General theory of multistage geminate reactions of isolated pairs of reactants. I. Kinetic equations.

PubMed

Doktorov, Alexander B; Kipriyanov, Alexey A

2014-05-14

General matrix approach to the consideration of multistage geminate reactions of isolated pairs of reactants depending on reactant mobility is formulated on the basis of the concept of "effective" particles. Various elementary reactions (stages of multistage reaction including physicochemical processes of internal quantum state changes) proceeding with the participation of isolated pairs of reactants (or isolated reactants) are taken into account. Investigation has been made in terms of kinetic approach implying the derivation of general (matrix) kinetic equations for local and mean probabilities of finding any of the reaction species in the sample under study (or for local and mean concentrations). The recipes for the calculation of kinetic coefficients of the equations for mean quantities in terms of relative coordinates of reactants have been formulated in the general case of inhomogeneous reacting systems. Important specific case of homogeneous reacting systems is considered.

Texas School Survey of Substance Abuse: Grades 7-12. 1992.

ERIC Educational Resources Information Center

Liu, Liang Y.; Fredlund, Eric V.

The 1992 Texas School Survey results for secondary students are based on data collected from a sample of 73,073 students in grades 7 through 12. Students were randomly selected from school districts throughout the state using a multi-stage probability design. The procedure ensured that students living in metropolitan and rural areas of Texas are…

A Population-Based Study of Job Stress in Mexican Americans, Non-Hispanic Blacks, and Non-Hispanic Whites

ERIC Educational Resources Information Center

Perez, Norma; Franzini, Luisa; Freeman, Daniel H.; Ju, Hyunsu; Peek, Kristen

2011-01-01

There is little known about the association between socioeconomic status and job stress in Mexican Americans. To address this issue, data were originated on a community level using personal interviews from working Mexican Americans using a multistage probability sample. In this study we described the population's sociodemographic characteristics,…

Age of Alcohol-Dependence Onset: Associations with Severity of Dependence and Seeking Treatment

ERIC Educational Resources Information Center

Hingson, Ralph W.; Heeren, Timothy; Winter, Michael R.

2007-01-01

Objective: We explored whether people who become alcohol dependent at younger ages are more likely to seek alcohol-related help or treatment or experience chronic relapsing dependence. Methods: In 2001-2002 the National Institute on Alcohol Abuse and Alcoholism completed a face-to-face interview survey with a multistage probability sample of 43…

SAS procedures for designing and analyzing sample surveys

USGS Publications Warehouse

Stafford, Joshua D.; Reinecke, Kenneth J.; Kaminski, Richard M.

2003-01-01

Complex surveys often are necessary to estimate occurrence (or distribution), density, and abundance of plants and animals for purposes of re-search and conservation. Most scientists are familiar with simple random sampling, where sample units are selected from a population of interest (sampling frame) with equal probability. However, the goal of ecological surveys often is to make inferences about populations over large or complex spatial areas where organisms are not homogeneously distributed or sampling frames are in-convenient or impossible to construct. Candidate sampling strategies for such complex surveys include stratified,multistage, and adaptive sampling (Thompson 1992, Buckland 1994).

Multi-stage decoding for multi-level block modulation codes

NASA Technical Reports Server (NTRS)

Lin, Shu; Kasami, Tadao

1991-01-01

Various types of multistage decoding for multilevel block modulation codes, in which the decoding of a component code at each stage can be either soft decision or hard decision, maximum likelihood or bounded distance are discussed. Error performance for codes is analyzed for a memoryless additive channel based on various types of multi-stage decoding, and upper bounds on the probability of an incorrect decoding are derived. It was found that, if component codes of a multi-level modulation code and types of decoding at various stages are chosen properly, high spectral efficiency and large coding gain can be achieved with reduced decoding complexity. It was found that the difference in performance between the suboptimum multi-stage soft decision maximum likelihood decoding of a modulation code and the single stage optimum decoding of the overall code is very small, only a fraction of dB loss in SNR at the probability of an incorrect decoding for a block of 10(exp -6). Multi-stage decoding of multi-level modulation codes really offers a way to achieve the best of three worlds, bandwidth efficiency, coding gain, and decoding complexity.

The Sampling Design of the China Family Panel Studies (CFPS)

PubMed Central

Xie, Yu; Lu, Ping

2018-01-01

The China Family Panel Studies (CFPS) is an on-going, nearly nationwide, comprehensive, longitudinal social survey that is intended to serve research needs on a large variety of social phenomena in contemporary China. In this paper, we describe the sampling design of the CFPS sample for its 2010 baseline survey and methods for constructing weights to adjust for sampling design and survey nonresponses. Specifically, the CFPS used a multi-stage probability strategy to reduce operation costs and implicit stratification to increase efficiency. Respondents were oversampled in five provinces or administrative equivalents for regional comparisons. We provide operation details for both sampling and weights construction. PMID:29854418

Multi-stage decoding for multi-level block modulation codes

NASA Technical Reports Server (NTRS)

Lin, Shu

1991-01-01

In this paper, we investigate various types of multi-stage decoding for multi-level block modulation codes, in which the decoding of a component code at each stage can be either soft-decision or hard-decision, maximum likelihood or bounded-distance. Error performance of codes is analyzed for a memoryless additive channel based on various types of multi-stage decoding, and upper bounds on the probability of an incorrect decoding are derived. Based on our study and computation results, we find that, if component codes of a multi-level modulation code and types of decoding at various stages are chosen properly, high spectral efficiency and large coding gain can be achieved with reduced decoding complexity. In particular, we find that the difference in performance between the suboptimum multi-stage soft-decision maximum likelihood decoding of a modulation code and the single-stage optimum decoding of the overall code is very small: only a fraction of dB loss in SNR at the probability of an incorrect decoding for a block of 10(exp -6). Multi-stage decoding of multi-level modulation codes really offers a way to achieve the best of three worlds, bandwidth efficiency, coding gain, and decoding complexity.

Multistage estimation of received carrier signal parameters under very high dynamic conditions of the receiver

NASA Technical Reports Server (NTRS)

Kumar, Rajendra (Inventor)

1991-01-01

A multistage estimator is provided for the parameters of a received carrier signal possibly phase-modulated by unknown data and experiencing very high Doppler, Doppler rate, etc., as may arise, for example, in the case of Global Positioning Systems (GPS) where the signal parameters are directly related to the position, velocity and jerk of the GPS ground-based receiver. In a two-stage embodiment of the more general multistage scheme, the first stage, selected to be a modified least squares algorithm referred to as differential least squares (DLS), operates as a coarse estimator resulting in higher rms estimation errors but with a relatively small probability of the frequency estimation error exceeding one-half of the sampling frequency, provides relatively coarse estimates of the frequency and its derivatives. The second stage of the estimator, an extended Kalman filter (EKF), operates on the error signal available from the first stage refining the overall estimates of the phase along with a more refined estimate of frequency as well and in the process also reduces the number of cycle slips.

Multistage estimation of received carrier signal parameters under very high dynamic conditions of the receiver

NASA Technical Reports Server (NTRS)

Kumar, Rajendra (Inventor)

1990-01-01

A multistage estimator is provided for the parameters of a received carrier signal possibly phase-modulated by unknown data and experiencing very high Doppler, Doppler rate, etc., as may arise, for example, in the case of Global Positioning Systems (GPS) where the signal parameters are directly related to the position, velocity and jerk of the GPS ground-based receiver. In a two-stage embodiment of the more general multistage scheme, the first stage, selected to be a modified least squares algorithm referred to as differential least squares (DLS), operates as a coarse estimator resulting in higher rms estimation errors but with a relatively small probability of the frequency estimation error exceeding one-half of the sampling frequency, provides relatively coarse estimates of the frequency and its derivatives. The second stage of the estimator, an extended Kalman filter (EKF), operates on the error signal available from the first stage refining the overall estimates of the phase along with a more refined estimate of frequency as well and in the process also reduces the number of cycle slips.

Multistage classification of multispectral Earth observational data: The design approach

NASA Technical Reports Server (NTRS)

Bauer, M. E. (Principal Investigator); Muasher, M. J.; Landgrebe, D. A.

1981-01-01

An algorithm is proposed which predicts the optimal features at every node in a binary tree procedure. The algorithm estimates the probability of error by approximating the area under the likelihood ratio function for two classes and taking into account the number of training samples used in estimating each of these two classes. Some results on feature selection techniques, particularly in the presence of a very limited set of training samples, are presented. Results comparing probabilities of error predicted by the proposed algorithm as a function of dimensionality as compared to experimental observations are shown for aircraft and LANDSAT data. Results are obtained for both real and simulated data. Finally, two binary tree examples which use the algorithm are presented to illustrate the usefulness of the procedure.

Handling Imbalanced Data Sets in Multistage Classification

NASA Astrophysics Data System (ADS)

López, M.

Multistage classification is a logical approach, based on a divide-and-conquer solution, for dealing with problems with a high number of classes. The classification problem is divided into several sequential steps, each one associated to a single classifier that works with subgroups of the original classes. In each level, the current set of classes is split into smaller subgroups of classes until they (the subgroups) are composed of only one class. The resulting chain of classifiers can be represented as a tree, which (1) simplifies the classification process by using fewer categories in each classifier and (2) makes it possible to combine several algorithms or use different attributes in each stage. Most of the classification algorithms can be biased in the sense of selecting the most populated class in overlapping areas of the input space. This can degrade a multistage classifier performance if the training set sample frequencies do not reflect the real prevalence in the population. Several techniques such as applying prior probabilities, assigning weights to the classes, or replicating instances have been developed to overcome this handicap. Most of them are designed for two-class (accept-reject) problems. In this article, we evaluate several of these techniques as applied to multistage classification and analyze how they can be useful for astronomy. We compare the results obtained by classifying a data set based on Hipparcos with and without these methods.

Protocol for Reliability Assessment of Structural Health Monitoring Systems Incorporating Model-assisted Probability of Detection (MAPOD) Approach

DTIC Science & Technology

2011-09-01

a quality evaluation with limited data, a model -based assessment must be...that affect system performance, a multistage approach to system validation, a modeling and experimental methodology for efficiently addressing a ...affect system performance, a multistage approach to system validation, a modeling and experimental methodology for efficiently addressing a wide range

A multi-stage drop-the-losers design for multi-arm clinical trials.

PubMed

Wason, James; Stallard, Nigel; Bowden, Jack; Jennison, Christopher

2017-02-01

Multi-arm multi-stage trials can improve the efficiency of the drug development process when multiple new treatments are available for testing. A group-sequential approach can be used in order to design multi-arm multi-stage trials, using an extension to Dunnett's multiple-testing procedure. The actual sample size used in such a trial is a random variable that has high variability. This can cause problems when applying for funding as the cost will also be generally highly variable. This motivates a type of design that provides the efficiency advantages of a group-sequential multi-arm multi-stage design, but has a fixed sample size. One such design is the two-stage drop-the-losers design, in which a number of experimental treatments, and a control treatment, are assessed at a prescheduled interim analysis. The best-performing experimental treatment and the control treatment then continue to a second stage. In this paper, we discuss extending this design to have more than two stages, which is shown to considerably reduce the sample size required. We also compare the resulting sample size requirements to the sample size distribution of analogous group-sequential multi-arm multi-stage designs. The sample size required for a multi-stage drop-the-losers design is usually higher than, but close to, the median sample size of a group-sequential multi-arm multi-stage trial. In many practical scenarios, the disadvantage of a slight loss in average efficiency would be overcome by the huge advantage of a fixed sample size. We assess the impact of delay between recruitment and assessment as well as unknown variance on the drop-the-losers designs.

Design and Weighting Methods for a Nationally Representative Sample of HIV-infected Adults Receiving Medical Care in the United States-Medical Monitoring Project

PubMed Central

Iachan, Ronaldo; H. Johnson, Christopher; L. Harding, Richard; Kyle, Tonja; Saavedra, Pedro; L. Frazier, Emma; Beer, Linda; L. Mattson, Christine; Skarbinski, Jacek

2016-01-01

Background: Health surveys of the general US population are inadequate for monitoring human immunodeficiency virus (HIV) infection because the relatively low prevalence of the disease (<0.5%) leads to small subpopulation sample sizes. Objective: To collect a nationally and locally representative probability sample of HIV-infected adults receiving medical care to monitor clinical and behavioral outcomes, supplementing the data in the National HIV Surveillance System. This paper describes the sample design and weighting methods for the Medical Monitoring Project (MMP) and provides estimates of the size and characteristics of this population. Methods: To develop a method for obtaining valid, representative estimates of the in-care population, we implemented a cross-sectional, three-stage design that sampled 23 jurisdictions, then 691 facilities, then 9,344 HIV patients receiving medical care, using probability-proportional-to-size methods. The data weighting process followed standard methods, accounting for the probabilities of selection at each stage and adjusting for nonresponse and multiplicity. Nonresponse adjustments accounted for differing response at both facility and patient levels. Multiplicity adjustments accounted for visits to more than one HIV care facility. Results: MMP used a multistage stratified probability sampling design that was approximately self-weighting in each of the 23 project areas and nationally. The probability sample represents the estimated 421,186 HIV-infected adults receiving medical care during January through April 2009. Methods were efficient (i.e., induced small, unequal weighting effects and small standard errors for a range of weighted estimates). Conclusion: The information collected through MMP allows monitoring trends in clinical and behavioral outcomes and informs resource allocation for treatment and prevention activities. PMID:27651851

Dynamic analysis for solid waste management systems: an inexact multistage integer programming approach.

PubMed

Li, Yongping; Huang, Guohe

2009-03-01

In this study, a dynamic analysis approach based on an inexact multistage integer programming (IMIP) model is developed for supporting municipal solid waste (MSW) management under uncertainty. Techniques of interval-parameter programming and multistage stochastic programming are incorporated within an integer-programming framework. The developed IMIP can deal with uncertainties expressed as probability distributions and interval numbers, and can reflect the dynamics in terms of decisions for waste-flow allocation and facility-capacity expansion over a multistage context. Moreover, the IMIP can be used for analyzing various policy scenarios that are associated with different levels of economic consequences. The developed method is applied to a case study of long-term waste-management planning. The results indicate that reasonable solutions have been generated for binary and continuous variables. They can help generate desired decisions of system-capacity expansion and waste-flow allocation with a minimized system cost and maximized system reliability.

The integration of manual and automatic image analysis techniques with supporting ground data in a multistage sampling framework for timber resource inventories: Three examples

NASA Technical Reports Server (NTRS)

Gialdini, M.; Titus, S. J.; Nichols, J. D.; Thomas, R.

1975-01-01

An approach to information acquisition is discussed in the context of meeting user-specified needs in a cost-effective, timely manner through the use of remote sensing data, ground data, and multistage sampling techniques. The roles of both LANDSAT imagery and Skylab photography are discussed as first stages of three separate multistage timber inventory systems and results are given for each system. Emphasis is placed on accuracy and meeting user needs.

Multistage open-tube trap for enrichment of part-per-trillion trace components of low-pressure (below 27-kPa) air samples

NASA Technical Reports Server (NTRS)

Ohara, D.; Vo, T.; Vedder, J. F.

1985-01-01

A multistage open-tube trap for cryogenic collection of trace components in low-pressure air samples is described. The open-tube design allows higher volumetric flow rates than densely packed glass-bead traps commonly reported and is suitable for air samples at pressures below 27 kPa with liquid nitrogen as the cryogen. Gas blends containing 200 to 2500 parts per trillion by volume each of ethane and ethene were sampled and hydrocarbons were enriched with 100 + or - 4 percent trap efficiency. The multistage design is more efficient than equal-length open-tube traps under the conditions of the measurements.

Epidemiology of major depression in four cities in Mexico.

PubMed

Slone, Laurie B; Norris, Fran H; Murphy, Arthur D; Baker, Charlene K; Perilla, Julia L; Diaz, Dayna; Rodriguez, Francisco Gutiérrez; Gutiérrez Rodriguez, José de Jesús

2006-01-01

Analyses were conducted to estimate lifetime and current prevalence of major depressive disorder (MDD) for four representative cities of Mexico, to identify variables that influence the probability of MDD, and to further describe depression in Mexican culture. A multistage probability sampling design was used to draw a sample of 2,509 adults in four different regions of Mexico. MDD was assessed according to DSM-IV criteria by using the Composite International Diagnostic Interview collected by trained lay interviewers. The prevalence of MDD in these four cities averaged 12.8% for lifetime and 6.1% for the previous 12 months. MDD was highly comorbid with other mental disorders. Women were more likely to have lifetime MDD than were men. Being divorced, separated, or widowed (compared to married or never married) and having experienced childhood trauma were related to higher lifetime prevalence but not to current prevalence. In addition, age and education level were related to current 12-month MDD. Data on the profile of MDD in urban Mexico are provided. This research expands our understanding of MDD across cultures.

Clonal Expansion (CE) Models in Cancer Risk Assessment

EPA Science Inventory

Cancer arises when cells accumulate sufficient critical mutations. Carcinogens increase the probability of mutation during cell division or promote clonal expansion within stages. Multistage CE models recapitulate this process and provide a framework for incorporating relevant da...

An inexact multistage fuzzy-stochastic programming for regional electric power system management constrained by environmental quality.

PubMed

Fu, Zhenghui; Wang, Han; Lu, Wentao; Guo, Huaicheng; Li, Wei

2017-12-01

Electric power system involves different fields and disciplines which addressed the economic system, energy system, and environment system. Inner uncertainty of this compound system would be an inevitable problem. Therefore, an inexact multistage fuzzy-stochastic programming (IMFSP) was developed for regional electric power system management constrained by environmental quality. A model which concluded interval-parameter programming, multistage stochastic programming, and fuzzy probability distribution was built to reflect the uncertain information and dynamic variation in the case study, and the scenarios under different credibility degrees were considered. For all scenarios under consideration, corrective actions were allowed to be taken dynamically in accordance with the pre-regulated policies and the uncertainties in reality. The results suggest that the methodology is applicable to handle the uncertainty of regional electric power management systems and help the decision makers to establish an effective development plan.

Psychomotor development and learning difficulties in preschool children with probable attention deficit hyperactivity disorder: An epidemiological study in Navarre and La Rioja.

PubMed

Marín-Méndez, J J; Borra-Ruiz, M C; Álvarez-Gómez, M J; Soutullo Esperón, C

2017-10-01

ADHD symptoms begin to appear at preschool age. ADHD may have a significant negative impact on academic performance. In Spain, there are no standardized tools for detecting ADHD at preschool age, nor is there data about the incidence of this disorder. To evaluate developmental factors and learning difficulties associated with probable ADHD and to assess the impact of ADHD in school performance. We conducted a population-based study with a stratified multistage proportional cluster sample design. We found significant differences between probable ADHD and parents' perception of difficulties in expressive language, comprehension, and fine motor skills, as well as in emotions, concentration, behaviour, and relationships. Around 34% of preschool children with probable ADHD showed global learning difficulties, mainly in patients with the inattentive type. According to the multivariate analysis, learning difficulties were significantly associated with both delayed psychomotor development during the first 3 years of life (OR: 5.57) as assessed by parents, and probable ADHD (OR: 2.34) CONCLUSIONS: There is a connection between probable ADHD in preschool children and parents' perception of difficulties in several dimensions of development and learning. Early detection of ADHD at preschool ages is necessary to start prompt and effective clinical and educational interventions. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Comorbid Visual and Psychiatric Disabilities Among the Chinese Elderly: A National Population-Based Survey.

PubMed

Guo, Chao; Wang, Zhenjie; Li, Ning; Chen, Gong; Zheng, Xiaoying

2017-12-01

To estimate the prevalence of, and association between, co-morbid visual and psychiatric disabilities among elderly (>65 years-of-age) persons in China. Random representative samples were obtained using multistage, stratified, cluster sampling, with probabilities proportional to size. Standard weighting procedures were used to construct sample weights that reflected this multistage, stratified cluster sampling survey scheme. Logistic regression models were used to elucidate associations between visual and psychiatric disabilities. Among the Chinese elderly, >160,000 persons have co-morbid visual and psychiatric disabilities. The weighted prevalence among this cohort is 123.7 per 100,000 persons. A higher prevalence of co-morbid visual and psychiatric disabilities was found in the oldest-old (p<0.001); women (65-79 years-of-age, p=0.001; ≥80 years-of-age, p=0.004); illiterate (65-79 years-of-age, p<0.001; ≥80 years-of-age, p=0.02); and single elders (65-79 years-of-age, p=0.01; ≥80 years-of-age, p=0.001). Presence of a visual disability was significantly associated with a higher risk of having a psychiatric disability among persons aged ≥80 years-of-age [adjusted odds ratio, 1.24; 95% confidence interval (CI), 1.03-1.54]. A significant number of Chinese elderly persons were living with co-morbid visual and psychiatric disabilities. To address the challenge of these co-morbid disorders among Chinese elders, it is incumbent upon the government to implement additional and more comprehensive prevention and rehabilitation strategies for health-care systems, reinforce health promotion among the elderly, and improve accessibility to health-care services.

Generation Expansion Planning With Large Amounts of Wind Power via Decision-Dependent Stochastic Programming

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

Zhan, Yiduo; Zheng, Qipeng P.; Wang, Jianhui

Power generation expansion planning needs to deal with future uncertainties carefully, given that the invested generation assets will be in operation for a long time. Many stochastic programming models have been proposed to tackle this challenge. However, most previous works assume predetermined future uncertainties (i.e., fixed random outcomes with given probabilities). In several recent studies of generation assets' planning (e.g., thermal versus renewable), new findings show that the investment decisions could affect the future uncertainties as well. To this end, this paper proposes a multistage decision-dependent stochastic optimization model for long-term large-scale generation expansion planning, where large amounts of windmore » power are involved. In the decision-dependent model, the future uncertainties are not only affecting but also affected by the current decisions. In particular, the probability distribution function is determined by not only input parameters but also decision variables. To deal with the nonlinear constraints in our model, a quasi-exact solution approach is then introduced to reformulate the multistage stochastic investment model to a mixed-integer linear programming model. The wind penetration, investment decisions, and the optimality of the decision-dependent model are evaluated in a series of multistage case studies. The results show that the proposed decision-dependent model provides effective optimization solutions for long-term generation expansion planning.« less

Design and operation of the national home health aide survey: 2007-2008.

PubMed

Bercovitz, Anita; Moss, Abigail J; Sengupta, Manisha; Harris-Kojetin, Lauren D; Squillace, Marie R; Emily, Rosenoff; Branden, Laura

2010-03-01

This report provides an overview of the National Home Health Aide Survey (NHHAS), the first national probability survey of home health aides. NHHAS was designed to provide national estimates of home health aides who provided assistance in activities of daily living (ADLs) and were directly employed by agencies that provide home health and/or hospice care. This report discusses the need for and objectives of the survey, the design process, the survey methods, and data availability. METHODS NHHAS, a multistage probability sample survey, was conducted as a supplement to the 2007 National Home and Hospice Care Survey (NHHCS). Agencies providing home health and/or hospice care were sampled, and then aides employed by these agencies were sampled and interviewed by telephone. Survey topics included recruitment, training, job history, family life, client relations, work-related injuries, and demographics. NHHAS was virtually identical to the 2004 National Nursing Assistant Survey of certified nursing assistants employed in sampled nursing homes with minor changes to account for differences in workplace environment and responsibilities. RESULTS From September 2007 to April 2008, interviews were completed with 3,416 aides. A public-use data file that contains the interview responses, sampling weights, and design variables is available. The NHHAS overall response rate weighted by the inverse of the probability of selection was 41 percent. This rate is the product of the weighted first-stage agency response rate of 57 percent (i.e., weighted response rate of 59 percent for agency participation in NHHCS times the weighted response rate of 97 percent for agencies participating in NHHCS that also participated in NHHAS) and the weighted second-stage aide response rate of 72 percent to NHHAS.

Multistage switching hardware and software implementations for student experiment purpose

NASA Astrophysics Data System (ADS)

Sani, A.; Suherman

2018-02-01

Current communication and internet networks are underpinned by the switching technologies that interconnect one network to the others. Students’ understanding on networks rely on how they conver the theories. However, understanding theories without touching the reality may exert spots in the overall knowledge. This paper reports the progress of the multistage switching design and implementation for student laboratory activities. The hardware and software designs are based on three stages clos switching architecture with modular 2x2 switches, controlled by an arduino microcontroller. The designed modules can also be extended for batcher and bayan switch, and working on circuit and packet switching systems. The circuit analysis and simulation show that the blocking probability for each switch combinations can be obtained by generating random or patterned traffics. The mathematic model and simulation analysis shows 16.4% blocking probability differences as the traffic generation is uniform. The circuits design components and interfacing solution have been identified to allow next step implementation.

"Unequal opportunity": neighbourhood disadvantage and the chance to buy illegal drugs.

PubMed

Storr, C L; Chen, C-Y; Anthony, J C

2004-03-01

This study investigates whether subgroups of people living in disadvantaged neighbourhoods may be more likely to come into contact with drug dealers as compared with persons living in more advantaged areas, with due attention to male-female and race-ethnicity differences. Standardised survey data collected using stratified, multistage area probability sampling. United States of America, 1998. Nationally representative sample of household residents age 12 or older (n = 25 500). Evidence supports an inference that women are less likely to be approached by someone selling illegal drugs. The study found no more than modest and generally null racial and ethnicity differences, even for residents living within socially disadvantaged neighbourhoods, where chances to buy illegal drugs are found to be more common. Limitations of survey data always merit attention, but this study evidence lends support to the inference that physical and social characteristics of a neighbourhood can set the stage for opportunities to become involved with drugs.

An analytic-geometric model of the effect of spherically distributed injection errors for Galileo and Ulysses spacecraft - The multi-stage problem

NASA Technical Reports Server (NTRS)

Longuski, James M.; Mcronald, Angus D.

1988-01-01

In previous work the problem of injecting the Galileo and Ulysses spacecraft from low earth orbit into their respective interplanetary trajectories has been discussed for the single stage (Centaur) vehicle. The central issue, in the event of spherically distributed injection errors, is what happens to the vehicle? The difficulties addressed in this paper involve the multi-stage problem since both Galileo and Ulysses will be utilizing the two-stage IUS system. Ulysses will also include a third stage: the PAM-S. The solution is expressed in terms of probabilities for total percentage of escape, orbit decay and reentry trajectories. Analytic solutions are found for Hill's Equations of Relative Motion (more recently called Clohessy-Wiltshire Equations) for multi-stage injections. These solutions are interpreted geometrically on the injection sphere. The analytic-geometric models compare well with numerical solutions, provide insight into the behavior of trajectories mapped on the injection sphere and simplify the numerical two-dimensional search for trajectory families.

Changes in Sexual Behavior and Attitudes Across Generations and Gender Among a Population-Based Probability Sample From an Urbanizing Province in Thailand.

PubMed

Techasrivichien, Teeranee; Darawuttimaprakorn, Niphon; Punpuing, Sureeporn; Musumari, Patou Masika; Lukhele, Bhekumusa Wellington; El-Saaidi, Christina; Suguimoto, S Pilar; Feldman, Mitchell D; Ono-Kihara, Masako; Kihara, Masahiro

2016-02-01

Thailand has undergone rapid modernization with implications for changes in sexual norms. We investigated sexual behavior and attitudes across generations and gender among a probability sample of the general population of Nonthaburi province located near Bangkok in 2012. A tablet-based survey was performed among 2,138 men and women aged 15-59 years identified through a three-stage, stratified, probability proportional to size, clustered sampling. Descriptive statistical analysis was carried out accounting for the effects of multistage sampling. Relationship of age and gender to sexual behavior and attitudes was analyzed by bivariate analysis followed by multivariate logistic regression analysis to adjust for possible confounding. Patterns of sexual behavior and attitudes varied substantially across generations and gender. We found strong evidence for a decline in the age of sexual initiation, a shift in the type of the first sexual partner, and a greater rate of acceptance of adolescent premarital sex among younger generations. The study highlighted profound changes among young women as evidenced by a higher number of lifetime sexual partners as compared to older women. In contrast to the significant gender gap in older generations, sexual profiles of Thai young women have evolved to resemble those of young men with attitudes gradually converging to similar sexual standards. Our data suggest that higher education, being never-married, and an urban lifestyle may have been associated with these changes. Our study found that Thai sexual norms are changing dramatically. It is vital to continue monitoring such changes, considering the potential impact on the HIV/STIs epidemic and unintended pregnancies.

Efficient design and inference for multistage randomized trials of individualized treatment policies.

PubMed

Dawson, Ree; Lavori, Philip W

2012-01-01

Clinical demand for individualized "adaptive" treatment policies in diverse fields has spawned development of clinical trial methodology for their experimental evaluation via multistage designs, building upon methods intended for the analysis of naturalistically observed strategies. Because often there is no need to parametrically smooth multistage trial data (in contrast to observational data for adaptive strategies), it is possible to establish direct connections among different methodological approaches. We show by algebraic proof that the maximum likelihood (ML) and optimal semiparametric (SP) estimators of the population mean of the outcome of a treatment policy and its standard error are equal under certain experimental conditions. This result is used to develop a unified and efficient approach to design and inference for multistage trials of policies that adapt treatment according to discrete responses. We derive a sample size formula expressed in terms of a parametric version of the optimal SP population variance. Nonparametric (sample-based) ML estimation performed well in simulation studies, in terms of achieved power, for scenarios most likely to occur in real studies, even though sample sizes were based on the parametric formula. ML outperformed the SP estimator; differences in achieved power predominately reflected differences in their estimates of the population mean (rather than estimated standard errors). Neither methodology could mitigate the potential for overestimated sample sizes when strong nonlinearity was purposely simulated for certain discrete outcomes; however, such departures from linearity may not be an issue for many clinical contexts that make evaluation of competitive treatment policies meaningful.

The Empirical Selection of Anchor Items Using a Multistage Approach

ERIC Educational Resources Information Center

Craig, Brandon

2017-01-01

The purpose of this study was to determine if using a multistage approach for the empirical selection of anchor items would lead to more accurate DIF detection rates than the anchor selection methods proposed by Kopf, Zeileis, & Strobl (2015b). A simulation study was conducted in which the sample size, percentage of DIF, and balance of DIF…

SSAIS: A Program to Assess Adverse Impact in Multistage Selection Decisions

ERIC Educational Resources Information Center

De Corte, Wilfried

2004-01-01

The article describes a Windows program to estimate the expected value and sampling distribution function of the adverse impact ratio for general multistage selections. The results of the program can also be used to predict the risk that a future selection decision will result in an outcome that reflects the presence of adverse impact. The method…

Traumatic Events and Suicide-Related Outcomes among Mexico City Adolescents

ERIC Educational Resources Information Center

Borges, Guilherme; Benjet, Corina; Medina-Mora, Maria Elena; Orozco, Ricardo; Molnar, Beth E.; Nock, Matthew K.

2008-01-01

Background: We report the prevalence and associations between traumatic events and suicidal ideation, suicide plans and suicide attempts among Mexican adolescents. Methods: The data are from a representative multistage probability household survey of 3,005 adolescents aged 12 to 17 years residing in the Mexico City Metropolitan Area that was…

Current Multistage Drug Delivery Systems Based on the Tumor Microenvironment

PubMed Central

Chen, Binlong; Dai, Wenbing; He, Bing; Zhang, Hua; Wang, Xueqing; Wang, Yiguang; Zhang, Qiang

2017-01-01

The development of traditional tumor-targeted drug delivery systems based on EPR effect and receptor-mediated endocytosis is very challenging probably because of the biological complexity of tumors as well as the limitations in the design of the functional nano-sized delivery systems. Recently, multistage drug delivery systems (Ms-DDS) triggered by various specific tumor microenvironment stimuli have emerged for tumor therapy and imaging. In response to the differences in the physiological blood circulation, tumor microenvironment, and intracellular environment, Ms-DDS can change their physicochemical properties (such as size, hydrophobicity, or zeta potential) to achieve deeper tumor penetration, enhanced cellular uptake, timely drug release, as well as effective endosomal escape. Based on these mechanisms, Ms-DDS could deliver maximum quantity of drugs to the therapeutic targets including tumor tissues, cells, and subcellular organelles and eventually exhibit the highest therapeutic efficacy. In this review, we expatiate on various responsive modes triggered by the tumor microenvironment stimuli, introduce recent advances in multistage nanoparticle systems, especially the multi-stimuli responsive delivery systems, and discuss their functions, effects, and prospects. PMID:28255348

Current Multistage Drug Delivery Systems Based on the Tumor Microenvironment.

PubMed

Chen, Binlong; Dai, Wenbing; He, Bing; Zhang, Hua; Wang, Xueqing; Wang, Yiguang; Zhang, Qiang

2017-01-01

The development of traditional tumor-targeted drug delivery systems based on EPR effect and receptor-mediated endocytosis is very challenging probably because of the biological complexity of tumors as well as the limitations in the design of the functional nano-sized delivery systems. Recently, multistage drug delivery systems (Ms-DDS) triggered by various specific tumor microenvironment stimuli have emerged for tumor therapy and imaging. In response to the differences in the physiological blood circulation, tumor microenvironment, and intracellular environment, Ms-DDS can change their physicochemical properties (such as size, hydrophobicity, or zeta potential) to achieve deeper tumor penetration, enhanced cellular uptake, timely drug release, as well as effective endosomal escape. Based on these mechanisms, Ms-DDS could deliver maximum quantity of drugs to the therapeutic targets including tumor tissues, cells, and subcellular organelles and eventually exhibit the highest therapeutic efficacy. In this review, we expatiate on various responsive modes triggered by the tumor microenvironment stimuli, introduce recent advances in multistage nanoparticle systems, especially the multi-stimuli responsive delivery systems, and discuss their functions, effects, and prospects.

Multi-stage versus single-stage inflation and deflation cycle for alternating low pressure air mattresses to prevent pressure ulcers in hospitalised patients: a randomised-controlled clinical trial.

PubMed

Demarré, L; Beeckman, D; Vanderwee, K; Defloor, T; Grypdonck, M; Verhaeghe, S

2012-04-01

The duration and the amount of pressure and shear must be reduced in order to minimize the risk of pressure ulcer development. Alternating low pressure air mattresses with multi-stage inflation and deflation cycle of the air cells have been developed to relieve pressure by sequentially inflating and deflating the air cells. Evidence about the effectiveness of this type of mattress in clinical practice is lacking. This study aimed to compare the effectiveness of an alternating low pressure air mattress that has a standard single-stage inflation and deflation cycle of the air cells with an alternating low pressure air mattress with multi-stage inflation and deflation cycle of the air cells. A randomised controlled trial was performed in a convenience sample of 25 wards in five hospitals in Belgium. In total, 610 patients were included and randomly assigned to the experimental group (n=298) or the control group (n=312). In the experimental group, patients were allocated to an alternating low pressure air mattress with multi-stage inflation and deflation cycle of the air cells. In the control group, patients were allocated to an alternating low pressure air mattress with a standard single-stage inflation and deflation cycle of the air cells. The outcome was defined as cumulative pressure ulcer incidence (Grade II-IV). An intention-to-treat analysis was performed. There was no significant difference in cumulative pressure ulcer incidence (Grade II-IV) between both groups (Exp.=5.7%, Contr.=5.8%, p=0.97). When patients developed a pressure ulcer, the median time was 5.0 days in the experimental group (IQR=3.0-8.5) and 8.0 days in the control group (IQR=3.0-8.5) (Mann-Whitney U-test=113, p=0.182). The probability to remain pressure ulcer free during the observation period in this trial did not differ significantly between the experimental group and the control group (log-rank χ(2)=0.013, df=1, p=0.911). An alternating low pressure air mattress with multi-stage inflation and deflation of the air cells does not result in a significantly lower pressure ulcer incidence compared to an alternating low pressure air mattress with a standard single-stage inflation and deflation cycle of the air cells. Both alternating mattress types are equally effective to prevent pressure ulcer development. © 2011 Elsevier Ltd. All rights reserved.

Trellises and Trellis-Based Decoding Algorithms for Linear Block Codes. Part 3; The Map and Related Decoding Algirithms

NASA Technical Reports Server (NTRS)

Lin, Shu; Fossorier, Marc

1998-01-01

In a coded communication system with equiprobable signaling, MLD minimizes the word error probability and delivers the most likely codeword associated with the corresponding received sequence. This decoding has two drawbacks. First, minimization of the word error probability is not equivalent to minimization of the bit error probability. Therefore, MLD becomes suboptimum with respect to the bit error probability. Second, MLD delivers a hard-decision estimate of the received sequence, so that information is lost between the input and output of the ML decoder. This information is important in coded schemes where the decoded sequence is further processed, such as concatenated coding schemes, multi-stage and iterative decoding schemes. In this chapter, we first present a decoding algorithm which both minimizes bit error probability, and provides the corresponding soft information at the output of the decoder. This algorithm is referred to as the MAP (maximum aposteriori probability) decoding algorithm.

Race/Ethnicity, Poverty, Urban Stressors and Telomere Length in a Detroit Community-Based Sample

PubMed Central

Geronimus, Arline T.; Pearson, Jay A.; Linnenbringer, Erin; Schulz, Amy J.; Reyes, Angela G.; Epel, Elissa S.; Lin, Jue; Blackburn, Elizabeth H.

2015-01-01

Residents of distressed urban areas suffer early aging-related disease and excess mortality. Using a community-based participatory research approach in a collaboration between social researchers and cellular biologists, we collected a unique data set of 239 black, white, or Mexican adults from a stratified, multi-stage probability sample of three Detroit neighborhoods. We drew venous blood and measured Telomere Length (TL), an indicator of stress-mediated biological aging, linking respondents’ TL to their community survey responses. We regressed TL on socioeconomic, psychosocial, neighborhood, and behavioral stressors, hypothesizing and finding an interaction between poverty and racial/ethnic group. Poor whites had shorter TL than nonpoor whites; poor and nonpoor blacks had equivalent TL; poor Mexicans had longer TL than nonpoor Mexicans. Findings suggest unobserved heterogeneity bias is an important threat to the validity of estimates of TL differences by race/ethnicity. They point to health impacts of social identity as contingent, the products of structurally-rooted biopsychosocial processes. PMID:25930147

Race-Ethnicity, Poverty, Urban Stressors, and Telomere Length in a Detroit Community-based Sample.

PubMed

Geronimus, Arline T; Pearson, Jay A; Linnenbringer, Erin; Schulz, Amy J; Reyes, Angela G; Epel, Elissa S; Lin, Jue; Blackburn, Elizabeth H

2015-06-01

Residents of distressed urban areas suffer early aging-related disease and excess mortality. Using a community-based participatory research approach in a collaboration between social researchers and cellular biologists, we collected a unique data set of 239 black, white, or Mexican adults from a stratified, multistage probability sample of three Detroit neighborhoods. We drew venous blood and measured telomere length (TL), an indicator of stress-mediated biological aging, linking respondents' TL to their community survey responses. We regressed TL on socioeconomic, psychosocial, neighborhood, and behavioral stressors, hypothesizing and finding an interaction between poverty and racial-ethnic group. Poor whites had shorter TL than nonpoor whites; poor and nonpoor blacks had equivalent TL; and poor Mexicans had longer TL than nonpoor Mexicans. Findings suggest unobserved heterogeneity bias is an important threat to the validity of estimates of TL differences by race-ethnicity. They point to health impacts of social identity as contingent, the products of structurally rooted biopsychosocial processes. © American Sociological Association 2015.

Methodology of a nationwide cross-sectional survey of prevalence and epidemiological patterns of hepatitis A, B and C infection in Brazil.

PubMed

Ximenes, Ricardo Arraes de Alencar; Pereira, Leila Maria Beltrão; Martelli, Celina Maria Turchi; Merchán-Hamann, Edgar; Stein, Airton Tetelbom; Figueiredo, Gerusa Maria; Braga, Maria Cynthia; Montarroyos, Ulisses Ramos; Brasil, Leila Melo; Turchi, Marília Dalva; Fonseca, José Carlos Ferraz da; Lima, Maria Luiza Carvalho de; Alencar, Luis Cláudio Arraes de; Costa, Marcelo; Coral, Gabriela; Moreira, Regina Celia; Cardoso, Maria Regina Alves

2010-09-01

A population-based survey to provide information on the prevalence of hepatitis viral infection and the pattern of risk factors was carried out in the urban population of all Brazilian state capitals and the Federal District, between 2005 and 2009. This paper describes the design and methodology of the study which involved a population aged 5 to 19 for hepatitis A and 10 to 69 for hepatitis B and C. Interviews and blood samples were obtained through household visits. The sample was selected using stratified multi-stage cluster sampling and was drawn with equal probability from each domain of study (region and age-group). Nationwide, 19,280 households and ~31,000 residents were selected. The study is large enough to detect prevalence of viral infection around 0.1% and risk factor assessments within each region. The methodology seems to be a viable way of differentiating between distinct epidemiological patterns of hepatitis A, B and C. These data will be of value for the evaluation of vaccination policies and for the design of control program strategies.

Age at First Drink, Drinking, Binge Drinking and DSM-5 Alcohol Use Disorder among Hispanic National Groups in the U.S.

PubMed Central

Caetano, Raul; Mills, Britain A.; Vaeth, Patrice A. C.; Reingle, Jennifer

2014-01-01

Background This paper examines age at first drink and adult drinking, binge drinking and DSM-5 alcohol use disorder (AUD) among U.S. Hispanic national groups. Methods Respondents come from two independent studies. The Hispanic Americans Baseline Alcohol Survey used a multistage cluster sample design to interview 5,224 individuals 18 years of age and older selected from the household population in: Miami, New York, Philadelphia, Houston and Los Angeles. Respondents in the border area (N=1,307) constituted a household probability sample of Mexican Americans living on U.S. counties that border Mexico. In both surveys, data were collected during computer assisted interviews conducted in respondents' homes. The HABLAS and the border sample response rates were 76% and 67%, respectively. Results U.S. born Hispanics begin drinking at a younger age than those who are foreign born, independent of national group. Among foreign born Hispanics, age of arrival in the U.S. is not associated with age at first drink. Results support the hypothesis that a younger age at first drink is associated with a higher mean volume of drinking, a higher probability of bingeing and a higher probability of DSM-5 AUD. But the results do not show a clear pattern by which a particular national group would consistently show no associations or stronger associations between age at first drink and the alcohol-related outcomes under consideration. Conclusions An earlier age at first drinking is positively associated with heavier drinking patterns among U.S. Hispanics. However, as in other areas of alcohol epidemiology, here too there is considerable variation in age at first drink and drinking across Hispanic national groups. PMID:24689445

Mental health status and related characteristics of Chinese male rural-urban migrant workers.

PubMed

Yang, Tingzhong; Xu, Xiaochao; Li, Mu; Rockett, Ian R H; Zhu, Waner; Ellison-Barnes, Alejandra

2012-06-01

To explore mental health status and related characteristics in a sample of Chinese male rural-urban migrants. Subjects were 1,595 male rural-urban migrant workers selected though a multi-stage sample survey conducted in two cities (Hangzhou and Guangzhou). Data were collected by means of a self-administered questionnaire. Both life and work stressors were examined. Stress and mental health status were measured by the Chinese Perceived Stress Scale (CPSS) and the Chinese Health Questionnaire (CHQ), respectively. Unconditional logistic regression analysis was performed to identify factors associated with probable mental disorders. There are approximately 120 million rural-urban migrants in China. The prevalence of probable mental disorders in the sample population was 24.4% (95% CI: 23.3-25.5%), which was higher than among urban residents (20.2%, 95% CI: 18.8-21.7%). Logistic regression analysis revealed that five characteristics were positively associated with risk for probable mental disorders: originating in the South (OR = 2.00; 95% CI = 1.02, 4.00), higher life stress (OR = 7.63; 95% CI = 5.88, 10.00), staying in the city for 5-9 months each year (OR = 2.56; 95% CI = 1.67, 3.85), higher work stress (OR = 2.56; 95% CI = 1.96, 3.33), and separation from wife (OR = 2.43; 95% CI = 1.61, 3.57). Employment in machinery and transportation (OR = 0.54; 95% CI = 0.36, 0.81) and higher self-worth (OR = 0.42; 95% CI = 0.28, 0.62) were negatively associated. Findings support an urgent need to develop specific policies and programs to address mental health problems among Chinese rural-urban migrants.

Extraction and classification of 3D objects from volumetric CT data

NASA Astrophysics Data System (ADS)

Song, Samuel M.; Kwon, Junghyun; Ely, Austin; Enyeart, John; Johnson, Chad; Lee, Jongkyu; Kim, Namho; Boyd, Douglas P.

2016-05-01

We propose an Automatic Threat Detection (ATD) algorithm for Explosive Detection System (EDS) using our multistage Segmentation Carving (SC) followed by Support Vector Machine (SVM) classifier. The multi-stage Segmentation and Carving (SC) step extracts all suspect 3-D objects. The feature vector is then constructed for all extracted objects and the feature vector is classified by the Support Vector Machine (SVM) previously learned using a set of ground truth threat and benign objects. The learned SVM classifier has shown to be effective in classification of different types of threat materials. The proposed ATD algorithm robustly deals with CT data that are prone to artifacts due to scatter, beam hardening as well as other systematic idiosyncrasies of the CT data. Furthermore, the proposed ATD algorithm is amenable for including newly emerging threat materials as well as for accommodating data from newly developing sensor technologies. Efficacy of the proposed ATD algorithm with the SVM classifier is demonstrated by the Receiver Operating Characteristics (ROC) curve that relates Probability of Detection (PD) as a function of Probability of False Alarm (PFA). The tests performed using CT data of passenger bags shows excellent performance characteristics.

Predicting risk for childhood asthma by pre-pregnancy, perinatal, and postnatal factors.

PubMed

Wen, Hui-Ju; Chiang, Tung-Liang; Lin, Shio-Jean; Guo, Yue Leon

2015-05-01

Symptoms of atopic disease start early in human life. Predicting risk for childhood asthma by early-life exposure would contribute to disease prevention. A birth cohort study was conducted to investigate early-life risk factors for childhood asthma and to develop a predictive model for the development of asthma. National representative samples of newborn babies were obtained by multistage stratified systematic sampling from the 2005 Taiwan Birth Registry. Information on potential risk factors and children's health was collected by home interview when babies were 6 months old and 5 yr old, respectively. Backward stepwise regression analysis was used to identify the risk factors of childhood asthma for predictive models that were used to calculate the probability of childhood asthma. A total of 19,192 children completed the study satisfactorily. Physician-diagnosed asthma was reported in 6.6% of 5-yr-old children. Pre-pregnancy factors (parental atopy and socioeconomic status), perinatal factors (place of residence, exposure to indoor mold and painting/renovations during pregnancy), and postnatal factors (maternal postpartum depression and the presence of atopic dermatitis before 6 months of age) were chosen for the predictive models, and the highest predicted probability of asthma in 5-yr-old children was 68.1% in boys and 78.1% in girls; the lowest probability in boys and girls was 4.1% and 3.2%, respectively. This investigation provides a technique for predicting risk of childhood asthma that can be used to developing a preventive strategy against asthma. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Sex differences in traumatic events and psychiatric morbidity associated to probable posttraumatic stress disorder among Latino prisoners.

PubMed

Pérez-Pedrogo, Coralee; Martínez-Taboas, Alfonso; González, Rafael A; Caraballo, José N; Albizu-García, Carmen E

2018-04-14

Latinos comprised 17.1% of the U.S. population and 33.1% of US prisoners, yet they are underrepresented in the psychopathology literature. Despite higher rates of trauma among incarcerated individuals than in the general population, most of the previous research in this area focused primarily on women samples, and very few studies examined sex differences in PTSD and traumatic experiences. In addition, there is a need for research assessing traumatic experiences and probable PTSD in men and women Latino inmates to inform culturally competent care and sex sensitive care for this vulnerable and underserved population. Our study examined whether men and women Latino inmates with probable Posttraumatic Stress Disorder (PTSD), based on the cut off 40 or more symptoms on the Davidson Trauma Scale (DTS), differed significantly by the number of event types experienced, the type of potentially traumatizing event, and in co-occurring psychiatric conditions. A multi-stage sample design was used to select a probabilistic sample of 1,331 inmates from 26 penal institutions in PR of which 1179 participated in the study. Bivariate associations were calculated for each type of traumatic event and probable PTSD. Mean number of types of potentially traumatizing event experienced was comparable for both sexes (F = 3.83, M = 3.74) yet sex differences were found in the nature of the event. Women with probable PTSD had higher rates of experiencing rape and sexual abuse. Men had higher rates of experiencing combat in war, a life-threatening accident, of witnessing violence, and being threatened with a weapon. Men with significant ADHD symptoms in childhood and with Generalized Anxiety Disorder (GAD) during adulthood were almost 5 and 7 times as likely to score above threshold on the DTS whereas women were >3 times as likely in the presence of ADHD symptoms in childhood or depression during adulthood. This study underscores the need to improve understanding of the clinical manifestations of trauma and co-occurring psychiatric conditions for appropriate sex sensitive interventions targeting Latinos living in prisons. Copyright © 2018 Elsevier B.V. All rights reserved.

Multistage bioassociation of uranium onto an extremely halophilic archaeon revealed by a unique combination of spectroscopic and microscopic techniques

DOE PAGES

Bader, Miriam; Müller, Katharina; Foerstendorf, Harald; ...

2016-12-27

The interactions of two extremely halophilic archaea with uranium were investigated in this paper at high ionic strength as a function of time, pH and uranium concentration. Halobacterium noricense DSM-15987 and Halobacterium sp. putatively noricense, isolated from the Waste Isolation Pilot Plant repository, were used for these investigations. The kinetics of U(VI) bioassociation with both strains showed an atypical multistage behavior, meaning that after an initial phase of U(VI) sorption, an unexpected interim period of U(VI) release was observed, followed by a slow reassociation of uranium with the cells. By applying in situ attenuated total reflection Fourier-transform infrared spectroscopy, themore » involvement of phosphoryl and carboxylate groups in U(VI) complexation during the first biosorption phase was shown. Differences in cell morphology and uranium localization become visible at different stages of the bioassociation process, as shown with scanning electron microscopy in combination with energy dispersive X-ray spectroscopy. Finally, our results demonstrate for the first time that association of uranium with the extremely halophilic archaeon is a multistage process, beginning with sorption and followed by another process, probably biomineralization.« less

Multistage bioassociation of uranium onto an extremely halophilic archaeon revealed by a unique combination of spectroscopic and microscopic techniques

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

Bader, Miriam; Müller, Katharina; Foerstendorf, Harald

The interactions of two extremely halophilic archaea with uranium were investigated in this paper at high ionic strength as a function of time, pH and uranium concentration. Halobacterium noricense DSM-15987 and Halobacterium sp. putatively noricense, isolated from the Waste Isolation Pilot Plant repository, were used for these investigations. The kinetics of U(VI) bioassociation with both strains showed an atypical multistage behavior, meaning that after an initial phase of U(VI) sorption, an unexpected interim period of U(VI) release was observed, followed by a slow reassociation of uranium with the cells. By applying in situ attenuated total reflection Fourier-transform infrared spectroscopy, themore » involvement of phosphoryl and carboxylate groups in U(VI) complexation during the first biosorption phase was shown. Differences in cell morphology and uranium localization become visible at different stages of the bioassociation process, as shown with scanning electron microscopy in combination with energy dispersive X-ray spectroscopy. Finally, our results demonstrate for the first time that association of uranium with the extremely halophilic archaeon is a multistage process, beginning with sorption and followed by another process, probably biomineralization.« less

Multistage bioassociation of uranium onto an extremely halophilic archaeon revealed by a unique combination of spectroscopic and microscopic techniques.

PubMed

Bader, Miriam; Müller, Katharina; Foerstendorf, Harald; Drobot, Björn; Schmidt, Matthias; Musat, Niculina; Swanson, Juliet S; Reed, Donald T; Stumpf, Thorsten; Cherkouk, Andrea

2017-04-05

The interactions of two extremely halophilic archaea with uranium were investigated at high ionic strength as a function of time, pH and uranium concentration. Halobacterium noricense DSM-15987 and Halobacterium sp. putatively noricense, isolated from the Waste Isolation Pilot Plant repository, were used for these investigations. The kinetics of U(VI) bioassociation with both strains showed an atypical multistage behavior, meaning that after an initial phase of U(VI) sorption, an unexpected interim period of U(VI) release was observed, followed by a slow reassociation of uranium with the cells. By applying in situ attenuated total reflection Fourier-transform infrared spectroscopy, the involvement of phosphoryl and carboxylate groups in U(VI) complexation during the first biosorption phase was shown. Differences in cell morphology and uranium localization become visible at different stages of the bioassociation process, as shown with scanning electron microscopy in combination with energy dispersive X-ray spectroscopy. Our results demonstrate for the first time that association of uranium with the extremely halophilic archaeon is a multistage process, beginning with sorption and followed by another process, probably biomineralization. Copyright © 2016. Published by Elsevier B.V.

THE NORTH CAROLINA HERALD PILOT STUDY

EPA Science Inventory

The sampling design for the National Children's Study (NCS) calls for a population-based, multi-stage, clustered household sampling approach. The full sample is designed to be representative of both urban and rural births in the United States, 2007-2011. While other sur...

Social networks and health-related quality of life: a population based study among older adults.

PubMed

Gallegos-Carrillo, Katia; Mudgal, Jyoti; Sánchez-García, Sergio; Wagner, Fernando A; Gallo, Joseph J; Salmerón, Jorge; García-Peña, Carmen

2009-01-01

To examine the relationship between components of social networks and health-related quality of life (HRQL) in older adults with and without depressive symptoms. Comparative cross-sectional study with data from the cohort study 'Integral Study of Depression', carried out in Mexico City during 2004. The sample was selected through a multi-stage probability design. HRQL was measured with the SF-36. Geriatric Depression Scale (GDS) and the Short Anxiety Screening Test (SAST) determined depressive symptoms and anxiety. T-test and multiple linear regressions were conducted. Older adults with depressive symptoms had the lowest scores in all HRQL scales. A larger network of close relatives and friends was associated with better HRQL on several scales. Living alone did not significantly affect HRQL level, in either the study or comparison group. A positive association between some components of social networks and good HRQL exists even in older adults with depressive symptoms.

Developing optimum sample size and multistage sampling plans for Lobesia botrana (Lepidoptera: Tortricidae) larval infestation and injury in northern Greece.

PubMed

Ifoulis, A A; Savopoulou-Soultani, M

2006-10-01

The purpose of this research was to quantify the spatial pattern and develop a sampling program for larvae of Lobesia botrana Denis and Schiffermüller (Lepidoptera: Tortricidae), an important vineyard pest in northern Greece. Taylor's power law and Iwao's patchiness regression were used to model the relationship between the mean and the variance of larval counts. Analysis of covariance was carried out, separately for infestation and injury, with combined second and third generation data, for vine and half-vine sample units. Common regression coefficients were estimated to permit use of the sampling plan over a wide range of conditions. Optimum sample sizes for infestation and injury, at three levels of precision, were developed. An investigation of a multistage sampling plan with a nested analysis of variance showed that if the goal of sampling is focusing on larval infestation, three grape clusters should be sampled in a half-vine; if the goal of sampling is focusing on injury, then two grape clusters per half-vine are recommended.

Estimating survival probabilities by exposure levels: utilizing vital statistics and complex survey data with mortality follow-up.

PubMed

Landsman, V; Lou, W Y W; Graubard, B I

2015-05-20

We present a two-step approach for estimating hazard rates and, consequently, survival probabilities, by levels of general categorical exposure. The resulting estimator utilizes three sources of data: vital statistics data and census data are used at the first step to estimate the overall hazard rate for a given combination of gender and age group, and cohort data constructed from a nationally representative complex survey with linked mortality records, are used at the second step to divide the overall hazard rate by exposure levels. We present an explicit expression for the resulting estimator and consider two methods for variance estimation that account for complex multistage sample design: (1) the leaving-one-out jackknife method, and (2) the Taylor linearization method, which provides an analytic formula for the variance estimator. The methods are illustrated with smoking and all-cause mortality data from the US National Health Interview Survey Linked Mortality Files, and the proposed estimator is compared with a previously studied crude hazard rate estimator that uses survey data only. The advantages of a two-step approach and possible extensions of the proposed estimator are discussed. Copyright © 2015 John Wiley & Sons, Ltd.

A Risk-Constrained Multi-Stage Decision Making Approach to the Architectural Analysis of Mars Missions

NASA Technical Reports Server (NTRS)

Kuwata, Yoshiaki; Pavone, Marco; Balaram, J. (Bob)

2012-01-01

This paper presents a novel risk-constrained multi-stage decision making approach to the architectural analysis of planetary rover missions. In particular, focusing on a 2018 Mars rover concept, which was considered as part of a potential Mars Sample Return campaign, we model the entry, descent, and landing (EDL) phase and the rover traverse phase as four sequential decision-making stages. The problem is to find a sequence of divert and driving maneuvers so that the rover drive is minimized and the probability of a mission failure (e.g., due to a failed landing) is below a user specified bound. By solving this problem for several different values of the model parameters (e.g., divert authority), this approach enables rigorous, accurate and systematic trade-offs for the EDL system vs. the mobility system, and, more in general, cross-domain trade-offs for the different phases of a space mission. The overall optimization problem can be seen as a chance-constrained dynamic programming problem, with the additional complexity that 1) in some stages the disturbances do not have any probabilistic characterization, and 2) the state space is extremely large (i.e, hundreds of millions of states for trade-offs with high-resolution Martian maps). To this purpose, we solve the problem by performing an unconventional combination of average and minimax cost analysis and by leveraging high efficient computation tools from the image processing community. Preliminary trade-off results are presented.

Radiolysis of lignin: Prospective mechanism of high-temperature decomposition

NASA Astrophysics Data System (ADS)

Ponomarev, A. V.

2017-12-01

The range of the radiation-thermal processes resulting in conversion of lignin into monomeric phenols is considered. Statistically the most probable places of macromolecule ionization are aromatic units. Release of phenolic products from a lignin macromolecule is the multistage process beginning via fragmentation of primary cation-radicals. Reactions of electrons and small radicals with macromolecules, also as degradation of cation-radicals, result in formation of phenoxyl radicals. Macroradicals possess lower heat stability in comparison with macromolecules. Thermal decomposition of macroradicals leads to release of monohydric and dihydric phenols. The probability of benzenediols formation increases in the presence of alkanes. As noted, partial transformation of lignin into charcoal is inevitable.

Bounds on Block Error Probability for Multilevel Concatenated Codes

NASA Technical Reports Server (NTRS)

Lin, Shu; Moorthy, Hari T.; Stojanovic, Diana

1996-01-01

Maximum likelihood decoding of long block codes is not feasable due to large complexity. Some classes of codes are shown to be decomposable into multilevel concatenated codes (MLCC). For these codes, multistage decoding provides good trade-off between performance and complexity. In this paper, we derive an upper bound on the probability of block error for MLCC. We use this bound to evaluate difference in performance for different decompositions of some codes. Examples given show that a significant reduction in complexity can be achieved when increasing number of stages of decoding. Resulting performance degradation varies for different decompositions. A guideline is given for finding good m-level decompositions.

A Bayesian multi-stage cost-effectiveness design for animal studies in stroke research

PubMed Central

Cai, Chunyan; Ning, Jing; Huang, Xuelin

2017-01-01

Much progress has been made in the area of adaptive designs for clinical trials. However, little has been done regarding adaptive designs to identify optimal treatment strategies in animal studies. Motivated by an animal study of a novel strategy for treating strokes, we propose a Bayesian multi-stage cost-effectiveness design to simultaneously identify the optimal dose and determine the therapeutic treatment window for administrating the experimental agent. We consider a non-monotonic pattern for the dose-schedule-efficacy relationship and develop an adaptive shrinkage algorithm to assign more cohorts to admissible strategies. We conduct simulation studies to evaluate the performance of the proposed design by comparing it with two standard designs. These simulation studies show that the proposed design yields a significantly higher probability of selecting the optimal strategy, while it is generally more efficient and practical in terms of resource usage. PMID:27405325

Physical education and academic achievement in elementary school: data from the early childhood longitudinal study.

PubMed

Carlson, Susan A; Fulton, Janet E; Lee, Sarah M; Maynard, L Michele; Brown, David R; Kohl, Harold W; Dietz, William H

2008-04-01

We examined the association between time spent in physical education and academic achievement in a longitudinal study of students in kindergarten through fifth grade. We used data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998 to 1999, which employed a multistage probability design to select a nationally representative sample of students in kindergarten (analytic sample = 5316). Time spent in physical education (minutes per week) was collected from classroom teachers, and academic achievement (mathematics and reading) was scored on an item response theory scale. A small but significant benefit for academic achievement in mathematics and reading was observed for girls enrolled in higher amounts (70-300 minutes per week) of physical education (referent: 0-35 minutes per week). Higher amounts of physical education were not positively or negatively associated with academic achievement among boys. Among girls, higher amounts of physical education may be associated with an academic benefit. Physical education did not appear to negatively affect academic achievement in elementary school students. Concerns about adverse effects on achievement may not be legitimate reasons to limit physical education programs.

Aerodynamic Analysis of Multistage Turbomachinery Flows in Support of Aerodynamic Design

NASA Technical Reports Server (NTRS)

Adamczyk, John J.

1999-01-01

This paper summarizes the state of 3D CFD based models of the time average flow field within axial flow multistage turbomachines. Emphasis is placed on models which are compatible with the industrial design environment and those models which offer the potential of providing credible results at both design and off-design operating conditions. The need to develop models which are free of aerodynamic input from semi-empirical design systems is stressed. The accuracy of such models is shown to be dependent upon their ability to account for the unsteady flow environment in multistage turbomachinery. The relevant flow physics associated with some of the unsteady flow processes present in axial flow multistage machinery are presented along with procedures which can be used to account for them in 3D CFD simulations. Sample results are presented for both axial flow compressors and axial flow turbines which help to illustrate the enhanced predictive capabilities afforded by including these procedures in 3D CFD simulations. Finally, suggestions are given for future work on the development of time average flow models.

The characteristics and controlling factor of the multi-stage eogenetic karst in the Longwangmiao Foramtion in Lower Cambrian, western Central Yangtze Block, SW China

NASA Astrophysics Data System (ADS)

Lu, C.

2017-12-01

This study utilized field outcrops, thin sections, geochemical data, and GR logging curves to investigate the development model of paleokarst within the Longwangmiao Formation in the Lower Cambrian, western Central Yangtze Block, SW China. The Longwangmiao Formation, which belongs to a third-order sequence, consists of four forth-order sequences and is located in the uppermost part of the Lower Cambrian. The vertical variations of the δ13C and δ18O values indicate the existence of multi-stage eogenetic karst events. The eogenetic karst event in the uppermost part of the Longwangmiao Formation is recognized by the dripstones developed within paleocaves, vertical paleoweathering crust with four zones (bedrock, a weak weathering zone, an intense weathering zone and a solution collapsed zone), two generations of calcsparite cement showing bright luminescence and a zonation from nonluminescent to bright to nonluminescent, two types breccias (matrix-rich clast-supported chaotic breccia and matrix-supported chaotic breccia) and rundkarren. The episodic variations of stratiform dissolution vugs and breccias in vertical, and facies-controlled dissolution and filling features indicated the development of multi-stages eogenetic karst. The development of the paleokarst model is controlled by multi-level sea-level changes. The long eccentricity cycle dictates the fluctuations of the forth-order sea-level, generating multi-stage eogenetic karst events. The paleokarst model is an important step towards better understanding the link between the probably orbitally forced sea-level oscillations and eogenetic karst in the Lower Cambrian. According to this paleokarst model, hydrocarbon exploration should focus on both the karst highlands and the karst transitional zone.

Descriptive epidemiology of chronic childhood adversity in Mexican adolescents.

PubMed

Benjet, Corina; Borges, Guilherme; Medina-Mora, María Elena; Zambrano, Joaquín; Cruz, Carlos; Méndez, Enrique

2009-11-01

To estimate the prevalence of adversity (neglect and abuse, parental loss, parental psychopathology, economic adversity, and serious physical illness), the interrelatedness of adversities, and their socio-demographic correlates. This is a multistage probability survey of 3005 adolescents aged 12-17 years residing in Mexico City. Youth were administered the computer-assisted adolescent version of the World Mental Health Composite International Diagnostic Interview in their homes. The childhood and posttraumatic stress disorder sections provided information regarding adversity. Descriptive and logistic regression analyses were performed considering the multistage and weighted sample design. A total of 68% of adolescents have experienced at least one type of chronic childhood adversity, whereas almost 7% have experienced four of more. The most frequent adversity is economic adversity followed by witnessing domestic violence. Boys experience more neglect than girls, and girls experience more sexual abuse than boys. Family dysfunction adversities tend to clump together such that youth exposed to abuse of any form also report witnessing domestic violence and parental mental pathology. Youth whose parents have divorced are likely to experience economic adversity. Parental death is independent of experiencing other childhood adversities. Older adolescents, school drop-outs, those with young mothers, those with more siblings, and those whose parents have less education are more likely to experience adversity. Although most adolescents have experienced some adversity, a small group is exposed to many adversities. Understanding the distribution of adversities may help us to identify at-risk youth and to better interpret the findings from studies on the role of adversity in diverse health outcomes.

Architecture of the parallel hierarchical network for fast image recognition

NASA Astrophysics Data System (ADS)

Timchenko, Leonid; Wójcik, Waldemar; Kokriatskaia, Natalia; Kutaev, Yuriy; Ivasyuk, Igor; Kotyra, Andrzej; Smailova, Saule

2016-09-01

Multistage integration of visual information in the brain allows humans to respond quickly to most significant stimuli while maintaining their ability to recognize small details in the image. Implementation of this principle in technical systems can lead to more efficient processing procedures. The multistage approach to image processing includes main types of cortical multistage convergence. The input images are mapped into a flexible hierarchy that reflects complexity of image data. Procedures of the temporal image decomposition and hierarchy formation are described in mathematical expressions. The multistage system highlights spatial regularities, which are passed through a number of transformational levels to generate a coded representation of the image that encapsulates a structure on different hierarchical levels in the image. At each processing stage a single output result is computed to allow a quick response of the system. The result is presented as an activity pattern, which can be compared with previously computed patterns on the basis of the closest match. With regard to the forecasting method, its idea lies in the following. In the results synchronization block, network-processed data arrive to the database where a sample of most correlated data is drawn using service parameters of the parallel-hierarchical network.

Managing Clustered Data Using Hierarchical Linear Modeling

ERIC Educational Resources Information Center

Warne, Russell T.; Li, Yan; McKyer, E. Lisako J.; Condie, Rachel; Diep, Cassandra S.; Murano, Peter S.

2012-01-01

Researchers in nutrition research often use cluster or multistage sampling to gather participants for their studies. These sampling methods often produce violations of the assumption of data independence that most traditional statistics share. Hierarchical linear modeling is a statistical method that can overcome violations of the independence…

Alcohol consumption and binge drinking among U.S.-Mexico border and non-border Mexican Americans

PubMed Central

Caetano, Raul; Mills, Britain; Vaeth, Patrice A. C.

2011-01-01

Background This paper examines differences in drinking and binge drinking between Mexican Americans living along the U.S.-Mexico border and those living in two metropolitan areas away from the border (Houston, Texas, and Los Angeles, California). Methods Respondents in the non-border area (Houston and Los Angeles) constitute a multistage probability sample (N=1,288) who were interviewed as part of the 2006 Hispanic Americans Baseline Alcohol Survey (HABLAS). Respondents in the border area (N=1,307) constitute a household probability sample of Mexican Americans living on the U.S.-Mexico border. In both surveys, data were collected during computer assisted interviews conducted in respondents’ homes. The HABLAS and the border sample response rates were 76% and 67%, respectively. Results There were no differences between border and non-border Mexican American men in the proportion of drinkers, the proportion who binge drink at least once a year and volume of alcohol consumption. However, within each location, there were significant differences in drinking by age, indicating that younger men drank more than men who were older. Border women showed significant differences across age groups in the proportion of drinkers, in binge drinking and volume of alcohol consumption, which were not seen among non-border women. Conclusions Women’s drinking seems to be more affected than men’s by their residence on or off the U.S.-Mexico border. This is seen most clearly among young women 18–29 years old and it is associated with an increased proportion of drinkers, a higher volume of drinking and an increased proportion of women who report binge drinking. Increased drinking in this group of younger women seems to be associated with drinking in Mexico. PMID:22017228

Multistage Electrophoretic Separators

NASA Technical Reports Server (NTRS)

Thomas, Nathan; Doyle, John F.; Kurk, Andy; Vellinger, John C.; Todd, Paul

2006-01-01

A multistage electrophoresis apparatus has been invented for use in the separation of cells, protein molecules, and other particles and solutes in concentrated aqueous solutions and suspensions. The design exploits free electrophoresis but overcomes the deficiencies of prior free-electrophoretic separators by incorporating a combination of published advances in mathematical modeling of convection, sedimentation, electro-osmotic flow, and the sedimentation and aggregation of droplets. In comparison with other electrophoretic separators, these apparatuses are easier to use and are better suited to separation in relatively large quantities characterized in the art as preparative (in contradistinction to smaller quantities characterized in the art as analytical). In a multistage electrophoretic separator according to the invention, an applied vertical steady electric field draws the electrically charged particles of interest from within a cuvette to within a collection cavity that has been moved into position of the cuvette. There are multiple collection cavities arranged in a circle; each is aligned with the cuvette for a prescribed short time. The multistage, short-migration-path character of the invention solves, possibly for the first time, the fluid-instability problems associated with free electrophoresis. The figure shows a prototype multistage electrophoretic separator that includes four sample stations and five collection stages per sample. At each sample station, an aqueous solution or suspension containing charged species to be separated is loaded into a cuvette, which is machined into a top plate. The apparatus includes a lower plate, into which 20 collection cavities have been milled. Each cavity is filled with an electrophoresis buffer solution. For the collection of an electrophoretic fraction, the lower plate is rotated to move a designated collection cavity into alignment with the opening of the cuvette. An electric field is then applied between a non-gassing electrode in the collection cavity and an electrolyte compartment, which is separated from the cuvette by a semipermeable membrane. The electrolyte is refreshed by circulation by use of a peristaltic pump. In subsequent steps, the lower plate is rotated to collect other electrophoretic fractions. Later, the collected fractions are removed from the collection cavities through ports that have threaded plugs. The base of the apparatus contains power supplies and a computer interface. The design includes provisions for monitoring and feedback control of cavity position, electric field, and temperature. The operation of the apparatus can easily be automated, as demonstrated by use of software that has already been written for this purpose.

Associations among Adolescent Risk Behaviours and Self-Esteem in Six Domains

ERIC Educational Resources Information Center

Wild, Lauren G.; Flisher, Alan J.; Bhana, Arvin; Lombard, Carl

2004-01-01

Background: This study investigated associations among adolescents' self-esteem in 6 domains (peers, school, family, sports/athletics, body image and global self-worth) and risk behaviours related to substance use, bullying, suicidality and sexuality. Method: A multistage stratified sampling strategy was used to select a representative sample of…

Traumatic life events and posttraumatic stress disorder among Mexican adolescents: results from a survey.

PubMed

Orozco, Ricardo; Borges, Guilherme; Benjet, Corina; Medina-Mora, María Elena; López-Carrillo, Lizbeth

2008-01-01

To estimate the prevalence and the association of Traumatic Life Events (LEs) and Posttraumatic Stress Disorder (PTSD) among the Mexico City Metropolitan Area (MCMA) adolescent population. Adolescents aged 12 to 17 were administered the adolescent version of the World Mental Health Composite International Diagnostic Interview (n=3 005). Data were collected using a stratified, multistage and probability sample. Prevalence, odds ratios and 95% confidence intervals for LEs and PTSD (assessed with DSM-IV criteria) were obtained. The percentage of adolescents reporting at least one traumatic event in their lifetimes was 68.9%, with differences by sex. Prevalence for PTSD were 1.8% (2.4% females and 1.2% males), and sexual-related traumas were the LEs most associated with PTSD [OR=3.9 (CI95%=1.8-8.2)], adjusted by sex, education and age. Exposure to traumatic life events is not uncommon among Mexico City adolescents. Effort should be made to reduce child and adolescent sexual abuse, a very traumatic event highly associated with PTSD.

Remote sensing applied to forest resources

NASA Technical Reports Server (NTRS)

Hernandezfilho, P. (Principal Investigator)

1984-01-01

The development of methodologies to classify reforested areas using remotely sensed data is discussed. A preliminary study was carried out in northeast of the Sao Paulo State in 1978. The reforested areas of Pinus spp and Eucalyptus spp were based on the spectral, spatial and temporal characteristics fo LANDSAT imagery. Afterwards, a more detailed study was carried out in the Mato Grosso do Sul State. The reforested areas were mapped in functions of the age (from: 0 to 1 year, 1 to 2 years, 2 to 3 years, 3 to 4 years, 4 to 5 years and 5 to 6 years) and of the heterogeneity stand (from: 0 to 20%, 20 to 40%, 40 to 60%, 60 to 80% and 80 to 100%). The relative differences between the artificial forest areas, estimated from LANDSAT data and ground information, varied from -8.72 to +9.49%. The estimation of forest volume through a multistage sampling technique, with probability proportional to size, is also discussed.

The health of older Mexican Americans in the long run.

PubMed

González, Hector M; Ceballos, Miguel; Tarraf, Wassim; West, Brady T; Bowen, Mary E; Vega, William A

2009-10-01

We compared risk for several medical illnesses between immigrant and US-born older Mexican Americans to determine the relationship between functional health and years of US residency among immigrants. Cross-sectional, multistage probability sample data for 3050 Mexican Americans aged 65 years or older from 5 US southwestern states were analyzed. Self-rated health, medical illnesses, and functional measures were examined in multivariate regression models that included nativity and years of US residency as key predictors. Self-rated health and medical illnesses of immigrant and US-born groups did not differ significantly. Immigrants with longer US residency had significantly higher cognitive functioning scores and fewer problems with functional activities after adjustment for predisposing and medical need factors. Among older Mexican Americans, immigrant health advantages over their US-born counterparts were not apparent. Immigrants had better health functioning with longer US residency that may derive from greater socioeconomic resources. Our findings suggest that the negative acculturation-health relationship found among younger immigrant adults may become a positive relationship in later life.

Screened selection design for randomised phase II oncology trials: an example in chronic lymphocytic leukaemia

PubMed Central

2013-01-01

Background As there are limited patients for chronic lymphocytic leukaemia trials, it is important that statistical methodologies in Phase II efficiently select regimens for subsequent evaluation in larger-scale Phase III trials. Methods We propose the screened selection design (SSD), which is a practical multi-stage, randomised Phase II design for two experimental arms. Activity is first evaluated by applying Simon’s two-stage design (1989) on each arm. If both are active, the play-the-winner selection strategy proposed by Simon, Wittes and Ellenberg (SWE) (1985) is applied to select the superior arm. A variant of the design, Modified SSD, also allows the arm with the higher response rates to be recommended only if its activity rate is greater by a clinically-relevant value. The operating characteristics are explored via a simulation study and compared to a Bayesian Selection approach. Results Simulations showed that with the proposed SSD, it is possible to retain the sample size as required in SWE and obtain similar probabilities of selecting the correct superior arm of at least 90%; with the additional attractive benefit of reducing the probability of selecting ineffective arms. This approach is comparable to a Bayesian Selection Strategy. The Modified SSD performs substantially better than the other designs in selecting neither arm if the underlying rates for both arms are desirable but equivalent, allowing for other factors to be considered in the decision making process. Though its probability of correctly selecting a superior arm might be reduced, it still performs reasonably well. It also reduces the probability of selecting an inferior arm. Conclusions SSD provides an easy to implement randomised Phase II design that selects the most promising treatment that has shown sufficient evidence of activity, with available R codes to evaluate its operating characteristics. PMID:23819695

Screened selection design for randomised phase II oncology trials: an example in chronic lymphocytic leukaemia.

PubMed

Yap, Christina; Pettitt, Andrew; Billingham, Lucinda

2013-07-03

As there are limited patients for chronic lymphocytic leukaemia trials, it is important that statistical methodologies in Phase II efficiently select regimens for subsequent evaluation in larger-scale Phase III trials. We propose the screened selection design (SSD), which is a practical multi-stage, randomised Phase II design for two experimental arms. Activity is first evaluated by applying Simon's two-stage design (1989) on each arm. If both are active, the play-the-winner selection strategy proposed by Simon, Wittes and Ellenberg (SWE) (1985) is applied to select the superior arm. A variant of the design, Modified SSD, also allows the arm with the higher response rates to be recommended only if its activity rate is greater by a clinically-relevant value. The operating characteristics are explored via a simulation study and compared to a Bayesian Selection approach. Simulations showed that with the proposed SSD, it is possible to retain the sample size as required in SWE and obtain similar probabilities of selecting the correct superior arm of at least 90%; with the additional attractive benefit of reducing the probability of selecting ineffective arms. This approach is comparable to a Bayesian Selection Strategy. The Modified SSD performs substantially better than the other designs in selecting neither arm if the underlying rates for both arms are desirable but equivalent, allowing for other factors to be considered in the decision making process. Though its probability of correctly selecting a superior arm might be reduced, it still performs reasonably well. It also reduces the probability of selecting an inferior arm. SSD provides an easy to implement randomised Phase II design that selects the most promising treatment that has shown sufficient evidence of activity, with available R codes to evaluate its operating characteristics.

Mouse allergen exposure and decreased risk of allergic rhinitis in school-aged children.

PubMed

Jacobs, Tammy S; Forno, Erick; Brehm, John M; Acosta-Pérez, Edna; Han, Yueh-Ying; Blatter, Joshua; Thorne, Peter; Metwali, Nervana; Colón-Semidey, Angel; Alvarez, María; Canino, Glorisa; Celedón, Juan C

2014-12-01

Little is known about exposure to mouse allergen (Mus m 1) and allergic rhinitis (AR). To evaluate the association between mouse allergen exposure and AR in children. We examined the relation between mouse allergen level in house dust and AR in 511 children aged 6 to 14 years in San Juan, Puerto Rico. Study participants were chosen from randomly selected households using a multistage probability sample design. The study protocol included questionnaires, allergy skin testing, and collection of blood and dust samples. AR was defined as current rhinitis symptoms and skin test reactivity to at least one allergen. In the multivariate analyses, mouse allergen level was associated with a 25% decreased odds of AR in participating children (95% confidence interval, 0.62-0.92). Although endotoxin and mouse allergen levels were significantly correlated (r = 0.184, P < .001), the observed inverse association between Mus m 1 and AR was not explained by levels of endotoxin or other markers of microbial or fungal exposure (peptidoglycan and glucan). Mouse allergen exposure is associated with decreased odds of AR in Puerto Rican school-aged children. Copyright © 2014 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Migration and depressive symptoms in migrant-sending areas: findings from the survey of internal migration and health in China.

PubMed

Lu, Yao; Hu, Peifeng; Treiman, Donald J

2012-08-01

China has experienced large-scale internal migration and growing mental health disorders. Limited research has examined the relationship between the two processes. We examined the association between labor out-migration and depressive symptoms of family members left behind in migrant-sending areas. We conducted a multistage probability sample survey of Chinese adults in 2008 ("Internal Migration and Health in China"), including 787 people in rural migrant-sending areas. To study whether adults in out-migrant households were more likely to experience depressive symptoms (CES-D) than were adults in non-migrant households, we used multivariate regressions and adjusted for a wide range of confounding factors and for the complex sampling design. Adults in households with labor out-migrants were more likely to report depressive symptoms than those in households without out-migrants, presumably a result of the absence of family members. However, monetary remittances from labor migrants buffered the mental health costs of out-migration. Labor out-migration has important consequences for the mental health in migrant-sending communities. There is an urgent need to address the psychological costs of migration and to promote regular remittances.

Systems perspective: understanding care giving of the elderly in India.

PubMed

Gupta, Rashmi

2009-12-01

In this article I propose a systems model of elder care giver burden among Indian care givers. The systems model specifies the effects of elder characteristics, family structure, and personal characteristics of the care giver on care giver burden. Sampling was conducted using a multistage probability method to generate a sample of 259 care givers. The care giver burden questionnaire was translated from English to Hindi and then back into English and pilot tested before implementation. The care givers were interviewed via face-to-face interviews. Regression analysis was used to estimate the effects of the hypothesized determinants on care giver burden. The r square explained 46% of the variance in care giver burden. The following variables were significant from three dimensions: personal characteristics, elder characteristics, and family level. Personal characteristics of the care giver included whether they adhered to Asian cultural norms, the age of the care giver, and gender. Elder characteristics included behavioral problems of the elder. Family functional variables included number of care giving tasks provided by the care giver, and level of family income. Social work practice issues are discussed in the context of this study.

Public perceptions toward mental illness in Japan.

PubMed

Kasahara-Kiritani, Mami; Matoba, Tomoko; Kikuzawa, Saeko; Sakano, Junko; Sugiyama, Katsumi; Yamaki, Chikako; Mochizuki, Mieko; Yamazaki, Yoshihiko

2018-05-16

The purpose was to characterize public perceptions in Japan of mental illness and how they related to stigma-related attitudes for the same. Data were obtained using a vignette survey conducted as a part of the Stigma in Global Context - Mental Health Study and contained a nationally representative sample (n = 994). The survey was conducted using a multi-mode approach (face-to-face interviews, the drop-off-and-pick-up, postal collection) from September to December 2006, with a multi-stage probability sample of Japanese residents aged 18-64 years. Respondents were randomly assigned one of four vignette conditions that described psychiatric disorders meeting the diagnostic criteria for schizophrenia and major depressive disorder (one vignette for each gender exhibiting each diagnosis). We compared respondents' stigma-related attitudes and perceptions toward mental illness between vignettes. Over 80% of Japanese participants believed that depressive disorder or schizophrenia could be cured via treatment. However, Japanese people still had relatively strong vigilance and denial of competency toward schizophrenia. Participants expressed the belief that mental illnesses are curable, but stigma toward people with schizophrenia was still relatively strong. Copyright © 2018 Elsevier B.V. All rights reserved.

Consumption of psychoactive substances in educational institutions: an inquiry into the state of affairs in the schools of Córdoba.

PubMed

Lucchese, M S M; Burrone, M S; Enders, J E; Fernández, A R

2014-01-01

This study describes and analyses the consumption of psychoactive substances in educational institutions, the school environment conditions and its relation to the school standing of the students. In the first stage, a quantitative evaluation was performed, based on the records of the Second National Survey of Secondary School Students carried out in Córdoba in 2005; the second stage used a qualitative approach. A multistage probabilistic sample of 4593 students was used for the quantitative assessment. The analysis comprised summary measurements, multivariate and factorial correspondence analysis, in all cases with a significance level of p < 0.05. For the qualitative stage, an ethnographic approach was applied. The state schools were chosen using an intentional, cumulative and sequential sampling method. Ten in-depth interviews were carried out to gather qualitative data that was analyzed using the comparative constant method. Results evince that consumption is lower among morning-shift students and that grade repetition and behavior problems are associated to consumption of illegal drugs. Furthermore, it was detected that students in night-shift schools with low academic and disciplinary demand standards have a higher probability of consumption. It is clear that as academic standards decrease, consumption increases.

Financial risk sharing with providers in health maintenance organizations, 1999.

PubMed

Gold, Marsha R; Lake, Timothy; Hurley, Robert; Sinclair, Michael

2002-01-01

The transfer of financial risk from health maintenance organizations (HMOs) to providers is controversial. To provide timely national data on these practices, we conducted a telephone survey in 1999 of a multi-staged probability sample of HMOs in 20 of the nation's 60 largest markets, accounting for 86% of all HMO enrollees nationally. Among those sampled, 82% responded. We found that HMOs' provider networks with physicians, hospitals, skilled nursing homes, and home health agencies are complex and multi-tiered Seventy-six percent of HMOs in our study use contracts for their HMO products that involve global, professional services, or hospital risk capitation to intermediate entities. These arrangements account for between 24.5 million and 27.4 million of the 55.9 million commercial and Medicare HMO enrollees in the 60 largest markets. While capitation arrangements are particularly common in California, they are more common elsewhere than many assume. The complex layering of risk sharing and delegation of care management responsibility raise questions about accountability and administrative costs in managed care. Do complex structures provide a way to involve providers more directly in managed care, or do they diffuse authority and add to administrative costs?

Receiving treatment, labor force activity, and work performance among people with psychiatric disorders: results from a population survey.

PubMed

Waghorn, Geoffrey; Chant, David

2011-12-01

Standard treatments for psychiatric disorders such as schizophrenia, depression and anxiety disorders are generally expected to benefit individuals, employers, and the wider community through improvements in work-functioning and productivity. We repeated a previous secondary investigation of receiving treatment, labor force activity and self-reported work performance among people with ICD-10 psychiatric disorders, in comparison to people with other types of health conditions. Data were collected by the Australian Bureau of Statistics in 2003 repeating a survey administered in 1998 using representative multistage sampling strategies. The 2003 household probability sample consisted of 36,241 working age individuals. Consistent with the previous secondary investigation based on the 1998 survey administration, receiving treatment was consistently associated with non-participation in the labor force, and was negatively associated with work performance. At a population level, receiving treatment was negatively associated with labor force activity and work performance. The stability of these results in two independent surveys highlights the need to investigate the longitudinal relationships between evidence-based treatments for psychiatric conditions as applied in real-world settings, and labor force participation and work performance outcomes.

[Ioduria and iodine concentration in table salt in Peruvian elementary schoolchildren].

PubMed

Tarqui-Mamani, Carolina; Alvarez-Dongo, Doris; Fernández-Tinco, Inés

2016-01-01

To determine the ioduria and iodine concentration in table salt in Peruvian elementary schoolchildren. A cross-sectional study was performed. A total of 8,023 elementary schoolchildren, who voluntarily participated, were included. Multistage stratified probability sampling was performed, and the sample was obtained by systematic selection. Ioduria was determined via spectrophotometry (Sandell-Kolthoff method), and the amount of iodine in salt was evaluated volumetrically. The data were processed by means of analysis for complex samples with a weighting factor. Medians, percentiles, and confidence intervals were calculated, and the Mann-Whitney U and Kruskal-Wallis H tests were used, where appropriate. Nationwide, the median ioduria in schoolchildren was 258.53 ug/L, being higher in boys (265.90 ug/L) than in girls (250.77 ug/L). The median ioduria in urban areas was higher (289.89 ug/L) than that in rural areas (199.67 ug/L), while it was 315.48 ug/L in private schools and 241.56 ug/L in public schools (p<0.001). The median iodine concentration in table salt was 28.69 mg/kg. Of the total salt samples, 23.1% contained less than 15 mg/kg of iodine. The median ioduria in elementary schoolchildren exceeded normal levels, according to the criteria of the World Health Organization, with differences between urban and rural areas and public and private schools.

Types of Bullying in the Senior High Schools in Ghana

ERIC Educational Resources Information Center

Antiri, Kwasi Otopa

2016-01-01

The main objective of the study was to examine the types of bullying that were taking place in the senior high schools in Ghana. A multi-stage sampling procedure, comprising purposive, simple random and snowball sampling technique, was used in the selection of the sample. A total of 354 respondents were drawn six schools in Ashanti, Central and…

Multistage point relascope and randomized branch sampling for downed coarse woody debris estimation

Treesearch

Jeffrey H. Gove; Mark J. Ducey; Harry T. Valentine

2002-01-01

New sampling methods have recently been introduced that allow estimation of downed coarse woody debris using an angle gauge, or relascope. The theory behind these methods is based on sampling straight pieces of downed coarse woody debris. When pieces deviate from this ideal situation, auxillary methods must be employed. We describe a two-stage procedure where the...

Alternatives to Three-Mode Factor Analysis: A Case Study with Data Evaluating Perceived Barriers to Medical School Training.

ERIC Educational Resources Information Center

Thomson, William A.; And Others

While educational researchers frequently collect data from a sample of individuals on a sample of variables, they sometimes collect data involving samples of: (1) subjects; (2) variables; and (3) occasions of measurement. A multistage procedure for analyzing such three-mode data is presented, focusing on effect sizes and graphic confidence…

Midwives Performance in Early Detection of Growth and Development Irregularities of Children Based on Task Commitment

ERIC Educational Resources Information Center

Utami, Sri; Nursalam; Hargono, Rachmat; Susilaningrum, Rekawati

2016-01-01

The purpose of this study was to analyze the performance of midwives based on the task commitment. This was an observational analytic with cross sectional approach. Multistage random sampling was used to determine the public health center, proportional random sampling to selected participants. The samples were 222 midwives in the public health…

Evaluation of a multi-arm multi-stage Bayesian design for phase II drug selection trials - an example in hemato-oncology.

PubMed

Jacob, Louis; Uvarova, Maria; Boulet, Sandrine; Begaj, Inva; Chevret, Sylvie

2016-06-02

Multi-Arm Multi-Stage designs aim at comparing several new treatments to a common reference, in order to select or drop any treatment arm to move forward when such evidence already exists based on interim analyses. We redesigned a Bayesian adaptive design initially proposed for dose-finding, focusing our interest in the comparison of multiple experimental drugs to a control on a binary criterion measure. We redesigned a phase II clinical trial that randomly allocates patients across three (one control and two experimental) treatment arms to assess dropping decision rules. We were interested in dropping any arm due to futility, either based on historical control rate (first rule) or comparison across arms (second rule), and in stopping experimental arm due to its ability to reach a sufficient response rate (third rule), using the difference of response probabilities in Bayes binomial trials between the treated and control as a measure of treatment benefit. Simulations were then conducted to investigate the decision operating characteristics under a variety of plausible scenarios, as a function of the decision thresholds. Our findings suggest that one experimental treatment was less efficient than the control and could have been dropped from the trial based on a sample of approximately 20 instead of 40 patients. In the simulation study, stopping decisions were reached sooner for the first rule than for the second rule, with close mean estimates of response rates and small bias. According to the decision threshold, the mean sample size to detect the required 0.15 absolute benefit ranged from 63 to 70 (rule 3) with false negative rates of less than 2 % (rule 1) up to 6 % (rule 2). In contrast, detecting a 0.15 inferiority in response rates required a sample size ranging on average from 23 to 35 (rules 1 and 2, respectively) with a false positive rate ranging from 3.6 to 0.6 % (rule 3). Adaptive trial design is a good way to improve clinical trials. It allows removing ineffective drugs and reducing the trial sample size, while maintaining unbiased estimates. Decision thresholds can be set according to predefined fixed error decision rates. ClinicalTrials.gov Identifier: NCT01342692 .

Development of Effective Teacher Program: Teamwork Building Program for Thailand's Municipal Schools

ERIC Educational Resources Information Center

Chantathai, Pimpka; Tesaputa, Kowat; Somprach, Kanokorn

2015-01-01

This research is aimed to formulate the effective teacher teamwork program in municipal schools in Thailand. Primary survey on current situation and problem was conducted to develop the plan to suggest potential programs. Samples were randomly selected from municipal schools by using multi-stage sampling method in order to investigate their…

The Impact of Education on Rural Women's Participation in Political and Economic Activities

ERIC Educational Resources Information Center

Bishaw, Alemayehu

2014-01-01

This study endeavored to investigate the impact of education on rural women's participation in political and economic activities. Six hundred rural women and 12 gender Activists were selected for this study from three Zones of Amhara Region, Ethiopia using multi-stage random sampling technique and purposeful sampling techniques respectively.…

Navigating complex sample analysis using national survey data.

PubMed

Saylor, Jennifer; Friedmann, Erika; Lee, Hyeon Joo

2012-01-01

The National Center for Health Statistics conducts the National Health and Nutrition Examination Survey and other national surveys with probability-based complex sample designs. Goals of national surveys are to provide valid data for the population of the United States. Analyses of data from population surveys present unique challenges in the research process but are valuable avenues to study the health of the United States population. The aim of this study was to demonstrate the importance of using complex data analysis techniques for data obtained with complex multistage sampling design and provide an example of analysis using the SPSS Complex Samples procedure. Illustration of challenges and solutions specific to secondary data analysis of national databases are described using the National Health and Nutrition Examination Survey as the exemplar. Oversampling of small or sensitive groups provides necessary estimates of variability within small groups. Use of weights without complex samples accurately estimates population means and frequency from the sample after accounting for over- or undersampling of specific groups. Weighting alone leads to inappropriate population estimates of variability, because they are computed as if the measures were from the entire population rather than a sample in the data set. The SPSS Complex Samples procedure allows inclusion of all sampling design elements, stratification, clusters, and weights. Use of national data sets allows use of extensive, expensive, and well-documented survey data for exploratory questions but limits analysis to those variables included in the data set. The large sample permits examination of multiple predictors and interactive relationships. Merging data files, availability of data in several waves of surveys, and complex sampling are techniques used to provide a representative sample but present unique challenges. In sophisticated data analysis techniques, use of these data is optimized.

Current status of contraceptive use among rural married women in Anhui Province of China.

PubMed

Zhang, X-J; Wang, G-Y; Shen, Q; Yu, Y-L; Sun, Y-H; Yu, G-B; Zhao, D; Ye, D-Q

2009-11-01

This study aims to explore the current status of married women in regard of their use of contraceptive methods (permanent methods versus non-permanent methods) and to find out factors that affect the use of contraceptive methods in rural areas of Anhui Province of China. Survey. Anhui, China. A total of 53,652 married women aged 18-49 years. A multistage probability sampling method was used to identify a representative sample of 53,652 married women aged 18-49 years. All women were asked to provide detailed information by completing detailed questionnaires. Contraceptive prevalence and influence factors. The total birth control rate of the sample was 95.2%. Samples choosing the permanent and nonpermanent contraceptive methods have taken up 46.7 and 48.5% respectively. Female sterilisation was the first choice with a usage rate of 43.6%, followed by intrauterine device (IUD), which was used by 41.1% of samples. Single-variable analysis showed that the choice of contraceptive methods was associated with age, education level, parity, frequency of sex intercourses in a month, contraceptive knowledge, RTI symptom and the gender of the last child of rural married women. A significant increase in contraceptive use of rural married women in Anhui Province of China. Female sterilisation and IUD still play the dominant role. Effective family planning methods should be advocated through adequate counselling on the correct use and proper management, with consideration of the background of custom and belief.

Adventures in Uncertainty: An Empirical Investigation of the Use of a Taylor's Series Approximation for the Assessment of Sampling Errors in Educational Research.

ERIC Educational Resources Information Center

Wilson, Mark

This study investigates the accuracy of the Woodruff-Causey technique for estimating sampling errors for complex statistics. The technique may be applied when data are collected by using multistage clustered samples. The technique was chosen for study because of its relevance to the correct use of multivariate analyses in educational survey…

[Influencing factors on depression among medical staff in Hunan province under ordinal regression analysis].

PubMed

Liu, Zhi-yu; Zhong, Meng; Hai, Yan; Du, Qi-yun; Wang, Ai-hua; Xie, Dong-hua

2012-11-01

To understand the situation of depression and its related influencing factors among medical staff in Hunan province. Data were collected through random sampling with multi-stage stratified cluster. Wilcoxon rank sum test, Kruskal-Wallis H test and Ordinal regression analysis were used for data analysis by SPSS 17.0 software. This survey was including 16,000 medical personnel with 14, 988 valid questionnaires and the effective rate was 93.68%. from the single factor analysis showed that factors as: level of the hospital grading, gender, education background, age, occupation, title, departments, the number of continue education, income, working overtime every week, the frequency of night work, the number of patients treated in the emergency room etc., had statistical significances (P < 0.05). Data from ordinal regression showed that the probabilities related to depression that clinicians and nurses suffering from were 1.58 times more than the pharmacists (OR = 1.58, 95%CI: 1.30 - 1.92). The probability among those whose income was less than 2000 Yuan/month was 2.19 times of the ones whose earned more than 3000 Yuan/month (OR = 2.19, 95%CI: 2.05 - 2.35). The higher the numbers of days with working overtime every week, the frequencies of night work, and the numbers of patients being treated at the emergency room, with more probabilities of the people with depression seen in our study. Depression seemed to be common among doctors and nurses. We suggested that the government need to increase the monthly income and to reduce the workload and intensity, lessen the overworking time, etc.

Determination of the Alternaria mycotoxin tenuazonic acid in cereals by high-performance liquid chromatography-electrospray ionization ion-trap multistage mass spectrometry after derivatization with 2,4-dinitrophenylhydrazine.

PubMed

Siegel, David; Rasenko, Tatjana; Koch, Matthias; Nehls, Irene

2009-05-22

Tenuazonic acid (TA) is a major Alternaria mycotoxin. In the present work a novel approach for the detection of TA in cereals by liquid chromatography-ion-trap multistage mass spectrometry after derivatization with 2,4-dinitrophenylhydrazine is described. The product of the derivatization reaction and its major MS(2) fragments were characterised by Fourier transform-ion cyclotron resonance tandem mass spectrometry. Without preconcentration, the established method features a limit of detection of 10 microg/kg using 2g of sample in a rapid workup procedure. Accuracy, precision and linearity were evaluated in the working range of 50-5000 microg/kg. TA was detected in 13 and quantified in 3 out of 27 cereal samples obtained from a local supermarket, the average content being 49 microg/kg (highest incidence: 851+/-41 microg/kg).

Cosmic ray exposure histories of Apollo 14, Apollo 15, and Apollo 16 rocks

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

Eugster, O.; Eberhardt, P.

1984-02-15

The regolith exposure history of six rocks returned by the Apollo 14, 15, and 16 missions is studied based on the cosmogenic noble gas isotopes. For each sample, the complete set of all stable noble gas isotopes and the radiaoctive isotope Kr-81 were measured. Kr-81-Kr exposure ages are calculated for rocks for which a single-stage exposure can be demonstrated. A two-stage model exposure history is derived for multistage-exposure basalt 14310 based on the amounts and isotopic ratios of the cosmogenic noble gases. The apparent Kr-81-Kr age, the depth-sensitive isostopic ratios, and fission Xe-136 results lead to the conclusion that thismore » sample was preexposed 1.75 AE ago to cosmic rays for a duration of 350 m.y. Basalt 15058 and anorthosite 15415 also reveal multistage exposures. 44 references.« less

Affective Structures among Students and Its Relationship with Academic Burnout with Emphasis on Gender

ERIC Educational Resources Information Center

Bikar, Somaye; Marziyeh, Afsaneh; Pourghaz, Abdolwahab

2018-01-01

This study aimed to determine the relationship between affective structures and academic burnout among male and female third-grade high school students in Zahedan in the academic year 2016-2017. The current descriptive-correlational study had a sample including 362 students selected using a multistage cluster sampling method. To collect data,…

Predicting Personality Resiliency by Psychological Well-Being and Its Components in Girl Students of Islamic Azad University

ERIC Educational Resources Information Center

Kajbafnezhad, Hadi; Khaneh Keshi, Ali

2015-01-01

The aim of this study was to predict psychological resilience by psychological well-being and its components. The research sample consisted of 216 girl students who were selected through multistage random sampling. The data were collected by implementing psychological resilience and psychological well-being questionnaire and analyzed by using…

The Relationship between Utilization of Computer Games and Spatial Abilities among High School Students

ERIC Educational Resources Information Center

Motamedi, Vahid; Yaghoubi, Razeyah Mohagheghyan

2015-01-01

This study aimed at investigating the relationship between computer game use and spatial abilities among high school students. The sample consisted of 300 high school male students selected through multi-stage cluster sampling. Data gathering tools consisted of a researcher made questionnaire (to collect information on computer game usage) and the…

Validity, Reliability and Difficulty Indices for Instructor-Built Exam Questions

ERIC Educational Resources Information Center

Jandaghi, Gholamreza; Shaterian, Fatemeh

2008-01-01

The purpose of the research is to determine college Instructor's skill rate in designing exam questions in chemistry subject. The statistical population was all of chemistry exam sheets for two semesters in one academic year from which a sample of 364 exam sheets was drawn using multistage cluster sampling. Two experts assessed the sheets and by…

Socio-Economic Background and Access to Internet as Correlates of Students' Achievement in Agricultural Science

ERIC Educational Resources Information Center

Adegoke, Sunday Paul; Osokoya, Modupe M.

2015-01-01

This study investigated access to internet and socio-economic background as correlates of students' achievement in Agricultural Science among selected Senior Secondary Schools Two Students in Ogbomoso South and North Local Government Areas. The study adopted multi-stage sampling technique. Simple random sampling was used to select 30 students from…

Inspection logistics planning for multi-stage production systems with applications to semiconductor fabrication lines

NASA Astrophysics Data System (ADS)

Chen, Kyle Dakai

Since the market for semiconductor products has become more lucrative and competitive, research into improving yields for semiconductor fabrication lines has lately received a tremendous amount of attention. One of the most critical tasks in achieving such yield improvements is to plan the in-line inspection sampling efficiently so that any potential yield problems can be detected early and eliminated quickly. We formulate a multi-stage inspection planning model based on configurations in actual semiconductor fabrication lines, specifically taking into account both the capacity constraint and the congestion effects at the inspection station. We propose a new mixed First-Come-First-Serve (FCFS) and Last-Come-First-Serve (LCFS) discipline for serving the inspection samples to expedite the detection of potential yield problems. Employing this mixed FCFS and LCFS discipline, we derive approximate expressions for the queueing delays in yield problem detection time and develop near-optimal algorithms to obtain the inspection logistics planning policies. We also investigate the queueing performance with this mixed type of service discipline under different assumptions and configurations. In addition, we conduct numerical tests and generate managerial insights based on input data from actual semiconductor fabrication lines. To the best of our knowledge, this research is novel in developing, for the first time in the literature, near-optimal results for inspection logistics planning in multi-stage production systems with congestion effects explicitly considered.

A Systematic Approach to Determining the Identifiability of Multistage Carcinogenesis Models.

PubMed

Brouwer, Andrew F; Meza, Rafael; Eisenberg, Marisa C

2017-07-01

Multistage clonal expansion (MSCE) models of carcinogenesis are continuous-time Markov process models often used to relate cancer incidence to biological mechanism. Identifiability analysis determines what model parameter combinations can, theoretically, be estimated from given data. We use a systematic approach, based on differential algebra methods traditionally used for deterministic ordinary differential equation (ODE) models, to determine identifiable combinations for a generalized subclass of MSCE models with any number of preinitation stages and one clonal expansion. Additionally, we determine the identifiable combinations of the generalized MSCE model with up to four clonal expansion stages, and conjecture the results for any number of clonal expansion stages. The results improve upon previous work in a number of ways and provide a framework to find the identifiable combinations for further variations on the MSCE models. Finally, our approach, which takes advantage of the Kolmogorov backward equations for the probability generating functions of the Markov process, demonstrates that identifiability methods used in engineering and mathematics for systems of ODEs can be applied to continuous-time Markov processes. © 2016 Society for Risk Analysis.

A new multistage groundwater transport inverse method: presentation, evaluation, and implications

USGS Publications Warehouse

Anderman, Evan R.; Hill, Mary C.

1999-01-01

More computationally efficient methods of using concentration data are needed to estimate groundwater flow and transport parameters. This work introduces and evaluates a three‐stage nonlinear‐regression‐based iterative procedure in which trial advective‐front locations link decoupled flow and transport models. Method accuracy and efficiency are evaluated by comparing results to those obtained when flow‐ and transport‐model parameters are estimated simultaneously. The new method is evaluated as conclusively as possible by using a simple test case that includes distinct flow and transport parameters, but does not include any approximations that are problem dependent. The test case is analytical; the only flow parameter is a constant velocity, and the transport parameters are longitudinal and transverse dispersivity. Any difficulties detected using the new method in this ideal situation are likely to be exacerbated in practical problems. Monte‐Carlo analysis of observation error ensures that no specific error realization obscures the results. Results indicate that, while this, and probably other, multistage methods do not always produce optimal parameter estimates, the computational advantage may make them useful in some circumstances, perhaps as a precursor to using a simultaneous method.

Multi-level scanning method for defect inspection

DOEpatents

Bokor, Jeffrey; Jeong, Seongtae

2002-01-01

A method for performing scanned defect inspection of a collection of contiguous areas using a specified false-alarm-rate and capture-rate within an inspection system that has characteristic seek times between inspection locations. The multi-stage method involves setting an increased false-alarm-rate for a first stage of scanning, wherein subsequent stages of scanning inspect only the detected areas of probable defects at lowered values for the false-alarm-rate. For scanning inspection operations wherein the seek time and area uncertainty is favorable, the method can substantially increase inspection throughput.

Impact of Dental Disorders and its Influence on Self Esteem Levels among Adolescents.

PubMed

Kaur, Puneet; Singh, Simarpreet; Mathur, Anmol; Makkar, Diljot Kaur; Aggarwal, Vikram Pal; Batra, Manu; Sharma, Anshika; Goyal, Nikita

2017-04-01

Self esteem is more of a psychological concept therefore, even the common dental disorders like dental trauma, tooth loss and untreated carious lesions may affect the self esteem thus influencing the quality of life. This study aims to assess the impact of dental disorders among the adolescents on their self esteem level. The present cross-sectional study was conducted among 10 to 17 years adolescents. In order to obtain a representative sample, multistage sampling technique was used and sample was selected based on Probability Proportional to Enrolment size (PPE). Oral health assessment was carried out using WHO type III examination and self esteem was estimated using the Rosenberg Self Esteem Scale score (RSES). The descriptive and inferential analysis of the data was done by using IBM SPSS software. Logistic and linear regression analysis was executed to test the individual association of different independent clinical variables with self esteem. Total sample of 1140 adolescents with mean age of 14.95 ±2.08 and RSES of 27.09 ±3.12 were considered. Stepwise multiple linear regression analysis was applied and best predictors in relation to RSES in the descending order were Dental Health Component (DHC), Aesthetic Component (AC), dental decay {(aesthetic zone), (masticatory zone)}, tooth loss {(aesthetic zone), (masticatory zone)} and anterior fracture of tooth. It was found that various dental disorders like malocclusion, anterior traumatic tooth, tooth loss and untreated decay causes a profound impact on aesthetics and psychosocial behaviour of adolescents, thus affecting their self esteem.

Quantitative Research on the Outcomes of China's Inland Tibetan Classes and Schools Policy: A Survey of Graduates

ERIC Educational Resources Information Center

Xiaorong, Wu

2015-01-01

Under the Inland Tibetan Classes and Schools Policy, China has trained a large number of personnel to facilitate the social, economic, and cultural development of Tibet. This study used a multistage, random sample survey to collect data on the comprehensive qualities of two sample groups of personnel in Tibet: graduates and nongraduates of inland…

The Role of Socio-Cognitive Variables in Predicting Learning Satisfaction in Smart Schools

ERIC Educational Resources Information Center

Firoozi, Mohammad Reza; Kazemi, Ali; Jokar, Maryam

2017-01-01

The present study aimed to investigate the role of Socio-Cognitive variables in predicting learning satisfaction in Smart Schools. The population was all the primary school students studying in smart schools in the city of Shiraz in the school year 2014-2015. The sample, randomly chosen through multi-stage cluster sampling, was 383 primary school…

Teachers' Methodologies and Sources of Information on HIV/AIDS for Students with Visual Impairments in Selected Residential and Integrated Schools in Ghana

ERIC Educational Resources Information Center

Hayford, Samuel K.; Ocansey, Frederick

2017-01-01

This study reports part of a national survey on sources of information, education and communication materials on HIV/AIDS available to students with visual impairments in residential, segregated, and integrated schools in Ghana. A multi-staged stratified random sampling procedure and a purposive and simple random sampling approach, where…

The prevalence of selected potentially hazardous workplace exposures in the US: findings from the 2010 National Health Interview Survey.

PubMed

Calvert, Geoffrey M; Luckhaupt, Sara E; Sussell, Aaron; Dahlhamer, James M; Ward, Brian W

2013-06-01

Assess the national prevalence of current workplace exposure to potential skin hazards, secondhand smoke (SHS), and outdoor work among various industry and occupation groups. Also, assess the national prevalence of chronic workplace exposure to vapors, gas, dust, and fumes (VGDF) among these groups. Data were obtained from the 2010 National Health Interview Survey (NHIS). NHIS is a multistage probability sample survey of the civilian non-institutionalized population of the US. Prevalence rates and their variances were calculated using SUDAAN to account for the complex NHIS sample design. The data for 2010 were available for 17,524 adults who worked in the 12 months that preceded interview. The highest prevalence rates of hazardous workplace exposures were typically in agriculture, mining, and construction. The prevalence rate of frequent handling of or skin contact with chemicals, and of non-smokers frequently exposed to SHS at work was highest in mining and construction. Outdoor work was most common in agriculture (85%), construction (73%), and mining (65%). Finally, frequent occupational exposure to VGDF was most common among mining (67%), agriculture (53%), and construction workers (51%). We identified industries and occupations with the highest prevalence of potentially hazardous workplace exposures, and provided targets for investigation and intervention activities. Copyright © 2012 Wiley Periodicals, Inc.

Does income inequality get under the skin? A multilevel analysis of depression, anxiety and mental disorders in Sao Paulo, Brazil.

PubMed

Chiavegatto Filho, Alexandre Dias Porto; Kawachi, Ichiro; Wang, Yuan Pang; Viana, Maria Carmen; Andrade, Laura Helena Silveira Guerra

2013-11-01

Test the original income inequality theory, by analysing its association with depression, anxiety and any mental disorders. We analysed a sample of 3542 individuals aged 18 years and older selected through a stratified, multistage area probability sample of households from the São Paulo Metropolitan Area. Mental disorder symptoms were assessed using the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. Bayesian multilevel logistic models were performed. Living in areas with medium and high-income inequality was statistically associated with increased risk of depression, relative to low-inequality areas (OR 1.76; 95% CI 1.21 to 2.55, and 1.53; 95% CI 1.07 to 2.19, respectively). The same was not true for anxiety (OR 1.25; 95% CI 0.90 to 1.73, and OR 1.07; 95% CI 0.79 to 1.46). In the case of any mental disorder, results were mixed. In general, our findings were consistent with the income inequality theory, that is, people living in places with higher income inequality had an overall higher odd of mental disorders, albeit not always statistically significant. The fact that depression, but not anxiety, was statistically significant could indicate a pathway by which inequality influences health.

Relationship between the levels of family burden in caring for older people with the incidence of mistreatment.

PubMed

Rekawati, Etty; Hamid, AchirYani S; Sahar, Junaiti; Widyatuti

2018-02-01

Caring for older people can be a burden for the family that led to mistreatment. To determine the relationship between the levels of family burden in caring for older people with the occurrence of mistreatment incidence. A cross sectional study design was conducted with 135 older people who live with their family as respondents. 135 families with older people at Kelurahan/Village of Harjamukti area, Kecamatan/ District of Cimanggis, Depok city. This study applied probability sampling technique with multistage cluster sampling. Family characteristics show that almost half of older people were caring by family members (caregivers) who were aged 20-39 years, nearly all caregivers were women, family income mostly less than UMK, families mostly monosyllabic nation Betawi and caregivers mostly were their own child. Most of the families stated that no expense in caring for the older people (89.6%), but there are still families who feel the burden of caring. The highest type of mistreatmet of the older people is psychological mistreatments. From the statistical test obtained by p value equals to 0.553, it was concluded there was no correlation between the incidences of any family burden with mistreatment. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

The Effect of Widowhood on Parent-Child Relationships in Korea: Do Parents' Filial Expectations and Geographic Proximity to Children Matter?

PubMed

Ha, Jung-Hwa; Yoon, Hyunsook; Lim, Yeon Ok; Heo, Sun-Young

2016-03-01

Although previous research based on data from the U.S. suggests that parents' widowhood is associated with increased emotional support from children, little is known about the impact of late-life widowhood on intergenerational relationships in other cultures. Using data of Korean older adults, this paper examined: (1) the effect of widowhood on both positive and negative aspects of parent-child relationships and (2) whether these effects are moderated by older adults' expectations about children's filial responsibilities and the geographic proximity to their children. Analyses are based on data from the Hallym Aging Study, a stratified multi-stage probability sample of older adults living in the cities of Seoul and Chuncheon in Korea. Compared to married older adults, widowed persons in this sample reported higher levels of ambivalence, lower levels of positive interactions, and higher levels of negative interactions with their children. Parents' notion about filial responsibilities did not have a significant moderating effect, whereas geographic proximity to children was a significant moderator. Findings suggest that widowhood is associated with greater strain in intergenerational relationships in Korea. Helping widowed older adults forge constructive relationships with their children may enhance both bereaved older adults' and their children's well-being in this cultural milieu.

The Prevalence of Selected Potentially Hazardous Workplace Exposures in the US: Findings From the 2010 National Health Interview Survey

PubMed Central

Calvert, Geoffrey M.; Luckhaupt, Sara E.; Sussell, Aaron; Dahlhamer, James M.; Ward, Brian W.

2015-01-01

Objective Assess the national prevalence of current workplace exposure to potential skin hazards, secondhand smoke (SHS), and outdoor work among various industry and occupation groups. Also, assess the national prevalence of chronic workplace exposure to vapors, gas, dust, and fumes (VGDF) among these groups. Methods Data were obtained from the 2010 National Health Interview Survey (NHIS). NHIS is a multistage probability sample survey of the civilian non-institutionalized population of the US. Prevalence rates and their variances were calculated using SUDAAN to account for the complex NHIS sample design. Results The data for 2010 were available for 17,524 adults who worked in the 12 months that preceded interview. The highest prevalence rates of hazardous workplace exposures were typically in agriculture, mining, and construction. The prevalence rate of frequent handling of or skin contact with chemicals, and of non-smokers frequently exposed to SHS at work was highest in mining and construction. Outdoor work was most common in agriculture (85%), construction (73%), and mining (65%). Finally, frequent occupational exposure to VGDF was most common among mining (67%), agriculture (53%), and construction workers (51%). Conclusion We identified industries and occupations with the highest prevalence of potentially hazardous workplace exposures, and provided targets for investigation and intervention activities. PMID:22821700

Self-Reported and Network Scale-Up Estimates of Substance Use Prevalence among University Students in Kerman, Iran.

PubMed

Zahedi, Razieh; Noroozi, Alireza; Hajebi, Ahmad; Haghdoost, Ali Akbar; Baneshi, Mohammad Reza; Sharifi, Hamid; Mirzazadeh, Ali

2018-04-30

This study aimed to estimate the prevalence of substance use among university students measured by direct and indirect methods, and to calculate the visibility factor (VF) defined as ratio of indirect to direct estimates of substance use prevalence. A cross-sectional study. Using a multistage non-random sampling approach, we recruited 2157 students from three universities in Kerman, Iran, in 2016. We collected data on substance use by individual face-to-face interview using direct (i.e. self-report of their own behaviors) and indirect (NSU: Network scale up) methods. All estimates from direct and indirect methods were weighted based on inverse probability weight of sampling university. The response rate was 83.6%. The last year prevalence of water pipe, alcohol, and cigarettes indirect method was 44.6%, 18.1%, and 13.2% respectively. Corresponding figures in NSU analysis were 36.4%, 18.2%, and 16.5% respectively. In the female population, VF for all types of substance was less than male. Considerable numbers of university students used substances like a water pipe, alcohol, and cigarettes. NSU seems a promising method, especially among male students. Among female students, direct method provided more reliable results mainly due to transmission and prestige biases.

Estimation and Selection via Absolute Penalized Convex Minimization And Its Multistage Adaptive Applications

PubMed Central

Huang, Jian; Zhang, Cun-Hui

2013-01-01

The ℓ1-penalized method, or the Lasso, has emerged as an important tool for the analysis of large data sets. Many important results have been obtained for the Lasso in linear regression which have led to a deeper understanding of high-dimensional statistical problems. In this article, we consider a class of weighted ℓ1-penalized estimators for convex loss functions of a general form, including the generalized linear models. We study the estimation, prediction, selection and sparsity properties of the weighted ℓ1-penalized estimator in sparse, high-dimensional settings where the number of predictors p can be much larger than the sample size n. Adaptive Lasso is considered as a special case. A multistage method is developed to approximate concave regularized estimation by applying an adaptive Lasso recursively. We provide prediction and estimation oracle inequalities for single- and multi-stage estimators, a general selection consistency theorem, and an upper bound for the dimension of the Lasso estimator. Important models including the linear regression, logistic regression and log-linear models are used throughout to illustrate the applications of the general results. PMID:24348100

The skin whitening industry in the Philippines.

PubMed

Mendoza, Roger Lee

2014-05-01

Skin whitening is a big and booming industry in many developing countries. Its popularity owes mainly to post-colonial, internalized racism. This study examines whether government intervention is necessary and more efficient than market-driven approaches in addressing the health risks and harms associated with skin whitening. We gathered empirical data on the quality and quantity of health-related information about skin whiteners with a multi-stage probability sample of consumers in two cities in the Philippines (n=110; α=0.05). Regardless of their socio-demographic characteristics, we find that cognitive biases and information asymmetries build and sustain consumers' trust in manufacturers and distributors of skin whiteners while, paradoxically, breeding uncertainties over the integrity of these products. The results are product adulteration and misbranding, leading to pricing advantages for toxic whiteners over safer products. This has impeded regulatory efficacy. We recommend anchoring government intervention in transaction cost-reduction, containing the externalities of skin bleaching, and institutionalizing third party partnerships. Failure to do so would leave consumers extremely vulnerable to the forces of supply and demand that favor toxic whiteners, particularly in a market where voluntary collective action is difficult to organize.

The association between second-hand smoke exposure and depressive symptoms among pregnant women.

PubMed

Huang, Jingya; Wen, Guoming; Yang, Weikang; Yao, Zhenjiang; Wu, Chuan'an; Ye, Xiaohua

2017-10-01

Tobacco smoking and depression are strongly associated, but the possible association between second-hand smoke (SHS) exposure and depression is unclear. This study aimed to examine the possible relation between SHS exposure and depressive symptoms among pregnant women. A cross-sectional survey was conducted in Shenzhen, China, using a multistage sampling method. The univariable and multivariable logistic regression models were used to explore the associations between SHS exposure and depressive symptoms. Among 2176 pregnant women, 10.5% and 2.0% were classified as having probable and severe depressive symptoms. Both binary and multinomial logistic regression revealed that there were significantly increased risks of severe depressive symptoms corresponding to SHS exposure in homes or regular SHS exposure in workplaces using no exposure as reference. In addition, greater frequency of SHS exposure was significantly associated with the increased risk of severe depressive symptoms. Our findings suggest that SHS exposure is positively associated with depressive symptoms in a dose-response manner among the pregnant women. Copyright © 2017 Elsevier B.V. All rights reserved.

Racial Targeting of Sexual Violence in Darfur

PubMed Central

Rymond-Richmond, Wenona; Palloni, Alberto

2009-01-01

Objectives. We used the Atrocities Documentation Survey to determine whether Sudanese government forces were involved in racially targeting sexual victimization toward ethnically African women in the Darfur region of western Sudan. Methods. The US State Department conducted the survey by interviewing a randomized multistage probability sample of 1136 Darfur refugees at 20 sites in Chad in 2004. For a subset of 932 respondents who had fled from village clusters that accounted for 15 or more respondents per cluster, we used hierarchical linear models to analyze village-level patterns of reported sexual violence. We statistically controlled for individual sexual victimization to remove bias. Results. Respondents reported being subjected to racial epithets associated with sexual victimization significantly more often during combined attacks by Sudanese government forces and Janjaweed militia forces than during separate attacks by either force. Conclusions. Combined attacks by Sudanese government forces and Janjaweed militia forces led to racial epithets being used more often during sexual victimization in Darfur. Our results suggest that the Sudanese government is participating in the use of sexual assault as a racially targeted weapon against ethnically African civilians. PMID:19542043

Racial targeting of sexual violence in Darfur.

PubMed

Hagan, John; Rymond-Richmond, Wenona; Palloni, Alberto

2009-08-01

We used the Atrocities Documentation Survey to determine whether Sudanese government forces were involved in racially targeting sexual victimization toward ethnically African women in the Darfur region of western Sudan. The US State Department conducted the survey by interviewing a randomized multistage probability sample of 1136 Darfur refugees at 20 sites in Chad in 2004. For a subset of 932 respondents who had fled from village clusters that accounted for 15 or more respondents per cluster, we used hierarchical linear models to analyze village-level patterns of reported sexual violence. We statistically controlled for individual sexual victimization to remove bias. Respondents reported being subjected to racial epithets associated with sexual victimization significantly more often during combined attacks by Sudanese government forces and Janjaweed militia forces than during separate attacks by either force. Combined attacks by Sudanese government forces and Janjaweed militia forces led to racial epithets being used more often during sexual victimization in Darfur. Our results suggest that the Sudanese government is participating in the use of sexual assault as a racially targeted weapon against ethnically African civilians.

Demand for Dental Services in Shiraz, Iran, 2013.

PubMed

Jahromi, Negin Nassaji; Jafari, Abdosaleh; Kavosi, Zahra; Shokrpour, Nasrin; Sajjadnia, Zahra; Ravangard, Ramin

This cross-sectional and descriptive-analytic study aimed to estimate the demands for the use of dental services by Shirazi inhabitants in Iran from June 2013 to October 2013. Six hundred eighty subjects older than 18 years were selected from among the people living in Shiraz, using a multistage sampling method. The collected data were analyzed using SPSS 16.0 and Stata 11.0. The results showed that the factors affecting the number of referrals to the dental services centers and the use of these services included the age groups of 28 to 37 and 38 to 47 years, household expenses per month, and having supplementary health insurance coverage (P < .05). According to the results, in order to improve access to dental services and increase the probability of utilizing such services by people in need, the researchers recommend that the authorities should design and develop basic and supplementary health insurance plans to cover different types of dental services, allocate subsidies to dental health services, and increase the knowledge of all the people in different age groups about adherence to dental health principles and prevention of oral and dental diseases.

Premarital sexual activity and contraceptive use in Santiago, Chile.

PubMed

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

1992-01-01

The Santiago Young Adult Reproductive Health Survey was conducted in 1988 to examine the sexual behavior of and contraceptive use among young adults in Chile. The survey was based on multistage household probability samples of 865 women and 800 men aged 15-24 who were living in Santiago in 1988. Findings show that 35 percent of females and 65 percent of males had had premarital intercourse. Among those who had done so, the median age at first experience was 18.4 years for women and 16.4 years for men. Only 20 percent of females and 19 percent of males used contraceptives at first premarital intercourse. Use of contraceptives increased with age at the time of that event. Fertility data reveal that 70 percent of first births were premaritally conceived, and more than one-third of these were born prior to union. The high rates of premarital and unintended pregnancy among young women and the low prevalence of effective contraceptive use indicate a need for greater emphasis on sex education and family planning services directed at adolescents and unmarried young adults in Santiago.

Pattern drilling exploration: Optimum pattern types and hole spacings when searching for elliptical shaped targets

USGS Publications Warehouse

Drew, L.J.

1979-01-01

In this study the selection of the optimum type of drilling pattern to be used when exploring for elliptical shaped targets is examined. The rhombic pattern is optimal when the targets are known to have a preferred orientation. Situations can also be found where a rectangular pattern is as efficient as the rhombic pattern. A triangular or square drilling pattern should be used when the orientations of the targets are unknown. The way in which the optimum hole spacing varies as a function of (1) the cost of drilling, (2) the value of the targets, (3) the shape of the targets, (4) the target occurrence probabilities was determined for several examples. Bayes' rule was used to show how target occurrence probabilities can be revised within a multistage pattern drilling scheme. ?? 1979 Plenum Publishing Corporation.

Grouping methods for estimating the prevalences of rare traits from complex survey data that preserve confidentiality of respondents.

PubMed

Hyun, Noorie; Gastwirth, Joseph L; Graubard, Barry I

2018-03-26

Originally, 2-stage group testing was developed for efficiently screening individuals for a disease. In response to the HIV/AIDS epidemic, 1-stage group testing was adopted for estimating prevalences of a single or multiple traits from testing groups of size q, so individuals were not tested. This paper extends the methodology of 1-stage group testing to surveys with sample weighted complex multistage-cluster designs. Sample weighted-generalized estimating equations are used to estimate the prevalences of categorical traits while accounting for the error rates inherent in the tests. Two difficulties arise when using group testing in complex samples: (1) How does one weight the results of the test on each group as the sample weights will differ among observations in the same group. Furthermore, if the sample weights are related to positivity of the diagnostic test, then group-level weighting is needed to reduce bias in the prevalence estimation; (2) How does one form groups that will allow accurate estimation of the standard errors of prevalence estimates under multistage-cluster sampling allowing for intracluster correlation of the test results. We study 5 different grouping methods to address the weighting and cluster sampling aspects of complex designed samples. Finite sample properties of the estimators of prevalences, variances, and confidence interval coverage for these grouping methods are studied using simulations. National Health and Nutrition Examination Survey data are used to illustrate the methods. Copyright © 2018 John Wiley & Sons, Ltd.

Private Universities in Kenya Seek Alternative Ways to Manage Change in Teacher Education Curriculum in Compliance with the Commission for University Education Reforms

ERIC Educational Resources Information Center

Amimo, Catherine Adhiambo

2016-01-01

This study investigated management of change in teacher education curriculum in Private universities in Kenya. The study employed a concurrent mixed methods design that is based on the use of both quantitative and qualitative approaches. A multi-stage sampling process which included purposive, convenience, cluster, and snowball sampling methods…

Relationship between the Religious Attitude, Self-Efficacy, and Life Satisfaction in High School Teachers of Mahshahr City

ERIC Educational Resources Information Center

Bigdeloo, Masoomeh; Bozorgi, Zahra Dasht

2016-01-01

This study aims to investigate the relationship between the religious attitude, self-efficacy, and life satisfaction in high school teachers of Mahshahr City. To this end, 253 people of all high school teachers in Mahshahr City, in Iran were selected as the sample using the multistage cluster sampling method. For data collection, Glock and Stark's…

Student Assessment of Quality of Access at the National Open University of Nigeria (NOUN)

ERIC Educational Resources Information Center

Inegbedion, Juliet O.; Adu, Folorunso I.; Ofulue, Christine Y.

2016-01-01

This paper presents a study conducted by Inegbedion, Adu and Ofulue from the National Open University of Nigeria. The study focused on the quality of access (admission and registration) at NOUN from a student perspective. A survey design was used for the study while a multi-stage sampling technique was used to select the sample size. All the…

A Gender Based Study on Job Satisfaction among Higher Secondary School Heads in Khyber Pakhtunkhwa, (Pakistan)

ERIC Educational Resources Information Center

Mumtaz, Safina; Suleman, Qaiser; Ahmad, Zubair

2016-01-01

The purpose of the study was to analyze and compare the job satisfaction with twenty dimensions of male and female higher secondary school heads in Khyber Pakhtunkhwa. A total of 108 higher secondary school heads were selected from eleven districts as sample through multi-stage sampling technique in which 66 were male and 42 were female. The study…

Novel methodology for wide-ranged multistage morphing waverider based on conical theory

NASA Astrophysics Data System (ADS)

Liu, Zhen; Liu, Jun; Ding, Feng; Xia, Zhixun

2017-11-01

This study proposes the wide-ranged multistage morphing waverider design method. The flow field structure and aerodynamic characteristics of multistage waveriders are also analyzed. In this method, the multistage waverider is generated in the same conical flowfield, which contains a free-stream surface and different compression-stream surfaces. The obtained results show that the introduction of the multistage waverider design method can solve the problem of aerodynamic performance deterioration in the off-design state and allow the vehicle to always maintain the optimal flight state. The multistage waverider design method, combined with transfiguration flight strategy, can lead to greater design flexibility and the optimization of hypersonic wide-ranged waverider vehicles.

American Healthy Homes Survey: A National Study of Residential Pesticides Measured from Floor Wipes.

EPA Science Inventory

The U.S. Department of Housing and Urban Development in collaboration with the United States Environmental Protection Agency conducted a survey measuring lead, allergens, and insecticides in a randomly selected nationally representative sample of resodential homes. Multistage sa...

Work Adjustment of Vocational Education Teachers.

ERIC Educational Resources Information Center

Muncrief, Martha Crawford

To investigate work adjustment of vocational education teachers, a nation-wide study was conducted focusing on vocational needs, job satisfaction, and job success. The study involved 180 secondary teachers from three vocational areas, business, home economics, and industrial education. A multistage sampling process was utilized to select…

ERTS data user investigation to develop a multistage forest sampling inventory system

NASA Technical Reports Server (NTRS)

Langley, P. G.; Vanroessel, J. W. (Principal Investigator)

1973-01-01

The author has identified the following significant results. A unique digital timber volume estimation system was developed for use with the MSS CCT tapes. The system was tested on a 64-square mile area in Northern California's Trinity Alps. The outcome of a systematic experiment, in which several possible combinations of bands 5 and 7 and a contrast measure were tried, showed that an estimated gain in precision of 50% can be obtained in a multistage sampling design. The difference between bands 5 and 7 proved to be of special importance for the estimation of biomass in the form of timber volume. In addition, an interpretation model for high flight U2 photographs was developed. A maximum multiple correlation coefficient of 0.74 was obtained for the regression model, explaining 55% of the variation in timber volume as estimated from aerial photos and ground measurments. An interpretation model for MSS color composites is in the testing stage.

A microprocessor-based automation test system for the experiment of the multi-stage compressor

NASA Astrophysics Data System (ADS)

Zhang, Huisheng; Lin, Chongping

1991-08-01

An automation test system that is controlled by the microprocessor and used in the multistage compressor experiment is described. Based on the analysis of the compressor experiment performances, a complete hardware system structure is set up. It is composed of a IBM PC/XT computer, a large scale sampled data system, the moving machine with three directions, the scanners, the digital instrumentation and some output devices. A program structure of real-time software system is described. The testing results show that this test system can take the measure of many parameter magnitudes in the blade row places and on a boundary layer in different states. The automatic extent and the accuracy of experiment is increased and the experimental cost is reduced.

American Healthy Homes Survey: A National Study of Residential Phthalates Measured from Floor Wipes

EPA Science Inventory

The United States Environmental Protection Agency (U.S. EPA), in collaboration with the U.S. Department of Housing and Urban Development (HUD), conducted a survey measuring phthalates in randomly selected residential homes throughout the U.S. Multistage sampling with clustering w...

Entrepreneurial Attributes among Postgraduate Students of a Pakistani University

ERIC Educational Resources Information Center

Ali, Akhtar; Topping, Keith J.; Tariq, Riaz H.

2010-01-01

This paper explores entrepreneurial attributes among the students of The Islamia University of Bahawalpur, a public sector Pakistani university. Multistage sampling was employed to maximize the representation. Five hundred and twenty one master's level students from thirty departments returned completed questionnaires. Three factors emerged: self…

Health and Dietary Patterns of the Elderly in Botswana

ERIC Educational Resources Information Center

Maruapula, Segametsi; Chapman-Novakofski, Karen

2007-01-01

Objective: To describe associations among socioeconomic conditions and dietary patterns of Botswana elderly. Design: Secondary analysis from a cross-sectional nationwide survey. Participants: Subjects (N = 1086, 60-99 years old) were selected after multistage sampling. Main Outcome Measures: Dietary patterns were dependent variables; health and…

SOURCE SAMPLING FINE PARTICULATE MATTER: WOOD-FIRED INDUSTRIAL BOILER

EPA Science Inventory

The report provides a profile for a wood-fired industrial boiler equipped with a multistage electrostatic precipitator control device. Along with the profile of emissions of fine particulate matter of aerodynamic diameter of 2.5 micrometers or less (PM-2.5), data are also provide...

Assessment of Validity, Reliability and Difficulty Indices for Teacher-Built Physics Exam Questions in First Year High School

ERIC Educational Resources Information Center

Jandaghi, Gholamreza

2010-01-01

The purpose of the research is to determine high school teachers' skill rate in designing exam questions in physics subject. The statistical population was all of physics exam shits for two semesters in one school year from which a sample of 364 exam shits was drawn using multistage cluster sampling. Two experts assessed the shits and by using…

Impacts of Long-Term Obesity on the Health Status of Samoan and Tongan Men in the United States: Results from the Pacific Islander Health Study.

PubMed

Panapasa, Sela V; McNally, James W; Heeringa, Steven G; Williams, David R

2015-08-07

To examine the impacts of long-standing obesity (BMIs ≥ 30.0 kg/m(2)) on health outcomes among Samoan and Tongan men (aged ≥ 18 years) in California using a life course perspective. Cross-sectional analysis of 103 males from the Pacific Islander Health Study (PIHS), a probability sample modeled after the National Health Interview Survey (NHIS). Urban residential neighborhoods in San Mateo and Los Angeles counties using a multistage, cluster sample design. BMI, diabetes, hypertension, total cholesterol, smoking, drinking, arthritis, gout and migraines. Bivariate analysis shows high rates of poor health outcomes distributed throughout the obese and non-obese sample. Logistic analysis finds that being obese does not significantly increase observed negative health outcomes. After controlling for socio-demographic characteristics, the presence of obesity results in non-significant findings for hypertension (OR=1.02; CI: .21, 4.91), and high cholesterol (OR=.52; CI: .10, 2.73), while obesity significantly reduces the risk of diabetes by 60% (OR=.40; CI: .14, 1.17). When applying disease counts, obese men have a significantly lower risk of reporting multiple health conditions (OR=.72; CI: .52, 1.00). Overall, the health of Samoan and Tongan males in California is uniformly poor and obesity alone does not significantly increase risks of poor health outcomes. Using a life course perspective, the analysis offers new insights on the basic health of this understudied population.

Incidence of acute occupational pesticide poisoning among male farmers in South Korea.

PubMed

Lee, Won Jin; Cha, Eun Shil; Park, Jinwoo; Ko, Yousun; Kim, Hyun Joong; Kim, Jaeyoung

2012-09-01

Pesticide poisoning from agricultural labor has been recognized as a major public health problem among farmers worldwide. The objective of this study was to examine the incidence of acute occupational pesticide poisoning among male farmers in South Korea. A nationwide sampling survey of male farmers was conducted in South Korea. This survey used a stratified multistage probability sampling design and adopted the face-to-face interview method. A total of 1,958 male farmers were interviewed in order to estimate the incidence of acute occupational pesticide poisoning in rural areas in 2010. Based on a self-reported definition, the incidence rate in 2010 and the lifetime hospitalization rate due to acute occupational pesticide poisoning among male farmers were estimated. The incidence rate of acute occupational pesticide poisoning was 24.7 (95% CI 22.1-27.2) per 100 male farmers, which corresponds to 209,512 cases across South Korea in 2010. About 12% of the pesticide poisoning cases included either visiting a medical doctor or hospitalization. The lifetime rate of hospitalization due to occupational pesticide poisoning was 6.1 (95% CI 4.9-7.3) among male farmers. Poisoning occurred mainly when farmers were applying pesticides during summer. Our nationwide sampling survey demonstrated that acute occupational pesticide poisonings are highly prevalent among male South Korean farmers. Intensive intervention efforts to reduce occupational pesticide poisoning are urgently needed in South Korea. Copyright © 2012 Wiley Periodicals, Inc.

Psychotic experiences and suicide attempt risk in common mental disorders and borderline personality disorder.

PubMed

Kelleher, I; Ramsay, H; DeVylder, J

2017-03-01

Recent research has demonstrated a strong relationship between psychotic experiences and suicidal behaviour. No research to date, however, has investigated the role of borderline personality disorder (BPD) in this relationship, despite the fact that BPD is highly comorbid with common mental disorders and is associated with both recurrent suicidal behaviour and psychotic experiences. This paper examined the relationship between psychotic experiences and suicide attempts, including interrelationships with BPD and common mental disorders. We used the 2007 Adult Psychiatric Morbidity Study, a stratified, multistage probability sample of households in England, which recruited a nationally representative sample aged 16 years and older. Participants were assessed for common mental disorders, BPD (clinical and subclinical), suicidal behaviour, and psychotic experiences. Approximately 4% of the total sample (n = 323) reported psychotic experiences. Psychotic experiences were associated with increased odds of suicide attempts in individuals with BPD (OR = 2.23, 95% CI = 1.03-4.85), individuals with a common mental disorder (OR = 2.47, 95% CI = 1.37-4.43), individuals without a common mental disorder (OR = 3.99, 95% CI = 2.47-6.43), and individuals with neither a common mental disorder nor BPD (OR = 3.20, 95% CI = 1.71-5.98). Psychotic experiences are associated with high odds of suicidal behaviour in individuals with and without psychopathology. This relationship is not explained by clinical or subclinical BPD. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Space debris detection in optical image sequences.

PubMed

Xi, Jiangbo; Wen, Desheng; Ersoy, Okan K; Yi, Hongwei; Yao, Dalei; Song, Zongxi; Xi, Shaobo

2016-10-01

We present a high-accuracy, low false-alarm rate, and low computational-cost methodology for removing stars and noise and detecting space debris with low signal-to-noise ratio (SNR) in optical image sequences. First, time-index filtering and bright star intensity enhancement are implemented to remove stars and noise effectively. Then, a multistage quasi-hypothesis-testing method is proposed to detect the pieces of space debris with continuous and discontinuous trajectories. For this purpose, a time-index image is defined and generated. Experimental results show that the proposed method can detect space debris effectively without any false alarms. When the SNR is higher than or equal to 1.5, the detection probability can reach 100%, and when the SNR is as low as 1.3, 1.2, and 1, it can still achieve 99%, 97%, and 85% detection probabilities, respectively. Additionally, two large sets of image sequences are tested to show that the proposed method performs stably and effectively.

Alcohol and Sexual Consent Scale: Development and Validation

ERIC Educational Resources Information Center

Ward, Rose Marie; Matthews, Molly R.; Weiner, Judith; Hogan, Kathryn M.; Popson, Halle C.

2012-01-01

Objective: To establish a short measure of attitudes toward sexual consent in the context of alcohol consumption. Methods: Using a multistage and systematic measurement development process, the investigators developed the Alcohol and Sexual Consent Scale using a sample of college students. Results: The resulting 12-item scale, the Alcohol and…

Diluted connectivity in pattern association networks facilitates the recall of information from the hippocampus to the neocortex.

PubMed

Rolls, Edmund T

2015-01-01

The recall of information stored in the hippocampus involves a series of corticocortical backprojections via the entorhinal cortex, parahippocampal gyrus, and one or more neocortical stages. Each stage is considered to be a pattern association network, with the retrieval cue at each stage the firing of neurons in the previous stage. The leading factor that determines the capacity of this multistage pattern association backprojection pathway is the number of connections onto any one neuron, which provides a quantitative basis for why there are as many backprojections between adjacent stages in the hierarchy as forward projections. The issue arises of why this multistage backprojection system uses diluted connectivity. One reason is that a multistage backprojection system with expansion of neuron numbers at each stage enables the hippocampus to address during recall the very large numbers of neocortical neurons, which would otherwise require hippocampal neurons to make very large numbers of synapses if they were directly onto neocortical neurons. The second reason is that as shown here, diluted connectivity in the backprojection pathways reduces the probability of more than one connection onto a receiving neuron in the backprojecting pathways, which otherwise reduces the capacity of the system, that is the number of memories that can be recalled from the hippocampus to the neocortex. For similar reasons, diluted connectivity is advantageous in pattern association networks in other brain systems such as the orbitofrontal cortex and amygdala; for related reasons, in autoassociation networks in, for example, the hippocampal CA3 and the neocortex; and for the different reason that diluted connectivity facilitates the operation of competitive networks in forward-connected cortical systems. © 2015 Elsevier B.V. All rights reserved.

Evaluation of usefulness of Skylab EREP S-190 and S-192 imagery in multistage forest surveys

NASA Technical Reports Server (NTRS)

Langley, P. G. (Principal Investigator)

1973-01-01

The author has identified the following significant results. A unique digital timber volume estimation system with digital data for two ERTS-1 MSS bands was tested. The system was tested on a 64-square mile area in Northern California's Trinity Alps. The outcome of a systematic experiment in which possible combinations of the two bands (MSS 5 and 7) were tried, showed than an estimated gain in precision of 50% can be obtained in a multistage sampling design. Especially the difference between the two bands proved to be of major importance for the estimation of biomass in the form of timber volume. Identical tests as the one performed will be conducted with various S-192 bands when the digital data become available.

Purposeful Sampling for Qualitative Data Collection and Analysis in Mixed Method Implementation Research.

PubMed

Palinkas, Lawrence A; Horwitz, Sarah M; Green, Carla A; Wisdom, Jennifer P; Duan, Naihua; Hoagwood, Kimberly

2015-09-01

Purposeful sampling is widely used in qualitative research for the identification and selection of information-rich cases related to the phenomenon of interest. Although there are several different purposeful sampling strategies, criterion sampling appears to be used most commonly in implementation research. However, combining sampling strategies may be more appropriate to the aims of implementation research and more consistent with recent developments in quantitative methods. This paper reviews the principles and practice of purposeful sampling in implementation research, summarizes types and categories of purposeful sampling strategies and provides a set of recommendations for use of single strategy or multistage strategy designs, particularly for state implementation research.

Monte Carlo uncertainty analysis of dose estimates in radiochromic film dosimetry with single-channel and multichannel algorithms.

PubMed

Vera-Sánchez, Juan Antonio; Ruiz-Morales, Carmen; González-López, Antonio

2018-03-01

To provide a multi-stage model to calculate uncertainty in radiochromic film dosimetry with Monte-Carlo techniques. This new approach is applied to single-channel and multichannel algorithms. Two lots of Gafchromic EBT3 are exposed in two different Varian linacs. They are read with an EPSON V800 flatbed scanner. The Monte-Carlo techniques in uncertainty analysis provide a numerical representation of the probability density functions of the output magnitudes. From this numerical representation, traditional parameters of uncertainty analysis as the standard deviations and bias are calculated. Moreover, these numerical representations are used to investigate the shape of the probability density functions of the output magnitudes. Also, another calibration film is read in four EPSON scanners (two V800 and two 10000XL) and the uncertainty analysis is carried out with the four images. The dose estimates of single-channel and multichannel algorithms show a Gaussian behavior and low bias. The multichannel algorithms lead to less uncertainty in the final dose estimates when the EPSON V800 is employed as reading device. In the case of the EPSON 10000XL, the single-channel algorithms provide less uncertainty in the dose estimates for doses higher than four Gy. A multi-stage model has been presented. With the aid of this model and the use of the Monte-Carlo techniques, the uncertainty of dose estimates for single-channel and multichannel algorithms are estimated. The application of the model together with Monte-Carlo techniques leads to a complete characterization of the uncertainties in radiochromic film dosimetry. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Novel product ions of 2-aminoanilide and benzimidazole Ag(I) complexes using electrospray ionization with multi-stage tandem mass spectrometry.

PubMed

Johnson, Byron S; Burinsky, David J; Burova, Svetlana A; Davis, Roman; Fitzgerald, Russ N; Matsuoka, Richard T

2012-05-15

The 2-aminoaniline scaffold is of significant value to the pharmaceutical industry and is embedded in a number of pharmacophores including 2-aminoanilides and benzimidazoles. A novel application of coordination ion spray mass spectrometry (CIS-MS) for interrogating the silver ion (Ag(+)) complexes of a homologous series of these compounds using multi-stage tandem mass spectrometry is described. Unlike the ubiquitous alkali metal ion complexes, Ag(+) complexes of 2-aminoanilides and benzimidazoles were found to yield [M - H](+) ions in significant abundance via gas-phase elimination of the metal hydride (AgH) resulting in unique product ion cascades. Sample introduction was by liquid chromatography with mass spectrometry analysis performed on a hybrid linear ion trap/orbitrap instrument capable of high-resolution measurements. Rigorous structural characterization by multi-stage tandem mass spectrometry using [M +  H](+), [M - H](-) and [M - H](+) precursor ions derived from ESI and CIS experiments was performed for the homologous series of 2-aminoanilide and benzimidazole compounds. A full tabular comparison of structural information resulting from these product ion cascades was produced. Multi-stage tandem mass spectrometry of [M - H](+) ions resulting from Ag(+) complexes of 2-aminoanilides and benzimidazoles in CIS-MS experiments produced unique product ion cascades that exhibited complementary structural information to that obtained from tandem mass spectrometry of [M  +  H](+) and [M - H](-) ions by electrospray ionization (ESI). These observations may be broadly applicable to other compounds that are observed to form Ag(+) complexes and eliminate AgH. Copyright © 2012 John Wiley & Sons, Ltd.

On the Study of Pre-Pregnancy Body Mass Index (BMI) and Weight Gain as Indicators of Nutritional Status of Pregnant Women Belonging to Low Socio-Economic Category: A Study from Assam.

PubMed

Mahanta, Lipi B; Choudhury, Manisha; Devi, Arundhuti; Bhattacharya, Arunima

2015-01-01

Women, particularly pregnant women, are the most vulnerable population of the society and their health status is one of the major indicators of development. There were enough studies on pre pregnancy body mass index (IPBMI) and inadequate weight gain during pregnancy (IWGP) of women in other part of the world and India, but none in Assam. In Assam a large number of population are in the category of low socio-economic group, a group most vulnerable to under nutrition. Thus this study was framed with the said indicators to throw light on the factors affecting the health status of pregnant women to accordingly address the situation. A cross sectional study using multistage sampling design with probability proportional to size was made comprising of 461 pregnant women belonging to low socio-economic status. Responses regarding their socio-economic, socio-cultural, health, diet and environmental background were collected and coded. The study revealed that although IPBMI (34.06%) was slightly lower than the reported state, national and global percentage the revealed IWGP (82%) was an astounding figure. The blood samples analyzed showed a high degree of inadequacy in almost all micronutrients (iron 63.1%, calcium 49.5% and copper 39.9%) studied in our survey.

Prevalence and associated factors of induced abortion among rural married women: a cross-sectional survey in Anhui, China.

PubMed

Gao, Guo-Peng; Zhang, Ren-Jie; Zhang, Xiu-Jun; Jia, Xiao-Min; Li, Xiu-De; Li, Xiang; Wang, Cheng-Cheng; Tong, Fei; Sun, Ye-Huan

2015-03-01

This study aims to assess the prevalence of and factors associated with induced abortion among married women in rural areas of Anhui Province, China. A multistage probability sampling method was used to identify a representative sample of 53,652 married women aged 18-49 years in rural areas of Anhui Province, China. All women were interviewed in the form of a standardized questionnaire. We found that 32.0% (16,800) of these women had had at least one induced abortion: 21.1% (11,090) of women had had one; 7.6% (3976) of women had had two; and 4.1% (1734) of women had had at least three. The number of induced abortions per 100 pregnancies was found to be 22.0. Multivariate analysis showed that education, the age of a woman at her first marriage, number of total births, number of total pregnancies, and contraceptive methods were significant predictors for induced abortion after controlling for women's current age, employment and family yearly income. The study shows that the prevalence of induced abortion is still very high among married women in rural China, and highly effective methods of contraception (sterilization, intrauterine device) decrease women's recourse to induced abortion. © 2014 The Authors. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.

Peers, tobacco advertising, and secondhand smoke exposure influences smoking initiation in diverse adolescents.

PubMed

Voorhees, Carolyn C; Ye, Cong; Carter-Pokras, Olivia; MacPherson, Laura; Kanamori, Mariano; Zhang, Guangyu; Chen, Lu; Fiedler, Robert

2011-01-01

Identify demographic, social, and environmental factors associated with smoking initiation in a large, racially and ethnically diverse sample of underage youth participating in the 2006 Maryland Youth Tobacco Survey. Cross-sectional, multistage, probability sample survey. Schools (308 middle and high schools) in Maryland. Subjects were 12- to 17-year-old adolescents participating in a school-based survey. New smokers and nonsmokers were included in the analysis (n  =  57,072). Social and media influence, secondhand smoke exposure, tobacco product use, and demographic information including age, race/ethnicity, and geographic region. Chi-square and multiple logistic regression analyses controlling for clustering. Hispanic and Hawaiian/Pacific Islander youth were most likely and Asian and Black youth were least likely to be new smokers. Smoking initiation was positively associated with higher age, living with a current smoker, secondhand smoke exposure, exposure to advertisements for tobacco products, having more friends that smoke, tobacco products offered by friends, risk perceptions, and use of other tobacco products such as smokeless tobacco and cigars. Multivariate logistic regression results suggested that composite measures of peer influence, advertising exposure, and secondhand smoke exposure were independently associated with smoking initiation. Media, peer influence, and secondhand smoke exposure were the most important factors influencing smoking initiation and were common to all racial/ethnic groups in this study. Interventions combining targeted public awareness, education, and media campaigns directed at parents/guardians should be investigated.

Risk factors for suicidal ideation, plans and attempts in Malaysia--results of an epidemiological survey.

PubMed

Maniam, T; Marhani, Midin; Firdaus, M; Kadir, A B; Mazni, M J; Azizul, A; Salina, A A; Fadzillah, A R; Nurashikin, I; Ang, K T; Jasvindar, K; Noor Ani, A

2014-01-01

This is an epidemiological study to determine the prevalence of suicidal behavior and its association with generalised anxiety disorder (GAD) and major depressive disorder (MDD) in a nationally representative sample. Suicidal ideation, plans and attempts were assessed in face-to-face interviews of respondents selected by a multistage probability sampling using items on suicidality from the WHO SUPRE-MISS questionnaire. The Mini International Neuropsychiatric Interview (MINI) was used to generate DSM-IV diagnoses of GAD and MDD. A total of 19309 subjects were studied. Multivariate regression analysis was conducted controlling for demographic characteristics such as age, gender and ethnicity. The prevalence estimates for suicide ideation, plans and attempts were 1.7% (95% CI: 1.4-1.9), 0.9% (CI: 0.7-1.1) and 0.5% (CI: 0.4-0.7) respectively. Younger people (16-24 years) had higher risk of suicidal behavior (OR: 2.6, CI: 1.08-6.2). Females (OR: 1.6, CI: 1.2-2.1) and Indians (OR: 3.3, CI: 2.2-4.9) also had higher risk. The prevalence of suicidal behavior in Malaysia is low, but it broadly corresponds to the pattern described in other countries. This national study confirms that Malaysians of Indian descent have much higher rates of suicidal behavior than other groups. The younger age group, females and the Indian ethnic group would need focused preventive efforts. © 2014.

Exploring breast cancer preventive lifestyle and social support of Iranian women: a study protocol for a mixed-methods approach.

PubMed

Khazaee-Pool, Maryam; Pashaei, Tahereh; Jahangiry, Leila; Ponnet, Koen; Gholami, Ali

2017-06-07

It is widely accepted that a healthy lifestyle may decrease the probability of developing cancer. This study aimed to describe a study protocol that makes it possible to explore preventive health lifestyles of Iranian women and their received social support for the purpose of developing cultural strategies to increase breast cancer prevention. A mixed-methods study will be accomplished in two sequential parts. First, a cross-sectional study will be conducted in which 2,250 Iranian women are recruited by using a random multistage cluster sampling of 20 health care centers. Structured face-to-face interviews will be conducted to obtain information on the participants' health lifestyle and perceived social support. Data will be analyzed using both multivariate regression and structural equation modeling techniques. Then, a qualitative study will be conducted among employed women using a purposive sampling design. Data will be collected by means of focus groups and semi-structured interviews and will be analyzed using a conventional content analysis approach. The results of the quantitative and qualitative study will be used to develop breast cancer preventive strategies. Researchers need to acquire knowledge regarding the lifestyle and perceived social support of Iranian women that will foster culturally competent approaches to promote healthy lifestyles to develop breast cancer preventive strategies. Examining breast cancer preventive lifestyles provides valuable information for designing applicable intervention programs for improving women's health.

Pulsed depressed collector

DOEpatents

Kemp, Mark A

2015-11-03

A high power RF device has an electron beam cavity, a modulator, and a circuit for feed-forward energy recovery from a multi-stage depressed collector to the modulator. The electron beam cavity include a cathode, an anode, and the multi-stage depressed collector, and the modulator is configured to provide pulses to the cathode. Voltages of the electrode stages of the multi-stage depressed collector are allowed to float as determined by fixed impedances seen by the electrode stages. The energy recovery circuit includes a storage capacitor that dynamically biases potentials of the electrode stages of the multi-stage depressed collector and provides recovered energy from the electrode stages of the multi-stage depressed collector to the modulator. The circuit may also include a step-down transformer, where the electrode stages of the multi-stage depressed collector are electrically connected to separate taps on the step-down transformer.

Maladaptive Personality and Neuropsychological Features of Highly Relationally Aggressive Adolescent Girls

ERIC Educational Resources Information Center

Savage, Michael; DiBiase, Anne-Marie

2016-01-01

The maladaptive personality and neuropsychological features of highly relationally aggressive females were examined in a group of 30 grade 6, 7, and 8 girls and group-matched controls. Employing a multistage cluster sampling procedure, a group of highly, yet almost exclusively, relationally aggressive females were identified and matched on a…

The Effect of Computer Games on Students' Critical Thinking Disposition and Educational Achievement

ERIC Educational Resources Information Center

Seifi, Mohammad; Derikvandi, Zahra; Moosavipour, Saeed; Khodabandelou, Rouhollah

2015-01-01

The main aim of this research was to investigate the effect of computer games on student' critical thinking disposition and educational achievement. The research method was descriptive, and its type was casual-comparative. The sample included 270 female high school students in Andimeshk town selected by multistage cluster method. Ricketts…

Students' Readiness for E-Learning Application in Higher Education

ERIC Educational Resources Information Center

Rasouli, Atousa; Rahbania, Zahra; Attaran, Mohammad

2016-01-01

The main goal of this research was to investigate the readiness of art students in applying e-learning. This study adopted a survey research design. From three public Iranian Universities (Alzahra, Tarbiat Modares, and Tehran), 347 students were selected by multistage cluster sampling and via Morgan Table. Their readiness for E-learning…

Impact Evaluation of Further Mathematics Curriculum in Nigeria

ERIC Educational Resources Information Center

Odili, Godwin Alo; Asuru, Vincent A.

2011-01-01

This research was a perceptual survey study carried out to determine whether the goals of Further Mathematics Curriculum (FMC) are being achieved at the Senior Secondary School level. The sample for the study consisted of 240 FM final year students, 45 FM teachers and 180 undergraduates who were selected by a multistage stratified random sampling…

Behavioural Problems of Juvenile Street Hawkers in Uyo Metropolis, Nigeria

ERIC Educational Resources Information Center

Udoh, Nsisong A.; Joseph, Eme U.

2012-01-01

The study sought the opinions of Faculty of Education Students of University of Uyo on the behavioural problems of juvenile street hawkers in Uyo metropolis. Five research hypotheses were formulated to guide the study. This cross-sectional survey employed multi-stage random sampling technique in selecting 200 regular undergraduate students in the…

Removing a Nail from the Boot Camp Coffin: An Outcome Evaluation of Minnesota's Challenge Incarceration Program

ERIC Educational Resources Information Center

Duwe, Grant; Kerschner, Deborah

2008-01-01

Using a retrospective, quasiexperimental design, this study evaluates Minnesota's Challenge Incarceration Program (CIP), examining whether it has lowered recidivism and saved money. In addition to utilizing a lengthy follow-up period and multiple measures of recidivism and participation, a multistage sampling design was employed to create a…

A Methodology to Teach Advanced A/D Converters, Combining Digital Signal Processing and Microelectronics Perspectives

ERIC Educational Resources Information Center

Quintans, C.; Colmenar, A.; Castro, M.; Moure, M. J.; Mandado, E.

2010-01-01

ADCs (analog-to-digital converters), especially Pipeline and Sigma-Delta converters, are designed using complex architectures in order to increase their sampling rate and/or resolution. Consequently, the learning of ADC devices also encompasses complex concepts such as multistage synchronization, latency, oversampling, modulation, noise shaping,…

Posttraumatic Stress Disorder Following Ethnoreligious Conflict in Jos, Nigeria

ERIC Educational Resources Information Center

Obilom, Rose E.; Thacher, Tom D.

2008-01-01

In September 2001, ethnoreligious rioting occurred in Jos, Nigeria. Using a multistage cluster sampling technique, 290 respondents were recruited in Jos 7 to 9 months after the riots. Data were collected regarding demographics, exposure to traumatic events, and psychological symptoms. Resting pulse and blood pressure were recorded. A total of 145…

Assessing Students' Metacognitive Awareness of Learning Strategies among Secondary School Students in Edo State, Nigeria

ERIC Educational Resources Information Center

Okoza, Jolly; Aluede, Oyaziwo; Owens-Sogolo, Osasere

2013-01-01

This study examined metacognitive awareness of learning strategies among Secondary School Students in Edo State, Nigeria. The study was an exploratory one, which utilized descriptive statistics. A total number of 1200 students drawn through multistage proportionate random sampling technique participated in the study. The study found that secondary…

Individual and societal impact on earnings associated with serious mental illness in metropolitan China

PubMed Central

Lee, Sing; Tsang, Adley; Huang, Yue-qin; He, Yan-ling; Liu, Zhao-rui; Zhang, Ming-yuan; Shen, Yu-cun; Kessler, Ronald C.

2013-01-01

To evaluate individual-level and societal-level losses of income associated with serious mental illness in metropolitan China, a multi-stage probability survey was administered to adults aged 18–70 in Beijing and Shanghai. We used data to estimate individual-level expected earnings from a model that included information about the respondents’ education level, marital status, age, and gender. Expected earnings were compared to observed earnings among respondents with mental illness and serious disability. The result shows that the 12-month prevalence of such serious mental illness was 0.6%. Its impact on earnings was significant in the total sample and was higher for males (76% of gender-specific expected salary was lost) than females (32%). When projected to societal level, the annual impact was estimated to be 466 million Renminbi (RMB 8.27= USD 1), less than 0.2% of the Gross Domestic Product (GDP) of the two cities. Serious mental illness was associated with a substantial decrease in individual-level earnings, but the burden that resulted from societal-level loss of earnings was not large enough to help drive mental health policy and programs in China. PMID:20493555

Seroprevalence of antibodies to measles and rubella eight months after a vaccination campaign in the southeast of Iran.

PubMed

Izadi, Shahrokh; Zahraei, Seyed Mohsen; Mokhtari-Azad, Talat

2018-02-08

Eight months after the mass immunization campaign of November 2015 against measles and rubella in the southeast of Iran, in order to evaluate the sero-immunity level of the people living in the mentioned region, a serosurvey study was performed. Using a multi-stage probability proportional to size cluster sampling, the sera of 1,056 participants, ranging from 15 months to 20 years old, were tested for measles and rubella IgG antibodies in the National Reference Laboratory at Tehran University of Medical Sciences, Tehran, Iran. The seroprevalence rates of antibodies against measles and rubella in the age groups below 16 years were respectively 98.4 and 93.2%. In the age group of 16 to 20 years, who was not the target of the mass immunization campaign, the said rates were respectively 91.7% and 87.4%. The herd immunity of the age groups below 16 years, who were the target of the campaign, is favourably high and reassuring both for measles and for rubella. Campaigns of supplementary vaccination play a substantial role for filling the gaps in the herd immunity.

Forecasting peak asthma admissions in London: an application of quantile regression models.

PubMed

Soyiri, Ireneous N; Reidpath, Daniel D; Sarran, Christophe

2013-07-01

Asthma is a chronic condition of great public health concern globally. The associated morbidity, mortality and healthcare utilisation place an enormous burden on healthcare infrastructure and services. This study demonstrates a multistage quantile regression approach to predicting excess demand for health care services in the form of asthma daily admissions in London, using retrospective data from the Hospital Episode Statistics, weather and air quality. Trivariate quantile regression models (QRM) of asthma daily admissions were fitted to a 14-day range of lags of environmental factors, accounting for seasonality in a hold-in sample of the data. Representative lags were pooled to form multivariate predictive models, selected through a systematic backward stepwise reduction approach. Models were cross-validated using a hold-out sample of the data, and their respective root mean square error measures, sensitivity, specificity and predictive values compared. Two of the predictive models were able to detect extreme number of daily asthma admissions at sensitivity levels of 76 % and 62 %, as well as specificities of 66 % and 76 %. Their positive predictive values were slightly higher for the hold-out sample (29 % and 28 %) than for the hold-in model development sample (16 % and 18 %). QRMs can be used in multistage to select suitable variables to forecast extreme asthma events. The associations between asthma and environmental factors, including temperature, ozone and carbon monoxide can be exploited in predicting future events using QRMs.

Forecasting peak asthma admissions in London: an application of quantile regression models

NASA Astrophysics Data System (ADS)

Soyiri, Ireneous N.; Reidpath, Daniel D.; Sarran, Christophe

2013-07-01

Asthma is a chronic condition of great public health concern globally. The associated morbidity, mortality and healthcare utilisation place an enormous burden on healthcare infrastructure and services. This study demonstrates a multistage quantile regression approach to predicting excess demand for health care services in the form of asthma daily admissions in London, using retrospective data from the Hospital Episode Statistics, weather and air quality. Trivariate quantile regression models (QRM) of asthma daily admissions were fitted to a 14-day range of lags of environmental factors, accounting for seasonality in a hold-in sample of the data. Representative lags were pooled to form multivariate predictive models, selected through a systematic backward stepwise reduction approach. Models were cross-validated using a hold-out sample of the data, and their respective root mean square error measures, sensitivity, specificity and predictive values compared. Two of the predictive models were able to detect extreme number of daily asthma admissions at sensitivity levels of 76 % and 62 %, as well as specificities of 66 % and 76 %. Their positive predictive values were slightly higher for the hold-out sample (29 % and 28 %) than for the hold-in model development sample (16 % and 18 %). QRMs can be used in multistage to select suitable variables to forecast extreme asthma events. The associations between asthma and environmental factors, including temperature, ozone and carbon monoxide can be exploited in predicting future events using QRMs.

Remote sensing of effects of land-use practices on water quality. [environmental surveys using Landsat satellites

NASA Technical Reports Server (NTRS)

Graves, D. H.

1975-01-01

Research efforts are presented for the use of remote sensing in environmental surveys in Kentucky. Ground truth parameters were established that represent the vegetative cover of disturbed and undisturbed watersheds in the Cumberland Plateau of eastern Kentucky. Several water quality parameters were monitored of the watersheds utilized in the establishment of ground truth data. The capabilities of multistage-multispectral aerial photography and satellite imagery were evaluated in detecting various land use practices. The use of photographic signatures of known land use areas utilizing manually-operated spot densitometers was studied. The correlation of imagery signature data to water quality data was examined. Potential water quality predictions were developed from forested and nonforested watersheds based upon the above correlations. The cost effectiveness of predicting water quality values was evaluated using multistage and satellite imagery sampling techniques.

Purposeful sampling for qualitative data collection and analysis in mixed method implementation research

PubMed Central

Palinkas, Lawrence A.; Horwitz, Sarah M.; Green, Carla A.; Wisdom, Jennifer P.; Duan, Naihua; Hoagwood, Kimberly

2013-01-01

Purposeful sampling is widely used in qualitative research for the identification and selection of information-rich cases related to the phenomenon of interest. Although there are several different purposeful sampling strategies, criterion sampling appears to be used most commonly in implementation research. However, combining sampling strategies may be more appropriate to the aims of implementation research and more consistent with recent developments in quantitative methods. This paper reviews the principles and practice of purposeful sampling in implementation research, summarizes types and categories of purposeful sampling strategies and provides a set of recommendations for use of single strategy or multistage strategy designs, particularly for state implementation research. PMID:24193818

A Correction to the Stress-Strain Curve During Multistage Hot Deformation of 7150 Aluminum Alloy Using Instantaneous Friction Factors

NASA Astrophysics Data System (ADS)

Jiang, Fulin; Tang, Jie; Fu, Dinfa; Huang, Jianping; Zhang, Hui

2018-04-01

Multistage stress-strain curve correction based on an instantaneous friction factor was studied for axisymmetric uniaxial hot compression of 7150 aluminum alloy. Experimental friction factors were calculated based on continuous isothermal axisymmetric uniaxial compression tests at various deformation parameters. Then, an instantaneous friction factor equation was fitted by mathematic analysis. After verification by comparing single-pass flow stress correction with traditional average friction factor correction, the instantaneous friction factor equation was applied to correct multistage stress-strain curves. The corrected results were reasonable and validated by multistage relative softening calculations. This research provides a broad potential for implementing axisymmetric uniaxial compression in multistage physical simulations and friction optimization in finite element analysis.

40 CFR 600.316-78 - Multistage manufacture.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Multistage manufacture. 600.316-78 Section 600.316-78 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY... and Later Model Year Automobiles-Labeling § 600.316-78 Multistage manufacture. Where more than one...

Exposure Control Using Adaptive Multi-Stage Item Bundles.

ERIC Educational Resources Information Center

Luecht, Richard M.

This paper presents a multistage adaptive testing test development paradigm that promises to handle content balancing and other test development needs, psychometric reliability concerns, and item exposure. The bundled multistage adaptive testing (BMAT) framework is a modification of the computer-adaptive sequential testing framework introduced by…

Mixed response and time-to-event endpoints for multistage single-arm phase II design.

PubMed

Lai, Xin; Zee, Benny Chung-Ying

2015-06-04

The objective of phase II cancer clinical trials is to determine if a treatment has sufficient activity to warrant further study. The efficiency of a conventional phase II trial design has been the object of considerable debate, particularly when the study regimen is characteristically cytostatic. At the time of development of a phase II cancer trial, we accumulated clinical experience regarding the time to progression (TTP) for similar classes of drugs and for standard therapy. By considering the time to event (TTE) in addition to the tumor response endpoint, a mixed-endpoint phase II design may increase the efficiency and ability of selecting promising cytotoxic and cytostatic agents for further development. We proposed a single-arm phase II trial design by extending the Zee multinomial method to fully use mixed endpoints with tumor response and the TTE. In this design, the dependence between the probability of response and the TTE outcome is modeled through a Gaussian copula. Given the type I and type II errors and the hypothesis as defined by the response rate (RR) and median TTE, such as median TTP, the decision rules for a two-stage phase II trial design can be generated. We demonstrated through simulation that the proposed design has a smaller expected sample size and higher early stopping probability under the null hypothesis than designs based on a single-response endpoint or a single TTE endpoint. The proposed design is more efficient for screening new cytotoxic or cytostatic agents and less likely to miss an effective agent than the alternative single-arm design.

Tracking fluorescent dissolved organic matter in multistage rivers using EEM-PARAFAC analysis: implications of the secondary tributary remediation for watershed management.

PubMed

Nie, Zeyu; Wu, Xiaodong; Huang, Haomin; Fang, Xiaomin; Xu, Chen; Wu, Jianyu; Liang, Xinqiang; Shi, Jiyan

2016-05-01

Profound understanding of behaviors of organic matter from sources to multistage rivers assists watershed management for improving water quality of river networks in rural areas. Ninety-one water samples were collected from the three orders of receiving rivers in a typical combined polluted subcatchment (diffuse agricultural pollutants and domestic sewage) located in China. Then, the fluorescent dissolved organic matter (FDOM) information for these samples was determined by the excitation-emission matrix coupled with parallel factor analysis (EEM-PARAFAC). Consequently, two typical humic-like (C1 and C2) and other two protein-like (C3 and C4) components were separated. Their fluorescence peaks were located at λ ex/em = 255(360)/455, <250(320)/395, 275/335, and <250/305 nm, which resembled the traditional peaks of A + C, A + M, T, and B, respectively. In addition, C1 and C2 accounted for the dominant contributions to FDOM (>60 %). Principal component analysis (PCA) further demonstrated that, except for the autochthonous produced C4, the allochthonous components (C1 and C2) had the same terrestrial origins, but C3 might possess the separate anthropogenic and biological sources. Moreover, the spatial heterogeneity of contamination levels was noticeable in multistage rivers, and the allochthonous FDOM was gradually homogenized along the migration directions. Interestingly, the average content of the first three PARAFAC components in secondary tributaries and source pollutants had significantly higher levels than that in subsequent receiving rivers, thus suggesting that the supervision and remediation for secondary tributaries would play a prominent role in watershed management works.

Environmental exposures to lead, mercury, and cadmium among South Korean teenagers (KNHANES 2010-2013): Body burden and risk factors.

PubMed

Kim, Nam-Soo; Ahn, Jaeouk; Lee, Byung-Kook; Park, Jungsun; Kim, Yangho

2017-07-01

Limited information is available on the association of age and sex with blood concentrations of heavy metals in teenagers. In addition, factors such as a shared family environment may have an association. We analyzed data from the Korean National Health and Nutrition Examination Survey (KNHANES, 2010-2013) to determine whether blood levels of heavy metals differ by risk factors such as age, sex, and shared family environment in a representative sample of teenagers. This study used data obtained in the KNHANES 2010-2013, which had a rolling sampling design that involved a complex, stratified, multistage, probability-cluster survey of a representative sample of the non-institutionalized civilian population in South Korea. Our cross-sectional analysis was restricted to teenagers and their parents who completed the health examination survey, and for whom blood measurements of cadmium, lead, and mercury were available. The final analytical sample consisted of 1585 teenagers, and 376 fathers and 399 mothers who provided measurements of blood heavy metal concentrations. Male teenagers had greater blood levels of lead and mercury, but sex had no association with blood cadmium level. There were age-related increases in blood cadmium, but blood lead decreased with age, and age had little association with blood mercury. The concentrations of cadmium and mercury declined from 2010 to 2013. The blood concentrations of lead, cadmium, and mercury in teenagers were positively associated with the levels in their parents after adjustment for covariates. Our results show that blood heavy metal concentrations differ by risk factors such as age, sex, and shared family environment in teenagers. Copyright © 2017 Elsevier Inc. All rights reserved.

Relationship between blood manganese and blood pressure in the Korean general population according to KNHANES 2008

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

Lee, Byung-Kook; Kim, Yangho, E-mail: yanghokm@nuri.net

Introduction: We present data on the association of manganese (Mn) level with hypertension in a representative sample of the adult Korean population who participated in the Korean National Health and Nutrition Examination Survey (KNHANES) 2008. Methods: This study was based on the data obtained by KNHANES 2008, which was conducted for three years (2007-2009) using a rolling sampling design involving a complex, stratified, multistage, probability-cluster survey of a representative sample of the noninstitutionalized civilian population of South Korea. Results: Multiple regression analysis after controlling for covariates, including gender, age, regional area, education level, smoking, drinking status, hemoglobin, and serum creatinine,more » showed that the beta coefficients of log blood Mn were 3.514, 1.878, and 2.517 for diastolic blood pressure, and 3.593, 2.449, and 2.440 for systolic blood pressure in female, male, and all participants, respectively. Multiple regression analysis including three other blood metals, lead, mercury, and cadmium, revealed no significant effects of the three metals on blood pressure and showed no effect on the association between blood Mn and blood pressure. In addition, doubling the blood Mn increased the risk of hypertension 1.828, 1.573, and 1.567 fold in women, men, and all participants, respectively, after adjustment for covariates. The addition of blood lead, mercury, and cadmium as covariates did not affect the association between blood Mn and the prevalence of hypertension. Conclusion: Blood Mn level was associated with an increased risk of hypertension in a representative sample of the Korean adult population. - Highlights: {yields} We showed the association of manganese with hypertension in Korean population. {yields} This study was based on the data obtained by KNHANES 2008. {yields} Blood manganese level was associated with an increased risk of hypertension.« less

Activities of daily living, instrumental activities for daily living and predictors of functional capacity of older men in Jamaica

PubMed Central

Bourne, Paul Andrew

2009-01-01

Background: An extensive search of the literature found no studies that have examined functional capacity [Activities of Daily Living (ADL) and Instrumental Activities for Daily Living (I) ADL)] of Jamaican older men as well as factors that determine their functional capacity. Aims: The current study examines 1) ADL, 2) (I) ADL), 3) self-reported health status, 4) functional capacity, and 5) factors that determine functional capacity of older men. Methods and Method: Stratified multistage probability sampling technique was used to draw a sample of 2,000 55+ year men. A132-item questionnaire was used to collect the data. Descriptive statistics provide background information on the sample, cross tabulations were used to examine non-metric variables and logistic regression provides a model of predictors of functional capacity. Result: Fifty-five percent of sample indicated good current health status. Four percent was mostly satisfied with life; 21.7% had moderate dependence; 77.1% had high dependence (i.e. independence); 1.2% had low dependence; 21.9% were ages 75 years and older; 35.6% were ages 65 to 74 years and 42.6% reported ages 55 to 64 years. Functional capacity can be determined by church attendance (β=0.245; 95% CI: 0.264, 1.291); social support (β=0.129; 95% CI: 0.129, 0.258), area of residence (β=-0.060; 95% CI: -0.427, -0.061) and lastly by age of respondents. Conclusion: Ageing in explains deterioration in their (I) ADL, suggesting the challenges of ageing men's independence. More rural men were rarely satisfied with life; but more of them had a greater functional capacity than urban men. Depression was found to negatively relate to functional capacity, and church attendees had a greater functional status than non-attendees. PMID:22666693

Family Functioning, Identity Formation, and the Ability of Conflict Resolution among Adolescents

ERIC Educational Resources Information Center

Kiani, Behnaz; Hojatkhah, Seyed Mohsen; Torabi-Nami, Mohammad

2016-01-01

Family is perhaps the most influential system in individuals' life in which various behaviors are learnt. Family functioning refers to the ability of family to meet its responsibilities. The present correlation study used a multi-stage cluster sampling method to recruit 686 subjects including 338 males and 348 females from all high school students…

Young People's Expressed Needs for Comprehensive Sexuality Education in Ecuadorian Schools

ERIC Educational Resources Information Center

Castillo Nuñez, Jessica; Derluyn, Ilse; Valcke, Martin

2018-01-01

This study analyses the expressed sexuality education needs of young people from Azuay, a region of Ecuador characterised by a large proportion of young people whose parents have migrated abroad, a group often considered at risk to developing of sexual health problems. Multi-stage stratified cluster sampling was used to recruit young people aged…

Psycho-Demographic Correlates of Behaviour towards Seeking Counselling Intervention among Workers in Lagos, Nigeria

ERIC Educational Resources Information Center

Gesinde, Abiodun Matthew; Sanu, Oluwafunto Jolade

2015-01-01

This study sought to examine the impact which age, gender and psychological adjustment have on behaviour towards seeking professional counselling intervention. Multistage sampling technique was employed to select a total of three hundred workers across Lagos metropolis. The ex post facto research design was adopted for the study. Inventory of…

Causal Factors Influencing Adversity Quotient of Twelfth Grade and Third-Year Vocational Students

ERIC Educational Resources Information Center

Pangma, Rachapoom; Tayraukham, Sombat; Nuangchalerm, Prasart

2009-01-01

Problem statement: The aim of this research was to study the causal factors influencing students' adversity between twelfth grade and third-year vocational students in Sisaket province, Thailand. Six hundred and seventy two of twelfth grade and 376 third-year vocational students were selected by multi-stage random sampling techniques. Approach:…

Socioeconomic Situations of the Elderly within the Context of Millennium Development Goals (MDGs) in Nigeria

ERIC Educational Resources Information Center

Wahab, Elias Olukorede

2011-01-01

It is still unknown how the MDGs have impacted the socioeconomic situations of the elderly in Nigeria. This has become essential to appraise the attainability of the MDGs in Nigeria. Quantitative data were collected through an individual-based questionnaire. Multistage sampling was employed to select local government areas, enumeration areas, and…

Teacher Use of Data to Guide Instructional Practice in Elementary Schools

ERIC Educational Resources Information Center

Burrows, Debra C.

2011-01-01

This descriptive study focused on the degree to which data-driven decision making as envisioned by the NCLB legislation was actually occurring in the elementary schools studied. A multi-stage random sample of six Pennsylvania school districts out of 19 located within the service area of Pennsylvania Intermediate Unit #17, one of 29 regional…

Multistage remote sensing: toward an annual national inventory

Treesearch

Raymond L. Czaplewski

1999-01-01

Remote sensing can improve efficiency of statistical information. Landsat data can identify and map a few broad categories of forest cover and land use. However, more-detailed information requires a sample of higher-resolution imagery, which costs less than field data but considerably more than Landsat data. A national remote sensing program would be a major...

A Chondrule from the Mokoia (CV3) Chondrite with Anomalously Low 26Mg*: Evidence for a Multi-Stage History-

NASA Astrophysics Data System (ADS)

Claydon, J. L.; Elliott, T.; Coath, C. D.; Chen, H. W.; Taylor, C. A.; Russell, S. S.

2015-07-01

MC-ICP-MS measurements of Mg isotopes in chondrule MOK13B reveal that it may have formed from low-Al/Mg material that underwent chemical fractionation to increase Al/Mg after decay of 26-Al, or it may sample a region with anomalous Al or Mg isotopes.

Students' Commitment, Engagement and Locus of Control as Predictor of Academic Achievement at Higher Education Level

ERIC Educational Resources Information Center

Sarwar, Muhammad; Ashrafi, Ghulam Muhammad

2014-01-01

The purpose of this study was to analyze Students' Commitment, Engagement and Locus of Control as predictors of Academic Achievement at Higher Education Level. We used analytical model and conclusive research approach to conduct study and survey method for data collection. We selected 369 students using multistage sampling technique from three…

How to Classify the Diversity of Seventh Grade Students' Mathematical Process Skills: An Application of Latent Profile Analysis

ERIC Educational Resources Information Center

Kaosa-ard, Chanapat; Erawan, Waraporn; Damrongpanit, Suntonrapot; Suksawang, Poonpong

2015-01-01

The researcher applied latent profile analysis to study the difference of the students' mathematical process skill. These skills are problem solving skills, reasoning skills, communication and presentation skills, connection knowledge skills, and creativity skills. Samples were 2,485 seventh-grade students obtained from Multi-stage Random…

Do Human-Figure Drawings of Children and Adolescents Mirror Their Cognitive Style and Self-Esteem?

ERIC Educational Resources Information Center

Dey, Anindita; Ghosh, Paromita

2016-01-01

The investigation probed relationships among human-figure drawing, field-dependent-independent cognitive style and self-esteem of 10-15 year olds. It also attempted to predict human-figure drawing scores of participants based on their field-dependence-independence and self-esteem. Area, stratified and multi-stage random sampling were used to…

What Puts Women at Risk of Violence from Their Husbands? Findings from a Large, Nationally Representative Survey in Turkey

ERIC Educational Resources Information Center

Yuksel-Kaptanoglu, Ilknur; Turkyilmaz, Ahmet Sinan; Heise, Lori

2012-01-01

A large, nationally representative, cross-sectional survey was conducted in Turkey in 2008. In this survey, which used the WHO (World Health Organization) study module on violence, information about lifetime and current violence (past 12 months) was obtained using weighted, stratified, and multistage cluster sampling. This article describes…

Liquid Chromatography Combined with Mass Spectrometry Utilising High-Resolution, Exact Mass, and Multi-Stage Fragmentation for the Identification of Oxysterols in Rat Brain

PubMed Central

Karu, Kersti; Hornshaw, Martin; Woffendin, Gary; Bodin, Karl; Hamberg, Mats; Alvelius, Gunvor; Sjövall, Jan; Turton, John; Wang, Yuqin; Griffiths, William J.

2008-01-01

In man the brain accounts for about 20% of the body's free cholesterol, most of which is synthesised de novo in brain. To maintain cholesterol balance throughout life, cholesterol becomes metabolised to 24S-hydroxycholesterol principally in neurons. In mouse, rat, and probably human, metabolism to 24S-hydroxycholesterol accounts for about 50% of cholesterol turnover, however, the route by which the remainder is turned over has yet to be elucidated. Here we describe a novel liquid chromatography (LC) – multi-stage fragmentation mass spectrometry (MSn) methodology for the identification, with high sensitivity (low pg), of cholesterol metabolites in rat brain. The methodology includes derivatisation to enhance ionisation, exact mass analysis at high-resolution to identify potential metabolites, and LC-MS3 to allow their characterisation. 24S-Hydroxycholesterol was confirmed as a major oxysterol in rat brain, while other oxysterols identified for the first time in brain included 24,25-, 24,27-, 25,27-, 6,24, 7α,25-, and 7α,27-dihydroxycholesterols. In addition, 3β-hydroxy-5-oxo-5,6-secocholestan-6-al and its aldol, two molecules linked to amyloidogenesis of proteins, were characterised in rat brain. PMID:17251593

An assessment of Lot Quality Assurance Sampling to evaluate malaria outcome indicators: extending malaria indicator surveys.

PubMed

Biedron, Caitlin; Pagano, Marcello; Hedt, Bethany L; Kilian, Albert; Ratcliffe, Amy; Mabunda, Samuel; Valadez, Joseph J

2010-02-01

Large investments and increased global prioritization of malaria prevention and treatment have resulted in greater emphasis on programme monitoring and evaluation (M&E) in many countries. Many countries currently use large multistage cluster sample surveys to monitor malaria outcome indicators on a regional and national level. However, these surveys often mask local-level variability important to programme management. Lot Quality Assurance Sampling (LQAS) has played a valuable role for local-level programme M&E. If incorporated into these larger surveys, it would provide a comprehensive M&E plan at little, if any, extra cost. The Mozambique Ministry of Health conducted a Malaria Indicator Survey (MIS) in June and July 2007. We applied LQAS classification rules to the 345 sampled enumeration areas to demonstrate identifying high- and low-performing areas with respect to two malaria program indicators-'household possession of any bednet' and 'household possession of any insecticide-treated bednet (ITN)'. As shown by the MIS, no province in Mozambique achieved the 70% coverage target for household possession of bednets or ITNs. By applying LQAS classification rules to the data, we identify 266 of the 345 enumeration areas as having bednet coverage severely below the 70% target. An additional 73 were identified with low ITN coverage. This article demonstrates the feasibility of integrating LQAS into multistage cluster sampling surveys and using these results to support a comprehensive national, regional and local programme M&E system. Furthermore, in the recommendations we outlined how to integrate the Large Country-LQAS design into macro-surveys while still obtaining results available through current sampling practices.

Association between use of marijuana and time to pregnancy in men and women: findings from the National Survey of Family Growth.

PubMed

Kasman, Alex M; Thoma, Marie E; McLain, Alexander C; Eisenberg, Michael L

2018-05-01

To determine if regular use of marijuana has an impact on time to pregnancy. Retrospective review of cross-sectional survey data from male and female respondents aged 15-44 years who participated in the 2002, 2006-2010, and 2011-2015 National Survey of Family Growth. Not applicable. The National Survey of Family Growth is a nationally representative population-based sample derived from stratified multistage area probability sampling of 121 geographic areas in the U.S. Our analytic sample was participants who were actively trying to conceive. Exposure status was based on the respondents' answers regarding their marijuana use in the preceding 12 months. The main outcome was estimated time to pregnancy, which was hypothesized before analysis to be delayed by regular marijuana use. A total of 758 male and 1,076 female participants responded that they were actively trying to conceive. Overall, 16.5% of men reported using any marijuana while attempting to conceive, versus 11.5% of women. The time ratio to pregnancy for never smokers versus daily users of marijuana in men was 1.08 (95% confidence interval 0.79-1.47) and in women 0.92 (0.43-1.95), demonstrating no statistically significant impact of marijuana use on time to pregnancy. Our study suggests that neither marijuana use nor frequency of marijuana use was associated with time to pregnancy for men and women. Copyright © 2018 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Jakarta socio-cultural ecology: a sustainable architecture concept in urban neighbourhood

NASA Astrophysics Data System (ADS)

Wijaksono, Sigit; Sasmoko; Indrianti, Y.; Widhoyoko, SA

2017-12-01

As a metropolitan city with densely populated and fast residential development Jakarta should be able to implement a concept that is Jakarta socio-cultural ecology Architecture as the basis of settlement development. The concept of Jakarta socio-cultural ecology architecture is characterized by residential development capabilities that reflect and express the indigenous culture, the settlements built by linking the social and economic activities of the people of Jakarta and the settlements built by maintaining the building with the value of existing heritage. The objectives of this research are 1) to find a relevant construct to housing condition in Jakarta which then called Jakarta socio-cultural ecology, and 2) to see the tendency of complex condition of Jakarta socio-cultural ecology settlement. This research uses Neuroresearch method, which is one of mix-method research method as a mixture research method between qualitative research (exploration) and quantitative research method (explanatory and confirmatory). The population of research as well as unit analysis are all settlements in Jakarta. Sampling technique using probability sampling that is with multistage sampling. The results show that nowadays the Jakarta residential complex tends to lead to socio-cultural ecology and rather reflects and expresses the indigenous culture, the residential complex in Jakarta tends to form the building has been linked fully with the social and economic activities of Jakarta society but tends to occasionally maintain buildings with existing heritage values. This study also found that indigenous culture is a significant determinant of the formation of the condition of Jakarta socio-cultural ecology.

A Testlet Assembly Design for Adaptive Multistage Tests

ERIC Educational Resources Information Center

Luecht, Richard; Brumfield, Terry; Breithaupt, Krista

2006-01-01

This article describes multistage tests and some practical test development considerations related to the design and implementation of a multistage test, using the Uniform CPA (certified public accountant) Examination as a case study. The article further discusses the use of automated test assembly procedures in an operational context to produce…

Longitudinal Multistage Testing

ERIC Educational Resources Information Center

Pohl, Steffi

2013-01-01

This article introduces longitudinal multistage testing (lMST), a special form of multistage testing (MST), as a method for adaptive testing in longitudinal large-scale studies. In lMST designs, test forms of different difficulty levels are used, whereas the values on a pretest determine the routing to these test forms. Since lMST allows for…

Health seeking behavior following snakebites in Sri Lanka: Results of an island wide community based survey.

PubMed

Ediriweera, Dileepa Senajith; Kasturiratne, Anuradhani; Pathmeswaran, Arunasalam; Gunawardena, Nipul Kithsiri; Jayamanne, Shaluka Francis; Lalloo, David Griffith; de Silva, Hithanadura Janaka

2017-11-01

Sri Lanka has a population of 21 million and about 80,000 snakebites occur annually. However, there are limited data on health seeking behavior following bites. We investigated the effects of snakebite and envenoming on health seeking behavior in Sri Lanka. In a community-based island-wide survey conducted in Sri Lanka 44,136 households were sampled using a multistage cluster sampling method. An individual who reported experiencing a snakebite within the preceding 12 months was considered a case. An interviewer-administered questionnaire was used to obtain details of the bite and health seeking behavior among cases. Among 165,665 individuals surveyed, there were 695 snakebite victims. 682 (98.1%) had sought health care after the bite; 381 (54.8%) sought allopathic treatment and 301 (43.3%) sought traditional treatment. 323 (46.5%) had evidence of probable envenoming, among them 227 (70.3%) sought allopathic treatment, 94 (29.1%) sought traditional treatment and 2 did not seek treatment. There was wide geographic variation in the proportion of seeking allopathic treatment from <20% in the Western province to > 90% in the Northern province. Multiple logistic regression analysis showed that seeking allopathic treatment was independently associated with being systemically envenomed (Odds Ratio = 1.99, 95% CI: 1.36-2.90, P < 0.001), distance to the healthcare facility (OR = 1.13 per kilometer, 95% CI: 1.09 to 1.17, P < 0.001), time duration from the bite (OR = 0.49 per day, 95% CI: 0.29-0.74, P = 0.002), and the local incidence of envenoming (OR = 1.31 for each 50 per 100,000, 95% CI: 1.19-1.46, P < 0.001) and snakebite (OR = 0.90 for each 50 per 100,000, 95% CI: 0.85-0.94, P < 0.001) in the relevant geographic area. In Sri Lanka, both allopathic and traditional treatments are sought following snakebite. The presence of probable envenoming was a major contribution to seeking allopathic treatment.

Severity of malocclusion in adolescents: populational-based study in the north of Minas Gerais, Brazil

PubMed Central

Silveira, Marise Fagundes; Freire, Rafael Silveira; Nepomuceno, Marcela Oliveira; Martins, Andrea Maria Eleutério de Barros Lima; Marcopito, Luiz Francisco

2016-01-01

ABSTRACT OBJECTIVE To identify the factors associated with severity of malocclusion in a population of adolescents. METHODS In this cross-sectional population-based study, the sample size (n = 761) was calculated considering a prevalence of malocclusion of 50.0%, with a 95% confidence level and a 5.0% precision level. The study adopted correction for the effect of delineation (deff = 2), and a 20.0% increase to offset losses and refusals. Multistage probability cluster sampling was adopted. Trained and calibrated professionals performed the intraoral examinations and interviews in households. The dependent variable (severity of malocclusion) was assessed using the Dental Aesthetic Index (DAI). The independent variables were grouped into five blocks: demographic characteristics, socioeconomic condition, use of dental services, health-related behavior and oral health subjective conditions. The ordinal logistic regression model was used to identify the factors associated with severity of malocclusion. RESULTS We interviewed and examined 736 adolescents (91.5% response rate), 69.9% of whom showed no abnormalities or slight malocclusion. Defined malocclusion was observed in 17.8% of the adolescents, being severe or very severe in 12.6%, with pressing or essential need of orthodontic treatment. The probabilities of greater severity of malocclusion were higher among adolescents who self-reported as black, indigenous, pardo or yellow, with lower per capita income, having harmful oral habits, negative perception of their appearance and perception of social relationship affected by oral health. CONCLUSIONS Severe or very severe malocclusion was more prevalent among socially disadvantaged adolescents, with reported harmful habits and perception of compromised esthetics and social relationships. Given that malocclusion can interfere with the self-esteem of adolescents, it is essential to improve public policy for the inclusion of orthodontic treatment among health care provided to this segment of the population, particularly among those of lower socioeconomic status. PMID:27143611

Multistage Planetary Power Transmissions

NASA Technical Reports Server (NTRS)

Hadden, G. B.; Dyba, G. J.; Ragen, M. A.; Kleckner, R. J.; Sheynin, L.

1986-01-01

PLANETSYS simulates thermomechanical performance of multistage planetary performance of multistage planetary power transmission. Two versions of code developed, SKF version and NASA version. Major function of program: compute performance characteristics of planet bearing for any of six kinematic inversions. PLANETSYS solves heat-balance equations for either steadystate or transient thermal conditions, and produces temperature maps for mechanical system.

Modeling of Unsteady Three-dimensional Flows in Multistage Machines

NASA Technical Reports Server (NTRS)

Hall, Kenneth C.; Pratt, Edmund T., Jr.; Kurkov, Anatole (Technical Monitor)

2003-01-01

Despite many years of development, the accurate and reliable prediction of unsteady aerodynamic forces acting on turbomachinery blades remains less than satisfactory, especially when viewed next to the great success investigators have had in predicting steady flows. Hall and Silkowski (1997) have proposed that one of the main reasons for the discrepancy between theory and experiment and/or industrial experience is that many of the current unsteady aerodynamic theories model a single blade row in an infinitely long duct, ignoring potentially important multistage effects. However, unsteady flows are made up of acoustic, vortical, and entropic waves. These waves provide a mechanism for the rotors and stators of multistage machines to communicate with one another. In other words, wave behavior makes unsteady flows fundamentally a multistage (and three-dimensional) phenomenon. In this research program, we have has as goals (1) the development of computationally efficient computer models of the unsteady aerodynamic response of blade rows embedded in a multistage machine (these models will ultimately be capable of analyzing three-dimensional viscous transonic flows), and (2) the use of these computer codes to study a number of important multistage phenomena.

Low-Dead-Volume Inlet for Vacuum Chamber

NASA Technical Reports Server (NTRS)

Naylor, Guy; Arkin, C.

2010-01-01

Gas introduction from near-ambient pressures to high vacuum traditionally is accomplished either by multi-stage differential pumping that allows for very rapid response, or by a capillary method that allows for a simple, single-stage introduction, but which often has a delayed response. Another means to introduce the gas sample is to use the multi-stage design with only a single stage. This is accomplished by using a very small conductance limit. The problem with this method is that a small conductance limit will amplify issues associated with dead -volume. As a result, a high -vacuum gas inlet was developed with low dead -volume, allowing the use of a very low conductance limit interface. Gas flows through the ConFlat flange at a relatively high flow rate at orders of magnitude greater than through the conductance limit. The small flow goes through a conductance limit that is a double-sided ConFlat.

Low-Dead-Volume Inlet for Vacuum Chamber

NASA Technical Reports Server (NTRS)

Naylor, Guy; Arkin, C.

2011-01-01

Gas introduction from near-ambient pressures to high vacuum traditionally is accomplished either by multi-stage differential pumping that allows for very rapid response, or by a capillary method that allows for a simple, single-stage introduction, but which often has a delayed response. Another means to introduce the gas sample is to use the multi-stage design with only a single stage. This is accomplished by using a very small conductance limit. The problem with this method is that a small conductance limit will amplify issues associated with dead-volume. As a result, a high-vacuum gas inlet was developed with low dead-volume, allowing the use of a very low conductance limit interface. Gas flows through the ConFlat flange at a relatively high flow rate at orders of magnitude greater than through the conductance limit. The small flow goes through a conductance limit that is a double-sided ConFlat.

Severe Headache or Migraine History Is Inversely Correlated With Dietary Sodium Intake: NHANES 1999–2004

PubMed Central

Pogoda, Janice M.; Gross, Noah B.; Arakaki, Xianghong; Fonteh, Alfred N.; Cowan, Robert P.

2016-01-01

Objective We investigated whether dietary sodium intake from respondents of a national cross‐sectional nutritional study differed by history of migraine or severe headaches. Background Several lines of evidence support a disruption of sodium homeostasis in migraine. Design Our analysis population was 8819 adults in the 1999–2004 National Health and Nutrition Examination Survey (NHANES) with reliable data on diet and headache history. We classified respondents who reported a history of migraine or severe headaches as having probable history of migraine. To reduce the diagnostic conflict from medication overuse headache, we excluded respondents who reported taking analgesic medications. Dietary sodium intake was measured using validated estimates of self‐reported total grams of daily sodium consumption and was analyzed as the residual value from the linear regression of total grams of sodium on total calories. Multivariable logistic regression that accounted for the stratified, multistage probability cluster sampling design of NHANES was used to analyze the relationship between migraine and dietary sodium. Results Odds of probable migraine history decreased with increasing dietary sodium intake (odds ratio = 0.93, 95% confidence interval = 0.87, 1.00, P = .0455). This relationship was maintained after adjusting for age, sex, and body mass index (BMI) with slightly reduced significance (P = .0505). In women, this inverse relationship was limited to those with lower BMI (P = .007), while in men the relationship did not differ by BMI. We likely excluded some migraineurs by omitting frequent analgesic users; however, a sensitivity analysis suggested little effect from this exclusion. Conclusions This study is the first evidence of an inverse relationship between migraine and dietary sodium intake. These results are consistent with altered sodium homeostasis in migraine and our hypothesis that dietary sodium may affect brain extracellular fluid sodium concentrations and neuronal excitability. PMID:27016121

Severe Headache or Migraine History is Inversely Correlated With Dietary Sodium Intake: NHANES 1999-2004.

PubMed

Pogoda, Janice M; Gross, Noah B; Arakaki, Xianghong; Fonteh, Alfred N; Cowan, Robert P; Harrington, Michael G

2016-04-01

We investigated whether dietary sodium intake from respondents of a national cross-sectional nutritional study differed by history of migraine or severe headaches. Several lines of evidence support a disruption of sodium homeostasis in migraine. Our analysis population was 8819 adults in the 1999-2004 National Health and Nutrition Examination Survey (NHANES) with reliable data on diet and headache history. We classified respondents who reported a history of migraine or severe headaches as having probable history of migraine. To reduce the diagnostic conflict from medication overuse headache, we excluded respondents who reported taking analgesic medications. Dietary sodium intake was measured using validated estimates of self-reported total grams of daily sodium consumption and was analyzed as the residual value from the linear regression of total grams of sodium on total calories. Multivariable logistic regression that accounted for the stratified, multistage probability cluster sampling design of NHANES was used to analyze the relationship between migraine and dietary sodium. Odds of probable migraine history decreased with increasing dietary sodium intake (odds ratio = 0.93, 95% confidence interval = 0.87, 1.00, P = .0455). This relationship was maintained after adjusting for age, sex, and body mass index (BMI) with slightly reduced significance (P = .0505). In women, this inverse relationship was limited to those with lower BMI (P = .007), while in men the relationship did not differ by BMI. We likely excluded some migraineurs by omitting frequent analgesic users; however, a sensitivity analysis suggested little effect from this exclusion. This study is the first evidence of an inverse relationship between migraine and dietary sodium intake. These results are consistent with altered sodium homeostasis in migraine and our hypothesis that dietary sodium may affect brain extracellular fluid sodium concentrations and neuronal excitability. © 2016 The Authors Headache published by Wiley Periodicals, Inc. on behalf of American Headache Society.

Multi-stage internal gear/turbine fuel pump

DOEpatents

Maier, Eugen; Raney, Michael Raymond

2004-07-06

A multi-stage internal gear/turbine fuel pump for a vehicle includes a housing having an inlet and an outlet and a motor disposed in the housing. The multi-stage internal gear/turbine fuel pump also includes a shaft extending axially and disposed in the housing. The multi-stage internal gear/turbine fuel pump further includes a plurality of pumping modules disposed axially along the shaft. One of the pumping modules is a turbine pumping module and another of the pumping modules is a gerotor pumping module for rotation by the motor to pump fuel from the inlet to the outlet.

The Effect of Instructional Analogies in Interaction with Logical Thinking Ability on Achievement and Attitude toward Chemistry

ERIC Educational Resources Information Center

Eskandar, Fathi-Azar; Bayrami, Mansor; Vahedi, Shahram; Ansar, Vahideh Abdollahi Adli

2013-01-01

We investigated the effect of instructional analogies in interaction with logical thinking ability on achievement and attitude towards chemistry. The participants were 147 female students from 6 8th grade classes in three public junior high schools selected by using a random multistage sampling method from five education districts in Tabriz, a…

Self-Reported Health among Older Bangladeshis: How Good a Health Indicator Is It?

ERIC Educational Resources Information Center

Rahman, M. Omar; Barsky, Arthur J.

2003-01-01

Purpose: This study examines the value of self-reported health (SRH) as an indicator of underlying health status in a developing country setting. Design and Methods: Logistic regression methods with adjustments for multistage sampling are used to examine the factors associated with SRH in 2,921 men and women aged 50 and older in rural Bangladesh.…

Gender Differences in Mathematics Achievement and Retention Scores: A Case of Problem-Based Learning Method

ERIC Educational Resources Information Center

Ajai, John T.; Imoko, Benjamin I.

2015-01-01

This study was undertaken to assess gender differences in mathematics achievement and retention by using Problem-Based Learning (PBL). The design of the study was pre-posttest quasi-experimental. Four hundred and twenty eight senior secondary one (SS I) students using multistage sampling from ten grant-aided and government schools were involved in…

The Hispanic Americans Baseline Alcohol Survey (HABLAS): Acculturation, Birthplace and Alcohol-Related Social Problems across Hispanic National Groups

ERIC Educational Resources Information Center

Caetano, Raul; Vaeth, Patrice A. C.; Rodriguez, Lori A.

2012-01-01

The purpose of this study was to examine the association between acculturation, birthplace, and alcohol-related social problems across Hispanic national groups. A total of 5,224 Hispanic adults (18+ years) were interviewed using a multistage cluster sample design in Miami, New York, Philadelphia, Houston, and Los Angeles. Multivariate analysis…

Farmers' Participation in Extension Programs and Technology Adoption in Rural Nepal: A Logistic Regression Analysis

ERIC Educational Resources Information Center

Suvedi, Murari; Ghimire, Raju; Kaplowitz, Michael

2017-01-01

Purpose: This paper examines the factors affecting farmers' participation in extension programs and adoption of improved seed varieties in the hills of rural Nepal. Methodology/approach: Cross-sectional farm-level data were collected during July and August 2014. A sample of 198 farm households was selected for interviewing by using a multistage,…

Testing a Multi-Stage Screening System: Predicting Performance on Australia's National Achievement Test Using Teachers' Ratings of Academic and Social Behaviors

ERIC Educational Resources Information Center

Kettler, Ryan J.; Elliott, Stephen N.; Davies, Michael; Griffin, Patrick

2012-01-01

This study addresses the predictive validity of results from a screening system of academic enablers, with a sample of Australian elementary school students, when the criterion variable is end-of-year achievement. The investigation included (a) comparing the predictive validity of a brief criterion-referenced nomination system with more…

Empirical Validation of Indices for Consideration in the Revision of Recommended Senior School Financial Accounting Textbooks in Southwestern Nigeria

ERIC Educational Resources Information Center

Oyetoro, Oyebode Stephen; Ojo, Oloyede Ezekiel

2017-01-01

The study determined a significant difference in teachers' overall evaluations of six recommended Financial Accounting Textbooks in Southwestern Nigeria. It also assessed the specific evaluation parameters that account for the difference. It adopted the survey research design. The multistage sampling technique was used to select a total of 80…

Measured Effect of Sexual Activities, Alcohol Consumption, Smoking and Aggression on Health Risk of Students in Rural Communities in Ikenne, Nigeria

ERIC Educational Resources Information Center

Ezeokoli, Rita; Ofole, Ndidi M.

2015-01-01

This study examined the joint and relative contribution of sexual activities, alcohol consumption, smoking and aggression to the prediction of health risk of students in rural communities in Ogun State. Descriptive research design of correlational type was adopted. Multi-stage sampling Technique was used to draw 300 respondents from an…

Awareness of the healthcare system and rights to healthcare in the Colombian population.

PubMed

Delgado Gallego, María Eugenia; Vázquez-Navarrete, María Luisa

2013-01-01

To analyze changes in users' awareness of the healthcare system and of their rights to healthcare in Colombia in the last 10 years, as well as the factors that influence users' awareness. We carried out a descriptive study to compare the results of two cross-sectional studies based on two surveys of users of the Colombian healthcare system. The first survey was performed in 2000 and the second in 2010. The municipalities of Tuluá (urban area) and Palmira (rural area) were surveyed. In both surveys, a stratified, multistage probability sample was selected. There were 1497 users in the first sample and 1405 in the second. Changes in awareness of the healthcare system and associated factors in each year were assessed through multivariate logistic regressions. Users' awareness of the healthcare system was limited in 2000 and was significantly lower in 2010, except for that relating to health insurers and providers. In contrast, more than 90% of users in both surveys perceived themselves as having healthcare rights. The factors consistently associated with greater awareness were belonging to a high socioeconomic stratum and having higher education. The most underprivileged users were less likely to be aware of the healthcare system, hampering their ability to make informed decisions and to exercise their health rights. To correct this situation, health institutions and the government should act decisively to reduce social inequalities. Copyright © 2012 SESPAS. Published by Elsevier Espana. All rights reserved.

Effects of education of the head of the household on the prevalence of malnutrition in children.

PubMed

El-Mouzan, Mohammad I; Al-Salloum, Abdullah A; Al-Herbish, Abdullah S; Qurachi, Mansour M; Al-Omar, Ahmad A

2010-03-01

To explore the effect of the educational level of the head of household on the prevalence of malnutrition in Saudi children. The study was conducted over 2 years in 2004 and 2005 in all regions of the Kingdom of Saudi Arabia (KSA). The design consisted of a stratified multistage probability random sampling of the population of the KSA. The educational level of the heads of the household, and measurements of weight and height of the children were obtained during house visits. Nutritional indicators in the form of weight for age, height for age, and weight for height for children below 5 years of age were determined, and the prevalence of each indicator below -2 standard deviations (SD) was calculated for each level of education. The sample size was 7390 in the weight for age, 7275 height for age, and 7335 for weight for height. The prevalence of underweight (weight for age below -2 SD) increased from 7.4% for the university level to 15.2% in the children of illiterate heads of household. Similar patterns were found for the prevalence of stunting (height for age below -2 SD) and wasting (weight for height below -2 SD). This study demonstrates that the higher the education level of the heads of the household, the lower the prevalence of malnutrition in their children, suggesting that completing at least 9-12 years of education (intermediate and secondary school) is needed for better improvement in the nutritional status of the children.

Serum Copper Status in School-Age Children and Pregnant Women in China Nutrition and Health Survey 2010-2012.

PubMed

Liu, Xiaobing; Piao, Jianhua; Zhang, Yu; Li, Min; Li, Weidong; Yang, Lichen; Yang, Xiaoguang

2016-10-01

Serum copper is an insensitive but reliable biomarker reflecting the change of copper nutritional status in both depleted and replete populations. The current study aimed to establish the reference values of serum copper in school-age children and pregnant women in China and to explore the adequate range of serum copper for both these two categories of people. A multistage, stratified, random sampling combined with probability proportionate to regional size sampling method was employed. A total of 4019 subjects (2736 school-age children and 1283 pregnant women) were selected from China Nutrition and Health Survey 2010-2012 (CNHS 2010-2012). The concentration of serum copper was determined by sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). The adequate range of serum copper was determined by the logistic sigmoid saturation curve of the median derivatives. The median concentration of serum copper was 1140.9 μg/L with a range of 746.7-1677.6 μg/L for school-age children and 1933.4 μg/L with a range of 947.4-3391.4 μg/L for pregnant women. The adequate range of serum copper was 905.7-1440.7 μg/L for school-age children and 1308.8-2537.8 μg/L for pregnant women. These parameters represent an essential prerequisite for the assessment of copper nutritional status, as well as nutrition interventions.

[Characterization of anemia in children under five years of age from urban areas of Huancavelica and Ucayali, Peru].

PubMed

Gonzales, Elena; Huamán-Espino, Lucio; Gutiérrez, César; Aparco, Juan Pablo; Pillaca, Jenny

2015-01-01

Characterize anemia in children aged between 12 and 59 months from urban areas in the provinces of Coronel Portillo and Huancavelica in Peru. Cross-sectional study carried out in two stages: a) population-based study to identify children with anemia using multistage probability sampling, and b) characterization of the serum levels of ferritin, vitamin B12, intraerythrocytic folic acid and presence of parasitosis in children with anemia. For the statistical analysis, expansion factors calculated from the sampling plan were applied. The prevalence of anemia was 55.9% in Huancavelica and 36.2% in Coronel Portillo. In Huancavelica, the coexistence of anemia with iron deficiency was 22.8% and anemia with vitamin B12 deficiency was 11%. In Coronel Portillo, the coexistence of anemia with iron deficiency and vitamin B12 deficiency was 15.2% and 29.7%, respectively. The most common types of anemia in Huancavelica were anemia with concurrent parasitosis (50.9%), iron deficiency anemia and parasitosis (12.3%), and iron deficiency alone (6.4%). In Coronel Portillo, it was anemia and parasitosis (54.4%), vitamin B12 deficiency and parasitosis (18.4%), and iron deficiency anemia and parasitosis (6.3%). The prevalence of anemia is higher than the national average, with anemia concurrent with parasitosis and anemia concurrent with two or more causes as the most common type. Consideration should be given to different causes other than iron deficiency in the programs of anemia contol for Peruvian children.

Prevalence of Cognitive Impairment and Depression among a Population Aged over 60 Years in the Metropolitan Area of Guadalajara, Mexico.

PubMed

Ortiz, Genaro G; Arias-Merino, Elva D; Flores-Saiffe, María E; Velázquez-Brizuela, Irma E; Macías-Islas, Miguel A; Pacheco-Moisés, Fermín P

2012-01-01

Background. Cognitive impairment is an important clinical issue among elderly patients with depression and has a more complex etiology because of the variable rate of neurodegenerative changes associated with depression. The aim of the present work was to examine the prevalence of cognitive impairment and depression in a representative sample of adults aged ≥60 years. Methods. The presented work was a cross-sectional study on the prevalence of cognitive impairment and depression. Door-to-door interview technique was assigned in condition with multistage probability random sampling to obtain subjects that represent a population of the Guadalajara metropolitan area (GMA), Mexico. Cognitive function and depression were assessed by applying standardized Mini-Mental State Examination of Folstein (MMSE) and the Geriatric Depression Scale (GDS), respectively. Results. Prevalence of cognitive impairment was 13.8% (14.5% women, 12.6% men); no significant differences by gender and retired or pensioner were found. Prevalence of depression was 29.1% (33.6% women, 21.1% men); no significant differences by retired or pensioner were found. Cognitive impairment was associated with depression (OR  =  3.26, CI 95%, 2.31-4.60). Prevalence of cognitive impairment and depression is associated with: being woman, only in depression being older than 75 years being married, and a low level of education. Conclusion. Cognitive impairment and depression are highly correlated in adults aged ≥60.

Prevalence of Cognitive Impairment and Depression among a Population Aged over 60 Years in the Metropolitan Area of Guadalajara, Mexico

PubMed Central

Ortiz, Genaro G.; Arias-Merino, Elva D.; Flores-Saiffe, María E.; Velázquez-Brizuela, Irma E.; Macías-Islas, Miguel A.; Pacheco-Moisés, Fermín P.

2012-01-01

Background. Cognitive impairment is an important clinical issue among elderly patients with depression and has a more complex etiology because of the variable rate of neurodegenerative changes associated with depression. The aim of the present work was to examine the prevalence of cognitive impairment and depression in a representative sample of adults aged ≥60 years. Methods. The presented work was a cross-sectional study on the prevalence of cognitive impairment and depression. Door-to-door interview technique was assigned in condition with multistage probability random sampling to obtain subjects that represent a population of the Guadalajara metropolitan area (GMA), Mexico. Cognitive function and depression were assessed by applying standardized Mini-Mental State Examination of Folstein (MMSE) and the Geriatric Depression Scale (GDS), respectively. Results. Prevalence of cognitive impairment was 13.8% (14.5% women, 12.6% men); no significant differences by gender and retired or pensioner were found. Prevalence of depression was 29.1% (33.6% women, 21.1% men); no significant differences by retired or pensioner were found. Cognitive impairment was associated with depression (OR  =  3.26, CI 95%, 2.31–4.60). Prevalence of cognitive impairment and depression is associated with: being woman, only in depression being older than 75 years being married, and a low level of education. Conclusion. Cognitive impairment and depression are highly correlated in adults aged ≥60. PMID:23243421

Analysis of the chemical composition of ultrafine particles from two domestic solid biomass fired room heaters under simulated real-world use

NASA Astrophysics Data System (ADS)

Ozgen, Senem; Becagli, Silvia; Bernardoni, Vera; Caserini, Stefano; Caruso, Donatella; Corbella, Lorenza; Dell'Acqua, Manuela; Fermo, Paola; Gonzalez, Raquel; Lonati, Giovanni; Signorini, Stefano; Tardivo, Ruggero; Tosi, Elisa; Valli, Gianluigi; Vecchi, Roberta; Marinovich, Marina

2017-02-01

Two common types of wood (beech and fir) were burned in commercial pellet (11.1 kW) and wood (8.2 kW) stoves following a combustion cycle simulating the behavior of a real-world user. Ultrafine particulate matter (UFP, dp < 100 nm) was sampled with three parallel multistage impactors and analyzed for metals, main water soluble ions, anhydrosugars, total carbon, and PAH content. The measurement of the number concentration and size distribution was also performed by a fourth multistage impactor. UFP mass emission factors averaged to 424 mg/kgfuel for all the tested stove and wood type (fir, beech) combinations except for beech log burning in the wood stove (838 mg/kgfuel). Compositional differences were observed for pellets and wood UFP samples, where high TC levels characterize the wood log combustion and potassium salts are dominant in every pellet sample. Crucial aspects determining the UFP composition in the wood stove experiments are critical situations in terms of available oxygen (a lack or an excess of combustion air) and high temperatures. Whereas for the automatically controlled pellets stove local situations (e.g., hindered air-fuel mixing due to heaps of pellets on the burner pot) determine the emission levels and composition. Wood samples contain more potentially carcinogenic PAHs with respect to pellets samples. Some diagnostic ratios related to PAH isomers and anhydrosugars compiled from experimental UFP data in the present study and compared to literature values proposed for the emission source discrimination for atmospheric aerosol, extend the evaluation usually limited to higher particle size fractions also to UFP.

Comparison of self-reported and biomedical data on hypertension and diabetes: findings from the China Health and Retirement Longitudinal Study (CHARLS)

PubMed Central

Ning, Meng; Zhang, Qiang; Yang, Min

2016-01-01

Objectives We examined the level of agreement between biomedical and self-reported measurements of hypertension and diabetes in a Chinese national community sample, and explored associations of the agreement and possible contextual effects among provinces and geographic regions in China. Design Secondary analysis of a cohort sample. Setting and participants Community samples were drawn from the national baseline survey of the China Health and Retirement Longitudinal Study (CHARLS, 2011–2012) through multistage probability sampling, which included households with members 45 years of age or above with a total sample size of 17 708 individuals. Outcome measures Sensitivity, specificity and κ were used as measurements of agreements or validity; variance of validity measures among provinces and communities was estimated using random-effects models. Results Self-reports for hypertension and diabetes showed high specificity (96.3% and 98.3%, respectively) but low sensitivity (56.3% and 61.5%, respectively). Agreement between self-reported data and biomedical measurements was moderate for both hypertension (κ 0.57) and diabetes (κ 0.65), with respondents who were older, of higher socioeconomic status, better educated and who had hospital admissions in the past 12 months showing stronger agreements than their counterparts. Large and significant variations in the sensitivity among provinces for hypertension, and among communities for both hypertension and diabetes, could neither be attributed to the effects of respondents’ characteristics nor to the contextual effects of city–village differences. Conclusions As a considerable number of people in the overall sample were unaware of their conditions, self-reports will lead to an underestimation of the prevalence of hypertension and diabetes. However, in more developed communities or provinces, self-reported data can be a reliable estimate of the prevalence of the two conditions. Further investigations of contextual effects at provincial and community levels could highlight public health strategies to improve awareness of the two conditions. PMID:26729390

Feet swelling in a multistage ultraendurance triathlete: a case study

PubMed Central

Knechtle, Beat; Zingg, Matthias Alexander; Knechtle, Patrizia; Rosemann, Thomas; Rüst, Christoph Alexander

2015-01-01

Recent studies investigating ultraendurance athletes showed an association between excessive fluid intake and swelling of the lower limbs such as the feet. To date, this association has been investigated in single-stage ultraendurance races, but not in multistage ultraendurance races. In this case study, we investigated a potential association between fluid intake and feet swelling in a multistage ultraendurance race such as a Deca Iron ultratriathlon with ten Ironman triathlons within 10 consecutive days. A 49-year-old well-experienced ultratriathlete competed in autumn 2013 in the Deca Iron ultratriathlon held in Lonata del Garda, Italy, and finished the race as winner within 129:33 hours:minutes. Changes in body mass (including body fat and lean body mass), foot volume, total body water, and laboratory measurements were assessed. Food and fluid intake during rest and competing were recorded, and energy and fluid turnovers were estimated. During the ten stages, the volume of the feet increased, percentage body fat decreased, creatinine and urea levels increased, hematocrit and hemoglobin values decreased, and plasma [Na+] remained unchanged. The increase in foot volume was significantly and positively related to fluid intake during the stages. The poststage volume of the foot was related to poststage total body water, poststage creatinine, and poststage urea. This case report shows that the volume of the foot increased during the ten stages, and the increase in volume was significantly and positively related to fluid intake during the stages. Furthermore, the poststage volume of the foot was related to poststage total body water, poststage creatinine, and poststage urea. The continuous feet swelling during the race was most probably due to a combination of a high fluid intake and a progressive decline in renal function (ie, continuous increase in creatinine and urea), leading to body fluid retention (ie, increase in total body water). PMID:26508884

Phase-I monitoring of standard deviations in multistage linear profiles

NASA Astrophysics Data System (ADS)

Kalaei, Mahdiyeh; Soleimani, Paria; Niaki, Seyed Taghi Akhavan; Atashgar, Karim

2018-03-01

In most modern manufacturing systems, products are often the output of some multistage processes. In these processes, the stages are dependent on each other, where the output quality of each stage depends also on the output quality of the previous stages. This property is called the cascade property. Although there are many studies in multistage process monitoring, there are fewer works on profile monitoring in multistage processes, especially on the variability monitoring of a multistage profile in Phase-I for which no research is found in the literature. In this paper, a new methodology is proposed to monitor the standard deviation involved in a simple linear profile designed in Phase I to monitor multistage processes with the cascade property. To this aim, an autoregressive correlation model between the stages is considered first. Then, the effect of the cascade property on the performances of three types of T 2 control charts in Phase I with shifts in standard deviation is investigated. As we show that this effect is significant, a U statistic is next used to remove the cascade effect, based on which the investigated control charts are modified. Simulation studies reveal good performances of the modified control charts.

An assessment of Lot Quality Assurance Sampling to evaluate malaria outcome indicators: extending malaria indicator surveys

PubMed Central

Biedron, Caitlin; Pagano, Marcello; Hedt, Bethany L; Kilian, Albert; Ratcliffe, Amy; Mabunda, Samuel; Valadez, Joseph J

2010-01-01

Background Large investments and increased global prioritization of malaria prevention and treatment have resulted in greater emphasis on programme monitoring and evaluation (M&E) in many countries. Many countries currently use large multistage cluster sample surveys to monitor malaria outcome indicators on a regional and national level. However, these surveys often mask local-level variability important to programme management. Lot Quality Assurance Sampling (LQAS) has played a valuable role for local-level programme M&E. If incorporated into these larger surveys, it would provide a comprehensive M&E plan at little, if any, extra cost. Methods The Mozambique Ministry of Health conducted a Malaria Indicator Survey (MIS) in June and July 2007. We applied LQAS classification rules to the 345 sampled enumeration areas to demonstrate identifying high- and low-performing areas with respect to two malaria program indicators—‘household possession of any bednet’ and ‘household possession of any insecticide-treated bednet (ITN)’. Results As shown by the MIS, no province in Mozambique achieved the 70% coverage target for household possession of bednets or ITNs. By applying LQAS classification rules to the data, we identify 266 of the 345 enumeration areas as having bednet coverage severely below the 70% target. An additional 73 were identified with low ITN coverage. Conclusions This article demonstrates the feasibility of integrating LQAS into multistage cluster sampling surveys and using these results to support a comprehensive national, regional and local programme M&E system. Furthermore, in the recommendations we outlined how to integrate the Large Country-LQAS design into macro-surveys while still obtaining results available through current sampling practices. PMID:20139435

Enhancing Community Knowledge and Health Behaviors to Eliminate Blinding Trachoma in Mali Using Radio Messaging as a Strategy

ERIC Educational Resources Information Center

Bamani, Sanoussi; Toubali, Emily; Diarra, Sadio; Goita, Seydou; Berte, Zana; Coulibaly, Famolo; Sangare, Hama; Tuinsma, Marjon; Zhang, Yaobi; Dembele, Benoit; Melvin, Palesa; MacArthur, Chad

2013-01-01

The National Blindness Prevention Program in Mali has broadcast messages on the radio about trachoma as part of the country's trachoma elimination strategy since 2008. In 2011, a radio impact survey using multi-stage cluster sampling was conducted in the regions of Kayes and Segou to assess radio listening habits, coverage of the broadcasts,…

Assessing insect-induced tree mortality across large areas with high-resolution aerial photography in a multistage sample

Treesearch

Randy Hamilton; Kevin Megown; James Ellenwood; Henry Lachowski; Paul Maus

2010-01-01

In recent years, unprecedented tree mortality has occurred throughout the national forests owing to insect infestations and disease outbreaks. The magnitude and extent of mortality, coupled with the lack of routine monitoring in some areas, has made it difficult to assess the damage, associated ecological impact, and fire hazard in a timely and cost-effective manner....

Teacher Self-Efficacy Enhancement and School Location: Implication for Students' Achievement in Economics in Senior Secondary School in Ibadan, Oyo State, Nigeria

ERIC Educational Resources Information Center

Durowoju, Esther O.; Onuka, Adams O. U.

2015-01-01

The paper investigated the effect of teacher self-efficacy enhancement and school location on students' achievement in Economics in Senior Secondary School in Ibadan Metropolis of Oyo State, Nigeria. Three hypotheses were tested at 0.05 level of significance. Multi-stage sampling technique was adopted in the study. Four Local Government Areas (two…

A multistage stochastic programming model for a multi-period strategic expansion of biofuel supply chain under evolving uncertainties

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

Xie, Fei; Huang, Yongxi

Here, we develop a multistage, stochastic mixed-integer model to support biofuel supply chain expansion under evolving uncertainties. By utilizing the block-separable recourse property, we reformulate the multistage program in an equivalent two-stage program and solve it using an enhanced nested decomposition method with maximal non-dominated cuts. We conduct extensive numerical experiments and demonstrate the application of the model and algorithm in a case study based on the South Carolina settings. The value of multistage stochastic programming method is also explored by comparing the model solution with the counterparts of an expected value based deterministic model and a two-stage stochastic model.

A multistage stochastic programming model for a multi-period strategic expansion of biofuel supply chain under evolving uncertainties

DOE PAGES

Xie, Fei; Huang, Yongxi

2018-02-04

Here, we develop a multistage, stochastic mixed-integer model to support biofuel supply chain expansion under evolving uncertainties. By utilizing the block-separable recourse property, we reformulate the multistage program in an equivalent two-stage program and solve it using an enhanced nested decomposition method with maximal non-dominated cuts. We conduct extensive numerical experiments and demonstrate the application of the model and algorithm in a case study based on the South Carolina settings. The value of multistage stochastic programming method is also explored by comparing the model solution with the counterparts of an expected value based deterministic model and a two-stage stochastic model.

Prevalence and treatment of pain in non-institutionalized very old population: transversal study at national level.

PubMed

Gálvez-Barrón, César; Narvaiza, Leire; Dapena, María D; Macho, Oscar; Rodríguez-Molinero, Alejandro

2016-04-01

In Europe, there is no conclusive data at national level about pain prevalence in non-institutionalized very old population. In USA, it has recently been reported a high prevalence (56 %); however, this data can not be extrapolated to other regions because the known influence of geographical and ethnic differences. Furthermore there are few data on use of treatments for pain in this population. To explore prevalence and considered pharmacological treatments for pain in this population. Transversal study on 551 participants aged 80 or more living in Spain (non-institutionalized). Probabilistic multistage sampling was carried out, stratified by sex and place of residence. All Spanish regions were considered for recruitment process. Pain (last 4 weeks), intensity (Face Pain Scale), localization and pharmacological treatments were evaluated by in-person interviews. Pain's prevalence was 52.5 % (CI 95 % 48.28-56.80) and 38.5 % experienced pain of at least moderate intensity. The most frequently involved body regions were lower limbs (26.6 %) and dorso-lumbar region (21.9 %). Only 40 % of participants with pain and 43.2 % with moderate or severe pain used analgesics, and paracetamol was less frequently used than non-steroidal anti-inflammatory drugs at any pain intensity. Age was not associated with higher prevalence [odds ratios 0.97 (CI 95 % 0.93-1.02) in females and 0.99 (CI 95 % 0.92-1.06) in males]. The prevalence of pain in non-institutionalized very old people is high. Pain is probably being undertreated, even moderate or severe pain. Guideline's recommendations are probably not being considered to select the analgesic therapy.

Eclogites and garnet pyroxenites from Kimberley, Kaapvaal craton, South Africa: their diverse origins and complex metasomatic signatures

NASA Astrophysics Data System (ADS)

Shu, Qiao; Brey, Gerhard P.; Pearson, D. Graham

2018-06-01

We describe the petrography and mineral chemistry of sixteen eclogite and garnet pyroxenite xenoliths from the reworked Boshof road dump (Kimberley) and define three groups that stem from different depths. Group A, the shallowest derived, has low HREE (heavy rare earth element) abundances, flat middle to heavy REE patterns and high Mg# [= 100·Mg/(Mg + Fe)]. Their protoliths probably were higher pressure cumulates ( 0.7 GPa) of mainly clinopyroxene (cpx) and subordinate orthopyroxene (opx) and olivine (ol). Group B1 xenoliths, derived from the graphite/diamond boundary and below show similarities to present-day N-MORB that were modified by partial melting (higher Mg# and positively inclined MREE (middle REE) and HREE (heavy REE) patterns of calculated bulk rocks). Group B2 samples from greatest depth are unique amongst eclogites reported so far worldwide. The calculated bulk rocks have humped REE patterns with very low La and Lu and prominent maxima at Sm or Eu and anomalously high Na2O (up to 5 wt%) which makes protolith identification difficult. The complex trace element signatures of the full spectrum of Kimberley eclogites belie a multi-stage history of melt depletion and metasomatism with the introduction of new phases especially of phlogopite (phlog). Phlogopite appears to be characteristic for Kimberley eclogites and garnet peridotites. Modelling the metasomatic overprint indicates that groups A and B1 were overprinted by volatile- and potassium-rich melts probably by a process of chromatographic fractionation. Using constraints from other metasomatized Kimberley mantle rocks suggest that much of the metasomatic phlogopite in the eclogites formed during an intense episode of metasomatism that affected the mantle beneath this region 1.1 Gyr ago.

A survey of computational methods and error rate estimation procedures for peptide and protein identification in shotgun proteomics

PubMed Central

Nesvizhskii, Alexey I.

2010-01-01

This manuscript provides a comprehensive review of the peptide and protein identification process using tandem mass spectrometry (MS/MS) data generated in shotgun proteomic experiments. The commonly used methods for assigning peptide sequences to MS/MS spectra are critically discussed and compared, from basic strategies to advanced multi-stage approaches. A particular attention is paid to the problem of false-positive identifications. Existing statistical approaches for assessing the significance of peptide to spectrum matches are surveyed, ranging from single-spectrum approaches such as expectation values to global error rate estimation procedures such as false discovery rates and posterior probabilities. The importance of using auxiliary discriminant information (mass accuracy, peptide separation coordinates, digestion properties, and etc.) is discussed, and advanced computational approaches for joint modeling of multiple sources of information are presented. This review also includes a detailed analysis of the issues affecting the interpretation of data at the protein level, including the amplification of error rates when going from peptide to protein level, and the ambiguities in inferring the identifies of sample proteins in the presence of shared peptides. Commonly used methods for computing protein-level confidence scores are discussed in detail. The review concludes with a discussion of several outstanding computational issues. PMID:20816881

The prevalence of tooth discolouration and the self-satisfaction with tooth colour in a Chinese urban population.

PubMed

Xiao, J; Zhou, X D; Zhu, W C; Zhang, B; Li, J Y; Xu, X

2007-05-01

To determine the prevalence of tooth discolouration, self-satisfaction with tooth colour, and correlation with socio-demographic-behavioural factors in adults and teenagers in Chengdu, China. A cross-sectional survey. 405 Chinese urban adults and teenagers from a multistage random probability sample. Tooth colour was measured on the maxillary central incisors using a colorimeter. Tooth discolouration was determined according to the discolouration level figure and evaluation criteria. Self-satisfaction with tooth colour was assessed on a five-point qualitative scale. Data were coded and analyzed using SPSS software. The mean values for L*, a* and b* were 70.67 (s.d. 1.91), 4.29 (s.d. 2.05) and 17.51 (s.d. 4.13), respectively. Age and sex were the most important factors associated with tooth colour (P < 0.05). About half of the study population (48.9%) suffered from some tooth discolouration, and 52.6% were dissatisfied with their tooth colour. Education and smoking were significant factors affecting self-satisfaction with tooth colour (P < 0.05). Tooth discolouration is common among the Chinese, and many Chinese are dissatisfied with their tooth colour. Self-satisfaction with tooth colour decreased with increasing severity of discolouration. Further research is needed to determine types of tooth discolouration among broader regions in China.

Prevalence of Dementia, Emotional State and Physical Performance among Older Adults in the Metropolitan Area of Guadalajara, Jalisco, Mexico

PubMed Central

Velázquez-Brizuela, Irma E.; Ortiz, Genaro G.; Ventura-Castro, Lucia; Árias-Merino, Elva D.; Pacheco-Moisés, Fermín P.; Macías-Islas, Miguel A.

2014-01-01

Background. Dementia affects memory, thinking, language, judgment, and behavior. Depression, is common in older adults with dementia. The concomitance of dementia and depression increases disability with impaired activities of daily living (ADL), increasing the chances of institutionalization and mortality. Methods. Cross-sectional study of a population 60 years and older who live in the State of Jalisco, Mexico. A total of 1142 persons were assessed regarding their cognitive function, emotional state, and physical performance. Door-to-door interview technique was assigned in condition with multistage probability random sampling. Cognitive function, depression and functional disability were assessed by applying standardized Minimental State Examination (Folstein), Geriatric Depression Scale, and the Katz index, respectively. Diagnosis of dementia was performed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, the Fourth Edition. Data were analyzed using SPSS software. Results. Prevalence of demency was 9.5% (63.35% women, and 36.7% men). Demency was associated with being woman, being older than 70 years, low level of education, not having the economic benefit of retirement, being single or living without a partner, low level of education, suffering from depression and have functional disability in ADL. Conclusion. Dementia is more common in women and is related to depression and disability. PMID:24795758

Prevalence of Dementia, Emotional State and Physical Performance among Older Adults in the Metropolitan Area of Guadalajara, Jalisco, Mexico.

PubMed

Velázquez-Brizuela, Irma E; Ortiz, Genaro G; Ventura-Castro, Lucia; Arias-Merino, Elva D; Pacheco-Moisés, Fermín P; Macías-Islas, Miguel A

2014-01-01

Background. Dementia affects memory, thinking, language, judgment, and behavior. Depression, is common in older adults with dementia. The concomitance of dementia and depression increases disability with impaired activities of daily living (ADL), increasing the chances of institutionalization and mortality. Methods. Cross-sectional study of a population 60 years and older who live in the State of Jalisco, Mexico. A total of 1142 persons were assessed regarding their cognitive function, emotional state, and physical performance. Door-to-door interview technique was assigned in condition with multistage probability random sampling. Cognitive function, depression and functional disability were assessed by applying standardized Minimental State Examination (Folstein), Geriatric Depression Scale, and the Katz index, respectively. Diagnosis of dementia was performed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, the Fourth Edition. Data were analyzed using SPSS software. Results. Prevalence of demency was 9.5% (63.35% women, and 36.7% men). Demency was associated with being woman, being older than 70 years, low level of education, not having the economic benefit of retirement, being single or living without a partner, low level of education, suffering from depression and have functional disability in ADL. Conclusion. Dementia is more common in women and is related to depression and disability.

[Reproductive health survey of young adults in greater Santiago].

PubMed

Valenzuela, M S; Herold, J M; Morris, L; López, I M

1992-01-01

In 1988 a survey was carried out in order to obtain information on knowledge about reproduction, sexual activity, attitudes, and use of contraceptive methods among residents between 15 and 24 years of age in Greater Santiago. For this purpose, a multistage, self-weighted, non-replacement probability sample was chosen from the entire Santiago urban area. After 2,898 households were visited, 865 women and 800 men were selected and interviewed. For the interview, a questionnaire with 156 questions was developed; many questions were similar to those included in similar surveys in Brazil and Guatemala. The interviewers were professionals who had received prior training. Although 75% of the interviewees had attended sex education classes, they had erroneous ideas on various basic subjects. Sixty-nine percent of the women interviewed had undergone menarche before attending these classes. In addition, 35.4% of the women and 65.0% of the men had had sexual relations prior to marriage, and less than 20% had used any contraceptive method. More than 60% of the interviewees who had children had conceived them before marrying. These findings point up the necessity of offering sex education classes for children and young people, as well as facilitating their access to family planning services, in order to decrease the number of illegitimate and unwanted children that are born in Chile.

Prevalence of depression among a population aged over 45 years in Chiang Mai, Thailand.

PubMed

Wangtongkum, Suparus; Sucharitakul, Phongsakorn; Wongjaroen, Sriwanna; Maneechompoo, Suthin

2008-12-01

To determine the prevalence of depression in Thai people of 45 years and over. The presented project was a cross sectional study on the prevalence of depression and cognitive impairment in Chiang Mai. Door-to-door interview technique was assigned in condition with multistage probability random sampling to obtain subjects that represent a population of Chiang Mai. The research was conducted between October 2004 and September 2005. Data were collected on subject that were 45 years old and over. All subjects were selected from all districts in Chiang Mai. Thai Mini Mental State Examination (TMSE) and Thai Beck Depression Inventory (BDI) were used as the assessment tool If the subjects had a TMSE score less than 24 points, it was assumed as a cognitive impairment. One thousand four hundred ninety two people, 610 males and 882 females, were enrolled in the present study. Their mean age was 59.7 +/- 10.4 years (45-88 year). The prevalence of depression only was 29.2%, the prevalence of cognitive impairment only was 5.63% and the prevalence of cognitive impairment with depression was 3.96%. The prevalence of depression increased with age. The prevalence of depression in Thai people of 45 years and over was 29.2% and increased with age.

Promoting health (implicitly)? A longitudinal content analysis of implicit health information in cigarette advertising, 1954-2003.

PubMed

Paek, Hye-Jin; Reid, Leonard N; Choi, Hojoon; Jeong, Hyun Ju

2010-10-01

Tobacco studies indicate that health-related information in cigarette advertising leads consumers to underestimate the detrimental health effects of smoking and contributes to their smoking-related perceptions, beliefs, and attitudes. This study examined the frequencies and kinds of implicit health information in cigarette advertising across five distinct smoking eras covering the years 1954-2003. Analysis of 1,135 cigarette advertisements collected through multistage probability sampling of three popular consumer magazines found that the level of implicit health information (i.e., "light" cigarette, cigarette pack color, verbal and visual health cues, cigarette portrayals, and human model-cigarette interaction) in post-Master Settlement Agreement [MSA] era ads is similar to the level in ads from early smoking eras. Specifically, "light" cigarettes were frequently promoted, and presence of light colors in cigarette packs seemed dominant after the probroadcast ban era. Impressionistic verbal health cues (e.g., soft, mild, and refreshing) appeared more frequently in post-MSA era ads than in pre-MSA era ads. Most notably, a majority of the cigarette ads portrayed models smoking, lighting, or offering a cigarette to others. The potential impact of implicit health information is discussed in the contexts of social cognition and Social Cognitive Theory. Policy implications regarding our findings are also detailed.

Drinking in different social contexts among white, black, and Hispanic men.

PubMed Central

Caetano, R.; Herd, D.

1988-01-01

This paper describes alcohol use by White, Black, and Hispanic men in eight different social settings. Data were obtained from a multi-stage probability sample of the household population of White, Black, and Hispanic adults aged 18 years and over, residing in the 48 contiguous United States. The response rate was 73 percent for Whites, 76 percent for Blacks, and 72 percent for Hispanics. Results show that Whites go more frequently and drink more frequently than Blacks and Hispanics at restaurants, in clubs or organizational meetings, and in bars. Blacks go more frequently than Whites and Hispanics to public settings such as parks, streets, and parking lots; however, the mean number of drinks consumed in these public places and the proportion of men drinking five or more drinks is higher for Hispanics than for Whites and Blacks. Other places where heavier drinking is common in all three ethnic groups are bars, taverns and cocktail lounges, and parties. In all three ethnic groups, men who are younger and those who are single go more frequently than other men to bars or public places such as streets, parks, and parking lots. Men who are younger and those who are single also have a higher rate of heavy drinking and of drunkenness than other men. PMID:3176527

A Multi-stage Carcinogenesis Model to Investigate Caloric Restriction as a Potential Tool for Post-irradiation Mitigation of Cancer Risk

PubMed Central

Tani, Shusuke; Blyth, Benjamin John; Shang, Yi; Morioka, Takamitsu; Kakinuma, Shizuko; Shimada, Yoshiya

2016-01-01

The risk of radiation-induced cancer adds to anxiety in low-dose exposed populations. Safe and effective lifestyle changes which can help mitigate excess cancer risk might provide exposed individuals the opportunity to pro-actively reduce their cancer risk, and improve mental health and well-being. Here, we applied a mathematical multi-stage carcinogenesis model to the mouse lifespan data using adult-onset caloric restriction following irradiation in early life. We re-evaluated autopsy records with a veterinary pathologist to determine which tumors were the probable causes of death in order to calculate age-specific mortality. The model revealed that in both irradiated and unirradiated mice, caloric restriction reduced the age-specific mortality of all solid tumors and hepatocellular carcinomas across most of the lifespan, with the mortality rate dependent more on age owing to an increase in the number of predicted rate-limiting steps. Conversely, irradiation did not significantly alter the number of steps, but did increase the overall transition rate between the steps. We show that the extent of the protective effect of caloric restriction is independent of the induction of cancer from radiation exposure, and discuss future avenues of research to explore the utility of caloric restriction as an example of a potential post-irradiation mitigation strategy. PMID:27390741

Hydraulic design to optimize the treatment capacity of Multi-Stage Filtration units

NASA Astrophysics Data System (ADS)

Mushila, C. N.; Ochieng, G. M.; Otieno, F. A. O.; Shitote, S. M.; Sitters, C. W.

2016-04-01

Multi-Stage Filtration (MSF) can provide a robust treatment alternative for surface water sources of variable water quality in rural communities at low operation and maintenance costs. MSF is a combination of Slow Sand Filters (SSFs) and Pre-treatment systems. The general objective of this research was to optimize the treatment capacity of MSF. A pilot plant study was undertaken to meet this objective. The pilot plant was monitored for a continuous 98 days from commissioning till the end of the project. Three main stages of MSF namely: The Dynamic Gravel Filter (DGF), Horizontal-flow Roughing Filter (HRF) and SSF were identified, designed and built. The response of the respective MSF units in removal of selected parameters guiding drinking water quality such as microbiological (Faecal and Total coliform), Suspended Solids, Turbidity, PH, Temperature, Iron and Manganese was investigated. The benchmark was the Kenya Bureau (KEBS) and World Health Organization (WHO) Standards for drinking water quality. With respect to microbiological raw water quality improvement, MSF units achieved on average 98% Faecal and 96% Total coliform removal. Results obtained indicate that implementation of MSF in rural communities has the potential to increase access to portable water to the rural populace with a probable consequent decrease in waterborne diseases. With a reduced down time due to illness, more time would be spent in undertaking other economic activities.

ERTS data user investigation to develop a multistage forest sampling inventory system

NASA Technical Reports Server (NTRS)

Langley, P. G.; Vanroessel, J. W. (Principal Investigator); Wert, S. L.

1973-01-01

The author has identified the following significant results. A system to provide precision annotation of predetermined forest inventory sampling units on the ERTS-1 MSS images was developed. In addition, an annotation system for high altitude U2 photographs was completed. MSS bulk image accuracy is good enough to allow the use of one square mile sampling units. IMANCO image analyzer interpretation work for small scale images demonstrated the need for much additional analyses. Continuing image interpretation work for the next reporting period is concentrated on manual image interpretation work as well as digital interpretation system development using the computer compatible tapes.

The prevalence of hepatitis C virus infection in Egypt 2015: implications for future policy on prevention and treatment.

PubMed

Kandeel, Amr; Genedy, Mohamad; El-Refai, Samir; Funk, Anna L; Fontanet, Arnaud; Talaat, Maha

2017-01-01

In 2015, a national Egyptian health issue survey was conducted to describe the prevalence of hepatitis C virus (HCV) infection. In this paper, we describe the HCV burden in 2015, compare the results with the national survey conducted in 2008, and discuss the implications of the new findings on prevention of HCV in Egypt. A multistage probability sampling approach was used, similar to the national demographic survey conducted in 2008. More than 90% of sampled individuals complied with the interview and provided blood samples. In the 15-59-year age groups, the prevalence of HCV antibody was found to be 10.0% (95% CI 9.5-10.5) and that of HCV RNA to be 7.0% (95% CI 6.6-7.4). In children, 1-14 years old, the prevalence of HCV antibody and HCV RNA were 0.4% (95% CI 0.3-0.5) and 0.2% (95% CI 0.1-0.3) respectively. Approximately, 3.7 million persons have chronic HCV infection in the age group 15-59 in 2015. An estimated 29% reduction in HCV RNA prevalence has been seen since 2008, which is largely attributable to the ageing of the group infected 40-50 years ago during the mass schistosomiasis treatment campaigns. Prevention efforts may have also contributed to this decline, with an estimated 75% (95% CI 6-45) decrease in HCV incidence in the 0-19 year age groups over the past 20 years. These findings can be used to shape future HCV prevention policies in Egypt. © 2016 The Authors. Liver International Published by John Wiley & Sons Ltd.

Prevalence of metabolic syndrome and its association with educational inequalities among Brazilian adults: a population-based study.

PubMed

Gronner, M F; Bosi, P L; Carvalho, A M; Casale, G; Contrera, D; Pereira, M A; Diogo, T M; Torquato, M T C G; Souza, G M D; Oishi, J; Leal, A M O

2011-07-01

The present study estimated the prevalence of metabolic syndrome (MS) according to the criteria established by the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATPIII) and the International Diabetes Federation (IDF) and analyzed the contribution of social factors in an adult urban population in the Southeastern region of Brazil. The sample plan was based on multistage probability sampling according to family head income and educational level. A random sample of 1116 subjects aged 30 to 79 years was studied. Participants answered a questionnaire about socio-demographic variables and medical history. Fasting capillary glucose (FCG), total cholesterol, high-density lipoprotein cholesterol (HDL-C), and triglycerides were determined and all non-diabetic subjects were submitted to the 75-g oral glucose tolerance test. Body mass index (BMI, kg/m(2)), waist circumference and blood pressure (BP) were determined. Age- and gender-adjusted prevalence of MS was 35.9 and 43.2% according to NCEP-ATPIII and IDF criteria, respectively. Substantial agreement was found between NCEP-ATPIII and IDF definitions. Low HDL-C levels and high BP were the most prevalent MS components according to NCEP-ATPIII criteria (76.3 and 59.2%, respectively). Considering the diagnostic criteria adopted, 13.5% of the subjects had diabetes and 9.7% had FCG ≥100 mg/dL. MS prevalence was significantly associated with age, skin color, BMI, and educational level. This cross-sectional population-based study in the Southeastern region of Brazil indicates that MS is highly prevalent and associated with an important social indicator, i.e., educational level. This result suggests that in developing countries health policy planning to reduce the risk of MS, in particular, should consider improvement in education.

Simulation of multistage turbine flows

NASA Technical Reports Server (NTRS)

Adamczyk, John J.; Mulac, Richard A.

1987-01-01

A flow model has been developed for analyzing multistage turbomachinery flows. This model, referred to as the average passage flow model, describes the time-averaged flow field with a typical passage of a blade row embedded within a multistage configuration. Computer resource requirements, supporting empirical modeling, formulation code development, and multitasking and storage are discussed. Illustrations from simulations of the space shuttle main engine (SSME) fuel turbine performed to date are given.

Public attitudes toward stuttering in Turkey: probability versus convenience sampling.

PubMed

Ozdemir, R Sertan; St Louis, Kenneth O; Topbaş, Seyhun

2011-12-01

A Turkish translation of the Public Opinion Survey of Human Attributes-Stuttering (POSHA-S) was used to compare probability versus convenience sampling to measure public attitudes toward stuttering. A convenience sample of adults in Eskişehir, Turkey was compared with two replicates of a school-based, probability cluster sampling scheme. The two replicates of the probability sampling scheme yielded similar demographic samples, both of which were different from the convenience sample. Components of subscores on the POSHA-S were significantly different in more than half of the comparisons between convenience and probability samples, indicating important differences in public attitudes. If POSHA-S users intend to generalize to specific geographic areas, results of this study indicate that probability sampling is a better research strategy than convenience sampling. The reader will be able to: (1) discuss the difference between convenience sampling and probability sampling; (2) describe a school-based probability sampling scheme; and (3) describe differences in POSHA-S results from convenience sampling versus probability sampling. Copyright © 2011 Elsevier Inc. All rights reserved.

Deep Vein Thrombosis After Complex Posterior Spine Surgery: Does Staged Surgery Make a Difference?

PubMed

Edwards, Charles C; Lessing, Noah L; Ford, Lisa; Edwards, Charles C

Retrospective review of a prospectively collected database. To assess the incidence of deep vein thrombosis (DVT) associated with single- versus multistage posterior-only complex spinal surgeries. Dividing the physiologic burden of spinal deformity surgery into multiple stages has been suggested as a potential means of reducing perioperative complications. DVT is a worrisome complication owing to its potential to lead to pulmonary embolism. Whether or not staging affects DVT incidence in this population is unknown. Consecutive patients undergoing either single- or multistage posterior complex spinal surgeries over a 12-year period at a single institution were eligible. All patients received lower extremity venous duplex ultrasonographic (US) examinations 2 to 4 days postoperatively in the single-stage group and 2 to 4 days postoperatively after each stage in the multistage group. Multivariate logistic regression was used to assess the independent contribution of staging to developing a DVT. A total of 107 consecutive patients were enrolled-26 underwent multistage surgery and 81 underwent single-stage surgery. The single-stage group was older (63 years vs. 45 years; p < .01) and had a higher Charlson comorbidity index (2.25 ± 1.27 vs. 1.23 ± 1.58; p < .01). More multistage patients had positive US tests than single-stage patients (5 of 26 vs. 6 of 81; 19% vs. 7%; p = .13). Adjusting for all the above-mentioned covariates, a multistage surgery was 8.17 (95% CI 0.35-250.6) times more likely to yield a DVT than a single-stage surgery. Patients who undergo multistage posterior complex spine surgery are at a high risk for developing a DVT compared to those who undergo single-stage procedures. The difference in DVT incidence may be understated as the multistage group had a lower pre- and intraoperative risk profile with a younger age, lower medical comorbidities, and less per-stage blood loss. Copyright © 2017 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

Infant mortality and family welfare: policy implications for Indonesia.

PubMed

Poerwanto, S; Stevenson, M; de Klerk, N

2003-07-01

To examine the effect of family welfare index (FWI) and maternal education on the probability of infant death. A population based multistage stratified clustered survey. Women of reproductive age in Indonesia between 1983-1997. The 1997 Indonesian Demographic and Health Survey. Infant mortality was associated with FWI and maternal education. Relative to families of high FWI, the risk of infant death was almost twice among families of low FWI (aOR=1.7, 95%CI=0.9 to 3.3), and three times for families of medium FWI (aOR=3.3,95%CI=1.7 to 6.5). Also, the risk of infant death was threefold higher (aOR=3.4, 95% CI=1.6 to 7.1) among mothers who had fewer than seven years of formal education compared with mothers with more than seven years of education. Fertility related indicators such as young maternal age, absence from contraception, birth intervals, and prenatal care, seem to exert significant effect on the increased probability of infant death. The increased probability of infant mortality attributable to family income inequality and low maternal education seems to work through pathways of material deprivation and chronic psychological stress that affect a person's health damaging behaviours. The policies that are likely to significantly reduce the family's socioeconomic inequality in infant mortality are implicated.

Purification and Quantification of an Isomeric Compound in a Mixture by Collisional Excitation in Multistage Mass Spectrometry Experiments.

PubMed

Jeanne Dit Fouque, Dany; Maroto, Alicia; Memboeuf, Antony

2016-11-15

The differentiation, characterization, and quantification of isomers and/or isobars in mixtures is a recurrent problem in mass spectrometry and more generally in analytical chemistry. Here we present a new strategy to assess the purity of a compound that is susceptible to be contaminated with another isomeric side-product in trace levels. Providing one of the isomers is available as pure sample, this new strategy allows the detection of isomeric contamination. This is done thanks to a "gas-phase collisional purification" inside an ion trap mass spectrometer paving the way for an improved analysis of at least similar samples. This strategy consists in using collision induced dissociation (CID) multistage mass spectrometry (MS 2 and MS 3 ) experiments and the survival yield (SY) technique. It has been successfully applied to mixtures of cyclic poly( L -lactide) (PLA) with increasing amounts of its linear topological isomer. Purification in gas phase of PLA mixtures was established based on SY curves obtained in MS 3 mode: all samples gave rise to the same SY curve corresponding then to the pure cyclic component. This new strategy was sensitive enough to detect traces of linear PLA (<3%) in a sample of cyclic PLA that was supposedly pure according to other characterization techniques ( 1 H NMR, MALDI-HRMS, and size-exclusion chromatography). Moreover, in this case, the presence of linear isomer was undetectable according to MS/MS or MS/MS/MS analysis only as fragment ions are also of the same m/z values. This type of approach could easily be implemented in hyphenated mass spectrometric techniques to improve the structural and quantitative analysis of complex samples.

DNA pooling: a comprehensive, multi-stage association analysis of ACSL6 and SIRT5 polymorphisms in schizophrenia.

PubMed

Chowdari, K V; Northup, A; Pless, L; Wood, J; Joo, Y H; Mirnics, K; Lewis, D A; Levitt, P R; Bacanu, S-A; Nimgaonkar, V L

2007-04-01

Many candidate gene association studies have evaluated incomplete, unrepresentative sets of single nucleotide polymorphisms (SNPs), producing non-significant results that are difficult to interpret. Using a rapid, efficient strategy designed to investigate all common SNPs, we tested associations between schizophrenia and two positional candidate genes: ACSL6 (Acyl-Coenzyme A synthetase long-chain family member 6) and SIRT5 (silent mating type information regulation 2 homologue 5). We initially evaluated the utility of DNA sequencing traces to estimate SNP allele frequencies in pooled DNA samples. The mean variances for the DNA sequencing estimates were acceptable and were comparable to other published methods (mean variance: 0.0008, range 0-0.0119). Using pooled DNA samples from cases with schizophrenia/schizoaffective disorder (Diagnostic and Statistical Manual of Mental Disorders edition IV criteria) and controls (n=200, each group), we next sequenced all exons, introns and flanking upstream/downstream sequences for ACSL6 and SIRT5. Among 69 identified SNPs, case-control allele frequency comparisons revealed nine suggestive associations (P<0.2). Each of these SNPs was next genotyped in the individual samples composing the pools. A suggestive association with rs 11743803 at ACSL6 remained (allele-wise P=0.02), with diminished evidence in an extended sample (448 cases, 554 controls, P=0.062). In conclusion, we propose a multi-stage method for comprehensive, rapid, efficient and economical genetic association analysis that enables simultaneous SNP detection and allele frequency estimation in large samples. This strategy may be particularly useful for research groups lacking access to high throughput genotyping facilities. Our analyses did not yield convincing evidence for associations of schizophrenia with ACSL6 or SIRT5.

Impact of healthy work environments and multistage nurse residency programs on retention of newly licensed RNs.

PubMed

Kramer, Marlene; Halfer, Diana; Maguire, Pat; Schmalenberg, Claudia

2012-03-01

The objective of the study was to examine effects of nurse-confirmed healthy unit work environments and multistage nurse residency programs (NRPs) on retention rates of newly licensed RNs (NLRNs). Establishing a culture of retention and healthy clinical nurse practice environments are two major challenges confronting nurse leaders today. Nurse residency programs are a major component of NLRN work environments and have been shown to be effective in abating nurse turnover. Sample for this study consisted of 5,316 new graduates in initial RN roles in 28 Magnet® hospitals. There were no differences in retention rates by education or patient population on clinical unit. NLRN retention rate was higher in community than in academic hospitals. More than half of NLRNs were placed on units with very healthy work environments. Newly licensed RNs on units with work environments needing improvement resigned at a significantly higher rate than did other NLRNs. The quality of clinical unit work environments is the most important factor in NLRN retention.

Effectiveness of Family, Child, and Family-Child Based Intervention on ADHD Symptoms of Students with Disabilities

ERIC Educational Resources Information Center

Malekpour, Mokhtar; Aghababaei, Sara; Hadi, Samira

2014-01-01

The aim of the present study was to investigate and compare the effectiveness of family, child, and family-child based intervention on the rate of ADHD symptoms in third grade students. The population for this study was all of students with ADHD diagnoses in the city of Isfahan, Iran. The multistage random sampling method was used to select the 60…

[Personality profile among cocaine users].

PubMed

Sánchez Huesca, R; Guisa Cruz, V M; Cedillo González, A; Pascual Blanco, Y

2002-01-01

Due to the psychiatric comorbidity seen among cocaine addicts, it is of clinical interest to know the personality traits associated to the use of this substance. Personality-profile comparative study of cocaine users and multiple-substance users obtained through the Multistage Personality Inventory. The study analyzed a sample of 30 cocaine users and 26 users of various substances who asked for treatment at a specialized institution. Results show the same profile for both groups, with high 8-4-2 scales. According to the Multistage Personality Inventory, this profile corresponds to an antisocial personality disorder with depressive and schizoid traits. The fact that there is a single profile for different drug users leads us to the hypothesis that there are addictive personality characteristics rather than specific traits related to the use of each substance. These subjects' personality characteristics suggest that the fear to relate to others could make it very difficult to establish a therapeutic link. This, in addition to the acting up tendency seen among users, constitutes a call of alert in terms of their likely abandonment of treatment. Further more, as they take impulses into actions, they build a barrier before words. This could be called acting up, doing instead of saying, which can become an obstacle for the appropriate development of the therapeutic process. The result must consider the size of the sample.

A bottom-up robust optimization framework for identifying river basin development pathways under deep climate uncertainty

NASA Astrophysics Data System (ADS)

Taner, M. U.; Ray, P.; Brown, C.

2016-12-01

Hydroclimatic nonstationarity due to climate change poses challenges for long-term water infrastructure planning in river basin systems. While designing strategies that are flexible or adaptive hold intuitive appeal, development of well-performing strategies requires rigorous quantitative analysis that address uncertainties directly while making the best use of scientific information on the expected evolution of future climate. Multi-stage robust optimization (RO) offers a potentially effective and efficient technique for addressing the problem of staged basin-level planning under climate change, however the necessity of assigning probabilities to future climate states or scenarios is an obstacle to implementation, given that methods to reliably assign probabilities to future climate states are not well developed. We present a method that overcomes this challenge by creating a bottom-up RO-based framework that decreases the dependency on probability distributions of future climate and rather employs them after optimization to aid selection amongst competing alternatives. The iterative process yields a vector of `optimal' decision pathways each under the associated set of probabilistic assumptions. In the final phase, the vector of optimal decision pathways is evaluated to identify the solutions that are least sensitive to the scenario probabilities and are most-likely conditional on the climate information. The framework is illustrated for the planning of new dam and hydro-agricultural expansions projects in the Niger River Basin over a 45-year planning period from 2015 to 2060.

Effect of multi-stage inoculation on the bacterial and fungal community structure during organic municipal solid wastes composting.

PubMed

Xi, Beidou; He, Xiaosong; Dang, Qiuling; Yang, Tianxue; Li, Mingxiao; Wang, Xiaowei; Li, Dan; Tang, Jun

2015-11-01

In this study, PCR-DGGE method was applied to investigate the impact of multi-stage inoculation treatment on the community composition of bacterial and fungal during municipal solid wastes (MSW) composting process. The results showed that the high temperature period was extended by the multi-stage inoculation treatment, 1day longer than initial-stage inoculation treatment, and 5days longer than non-inoculation treatment. The temperature of the secondary fermentation increased to 51°C with multi-stage inoculation treatment. The multi-stage inoculation method improved the community diversity of bacteria and fungi that the diversity indexes reached the maximum on the 17days and 20days respectively, avoided the competition between inoculations and indigenous microbes, and enhanced the growth of dominant microorganisms. The DNA sequence indicated that various kinds of uncultured microorganisms with determined ratios were detected, which were dominant microbes during the whole fermentation process. These findings call for further researches of compost microbial cultivation technology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bio-inspired approach to multistage image processing

NASA Astrophysics Data System (ADS)

Timchenko, Leonid I.; Pavlov, Sergii V.; Kokryatskaya, Natalia I.; Poplavska, Anna A.; Kobylyanska, Iryna M.; Burdenyuk, Iryna I.; Wójcik, Waldemar; Uvaysova, Svetlana; Orazbekov, Zhassulan; Kashaganova, Gulzhan

2017-08-01

Multistage integration of visual information in the brain allows people to respond quickly to most significant stimuli while preserving the ability to recognize small details in the image. Implementation of this principle in technical systems can lead to more efficient processing procedures. The multistage approach to image processing, described in this paper, comprises main types of cortical multistage convergence. One of these types occurs within each visual pathway and the other between the pathways. This approach maps input images into a flexible hierarchy which reflects the complexity of the image data. The procedures of temporal image decomposition and hierarchy formation are described in mathematical terms. The multistage system highlights spatial regularities, which are passed through a number of transformational levels to generate a coded representation of the image which encapsulates, in a computer manner, structure on different hierarchical levels in the image. At each processing stage a single output result is computed to allow a very quick response from the system. The result is represented as an activity pattern, which can be compared with previously computed patterns on the basis of the closest match.

The usefulness of Skylab/EREP S-190 and S-192 imagery in multistage forest surveys

NASA Technical Reports Server (NTRS)

Langley, P. G.; Vanroessel, J. (Principal Investigator)

1976-01-01

The author has identified the following significant results. The RMSE of point location achieved with the annotation system on S190A imagery was 100 m and 90 m in the x and y direction, respectively. Potential gains in sampling precision attributable to space derived imagery ranged from 4.9 to 43.3 percent depending on the image type, interpretation method, time of year, and sampling method applied. Seasonal variation was significant. S190A products obtained in September yielded higher gains than those obtained in June. Using 100 primary sample units as a base under simple random sampling, the revenue made available for incorporating space acquired data into the sample design to estimate timber volume was as high as $39,400.00.

Prevalence of chronic disease and its controlled status according to income level.

PubMed

Kim, Seohyun; Lee, Byungmo; Park, Mingu; Oh, Sewon; Chin, Ho Jun; Koo, Hoseok

2016-11-01

The relationship between the prevalence of chronic diseases and income level has now become a main theme in poor national economic situations. We examined the prevalence of well-controlled chronic diseases according to income level. Data from the 2008 to 2014 Korea National Health and Nutrition Examination Survey, conducted by using a stratified, multistage, probability-cluster sampling method, were used. Systolic blood pressure (SBP) inversely correlated with income level (P < 0.001). Diastolic blood pressure (DBP) showed no relationship. In the low-income group, the prevalence rates of hypertension and diabetes mellitus (DM) were highest but the proportion of patients with well-controlled chronic disease and the SBPs of the patients with hypertension showed a decreasing trend. In the high-income group, the proportions of patients with well-controlled DM and chronic kidney disease were higher than those in other groups. After adjusting for age, body mass index, SBP, DBP, HbA1c level, and serum creatinine level, income level significantly affected the prevalence of chronic diseases (for income, β=0.184; 95% confidence interval, 1.105-1.042). The daily sodium intake estimated by using spot urine samples was higher in the low- and low-to-mid-income groups. The prevalence of not using essential medical service for chronic disease was highest in the low- and low-to-mid-income groups for economic reasons. In the low- and low-to-mid-income groups, the prevalence of chronic disease was higher and the proportion of patients with well-controlled chronic disease was lower than in the other groups.

Growth reference for Saudi preschool children: LMS parameters and percentiles.

PubMed

Shaik, Shaffi Ahamed; El Mouzan, Mohammad Issa; AlSalloum, Abdullah Abdulmohsin; AlHerbish, Abdullah Sulaiman

2016-01-01

Previous growth charts for Saudi children have not included detailed tables and parameters needed for research and incorporation in electronic records. The objective of this report is to publish the L, M, and S parameters and percentiles as well as the corresponding growth charts for Saudi preschool children. Community-based survey and measurement of growth parameters in a sample selected by a multistage probability procedure. A stratified listing of the Saudi population. Raw data from the previous nationally-representative sample were reanalyzed using the Lambda-Mu-Sigma (LMS) methodology to calculate the L, M, and S parameters of percentiles (from 3rd to 97th) for weight, length/height, head circumference, and body mass index-for-age, and weight for-length/height for boys and girls from birth to 60 months. Length or height and weight of Saudi preschool children. There were 15601 Saudi children younger than 60 months of age, 7896 (50.6 %) were boys. The LMS parameters for weight for age from birth to 60 months (5 years) are reported for the 3rd, 5th, 10th, 25th, 50th, 75th, 90th, 95th, and 97th percentiles as well as the corresponding graphs. Similarly, the LMS parameters for length/height-for-age, head circumference-for-age, weight-for-length/height and body mass index-for-age (BMi) are shown with the corresponding graphs for boys and girls. Using the data in this report, clinicians and researchers can assess the growth of Saudi preschool children. The report does not reflect interregional variations in growth.

Living Conditions, Low Socioeconomic Position, and Mortality in the Ibadan Study of Aging.

PubMed

Ojagbemi, Akin; Bello, Toyin; Luo, Zhehui; Gureje, Oye

2017-07-01

Very little is known about socioeconomic differentials in mortality among persons surviving to old age in sub-Saharan Africa. We report on the impact of low socioeconomic position (SEP) on mortality over a 5-year observation period among community-dwelling older adults living in southwestern Nigeria. Data are from a household multistage probability sample of 2,149 Yoruba Nigerians aged 65 years or older. We collected information on indices related to health and well-being at baseline (2003/2004). Socioeconomic positions were estimated using asset-based measures relevant to low income settings. Information on mortality was obtained by research supervisors in multiple waves (2007, 2008, and 2009). Associations between baseline covariates and mortality were explored using discrete time survival models and life tables. We recorded 357 deaths over 5 years, or an annual mortality rate of 4.7% (95% CI = 4.2-5.2). Being 80 years or older (HR = 1.6, 95% CI = 1.1-2.5) and belonging to the lowest SEP (HR = 1.5, 95% CI = 1.1-2.1) were the main predictors of mortality. The significant effect of lowest SEP on mortality risk over the study period was independent of age, gender, education, rural or urban residence, weight, physical activity level, and social engagement. In this sample of older persons living in an economically disadvantaged context, we found persistent socioeconomic differentials in mortality estimated, conservatively, over 5 years. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Configuration of management accounting information system for multi-stage manufacturing

NASA Astrophysics Data System (ADS)

Mkrtychev, S. V.; Ochepovsky, A. V.; Enik, O. A.

2018-05-01

The article presents an approach to configuration of a management accounting information system (MAIS) that provides automated calculations and the registration of normative production losses in multi-stage manufacturing. The use of MAIS with the proposed configuration at the enterprises of textile and woodworking industries made it possible to increase the accuracy of calculations for normative production losses and to organize accounting thereof with the reference to individual stages of the technological process. Thus, high efficiency of multi-stage manufacturing control is achieved.

Multi-megavolt low jitter multistage switch

DOEpatents

Humphreys, D.R.; Penn, K.J. Jr.

1985-06-19

It is one object of the present invention to provide a multistage switch capable of holding off numerous megavolts, until triggered, from a particle beam accelerator of the type used for inertial confinement fusion. The invention provides a multistage switch having low timing jitter and capable of producing multiple spark channels for spreading current over a wider area to reduce electrode damage and increase switch lifetime. The switch has fairly uniform electric fields and a short spark gap for laser triggering and is engineered to prevent insulator breakdowns.

Probability sampling in legal cases: Kansas cellphone users

NASA Astrophysics Data System (ADS)

Kadane, Joseph B.

2012-10-01

Probability sampling is a standard statistical technique. This article introduces the basic ideas of probability sampling, and shows in detail how probability sampling was used in a particular legal case.

What is the optimal systemic treatment of men with metastatic, hormone-naive prostate cancer? A STOPCAP systematic review and network meta-analysis.

PubMed

Vale, C L; Fisher, D J; White, I R; Carpenter, J R; Burdett, S; Clarke, N W; Fizazi, K; Gravis, G; James, N D; Mason, M D; Parmar, M K B; Rydzewska, L H; Sweeney, C J; Spears, M R; Sydes, M R; Tierney, J F

2018-05-01

Our prior Systemic Treatment Options for Cancer of the Prostate systematic reviews showed improved survival for men with metastatic hormone-naive prostate cancer when abiraterone acetate plus prednisolone/prednisone (AAP) or docetaxel (Doc), but not zoledronic acid (ZA), were added to androgen-deprivation therapy (ADT). Trial evidence also suggests a benefit of combining celecoxib (Cel) with ZA and ADT. To establish the optimal treatments, a network meta-analysis (NMA) was carried out based on aggregate data (AD) from all available studies. Overall survival (OS) and failure-free survival data from completed Systemic Treatment Options for Cancer of the Prostate reviews of Doc, ZA and AAP and from recent trials of ZA and Cel contributed to this comprehensive AD-NMA. The primary outcome was OS. Correlations between treatment comparisons within one multi-arm, multi-stage trial were estimated from control-arm event counts. Network consistency and a common heterogeneity variance were assumed. We identified 10 completed trials which had closed to recruitment, and one trial in which recruitment was ongoing, as eligible for inclusion. Results are based on six trials including 6204 men (97% of men randomised in all completed trials). Network estimates of effects on OS were consistent with reported comparisons with ADT alone for AAP [hazard ration (HR) = 0.61, 95% confidence interval (CI) 0.53-0.71], Doc (HR = 0.77, 95% CI 0.68-0.87), ZA + Cel (HR = 0.78, 95% CI 0.62-0.97), ZA + Doc (HR = 0.79, 95% CI 0.66-0.94), Cel (HR = 0.94 95% CI 0.75-1.17) and ZA (HR = 0.90 95% CI 0.79-1.03). The effect of ZA + Cel is consistent with the additive effects of the individual treatments. Results suggest that AAP has the highest probability of being the most effective treatment both for OS (94% probability) and failure-free survival (100% probability). Doc was the second-best treatment of OS (35% probability). Uniquely, we have included all available results and appropriately accounted for inclusion of multi-arm, multi-stage trials in this AD-NMA. Our results support the use of AAP or Doc with ADT in men with metastatic hormone-naive prostate cancer. AAP appears to be the most effective treatment, but it is not clear to what extent and whether this is due to a true increased benefit with AAP or the variable features of the individual trials. To fully account for patient variability across trials, changes in prognosis or treatment effects over time and the potential impact of treatment on progression, a network meta-analysis based on individual participant data is in development.

Health seeking behavior following snakebites in Sri Lanka: Results of an island wide community based survey

PubMed Central

Gunawardena, Nipul Kithsiri; Jayamanne, Shaluka Francis

2017-01-01

Introduction Sri Lanka has a population of 21 million and about 80,000 snakebites occur annually. However, there are limited data on health seeking behavior following bites. We investigated the effects of snakebite and envenoming on health seeking behavior in Sri Lanka. Methods In a community-based island-wide survey conducted in Sri Lanka 44,136 households were sampled using a multistage cluster sampling method. An individual who reported experiencing a snakebite within the preceding 12 months was considered a case. An interviewer-administered questionnaire was used to obtain details of the bite and health seeking behavior among cases. Results Among 165,665 individuals surveyed, there were 695 snakebite victims. 682 (98.1%) had sought health care after the bite; 381 (54.8%) sought allopathic treatment and 301 (43.3%) sought traditional treatment. 323 (46.5%) had evidence of probable envenoming, among them 227 (70.3%) sought allopathic treatment, 94 (29.1%) sought traditional treatment and 2 did not seek treatment. There was wide geographic variation in the proportion of seeking allopathic treatment from <20% in the Western province to > 90% in the Northern province. Multiple logistic regression analysis showed that seeking allopathic treatment was independently associated with being systemically envenomed (Odds Ratio = 1.99, 95% CI: 1.36–2.90, P < 0.001), distance to the healthcare facility (OR = 1.13 per kilometer, 95% CI: 1.09 to 1.17, P < 0.001), time duration from the bite (OR = 0.49 per day, 95% CI: 0.29–0.74, P = 0.002), and the local incidence of envenoming (OR = 1.31 for each 50 per 100,000, 95% CI: 1.19–1.46, P < 0.001) and snakebite (OR = 0.90 for each 50 per 100,000, 95% CI: 0.85–0.94, P < 0.001) in the relevant geographic area. Conclusions In Sri Lanka, both allopathic and traditional treatments are sought following snakebite. The presence of probable envenoming was a major contribution to seeking allopathic treatment. PMID:29108023

Adaptation of Decoy Fusion Strategy for Existing Multi-Stage Search Workflows

NASA Astrophysics Data System (ADS)

Ivanov, Mark V.; Levitsky, Lev I.; Gorshkov, Mikhail V.

2016-09-01

A number of proteomic database search engines implement multi-stage strategies aiming at increasing the sensitivity of proteome analysis. These approaches often employ a subset of the original database for the secondary stage of analysis. However, if target-decoy approach (TDA) is used for false discovery rate (FDR) estimation, the multi-stage strategies may violate the underlying assumption of TDA that false matches are distributed uniformly across the target and decoy databases. This violation occurs if the numbers of target and decoy proteins selected for the second search are not equal. Here, we propose a method of decoy database generation based on the previously reported decoy fusion strategy. This method allows unbiased TDA-based FDR estimation in multi-stage searches and can be easily integrated into existing workflows utilizing popular search engines and post-search algorithms.

Patient safety culture and job stress among nurses in Mazandaran, Iran.

PubMed

Asefzadeh, Saeed; Kalhor, Rohollah; Tir, Mohammad

2017-12-01

Paying attention to patient safety is a basic right and a necessary issue in providing medical care, and failure to observe it leads to irreparable damage. One of the factors affecting an individuals' performance in an organization is stress, which also endangers their health. To determine the relationship between patient safety culture and levels of job stress among the nurses working in the hospitals affiliated with Mazandaran University of Medical Sciences. The present study was carried out using a cross-sectional method in the hospitals affiliated with Mazandaran University of Medical Sciences in 2016. A multistage stratified sampling method using a Morgan Table was employed to select 380 nurses as the study sample from among 3,180 nurses. They were selected by a multistage stratified sampling method. The study instruments were Stinemetz Standard Job Stress Questionnaire and Hospital Survey on Patient Safety Culture (HSOPSC). After the required data were collected, they were analyzed using descriptive and inferential statistical methods (Pearson correlation, independent-samples t-test, and ANOVA) through SPSS version 23. The results of the present study showed that 75% of the nurses experienced average and high levels of stress. Among different dimensions of safety culture, organizational learning and handoffs and transitions obtained the highest and the lowest scores, respectively (72.5 and 24.5). The mean score of safety culture dimensions was 51.52. The results of the Pearson correlation test showed that there was a direct significant relationship between different dimensions of safety culture among nurses and the level of stress (p≤0.05). According to the findings, patient safety should be considered as a strategic priority for the senior managers of the health system. In order to enhance patient safety, managers should pay special attention to evaluating safety culture in organizations that deliver health service, especially hospitals.

Changes in Cartilage Biomarker Levels During a Transcontinental Multistage Footrace Over 4486 km.

PubMed

Mündermann, Annegret; Klenk, Christopher; Billich, Christian; Nüesch, Corina; Pagenstert, Geert; Schmidt-Trucksäss, Arno; Schütz, Uwe

2017-09-01

Cartilage turnover and load-induced tissue changes are frequently assessed by quantifying concentrations of cartilage biomarkers in serum. To date, information on the effects of ultramarathon running on articular cartilage is scarce. Serum concentrations of cartilage oligomeric matrix protein (COMP), matrix metalloproteinase (MMP)-1, MMP-3, MMP-9, COL2-3/4C long mono (C2C), procollagen type II C-terminal propeptide (CPII), and C2C:CPII will increase throughout a multistage ultramarathon. Descriptive laboratory study. Blood samples were collected from 36 runners (4 female; mean age, 49.0 ± 10.7 years; mean body mass index, 23.1 ± 2.3 kg/m 2 [start] and 21.4 ± 1.9 kg/m 2 [finish]) before (t 0 ) and during (t 1 : 1002 km; t 2 : 2132 km; t 3 : 3234 km; t 4 : 4039 km) a 4486-km multistage ultramarathon. Serum COMP, MMP-1, MMP-3, MMP-9, C2C, and CPII levels were assessed using commercial enzyme-linked immunosorbent assays. Linear mixed models were used to detect significant changes in serum biomarker levels over time with the time-varying covariates of body weight, running speed, and daily running time. Serum concentrations of COMP, MMP-9, and MMP-3 changed significantly throughout the multistage ultramarathon. On average, concentrations increased during the first measurement interval (MI1: t 1 -t 0 ) by 22.5% for COMP (95% CI, 0.29-0.71 ng/mL), 22.3% for MMP-3 (95% CI, 0.24-15.37 ng/mL), and 95.6% for MMP-9 (95% CI, 81.7-414.5 ng/mL) and remained stable throughout MI2, MI3, and MI4. Serum concentrations of MMP-1, C2C, CPII, and C2C:CPII did not change significantly throughout the multistage ultramarathon. Changes in MMP-3 were statistically associated with changes in COMP throughout the ultramarathon race (MMP-3: Wald Z = 3.476, P = .001). Elevated COMP levels indicate increased COMP turnover in response to extreme running, and the association between load-induced changes in MMP-3 and changes in COMP suggests the possibility that MMP-3 may be involved in the degradation of COMP. These results suggest that articular cartilage is able to adapt even to extreme physical activity, possibly explaining why the risk of degenerative joint disease is not elevated in the running population.

Speech coding at low to medium bit rates

NASA Astrophysics Data System (ADS)

Leblanc, Wilfred Paul

1992-09-01

Improved search techniques coupled with improved codebook design methodologies are proposed to improve the performance of conventional code-excited linear predictive coders for speech. Improved methods for quantizing the short term filter are developed by employing a tree search algorithm and joint codebook design to multistage vector quantization. Joint codebook design procedures are developed to design locally optimal multistage codebooks. Weighting during centroid computation is introduced to improve the outlier performance of the multistage vector quantizer. Multistage vector quantization is shown to be both robust against input characteristics and in the presence of channel errors. Spectral distortions of about 1 dB are obtained at rates of 22-28 bits/frame. Structured codebook design procedures for excitation in code-excited linear predictive coders are compared to general codebook design procedures. Little is lost using significant structure in the excitation codebooks while greatly reducing the search complexity. Sparse multistage configurations are proposed for reducing computational complexity and memory size. Improved search procedures are applied to code-excited linear prediction which attempt joint optimization of the short term filter, the adaptive codebook, and the excitation. Improvements in signal to noise ratio of 1-2 dB are realized in practice.

Multistage Estimation Of Frequency And Phase

NASA Technical Reports Server (NTRS)

Kumar, Rajendra

1991-01-01

Conceptual two-stage software scheme serves as prototype of multistage scheme for digital estimation of phase, frequency, and rate of change of frequency ("Doppler rate") of possibly phase-modulated received sinusoidal signal in communication system in which transmitter and/or receiver traveling rapidly, accelerating, and/or jerking severely. Each additional stage of multistage scheme provides increasingly refined estimate of frequency and phase of signal. Conceived for use in estimating parameters of signals from spacecraft and high dynamic GPS signal parameters, also applicable, to terrestrial stationary/mobile (e.g., cellular radio) and land-mobile/satellite communication systems.

Factorial versus multi-arm multi-stage designs for clinical trials with multiple treatments.

PubMed

Jaki, Thomas; Vasileiou, Despina

2017-02-20

When several treatments are available for evaluation in a clinical trial, different design options are available. We compare multi-arm multi-stage with factorial designs, and in particular, we will consider a 2 × 2 factorial design, where groups of patients will either take treatments A, B, both or neither. We investigate the performance and characteristics of both types of designs under different scenarios and compare them using both theory and simulations. For the factorial designs, we construct appropriate test statistics to test the hypothesis of no treatment effect against the control group with overall control of the type I error. We study the effect of the choice of the allocation ratios on the critical value and sample size requirements for a target power. We also study how the possibility of an interaction between the two treatments A and B affects type I and type II errors when testing for significance of each of the treatment effects. We present both simulation results and a case study on an osteoarthritis clinical trial. We discover that in an optimal factorial design in terms of minimising the associated critical value, the corresponding allocation ratios differ substantially to those of a balanced design. We also find evidence of potentially big losses in power in factorial designs for moderate deviations from the study design assumptions and little gain compared with multi-arm multi-stage designs when the assumptions hold. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Design of Multistage Axial-Flow Compressors

NASA Technical Reports Server (NTRS)

Crouse, J. E.; Gorrell, W. T.

1983-01-01

Program developed for computing aerodynamic design of multistage axialflow compressor and associated blading geometry input for internal flow analysis. Aerodynamic solution gives velocity diagrams on selected streamlines of revolution at blade row edges. Program written in FORTRAN IV.

The influence of the "cage" effect on the mechanism of reversible bimolecular multistage chemical reactions proceeding from different sites in solutions.

PubMed

Doktorov, Alexander B

2016-08-28

Manifestations of the "cage" effect at the encounters of reactants have been theoretically treated on the example of multistage reactions (including bimolecular exchange reactions as elementary stages) proceeding from different active sites in liquid solutions. It is shown that for reactions occurring near the contact of reactants, consistent consideration of quasi-stationary kinetics of such multistage reactions (possible in the framework of the encounter theory only) can be made on the basis of chemical concepts of the "cage complex," just as in the case of one-site model described in the literature. Exactly as in the one-site model, the presence of the "cage" effect gives rise to new channels of reactant transformation that cannot result from elementary event of chemical conversion for the given reaction mechanism. Besides, the multisite model demonstrates new (as compared to one-site model) features of multistage reaction course.

Tobacco smoking in urban neighborhoods: exploring social capital as a protective factor in Santiago, Chile.

PubMed

Sapag, Jaime C; Poblete, Fernando C; Eicher, Caitlin; Aracena, Marcela; Caneo, Constanza; Vera, Gloria; Martínez, Mayra; Hoyos, Rodrigo; Villarroel, Luis; Bradford, Elizabeth

2010-09-01

Research examining the relationship between social capital and health in Latin America has been limited. The aim of this study is to evaluate the association between social capital and tobacco use in four low-income neighborhoods in Santiago, Chile. A multistage probability sample was used to select households in 4 of the 10 poorest neighborhoods in the district of Puente Alto, in Santiago, Chile. A cross-sectional survey of 781 participants (81.2% response rate for households) included sociodemographic variables, questions pertaining to neighborhood social capital, and questions pertaining to tobacco. Main analyses were carried out at the individual level by performing a multiple logistic regression of individual tobacco use on individual perceptions of community social capital. The prevalence of smoking was 43.9% of the surveyed population. A five-factor structure for social capital was identified, including "perceived trust in neighbors," "perceived trust in organizations," "reciprocity within the neighborhood," "neighborhood integration," and "social participation." An inverse relationship between trust in neighbors and tobacco smoking was statistically significantly with an adjusted odds ratio of 0.95 (95% CI: 0.91-0.99). Trust in neighbors was also significantly inversely associated with the number of cigarettes smoked. Tobacco control remains a significant challenge in global health, requiring innovative strategies that address changing social contexts as well as the changing epidemiological profile of developing regions.

When the going gets tough: Mental toughness and its relationship with behavioural perseverance.

PubMed

Gucciardi, Daniel F; Peeling, Peter; Ducker, Kagan J; Dawson, Brian

2016-01-01

This study examined the association between self-reported mental toughness and behavioural perseverance among a sample of male Australian footballers in a naturalistic context. Cross-sectional field study, with the multistage 20m shuttle run test (MST) employed as a proxy for behavioural perseverance. 330 male Australian footballers aged between 15 and 18 years (M=16.86; SD=.71) with between 2 and 14 years playing experience (M=9.32; SD=2.51) participated. Initially, footballers completed a mental toughness questionnaire, before having their height and body mass measurements taken. Subsequently, a performance testing session was completed, which included the 20m sprint, Australian football-specific agility run, vertical jump, and the MST. Bayesian estimation was employed to allow for the simultaneous examination of existing findings with our new data in a way that provides an automatic meta-analysis of evidence in this area. The analysis indicated a 95% probability that the association between mental toughness and behavioural perseverance lies between .14 and .34, even when controlling for other factors known to influence MST performance, including age, height, body mass, and years playing experience. Taken together with previous research, these findings support the theoretical proposition that persistence, effort or perseverance represents a behavioural signature of mental toughness. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Social anxiety disorder in the Chinese military: prevalence, comorbidities, impairment, and treatment-seeking.

PubMed

Wang, Huaning; Zhang, Ruiguo; Chen, Yunchun; Wang, Huaihai; Zhang, Yahong; Gan, Jingli; Zhang, Liyi; Tan, Qingrong

2014-12-30

The objective of this work is To investigate the prevalence, comorbidities, impairment, and treatment-seeking of social anxiety disorder in the Chinese military personnel. Military personnel (n=11,527) were surveyed from May to August 2007 using a multistage whole cohort probability sampling method. A Chinese version of the World Health Organization Composite International Diagnostic Interview (CIDI) was used for assessment, and a military-related socio-demographic questionnaire was used to describe the prevalence distribution. A unified survey was performed to investigate 11 different social situations. The short-form health survey was used to assess role impairment. The 12-month and lifetime prevalence rates of social anxiety disorder were 3.34% (95% CI: 3.25-3.42%) and 6.22% (95% CI: 6.11-6.32%), respectively. Social anxiety disorder was associated with increased odds of depression, substance abuse, panic attacks/disorder, and generalized anxiety disorder. Childhood foster, female, stressful life events, younger age, and being divorced/widowed increase the incidence of social anxiety disorder. Treatment-seeking was relatively rare. Social anxiety disorder is a common disorder in military personnel in China, and it is a risk factor for subsequent depressive illness, substance abuse and other mental disorder. Early detection and treatment of social anxiety disorder are important because of the low rate of treatment-seeking. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Body image and body change: predictive factors in an Iranian population.

PubMed

Garrusi, Behshid; Garousi, Saeide; Baneshi, Mohammad R

2013-08-01

Body concerns and its health consequences such as eating disorders and harmful body change activities are mentioned in Asian countries. This study evaluates factors contributing to body image/shape changes in an Iranian population. In this cross-sectional study we focused on four main body change activity (diet, exercise, substance use, and surgery) and their risk factors such as demographic variables, Body Mass Index (BMI), Media, Body-Esteem, Perceived Socio-cultural Pressure, Body dissatisfaction and, Self-Esteem. Approximately, 1,200 individuals between 14-55 years old participated in this study. We used a multistage sampling method. In each region, the first household was selected at random. The probability of outcomes was estimated from logistic models. About 54.3% of respondents were females. The mean (SD) of age was 31.06 (10.24) years. Variables such as gender, age, BMI, use of media and socio cultural factors as, body dissatisfaction, body-esteem and pressure by relatives were the main factors that influenced body change methods. In particular we have seen that male are 53% less likely to follow surgical treatments, but 125% were more likely to use substances. Investigation of body concern and its health related problem should be assessed in cultural context. For effectiveness of interventional programs and reducing harmful body image/shape changes activities, socio-cultural background should be noted.

Cigarette smoking status and recurrent subjective health complaints among US school-aged adolescents.

PubMed

Botello-Harbaum, M; Haynie, D L; Murray, K W; Iannotti, R J

2011-07-01

Subjective health complaints are common among adolescents. There is evidence that girls are more likely to register complaints than boys. This study examines gender differences in the relationship between daily smoking and recurrent subjective health complaints in school-aged adolescents in the USA. A cross-sectional design with a multistage probability sample was used to survey 13,339 middle and high school students (grades 6 through 10) with the US 2001-2002 Health Behavior in School-Aged Children Survey. Recurrent subjective health complaints were higher for adolescents who smoke daily and experiment with cigarettes than for those who never smoke. In logistic regression analyses, the odds of daily smoking increased twofold for both boys and girls who report recurrent irritability/bad temper. For girls, the odds of daily smoking were higher among those who reported recurrent headache, stomachache and backache compared with never smokers. For boys only recurrent backache and feeling dizzy were associated with increased odds of daily smoking. The relationship between recurrent subjective health complaints and daily smoking provides new insights into both conditions for school-aged adolescents. Findings from this study suggest different patterns of association between daily smoking and recurrent subjective health complaints occur for girls and boys. Further studies are needed to explore causes and treatment of daily smoking and recurrent health complaints among school-aged children. © 2010 Blackwell Publishing Ltd.

The prevalence of metabolic disorders in various phenotypes of polycystic ovary syndrome: a community based study in Southwest of Iran.

PubMed

Tehrani, Fahimeh Ramezani; Rashidi, Homeira; Khomami, Mahnaz Bahri; Tohidi, Maryam; Azizi, Fereidoun

2014-09-16

Polycystic ovary syndrome (PCOS) is a common endocrinopathy, associated with metabolic abnormalities. Metabolic features of various phenotypes of this syndrome are still debatable. The aim of present study hence was to evaluate the metabolic and hormonal features of PCOS phenotypes in comparison to a group of healthy control. A total of 646 reproductive-aged women were randomly selected using the stratified, multistage probability cluster sampling method. The subjects were divided into five phenotypes: A (oligo/anovulation + hyperandrogenism + polycystic ovaries), B (oligo/anovulation + hyperandrogenism), C (hyperandrogenism + polycystic ovaries) and D (oligo/anovulation + polycystic ovaries). Hormonal and metabolic profiles and the prevalence of metabolic syndrome among these groups were compared using ANCOVA adjusted for age and body mass index. Among women with PCOS (n = 85), those of groups A and C had higher serum levels of insulin and homeostatic model assessment for insulin resistance (HOMA-IR), compared to PCOS women of group D. Serum concentrations of cholesterol, low density lipoprotein, triglycerides and glucose in group A were higher than in other phenotypes, whereas the metabolic syndrome was more prevalent among group B. Women who had all three components of the syndrome showed the highest level of metabolic disturbances indicating that metabolic screening of the severest phenotype of PCOS may be necessary.

Emotional abuse in childhood and suicidality: The mediating roles of re-victimization and depressive symptoms in adulthood.

PubMed

Lee, Min-Ah

2015-06-01

This study examined the effects of emotional abuse in childhood, along with physical and sexual abuse, on suicidality in adulthood, and whether and how emotional abuse and depressive symptoms in adulthood mediate the association between the childhood emotional abuse and suicidality. The data were drawn from the 2012 Korean General Social Survey, a nationally representative survey with a multistage area proportional probability sampling method. Random effects regression and the Sobel test were used to analyze the relationships between childhood emotional abuse and suicidality and the mediating effects. Random effects models showed that emotional abuse in childhood was positively associated with suicidality in adulthood, even after controlling for physical and sexual abuse in childhood. Emotional abuse and depressive symptoms in adulthood mediated the association between emotional abuse in childhood and suicidality. Depressive symptoms also mediated between emotional abuse in adulthood and suicidality. These findings suggest that emotional abuse in childhood has indirect harmful effects on suicidality in adulthood. It increases suicidality through higher occurrences of re-victimization and depressive symptoms in adulthood. Practitioners and policy makers should recognize that experiences of emotional abuse in childhood may result in re-victimization in adulthood, which, in turn, lead to suicidality. Early intervention programs to reduce the likelihood of experiencing re-victimization may be critical for people exposed to emotional abuse in childhood. Copyright © 2015 Elsevier Ltd. All rights reserved.

Body Image and Body Change: Predictive Factors in an Iranian Population

PubMed Central

Garrusi, Behshid; Garousi, Saeide; Baneshi, Mohammad R.

2013-01-01

Background: Body concerns and its health consequences such as eating disorders and harmful body change activities are mentioned in Asian countries. This study evaluates factors contributing to body image/shape changes in an Iranian population. Methods: In this cross-sectional study we focused on four main body change activity (diet, exercise, substance use, and surgery) and their risk factors such as demographic variables, Body Mass Index (BMI), Media, Body-Esteem, Perceived Socio-cultural Pressure, Body dissatisfaction and, Self-Esteem. Approximately, 1,200 individuals between 14-55 years old participated in this study. We used a multistage sampling method. In each region, the first household was selected at random. The probability of outcomes was estimated from logistic models. Results: About 54.3% of respondents were females. The mean (SD) of age was 31.06 (10.24) years. Variables such as gender, age, BMI, use of media and socio cultural factors as, body dissatisfaction, body-esteem and pressure by relatives were the main factors that influenced body change methods. In particular we have seen that male are 53% less likely to follow surgical treatments, but 125% were more likely to use substances. Conclusions: Investigation of body concern and its health related problem should be assessed in cultural context. For effectiveness of interventional programs and reducing harmful body image/shape changes activities, socio-cultural background should be noted. PMID:24049621

Body weight, perceived weight stigma and mental health among women at the intersection of race/ethnicity and socioeconomic status: insights from the modified labelling approach.

PubMed

Ciciurkaite, Gabriele; Perry, Brea L

2018-01-01

With increasing rates of obesity in the United States, attention to life chances and psychological consequences associated with weight stigma and weight-based discrimination has also intensified. While research has demonstrated the negative effects of weight-based discrimination on mental health, little is known about whether different social groups are disproportionately vulnerable to these experiences. Drawing on the modified labelling theory, the focus of this paper is to investigate the psychological correlates of body weight and self-perceived weight-based discrimination among American women at the intersection of race/ethnicity and socioeconomic status (SES). Analyses use data from the National Health Measurement Study (NHMS), a national multi-stage probability sample of non-institutional, English-speaking adults, ages 35 to 89 in 2005-2006. Our findings demonstrate that the effect of weight-based discrimination on psychological well-being is highly contingent on social status. Specifically, the psychological consequences of discrimination on Hispanic women and women in the lowest household income group is significantly greater relative to White women and women with higher household income, controlling for obesity status and self-rated health. These results suggest that higher social status has a buffering effect of weight stigma on psychological well-being. © 2017 Foundation for the Sociology of Health & Illness.

Childhood abuse, personality traits, and depressive symptoms in adulthood.

PubMed

Lee, Min-Ah; Song, Rira

2017-03-01

This study examined associations among childhood abuse, personality traits, and depressive symptoms in adulthood, and whether and how the effects of childhood abuse on depressive symptoms are mediated by the Big Five personality traits (i.e., extraversion, conscientiousness, emotional stability, agreeableness, and openness). The data were drawn from the 2012 Korean General Social Survey, a nationally representative survey using a multistage area proportional probability sampling method. Random effects regression and the Sobel test were used. Random effects models showed that physical and emotional abuse in childhood significantly increased depressive symptoms in adulthood, even after controlling for personality traits and socio-demographic factors. The coefficients of childhood abuse slightly decreased when personality traits were controlled, suggesting that personality traits mediated the relationship between childhood abuse and depressive symptoms. Among the personality traits, extraversion and emotional stability were negatively associated with depressive symptoms whereas agreeableness was positively associated with depressive symptoms. The results of the Sobel test showed that only emotional stability significantly mediated the effects of childhood abuse on depressive symptoms. Those who were exposed to childhood abuse had lower levels of emotional stability, which, in turn, led to depressive symptoms in adulthood. The findings suggest that childhood abuse may have a long lasting effect on mental health over the life course by influencing the formation of personality traits through developmental periods. Copyright © 2017 Elsevier Ltd. All rights reserved.

An Analysis of the Impact of the Research Utilization Project on Principals' Attitudes and on the Use of Information Services By Teachers and Other Field Personnel in 16 Target Elementary Schools of the District of Columbia.

ERIC Educational Resources Information Center

Robinson, Erika L.

Bridging the gap between the research resources and field personnel becomes an increasingly important problem. This study investigated the impact of the Research Utilization Project (RUP) on public elementary schools in the District of Columbia. In the 16 schools selected by a multistage stratified sampling method, the total number of information…

Multi-stage Mass Spectrometry of Poly(vinyl pyrrolidone) and Its Vinyl Succinimide Copolymer Formed upon Exposure to Sodium Hypochlorite

PubMed Central

Fouquet, Thierry; Torimura, Masaki; Sato, Hiroaki

2016-01-01

The degradation routes of poly(vinyl pyrrolidone) (PVP) exposed to sodium hypochlorite (bleach) have been previously investigated using chemical analyses such as infrared spectroscopy. So far, no reports have proposed mass spectrometry (MS) as an alternative tool despite its capability to provide molecular and structural information using its single stage electrospray (ESI) or matrix assisted laser desorption ionization (MALDI) and multi stage (MSn) configurations, respectively. The present study thus reports on the characterization of PVP after its exposure to bleach by high resolution MALDI spiralTOF-MS and Kendrick mass defect analysis providing clues as to the formation of a vinyl pyrrolidone/vinyl succinimide copolymeric degradation product. A thorough investigation of the fragmentation pathways of PVP adducted with sodium and proton allows one main route to be described—namely the release of the pyrrolidone pendant group in a charge remote and charge driven mechanism, respectively. Extrapolating this fragmentation pathway, the oxidation of vinyl pyrrolidone into vinyl succinimide hypothesized from the single stage MS is validated by the detection of an alternative succinimide neutral loss in lieu of the pyrrolidone release in the ESI-MSn spectra of the aged PVP sample. It constitutes an example of application of multi-stage mass spectrometry for the characterization of the degradation of polymeric samples at a molecular level. PMID:27800293

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

Spitz, A.H.; Boynton, W.V.

Six ureilites (ALHA77257, ALHA81101, ALH82130, PCA82506, Kanna, and Novo Urei) were analyzed using neutron activation analysis for Ca, Sc, Cr, Mn, Fe, Co, Ni, Zn, Ga, REE, W, Re, Os, Ir, and Au. The authors examined bulk samples as well as acid-treated samples. In bulk samples the refractory siderophiles' concentrations range from approximately 0.1 to 1.0 times CI chondrites while the volatile siderophiles' concentrations range from approximately 0.1 to 1.0 times CI chondrites while the volatile siderophiles range from about 0.07 to 0.3 times CI chondrites. Rare earth elements (REEs) in ureilites are quite depleted and display light and heavymore » rare earth enrichments. The Antarctic meteorites display either much less pronounced v-shaped patterns or no enrichment in the light rare earths at all. In terms of the new trace-element results, ureilites do not fall into the coherent groups that other workers have defined by chemical or petrographic characteristics. Trace elements do provide additional constraints on the models for the petrogenesis of ureilites. In particular, the siderophile element abundances call for simplified models of chemical processing rather than the complex, multistage processing called for in silicate fractionation models. REE concentrations, on the other hand, imply multistage processing to produce the ureilites. None of the ureilite petrogenesis models extant account for the trace element data. These new data and the considerations of them with respect to the proposed ureilite petrogenesis models indicate that the direction of modeling should be toward contemplation of mixtures and how the components the authors observe in ureilites behave under such conditions.« less

Attitudes Toward Domestic Violence and Corporal Punishment Among Former Soviet Union Immigrants in Israel.

PubMed

Enosh, Guy; Leshem, Elazar; Buchbinder, Eli

2016-10-01

The study regards attitudes of Russian immigrants in Israel toward wife abuse and corporal punishment. The sample consisted of 1,028 participants, based on a multistage cluster sampling. The study used a questionnaire related to immigration, acculturation, and attitudinal issues. The findings indicate a dual-causal model, in which corporal punishment attitudes contribute to wife abuse attitudes and vice versa. However, the effect of attitudes supporting corporal punishment was stronger than the effect of wife abuse attitudes, indicating that the attitudinal system as a precursor of violent behavior is already merging the two types of violence. © The Author(s) 2016.

Spatial dynamics of large-scale, multistage crab (Callinectes sapidus) dispersal: Determinants and consequences for recruitment

USGS Publications Warehouse

Etherington, L.L.; Eggleston, D.B.

2003-01-01

We assessed determinants and consequences of multistage dispersal on spatial recruitment of the blue crab, Callinectes sapidus, within the Croatan, Albemarle, Pamlico Estuarine System (CAPES), North Carolina, U.S.A. Large-scale sampling of early juvenile crabs over 4 years indicated that spatial abundance patterns were size-dependent and resulted from primary post-larval dispersal (pre-settlement) and secondary juvenile dispersal (early post-settlement). In general, primary dispersal led to high abundances within more seaward habitats, whereas secondary dispersal (which was relatively consistent) expanded the distribution of juveniles, potentially increasing the estuarine nursery capacity. There were strong relationships between juvenile crab density and specific wind characteristics; however, these patterns were spatially explicit. Various physical processes (e.g., seasonal wind events, timing and magnitude of tropical cyclones) interacted to influence dispersal during multiple stages and determined crab recruitment patterns. Our results suggest that the nursery value of different habitats is highly dependent on the dispersal potential (primary and secondary dispersal) to and from these areas, which is largely determined by the relative position of habitats within the estuarine landscape.

Removal of CO2 in a multistage fluidized bed reactor by diethanol amine impregnated activated carbon.

PubMed

Das, Dipa; Samal, Debi Prasad; Meikap, Bhim C

2016-07-28

To mitigate the emission of carbon dioxide (CO2), we have developed and designed a four-stage fluidized bed reactor. There is a counter current exchange between solid adsorbent and gas flow. In this present investigation diethanol amine (DEA) impregnated activated carbon made from green coconut shell was used as adsorbent. This type of adsorbent not only adsorbs CO2 due to the presence of pore but also chemically reacts with CO2 and form secondary zwitterions. Sampling and analysis of CO2 was performed using Orsat apparatus. The effect of initial CO2 concentration, gas velocity, solid rate, weir height etc. on removal efficiency of CO2 have been investigated and presented. The percentage removal of CO2 has been found close to 80% under low gas flow rate (0.188 m/s), high solid flow rate (4.12 kg/h) and weir height of 50 mm. From this result it has been found out that multistage fluidized bed reactor may be a suitable equipment for removal of CO2 from flue gas.

The influence of microwave-assisted drying techniques on the rehydration behavior of blueberries (Vaccinium corymbosum L.).

PubMed

Zielinska, Magdalena; Markowski, Marek

2016-04-01

The aim of this study was to determine the effect of: (a) different drying methods, (b) hot air temperature in a convection oven, and (c) the moisture content of fruits dehydrated by multi-stage drying which involves a transition between different stages of drying, on the rehydration kinetics of dry blueberries. Models describing rehydration kinetics were also studied. Blueberries dehydrated by multi-stage microwave-assisted drying, which involved a hot air pre-drying step at 80 °C until the achievement of a moisture content of 1.95 kg H2O kg(-1)DM, were characterized by significantly higher rates of initial and successive rehydration as well as smaller initial loss of soluble solids in comparison with the samples dried by other methods. The highest initial rehydration rate and the smallest loss of soluble solids after 30 min of soaking were determined at 0.46 min(-1) and 0.29 kg DM kg(-1)DM, respectively. The Peleg model and the first-order-kinetic model fit the experimental data well. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mars integrated transportation system multistage Mars mission

NASA Technical Reports Server (NTRS)

1991-01-01

In accordance with the objective of the Mars Integrated Transport System (MITS) program, the Multistage Mars Mission (MSMM) design team developed a profile for a manned mission to Mars. The purpose of the multistage mission is to send a crew of five astronauts to the martian surface by the year 2019. The mission continues man's eternal quest for exploration of new frontiers. This mission has a scheduled duration of 426 days that includes experimentation en route as well as surface exploration and experimentation. The MSMM is also designed as a foundation for a continuing program leading to the colonization of the planet Mars.

[Advances in studies on multi-stage countercurrent extraction technology in traditional Chinese medicine].

PubMed

Xie, Zhi-Peng; Liu, Xue-Song; Chen, Yong; Cai, Ming; Qu, Hai-Bin; Cheng, Yi-Yu

2007-05-01

Multi-stage countercurrent extraction technology, integrating solvent extraction, repercolation with dynamic and countercurrent extraction, is a novel extraction technology for the traditional Chinese medicine. This solvent-saving, energy-saving and high-extraction-efficiency technology can at the most drive active compounds to diffuse from the herbal materials into the solvent stage by stage by creating concentration differences between the herbal materials and the solvents. This paper reviewed the basic principle, the influence factors and the research progress and trends of the equipments and the application of the multi-stage countercurrent extraction.

Full 3D Analysis of the GE90 Turbofan Primary Flowpath

NASA Technical Reports Server (NTRS)

Turner, Mark G.

2000-01-01

The multistage simulations of the GE90 turbofan primary flowpath components have been performed. The multistage CFD code, APNASA, has been used to analyze the fan, fan OGV and booster, the 10-stage high-pressure compressor and the entire turbine system of the GE90 turbofan engine. The code has two levels of parallel, and for the 18 blade row full turbine simulation has 87.3 percent parallel efficiency with 121 processors on an SGI ORIGIN. Grid generation is accomplished with the multistage Average Passage Grid Generator, APG. Results for each component are shown which compare favorably with test data.

A Multistage Approach for Image Registration.

PubMed

Bowen, Francis; Hu, Jianghai; Du, Eliza Yingzi

2016-09-01

Successful image registration is an important step for object recognition, target detection, remote sensing, multimodal content fusion, scene blending, and disaster assessment and management. The geometric and photometric variations between images adversely affect the ability for an algorithm to estimate the transformation parameters that relate the two images. Local deformations, lighting conditions, object obstructions, and perspective differences all contribute to the challenges faced by traditional registration techniques. In this paper, a novel multistage registration approach is proposed that is resilient to view point differences, image content variations, and lighting conditions. Robust registration is realized through the utilization of a novel region descriptor which couples with the spatial and texture characteristics of invariant feature points. The proposed region descriptor is exploited in a multistage approach. A multistage process allows the utilization of the graph-based descriptor in many scenarios thus allowing the algorithm to be applied to a broader set of images. Each successive stage of the registration technique is evaluated through an effective similarity metric which determines subsequent action. The registration of aerial and street view images from pre- and post-disaster provide strong evidence that the proposed method estimates more accurate global transformation parameters than traditional feature-based methods. Experimental results show the robustness and accuracy of the proposed multistage image registration methodology.

The estimation of tree posterior probabilities using conditional clade probability distributions.

PubMed

Larget, Bret

2013-07-01

In this article I introduce the idea of conditional independence of separated subtrees as a principle by which to estimate the posterior probability of trees using conditional clade probability distributions rather than simple sample relative frequencies. I describe an algorithm for these calculations and software which implements these ideas. I show that these alternative calculations are very similar to simple sample relative frequencies for high probability trees but are substantially more accurate for relatively low probability trees. The method allows the posterior probability of unsampled trees to be calculated when these trees contain only clades that are in other sampled trees. Furthermore, the method can be used to estimate the total probability of the set of sampled trees which provides a measure of the thoroughness of a posterior sample.

Multi-stage separations based on dielectrophoresis

DOEpatents

Mariella, Jr., Raymond P.

2004-07-13

A system utilizing multi-stage traps based on dielectrophoresis. Traps with electrodes arranged transverse to the flow and traps with electrodes arranged parallel to the flow with combinations of direct current and alternating voltage are used to trap, concentrate, separate, and/or purify target particles.

SOX OUT ON A LIMB (LIMESTONE INJECTION MULTISTAGE BURNER)

EPA Science Inventory

The paper describes the most recent results from the Limestone Injection Multistage Burner (LIMB) program, covering results from the wall-fired demonstration. Tests were conducted to determine the efficacy of commercial calcium hydroxide (Ca(OH)2) and of calcium-lignosulfonate-mo...

DEVELOPMENTS IN LIMB (LIMESTONE INJECTION MULTISTAGE BURNER) TECHNOLOGY

EPA Science Inventory

The paper describes the most recent results from the Limestone Injection Multistage Burner (LIMB) program, results from the wall-fired demonstration. Tests were conducted to determine the efficacy of commercial calcium hydroxide--Ca(OH)2--supplied by Marblehead Lime Co. and of ca...

Disdrometer-based C-Band Radar Quantitative Precipitation Estimation (QPE) in a highly complex terrain region in tropical Colombia.

NASA Astrophysics Data System (ADS)

Sepúlveda, J.; Hoyos Ortiz, C. D.

2017-12-01

An adequate quantification of precipitation over land is critical for many societal applications including agriculture, hydroelectricity generation, water supply, and risk management associated with extreme events. The use of rain gauges, a traditional method for precipitation estimation, and an excellent one, to estimate the volume of liquid water during a particular precipitation event, does not allow to fully capture the highly spatial variability of the phenomena which is a requirement for almost all practical applications. On the other hand, the weather radar, an active remote sensing sensor, provides a proxy for rainfall with fine spatial resolution and adequate temporary sampling, however, it does not measure surface precipitation. In order to fully exploit the capabilities of the weather radar, it is necessary to develop quantitative precipitation estimation (QPE) techniques combining radar information with in-situ measurements. Different QPE methodologies are explored and adapted to local observations in a highly complex terrain region in tropical Colombia using a C-Band radar and a relatively dense network of rain gauges and disdrometers. One important result is that the expressions reported in the literature for extratropical locations are not representative of the conditions found in the tropical region studied. In addition to reproducing the state-of-the-art techniques, a new multi-stage methodology based on radar-derived variables and disdrometer data is proposed in order to achieve the best QPE possible. The main motivation for this new methodology is based on the fact that most traditional QPE methods do not directly take into account the different uncertainty sources involved in the process. The main advantage of the multi-stage model compared to traditional models is that it allows assessing and quantifying the uncertainty in the surface rain rate estimation. The sub-hourly rainfall estimations using the multi-stage methodology are realistic compared to observed data in spite of the many sources of uncertainty including the sampling volume, the different physical principles of the sensors, the incomplete understanding of the microphysics of precipitation and, the most important, the rapidly varying droplet size distribution.

The Estimation of Tree Posterior Probabilities Using Conditional Clade Probability Distributions

PubMed Central

Larget, Bret

2013-01-01

In this article I introduce the idea of conditional independence of separated subtrees as a principle by which to estimate the posterior probability of trees using conditional clade probability distributions rather than simple sample relative frequencies. I describe an algorithm for these calculations and software which implements these ideas. I show that these alternative calculations are very similar to simple sample relative frequencies for high probability trees but are substantially more accurate for relatively low probability trees. The method allows the posterior probability of unsampled trees to be calculated when these trees contain only clades that are in other sampled trees. Furthermore, the method can be used to estimate the total probability of the set of sampled trees which provides a measure of the thoroughness of a posterior sample. [Bayesian phylogenetics; conditional clade distributions; improved accuracy; posterior probabilities of trees.] PMID:23479066

Multi-stage responsive 4D printed smart structure through varying geometric thickness of shape memory polymer

NASA Astrophysics Data System (ADS)

Teoh, Joanne Ee Mei; Zhao, Yue; An, Jia; Chua, Chee Kai; Liu, Yong

2017-12-01

Shape memory polymers (SMPs) have gained a presence in additive manufacturing due to their role in 4D printing. They can be printed either in multi-materials for multi-stage shape recovery or in a single material for single-stage shape recovery. When printed in multi-materials, material or material-based design is used as a controlling factor for multi-stage shape recovery. However, when printed in a single material, it is difficult to design multi-stage shape recovery due to the lack of a controlling factor. In this research, we explore the use of geometric thickness as a controlling factor to design smart structures possessing multi-stage shape recovery using a single SMP. L-shaped hinges with a thickness ranging from 0.3-2 mm were designed and printed in four different SMPs. The effect of thickness on SMP’s response time was examined via both experiment and finite element analysis using Ansys transient thermal simulation. A method was developed to accurately measure the response time in millisecond resolution. Temperature distribution and heat transfer in specimens during thermal activation were also simulated and discussed. Finally, a spiral square and an artificial flower consisting of a single SMP were designed and printed with appropriate thickness variation for the demonstration of a controlled multi-stage shape recovery. Experimental results indicated that smart structures printed using single material with controlled thickness parameters are able to achieve controlled shape recovery characteristics similar to those printed with multiple materials and uniform geometric thickness. Hence, the geometric parameter can be used to increase the degree of freedom in designing future smart structures possessing complex shape recovery characteristics.

An evaluation of the utility of ERTS-1 data for mapping and developing natural resources of Iran

NASA Technical Reports Server (NTRS)

Ebtehadj, K. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Significant results are reported in the creation of an Iranian photomosaic from ERTS-1 imagery; in tectonic and structural mapping and interpretation, including discovery of significant new fault patterns in Iran; in river and lake mapping; in wetlands and fisheries nursery delineation and mapping; in range and agricultural surveys and inventories using multi-stage sample methods; and in the computer analysis of ERTS-1 digital tapes for urban land use.

Social network and individual correlates of sexual risk behavior among homeless young men who have sex with men.

PubMed

Tucker, Joan S; Hu, Jianhui; Golinelli, Daniela; Kennedy, David P; Green, Harold D; Wenzel, Suzanne L

2012-10-01

There is growing interest in network-based interventions to reduce HIV sexual risk behavior among both homeless youth and men who have sex with men. The goal of this study was to better understand the social network and individual correlates of sexual risk behavior among homeless young men who have sex with men (YMSM) to inform these HIV prevention efforts. A multistage sampling design was used to recruit a probability sample of 121 homeless YMSM (ages: 16-24 years) from shelters, drop-in centers, and street venues in Los Angeles County. Face-to-face interviews were conducted. Because of the different distributions of the three outcome variables, three distinct regression models were needed: ordinal logistic regression for unprotected sex, zero-truncated Poisson regression for number of sex partners, and logistic regression for any sex trade. Homeless YMSM were less likely to engage in unprotected sex and had fewer sex partners if their networks included platonic ties to peers who regularly attended school, and had fewer sex partners if most of their network members were not heavy drinkers. Most other aspects of network composition were unrelated to sexual risk behavior. Individual predictors of sexual risk behavior included older age, Hispanic ethnicity, lower education, depressive symptoms, less positive condom attitudes, and sleeping outdoors because of nowhere else to stay. HIV prevention programs for homeless YMSM may warrant a multipronged approach that helps these youth strengthen their ties to prosocial peers, develop more positive condom attitudes, and access needed mental health and housing services. Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Overweight and obesity are not associated with dental caries among 12-year-old South Brazilian schoolchildren.

PubMed

Alves, Luana Severo; Susin, Cristiano; Damé-Teixeira, Nailê; Maltz, Marisa

2013-06-01

To assess the association between weight status and dental caries among 12-year-old Brazilian schoolchildren. This cross-sectional study was carried out in Porto Alegre using a multistage probability sampling strategy to draw a representative sample of schoolchildren attending public and private schools. Data on demographics, socioeconomic status, oral hygiene habits, anthropometrics, and dental caries were collected. Overweight and obesity were defined according to WHO categories for BMI (body mass index)-for-age Z-scores. Survey Poisson regression models were used to assess the association between weight status and dental caries. Estimates were adjusted for gender, socioeconomic status, and brushing frequency. Prevalence ratios (PR), rate ratios (RR) and 95% confidence intervals (95% CI) were reported. One thousand five hundred and twenty-eight of 1837 eligible schoolchildren were examined. Prevalence of overweight and obesity were 22.15% (95% CI = 20.59-23.72) and 13.61% (95% CI = 11.44-15.78), respectively. Caries experience was observed in 55.23% (95% CI = 45.26-65.19) of children. Schoolchildren presented, on average, 1.39 (95% CI = 1.07-1.71) decayed, missing or filled teeth. No significant differences in caries experience or extent were observed among BMI groups. After adjusting for important cofactors, weight status was not associated with caries prevalence (overweight, PR = 0.99; 95% CI = 0.89-1.10; obese, PR = 1.00; 95% CI = 0.87-1.16) or caries extent (overweight, RR = 0.91; 95% CI = 0.74-1.12; obese, RR = 0.86; 95% CI = 0.72-1.04). Our findings indicate that overweight and obese adolescents should not be regarded as at higher risk of dental caries in this population. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The correlation between exposure to neighborhood violence and perpetration of moderate physical violence among Arab-Palestinian youth: Can it be moderated by parent-child support and gender?

PubMed

Massarwi, Adeem Ahmad

2017-01-01

In the current study, we examined the role of parent-child support as a protective factor that moderates the correlation between exposure to neighborhood violence and perpetration of moderate physical violence among 3,187 Arab-Palestinian adolescents who live in Israel (aged 12 to 18), from 21 different schools who were selected randomly. The probability sampling method was a nonproportional multistage stratified cluster sample. We also examined gender differences across this protective process. Participants completed a structured, anonymous self-report questionnaire. The findings of the study reveal that 47.3% of the adolescents had perpetrated moderate physical violence against others at least once during the month preceding the study. Moreover, exposure of adolescents to violence in their neighborhood correlated significantly and positively with perpetration of moderate physical violence. A moderation analysis was tested and found that this correlation was stronger among adolescents who had poor parent-child support than among those who had strong parent-child support. Furthermore, the findings reveal that the correlation of exposure to neighborhood violence with perpetration of moderate physical violence was not moderated by gender. However, parent-child support correlated strongly with lower levels of perpetration of moderate physical violence among males than females. The findings of the study highlight the critical role of parental factors in decreasing violent behaviors among adolescents (especially boys) as well as among adolescents who are at risk for exposure to violence in their neighborhoods. In light of the findings, we recommend that practitioners working with these adolescents include parents in intervention programs. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Rural and urban disparities in health-seeking for fever in Myanmar: findings from a probability-based household survey.

PubMed

Aung, Tin; Lwin, Moh Moh; Sudhinaraset, May; Wei, Chongyi

2016-07-25

The World Health Organization (WHO) recognizes Myanmar as having the highest burden of malaria in the Greater Mekong Sub-region (GMS). Early diagnosis and proper treatment are critical in containing malaria. The objective of this study was to assess determinants of seeking treatment for fever from trained providers across rural and urban areas in Eastern Myanmar. A cross-sectional survey was conducted during the high malaria seasons in the eastern part Myanmar between August and September 2014. Multi-staged cluster sampling was used to sample households. A series of questions related to treatment-seeking for fever were asked. Bivariate and multivariate logistic regressions were conducted to identify independent correlates of seeking treatment for fever from trained providers. The analysis was restricted to 637 participants who reported either themselves or their family members having had fever 2 weeks prior to the interview. In the multivariate analysis, rural residents were less likely to have sought treatment from trained providers (AOR = 0.60, 95 % CI 0.42-0.88; p = 0.01) while residents who had fever patients between the ages of 5 and 14 years (AOR = 1.60, 95 % CI 0.90-2.53; p = 0.05); and those who knew that sleeping under bed nets can prevent malaria (AOR = 2.08, 95 % CI 1.00-4.30; p = 0.05); were borderline more likely to have sought treatment. This study suggests that rural populations need improved access to trained providers. Additionally, future programmes should focus on increasing knowledge around malaria prevention and treatment.

HIV prevalence and related risk behaviours among prisoners in Iran: results of the national biobehavioural survey, 2009

PubMed Central

Navadeh, Soodabeh; Mirzazadeh, Ali; Gouya, Mohammad Mehdi; Farnia, Marziyeh; Alasvand, Ramin; Haghdoost, Ali-Akbar

2013-01-01

Objectives To estimate the prevalence of HIV and related risk behaviours among prisoners in Iran in 2009. Methods Using multistage random sampling, we recruited 5,530 prisoners from 27 prisons in Iran. Behavioural data were collected using a face-to-face questionnaire-based interview, and HIV status was determined by ELISA of dried blood spots. Weighted estimates were calculated based on the sampling probability and response rate. Results HIV prevalence was 2.1% (95% CI 1.2 to 3.6). One in eight prisoners (12.3%, 95% CI 8.0% to 16.6%) had been tested for HIV in the last year and received results, 20.5% (95% CI 15.1 to 27.4%) had comprehensive knowledge about HIV and 24.7% (95% CI 17.9% to 32.9%) reported condom use at last vaginal/anal sex in prison. Although 16.5% (95% CI 12.5% to 21.5%) acknowledged a lifetime history of drug injection, only 22 prisoners reported drug injection inside the prison in the month preceding the interview. Of note, 12.9% (95% CI 10.6% to 15.6%) had been tattooed in prison. There were significant associations between HIV prevalence and a history of drug injection (adjusted odds ratio (AOR): 7.8, 95% CI 4.7 to 13.2), tattooing (AOR: 2.1, 95% CI 1.1 to 4.2) and age over 30 years (AOR: 1.4, 95% CI 1.1 to 1.9). Conclusions Considerable HIV prevalence among prisoners is found in Iran. Expanding harm reduction programmes inside prisons with inclusion of sexual risk reduction programmes and post-release programmes will help directly prevent acquisition and transmission of infection inside prisons and indirectly slow onward transmission in the outside communities. PMID:23986417

Medical pluralism among indigenous peoples in northeast India - implications for health policy.

PubMed

Albert, Sandra; Nongrum, Melari; Webb, Emily L; Porter, John D H; Kharkongor, Glenn C

2015-07-01

The government of India is promoting and increasing investment in the traditional medicine systems of Ayurveda, Yoga, Unani, Siddha and Homeopathy (AYUSH) in the northeast region of India. But there are few empirical data that support this policy decision. This study estimates the awareness and use of the different medical systems in rural Meghalaya, a state in north-east India with a predominantly ethnic tribal population. We conducted a cross-sectional multistage random sample household survey across all districts of Meghalaya. To enable appropriate estimates for the whole of rural Meghalaya, the data were weighted to allow for the probability of selection of households at each stage of the sampling process. Both local tribal medicine and biomedicine were widely accepted and used, but the majority (68.7%, 95% CI: 51.9-81.7) had not heard of AYUSH and even fewer had used it. Tribal medicine was used (79.1%, 95% CI 66.3-88.0), thought to be effective (87.5%, 95% CI: 74.2-94.1) and given in a variety of disorders, including both minor and major diseases. In the 3 months prior to the survey, 46.2% (95% CI: 30.5-62.8) had used tribal medicine. Only 10.5% (95% CI: 6.1-17.6) reported ever using any of the AYUSH systems. Our comparative estimates of the awareness and use of tribal medicine, different systems of AYUSH and of biomedicine among indigenous populations of India question the basis on which AYUSH is promoted in the northeast region of India and in the state of Meghalaya in particular. © 2015 John Wiley & Sons Ltd.

Food consumption and nutritional and biochemical status of 0·5-12-year-old Indonesian children: the SEANUTS study.

PubMed

Sandjaja, Sandjaja; Budiman, Basuki; Harahap, Heryudarini; Ernawati, Fitrah; Soekatri, Moesijanti; Widodo, Yekti; Sumedi, Edith; Rustan, Effendi; Sofia, Gustina; Syarief, Sainstiani N; Khouw, Ilse

2013-09-01

Indonesia is currently facing the double burden of malnutrition. While undernutrition is still a major public health problem, the prevalence of overnutrition is increasing. The objective of the South East Asian Nutrition Survey (SEANUTS) was to provide up-to-date data on nutritional status, food consumption and biochemical parameters related to nutrition for children aged 0·5-12 years. The SEANUTS study in Indonesia was conducted in a nationwide representative sample of 7·211 children using multistage cluster sampling based on probability proportional to size, stratified for geographical location, in forty-eight out of 440 districts/cities. The results show that the growth (weight for age, height for age, weight for height and BMI for age) of Indonesian pre-school- and school-aged children is below the WHO standards. The older the children, the more the deviation from the WHO standard curves. Underweight was more prevalent in rural areas (28·9 v. 19·2%) and overweight/obesity was observed to be more widespread in urban areas (5·6 v. 3·2%). The prevalence varied with age groups and sexes. The overall prevalence of stunting was 25·2 and 39·2% in urban and rural areas, respectively. The prevalence of anaemia was nearly 55% in children aged 0·5-1·9 years and ranged from 10·6 to 15·5% in children aged 2-12 years. Fe deficiency was observed in 4·1-8·8% of the children. The percentage of children with dietary intakes of energy, protein, and vitamins A and C below the Indonesian RDA was high and differed across urban and rural areas and age groups.

[Update on pubertal development among primary school students in Shanghai, 2014].

PubMed

Chen, Y; Zhang, Y T; Chen, C; Jiang, Y R; Song, Y J; Liu, S J; Jiang, F

2016-11-06

Objective: To investigate the current prevalence of pubertal development in healthy Shanghai schoolchildren. Methods: This study was a cross-sectional investigation focused on current pubertal development conducted in healthy Shanghai schoolchildren by multi-stage cluster sampling. The sample included 17 571 children in grades 1-5 investigated in June 2014. The data were weighted by inverse probability weighting (IPW) to make them more representative. At examination, stages of breast and pubic hair development were rated according to the Tanner method. Testicular volume was determined. Data on menarche and spermatorrhea were collected by the status quo method. The rates of precocious puberty, breast, and pubic hair development of Tanner stage ≥Ⅱ in girls aged 6-7 years, menarche in girls aged 6-9 years, and testicular volume ≥4 ml and pubic hair development of Tanner stage ≥Ⅱ in boys aged 6-8 years were calculated. All the data were weighted by IPW. Results: After data processing, 16 197 children's data were analyzed. In girls aged 6-7 years, 17.2% and 2.5% showed evidence of breast and pubic hair development at Tanner stage ≥Ⅱ, respectively. In girls aged 6-9 years, 0.3% had experienced menarche. Schoolgirls' rate of menarche was 4.7%. In girls aged 6-7 years, 19.0% were diagnosed with precocious puberty according to the classic criteria. In boys aged 6-8 years, 1.7% had testicular volume ≥4 ml, and 0.6% showed evidence of pubic hair development at Tanner stage ≥Ⅱ. Schoolboys' incidence rate of spermatorrhea was 0.1%. In boys aged 6-8 years, 2.3% were diagnosed with precocious puberty according to the classic criteria. All the numbers above were weighted. Conclusion: Proper education on adolescence and sex is essential for Shanghai schoolchildren.

Determinants of neonatal mortality in rural and urban Nigeria: Evidence from a population-based national survey.

PubMed

Adewuyi, Emmanuel O; Zhao, Yun

2017-02-01

Significant reduction in the global burden of neonatal mortality was achieved through the millennium development goals. In Nigeria, however, only a marginal reduction was realized. This study assesses the rural-urban differences in neonatal mortality rate (NMR) and the associated risk factors in Nigeria. The dataset from the 2013 Nigeria demographic and health survey (NDHS), disaggregated by rural-urban residence (n = 20 449 and 9935, respectively), was explored using univariate, bivariate, and multivariable analysis. Complex samples analysis was applied to adjust for the unequal selection probabilities due to the multi-stage cluster sampling method used in the 2013 NDHS. The adjusted relationship between the outcome and predictor variables was assessed on multi-level logistic regression analysis. NMR for rural and urban populations was 36 and 28 deaths per 1000 live births, respectively. Risk factors in urban residence were lack of electricity access (adjusted OR [AOR], 1.555; 95%CI: 1.089-2.220), small birth size (as a proxy for low birthweight; AOR, 3.048; 95%CI: 2.047-4.537), and male gender (AOR, 1.666; 95%CI: 1.215-2.284). Risk factors in rural residence were small birth size (a proxy for low birthweight; AOR, 2.118; 95%CI: 1.600-2.804), and birth interval <2 years (AOR, 2.149; 95%CI: 1.760-2.624). Cesarean delivery was a risk factor both in rural (AOR, 5.038; 95%CI: 2.617-9.700) and urban Nigeria (AOR, 2.632; 95%CI: 1.543-4.489). Determinants of neonatal mortality were different in rural and urban Nigeria, and rural neonates had greater risk of mortality than their urban counterparts. © 2016 Japan Pediatric Society.

[New design of the Health Survey of Catalonia (Spain, 2010-2014): a step forward in health planning and evaluation].

PubMed

Alcañiz-Zanón, Manuela; Mompart-Penina, Anna; Guillén-Estany, Montserrat; Medina-Bustos, Antonia; Aragay-Barbany, Josep M; Brugulat-Guiteras, Pilar; Tresserras-Gaju, Ricard

2014-01-01

This article presents the genesis of the Health Survey of Catalonia (Spain, 2010-2014) with its semiannual subsamples and explains the basic characteristics of its multistage sampling design. In comparison with previous surveys, the organizational advantages of this new statistical operation include rapid data availability and the ability to continuously monitor the population. The main benefits are timeliness in the production of indicators and the possibility of introducing new topics through the supplemental questionnaire as a function of needs. Limitations consist of the complexity of the sample design and the lack of longitudinal follow-up of the sample. Suitable sampling weights for each specific subsample are necessary for any statistical analysis of micro-data. Accuracy in the analysis of territorial disaggregation or population subgroups increases if annual samples are accumulated. Copyright © 2013 SESPAS. Published by Elsevier Espana. All rights reserved.

A false sense of security? Can tiered approach be trusted to accurately classify immunogenicity samples?

PubMed

Jaki, Thomas; Allacher, Peter; Horling, Frank

2016-09-05

Detecting and characterizing of anti-drug antibodies (ADA) against a protein therapeutic are crucially important to monitor the unwanted immune response. Usually a multi-tiered approach that initially rapidly screens for positive samples that are subsequently confirmed in a separate assay is employed for testing of patient samples for ADA activity. In this manuscript we evaluate the ability of different methods used to classify subject with screening and competition based confirmatory assays. We find that for the overall performance of the multi-stage process the method used for confirmation is most important where a t-test is best when differences are moderate to large. Moreover we find that, when differences between positive and negative samples are not sufficiently large, using a competition based confirmation step does yield poor classification of positive samples. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Analysis of internal flow of J85-13 multistage compressor

NASA Technical Reports Server (NTRS)

Hager, R. D.

1977-01-01

Interstage data recorded on a J85-13 engine were used to analyze the internal flow of the compressor. Measured pressures and temperatures were used as input to a streamline analysis program to calculate the velocity diagrams at the inlet and outlet of each blade row. From the velocity diagrams and blade geometry, selected blade-element performance parameters were calculated. From the detailed analysis it is concluded that the compressor is probably hub critical (stall initiates at the hub) in the latter stages for the design speed conditions. As a result, the casing treatment over the blade tips has little or no effect on stall margin at design speed. Radial inlet distortion did not appear to change the flow in the stages that control stall because of the rapid attenuation of the distortion within the compressor.

More than Just Convenient: The Scientific Merits of Homogeneous Convenience Samples

PubMed Central

Jager, Justin; Putnick, Diane L.; Bornstein, Marc H.

2017-01-01

Despite their disadvantaged generalizability relative to probability samples, non-probability convenience samples are the standard within developmental science, and likely will remain so because probability samples are cost-prohibitive and most available probability samples are ill-suited to examine developmental questions. In lieu of focusing on how to eliminate or sharply reduce reliance on convenience samples within developmental science, here we propose how to augment their advantages when it comes to understanding population effects as well as subpopulation differences. Although all convenience samples have less clear generalizability than probability samples, we argue that homogeneous convenience samples have clearer generalizability relative to conventional convenience samples. Therefore, when researchers are limited to convenience samples, they should consider homogeneous convenience samples as a positive alternative to conventional or heterogeneous) convenience samples. We discuss future directions as well as potential obstacles to expanding the use of homogeneous convenience samples in developmental science. PMID:28475254

Development of novel general equation for multistage epicyclic gearset with corrected teeth: non-constrained approach

NASA Astrophysics Data System (ADS)

Kijanka, Piotr; Jablonski, Adam; Dziedziech, Kajetan; Dworakowski, Ziemowit; Uhl, Tadeusz

2016-04-01

A large number of commercial systems for condition monitoring of most common planetary gearboxes used in wind turbines and mining machinery have been developed for years. However nowadays, multistage constructions are encountered in industries. These are not necessarily planetary, but generally epicyclic. Current state of the art, according to the authors knowledge, does not give general equations for a case where multistage systems are considered, where some of the gears consist all moving parts. Hence, currently available CMS systems are not suitable for condition monitoring of these kinds of systems. The paper presents a new general equation, which allows calculating the characteristic frequencies of any kind of multistage gear sets, as a result of theoretical investigation. Illustrated solution does not assume a fixed speed of any element. Moreover, presented equation takes into account corrected teeth, making developed equations most general from all available in tribology science. Presented scientific development is currently implemented in a modern European CMS.

On use of the multistage dose-response model for assessing laboratory animal carcinogenicity

PubMed Central

Nitcheva, Daniella; Piegorsch, Walter W.; West, R. Webster

2007-01-01

We explore how well a statistical multistage model describes dose-response patterns in laboratory animal carcinogenicity experiments from a large database of quantal response data. The data are collected from the U.S. EPA’s publicly available IRIS data warehouse and examined statistically to determine how often higher-order values in the multistage predictor yield significant improvements in explanatory power over lower-order values. Our results suggest that the addition of a second-order parameter to the model only improves the fit about 20% of the time, while adding even higher-order terms apparently does not contribute to the fit at all, at least with the study designs we captured in the IRIS database. Also included is an examination of statistical tests for assessing significance of higher-order terms in a multistage dose-response model. It is noted that bootstrap testing methodology appears to offer greater stability for performing the hypothesis tests than a more-common, but possibly unstable, “Wald” test. PMID:17490794

Influence of dispatching rules on average production lead time for multi-stage production systems.

PubMed

Hübl, Alexander; Jodlbauer, Herbert; Altendorfer, Klaus

2013-08-01

In this paper the influence of different dispatching rules on the average production lead time is investigated. Two theorems based on covariance between processing time and production lead time are formulated and proved theoretically. Theorem 1 links the average production lead time to the "processing time weighted production lead time" for the multi-stage production systems analytically. The influence of different dispatching rules on average lead time, which is well known from simulation and empirical studies, can be proved theoretically in Theorem 2 for a single stage production system. A simulation study is conducted to gain more insight into the influence of dispatching rules on average production lead time in a multi-stage production system. We find that the "processing time weighted average production lead time" for a multi-stage production system is not invariant of the applied dispatching rule and can be used as a dispatching rule independent indicator for single-stage production systems.

Multistage Polymeric Lens Structures Integrated into Silica Waveguides

NASA Astrophysics Data System (ADS)

Tate, Atsushi; Suzuki, Takanori; Tsuda, Hiroyuki

2006-08-01

A waveguide lens, composed of multistage polymer-filled thin grooves in a silica planar lightwave circuit (PLC) is proposed and a low-loss structure has been designed. A waveguide lens in a silica slab waveguide has been fabricated using reactive ion etching (RIE) and formed by filling with polymer. Both an imagding optical system and a Fourier-transform optical system can be configured in a PLC using a waveguide lens. It renders the PLC functional and its design flexible. To obtain a shorter focal length with a low insertion loss, it is more effective to use a multistage lens structure. An imaging optical system and a Fourier-transform optical system with a focal length of less than 1000 μm were fabricated in silica waveguides using a multistage lens structure. The lens imaging waveguides incorporate a 16-24-stage lens, with insertion losses of 4-7 dB. A 4 × 4 optical coupler, using a Fourier-transform optical system, utilizes a 6-stage lens with losses of 2-4 dB.

Multistage degradation modeling for BLDC motor based on Wiener process

NASA Astrophysics Data System (ADS)

Yuan, Qingyang; Li, Xiaogang; Gao, Yuankai

2018-05-01

Brushless DC motors are widely used, and their working temperatures, regarding as degradation processes, are nonlinear and multistage. It is necessary to establish a nonlinear degradation model. In this research, our study was based on accelerated degradation data of motors, which are their working temperatures. A multistage Wiener model was established by using the transition function to modify linear model. The normal weighted average filter (Gauss filter) was used to improve the results of estimation for the model parameters. Then, to maximize likelihood function for parameter estimation, we used numerical optimization method- the simplex method for cycle calculation. Finally, the modeling results show that the degradation mechanism changes during the degradation of the motor with high speed. The effectiveness and rationality of model are verified by comparison of the life distribution with widely used nonlinear Wiener model, as well as a comparison of QQ plots for residual. Finally, predictions for motor life are gained by life distributions in different times calculated by multistage model.

Laboratory research of fracture geometry in multistage HFF in triaxial state

NASA Astrophysics Data System (ADS)

Bondarenko, T. M.; Hou, B.; Chen, M.; Yan, L.

2017-05-01

Multistage hydraulic fracturing of formation (HFF) in wells with horizontal completion is an efficientmethod for intensifying oil extraction which, as a rule, is used to develop nontraditional collectors. It is assumed that the complicated character of HFF fractures significantly influences the fracture geometry in the rock matrix. Numerous theoretical models proposed to predict the fracture geometry and the character of interaction of mechanical stresses in the multistage HFF have not been proved experimentally. In this paper, we present the results of laboratory modeling of the multistage HFF performed on a contemporary laboratory-scale plant in the triaxial stress state by using a gel-solution as the HFF agent. As a result of the experiment, a fracturing pattern was formed in the cubic specimen of the model material. The laboratory results showed that a nearly plane fracture is formed at the firstHFF stage, while a concave fracture is formed at the second HFF stage. The interaction of the stress fields created by the two principal HFF fractures results in the growth of secondary fractures whose directions turned out to be parallel to the modeled well bore. But this stress interference leads to a decrease in the width of the second principal fracture. It is was discovered that the penny-shaped fracture model is more appropriate for predicting the geometry of HFF fractures in horizontal wells than the two-dimensional models of fracture propagation (PKN model, KGD model). A computational experiment based on the boundary element method was carried out to obtain the qualitative description of the multistage HFF processes. As a result, a mechanical model of fracture propagation was constructed,which was used to obtain the mechanical stress field (the stress contrast) and the fracture opening angle distribution over fracture length and fracture orientation direction. The conclusions made in the laboratory modeling of the multistage HFF technology agree well with the conclusions made in the computational experiment. Special attention must be paid to the design of the HFF stage spacing density in the implementation of the multistage HFF in wells with horizontal completion.

Numerical solutions of 2-D multi-stage rotor/stator unsteady flow interactions

NASA Astrophysics Data System (ADS)

Yang, R.-J.; Lin, S.-J.

1991-01-01

The Rai method of single-stage rotor/stator flow interaction is extended to handle multistage configurations. In this study, a two-dimensional Navier-Stokes multi-zone approach was used to investigate unsteady flow interactions within two multistage axial turbines. The governing equations are solved by an iterative, factored, implicit finite-difference, upwind algorithm. Numerical accuracy is checked by investigating the effect of time step size, the effect of subiteration in the Newton-Raphson technique, and the effect of full viscous versus thin-layer approximation. Computer results compared well with experimental data. Unsteady flow interactions, wake cutting, and the associated evolution of vortical entities are discussed.

Maisotsenko cycle applications in multi-stage ejector recycling module for chemical production

NASA Astrophysics Data System (ADS)

Levchenko, D. O.; Artyukhov, A. E.; Yurko, I. V.

2017-08-01

The article is devoted to the theoretical bases of multistage (multi-level) utilization modules as part of chemical plants (on the example of the technological line for obtaining nitrogen fertilizers). The possibility of recycling production waste (ammonia vapors, dust and substandard nitrogen fertilizers) using ejection devices and waste heat using Maisotsenko cycle technology (Maisotsenko heat and mass exchanger (HMX), Maisotsenko power cycles and recuperators, etc.) is substantiated. The principle of operation of studied recycling module and prospects for its implementation are presented. An improved technological scheme for obtaining granular fertilizers and granules with porous structure with multistage (multi-level) recycling module is proposed.

Multi-stage decoding of multi-level modulation codes

NASA Technical Reports Server (NTRS)

Lin, Shu; Kasami, Tadao; Costello, Daniel J., Jr.

1991-01-01

Various types of multi-stage decoding for multi-level modulation codes are investigated. It is shown that if the component codes of a multi-level modulation code and types of decoding at various stages are chosen properly, high spectral efficiency and large coding gain can be achieved with reduced decoding complexity. Particularly, it is shown that the difference in performance between the suboptimum multi-stage soft-decision maximum likelihood decoding of a modulation code and the single-stage optimum soft-decision decoding of the code is very small, only a fraction of dB loss in signal to noise ratio at a bit error rate (BER) of 10(exp -6).

Shock and vibration response of multistage structure

NASA Technical Reports Server (NTRS)

Lee, S. Y.; Liyeos, J. G.; Tang, S. S.

1968-01-01

Study of the shock and vibration response of a multistage structure employed analytically, lumped-mass, continuous-beam, multimode, and matrix-iteration methods. The study was made on the load paths, transmissibility, and attenuation properties along a longitudinal axis of a long, slender structure with increasing degree of complexity.

Automated Simultaneous Assembly for Multistage Testing

ERIC Educational Resources Information Center

Breithaupt, Krista; Ariel, Adelaide; Veldkamp, Bernard P.

2005-01-01

This article offers some solutions used in the assembly of the computerized Uniform Certified Public Accountancy (CPA) licensing examination as practical alternatives for operational programs producing large numbers of forms. The Uniform CPA examination was offered as an adaptive multistage test (MST) beginning in April of 2004. Examples of…

Microfiltration of thin stillage: Process simulation and economic analyses

USDA-ARS?s Scientific Manuscript database

In plant scale operations, multistage membrane systems have been adopted for cost minimization. We considered design optimization and operation of a continuous microfiltration (MF) system for the corn dry grind process. The objectives were to develop a model to simulate a multistage MF system, optim...

40 CFR 600.316-08 - Multistage manufacture.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Multistage manufacture. 600.316-08 Section 600.316-08 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Labeling § 600.316-08...

40 CFR 600.316-08 - Multistage manufacture.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Multistage manufacture. 600.316-08 Section 600.316-08 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Labeling § 600.316-08...

40 CFR 600.316-08 - Multistage manufacture.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Multistage manufacture. 600.316-08 Section 600.316-08 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY AND GREENHOUSE GAS EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Labeling § 600.316-08...

The multistage crystallization of zircon in calc-alkaline granitoids: U-Pb age constraints on the timing of Variscan tectonic activity in SW Iberia

NASA Astrophysics Data System (ADS)

Pereira, M. F.; Chichorro, M.; Moita, P.; Santos, J. F.; Solá, A. M. R.; Williams, I. S.; Silva, J. B.; Armstrong, R. A.

2015-07-01

CL imaging and U-Th-Pb data for a population of zircons from two of the Évora Massif granitoids (Ossa-Morena Zone, SW Iberia) show that both calc-alkaline granitoids have zircon populations dominated by grains with cores and rims either showing or not showing differences in Th/U ratio, and having ages in the range ca. 350-335 Ma (Early Carboniferous). Multistage crystallization of zircon is revealed in two main growth stages (ca. 344-342 Ma and ca. 336-335 Ma), well represented by morphologically complex zircons with cores and rims with different ages and different Th/U ratios that can be explained by: (1) crystallization from melts with different compositions (felsic peraluminous to felsic-intermediate metaluminous; 0.001 < Th/U ratio < 0.5) and (2) transient temperature fluctuations in a system where anatectic felsic melts periodically underwent injection of more mafic magmas at higher temperatures. The two studied calc-alkaline granitoids do not include inherited zircons (pre-Carboniferous), probably because they were formed at the highest grade of metamorphism ( T > 837 °C; granulite facies) and/or because they were derived from inheritance-poor felsic and mafic rocks from a previous cycle, as suggested by the internal structures of zircon cores. These Variscan magmatic rocks with crystallization ages estimated at ca. 336-335 Ma are spatially and temporally related to high-temperature metamorphism, anatexis, processes of interaction between crustal- and mantle-derived magmas and intra-orogenic extension that acted in SW Iberia during the Early Carboniferous.

Multi-stage volcanic island flank collapses with coeval explosive caldera-forming eruptions.

PubMed

Hunt, James E; Cassidy, Michael; Talling, Peter J

2018-01-18

Volcanic flank collapses and explosive eruptions are among the largest and most destructive processes on Earth. Events at Mount St. Helens in May 1980 demonstrated how a relatively small (<5 km 3 ) flank collapse on a terrestrial volcano could immediately precede a devastating eruption. The lateral collapse of volcanic island flanks, such as in the Canary Islands, can be far larger (>300 km 3 ), but can also occur in complex multiple stages. Here, we show that multistage retrogressive landslides on Tenerife triggered explosive caldera-forming eruptions, including the Diego Hernandez, Guajara and Ucanca caldera eruptions. Geochemical analyses were performed on volcanic glasses recovered from marine sedimentary deposits, called turbidites, associated with each individual stage of each multistage landslide. These analyses indicate only the lattermost stages of subaerial flank failure contain materials originating from respective coeval explosive eruption, suggesting that initial more voluminous submarine stages of multi-stage flank collapse induce these aforementioned explosive eruption. Furthermore, there are extended time lags identified between the individual stages of multi-stage collapse, and thus an extended time lag between the initial submarine stages of failure and the onset of subsequent explosive eruption. This time lag succeeding landslide-generated static decompression has implications for the response of magmatic systems to un-roofing and poses a significant implication for ocean island volcanism and civil emergency planning.

Prevalence, Incidence, Prognosis, Early Stroke Risk, and Stroke-Related Prognostic Factors of Definite or Probable Transient Ischemic Attacks in China, 2013

PubMed Central

Jiang, Bin; Sun, Haixin; Ru, Xiaojuan; Sun, Dongling; Chen, Zhenghong; Liu, Hongmei; Li, Yichong; Zhang, Mei; Wang, Limin; Wang, Linhong; Wu, Shengping; Wang, Wenzhi

2017-01-01

The epidemiological characteristics of transient ischemic attacks (TIAs) in China are unclear. In 2013, we conducted a nationally representative, door-to-door epidemiological survey on TIA in China using a complex, multistage, probability sampling design. Results showed that the weighted prevalence of TIA in China was 103.3 [95% confidence interval (CI): 83.9–127.2] per 100,000 in the population, 92.4 (75.0–113.8) per 100,000 among men, and 114.7 (87.2–151.0) per 100,000 among women. The weighted incidence of TIA was 23.9 (17.8–32.0) per 100,000 in the population, 21.3 (14.3–31.5) per 100,000 among men, and 26.6 (17.0–41.7) per 100,000 among women. No difference in average prognosis was found between TIA and stroke in the population. Weighted risk of stroke among TIA patients was 9.7% (6.5–14.3%), 11.1% (7.5–16.1%), and 12.3% (8.4–17.7%) at 2, 30, and 90 days, respectively. The risk of stroke was higher among male patients with a history of TIA than among female patients with a history of TIA (OR: 2.469; 95% CI: 1.172–5.201; P = 0.018), and higher among TIA patients with hypertension than among TIA patients without hypertension (OR: 2.671; 1.547–4.613; P < 0.001). It can be concluded that there are an estimated 1.35 million TIA patients nationwide, with 0.31 million new cases of TIA annually in China. TIA patients were not better managed prior to a stroke event. Early risk of stroke among TIA patients is high. Sex and hypertension may be stroke-associated prognostic factors among TIA patients. TIA clinics and surveillance should be integrated into the national health-care system. PMID:28713329

Medium-to-high prevalence of screening-detected parkinsonism in the urban area of Tehran, Iran: data from a community-based door-to-door study.

PubMed

Fereshtehnejad, Seyed-Mohammad; Shafieesabet, Mahdiyeh; Rahmani, Arash; Delbari, Ahmad; Lökk, Johan

2015-01-01

Parkinsonism occurs in all ethnic groups worldwide; however, there are wide variations in the prevalence rates reported from different countries, even for neighboring regions. The huge socioeconomic burden of parkinsonism necessitates the need for prevalence studies in each country. So far, there is neither data registry nor prevalence information on parkinsonism in the Iranian population. The aim of our study was to estimate the prevalence rate of probable parkinsonism in a huge urban area in Iran, Tehran using a community-based door-to-door survey. We used a random multistage sampling of the households within the network of health centers consisting of 374 subunits in all 22 districts throughout the entire urban area of Tehran. Overall, 20,621 individuals answered the baseline checklist and screening questionnaire and data from 19,500 persons aged ≥30 years were entered in the final analysis. Health care professionals used a new six-item screening questionnaire for parkinsonism, which has been previously shown to have a high validity and diagnostic value in the same population. A total of 157 cases were screened for parkinsonism using the validated six-item questionnaire. After age and sex adjustment based on the Tehran population, the prevalence of parkinsonism was calculated as 222.9 per 100,000. Using the World Health Organization's World Standard Population, the standardized prevalence rate of parkinsonism was 285 per 100,000 (95% confidence interval 240-329). The male:female ratio of probable parkinsonism was calculated as 1.62, and there was a significant increase in the screening rate by advancing age. The calculated rates for the prevalence of parkinsonism in our study are closer to reports from some European and Middle Eastern countries, higher than reports from Eastern Asian and African populations, and lower than Australia. The prevalence rate of >200 in 100,000 for parkinsonism in Tehran, Iran could be considered a medium-to-high rate.

Women's authority during childbirth and Safe Motherhood in Yemen.

PubMed

Kempe, Annica; Noor-Aldin Alwazer, Fatoom A; Theorell, Töres

2010-11-01

In the effort to increase utilization of professional care during childbirth in low-income countries, few studies have taken a holistic approach to investigating women's perspective of safety and the link to perceived own authority at birth. The aim of the study was to examine women's authority at birth with reference to the intrapartum factors, the level of training of staff and the social and demographic background of women. A multistage (stratified-purposive-random) sampling process was used. We interviewed 220 women with childbirth experience in urban/rural Yemen. We performed bivariate chi-square tests and multiple logistic regression analysis. Women who had their questions answered and requests met during childbirth had 83% higher probability (95% CI 1.66-2.02) to perceive own authority. Women who reported skin-to-skin contact/newborn in arms had 28% higher (95% CI 1.03-1.59) and those who had more distant contact 15% lower (95% CI 0.75-0.95) probability. A graded negative association was found between the perceived authority of the woman in childbirth and the level of biomedical training of staff (p<.0001). Women's social and demographic background played no role for their perceived own authority at birth. This paper argues that supporting Yemeni women to exercise their own authority during childbirth would significantly facilitate their ability to give birth successfully and with personal satisfaction. In a country where women are routinely disempowered, their personal empowerment at birth is very important to them. Skilled birth assistants often, in women's perceptions, work against their personal power and authority, most especially MDs but also midwives. This failure results in women failing to seek medical care when needed. Supporting women to experience their own authority at birth would facilitate the accomplishment of both the Millennium Development Goals and those of the Safe Motherhood Initiative. We call for increased cooperation between modern and traditional methods of care. Copyright © 2010 Elsevier B.V. All rights reserved.

Thermal analysis applied to irradiated propolis

NASA Astrophysics Data System (ADS)

Matsuda, Andrea Harumi; Machado, Luci Brocardo; del Mastro, Nélida Lucia

2002-03-01

Propolis is a resinous hive product, collected by bees. Raw propolis requires a decontamination procedure and irradiation appears as a promising technique for this purpose. The valuable properties of propolis for food and pharmaceutical industries have led to increasing interest in its technological behavior. Thermal analysis is a chemical analysis that gives information about changes on heating of great importance for technological applications. Ground propolis samples were 60Co gamma irradiated with 0 and 10 kGy. Thermogravimetry curves shown a similar multi-stage decomposition pattern for both irradiated and unirradiated samples up to 600°C. Similarly, through differential scanning calorimetry , a coincidence of melting point of irradiated and unirradiated samples was found. The results suggest that the irradiation process do not interfere on the thermal properties of propolis when irradiated up to 10 kGy.

KINETIC STUDIES RELATED TO THE LIMB (LIMESTONE INJECTION MULTISTAGE BURNER) BURNER

EPA Science Inventory

The report gives results of theoretical and experimental studies of subjects related to the limestone injection multistage burner (LIMB). The main findings include data on the rate of evolution of H2S from different coals and on the dependence of the rate of evolution on the dist...

Optimal Testlet Pool Assembly for Multistage Testing Designs

ERIC Educational Resources Information Center

Ariel, Adelaide; Veldkamp, Bernard P.; Breithaupt, Krista

2006-01-01

Computerized multistage testing (MST) designs require sets of test questions (testlets) to be assembled to meet strict, often competing criteria. Rules that govern testlet assembly may dictate the number of questions on a particular subject or may describe desirable statistical properties for the test, such as measurement precision. In an MST…

Test Information Targeting Strategies for Adaptive Multistage Testing Designs.

ERIC Educational Resources Information Center

Luecht, Richard M.; Burgin, William

Adaptive multistage testlet (MST) designs appear to be gaining popularity for many large-scale computer-based testing programs. These adaptive MST designs use a modularized configuration of preconstructed testlets and embedded score-routing schemes to prepackage different forms of an adaptive test. The conditional information targeting (CIT)…

Multi-stage Continuous Culture Fermentation of Glucose-Xylose Mixtures to Fuel Ethanol using Genetically Engineered Saccharomyces cerevisiae 424A

EPA Science Inventory

Multi-stage continuous (chemostat) culture fermentation (MCCF) with variable fermentor volumes was carried out to study utilizing glucose and xylose for ethanol production by means of mixed sugar fermentation (MSF). Variable fermentor volumes were used to enable enhanced sugar u...

Prevalence and Correlates of Direct Self-Injurious Behavior among Chinese Adolescents: Findings from a Multicenter and Multistage Survey.

PubMed

Xin, Xiuhong; Wang, Yuping; Fang, Jianqun; Ming, Qingsen; Yao, Shuqiao

2017-05-01

Direct self-injurious behavior (DSIB) has become an important focus due to its perniciousness and perplexity. Little is known about its prevalence and correlative factors in Chinese adolescents, including how data may differ according to gender. A multicenter, multistage stratified cluster random sampling was used to examine the previous 12-month prevalence of DSIB, as well as the possible correlates of demographics, risky behaviors, suicidality, and psychosocial factors associated with DSIB in a school-based sample of 11,880 students (49.5 % boys and 50.5 % girls). Approximately 30 % of the adolescents in the sample reported at least one incident of DSIB in the past 12-month period. After controlling for demographic variables, analyses of the independent relationships of DSIB with risky behaviors, suicidality, and psychosocial factors were conducted for each gender. Smoking, binge drinking, running away from home, suicide ideation, suicide plans, positive affect, and physical symptoms were identified as common factors associated with DSIB for both genders in the final model. In addition, truancy, fighting, physical inactivity, motor impulsiveness, and depressed affect were found to be related to DSIB in boys, whereas suicide attempts and somatic complaints were found to be related to DSIB in girls. Separation anxiety and social anxiety associated negatively with DSIB in boys and girls, respectively. DSIB was not found to independently relate to attention impulsiveness, non-planned impulsiveness, self-esteem, or harm avoidance in either genders. DSIB was prevalent in Chinese adolescents. Programs intended to promote physical and mental health in adolescents should take into account gender differences in DSIB-associated factors, including risky behaviors, suicidality, and psychosocial factors.

High-performance liquid chromatography-diode array detection-electrospray ionization multi-stage mass spectrometric screening of an insect/plant system: the case of Spodoptera littoralis/Lycopersicon esculentum phenolics and alkaloids.

PubMed

Ferreres, Federico; Taveira, Marcos; Gil-Izquierdo, Angel; Oliveira, Luísa; Teixeira, Tânia; Valentão, Patrícia; Simões, Nelson; Andrade, Paula B

2011-07-30

High-performance liquid chromatography-diode array detection-electrospray ionization multi-stage mass spectrometry (HPLC-DAD-ESI-MS(n)) is considered to be a very valuable tool for the characterization of compounds found in trace amounts in natural matrices, as their previous isolation and clean-up steps can be avoided. Micro-scale separation increases the potential of this analytical technique, allowing the determination of compounds in reduced samples. Spodoptera littoralis represents a major challenge to Solanaceae plants, as it is one of the most deleterious pests. The S. littoralis/Lycopersicon esculentum system was studied for the first time concerning glycoalkaloids and phenolics. Using HPLC-DAD-ESI-MS(n) we were able to characterize 15 phenolic compounds in L. esculentum leaves. Nine of them are reported for the first time. Some differences were found between leaves of cerasiforme and 'Bull's heart' varieties. However, in the materials of S. littoralis (larvae, adults, exuviae and excrements) reared in both L. esculentum leaves no phenolics were identified. α-Tomatine was the main glycoalkaloid in the host plant. The glycoalkaloid composition of the different S. littoralis materials was distinct, with α-tomatine and dehydrotomatine being the main detected compounds in larvae and excrements. These results add knowledge to the ecological interaction in this insect/plant duo, for which it is hard to obtain considerable sample amounts. Copyright © 2011 John Wiley & Sons, Ltd.

Loading, Release, Biodegradation, and Biocompatibility of a Nanovector Delivery System

NASA Technical Reports Server (NTRS)

Ferrai, Mauro; Tasciotti, Ennio

2012-01-01

A nanovector multistage system has been created to overcome or bypass sequential barriers within the human body, in order to deliver a therapeutic or imaging agent to a specific location. This innovation consists of a composition that includes two or more stages of particles, such that smaller, later-stage particles are contained in the larger, early-stage particles. An active agent, such as a therapeutic agent or imaging agent, is preferentially delivered and/or localized to a particular target site in the body of a subject. The multistage composition overcomes multiple biological barriers in the body. The multistage composition also allows for simultaneous delivery and localization at the same or different target sites of multiple active agents.

Limitations Of The Current State Space Modelling Approach In Multistage Machining Processes Due To Operation Variations

NASA Astrophysics Data System (ADS)

Abellán-Nebot, J. V.; Liu, J.; Romero, F.

2009-11-01

The State Space modelling approach has been recently proposed as an engineering-driven technique for part quality prediction in Multistage Machining Processes (MMP). Current State Space models incorporate fixture and datum variations in the multi-stage variation propagation, without explicitly considering common operation variations such as machine-tool thermal distortions, cutting-tool wear, cutting-tool deflections, etc. This paper shows the limitations of the current State Space model through an experimental case study where the effect of the spindle thermal expansion, cutting-tool flank wear and locator errors are introduced. The paper also discusses the extension of the current State Space model to include operation variations and its potential benefits.

Optimizing Integrated Terminal Airspace Operations Under Uncertainty

NASA Technical Reports Server (NTRS)

Bosson, Christabelle; Xue, Min; Zelinski, Shannon

2014-01-01

In the terminal airspace, integrated departures and arrivals have the potential to increase operations efficiency. Recent research has developed geneticalgorithm- based schedulers for integrated arrival and departure operations under uncertainty. This paper presents an alternate method using a machine jobshop scheduling formulation to model the integrated airspace operations. A multistage stochastic programming approach is chosen to formulate the problem and candidate solutions are obtained by solving sample average approximation problems with finite sample size. Because approximate solutions are computed, the proposed algorithm incorporates the computation of statistical bounds to estimate the optimality of the candidate solutions. A proof-ofconcept study is conducted on a baseline implementation of a simple problem considering a fleet mix of 14 aircraft evolving in a model of the Los Angeles terminal airspace. A more thorough statistical analysis is also performed to evaluate the impact of the number of scenarios considered in the sampled problem. To handle extensive sampling computations, a multithreading technique is introduced.

A Top-Down Approach to Designing the Computerized Adaptive Multistage Test

ERIC Educational Resources Information Center

Luo, Xiao; Kim, Doyoung

2018-01-01

The top-down approach to designing a multistage test is relatively understudied in the literature and underused in research and practice. This study introduced a route-based top-down design approach that directly sets design parameters at the test level and utilizes the advanced automated test assembly algorithm seeking global optimality. The…

Multi-stage flash degaser

DOEpatents

Rapier, P.M.

1980-06-26

A multi-stage flash degaser is incorporated in an energy conversion system having a direct-contact, binary-fluid heat exchanger to remove essentially all of the noncondensable gases from geothermal brine ahead of the direct-contact binary-fluid heat exchanger in order that the heat exchanger and a turbine and condenser of the system can operate at optimal efficiency.

Panel Design Variations in the Multistage Test Using the Mixed-Format Tests

ERIC Educational Resources Information Center

Kim, Jiseon; Chung, Hyewon; Dodd, Barbara G.; Park, Ryoungsun

2012-01-01

This study compared various panel designs of the multistage test (MST) using mixed-format tests in the context of classification testing. Simulations varied the design of the first-stage module. The first stage was constructed according to three levels of test information functions (TIFs) with three different TIF centers. Additional computerized…

A Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success

ERIC Educational Resources Information Center

Luong, Ming; Stevens, Jeff

2015-01-01

The Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success, a theoretical stages-of-growth model, explains long-term success in IT outsourcing relationships. Research showed the IT outsourcing relationship life cycle consists of four distinct, sequential stages: contract, transition, support, and partnership. The model was…

Development of JSTAMP-Works/NV and HYSTAMP for Multipurpose Multistage Sheet Metal Forming Simulation

NASA Astrophysics Data System (ADS)

Umezu, Yasuyoshi; Watanabe, Yuko; Ma, Ninshu

2005-08-01

Since 1996, Japan Research Institute Limited (JRI) has been providing a sheet metal forming simulation system called JSTAMP-Works packaged the FEM solvers of LS-DYNA and JOH/NIKE, which might be the first multistage system at that time and has been enjoying good reputation among users in Japan. To match the recent needs, "faster, more accurate and easier", of process designers and CAE engineers, a new metal forming simulation system JSTAMP-Works/NV is developed. The JSTAMP-Works/NV packaged the automatic healing function of CAD and had much more new capabilities such as prediction of 3D trimming lines for flanging or hemming, remote control of solver execution for multi-stage forming processes and shape evaluation between FEM and CAD. On the other way, a multi-stage multi-purpose inverse FEM solver HYSTAMP is developed and will be soon put into market, which is approved to be very fast, quite accurate and robust. Lastly, authors will give some application examples of user defined ductile damage subroutine in LS-DYNA for the estimation of material failure and springback in metal forming simulation.

First demonstration of an emulsion multi-stage shifter for accelerator neutrino experiments in J-PARC T60

NASA Astrophysics Data System (ADS)

Yamada, K.; Aoki, S.; Cao, S.; Chikuma, N.; Fukuda, T.; Fukuzawa, Y.; Gonin, M.; Hayashino, T.; Hayato, Y.; Hiramoto, A.; Hosomi, F.; Inoh, T.; Iori, S.; Ishiguro, K.; Kawahara, H.; Kim, H.; Kitagawa, N.; Koga, T.; Komatani, R.; Komatsu, M.; Matsushita, A.; Mikado, S.; Minamino, A.; Mizusawa, H.; Matsumoto, T.; Matsuo, T.; Morimoto, Y.; Morishima, K.; Morishita, M.; Naganawa, N.; Nakamura, K.; Nakamura, M.; Nakamura, Y.; Nakano, T.; Nakatsuka, Y.; Nakaya, T.; Nishio, A.; Ogawa, S.; Oshima, H.; Quilain, B.; Rokujo, H.; Sato, O.; Seiya, Y.; Shibuya, H.; Shiraishi, T.; Suzuki, Y.; Tada, S.; Takahashi, S.; Yokoyama, M.; Yoshimoto, M.

2017-06-01

We describe the first ever implementation of a clock-based, multi-stage emulsion shifter in an accelerator neutrino experiment. The system was installed in the neutrino monitoring building at the Japan Proton Accelerator Research Complex as part of a test experiment, T60, and stable operation was maintained for a total of 126.6 days. By applying time information to emulsion films, various results were obtained. Time resolutions of 5.3-14.7 s were evaluated in an operation spanning 46.9 days (yielding division numbers of 1.4-3.8×105). By using timing and spatial information, reconstruction of coincident events consisting of high-multiplicity and vertex-contained events, including neutrino events, was performed. Emulsion events were matched to events observed by INGRID, one of the on-axis near detectors of the T2K experiment, with high reliability (98.5%), and hybrid analysis of the emulsion and INGRID events was established by means of the multi-stage shifter. The results demonstrate that the multi-stage shifter can feasibly be used in neutrino experiments.

The influence of the "cage effect" on the mechanism of reversible bimolecular multistage chemical reactions in solutions.

PubMed

Doktorov, Alexander B

2015-08-21

Manifestations of the "cage effect" at the encounters of reactants are theoretically treated by the example of multistage reactions in liquid solutions including bimolecular exchange reactions as elementary stages. It is shown that consistent consideration of quasi-stationary kinetics of multistage reactions (possible only in the framework of the encounter theory) for reactions proceeding near reactants contact can be made on the basis of the concepts of a "cage complex." Though mathematically such a consideration is more complicated, it is more clear from the standpoint of chemical notions. It is established that the presence of the "cage effect" leads to some important effects not inherent in reactions in gases or those in solutions proceeding in the kinetic regime, such as the appearance of new transition channels of reactant transformation that cannot be caused by elementary event of chemical conversion for the given mechanism of reaction. This results in that, for example, rate constant values of multistage reaction defined by standard kinetic equations of formal chemical kinetics from experimentally measured kinetics can differ essentially from real values of these constants.

Health condition identification of multi-stage planetary gearboxes using a mRVM-based method

NASA Astrophysics Data System (ADS)

Lei, Yaguo; Liu, Zongyao; Wu, Xionghui; Li, Naipeng; Chen, Wu; Lin, Jing

2015-08-01

Multi-stage planetary gearboxes are widely applied in aerospace, automotive and heavy industries. Their key components, such as gears and bearings, can easily suffer from damage due to tough working environment. Health condition identification of planetary gearboxes aims to prevent accidents and save costs. This paper proposes a method based on multiclass relevance vector machine (mRVM) to identify health condition of multi-stage planetary gearboxes. In this method, a mRVM algorithm is adopted as a classifier, and two features, i.e. accumulative amplitudes of carrier orders (AACO) and energy ratio based on difference spectra (ERDS), are used as the input of the classifier to classify different health conditions of multi-stage planetary gearboxes. To test the proposed method, seven health conditions of a two-stage planetary gearbox are considered and vibration data is acquired from the planetary gearbox under different motor speeds and loading conditions. The results of three tests based on different data show that the proposed method obtains an improved identification performance and robustness compared with the existing method.

Sampling bias in an international internet survey of diversion programs in the criminal justice system.

PubMed

Hartford, Kathleen; Carey, Robert; Mendonca, James

2007-03-01

Despite advances in the storage and retrieval of information within health care systems, health researchers conducting surveys for evaluations still face technical barriers that may lead to sampling bias. The authors describe their experience in administering a Web-based, international survey to English-speaking countries. Identifying the sample was a multistage effort involving (a) searching for published e-mail addresses, (b) conducting Web searches for publicly funded agencies, and (c) performing literature searches, personal contacts, and extensive Internet searches for individuals. After pretesting, the survey was converted into an electronic format accessible by multiple Web browsers. Sampling bias arose from (a) system incompatibility, which did not allow potential respondents to open the survey, (b) varying institutional gate-keeping policies that "recognized" the unsolicited survey as spam, (c) culturally unique program terminology, which confused some respondents, and (d) incomplete sampling frames. Solutions are offered to the first three problems, and the authors note that sampling bias remains a crucial problem.

New generation of universal modeling for centrifugal compressors calculation

NASA Astrophysics Data System (ADS)

Galerkin, Y.; Drozdov, A.

2015-08-01

The Universal Modeling method is in constant use from mid - 1990th. Below is presented the newest 6th version of the Method. The flow path configuration of 3D impellers is presented in details. It is possible to optimize meridian configuration including hub/shroud curvatures, axial length, leading edge position, etc. The new model of vaned diffuser includes flow non-uniformity coefficient based on CFD calculations. The loss model was built from the results of 37 experiments with compressors stages of different flow rates and loading factors. One common set of empirical coefficients in the loss model guarantees the efficiency definition within an accuracy of 0.86% at the design point and 1.22% along the performance curve. The model verification was made. Four multistage compressors performances with vane and vaneless diffusers were calculated. As the model verification was made, four multistage compressors performances with vane and vaneless diffusers were calculated. Two of these compressors have quite unusual flow paths. The modeling results were quite satisfactory in spite of these peculiarities. One sample of the verification calculations is presented in the text. This 6th version of the developed computer program is being already applied successfully in the design practice.

Talent identification model for sprinter using discriminant factor

NASA Astrophysics Data System (ADS)

Kusnanik, N. W.; Hariyanto, A.; Herdyanto, Y.; Satia, A.

2018-01-01

The main purpose of this study was to identify young talented sprinter using discriminant factor. The research was conducted in 3 steps including item pool, screening of item pool, and trial of instruments at the small and big size of samples. 315 male elementary school students participated in this study with mean age of 11-13 years old. Data were collected by measuring anthropometry (standing height, sitting height, body mass, and leg length); testing physical fitness (40m sprint for speed, shuttle run for agility, standing broad jump for power, multistage fitness test for endurance). Data were analyzed using discriminant factor. The result of this study found that there were 5 items that selected as an instrument to identify young talented sprinter: sitting height, body mass, leg length, sprint 40m, and multistage fitness test. Model of Discriminant for talent identification in sprinter was D = -24,497 + (0,155 sitting height) + (0,080 body mass) + (0,148 leg length) + (-1,225 Sprint 40m) + (0,563 MFT). The conclusion of this study: instrument tests that have been selected and discriminant model that have been found can be applied to identify young talented as a sprinter.

Acceptability of domestic violence against women in the European Union: a multilevel analysis.

PubMed

Gracia, Enrique; Herrero, Juan

2006-02-01

The acceptability of domestic violence against women (DVAW) plays an important part in shaping the social environment in which the victims are embedded, which in turn may contribute either to perpetuate or to reduce the levels of DVAW in our societies. This study analyses correlates of the acceptability of DVAW in the European Union (EU). Three level ordinal logistic regression of 13 457 people nested within 212 localities (cities), nested within 15 countries of the EU. Sampling is multistage with random probability. All interviews were face to face in people's homes. The outcome variable was acceptability of DVAW. Multiple correlates at the individual, locality, and country level were analysed. European Union, 1999. National data were used of residents 15 years old and above of all member states in 1999 (n = 13 457). Average response rate was 47%, although it varied across countries (23%-73%). Higher levels of acceptability were reported by those who perceived DVAW as less severe and less frequent. Acceptability is higher among men who know a perpetrator and lower among men who know a victim. Victim blaming attitude is associated with higher levels of acceptability. In countries with higher gender empowerment measure the difference in acceptability among those who blame and those who do not blame the victim is greater. There are still widespread attitudes in the EU such as victim blaming that condone DVAW, contributing to a climate of social acceptability of DVAW. Further efforts to reduce the acceptability of DVAW are still needed.

Availability of convenience stores and adolescent alcohol use in Taiwan: a multi-level analysis of national surveys.

PubMed

Wang, Shi-Heng; Lin, I-Chin; Chen, Chuan-Yu; Chen, Duan-Rung; Chan, Ta-Chien; Chen, Wei J

2013-12-01

To examine the association between alcohol in school environments and adolescent alcohol use over the previous 6 months. A multi-level logistic regression analysis was performed of cross-sectional surveys conducted in 2004, 2005 and 2006. A total of 52 214 students aged 11-19 years from 387 middle or high schools were selected from a nationally representative, multi-stage, stratified probability sampling across Taiwan. Information on socio-demographic features and substance use experiences was collected using self-administered questionnaires. The alcohol in the environment was measured using the availability of convenience stores surrounding the schools. Using geographical information systems, the weighted numbers of convenience stores within 1 km, a 12-15-minute walk, of a school were calculated. The schools were later categorized into three subgroups via the tertile of nearby convenience stores. Considering the compositional characteristics, the availability of convenience stores was found to account for 1.5% of the school-level variance of youthful drinking. The odds ratios (95% confidence interval) of alcohol use over the previous 6 months among youth attending schools with medium and high availability were 1.04 (0.96-1.13) and 1.08 (1.00-1.17), respectively, with a P-value of 0.04 in the trend test. The greater availability of convenience stores near a school is associated with an increased risk of alcohol use among adolescents over the previous 6 months. © 2013 Society for the Study of Addiction.

Ocular Health and Safety Assessment among Mechanics of the Cape Coast Metropolis, Ghana.

PubMed

Abu, Emmanuel Kwasi; Boadi-Kusi, Samuel Bert; Opuni, Prince Quarcoo; Kyei, Samuel; Owusu-Ansah, Andrew; Darko-Takyi, Charles

2016-01-01

To conduct an ocular health and safety assessment among mechanics in the Cape Coast Metropolis, Ghana. This descriptive cross sectional study included 500 mechanics using multistage sampling. All participants filled a structured questionnaire on demographic data, occupational history and ocular health history. Study participants underwent determination of visual acuity (VA) using LogMAR chart, external eye examination with a handheld slit lamp biomicroscope, dilated fundus examination, applanation tonometry and refraction. Out of 500 mechanics, 433 were examined (response rate, 87%) comprised of 408 (94.2%) male and 25 (5.8%) female subjects. The prevalence of visual impairment (i.e. presenting VA < 6/18) among the respondents was 2.1%. Eye injuries were reported in 171 (39.5%) mechanics probably due to the large number of workers, 314 (72.5%), who did not use eye protective devices. Mechanics in the auto welding category were at the highest risk of sustaining an eye injury (odds ratio [OR], 13.4; P < 0.001). Anterior segment ocular disorders were mostly pterygia while posterior segment eye disorders included glaucoma suspects and retinochoroidal lesions. The development of pterygia was associated with the number of years a mechanic stayed on the job. Eye care seeking behavior among the participants was poor. Eye injuries were prevalent among the mechanics as the use of eye protection was low. Eye safety should be made an integral part of the public health agenda in the Cape Coast Metropolis.

Young people, alcohol, and designer drinks: quantitative and qualitative study.

PubMed Central

Hughes, K.; MacKintosh, A. M.; Hastings, G.; Wheeler, C.; Watson, J.; Inglis, J.

1997-01-01

OBJECTIVE: To examine the appeal of "designer drinks" to young people. DESIGN: Qualitative and quantitative research comprising group discussions and questionnaire led interviews with young people accompanied by a self completion questionnaire. SETTINGS: Argyll and Clyde Health Board area, west Scotland. SUBJECTS: Eight groups aged 12-17 years; 824 aged 12-17 recruited by multistage cluster probability sample from the community health index. RESULTS: Young people were familiar with designer drinks, especially MD 20/20 and leading brands of strong white cider. Attitudes towards these drinks varied quite distinctly with age, clearly reflecting their attitudes towards and motivations for drinking in general. The brand imagery of designer drinks-in contrast with that of more mainstream drinks-matched many 14 and 15 year olds' perceptions and expectations of drinking. Popularity of designer drinks peaked between the ages of 13 and 16 while more conventional drinks showed a consistent increase in popularity with age. Consumption of designer drinks tended to be in less controlled circumstances and was associated with heavier alcohol intake and greater drunkenness. CONCLUSIONS: Designer drinks are a cause for concern. They appeal to young people, often more so than conventional drinks, and are particularly attractive to 14-16 year olds. Consumption of designer drinks is also associated with drinking in less controlled environments, heavier drinking, and greater drunkenness. There is a need for policy debate to assess the desirability of these drinks and the extent to which further controls on their marketing are required. PMID:9040387

Peer attitudes effects on adolescent substance use: the moderating role of race and gender.

PubMed

Mason, Michael J; Mennis, Jeremy; Linker, Julie; Bares, Cristina; Zaharakis, Nikola

2014-02-01

We examined the relationship between adolescents' perceptions of their close friends' attitudes about substance use, and their own use of cigarettes, alcohol, and marijuana. Using data from the 2010 National Survey on Drug Use and Health, a multistage area probability sample sponsored by the Substance Abuse and Mental Health Services Administration (n = 17,865), we tested the direct and moderating effects of subgroups of race and gender on perceptions of adolescents' close friends on past month substance use. Significant effects were found on peer attitudes influencing substance use for all race and gender subgroups. Close friends' attitudes of indifference were associated with increased substance use and disapproval associated with reduced use, controlling for age, income, family structure, and adolescents' own attitudes of risk of substance use. Significant moderating effects of peer attitudes on cigarette and marijuana use were found for both gender and race moderators. Conditional effects of the moderation by race were also examined for gender subgroups. The moderating effect of race on close friends' attitudes impacting cigarette and marijuana use was stronger in magnitude and significance for females compared to males. Female marijuana and cigarette use was more influenced by close friends' attitudes than males, and whites were more influenced by their close friends than Hispanics and blacks. White females are more susceptible to close friends' attitudes on cigarette use as compared to white males and youth of other races. Implications for socially oriented preventive interventions are discussed.

Novel sulphur-containing imatinib metabolites found by untargeted LC-HRMS analysis.

PubMed

Vrobel, Ivo; Friedecký, David; Faber, Edgar; Najdekr, Lukáš; Mičová, Kateřina; Karlíková, Radana; Adam, Tomáš

2017-06-15

Untargeted metabolite profiling using high-resolution mass spectrometry coupled with liquid chromatography (LC-HRMS), followed by data analysis with the Compound Discoverer 2.0™ software, was used to study the metabolism of imatinib in humans with chronic myeloid leukemia. Plasma samples from control (drug-free) and patient (treated with imatinib) groups were analyzed in full-scan mode and the unknown ions occurring only in the patient group were then, as potential imatinib metabolites, subjected to multi-stage fragmentation in order to elucidate their structure. The application of an untargeted approach, as described in this study, enabled the detection of 24 novel structurally unexpected metabolites. Several sulphur-containing compounds, probably originating after the reaction of reactive intermediates of imatinib with endogenous glutathione, were found and annotated as cysteine and cystine adducts. In the proposed mechanism, the cysteine adducts were formed after the rearrangement of piperazine moiety to imidazoline. On the contrary, in vivo S-N exchange occurred in the case of the cystine adducts. In addition, N-O exchange was observed in the collision cell in the course of the fragmentation of the cystine adducts. The presence of sulphur in the cysteine and cystine conjugates was proved by means of ultra-high resolution measurements using Orbitrap Elite. The detection of metabolites derived from glutathione might improve knowledge about the disposition of imatinib towards bioactivation and help to improve understanding of the mechanism of its hepatotoxicity or nephrotoxicity in humans. Copyright © 2017 Elsevier B.V. All rights reserved.

A theory of rotating stall of multistage axial compressors. III - Limit cycles

NASA Technical Reports Server (NTRS)

Moore, F. K.

1983-01-01

A theory of rotating stall, based on single parameters for blade-passage lag and external-flow lag and a given compressor characteristic yields limit cycles in velocity space. These limit cycles are governed by Lienard's equation with the characteristic playing the role of nonlinear damping function. Cyclic integrals of the solution determine stall propagation speed and the effect of rotating stall on average performance. Solution with various line-segment characteristics and various throttle settings are found and discussed. There is generally a limiting flow coefficient beyond which no solution is possible; this probably represents stall recovery. This recovery point is independent of internal compressor lag, but does depend on external lags and on the height-to-width ratio of the diagram. Tall diagrams and small external lags (inlet and diffusor) favor recovery. Suggestions for future theoretical and experimental research are discussed.

Sampling considerations for disease surveillance in wildlife populations

USGS Publications Warehouse

Nusser, S.M.; Clark, W.R.; Otis, D.L.; Huang, L.

2008-01-01

Disease surveillance in wildlife populations involves detecting the presence of a disease, characterizing its prevalence and spread, and subsequent monitoring. A probability sample of animals selected from the population and corresponding estimators of disease prevalence and detection provide estimates with quantifiable statistical properties, but this approach is rarely used. Although wildlife scientists often assume probability sampling and random disease distributions to calculate sample sizes, convenience samples (i.e., samples of readily available animals) are typically used, and disease distributions are rarely random. We demonstrate how landscape-based simulation can be used to explore properties of estimators from convenience samples in relation to probability samples. We used simulation methods to model what is known about the habitat preferences of the wildlife population, the disease distribution, and the potential biases of the convenience-sample approach. Using chronic wasting disease in free-ranging deer (Odocoileus virginianus) as a simple illustration, we show that using probability sample designs with appropriate estimators provides unbiased surveillance parameter estimates but that the selection bias and coverage errors associated with convenience samples can lead to biased and misleading results. We also suggest practical alternatives to convenience samples that mix probability and convenience sampling. For example, a sample of land areas can be selected using a probability design that oversamples areas with larger animal populations, followed by harvesting of individual animals within sampled areas using a convenience sampling method.

Approximation of Failure Probability Using Conditional Sampling

NASA Technical Reports Server (NTRS)

Giesy. Daniel P.; Crespo, Luis G.; Kenney, Sean P.

2008-01-01

In analyzing systems which depend on uncertain parameters, one technique is to partition the uncertain parameter domain into a failure set and its complement, and judge the quality of the system by estimating the probability of failure. If this is done by a sampling technique such as Monte Carlo and the probability of failure is small, accurate approximation can require so many sample points that the computational expense is prohibitive. Previous work of the authors has shown how to bound the failure event by sets of such simple geometry that their probabilities can be calculated analytically. In this paper, it is shown how to make use of these failure bounding sets and conditional sampling within them to substantially reduce the computational burden of approximating failure probability. It is also shown how the use of these sampling techniques improves the confidence intervals for the failure probability estimate for a given number of sample points and how they reduce the number of sample point analyses needed to achieve a given level of confidence.

Method of and apparatus for testing the integrity of filters

DOEpatents

Herman, R.L.

1985-05-07

A method of and apparatus are disclosed for testing the integrity of individual filters or filter stages of a multistage filtering system including a diffuser permanently mounted upstream and/or downstream of the filter stage to be tested for generating pressure differentials to create sufficient turbulence for uniformly dispersing trace agent particles within the airstream upstream and downstream of such filter stage. Samples of the particle concentration are taken upstream and downstream of the filter stage for comparison to determine the extent of particle leakage past the filter stage. 5 figs.

Method of and apparatus for testing the integrity of filters

DOEpatents

Herman, Raymond L [Richland, WA

1985-01-01

A method of and apparatus for testing the integrity of individual filters or filter stages of a multistage filtering system including a diffuser permanently mounted upstream and/or downstream of the filter stage to be tested for generating pressure differentials to create sufficient turbulence for uniformly dispersing trace agent particles within the airstream upstream and downstream of such filter stage. Samples of the particle concentration are taken upstream and downstream of the filter stage for comparison to determine the extent of particle leakage past the filter stage.

Methods of and apparatus for testing the integrity of filters

DOEpatents

Herman, R.L.

1984-01-01

A method of and apparatus for testing the integrity of individual filters or filter stages of a multistage filtering system including a diffuser permanently mounted upstream and/or downstream of the filter stage to be tested for generating pressure differentials to create sufficient turbulence for uniformly dispersing trace agent particles within the airstram upstream and downstream of such filter stage. Samples of the particel concentration are taken upstream and downstream of the filter stage for comparison to determine the extent of particle leakage past the filter stage.

Multistage, multiseasonal and multiband imagery to identify and qualify non-forest vegetation resources

NASA Technical Reports Server (NTRS)

Driscoll, R. S.; Francis, R. E.

1970-01-01

A description of space and supporting aircraft photography for the interpretation and analyses of non-forest (shrubby and herbaceous) native vegetation is presented. The research includes the development of a multiple sampling technique to assign quantitative area values of specific plant community types included within an assigned space photograph map unit. Also, investigations of aerial film type, scale, and season of photography for identification and quantity measures of shrubby and herbaceous vegetation were conducted. Some work was done to develop automated interpretation techniques with film image density measurement devices.

Is occupation a good predictor of self-rated health in China?

PubMed

Xie, Zheng; Poon, Adrienne N; Wu, Zhijun; Jian, Weiyan; Chan, Kit Yee

2015-01-01

China's rapidly changing economic landscape has led to widening social inequalities. Occupational status in terms of occupational type and prestige may reflect these socio-structural shifts of social position and be more predictive of self-rated health status than income and education, which may only reflect more gradual acquisitions of social status over time. The goals of this study were to understand the role of occupational status in predicting self-rated health, which is well known to be associated with long-term mortality, as well as compare the occupational status to the other major socioeconomic indicators of income and education. Data from the 2010 baseline surveys of the China Family Panel Studies, which utilized multi-stage probability sampling with implicit stratification was used. Logistic regression was used to examine the relationship of various socioeconomic indicators (i.e. occupational status, income, and education) with self-rated health as the primary outcome of interest. A series of models considered the associations of occupational category or occupational prestige with self-rated health. The final sample consisted of 14,367 employed adults aged 18-60, which was nationally representative of working adults in China. We found that occupation was not a major predictor of self-rated health in China when age, ethnicity, location, marital status, physical and mental health status were controlled for, with the exception of women working in lower grade management and professional jobs (OR = 1.82, 95% CI: 1.03-3.22). In comparison, income followed by education exhibited greater association with self-rated health. The highest income group had the least probability to report poor health (In men: OR = 0.30, 95% CI: 0.21-0.43. In women: OR = 0.44, 95% CI: 0.26-0.73). People educated with junior high school had better self-rated health than those with primary and below education level (In men: OR = 0.62, 95% CI: 0.50-0.75. In women: OR = 0.53, 95% CI: 0.42-0.68). Income, education and occupation were correlated with each other. Within the context of rapid societal changes in China, income and its implications for greater healthcare access and benefits had the greatest association with self-rated health followed by education. Occupational status was not associated. Occupational categories and prestige should be better adapted to reflect China's unique sociopolitical and historical context.

[National Health and Nutrition Survey 2012: design and coverage].

PubMed

Romero-Martínez, Martín; Shamah-Levy, Teresa; Franco-Núñez, Aurora; Villalpando, Salvador; Cuevas-Nasu, Lucía; Gutiérrez, Juan Pablo; Rivera-Dommarco, Juan Ángel

2013-01-01

To describe the design and population coverage of the National Health and Nutrition Survey 2012 (NHNS 2012). The design of the NHNS 2012 is reported, as a probabilistic population based survey with a multi-stage and stratified sampling, as well as the sample inferential properties, the logistical procedures, and the obtained coverage. Household response rate for the NHNS 2012 was 87%, completing data from 50,528 households, where 96 031 individual interviews selected by age and 14,104 of ambulatory health services users were also obtained. The probabilistic design of the NHNS 2012 as well as its coverage allowed to generate inferences about health and nutrition conditions, health programs coverage, and access to health services. Because of their complex designs, all estimations from the NHNS 2012 must use the survey design: weights, primary sampling units, and stratus variables.

An Investigation on Computer-Adaptive Multistage Testing Panels for Multidimensional Assessment

ERIC Educational Resources Information Center

Wang, Xinrui

2013-01-01

The computer-adaptive multistage testing (ca-MST) has been developed as an alternative to computerized adaptive testing (CAT), and been increasingly adopted in large-scale assessments. Current research and practice only focus on ca-MST panels for credentialing purposes. The ca-MST test mode, therefore, is designed to gauge a single scale. The…

A Fair Comparison of the Performance of Computerized Adaptive Testing and Multistage Adaptive Testing

ERIC Educational Resources Information Center

Wang, Keyin

2017-01-01

The comparison of item-level computerized adaptive testing (CAT) and multistage adaptive testing (MST) has been researched extensively (e.g., Kim & Plake, 1993; Luecht et al., 1996; Patsula, 1999; Jodoin, 2003; Hambleton & Xing, 2006; Keng, 2008; Zheng, 2012). Various CAT and MST designs have been investigated and compared under the same…

"MSTGen": Simulated Data Generator for Multistage Testing

ERIC Educational Resources Information Center

Han, Kyung T.

2013-01-01

Multistage testing, or MST, was developed as an alternative to computerized adaptive testing (CAT) for applications in which it is preferable to administer a test at the level of item sets (i.e., modules). As with CAT, the simulation technique in MST plays a critical role in the development and maintenance of tests. "MSTGen," a new MST…

A Comparison of IRT Proficiency Estimation Methods under Adaptive Multistage Testing

ERIC Educational Resources Information Center

Kim, Sooyeon; Moses, Tim; Yoo, Hanwook

2015-01-01

This inquiry is an investigation of item response theory (IRT) proficiency estimators' accuracy under multistage testing (MST). We chose a two-stage MST design that includes four modules (one at Stage 1, three at Stage 2) and three difficulty paths (low, middle, high). We assembled various two-stage MST panels (i.e., forms) by manipulating two…

Identifying Differential Item Functioning in Multi-Stage Computer Adaptive Testing

ERIC Educational Resources Information Center

Gierl, Mark J.; Lai, Hollis; Li, Johnson

2013-01-01

The purpose of this study is to evaluate the performance of CATSIB (Computer Adaptive Testing-Simultaneous Item Bias Test) for detecting differential item functioning (DIF) when items in the matching and studied subtest are administered adaptively in the context of a realistic multi-stage adaptive test (MST). MST was simulated using a 4-item…

The Effects of Routing and Scoring within a Computer Adaptive Multi-Stage Framework

ERIC Educational Resources Information Center

Dallas, Andrew

2014-01-01

This dissertation examined the overall effects of routing and scoring within a computer adaptive multi-stage framework (ca-MST). Testing in a ca-MST environment has become extremely popular in the testing industry. Testing companies enjoy its efficiency benefits as compared to traditionally linear testing and its quality-control features over…

Fractional Multistage Hydrothermal Liquefaction of Biomass and Catalytic Conversion into Hydrocarbons

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

Cortright, Randy; Rozmiarek, Robert; Dally, Brice

2017-08-31

The objective of this project was to develop an improved multistage process for the hydrothermal liquefaction (HTL) of biomass to serve as a new front-end, deconstruction process ideally suited to feed Virent’s well-proven catalytic technology, which is already being scaled up. This process produced water soluble, partially de-oxygenated intermediates that are ideally suited for catalytic finishing to fungible distillate hydrocarbons. Through this project, Virent, with its partners, demonstrated the conversion of pine wood chips to drop-in hydrocarbon distillate fuels using a multi-stage fractional conversion system that is integrated with Virent’s BioForming® process. The majority of work was in the liquefactionmore » task and included temperature scoping, solvent optimization, and separations.« less

Hypoplastic left heart syndrome - a review of supportive percutaneous treatment.

PubMed

Moszura, Tomasz; Góreczny, Sebastian; Dryżek, Paweł

2014-01-01

Due to the complex anatomical and haemodynamic consequences of hypoplastic left heart syndrome (HLHS), patients with the condition require multistage surgical and supportive interventional treatment. Percutaneous interventions may be required between each stage of surgical palliation, sometimes simultaneously with surgery as hybrid interventions, or after completion of multistage treatment. Recent advances in the field of interventional cardiology, including new devices and techniques, have significantly contributed to improving results of multistage HLHS palliation. Knowledge of the potential interventional options as well as the limitation of percutaneous interventions will enable the creation of safe and effective treatment protocols in this highly challenging group of patients. In this comprehensive review we discuss the types, goals, and potential complications of transcatheter interventions in patients with HLHS.

Probability of coincidental similarity among the orbits of small bodies - I. Pairing

NASA Astrophysics Data System (ADS)

Jopek, Tadeusz Jan; Bronikowska, Małgorzata

2017-09-01

Probability of coincidental clustering among orbits of comets, asteroids and meteoroids depends on many factors like: the size of the orbital sample searched for clusters or the size of the identified group, it is different for groups of 2,3,4,… members. Probability of coincidental clustering is assessed by the numerical simulation, therefore, it depends also on the method used for the synthetic orbits generation. We have tested the impact of some of these factors. For a given size of the orbital sample we have assessed probability of random pairing among several orbital populations of different sizes. We have found how these probabilities vary with the size of the orbital samples. Finally, keeping fixed size of the orbital sample we have shown that the probability of random pairing can be significantly different for the orbital samples obtained by different observation techniques. Also for the user convenience we have obtained several formulae which, for given size of the orbital sample can be used to calculate the similarity threshold corresponding to the small value of the probability of coincidental similarity among two orbits.

Method- and species-specific detection probabilities of fish occupancy in Arctic lakes: Implications for design and management

USGS Publications Warehouse

Haynes, Trevor B.; Rosenberger, Amanda E.; Lindberg, Mark S.; Whitman, Matthew; Schmutz, Joel A.

2013-01-01

Studies examining species occurrence often fail to account for false absences in field sampling. We investigate detection probabilities of five gear types for six fish species in a sample of lakes on the North Slope, Alaska. We used an occupancy modeling approach to provide estimates of detection probabilities for each method. Variation in gear- and species-specific detection probability was considerable. For example, detection probabilities for the fyke net ranged from 0.82 (SE = 0.05) for least cisco (Coregonus sardinella) to 0.04 (SE = 0.01) for slimy sculpin (Cottus cognatus). Detection probabilities were also affected by site-specific variables such as depth of the lake, year, day of sampling, and lake connection to a stream. With the exception of the dip net and shore minnow traps, each gear type provided the highest detection probability of at least one species. Results suggest that a multimethod approach may be most effective when attempting to sample the entire fish community of Arctic lakes. Detection probability estimates will be useful for designing optimal fish sampling and monitoring protocols in Arctic lakes.

A sampling procedure to guide the collection of narrow-band, high-resolution spatially and spectrally representative reflectance data. [satellite imagery of earth resources

NASA Technical Reports Server (NTRS)

Brand, R. R.; Barker, J. L.

1983-01-01

A multistage sampling procedure using image processing, geographical information systems, and analytical photogrammetry is presented which can be used to guide the collection of representative, high-resolution spectra and discrete reflectance targets for future satellite sensors. The procedure is general and can be adapted to characterize areas as small as minor watersheds and as large as multistate regions. Beginning with a user-determined study area, successive reductions in size and spectral variation are performed using image analysis techniques on data from the Multispectral Scanner, orbital and simulated Thematic Mapper, low altitude photography synchronized with the simulator, and associated digital data. An integrated image-based geographical information system supports processing requirements.

Relative importance index (RII) in ranking of procrastination factors among university students

NASA Astrophysics Data System (ADS)

Aziz, Nazrina; Zain, Zakiyah; Mafuzi, Raja Muhammad Zahid Raja; Mustapa, Aini Mastura; Najib, Nur Hasibah Mohd; Lah, Nik Fatihah Nik

2016-08-01

Procrastination is the action of delaying or postponing something such as making a decision or starting or completing some tasks or activities. According to previous studies, students who have a strong tendency to procrastinate get low scores in their tests, resulting in poorer academic performance compared to those who do not procrastinate. This study aims to identify the procrastination factors in completing assignments among three groups of undergraduate students. The relative importance of procrastination factors was quantified by the relative importance index (RII) method prior to ranking. A multistage sampling technique was used in selecting the sample. The findings revealed that `too many works in one time' is one of the top three factors contributing to procrastination in all groups.

High-Throughput Direct Fecal PCR Assay for Detection of Mycobacterium avium subsp. paratuberculosis in Sheep and Cattle

PubMed Central

Waldron, Anna M.; Galea, Francesca; Whittington, Ann-Michele; Saunders, Vanessa F.; Begg, Douglas J.; de Silva, Kumudika; Purdie, Auriol C.; Whittington, Richard J.

2014-01-01

Johne's disease (JD) is a chronic enteric disease caused by Mycobacterium avium subsp. paratuberculosis that affects ruminants. Transmission occurs by the fecal-oral route. A commonly used antemortem diagnostic test for the detection of M. avium subsp. paratuberculosis in feces is liquid culture; however, a major constraint is the 2- to 3-month incubation period needed for this method. Rapid methods for the detection of M. avium subsp. paratuberculosis based on PCR have been reported, but comprehensive validation data are lacking. We describe here a new test, the high-throughput-Johnes (HT-J), to detect M. avium subsp. paratuberculosis in feces. Its diagnostic accuracy was compared with that of liquid radiometric (Bactec) fecal culture using samples from cattle (1,330 samples from 23 herds) and sheep (596 samples from 16 flocks). The multistage protocol involves the recovery of M. avium subsp. paratuberculosis cells from a fecal suspension, cell rupture by bead beating, extraction of DNA using magnetic beads, and IS900 quantitative PCR. The limit of detection of the assay was 0.0005 pg, and the limit of quantification was 0.005 pg M. avium subsp. paratuberculosis genomic DNA. Only M. avium subsp. paratuberculosis was detected from a panel of 51 mycobacterial isolates, including 10 with IS900-like sequences. Of the 549 culture-negative fecal samples from unexposed herds and flocks, 99% were negative in the HT-J test, while 60% of the bovine- and 84% of the ovine-culture-positive samples were positive in the HT-J test. As similar total numbers of samples from M. avium subsp. paratuberculosis-exposed animals were positive in culture and HT-J tests in both species, and as the results of a McNemar's test were not significant, these methods probably have similar sensitivities, but the true diagnostic sensitivities of these tests are unknown. These validation data meet the consensus-based reporting standards for diagnostic test accuracy studies for paratuberculosis and the Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines (S. A. Bustin et al., Clin. Chem. 55:611–622, 2009, doi:10.1373/clinchem.2008.112797). The HT-J assay has been approved for use in JD control programs in Australia and New Zealand. PMID:24352996

The evolution of tumor metastases during clonal expansion.

PubMed

Haeno, Hiroshi; Michor, Franziska

2010-03-07

Cancer is a leading cause of morbidity and mortality in many countries. Solid tumors generally initiate at one particular site called the primary tumor, but eventually disseminate and form new colonies in other organs. The development of such metastases greatly diminishes the potential for a cure of patients and is thought to represent the final stage of the multi-stage progression of human cancer. The concept of early metastatic dissemination, however, postulates that cancer cell spread might arise early during the development of a tumor. It is important to know whether metastases are present at diagnosis since this determines treatment strategies and outcome. In this paper, we design a stochastic mathematical model of the evolution of tumor metastases in an expanding cancer cell population. We calculate the probability of metastasis at a given time during tumor evolution, the expected number of metastatic sites, and the total number of cancer cells as well as metastasized cells. Furthermore, we investigate the effect of drug administration and tumor resection on these quantities and predict the survival time of cancer patients. The model presented in this paper allows us to determine the probability and number of metastases at diagnosis and to identify the optimum treatment strategy to maximally prolong survival of cancer patients. 2009 Elsevier Ltd. All rights reserved.

[Analysis of X-Ray Fluorescence Spectroscopy and Plasma Mass Spectrometry of Pangxidong Composite Granitoid Pluton and Its Implications for Magmatic Differentiation].

PubMed

Zeng, Chang-yu; Ding, Ru-xin; Li, Hong-zhong; Zhou, Yong-zhang; Niu, Jia; Zhang, Jie-tang

2015-11-01

Pangxidong composite granitoid pluton located in the southwestern margin of Yunkai massif. The metamorphic grade of this pluton increases from outside to inside, that is, banded-augen granitic gneisses, gneissoid granites and granites distribute in order from edge to core. X-Ray Fluorescence Spectroscopy and Plasma Mass Spectrometry are conducted to study the geochemical characteristics of the three types of rocks. The result shows that all the three types of rocks are peraluminous rocks and their contents of main elements and rare earth elements change gradually. From granitic gneisses to granites, the contents of Al₂O₃, CaO, MgO, TiO₂, total rare earth elements and light rare earth elements increase, but the contents of SiO₂ and heavy rare earth elements decrease. It is suggested that the phylogenetic relationship exists between granitic gneisses, gneissoid granites and granites during the multi-stage tectonic evolution process. Furthermore, the remelting of metamorphosed supracrustal rocks in Yunkai massif is probably an important cause of granitoid rocks forming. The evolutionary mechanism is probably that SiO₂ and heavy rare earth elements were melt out from the protolith and gradually enriched upward, but Al₂O₃, CaO, MgO, TiO₂ and light rare earth elements enriched downward.

Catalytic multi-stage liquefaction of coal at HTI: Bench-scale studies in coal/waste plastics coprocessing

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

Pradhan, V.R.; Lee, L.K.; Stalzer, R.H.

1995-12-31

The development of Catalytic Multi-Stage Liquefaction (CMSL) at HTI has focused on both bituminous and sub-bituminous coals using laboratory, bench and PDU scale operations. The crude oil equivalent cost of liquid fuels from coal has been curtailed to about $30 per barrel, thus achieving over 30% reduction in the price that was evaluated for the liquefaction technologies demonstrated in the late seventies and early eighties. Contrary to the common belief, the new generation of catalytic multistage coal liquefaction process is environmentally very benign and can produce clean, premium distillates with a very low (<10ppm) heteroatoms content. The HTI Staff hasmore » been involved over the years in process development and has made significant improvements in the CMSL processing of coals. A 24 month program (extended to September 30, 1995) to study novel concepts, using a continuous bench scale Catalytic Multi-Stage unit (30kg coal/day), has been initiated since December, 1992. This program consists of ten bench-scale operations supported by Laboratory Studies, Modelling, Process Simulation and Economic Assessments. The Catalytic Multi-Stage Liquefaction is a continuation of the second generation yields using a low/high temperature approach. This paper covers work performed between October 1994- August 1995, especially results obtained from the microautoclave support activities and the bench-scale operations for runs CMSL-08 and CMSL-09, during which, coal and the plastic components for municipal solid wastes (MSW) such as high density polyethylene (HDPE)m, polypropylene (PP), polystyrene (PS), and polythylene terphthlate (PET) were coprocessed.« less

A Multi-Stage Longitudinal Comparative Design Stage II Evaluation of the Changing Lives Program: The Life Course Interview (RDA-LCI)

ERIC Educational Resources Information Center

Arango, Lisa Lewis; Kurtines, William M.; Montgomery, Marilyn J.; Ritchie, Rachel

2008-01-01

The study reported in this article, a Multi-Stage Longitudinal Comparative Design Stage II evaluation conducted as a planned preliminary efficacy evaluation (psychometric evaluation of measures, short-term controlled outcome studies, etc.) of the Changing Lives Program (CLP), provided evidence for the reliability and validity of the qualitative…

Interaction between Gaming and Multistage Guiding Strategies on Students' Field Trip Mobile Learning Performance and Motivation

ERIC Educational Resources Information Center

Chen, Chih-Hung; Liu, Guan-Zhi; Hwang, Gwo-Jen

2016-01-01

In this study, an integrated gaming and multistage guiding approach was proposed for conducting in-field mobile learning activities. A mobile learning system was developed based on the proposed approach. To investigate the interaction between the gaming and guiding strategies on students' learning performance and motivation, a 2 × 2 experiment was…

Suicide Prevention among High School Students: Evaluation of a Nonrandomized Trial of a Multi-Stage Suicide Screening Program

ERIC Educational Resources Information Center

Torcasso, Gina; Hilt, Lori M.

2017-01-01

Background: Suicide is a leading cause of death among youth. Suicide screening programs aim to identify mental health issues and prevent death by suicide. Objective: The present study evaluated outcomes of a multi-stage screening program implemented over 3 school years in a moderately-sized Midwestern high school. Methods: One hundred ninety-three…

Multi-stage flash degaser

DOEpatents

Rapier, Pascal M.

1982-01-01

A multi-stage flash degaser (18) is incorporated in an energy conversion system (10) having a direct-contact, binary-fluid heat exchanger to remove essentially all of the noncondensable gases from geothermal brine ahead of the direct-contact binary-fluid heat exchanger (22) in order that the heat exchanger (22) and a turbine (48) and condenser (32) of the system (10) can operate at optimal efficiency.

Analysis of non-enzymatically glycated peptides: neutral-loss-triggered MS3 versus multi-stage activation tandem mass spectrometry

PubMed Central

Zhang, Qibin; Petyuk, Vladislav A.; Schepmoes, Athena A.; Orton, Daniel J.; Monroe, Matthew E.; Yang, Feng; Smith, Richard D.; Metz, Thomas O.

2009-01-01

Non-enzymatic glycation of tissue proteins has important implications in the development of complications of diabetes mellitus. While electron transfer dissociation (ETD) has been shown to outperform collision-induced dissociation (CID) in sequencing glycated peptides by tandem mass spectrometry, ETD instrumentation is not yet widely available and often suffers from significantly lower sensitivity than CID. In this study, we evaluated different advanced CID techniques (i.e., neutral-loss-triggered MS3 and multi-stage activation) during liquid chromatography/multi-stage mass spectrometric (LC/MSn) analyses of Amadori-modified peptides enriched from human serum glycated in vitro. During neutral-loss-triggered MS3 experiments, MS3 scans triggered by neutral losses of 3 H2O or 3 H2O + HCHO produced similar results in terms of glycated peptide identifications. However, neutral losses of 3 H2O resulted in significantly more glycated peptide identifications during multi-stage activation experiments. Overall, the multi-stage activation approach produced more glycated peptide identifications, while the neutral-loss-triggered MS3 approach resulted in much higher specificity. Both techniques are viable alternatives to ETD for identifying glycated peptides. PMID:18763275

Design of the South East Asian Nutrition Survey (SEANUTS): a four-country multistage cluster design study.

PubMed

Schaafsma, Anne; Deurenberg, Paul; Calame, Wim; van den Heuvel, Ellen G H M; van Beusekom, Christien; Hautvast, Jo; Sandjaja; Bee Koon, Poh; Rojroongwasinkul, Nipa; Le Nguyen, Bao Khanh; Parikh, Panam; Khouw, Ilse

2013-09-01

Nutrition is a well-known factor in the growth, health and development of children. It is also acknowledged that worldwide many people have dietary imbalances resulting in over- or undernutrition. In 2009, the multinational food company FrieslandCampina initiated the South East Asian Nutrition Survey (SEANUTS), a combination of surveys carried out in Indonesia, Malaysia, Thailand and Vietnam, to get a better insight into these imbalances. The present study describes the general study design and methodology, as well as some problems and pitfalls encountered. In each of these countries, participants in the age range of 0·5-12 years were recruited according to a multistage cluster randomised or stratified random sampling methodology. Field teams took care of recruitment and data collection. For the health status of children, growth and body composition, physical activity, bone density, and development and cognition were measured. For nutrition, food intake and food habits were assessed by questionnaires, whereas in subpopulations blood and urine samples were collected to measure the biochemical status parameters of Fe, vitamins A and D, and DHA. In Thailand, the researchers additionally studied the lipid profile in blood, whereas in Indonesia iodine excretion in urine was analysed. Biochemical data were analysed in certified laboratories. Study protocols and methodology were aligned where practically possible. In December 2011, data collection was finalised. In total, 16,744 children participated in the present study. Information that will be very relevant for formulating nutritional health policies, as well as for designing innovative food and nutrition research and development programmes, has become available.

Health and human rights in Chin State, Western Burma: a population-based assessment using multistaged household cluster sampling.

PubMed

Sollom, Richard; Richards, Adam K; Parmar, Parveen; Mullany, Luke C; Lian, Salai Bawi; Iacopino, Vincent; Beyrer, Chris

2011-02-08

The Chin State of Burma (also known as Myanmar) is an isolated ethnic minority area with poor health outcomes and reports of food insecurity and human rights violations. We report on a population-based assessment of health and human rights in Chin State. We sought to quantify reported human rights violations in Chin State and associations between these reported violations and health status at the household level. Multistaged household cluster sampling was done. Heads of household were interviewed on demographics, access to health care, health status, food insecurity, forced displacement, forced labor, and other human rights violations during the preceding 12 months. Ratios of the prevalence of household hunger comparing exposed and unexposed to each reported violation were estimated using binomial regression, and 95% confidence intervals (CIs) were constructed. Multivariate models were done to adjust for possible confounders. Overall, 91.9% of households (95% CI 89.7%-94.1%) reported forced labor in the past 12 months. Forty-three percent of households met FANTA-2 (Food and Nutrition Technical Assistance II project) definitions for moderate to severe household hunger. Common violations reported were food theft, livestock theft or killing, forced displacement, beatings and torture, detentions, disappearances, and religious and ethnic persecution. Self reporting of multiple rights abuses was independently associated with household hunger. Our findings indicate widespread self-reports of human rights violations. The nature and extent of these violations may warrant investigation by the United Nations or International Criminal Court. Please see later in the article for the Editors' Summary.

Health and Human Rights in Chin State, Western Burma: A Population-Based Assessment Using Multistaged Household Cluster Sampling

PubMed Central

Sollom, Richard; Richards, Adam K.; Parmar, Parveen; Mullany, Luke C.; Lian, Salai Bawi; Iacopino, Vincent; Beyrer, Chris

2011-01-01

Background The Chin State of Burma (also known as Myanmar) is an isolated ethnic minority area with poor health outcomes and reports of food insecurity and human rights violations. We report on a population-based assessment of health and human rights in Chin State. We sought to quantify reported human rights violations in Chin State and associations between these reported violations and health status at the household level. Methods and Findings Multistaged household cluster sampling was done. Heads of household were interviewed on demographics, access to health care, health status, food insecurity, forced displacement, forced labor, and other human rights violations during the preceding 12 months. Ratios of the prevalence of household hunger comparing exposed and unexposed to each reported violation were estimated using binomial regression, and 95% confidence intervals (CIs) were constructed. Multivariate models were done to adjust for possible confounders. Overall, 91.9% of households (95% CI 89.7%–94.1%) reported forced labor in the past 12 months. Forty-three percent of households met FANTA-2 (Food and Nutrition Technical Assistance II project) definitions for moderate to severe household hunger. Common violations reported were food theft, livestock theft or killing, forced displacement, beatings and torture, detentions, disappearances, and religious and ethnic persecution. Self reporting of multiple rights abuses was independently associated with household hunger. Conclusions Our findings indicate widespread self-reports of human rights violations. The nature and extent of these violations may warrant investigation by the United Nations or International Criminal Court. Please see later in the article for the Editors' Summary PMID:21346799

Stator Indexing in Multistage Compressors

NASA Technical Reports Server (NTRS)

Barankiewicz, Wendy S.

1997-01-01

The relative circumferential location of stator rows (stator indexing) is an aspect of multistage compressor design that has not yet been explored for its potential impact on compressor aerodynamic performance. Although the inlet stages of multistage compressors usually have differing stator blade counts, the aft stages of core compressors can often have stage blocks with equal stator blade counts in successive stages. The potential impact of stator indexing is likely greatest in these stages. To assess the performance impact of stator indexing, researchers at the NASA Lewis Research Center used the 4 ft diameter, four-stage NASA Low Speed Axial Compressor for detailed experiments. This compressor has geometrically identical stages that can circumferentially index stator rows relative to each other in a controlled manner; thus it is an ideal test rig for such investigations.

Calculation of recovery plasticity in multistage hot forging under isothermal conditions.

PubMed

Zhbankov, Iaroslav G; Perig, Alexander V; Aliieva, Leila I

2016-01-01

A widely used method for hot forming steels and alloys, especially heavy forging, is the process of multistage forging with pauses between stages. The well-known effect which accompanies multistage hot forging is metal plasticity recovery in comparison with monotonic deformation. A method which takes into consideration the recovery of plasticity in pauses between hot deformations of a billet under isothermal conditions is proposed. This method allows the prediction of billet forming limits as a function of deformation during the forging stage and the duration of the pause between the stages. This method takes into account the duration of pauses between deformations and the magnitude of subdivided deformations. A hot isothermal upsetting process with pauses was calculated by the proposed method. Results of the calculations have been confirmed with experimental data.

Statistical methods for efficient design of community surveys of response to noise: Random coefficients regression models

NASA Technical Reports Server (NTRS)

Tomberlin, T. J.

1985-01-01

Research studies of residents' responses to noise consist of interviews with samples of individuals who are drawn from a number of different compact study areas. The statistical techniques developed provide a basis for those sample design decisions. These techniques are suitable for a wide range of sample survey applications. A sample may consist of a random sample of residents selected from a sample of compact study areas, or in a more complex design, of a sample of residents selected from a sample of larger areas (e.g., cities). The techniques may be applied to estimates of the effects on annoyance of noise level, numbers of noise events, the time-of-day of the events, ambient noise levels, or other factors. Methods are provided for determining, in advance, how accurately these effects can be estimated for different sample sizes and study designs. Using a simple cost function, they also provide for optimum allocation of the sample across the stages of the design for estimating these effects. These techniques are developed via a regression model in which the regression coefficients are assumed to be random, with components of variance associated with the various stages of a multi-stage sample design.

II. MORE THAN JUST CONVENIENT: THE SCIENTIFIC MERITS OF HOMOGENEOUS CONVENIENCE SAMPLES.

PubMed

Jager, Justin; Putnick, Diane L; Bornstein, Marc H

2017-06-01

Despite their disadvantaged generalizability relative to probability samples, nonprobability convenience samples are the standard within developmental science, and likely will remain so because probability samples are cost-prohibitive and most available probability samples are ill-suited to examine developmental questions. In lieu of focusing on how to eliminate or sharply reduce reliance on convenience samples within developmental science, here we propose how to augment their advantages when it comes to understanding population effects as well as subpopulation differences. Although all convenience samples have less clear generalizability than probability samples, we argue that homogeneous convenience samples have clearer generalizability relative to conventional convenience samples. Therefore, when researchers are limited to convenience samples, they should consider homogeneous convenience samples as a positive alternative to conventional (or heterogeneous) convenience samples. We discuss future directions as well as potential obstacles to expanding the use of homogeneous convenience samples in developmental science. © 2017 The Society for Research in Child Development, Inc.

Nonprobability and probability-based sampling strategies in sexual science.

PubMed

Catania, Joseph A; Dolcini, M Margaret; Orellana, Roberto; Narayanan, Vasudah

2015-01-01

With few exceptions, much of sexual science builds upon data from opportunistic nonprobability samples of limited generalizability. Although probability-based studies are considered the gold standard in terms of generalizability, they are costly to apply to many of the hard-to-reach populations of interest to sexologists. The present article discusses recent conclusions by sampling experts that have relevance to sexual science that advocates for nonprobability methods. In this regard, we provide an overview of Internet sampling as a useful, cost-efficient, nonprobability sampling method of value to sex researchers conducting modeling work or clinical trials. We also argue that probability-based sampling methods may be more readily applied in sex research with hard-to-reach populations than is typically thought. In this context, we provide three case studies that utilize qualitative and quantitative techniques directed at reducing limitations in applying probability-based sampling to hard-to-reach populations: indigenous Peruvians, African American youth, and urban men who have sex with men (MSM). Recommendations are made with regard to presampling studies, adaptive and disproportionate sampling methods, and strategies that may be utilized in evaluating nonprobability and probability-based sampling methods.

Research on Aero-Thermodynamic Distortion Induced Structural Dynamic Response of Multi-Stage Compressor Blading.

DTIC Science & Technology

1988-01-15

However. only very engineering limited experimental data exists to assess the Director, Thermal Sciences and range of validity and to direct the... experimental results of Goldstein et. al. "A 1111 and also the Navier Stokes numerical solutions of Morihara 1121. Diffuser The predicted stream function...Unsteady Aerodynamic Interactions in a Multistage Compressor............................................................ 53 I APPENDIX VI. Experimental

Body Mass and Circumference of Upper Arm Are Associated with Race Performance in Ultraendurance Runners in a Multistage Race--The Isarrun 2006

ERIC Educational Resources Information Center

Knechtle, Beat; Duff, Brida; Welzel, Ulrich; Kohler, Gotz

2009-01-01

In the present study, we investigated the association of anthropometric parameters with race performance in ultraendurance runners in a multistage ultraendurance run, in which athletes had to run 338 km within 5 consecutive days. In 17 male successful finishers, calculations of body mass, body height, skinfold thicknesses, extremity circumference,…

Multistage aerospace craft. [perspective drawings of conceptual design

NASA Technical Reports Server (NTRS)

Kelly, D. L. (Inventor)

1973-01-01

A conceptual design of a multi-stage aerospace craft is presented. Two perspective views of the vehicle are developed to show the two component configuration with delta wing, four vertical tail surfaces, tricycle landing gear, and two rocket exhaust nozzles at the rear of the fuselage. Engines for propulsion in the atmosphere are mounted on the fuselage in front of the wing root attachment.

Preliminary Experience with High Response Pressure Measurements in a Multistage, High Speed Compressor

DTIC Science & Technology

1988-05-01

MEASUREMENTS IN A MULTISTAGE, HIGH SPEED COMPRESSOR by M. A. Cherrett J. D. Bryce SUMMARY The investigation of unsteady aerodynamic phenomena within high...X Vli 1. Siurii-nue. Initials 9Ia. Author 2 9b. Authors 3. 4 ... 10. Date l’ag,- ReI\\ ’ Cherrett , M.A. Bryce, J.D. May i 4 1988 4 It I

The task of validation of gas-dynamic characteristics of a multistage centrifugal compressor for a natural gas booster compressor station

NASA Astrophysics Data System (ADS)

Danilishin, A. M.; Kozhukhov, Y. V.; Neverov, V. V.; Malev, K. G.; Mironov, Y. R.

2017-08-01

The aim of this work is the validation study for the numerical modeling of characteristics of a multistage centrifugal compressor for natural gas. In the research process was the analysis used grid interfaces and software systems. The result revealed discrepancies between the simulated and experimental characteristics and outlined the future work plan.

Ram-air sample collection device for a chemical warfare agent sensor

DOEpatents

Megerle, Clifford A.; Adkins, Douglas R.; Frye-Mason, Gregory C.

2002-01-01

In a surface acoustic wave sensor mounted within a body, the sensor having a surface acoustic wave array detector and a micro-fabricated sample preconcentrator exposed on a surface of the body, an apparatus for collecting air for the sensor, comprising a housing operatively arranged to mount atop the body, the housing including a multi-stage channel having an inlet and an outlet, the channel having a first stage having a first height and width proximate the inlet, a second stage having a second lower height and width proximate the micro-fabricated sample preconcentrator, a third stage having a still lower third height and width proximate the surface acoustic wave array detector, and a fourth stage having a fourth height and width proximate the outlet, where the fourth height and width are substantially the same as the first height and width.

Remote sensing-aided systems for snow qualification, evapotranspiration estimation, and their application in hydrologic models

NASA Technical Reports Server (NTRS)

Korram, S.

1977-01-01

The design of general remote sensing-aided methodologies was studied to provide the estimates of several important inputs to water yield forecast models. These input parameters are snow area extent, snow water content, and evapotranspiration. The study area is Feather River Watershed (780,000 hectares), Northern California. The general approach involved a stepwise sequence of identification of the required information, sample design, measurement/estimation, and evaluation of results. All the relevent and available information types needed in the estimation process are being defined. These include Landsat, meteorological satellite, and aircraft imagery, topographic and geologic data, ground truth data, and climatic data from ground stations. A cost-effective multistage sampling approach was employed in quantification of all the required parameters. The physical and statistical models for both snow quantification and evapotranspiration estimation was developed. These models use the information obtained by aerial and ground data through appropriate statistical sampling design.

Stackable differential mobility analyzer for aerosol measurement

DOEpatents

Cheng, Meng-Dawn [Oak Ridge, TN; Chen, Da-Ren [Creve Coeur, MO

2007-05-08

A multi-stage differential mobility analyzer (MDMA) for aerosol measurements includes a first electrode or grid including at least one inlet or injection slit for receiving an aerosol including charged particles for analysis. A second electrode or grid is spaced apart from the first electrode. The second electrode has at least one sampling outlet disposed at a plurality different distances along its length. A volume between the first and the second electrode or grid between the inlet or injection slit and a distal one of the plurality of sampling outlets forms a classifying region, the first and second electrodes for charging to suitable potentials to create an electric field within the classifying region. At least one inlet or injection slit in the second electrode receives a sheath gas flow into an upstream end of the classifying region, wherein each sampling outlet functions as an independent DMA stage and classifies different size ranges of charged particles based on electric mobility simultaneously.

The development of deep karst in the anticlinal aquifer structure based on the coupling of multistage flow systems

NASA Astrophysics Data System (ADS)

Xu, M.; Zhong, L.; Yang, Y.

2017-12-01

Under the background of neotectonics, the multistage underground flow system has been form due the different responses of main stream and tributaries to crust uplift. The coupling of multistage underground flow systems influences the development of karst thoroughly. At first, the research area is divided into vadose area, shunted area and exorheic area based on the development characteristics of transverse valley. Combining the controlling-drain action with topographic index and analyzing the coupling features of multistage underground flow system. And then, based on the coupling of multistage underground flow systems, the characteristics of deep karst development were verified by the lossing degree of surface water, water bursting and karst development characteristics of tunnels. The vadose area is regional water system based, whose deep karst developed well. It resulted the large water inflow of tunnels and the surface water drying up. The shunted area, except the region near the transverse valleys, is characterized by regional water system. The developed deep karst make the surface water connect with deep ground water well, Which caused the relatively large water flow of tunnels and the serious leakage of surface water. The deep karst relatively developed poor in the regions near transverse valleys which is characterized by local water system. The exorheic area is local water system based, whose the deep karst developed poor, as well as the connection among surface water and deep ground water. It has result in the poor lossing of the surface water under the tunnel construction. This study broadens the application field of groundwater flow systems theory, providing a new perspective for the study of Karst development theory. Meanwhile it provides theoretical guidance for hazard assessment and environmental negative effect in deep-buried Karst tunnel construction.

Long-term Outcomes With Planned Multistage Reduced Dose Repeat Stereotactic Radiosurgery for Treatment of Inoperable High-Grade Arteriovenous Malformations: An Observational Retrospective Cohort Study.

PubMed

Marciscano, Ariel E; Huang, Judy; Tamargo, Rafael J; Hu, Chen; Khattab, Mohamed H; Aggarwal, Sameer; Lim, Michael; Redmond, Kristin J; Rigamonti, Daniele; Kleinberg, Lawrence R

2017-07-01

There is no consensus regarding the optimal management of inoperable high-grade arteriovenous malformations (AVMs). This long-term study of 42 patients with high-grade AVMs reports obliteration and adverse event (AE) rates using planned multistage repeat stereotactic radiosurgery (SRS). To evaluate the efficacy and safety of multistage SRS with treatment of the entire AVM nidus at each treatment session to achieve complete obliteration of high-grade AVMs. Patients with high-grade Spetzler-Martin (S-M) III-V AVMs treated with at least 2 multistage SRS treatments from 1989 to 2013. Clinical outcomes of obliteration rate, minor/major AEs, and treatment characteristics were collected. Forty-two patients met inclusion criteria (n = 26, S-M III; n = 13, S-M IV; n = 3, S-M V) with a median follow-up was 9.5 yr after first SRS. Median number of SRS treatment stages was 2, and median interval between stages was 3.5 yr. Twenty-two patients underwent pre-SRS embolization. Complete AVM obliteration rate was 38%, and the median time to obliteration was 9.7 yr. On multivariate analysis, higher S-M grade was significantly associated ( P = .04) failure to achieve obliteration. Twenty-seven post-SRS AEs were observed, and the post-SRS intracranial hemorrhage rate was 0.027 events per patient year. Treatment of high-grade AVMs with multistage SRS achieves AVM obliteration in a meaningful proportion of patients with acceptable AE rates. Lower obliteration rates were associated with higher S-M grade and pre-SRS embolization. This approach should be considered with caution, as partial obliteration does not protect from hemorrhage. Copyright © 2017 by the Congress of Neurological Surgeons

Importance Sampling in the Evaluation and Optimization of Buffered Failure Probability

DTIC Science & Technology

2015-07-01

12th International Conference on Applications of Statistics and Probability in Civil Engineering, ICASP12 Vancouver, Canada, July 12-15, 2015...Importance Sampling in the Evaluation and Optimization of Buffered Failure Probability Marwan M. Harajli Graduate Student, Dept. of Civil and Environ...criterion is usually the failure probability . In this paper, we examine the buffered failure probability as an attractive alternative to the failure

Multi-stage mixing in subduction zone: Application to Merapi volcano, Indonesia

NASA Astrophysics Data System (ADS)

Debaille, V.; Doucelance, R.; Weis, D.; Schiano, P.

2003-04-01

Basalts sampling subduction zone volcanism (IAB) often show binary mixing relationship in classical Sr-Nd, Pb-Pb, Sr-Pb isotopic diagrams, generally interpreted as reflecting the involvement of two components in their source. However, several authors have highlighted the presence of minimum three components in such a geodynamical context: mantle wedge, subducted and altered oceanic crust and subducted sediments. The overlying continental crust can also contribute by contamination and assimilation in magma chambers and/or during magma ascent. Here we present a multi-stage model to obtain a two end-member mixing from three components (mantle wedge, altered oceanic crust and sediments). The first stage of the model considers the metasomatism of the mantle wedge by fluids and/or melts released by subducted materials (altered oceanic crust and associated sediments), considering mobility and partition coefficient of trace elements in hydrated fluids and silicate melts. This results in the generation of two distinct end-members, reducing the number of components (mantle wedge, oceanic crust, sediments) from three to two. The second stage of the model concerns the binary mixing of the two end-members thus defined: mantle wedge metasomatized by slab-derived fluids and mantle wedge metasomatized by sediment-derived fluids. This model has been applied on a new isotopic data set (Sr, Nd and Pb, analyzed by TIMS and MC-ICP-MS) of Merapi volcano (Java island, Indonesia). Previous studies have suggested three distinct components in the source of indonesian lavas: mantle wedge, subducted sediments and altered oceanic crust. Moreover, it has been shown that crustal contamination does not significantly affect isotopic ratios of lavas. The multi-stage model proposed here is able to reproduce the binary mixing observed in lavas of Merapi, and a set of numerical values of bulk partition coefficient is given that accounts for the genesis of lavas.

Performance Improvement of a Return Channel in a Multistage Centrifugal Compressor Using Multiobjective Optimization.

PubMed

Nishida, Yoshifumi; Kobayashi, Hiromi; Nishida, Hideo; Sugimura, Kazuyuki

2013-05-01

The effect of the design parameters of a return channel on the performance of a multistage centrifugal compressor was numerically investigated, and the shape of the return channel was optimized using a multiobjective optimization method based on a genetic algorithm to improve the performance of the centrifugal compressor. The results of sensitivity analysis using Latin hypercube sampling suggested that the inlet-to-outlet area ratio of the return vane affected the total pressure loss in the return channel, and that the inlet-to-outlet radius ratio of the return vane affected the outlet flow angle from the return vane. Moreover, this analysis suggested that the number of return vanes affected both the loss and the flow angle at the outlet. As a result of optimization, the number of return vane was increased from 14 to 22 and the area ratio was decreased from 0.71 to 0.66. The radius ratio was also decreased from 2.1 to 2.0. Performance tests on a centrifugal compressor with two return channels (the original design and optimized design) were carried out using two-stage test apparatus. The measured flow distribution exhibited a swirl flow in the center region and a reversed swirl flow near the hub and shroud sides. The exit flow of the optimized design was more uniform than that of the original design. For the optimized design, the overall two-stage efficiency and pressure coefficient were increased by 0.7% and 1.5%, respectively. Moreover, the second-stage efficiency and pressure coefficient were respectively increased by 1.0% and 3.2%. It is considered that the increase in the second-stage efficiency was caused by the increased uniformity of the flow, and the rise in the pressure coefficient was caused by a decrease in the residual swirl flow. It was thus concluded from the numerical and experimental results that the optimized return channel improved the performance of the multistage centrifugal compressor.

Multistage Schemes with Multigrid for Euler and Navier-Strokes Equations: Components and Analysis

NASA Technical Reports Server (NTRS)

Swanson, R. C.; Turkel, Eli

1997-01-01

A class of explicit multistage time-stepping schemes with centered spatial differencing and multigrids are considered for the compressible Euler and Navier-Stokes equations. These schemes are the basis for a family of computer programs (flow codes with multigrid (FLOMG) series) currently used to solve a wide range of fluid dynamics problems, including internal and external flows. In this paper, the components of these multistage time-stepping schemes are defined, discussed, and in many cases analyzed to provide additional insight into their behavior. Special emphasis is given to numerical dissipation, stability of Runge-Kutta schemes, and the convergence acceleration techniques of multigrid and implicit residual smoothing. Both the Baldwin and Lomax algebraic equilibrium model and the Johnson and King one-half equation nonequilibrium model are used to establish turbulence closure. Implementation of these models is described.

Multi-stage learning aids applied to hands-on software training.

PubMed

Rother, Kristian; Rother, Magdalena; Pleus, Alexandra; Upmeier zu Belzen, Annette

2010-11-01

Delivering hands-on tutorials on bioinformatics software and web applications is a challenging didactic scenario. The main reason is that trainees have heterogeneous backgrounds, different previous knowledge and vary in learning speed. In this article, we demonstrate how multi-stage learning aids can be used to allow all trainees to progress at a similar speed. In this technique, the trainees can utilize cards with hints and answers to guide themselves self-dependently through a complex task. We have successfully conducted a tutorial for the molecular viewer PyMOL using two sets of learning aid cards. The trainees responded positively, were able to complete the task, and the trainer had spare time to respond to individual questions. This encourages us to conclude that multi-stage learning aids overcome many disadvantages of established forms of hands-on software training.

Multi-stage classification method oriented to aerial image based on low-rank recovery and multi-feature fusion sparse representation.

PubMed

Ma, Xu; Cheng, Yongmei; Hao, Shuai

2016-12-10

Automatic classification of terrain surfaces from an aerial image is essential for an autonomous unmanned aerial vehicle (UAV) landing at an unprepared site by using vision. Diverse terrain surfaces may show similar spectral properties due to the illumination and noise that easily cause poor classification performance. To address this issue, a multi-stage classification algorithm based on low-rank recovery and multi-feature fusion sparse representation is proposed. First, color moments and Gabor texture feature are extracted from training data and stacked as column vectors of a dictionary. Then we perform low-rank matrix recovery for the dictionary by using augmented Lagrange multipliers and construct a multi-stage terrain classifier. Experimental results on an aerial map database that we prepared verify the classification accuracy and robustness of the proposed method.

Influence of spatial beam inhomogeneities on the parameters of a petawatt laser system based on multi-stage parametric amplification

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

Frolov, S A; Trunov, V I; Pestryakov, Efim V

2013-05-31

We have developed a technique for investigating the evolution of spatial inhomogeneities in high-power laser systems based on multi-stage parametric amplification. A linearised model of the inhomogeneity development is first devised for parametric amplification with the small-scale self-focusing taken into account. It is shown that the application of this model gives the results consistent (with high accuracy and in a wide range of inhomogeneity parameters) with the calculation without approximations. Using the linearised model, we have analysed the development of spatial inhomogeneities in a petawatt laser system based on multi-stage parametric amplification, developed at the Institute of Laser Physics, Siberianmore » Branch of the Russian Academy of Sciences (ILP SB RAS). (control of laser radiation parameters)« less

Remote sensing advances in agricultural inventories

NASA Technical Reports Server (NTRS)

Dragg, J. L.; Bizzell, R. M.; Trichel, M. C.; Hatch, R. E.; Phinney, D. E.; Baker, T. C.

1984-01-01

As the complexity of the world's agricultural industry increases, more timely and more accurate world-wide agricultural information is required to support production and marketing decisions, policy formulation, and technology development. The Inventory Technology Development Project of the AgRISTARS Program has developed new automated technology that uses data sets acquired by spaceborne remote sensors. Research has emphasized the development of multistage, multisensor sampling and estimation techniques for use in global environments where reliable ground observations are not available. This paper presents research results obtained from data sets acquired by four different sensors: Landsat MSS, Landsat TM, Shuttle-Imaging Radar and environmental satellite (AVHRR).

Prayer Attendance and General Health in the Iranian Adult Urban Population.

PubMed

Sotodehasl, Nemat; Ghorbani, Raheb; Mahdavi-Nejad, Gholamhosein; Haji-Aghajani, Saeed; Mehdizadeh, Jamileh

2016-02-01

This study was conducted to determine the relationship between prayer attendance and general health among adult urban population in Iran. A total of 470 males older than 17 years, chosen by multistage sampling, were investigated. The results showed that people who did not perform prayers compared to those who said prayers on time and performed Nafilahs (supererogatory prayers) were 2.87 (OR 2.87, 95 % CI 1.23-6.70, p = 0.015) times at risk of general health problems. In conclusion, the findings show that increasing the degree of people's belief in prayer can lead to improve general health.

Enzyme-regulated the changes of pH values for assembling a colorimetric and multistage interconnection logic network with multiple readouts.

PubMed

Huang, Yanyan; Ran, Xiang; Lin, Youhui; Ren, Jinsong; Qu, Xiaogang

2015-04-22

Based on enzymatic reactions-triggered changes of pH values and biocomputing, a novel and multistage interconnection biological network with multiple easy-detectable signal outputs has been developed. Compared with traditional chemical computing, the enzyme-based biological system could overcome the interference between reactions or the incompatibility of individual computing gates and offer a unique opportunity to assemble multicomponent/multifunctional logic circuitries. Our system included four enzyme inputs: β-galactosidase (β-gal), glucose oxidase (GOx), esterase (Est) and urease (Ur). With the assistance of two signal transducers (gold nanoparticles and acid-base indicators) or pH meter, the outputs of the biological network could be conveniently read by the naked eyes. In contrast to current methods, the approach present here could realize cost-effective, label-free and colorimetric logic operations without complicated instrument. By designing a series of Boolean logic operations, we could logically make judgment of the compositions of the samples on the basis of visual output signals. Our work offered a promising paradigm for future biological computing technology and might be highly useful in future intelligent diagnostics, prodrug activation, smart drug delivery, process control, and electronic applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Handwritten numeral databases of Indian scripts and multistage recognition of mixed numerals.

PubMed

Bhattacharya, Ujjwal; Chaudhuri, B B

2009-03-01

This article primarily concerns the problem of isolated handwritten numeral recognition of major Indian scripts. The principal contributions presented here are (a) pioneering development of two databases for handwritten numerals of two most popular Indian scripts, (b) a multistage cascaded recognition scheme using wavelet based multiresolution representations and multilayer perceptron classifiers and (c) application of (b) for the recognition of mixed handwritten numerals of three Indian scripts Devanagari, Bangla and English. The present databases include respectively 22,556 and 23,392 handwritten isolated numeral samples of Devanagari and Bangla collected from real-life situations and these can be made available free of cost to researchers of other academic Institutions. In the proposed scheme, a numeral is subjected to three multilayer perceptron classifiers corresponding to three coarse-to-fine resolution levels in a cascaded manner. If rejection occurred even at the highest resolution, another multilayer perceptron is used as the final attempt to recognize the input numeral by combining the outputs of three classifiers of the previous stages. This scheme has been extended to the situation when the script of a document is not known a priori or the numerals written on a document belong to different scripts. Handwritten numerals in mixed scripts are frequently found in Indian postal mails and table-form documents.

[Tobacco, alcohol, and drug use by teenagers in Pelotas, Rio Grande do Sul State, Brazil: a gender approach].

PubMed

Horta, Rogério Lessa; Horta, Bernardo Lessa; Pinheiro, Ricardo Tavares; Morales, Blanca; Strey, Marlene Neves

2007-04-01

This study assesses the relationship between gender and use of psychoactive substances (alcohol, nicotine, and illicit drugs) by teenagers. In 2002, a cross-sectional study was carried out in the urban area of Pelotas, southern Brazil. Multi-stage sampling was used to obtain a sample of adolescents, 15 to 18 years of age. Subjects were interviewed using a self-applied confidential questionnaire. Smoking was more prevalent among girls, while alcohol consumption in the previous month was more common among boys. Meanwhile, the proportion of adolescents that reported drug use in the previous month was unrelated to gender. Higher cigarette consumption by girls suggests an increase in smoking by women in the future, which highlights the need for a special focus on this area.

Variability of Mercury Content in Coal Matter From Coal Seams of The Upper Silesia Coal Basin

NASA Astrophysics Data System (ADS)

Wierzchowski, Krzysztof; Chećko, Jarosław; Pyka, Ireneusz

2017-12-01

The process of identifying and documenting the quality parameters of coal, as well as the conditions of coal deposition in the seam, is multi-stage and extremely expensive. The taking and analyzing of seam samples is the method of assessment of the quality and quantity parameters of coals in deep mines. Depending on the method of sampling, it offers quite precise assessment of the quality parameters of potential commercial coals. The main kind of seam samples under consideration are so-called "documentary seam samples", which exclude dirt bands and other seam contaminants. Mercury content in coal matter from the currently accessible and exploited coal seams of the Upper Silesian Coal Basin (USCB) was assessed. It was noted that the mercury content in coal seams decreases with the age of the seam and, to a lesser extent, seam deposition depth. Maps of the variation of mercury content in selected lithostratigraphic units (layers) of the Upper Silesian Coal Basin have been created.

A Comparison of EPI Sampling, Probability Sampling, and Compact Segment Sampling Methods for Micro and Small Enterprises

PubMed Central

Chao, Li-Wei; Szrek, Helena; Peltzer, Karl; Ramlagan, Shandir; Fleming, Peter; Leite, Rui; Magerman, Jesswill; Ngwenya, Godfrey B.; Pereira, Nuno Sousa; Behrman, Jere

2011-01-01

Finding an efficient method for sampling micro- and small-enterprises (MSEs) for research and statistical reporting purposes is a challenge in developing countries, where registries of MSEs are often nonexistent or outdated. This lack of a sampling frame creates an obstacle in finding a representative sample of MSEs. This study uses computer simulations to draw samples from a census of businesses and non-businesses in the Tshwane Municipality of South Africa, using three different sampling methods: the traditional probability sampling method, the compact segment sampling method, and the World Health Organization’s Expanded Programme on Immunization (EPI) sampling method. Three mechanisms by which the methods could differ are tested, the proximity selection of respondents, the at-home selection of respondents, and the use of inaccurate probability weights. The results highlight the importance of revisits and accurate probability weights, but the lesser effect of proximity selection on the samples’ statistical properties. PMID:22582004

Multi-stage depressed collector for small orbit gyrotrons

DOEpatents

Singh, Amarjit; Ives, R. Lawrence; Schumacher, Richard V.; Mizuhara, Yosuke M.

1998-01-01

A multi-stage depressed collector for receiving energy from a small orbit gyrating electron beam employs a plurality of electrodes at different potentials for sorting the individual electrons on the basis of their total energy level. Magnetic field generating coils, for producing magnetic fields and magnetic iron for magnetic field shaping produce adiabatic and controlled non-adiabatic transitions of the incident electron beam to further facilitate the sorting.

Multi-stage depressed collector for small orbit gyrotrons

DOEpatents

Singh, A.; Ives, R.L.; Schumacher, R.V.; Mizuhara, Y.M.

1998-07-14

A multi-stage depressed collector for receiving energy from a small orbit gyrating electron beam employs a plurality of electrodes at different potentials for sorting the individual electrons on the basis of their total energy level. Magnetic field generating coils, for producing magnetic fields and magnetic iron for magnetic field shaping produce adiabatic and controlled non-adiabatic transitions of the incident electron beam to further facilitate the sorting. 9 figs.

Accuracy of a Classical Test Theory-Based Procedure for Estimating the Reliability of a Multistage Test. Research Report. ETS RR-17-02

ERIC Educational Resources Information Center

Kim, Sooyeon; Livingston, Samuel A.

2017-01-01

The purpose of this simulation study was to assess the accuracy of a classical test theory (CTT)-based procedure for estimating the alternate-forms reliability of scores on a multistage test (MST) having 3 stages. We generated item difficulty and discrimination parameters for 10 parallel, nonoverlapping forms of the complete 3-stage test and…

The automated multi-stage substructuring system for NASTRAN

NASA Technical Reports Server (NTRS)

Field, E. I.; Herting, D. N.; Herendeen, D. L.; Hoesly, R. L.

1975-01-01

The substructuring capability developed for eventual installation in Level 16 is now operational in a test version of NASTRAN. Its features are summarized. These include the user-oriented, Case Control type control language, the automated multi-stage matrix processing, the independent direct access data storage facilities, and the static and normal modes solution capabilities. A complete problem analysis sequence is presented with card-by-card description of the user input.

Multi-stage, isothermal CO preferential oxidation reactor

DOEpatents

Skala, Glenn William; Brundage, Mark A.; Borup, Rodney Lynn; Pettit, William Henry; Stukey, Kevin; Hart-Predmore, David James; Fairchok, Joel

2000-01-01

A multi-stage, isothermal, carbon monoxide preferential oxidation (PrOx) reactor comprising a plurality of serially arranged, catalyzed heat exchangers, each separated from the next by a mixing chamber for homogenizing the gases exiting one heat exchanger and entering the next. In a preferred embodiment, at least some of the air used in the PrOx reaction is injected directly into the mixing chamber between the catalyzed heat exchangers.

Multistage Adaptive Testing for a Large-Scale Classification Test: Design, Heuristic Assembly, and Comparison with Other Testing Modes. ACT Research Report Series, 2012 (6)

ERIC Educational Resources Information Center

Zheng, Yi; Nozawa, Yuki; Gao, Xiaohong; Chang, Hua-Hua

2012-01-01

Multistage adaptive tests (MSTs) have gained increasing popularity in recent years. MST is a balanced compromise between linear test forms (i.e., paper-and-pencil testing and computer-based testing) and traditional item-level computer-adaptive testing (CAT). It combines the advantages of both. On one hand, MST is adaptive (and therefore more…

A multistage decision support framework to guide tree species management under climate change via habitat suitability and colonization models, and a knowledge-based scoring system

Treesearch

Anantha M. Prasad; Louis R. Iverson; Stephen N. Matthews; Matthew P. Peters

2016-01-01

Context. No single model can capture the complex species range dynamics under changing climates--hence the need for a combination approach that addresses management concerns. Objective. A multistage approach is illustrated to manage forested landscapes under climate change. We combine a tree species habitat model--DISTRIB II, a species colonization model--SHIFT, and...

Effect of proton-conduction in electrolyte on electric efficiency of multi-stage solid oxide fuel cells

PubMed Central

Matsuzaki, Yoshio; Tachikawa, Yuya; Somekawa, Takaaki; Hatae, Toru; Matsumoto, Hiroshige; Taniguchi, Shunsuke; Sasaki, Kazunari

2015-01-01

Solid oxide fuel cells (SOFCs) are promising electrochemical devices that enable the highest fuel-to-electricity conversion efficiencies under high operating temperatures. The concept of multi-stage electrochemical oxidation using SOFCs has been proposed and studied over the past several decades for further improving the electrical efficiency. However, the improvement is limited by fuel dilution downstream of the fuel flow. Therefore, evolved technologies are required to achieve considerably higher electrical efficiencies. Here we present an innovative concept for a critically-high fuel-to-electricity conversion efficiency of up to 85% based on the lower heating value (LHV), in which a high-temperature multi-stage electrochemical oxidation is combined with a proton-conducting solid electrolyte. Switching a solid electrolyte material from a conventional oxide-ion conducting material to a proton-conducting material under the high-temperature multi-stage electrochemical oxidation mechanism has proven to be highly advantageous for the electrical efficiency. The DC efficiency of 85% (LHV) corresponds to a net AC efficiency of approximately 76% (LHV), where the net AC efficiency refers to the transmission-end AC efficiency. This evolved concept will yield a considerably higher efficiency with a much smaller generation capacity than the state-of-the-art several tens-of-MW-class most advanced combined cycle (MACC). PMID:26218470

Effect of proton-conduction in electrolyte on electric efficiency of multi-stage solid oxide fuel cells.

PubMed

Matsuzaki, Yoshio; Tachikawa, Yuya; Somekawa, Takaaki; Hatae, Toru; Matsumoto, Hiroshige; Taniguchi, Shunsuke; Sasaki, Kazunari

2015-07-28

Solid oxide fuel cells (SOFCs) are promising electrochemical devices that enable the highest fuel-to-electricity conversion efficiencies under high operating temperatures. The concept of multi-stage electrochemical oxidation using SOFCs has been proposed and studied over the past several decades for further improving the electrical efficiency. However, the improvement is limited by fuel dilution downstream of the fuel flow. Therefore, evolved technologies are required to achieve considerably higher electrical efficiencies. Here we present an innovative concept for a critically-high fuel-to-electricity conversion efficiency of up to 85% based on the lower heating value (LHV), in which a high-temperature multi-stage electrochemical oxidation is combined with a proton-conducting solid electrolyte. Switching a solid electrolyte material from a conventional oxide-ion conducting material to a proton-conducting material under the high-temperature multi-stage electrochemical oxidation mechanism has proven to be highly advantageous for the electrical efficiency. The DC efficiency of 85% (LHV) corresponds to a net AC efficiency of approximately 76% (LHV), where the net AC efficiency refers to the transmission-end AC efficiency. This evolved concept will yield a considerably higher efficiency with a much smaller generation capacity than the state-of-the-art several tens-of-MW-class most advanced combined cycle (MACC).

Performance Evaluation of Reduced-Chord Rotor Blading as Applied to J73 Two-Stage Turbine

NASA Technical Reports Server (NTRS)

Schurn, Harold J.

1957-01-01

The multistage turbine from the J73 turbojet engine has previously been investigated with standard and with reduced-chord rotor blading in order to determine the individual performance characteristics of each configuration over a range of over-all pressure ratio and speed. Because both turbine configurations exhibited peak efficiencies of over 90 percent, and because both units had relatively wide efficient operating ranges, it was considered of interest to determine the performance of the first stage of the turbine as a separate component. Accordingly, the standard-bladed multistage turbine was modified by removing the second-stage rotor disk and stator and altering the flow passage so that the first stage of the unit could be operated independently. The modified single-stage turbine was then operated over a range of stage pressure ratio and speed. The single-stage turbine operated at a peak brake internal efficiency of over 90 percent at an over-all stage pressure ratio of 1.4 and at 90 percent of design equivalent speed. Furthermore, the unit operated at high efficiencies over a relatively wide operating range. When the single-stage results were compared with the multistage results at the design operating point, it was found that the first stage produced approximately half the total multistage-turbine work output.

Methodology Series Module 5: Sampling Strategies.

PubMed

Setia, Maninder Singh

2016-01-01

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

Identification of a New Susceptibility Locus for Systemic Lupus Erythematosus on Chromosome 12 in Individuals of European Ancestry

PubMed Central

Demirci, F. Yesim; Wang, Xingbin; Kelly, Jennifer A.; Morris, David L.; Barmada, M. Michael; Feingold, Eleanor; Kao, Amy H.; Sivils, Kathy L.; Bernatsky, Sasha; Pineau, Christian; Clarke, Ann; Ramsey-Goldman, Rosalind; Vyse, Timothy J.; Gaffney, Patrick M.; Manzi, Susan; Kamboh, M. Ilyas

2016-01-01

Objective Genome-wide association studies (GWASs) in individuals of European ancestry identified a number of systemic lupus erythematosus (SLE) susceptibility loci using earlier versions of high-density genotyping platforms. Follow-up studies on suggestive GWAS regions using larger samples and more markers identified additional SLE loci in European-descent subjects. Here we report the results of a multi-stage study that we performed to identify novel SLE loci. Methods In Stage 1, we conducted a new GWAS of SLE in a North American case-control sample of European ancestry (n=1,166) genotyped on Affymetrix Genome-Wide Human SNP Array 6.0. In Stage 2, we further investigated top new suggestive GWAS hits by in silico evaluation and meta-analysis using an additional dataset of European-descent subjects (>2,500 individuals), followed by replication of top meta-analysis findings in another dataset of European-descent subjects (>10,000 individuals) in Stage 3. Results As expected, our GWAS revealed most significant associations at the major histocompatibility complex locus (6p21), which easily surpassed genome-wide significance threshold (P<5×10−8). Several other SLE signals/loci previously implicated in Caucasians and/or Asians were also supported in Stage 1 discovery sample and strongest signals were observed at 2q32/STAT4 (P=3.6×10−7) and at 8p23/BLK (P=8.1×10−6). Stage 2 meta-analyses identified a new genome-wide significant SLE locus at 12q12 (meta P=3.1×10−8), which was replicated in Stage 3. Conclusion Our multi-stage study identified and replicated a new SLE locus that warrants further follow-up in additional studies. Publicly available databases suggest that this new SLE signal falls within a functionally relevant genomic region and near biologically important genes. PMID:26316170

Red-shouldered hawk occupancy surveys in central Minnesota, USA

USGS Publications Warehouse

Henneman, C.; McLeod, M.A.; Andersen, D.E.

2007-01-01

Forest-dwelling raptors are often difficult to detect because many species occur at low density or are secretive. Broadcasting conspecific vocalizations can increase the probability of detecting forest-dwelling raptors and has been shown to be an effective method for locating raptors and assessing their relative abundance. Recent advances in statistical techniques based on presence-absence data use probabilistic arguments to derive probability of detection when it is <1 and to provide a model and likelihood-based method for estimating proportion of sites occupied. We used these maximum-likelihood models with data from red-shouldered hawk (Buteo lineatus) call-broadcast surveys conducted in central Minnesota, USA, in 1994-1995 and 2004-2005. Our objectives were to obtain estimates of occupancy and detection probability 1) over multiple sampling seasons (yr), 2) incorporating within-season time-specific detection probabilities, 3) with call type and breeding stage included as covariates in models of probability of detection, and 4) with different sampling strategies. We visited individual survey locations 2-9 times per year, and estimates of both probability of detection (range = 0.28-0.54) and site occupancy (range = 0.81-0.97) varied among years. Detection probability was affected by inclusion of a within-season time-specific covariate, call type, and breeding stage. In 2004 and 2005 we used survey results to assess the effect that number of sample locations, double sampling, and discontinued sampling had on parameter estimates. We found that estimates of probability of detection and proportion of sites occupied were similar across different sampling strategies, and we suggest ways to reduce sampling effort in a monitoring program.

Methodology Series Module 5: Sampling Strategies

PubMed Central

Setia, Maninder Singh

2016-01-01

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

What Are Probability Surveys used by the National Aquatic Resource Surveys?

EPA Pesticide Factsheets

The National Aquatic Resource Surveys (NARS) use probability-survey designs to assess the condition of the nation’s waters. In probability surveys (also known as sample-surveys or statistical surveys), sampling sites are selected randomly.

Association between physical activity and kidney function: National Health and Nutrition Examination Survey.

PubMed

Hawkins, Marquis S; Sevick, Mary Ann; Richardson, Caroline R; Fried, Linda F; Arena, Vincent C; Kriska, Andrea M

2011-08-01

Chronic kidney disease is a condition characterized by the deterioration of the kidney's ability to remove waste products from the body. Although treatments to slow the progression of the disease are available, chronic kidney disease may eventually lead to a complete loss of kidney function. Previous studies have shown that physical activities of moderate intensity may have renal benefits. Few studies have examined the effects of total movement on kidney function. The purpose of this study was to determine the association between time spent at all levels of physical activity intensity and sedentary behavior and kidney function. Data were obtained from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey, a cross-sectional study of a complex, multistage probability sample of the US population. Physical activity was assessed using an accelerometer and questionnaire. Glomerular filtration rate (eGFR) was estimated using the Modification of Diet in Renal Disease study formula. To assess linear associations between levels of physical activity and sedentary behavior with log-transformed estimated GFR (eGFR), linear regression was used. In general, physical activity (light and total) was related to log eGFR in females and males. For females, the association between light and total physical activity with log eGFR was consistent regardless of diabetes status. For males, the association between light and total physical activity and log eGFR was only significant in males without diabetes. When examining the association between physical activity, measured objectively with an accelerometer, and kidney function, total and light physical activities were found to be positively associated with kidney function.

Satisfaction with the humanitarian response to the 2010 Pakistan floods: a call for increased accountability to beneficiaries.

PubMed

Kirsch, Thomas; Siddiqui, Muhammad Ahmed; Perrin, Paul Clayton; Robinson, W Courtland; Sauer, Lauren M; Doocy, Shannon

2013-07-01

Ascertain recipients' level of satisfaction with humanitarian response efforts. A multi-stage, 80×20 cluster sample randomized survey (1800 households) with probability proportional to size of households affected by the 2010 Indus river floods in Pakistan. The floods affected over 18 million households and led to more than 8 billion USD in response dollars. Less than 20% of respondents reported being satisfied with response, though a small increase in satisfaction levels was observed over the three time periods of interest. Within the first month, receipt of hygiene items, food and household items was most strongly predictive of overall satisfaction. At 6 months, positive receipt of medicines was also highly predictive of satisfaction. The proportion of households reporting unmet needs remained elevated throughout the 6-month period following the floods and varied from 50% to 80%. Needs were best met between 1 and 3 months postflood, when response was at its peak. Unmet needs were the greatest at 6 months, when response was being phased down. Access-limiting issues were rarely captured during routine monitoring and evaluation efforts and seem to be a significant predictor in dissatisfaction with relief efforts, at least in the case of Pakistan, another argument in favor of independent, population-based surveys of this kind. There is also need to better identify and serve those not residing in camps. Direct surveys of the affected population can be used operationally to assess ongoing needs, more appropriately redirect humanitarian resources, and ultimately, judge the overall quality of a humanitarian response.

Suicide behavior and associated psychosocial factors among adolescents in Campeche, Mexico.

PubMed

González-Forteza, Catalina; Juárez-López, Carlos E; Jiménez, Alberto; Montejo-León, Liliana; Rodríguez-Santisbón, Ulises R; Wagner, Fernando A

2017-12-01

Suicide is an important public health problem that requires a preventive approach. The present study aimed at assessing suicidal behaviors and their relations with other psychosocial factors in Campeche, Mexico, in order to inform the design of potential preventive interventions. A multistage probability sample of 2386 students representative of all middle schools of the state of Campeche, Mexico, took a standardized, paper-and-pencil survey covering selected psychosocial constructs including suicide behavior, depression, drug use, familial relationships, locus of control, impulsivity, and self-esteem, among others. Latent classes were identified and multinomial logistic regression was used to analyze associations between class membership and psychosocial covariates. An estimated 8% of the middle school population in Campeche had three or more psychosocial problems in the past month including drug use, major depression episode symptoms, as well as suicidal problems like attempts and self-inflicted injuries. Four latent classes were identified, one with lowest risk and three with varying characteristics in terms of binge alcohol and other drug use, depression, and suicide behaviors. Associations between psychosocial covariates and latent class were observed, as predicted based on a multi-dimensional theoretical framework. Heterogeneity across "High-Risk" groups and their potential determinants highlight the need for differentiated, specialized efforts ranging from universal to indicated interventions. Given the high level of risk factors in this population, universal preventive interventions should aim at building resiliency among youth by helping them develop an array of coping resources, as well as by creating a more nurturing psychosocial environment. Copyright © 2017 Elsevier Inc. All rights reserved.

Republic of Georgia estimates for prevalence of drug use: Randomized response techniques suggest under-estimation.

PubMed

Kirtadze, Irma; Otiashvili, David; Tabatadze, Mzia; Vardanashvili, Irina; Sturua, Lela; Zabransky, Tomas; Anthony, James C

2018-06-01

Validity of responses in surveys is an important research concern, especially in emerging market economies where surveys in the general population are a novelty, and the level of social control is traditionally higher. The Randomized Response Technique (RRT) can be used as a check on response validity when the study aim is to estimate population prevalence of drug experiences and other socially sensitive and/or illegal behaviors. To apply RRT and to study potential under-reporting of drug use in a nation-scale, population-based general population survey of alcohol and other drug use. For this first-ever household survey on addictive substances for the Country of Georgia, we used the multi-stage probability sampling of 18-to-64-year-old household residents of 111 urban and 49 rural areas. During the interviewer-administered assessments, RRT involved pairing of sensitive and non-sensitive questions about drug experiences. Based upon the standard household self-report survey estimate, an estimated 17.3% [95% confidence interval, CI: 15.5%, 19.1%] of Georgian household residents have tried cannabis. The corresponding RRT estimate was 29.9% [95% CI: 24.9%, 34.9%]. The RRT estimates for other drugs such as heroin also were larger than the standard self-report estimates. We remain unsure about what is the "true" value for prevalence of using illegal psychotropic drugs in the Republic of Georgia study population. Our RRT results suggest that standard non-RRT approaches might produce 'under-estimates' or at best, highly conservative, lower-end estimates. Copyright © 2018 Elsevier B.V. All rights reserved.

Prevalence of dementia among population age over 45 years in Chiang Mai, Thailand.

PubMed

Wangtongkum, Suparus; Sucharitkul, Phongsakorn; Silprasert, Nutcharut; Inthrachak, Rudeethawinl

2008-11-01

To determine the prevalence of dementia in Thai people with age 45 years and above. This project used a cross sectional research design to study the prevalence of dementia in Chiang Mai. Door-to-door technique was assigned in condition with multi-stage probability random sampling to obtain subjects representing the population of Chiang Mai between Oct 2004 and Sep 2005. The researchers collected the data from the subjects aged 45 years and above. All subjects were located from every Amphurs of Chiang Mai. They were first screened with Thai Mini Mental State Examination (TMSE) and Thai Beck Depression Inventory (BDI). The subjects whose TMSE was less than 24 were assessed and diagnosed by a neurologist. Subjects who were determined as having dementia might be laboratory analyzed and classified based on DSM-IV and NINDS-AIREN criteria. The authors enrolled 2,311 people and screened them with Batteries test. One thousand four hundred ninety two people qualified with 610 males and 882 females, whose mean age was 59.7 +/- 10.4 years. The authors found that among the 35 people with dementia, the mean age was 67.9 +/- 8.9 years (45-88 years). The prevalence of dementia among the study participants was 2.35%. In the present study, Alzheimer's disease was the most common type of dementia diagnosed (75.0%) and vascular dementia was the second most commonly diagnosed (12.5%). The prevalence of dementia in Chiang Mai was 2.35%, which does not differ from the previous study Alzheimer's disease was the most common type of dementia diagnosed.

[Onset of alcohol and tobacco use and transition to other drug use among students from Morelos, Mexico].

PubMed

Herrera-Vázquez, Magdalena; Wagner, Fernando A; Velasco-Mondragón, Eduardo; Borges, Guilherme; Lazcano-Ponce, Eduardo

2004-01-01

To estimate the cumulative probability of occurrence of first use of alcohol and tobacco, and the risk of transition to illegal drugs (marijuana, cocaine, and heroine, among others), in adolescents and young adults, in Morelos State, Mexico. A cross-sectional study was conducted during schoolyear 1998-1999, among 13 293 students aged 11-24 years, selected from public schools by probabilistic multistage sampling. Data were collected on sociodemographic, health status, and substance abuse variables, using a validated self-applied questionnaire. Data were restructured to assemble a synthetic cohort for discrete time survival analysis. Associations were assessed with hazard rates and 95% confidence intervals obtained by means of multivariate Cox regression models. Sixty percent of males started drinking alcohol at 17 years of age, and smoking tobacco at 18 years of age, on average. Women started using alcohol and tobacco one year after men. Utilization of illicit drugs occurred at 19 years of age on average in 5% of women and 13% of men. Nine out of every 100 illicit drug users started directly using illicit drugs without previous use of alcohol and/or tobacco. In general, alcohol or tobacco users were at greater risk of starting drug use than nonusers (RR=6.72; 95 % confidence interval [CI]=4.13-10.93). Study findings suggest that interventions to decrease drug abuse should go together with efforts to delay initiation of alcohol and tobacco use. The innovative method used in this study yields epidemiologic evidence relating early use of alcohol and tobacco with initiation of illegal drugs in Mexican students.

Trends in the use of illicit substances in Thailand: Results from national household surveys.

PubMed

Angkurawaranon, Chaisiri; Jiraporncharoen, Wichuda; Likhitsathian, Surinporn; Thaikla, Kanittha; Kanato, Manop; Perngparn, Usaneya; Assanangkornchai, Sawitri; Aramrattana, Apinun

2018-02-27

Thailand borders some of the world's largest methamphetamine and opioid producing countries and trafficking routes. Thailand's 'War on Drugs' campaign was launched in 2003. This study reports trends in illicit substance use in Thailand over the period 2001-2011. National Household surveys on illicit drug use were conducted in 2001, 2003, 2007, 2008 and 2011. A stratified multi-stage cluster random sampling technique was implemented for each survey. Provinces in four regions were systematically selected using a probability proportionate to the size of the targeted population. Participants were interviewed using structured questionnaires on their history of substance use. The prevalence of illicit drug use within the past drastically decreased from 4.5% in 2001 to 1.0% in 2003 (P < 0.05). Since 2003, the prevalence of illicit use within the past year varied between 1.0% and 1.3%. By 2011, it was estimated that 0.84% have used kratom (a substance derived from Mitragyna speciosa) within the past year. Around 0.20% and 0.19% reported using cannibis and yaba (metamphetamine tablet) within a year of the 2011 survey. Other types of illicit drugs were less commonly used in Thailand. There was a decrease in prevalence of illicit drug use within the past year between 2001 and 2003 in Thailand. Since 2003, the past year prelavence of illicit drug use has remained relatively stable. From 2001 to 2011, cannabis, kratom and yaba have remained the three most commonly reported types of illicit drugs used in Thailand. © 2018 Australasian Professional Society on Alcohol and other Drugs.

Cross-sectional studies of tuberculosis prevalence in Cambodia between 2002 and 2011.

PubMed

Mao, Tan Eang; Okada, Kosuke; Yamada, Norio; Peou, Satha; Ota, Masaki; Saint, Saly; Kouet, Pichenda; Chea, Manith; Keo, Sokonth; Pheng, Sok Heng; Tieng, Sivanna; Khun, Kim Eam; Sugamoto, Tetsuhiro; Matsumoto, Hiroko; Yoshiyama, Takashi; Ito, Kunihiko; Onozaki, Ikushi

2014-08-01

To measure trends in the pulmonary tuberculosis burden between 2002 and 2011 and to assess the impact of the DOTS (directly observed treatment, short-course) strategy in Cambodia. Cambodia's first population-based nationwide tuberculosis survey, based on multistage cluster sampling, was conducted in 2002. The second tuberculosis survey, encompassing 62 clusters, followed in 2011. Participants aged 15 years or older were screened for active pulmonary tuberculosis with chest radiography and/or for tuberculosis symptoms. For diagnostic confirmation, sputum smear and culture were conducted on those whose screening results were positive. Of the 40,423 eligible subjects, 37,417 (92.6%) participated in the survey; 103 smear-positive cases and 211 smear-negative, culture-positive cases were identified. The weighted prevalences of smear-positive tuberculosis and bacteriologically-positive tuberculosis were 271 (95% confidence interval, CI: 212-348) and 831 (95% CI: 707-977) per 100,000 population, respectively. Tuberculosis prevalence was higher in men than women and increased with age. A 38% decline in smear-positive tuberculosis (P = 0.0085) was observed with respect to the 2002 survey, after participants were matched by demographic and geographical characteristics. The prevalence of symptomatic, smear-positive tuberculosis decreased by 56% (P = 0.001), whereas the prevalence of asymptomatic, smear-positive tuberculosis decreased by only 7% (P = 0.7249). The tuberculosis burden in Cambodia has declined significantly, most probably because of the decentralization of DOTS to health centres. To further reduce the tuberculosis burden in Cambodia, tuberculosis control should be strengthened and should focus on identifying cases without symptoms and in the middle-aged and elderly population.

Useful information for hypertension management reform in community health care: prevalence, awareness, treatment and control among Guangzhou adults.

PubMed

Wu, Xueji; Pan, Bingying; Chen, Xiongfei; Zhuang, Xiaoxia; Zhu, Kaixing; Zeng, Lizhong; Dai, Liping; Dong, Xiaomei

2014-01-01

Objective data on hypertension prevalence and management in local areas are scarce. We assessed the prevalence of hypertension and its management in Guangzhou adult population. A stratified multistage cluster sampling with probability proportional to size method was used in this survey. Information on a total of 23 939 respondents, aged 15 years old or above, having a gender ratio of 0.997 (male versus female) with completed questionnaire and blood pressure measurement, was obtained. Hypertension was defined as having a mean SBP of at least 140 mm Hg, a DBP of at least 90 mm Hg, and/or the prescription of antihypertensive drugs. Information related to the history of hypertension and treatment of hypertension was collected through a questionnaire. The prevalence of hypertension was 11.8%. Among patients with hypertension, 54.4% were aware of their elevated BP, 49.3% had treatment, and 23.3% achieved targeted BP control. Among those who were aware of their hypertension, 90.4% underwent treatment, and among those who were treated, 43.6% were well controlled. Although the prevalence, awareness and treatment of hypertension varied significantly among adults with several social economics status, the control of hypertension did not show significant differences. Among treated patients, the control of hypertension showed significant differences among adults with education, occupation, insurance and income. It is the first time for Guangzhou to describe epidemic and management of hypertension. A baseline was established, which could provide useful information not only to policymakers but also to developing countries with a close urbanization and aging rate similar to Guangzhou.

Association between visual impairment and sleep duration: analysis of the 2009 National Health Interview Survey (NHIS).

PubMed

Ramos, Alberto R; Wallace, Douglas M; Williams, Natasha J; Spence, David Warren; Pandi-Perumal, Seithikurippu Ratnas; Zizi, Ferdinand; Jean-Louis, Girardin

2014-10-01

Visual impairment (VI) is associated with increased mortality and health factors such as depression and cardiovascular disease. Epidemiologic studies consistently show associations between sleep duration with adverse health outcomes, but these have not systematically considered the influence of VI. The aim of this study was to ascertain the independent association between VI and sleep duration using the National Health Interview Survey (NHIS) data. We also examined whether race/ethnicity influenced these associations independently of sociodemographic and medical characteristics. Our analysis was based on the 2009 NHIS, providing valid sleep and vision data for 29,815 participants. The NHIS is a cross-sectional household interview survey utilizing a multistage area probability design. Trained personnel from the US census bureau gathered data during face-to-face interview and obtained socio-demographic, self-reported habitual sleep duration and physician-diagnosed chronic conditions. The mean age of the sample was 48 years and 56% were female. Short sleep and long sleep durations were reported by 49% and 23% of the participants, respectively. Visual impairment was observed in 10%. Multivariate-adjusted logistic regression models showed significant associations between VI and short sleep (OR = 1.6, 95% CI = 1.5-1.9 and long sleep durations (OR = 1.6, 95% CI = 1.3-1.9). These associations persisted in multivariate models stratified by race-ethnic groups. Visual impairment was associated with both short and long sleep durations. Analysis of epidemiologic sleep data should consider visual impairment as an important factor likely to influence the amount of sleep experienced habitually.

Reconsidering the definition of Major Depression based on Collaborative Psychiatric Epidemiology Surveys.

PubMed

Rosenström, Tom; Jokela, Markus

2017-01-01

Diagnostic definitions for depressive disorders remain a debated topic, despite their central role in clinical practice and research. We use both recent evidence and nationally representative data to derive an empirically-based modification of DSM-IV/-5 Major Depressive Disorder (MDD). A modified MDD diagnosis was derived by analyzing data from Collaborative Psychiatric Epidemiology Surveys, a multistage probability sample of adults (n=20 013; age ≥ 18 years) in coterminous USA, Alaska and Hawaii. The old and the newly suggested MDD definitions were compared for their associated disability (WHO Disability Assessment Schedule and number of disability days in past month), suicide attempt, and other covariates. Our data-driven definition for major depression was "lack of interest to all or most things" plus four other symptoms from the set {weight gain, weight loss, insomnia, psychomotor retardation, fatigue, feelings of worthlessness, diminished ability to think/concentrate, suicidal ideation/attempt}. The new definition captured all the disability implied by MDD and excluded cases that showed no greater disability than the general population nor increased risk of suicide attempts. The lifetime prevalence of the new diagnosis was 14.7% (95% CI=14-15.4%) of the population, slightly less than for the old definition (16.4%; CI=15.4-17.3%). Only conservative modifications of MDD could be studied, because of restrictions in the symptom data. With only small adjusting, the new definition for major depression may be more clinically relevant than the old one, and could serve as a conservative replacement for the old definition. Copyright © 2016 Elsevier B.V. All rights reserved.

Systematic sampling for suspended sediment

Treesearch

Robert B. Thomas

1991-01-01

Abstract - Because of high costs or complex logistics, scientific populations cannot be measured entirely and must be sampled. Accepted scientific practice holds that sample selection be based on statistical principles to assure objectivity when estimating totals and variances. Probability sampling--obtaining samples with known probabilities--is the only method that...

Effectiveness of Item Response Theory (IRT) Proficiency Estimation Methods under Adaptive Multistage Testing. Research Report. ETS RR-15-11

ERIC Educational Resources Information Center

Kim, Sooyeon; Moses, Tim; Yoo, Hanwook Henry

2015-01-01

The purpose of this inquiry was to investigate the effectiveness of item response theory (IRT) proficiency estimators in terms of estimation bias and error under multistage testing (MST). We chose a 2-stage MST design in which 1 adaptation to the examinees' ability levels takes place. It includes 4 modules (1 at Stage 1, 3 at Stage 2) and 3 paths…

Patient-centred screening for primary immunodeficiency, a multi-stage diagnostic protocol designed for non-immunologists: 2011 update

PubMed Central

de Vries, E

2012-01-01

Members of the European Society for Immunodeficiencies (ESID) and other colleagues have updated the multi-stage expert-opinion-based diagnostic protocol for non-immunologists incorporating newly defined primary immunodeficiency diseases (PIDs). The protocol presented here aims to increase the awareness of PIDs among doctors working in different fields. Prompt identification of PID is important for prognosis, but this may not be an easy task. The protocol therefore starts from the clinical presentation of the patient. Because PIDs may present at all ages, this protocol is aimed at both adult and paediatric physicians. The multi-stage design allows cost-effective screening for PID of the large number of potential cases in the early phases, with more expensive tests reserved for definitive classification in collaboration with a specialist in the field of immunodeficiency at a later stage. PMID:22132890

Reentry trajectory optimization based on a multistage pseudospectral method.

PubMed

Zhao, Jiang; Zhou, Rui; Jin, Xuelian

2014-01-01

Of the many direct numerical methods, the pseudospectral method serves as an effective tool to solve the reentry trajectory optimization for hypersonic vehicles. However, the traditional pseudospectral method is time-consuming due to large number of discretization points. For the purpose of autonomous and adaptive reentry guidance, the research herein presents a multistage trajectory control strategy based on the pseudospectral method, capable of dealing with the unexpected situations in reentry flight. The strategy typically includes two subproblems: the trajectory estimation and trajectory refining. In each processing stage, the proposed method generates a specified range of trajectory with the transition of the flight state. The full glide trajectory consists of several optimal trajectory sequences. The newly focused geographic constraints in actual flight are discussed thereafter. Numerical examples of free-space flight, target transition flight, and threat avoidance flight are used to show the feasible application of multistage pseudospectral method in reentry trajectory optimization.

Reentry Trajectory Optimization Based on a Multistage Pseudospectral Method

PubMed Central

Zhou, Rui; Jin, Xuelian

2014-01-01

Of the many direct numerical methods, the pseudospectral method serves as an effective tool to solve the reentry trajectory optimization for hypersonic vehicles. However, the traditional pseudospectral method is time-consuming due to large number of discretization points. For the purpose of autonomous and adaptive reentry guidance, the research herein presents a multistage trajectory control strategy based on the pseudospectral method, capable of dealing with the unexpected situations in reentry flight. The strategy typically includes two subproblems: the trajectory estimation and trajectory refining. In each processing stage, the proposed method generates a specified range of trajectory with the transition of the flight state. The full glide trajectory consists of several optimal trajectory sequences. The newly focused geographic constraints in actual flight are discussed thereafter. Numerical examples of free-space flight, target transition flight, and threat avoidance flight are used to show the feasible application of multistage pseudospectral method in reentry trajectory optimization. PMID:24574929

Efficient Multi-Stage Time Marching for Viscous Flows via Local Preconditioning

NASA Technical Reports Server (NTRS)

Kleb, William L.; Wood, William A.; vanLeer, Bram

1999-01-01

A new method has been developed to accelerate the convergence of explicit time-marching, laminar, Navier-Stokes codes through the combination of local preconditioning and multi-stage time marching optimization. Local preconditioning is a technique to modify the time-dependent equations so that all information moves or decays at nearly the same rate, thus relieving the stiffness for a system of equations. Multi-stage time marching can be optimized by modifying its coefficients to account for the presence of viscous terms, allowing larger time steps. We show it is possible to optimize the time marching scheme for a wide range of cell Reynolds numbers for the scalar advection-diffusion equation, and local preconditioning allows this optimization to be applied to the Navier-Stokes equations. Convergence acceleration of the new method is demonstrated through numerical experiments with circular advection and laminar boundary-layer flow over a flat plate.

Multi-stage phononic crystal structure for anchor-loss reduction of thin-film piezoelectric-on-silicon microelectromechanical-system resonator

NASA Astrophysics Data System (ADS)

Bao, Fei-Hong; Bao, Lei-Lei; Li, Xin-Yi; Ammar Khan, Muhammad; Wu, Hua-Ye; Qin, Feng; Zhang, Ting; Zhang, Yi; Bao, Jing-Fu; Zhang, Xiao-Sheng

2018-06-01

Thin-film piezoelectric-on-silicon acoustic wave resonators are promising for the development of system-on-chip integrated circuits with micro/nano-engineered timing reference. However, in order to realize their large potentials, a further enhancement of the quality factor (Q) is required. In this study, a novel approach, based on a multi-stage phononic crystal (PnC) structure, was proposed to achieve an ultra-high Q. A systematical study revealed that the multi-stage PnC structure formed a frequency-selective band-gap to effectively prohibit the dissipation of acoustic waves through tethers, which significantly reduced the anchor loss, leading to an insertion-loss reduction and enhancement of Q. The maximum unloaded Q u of the fabricated resonators reached the value of ∼10,000 at 109.85 MHz, indicating an enhancement by 19.4 times.

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

Doktorov, Alexander B., E-mail: doktorov@kinetics.nsc.ru

Manifestations of the “cage” effect at the encounters of reactants have been theoretically treated on the example of multistage reactions (including bimolecular exchange reactions as elementary stages) proceeding from different active sites in liquid solutions. It is shown that for reactions occurring near the contact of reactants, consistent consideration of quasi-stationary kinetics of such multistage reactions (possible in the framework of the encounter theory only) can be made on the basis of chemical concepts of the “cage complex,” just as in the case of one-site model described in the literature. Exactly as in the one-site model, the presence of themore » “cage” effect gives rise to new channels of reactant transformation that cannot result from elementary event of chemical conversion for the given reaction mechanism. Besides, the multisite model demonstrates new (as compared to one-site model) features of multistage reaction course.« less

An integrated experimental and theoretical reaction path search: analyses of the multistage reaction of an ionized diethylether dimer involving isomerization, proton transfer, and dissociation.

PubMed

Matsuda, Yoshiyuki; Xie, Min; Fujii, Asuka

2018-05-30

An ionization-induced multistage reaction of an ionized diethylether (DEE) dimer involving isomerization, proton transfer, and dissociation is investigated by combining infrared (IR) spectroscopy, tandem mass spectrometry, and a theoretical reaction path search. The vertically-ionized DEE dimer isomerizes to a hydrogen-bonded cluster of protonated DEE and the [DEE-H] radical through barrierless intermolecular proton transfer from the CH bond of the ionized moiety. This isomerization process is confirmed by IR spectroscopy and the theoretical reaction path search. The multiple dissociation pathways following the isomerization are analyzed by tandem mass spectrometry. The isomerized cluster dissociates stepwise into a [protonated DEE-acetaldehyde (AA)] cluster, protonated DEE, and protonated AA. The structure of the fragment ion is also analyzed by IR spectroscopy. The reaction map of the multistage processes is revealed through a harmony of these experimental and theoretical methods.

Inverse relationship between fat intake and blood lead levels in the Korean adult population in the KNHANES 2007-2009.

PubMed

Park, Sunmin; Lee, Byung-Kook

2012-07-15

Blood lead levels (BLLs) in the Korean adult population are about twofold higher than those in the US adult population, which may be related to nutrient intake. We examined which nutritional factors might be associated with decreased BLL. This study was based on Korean National Health and Nutrition Examination Survey data obtained over 3 years (2007-2009) using a rolling sampling design involving a complex, stratified, multistage, probability-cluster survey of a representative sample of the non-institutionalized civilian population of South Korea. A multiple regression analysis after controlling for covariates indicated that dietary fat and protein were significant opposite predictors of BLL in five different models; fat and protein intake had negative and positive associations with BLL, respectively. Covariates used in the analysis were sex, age, regional area, education level, smoking and drinking status, hypertension, use of antihypertensive drugs, diabetes, use of antidiabetic drugs, use of cholesterol-lowering drugs, hemoglobin level, and exposure to chemical substances during daily life. Intake levels of other nutrients, such as dietary fiber, carbohydrates, and calcium, did not show any significant effect on BLL. Gender was also an important predictor: BLL was significantly higher in men than women. However, total femur T-score, which represents bone mass, was unaffected by BLL. When calculating adjusted predicted marginal values of blood lead according to dietary fat percentage, BLL was lower by 5.3% and 8.0% in men when fat intake was increased from 10% to 20% and 25%, respectively. This effect of fat intake on BLL was minimal in women. The accumulation of body stores of lead from lead exposure may be reduced by increasing dietary fat consumption to 25% of energy intake, especially in men. However, this must be weighed against possible cardiovascular risks of higher fat diets. Copyright © 2012 Elsevier B.V. All rights reserved.

Assessment of maternal anemia in rural Western China between 2001 and 2005: a two-level logistic regression approach

PubMed Central

2013-01-01

Background There are multiple adverse effects of anemia on human function, particularly on women. However, few researches are conducted on women anemia in rural Western China. This study mainly aims to investigate the levels and associated factors of maternal anemia between 2001 and 2005 in this region. Methods 6172 and 5372 mothers with children under three years old were selected from 8 provinces in 2001 and from 9 provinces in 2005 respectively in Western China by means of a multi-stage probability proportion to size sampling method (PPS). The blood samples were tested and related socio-demographic information was obtained through questionnaires. A two-level logistic regression model was employed to identify the determinants and provincial variations of women anemia in 2001 and 2005. Results The results indicated that the crude prevalence of women anemia in 2005 was higher than the rate in 2001(45.7% vs 33.6%). Based on the nationwide census data in 2000, the age-standardized prevalence of women anemia in the study were obtained as 38.0% in 2001 and 50.0% in 2005 respectively. Two-level logistic model analysis showed that compared to the average, women were more likely to be anemic in Guangxi and Qinghai in 2001 as well as in Chongqing and Qinghai in 2005; that women from Minority groups had higher odds of anemia in contrast with Han; that women with higher parity, longer breastfeeding duration and higher socioeconomic level had a lower rate of anemia, while age of women was positively associated with anemia. The positive correlation between women anemia and altitude was also observed. Conclusions The study demonstrated that the burden of maternal anemia in rural Western China increased considerably between 2001 and 2005. The Chinese government should conduct integrated interventions on anemia of mothers in this region. PMID:23597320

Decomposing associations between acculturation and drinking in Mexican Americans

PubMed Central

Mills, Britain A.; Caetano, Raul

2011-01-01

Background Acculturation to life in the United States is a known predictor of Hispanic drinking behavior. We compare the ability of 2 theoretical models of this effect – sociocultural theory and general stress theory – to account for associations between acculturation and drinking in a sample of Mexican Americans. Limitations of previous evaluations of these theoretical models are addressed by using a broader range of hypothesized cognitive mediators and a more direct measure of acculturative stress. In addition, we explore nonlinearities as possible underpinnings of attenuated acculturation effects among males. Methods Respondents (N = 2,595, current drinker N = 1,351) were interviewed as part of 2 recent multistage probability samples in a study of drinking behavior among Mexican Americans in the United States. The ability of norms, drinking motives, alcohol expectancies, and acculturation stress to account for relations between acculturation and drinking outcomes (volume and heavy drinking days) were assessed with a hierarchical linear regression strategy. Nonlinear trends were assessed by modeling quadratic effects of acculturation and acculturation stress on cognitive mediators and drinking outcomes. Results Consistent with previous findings, acculturation effects on drinking outcomes were stronger for females than males. Among females, only drinking motives explained acculturation associations with volume or heavy drinking days. Among males, acculturation was linked to increases in norms, and norms were positive predictors of drinking outcomes. However, adjusted effects of acculturation were non-existent or trending in a negative direction, which counter-acted this indirect normative influence. Acculturation stress did not explain positive associations between acculturation and drinking. Conclusions Stress and alcohol outcome expectancies play little role in the positive linear association between acculturation and drinking outcomes, but drinking motives appears to at least partially account for this effect. Consistent with recent reports, these results challenge stress models of linear acculturation effects on drinking outcomes and provide (partial) support for sociocultural models. Inconsistent mediation patterns – rather than nonlinearities – represented a more plausible statistical description of why acculturation-drinking associations are weakened among males. PMID:22316139

Decomposing associations between acculturation and drinking in Mexican Americans.

PubMed

Mills, Britain A; Caetano, Raul

2012-07-01

Acculturation to life in the United States is a known predictor of Hispanic drinking behavior. We compare the ability of 2 theoretical models of this effect-sociocultural theory and general stress theory-to account for associations between acculturation and drinking in a sample of Mexican Americans. Limitations of previous evaluations of these theoretical models are addressed using a broader range of hypothesized cognitive mediators and a more direct measure of acculturative stress. In addition, we explore nonlinearities as possible underpinnings of attenuated acculturation effects among men. Respondents (N = 2,595, current drinker N = 1,351) were interviewed as part of 2 recent multistage probability samples in a study of drinking behavior among Mexican Americans in the United States. The ability of norms, drinking motives, alcohol expectancies, and acculturation stress to account for relations between acculturation and drinking outcomes (volume and heavy drinking days) were assessed with a hierarchical linear regression strategy. Nonlinear trends were assessed by modeling quadratic effects of acculturation and acculturation stress on cognitive mediators and drinking outcomes. Consistent with previous findings, acculturation effects on drinking outcomes were stronger for women than men. Among women, only drinking motives explained acculturation associations with volume or heavy drinking days. Among men, acculturation was linked to increases in norms, and norms were positive predictors of drinking outcomes. However, adjusted effects of acculturation were nonexistent or trending in a negative direction, which counteracted this indirect normative influence. Acculturation stress did not explain the positive associations between acculturation and drinking. Stress and alcohol outcome expectancies play little role in the positive linear association between acculturation and drinking outcomes, but drinking motives appear to at least partially account for this effect. Consistent with recent reports, these results challenge stress models of linear acculturation effects on drinking outcomes and provide (partial) support for sociocultural models. Inconsistent mediation patterns-rather than nonlinearities-represented a more plausible statistical description of why acculturation-drinking associations are weakened among men. Copyright © 2012 by the Research Society on Alcoholism.

Trends in risk behaviors among female sex workers in south India: priorities for sustaining the reversal of HIV epidemic.

PubMed

Charles, Bimal; Jeyaseelan, Lakshmanan; Edwin Sam, Asirvatham; Kumar Pandian, Arvind; Thenmozhi, Mani; Jeyaseelan, Visalakshi

2013-01-01

HIV epidemic in India is predominantly concentrated in subgroups of population, such as female sex workers (FSWs) and their clients, whose behavior exposes them to a higher risk of acquiring HIV infection. This paper aims to present the changing patterns of socio-demographic characteristics, behaviors, reported sexually transmitted infections (STIs), and associated factors among FSWs over 11 years. Multistage cluster sampling with probability-proportional-to-size (PPS) method was used in the surveys. A sample of 400 FSWs was studied every year. The mean age and literacy at the baseline level increased significantly over the years. House-based sex increased by 40% from 43.3% in 1997 to 83% in 2008 (p<0.001). Condom use at last sex with one-time clients; consistent condom use (CCU) with one-time and regular clients indicated increasing trends. FSWs reported low levels of condom use at last sex (14.5% in 1997 to 5% in 2008; p<0.001) and CCU (12.6% in 2004 to 3.6% in 2008; p<0.01) with regular partners. FSWs who used condom with one-time clients at last sex reported significantly less STI symptoms. A two-third reduction in genital ulcers was found from 13.1% in 1997 to 4.5% in 2008 (p<0.001). Nonliterate and hotel-based sex workers were 1.6 (1.0-2.5; 95% CI) and 2.2(1.3-3.7; 95% CI) times more likely to have reported STI symptoms. The percentage of FSWs who underwent HIV testing increased (p<0.001); similarly, a 20% increase was found in FSWs who availed counseling services from 65.2% in 1997 to 85.4% in 2008 (p<0.001). Poor, illiterate, and marginalized were more likely to get involved in risky behaviors which suggest the need for structural interventions as part of HIV prevention strategy.

The Challenge of Living On: Psychopathology and Its Mediating Influence on the Readjustment of Former Child Soldiers

PubMed Central

Ertl, Verena; Pfeiffer, Anett; Schauer-Kaiser, Elisabeth; Elbert, Thomas; Neuner, Frank

2014-01-01

Current civil wars are characterized by the increasing involvement of civilian populations and the systematic employment of child soldiers. An example of such wars was the conflict in Northern Uganda, where the war-affected population is still challenged by the reintegration of formerly abducted children and youths. A cross-sectional, population-based survey, using a multistage cluster sampling approach of 1,113 Northern Ugandans aged between 12 and 25 in camps for internally displaced persons and locally validated instruments was conducted to assess symptoms and diagnoses of Posttraumatic Stress Disorder (PTSD) and probable Depression in war-affected, as well as formerly abducted individuals. Further objectives were to determine predictors of psychopathology and to relate indicators of maladjustment (i.e., impairments in daily and community functioning, somatic complaints, suicidality, aggressiveness and discrimination) to abduction, level of exposure to violence and psychopathology. 43% of the sample reported abduction by the rebel army. Exposure to violence among this group was higher than for non-abducted youths (t = 28.05; p<.001). PTSD point prevalence rates were 25% among former child soldiers and 7% among the comparison group. High suicidal ideation was present in 16% and 6% respectively. A higher amount of experienced and witnessed event-types (β = . 32. p<.001), loss of first-degree relatives (β = .13. p<.001) and the number of event-types involving forced perpetration (β = .23. p<.001) were identified as risk factors of PTSD symptoms in former child soldiers. The associations between abductee-status and indicators of maladjustment were fully mediated by level of trauma exposure and psychopathology. Results show that child soldiering and its psychological sequelae affect a substantial proportion of children and youths. After release or flight, their readjustment depends at least partly on their level of mental traumatization. PMID:25054324

Hearing impairment associated with depression in US adults, National Health and Nutrition Examination Survey 2005-2010.

PubMed

Li, Chuan-Ming; Zhang, Xinzhi; Hoffman, Howard J; Cotch, Mary Frances; Themann, Christa L; Wilson, M Roy

2014-04-01

Depression among hearing impaired US adults has not been studied previously. To estimate the prevalence of and risk factors for depression among adults with hearing loss. Adults aged 18 years or older (N = 18 318) who participated in the National Health and Nutrition Examination Survey (NHANES), 2005-2010, a nationally representative sample. Multistage probability sampling of US population. Depression, assessed by the 9-item Patient Health Questionnaire (PHQ-9) scale, and hearing impairment (HI), assessed by self-report and audiometric examination for adults aged 70 years or older. The prevalence of moderate to severe depression (PHQ-9 score, ≥10) was 4.9% for individuals reporting excellent hearing, 7.1% for those with good hearing, and 11.4% for participants who reported a little trouble or greater HI. Using excellent hearing as the reference, after adjusting for all covariates, multivariate odds ratios (ORs) for depression were 1.4 (95% CI, 1.1-1.8) for good hearing, 1.7 (1.3-2.2) for a little trouble, 2.4 (1.7-3.2) for moderate trouble, 1.5 (0.9-2.6) for a lot of trouble, and 0.6 (0.1-2.6) for deaf. Moderate HI (defined by better ear pure-tone average of hearing thresholds at 0.5, 1, 2, and 4 kHz within the range 35- to 49-dB hearing level) was significantly associated with depression among older women (OR, 3.9; 95% CI, 1.3-11.3), after adjusting for age, sex, race/ethnicity, lifestyle characteristics, and selected health conditions. After accounting for health conditions and other factors, including trouble seeing, self-reported HI and audiometrically determined HI were significantly associated with depression, particularly in women. Health care professionals should be aware of an increased risk for depression among adults with hearing loss.

On the use of secondary capture-recapture samples to estimate temporary emigration and breeding proportions

USGS Publications Warehouse

Kendall, W.L.; Nichols, J.D.; North, P.M.; Nichols, J.D.

1995-01-01

The use of the Cormack- Jolly-Seber model under a standard sampling scheme of one sample per time period, when the Jolly-Seber assumption that all emigration is permanent does not hold, leads to the confounding of temporary emigration probabilities with capture probabilities. This biases the estimates of capture probability when temporary emigration is a completely random process, and both capture and survival probabilities when there is a temporary trap response in temporary emigration, or it is Markovian. The use of secondary capture samples over a shorter interval within each period, during which the population is assumed to be closed (Pollock's robust design), provides a second source of information on capture probabilities. This solves the confounding problem, and thus temporary emigration probabilities can be estimated. This process can be accomplished in an ad hoc fashion for completely random temporary emigration and to some extent in the temporary trap response case, but modelling the complete sampling process provides more flexibility and permits direct estimation of variances. For the case of Markovian temporary emigration, a full likelihood is required.

Environment factors associated with adolescents' body mass index, physical activity and physical fitness in Kuching South City, Sarawak: a cross-sectional study.

PubMed

Cheah, Whye L; Chang, Ching T; Saimon, Rosalia

2012-01-01

This study examined the relationship between perceived built environment attributes and physical activity, physical fitness and body weight among adolescents aged 14-16 years in Sarawak. This was a cross-sectional study, using multi-stage sampling. A set of questionnaires consisting of socio-demographic information, a self-administered physical activity checklist and a Neighborhood Environment Walkability Scale-Youth (NEWS-Y) was used. Body mass index (BMI) was measured and physical fitness was tested using a maximal multistage 20 m shuttle run test. Data analysis was done using SPSS version 17.0. A total of 316 respondents participated. The mean BMI for boys was almost equal to the mean BMI for girls. Only 7.9% of the sampled population was found to be overweight or obese. The overall mean duration spent per day on physical activity was 128.4 min (SD 118.43), with mean of 56.1 min (SD 73.94) after school time. Girls reported to spend longer each day taking physical activity before and during school. Boys were found to have significantly higher VO2max of 27.79±5.91 mL/kg/min as compared to girls (t=11.22, p<0.000). Based on comparison with other countries, the NEWS-Y scores indicated a mixture of low and high walkability neighborhoods. Respondents who had lower BMIs reported living in lower residential density areas and less risk of crime, and respondents who had better physical fitness reported less suitable infrastructure for walking. Promotion of exercise at all levels should be continuously encouraged as it would lead to improvement in the well-being of an individual.

Musculoskeletal impairment survey in Rwanda: Design of survey tool, survey methodology, and results of the pilot study (a cross sectional survey)

PubMed Central

Atijosan, Oluwarantimi; Kuper, Hannah; Rischewski, Dorothea; Simms, Victoria; Lavy, Christopher

2007-01-01

Background Musculoskeletal impairment (MSI) is an important cause of morbidity and mortality worldwide, especially in developing countries. Prevalence studies for MSI in the developing world have used varying methodologies and are seldom directly comparable. This study aimed to develop a new tool to screen for and diagnose MSI and to pilot test the methodology for a national survey in Rwanda. Methods A 7 question screening tool to identify cases of MSI was developed through literature review and discussions with healthcare professionals. To validate the tool, trained rehabilitation technicians screened 93 previously identified gold standard 'cases' and 86 'non cases'. Sensitivity, specificity and positive predictive value were calculated. A standardised examination protocol was developed to determine the aetiology and diagnosis of MSI for those who fail the screening test. For the national survey in Rwanda, multistage cluster random sampling, with probability proportional to size procedures will be used for selection of a cross-sectional, nationally representative sample of the population. Households to be surveyed will be chosen through compact segment sampling and all individuals within chosen households will be screened. A pilot survey of 680 individuals was conducted using the protocol. Results: The screening tool demonstrated 99% sensitivity and 97% specificity for MSI, and a positive predictive value of 98%. During the pilot study 468 out of 680 eligible subjects (69%) were screened. 45 diagnoses were identified in 38 persons who were cases of MSI. The subjects were grouped into categories based on diagnostic subgroups of congenital (1), traumatic (17), infective (2) neurological (6) and other acquired(19). They were also separated into mild (42.1%), moderate (42.1%) and severe (15.8%) cases, using an operational definition derived from the World Health Organisation's International Classification of Functioning, Disability and Health. Conclusion: The screening tool had good sensitivity and specificity and was appropriate for use in a national survey. The pilot study showed that the survey protocol was appropriate for measuring the prevalence of MSI in Rwanda. This survey is an important step to building a sound epidemiological understanding of MSI, to enable appropriate health service planning. PMID:17391509

Probability Issues in without Replacement Sampling

ERIC Educational Resources Information Center

Joarder, A. H.; Al-Sabah, W. S.

2007-01-01

Sampling without replacement is an important aspect in teaching conditional probabilities in elementary statistics courses. Different methods proposed in different texts for calculating probabilities of events in this context are reviewed and their relative merits and limitations in applications are pinpointed. An alternative representation of…

Retrospective on 30 years of nonimaging optics development for solar energy at the University of Chicago

NASA Astrophysics Data System (ADS)

O'Gallagher, Joseph J.

2016-09-01

As the field of nonimaging optics has developed over the last 50 years, among its many applications, the best known and recognized is probably in solar energy. In particular, the approach provides the formalism that allows the design of devices that approach the maximum physically attainable geometric concentration for a given set of optical tolerances. This means that it has the potential to revolutionize the design of solar concentrators. Much of the experimental development and early testing of these concepts was carried out at the University of Chicago by Roland Winston and his colleagues and students. In this presentation, some of many embodiments and variations of the basic Compound Parabolic Concentrator that were developed and tested over a thirty-year period at Chicago are reviewed. Practical and economic aspects of concentrator design for both thermal and photovoltaic applications are discussed. Examples covering the whole range of concentrator applications from simple low-concentration non-tracking designs to ultrahigh-concentration multistage configurations are covered.

Far field beam pattern of one MW combined beam of laser diode array amplifiers for space power transmission

NASA Technical Reports Server (NTRS)

Kwon, Jin H.; Lee, Ja H.

1989-01-01

The far-field beam pattern and the power-collection efficiency are calculated for a multistage laser-diode-array amplifier consisting of about 200,000 5-W laser diode arrays with random distributions of phase and orientation errors and random diode failures. From the numerical calculation it is found that the far-field beam pattern is little affected by random failures of up to 20 percent of the laser diodes with reference of 80 percent receiving efficiency in the center spot. The random differences in phases among laser diodes due to probable manufacturing errors is allowed to about 0.2 times the wavelength. The maximum allowable orientation error is about 20 percent of the diffraction angle of a single laser diode aperture (about 1 cm). The preliminary results indicate that the amplifier could be used for space beam-power transmission with an efficiency of about 80 percent for a moderate-size (3-m-diameter) receiver placed at a distance of less than 50,000 km.

Assessing performance and validating finite element simulations using probabilistic knowledge

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

Dolin, Ronald M.; Rodriguez, E. A.

Two probabilistic approaches for assessing performance are presented. The first approach assesses probability of failure by simultaneously modeling all likely events. The probability each event causes failure along with the event's likelihood of occurrence contribute to the overall probability of failure. The second assessment method is based on stochastic sampling using an influence diagram. Latin-hypercube sampling is used to stochastically assess events. The overall probability of failure is taken as the maximum probability of failure of all the events. The Likelihood of Occurrence simulation suggests failure does not occur while the Stochastic Sampling approach predicts failure. The Likelihood of Occurrencemore » results are used to validate finite element predictions.« less

Quantifying Dental Office-Originating Adverse Events: The Dental Practice Study Methods.

PubMed

Tokede, Oluwabunmi; Walji, Muhammad; Ramoni, Rachel; Rindal, Donald B; Worley, Donald; Hebballi, Nutan; Kumar, Krishna; van Strien, Claire; Chen, Mengxia; Navat-Pelli, Shaked; Liu, Hongchun; Etolue, Jini; Yansane, Alfa; Obadan-Udoh, Enihomo; Easterday, Casey; Enstad, Chris; Kane, Sheryl; Rush, William; Kalenderian, Elsbeth

2017-12-05

Preventable medical errors in hospital settings are the third leading cause of deaths in the United States. However, less is known about harm that occurs in patients in outpatient settings, where the majority of care is delivered. We do not know the likelihood that a patient sitting in a dentist chair will experience harm. Additionally, we do not know if patients of certain race, age, sex, or socioeconomic status disproportionately experience iatrogenic harm. We initiated the Dental Practice Study (DPS) with the aim of determining the frequency and types of adverse events (AEs) that occur in dentistry on the basis of retrospective chart audit. This article discusses the 6-month pilot phase of the DPS during which we explored the feasibility and efficiency of our multistaged review process to detect AEs. At sites 1, 2, and 3, respectively, 2 reviewers abstracted 21, 11, and 23 probable AEs, respectively, from the 100 patient charts audited per site. At site 2, a third reviewer audited the same 100 charts and found only 1 additional probable AE. Of the total 56 probable AEs (from 300 charts), the expert panel confirmed 9 AE cases. This equals 3 AEs per 100 patients per year. Patients who experienced an AE tended to be male and older and to have undergone more procedures within the study year. This article presents an overview of the DPS. It describes the methods used and summarizes the results of its pilot phase. To minimize threats to dental patient safety, a starting point is to understand their basic epidemiology, both in terms of their frequency and the extent to which they affect different populations.

Comparison of alternative MS/MS and bioinformatics approaches for confident phosphorylation site localization.

PubMed

Wiese, Heike; Kuhlmann, Katja; Wiese, Sebastian; Stoepel, Nadine S; Pawlas, Magdalena; Meyer, Helmut E; Stephan, Christian; Eisenacher, Martin; Drepper, Friedel; Warscheid, Bettina

2014-02-07

Over the past years, phosphoproteomics has advanced to a prime tool in signaling research. Since then, an enormous amount of information about in vivo protein phosphorylation events has been collected providing a treasure trove for gaining a better understanding of the molecular processes involved in cell signaling. Yet, we still face the problem of how to achieve correct modification site localization. Here we use alternative fragmentation and different bioinformatics approaches for the identification and confident localization of phosphorylation sites. Phosphopeptide-enriched fractions were analyzed by multistage activation, collision-induced dissociation and electron transfer dissociation (ETD), yielding complementary phosphopeptide identifications. We further found that MASCOT, OMSSA and Andromeda each identified a distinct set of phosphopeptides allowing the number of site assignments to be increased. The postsearch engine SLoMo provided confident phosphorylation site localization, whereas different versions of PTM-Score integrated in MaxQuant differed in performance. Based on high-resolution ETD and higher collisional dissociation (HCD) data sets from a large synthetic peptide and phosphopeptide reference library reported by Marx et al. [Nat. Biotechnol. 2013, 31 (6), 557-564], we show that an Andromeda/PTM-Score probability of 1 is required to provide an false localization rate (FLR) of 1% for HCD data, while 0.55 is sufficient for high-resolution ETD spectra. Additional analyses of HCD data demonstrated that for phosphotyrosine peptides and phosphopeptides containing two potential phosphorylation sites, PTM-Score probability cutoff values of <1 can be applied to ensure an FLR of 1%. Proper adjustment of localization probability cutoffs allowed us to significantly increase the number of confident sites with an FLR of <1%.Our findings underscore the need for the systematic assessment of FLRs for different score values to report confident modification site localization.

Development of Optical Crystals for High Power and Tunable Visible and Infrared Light Generation

DTIC Science & Technology

2015-02-11

ultra high chemical purity (5N), 95% isotopically enriched 6Li was purified in a multi-stage vacuum distillation process previously reported by...enriched 6Li was purified in a multi-stage vacuum distillation process previously reported by Stowe et al.[4]. 6LiIn alloy was synthesized in a... quantum mechanics, it has been determined that atoms, molecules, ions have discrete energy levels. Therefore there exists allowed atomic transitions

Fuel system for diesel engine with multi-stage heated

NASA Astrophysics Data System (ADS)

Ryzhov, Yu N.; Kuznetsov, Yu A.; Kolomeichenko, A. V.; Kuznetsov, I. S.; Solovyev, R. Yu; Sharifullin, S. N.

2017-09-01

The article describes a fuel system of a diesel engine with a construction tractor multistage heating, allowing the use of pure rapeseed oil as a diesel engine fuel. The paper identified the kinematic viscosity depending on the temperature and composition of the mixed fuel, supplemented by the existing recommendations on the use of mixed fuels based on vegetable oils and developed the device allowing use as fuel for diesel engines of biofuels based on vegetable oils.

MULTI-STAGE DELIVERY NANO-PARTICLE SYSTEMS FOR THERAPEUTIC APPLICATIONS

PubMed Central

Serda, Rita E.; Godin, Biana; Blanco, Elvin; Chiappini, Ciro; Ferrari, Mauro

2010-01-01

Background The daunting task for drug molecules to reach pathological lesions has fueled rapid advances in Nanomedicine. The progressive evolution of nanovectors has led to the development of multi-stage delivery systems aimed at overcoming the numerous obstacles encountered by nanovectors on their journey to the target site. Scope of Review This review summarizes major findings with respect to silicon-based drug delivery vectors for cancer therapeutics and imaging. Based on rational design, well established silicon technologies have been adapted for the fabrication of nanovectors with specific shapes, sizes, and porosities. These vectors are part of a multi-stage delivery system that contains multiple nano-components, each designed to achieve a specific task with the common goal of site-directed delivery of therapeutics. Major Conclusions Quasi-hemispherical and discoidal silicon microparticles are superior to spherical particles with respect to margination in the blood, with particles of different shapes and sizes having unique distributions in vivo. Cellular adhesion and internalization of silicon microparticles is influenced by microparticle shape and surface charge, with the latter dictating binding of serum opsonins. Based on in vitro cell studies, the internalization of porous silicon microparticles by endothelial cells and macrophages is compatible with cellular morphology, intracellular trafficking, mitosis, cell cycle progression, cytokine release, and cell viability. In vivo studies support superior therapeutic efficacy of liposomal encapsulated siRNA when delivered in multi-stage systems compared to free nanoparticles. PMID:20493927

Removal of hazardous gaseous pollutants from industrial flue gases by a novel multi-stage fluidized bed desulfurizer.

PubMed

Mohanty, C R; Adapala, Sivaji; Meikap, B C

2009-06-15

Sulfur dioxide and other sulfur compounds are generated as primary pollutants from the major industries such as sulfuric acid plants, cupper smelters, catalytic cracking units, etc. and cause acid rain. To remove the SO(2) from waste flue gas a three-stage counter-current multi-stage fluidized bed adsorber was developed as desulfurization equipment and operated in continuous bubbling fluidization regime for the two-phase system. This paper represents the desulfurization of gas mixtures by chemical sorption of sulfur dioxide on porous granular calcium oxide particles in the reactor at ambient temperature. The advantages of the multi-stage fluidized bed reactor are of high mass transfer and high gas-solid residence time that can enhance the removal of acid gas at low temperature by dry method. Experiments were carried out in the bubbling fluidization regime supported by visual observation. The effects of the operating parameters such as sorbent (lime) flow rate, superficial gas velocity, and the weir height on SO(2) removal efficiency in the multistage fluidized bed are reported. The results have indicated that the removal efficiency of the sulfur dioxide was found to be 65% at high solid flow rate (2.0 kg/h) corresponding to lower gas velocity (0.265 m/s), wier height of 70 mm and SO(2) concentration of 500 ppm at room temperature.

Applications of the Magnetocaloric Effect in Single-Stage, Multi-Stage and Continuous Adiabatic Demagnetization Refrigerators

NASA Technical Reports Server (NTRS)

Shirron, Peter J.

2014-01-01

Adiabatic demagnetization refrigerators (ADR), based on the magnetocaloric effect, are solid-state coolers that were the first to achieve cooling well into the sub-kelvin regime. Although supplanted by more powerful dilution refrigerators in the 1960s, ADRs have experienced a revival due to the needs of the space community for cooling astronomical instruments and detectors to temperatures below 100 mK. The earliest of these were single-stage refrigerators using superfluid helium as a heat sink. Their modest cooling power (<1 µW at 60 mK[1]) was sufficient for the small (6x6) detector arrays[2], but recent advances in arraying and multiplexing technologies[3] are generating a need for higher cooling power (5-10 µW), and lower temperature (<30 mK). Single-stage ADRs have both practical and fundamental limits to their operating range, as mass grows very rapidly as the operating range is expanded. This has led to the development of new architectures that introduce multi-staging as a way to improve operating range, efficiency and cooling power. Multi-staging also enables ADRs to be configured for continuous operation, which greatly improves cooling power per unit mass. This paper reviews the current field of adiabatic demagnetization refrigeration, beginning with a description of the magnetocaloric effect and its application in single-stage systems, and then describing the challenges and capabilities of multi-stage and continuous ADRs.

Extended Importance Sampling for Reliability Analysis under Evidence Theory

NASA Astrophysics Data System (ADS)

Yuan, X. K.; Chen, B.; Zhang, B. Q.

2018-05-01

In early engineering practice, the lack of data and information makes uncertainty difficult to deal with. However, evidence theory has been proposed to handle uncertainty with limited information as an alternative way to traditional probability theory. In this contribution, a simulation-based approach, called ‘Extended importance sampling’, is proposed based on evidence theory to handle problems with epistemic uncertainty. The proposed approach stems from the traditional importance sampling for reliability analysis under probability theory, and is developed to handle the problem with epistemic uncertainty. It first introduces a nominal instrumental probability density function (PDF) for every epistemic uncertainty variable, and thus an ‘equivalent’ reliability problem under probability theory is obtained. Then the samples of these variables are generated in a way of importance sampling. Based on these samples, the plausibility and belief (upper and lower bounds of probability) can be estimated. It is more efficient than direct Monte Carlo simulation. Numerical and engineering examples are given to illustrate the efficiency and feasible of the proposed approach.

Nutrient concentrations, loads, and yields in the Eucha-Spavinaw Basin, Arkansas and Oklahoma, 2002-09

USGS Publications Warehouse

Esralew, Rachel A.; Tortorelli, Robert L.

2010-01-01

The city of Tulsa, Oklahoma, uses Lake Eucha and Spavinaw Lake in the Eucha-Spavinaw Basin in northwestern Arkansas and northeastern Oklahoma for public water supply. The city has spent millions of dollars over the last decade to eliminate taste and odor problems in the drinking water from the Eucha-Spavinaw system, which may be attributable to blue-green algae. Increases in the algal biomass in the lakes may be attributable to increases in nutrient concentrations in the lakes and in the waters feeding the lakes. The U.S. Geological Survey, in cooperation with the City of Tulsa, investigated and summarized total nitrogen and total phosphorus concentrations in water samples and provided estimates of nitrogen and phosphorus loads, yields, and flow-weighted concentrations during base flow and runoff for two streams discharging to Lake Eucha for the period January 2002 through December 2009. This report updates a previous report that used data from water-quality samples collected from January 2002 through December 2006. Based on the results from the Mann-Whitney statistical test, unfiltered total nitrogen concentrations were significantly greater in runoff water samples than in base-flow water samples collected from Spavinaw Creek near Maysville and near Cherokee City, Arkansas; Spavinaw Creek near Colcord, Oklahoma, and Beaty Creek near Jay, Oklahoma. Nitrogen concentrations in runoff water samples collected from all stations generally increased with increasing streamflow. Nitrogen concentrations in base-flow and runoff water samples collected in Spavinaw Creek significantly increased from the station furthest upstream (near Maysville) to the Sycamore station and then significantly decreased from the Sycamore station to the station furthest downstream (near Colcord). Nitrogen concentrations in base-flow and runoff water samples collected from Beaty Creek were significantly less than base-flow and runoff water samples collected from Spavinaw Creek. Based on the results from the Mann-Whitney statistical test, unfiltered total phosphorus concentrations were significantly greater in runoff water samples than in base-flow water samples for the entire period for most stations, except in water samples collected from Spavinaw Creek near Cherokee City, in which no significant difference was detected for the entire period nor for any season. Phosphorus concentrations in runoff water samples collected from all stations generally increased with increasing streamflow. Based on results from a multi-stage Kruskal-Wallis statistical test, phosphorus concentrations in base-flow water samples collected from Spavinaw Creek significantly increased from the Maysville station to the Cherokee City station, probably because of discharge from a municipal wastewater-treatment plant between those stations. Phosphorus concentrations significantly decreased downstream from the Cherokee City station to the Colcord station. Phosphorus concentrations in base-flow water samples collected from Beaty Creek were significantly less than phosphorus in base-flow water samples collected from Spavinaw Creek downstream from the Maysville station. View report for unabridged abstract.

PROBABILITY SAMPLING AND POPULATION INFERENCE IN MONITORING PROGRAMS

EPA Science Inventory

A fundamental difference between probability sampling and conventional statistics is that "sampling" deals with real, tangible populations, whereas "conventional statistics" usually deals with hypothetical populations that have no real-world realization. he focus here is on real ...

Using lot quality-assurance sampling and area sampling to identify priority areas for trachoma control: Viet Nam.

PubMed

Myatt, Mark; Mai, Nguyen Phuong; Quynh, Nguyen Quang; Nga, Nguyen Huy; Tai, Ha Huy; Long, Nguyen Hung; Minh, Tran Hung; Limburg, Hans

2005-10-01

To report on the use of lot quality-assurance sampling (LQAS) surveys undertaken within an area-sampling framework to identify priority areas for intervention with trachoma control activities in Viet Nam. The LQAS survey method for the rapid assessment of the prevalence of active trachoma was adapted for use in Viet Nam with the aim of classifying individual communes by the prevalence of active trachoma among children in primary school. School-based sampling was used; school sites to be sampled were selected using an area-sampling approach. A total of 719 communes in 41 districts in 18 provinces were surveyed. Survey staff found the LQAS survey method both simple and rapid to use after initial problems with area-sampling methods were identified and remedied. The method yielded a finer spatial resolution of prevalence than had been previously achieved in Viet Nam using semiquantitative rapid assessment surveys and multistage cluster-sampled surveys. When used with area-sampling techniques, the LQAS survey method has the potential to form the basis of survey instruments that can be used to efficiently target resources for interventions against active trachoma. With additional work, such methods could provide a generally applicable tool for effective programme planning and for the certification of the elimination of trachoma as a blinding disease.

Does Psychosocial Work Environment Factors Predict Stress and Mean Arterial Pressure in the Malaysian Industry Workers?

PubMed

Javaid, Muhammad Umair; Isha, Ahmad Shahrul Nizam; Sabir, Asrar Ahmed; Ghazali, Zulkipli; Nübling, Matthias

2018-01-01

Psychosocial risks are considered as a burning issue in the Asia-Pacific region. The aim of this study was to investigate the impact of psychosocial work environment factors on health of petrochemical industry workers of Malaysia. In lieu to job demands-resources theory, significant positive associations were found between quantitative demands, work-family conflict, and job insecurity with stress, while a significant negative association of role clarity as a resource factor with stress was detected. We also found that quantitative demands were significantly associated with the mean arterial pressure (MAP). Multistage sampling procedure was used to collect study sample. Structural Equation Modeling was used to identify relationship between the endogenous and exogenous variables. Finally, the empirically tested psychosocial work environment model will further help in providing a better risk assessment in different industries and enterprises.

Benchmark Dataset for Whole Genome Sequence Compression.

PubMed

C L, Biji; S Nair, Achuthsankar

2017-01-01

The research in DNA data compression lacks a standard dataset to test out compression tools specific to DNA. This paper argues that the current state of achievement in DNA compression is unable to be benchmarked in the absence of such scientifically compiled whole genome sequence dataset and proposes a benchmark dataset using multistage sampling procedure. Considering the genome sequence of organisms available in the National Centre for Biotechnology and Information (NCBI) as the universe, the proposed dataset selects 1,105 prokaryotes, 200 plasmids, 164 viruses, and 65 eukaryotes. This paper reports the results of using three established tools on the newly compiled dataset and show that their strength and weakness are evident only with a comparison based on the scientifically compiled benchmark dataset. The sample dataset and the respective links are available @ https://sourceforge.net/projects/benchmarkdnacompressiondataset/.