.7 (2.7 to 4.8) after preterm pre-eclampsia). Among women with only one lifetime pregnancy, the increase in risk of cardiovascular death was higher than for those with two or more children (3.4 (2.6 to 4.6) after term pre-eclampsia; 9.4 (6.5 to 13.7) after preterm pre-eclampsia). The risk of cardiovascular death was only moderately elevated among women with pre-eclamptic first pregnancies who went on to have additional children (1.5 (1.2 to 2.0) after term pre-eclampsia; 2.4 (1.5 to 3.9) after preterm pre-eclampsia). There was little evidence of additional risk after recurrent pre-eclampsia. All cause mortality for women with two or more lifetime births, who had pre-eclampsia in first pregnancy, was not elevated, even with preterm pre-eclampsia in first

  5. Lifetime physical activity and female stress urinary incontinence.

    PubMed

    Nygaard, Ingrid E; Shaw, Janet M; Bardsley, Tyler; Egger, Marlene J

    2015-07-01

    We sought to estimate whether moderate/severe stress urinary incontinence (SUI) in middle-aged women is associated with overall lifetime physical activity (including leisure, household, outdoor, and occupational), as well as lifetime leisure (recreational), lifetime strenuous, and strenuous activity during the teen years. Recruitment for this case-control study was conducted in primary-care-level family medicine and gynecology clinics. A total of 1538 enrolled women ages 39-65 years underwent a Pelvic Organ Prolapse Quantification examination to assess vaginal support. Based on Incontinence Severity Index scores, cases had moderate/severe and controls had no/mild SUI. We excluded 349 with vaginal descent at/below the hymen (pelvic organ prolapse), 194 who did not return questionnaires, and 110 with insufficient activity data for analysis. In all, 213 cases were frequency matched 1:1 by age group to controls. Physical activity was measured using the Lifetime Physical Activity Questionnaire, in which women recall activity from menarche to present. We created separate multivariable logistic regression models for activity measures. SUI odds increased slightly with overall lifetime activity (odds ratio [OR], 1.20 per 70 additional metabolic equivalent of task-h/wk; 95% confidence interval [CI], 1.02-1.41), and were not associated with lifetime strenuous activity (OR, 1.11; 95% CI, 0.99-1.25). In quintile analysis of lifetime leisure activity, which demonstrated a nonlinear pattern, all quintiles incurred about half the odds of SUI compared to reference (second quintile; P = .009). Greater strenuous activity in teen years modestly increased SUI odds (OR, 1.37 per 7 additional h/wk; 95% CI, 1.09-1.71); OR, 1.75; 95% CI, 1.15-2.66 in sensitivity analysis adjusting for measurement error. The predicted probability of SUI rose linearly in women exceeding 7.5 hours of strenuous activity/wk during teen years. Teen strenuous activity had a similar effect on SUI odds when

  6. Gastro oesophageal reflux disease (GORD)-related symptoms and its association with mood and anxiety disorders and psychological symptomology: a population-based study in women

    PubMed Central

    2013-01-01

    Background Psychopathology seems to play a role in reflux pathogenesis and vice versa, yet few population-based studies have systematically investigated the association between gastro-oesophageal reflux disease (GORD) and psychopathology. We thus aimed to investigate the relationship between GORD-related symptoms and psychological symptomatology, as well as clinically diagnosed mood and anxiety disorders in a randomly selected, population-based sample of adult women. Methods This study examined data collected from 1084 women aged 20-93 yr participating in the Geelong Osteoporosis Study. Mood and anxiety disorders were identified using the Structured Clinical Interview for DSM-IV-TR Research Version, Non-patient edition (SCID-I/NP), and psychological symptomatology was assessed using the General Health Questionnaire (GHQ-12). GORD-related symptoms were self-reported and confirmed by medication use where possible and lifestyle factors were documented. Results Current psychological symptomatology and mood disorder were associated with increased odds of concurrent GORD-related symptoms (adjusted OR 2.1, 95% CI 1.3-3.5, and OR 3.0, 95% CI 1.7-5.6, respectively). Current anxiety disorder also tended to be associated with increased odds of current GORD-related symptoms (p = 0.1). Lifetime mood disorder was associated with a 1.6-fold increased odds of lifetime GORD-related symptoms (adjusted OR 1.6, 95% CI 1.1-2.4) and lifetime anxiety disorder was associated with a 4-fold increased odds of lifetime GORD-related symptoms in obese but not non-obese participants (obese, age-adjusted OR 4.0, 95% CI 1.8-9.0). Conclusions These results indicate that psychological symptomatology, mood and anxiety disorders are positively associated with GORD-related symptoms. Acknowledging this common comorbidity may facilitate recognition and treatment, and opens new questions as to the pathways and mechanisms of the association. PMID:23883104

  7. Gastro oesophageal reflux disease (GORD)-related symptoms and its association with mood and anxiety disorders and psychological symptomology: a population-based study in women.

    PubMed

    Sanna, Livia; Stuart, Amanda L; Berk, Michael; Pasco, Julie A; Girardi, Paolo; Williams, Lana J

    2013-07-24

    Psychopathology seems to play a role in reflux pathogenesis and vice versa, yet few population-based studies have systematically investigated the association between gastro-oesophageal reflux disease (GORD) and psychopathology. We thus aimed to investigate the relationship between GORD-related symptoms and psychological symptomatology, as well as clinically diagnosed mood and anxiety disorders in a randomly selected, population-based sample of adult women. This study examined data collected from 1084 women aged 20-93 yr participating in the Geelong Osteoporosis Study. Mood and anxiety disorders were identified using the Structured Clinical Interview for DSM-IV-TR Research Version, Non-patient edition (SCID-I/NP), and psychological symptomatology was assessed using the General Health Questionnaire (GHQ-12). GORD-related symptoms were self-reported and confirmed by medication use where possible and lifestyle factors were documented. Current psychological symptomatology and mood disorder were associated with increased odds of concurrent GORD-related symptoms (adjusted OR 2.1, 95% CI 1.3-3.5, and OR 3.0, 95% CI 1.7-5.6, respectively). Current anxiety disorder also tended to be associated with increased odds of current GORD-related symptoms (p = 0.1). Lifetime mood disorder was associated with a 1.6-fold increased odds of lifetime GORD-related symptoms (adjusted OR 1.6, 95% CI 1.1-2.4) and lifetime anxiety disorder was associated with a 4-fold increased odds of lifetime GORD-related symptoms in obese but not non-obese participants (obese, age-adjusted OR 4.0, 95% CI 1.8-9.0). These results indicate that psychological symptomatology, mood and anxiety disorders are positively associated with GORD-related symptoms. Acknowledging this common comorbidity may facilitate recognition and treatment, and opens new questions as to the pathways and mechanisms of the association.

  8. Accelerated lifetime test of vibration isolator made of Metal Rubber material

    NASA Astrophysics Data System (ADS)

    Ao, Hongrui; Ma, Yong; Wang, Xianbiao; Chen, Jianye; Jiang, Hongyuan

    2017-01-01

    The Metal Rubber material (MR) is a kind of material with nonlinear damping characteristics for its application in the field of aerospace, petrochemical industry and so on. The study on the lifetime of MR material is impendent to its application in engineering. Based on the dynamic characteristic of MR, the accelerated lifetime experiments of vibration isolators made of MR working under random vibration load were conducted. The effects of structural parameters of MR components on the lifetime of isolators were studied and modelled with the fitting curves of degradation data. The lifetime prediction methods were proposed based on the models.

  9. Influences on lifetime of wire ropes in traction lifts

    NASA Astrophysics Data System (ADS)

    Vogel, W.

    2016-05-01

    Traction lifts are complex systems with rotating and translating moving masses, springs and dampers and several system inputs from the lifts and the users. The wire ropes are essential mechanical elements. The mechanical properties of the ropes in use depend on the rope construction, the load situation, nonlinearities and the lift dimensions. The mechanical properties are important for the proper use in lifts and the ride quality. But first of all the wire ropes (for all other suspension means as well) have to satisfy the safety relevant requirements sufficient lifetime, reliable determination of discard and sufficient and limited traction capacity. The lifetime of the wire ropes better the number of trips until rope discard depends on a lot of parameters of the rope and the rope application eg use of plastic deflection sheaves and reverse bending layouts. New challenges for rope lifetime are resulting from the more or less open D/d-ratio limits possible by certificates concerning the examination of conformity by notified bodies. This paper will highlight the basics of wire rope technology, the endurance and lifetime of wire ropes running over sheaves, and the different influences from the ropes and more and more important from the lift application parameters. Very often underestimated are the influences of transport, storage, installation and maintenance. With this background we will lead over to the calculation methods of wire rope lifetime considering the actual findings of wire rope endurance research. We'll show in this paper new and innovative facts as the influence of rope length and size factor in the lifetime formular, the reduction of lifetime caused by traction grooves, the new model for the calculation in reverse bending operations and the statistically firmed possibilities for machine roomless lifts (MRL) under very small bending conditions.

  10. Lifelong risk factors for osteoporosis and fractures in elderly women with low body mass index--a population-based study.

    PubMed

    Korpelainen, R; Korpelainen, J; Heikkinen, J; Väänänen, K; Keinänen-Kiukaanniemi, S

    2006-08-01

    Low body weight is associated with an increased risk for osteoporosis and fractures, but the contribution of other lifestyle related factors have not been previously studied within lean elderly women. The present study evaluated the association between lifelong lifestyle factors and bone density, falls and postmenopausal fractures in elderly women with low body mass index (BMI). A population-based sample of 1,222 women aged 70 to 73 years was stratified by BMI tertiles, and all 407 women in the lowest tertile participated. Data on falls and postmenopausal fractures, physical activity, functional capacity, calcium intake, smoking, alcohol intake and medical factors at different ages were obtained by a questionnaire. Calcaneum bone mass as broadband ultrasound attenuation (BUA) was assessed with a quantitative ultrasound (QUS) device, and bone mineral density (BMD) at the distal radius was measured with a dual-energy X-ray absorptiometry (DXA). Low current physical activity was associated with lower calcaneum BUA and factors associated with higher BUA were body weight, low lifetime occupational physical activity, hormone replacement and type 2 diabetes. Weight, type 2 diabetes and thiatzide use were associated with higher radius BMD. The final multivariate model consisted of four independent factors associated with fractures: low lifetime habitual physical activity (OR 3.7, 95% CI 1.9-7.1), diabetes (OR 0.2, 95% CI 0.1-1.0), living alone (OR 1.7, 95% CI 1.0-3.0) and calcaneum BUA (1.8, 95% CI 1.3-2.4). Poor functional ability and symptoms of depression were associated with recent falling. In elderly women with low BMI, lifelong physical activity may protect from fractures, while low calcaneum bone mass and living unpartnered appear to be associated with an increased risk for fractures. Poor functional ability and presence of depression may be associated with risk of falling. Type 2 diabetes may modify the risk of low bone mass and low-trauma postmenopausal fractures

  11. A systematic review of economic evaluations of population-based sodium reduction interventions.

    PubMed

    Hope, Silvia F; Webster, Jacqui; Trieu, Kathy; Pillay, Arti; Ieremia, Merina; Bell, Colin; Snowdon, Wendy; Neal, Bruce; Moodie, Marj

    2017-01-01

    To summarise evidence describing the cost-effectiveness of population-based interventions targeting sodium reduction. A systematic search of published and grey literature databases and websites was conducted using specified key words. Characteristics of identified economic evaluations were recorded, and included studies were appraised for reporting quality using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist. Twenty studies met the study inclusion criteria and received a full paper review. Fourteen studies were identified as full economic evaluations in that they included both costs and benefits associated with an intervention measured against a comparator. Most studies were modelling exercises based on scenarios for achieving salt reduction and assumed effects on health outcomes. All 14 studies concluded that their specified intervention(s) targeting reductions in population sodium consumption were cost-effective, and in the majority of cases, were cost saving. Just over half the studies (8/14) were assessed as being of 'excellent' reporting quality, five studies fell into the 'very good' quality category and one into the 'good' category. All of the identified evaluations were based on modelling, whereby inputs for all the key parameters including the effect size were either drawn from published datasets, existing literature or based on expert advice. Despite a clear increase in evaluations of salt reduction programs in recent years, this review identified relatively few economic evaluations of population salt reduction interventions. None of the studies were based on actual implementation of intervention(s) and the associated collection of new empirical data. The studies universally showed that population-based salt reduction strategies are likely to be cost effective or cost saving. However, given the reliance on modelling, there is a need for the effectiveness of new interventions to be evaluated in the field using strong

  12. Estimating HIV Prevalence in Zimbabwe Using Population-Based Survey Data

    PubMed Central

    Chinomona, Amos; Mwambi, Henry Godwell

    2015-01-01

    Estimates of HIV prevalence computed using data obtained from sampling a subgroup of the national population may lack the representativeness of all the relevant domains of the population. These estimates are often computed on the assumption that HIV prevalence is uniform across all domains of the population. Use of appropriate statistical methods together with population-based survey data can enhance better estimation of national and subgroup level HIV prevalence and can provide improved explanations of the variation in HIV prevalence across different domains of the population. In this study we computed design-consistent estimates of HIV prevalence, and their respective 95% confidence intervals at both the national and subgroup levels. In addition, we provided a multivariable survey logistic regression model from a generalized linear modelling perspective for explaining the variation in HIV prevalence using demographic, socio-economic, socio-cultural and behavioural factors. Essentially, this study borrows from the proximate determinants conceptual framework which provides guiding principles upon which socio-economic and socio-cultural variables affect HIV prevalence through biological behavioural factors. We utilize the 2010–11 Zimbabwe Demographic and Health Survey (2010–11 ZDHS) data (which are population based) to estimate HIV prevalence in different categories of the population and for constructing the logistic regression model. It was established that HIV prevalence varies greatly with age, gender, marital status, place of residence, literacy level, belief on whether condom use can reduce the risk of contracting HIV and level of recent sexual activity whereas there was no marked variation in HIV prevalence with social status (measured using a wealth index), method of contraceptive and an individual’s level of education. PMID:26624280

  13. A systematic review of economic evaluations of population-based sodium reduction interventions

    PubMed Central

    Hope, Silvia F.; Webster, Jacqui; Trieu, Kathy; Pillay, Arti; Ieremia, Merina; Bell, Colin; Snowdon, Wendy; Neal, Bruce; Moodie, Marj

    2017-01-01

    Objective To summarise evidence describing the cost-effectiveness of population-based interventions targeting sodium reduction. Methods A systematic search of published and grey literature databases and websites was conducted using specified key words. Characteristics of identified economic evaluations were recorded, and included studies were appraised for reporting quality using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist. Results Twenty studies met the study inclusion criteria and received a full paper review. Fourteen studies were identified as full economic evaluations in that they included both costs and benefits associated with an intervention measured against a comparator. Most studies were modelling exercises based on scenarios for achieving salt reduction and assumed effects on health outcomes. All 14 studies concluded that their specified intervention(s) targeting reductions in population sodium consumption were cost-effective, and in the majority of cases, were cost saving. Just over half the studies (8/14) were assessed as being of ‘excellent’ reporting quality, five studies fell into the ‘very good’ quality category and one into the ‘good’ category. All of the identified evaluations were based on modelling, whereby inputs for all the key parameters including the effect size were either drawn from published datasets, existing literature or based on expert advice. Conclusion Despite a clear increase in evaluations of salt reduction programs in recent years, this review identified relatively few economic evaluations of population salt reduction interventions. None of the studies were based on actual implementation of intervention(s) and the associated collection of new empirical data. The studies universally showed that population-based salt reduction strategies are likely to be cost effective or cost saving. However, given the reliance on modelling, there is a need for the effectiveness of new

  14. Familial risk of epilepsy: a population-based study

    PubMed Central

    Peljto, Anna L.; Barker-Cummings, Christie; Vasoli, Vincent M.; Leibson, Cynthia L.; Hauser, W. Allen; Buchhalter, Jeffrey R.

    2014-01-01

    Almost all previous studies of familial risk of epilepsy have had potentially serious methodological limitations. Our goal was to address these limitations and provide more rigorous estimates of familial risk in a population-based study. We used the unique resources of the Rochester Epidemiology Project to identify all 660 Rochester, Minnesota residents born in 1920 or later with incidence of epilepsy from 1935–94 (probands) and their 2439 first-degree relatives who resided in Olmsted County. We assessed incidence of epilepsy in relatives by comprehensive review of the relatives’ medical records, and estimated age-specific cumulative incidence and standardized incidence ratios for epilepsy in relatives compared with the general population, according to proband and relative characteristics. Among relatives of all probands, cumulative incidence of epilepsy to age 40 was 4.7%, and risk was increased 3.3-fold (95% confidence interval 2.75–5.99) compared with population incidence. Risk was increased to the greatest extent in relatives of probands with idiopathic generalized epilepsies (standardized incidence ratio 6.0) and epilepsies associated with intellectual or motor disability presumed present from birth, which we denoted ‘prenatal/developmental cause’ (standardized incidence ratio 4.3). Among relatives of probands with epilepsy without identified cause (including epilepsies classified as ‘idiopathic’ or ‘unknown cause’), risk was significantly increased for epilepsy of prenatal/developmental cause (standardized incidence ratio 4.1). Similarly, among relatives of probands with prenatal/developmental cause, risk was significantly increased for epilepsies without identified cause (standardized incidence ratio 3.8). In relatives of probands with generalized epilepsy, standardized incidence ratios were 8.3 (95% confidence interval 2.93–15.31) for generalized epilepsy and 2.5 (95% confidence interval 0.92–4.00) for focal epilepsy. In relatives of

  15. Finite quasiparticle lifetime in disordered superconductors.

    SciTech Connect

    Zemlicka, M.; Neilinger, P.; Trgala, M

    We investigate the complex conductivity of a highly disordered MoC superconducting film with k(F)l approximate to 1, where k(F) is the Fermi wave number and l is the mean free path, derived from experimental transmission characteristics of coplanar waveguide resonators in a wide temperature range below the superconducting transition temperature T-c. We find that the original Mattis-Bardeen model with a finite quasiparticle lifetime, tau, offers a perfect description of the experimentally observed complex conductivity. We show that iota is appreciably reduced by scattering effects. Characteristics of the scattering centers are independently found by scanning tunneling spectroscopy and agree with thosemore » determined from the complex conductivity.« less

  16. Predicting the Lifetimes of Nuclear Waste Containers

    NASA Astrophysics Data System (ADS)

    King, Fraser

    2014-03-01

    As for many aspects of the disposal of nuclear waste, the greatest challenge we have in the study of container materials is the prediction of the long-term performance over periods of tens to hundreds of thousands of years. Various methods have been used for predicting the lifetime of containers for the disposal of high-level waste or spent fuel in deep geological repositories. Both mechanical and corrosion-related failure mechanisms need to be considered, although until recently the interactions of mechanical and corrosion degradation modes have not been considered in detail. Failure from mechanical degradation modes has tended to be treated through suitable container design. In comparison, the inevitable loss of container integrity due to corrosion has been treated by developing specific corrosion models. The most important aspect, however, is to be able to justify the long-term predictions by demonstrating a mechanistic understanding of the various degradation modes.

  17. Occupational solvent exposure and adult chronic lymphocytic leukemia: No risk in a population-based case-control study in four Nordic countries.

    PubMed

    Talibov, Madar; Auvinen, Anssi; Weiderpass, Elisabete; Hansen, Johnni; Martinsen, Jan-Ivar; Kjaerheim, Kristina; Tryggvadottir, Laufey; Pukkala, Eero

    2017-09-15

    The aim of this study was to assess the effect of occupational solvent exposure on the risk of adult chronic lymphocytic leukemia (CLL). The current case-control study was nested in the Nordic Occupational Cancer Study (NOCCA) cohort. 20,615 CLL cases diagnosed in 1961-2005 in Finland, Iceland, Norway, and Sweden, and 103,075 population-based controls matched by year of birth, sex, and country were included. Occupational histories for cases and controls were obtained from census records in 1960, 1970, 1980/1981, and 1990. Exposure to selected solvents was estimated by using the NOCCA job-exposure matrix (NOCCA-JEM). Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated by using conditional logistic regression models. Overall, nonsignificant CLL risk elevations were observed for methylene chloride, perchloroethylene, and 1,1,1-trichloroethane. Compared to unexposed, significantly increased risks were observed for cumulative perchloroethylene exposure ≤13.3 ppm-years (OR = 1.85, 95% CI 1.16-2.96) and average life-time perchloroethylene exposure ≤2.5 ppm (1.61, 95% CI 1.01-2.56) among women, and cumulative methylene chloride exposure ≤12.5 ppm-years (OR = 1.19, 95% CI 1.01-1.41) and 12.5-74.8 ppm-years (OR = 1.23, 95% CI 1.01-1.51) among men in an analysis with 5 years lag-time, though without dose-response pattern. Decreased CLL risk was observed for aliphatic and alicyclic hydrocarbon solvents and toluene. This study did not support associations for solvent exposure and CLL. Observed weak associations for methylene chloride, perchloroethylene, 1,1,1-trichloroethane exposures, aliphatic and alicyclic hydrocarbons and toluene were not consistent across sexes, and showed no gradient with amount of exposure. © 2017 UICC.

  18. Metabolic Mapping of Breast Cancer with Multiphoton Spectral and Lifetime Imaging

    DTIC Science & Technology

    2007-03-01

    spectral and lifetime characterization of NADH may be used to reveal metabolic changes in vivo and has potential to be used as an early diagnostic...combined spectral lifetime imaging modality will help for 5 characterization of breast cancer cells from cell culture based models to a relevant in... spectral and lifetime system and integrated into a multiphoton fluorescence excitation microscopy system 7 • Calibrated and characterized this

  19. Exposure to ambient air pollution and the incidence of dementia: A population-based cohort study.

    PubMed

    Chen, Hong; Kwong, Jeffrey C; Copes, Ray; Hystad, Perry; van Donkelaar, Aaron; Tu, Karen; Brook, Jeffrey R; Goldberg, Mark S; Martin, Randall V; Murray, Brian J; Wilton, Andrew S; Kopp, Alexander; Burnett, Richard T

    2017-11-01

    Emerging studies have implicated air pollution in the neurodegenerative processes. Less is known about the influence of air pollution, especially at the relatively low levels, on developing dementia. We conducted a population-based cohort study in Ontario, Canada, where the concentrations of pollutants are among the lowest in the world, to assess whether air pollution exposure is associated with incident dementia. The study population comprised all Ontario residents who, on 1 April 2001, were 55-85years old, Canadian-born, and free of physician-diagnosed dementia (~2.1 million individuals). Follow-up extended until 2013. We used population-based health administrative databases with a validated algorithm to ascertain incident diagnosis of dementia as well as prevalent cases. Using satellite observations, land-use regression model, and an optimal interpolation method, we derived long-term average exposure to fine particulate matter (≤2.5μm in diameter) (PM 2.5 ), nitrogen dioxide (NO 2 ), and ozone (O 3 ), respectively at the subjects' historical residences based on a population-based registry. We used multilevel spatial random-effects Cox proportional hazards models, adjusting for individual and contextual factors, such as diabetes, brain injury, and neighborhood income. We conducted various sensitivity analyses, such as lagging exposure up to 10years and considering a negative control outcome for which no (or weaker) association with air pollution is expected. We identified 257,816 incident cases of dementia in 2001-2013. We found a positive association between PM 2.5 and dementia incidence, with a hazard ratio (HR) of 1.04 (95% confidence interval (CI): 1.03-1.05) for every interquartile-range increase in exposure to PM 2.5 . Similarly, NO 2 was associated with increased incidence of dementia (HR=1.10; 95% CI: 1.08-1.12). No association was found for O 3 . These associations were robust to all sensitivity analyses examined. These estimates translate to 6.1% of

  20. Single photon counting fluorescence lifetime detection of pericellular oxygen concentrations

    NASA Astrophysics Data System (ADS)

    Hosny, Neveen A.; Lee, David A.; Knight, Martin M.

    2012-01-01

    Fluorescence lifetime imaging microscopy offers a non-invasive method for quantifying local oxygen concentrations. However, existing methods are either invasive, require custom-made systems, or show limited spatial resolution. Therefore, these methods are unsuitable for investigation of pericellular oxygen concentrations. This study describes an adaptation of commercially available equipment which has been optimized for quantitative extracellular oxygen detection with high lifetime accuracy and spatial resolution while avoiding systematic photon pile-up. The oxygen sensitive fluorescent dye, tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate [Ru(bipy)3]2+, was excited using a two-photon excitation laser. Lifetime was measured using a Becker & Hickl time-correlated single photon counting, which will be referred to as a TCSPC card. [Ru(bipy)3]2+ characterization studies quantified the influences of temperature, pH, cellular culture media and oxygen on the fluorescence lifetime measurements. This provided a precisely calibrated and accurate system for quantification of pericellular oxygen concentration based on measured lifetimes. Using this technique, quantification of oxygen concentrations around isolated viable chondrocytes, seeded in three-dimensional agarose gel, revealed a subpopulation of cells that exhibited significant spatial oxygen gradients such that oxygen concentration reduced with increasing proximity to the cell. This technique provides a powerful tool for quantifying spatial oxygen gradients within three-dimensional cellular models.

  1. Single photon counting fluorescence lifetime detection of pericellular oxygen concentrations.

    PubMed

    Hosny, Neveen A; Lee, David A; Knight, Martin M

    2012-01-01

    Fluorescence lifetime imaging microscopy offers a non-invasive method for quantifying local oxygen concentrations. However, existing methods are either invasive, require custom-made systems, or show limited spatial resolution. Therefore, these methods are unsuitable for investigation of pericellular oxygen concentrations. This study describes an adaptation of commercially available equipment which has been optimized for quantitative extracellular oxygen detection with high lifetime accuracy and spatial resolution while avoiding systematic photon pile-up. The oxygen sensitive fluorescent dye, tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate [Ru(bipy)(3)](2+), was excited using a two-photon excitation laser. Lifetime was measured using a Becker & Hickl time-correlated single photon counting, which will be referred to as a TCSPC card. [Ru(bipy)(3)](2+) characterization studies quantified the influences of temperature, pH, cellular culture media and oxygen on the fluorescence lifetime measurements. This provided a precisely calibrated and accurate system for quantification of pericellular oxygen concentration based on measured lifetimes. Using this technique, quantification of oxygen concentrations around isolated viable chondrocytes, seeded in three-dimensional agarose gel, revealed a subpopulation of cells that exhibited significant spatial oxygen gradients such that oxygen concentration reduced with increasing proximity to the cell. This technique provides a powerful tool for quantifying spatial oxygen gradients within three-dimensional cellular models.

  2. Systems and methods for circuit lifetime evaluation

    NASA Technical Reports Server (NTRS)

    Heaps, Timothy L. (Inventor); Sheldon, Douglas J. (Inventor); Bowerman, Paul N. (Inventor); Everline, Chester J. (Inventor); Shalom, Eddy (Inventor); Rasmussen, Robert D. (Inventor)

    2013-01-01

    Systems and methods for estimating the lifetime of an electrical system in accordance with embodiments of the invention are disclosed. One embodiment of the invention includes iteratively performing Worst Case Analysis (WCA) on a system design with respect to different system lifetimes using a computer to determine the lifetime at which the worst case performance of the system indicates the system will pass with zero margin or fail within a predetermined margin for error given the environment experienced by the system during its lifetime. In addition, performing WCA on a system with respect to a specific system lifetime includes identifying subcircuits within the system, performing Extreme Value Analysis (EVA) with respect to each subcircuit to determine whether the subcircuit fails EVA for the specific system lifetime, when the subcircuit passes EVA, determining that the subcircuit does not fail WCA for the specified system lifetime, when a subcircuit fails EVA performing at least one additional WCA process that provides a tighter bound on the WCA than EVA to determine whether the subcircuit fails WCA for the specified system lifetime, determining that the system passes WCA with respect to the specific system lifetime when all subcircuits pass WCA, and determining that the system fails WCA when at least one subcircuit fails WCA.

  3. Fluorescence lifetime imaging of skin cancer

    NASA Astrophysics Data System (ADS)

    Patalay, Rakesh; Talbot, Clifford; Munro, Ian; Breunig, Hans Georg; König, Karsten; Alexandrov, Yuri; Warren, Sean; Neil, Mark A. A.; French, Paul M. W.; Chu, Anthony; Stamp, Gordon W.; Dunsby, Chris

    2011-03-01

    Fluorescence intensity imaging and fluorescence lifetime imaging microscopy (FLIM) using two photon microscopy (TPM) have been used to study tissue autofluorescence in ex vivo skin cancer samples. A commercially available system (DermaInspect®) was modified to collect fluorescence intensity and lifetimes in two spectral channels using time correlated single photon counting and depth-resolved steady state measurements of the fluorescence emission spectrum. Uniquely, image segmentation has been used to allow fluorescence lifetimes to be calculated for each cell. An analysis of lifetime values obtained from a range of pigmented and non-pigmented lesions will be presented.

  4. Cost of traumatic brain injury in New Zealand: evidence from a population-based study.

    PubMed

    Te Ao, Braden; Brown, Paul; Tobias, Martin; Ameratunga, Shanthi; Barker-Collo, Suzanne; Theadom, Alice; McPherson, Kathryn; Starkey, Nicola; Dowell, Anthony; Jones, Kelly; Feigin, Valery L

    2014-10-28

    We aimed to estimate from a societal perspective the 1-year and lifetime direct and indirect costs of traumatic brain injury (TBI) for New Zealand (NZ) in 2010 projected to 2020. An incidence-based cost of illness model was developed using data from the Brain Injury Outcomes New Zealand in the Community Study. Details of TBI-related resource use during the first 12 months after injury were obtained for 725 cases using resource utilization information from participant surveys and medical records. Total costs are presented in US dollars year 2010 value. In 2010, 11,301 first-ever TBI cases were estimated to have occurred in NZ; total first-year cost of all new TBI cases was estimated to be US $47.9 million with total prevalence costs of US $101.4 million. The average cost per new TBI case during the first 12 months and over a lifetime was US $5,922 (95% confidence interval [CI] $4,777-$7,858), varying from US $4,636 (95% CI $3,756-$5,561) for mild cases to US $36,648 (95% CI $16,348-$65,350) for moderate/severe cases. Because of the unexpectedly large number of mild TBI cases (95% of all TBI cases), the total cost of treating these cases is nearly 3 times that of moderate/severe. The total lifetime cost of all TBI survivors in 2010 was US $146.5 million and is expected to increase to US $177.1 million in 2020. The results suggest that there is an urgent need to develop effective interventions to prevent both mild and moderate/severe TBI. © 2014 American Academy of Neurology.

  5. Waiting time disparities in breast cancer diagnosis and treatment: a population-based study in France.

    PubMed

    Molinié, F; Leux, C; Delafosse, P; Ayrault-Piault, S; Arveux, P; Woronoff, A S; Guizard, A V; Velten, M; Ganry, O; Bara, S; Daubisse-Marliac, L; Tretarre, B

    2013-10-01

    Waiting times are key indicators of a health's system performance, but are not routinely available in France. We studied waiting times for diagnosis and treatment according to patients' characteristics, tumours' characteristics and medical management options in a sample of 1494 breast cancers recorded in population-based registries. The median waiting time from the first imaging detection to the treatment initiation was 34 days. Older age, co-morbidity, smaller size of tumour, detection by organised screening, biopsy, increasing number of specimens removed, multidisciplinary consulting meetings and surgery as initial treatment were related to increased waiting times in multivariate models. Many of these factors were related to good practices guidelines. However, the strong influence of organised screening programme and the disparity of waiting times according to geographical areas were of concern. Better scheduling of diagnostic tests and treatment propositions should improve waiting times in the management of breast cancer in France. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Estimating risk factors for HIV infection among women in Mozambique using population-based survey data.

    PubMed

    Dias, Sara S; Mbofana, Francisco; Cassy, Sheyla R; Dias, Sónia; Augusto, Gonçalo F; Agadjanian, Victor; Martins, Maria R O

    2018-03-01

    The use of population-based survey data together with sound statistical methods can enhance better estimation of HIV risk factors and explain variations across subgroups of the population. The distribution and determinants of HIV infection in populations must be taken into consideration. We analysed data from the HIV Prevalence and Behaviour Survey in Mozambique aiming to find risk factors associated with HIV infection among Mozambican women. The paper provides a complex survey logistic regression model to explain the variation in HIV seropositivity using demographic, socio-economic and behavioural factors. Results show that women aged 25-29 years, living in female-headed households, living in richer households and those widowed, divorced or not living with a partner have higher odds of being HIV-positive. Findings from our study provide a unique and integrated perspective on risk factors for being HIV-positive among Mozambican women and could support the implementation of programmes aiming to reduce HIV infection in Mozambique.

  7. ASSOCIATON BETWEEN INTIMATE PARTNER VIOLENCE AND IRRITABLE BOWEL SYNDROME: A POPULATION-BASED STUDY IN NICARAGUA

    PubMed Central

    Becker-Dreps, Sylvia; Morgan, Douglas; Peña, Rodolfo; Cortes, Loreto; Martin, Christopher F.; Valladares, Eliette

    2010-01-01

    Irritable bowel syndrome (IBS) is a disabling functional gastrointestinal disorder, which serves as a model for abdominal pain syndromes. An association between intimate partner violence and IBS has been shown among Caucasian women in the industrialized world. To determine whether this relationship transcends cultural boundaries, we conducted a population-based, cross-sectional survey in Nicaragua, using the innovative Health and Demographic Surveillance System in the León province. Women who had experienced physical intimate partner violence had significantly increased risk of IBS (OR 2.08, 95% CI, 1.35, 3.21), as did those who had experienced sexual intimate partner violence (OR 2.85, 95% CI 1.45, 5.59). These findings argue for intimate partner violence screening among Latina women with IBS. PMID:20558772

  8. Association between intimate partner violence and irritable bowel syndrome: a population-based study in Nicaragua.

    PubMed

    Becker-Dreps, Sylvia; Morgan, Douglas; Peña, Rodolfo; Cortes, Loreto; Martin, Christopher F; Valladares, Eliette

    2010-07-01

    Irritable bowel syndrome (IBS) is a disabling functional gastrointestinal disorder, which serves as a model for abdominal pain syndromes. An association between intimate partner violence and IBS has been shown among White women in the industrialized world. To determine whether this relationship transcends cultural boundaries, we conducted a population-based, cross-sectional survey in Nicaragua using the innovative Health and Demographic Surveillance System in the León province. Women who had experienced physical intimate partner violence had significantly increased risk of IBS (odds ratio [OR] = 2.08; 95% confidence interval [CI] = 1.35, 3.21), as did those who had experienced sexual intimate partner violence (OR = 2.85; 95% CI = 1.45, 5.59). These findings argue for intimate partner violence screening among Latina women with IBS.

  9. SU-F-T-202: An Evaluation Method of Lifetime Attributable Risk for Comparing Between Proton Beam Therapy and Intensity Modulated X-Ray Therapy for Pediatric Cancer Patients by Averaging Four Dose-Response Models for Carcinoma Induction

    SciTech Connect

    Tamura, M; Shirato, H; Ito, Y

    Purpose: To examine how much lifetime attributable risk (LAR) as an in silico surrogate marker of radiation-induced secondary cancer would be lowered by using proton beam therapy (PBT) in place of intensity modulated x-ray therapy (IMXT) in pediatric patients. Methods: From 242 pediatric patients with cancers who were treated with PBT, 26 patients were selected by random sampling after stratification into four categories: a) brain, head, and neck, b) thoracic, c) abdominal, and d) whole craniospinal (WCNS) irradiation. IMXT was re-planned using the same computed tomography and region of interest. Using dose volume histogram (DVH) of PBT and IMXT, themore » LAR of Schneider et al. was calculated for the same patient. The published four dose-response models for carcinoma induction: i) full model, ii) bell-shaped model, iii) plateau model, and ix) linear model were tested for organs at risk. In the case that more than one dose-response model was available, the LAR for this patient was calculated by averaging LAR for each dose-response model. Results: Calculation of the LARs of PBT and IMXT based on DVH was feasible for all patients. The mean±standard deviation of the cumulative LAR difference between PBT and IMXT for the four categories was a) 0.77±0.44% (n=7, p=0.0037), b) 23.1±17.2%,(n=8, p=0.0067), c) 16.4±19.8% (n=8, p=0.0525), and d) 49.9±21.2% (n=3, p=0.0275, one tailed t-test), respectively. The LAR was significantly lower by PBT than IMXT for the the brain, head, and neck region, thoracic region, and whole craniospinal irradiation. Conclusion: In pediatric patients who had undergone PBT, the LAR of PBT was significantly lower than the LAR of IMXT estimated by in silico modeling. This method was suggested to be useful as an in silico surrogate marker of secondary cancer induced by different radiotherapy techniques. This research was supported by the Translational Research Network Program, JSPS KAKENHI Grant No. 15H04768 and the Global Institution for

  10. Radiative lifetimes and cooling functions for astrophysically important molecules

    NASA Astrophysics Data System (ADS)

    Tennyson, Jonathan; Hulme, Kelsey; Naim, Omree K.; Yurchenko, Sergei N.

    2016-02-01

    Extensive line lists generated as part of the ExoMol project are used to compute lifetimes for individual rotational, rovibrational and rovibronic excited states, and temperature-dependent cooling functions by summing over all dipole-allowed transitions for the states concerned. Results are presented for SiO, CaH, AlO, ScH, H2O and methane. The results for CH4 are particularly unusual with four excited states with no dipole-allowed decay route and several others, where these decays lead to exceptionally long lifetimes. These lifetime data should be useful in models of masers and estimates of critical densities, and can provide a link with laboratory measurements. Cooling functions are important in stellar and planet formation.

  11. Predicting a future lifetime through Box-Cox transformation.

    PubMed

    Yang, Z

    1999-09-01

    In predicting a future lifetime based on a sample of past lifetimes, the Box-Cox transformation method provides a simple and unified procedure that is shown in this article to meet or often outperform the corresponding frequentist solution in terms of coverage probability and average length of prediction intervals. Kullback-Leibler information and second-order asymptotic expansion are used to justify the Box-Cox procedure. Extensive Monte Carlo simulations are also performed to evaluate the small sample behavior of the procedure. Certain popular lifetime distributions, such as Weibull, inverse Gaussian and Birnbaum-Saunders are served as illustrative examples. One important advantage of the Box-Cox procedure lies in its easy extension to linear model predictions where the exact frequentist solutions are often not available.

  12. A New Lifetime Distribution with Bathtube and Unimodal Hazard Function

    NASA Astrophysics Data System (ADS)

    Barriga, Gladys D. C.; Louzada-Neto, Francisco; Cancho, Vicente G.

    2008-11-01

    In this paper we propose a new lifetime distribution which accommodate bathtub-shaped, unimodal, increasing and decreasing hazard function. Some special particular cases are derived, including the standard Weibull distribution. Maximum likelihood estimation is considered for estimate the tree parameters present in the model. The methodology is illustrated in a real data set on industrial devices on a lite test.

  13. Hybrid Stochastic Models for Remaining Lifetime Prognosis

    DTIC Science & Technology

    2004-08-01

    literature for techniques and comparisons. Os- ogami and Harchol-Balter [70], Perros [73], Johnson [36], and Altiok [5] provide excellent summaries of...and type of PH-distribution approximation for c2 > 0.5 is not as obvious. In order to use the minimum distance estimation, Perros [73] indicated that...moment-matching techniques. Perros [73] indicated that the maximum likelihood and minimum distance techniques require nonlinear optimization. Johnson

  14. Seroprevalence of Helicobacter pylori in Hispanics living in Puerto Rico: A population-based study.

    PubMed

    González-Pons, María; Soto-Salgado, Marievelisse; Sevilla, Javier; Márquez-Lespier, Juan M; Morgan, Douglas; Pérez, Cynthia M; Cruz-Correa, Marcia

    2018-02-01

    Helicobacter pylori is an important etiologic factor for peptic ulcers and gastric cancer, one of the top ten leading causes of cancer death in Puerto Rico. However, the prevalence of H. pylori infections in this population was previously unknown. The aim of this study was to examine the seroprevalence of H. pylori and its associated risk factors in Puerto Rico. A cross-sectional study was designed using an existing population-based biorepository. Seropositivity was determined using the Premier ™ H. pylori immunoassay. Helicobacter pylori seroprevalence was estimated with 95% confidence using marginal standardization following logistic regression. To assess the risk factors associated with H. pylori seropositivity, a multivariable log-binomial model was fitted to estimate the prevalence ratio (PR) and its 95% confidence interval (95% CI). A total of 528 population-based serum samples were analyzed. The mean age of the study population was 41 ± 12 years, of whom 55.3% were females. The overall seroprevalence of H. pylori was 33.0% (95% CI = 28.3%-38.1%). Increasing age and having <12 years of education were significantly (P < .05) associated with H. pylori seropositivity in the multivariable model; however, residing in counties with low population density reached marginal significance (P = .085). We report that H. pylori infection is common among Hispanics living in Puerto Rico. The H. pylori seroprevalence observed in Puerto Rico is similar to the seroprevalence reported in the overall population of the United States. The association between H. pylori seroprevalence and the risk factors analyzed offers insight into the epidemiology of gastric cancer in Puerto Rico and warrants further investigation. © 2017 The Authors. Helicobacter Published by John Wiley & Sons Ltd.

  15. Segmenting lung fields in serial chest radiographs using both population-based and patient-specific shape statistics.

    PubMed

    Shi, Y; Qi, F; Xue, Z; Chen, L; Ito, K; Matsuo, H; Shen, D

    2008-04-01

    This paper presents a new deformable model using both population-based and patient-specific shape statistics to segment lung fields from serial chest radiographs. There are two novelties in the proposed deformable model. First, a modified scale invariant feature transform (SIFT) local descriptor, which is more distinctive than the general intensity and gradient features, is used to characterize the image features in the vicinity of each pixel. Second, the deformable contour is constrained by both population-based and patient-specific shape statistics, and it yields more robust and accurate segmentation of lung fields for serial chest radiographs. In particular, for segmenting the initial time-point images, the population-based shape statistics is used to constrain the deformable contour; as more subsequent images of the same patient are acquired, the patient-specific shape statistics online collected from the previous segmentation results gradually takes more roles. Thus, this patient-specific shape statistics is updated each time when a new segmentation result is obtained, and it is further used to refine the segmentation results of all the available time-point images. Experimental results show that the proposed method is more robust and accurate than other active shape models in segmenting the lung fields from serial chest radiographs.

  16. Cosmology in Mr. Tompkins' Lifetime

    NASA Astrophysics Data System (ADS)

    Lindner, Rudi Paul

    2016-01-01

    Mr. Tompkins, the hero of George Gamow's most famous book, was born in the first decade of the twentieth century and lived until its end. A bank clerk by day, Mr. Tompkins had wide-ranging interests, and his curiosity led him to popular scientific presentations, and these in turn brought him a long and happy marriage to Maud, the daughter of a professor of physics. His lifetime offers an appropriate framework for a meditation on the history of cosmology during the century in which cosmology became a scientific enterprise. As it happens, Mr. Tompkins' first exposure to cosmology, in which he observed both the expansion and contraction of an oscillating universe in 1939, happened during the long night of relativity, the generation in which relativity specialists became few and, like the galaxies, far between. This talk will consider the heyday of early relativistic cosmology from 1917 to 1935, the causes and consequences of the "long night" from 1935 until 1963, and the renaissance of cosmology, which, occurring as it did upon the retirement of Mr. Tompkins, afforded him great pleasure in his later years.

  17. Lifetime Evolution of UV Jets

    NASA Technical Reports Server (NTRS)

    Corti, G.; Poletto, G.; Suess, S. T.; Moore, R.; Sterling, A.

    2006-01-01

    We report on observations acquired in May 2003 during a SOHO-Ulysses quadrature campaign. From May 25 to May 28, the SoHO LASCO Coronal Mass Ejection (CME) catalog lists a number of events which might have been observed by SOHO/UVCS, whose slit was centered along the Ulysses direction. However, because of time gaps in the observing schedule, or because of the unfavorable position of some CMEs, the most interesting events recorded by UVCS were a few short-lived ejections that represent the extension at higher altitudes of recursive EIT jets. We focus on jets occurring on May 26/27, visible also in EIT and LASCO images, which seem to propagate along the radial to Ulysses. UVCS spectra at 1.7 Rsun showed an unusually high emission in cool lines, lasting for about 10 to 25 minutes, with no evidence of hot plasma. Analysis of the cool line emission allowed us to infer the evolution of physical parameters during the jets lifetime and derive a crude estimate of the energy needed to account for their properties. We also looked for any evidence of the event in in situ data. Whether UVCS is observing jets or narrow CMEs is discussed in the contest of previous works on these classes of events and, in the last Section, we propose a scenario that accounts for our observations.

  18. Aspects of silicon bulk lifetimes

    NASA Technical Reports Server (NTRS)

    Landsberg, P. T.

    1985-01-01

    The best lifetimes attained for bulk crytalline silicon as a function of doping concentrations are analyzed. It is assumed that the dopants which set the Fermi level do not contribute to the recombination traffic which is due to the unknown defect. This defect is assumed to have two charge states: neutral and negative, the neutral defect concentration is frozen-in at some temperature T sub f. The higher doping concentrations should include the band-band Auger effect by using a generalization of the Shockley-Read-Hall (SRH) mechanism. The generalization of the SRH mechanism is discussed. This formulation gives a straightforward procedure for incorporating both band-band and band-trap Auger effects in the SRH procedure. Two related questions arise in this context: (1) it may sometimes be useful to write the steady-state occupation probability of the traps implied by SRH procedure in a form which approximates to the Fermi-Dirac distribution; and (2) the effect on the SRH mechanism of spreading N sub t levels at one energy uniformly over a range of energies is discussed.

  19. Lifetime measurement in ^170Yb

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Krücken, R.; Beausang, C. W.; Casten, R. F.; Cooper, J. R.; Cederkäll, J.; Caprio, M.; Novak, J. R.; Zamfir, N. V.; Barton, C.

    1999-10-01

    The nature of the low lying K^π=0^+ excitations in deformed nuclei have recently been subject of intense discussion. In this context we present results from a Coulomb excitation experiment on ^170Yb using a 70MeV ^16O beam on a gold backed, 1.5 mg/cm^2 thick ^170Yb target. The beam was delivered by the ESTU tandem accelerator of WNSL at Yale University. Gamma rays were detected by the YRAST Ball array in coincidence with back-scattered ^16O particles, which were detected in an array of 8 solar cells. Lineshapes were observed for several transitions from collective states in ^170Yb and the lifetimes for those states were extracted using a standard DSAM analysis. The results will be presented together with a short introduction to the solar cell array at Yale (SCARY) that was used to make angular selection of the excited ^170Yb nuclei. This work is supported by the US-DOE under grant numbers DE-FG02-91ER-40609 and DE-FG02-88ER-40417.

  20. Population-Based Study of Sleep Apnea in Pregnancy and Maternal and Infant Outcomes

    PubMed Central

    Bin, Yu Sun; Cistulli, Peter A.; Ford, Jane B.

    2016-01-01

    Study Objectives: To examine the association between sleep apnea and pregnancy outcomes in a large population-based cohort. Methods: Population-based cohort study using linked birth and hospital records was conducted in New South Wales, Australia. Participants were all women who gave birth from 2002 to 2012 (n = 636,227). Sleep apnea in the year before pregnancy or during pregnancy was identified from hospital records. Outcomes of interest were gestational diabetes, pregnancy hypertension, planned delivery, caesarean section, preterm birth, perinatal death, 5-minute Apgar score, admission to neonatal intensive care or special care nursery, and infant size for gestational age. Maternal outcomes were identified using a combination of hospital and birth records. Infant outcomes came from the birth record. Modified Poisson regression models were used to examine associations between sleep apnea and each outcome taking into account maternal age, country of birth, socioeconomic disadvantage, smoking, obesity, parity, pre-existing diabetes and hypertension. Results: Sleep apnea was significantly associated with pregnancy hypertension (adjusted RR 1.43; 95% CI 1.18–1.73), planned delivery (1.15; 1.07–1.23), preterm birth (1.50; 1.21–1.84), 5-minute Apgar < 7 (1.60; 1.07–2.38), admission to neonatal intensive care/special care nursery (1.26; 1.11–1.44), large-for-gestational-age infants (1.27; 1.04–1.55) but not with gestational diabetes (1.09; 0.82–1.46), caesarean section (1.06; 0.96–1.17), perinatal death (1.73; 0.92–3.25), or small-for-gestational-age infants (0.81; 0.61–1.08). Conclusions: Sleep apnea is associated with higher rates of obstetric complications and intervention, as well as preterm delivery. Future research should examine if these are independent of obstetric history. Citation: Bin YS, Cistulli PA, Ford JB. Population-based study of sleep apnea in pregnancy and maternal and infant outcomes. J Clin Sleep Med 2016;12(6):871–877. PMID

  1. Cardiovascular Disease Mortality After Chemotherapy or Surgery for Testicular Nonseminoma: A Population-Based Study

    PubMed Central

    Fung, Chunkit; Fossa, Sophie D.; Milano, Michael T.; Sahasrabudhe, Deepak M.; Peterson, Derick R.; Travis, Lois B.

    2015-01-01

    Purpose Increased risks of incident cardiovascular disease (CVD) in patients with testicular cancer (TC) given chemotherapy in European studies were largely restricted to long-term survivors and included patients from the 1960s. Few population-based investigations have quantified CVD mortality during, shortly after, and for two decades after TC diagnosis in the era of cisplatin-based chemotherapy. Patients and Methods Standardized mortality ratios (SMRs) for CVD and absolute excess risks (AERs; number of excess deaths per 10,000 person-years) were calculated for 15,006 patients with testicular nonseminoma reported to the population-based Surveillance, Epidemiology, and End Results program (1980 to 2010) who initially received chemotherapy (n = 6,909) or surgery (n = 8,097) without radiotherapy and accrued 60,065 and 81,227 person-years of follow-up, respectively. Multivariable modeling evaluated effects of age, treatment, extent of disease, and other factors on CVD mortality. Results Significantly increased CVD mortality occurred after chemotherapy (SMR, 1.36; 95% CI, 1.03 to 1.78; n = 54) but not surgery (SMR, 0.81; 95% CI, 0.60 to 1.07; n = 50). Significant excess deaths after chemotherapy were restricted to the first year after TC diagnosis (SMR, 5.31; AER, 13.90; n = 11) and included cerebrovascular disease (SMR, 21.72; AER, 7.43; n = 5) and heart disease (SMR, 3.45; AER, 6.64; n = 6). In multivariable analyses, increased CVD mortality after chemotherapy was confined to the first year after TC diagnosis (hazard ratio, 4.86; 95% CI, 1.25 to 32.08); distant disease (P < .05) and older age at diagnosis (P < .01) were independent risk factors. Conclusion This is the first population-based study, to our knowledge, to quantify short- and long-term CVD mortality after TC diagnosis. The increased short-term risk of CVD deaths should be further explored in analytic studies that enumerate incident events and can serve to develop comprehensive evidence-based approaches

  2. Air toxics and early childhood acute lymphocytic leukemia in Texas, a population based case control study.

    PubMed

    Symanski, Elaine; Tee Lewis, P Grace; Chen, Ting-Yu; Chan, Wenyaw; Lai, Dejian; Ma, Xiaomei

    2016-06-14

    Traffic exhaust, refineries and industrial facilities are major sources of air toxics identified by the U.S. Environmental Protection Agency (U.S. EPA) for their potential risk to human health. In utero and early life exposures to air toxics such as benzene and 1,3-butadiene, which are known leukemogens in adults, may play an etiologic role in childhood leukemia that comprises the majority of pediatric cancers. We conducted a population based case-control study to examine individual effects of benzene, 1,3-butadiene and polycyclic organic matter (POM) in ambient residential air on acute lymphocytic leukemia (ALL) diagnosed in children under age 5 years in Texas from 1995-2011. Texas Cancer Registry cases were linked to birth records and then were frequency matched by birth month and year to 10 population-based controls. Maternal and infant characteristics from birth certificates were abstracted to obtain information about potential confounders. Modelled estimates of benzene, 1,3-butadiene and POM exposures at the census tract level were assigned by linking geocoded maternal addresses from birth certificates to U.S. EPA National-Scale Air Toxics Assessment data for single and co-pollutant statistical analyses. Mixed-effects logistic regression models were applied to evaluate associations between air toxics and childhood leukemia. In adjusted single pollutant models, odds of childhood leukemia among mothers with the highest ambient air exposures compared to those in the lowest quartile were 1.11 (95 % CI: 0.94-1.32) for POM, 1.17 (95 % CI: 0.98-1.39) for benzene and 1.29 (95 % CI: 1.08-1.52) for 1,3-butadiene. In co-pollutant models, odds ratios for childhood leukemia remained elevated for 1,3-butadiene but were close to the null value for benzene and POM. We observed positive associations between 1,3-butadiene and childhood leukemia in single and co-pollutant models whereas effect estimates from single pollutant models were diminished for benzene and POM in co

  3. Non-invasive imaging of skin cancer with fluorescence lifetime imaging using two photon tomography

    NASA Astrophysics Data System (ADS)

    Patalay, Rakesh; Talbot, Clifford; Alexandrov, Yuriy; Munro, Ian; Breunig, Hans Georg; König, Karsten; Warren, Sean; Neil, Mark A. A.; French, Paul M. W.; Chu, Anthony; Stamp, Gordon W.; Dunsby, Christopher

    2011-07-01

    Multispectral fluorescence lifetime imaging (FLIM) using two photon microscopy as a non-invasive technique for the diagnosis of skin lesions is described. Skin contains fluorophores including elastin, keratin, collagen, FAD and NADH. This endogenous contrast allows tissue to be imaged without the addition of exogenous agents and allows the in vivo state of cells and tissues to be studied. A modified DermaInspect® multiphoton tomography system was used to excite autofluorescence at 760 nm in vivo and on freshly excised ex vivo tissue. This instrument simultaneously acquires fluorescence lifetime images in four spectral channels between 360-655 nm using time-correlated single photon counting and can also provide hyperspectral images. The multispectral fluorescence lifetime images were spatially segmented and binned to determine lifetimes for each cell by fitting to a double exponential lifetime model. A comparative analysis between the cellular lifetimes from different diagnoses demonstrates significant diagnostic potential.

  4. Rapid Global Fitting of Large Fluorescence Lifetime Imaging Microscopy Datasets

    PubMed Central

    Warren, Sean C.; Margineanu, Anca; Alibhai, Dominic; Kelly, Douglas J.; Talbot, Clifford; Alexandrov, Yuriy; Munro, Ian; Katan, Matilda

    2013-01-01

    Fluorescence lifetime imaging (FLIM) is widely applied to obtain quantitative information from fluorescence signals, particularly using Förster Resonant Energy Transfer (FRET) measurements to map, for example, protein-protein interactions. Extracting FRET efficiencies or population fractions typically entails fitting data to complex fluorescence decay models but such experiments are frequently photon constrained, particularly for live cell or in vivo imaging, and this leads to unacceptable errors when analysing data on a pixel-wise basis. Lifetimes and population fractions may, however, be more robustly extracted using global analysis to simultaneously fit the fluorescence decay data of all pixels in an image or dataset to a multi-exponential model under the assumption that the lifetime components are invariant across the image (dataset). This approach is often considered to be prohibitively slow and/or computationally expensive but we present here a computationally efficient global analysis algorithm for the analysis of time-correlated single photon counting (TCSPC) or time-gated FLIM data based on variable projection. It makes efficient use of both computer processor and memory resources, requiring less than a minute to analyse time series and multiwell plate datasets with hundreds of FLIM images on standard personal computers. This lifetime analysis takes account of repetitive excitation, including fluorescence photons excited by earlier pulses contributing to the fit, and is able to accommodate time-varying backgrounds and instrument response functions. We demonstrate that this global approach allows us to readily fit time-resolved fluorescence data to complex models including a four-exponential model of a FRET system, for which the FRET efficiencies of the two species of a bi-exponential donor are linked, and polarisation-resolved lifetime data, where a fluorescence intensity and bi-exponential anisotropy decay model is applied to the analysis of live cell

  5. Modelling of the urban concentrations of PM2.5 on a high resolution for a period of 35 years, for the assessment of lifetime exposure and health effects

    NASA Astrophysics Data System (ADS)

    Kukkonen, Jaakko; Kangas, Leena; Kauhaniemi, Mari; Sofiev, Mikhail; Aarnio, Mia; Jaakkola, Jouni J. K.; Kousa, Anu; Karppinen, Ari

    2018-06-01

    Reliable and self-consistent data on air quality are needed for an extensive period of time for conducting long-term, or even lifetime health impact assessments. We have modelled the urban-scale concentrations of fine particulate matter (PM2.5) in the Helsinki Metropolitan Area for a period of 35 years, from 1980 to 2014. The regional background concentrations were evaluated based on reanalyses of the atmospheric composition on global and European scales, using the SILAM model. The high-resolution urban computations included both the emissions originated from vehicular traffic (separately exhaust and suspension emissions) and those from small-scale combustion, and were conducted using the road network dispersion model CAR-FMI and the multiple-source Gaussian dispersion model UDM-FMI. The modelled concentrations of PM2.5 agreed fairly well with the measured data at a regional background station and at four urban measurement stations, during 1999-2014. The modelled concentration trends were also evaluated for earlier years, until 1988, using proxy analyses. There was no systematic deterioration of the agreement of predictions and data for earlier years (the 1980s and 1990s), compared with the results for more recent years (2000s and early 2010s). The local vehicular emissions were about 5 times higher in the 1980s, compared with the emissions during the latest considered years. The local small-scale combustion emissions increased slightly over time. The highest urban concentrations of PM2.5 occurred in the 1980s; these have since decreased to about to a half of the highest values. In general, regional background was the largest contribution in this area. Vehicular exhaust has been the most important local source, but the relative shares of both small-scale combustion and vehicular non-exhaust emissions have increased in time. The study has provided long-term, high-resolution concentration databases on regional and urban scales that can be used for the assessment of

  6. Predictors of Cerebral Palsy in Very Preterm Infants: The EPIPAGE Prospective Population-Based Cohort Study

    ERIC Educational Resources Information Center

    Beaino, Ghada; Khoshnood, Babak; Kaminski, Monique; Pierrat, Veronique; Marret, Stephane; Matis, Jacqueline; Ledesert, Bernard; Thiriez, Gerard; Fresson, Jeanne; Roze, Jean-Christophe; Zupan-Simunek, Veronique; Arnaud, Catherine; Burguet, Antoine; Larroque, Beatrice; Breart, Gerard; Ancel, Pierre-Yves

    2010-01-01

    Aim: The aim of this study was to assess the independent role of cerebral lesions on ultrasound scan, and several other neonatal and obstetric factors, as potential predictors of cerebral palsy (CP) in a large population-based cohort of very preterm infants. Method: As part of EPIPAGE, a population-based prospective cohort study, perinatal data…

  7. Epidemiology of kidney stones in Iceland: a population-based study.

    PubMed

    Indridason, Olafur S; Birgisson, Sigurjon; Edvardsson, Vidar O; Sigvaldason, Helgi; Sigfusson, Nikulas; Palsson, Runolfur

    2006-01-01

    The prevalence of kidney stones varies greatly between ethnic groups and geographic locations, ranging from 8% to 19% in males and from 3% to 5% in females in Western countries. The aim of this study was to examine the epidemiology of kidney stones in Iceland. Data were derived from the Reykjavik Study, a population-based cohort study carried out between 1967 and 1991. All subjects answered a thorough questionnaire concerning their medical history at each visit. The lifetime prevalence of kidney stones was calculated based on the answer to the question "Have you ever been diagnosed with a kidney stone?" at each person's first visit. Incidence was calculated based on answers from subjects who had made two or more visits. Prevalence and incidence were age-standardized to the truncated world population. Family history of kidney stones was also evaluated. A total of 9039 men aged 33-80 years and 9619 women aged 33-81 years participated. Of these, 423 males and 307 females had a history of kidney stones (p=0.001). Prevalence increased significantly with age for both genders. Men aged 30-34 years had a prevalence of 2.9%, compared to 8.8% for those aged 65-69 years, whereas corresponding values for women were 2.5% and 5.0%. The age-standardized prevalence for the 30-79 years age group was 4.3% for men and 3.0% for women. No significant increase in prevalence was observed over time. The incidence was 562 per 100 000 per year among men and increased significantly with age. The incidence among women was 197 per 100 000 per year and did not differ between age groups. A family history of nephrolithiasis was present in 25% of subjects with a history of kidney stones, and in 4% of those without. The incidence and prevalence of kidney stones in Icelandic women are similar to those that have been reported in other Western countries. The prevalence among men is lower that in neighboring countries but the incidence is similar. A strong family history of kidney stones suggests a

  8. Incidence and Risk Factors of Insomnia in a Population-Based Sample

    PubMed Central

    LeBlanc, Mélanie; Mérette, Chantal; Savard, Josée; Ivers, Hans; Baillargeon, Lucie; Morin, Charles M.

    2009-01-01

    effective public health prevention and intervention programs to promote better sleep quality. Citation: LeBlanc M; Mérette C; Savard J; Ivers H; Baillargeon L; Morin CM. Incidence and risk factors of insomnia in a population-based sample. SLEEP 2009;32(8):1027-1037. PMID:19725254

  9. Self-esteem and Mortality: Prospective Evidence from a Population-based Study

    PubMed Central

    STAMATAKIS, KATHERINE A.; LYNCH, JOHN; EVERSON, SUSAN A.; RAGHUNATHAN, TRIVELLORE; SALONEN, JUKKA T.; KAPLAN, GEORGE A.

    2011-01-01

    OBJECTIVE Self-esteem is considered to be importantly associated with both psychosocial states such as depression as well as physical health. There are no population-based studies that examine the association between self-esteem and mortality. The objective of this study was to assess whether low self-esteem was prospectively associated with increased risk of death in a population-based sample of Finnish men. METHODS A sample of 2682 male residents of Kuopio, Finland were interviewed and followed prospectively as part of the Kuopio Ischemic Heart Disease Risk Factor Study (KIHD). Characteristics of the KIHD sample at baseline included self-esteem, measured by the Rosenberg ten-item scale, socioeconomic factors, behavioral risk factors, other psychosocial characteristics, and prevalent diseases. Mortality was ascertained through linkage to the Finnish national death registry. We assessed the relationship between self-esteem and all-cause mortality using Cox proportional hazards models. RESULTS Low self-esteem was associated with a two-fold [hazard ratio (HR) = 2.0, 95% confidence interval (CI) = 1.3–3.2] increase in age-adjusted mortality. This relationship was partially explained by behavioral and socioeconomic factors, and prevalent diseases, and fully explained by other psychosocial characteristics (hopelessness, depression, cynical hostility, and sullenness). When adjusted for hopelessness alone there was no increased risk associated with low self-esteem (HR = 1.3, 95% CI = 0.8–2.2). CONCLUSIONS This study found no association between self-esteem and all-cause mortality after adjustment for other psychosocial characteristics, primarily hopelessness. Our understanding of the observed relationships between some psychosocial factors and mortality may be improved by simultaneous measurement of multiple psychosocial domains, thus diminishing the potential for residual confounding. PMID:14664781

  10. Migraine and Mental Health in a Population-Based Sample of Adolescents.

    PubMed

    Orr, Serena L; Potter, Beth K; Ma, Jinhui; Colman, Ian

    2017-01-01

    To explore the relationship between migraine and anxiety disorders, mood disorders and perceived mental health in a population-based sample of adolescents. The Canadian Community Health Survey (CCHS) is a cross-sectional health survey sampling a nationally representative group of Canadians. In this observational study, data on all 61,375 participants aged 12-19 years from six survey cycles were analyzed. The relationships between self-reported migraine, perceived mental health, and mood/anxiety disorders were modeled using univariate and multivariate logistic regression. The migraine-depression association was also explored in a subset of participants using the Composite International Diagnostic Interview-Short Form (CIDI-SF) depression scale. The odds of migraine were higher among those with mood disorders, with the strongest association in 2011-2 (adjusted odds ratio [aOR]=4.59; 95% confidence interval [CI 95%]=3.44-6.12), and the weakest in 2009-10 (aOR=3.06, CI 95%=2.06-4.55). The migraine-mood disorders association was also significant throughout all cycles, other than 2011-2, when the CIDI-SF depression scale was employed. The odds of migraine were higher among those with anxiety disorders, with the strongest association in 2011-2 (aOR=4.21, CI 95%=3.31-5.35) and the weakest in 2010 (aOR=1.87, CI 95%=1.10-3.37). The inverse association between high perceived mental health and the odds of migraine was observed in all CCHS cycles, with the strongest association in 2011-2 (aOR=0.58, CI 95%=0.48-0.69) and the weakest in 2003-4 (aOR=0.75, CI 95%=0.62-0.91). This study provides evidence, derived from a large population-based sample of adolescents, for a link between migraine and mood/anxiety disorders.

  11. Population-based studies of antithyroid drugs and sudden cardiac death

    PubMed Central

    van Noord, Charlotte; Sturkenboom, Miriam C J M; Straus, Sabine M J M; Hofman, Albert; Witteman, Jacqueline C M; Stricker, Bruno H Ch

    2009-01-01

    AIM Thyroid free T4 is associated with QTc-interval prolongation, which is a risk factor for sudden cardiac death (SCD). Hyperthyroidism has been associated with SCD in case reports, but there are no population-based studies confirming this. The aim was to investigate whether use of antithyroid drugs (as a direct cause or as an indicator of poorly controlled hyperthyroidism) is associated with an increased risk of SCD. METHODS We studied the occurrence of SCD in a two-step procedure in two different Dutch populations. First, the prospective population-based Rotterdam Study including 7898 participants (≥55 years old). Second, we used the Integrated Primary Care Information (IPCI) database, which is a longitudinal general practice research database to see whether we could replicate results from the first study. Drug use at the index date was assessed with prescription information from automated pharmacies (Rotterdam Study) or drug prescriptions from general practices (IPCI). We used a Cox proportional hazards model in a cohort analysis, adjusted for age, gender and use of QTc prolonging drugs (Rotterdam Study) and conditional logistic regression analysis in a case–control analysis, matched for age, gender, practice and calendar time and adjusted for arrhythmia and cerebrovascular ischaemia (IPCI). RESULTS In the Rotterdam Study, 375 participants developed SCD during follow-up. Current use of antithyroid drugs was associated with SCD [adjusted hazard ratio 3.9; 95% confidence interval (CI) 1.7, 8.7]. IPCI included 1424 cases with SCD and 14 443 controls. Also in IPCI, current use of antithyroid drugs was associated with SCD (adjusted odds ratio 2.9; 95% CI 1.1, 7.4). CONCLUSIONS Use of antithyroid drugs was associated with a threefold increased risk of SCD. Although this might be directly caused by antithyroid drug use, it might be more readily explained by underlying poorly controlled hyperthyroidism, since treated patients who developed SCD still had low thyroid

  12. Organization of population-based cancer control programs: Europe and the world.

    PubMed

    Otter, Renée; Qiao, You-Lin; Burton, Robert; Samiei, Massoud; Parkin, Max; Trapido, Edward; Weller, David; Magrath, Ian; Sutcliffe, Simon

    2009-01-01

    As cancer is to a large extent avoidable and treatable, a cancer control program should be able to reduce mortality and morbidity and improve the quality of life of cancer patients and their families. However, the extent to which the goals of a cancer control program can be achieved will depend on the resource constraints a country faces. Such population-based cancer control plans should prioritize effective interventions and programs that are beneficial to the largest part of the population, and should include activities devoted to prevention, screening and early detection, treatment, palliation and end-of-life care, and rehabilitation. In order to develop a successful cancer control program, leadership and the relevant stakeholders, including patient organizations, need to be identified early on in the process so that all partners can take ownership and responsibility for the program. Various tools have been developed to aid them in the planning and implementation process. However, countries developing a national cancer control program would benefit from a discussion of different models for planning and delivery of population-based cancer control in settings with differing levels of resource commitment, in order to determine how best to proceed given their current level of commitment, political engagement and resources. As the priority assigned to different components of cancer control will differ depending on available resources and the burden and pattern of cancer, it is important to consider the relative roles of prevention, early detection, diagnosis, treatment, rehabilitation and palliative care in a cancer control program, as well as how to align available resources to meet prioritized needs. Experiences from countries with differing levels of resources are presented and serve to illustrate the difficulties in developing and implementing cancer control programs, as well as the innovative strategies that are being used to maximize available resources and

  13. Exploratory factor analysis of self-reported symptoms in a large, population-based military cohort

    PubMed Central

    2010-01-01

    Background US military engagements have consistently raised concern over the array of health outcomes experienced by service members postdeployment. Exploratory factor analysis has been used in studies of 1991 Gulf War-related illnesses, and may increase understanding of symptoms and health outcomes associated with current military conflicts in Iraq and Afghanistan. The objective of this study was to use exploratory factor analysis to describe the correlations among numerous physical and psychological symptoms in terms of a smaller number of unobserved variables or factors. Methods The Millennium Cohort Study collects extensive self-reported health data from a large, population-based military cohort, providing a unique opportunity to investigate the interrelationships of numerous physical and psychological symptoms among US military personnel. This study used data from the Millennium Cohort Study, a large, population-based military cohort. Exploratory factor analysis was used to examine the covariance structure of symptoms reported by approximately 50,000 cohort members during 2004-2006. Analyses incorporated 89 symptoms, including responses to several validated instruments embedded in the questionnaire. Techniques accommodated the categorical and sometimes incomplete nature of the survey data. Results A 14-factor model accounted for 60 percent of the total variance in symptoms data and included factors related to several physical, psychological, and behavioral constructs. A notable finding was that many factors appeared to load in accordance with symptom co-location within the survey instrument, highlighting the difficulty in disassociating the effects of question content, location, and response format on factor structure. Conclusions This study demonstrates the potential strengths and weaknesses of exploratory factor analysis to heighten understanding of the complex associations among symptoms. Further research is needed to investigate the relationship between

  14. Two-Year Outcomes of a Population-Based Intervention for Preschool Language Delay: An RCT.

    PubMed

    Wake, Melissa; Levickis, Penny; Tobin, Sherryn; Gold, Lisa; Ukoumunne, Obioha C; Goldfeld, Sharon; Zens, Naomi; Le, Ha N D; Law, James; Reilly, Sheena

    2015-10-01

    We have previously shown short-term benefits to phonology, letter knowledge, and possibly expressive language from systematically ascertaining language delay at age 4 years followed by the Language for Learning intervention. Here, we report the trial's definitive 6-year outcomes. Randomized trial nested in a population-based ascertainment. Children with language scores >1.25 SD below the mean at age 4 were randomized, with intervention children receiving 18 1-hour home-based therapy sessions. Primary outcome was receptive/expressive language. Secondary outcomes were phonological, receptive vocabulary, literacy, and narrative skills; parent-reported pragmatic language, behavior, and health-related quality of life; costs of intervention; and health service use. For intention-to-treat analyses, trial arms were compared using linear regression models. Of 1464 children assessed at age 4, 266 were eligible and 200 randomized; 90% and 82% of intervention and control children were retained respectively. By age 6, mean language scores had normalized, but there was little evidence of a treatment effect for receptive (adjusted mean difference 2.3; 95% confidence interval [CI] -1.2 to 5.7; P = .20) or expressive (0.8; 95% CI -1.6 to 3.2; P = .49) language. Of the secondary outcomes, only phonological awareness skills (effect size 0.36; 95% CI 0.08-0.65; P = .01) showed benefit. Costs were higher for intervention families (mean difference AU$4276; 95% CI: $3424 to $5128). Population-based intervention targeting 4-year-old language delay was feasible but did not have lasting impacts on language, possibly reflecting resolution in both groups. Long-term literacy benefits remain possible but must be weighed against its cost. Copyright © 2015 by the American Academy of Pediatrics.

  15. Survival in pediatric medulloblastoma: a population-based observational study to improve prognostication.

    PubMed

    Weil, Alexander G; Wang, Anthony C; Westwick, Harrison J; Ibrahim, George M; Ariani, Rojine T; Crevier, Louis; Perreault, Sebastien; Davidson, Tom; Tseng, Chi-Hong; Fallah, Aria

    2017-03-01

    Medulloblastoma is the most common form of brain malignancy of childhood. The mainstay of epidemiological data regarding childhood medulloblastoma is derived from case series, hence population-based studies are warranted to improve the accuracy of survival estimates. To utilize a big-data approach to update survival estimates in a contemporary cohort of children with medulloblastoma. We performed a population-based retrospective observational cohort study utilizing the Surveillance, Epidemiology, and End Results Program database that captures all children, less than 20 years of age, between 1973 and 2012 in 18 geographical regions representing 28% of the US population. We included all participants with a presumed or histologically diagnosis of medulloblastoma. The main outcome of interest is survivors at 1, 5 and 10 years following diagnosis. A cohort of 1735 children with a median (interquartile range) age at diagnosis of 7 (4-11) years, with a diagnosis of medulloblastoma were identified. The incidence and prevalence of pediatric medulloblastoma has remained stable over the past 4 decades. There is a critical time point at 1990 when the overall survival has drastically improved. In the contemporary cohort (1990 onwards), the percentage of participants alive was 86, 70 and 63% at 1, 5 and 10 years, respectively. Multivariate Cox-Regression model demonstrated Radiation (HR 0.37; 95% CI 0.30-0.46, p < 0.001) and Surgery (HR 0.42; 95% CI 0.30-0.58, p < 0.001) independently predict survival. The probability of mortality from a neurological cause is <5% in patients who are alive 8 years following diagnosis. The SEER cohort analysis demonstrates significant improvements in pediatric medulloblastoma survival. In contrast to previous reports, the majority of patients survive in the modern era, and those alive 8 years following initial diagnosis are likely a long-term survivor. The importance of minimizing treatment-related toxicity is increasingly apparent given

  16. Atopic disorders and depression: findings from a large, population-based study.

    PubMed

    Sanna, Livia; Stuart, Amanda L; Pasco, Julie A; Jacka, Felice N; Berk, Michael; Maes, Michael; O'Neil, Adrienne; Girardi, Paolo; Williams, Lana J

    2014-02-01

    Atopy, a common disorder characterized by a sensitivity to allergic reactions, affects a large proportion of the adult population and, as with depression, is associated with immune-inflammatory pathway changes. We sought to determine the role of atopic disorders in depression using data from a randomly-selected, population-based study of men and women. Cross-sectional data derived from the Geelong Osteoporosis Study for 942 males and 1085 females were analyzed. Depression [major depressive disorder (MDD), minor depression and dysthymia] was assessed using the Structured Clinical Interview for DSM-IV-TR Research Version, Non-patient edition. Data on medical conditions, including atopic disorders (asthma, hay fever and eczema), smoking status, alcohol consumption, socioeconomic status, and physical activity were documented by self-report. Logistic regression modeling was used to explore the associations between atopic disorders and depression. Atopic disorders were associated with a 59% increased likelihood of depression [gender and smoking-adjusted odds ratio (OR) 1:50, 95% CI 1.20-1.97]. Sub-group analyses revealed a similar pattern for those with MDD [gender and smoking-adjusted OR 1:54, 95% CI 1.22-1.94]. These associations were independent of socio-demographic characteristics, clinical and lifestyle factors. Reliance on self-report for allergic symptoms and cross-sectional nature of study. This population-based study provides evidence of the potential contribution of allergic disorders to depression. Further research is required to elucidate the direction of this association and to further explicate its underlying physiology, including immune-inflammation markers. © 2013 Published by Elsevier B.V.

  17. Physical Activity as Protective Factor against Dementia: A Prospective Population-Based Study (NEDICES).

    PubMed

    Llamas-Velasco, Sara; Contador, Israel; Villarejo-Galende, Alberto; Lora-Pablos, David; Bermejo-Pareja, Félix

    2015-11-01

    The aim of this study was to analyze whether physical activity (PA) is a protective factor for the incidence of dementia after 3 years of follow-up. The Neurological Disorders in Central Spain (NEDICES) is a prospective population-based survey of older adults (age 65 years and older) that comprised 5278 census-based participants at baseline (1994-1995). A broad questionnaire was used to assess participants' sociodemographic characteristics, health status, and lifestyle. Subsequently, a modified version of Rosow-Breslau questionnaire was applied to classify individuals' baseline PA into groups (i.e., sedentary, light, moderate, and high). Cox regression models adjusted for several covariates (age, sex, education, previous stroke, alcohol consumption, hypertension, health related variables) were carried out to estimate the association between the PA groups and risk of dementia at the 3-year follow-up (1997-1998). A total of 134 incident dementia cases were identified among 3105 individuals (56.6% female; mean age=73.15 ± 6.26) after 3 years. Hazard ratios (HRs) of the light, moderate, and high PA groups (vs. sedentary group) were 0.40 (95% confidence interval {CI} [0.26, 0.62]; p<.001), 0.32 (95% CI [0.20, 0.54]; p<.001) and 0.23 (95% CI [0.13, 0.40]; p<.001), respectively. Even after controlling for covariates and the exclusion of doubtful dementia cases, HRs remained significant. However, a supplementary analysis showed that the dose-effect hypothesis did not reach statistical significance. PA is a protective factor of incident dementia in this population-based cohort.

  18. The Global Incidence of Appendicitis: A Systematic Review of Population-based Studies.

    PubMed

    Ferris, Mollie; Quan, Samuel; Kaplan, Belle S; Molodecky, Natalie; Ball, Chad G; Chernoff, Greg W; Bhala, Nij; Ghosh, Subrata; Dixon, Elijah; Ng, Siew; Kaplan, Gilaad G

    2017-08-01

    We compared the incidence of appendicitis or appendectomy across the world and evaluated temporal trends. Population-based studies reported the incidence of appendicitis. We searched MEDLINE and EMBASE databases for population-based studies reporting the incidence of appendicitis or appendectomy. Time trends were explored using Poisson regression and reported as annual percent change (APC) with 95% confidence intervals (CI). APC were stratified by time periods and pooled using random effects models. Incidence since 2000 was pooled for regions in the Western world. The search retrieved 10,247 citations with 120 studies reporting on the incidence of appendicitis or appendectomy. During the 21st century the pooled incidence of appendicitis or appendectomy (in per 100,000 person-years) was 100 (95% CI: 91, 110) in Northern America, and the estimated number of cases in 2015 was 378,614. The pooled incidence ranged from 105 in Eastern Europe to 151 in Western Europe. In Western countries, the incidence of appendectomy steadily decreased since 1990 (APC after 1989=-1.54; 95% CI: -2.22, -0.86), whereas the incidence of appendicitis stabilized (APC=-0.36; 95% CI: -0.97, 0.26) for both perforated (APC=0.95; 95% CI: -0.25, 2.17) and nonperforated appendicitis (APC=0.44; 95% CI: -0.84, 1.73). In the 21st century, the incidence of appendicitis or appendectomy is high in newly industrialized countries in Asia (South Korea pooled: 206), the Middle East (Turkey pooled: 160), and Southern America (Chile: 202). Appendicitis is a global disease. The incidence of appendicitis is stable in most Western countries. Data from newly industrialized countries is sparse, but suggests that appendicitis is rising rapidly.

  19. An intelligent case-adjustment algorithm for the automated design of population-based quality auditing protocols.

    PubMed

    Advani, Aneel; Jones, Neil; Shahar, Yuval; Goldstein, Mary K; Musen, Mark A

    2004-01-01

    We develop a method and algorithm for deciding the optimal approach to creating quality-auditing protocols for guideline-based clinical performance measures. An important element of the audit protocol design problem is deciding which guide-line elements to audit. Specifically, the problem is how and when to aggregate individual patient case-specific guideline elements into population-based quality measures. The key statistical issue involved is the trade-off between increased reliability with more general population-based quality measures versus increased validity from individually case-adjusted but more restricted measures done at a greater audit cost. Our intelligent algorithm for auditing protocol design is based on hierarchically modeling incrementally case-adjusted quality constraints. We select quality constraints to measure using an optimization criterion based on statistical generalizability coefficients. We present results of the approach from a deployed decision support system for a hypertension guideline.

  20. Reasons for quitting: intrinsic and extrinsic motivation for smoking cessation in a population-based sample of smokers.

    PubMed

    Curry, S J; Grothaus, L; McBride, C

    1997-01-01

    An intrinsic-extrinsic model of motivation for smoking cessation is extended to a population-based sample of smokers (N = 1,137), using a previously validated Reasons for Quitting (RFQ) scale. Psychometric evaluation of the RFQ replicated the model that includes health concerns and self-control as intrinsic motivation dimensions and immediate reinforcement and social influence as extrinsic motivation dimensions. Compared to volunteers, the population-based sample of smokers reported equivalent health concerns, lower self-control, and higher social influence motivation for cessation. Within the population-based sample, women compared to men were less motivated to quit by health concerns and more motivated by immediate reinforcement; smokers above age 55 expressed lower health concerns and higher self-control motivation than smokers below age 55. Higher baseline levels of intrinsic relative to extrinsic motivation were associated with more advanced stages of readiness to quit smoking and successful smoking cessation at a 12-month follow-up. Among continuing smokers, improvement in stage of readiness to quit over time was associated with significant increases in health concerns and self-control motivation.

  1. Societal and Family Lifetime Cost of Dementia: Implications for Policy.

    PubMed

    Jutkowitz, Eric; Kane, Robert L; Gaugler, Joseph E; MacLehose, Richard F; Dowd, Bryan; Kuntz, Karen M

    2017-10-01

    To estimate the cost of dementia and the extra cost of caring for someone with dementia over the cost of caring for someone without dementia. We developed an evidence-based mathematical model to simulate disease progression for newly diagnosed individuals with dementia. Data-driven trajectories of cognition, function, and behavioral and psychological symptoms were used to model disease progression and predict costs. Using modeling, we evaluated lifetime and annual costs of individuals with dementia, compared costs of those with and without clinical features of dementia, and evaluated the effect of reducing functional decline or behavioral and psychological symptoms by 10% for 12 months (implemented when Mini-Mental State Examination score ≤21). Mathematical model. Representative simulated U.S. incident dementia cases. Value of informal care, out-of-pocket expenditures, Medicaid expenditures, and Medicare expenditures. From time of diagnosis (mean age 83), discounted total lifetime cost of care for a person with dementia was $321,780 (2015 dollars). Families incurred 70% of the total cost burden ($225,140), Medicaid accounted for 14% ($44,090), and Medicare accounted for 16% ($52,540). Costs for a person with dementia over a lifetime were $184,500 greater (86% incurred by families) than for someone without dementia. Total annual cost peaked at $89,000, and net cost peaked at $72,400. Reducing functional decline or behavioral and psychological symptoms by 10% resulted in $3,880 and $680 lower lifetime costs than natural disease progression. Dementia substantially increases lifetime costs of care. Long-lasting, effective interventions are needed to support families because they incur the most dementia cost. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

  2. Engineering a lifetime-based activatable probe for photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Morgounova, Ekaterina; Shao, Qi; Hackel, Benjamin; Ashkenazi, Shai

    2013-02-01

    High-resolution, high-penetration depth activatable probes are needed for in-vivo imaging of enzyme activity. In this paper, we will describe the contrast mechanism of a new photoacoustic activatable probe that changes its excitation lifetime upon activation. The excitation decay of methylene blue (MB), a chromophore commonly used in therapeutic and diagnostic applications, is probed by photoacoustic lifetime contrast imaging (PLCI). The monomer of the dye presents a high-quantum yield of intersystem-crossing and long lifetime (70 μs) whereas the dimer is statically quenched with a short lifetime (a few ns). This forms the basis of a highly sensitive contrast mechanism between monomers and dimers. Two dimerization models - one using sodium sulfate, the other using sodium dodecyl sulfate - were applied to control the monomer-to-dimer ratio in MB solutions. Preliminary results show that the photoacoustic signal of a dimer solution is efficiently suppressed (< 20 dB) due to their short lifetime compared to the monomer sample. Flash-photolysis of the same solutions reveals a 99% decrease in transient absorption confirming PLCI results. This contrast mechanism can be applied to design a MB dual-labeled activatable probe bound by an enzyme-specific cleavable peptide linker. When the probe is cleaved by its target, MB molecules will separate by molecular diffusion and recover their long excitation lifetime enabling their detection by PLCI. Our long-term goal is to investigate enzyme-specific imaging in small animals and establish pre-clinical data for translational research and implementation of the technology in clinical applications.

  3. Lifetime Economic Burden of Rape Among U.S. Adults.

    PubMed

    Peterson, Cora; DeGue, Sarah; Florence, Curtis; Lokey, Colby N

    2017-06-01

    This study estimated the per-victim U.S. lifetime cost of rape. Data from previous studies was combined with current administrative data and 2011 U.S. National Intimate Partner and Sexual Violence Survey data in a mathematical model. Rape was defined as any lifetime completed or attempted forced penetration or alcohol- or drug-facilitated penetration, measured among adults not currently institutionalized. Costs included attributable impaired health, lost productivity, and criminal justice costs from the societal perspective. Average age at first rape was assumed to be 18 years. Future costs were discounted by 3%. The main outcome measures were the average per-victim (female and male) and total population discounted lifetime cost of rape. Secondary outcome measures were marginal outcome probabilities among victims (e.g., suicide attempt) and perpetrators (e.g., incarceration) and associated costs. Analysis was conducted in 2016. The estimated lifetime cost of rape was $122,461 per victim, or a population economic burden of nearly $3.1 trillion (2014 U.S. dollars) over victims' lifetimes, based on data indicating >25 million U.S. adults have been raped. This estimate included $1.2 trillion (39% of total) in medical costs; $1.6 trillion (52%) in lost work productivity among victims and perpetrators; $234 billion (8%) in criminal justice activities; and $36 billion (1%) in other costs, including victim property loss or damage. Government sources pay an estimated $1 trillion (32%) of the lifetime economic burden. Preventing sexual violence could avoid substantial costs for victims, perpetrators, healthcare payers, employers, and government payers. These findings can inform evaluations of interventions to reduce sexual violence. Published by Elsevier Inc.

  4. Lifetime Economic Burden of Rape Among U.S. Adults

    PubMed Central

    Peterson, Cora; DeGue, Sarah; Florence, Curtis; Lokey, Colby N.

    2017-01-01

    Introduction This study estimated the per-victim U.S. lifetime cost of rape. Methods Data from previous studies was combined with current administrative data and 2011 U.S. National Intimate Partner and Sexual Violence Survey data in a mathematical model. Rape was defined as any lifetime completed or attempted forced penetration or alcohol- or drug-facilitated penetration, measured among adults not currently institutionalized. Costs included attributable impaired health, lost productivity, and criminal justice costs from the societal perspective. Average age at first rape was assumed to be 18 years. Future costs were discounted by 3%. The main outcome measures were the average per-victim (female and male) and total population discounted lifetime cost of rape. Secondary outcome measures were marginal outcome probabilities among victims (e.g., suicide attempt) and perpetrators (e.g., incarceration) and associated costs. Analysis was conducted in 2016. Results The estimated lifetime cost of rape was $122,461 per victim, or a population economic burden of nearly $3.1 trillion (2014 U.S. dollars) over victims’ lifetimes, based on data indicating >25 million U.S. adults have been raped. This estimate included $1.2 trillion (39% of total) in medical costs; $1.6 trillion (52%) in lost work productivity among victims and perpetrators; $234 billion (8%) in criminal justice activities; and $36 billion (1%) in other costs, including victim property loss or damage. Government sources pay an estimated $1 trillion (32%) of the lifetime economic burden. Conclusions Preventing sexual violence could avoid substantial costs for victims, perpetrators, healthcare payers, employers, and government payers. These findings can inform evaluations of interventions to reduce sexual violence. PMID:28153649

  5. Multimodel Estimates of Atmospheric Lifetimes of Long-Lived Ozone-Depleting Substances: Present and Future

    NASA Technical Reports Server (NTRS)

    Chipperfield, M. P.; Liang, Q.; Strahan, S. E.; Morgenstern, O.; Dhomse, S. S.; Abraham, N. L.; Archibald, A. T.; Bekki, S.; Braesicke, P.; Di Genova, G.; hide

    2014-01-01

    We have diagnosed the lifetimes of long-lived source gases emitted at the surface and removed in the stratosphere using six three-dimensional chemistry-climate models and a two-dimensional model. The models all used the same standard photochemical data. We investigate the effect of different definitions of lifetimes, including running the models with both mixing ratio (MBC) and flux (FBC) boundary conditions. Within the same model, the lifetimes diagnosed by different methods agree very well. Using FBCs versus MBCs leads to a different tracer burden as the implied lifetime contained in theMBC value does not necessarilymatch a model's own calculated lifetime. In general, there are much larger differences in the lifetimes calculated by different models, the main causes of which are variations in the modeled rates of ascent and horizontal mixing in the tropical midlower stratosphere. The model runs have been used to compute instantaneous and steady state lifetimes. For chlorofluorocarbons (CFCs) their atmospheric distribution was far from steady state in their growth phase through to the 1980s, and the diagnosed instantaneous lifetime is accordingly much longer. Following the cessation of emissions, the resulting decay of CFCs is much closer to steady state. For 2100 conditions the model circulation speeds generally increase, but a thicker ozone layer due to recovery and climate change reduces photolysis rates. These effects compensate so the net impact on modeled lifetimes is small. For future assessments of stratospheric ozone, use of FBCs would allow a consistent balance between rate of CFC removal and model circulation rate.

  6. Multimodel Estimates of Atmospheric Lifetimes of Long-lived Ozone-Depleting Substances: Present and Future

    NASA Technical Reports Server (NTRS)

    Chipperfield, M. P.; Liang, Q.; Strahan, S. E.; Morgenstern, O.; Dhomse, S. S.; Abraham, N. L.; Archibald, A. T.; Bekki, S.; Braesicke, P.; Di Genova, G.; hide

    2014-01-01

    We have diagnosed the lifetimes of long-lived source gases emitted at the surface and removed in the stratosphere using six three-dimensional chemistry-climate models and a two-dimensional model. The models all used the same standard photochemical data. We investigate the effect of different definitions of lifetimes, including running the models with both mixing ratio (MBC) and flux (FBC) boundary conditions. Within the same model, the lifetimes diagnosed by different methods agree very well. Using FBCs versus MBCs leads to a different tracer burden as the implied lifetime contained in the MBC value does not necessarily match a model's own calculated lifetime. In general, there are much larger differences in the lifetimes calculated by different models, the main causes of which are variations in the modeled rates of ascent and horizontal mixing in the tropical midlower stratosphere. The model runs have been used to compute instantaneous and steady state lifetimes. For chlorofluorocarbons (CFCs) their atmospheric distribution was far from steady state in their growth phase through to the 1980s, and the diagnosed instantaneous lifetime is accordingly much longer. Following the cessation of emissions, the resulting decay of CFCs is much closer to steady state. For 2100 conditions the model circulation speeds generally increase, but a thicker ozone layer due to recovery and climate change reduces photolysis rates. These effects compensate so the net impact on modeled lifetimes is small. For future assessments of stratospheric ozone, use of FBCs would allow a consistent balance between rate of CFC removal and model circulation rate

  7. Estimating the personal cure rate of cancer patients using population-based grouped cancer survival data.

    PubMed

    Binbing Yu; Tiwari, Ram C; Feuer, Eric J

    2011-06-01

    Cancer patients are subject to multiple competing risks of death and may die from causes other than the cancer diagnosed. The probability of not dying from the cancer diagnosed, which is one of the patients' main concerns, is sometimes called the 'personal cure' rate. Two approaches of modelling competing-risk survival data, namely the cause-specific hazards approach and the mixture model approach, have been used to model competing-risk survival data. In this article, we first show the connection and differences between crude cause-specific survival in the presence of other causes and net survival in the absence of other causes. The mixture survival model is extended to population-based grouped survival data to estimate the personal cure rate. Using the colorectal cancer survival data from the Surveillance, Epidemiology and End Results Programme, we estimate the probabilities of dying from colorectal cancer, heart disease, and other causes by age at diagnosis, race and American Joint Committee on Cancer stage.

  8. How shorter black carbon lifetime alters its climate effect.

    PubMed

    Hodnebrog, Øivind; Myhre, Gunnar; Samset, Bjørn H

    2014-09-25

    Black carbon (BC), unlike most aerosol types, absorbs solar radiation. However, the quantification of its climate impact is uncertain and presently under debate. Recently, attention has been drawn both to a likely underestimation of global BC emissions in climate models, and an overestimation of BC at high altitudes. Here we show that doubling present day BC emissions in a model simulation, while reducing BC lifetime based on observational evidence, leaves the direct aerosol effect of BC virtually unchanged. Increased emissions, together with increased wet removal that reduces the lifetime, yields modelled BC vertical profiles that are in strongly improved agreement with recent aircraft observations. Furthermore, we explore the consequences of an altered BC profile in a global circulation model, and show that both the vertical profile of BC and rapid climate adjustments need to be taken into account in order to assess the total climate impact of BC.

  9. Lifetime risks for aneurysmal subarachnoid haemorrhage: multivariable risk stratification.

    PubMed

    Vlak, Monique H M; Rinkel, Gabriel J E; Greebe, Paut; Greving, Jacoba P; Algra, Ale

    2013-06-01

    The overall incidence of aneurysmal subarachnoid haemorrhage (aSAH) in western populations is around 9 per 100 000 person-years, which confers to a lifetime risk of around half per cent. Risk factors for aSAH are usually expressed as relative risks and suggest that absolute risks vary considerably according to risk factor profiles, but such estimates are lacking. We aimed to estimate incidence and lifetime risks of aSAH according to risk factor profiles. We used data from 250 patients admitted with aSAH and 574 sex-matched and age-matched controls, who were randomly retrieved from general practitioners files. We determined independent prognostic factors with multivariable logistic regression analyses and assessed discriminatory performance using the area under the receiver operating characteristic curve. Based on the prognostic model we predicted incidences and lifetime risks of aSAH for different risk factor profiles. The four strongest independent predictors for aSAH, namely current smoking (OR 6.0; 95% CI 4.1 to 8.6), a positive family history for aSAH (4.0; 95% CI 2.3 to 7.0), hypertension (2.4; 95% CI 1.5 to 3.8) and hypercholesterolaemia (0.2; 95% CI 0.1 to 0.4), were used in the final prediction model. This model had an area under the receiver operating characteristic curve of 0.73 (95% CI 0.69 to 0.76). Depending on sex, age and the four predictors, the incidence of aSAH ranged from 0.4/100 000 to 298/100 000 person-years and lifetime risk between 0.02% and 7.2%. The incidence and lifetime risk of aSAH in the general population varies widely according to risk factor profiles. Whether persons with high risks benefit from screening should be assessed in cost-effectiveness studies.

  10. Tracking Brain Development and Dimensional Psychiatric Symptoms in Children: A Longitudinal Population-Based Neuroimaging Study.

    PubMed

    Muetzel, Ryan L; Blanken, Laura M E; van der Ende, Jan; El Marroun, Hanan; Shaw, Philip; Sudre, Gustavo; van der Lugt, Aad; Jaddoe, Vincent W V; Verhulst, Frank C; Tiemeier, Henning; White, Tonya

    2018-01-01

    Psychiatric symptomatology during childhood predicts persistent mental illness later in life. While neuroimaging methodologies are routinely applied cross-sectionally to the study of child and adolescent psychopathology, the nature of the relationship between childhood symptoms and the underlying neurodevelopmental processes remains unclear. The authors used a prospective population-based cohort to delineate the longitudinal relationship between childhood psychiatric problems and brain development. A tot